Metallo-β-lactamases (MBLs) are members of the structurally conserved but functionally diverse MBL-fold superfamily of metallohydrolases. MBLs are a major concern for global health care as they efficiently inactivate β-lactam antibiotics, including the “last-resort” carbapenems, and no clinically suitable inhibitors are currently available. Increasingly, promiscuous β-lactamase activity is also observed in other members of the superfamily, including from viruses, which represents an underexplored reservoir for future pathways to antibiotic resistance. Here, two such MBL-fold enzymes from Bacillus phages, the cyclic mononucleotide-degrading proteins ApycGoe3 and ApycGrass, are shown to efficiently degrade β-lactam substrates in vitro. In particular, ApycGrass displays a distinct preference for carbapenem substrates with a catalytic efficiency that is within one order of magnitude of that of the clinically relevant MBL NDM-1. Mutagenesis experiments also demonstrate that the loss of a metal-bridging aspartate residue reduces nuclease activity up to 35-fold, but improves carbapenemase activity. In addition, we propose that the oligomeric state significantly influences β-lactamase activity by modifying access to the active site pocket. Together, these observations hint at a possible new avenue of resistance via the spread of phage-borne MBL-fold enzymes with β-lactamase activity.

Bacteriophages (phages) are potential alternatives to chemical antimicrobials against pathogens of public health significance. Understanding the diversity and host specificity of phages is important for developing effective phage biocontrol approaches. Here, we assessed the host range, morphology, and genetic diversity of eight Salmonella enterica phages isolated from a wastewater treatment plant. The host range analysis revealed that six out of eight phages lysed more than 81% of the 43 Salmonella enterica isolates tested. The genomic sequences of all phages were determined. Whole genome sequencing data (WGS) data revealed that phage genome sizes ranged from 41 to 114 kb with GC contents be-tween 39.9 and 50.0 %. Two of the phages SB13 and SB28 represent new species Epsep-timavirus SB13 and genera Macdonaldcampvirus, respectively as designated by the In-ternational Committee for the Taxonomy of Viruses (ICTV) as per genome based taxonomic classification. One phage (SB18) belonged to the Myoviridae morphotype while the re-maining phages belonged to the Siphoviridae morphotype. The gene content analyses showed that none of the phages possessed virulence, toxin, antibiotic resistance, type I-VI toxin-antitoxin modules or lysogeny genes. Three (SB3, SB15 and SB18) out of the eight phages possessed tailspike proteins. Whole genome-based phylogeny of the eight phages with their 113 homologs revealed three clusters A, B, C and seven subclusters (A1, A2, A3, B1, B2, C1 and C2). While cluster C1 phages were predominantly isolated from animal sources, cluster B contained phages from both wastewater and animal sources. The broad host range of these phages highlights their potential use to control the presence of S. enterica in foods.

The sandwich format immunoassay is generally more sensitive and specific than more common assay formats, including direct, indirect, or competitive. A sandwich assay, however, requires two receptors to bind non-competitively to the target analyte. Typically, pairs of antibodies (Abs) or antibody fragments (Fabs) capable of forming a sandwiching with the target are identified through a slow, guess-and-check method with panels of candidate binding partners. Additionally, sandwich assays reliant on commercial antibodies can suffer from changes to reagent quality outside the researchers’ control. This report presents a reimagined and simplified phage display selection protocol that directly identifies sandwich binding peptides and Fabs. The approach yielded two sandwich pairs, one peptide-peptide and one Fab-peptide sandwich for the cancer and Parkinson’s disease biomarker DJ-1. Requiring just a few weeks to identify, the sandwich pairs delivered apparent affinity comparable to other commercial peptide and antibody sandwiches. The results reported here could expand the availability of sandwich binding partners for a wide range of clinical biomarker assays.

In this review we aim to address the current status of phage therapy in the management of multidrug-resistant infections, from compassionate use cases to ongoing clinical trials, as well as the challenges this approach presents in the particular context of CF patients.

: As antibiotic resistance undermines efforts to treat bacterial infections, phage therapy is being increasingly considered as an alternative in clinical settings and agriculture. However, a major concern in using phages is that pathogens will develop resistance to the phage. Due to the constant evolutionary pressure by phages, bacteria have evolved numerous mechanisms to block infection. If we determine the most common among them, we could use this knowledge to guide phage therapeutics. Here we compile data from 88 peer-reviewed studies where phage resistance was experimentally observed and linked to a bacterial gene, then assessed these data for patterns. In total, 141 host genes were identified to block infection against one or more of 80 phages (representing five families of the Caudovirales) across 16 microbial host genera. These data suggest that bacterial phage resistance is diverse, but even well-studied systems are understudied, and there are gaping holes in our knowledge of phage resistance across lesser-studied regions of microbial and viral sequence space. Fortunately, scalable approaches are newly available that, if broadly adopted, can provide data to power ecosystem-aware models that will guide harvesting natural variation towards designing effective, broadly applicable phage therapy cocktails as an alternative to antibiotics.

The nuclear hormone family of receptors regulates gene expression. The androgen receptor (AR) shuttles upon ligand binding and homodimerization from the cytosol into the nucleus to activate gene expression. Thyroid hormone receptors(TR), retinoic acid receptors (RAR), and the vitamin D receptor (VDR) are present in the nucleus bound to chromatin as a heterodimer with the retinoid X receptors (RXR) and repress gene expression. Ligand binding leads to transcription activation. The hormonal ligands for these receptors play crucial roles to ensure the proper conduct of very many tissues and exert effects on prostate cancer (PCa) cells. Androgens support PCa proliferation and deprivation alone or with chemotherapy is the standard therapy for PCa. RAR activation and 3,5,3'-triiodo-L-thyronine (T3) stimulation of TR support the growth of PCa cells. Ligand stimulation of VDR drives growth arrest, differentiation, and apoptosis of PCa cells. Often these receptors are explored as separate avenues to find treatments for PCa and other cancers. However, there is accumulating evidence to support receptor interactions and crosstalk of regulatory events whereby a better understanding might lead to new combinatorial treatments.

Considering that life on earth evolved about 3.7 billion years ago, vertebrates are young, appearing in the fossil record during the Cambrian explosion about 542 to 515 million years ago. Results from sequence analyses of genomes from bacteria, yeast, plants, invertebrates and vertebrates indicate that receptors for adrenal steroids (aldosterone, cortisol), and sex steroids (estrogen, progesterone, testosterone) also are young, with an estrogen receptor and a 3-ketosteroid receptor first appearing in basal chordates (cephalochordates: amphioxus), which are close ancestors of vertebrates. Through gene duplication and divergence of the 3-ketosteroid receptor, receptors that respond to androgens, glucocorticoids, mineralocorticoids and progestins evolved in vertebrates. Thus, an ancestral progesterone receptor and an ancestral corticoid receptor, the common ancestor of the glucocorticoid and mineralocorticoid receptors, evolved in jawless vertebrates (cyclostomes: lampreys, hagfish). This was followed by evolution of an androgen receptor, distinct glucocorticoid and mineralocorticoid receptors and estrogen receptor-α and -β in cartilaginous fishes (gnathostomes: sharks). Further evolution of mineralocorticoid signaling occurred with the evolution of aldosterone synthase in lungfish, a forerunner of terrestrial vertebrates. Adrenal and sex steroid receptors are not found in echinoderms: and hemichordates, which are ancestors in the lineage of cephalochordates and vertebrates. The evolution of steroid receptors at key nodes in the evolution of vertebrates, in which steroid receptors act as master switches to regulate differentiation, development, reproduction, immune responses, electrolyte homeostasis and stress responses, argues for an important role for steroid receptors in the evolutionary success of vertebrates, considering that the human genome contains about 22,000 genes, which is not much larger than genomes of invertebrates, such as Caenorhabditis elegans (~18,000 genes) and Drosophila (~14,000 genes).

The mechanisms by which bacteriophage T4 converts the metabolism of its E. coli host to one dedicated to progeny phage production was the subject of decades of intense research in many labs from the 1950’s through the 1980’s. At this point, a wide range of phages are starting to be used therapeutically and in many other applications and also the range of available phage sequence data is skyrocketing. It is thus important to re-explore the extensive available data about the intricacies of the T4 infection process as summarized here, expand it to looking much more broadly at other genera of phages, and explore phage infections using newly-available modern techniques and a range of appropriate environmental conditions.

Long COVID, also referred to as post-COVID-19 condition, describes the lingering after-effects of COVID-19 infection. This complex syndrome encompasses a range of symptoms affecting physical well-being, cognitive function, and mental health. The widespread impact of long COVID extends beyond individual sufferers, placing significant strain on healthcare systems and causing far-reaching socioeconomic consequences. The scale of this multifaceted health crisis is unparalleled in recent history, affecting millions globally and challenging our understanding of post-viral conditions. This study aimed to explore the possibility of targeting G protein-coupled receptors (GPCRs) signaling pathway-related genes as therapeutics for long COVID using computational analysis. Targeting GPCRs and their signaling pathways holds significant promise for long COVID therapeutics, as these receptors are involved in crucial physiological processes including immune regulation, inflammation control, and neurotransmission. All of these are implicated in the diverse and persistent symptoms of long COVID, potentially offering a versatile approach to addressing multiple aspects of the condition simultaneously. This study identified 21 genes associated with GPCRs for further exploration as potential targets. Notably, GPCR genes such as HRAS, KRAS, GNAQ, and GNA11 were determined to be possible therapeutic targets for the pathophysiological mechanisms of long COVID. FDA-approved drugs targeting these genes were identified, including Binimetinib, Cabozantinib, Selumetinib, Panitumumab, Cetuximab, Adagrasib, Tipifarnib, and Sotorasib. Additionally, Naltrexone and Tipifarnib have emerged as potential new treatment options for long COVID. SARS-CoV-2 may hijack GPCR signaling pathways to dysregulate lung ion and fluid transport, contributing to the pathophysiology of pulmonary edema in patients with COVID-19. Further research is required to translate the findings into the development of therapeutics and to investigate the relationship between viral infection and GPCR signalling.

In this review, we outline our current understanding of the mechanisms involved in the absorption, storage, and transport of dietary vitamin A to the eye, the trafficking of rod opsin protein to the photoreceptor outer segments, which encompasses the logistical backbone required for visual function. Two key mechanisms of this process are emphasized in this manuscript: Ocular and systemic vitamin A membrane transporters, and rhodopsin transporters. Understanding the complementary mechanisms responsible for the generation and proper transport of the retinylidene opsin to the photoreceptor outer segment will eventually shed light on the importance of genes encoded by these proteins, and their relationship on normal visual function and in the pathophysiology of retinal degenerative diseases.

Both bacteria product flagellin and macrophages are implicated in HIV infection/disease progression. However, the impact of their interaction on HIV infection and the associated mechanisms remain to be determined. We thus examined the effect of the flagellins on HIV infection of primary human macrophages. We observed that the pretreatment of macrophages with the flagellins from the different bacteria significantly inhibited HIV infection. The mechanistic investigation showed that the flagellin treatment of macrophages downregulated the major HIV entry receptors (CD4 and CCR5) and upregulated the CC chemokines (MIP-1α, MIP-1β, and RANTES), the ligands of CCR5. These effects of the flagellin could be compromised by a toll like receptor 5 (TLR5) antagonist. Given the important role of flagellin as a vaccine adjuvant in TLR5 activation-mediated immune regulation and in HIV infection of macrophages, future investigations are necessary to determine the in vivo impact of flagellin-TLR5 interaction on macrophage-mediated innate immunity against HIV infection and the effectiveness of flagellin adjuvant-based vaccines studies.

Factors affecting the host-virus interaction must be understood for the effective application of bacteriophages to combat bacterial pathogens. Two novel E. coli phages, the T1-like siphophage LL5 and the rV5-like myophage LL12, were subjected to forward genetic screens against the Keio collection, a library of single non-essential gene deletions in E.coli str. BW25113. These genome-wide screens and subsequent experiments identified eight genes required for efficient propagation of phage LL5 and six genes required for propagation of LL12. The majority of the genes identified were involved in production of the phage receptors. E. coli mutants deficient in heptose II and the phosphoryl substituent of heptose I of the inner core lipopolysaccharide (LPS) were unable to propagate phage LL5, as were mutants deficient in the outer membrane protein TolC. Mutants lacking glucose I of the LPS outer core failed to propagate LL12. Two cytoplasmic chaperones, PpiB and SecB, were found to be required for efficient propagation of phage LL5 but not LL12. This approach may be useful for identifying phage receptors and required host factors in other phages, which would provide valuable information for their potential use as therapeutics and for phage engineering.

Keywords: leptophages; Cas system; bacteriophages; Leptospira interrogans

This study provides a comprehensive analysis of the conformational dynamics of pseudo-endocannabinoid receptors (p-CBRs) CB₁ and CB₂ in response to ligand binding. The ligands studied include N-arachidonoyl dopamine (NADA), Cannabidiol (CBD), known agonists (FUB-MDMB and E3R), and inverse agonists (Taranabant and AM630). Using homology models based on crystal structures (PDB ID: 5U09 for CB₁ and 5ZTY for CB₂), molecular docking, and molecular dynamics (MD) simulations, the research validates the structural integrity and dynamic behaviours of these pseudo-receptors. Induced-fit docking revealed NADA as having the highest binding affinity for both receptors, with docking scores of −13.92 kcal/mol for CB₁ and −13.32 kcal/mol for CB₂, facilitated by key hydrogen bond interactions. MD simulations over 250 ns at ~298 K showed successful equilibration, indicating the most stable interaction for NADA, thereby further validating the models. CB₁ and CB₂ exhibited distinct conformational responses to ligands, with Cα RMSD and Cα RMSF analyses suggesting a more rigid binding pocket for CB₁ and a flexible binding pocket for CB₂. These findings highlight the significance of receptor behaviour and dynamics in the development of cannabinoid-based therapeutics, supporting the potential of CBD and NADA as modulators for CB₁ and CB₂, respectively.

Several recent surges in COVID-19 cases due to newly emerging variant strains of SARS-CoV-2 with greater transmissibility have highlighted the virus’s capability to directly modulate spike-ACE2 interactions and promote immune evasion by sterically masking the immunogenic epitopes. Recently, there have also been reports of the bidirectional transfer of coronavirus between different animal species and humans. The ability of coronavirus to infect and adapt to a wide range of hosts can be attributed to new variants that modify the molecular recognition profile of the spike protein (S protein). The receptor-binding domain of the spike protein specifically interacts with key host receptor molecules present on the host cell membranes to gain entry into the host and begin the infection cycle. In this review, we discuss the molecular, structural, and functional diversity associated with the coronavirus receptors across their different phylogenetic lineages and its relevance to various symptomatology in the rapid human-to-human infection in COVID-19 patients, tropism, and zoonosis. Despite this seeming diversity of host receptors, there may be some common underlying mechanisms that influence the host range, virus transmissibility, and pathogenicity. Understanding these mechanisms may be crucial in not only controlling the ongoing pandemic but also help in stopping the resurgence of such virus threats in the future.

