Receptor Ligands Research Articles

Stereoselective Synthesis of the Gal-α-(1→3)-Gal-β-(1→3)-GlcNAc Trisaccharide: a new Ligand for DCAR and Mincle C-Type Lectin Receptors.

In this work, we have discovered that the Gal-α-(1→3)-Gal-β-(1→3)-GlcNAc trisaccharide, a fragment of the B antigen Type-1, is a new ligand of two C-type lectin receptors (CLRs) i. e. DCAR and Mincle which are key players in different types of autoimmune diseases. Accordingly, we report here on a straightforward methodology to access pure Gal-α-(1→3)-Gal-β-(1→3)-GlcNAc trisaccharide. A spacer with a terminal primary amine group was included at the reducing end of the GlcNAc residue thus ensuring the further functionalization of the trisaccharide Gal-α-(1→3)-Gal-β-(1→3)-GlcNAc.

Virus-Induced Acute Respiratory Distress Syndrome Causes Cardiomyopathy Through Eliciting Inflammatory Responses in the Heart.

Viral infections can cause acute respiratory distress syndrome (ARDS), systemic inflammation, and secondary cardiovascular complications. Lung macrophage subsets change during ARDS, but the role of heart macrophages in cardiac injury during viral ARDS remains unknown. Here we investigate how immune signals typical for viral ARDS affect cardiac macrophage subsets, cardiovascular health, and systemic inflammation. We assessed cardiac macrophage subsets using immunofluorescence histology of autopsy specimens from 21 patients with COVID-19 with SARS-CoV-2-associated ARDS and 33 patients who died from other causes. In mice, we compared cardiac immune cell dynamics after SARS-CoV-2 infection with ARDS induced by intratracheal instillation of Toll-like receptor ligands and an ACE2 (angiotensin-converting enzyme 2) inhibitor. In humans, SARS-CoV-2 increased total cardiac macrophage counts and led to a higher proportion of CCR2+ (C-C chemokine receptor type 2 positive) macrophages. In mice, SARS-CoV-2 and virus-free lung injury triggered profound remodeling of cardiac resident macrophages, recapitulating the clinical expansion of CCR2+ macrophages. Treating mice exposed to virus-like ARDS with a tumor necrosis factor α-neutralizing antibody reduced cardiac monocytes and inflammatory MHCIIlo CCR2+ macrophages while also preserving cardiac function. Virus-like ARDS elevated mortality in mice with pre-existing heart failure. Our data suggest that viral ARDS promotes cardiac inflammation by expanding the CCR2+ macrophage subset, and the associated cardiac phenotypes in mice can be elicited by activating the host immune system even without viral presence in the heart.

BMP9 is a key player in endothelial identity and its loss is sufficient to induce arteriovenous malformations.

BMP9 is a high affinity ligand of ALK1 and endoglin receptors that are mutated in the rare genetic vascular disorder Hereditary Hemorrhagic Telangiectasia (HHT). We have previously shown that loss of Bmp9 in the 129/Ola genetic background leads to spontaneous liver fibrosis via capillarization of liver sinusoidal endothelial cells (LSEC) and kidney lesions. We aimed to decipher the molecular mechanisms downstream of BMP9 to better characterize its role in vascular homeostasis in different organs. For this, we performed a RNAseq analysis on LSEC from adult WT and Bmp9-KO mice and identified over 2000 differentially expressed genes. Gene ontology analysis showed that Bmp9 deletion led to a decrease in BMP and Notch signaling, but also LSEC capillary identity while increasing their cell cycle. The gene ontology term "glomerulus development" was also negatively enriched in Bmp9-KO mice versus WT supporting a role for BMP9 in kidney vascularization. Through different imaging approaches (electron microscopy, immunostainings), we found that loss of Bmp9 led to vascular enlargement of the glomeruli capillaries associated with alteration of podocytes. Importantly, we also showed for the first time that the loss of Bmp9 led to spontaneous arteriovenous malformations (AVMs) in the liver, gastro-intestinal tract and uterus. Altogether, these results demonstrate that BMP9 plays an important role in vascular quiescence both locally in the liver by regulating endothelial capillary differentiation markers and cell cycle but also at distance in many organs via its presence in the circulation. It also reveals that loss of Bmp9 is sufficient to induce spontaneous AVMs, supporting a key role for BMP9 in the pathogenesis of HHT.

Current perspectives and trend of computer-aided drug design: a review and bibliometric analysis.

