GPR30 Research Articles

Association of GPR120 and NGF with perineural invasion in cholangiocarcinoma: Clinical and experimental insights.

622 Background: Cholangiocarcinoma (CCA) is a highly malignant biliary tumor characterized by frequent perineural invasion (PNI), which is associated with a poor prognosis; however, the underlying mechanisms remain unclear. G-protein-coupled receptor 120 (GPR120) has been implicated in the development of various tumors, while nerve growth factor (NGF) has a strong correlation with PNI. This study aims to elucidate the role of GPR120 in the production of NGF and to investigate the mechanisms by which PNI is induced in CCA. Methods: We conducted a retrospective review of medical records for 386 patients with cholangiocarcinoma (CCA), including both extrahepatic (ECC) and intrahepatic (ICC) types, who underwent curative resection at the Department of General Surgery, First Affiliated Hospital of Soochow University, between January 2015 and December 2021. NGF and GPR120 expression were assessed in 60 paraffin-embedded archived CCA tissue samples via immunohistochemical staining (IHC), with an additional 60 normal bile duct samples serving as controls. All tissues were sourced from the aforementioned 386 patients, none of whom received preoperative treatment. Tumors were staged according to AJCC classification. Western blot analysis was employed to evaluate NGF and GPR120 expression in CCA cell lines (QBC 939, RBE, HUCCT-1, and HCCC-9810). To assess the invasion and migration capabilities of CCA cell lines, QBC 939 and HCCC-9810 were treated with TUG-891 (a GPR120 agonist) and AH7614 (a GPR120 inhibitor). Results: Both GPR120 and NGF were found to be upregulated in CCA tissues, correlating with aggressive clinicopathological features. IHC staining revealed cytoplasmic localization of GPR120 and NGF, with significantly higher expression in cancerous tissues compared to adjacent noncancerous samples. Among the 386 patients, PNI was observed in 339 (87.8%). PNI correlated with tumor diameter, CA 19-9 levels, TNM stage, preoperative bilirubin levels, tumor differentiation, and preoperative drainage. Notably, GPR120 expression increased in poorly differentiated tumors and advanced clinical stages, indicating a clinical association with CCA progression. In vitro studies demonstrated that GPR120 promoted invasion and migration in the QBC 939 and HCCC-9810 cell lines. Western blot analysis confirmed elevated GPR120 levels in these lines, which also exhibited higher NGF expression. The GPR120 inhibitor AH7614 significantly reduced invasion in QBC 939 and HCCC-9810 cells, while the GPR120 agonist TUG-891 showed no effect on any of the CCA cell lines tested. Conclusions: GPR120 and NGF are implicated in perineural invasion (PNI) in CCA, with a notable correlation between GPR120 and NGF in the context of PNI occurrence.

G Protein-coupled Estrogen Receptor 1 (GPER1) Regulates Expression of SERPINE1/PAI-1 and Inhibits Tumorigenic Potential of Cervical Squamous Cell Carcinoma Cells In Vitro.

G protein-coupled estrogen receptor 1 (GPER1) appears to play a tumor-suppressive role in cervical squamous cell carcinoma (CSCC)GPER1 suppression leads to significantly increased expression of serpin family E member 1 (SERPINE1)/protein plasminogen activator inhibitor type 1 (PAI-1). The question arises, what role does SERPINE1/PAI-1 play in GPER1-dependent tumorigenic potential of CSCC. SiHa and C33A CSCC cells were treated with GPER1 agonist G1 or antagonist G36. SERPINE1/PAI-1 expression was suppressed by RNAi and success was confirmed by RT-qPCR. Protein expression of PAI-1 was quantified by Western blot. Viability was analyzed using resazurin assay, while migration was investigated using gap closure. Colony and tumor sphere formation were used to test clonogenicity. After G1 treatment, viability of SiHa and C33A cells remained unchanged. Cell migration was dose-dependently reduced. SiHa and C33A cells formed significantly fewer and smaller colonies as well as spheroids. Furthermore, treatment with G1 led to decreased expression of SERPINE1/PAI-1, while blockade of GPER1 with G36 resulted in significantly increased SERPINE1/PAI-1 expression. After suppression of SERPINE1/PAI-1 in SiHa cells using RNAi, cell viability remained unaffected; however, significantly smaller colonies were formed, and fewer and smaller spheroids were developed. Cell migration remained unaffected. Activation of GPER1 reduces clonogenicity and migration of CSCC cells and suppresses expression of SERPINE1/PAI-1. Suppression of SERPINE1/PAI-1 in CSCC cells reduces tumorigenic potential. GPER1 may be a suitable target for suppression of SERPINE1/PAI-1 in CSCC. However, SERPINE1/PAI-1 does not appear to be the decisive factor for GPER1-regulated cell migration.

Interaction of GPER-1 with the endocrine signaling axis in breast cancer

G Protein-Coupled Estrogen Receptor 1 (GPER-1) is a membrane estrogen receptor that has emerged as a key player in breast cancer development and progression. In addition to its direct influence on estrogen signaling, a crucial interaction between GPER-1 and the hypothalamic-pituitary-gonadal (HPG) axis has been evidenced. The novel and complex relationship between GPER-1 and HPG implies a hormonal regulation with important homeostatic effects on general organ development and reproductive tissues, but also on the pathophysiology of cancer, especially breast cancer. Recent research points to a great versatility of GPER-1, interacting with classical estrogen receptors and with signaling pathways related to inflammation. Importantly, through its activation by environmental and synthetic estrogens, GPER-1 is associated with hormone therapy resistance in breast cancer. These findings open new perspectives in the understanding of breast tumor development and raise the possibility of future applications in the design of more personalized and effective therapeutic approaches.

