Releasing Hormone Research Articles

Ex vivo and miniaturized in vitro models to study microbiota-gut-brain axis.

The microbiota-gut-brain axis involves complex bidirectional communication through neural, immune, and endocrine pathways. Microbial metabolites, such as short-chain fatty acids, influence gut motility and brain function by interacting with gut receptors and modulating hormone release. Additionally, microbial components such as lipopolysaccharides and cytokines can cross the gut epithelium and the blood-brain barrier, impacting immune responses and cognitive function. Ex vivo models, which preserve gut tissue and neural segments, offer insight into localized gut-brain communication by allowing for detailed study of nerve excitability in response to microbial signals, but they are limited in systemic complexity. Miniaturized in vitro models, including organ-on-chip platforms, enable precise control of the cellular environment and simulate complex microbiota-host interactions. These systems allow for the study of microbial metabolites, immune responses, and neuronal activity, providing valuable insights into gut-brain communication. Despite challenges such as replicating long-term biological processes and integrating immune and hormonal systems, advancements in bioengineered platforms are enhancing the physiological relevance of these models, offering new opportunities for understanding the mechanisms of the microbiota-gut-brain axis. This review aims to describe the ex vivo and miniaturized in vitro models which are used to mimic the in vivo conditions and facilitate more precise studies of gut brain communication.

Complement factor D deficiency ameliorates adverse cardiac remodelling by inhibiting C5a-C5aR mediated ISGs+ neutrophil activation post myocardial infarction

Abstract Background Exaggerated inflammatory response after myocardial infarction (MI) exacerbates myocardial injury and adverse cardiac remodeling, leading to heart failure. Current management of MI involves myocardial protection and antifibrotic therapy but do not target the inflammatory response per se. Complement factor D (CFD) is an upstream rate-limiting enzyme of complement system activation, which is the early event of inflammatory response post MI. We hypothesize that CFD can be an important modulator of the inflammation-remodeling cascade post MI, but the specific mechanism remains elusive. Purpose To investigate the role and mechanism of CFD in regulating inflammatory expansion and adverse remodeling post MI. Methods We generated Cfd-AKO (Cfdfl/fl Adipoq-cre) mice using the Cre-LoxP recombination system, as CFD is mainly secreted by adipocytes. Immune status and cardiac remodeling progress were assessed by cardiovascular magnetic resonance (CMR), histology, flow cytometry, immunofluorescence, and ELISA. Single cell RNA sequencing (scRNA-seq) analyzed non­cardiomyocytes isolated from Cfd-AKO and WT mice post MI or sham operation. Genetic ablation and co-culture experiments dissected the functional molecular properties and intercellular communication. An CFD inhibitor ACH-4471 was used to explore the role of CFD in ischemia-reperfusion (IR) injury. Results The survival of Cfd-AKO mice was strongly improved, while ventricular arrhythmia induction rates and number of episodes were significantly reduced compared with those of WT mice. CMR imaging showed that Cfd-AKO mice had higher ejection fraction and reduced left ventricular dilation than WTs. Masson trichrome and picrosirius red staining revealed that besides smaller infarct size, the extent of fibrosis in the border and distal remote area decreased in Cfd-AKO mice. Cfd loss reduced myocardial injury, inhibited the release of inflammatory factors, and limits the amplification of complement components C3a and C5a post MI. ScRNA-seq revealed that CFD modulated neutrophil chemotactic ability and pro-inflammatory function by inducing interferon-stimulated genes expressing (ISG+) neutrophil CXCL10 expression. Mechanistically, CFD activates the ISG transcriptional profile via the C5a/C5aR dependent STAT1/2-IRF9 pathway. Activated neutrophils promote myofibroblast transformation through IL1β/IL1R dependent intercellular communication, thus facilitating pathological fibrosis. Early pharmacological blocking of CFD in mice IR injury models inhibited inflammation, reduced infarct size and ameliorated cardiac dysfunction. Conclusions We demonstrate the crucial role of CFD in cardiac remodeling post MI. This process is critically regulated by C5a-C5aR, an important component of complement-inflammation cascade. This CFD-C5a mediated neutrophil pro-inflammatory and pro-fibrotic dual activity represents a novel pathway and an attractive therapeutic window for heart failure post MI.CFD in cardiac remodelling post MI

Corticotropin releasing hormone receptor 1 in the medial prefrontal cortex mediates aversion resistant alcohol intake.