Computer-aided drug design (CADD) is a drug design technique for computing ligand‒receptor interactions and is involved in various stages of drug development. To better grasp the frontiers and hotspots of CADD, we conducted a review analysis through bibliometrics. A systematic review of studies published between 2000 and July 20, 2023 was conducted following the PRISMA guidelines. Literature on CADD was selected from the Web of Science Core Collection. General information, publications, output trends, countries/regions, institutions, journals, keywords, and influential authors were visually analysed using software such as Excel, VOSviewer, RStudio, and CiteSpace. A total of 2,031 publications were included. These publications primarily originated from 99 countries or regions, led by the U.S. and China. Among the contributors, MacKerell AD had the highest number of articles and greatest influence. The Journal of Medicinal Chemistry was the most cited journal, whereas the Journal of Chemical Information and Modeling had the highest number of publications. Influential authors in the field were identified. Current research shows active collaboration between countries, institutions, and companies. CADD technologies such as homology modelling, pharmacophore modelling, quantitative conformational relationships, molecular docking, molecular dynamics simulation, binding free energy prediction, and high-throughput virtual screening can effectively improve the efficiency of new drug discovery. Artificial intelligence-assisted drug design and screening based on CADD represent key topics direction for future development. Furthermore, this paper will be helpful for better understanding the frontiers and hotspots of CADD.

Fundamental Mechanisms in Membrane Receptology: Old Paradigms, New Concepts and Perspectives

Receptology, the science of receptors, is a multidimensional field of research which can be dissected into biosynthesis, membrane sorting, ligand binding and signal transduction. Plasma membrane receptors connect the cells with their environment and transmit signals that are translated into biological information. The historical paradigm of ligand–receptor interactions is the lock-and-key model. This model presupposes that both partners have a precise 3D shape that perfectly fits together to form the ligand–receptor complex. However, this simple model suffers from severe limitations due to several levels of simplifications: (i) water molecules and membrane lipids are not considered; (ii) not all ligands have a stable 3D structure; (iii) the ligand-binding pocket of the receptor is often flexible and conformationally rearranged after the initial binding step (induced fit mechanism) and/or subjected to conformational selection by the ligand; (iv) there are signal transduction mechanisms which can be either purely mechanical (conformational change of the receptor induced after binding of the ligand), lipid-assisted (e.g., by raft lipids such as cholesterol or gangliosides), or in some instances of quantic nature (detection of odorant molecules). The aim of the present review is to challenge the old paradigms and present new concepts of membrane receptology that consider the impact of critical parameters such as water molecules, membrane lipids, electrostatic surface potential and quantum mechanisms.

The monocyte-derived cytokine response in whole blood from preterm newborns against sepsis-related bacteria is similar to term newborns and adults.

Sepsis is characterized by a dysregulated innate immune response. It is a leading cause of morbidity and mortality in newborns, in particular for newborns that are born premature. Although previous literature indicate that the pro-inflammatory response may be impaired in preterm newborns, serum levels of monocyte-derived cytokines, such as TNF-α and IL-6, vary highly between newborns and can reach adult-like concentrations during sepsis. These contradictory observations and the severe consequences of neonatal sepsis in preterm newborns highlight the need for a better understanding of the pro-inflammatory cytokine response of preterm newborns to improve sepsis-related outcomes. Using an in vitro model with multiple read outs at the transcriptional and protein level, we consistently showed that the monocyte-derived cytokine response induced by sepsis-related bacteria is comparable between preterm newborns, term newborns and adults. We substantiated these findings by employing recombinant Toll-like receptor (TLR) ligands and showed that the activation of specific immune pathways, including the expression of TLRs, is also similar between preterm newborns, term newborns and adults. Importantly, we showed that at birth the production of TNF-α and IL-6 is highly variable between individuals and independent of gestational age. These findings indicate that preterm newborns are equally capable of mounting a pro-inflammatory response against a broad range of bacterial pathogens that is comparable to term newborns and adults. Our results provide a better understanding of the pro-inflammatory response by preterm newborns and could guide the development of interventions that specifically modulate the pro-inflammatory response during sepsis in preterm newborns.

Validation of CDC45 as a novel biomarker for diagnosis and prognosis of gastric cancer.

