Receptor Type Research Articles

The serotonin 1A receptor promoter polymorphism, rs6295, is associated with morphofunctional features

Introduction. The tendency to weight gain is influenced by many genetic and environmental factors (nutrition, level of physical activity, social well-being, etc.), as well as complex interactions of these factors. Studying the genetic factors of obesity can help in developing individual strategies for the prevention and treatment of this common disease. One of the most important hereditary factors is the neurotransmitter systems gene polymorphism, (including the serotonin system gene polymorphism). The aim of the investigation is to study the associations of single nucleotide polymorphism of the rs6295 locus of the serotonin receptor gene 1A HTR1A with morphofunctional features and body weight gain. Material and methods. The study used the materials of a comprehensive anthropogenetic examination of 386 men and 418 women aged 17 to 30 years. More than 20 morphofunctional indicators were measured using the traditional anthropometric method. The material for genetic analysis was genomic DNA isolated from buccal epithelium. The reliability of intergroup differences was assessed using the Mann-Whitney criterion, while canonical discriminant analysis was used to study intergroup variability. Results. For the first time, a significant correlation was shown between the polymorphism of the serotonin receptor type 1 gene HTR1A and morphofunctional features: individuals with the G/G genotype with greater body weight have lower (compared to carriers of the C/C and C/G genotypes) values of the indicators of the level of metabolic processes and specific metabolism. Conclusion. The statistically significant obtained results may be used in the development of individual strategies for the prevention and treatment of obesity, and also allow us to supplement the information on the association of serotonin system gene polymorphism with morphofunctional features and contribute to expanding our understanding of the human physique features formation and their relationships with hereditary predisposition.

7454 Angiotensin AT1 Receptor Type 1 (AT1) Autoantibodies In Patients with Primary Aldosteronism

Abstract Disclosure: J.K. Waraich: None. G. Kline: None. M.Y. Choi: None. R.J. Sigal: None. C. Caughlin: None. S.J. Przybojewski: None. A. Leung: None. Background: Primary aldosteronism (PA) is a condition characterized by excessive aldosterone secretion, and accounts for at least 10% - 20% of all cases of hypertension. Determination of PA subtype (i.e., unilateral vs. bilateral aldosterone hypersecretion) is clinically important to inform targeted treatment. We hypothesized that pathogenesis of PA is immune-mediated and autoantibodies to angiotensin receptor type 1 (AT1) may determine PA subtype. Aims: The aim of this study was to examine whether AT1 autoantibodies predict PA subtype. Methods: We conducted a cross-sectional study of patients with PA who were referred for adrenal vein sampling (AVS) for subtyping. AT1 autoantibody titres were measured using an enzyme-linked immunosorbent assay. AT1 antibodies were defined as present when the titre was >17 U/mL, negative if <10 U/mL, and indeterminate if between 10-17 U/mL. AVS was used as a gold standard to determine lateralization and PA . The frequency of positive AT1 autoantibodies was determined according to PA subtype and clinical predictors of lateralization. Baseline patient characteristics were reported as means (and standard deviations) for normally distributed variables, and medians (and interquartile ranges) for non-normally distributed variables. Fisher’s exact test was performed for categorical variables and Kruskal-Wallis test for continuous variables. Results: 54 patients had successful cannulation of both adrenal veins (mean age, 52.7 years; 46.3% male; mean body mass index, 31.2 kg/m2). AT1 antibodies were detected in 14 (25.9%) of the patients, absent in 32 (59.3%), and indeterminate in 8 (14.8%). Among the 25 patients with unilateral PA, 8 (32.0%) had positive AT1 antibodies, 15 (60.0%) negative, and 2 (8.0%) indeterminate. Similarly, among the 29 patients with bilateral PA, 6 (20.7%) had positive AT1 antibodies, 17 (58.6%) negative, and 6 (20.7%) indeterminate. There was no significant association detected between AT1 antibody status and lateralization (p=0.39). There were no associations between AT1 autoantibody status and any of the clinical factors traditionally predictive of PA, including sex (p=0.94), older age (p=0.76), hypokalemia (p=0.91), higher estimated glomerular filtration rate (p=0.46), or magnitude of aldosterone-to-renin ratio elevation (p=0.58). There was also no association between AT1 titres and these factors. Conclusion: AT1 autoantibodies are common in patients with PA; over a quarter of patients who underwent AVS in our study. Although they were not predictive of PA subtype, these results may still suggest that PA is immune-mediated. Future studies comparing AT1 autoantibodies in PA to other controls are underway. Presentation: 6/1/2024

Heterobivalent Dual-Target Peptide for Integrin-αvβ3 and Neuropeptide Y Receptors on Breast Tumor.