Alcohol consumption despite negative consequences is a core symptom of Alcohol Use Disorder. In animal models, this is studied by pairing aversive stimuli with alcohol access, and continuation of drinking under these conditions is known as aversion resistance. Previously, we found that female mice are more aversion resistant than males. Corticotropin releasing hormone (Crh) and the Crh receptor 1 (Crhr1) regulate stress-induced reinstatement, alcohol dependence, and binge-like drinking. However, the role of the Crh system in aversion resistance has not been assessed. We aimed to identify sex differences in the Crh system during quinine-adulterated alcohol intake. We used two-bottle choice and adulterated the alcohol solution with quinine. Next, we measured Crh and Crhr1 levels in brain tissue using real-time polymerase chain reaction (RT-qPCR) and RNAscope in situ hybridization. We then infused a Crhr1 antagonist into the medial prefrontal cortex (mPFC) prior to quinine-alcohol intake. After quinine-alcohol consumption, females exhibited increased mPFC Crhr1 mRNA levels as measured by RT-qPCR. This was confirmed with greater anatomical specificity using RNAscope, with females exhibiting an increased number of Crhr1 + cells in the dorsomedial PFC and the ventromedial PFC. mPFC Crhr1 antagonist treatment reduced quinine-alcohol consumption in females but did not impact consumption in males. Quinine-free alcohol intake was unaffected by Crhr1 antagonist treatment. Our findings suggest that Crhr1 in mPFC plays a role in aversion resistant alcohol intake in females. Future experiments will examine the sources of Crh innervation to the mPFC and their distinct roles in alcohol seeking.

Investigating the Biological Efficacy of Albumin-Enriched Platelet-Rich Fibrin (Alb-PRF): A Study on Cytokine Dynamics and Osteoblast Behavior

The development of effective biomaterials for tissue regeneration has led to the exploration of blood derivatives such as leucocyte- and platelet-rich fibrin (L-PRF). A novel variant, Albumin-Enriched Platelet-Rich Fibrin (Alb-PRF), has been introduced to improve structural stability and bioactivity, making it a promising candidate for bone regeneration. This study aimed to evaluate Alb-PRF’s capacity for cytokine and growth factor release, along with its effects on the proliferation, differentiation, and mineralization of human osteoblasts in vitro. Alb-PRF membranes were analyzed using histological, scanning electron microscopy, and fluorescence microscopy techniques. Cytokine and growth factor release was quantified over seven days, and osteoinductive potential was evaluated with MG-63 osteoblast-like cells. Structural analysis showed Alb-PRF as a biphasic, highly cellularized material that releases lower levels of inflammatory cytokines and higher concentrations of platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) compared to L-PRF. Alb-PRF exhibited higher early alkaline phosphatase activity and in vitro mineralization (p < 0.05) and significantly increased the OPG/RANKL mRNA ratio (p < 0.05). These results indicate that Alb-PRF has promising potential as a scaffold for bone repair, warranting further in vivo and clinical assessments to confirm its suitability for clinical applications.

Reduced glutathione attenuates pediatric sepsis-associated encephalopathy by inhibiting inflammatory cytokine release and mitigating lipid peroxidation-induced brain injury.