Cell division cycle protein 45 (CDC45) has been demonstrated to play vital roles in the progression of various malignancies. However, the clinical significance of CDC45 in gastric cancer (GC) remains unreported. In this study, we employed the TCGA database and the TCGA & GTEx dataset to compare the mRNA expression levels of CDC45 between gastric cancer tissues and adjacent or normal tissues (p < 0.05 was considered statistically significant), which was further validated in multiple datasets including GSE13911, GSE29272, GSE118916, GSE66229, as well as RT-qPCR. Furthermore, we harnessed the Human Protein Atlas (HPA) to evaluate the protein expression of CDC45, which was subsequently verified through immunohistochemistry (IHC). To ascertain the diagnostic utility of CDC45, receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were calculated in TCGA database, and further validated it in TCGA & GTEx and GSE66229 datasets. The Kaplan-Meier method was used to reveal the prognostic importance of CDC45 in The Cancer Genome Atlas (TCGA) database and authenticated through the GSE66229, GSE84433, and GSE84437 datasets. Through cBioPortal, we identified co-expressed genes of CDC45, and pursued enrichment analysis. Additionally, we availed gene set enrichment analysis (GSEA) to annotate the biological functions of CDC45. Differential expression analysis revealed that CDC45 was significantly upregulated at both the mRNA and protein levels in GC (all p < 0.05). Remarkably, CDC45 emerged as a promising prognostic indicator and a novel diagnostic biomarker for GC. In a comprehensive the drug susceptibility analysis, we found that patients with high expression of CDC45 had high sensitivity to various chemotherapeutic agents, among which 5-fluorouracil, docetaxel, cisplatin, and elesclomol were most evident. Furthermore, our findings suggested a plausible association between CDC45 and immune cell infiltration. Enrichment analysis revealed that CDC45 and its associated genes may play crucial roles in muscle biofunction, whereas GSEA demonstrated significant enrichment of gene sets pertaining to G protein-coupled receptor ligand binding and G alpha (i) signaling events. Our study elucidates that upregulation of CDC45 is intricately associated with immune cell infiltration and holds promising potential as a favorable prognostic marker and a novel diagnostic biomarker for GC.

Simple ammonium salt and sigma-1 receptor ligand dipentylammonium provides neuroprotective effects in cell culture and Caenorhabditis elegans models of Alzheimer's disease

The sigma-1 receptor (σ-1R), a chaperone protein located at the mitochondria-associated membrane (MAM) of the endoplasmic reticulum, can interact with and modify the signaling pathways of various proteins, thereby modulating many disease pathologies, including Alzheimer's disease (AD). The σ-1R ligand dipentylammonium (DPA) was analyzed for its anti-AD properties using PC12 cells (in vitro) and Caenorhabditis elegans (in vivo) models along with molecular docking (in silico) analysis. DPA at 1 and 10 µM concentrations was able to significantly potentiate NGF-induced neurite growth length by 137.7 ± 12.0 and 187.8 ± 16.4, respectively, when compared to the control 76.9 ± 7.4. DPA also regulated neurite damage caused by Aβ(25−35) treatment in differentiated PC12 cells by improving cell viability and neurite length. In C. elegans, DPA could significantly extend the median and maximum lifespan of Aβ transgenic strain CL2006 without impacting wild-type nematodes. Additionally, it could significantly reduce the paralysis phenotype of another Aβ transgenic strain, CL4176, thereby improving the overall health in AD pathogenesis. This effect depended on σ-1R, as DPA could not modulate the lifespan of σ-1R mutant TM3443. This was further confirmed using agonist PRE084 and antagonist BD1047, wherein the agonist alone could extend the lifespan of CL2006, while the antagonist suppressed the effect of DPA in CL2006. Interestingly, neither had an TM3443. Further, molecular docking analysis showed that DPA had a similar binding affinity as that of PRE084, BD1047 and pentazocine against the σ-1R receptor in humans and C. elegans, which collectively suggests the anti-AD properties of DPA.

The Effect of Retinoic Acid on Arsenite-Transformed Malignant UROtsa Bladder Cancer Cells: In Vitro Model of Basal Muscle-Invasive Bladder Cancer.