Some of neurodegenerative diseases may be characterized by continuing behavioral and cognitive dysfunction that contains memory loss and/or apathy. Alzheimer's disease is the most typical type of such neurodegenerative disease characterized by deficit of cognition and alteration of behavior. Despite the huge efforts against Alzheimer's disease, there has been yet no successful treatment for this disease. Interestingly, several possible risk genes to cognitive dysfunction are frequently expressed within brain cells, which may also be linked to cholesterol metabolism, lipid transport, exosomes and/or caveolae formation, suggesting that caveolae may be a therapeutic target to consider cognitive dysfunctions. Interestingly, modulation of autophagy/mitophagy with the alteration of glucagon-like peptide-1 (GLP-1) and N-methyl-d-aspartate (NMDA) receptors signaling may offer a novel approach to prevent and alleviate the cognitive dysfunction. A paradigm that both GLP-1 and NMDA receptors at caveolae sites is promising and crucial for the treatment of cognitive dysfunctions has been presented here, which might also be able to modify the progression of Alzheimer's disease. This research direction may open the potential to move a clinical care toward disease-modifying treatment strategies with maximal benefits for patients without detrimental adverse events for neurodegenerative diseases.

Enterococcus faecalis is a growing cause of nosocomial and antibiotic-resistant infections. Treating drug-resistant E. faecalis requires novel approaches. The use of bacteriophages (phages) against multidrug-resistant (MDR) bacteria has recently garnered global attention. Biofilms play a vital role in E. faecalis pathogenesis as they enhance antibiotic resistance. Phages eliminate biofilms by producing lytic enzymes, including depolymerases. In this study, Enterococcus phage vB_Efs8_KEN04 (ФKEN04), isolated from a sewage treatment plant in Nairobi, Kenya, was tested against clinical strains of MDR Enterococcus faecalis. This phage had a broad host range against 100% (26/26) of MDR E. faecalis clinical isolates and cross-species activity against Enterococcus faecium. It was able to withstand acidic and alkaline conditions, from pH 3 to 11, as well as temperatures between -80ᵒC and 37ᵒC. It could inhibit and disrupt the biofilms of MDR E. faecalis. Its linear double-stranded DNA genome of 142,402 bp contains 238 coding sequences with a G+C content and coding gene density of 36.01% and 91.46%, respectively. Genomic analyses showed that ФKEN04 belongs to the genus Kochikohdavirus in the family Herelleviridae. It lacked antimicrobial resistance, virulence, and lysogeny genes, and its stability, broad host range, and cross-species lysis indicate strong potential for the treatment of Enterococcus infections.

GABAA receptors are channel proteins crucial to mediating neuronal balance in the CNS. The structure of GABAA receptors allows for multiple binding sites and is key to drug development. Yet, the formation mechanism of the receptor’s distinctive pentameric structure is still unknown. This study aims to investigate the role of three predominant subunits of the human GABAA receptor in the formation of protein pentamers. Through purifying and refolding the protein fragments of the GABAA receptor α1, β2, and γ2 subunits, homopentamers were visualised with negative staining and Cryo-EM. To aid the analysis, AlphaFold2 was used to compare the structures. Results show that α1 and β2 subunit fragments successfully formed homo-oligomers, particularly homopentameric structures, while the predominant heteropentameric GABAA receptor was also replicated through the combination of the three subunits. However, it is still unclear whether γ2 subunits can form homopentamers or their main purpose is to bring together the α1 and β2 subunits to form GABAA receptors. Nevertheless, this study will lead to a deeper understanding of the atomic structure of GABAA receptors, especially in the formation mechanism of complex protein structures, and hopefully pave the way to the development of novel therapeutics for neuropsychiatric diseases.

Background: The identification of new cellular receptors has been increasing rapidly. A receptor is called “orphan” if an endogenous ligand has not been identified yet. Methods: Here we review receptors that contribute to prostate cancer and are considered orphan or partially orphan. This means that the full spectrum of their endogenous ligands remains unknown. Results: The orphan receptors are divided into two major families. The first group includes G protein-coupled receptors. Most are orphan olfactory receptors. OR51E1 inhibits cell proliferation and induces senescence in prostate cancer. OR51E2 inhibits prostate cancer growth, but promotes invasiveness and metastasis. GPR158, GPR110 and GPCR-X play significant roles in prostate cancer development and progression. However, GPR160 induces cell cycle arrest and apoptosis. The other major subset of orphan receptors are nuclear receptors. RORα inhibits tumor growth, but RORγ stimulates androgen receptor signaling. PXR contributes to metabolic deactivation of androgens and inhibits cell proliferation. TLX has pro-tumorigenic effects in prostate cancer, while its knockdown triggers cellular senescence and growth arrest. Estrogen-related receptor ERRγ can inhibit tumor growth but ERRα is pro-tumorigenic. Dax1 and Shp are also inhibitory in prostate cancer. Conclusion: There is a “zoo” of relatively underappreciated orphan receptors that play key roles in prostate cancer.

Staphylococcus aureus and Pseudomonas aeruginosa are opportunistic pathogens commonly associated with burn wound infections. These bacteria can form biofilm and contribute a high-level drug resistance to available antibiotics. This study focused on the bacteriolytic activity of phages vB_SAnS_SADP1 and vB_PAnP_PADP4 on 24 h old single or dual-species biofilms of Staphylococcus aureus and Pseudomonas aeruginosa in alone and in combination. Scanning and confocal laser scanning microscopic studies confirmed the structural organization of biofilms in single or dual-species combinations in in-vitro conditions. Single species biofilms are more robust and densely packed at 24 h of incubation. In contrast, dual-species biofilms (0.67± 0.02) are weakly associated due to their inter-species competition and are easily affected by phage cocktails (0.16 ± 0.02). In Invitro conditions, dual-species biofilms were more easily affected by phage cocktail than single phage. Scanning electron microscopic studies revealed the complete diminishment of biofilm formation by four h treatment with single phage or phage cocktails on single species or dual-species biofilms. Confocal laser scanning microscopic images with stains Syto®9 and propidium iodide revealed that phage treatment showed significant uptake of propidium iodide, indicating massive cell death mediated by respective phage or phage cocktail.

Purinergic receptors (P2X) are ATP-gated ion channels with an elusive role in the CNS. While the P2X2 and P2X4 subtypes are widely expressed in most neurons (i.e. at the edge of the postsynaptic densities of excitatory synapses), the direct contribution of P2X to synaptic transmission is uncertain. Several P2X have been shown to participate in receptor cross-talk: an interaction where one receptor (e.g. P2X2) influences the activity of another (e.g. GABA or AMPA receptors.) In this study, we tested for interactions between P2X2 or P2X4 and N-methyl-D-aspartate receptors (NMDARs). Using two-electrode voltage-clamp electrophysiology experiments in X. laevis oocytes, we demonstrate that both P2X2 and P2X4 interact with NMDARs in an inhibitory manner. When investigating the molecular domains responsible for this phenomenon, we found that the P2X2 c-terminus (CT) could interfere with P2X2 and P2X4 interactions with NMDARs. We also report that 11 distal CT residues on the P2X4 facilitate the P2X4-NMDAR interaction, and that a peptide consisting of these P2X4 CT residues (11C) can disrupt the interaction between NMDARs and P2X2 or P2X4. Collectively, these results provide new evidence for the modulatory nature of P2X2 and P2X4, suggesting they might play a more nuanced role in the CNS.

Prostate cancer (PC) is the second most diagnosed cancer among men. It was observed that early diagnosis of disease is highly beneficial for survival of cancer patients. Therefore, extension and increasing quality of life of PC patients can be achieved by broadening the Cancer Screening programs that are aimed at the identification of cancer manifestation in patients at earlier stages before they demonstrate well-understood signs of the disease. Therefore, there is an urgent need in standard, sensitive, robust, and commonly available screening and diagnosis tools for identification of early signs of cancer pathologies. In this respect, “Holy Grail” of cancer researchers and bioengineers for decades have been molecular sensing probes that would allow diagnosis, prognosis, and monitoring of cancer diseases by their interaction with cell-secreted and cellassociated PC biomarkers, e.g. PSA and PSMA correspondinly. At present, most PSA tests are performed at centralized laboratories using high throughput Total PSA immune analyzers which are suitable for dedicated laboratories and are not readily available for the broad health screening. Therefore, the current trend in detection of PC is developments of the portable biosensors for mobile laboratories and individual use. Phage display since its conception by George Smith in 1985 has emerged as a premier tool in molecular biology with widespread applications. This review describes how the paradigm of molecular evolution and phage display revolutionized the methods of early diagnosis and monitoring of PC.

Leptospira, which are known to be important disease-causing agents transmitted between animals and humans, results in significant illness and, in some cases, significant death in human populations. This study aims to examine the genomic structure of Leptospira interrogans serovar Copenhageni strain FDAARGOS_203 to identify the specific genetic factors that contribute to antimicrobial resistance (AMR) and defense against phages. The genome, consisting of two contigs totaling 4,630,574 base pairs, underwent thorough examination for protein-coding sequences, transfer RNA genes, and ribosomal RNA genes. A total of twenty-two antibiotic resistance genes that specifically target essential cellular processes such as cell wall synthesis, DNA replication, and protein synthesis have been identified. Significant among these were gidB, GdpD, and PgsA, each involved in separate aspects of antibiotic resistance. In addition, the investigation explored the defense mechanisms of bacteriophages, revealing the presence of defense islands that contain a range of anti-phage systems, including RM_Type_IV, PrrC, Borvo, CAS_Class1-Subtype-IC, and CAS_Class1-Subtype-IB. This comprehensive genomic analysis enhances our understanding of the molecular mechanisms that determine Leptospira's ability to adapt to various environments. The identified genetic factors linked to AMR and defense against phages not only enhance our scientific comprehension but also provide a basis for focused interventions to reduce the impact of leptospirosis.

Platelet P2Y₁₂ is an important ADP receptor that is involved in agonist-induced platelet aggregation and is a valuable target for the development of anti-platelet drugs. Here we characterise the effects of thio-analogues of uridine triphosphate (UTP) on ADP-induced platelet aggregation. Using human platelet-rich plasma we demonstrate that UTP inhibits P2Y₁₂ but not P2Y₁ receptors and antagonises 10 μM ADP-induced platelet aggregation in a concentration-dependent manner with an IC₅₀ value of ~250 μM. An 8-fold higher platelet inhibitory activity was observed with a 2-thio analogue of UTP (2S-UTP), with an IC₅₀ of 30 μM. The 4-thio analogue (4S-UTP) with an IC₅₀ of 7.5 μM was 33-fold more effective. A 3-fold decrease in inhibitory activity, however, was observed by introducing an isobutyl group at the 4S- position. A complete loss of inhibition was observed with thio-modification of the γ phosphate of the sugar moiety, which yields an enzymatically stable analogue. The interaction of UTP analogues with P2Y₁₂ receptors was verified by P2Y₁₂ receptor binding and cAMP assays. These novel data demonstrate for the first time that 2- and 4-thio analogues of UTP are potent P2Y₁₂ receptor antagonists that may be useful for therapeutic intervention.

Abstract: The glucocorticoid receptor (GR), including both alternative spliced isoforms (GRa and GRb), has been implicated in the development of primary open-angle glaucoma (POAG) and iatrogenic glucocorticoid-induced glaucoma (GIG). POAG is the most common form of glaucoma, which is the leading cause of irreversible vision loss and blindness in the world. Glucocorticoids (GCs) are commonly used therapeutically for ocular and numerous other diseases/conditions. One serious side effect of prolonged GC therapy is the development of iatrogenic secondary ocular hypertension (OHT) and OAG (i.e. GC-induced glaucoma (GIG)) that clinically and pathologically mimics POAG. GC-induced OHT is caused by pathogenic damage to the trabecular meshwork (TM), a tissue involved in regulating aqueous humor outflow and intraocular pressure. TM cells derived from POAG eyes (GTM cells) have lower expression of GRb, a dominant negative regulator of GC activity, compared to TM cells from age-matched control eyes. Therefore, GTM cells have a greater pathogenic response to GCs. Almost all POAG patients develop GC-OHT when treated with GCs, in contrast to a GC responder rate of 40% in the normal population. Increased expression of GRb can block GC-induced pathogenic changes in TM cells and reverse GC-OHT in mice. Endogenous expression of GRb in the TM may relate to differences in the development of GC-OHT among the normal population. A number of studies have suggested increased levels of endogenous cortisol in POAG patients as well as differences in cortisol metabolism, suggesting that GCs may be involved in the development of POAG. Additional studies are warranted to better understand the molecular mechanisms involved in POAG and GIG in order to develop new disease modifying therapies to better treat these two sight threatening forms of glaucoma.

The selectivity in selective autophagy pathways is achieved via the selective autophagy receptors (SARs) – proteins that bind a ligand on the substrate to be degraded and the Atg8-family protein on the growing autophagic membrane, phagophore, effectively bridging them. In mammals, the most common ligand of SARs is ubiquitin, a small protein modifier that tags substrates for their preferential degradation by autophagy. Consequently, the most common SARs are the ubiquitin-binding SARs, such as SQSTM1/p62 (sequestosome 1). Surprisingly, there is only one SAR of this type in yeast – Cue5, which acts as a receptor for aggrephagy and proteaphagy – pathways that remove the ubiquitinated protein aggregates and proteasomes, respectively. However, recent studies described the ubiquitin-dependent autophagic pathways that do not require Cue5, e.g. stationary phase lipophagy for intracellular lipid droplets and nitrogen starvation-induced mitophagy for mitochondria. What is the role of ubiquitin in these pathways? Here, we propose that the ubiquitinated lipid droplets and mitochondria are recognized by the alternative ubiquitin-binding SARs. Our analysis identifies the proteins that could potentially fulfill this role in yeast. We think that matching of the ubiquitin-dependent (but Cue5-independent) autophagic pathways with the ubiquitin-and-Atg8-binding proteins enlisted here might uncover the novel ubiquitin-binding SARs in yeast.