Background/Objectives: Heterodimer peptides targeting more than one receptor can be advantageous, as tumors can simultaneously express more than one receptor type. For human breast cancer, a promising biological target is tumor angiogenesis through αvβ3 integrin expression. Another promising target is Neuropeptide Y receptors, considering Y1R is overexpressed in 90% of human breast tumors. This article details the development and preclinical evaluation, both in vitro and in vivo, of a novel heterodimer peptide dual-receptor-targeting probe, [99mTc]HYNIC-cRGDfk-NPY, designed for imaging breast tumors. Methods: Female BALB/c healthy mice were used to perform biodistrubution studies and female SCID mice were subcutaneously injected with MCF-7 and MDA-MB-231 tumor cells. [99mTc]HYNIC-cRGDfk-NPY was intravenously administered to the mice, followed by ex vivo biodistribution studies and small-animal SPECT/CT imaging. Nonspecific tracer uptake in both models was determined by coinjecting an excess of unlabeled HYNIC-cRGDfk-NPY (100 µg) along with the radiolabeled tracer. Results: Imaging and biodistribution data demonstrate good uptake to estrogen receptor-positive (MCF-7) and triple-negative (MDA-MB-231) tumor models. The in vivo tumor uptakes of radiolabeled conjugate were 9.30 ± 3.25% and 4.93 ± 1.01% for MCF-7 and MDA-MB231, respectively. The tumor/muscle ratios were 5.65 ± 0.94 for the MCF-7 model and 7.78 ± 3.20 for MDA-MB231. Conclusions: [99mTc]HYNIC-cRGDfk-NPY demonstrated rapid blood clearance, renal excretion, and in vivo tumor uptake, highlighting its potential as a tumor imaging agent.

Lubiprostone Improves Distal Segment-Specific Colonic Contractions through TRPC4 Activation Stimulated by EP3 Prostanoid Receptor

Background: Prokinetic agents are effective in increasing gastrointestinal (GI) contractility and alleviating constipation, often caused by slow intestinal motility. Lubiprostone (LUB), known for activating CLC-2 chloride channels, increases the chloride ion concentration in the GI tract, supporting water retention and stool movement. Despite its therapeutic efficacy, the exact mechanisms underlying its pharmacological action are poorly understood. Here, we investigated whether LUB activates the canonical transient receptor potential cation channel type 4 (TRPC4) through stimulation with E-type prostaglandin receptor (EP) type 3. Methods: Using isotonic tension recordings on mouse colon strips, we examined LUB-induced contractility in both proximal and distal colon segments. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine mRNA levels of EP1-4 receptor subtypes in distal colonic muscular strips and isolated myocytes. The effects of a TRPC4 blocker and EP3 antagonist on LUB-stimulated contractions were also evaluated. Results: LUB showed significant contraction in the distal segment compared to the proximal segment. EP3 receptor mRNA levels were highly expressed in the distal colon tissue, which correlated with the observed enhanced contraction. Furthermore, LUB-induced spontaneous contractions in distal colon muscles were reduced by a TRPC4 blocker or EP3 antagonist, indicating that LUB-stimulated EP3 receptor activation may lead to TRPC4 activation and increased intracellular calcium in colonic smooth muscle. Conclusions: These findings suggest that LUB improves mass movement through indirect activation of the TRPC4 channel in the distal colon. The segment-specific action of prokinetic agents like LUB provides compelling evidence for a personalized approach to symptom management, supporting the defecation reflex.

Regulation of Bone Morphogenetic Protein Receptor Type II Expression by FMR1/Fragile X Mental Retardation Protein in Human Granulosa Cells in the Context of Poor Ovarian Response.