Sepsis-associated encephalopathy (SAE) is a severe complication of sepsis. Reduced glutathione (GSH) has antioxidant properties and is used as a neuroprotective agent in some studies. However, research on the application of exogenous GSH in the treatment of SAE is limited. This study aimed to determine the effects of exogenous GSH in pediatric SAE patients and mice. We evaluated clinical parameters, inflammatory factors, and oxidative stress before and after GSH treatment. The clinical trials demonstrated that GSH treatment improved brain damage markers (S-100 beta protein, brain fatty acid-binding protein), increased neurological status scores (Glasgow coma scale), and reduced Pediatric Risk of Mortality III scores in children with SAE. GSH treatment also significantly reduced the levels of inflammatory factors (interleukin-6, tumor necrosis factor-α) and decreased lipid peroxidation (superoxide dismutase). Additionally, GSH reduced lipid peroxidation resulting from abnormal lipid metabolism, as indicated by the levels of acyl-CoA synthetase long-chain family member 4, lysophosphatidylcholine acyltransferase 3, and glutathione peroxidase 4. In-vivo experiments showed that the neuroprotective effect of GSH was dose-dependent, with better effects observed at medium and high doses. Furthermore, GSH alleviated brain damage, suppressed the release of inflammatory factors, and inhibited lipid peroxidation in SAE mice. The animal experiments also showed that GSH reduces lipid peroxidation through the 15-lipoxygenase/phosphatidylethanolamine binding protein 1/glutathione peroxidase 4 pathway. Our study suggests that exogenous GSH has neuroprotective effects in pediatric SAE. These findings provide a basis for the potential use of GSH as a therapeutic method for SAE.

Preparation and characterization of bovine dental pulp-derived extracellular matrix hydrogel for regenerative endodontic applications: an in vitro study

BackgroundThe use of biological scaffolds in regenerative endodontics has gained much attention in recent years. The search for a new biomimetic scaffold that contains tissue-specific cell homing factors could lead to more predictable tissue regeneration. The aim of this study was to prepare and characterize decellularized bovine dental pulp-derived extracellular matrix (P-ECM) hydrogels for regenerative endodontic applications.MethodsFreshly extracted bovine molar teeth were collected. Bovine dental pulp tissues were harvested, and stored at -40º C. For decellularization, a 5-day protocol was implemented incorporating trypsin/EDTA, deionized water and DNase treatment. Decellularization was evaluated by DNA quantification and histological examination to assess collagen and glycosaminoglycans (GAGs) content. This was followed by the preparation of P-ECM hydrogel alone or combined with hyaluronic acid gel (P-ECM + HA). The fabricated scaffolds were then characterized using protein quantification, hydrogel topology and porosity, biodegradability, and growth factor content using Enzyme-linked immunosorbent assay (ELISA): transforming growth factor beta-1(TGF-β1), basic fibroblast growth factor (bFGF), bone morphogenetic protein 2 (BMP-2) and vascular endothelial growth factor (VEGF).ResultsDecellularization was histologically confirmed, and DNA content was below (50 ng/mg tissue). P-ECM hydrogel was prepared with a final ECM concentration of 3.00 mg/ml while P-ECM + HA hydrogel was prepared with a final ECM concentration of 1.5 mg/ml. Total protein content in P-ECM hydrogel was found to be (439.0 ± 123.4 µg/µl). P-ECM + HA showed sustained protein release while the P-ECM group showed gradual decreasing release. Degradation was higher in P-ECM + HA which had a significantly larger fiber diameter, while P-ECM had a larger pore area percentage. ELISA confirmed the retention and release of growth factors where P-ECM hydrogel had higher BMP-2 release, while P-ECM + HA had higher release of TGF-β1, bFGF, and VEGF.ConclusionsBoth P-ECM and P-ECM + HA retained their bioactive properties demonstrating a potential role as functionalized scaffolds for regenerative endodontic procedures.

Sleep is altered during menstruation but not inflammatory parameters: Results from polysomnography of EPISONO database.