Tuberculosis (TB), caused by Mycobacterium tuberculosis, is an infectious disease that seriously affects human life and health. Despite centuries of efforts to control it, in recent years the emergence of multidrug-resistant bacterial pathogens of M. tuberculosis due to various factors has exacerbated the disease, posing a serious threat to global health. Therefore, a new method to control M. tuberculosis is urgently needed. Phages, viruses that specifically infect bacteria, have emerged as potential biocontrol agents for bacterial pathogens due to their host specificity. In this study, a Mycobacterium phage, Henu3, was isolated from soil around a hospital. The particle morphology, biological characteristics, genomics and phylogeny of Henu3 were characterized. Additionally, to explore the balance between phage resistance and stress response, phage Henu3-resistant strains 0G10 and 2E1 were screened by sequence passage and bidirectional validation methods, which significantly improved the sensitivity of phage to antibiotics (cefotaxime and kanamycin). By whole genome resequencing of strains 0G10 and 2E1, 12 genes involved in cell wall synthesis, transporter-encoded genes, two-component regulatory proteins and transcriptional regulatory factor-encoded genes were found to have mutations. These results suggest that phage Henu3 has the potential to control M. tuberculosis pathogens, and phage Henu3 has the potential to be a new potential solution for the treatment of M. tuberculosis infection.

In antimicrobial-peptide/protein engineering, understanding the peptide/protein’s adaptability to harsh environmental conditions such as urea, proteases, fluctuating temperatures, high salts provide enormous insight into the pharmacokinetics and pharmacodynamics of the engineered peptide/protein and its ability to survive the harsh internal environment of the human body such as the gut or the harsh external environment to which they are applied. A previous work in our laboratory demonstrated that our cloned Eɛ34 TSP showed potent antimicrobial activity against Salmonella newington, and more so, could prevent biofilm formation on decellularized tissue. In this work, the effects of urea-acid on the Eɛ34 stability is studied, and the results demonstrates that at lower pHs of 3 and 4 with urea the protein was denatured into monomeric species. However, the protein withstood urea denaturation above pH of 5 and thus remained as trimeric protein. The mechanism of denaturation of Eɛ34 TSP seems to show that urea denatures proteins by depleting hydrophobic core of the protein by directly binding to the amide units via hydrogen bonds. The results of our in-silico investigation determined that urea binds with Eɛ34 TSP with relative free energies range of -3.4 to -2.9 kcal/mol at the putative globular head binding domain of the protein. The urea molecules interacts with with the protein’s predicted hydrophobic core, thus, disrupting and exposing the shielded hydrophobic moieties of Eɛ34 TSP to the solvent. We further showed that after the unfolding of Eɛ34 TSP via urea-acid, renaturation of the protein to its native conformation was possible within few hours. This unique characteristic of refolding of Eɛ34 TSP which is similar to that of the P22 phage tailspike protein is of special interest to protein scientists and can also be exploited in antimicrobial-protein engineering.

The prevalence of multidrug resistant bacterial diseases is a major global health risk. Multidrug resistant bacterial diseases are prevalent, and the need for novel methods of treatment is essential to the preservation of public health. Annually foodborne pathogens cause 1.35 million infections and 26,500 hospitalizations in the United States alone. Foodborne pathogens such as Salmonella spp. are a major threat to public health. Bacteriophages offer a unique method for the treatment of these multidrug resistant bacteria. We studied the infection dynamics of a potential mono-phage therapy of Salmonella typhimurium under various pathophysiological conditions. Furthermore, we determined the resistance dynamics of Salmonella typhimurium against P22 phage treatment. We also determined synergy with antibiotics such as ampicillin and kanamycin. This research helps to further define and show the versatility of bacteriophages as potential novel treatment methods.

Escherichia coli phage Eco_BIFF was isolated from several laboratory stocks of E. coli K-12 MG1655 derivatives. The source of the contamination is unknown. Eco_BIFF is a lytic phage that shows effective growth inhibition of E. coli K-12. Here, we announce the complete genome sequence of Eco_BIFF, and major findings from its genome annotation.

Acinetobacter baumannii is a multidrug-resistant and invasive pathogen associated with the etiopathology of both an increasing number of nosocomial infections and of relevance to poultry production systems. Multidrug-resistant Acinetobacter baumannii has been reported in connection to severe challenges to clinical treatment, mostly due to an increase rate of resistance to carbapenems. Amid the possible strategies aiming to reduce the insurgence of antimicrobial resistance, phage therapy has gained particular importance for the treatment of bacterial infections. This review summarises the different phage-therapy approaches currently in use for multiple-drug resistant Acinetobacter baumannii, including single phage therapy, phage cocktails, phage -antibiotic combination therapy, phage coding Acinetobacter baumannii and the novel phage enzyme treatment. Although phage therapy represents a potential treatment solution for multidrug-resistant Acinetobacter baumannii, further research is needed to unravel some unanswered questions especially in regard to its in vivo applications, before possible routine clinical use.

Background Olfactory perception is an important physiological function for the human well-being and health. Loss of olfaction, or anosmia, caused by viral infections such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) received a considerable attention especially in the persistent cases that take long time to recover. Objectives This review discusses the integration of different components of the olfactory epithelium to serve as a structural and functional unit, and explores how they are affected during viral infections, leading to the development of olfactory dysfunction. Methods The review mainly focused on the role of receptors mediating the disruption of olfactory signal transduction pathways such as ACE2, TMPRSS2 protease, neuropilin 1 (NRP1), basigin (CD147), olfactory, TRPV1, purinergic, and interferon gamma receptors. Furthermore, the compromised function of the epithelial sodium channel (ENaC) induced by SARS-CoV-2 infection and its contribution in olfactory dysfunction is also discussed. Results Collectively, this review provides fundamental information about the many types of receptors that may modulate olfaction and participate in olfactory dysfunction. It will help to understand the underlying pathophysiology of virus-induced anosmia which may help in finding and designing effective therapies targeting molecules involved in viral invasion and in olfaction. Conclusion This wide and complex spectrum of receptors that mediates the pathophysiology of olfactory dysfunction reflects the many ways by which anosmia can be therapeutically managed.

Neurological / neurovascular disorders constitute the leading cause of disability and second leading cause of deaths in the world. Some of the major neurological / neurovascular disorders or diseases include stroke, Alzheimer’s disease, spinal cord injury, neonatal hypoxic-ischemic encephalopathy, etc. Their pathophysiology is considered as highly complex and has been blamed as the main obstacle in the development of any drugs for these diseases. In this review, we have described the endothelin system, their involvement in neurovascular disorders, importance of endothelin B receptors (ETBRs) as a novel potential drug target, and its agonism by IRL-1620 (INN - sovateltide), which we are developing as a drug candidate for treating the above-mentioned neurological disorders / diseases. We have highlighted the results of our pre-clinical and clinical studies related to these diseases. The phase I, safety and tolerability study of sovateltide has shown it as a highly safe and well tolerable compound at tested dosages, while pre-clinical and clinical phase II studies have demonstrated its efficacy in treating acute ischemic stroke, where it is currently being developed as a “First in Class” drug. Its testing in Alzheimer’s disease (AD), acute spinal cord injury and neonatal hypoxic-ischemic encephalopathy (HIE) is currently being carried out and are at different stages of drug development. Successful completion of these studies will prove the involvement of ETBRs signaling in neurological / neurovascular diseases and help in development of novel neurological drugs in future.

Salmonella can cause acute and chronic infections in humans. Salmonella species are known to cause food poisoning and other diseases in developing countries. Their role in the pathogenesis of these diseases has received increased international attention. Despite numerous advances in sanitation, they still can infect humans and cause outbreaks in developed countries. For example, Salmonella causes about 1.2 million illnesses in the US each year with over 450 deaths. Additionally, Salmonella outbreaks cause significant losses to chicken producers globally. The Salmonella species is also prone to acquiring resistance to various classes of antibiotics. Hence, the need for a paradigm shift from antibiotics to bacteriophages to manage, control and treat bacterial infections. The ɛ34 phage belongs to Podoviruses and categorized into the P22-like phages. The P22-like phages include ɛ34, ES18, P22, ST104, and ST64T. In this work, we investigated the antibacterial property of ɛ34 phage tailspike protein against Salmonella newington (S. newington). We demonstrate here that, the phage’s tailspike protein enzymatic property as a LPS hydrolase synergizes with Vero Cell culture supernatant in killing S. newington. Using decellularized cartilage scaffold as an ex vivo tissue model, the ɛ34 TSP protected the scaffold from S. newington biofilm formation. Computational analysis of the ɛ34 TSP interaction with membrane proteins of S. newington demonstrated a higher probability (0.7318) of binding to ompA of S. newington, and when docked to ompA extracellular component, it produced a high free energy of -11.3kcal/mol. We also demonstrate the resistance/sensitivity of the tailspike to the digestive enzyme trypsin. The data obtained in this work indicates that the trypsin resistant tailspike protein of Ɛ34 phage can be formulated as a novel antibacterial agent against S. newington.

Bacteriophages, viruses that are widespread throughout the world, are highly specific for bacteria, usually of a single species and often of a particular strain. After being discovered and isolated 100 years ago, their use, called phage therapy, was instituted in medicine two years later and quickly used around the world to treat various bacterial infections. In the West, phage therapy was overshadowed in the second half of the 20th century by antibiotic therapy, which was then thought to be the definitive solution. But because of the increase in bacterial resistance to antibiotics, the idea of using bacteriophages in medicine has been reawakened. The innumerable observations reported over the years in the literature constitute an invaluable experience. We and some of our colleagues have, in the last decade treated some patients compassionately. With the available documentation and our own experience we discuss the potential indications and limitations of phage therapy. The observation of the increasing number of therapeutic failures in the announced perspective of a post-antibiotic era, we believe, that the introduction of bacteriophages into the therapeutic arsenal seems conceivable today to two preconditions: that their production as biologic drug meets current regulatory standards and that the benefit-risk assessment was conducted in a modern setting. Phage therapy could be applied as a substitution or supplement to antibiotic therapy under multiple circumstances in different modes, precise indications and limits.

Phage therapeutics offer a potentially powerful approach to combat multidrug-resistant bacterial infections. However, to be effective, phage therapy must overcome existing and developing phage resistance. While phage cocktails can reduce this risk by targeting multiple receptors in a single therapeutic, bacteria have mechanisms of resistance beyond receptor modification. A rapidly growing body of knowledge describes a broad and varied arsenal of antiphage systems encoded by bacteria to counter phage infection. We sought to understand the types and frequencies of antiphage systems present in a highly diverse panel of Pseudomonas aeruginosa clinical isolates utilized to characterize novel antibacterials. Using web-server tool PADLOC (Prokaryotic Antiviral Defense Locator), putative antiphage systems were identified in these P. aeruginosa clinical isolates based on sequence homology to a validated and curated catalog of known defense systems. Coupling this host bacterium sequence analysis with host range data for 70 phages, we observed a correlation between existing phage resistance and the presence of higher numbers of antiphage systems in bacterial genomes. We were also able to identify antiphage systems that were more prevalent in highly phage-resistant P. aeruginosa strains, suggesting their importance in conferring the resistance.

Immunohistochemistry is a widely used technique for research and diagnostic purposes that relies on the recognition by antibodies of antigens expressed in tissues. However, tissue processing and particularly formalin fixation affect the conformation of these antigens through the formation of methylene bridges. Although antigen retrieval techniques can partially restore antigen immunoreactivity, it is difficult to identify antibodies that can recognize their target especially in formalin-fixed paraffin-embedded tissues. Most of the antibodies currently used in immunohistochemistry have been obtained by animal immunization; however, in vitro display techniques represent alternative strategies that have not been fully explored yet. This review provides an overview of phage display-based antibody selections using naïve antibody libraries on various supports (fixed cells, dissociated tissues, tissue fragments, and tissue sections) that have led to the identification of antibodies suitable for immunohistochemistry.

Increasing rates of infection by antibiotic resistant bacteria have led to a resurgence of interest in bacteriophage (phage) therapy. Several phage therapy studies in animals and humans have been completed over the last two decades. We conducted a systematic review of safety and toxicity data associated with phage therapy in both animals and humans reported in English-language publications from 2008 – 2021. Overall, 69 publications met our eligibility criteria including 20 animal studies, 35 clinical case reports or case series, and 14 clinical trials. After summarizing safety and toxicity data from these publications, we discuss potential approaches to optimizing safety and toxicity monitoring with the therapeutic use of phage moving forward. In our systematic review of the literature, we found few, but no serious, adverse events associated with phage therapy. Comprehensive and standardized reporting of potential toxicities associated with phage therapy has generally been lacking in the published literature. Structured safety and tolerability endpoints are necessary when phages are administered as anti-infective therapeutics.

The rise of antibiotic-resistant strains demands new alternatives in antibacterial treatments. Bacteriophages, with their precise host specificity and ability to target and eliminate bacteria safely, present a valuable option. Meanwhile, hydrogels, known for their excellent biodegradability and biocompatibility, serve as ideal carriers for bacteriophages. The combination of bacteriophages and hydrogels ensures heightened phage activity, concentration, controlled release, and strong antibacterial properties, making it a promising avenue for antibacterial treatment. This article provides a comprehensive review of different cross-linking methods for phage hydrogels and focuses on their application in treating infections caused by various drug-resistant bacteria.

Allosteric modulators are ligands that bind to a site on the receptor that is spatially separated from the orthosteric binding site for the endogenous neurotransmitter. Allosteric modulators modulate the binding affinity, potency and efficacy of orthosteric ligands. Muscarinic acetylcholine receptors are prototypical allosterically-modulated G-protein-coupled receptors. They are a potential therapeutic target for the treatment of psychiatric, neurologic and internal diseases like schizophrenia, Alzheimer’s disease, Huntington disease, type 2 diabetes or chronic pulmonary obstruction. Here we review progress made during the last decade in our understanding of their mechanisms of binding, allosteric modulation and in vivo actions of in order to understand the translational impact of studying this important class of pharmacological agents. We overview newly developed allosteric modulators of muscarinic receptors as well as new spin-off ideas like bitopic ligands combining allosteric and orthosteric moieties and photo-switchable ligands based on bitopic agents.