Bladder cancer (BC) is the eighth most common cause of cancer death in the United States of America. BC is classified into non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Genetically, MIBCs are categorized into the more aggressive basal subtype or less aggressive luminal subtype. All-trans retinoic acid (tretinoin), the ligand for the RAR-RXR retinoic acid receptor, is clinically used as a differentiation therapy in hematological malignancies. This study aims to determine the effects of retinoic acid on arsenite-transformed malignant urothelial cells (UROtsa As), serving as a model for basal muscle-invasive bladder cancer. We treated three independent isolates of arsenite-transformed malignant human urothelial UROtsa cells (UROtsa As) with tretinoin for 48 h. Cell viability, proliferation, and apoptosis were analyzed using crystal violet staining and flow cytometry. mRNA and protein level analyses were performed using RT-qPCR and the Simple Western™ platform, respectively. Tretinoin was found to reduce cell proliferation and urosphere formation, as well as decrease the expression of basal markers (KRT1, KRT5, KRT6, EGFR) and increase the expression of luminal differentiation markers (GATA3, FOXA1). Mechanistically, the antiproliferative effect of tretinoin was attributed to the downregulation of c-myc. Our results suggest that targeting the retinoic acid pathway can diminish the aggressive behavior of basal muscle-invasive urothelial cancer and may enhance patient survival.

Androgens and Notch signaling cooperate in seminiferous epithelium to regulate genes related to germ cell development and apoptosis

It was reported previously that in adult males disruption of both androgen and Notch signaling impairs spermatid development and germ cell survival in rodent seminiferous epithelium. To explain the molecular mechanisms of these effects, we focused on the interaction between Notch signaling and androgen receptor (AR) in Sertoli cells and investigate its role in the control of proteins involved in apical ectoplasmic specializations, actin remodeling during spermiogenesis, and induction of germ cell apoptosis. First, it was revealed that in rat testicular explants ex vivo both testosterone and Notch signaling modulate AR expression and cooperate in the regulation of spermiogenesis-related genes (Nectin2, Afdn, Arp2, Eps8) and apoptosis-related genes (Fasl, Fas, Bax, Bcl2). Further, altered expression of these genes was found following exposure of Sertoli cells (TM4 cell line) and germ cells (GC-2 cell line) to ligands for Notch receptors (Delta-like1, Delta-like4, and Jagged1) and/or Notch pathway inhibition. Finally, direct interactions of Notch effector, Hairy/enhancer-of-split related with YRPW motif protein 1, and the promoter of Ar gene or AR protein were revealed in TM4 Sertoli cells. In conclusion, Notch pathway activity in Sertoli and germ cells regulates genes related to germ cell development and apoptosis acting both directly and indirectly by influencing androgen signaling in Sertoli cells.

TRAF3 regulation of proximal TLR signaling in B cells.

Toll-like receptors are pattern recognition receptors that bridge the innate and adaptive immune responses and are critical for host defense. Most studies of Toll-like receptors have focused upon their roles in myeloid cells. B lymphocytes express most Toll-like receptors and are responsive to Toll-like receptor ligands, yet Toll-like receptor-mediated signaling in B cells is relatively understudied. This is an important knowledge gap, as Toll-like receptor functions can be cell type specific. In striking contrast to myeloid cells, TRAF3 inhibits TLR-mediated functions in B cells. TRAF3-deficient B cells display enhanced IRF3 and NFκB activation, cytokine production, immunoglobulin isotype switching, and antibody production in response to Toll-like receptors 3, 4, 7, and 9. Here, we address the question of how TRAF3 impacts initial B-cell Toll-like receptor signals to regulate downstream activation. We found that TRAF3 in B cells associated with proximal Toll-like receptor 4 and 7 signaling proteins, including MyD88, TRAF6, and the tyrosine kinase Syk. In the absence of TRAF3, TRAF6 showed a greater association with several Toll-like receptor signaling proteins, suggesting that TRAF3 may inhibit TRAF6 access to Toll-like receptor signaling complexes and thus early Toll-like receptor signaling. In addition, our results highlight a key role for Syk in Toll-like receptor signaling in B cells. In the absence of TRAF3, Syk activation was enhanced in response to ligands for Toll-like receptors 4 and 7, and Syk inhibition reduced downstream Toll-like receptor-mediated NFκB activation and proinflammatory cytokine production. This study reveals multiple mechanisms by which TRAF3 serves as a key negative regulator of early Toll-like receptor signaling events in B cells.

Construction of an immune-related gene signature for overall survival prediction and immune infiltration in gastric cancer.