Fragile X mental retardation protein (FMRP) is a translational repressor encoded by FMR1. It targets bone morphogenetic protein receptor type II (BMPR2), which regulates granulosa cell (GC) function and follicle development. However, whether this interaction affects folliculogenesis remains unclear. Therefore, this study investigated the potential effect of FMRP-BMPR2 dysregulation in ovarian reserves and infertility. COV434 cells and patient-derived GCs were used to evaluate FMRP and BMPR2 expression. Similarly, FMR1, BMPR2, LIMK1, and SMAD expression were evaluated in GCs with normal (NOR) and poor (POR) ovarian responses. FMRP and BMPR2 were expressed in both cell types. They were co-localized to the nuclear membrane of COV434 cells and cytoplasm of primary GCs. FMR1 silencing increased the mRNA and protein levels of BMPR2. However, the mRNA levels of FMR1 and BMPR2 were significantly lower in the POR group. FMR1 and BMPR2 levels were strongly positively correlated in the NOR group but weakly correlated in the POR group. Additionally, SMAD9 expression was significantly reduced in the POR group. This study highlights the crucial role of FMR1/FMRP in the regulation of BMPR2 expression and its impact on ovarian function. These findings indicate that the disruption of FMRP-BMPR2 interactions may cause poor ovarian responses and infertility.

Truncated NPY-based NPY(Y1)R-specific radiopeptides: Improved in vivo PET tumor imaging by application of peptidase inhibitors

The neuropeptide Y receptor subtype 1 (NPY(Y1)R) exhibits high expression rates on human breast cancer and is therefore an important target structure for the sensitive and specific visualization and characterization of the disease by Positron Emission Tomography (PET). However, imaging of this receptor type has been of limited success so far due to the low stability of peptide-based NPY-derived NPY(Y1)R-specific radiotracer candidates due to in vivo degradation. Given the challenges in stabilizing these agents, our study sought to explore whether the stability of NPY(Y1)R-specific radiopeptides could be enhanced. We aimed to achieve this by either modifying the peptide structure with various molecular scaffolds or by applying peptidase inhibitors. This evaluation aimed to identify the optimal approach for achieving effective NPY(Y1)R-specific imaging in the following. To validate our approach, we systematically investigated four new truncated 68Ga-labeled analogs of NPY and the reference compound [68Ga]Ga-[Lys4(Nε-DOTA)]BVD15, bearing different molecular scaffolds such as a DOTA or NODA-GA chelator, a 4-APipAc linker, a Bip unit, and an N-terminal Lys(lauryl) group. The four new radiotracers as well as the reference compound were obtained in high chemical and radiochemical yields with molar activities of 33–39 GBq/μmol. The radiopeptides exhibited varying logD7.4 values, ranging from −3.37 ± 0.09 to +0.35 ± 0.11, and showed different levels of stability in human serum and liver microsomes, depending on their molecular structure. Subsequently, the influence of the peptidase inhibitors actinonin, phosphoramidon, captopril and E−64 on the in vitro stability of the radiotracers was investigated. In these studies, only actinonin demonstrated a positive effect on the stability of all radiopeptides. In contrast, phosphoramidon yielded variable results, and neither captopril nor E−64 showed a significant stabilizing effect.Consequently, the effect of actinonin administration on the in vivo PET/CT imaging results of the most promising ligand [68Ga]Ga-[Lys4(Nε-NODA-GA)]BVD15 ([68Ga]Ga-2) was investigated in a T47D tumor-bearing xenograft mouse model, followed by ex vivo biodistribution studies. In these experiments, the administration of 250 μg actinonin resulted in a significantly increased uptake of [68Ga]Ga-2 in the T47D tumor (5.9 ± 1.0 % ID/g (with actinonin) instead of 3.1 ± 0.9 % ID/g (without actinonin) at 2h p.i.), and an increase in tumor-to-muscle ratios from 1.8 to 4.0 upon co-administration of the inhibitor.The results impressively demonstrate the positive influence of actinonin on the in vivo stability of the NPY(Y1)R-specific radiopeptide [68Ga]Ga-2, resulting in an increased tumor accumulation and improved tumor-to-background ratios. These findings thus provide important incentive for further advancement of NPY(Y1)R-specific tumor imaging using PET.