G protein-coupled receptors (GPCRs) comprise the largest family of membrane receptors that control many cellular processes and consequently often serve as drug targets. These receptors undergo a strict regulation by mechanisms such as internalization and desensitization, which are strongly influenced by posttranslational modifications. Ubiquitination is a posttranslational modification with a broad range of functions that is currently gaining increased appreciation as a regulator of GPCR activity. The role of ubiquitination in directing GPCRs for lysosomal degradation has already been well-established. Furthermore, this modification can also play a role in targeting membrane and endoplasmic reticulum-associated receptors to the proteasome. Most recently, ubiquitination was also shown to be involved in GPCR signaling. In this review, we present current knowledge on the molecular basis of GPCR regulation by ubiquitination, and highlight the importance of E3 ubiquitin ligases, deubiquitinating enzymes and β-arrestins. Finally, we discuss classical and newly-discovered functions of ubiquitination in controlling GPCR activity.

Most neurodegenerative diseases, including Alzheimer's disease, ischemic stroke, subarachnoid hemorrhage, and intracerebral hemorrhage are associated with inflammation. Tumor necrosis factor (TNF) is a pleiotropic pro-inflammatory cytokine that regulates cerebral infarction in stroke pathology, and its action is influenced by the bioavailability of its membrane-bound receptors, TNFR1 and TNFR2, and microglial activation. During the initial onset of these diseases, the soluble variant of the cytokine presents with prolonged and excessive activation of TNFR1, resulting in cell death and long-term neurological impairments. Therapeutic interventions for neurodegenerative diseases have targeted TNF to limit the onset of neuroinflammation. First-generation therapeutics have been demonstrated to inhibit membrane-bound TNF to TNFR2 receptor binding, resulting in severe side effects such as infections and cancer. As such, second-generation drugs, including XPro1595, have been developed to selectively inhibit soluble TNF and impede the effects of TNFR1 while still allowing for TNFR2 activation. Early results in murine TBI models demonstrate reduced glial reactivity by 50%, reduced dendritic degeneration by 30%, increased plasticity by 15%, and improved functional outcomes by 20% post-TBI. This scoping review of TNF receptors in various neurodegenerative diseases seeks to evaluate current and future therapeutic strategies as well as highlight potential strategies to eliminate confounding variables present in the current literature.

Streptococcus mutans is a key bacterium in dental caries- one of the most prevalent chronic infectious diseases. Conventional treatment both fails to specifically target the pathogenic bacteria and at-tempts to eradicate commensal bacteria as well. Thus, caries remains one of most common and challenging diseases. The use of bacterial viruses as anti-bacterial agents, is gaining interest worldwide. Hardly any phages were described against S. mutans. The objective of this study was to isolate anti-S. mutans phages and to characterize their antimi-crobial properties. Human saliva samples were filtered and screened for potential phages. Standard double-layered agar method was used for isolation. Whole genome sequence analysis and morphology visualization by TEM, were used for anti-S. mutans phage identification. Antibacterial properties were evaluated using clinical strains and ATCC strains of S. mutans in various states. Antibacterial effect was also tested on human cariogenic dentin. One phage against S. mutans was isolated and termed SMHBZ8. This phage showed effective lytic activity in vitro against both planktonic and biofilm S. mutans cultures. Moreover, the phage showed antibacterial effect when used on cariogenic dentin. The isolation and characterization of SMHBZ8 may be the first step in developing a potential phage therapy for dental caries.

We have synthesized and examined a series of calix[4]arene-based chemosensors containing thiosemicarbazone or thiourea as a binding site and a pyridine-chromophore unit in various conformations. These conformations include pinched cone (I), cone (III and IV), and 1,3-alternate (II and V). Our objective was to assess the binding abilities of these sensors towards anions and cations using different spectroscopic techniques. All receptors demonstrate the ability to recognize cations, with notable distinctions between them. Receptor I demonstrates a broad spectrum of ion recognition, encompassing Ag+, Cu2+, Co2+, Ni2+, and Zn2+. Receptors IV and V also exhibit complex formation with Co2+, Ni2+, and Cu2+ ions. Sensors II and III demonstrate exceptional selectivity for recognizing the copper (II) ion. When studying anions, only receptor I yielded satisfactory results. This is due to the thiosemicarbazone bridge and its spatial orientation in the pinched cone conformation, which allows for an interaction to occur. It is worth noting that sensors IV and V, which are fluorescent molecules due to the triazolo pyridine unit in their structure, exhibit particularly noteworthy behavior. The highest association constant is observed for cobalt (II) complexes, with values of 6.59 and 2.38 (x1012 mol/L)-2 for receptors IV and V, respectively. Our findings indicate that there are no significant differences in selectivity and sensitivity between ca-lix[4]arene receptors in 1,3-alternate and cone conformations.

G-protein-coupled receptors (GPCRs) are ubiquitous sensors and regulators of cellular functions. Each GPCR exists in complex aggregates with multiple resting and active conformations. Designed to detect weak stimuli, GPCRs can also activate spontaneously, resulting in basal ligand-free signaling. Agonists trigger a cascade of events leading to an activate agonist-receptor-G protein complex with high agonist affinity. However, the ensuing signaling process can further remodel the receptor complex to reduce agonist affinity, causing rapid ligand dissociation. The acutely activated ligand-free receptor can continue signaling, as proposed for rhodopsin and  opioid receptors, resulting in robust receptor activation at low agonist occupancy with enhanced agonist potency. Continued receptor stimulation can further modify the receptor complex, regulating sustained ligand-free signaling - proposed to play a role in opioid dependence. Basal, acutely agonist-triggered, and sustained elevated ligand-free signaling could each have distinct functions, reflecting multi-state conformations of GPCRs. This review addresses basal and stimulus-activated ligand-free signaling, its regulation, genetic factors, and pharmacological implications, focusing on opioid and serotonin receptors, and the growth hormone secretagogue receptor (GHSR). Ligand-free signaling of intracellular 5-HT2A receptors could mediate therapeutic effects of psychedelic drugs. Research avenues are suggested to close gaps in our knowledge of ligand-free GPCR signaling.

Fatty acids (FFAs) are important biological molecules that serve as a major energy source and are key components of biological membranes. Besides, FFAs play important roles in metabolic regulation and contribute to the development and progression of metabolic disorders like diabetes. Recent studies have shown that FFAs can act as important ligands of G-protein coupled receptors (GPCRs) on the surface of cells and impact key physiological processes. Free fatty acid activated receptors include FFAR1 (GPR40), FFAR2 (GPR43), FFAR3 (GPR41) and FFAR4 (GPR120). FFAR2 and FFAR3are activated by short chain fatty acids like acetate, propionate and butyrate whereas FFAR1 and FFAR4 are activated by medium and long chain fatty acids like palmitate, oleate, linoleate and others. FFARs have generated considerable attention over the last few years and have become attractive pharmacological targets in the treatment of type 2 diabetes and metabolic syndrome. Several lines of evidence point to their importance in the regulation of whole-body metabolic homeostasis including adipose metabolism. Here we summarize our current understanding of the physiological functions of FFAR isoforms in adipose biology and explore the prospect of FFAR based therapies to treat patients with obesity and Type 2 Diabetes.

Cytokines are a family of proteins which play a major role in the regulation of immune system, and enter the development of several diseases from rheumatoid arthritis to cancer and, more recently, COVID-19. Therefore, many efforts are currently being spent in therapy and diagnosis, producing inhibitory drugs, as well as biosensors for a rapid, poor invasive, and effective detection. In this regards, even more efficient cytokine receptors are under investigation. In this paper we analyze a set of receptors of cytokine IL-6, investigating their topological features by means of a theoretical approach. Our results suggest a topological indicator that may help in the identification of those receptors having the highest complementarity with the protein, a feature expected to ensure a stable binding. Furthermore, we propose and discuss the use of these receptors in an ideal experiment.

This paper develops mathematical models examining possible roles of oxytocin and oxytocin receptors in the development of autism. This is done by demonstrating that mathematical operations on normalized data from the Stanford study (K.J. Parker, 2016), which establishes a correspondence between severity of autism in children and their oxytocin blood levels, generates a graph that is the same as the graph of mathematical operations on a normalized theoretical model for the severity of autism. This procedure establishes the validity of the theoretical model and the significance of oxytocin receptors in autism. A steady-state model follows, explaining the constant baseline concentrations of oxytocin observed in the cerebral spinal fluid and blood in terms of the neuromodulation by oxytocin of oxytocin receptors on the magnocellular neurons that produce oxytocin in nuclei in the hypothalamus. The implications of these models for possible roles of oxytocin and oxytocin receptors in autism is considered for several unrelated conditions that may be associated with autism. These are: oxytocin receptor desensitization and down-regulation as factors during labor in offspring autism development; reductions in the oxytocin receptor numbers in the fixed oxytocin receptor expression that occurs before birth; MAST Immune System disease; and the excess number of dendritic spines from lack of pruning observed in brains of autistic people. Research into the feasibility of generating magnocellular neurons and other neurons from adult stem cells is suggested as a way of doing invitro studies of oxytocin and oxytocin receptors to assess the validity of theories presented in this paper.

The emergence of multidrug-resistant bacterial strains, especially in the clinical setting, has renewed interest in alternative treatment methods. The utilization of prokaryotic viruses in phage therapy has demonstrated potential as a novel treatment method against multidrug-resistant bacterial infections. As the post-antibiotic era quickly approaches, the development and standardization of phage therapy is critically relevant to public health. This review serves to highlight the development of phage therapy against methicillin-resistant Staphylococcus aureus (MRSA), an antibiotic-resistant bacterial strain responsible for severe clinical infections.

Directed evolution methods are becoming increasingly popular, as they are extremely powerful toward developing new biomolecules with altered/novel activities, e.g., proteins with new catalytic functions or substrate specificities, and nucleic acids that recognize an intended target. Especially useful are systems that have incorporated continuous evolution, where the protein to be evolved undergoes continuous mutagenesis to evolve a desired trait with little to no input from the researcher once the system is started. However, continuous evolution methods can be challenging to implement in the lab and daunting for researchers to invest time and resources. Our intent is to provide basic information and helpful suggestions that we have gained from our experience with bacterial phage-assisted continuous evolution (PACE). Specifically, we review factors to consider before adopting PACE for a given evolution scheme, different types of selection circuits that can be utilized with particular focus on the PACE-B1H selection system, what optimization of a PACE selection circuit may look like using directed evolution of ME47 as a case study, and additional techniques that may be incorporated into a PACE experiment. With this information, researchers will be better equipped to determine if PACE is a valid strategy to use to evolve their proteins and how to set up a valid selection circuit.

N-methyl-D-aspartate receptors (NMDARs) are the main class of ionotropic receptor for the ex-citatory neurotransmitter glutamate. It plays a crucial role in the permeability of Ca2+ ions and excitatory neurotransmission in the brain. Being heteromeric receptors, they are composed of sev-eral subunits, including two obligatory GluN1 subunits (eight splice variants) and regulatory GluN2 (GluN2A~D) and/or GluN3 (GluN3A~B) subunits. Widely distributed in the brain, they regulate other neurotransmission systems and are therefore involved in essential functions such as synaptic transmission, learning and memory, plasticity, excitotoxicity. The present review will discuss the physiopathological impacts of NMDAR and particularly GluN2A and GluN2B subu-nits in cognitive processes and neurodegenerative diseases (Alzheimer's disease, Huntington's disease, Parkinson's disease). The pharmacology of different NMDAR antagonists and their po-tentialities will be presented. In particular, a focus will be given on fluoroethylnormemantine (FENM), an investigational drug with very promising developments as a tomography radiotracer for NMDARs, an anxiolytic in post-traumatic stress disorder and a neuroprotective agent in Alzheimer's disease.

Chimeric antigen receptors (CARs) is one of the curative immunotherapeutic approaches that exploit the antigen specificity and cytotoxicity function of potent immune cells against cancers. Neuroblastoma, the most common extracranial pediatric solid tumors with diverse comportment, could be a promising candidate for using CARs therapies. Several methods harness CARs modified cells in neuroblastoma to increase therapeutic efficiency, albeit the assessment has still been less successful. Regarding the improvement of CARs, various trials have been launched to overcome insufficient capacity. However, the reason behind the inadequate response against neuroblastoma of CARs modified cells are still not well understood. It is essential to update the present reveal of comprehension of CARs to improve the efficiency of CARs therapies. This review summarizes the crucial features of CARs and its design for neuroblastoma, discusses challenges that impact the outcomes of the immunotherapeutic competence, and focuses on devising strategies currently investigated to improve the efficacy of CARs for neuroblastoma immunotherapy.

Phage, which is often used therapeutically, has begun to receive interest as an alternative to antibiotic growth promoters (AGPs) to enhance chicken growth. Another option that has been extensively studied as a growth promoter in chicken is probiotics. However, there are no studies using phages and probiotics as prospective feed additives for broiler chickens. Therefore, this study demonstrated the effects of phage cocktail, probiotics and their combinations on growth performance and gut microbiota of broiler chickens. A total of 288 one-day-old male Cobb 500 broilers were randomly allotted to 1 of 6 treatments in a completely randomised design. The treatments were: (i) C (basal diet (BD) only), (ii) 1ɸ (BD + 0.1% phage cocktail), (iii) 2ɸ (BD + 0.2% phage cocktail), (iv) P (BD + 0.1% probiotic), (v) 1ɸP (BD + 0.1% phage cocktail + 0.1% probiotic), (vi) 2ɸP (BD + 0.2% phage cocktail + 0.1% probiotic). The 1ɸP treatment had significantly (P < 0.05) better BW (35 d), BWG (22 – 35 d, 1 – 35d), and FCR (1-21 d. 22-35 d, 1-35 d) compared to C. Unique gut microbiota diversity was also found between the ɸP (1ɸP and 2ɸP) and non-ɸP groups (C, 1ɸ, 2ɸ and P) in ilea, particularly in the 35 d chickens. Microorganisms associated with short-chain fatty acid (SCFA) producers were significantly (P <0.05) present in the ɸP group than in the non- ɸP group. The carbohydrate and amino acid metabolism predicted genes were significantly upregulated in ɸP groups compared to non- ɸP groups. These genes were involved in the digestion and absorption of nutrients as well as the production of energy. Our findings showed that 1ɸP treatment could be a potential alternative to AGPs for poultry where growth performance was enhanced, and gut microbiota was positively modulated.