Treatment options for patients with gastric cancer (GC) continue to improve, but the overall prognosis is poor. The use of PD-1 inhibitors has also brought benefits to patients with advanced GC and has gradually become the new standard treatment option at present, and there is an urgent need to identify valuable biomarkers to classify patients with different characteristics into subgroups. To determined the effects of differentially expressed immune-related genes (DEIRGs) on the development, prognosis, tumor microenvironment (TME), and treatment response among GC patients with the expectation of providing new biomarkers for personalized treatment of GC populations. Gene expression data and clinical pathologic information were downloaded from The Cancer Genome Atlas (TCGA), and immune-related genes (IRGs) were searched from ImmPort. DEIRGs were extracted from the intersection of the differentially-expressed genes (DEGs) and IRGs lists. The enrichment pathways of key genes were obtained by analyzing the Kyoto Encyclopedia of Genes and Genomes (KEGGs) and Gene Ontology (GO) databases. To identify genes associated with prognosis, a tumor risk score model based on DEIRGs was constructed using Least Absolute Shrinkage and Selection Operator and multivariate Cox regression. The tumor risk score was divided into high- and low-risk groups. The entire cohort was randomly divided into a 2:1 training cohort and a test cohort for internal validation to assess the feasibility of the risk model. The infiltration of immune cells was obtained using 'CIBERSORT,' and the infiltration of immune subgroups in high- and low-risk groups was analyzed. The GC immune score data were obtained and the difference in immune scores between the two groups was analyzed. We collected 412 GC and 36 adjacent tissue samples, and identified 3627 DEGs and 1311 IRGs. A total of 482 DEIRGs were obtained. GO analysis showed that DEIRGs were mainly distributed in immunoglobulin complexes, receptor ligand activity, and signaling receptor activators. KEGG pathway analysis showed that the top three DEIRGs enrichment types were cytokine-cytokine receptors, neuroactive ligand receptor interactions, and viral protein interactions. We ultimately obtained an immune-related signature based on 10 genes, including 9 risk genes (LCN1, LEAP2, TMSB15A mRNA, DEFB126, PI15, IGHD3-16, IGLV3-22, CGB5, and GLP2R) and 1 protective gene (LGR6). Kaplan-Meier survival analysis, receiver operating characteristic curve analysis, and risk curves confirmed that the risk model had good predictive ability. Multivariate COX analysis showed that age, stage, and risk score were independent prognostic factors for patients with GC. Meanwhile, patients in the low-risk group had higher tumor mutation burden and immunophenotype, which can be used to predict the immune checkpoint inhibitor response. Both cytotoxic T lymphocyte antigen4+ and programmed death 1+ patients with lower risk scores were more sensitive to immunotherapy. In this study a new prognostic model consisting of 10 DEIRGs was constructed based on the TME. By providing risk factor analysis and prognostic information, our risk model can provide new directions for immunotherapy in GC patients.

CYP7A1 Gene Induction via SHP-Dependent or Independent Mechanisms can Increase the Risk of Drug-Induced Liver Injury Independently or in Synergy with BSEP Inhibition.

Drug-induced liver injury (DILI) is a frequent cause of clinical trial failures during drug development. While inhibiting bile salt export pump (BSEP) is a well-documented DILI mechanism, interference with genes related to bile acid (BA) metabolism and transport can further complicate DILI development. Here, the effects of twenty-eight compounds on genes associated with BA metabolism and transport were evaluated, including those with discontinued development or use, boxed warnings, and clean labels for DILI. The study also included rifampicin and omeprazole, pregnane X receptor and aryl hydrocarbon receptor ligands, and four mitogen-activated protein kinase kinase (MEK1/2) inhibitors. BSEP inhibitors with more severe DILI, notably pazopanib and CP-724714, significantly upregulated the expression of 7 alpha-hydroxylase (CYP7A1), independent of small heterodimer partner (SHP) expression. CYP7A1 expression was marginally induced by omeprazole. In contrast, its expression was suppressed by mometasone (10-fold), vinblastine (18-fold), hexachlorophene (2-fold), bosentan (2.1-fold), and rifampin (2-fold). All four MEK1/2 inhibitors that show clinical DILI were not potent BSEP inhibitors but significantly induced CYP7A1 expression, accompanied by a significant SHP gene suppression. Sulfotransferase 2A1 and BSEP were marginally upregulated, but no other genes were altered by the drugs tested. Protein levels of CYP7A1 were increased with the treatment of CYP7A1 inducers and decreased with obeticholic acid, an farnesoid X receptor ligand. CYP7A1 inducers significantly increased bile acid (BA) production in hepatocytes, indicating the overall regulatory effects of BA metabolism. This study demonstrates that CYP7A1 induction via various mechanisms can pose a risk for DILI, independently or in synergy with BSEP inhibition, and it should be evaluated early in drug discovery. SIGNIFICANCE STATEMENT: Kinase inhibitors, pazopanib and CP-724714, inhibit BSEP and induce CYP7A1 expression independent of small heterodimer partner (SHP) expression, leading to increased bile acid (BA) production and demonstrating clinically elevated drug-induced liver toxicity. MEK1/2 inhibitors that show BSEP-independent drug-induced liver injury (DILI) induced the CYP7A1 gene accompanied by SHP suppression. CYP7A1 induction via SHP-dependent or independent mechanisms can pose a risk for DILI, independently or in synergy with BSEP inhibition. Monitoring BA production in hepatocytes can reliably detect the total effects of BA-related gene regulation for de-risking.