Longitudinal Assessment of Transfusion Intensity in Patients With JAK Inhibitor–Naive or –Experienced Myelofibrosis Treated With Momelotinib

PurposeAnemia is a cardinal feature of myelofibrosis often managed with red blood cell (RBC) transfusions, which may contribute to negative prognostic, quality-of-life, and healthcare-related economic impacts. The Janus kinase (JAK) 1/JAK2/activin A receptor type 1 inhibitor momelotinib was approved for the treatment of patients with myelofibrosis and anemia based on clinical trial evidence of anemia, spleen, and symptom benefits illustrated using binomial response/nonresponse endpoints. In the present post hoc, descriptive analyses, the impact of momelotinib on RBC transfusion burden over time was further characterized across JAK inhibitor–naive and –experienced patients. MethodsAll RBC units transfused were collected during the baseline and 24-week treatment periods, initially in a single-arm phase 2 study as proof-of-concept analysis, and then versus comparators (ruxolitinib, best available therapy [BAT], and danazol) in the phase 3 SIMPLIFY-1, SIMPLIFY-2, and MOMENTUM studies, respectively. ResultsIn the phase 2 study, mean transfusion requirement changed by −1.5 units/28 days, with 85% of patients (35/41) achieving numeric transfusion reduction. Across SIMPLIFY-1, SIMPLIFY-2, and MOMENTUM, mean transfusion requirements decreased with momelotinib (−0.1, −0.36, and −0.86 units/28 days), while mean requirements with ruxolitinib, BAT, and danazol changed by +0.39, 0, and ‒0.28 units/28 days, respectively. Overall, 87% (185/213), 77% (79/103), and 85% (110/130) of patients had improved or stable transfusion intensities with momelotinib versus 54% (117/216), 62% (32/52), and 63% (41/65) with ruxolitinib, BAT, and danazol. ConclusionThese novel time-dependent transfusion burden analyses demonstrate that momelotinib is associated with anemia-related benefits in most patients and greater transfusion burden reduction versus comparators. Trial registrationClinicalTrials.gov identifiers: NCT02515630, NCT01969838, NCT02101268, NCT04173494.

Neurochemical Characterization of Dopaminoceptive Cells in Song Control Nuclei of Canaries and Their Activation During Song Production: A Multiplex Fluorescent In Situ Hybridization Study.

Highly sensitive in situ hybridization procedures (RNAScope) were used to quantify the expression of three dopamine receptors (Drd1, Drd2, and Drd3) in two song control nuclei (HVC and the Area X of the basal ganglia) that are known to receive dopaminergic inputs and in the periaqueductal gray (PAG) of male and female canaries. Both sexes were treated with testosterone to ensure they would sing actively. We also determined the excitatory versus inhibitory phenotype of the cells expressing these receptors as well as their activation following a period of song production. The three receptor types were identified in each brain area, with the exception of Drd3 in Area X. The density of cells expressing each receptor varied as a function of receptor type and brain area. Surprisingly few sex differences were detected; they do not seem to explain the sex differences in testosterone-induced song. Overall, the density of Drd-positive cells was much lower in PAG than in the two song control nuclei. In HVC, the majority of cells expressing the three receptor subtypes were VGlut2-positive, whereas colocalization with Vglut2 occurred in few cells in Area X and in an intermediate proportion of cells in PAG. The number of inhibitory cells expressing dopamine receptors was limited. Most dopaminoceptive cells in Area X did not express either excitatory or inhibitory markers. Finally, cellular activation during singing behavior, as measured by the expression of Egr1, was observed in cells expressing each of the three dopamine receptor subtypes, except Drd3 in the PAG.

Organotypic brain slices as a model to study the neurotropism of the highly pathogenic Nipah and Ebola viruses.

Nipah virus (NiV) and Ebola virus (EBOV) are highly pathogenic zoonotic viruses with case fatality rates of up to 90%. While the brain is a known target organ following NiV infection, involvement of the central nervous system in EBOV-infected patients only became more evident after the West African epidemic in 2013-2016. To gain a deeper comprehension of the neurotropism of NiV and EBOV with respect to target cells, affected brain regions and local inflammatory responses, murine organotypic brain slices (BS) were established and infected. Both NiV and EBOV demonstrated the capacity to infect BS from adult wt mice and mice lacking the receptor for type I IFNs (IFNAR-/-) and targeted various cell types. NiV was observed to replicate in BS derived from both mouse strains, yet no release of infectious particles was detected. In contrast, EBOV replication was limited in both BS models. The release of several pro-inflammatory cytokines and chemokines, including eotaxin, IFN-γ, IL-1α, IL-9, IL-17a and keratinocyte-derived chemokine (KC), was observed in both virus-infected models, suggesting a potential role of the inflammatory response in NiV- or EBOV-induced neuropathology. It is noteworthy that the choroid plexus was identified as a highly susceptible target for EBOV and NiV infection, suggesting that the blood-cerebrospinal fluid barrier may serve as a potential entry point for these viruses.