Bacteria are engaged in a constant battle against preying viruses, called bacteriophages (or phag-es). These remarkable nano-machines pack and store their genomes in a capsid and inject it into the cytoplasm of their bacterial prey following specific adhesion to the host cell surface. Tailed phages possessing dsDNA genomes are the most abundant phages in the bacterial virosphere, particularly those with long, non-contractile tails. All tailed phages possess a nano-device at their tail tip that specifically recognizes and adheres to a suitable host cell surface receptor, being pro-teinaceous and/or saccharidic. Adhesion devices of tailed phages infecting Gram-positive bacte-ria are highly diverse and, for the majority, remain poorly understood. Their long, flexible and multi-domain encompassing tail limits experimental approaches to determine their complete structure. We have previously shown that the recently developed protein structure prediction program AlphaFold2 can overcome this limitation by predicting the structures of phage adhesion devices with confidence. Here, we extend this approach and employ AlphaFold2 to determine the structure of a complete phage, the lactococcal P335 phage TP901-1. Herein we report the structures of its capsid and neck, its extended tail, and the complete adhesion device, the baseplate, which was previously partially determined by X-ray crystallography.

Caffeine is the most popular and widely-consumed behaviourally-active substance in the world. This review focuses on the influence of caffeine on the cardiovascular system, with a special focus on blood platelets. For many years, caffeine was thought to have a negative effect on the cardiovascular system mainly due to increasing blood pressure. However, more recent data suggests that habitual caffeine consumption may reduce the risk of cardiovascular disease and hypertension. This could be a significant finding as cardiovascular disease is the leading cause of death worldwide. Caffeine is known to inhibit A1 adenosine receptors, through which it is believed to modulate inter alia coronary blood flow, total peripheral resistance, diuresis and heart rate. Although few publications have reported the effects of caffeine on platelet function, it seems reasonable to conclude that caffeine has antiplatelet activity. Platelet activation is known to play a crucial role in the development of arterial thrombotic diseases such as coronary heart disease and stroke, and hence there is a need to develop novel platelet inhibitors. One promising strategy to develop effective antiplatelet therapy involves targeting multiple pathways of platelet activation. Therefore, this review also examines the concept of dual antiplatelet therapy and the potential benefits associated with the therapeutic use of combined P2Y12 antagonists and adenosine receptor agonists in cardioprotection.

An event of increasing interest during host-pathogen interactions is the differentiation of patrolling monocytes (MOs) and the polarization of naive MOs into macrophage subsets (MФs). Therapeutic strategies aimed at modulating this event are under investigation. This review focuses on the mechanisms of induction, development, and profile of MФs polarized toward classically proinflammatory (M1) or alternatively anti-inflammatory (M2) phenotypes in response to bac-teria, fungi, parasites, and viruses. It highlights nuclear (PPARγ), cytoplasmic, and cell surface receptors (pattern recognition receptors/PPRs), microenvironmental mediators, and immune signaling. MФs polarize into phenotypes: M1 MФs, activated by IFN-γ, pathogen-associated mo-lecular patterns (PAMPs, e.g. LPS)/DAMPs and membrane-bound PPRs ligands (TLRs/CLRs lig-ands); or M2 MФs (a, b, c and d), induced by IL-4, -10 and -13, antigen-antibody complexes, and helminth PAMPs. The kinetics of M1 and M2 polarization evolve in a pathogen-specific manner, with or without canonicity, and can vary widely. Ultimately, this can result in varying degrees of host protection or more severe disease outcome. While the host is driving an effective MФs po-larization, pathogens are attempting to shift it to increase pathogenicity. The latter results from a bias toward an ineffective M1 or M2 response due to microbial virulence factors, culminating in pathogen evasion of host defenses. Plasticity of M1/M2 phenotypes is also ensured by cellu-lar/genomic reprogramming. Because modulation of this event can occur at multiple points, providing a therapeutic/vaccine design target to boost microbicidal (M1) or tissue repair (M2) response during the inflammation-to-resolution transition; new insights and emerging perspec-tives may have clinical implications.

In recent years, the interaction between adiponectin (APN), a versatile fat-associated adipokines, and eye disorders has become a captivating focus of interest. Unveiling the intricate relationship between APN and its receptors (AdipoRs) with aging eye disorders has emerged as a fascinating frontier in medical research. This review article delves into this captivating connection, illuminating the hidden influence of adipocytokine, APN on retinal health. This comprehensive review critically examines the latest findings and breakthroughs that underscore the pivotal roles of APN/AdipoRs signaling in maintaining ocular homeostasis and protecting against eye ailments. Here, we meticulously explore the intriguing mechanisms by which APN protein influences retinal function, lens clarity, and overall visual acuity. Drawing from an extensive array of cutting-edge studies, the article highlights APN's multifaceted functions, ranging from anti-inflammatory properties and oxidative stress reduction to angiogenic regulation within retinal and macula tissues. The involvement of APN/AdipoRs in mediating these effects opens up novel avenues for potential therapeutic interventions targeting prevalent aging eye conditions. Moreover, this review unravels the interplay between APN signaling pathways and age-related macular degeneration (AMD). The single-cell RNA seq results validate the expression of both the receptor isoform (AdipoR1/R2) in retinal cells. The transcriptomic analysis showed lower expression of AdipoR1/2 in dry AMD pathogenesis compared to healthy subjects. The inhibitory peptide (APN1) demonstrated over 75% suppression of CNV, whereas the control peptide did not exert any inhibitory effect on CNV. The elucidation of these relationships fosters a deeper under-standing of adipose tissue's profound influence on ocular health, presenting new prospects for personalized treatments and preventative measures. In conclusion, "Obesity Hormone's Role in Aging Eyes: Linking Adiponectin/AdipoRs to AMD" provides a captivating journey into the enthralling world of APN intertwining the realms of adipose biology and aged ophthalmology.

Parascaris sp. is the only ascarid parasitic nematode in equids and one of the most threatening infectious organisms in horses. Only a limited number of compounds are available for treatment of horse helminthiasis and Parascaris sp. worms have developed resistance to the three major anthelmintic families. In order to overcome the appearance of resistance, there is an urgent need for new therapeutic strategies. The active ingredients of herbal essential oils are potentially effective antiparasitic drugs. Carvacrol is one of the principal chemicals of essential oil from Origanum, Thymus, Coridothymus, Thymbra, Satureja and Lippia herbs. However, the antiparasitic mode of action of carvacrol is poorly understood so far. Here, the objective of the work was to characterize the activity of carvacrol on Parascaris sp. nicotinic acetylcholine receptors (nAChRs) function both in vivo with the use of worm neuro-muscular flap preparations and in vitro with two-electrode voltage-clamp electrophysiology on nAChRs expressed in Xenopus oocytes. We have developed a neuromuscular contraction assay on Parascaris body flaps and obtained acetylcholine concentration-dependent contraction responses. Strikingly, we observed that 300 µM carvacrol fully and irreversibly abolished Parascaris sp. muscle contractions elicited by acetylcholine. Conversely, carvacrol antagonized acetylcholine-induced currents from both the nicotine-sensitive AChR and the morantel-sensitive AChR subtypes. Thus, we show for the first time that the body muscle flap preparation is a tractable approach to investigate the pharmacology of Parascaris sp. neuro-muscular system. Our results suggest an intriguing mode of action for carvacrol being a potent antagonist of muscle nAChRs of Parascaris sp. worms which may account for its antiparasitic potency.

Reduced inhibitory glycinergic neurotransmission is implicated in a number of neurological conditions such as neuropathic pain, schizophrenia, epilepsy and hyperekplexia. Restoring glycinergic signalling may be an effective method of treating these pathologies. Glycine transporters (GlyTs) control synaptic and extra-synaptic glycine concentrations and slowing the reuptake of glycine using specific GlyT inhibitors will increase glycine extracellular concentrations and increase glycine receptor (GlyR) activation. Glycinergic neurotransmission can also be improved through positive allosteric modulation (PAM) of GlyRs. Despite efforts to manipulate this synapse, no therapeutics currently target it. We propose that dual action modulators of both GlyTs and GlyRs may show greater therapeutic potential than those targeting individual proteins. To show this, we have characterized a co-expression system in Xenopus laevis oocytes consisting of GlyT1 or GlyT2 co-expressed with GlyRα1. We use two electrode voltage clamp recording techniques to measure the impact of GlyTs on GlyRs and the effects of modulators of these proteins. We show that increases in GlyT density in close proximity to GlyRs diminish receptor currents. Reductions in GlyR mediated currents are not observed when non-transportable GlyR agonists are applied or when Na+ is not available. GlyTs reduce glycine concentrations across different concentration ranges, corresponding with their ion-coupling stoichiometry, and full receptor currents can be restored when GlyTs are blocked with selective inhibitors. We show that partial inhibition of GlyT2 and modest GlyRα1 potentiation using a dual action compound, is as useful in restoring GlyR currents as a full and potent single target GlyT2 inhibitor or single target GlyRα1 PAM.

Orthologs of human glucocorticoid receptor (GR) and human mineralocorticoid receptor (MR) first appear in cartilaginous fishes. Subsequently, the MR and GR diverged to respond to different steroids: the MR to aldosterone and the GR to cortisol and corticosterone. We report that cortisol, corticosterone and aldosterone activate full-length elephant shark GR, and progesterone, which activates elephant shark MR, does not activate elephant shark GR. However, progesterone inhibits steroid binding to elephant shark GR, but not to human GR. Together, this indicates partial functional divergence of elephant shark GR from the MR. Deletion of the N-terminal domain (NTD) from elephant shark GR (truncated GR) reduced the response to corticosteroids, while truncated and full-length elephant shark MR had similar responses to corticosteroids. Swapping of NTDs of elephant shark GR and MR yielded an elephant shark MR chimera with full-length GR-like increased activation by corticosteroids and progesterone compared to full-length elephant shark MR. Elephant shark MR NTD fused to GR DBD+LBD had similar activation as full-length MR, indicating that the MR NTD lacked GR-like NTD activity. We propose that NTD activation of human GR evolved early in GR divergence from the MR.

Antimicrobial resistance (AMR) has become a worldwide health problem. Consequently, there is a global interest in the study of the antimicrobial activity of natural compounds as an alternative to antibiotics. One of the possibilities studied during the last years is the use of bacteriophages and their derived proteins. More specifically, phage lytic proteins or endolysins are specific enzymes that cause cell lysis and can be easily produced and purified after overexpression in bacteria. However, one of the major disadvantages of these proteins is their sensitivity to some environmental conditions that can reduce their efficiency. The use of vesicles for endolysin encapsulation could help overcome this disadvantage, offering an additional protection to the protein and allowing its controlled release and long-term stability.

Tick-borne diseases are a growing concern worldwide, affecting both human and animal populations. Ticks are known to harbor a wide range of pathogens and are considered one of the most important vectors of disease. Lyme disease, caused by Borrelia burgdorferi sensu lato, is the most common tick-borne disease in the US and Europe. However, accurate diagnosis of Lyme disease can be challenging due to the complex immune evasion strategies employed by Borrelia species and the limitations of existing diagnostic tests. To address this issue, researchers are exploring novel approaches, including the use of bacteriophages as diagnostic tools. Bacteriophages are highly specific and offer advantages over traditional methods for detecting bacteria, including Borrelia. In particular, the use of multicopy bacteriophages as molecular markers for Borrelia detection is a promising approach that may provide greater sensitivity than targeting single-copy bacterial genes. Nonetheless, the task of identifying trace amounts of bacteriophages in blood samples necessitates attention, and scientists are devising innovative techniques to surmount this hurdle. In summary, employing bacteriophages as a diagnostic tool for tick-borne diseases, such as Lyme disease, by specifically targeting free circulating bacteriophages in blood samples, offers significant potential for enhancing patient outcomes and public health.

The problem of antimicrobial resistance has created a new need for alternative/ complementary treatments. To this end, bacteriophages offer an exciting prospect, as they can infect and kill specific bacteria without harming the host. This survey aimed to evaluate the state of applied phage research in Africa, among the members of the Africa phage Forum (APF). This was a cross-sectional survey whereby a google form was created for the members of the Africa Phage forum to fill so as to access the stage of phage research in Africa. Data was collected between June and July 2021 using a structured questionnaire form. A total of 65 out of a total of 101 forum members completed the questionnaire. The survey indicated that a majority 68% of phage researchers in Africa were at the training stages of their career. Some available participants were limited (8%). Most of the members identified funding, lack of skill set, near absence of adequate laboratory infrastructure as major hurdles for phage research. Despite these challenges, 73.3% of APF members work with the ESKAPE group with the majority of its members carrying out research in Phage in Biocontrol (80%), whereas others perform research related to human phage therapy (60%). However, it appeared this research has not yet reached the stage of commercialization. Overall, Phage research is in its infancy in Africa. Key challenges included poor laboratory infrastructure, lack of capacity building in the phage field, and lack of local awareness on the significance of phages for policymakers and governments. APF could, therefore, play a role in creating phage awareness in Africa; mobilizing resources; enhancing networks and collaborations amongst APF members and beyond, especially with more experienced phage mentors in the Western countries, to greatly reduce the gap in knowledge and enhance phage research in Africa.

Bacteria develop various defense mechanisms against stresses, including the bacteriophage infection. The giant phiKZ phage infection induced the appearance of a pseudo-nucleus inside the bacterial cytoplasm. Here, we used FISH, electron tomography and analytical electron microscopy to study the morphology of this unique nucleus-like shell and to demonstrate the distribution of phiKZ and bacterial DNA in infected P. aeruginosa cells. The maturation of the pseudo-nucleus was traced in short intervals for 40 min after infection. This study was accompanied by the identification of phiKZ and bacterial DNA by real-time RCR. We demonstrated that phage DNA that isolated from the cytoplasm during all infection stages were compacted within the pseudo-nucleus in a specific structure. Bacterial DNA was diminished in the course of infection, but did not completely degrade until at least 40 min after phage application. The content of the total phage DNA, on the other hand, increased. EDX analysis confirmed these results and revealed that, during the infection, Sulfur content in the bacterial cytoplasm increased, which suggests the increase of DNA-binding Met-reach proteins synthesis, which could protect bacterial DNA from stress.