Menstruation is an inflammatory process that involves changes in women's physiology leading to mental and physical complaints. Sleep is essential for optimal hormonal release, immune response, and wellbeing, becoming an important factor to be evaluated. We compared sleep, inflammatory mediators, fatigue, anxiety and depression symptoms, and quality of life in menstruating and non-menstruating women. We used the polysomnographic data of 232 women from EPISONO 2007, an epidemiological study from São Paulo city, Brazil. Women were distributed into menstruating (N = 61) and non-menstruating groups (N = 171). We applied questionnaires related to sleep quality, sleepiness, insomnia, fatigue, anxiety and depression symptoms, and quality of life. The serum levels of interleukin 6, tumour necrosis factor-alpha, and C-reactive protein were analysed. For statistical analysis the significance level adopted was p < 0.05. Sleep efficiency was statistically lower in menstruating women (81% ± 13) compared with the non-menstruating group (84.2% ± 13.3, p < 0.023). No statistical differences between the two groups were found in respect to the other parameters analysed. Both groups scored for fatigue symptoms, but no statistical significance was observed between the groups. Our findings indicate that menstruation was associated with lower objective sleep efficiency, suggesting that menstruation may be a physiological factor impairing sleep. Further studies evaluating menstrual variables, and each phase of the menstrual cycle, should be undertaken to detect the main factors associated with sleep complaints, fatigue, and objective parameters of sleep.

Advanced Hydrogels: Enhancing Tissue Bioengineering with RGD Peptides and Carbon Nanomaterials.

The advancement of tissue engineering (TE) is driven by the development of scaffolds that mimic the mechanical, spatial, and biological environment of the extracellular matrix (ECM), crucial for regulating cell behavior and tissue repair. Hydrogels, 3D networks of polymer chains, are particularly suited for TE due to their high biocompatibility, ability to mimic tissue water content, facilitate cell migration, sustain growth factor release, and offer controllable physical properties. However, hydrogels mimicking the ECM often face challenges related to cell adhesion due to the absence of specific receptors. This issue can be addressed by incorporating ECM components into the polymer matrix, such as the peptide sequence arginine-glycine-aspartic acid (RGD), known for its role in cell adhesion. Additionally, carbon nanomaterials (CNMs) offer unique physicochemical properties that can improve scaffold-cell interactions. Despite the potential benefits, there are limited reports on their combination. RGD-CNM hydrogels enable a more accurate emulation of the natural cellular environment, enhancing tissue engineering applications. This hybrid approach may promote robust cell adhesion along with exceptional mechanical and electrical properties. This review outlines the potential benefits of these hybrid scaffolds and their synergistic potential, aiming to inspire new research directions in this innovative field.

Increased TRPV4 Channel Expression Enhances and Impairs Blood Vessel Function in Hypertension.

Endothelial cell TRPV4 (transient receptor potential vanilloid 4) channels provide a control point that is pivotal in regulating blood vessel diameter by mediating the Ca2+-dependent release of endothelial-derived vasoactive factors. In hypertension, TRPV4-mediated control of vascular function is disrupted, but the underlying mechanisms and precise physiological consequences remain controversial. Here, using a comprehensive array of methodologies, endothelial TRPV4 channel function was examined in intact mesenteric resistance arteries from normotensive Wistar-Kyoto and spontaneously hypertensive rats. Our results show there is a notable shift in vascular reactivity in hypertension characterized by enhanced endothelium-dependent vasodilation at low levels of TRPV4 channel activation. However, at higher levels of TRPV4 activity, this vasodilatory response is reversed, contributing to the aberrant vascular tone observed in hypertension. The change in response, from dilation to constriction, was accompanied by a shift in intracellular Ca2+ signaling modalities arising from TRPV4 activity. Oscillatory TRPV4-evoked IP3 (inositol triphosphate)-mediated Ca2+ release, which underlies dilation, decreased, while the contraction inducing sustained Ca2+ rise, arising from TRPV4-mediated Ca2+ influx, increased. Our findings also reveal that while the sensitivity of endothelial cell TRPV4 to activation was unchanged, expression of the channel is upregulated and IP3 receptors are downregulated in hypertension. These data highlight the intricate interplay between endothelial TRPV4 channel expression, intracellular Ca2+ signaling dynamics, and vascular reactivity. Moreover, the data support a new unifying hypothesis for the vascular impairment that accompanies hypertension. Specifically, endothelial cell TRPV4 channels play a dual role in modulating blood vessel function in hypertension.