Covalent and Visible‐Light Photoswitchable Derivatives of the Potent Synthetic Opioid Isotonitazene and Other Nitazenes

Isotonitazene belongs to a potent class of m‐opioid receptor (µOR) ligands, known as nitazenes. The lack of knowledge surrounding this agonist and others in its class has sparked thorough re‐investigations. To aid in these investigations, the purportedly covalent yet underexplored nitazene BIT was biochemically re‐evaluated in this work, along with a newly synthesized analogue, Iso‐BIT. Moreover, in the pursuit of understanding the mechanism, function, and interactions of µOR, this study involved developing photoswitchable derivatives of nitazene as potential probe molecules. Converting known ligands into azo‐containing photoswitchable derivatives offers the opportunity to modulate ligand structure with light, allowing for photocontrol of compound activity. While photocontrol of µOR activity could not be entirely achieved, photophysical evaluation of these arylazobenzimidazole derivatives revealed a novel photoswitch scaffold that responds to visible light. Furthermore, azo‐containing 2e and 3e emerged as promising nitazene derivatives that were able to form an exceptionally high fraction of covalent‐ligand receptor complexes with wild‐type µOR at physiological pH.

Topical Peroxisome Proliferator-Activated Receptor Agonist Induces Molecular Alterations Enhancing Barrier Function and Water-Holding Capacity of the Human Stratum Corneum In Vivo

The peroxisome proliferator-activated receptor (PPAR) ligands modulate a variety of skin functions but are rarely used in cosmetics. The aim of this double-blind, placebo-controlled, in vivo study was to determine the effect of a topically applied 0.1% PPAR ligand on the composition and physiological parameters of the stratum corneum (SC). By comparing verum and placebo groups post-treatment, we demonstrate (via lipidomic analysis of tape strips) an unstatistically significant trend toward an increase in long-chain triacylglycerols (C50–C56) and medium- and long-chain ceramides (C42–C50) at the superficial SC. By comparing treated and untreated skin using confocal Raman microspectroscopy, we found that the changes in lipid composition in the verum group led to a significant increase in the number of trans conformers and orthorhombic organisation of lipids at the exemplary SC depth. An increase in unfolded states in the secondary and tertiary keratin structures results in an increased ability to bind water. The concentrations of tightly and strongly bound water increase, while weakly bound and unbound water decrease in the entire SC, indicating a transformation of water mobility to a state of increased hydrogen bonding. Thus, the topical PPAR ligands improve the water-holding capacity and the barrier function of the SC.

Are there sex differences in oxytocin and vasopressin V1a receptors ligand binding affinities?

There is substantial evidence for sex differences in the functioning of one of the most common receptor systems; G protein-coupled receptors (GPCRs). There are many points along the GPCR-mediated molecular signaling pathway at which males and females may differ, one of the first of which, chronologically, is in the stability of the interaction between the ligand and the receptor, or its binding affinity. Here we investigate the binding affinities of oxytocin (OT) and vasopressin (AVP) at the oxytocin receptor (OTR) and the vasopressin V1a receptor (V1aR), both of which are present in numerous in brain regions associated with social behavior. In order to investigate sex- and estrous cycle-dependent differences in ligand-receptor binding affinity, male (n = 6) Syrian hamsters (Mesocricetus auratus), females on the day of estrus (E females, n = 6), and females on the second day of diestrus (D2 females n = 6) were chosen for study. Brains from hamsters were mounted on slides and competition and saturation binding assays were conducted. We report a remarkable similarity in the binding affinities of OT and AVP in males and females. Small differences were detected, however, in receptor and ligand specificity in females depending on whether they were in the estrous or diestrous stage of their ovulatory cycle. These data suggest that sex differences in binding affinity are not a likely source of the many sex differences that have been observed in the effects of OT and AVP in hamsters and other species.