Background: Dual function tail tubular proteins (TTP) belonging to the lytic bacteriophages are the interesting group of biologically active enzymes. Surprisingly, apart from their structural function, they are also polysaccharide hydrolyzes destroying bacterial extracellular components. One of the representatives of this group is TTPB from Klebsiella pneumoniae phage – KP32. TTPB hydrolyzes exopolysaccharide (EPS) of Klebsiella pneumoniae and Enterococcus faecalis strain. This depolymerizing feature was associated with the activity to prevent bacterial biofilm formation. TTPB can inhibit biofilm formation by K. pneumoniae, Enterobacter cloacae, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa strains. Moreover, synergistic activity with antibiotic action has been observed, most likely due to depolymerases’ facilitation of contact of antibiotic with bacterial cells. Methods: TTPB was overexpressed in E coli system, purified and tested towards the bacterial strains using agar overlay method. The hydrolytic activity of TTPB was performed using EPSs of K. pneumoniae PCM2713 and E. cloacae ATCC 13047 as the substrates. Next, we determined the reducing sugar (RS) levels in the TTPB/EPS mixtures, regarding the RS amount obtained after acidic hydrolysis. The antibiofilm activity of TTPB has been set down on bacterial biofilm using a biochemical method. Finally, we have demonstrated the synergistic activity of TTPB with kanamycin. Results: For the first time, the hydrolytic activity of TTPB towards bacterial EPSs has been shown. TTPB releases about a half of the whole RS amount of EPSs belonging to K. pneumoniae PCM 2713 and E. cloacae ATCC 13047 strains. 1.12 µM of the phage protein reduces biofilm of both strains by over 60%. Destroying the bacterial biofilm the phage protein improves the antibiotic action increasing kanamycin effectiveness up to four times.

Nuclear receptors (NRs) constitute a superfamily of ligand-activated transcription factors with a paramount role in ubiquitous physiological functions such as metabolism, growth, and reproduction. Owing to their physiological role and druggability, NRs are deemed attractive and valid targets for medicinal chemists. Pentacyclic triterpenes (PTs) represent one of the most important phytochemical classes present in higher plants, where oleanolic acid (OA) is the most studied PTs representative owing to its multitude of biological activities against cancer, inflammation, diabetes, and liver injury. PTs possess a lipophilic skeleton that imitates the NRs endogenous ligands. Herein, we report a literature overview on the modulation of metabolic NRs by OA and its semi-synthetic derivatives, highlighting their health benefits and potential therapeutic applications. Indeed, OA exhibited varying pharmacological effects on FXR, PPAR, LXR, RXR, PXR, and ROR in a tissue-specific manner. Owing to those NRs modulation, OA exhibited prominent hepatoprotective properties comparable to ursodeoxycholic acid (UDCA) in a bile duct ligation mice model and antiatherosclerosis effect as simvastatin in a model of New Zealand white (NZW) rabbits. It also demonstrated a great promise in alleviating non-alcoholic steatohepatitis (NASH) and liver fibrosis, attenuated alpha-naphthol isothiocyanate (ANIT)-induced cholestatic liver injury, and controlled blood glucose levels, making it a key player in the therapy of metabolic diseases. We also compiled OA semi-synthetic derivatives and explored their synthetic pathways and pharmacological effects on NRs, showcasing their structure-activity relationship (SAR). To the best of our knowledge, this is the first review article to highlight OA activity in terms of NRs modulation.

There is much concern about disruption of endocrine physiology regulated by steroid hormones in humans, other terrestrial vertebrates and fish by industrial chemicals, such as bisphenol A, and pesticides, such as DDT. These endocrine-disrupting chemicals influence steroid-mediated physiology in humans and other vertebrates by competing with steroids for receptor binding sites, disrupting diverse responses involved in reproduction, development and differentiation. Here I discuss that due to evolution of the progesterone receptor (PR) and mineralocorticoid receptor (MR) after ray-finned fish and terrestrial vertebrates diverged from a common ancestor, each receptor evolved to respond to different steroids in ray-finned fish and terrestrial vertebrates. In elephant shark, a cartilaginous fish, ancestral to ray-finned fish and terrestrial vertebrates, both progesterone and 17,20-beta-dihydroxy-progesterone activate the PR. During the evolution of ray-finned fish and terrestrial vertebrates, the PR in terrestrial vertebrates continued responding to progesterone and evolved to weakly respond to 17,20-beta-dihydroxy-progesterone. In contrast, the physiological progestin for the PR in zebrafish and other ray-finned fish is 17,20-beta-dihydroxy-progesterone, and ray-finned fish PR responds weakly to progesterone. The MR in fish and terrestrial vertebrates also diverged to have different responses to progesterone. Progesterone is a potent agonist for elephant shark MR, zebrafish MR and other fish MRs, in contrast to progesterone’s opposite activity as an antagonist for aldosterone, the physiological mineralocorticoid for human MR. These different physiological ligands for fish and terrestrial vertebrate PR and MR need to be considered in applying data for their disruption by chemicals in fish and terrestrial vertebrates to each other.

Probiotics are increasingly used by consumers and practitioners to reduce gastrointestinal (GI) distress and improve gut function. Here, we sought to determine whether addition of supplemental bacteriophages (PreforPro) could enhance the effects of a common probiotic, Bifidobacterium animalis subsp. lactis (B. lactis) on GI health. We conducted a 4-week, randomized, parallel-arm, double-blind, placebo-controlled trial where primary outcomes included self-assessments of GI health, a daily stool log, and 16s rRNA analysis of gut microbial populations. We observed within group improvements in GI inflammation (p=0.01) and a trending improvement in colon pain (p=0.08) in individuals consuming B. lactis with PreforPro, but not in the group consuming only the probiotic. There was also a larger increase in Lactobacillus and short chain fatty acid-producing microbial taxa detected in stool of participants taking PreforPro with B. lactis compared to the probiotic alone. Overall, these results suggest the addition of PreforPro as a combination therapy may alter gut ecology to extend the GI benefits of consuming B. lactis or other probiotics.

Lytic bacteriophages have the efficacy to act and eradicate pathogenic bacteria as an attractive tool in the near future. Bacteriophages specifically kill multidrug-resistant bacteria even which have the capacity to form biofilms. The present review mainly focused on the efficacy of bacteriophages and cocktails as therapeutic agents against predominate MDR-bacteria and their biofilms which are isolated from septic wound infections. The body of evidence includes data from studies investigating bacteriophages from sewage samples as novel antibacterial and antibiofilm agents against pathogenic bacteria. The goal of this review is to present an overview on predominant bacteria from septic wound infection, the biofilm-forming capacity of bacteria, lytic effect of bacteriophages and phage cocktails with an emphasis on the application of bacteriophages against septic wound causing bacteria.

Prostate cancer (PCa) is a major cause of cancer-related mortality worldwide, with a rising incidence observed over the years. The androgen receptor (AR) signaling pathway plays a pivotal role in male development and maintaining masculine characteristics. Dysregulation of AR signaling in prostate cancer can lead to disease progression and resistance to standard therapies. Understanding the intricate regulation and function of AR in both healthy and diseased states is crucial for developing effective treatment strategies. This review comprehensively explores the role of androgen receptors in prostate cancer susceptibility, disease progression, and treatment response by analyzing recent literature. An extensive search of peer-reviewed publications in major databases, including PubMed, Scopus, and Web of Science, was conducted using specific keywords related to androgen receptor, prostate cancer, disease progression, and treatment resistance. Relevant conference abstracts and clinical trial reports were also included. The review presents an overview of the role of androgen receptors in prostate cancer initiation, progression, and treatment resistance. It highlights emerging biomarkers associated with AR signaling dysregulation and their potential utility for early detection and personalized treatment approaches. Additionally, recent advances in targeting the AR pathway for novel therapeutic strategies to improve patient outcomes and overcome treatment resistance in advanced prostate cancer are discussed. The findings contribute to a comprehensive understanding of the AR signaling pathway in prostate cancer and offer insights into its multifaceted role in disease development and treatment response. They may pave the way for innovative therapeutic interventions and precision medicine approaches based on specific AR signaling profiles, enhancing patient care and reducing the burden of this lethal disease.

CD8 T cells and Natural Killer (NK) cells are cytotoxic lymphocytes important in the response to intracellular pathogens and cancer. Their activity depends on the integration of a large set of intracellular and environmental cues, including antigenic signal, cytokine stimulation and nutrients availability. This integration is achieved by signaling hubs such as the mechanistic target of Rapamycin (mTOR). mTOR is a conserved protein kinase, controlling cellular growth and metabolism in eukaryotic cells and therefore is essential for lymphocyte development and maturation. However, our current understanding of mTOR signaling comes mostly from studies performed in transformed cell lines, which constitute a poor model to comprehend metabolic pathway regulation. Therefore, it is only quite recently that the regulation of mTOR in primary cells has been assessed. Here we review the signaling pathways leading to mTOR activation in CD8 T and NK cells, focusing on activation by cytokines. We also discussed how this knowledge can contribute to immunotherapy development for intracellular pathogen and cancer treatment.

(1) Background: Many malignancies are driven by mutations which affect the gene for fibroblast growth factor receptor (FGFR) 1. Previously we have documented that signal transduction from FOP2–FGFR1 fusion protein in KG1 cells downregulated the expression of vitamin D receptor (VDR) gene. In this paper we investigated if also other FGFRs were responsible for the regulation of the VDR expression. (2) Methods: We used human myeloid leukemia cells U937, and bone cancer cell line U2OS, and cell transfection methods in order to address the above questions. (3) Results: In myeloid leukemia cells overexpression of FGFR 1-4 caused shift to granulocytic differentiation, upregulated expression of VDR, and sensitized these cells to 1,25-dihydroxyvitamin D (1,25D)-induced monocytic differentiation, while in bone cells, signal transduction activated by FGF1 was not responsible for regulation of VDR expression and activity. (4) Conclusions: Since the overexpression of FGFRs occurs in many neoplasms, it may be reasonable to use 1,25D analogs in these cancers, in which overexpression of FGFRs leads to VDR upregulation.

From the hospital wastewater, a novel bacteriophage was isolated and characterized. According to characterization properties, this bacteriophage belongs to the Siphoviridae family, the maximum bacteriophage titer was recorded at 37°C and a pH of 7.2, had a 44,789 bp linear double-strand DNA genome, and within the genome sequence, there are 61 genes, all of which are encoded into proteins. Although this bacteriophage does not have any virulence factors or antimicrobial resistance genes and had specific lytic activity against some antimicrobial resistance S. aureus clinical isolates.

Fire blight, caused by Erwinia amylovora, is a devastating bacterial disease that threatens world-wide production of apples and pears. In Canada and the US, streptomycin and kasugamycin are commonly used for the control of this pathogen. There is an urgent need for development of biocontrol agents (BCAs) that can be easily incorporated into integrated pest management pro-grams with high efficacy against streptomycin sensitive and resistant strains of E. amylovora. In addition, excessive use of antibiotics in agriculture has increased awareness of the possibility of antibiotic resistance gene transfer to human, animal and environmental microbes. To address this issue, a phage-carrier system (PCS) that combines Pantoea agglomerans as an antagonistic bacterial carrier of Erwinia phages as a double-pronged treatment for fire blight have been de-veloped. The low viability of P. agglomerans cells following spray drying challenged the industrial scale production of this PCS. In the present research, a spray drying protocol was developed for P. agglomerans by modifying the growth medium and the bacterial cell formulation using D(+)-trehalose and maltodextrin. The developed protocol is amenable to industrial scale pro-duction of the BCA/PCS. The P. agglomerans viability was greater than 90% after spray drying, had a prolonged shelf life of 4 months at 4 C, and the reconstituted cells showed an approximate 3 log reduction in E. amylovora counts with a green pear disc challenge assay.

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants of emerging concern, recognized for their toxicity and potential carcinogenic properties. PFAS chemicals are reported to act as endocrine disruptors through their interactions with various nuclear receptors (NRs). Despite their significant impact, comprehensive screenings and detailed analyses of PFAS binding strengths at both the orthosteric and allosteric sites of NRs are currently lacking in the literature. Our study addresses this gap by focusing on the binding interaction analysis of both common and uncommon PFAS with key nuclear receptors such as the vitamin D receptor (VDR), peroxisome proliferator-activated receptor gamma (PPARγ), pregnane X receptor (PXR), and estrogen receptor alpha (ERα). We used advanced docking simulations to screen 9,507 PFAS chemicals at the orthosteric and allosteric sites of the PPARγ, PXR, VDR, and ERα. We verified the accuracy of our docking protocol through multiple docking procedures and validations. The python code used for PFAS chemical screening is deposited in the supplementary file. Among the PFAS assessed at the orthosteric site of the VDR, 21 demonstrated similar binding affinities compared to the calcitriol, while 130 PFAS, exhibited stronger binding affinities than calcitriol. At the VDR allosteric site, where lithocholic acid (LCA) natively binds, 412 PFAS matched the binding energies of LCA, and 2,229 showed even greater binding energies. Similar testing on the PXR, PPARγ, and ERα revealed that the orthosteric site of PPARγ had 1,863 PFAS binding with a higher affinity than native ligand ET1 and 693 PFAS binding at the allosteric site with greater affinity than T35 native ligand. At the PXR orthosteric site, 650 PFAS bound with a greater affinity than native ligand 4WH, while at the allosteric site, 9,148 PFAS demonstrated a greater binding affinity than the known allosetric ligand glycerol. At the orthosteric site of ERα, 40 PFAS displayed binding with a greater affinity than the native ligand estradiol and at the allosteric site, only 8 PFAS exhibited greater binding affinity than coactivator ligand SRC-1. Further, our mixture modeling analysis indicates that PFAS can bind in various combinations with themselves and with endogenous or native ligands simultaneously, to disrupt the endocrine system and cause carcinogenic responses. These findings reveal that PFAS can interfere with nuclear receptor activity by displacing endogenous or native ligands by binding to the orthosteric and allosteric sites. This study elucidates the mechanisms through which PFAS exert their endocrine-disrupting effects, potentially leading to more targeted environmental regulations and therapeutic strategies. Importantly, this study is the first to explore the binding of PFAS at allosteric sites and to model PFAS mixtures at nuclear receptors. Given the high concentration and persistence of PFAS in humans, this study called for the urgent need for further research into the carcinogenic mechanisms of PFAS and the development of intervention strategies that target nuclear receptors. Our ongoing studies extend these findings by further investigating the interactions of PFAS and co-exposed chemicals with nuclear receptors. These investigations are supported by experimental verification, which will enhance our understanding of PFAS broad effects and aid in the design of effective mitigation strategies.