Hydrogen sulfide donor NaHS inhibits formaldehyde-induced epithelial-mesenchymal transition in human lung epithelial cells via activating TGF-β1/Smad2/3 and MAPKs signaling pathways

Formaldehyde (FA) long term exposure leads to abnormal pulmonary function and small airway obstruction of the patients. Hydrogen sulfide (H2S) is one of the recognized gaseous transmitters involved in a wide range of cellular functions. It is unknown the involvement of H2S in FA-induced lung injury. The purpose of this study is to investigate the therapeutic potential and mechanism of H2S on FA-induced epithelial-mesenchymal transition (EMT) of human lung epithelial cells. The cell viability of Beas2B and A549 cells after FA treatment were assessed using MTT assay. The endogenous H2S was visualized by fluorescence microscopy using of the 7-azido-4-methylcoumarin (AzMC). Cell morphology was observed under phase contrast microscope. The mRNAs and proteins level were evaluated by reverse transcription-polymerase chain reaction and western blotting assays. FA treatment downregulated the endogenous H2S levels and the mRNAs and proteins level of H2S synthesizing enzymes, such as cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3-MST) in Beas2B and A549 cells. FA treatment changed the cell morphology of Beas2B cells from cuboid to a spindle-shape, while declined the protein level of E-cadherin and increased the protein level of Vimentin. Moreover, FA treatment increased the proteins level of transforming growth factor-β1 (TGF-β1), phosphorylated-Smad2 (p-Smad2), phosphorylated-Smad3 (p-Smad3), phosphorylated-extracellular signal-regulated kinase (p-ERK), phosphorylated-c-Jun N-terminal kinase (p-JNK), and phosphorylated-P38 (p-P38). Furthermore, the inhibitors of TGF-β receptor type 1 (TGFβRI) and mitogen-activated protein kinases (MAPKs) signaling pathways reversed FA-induced decrease in E-cadherin expression and increase in Vimentin expression in Beas2B cells. Sodium hydrogen sulfide (NaHS) increased the level of H2S, while reversed FA-induced the low expression of E-cadherin and the high expression of Vimentin, TGF-β1, p-Smad2, p-Smad3, p-ERK, p-JNK, and p-P38. These findings indicates FA treatment downregulating the endogenous H2S in human lung epithelial cells. NaHS may inhibit FA-induced EMT in human lung epithelial cells via modulating TGF-β1/Smad2/3 and MAPKs signaling pathways. Therefore, we demonstrated that supplementation of exogenous H2S may inhibit FA-induced lung injury.

A1 adenosine receptor evoked Ca2+ signals in astrocytes

Abstract In addition to neurons, glial cells make up the nervous system. These glial cells are divided into macroglial cells - including astrocytes - and microglial cells. Astrocytes have several important functions in the central nervous system, such as synthesizing transmitters and releasing them, thereby activating the surrounding neurons and astrocytes. Astrocytes do not generate action potentials, but they can transmit information to neighboring cells and react to external stimuli by employing Ca2+ dynamics. Increased neuronal activity can lead to an increased extracellular level of adenosine, reflected by a change in the metabolic state. Adenosine is a naturally occurring nucleoside distributed throughout the body as a metabolic intermediary. Its action is mediated by binding to adenosine receptors, such as the G-protein coupled receptors (GPCRs) A1 adenosine receptor. The binding of adenosine to the specific receptor type activates different signaling pathways in astrocytes. In our work, we studied Ca2+ signals generated upon adenosine A1 receptor activation by adding the pathway to the computational astrocyte model by Oschmann et.al (2017). We investigated the influence of the high-affinity A1 adenosine receptor in various astrocyte domains on the regulated Ca2+ release from the endoplasmic reticulum (ER) of astrocytes and concluded that the receptor-dependent pathway contributes to Ca2+ signals mainly in the soma.