Ab initio modeling of human IRS1 protein to find novel target to dock with drug MH to mitigateT2DM diabetes by insulin signaling.

IRS1 is a cytoplasmic adaptor protein that helps incellulargrowth, glucose metabolism, proliferation, anddifferentiation. Highly disordered (insulin receptor substrate 1) IRS1 protein sequence (mol.wt- 131,590.97da) has been used to develop model using ab initio modeling technique by I-Tassar tool and Discovery Studio/ DogSite Server to decipher a novel active site. The constructed protein model has been submitted with PMDB Id- PM0082210. GRAVY index of IRS1 model ( - 0.675) indicated surface protein-water interaction. Protparam tool instability index (75.22) demonstrated disorderedness combined with loops owing to prolines/glycines. After refinement,the Ramachandran plot showed that 88 percent of AAs were presentin the allowed region and only 0.5% in the disallowed region.Novel IRS1 model proteinhas 10 α-helices, 22 β-sheets, 20 β-hairpins, 5 β-bulges, 47 strands, 105 β-turns, and 8 γ-turns. Docking of IRS1 with drug MH demonstrated interaction of Ser-70, Thr-18, and Pro-69 with C-H bonds; Gln-71, and Glu-113 with hydrogen bonds; while both Glu-114 and Glu-113 with salt-bridge connection. Permissible 1.0-1.5Å range of RMSD fluctuation between 20 and 45ns was obtained in simulation of IRS1 and IRS1-met complex confirmed that both complexes were stable during whole simulation process. RMSF result showed that except positions 57AA and 114AA, the binding of drug had no severe effects on the flexibility of the IRS1 and IRS1-met complex. The RoG value of compactness and rigidity showed little change in IRS1 protein. SASA value of IRS1 indicated non-significant fluctuation between IRS1 and drug MH means ligand (drug) and IRS1 receptor form stable structure. Hydrogen bond strength of IRS1 and IRS1-met was 81.2 and 76.4, respectively, which suggested stable interaction.

HLA-G isoforms, HLA-C allotype and their expressions differ between early abortus and placenta in relation to spontaneous abortions

IntroductionSpontaneous abortion (SAB) affects approximately 10% of clinically recognized pregnancies. Fetal trophobalst invasion and remodeling of maternal spiral arteries is reported to be dependent on crosstalk between HLA-C/HLA-G expressed on extra villous trophoblast (EVTs)and Killer cell Immunoglobin like receptors (KIRs) of decidual NK (dNK). Immune dysfunction in decidua contributes to early miscarriage. MethodologyThe study used mother neonate paired cord blood and term placenta samples (n = 46), elective abortus (n = 17,gestational age = 10–12 weeks of pregnancy) and SAB abortus (n = 24, gestational age = 12–15 weeks of pregnancy) for HLA-G, KIR2D and HLA-C. In addition, term placenta was collected from women with history of spontaneous pregnancy loss (n = 24) and women with history of live birth (n = 32). SSP-PCR was used for genotyping, RT-PCR for gene expression, copy number variation (CNVs) and HLA-C allotyping and ELISA for protein expression studies. ResultsMembrane bound HLA-G4 isoform proportion was higher 39.28%, p = 0.02) in term placenta. SAB abortus had higher proportion of HLA-G3 (50%),while elective abortus exhibited higher proportion of soluble isoforms (HLA-G5, = 5.9, HLA-G6 = 5.9%, HLA-G7 = 11.8%).Higher inhibitory KIR2DL1 content and copy numbers with lower HLA-C2 in SAB contrasted with higher copy numbers of KIR2DS1(p = 0.001), KIR2DS1+/2DL1+- HLA-C2 combined genotype in healthy placenta. Elevated KIR2D protein levels (p = 0.001), and concurrently, HLA-C levels were upregulated in healthy placenta. ConclusionOur data supports lower cognate receptor ligand KIR2DS1+/2DL1+ HLA–C2 together with predominance of HLA-G3 isoform in SAB as confounding factors in spontaneous pregnancy loss. HLA-G isoforms and expression differed between first trimester abortus and term placenta suggesting temporal modulation and marks novelty of the study.