Cyclic Diguanylate G-Quadruplex Inducer-Quorum Sensing Inhibitor Hybrids as Bifunctional Anti-biofilm and Anti-virulence Agents Against Pseudomonas aeruginosa.

The release of virulence factors and biofilm formation by Pseudomonas aeruginosa are pivotal drivers of its severe pathogenicity and antibiotic resistance. Based on our prior findings, cyclic di-GMP (c-di-GMP) G-quadruplex inducers are promising biofilm inhibitors and that quorum sensing systems are central regulators of virulence, we aimed to design and synthesize c-di-GMP G-quadruplex inducer-quorum sensing inhibitor hybrids. These hybrids were envisioned as bifunctional agents with both antibiofilm and antivirulence capabilities. Hybrids A7 and A11, characterized by their quinoline and 3-indole rings, emerged as potent inhibitors. They achieve this dual action by inducing c-di-GMP G-quadruplex formation and disrupting the las and pqs signaling system. Additionally, hybrids A7 and A11 attenuated virulence factors and inhibited the motility phenotypes of P. aeruginosa. Furthermore, when tested in in vivo Caenorhabditis elegans infection models, these hybrids, in combination with antibiotics such as tetracycline, improved survival rates, all while maintaining a favorable biosafety profile.

Effects of multiple stress events at different stages of life on the incidence of metabolic syndrome

ObjectiveTo investigate the effects of multiple stress events in different stages of life on the incidence of metabolic syndrome (MetS).MethodsMiners from Tangshan, China, were recruited for this study. Workers of the Kailuan Mining Group were evaluated to investigate whether exposure to Tangshan earthquakes during the fetal period in 1976. Adult life events and childhood trauma were assessed separately via the Life Event Scale and Childhood Trauma Questionnaire. The subjects were physically examined and general demographic data such as waist circumference were collected. Blood samples were collected for measurement of metabolic parameters. Corticotropin releasing hormone(CRH) levels was measured by enzyme-linked immunosorbent assay (ELISA). The subjects were divided into four groups according to their exposure to traumatic events in different stages of life: no exposure group, 1-exposure group, 2-exposures group, and 3-exposures group. The incidence of MetS, metabolic parameters and CRH levels in each of the four groups was compared.ResultsIn all, 626 people were enrolled; of these, 183, 262, 150, and 31 were in the no exposure, 1-exposure, 2-exposures, and 3-exposure groups, respectively. A remarkable variation in the incidence of MetS was observed among the four groups (x2 = 16.462, P&amp;lt;0.001). MetS incidence increased with the increasing number of traumatic events, except for in the no exposure group (17.9% in 1-exposure group, 24.7% in 2-exposure group, and 48.4% in the 3-exposure group). Multivariate logistic regression analysis showed that exposure to multiple stress during the fetal, childhood, and adult stages of life represent independent risk factors for developing MetS (OR=3.134, 95%CI=1.042–9.429). Smoking increased the risk of developing MetS (OR=1.809, 95%CI=1.140–2.871).ConclusionsExposure to multiple traumatic events in distinct life stages increases the risk of developing MetS. Smoking is a risk factor for developing MetS.

Deep phenotyping reveals CRH and FKBP51-dependent behavioral profiles following chronic social stress exposure in male mice.