Impact of neonatal hyperoxia on adult cardiac autonomic function in rats: Role of angiotensin II type 1 receptor activation

Individuals born preterm present altered cardiac autonomic function, a risk factor to heart diseases. Neonatal renin-angiotensin-system activation contributes to adult cardiomyopathy in rats exposed to neonatal hyperoxia, a well-established model of preterm birth-related conditions. Central angiotensin II receptor activation is a key modulator of the autonomic drive to the heart. Whether neonatal hyperoxia leads to alteration of the cardiac autonomic function through activation of the angiotensin II receptor type 1 (AT1) is unknown and was examined in the present study.Sprague-Dawley pups were exposed to hyperoxia or room air from postnatal days 3–10. AT1 antagonist losartan or water was given orally postnatal days 8–10. Blood pressure, autonomic function, left ventricular sympathetic innervation, β-adrenergic-receptors expression, and AT1 expression in the solitary-tract-nucleus were examined in adult rats.Neonatal hyperoxia led to loss of day-night blood pressure variation, decreased heart rate variability, increased sympathovagal balance, increased AT1 expression in the solitary-tract, decreased left ventricle sympathetic innervation, and increased β1-adrenergic-receptor protein expression. Losartan prevented the autonomic changes and AT1 expression in the solitary-tract but did not impact the loss of circadian blood pressure variation nor the changes in sympathetic innervation and in β1-adrenergic-receptor expression.In conclusion, neonatal hyperoxia leads to both central autonomic and cardiac sympathetic changes, partly programmed by neonatal activation of the renin-angiotensin system.

Clinical and Genomic Characterization of ERBB2-Altered Gallbladder Cancer: Exploring Differences Between an American and a Chilean Cohort.

Gallbladder cancer (GBC) is a biliary tract malignancy characterized by its high lethality. Although the incidence of GBC is low in most countries, specific areas such as Chile display a high incidence. Our collaborative study sought to compare clinical and molecular features of GBC cohorts from Chile and the United States with a focus on ERBB2 alterations. Patients were accrued at Memorial Sloan Kettering Cancer Center (MSK) or the Pontificia Universidad Católica de Chile (PUC). Clinical information was retrieved from medical records. Genomic analysis was performed by the next-generation sequencing platform MSK-Integrated Mutation Profiling of Actionable Cancer Targets. A total of 260 patients with GBC were included, 237 from MSK and 23 from PUC. There were no significant differences in the clinical characteristics between the patients identified at MSK and at PUC except in terms of lithiasis prevalence which was significantly higher in the PUC cohort (85% v 44%; P = .0003). The prevalence of ERBB2 alterations was comparable between the two cohorts (15% v 9%; P = .42). Overall, ERBB2 alterations were present in 14% of patients (8% with ERBB2 amplification, 4% ERBB2 mutation, 1.5% concurrent amplification and mutation, and 0.4% ERBB2 fusion). Notably, patients with GBC that harbored ERBB2 alterations had better overall survival (OS) versus their ERBB2-wild type counterparts (22.3 months v 11.8 months; P = .024). The prevalence of lithiasis seems to be higher in Chilean versus US patients with GBC. A similar prevalence of ERBB2 alterations of overall 14% and better OS suggests that a proportion of them could benefit from human epidermal growth factor receptor type 2-targeted therapies. The smaller cohort of Chile, where the disease prevalence is higher, is a reminder and invitation for the need of more robust next-generation sequencing analyses globally.

The endocannabinoid system in appetite regulation and treatment of obesity.

The endocannabinoid system (ECS) is a complex cell-signaling system that is responsible for maintaining homeostasis by modulating various regulatory reactions in response to internal and environmental changes. The influence of ECS on appetite regulation has been a subject of much recent research, however, the full extent of its impact remains unknown. Current evidence links human obesity to ECS activation, increased endocannabinoid levels in both central and peripheral tissues, along with cannabinoid receptor type 1 (CBR1) up-regulation. These findings imply the potential pharmacological use of the ECS in the treatment of obesity. Here, we present various pathophysiological processes in obesity involving the ECS, highlighting different pharmacological options for modulating endocannabinoid activity to treat obesity. However, the potential of those pharmacological possibilities remains under investigation and requires further research.

Combination of the chemokine receptor type 2 (CCR2) antagonist DMX-200 and candesartan for COVID-19: a randomised controlled trial

ObjectiveTo determine whether a chemokine receptor type 2 antagonist, DMX-200 (repagermanium), in combination with an angiotensin receptor blocker, candesartan, improves clinical outcomes in people with COVID-19.DesignProspective, multicentre, double-blind, placebo-controlled trial.SettingTen...