Co-inhibitory receptors (Co-IRs) are essential in controlling the progression of immunopathology in rheumatoid arthritis (RA) by limiting T cell activation. The objective of this investigation was to determine the phenotypic expression of Co-IRs T cells and to assess the levels of serum soluble PD-1, PDL-2, and Tim3 in Taiwanese RA patients. Co-IRs T cells were immunophenotyped employing multicolor flow cytometry, and ELISA was utilized for measuring soluble PD-1, PDL-2, and Tim3. Correlations have been detected across the percentage of T cells expressing Co-IRs (MFI) and different indicators in the blood, including ESR, high sensitivity CRP (hsCRP), 28 joint disease activity scores (DAS28), and soluble PD-1/PDL-2/Tim3. In RA patients, we recognized elevated levels of PD-1 (CD279), CTLA-4, and TIGIT on CD4+ T cells; TIGIT, HLA-DR, TIM3, and LAG3 on CD8+ T cells; and CD8+CD279+TIM3+, CD8+HLA-DR+CD38+ T cells. The following tests proved to be correlated with hsCRP: CD4/CD279 MFI, CD4/CD279%, CD4/TIM3%, CD8/TIM3%, CD8/TIM3 MFI, CD8/LAG3%, and CD8+HLA-DR+CD38+%. CD8/LAG3 and CD8/TIM3 MFIs are linked to ESR. DAS28-ESR and DAS28-CRP exhibited relationships with CD4/CD127 MFI, CD8/CD279%, and CD8/CD127 MFI, respectively. CD4+CD279+TIM3+% was correlated with DAS28-ESR (p=0.0084, N=46), DAS28-CRP (p=0.007, N=47), and hsCRP (p=0.002, N=56), respectively. In the serum of patients with RA, levels of soluble PD-1, PDL-2, and Tim3 were extremely elevated. CD4+ TIM3+% (p=0.0089, N=46) and CD8+ TIM3+% (p=0.0305, N=46) were correlated with sTIM3 levels; sPD1 levels were correlated with CD4+CD279+% (p<0.0001, N=31) and CD3+CD279+% (p=0.0084, N=30). Co-IRs expressions on CD4+ and CD8+ T cells, as well as soluble PD-1, PDL-2, and Tim3 levels, could function as indicators of disease activity and potentially play crucial roles in the pathogenesis of RA, in accordance to our findings.

Trace amines are a separate, independent group of biogenic amines, close in structure to classical monoamine neurotransmitters such as dopamine, serotonin and norepinephrine. G protein-coupled Trace Amine-Associated Receptors (TAAR) are mostly investigated for their involvement in the pathogenesis of neuropsychiatric disorders, but expression of TAAR family receptors is observed also in various populations of cells of the immune system. The review is focused on the basic information on the interaction of trace amines and their receptors with cells of the general immune system of humans and other mammals, as well as on data on TAARs role in the function of individual populations of myeloid and lymphoid cells. With further research on the regulatory role of the trace amine system in the pathogenesis of the immune response and determination of the biological mechanisms for their action it would be possible to develop new methods for treating diseases related to immune system dysfunctions.

Parkinson’s disease (PD) is a progressive neurodegenerative disease characterized by resting tremor, bradykinesia, rigidity, postural instability, that also includes non-motor symptoms such as mood dysregulation. Dopamine (DA) is the primary neurotransmitter involved in this disease, but cholinergic imbalance has also been implicated. Current intervention in PD is focused on replenishing central DA, which provides remarkable temporary symptomatic relief but does not address the neuronal loss and the progression of the disease. It has been well established that neuronal nicotinic cholinergic receptors (nAChRs) can regulate DA release and that nicotine itself may have neuroprotective effects. Recent studies have identified nAChRs in nonneuronal cell types including glial cells, where they may regulate inflammatory responses. Given the crucial role of neuroinflammation in dopaminergic degeneration, and the involvement of microglia and astrocytes in this response, glial nAChRs may provide a novel therapeutic target in prevention and/or treatment of PD. In this review, following a brief discussion of PD, we focus on the role of glial cells and specifically their nAChRs in PD pathology and/or treatment.

Findings of new targeted treatments with adequate safety evaluations is essential for better cancer cures and mortality rates. Immunotherapy holds promise for patients with relapsed disease, with the ability to elicit long-term remissions. Emerging promising clinical results in B-cell malignancy using gene-altered T-lymphocytes uttering chimeric antigen receptors have sparked a lot of interest. This treatment could open the path for a major difference in the way we treat tumors that are resistant or recurring. Genetically altered T cells used to produce tumor-specific chimeric antigen receptors are resurrected field of adoptive cell therapy by demonstrating remarkable success in the treatment of malignant tumors. Because of the molecular complexity of chimeric antigen receptors -T cells, a variety of engineering approaches to improve safety and effectiveness are necessary to realize larger therapeutic uses. In this study, we investigate at new strategies for enhancing chimeric antigen receptors-T cell therapy by altering chimeric antigen receptors proteins, T lymphocytes, and their relations with other solid tumor microenvironment (TME) aspects.

G-protein coupled receptors (GPCRs) are large protein families known to be important in many cellular processes. They are well known for their allosteric activation mechanisms. They are drug targets for several FDA-approved drugs. We have investigated the diversity of the ligand binding site for these class of proteins against their cognate ligands using computational docking, even if their structures are known in the ligand-complexed form. The cognate ligand of some of these receptors dock at allosteric binding site, with better score than the binding at the conservative site. Further, ligands obtained from GLASS database, which consists of experimentally verified GPCR ligands, also show allosteric binding to GPCRs. The allosteric binders show strong affinity to the binding site, though the residues at the binding site are not conserved across GPCR subfamilies.

Breast cancer (BC) is the most frequent form of malignancy and the second only to lung cancer as common cause of cancer-causing deaths in women. Notwithstanding many progresses in the field, metastatic BC has a very poor prognosis. As therapies are becoming more personalized to meet patients‘ needs, a better knowledge of the molecular biology leading to the disease unfolds the possibility to project more precise compounds or antibodies targeting definite alteration at the molecular level expressed in cancer cells of patients or as antigens on the surface of cell membranes. Fibroblast growth factor receptor (FGFR) is a druggable target -which is activated by its own ligands -namely the Fibroblast Growth Factors (FGFs). This pathway provides a vast range of interesting molecular targets pursued at different levels of clinical investigation. Herein we provide an update on the knowledge on genetic alterations of the receptors in breast cancer, their role in tumorigenesis and the most recent drugs against this particular receptor to treat the disease.

Breast cancer (BC) is the most common malignancy and second only to lung cancer in terms of mortality in women. Despite the incredible progress made in this field, the metastatic breast cancer leaves a poor prognosis. In an era of personalized medicine, there is an urgent need for a better knowledge of the biology leading to the disease, which can lead to the design of always more accurate drugs against patients’ specific molecular aberrations. Among one of the actionable targets is the Fibroblast Growth Factor Receptor (FGFR) pathway, triggered by specific ligands. The FGFRs/FGFs axis offers interesting molecular targets to be pursued in clinical development. This mini-review will focus on the current knowledge of the FGFRs mutations leading to tumour formation and summarizes the state-of-the-art of therapeutic strategies for targeted treatments against the FGFRs/FGFs axis in the context of BC.

The global health emergency caused by multi-drug resistant bacteria has led to the search for and development of new antimicrobial agents. Phage therapy is an abandoned antimicrobial therapy that has been resumed in recent years. In this study, we mutated a lysogenic phage from Acinetobacter baumannii into a lytic phage (Ab105-2phiΔCI) showing antimicrobial activity against A.baumannii clinical strains (such as Ab177_GEIH-2000 which showed MICs to meropenem and imipenem of 32 µg/ml and 16 µg/ml, respectively as well as belonging to GEIH-REIPI Spanish Multicenter A. baumannii Study II 2000/2010, Umbrella Genbank Bioproject PRJNA422585). We then enhanced the time kill curves (in vitro) and in Galleria mellonella survival assays (in vivo) antimicrobial activity of the new lytic phage by combining it with carbapenem antibiotics (meropenem and imipenem). We observed in vitro, an antimicrobial synergistic effect (from 4 log to 7 log CFU/ml) with meropenem plus lytic phage in all combinations analysed (0.1, 1 and 10 MOI of Ab105-2phiΔCI mutant as well as 1/4 and 1/8 MIC of meropenem). Moreover, we had a decrease in bacterial growth of 8 log CFU/ml for the combination of imipenem at 1/4 MIC plus lytic phage (Ab105-2phiΔCI mutant) and of 4 log CFU/ml for the combination of imipenem at 1/8 MIC plus lytic phage (Ab105-2phiΔCI mutant) in both MOI 1 and 10. These results were confirmed in in vivo (G. mellonella) obtaining a higher effectiveness in the combination of imipenem and Ab105-2phiΔCI mutant (P<0.05 by Log Rank-Matel Cox test). This approach could help to reduce the emergence of phage resistant bacteria and restore sensitivity to the antibiotics when used to combat multiresistant strains of Acinetobacter baumannii.

In contrast to lytic phages, filamentous phages are assembled in the inner membrane and secreted across the bacterial envelope without killing the host. For assembly and extrusion of the phage across the host cell wall, filamentous phages code for membrane-embedded morphogenesis proteins. In the outer membrane of E. coli, the protein gp4 forms a pore-like complex, while gp1 and gp11 form a complex in the inner membrane of the host. By comparing sequences with other filamentous phages, we identified putative Walker A and B motifs in gp1 with a conserved lysine in the Walker A motif (K14), and a glutamic and aspartic acid in the Walker B motif (D88, E89). In this work we demonstrate that both, Walker A and Walker B, are essential for phage production. The crucial role of these key residues suggest that gp1 is likely to be a molecular motor driving phage assembly. We further identified essential residues for the function of the assembly complex. Mutations in three out of six cysteine residues abolish phage production. Similarly, two out of six conserved glycine residues are crucial for gp1 function. We hypothesise that the residues represent molecular hinges allowing domain movement for nucleotide binding and phage assembly.

REV-ERBα and its paralog, REV-ERBβ encoded by NR1D1 and NR1D2 genes, are key nuclear receptors that link the circadian timing system and metabolic homeostasis. Since heme is an endogenous ligand, REV-ERBs have been considered key components of the circadian molecular clock that can be pharmacologically targeted to treat various circadian rhythm-related diseases, such as cardiometabolic, inflammatory, and neuropsychiatric diseases, as well as cancer. REV-ERBs are believed to be functionally redundant and compensatory, although they often affect the expression of gene subsets in an isoform-specific manner. Therefore, this study aimed to identify the redundant and distinct roles of each isoform in controlling its target genes by comparing the transcriptome profiles of a panel of mutant U2OS human osteosarcoma cells in which either NR1D1 or NR1D2 was ablated. Indeed, our transcriptomic analyses revealed that most REV-ERB-regulated genes were controlled by redundant or even additive actions. However, the RNA expression profiles of each single mutant cell line also provided strong evidence for isoform-dependent actions. For example, REV-ERBα were more responsible for regulating the NF-κΒ signaling pathway, whereas a group of extracellular matrix components required REV-ERBβ to maintain their expression. We found that REV-ERBs have isoform-selective functions in the regulation of certain circadian output pathways, despite their overlapping roles in the circadian molecular clock. Thus, the development of isoform-selective REV-ERB modulators may help treat metabolic disturbances and certain types of cancer.

Olfactory Receptors (ORs) are a large family of G protein coupled receptors predominantly expressed by the main olfactory epithelium at nasal level and are responsible for the generation of smelling sense. Microarray and deep sequencing analyses, however, have demonstrated that ORs are ectopically expressed in various human tissues including testis, kidneys, adipose tissue and liver and their biological functions become to be unrevealed. Molecular and pharmacological approaches have shown that some of these ORs modulate glucose and lipid metabolism at multiple interfaces, suggesting that ORs might be part of the large family of nutrient sensors. i.e. molecular/ cellular machines that respond to a specific nutrient component. By using nutrients- derived agonists it has been shown that ORs effectively modulates glucose and lipid metabolism raising interest on their possible therapeutic application in the treatment of metabolic disorders including dyslipidemia, obesity and metabolic syndrome.

Dengue virus (DENV), being one of the lethal pathogens in the hot climatic regions of the world, have been extensively studied to decipher its mechanism of pathogenesis and missing links of its life cycle. With respect to the entry of DENV, multiple receptors have been recognised in different cells of the human body. However, scientists still argue whether these identified receptors are the exclusive entry mediators for the virus. Adding to the complexity, DENV has been reported to be infecting multiple organ types in its human host. Also, more than one receptor in a particular cell has been discerned to take part in mediating the ingress of DENV. In this review, we aim to discuss about the different cells of the human immune system that support DENV infection and their corresponding receptors that DENV deploy to gain access to the cells.

Diversity-generating retroelements (DGRs) are prokaryotic systems providing rapid modification and adaptation of target proteins. In phages, the main targets of DGRs are receptor-binding proteins that are usually parts of tail structures and the variability of such host-recognizing structures enables phage adaptation to changes on the bacterial host surface. Sometimes, more than one target gene containing a hypermutated variable repeat (VR) can be found in phage DGRs. The role of mutagenesis of two functionally different genes is unclear. In this study, several phage genomes that contain DGRs with two target genes were found in the gut virome of healthy volunteer. Bioinformatics analysis of these genes indicated that they encode proteins with different topology; however, both proteins contain the C-type lectin (C-lec) domain with a hypermutated beta-hairpin on its surface. One of the target proteins belongs to a new family of proteins with a specific topology: N-terminal C-lec domain followed by one or more immunoglobulin domains. Proteins from the new family were named tentaclins after TENTACLe+proteIN. The genes encoding such proteins were found in the genomes of prophages and phages from the gut metagenomes. We hypothesized that tentaclins are involved in binding either to bacterial receptors or intestinal/immune cells.

5-Hydroxytryptamine (5-HT) or serotonin plays a crucial role as a neuromodulator and/or neurotransmitter of several nervous system functions. Its actions are complex and depend on multiple factors, including the type of effector or receptor activated. Briefly, 5-HT can activate: (i) metabotropic (G-protein-coupled) receptors to promote inhibition (5-HT1, 5-HT5) or activation (5-HT4, 5-HT6, 5 HT7) of adenylate cyclase, as well as activation (5-HT2) of phospholipase C; and (ii) ionotropic receptors (5-HT3), which form a ligand-gated Na+/K+ channel. Regarding blood pressure regulation (and beyond the intricacy of central 5-HT effects), this monoamine also exerts direct postjunctional (on vascular smooth muscle and endothelium) or indirect prejunctional (on autonomic and sensory perivascular nerves) effects. At the prejunctional level, 5-HT can facilitate or preclude the release of autonomic (e.g., noradrenaline and acetylcholine) or sensory (e.g., calcitonin gene-related peptide) neurotransmitters facilitating hypertensive or hypotensive effects. Hence, we cannot formulate a specific impact of 5-HT on blood pressure level, since an increase or decrease in neurotransmitter release would be favoured depending on the type of prejunctional receptor involved. This review summarizes and discusses the current knowledge on the prejunctional mechanisms involved in blood pressure regulation by 5-HT and its impact on some vascular-related diseases.