The co-chaperone FKBP51, encoded by FKBP5 gene, is recognized as a psychiatric risk factor for anxiety and depressive disorders due to its crucial role in the stress response. Another key modulator in stress response regulation is the corticotropin releasing hormone (CRH), which is co-expressed with FKBP51 in many stress-relevant brain-regions and cell-types. Together, they intricately influence the balance of the hypothalamic-pituitary-adrenal (HPA) axis, one of the primary stress response systems. Previous research underscores the potential moderating effects these genes have on the regulation of the stressful life events towards the vulnerability of major depressive disorder (MDD). However, the specific function of FKBP51 in CRH-expressing neurons remains largely unexplored. Here, through deep behavioral phenotyping, we reveal heightened stress effects in mice lacking FKBP51 in CRH co-expressing neurons (CRHFKBP5-/-), particularly evident in social contexts. Our findings highlight the importance of considering cell-type specificity and context in comprehending stress responses and advocate for the utilization of machine-learning-driven phenotyping of mouse models. By elucidating these intricacies, we lay down the groundwork for personalized interventions aimed at enhancing stress resilience and individual well-being.

Apigenin as a Promising Agent for Enhancing Female Reproductive Function and Treating Associated Disorders.

Apigenin is an organic flavonoid abundant in some plants such as parsley, chamomile, or celery. Recently, it has been investigated for several of its pharmacological characteristics, such as its ability to act as an antioxidant, reduce inflammation, and inhibit the growth of cancer cells. The purpose of this review is to provide a summary of the existing knowledge regarding the effects of apigenin on female reproductive systems and its dysfunctions. Apigenin can influence reproductive processes by regulating multiple biological events, including oxidative processes, cell proliferation, apoptosis, cell renewal and viability, ovarian blood supply, and the release of reproductive hormones. It could stimulate ovarian folliculogenesis, as well as ovarian and embryonal cell proliferation and viability, which can lead to an increase in fertility and influence the release of reproductive hormones, which may exert its effects on female reproductive health. Furthermore, apigenin could inhibit the activities of ovarian cancer cells and alleviate the pathological changes in the female reproductive system caused by environmental pollutants, harmful medications, cancer, polycystic ovarian syndrome, ischemia, as well as endometriosis. Therefore, apigenin may have potential as a biostimulator for female reproductive processes and as a therapeutic agent for certain reproductive diseases.

QRFP and GPR103 in the paraventricular nucleus play a role in chronic stress-induced depressive-like symptomatology by enhancing the hypothalamic-pituitary-adrenal axis

Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis during chronic stress is essential for depression neurobiology. As the latest member of the RFamide peptide family in mammals, pyroglutamylated RFamide peptide (QRFP) is closely implicated in neuroendocrine maintenance by activating G-protein-coupled receptor 103 (GPR103). We hypothesized that QRFP and GPR103 might contribute to chronic stress-induced depression by promoting corticotropin-releasing hormone (CRH) release from neurons in the paraventricular nucleus (PVN), and various methods were employed in this study, with male C57BL/6J mice adopted as the experimental subjects. Chronic stress induced not only depression-like behaviors but also significant enhancement in QRFP and GPR103 in the PVN. Genetic overexpression of QRFP/GPR103 and stereotactic infusion of QRFP-26/QRFP-43 peptide in the PVN all mimicked chronic stress that induced various depression-like phenotypes in naïve mice, and this was mediated by promoting CRH biosynthesis and HPA activity. In contrast, genetic knockdown of QRFP/GPR103 in the PVN produced notable antidepressant-like effects in mice exposed to chronic stress. Furthermore, genetic knockout of QRFP also protected against chronic stress in mice. In addition, both the C-terminal biological region of QRFP and the downstream PKA/PKC-CREB signaling coupled to GPR103 stimulation underlie the role of QRFP and GPR103 in depression. Collectively, QRFP and GPR103 in PVN neurons could be viable targets for novel antidepressants.

Description and functional validation of human enteroendocrine cell sensors.

Enteroendocrine cells (EECs) are gut epithelial cells that respond to intestinal contents by secreting hormones, including the incretins glucagon-like peptide 1 (GLP-1) and gastric inhibitory protein (GIP), which regulate multiple physiological processes. Hormone release is controlled through metabolite-sensing proteins. Low expression, interspecies differences, and the existence of multiple EEC subtypes have posed challenges to the study of these sensors. We describe differentiation of stomach EECs to complement existing intestinal organoid protocols. CD200 emerged as a pan-EEC surface marker, allowing deep transcriptomic profiling from primary human tissue along the stomach-intestinal tract. We generated loss-of-function mutations in 22 receptors and subjected organoids to ligand-induced secretion experiments. We delineate the role of individual human EEC sensors in the secretion of hormones, including GLP-1. These represent potential pharmacological targets to influence appetite, bowel movement, insulin sensitivity, and mucosal immunity.