Taste receptor T1R3 regulates testosterone synthesis via the cAMP-PKA-SP1 pathway in testicular Leydig cells

Taste receptor type 1 subunit 3 (T1R3) is a G protein-coupled receptor encoded by the TAS1R3 gene that can be specifically activated by certain sweeteners or umami agents for sweet/umami recognition. T1R3 is a potential target for regulating male reproduction. However, studies on the impact of non-nutritive sweeteners on reproduction are limited. In the present study, we evaluated the impact of the non-nutritive sweeteners (saccharin sodium, sucralose and acesulfame-K) on testosterone synthesis in testicular Leydig cells of Xiang pigs by comparing the relative abundance of mRNA transcripts and protein expression of T1R3, steroidogenic related factors, and intracellular cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), as well as testosterone levels using Western blotting, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA). To clarify the specific mechanism, a dual luciferase assay was used to uncover the relationship between the transcription factors and steroidogenic enzyme. The acute intratesticular injection of a typical non-nutritive sweeteners was conducted to verify this impact in mouse. The results showed that saccharin sodium not only enhanced T1R3 expression in Leydig cells of Xiang pigs, but also caused significant increases in testosterone, cAMP, PKA, phosphorylation of specificity protein 1 (p-SP1), total protein of specificity protein 1 (SP1), steroidogenic acute regulatory protein (StAR), and 3β-hydroxysteroid dehydrogenase type 1 (3β-HSD1) (P<0.05). Similarly, treatment of Leydig cells with sucralose and acesulfame-K also increased testosterone level, protein expression of T1R3, 17-α-hydroxylase/17, 20-lyase (CYP17A1), and 3β-HSD1 (P<0.05). Treatment with SQ22536 (an adenylate cyclas inhibitor) or H89 (a PKA inhibitor) significantly reduced saccharin sodium-induced protein levels of p-SP1, StAR, CYP17A1, and 3β-HSD1 (P<0.05). In addition, a dual luciferase assay further demonstrated that SP1 significantly increased the promoter activity of CYP17A1 (P<0.05). When mouse testes were injected with saccharin sodium, T1R3, p-SP1, CYP17A1, and 3β-HSD1 were upregulated, leading to a significant testicular increase in testosterone and cAMP levels (P<0.05). These results suggest a mechanism by which the taste receptor T1R3 regulates testosterone production, and this mechanism may be linked to the cAMP-PKA pathway. Understanding the interrelationship between T1R3 and the cAMP-PKA-SP1 pathway contributes to clarify the regulatory mechanisms of male reproduction.

The chemokine receptor type 5 inhibitor maraviroc alleviates sepsis-associated liver injury by regulating MAPK/NF-κB signaling.

Sepsis-related organ damage, as the most intractable problem in intensive care units (ICUs), receives a great deal of attention from healthcare professionals. Sepsis-associated liver injury (SALI) often leads to poor clinical outcomes due to its complex physiological mechanism. In previous studies, chemokine receptor 5 (CCR5) inhibitors were shown to exert unique anti-inflammatory effects. As the therapeutic effect of maraviroc (MVC) on SALI is still unclear, we aimed to explore whether MVC is effective in treating SALI. We established a model of SALI by cecal ligation and puncture (CLP) and intraperitoneally injected 20mg/kg MVC 2h after CLP. The results showed that MVC could significantly ameliorate liver injury after CLP. Furthermore, we demonstrated that MVC reduced inflammatory infiltration and apoptosis after SALI. In addition, we found that the function of MVC in reducing inflammation was obtained through the inhibition of the two inflammatory signaling pathways mentioned above. Finally, the JNK agonist AN was chosen for reverse research. As shown by the results, the therapeutic effects of MVC disappeared after AN treatment, indicating that MVC exerted anti-inflammatory and antiapoptotic effects through JNK. Our study revealed that MVC could reduce liver injury after SALI by inhibiting liver inflammation and hepatocyte apoptosis induced by CLP and that MVC exerted diminish inflammatory effects by inhibiting the NF-κB and MAPK signaling pathways.

Omeprazole affects the expression of serotonin-1A in the brain regions and alleviates anxiety in rat model of immobilization-induced stress.