Purinergic receptors are inflammatory mediators activated by extracellular nucleotides released by dying or injured cells. Several studies have described an important role for these receptors in HIV-1 entry, particularly regarding their activity on HIV-1 viral membrane fusion. Several reports identify purinergic receptor antagonists that inhibit HIV-1 membrane fusion; these drugs are suspected to act through antagonizing Env-chemokine receptor interactions. They also appear to abrogate activity of downstream mediators that potentiate activation of the NLRP3 inflammasome pathway. Here we review the literature on purinergic receptors, the drugs that inhibit their function, and the evidence implicating these receptors in HIV-1 entry.

Oral mucositis (OM) is one of the common adverse events associated with cancer treatment that decreases quality of life and affects treatment outcome. However, the medications used to manage OM are generally only palliative, and our knowledge of the syndrome is limited. The etiology of the syndrome is thought to be complex and multifactorial. We investigated the trends and characteristics of OM and estimated molecular initiating events (MIEs) associated with the development of the syndrome using FDA Adverse Event Reporting System. The study of trends and characteristics suggested that OM is significantly more likely to occur in females and nonelderly patients and is likely to be induced by protein kinase inhibitors such as afatinib and everolimus. Next, we used Toxicity Predictor, an in-house quantitative structure–activity relationship system, to estimate OM-associated MIEs. The results revealed that agonist activity of human pregnane X receptor, thyroid-stimulating hormone-releasing hormone receptor, and androgen receptor may be associated with OM development. Our study findings are expected to help avoid the risk of OM induction during the drug discovery process and clinical use of antineoplastic agents.

Sepsis is associated with dysregulated cortisol secretion, leading to abnormal levels of cortisol in the blood. In the early stages of sepsis, cortisol levels are typically elevated due to increased secretion from the adrenal glands. However, as the disease progresses, cortisol levels may decline due to impaired adrenal function, leading to relative adrenal insufficiency. The latter is thought to be caused by a combination of factors, including impaired adrenal function, decreased production of corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) by the hypothalamus and pituitary gland, and increased breakdown of cortisol by enzymes such as 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2). The dysregulation of cortisol secretion in sepsis is thought to contribute to the pathophysiology of the disease by impairing the body's ability to mount an appropriate inflammatory response. The actions of cortisol are mediated through two types of corticosteroid receptors: the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GCR). In sepsis, the expression and activity of GCR is altered, contributing to the pathophysiology of the disease. GCR expression and activity are typically downregulated in sepsis, impairing the body's ability to mount an appropriate inflammatory response. Given the dysregulation of cortisol secretion and corticosteroid receptors in sepsis, there has been considerable interest in the use of steroids as a treatment for sepsis. The rationale for steroid-based treatment is to supplement the body's endogenous cortisol production, restore normal cortisol levels, and improve the body's ability to mount an appropriate inflammatory response. However, the use of steroids in sepsis remains controversial, and clinical trials have yielded mixed results. Some studies have shown that steroid-based treatment can improve shock reversal, reduce the need for vasopressors, and improve overall survival in patients with septic shock, whereas other studies have found no benefit or even harm from steroid-based treatment in sepsis.

Purpose: The study aimed to investigate if there were any links between liver function biomarkers and immunoglobulins levels in serum, and Toll-like receptors (TLRs) and neuropilin-1 (NRP1) in COVID-19 patients. The study also aimed to assess the accuracy—sensitivity, specificity, and area under the curve (AUC) by the receiver operator curve (ROC) analysis for immunoglobulins levels and TLRs expressions. Patients and Methods: This study included 150 patients (100 patients with confirmed COVID-19 and 50 healthy volunteers as a control group). Patients with COVID-19 were subdivided into two groups according to the severity of symptoms (moderate and severe, with 50 patients each). Serum C-reactive protein (CRP), alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), albumin, lactate dehydrogenase (LDH), immunoglobulin (Ig) G, and IgM levels were estimated. TLRs (TLR2 and TLR4) and NRP1 gene expression in blood samples were investigated using quantitative real-time polymerase chain reaction (qRT-PCR). ROC analysis was also applied to determine the accuracy of various detected parameters in predicting the possibility of COVID-19 infection. Results: In COVID-19 patients, serum parameters related to liver function, except serum albumin, CRP, IgG, IgM, and TLR2, TLR4, and NRP1 mRNA expression levels, significantly elevated compared to controls. Severe COVID-19 patients exhibited significantly higher liver enzymes (ALT, AST and LDH), CRP, and TLR2 mRNA expression levels and lower albumin levels than the moderate group. In the moderate and severe groups, ALT, CRP, TLR2, and TLR4 had a significant positive correlation with IgM levels. ALT, AST, LDH, CRP, TLR2, and TLR4 showed a significant positive correlation with IgG levels in both groups. In both the moderate and severe groups, NRP1 expression was found to be significantly correlated with CRP, IgG, IgM, TLR2, and TLR4. In contrast, serum albumin levels exhibited a significant negative correlation with IgG and IgM levels only in the severe group, but they showed a significant negative correlation with TLR2, TLR4, and NRP1 expression in both moderate and severe groups. Serum ALT and AST activities were positively correlated with NRP1 expression in the moderate group but not in the severe group and as well as TLR2 and TLR4 expression in both the moderate and severe groups. ROC analysis indicated that AUC was higher than 0.800 for serum IgM level and TLR4 gene expression in moderate COVID-19 group. Conclusions: The increased liver function biomarkers in serum and NRP1 expression are closely correlated with sustained activations in humoral and innate immune responses during COVID-19 infection. As a result, TLR2, TLR4, and NRP1 could be targets for limiting COVID-19 infection and impairment effects on liver function. Moreover, detection of IgM level in serum and TLR4 expression in blood have a good accuracy in predicting the possibility of infection with COVID-19 in moderate cases.

While SARS-CoV-2 uses angiotensin converting enzyme 2 (ACE2) as the receptor for cell entry, it is important to examine for other potential interactions between the virus and other cell receptors. Based on the clinical observation of low smoking prevalence among hospitalized COVID-19 patients, we recently identified a “toxin-like” amino acid (aa) sequence on the receptor binding domain of the spike glycoprotein of SARS-CoV-2 (aa 375-390) with homology to a sequence of a snake venom toxin, which could interact with nicotinic acetylcholine receptors (nAChRs). We now present computational molecular modelling and docking experiments using 3D structures of the SARS-CoV-2 spike glycoprotein and the extracellular domain of the nAChR alpha9 subunit. We identified an interaction between the aa381-386 of the SARS-CoV-2 spike glycoprotein and the aa189-192 of the extracellular domain of the nAChR alpha9 subunit, a region which forms the core of the “toxin-binding site” of the nAChRs. The mode of interaction is very similar to the interaction between the alpha9 nAChR and alpha-bungarotoxin. A similar interaction was observed between the pentameric alpha7 AChR and the SARS-CoV-2 spike glycoprotein. Our findings support the hypothesis that severe COVID-19 may be associated with disruption of the nicotinic cholinergic system which could be caused by an interaction between SARS-CoV-2 and nAChRs.

The mineralocorticoid hormone aldosterone regulates sodium and potassium homeostasis but also adversely modulates the maladaptive process of cardiac adverse remodeling post-myocardial infarction. Through activation of its mineralocorticoid receptor (MR), a classic steroid hormone receptor/transcription factor, aldosterone promotes inflammation and fibrosis of the heart, the vasculature, and the kidneys. This is why MR antagonists reduce morbidity and mortality of heart disease patients and are part of the mainstay pharmacotherapy of advanced human heart failure. A plethora of animal studies using cell type–specific targeting of the MR gene have established the importance of MR signaling and function in cardiac myocytes, vascular endothelial and smooth muscle cells, renal cells, and macrophages. In terms of its signaling properties, the MR is distinct from nuclear receptors in that it has, in reality, two physiological hormonal agonists: not only aldosterone but also cortisol. In fact, in several tissues, including in the myocardium, cortisol is the primary hormone activating the MR. There is a considerable amount of evidence indicating that the effects of the MR in each tissue expressing it depend on tissue- and ligand-specific engagement of molecular co-regulators that either activate or suppress its transcriptional activity. Identification of these co-regulators for every ligand that interacts with the MR in the heart (and in other tissues) is of utmost importance therapeutically, since it can not only help elucidate fully the pathophysiological ramifications of the cardiac MR`s actions but also help design and develop novel better MR antagonist drugs for heart disease therapy. Among the various proteins the MR interacts with are molecules involved in cardiac G protein-coupled receptor (GPCR) signaling. This results in a significant amount of crosstalk between GPCRs and the MR, which can affect the latter`s activity dramatically in the heart and in other cardiovascular tissues. This review summarizes the current experimental evidence for this GPCR-MR crosstalk in the heart and discusses its pathophysiological implications for cardiac adverse remodeling as well as for heart disease therapy. Novel findings revealing non-conventional roles of GPCR signaling molecules, specifically of GPCR-kinase (GRK)-5, in cardiac MR regulation are also highlighted.

Rat H9c2 cardiomyocytes overexpressing the abscisic acid (ABA) hormone receptors LANCL1 and LANCL2 have an increased mitochondrial proton gradient, respiration and vitality after hypoxia/reoxygenation. Our aim was to investigate the role of the ABA/LANCL1-2 system in ROS turnover in H9c2. H9c2 cells were retrovirally infected to induce overexpression or silencing of LANCL1 and LANCL2, without or with the concomitant silencing of the transcription factor ERRα. Enzymes involved in radical production or scavenging were studied by qPCR and Western blot. Mitochondrial proton gradient and ROS were measured with specific fluorescent probes. ROS generating enzymes decreased, ROS-scavenging enzymes increased, and mitochondrial ROS were reduced in LANCL1/2-overexpressing vs. control cells infected with the empty vector, while the opposite occurred in LANCL1/2-silenced cells. Knock-down of ERRα abrogated all beneficial effects on ROS turnover in LANCL1/2 overexpressing cells. Taken together, these results indicate that the ABA/LANCL1-2 system controls ROS turnover in H9c2 via ERRα. The ABA/LANCL system emerges as a promising target to improve cardiomyocyte mitochondrial function and resilience to oxidative stress.

Here, our data provide the first evidence for the existence of a previously unknown receptive system formed by novel DNA- and RNA-based receptors in eukaryotes. This system, named the TR-system, is capable of recognizing and generating a response to different environmental factors and has been shown to orchestrate major vital functions of fungi, mammalian cells, and plants.Recently, we discovered the existence of a similar regulatory system in prokaryotes. These DNA- and RNA-based receptors are localized outside of the membrane forming a type of a network around cells that respond to a variety of chemical, biological, and physical factors and enabled the TR-system to regulate major aspects of eukaryotic cell life as follows: growth, including reproduction and development of multicellular structures; sensitivity to temperature, geomagnetic field, UV, light, and hormones; interaction with viruses; gene expression, recognition and utilization of nutrients. The TR-system was also implicated in cell memory formation and was determined to be responsible for its maintenance and the forgetting of preceding events. This system is the most distant receptive and regulatory system of the cell that regulates interactions with the outer environment and governs the functions of other receptor-mediated signaling pathways.

C-type lectin CD209/DC-SIGN and CD209L/L-SIGN proteins are distinct cell adhesion and pathogen recognition receptors that mediate cellular interactions and recognize a wide range of pathogens including, viruses such as SARS, SARS-CoV-2, bacteria, fungi and parasites. Pathogens exploit CD209L family proteins to promote infection and evade the immune recognition system. CD209L and CD209 are widely expressed in SARS-CoV-2 target organs and can contribute to infection and pathogenesis. CD209L family receptors are highly susceptible to alternative splicing and genomic polymorphism, which may influence virus tropism and transmission in vivo. The carbohydrate-recognition domain (CRD) and the neck/repeat region represent the key features of CD209L family proteins that are also central to facilitating cellular ligand interactions and pathogen recognition. While, the neck/repeat region is involved in oligomeric dimerization, the CRD recognizes the mannose containing structures present on specific glycoproteins such as those found on the SARS-CoV-2 spike protein. Considering the role of CD209L and related proteins in diverse pathogen recognition, this review article discusses the recent advances in the cellular and biochemical characterization of CD209 and CD209L and their roles in viral uptake, which has important implications in understanding the host-pathogen interaction, the viral pathobiology and driving vaccine development of SARS-CoV-2.

Toll-like receptors (TLRs) play a key role in the innate immune response to numerous pathogens, including Acanthamoeba sp. The aim of this study was to determine the expression of TLR2 and TLR4 in the eyes of mice following intranasal infection with Acanthamoeba sp. Amoebae used in this study were isolated from the bronchial aspirate of a patient with acute myeloid leukemia (AML) and atypical symptoms of pneumonia. We found statistically significant differences in the expression of TLR2 and TLR4 in the eyes of immunocompetent mice at 8, 16, and 24 days post Acanthamoeba sp. infection (dpi) compared to control. Immunosuppressed mice showed significant differences in the expression of TLR2 at 16 and 24 dpi compared to uninfected animals. Our results indicate that TLR2 and TLR4 are upregulated in the eyes of mice in response to Acanthamoeba sp. We suggest that it is possible for trophozoites to migrate through the optic nerve from the brain to the eyes.

The Burkholderia cepacia complex (Bcc) are a group of increasingly multi-drug resistant opportunistic bacteria that can cause severe pulmonary infections. This resistance is driven through a combination of intrinsic factors and the carriage of a broad range of conjugative plasmids harbouring virulence determinants. Therefore, novel treatments are required to not only treat Bcc infection but also to prevent further spread of these virulence determinants. In the search for phages infective for two clinical Bcc isolates, CSP1 phage, a PRD1-like phage was isolated. CSP1 phage was found to require pilus machinery commonly encoded on conjugative plasmids to facilitate infection of multiple Gram-negative bacteria genera including Escherichia and Pseudomonas. Whole genome sequencing and characterisation of one of the clinical Burkholderia isolates revealed it to be Burkholderia contaminans. B. contaminans 5080 was found to contain a genome of over 8 Mbp encoding multiple intrinsic resistance factors, such as efflux pump systems, but more interestingly, carried three novel plasmids encoding multiple putative virulence factors for increased host fitness, including antimicrobial resistance. Even though PRD1-like phages are broad host range, their use in novel antimicrobial treatments shouldn’t be dismissed, as the dissemination potential of conjugative plasmids is extensive. Continued survey of clinical bacterial strains is