Growth hormone-releasing hormone and cancer.

The hypothalamic hormone growth hormone-releasing hormone (GHRH), in addition to promoting the synthesis and release of growth hormone (GH), stimulates the proliferation of human normal and malignant cells by binding to GHRH-receptor (GHRH-R) and its main splice variant, SV1. Both GHRH and GHRH-Rs are expressed in various cancers, forming a stimulatory pathway for cancer cell growth; additionally, SV1 possesses ligand independent proliferative effects. Therefore, targeting GHRH-Rs pharmacologically has been proposed for the treatment of cancer. Various classes of synthetic GHRH antagonists have been developed, endowed with strong anticancer activity in vitro and in vivo, in addition to displaying anti-inflammatory, antioxidant and immune-modulatory functions. GHRH antagonists exert indirect effects by blocking the pituitary GH/hepatic insulin-like growth factor I (IGF-I) axis, or directly inhibiting the binding of GHRH on tumor GHRH-Rs. Additionally, GHRH antagonists block the mitogenic functions of SV1 in tumor cells. This review illustrates the main findings on the antitumor effects of GHRH antagonists in experimental human cancers, along with their underlying mechanisms. The development of GHRH antagonists, with reduced toxicity and high stability, could lead to novel therapeutic agents for the treatment of cancer and inflammatory diseases.

Long-term, dynamic remodelling of the corticotroph transcriptome and excitability after a period of chronic stress.

Chronic stress results in long-term dynamic changes at multiple levels of the hypothalamic-pituitary-adrenal (HPA) axis resulting in stress axis dysregulation with long term impacts on human and animal health. However, the underlying mechanisms and dynamics of altered of HPA axis function, in particular at the level of pituitary corticotrophs, during a period of chronic stress and in the weeks after its cessation (defined as "recovery") are very poorly understood. Here we address the fundamental question of how a period of chronic stress results in altered anterior pituitary corticotroph function and whether this persists in recovery, as well as the transcriptomic changes underlying this. We demonstrate that in mice spontaneous and corticotrophin releasing hormone (CRH)-stimulated electrical excitability of corticotrophs, essential for ACTH secretion, is suppressed for weeks-months of recovery following a period of chronic stress. Surprisingly, there are only modest changes in the corticotroph transcriptome during the period of stress but major alterations occur in recovery. Importantly, while transcriptional changes for a large proportion of mRNAs follow the time course suppression of corticotroph excitability, many other genes display highly dynamic transcriptional changes with distinct time courses throughout recovery. Taken together, this suggests that chronic stress results in complex dynamic transcriptional and functional changes in corticotroph physiology, which are highly dynamic for weeks following cessation of chronic stress. These insights provide a fundamental new framework to further understand underlying molecular mechanisms as well approaches to both diagnosis and treatment of stress-related dysfunction of the HPA axis.

N4BP3 facilitates NOD2-MAPK/NF-κB pathway in inflammatory bowel disease through mediating K63-linked RIPK2 ubiquitination