Omeprazole, a drug of choice for the management of gastric hyperacidity, influences serotonergic neurotransmission in brain regions and its long-term use is known to cause stress-related behavioral deficits including anxiety. Aim of the current study was to explore the effects of omeprazole treatment on immobilization-induced anxiety in rats, specifically on the role of serotonin (5-HT). In view of the role of serotonin-1A (5-HT1A) autoreceptor in the availability of 5-HT in brain regions, mRNA expression of this autoreceptor was performed in raphe nuclei. Similarly, because of the role of hippocampal 5-HT neurotransmission in anxiety-like disorders, expression of the 5-HT1A heteroreceptors was determined in this region. We found that the treatment with omeprazole reduces anxiety-like behavior in rats, increases the expression of 5-HT1A autoreceptor in the raphe and decreases the hippocampal expression of 5-HT1A heteroreceptor. This suggests a role of 5-HT1A receptor types in omeprazole-induced behavioral changes. It also indicates a potential role of omeprazole in the management of serotonergic disorders.

Ovalbumin-induced food allergy suppression via regulatory T cell expansion mediated by a TNFR2 agonist in mice

Food allergies represent a growing health concern worldwide, characterized by abnormal immune responses to specific dietary antigens. This condition is often associated with a dysregulation of immune tolerance, especially within the intestinal mucosa. Regulatory T cells (Tregs), a crucial subset of lymphocytes, play a central role in maintaining peripheral immune tolerance and are abundant in the intestinal lamina propria. Recent studies have highlighted Treg dysfunction in patients with food allergies, suggesting a potential connection between impaired Treg function and allergy onset. Therefore, strategies to adequately control and activate Tregs could offer new avenues for the prevention and treatment of food allergies. Our research focuses on targeting the regulatory molecule, tumor necrosis factor receptor type 2 (TNFR2), a key modulator of Treg function. We have developed a TNFR2 agonist, scR2agoTNF-Fc, characterized by high TNFR2-stimulating activity and enhanced blood retention in vivo for Treg expansion. In this study, we utilized an ovalbumin (OVA)-induced food allergy mouse model to verify the therapeutic potential of scR2agoTNF-Fc in modulating allergic responses and restoring immune balance. The results showed that scR2agoTNF-Fc promoted the expansion of Treg population in vivo in mice. In addition, scR2agoTNF-Fc reduced diarrhea caused by the food allergy. This was consistent with the molecular mechanisms of suppression of blood immunoglobulins and Th2 cells. Therefore, it was shown that quantitative and functional enhancement of Tregs by the TNFR2 agonist, scR2agoTNF-Fc, may be effective in treating food allergies.

Structure-activity optimization of ryanodine receptor modulators for the treatment of catecholaminergic polymorphic ventricular tachycardia

BackgroundCatecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia disorder associated with potentially lethal arrhythmias. Most CPVT cases are caused by inherited variants in the gene encoding ryanodine receptor type 2 (RYR2). ObjectiveThe goal of this study was to investigate the structure-activity relationship of tetracaine derivatives and to test a lead compound in a mouse model of CPVT. MethodsWe synthesized >200 tetracaine derivatives and characterized 11 of those. The effects of these compounds on Ca2+ handling in cardiomyocytes from R176Q/+ mice was tested with confocal microscopy. The effects of lead compound MSV1302 on arrhythmia inducibility and cardiac contractility were tested by programmed electrical stimulation and echocardiography, respectively. Plasma and microsomal stability and cytotoxicity assays were also performed. ResultsCa2+ imaging revealed that 4 of 11 compounds suppressed sarcoplasmic reticulum Ca2+ leak through mutant RyR2. Two compounds selected for further testing exhibited a half-maximal effective concentration of 146 nM (MSV1302) and 49 nM (MSV1406). Whereas neither compound altered baseline electrocardiogram intervals, only MSV1302 suppressed stress- and pacing-induced ventricular tachycardia in vivo in R176Q/+ mice. Echocardiography revealed that the lead compound MSV1302 did not negatively affect cardiac inotropy and chronotropy. Finally, compound MSV1302 did not block INa, ICa,L, or IKr; it exhibited excellent stability in plasma and microsomes, and it was not cytotoxic. ConclusionStructure-activity relationship studies of second-generation tetracaine derivatives identified lead compound MSV1302 with a favorable pharmacokinetic profile. MSV1302 normalized aberrant RyR2 activity in vitro and in vivo, without altering cardiac inotropy, chronotropy, or off-target effects on other ion channels. This compound may be a strong candidate for future clinical studies to determine its efficacy in CPVT patients.