New insights and potential biomarkers for intraventricular hemorrhage in extremely premature infant, case-control study.

Despite advancements in neonatal care, germinal matrix-intraventricular hemorrhage impacts 20% of very preterm infants, exacerbating their neurological prognosis. Understanding its complex, multifactorial pathophysiology and rapid onset remains challenging. This study aims to link specific cord blood biomolecules at birth with post-natal germinal matrix-intraventricular hemorrhage onset. A monocentric, prospective case-control study was conducted at Rouen University Hospital from 2015 to 2020. Premature newborns ( < 30 gestational age) were included and cord blood was sampled in the delivery room. A retrospective matching procedure was held in 2021 to select samples for proteomic and metabolomic analysis of 370 biomolecules. 26 patients with germinal matrix-intraventricular hemorrhage cases and 60 controls were included. Clinical differences were minimal, except for higher invasive ventilation rates in the germinal matrix-intraventricular hemorrhage group. Germinal matrix-intraventricular hemorrhage newborns exhibited lower phosphatidylcholine levels and elevated levels of four proteins: BOC cell adhesion-associated protein, placental growth factor, Leukocyte-associated immunoglobulin-like receptor 2, and tumor necrosis factor-related apoptosis-inducing ligand receptor 2. This study identifies biomolecules that may be linked to subsequent germinal matrix-intraventricular hemorrhage, suggesting heightened vascular disruption risk as an independent factor. These results need further validation but could serve as early germinal matrix-intraventricular hemorrhage risk biomarkers for future evaluations. Decrease in certainphosphatidylcholines and increase in four proteins in cord blood at birthmay be linked to subsequent germinal matrix-intraventricular hemorrhagein premature newborns. The four proteins are BOC cell adhesion-associated protein, placental growth factor, leukocyte-associated immunoglobulin-like receptor 2, and TNF-related apoptosis-inducing ligand receptor 2. This biological imprint could point toward higher vascular disruption risk as an independent risk factor for this complication and with further validations, could be used for better stratification of premature newborns at birth.

Frequency of Programmed Death Receptor Ligand 1 Expression and Clinicopathological Factors Associated With Metastatic Triple-Negative Breast Cancer at a Tertiary Cancer Care Centre in South India.

Purpose Triple-negative breast cancer (TNBC) has a poor outcome compared to other subtypes. Immune checkpoint inhibitors (ICIs) have changed the treatment paradigm in metastatic diseases as well as in neoadjuvant setting. The response to these agents is affected by programmed death ligand 1 (PDL1) receptor expression which are reported objectively as a score. PDL1 is a prognostic marker also. Here, we present clinicopathological characteristics of metastatic TNBCs, report the proportion of PDL1 expression and its association with clinicopathological factors as well as survival. Methods This is a prospective study carried out at a tertiary cancer care centre in South India. Case records of all breast cancer patients treated in two years between August 2021 and July 2023 were reviewed, patients with metastatic TNBC were selected. Patient's characteristics, histological features, molecular profile, and treatment were analyzed. PDL1 testing was carried out on pretreatment tumor tissue sections with immunohistochemistry (IHC) (Dako 22C3). PDL1 staining was interpreted as negative or positive based on combined positive score (CPS), with an expression less than 10 considered negative. Results A total of 118 patients were analyzed. With a median age of 46 years (36-65 years), 52.5% (62/118) were premenopausal. Family history of Ca Breast was seen in 22% (26/118) patients. A majority of patients had left-sided tumor 55.9% (66/118). Visceral metastasis was more common 96.6% (82/118) than skeletal. Radical intent of treatment was adopted in 10% as patients had oligometastatic disease at presentation. As front-line treatment, anthracycline-based chemotherapy was administered to the majority 54.2% (64/118). The PDL1 expression with CPS more or equal to 10 was seen in 32.2% (38/118) patients. Survival was associated with menopausal status (p value=0.000) and family history (p value=0.028) but notwith PDL1 nor sidedness in our study. Estimated survival at 12 months in PDL1 negative case is 10 ± 0.29 months, while in PDL1 positive case it is slightly more at 10± 0.75 months, but difference was not found to be statistically significant (p value=0.15). Conclusion TNBCs are highly aggressive subtype with limited treatment options and poorer outcomes. Our study shows PDL1 expression in 31.66% of the cases similar to other literature from India. Survival is associated with menopausal status and family history. No association was found between survival and PDL1 as well sidedness in our study.