The NOD2 signaling pathway, which plays an important role in the mechanisms of inflammatory bowel disease (IBD) development, has been closely associated with ubiquitination. It was revealed in this study that NOD2 receptor activation could obviously affect the expression of 19 ubiquitination-related genes, with N4BP3 being the most prominently expressed and upregulated. In addition, N4BP3 knockdown was found to reduce the mRNA levels of MDP-induced inflammatory factors, while N4BP3 overexpression elevated their mRNA levels as well as the levels of phospho-ERK1/2, phospho-JNK, phospho-P38 and phospho-NF-κB P65 proteins. Immunoprecipitation tests showed that N4BP3 could pull down RIPK2 and promote its K63-linked ubiquitination. In human tissue specimen assays and mouse experiments, we found that the expression of N4BP3 was significantly elevated in Crohn’s disease (CD) patients and IBD mice, and N4BP3 knockdown reduced the dextran sulfate sodium-induced pathological score and the expression of inflammatory factors in the mouse colon tissue. In conclusion, N4BP3 is able to interact with RIPK2 and promote its K63-linked ubiquitination, to further promote the NOD2-MAPK/NF-κB pathway, thereby increasing promoting the release of inflammation factors and the degree of IBD inflammation.

Baseline differences in cardiorespiratory fitness by gonadotropin releasing hormone agonist treatment converge after testosterone in transgender adolescents.

There are known sex differences in cardiorespiratory fitness (CRF). Little is known about the impact of pubertal blockade with a gonadotropin releasing hormone agonist (GnRHa) followed by hormone therapy on CRF for transgender adolescents. We aimed to (1) determine the effect of GnRHa monotherapy on CRF and mitochondrial function and associations with metabolomic profiles, and (2) evaluate for changes after 1 and 12 months of testosterone therapy among transgender adolescents . Participants assigned female at birth (n=19, baseline age 15.0+1.0 years) from two groups: GnRHa+ (n=8) and GnRHa- (n=11) were examined at baseline and 1- and 12-months post-testosterone therapy in a longitudinal observational study to assess cardiorespiratory fitness, mitochondrial respiration and metabolic profile. Fasted morning labs including assessment of metabolomics and peripheral blood mononuclear cell mitochondrial respiration and degree of mitochondrial coupling (respiratory control ratio, RCR). A graded cycle ergometer test was performed. Baseline differences were evaluated between groups. Changes were compared with mixed linear regression models evaluating time (baseline, 1 and 12 months), group (GnRHa treatment yes/no), and their interaction. At baseline GnRHa+ individuals had higher relative VO2peak (30.1+4.83 vs. 25.24+4.47 ml/kg/min, p=0.042) than GnRHa- individuals. In regression models, GnRHa+ individuals had a significant increase in peak watts (p=0.011) and total exercise time (p=0.005)after 12 months of testosterone (p=0.012), but not GnRHa- individuals. GnRHa+ individuals have significantly higher RCR under carbohydrate (p=0.0007) and lipid (p=0.0002) conditions than GnRHa+ individuals. Pretreatment with GnRHa positively influences peak CRF and mitochondrial respiration in adolescent transgender males undergoing testosterone therapy.

Rising Prevalence of Obesity and Primary Hyperaldosteronism: Co-incidence or Connected Circumstances Leading to Hypertension? A Narrative Review.

While obesity and its associated complications, mainly diabetes and hypertension, have been the largest public health problems of modern world, the emerging data suggests an increasing prevalence of primary hyperaldosteronism (PA) as one of the most common undiagnosed causes of hypertension. We believe that rising prevalence of PA in the era of high rates of obesity is likely not a chance finding but is deeply intersected with the rising rates of obesity. Higher serum aldosterone concentrations and urinary aldosterone excretion have been observed in patients with increased body mass index or larger waist circumference. The in vitro and pre-clinical studies suggest that adipocytes not only synthesize and secrete aldosterone but also release factors which stimulate production of aldosterone from adrenal glands. Aldosterone excess causing ligand-dependent activation of the mineralocorticoid receptor (MR) has increasingly been recognized as one of the important mechanisms of obesity-related hypertension. The aldosterone excess in these cases can be labelled as acquired hyperaldosteronism to differentiate it from the non-obesity related classical cases of PA. Because of serious consequences, recognizing aldosterone excess in obesity is important, as it gives a more compelling reason for weight loss and guidance to choosing pharmacotherapy wisely. Dietary sodium restriction and mineralocorticoid receptor antagonists play important roles in the management of PA associated with obesity.