Estrogen deficiency promotes neurodegeneration in female hemi-parkinsonian mice: The role of regulatory T cells.

Circulating levels of the female hormone estrogen has been associated with the development of Parkinson's disease (PD), although the underlying mechanism remains unclear. Immune homeostasis mediated by peripheral regulatory T cells (Treg) is a crucial factor in PD. The aim of this study was to explore the effects of estrogen deficiency on neuroinflammation and neurodegeneration in a rodent model of PD, with particular reference to Treg. Estrogen deficiency was established in a mouse model by bilateral ovariectomy (OVX). PD was modeled by the injection of LPS into the striatum. Motor performance was assessed in each experimental group. Dopaminergic degeneration was evaluated using tyrosine-hydroxylase (Th) immunohistochemical staining of the substantia nigra (SN) and striatum. Dopamine and dopamine metabolite levels in the striatum were also evaluated, together with the infiltration of CD4 T cells into the SN. Neuroinflammation was assessed by evaluating the mRNA level of microglial and M1/M2 phenotype markers, as well as the abundance of pro-inflammatory cytokines in the midbrain. The frequency of peripheral Treg cells was evaluated using flow cytometry. OVX prior to LPS injection markedly aggravated neurodegeneration, neuroinflammation, motor performance, and CD4 T cell infiltration compared to the LPS-only group. Estradiol treatment or activation of the G protein-coupled estrogen receptor (GPER) in OVX mice prior to LPS injection induced functional improvement and reduced the levels of neurodegeneration, neuroinflammation, and CD4 T cell infiltration. OVX prior to LPS injection also led to a decreased frequency of Treg compared to the LPS-only group. Moreover, estradiol treatment or GPER activation of OVX mice prior to LPS injection significantly increased the Treg frequency. Antibody-mediated depletion of Treg after GPER activation counteracted the ability of GPER to alleviate neurodegeneration, CD4 T cell infiltration, the release of pro-inflammatory cytokines, and motor performance in the PD model. Estrogen deficiency can disrupt Treg-mediated immune homeostasis and thus further aggravate microglial inflammation and dopaminergic degeneration in PD model. The effects of estrogen on Treg may be partially mediated by GPER signaling, and thus GPER is a promising target for PD, especially in estrogen-deficient women.

P0164 Lauric Acid in Inflammatory Bowel Disease: Balancing Fibrosis Modulation and epithelial-mesenchymal transition Activation

Abstract Background Metabolomics has recently emerged as a valuable tool for understanding inflammatory bowel disease (IBD), revealing distinct metabolic profiles for ulcerative colitis (UC) and Crohn’s disease (CD). Lauric acid (LA), a medium-chain fatty acid with anti-inflammatory properties, has an unclear role in IBD, particularly within a fibrotic context. LA interacts with G protein-coupled receptor 84 (GPR84), which is notably elevated in UC1. Methods We evaluated the effects of LA (0, 50, 100, and 250 µM) on human intestinal fibroblasts (HSIF) and colonic epithelial cells (CoEpi) under basal and pro-fibrotic (TGFβ1 10 ng/ml) conditions. Fibrotic markers were analyzed using PCR (HSIF: COLA1A, COL3A1, COL4A1, ACTA2, FN1, TGFβ, GPR84; CoEpi: SNAI1/2, CDH1, COLA1A, FNCD4, VIM, GPR84) and Western blot (HSIF: GPR84). Data, expressed as fold induction (mean ± SEM) relative to 0 µM LA, were analyzed using either parametric or non-parametric ANOVA (Kruskal-Wallis) based on normality testing (*P < 0.05 vs. 0 nM LA, **P < 0.01 vs. 0 µM LA, #P < 0.05 vs. 0 µM LA + TGFβ1, ##P < 0.05 vs. 0 µM LA + TGFβ1). Results Under basal conditions, LA significantly reduced mRNA expression of collagen molecules [COL1A1 (250 µM: 0.2 ± 0.07**) and COL3A1 (50 µM: 0.4 ± 0.1**)] and αSMA [ACTA2 (100 µM: 0.1 ± 0.1**)] in HSIF cells. In pro-fibrotic conditions, LA maintained or enhanced its protective effect, often at lower doses [COL1A1 (50 µM: 1.1 ± 0.15##), COL3A1 (50 µM: 0.24 ± 0.1#), COL4A1 (250 µM: 0.6 ± 0.1#), ACTA2 (100 µM: 0.7 ± 0.4#)]. LA also increased GPR84 mRNA and protein expression under basal (250 µM: 1167 ± 646*) and pro-fibrotic (250 µM: 1048 ± 505##) conditions, with no changes in fibronectin or TGF expression in HSIF cells. In CoEpi cells, LA promoted epithelial-mesenchymal transition (EMT) under both conditions, shown by changes in mRNA for VIMENTIN (250 µM: 3.9 ± 0.6*; 250 µM + TGFβ1: 6.4 ± 1.5#), SNAI2 (250 µM: 3.4 ± 0.5*; 250 µM + TGFβ1: 3.9 ± 0.5##), E-CADHERIN (250 µM: 0.5 ± 0.08*; 250 µM + TGFβ1: 0.3 ± 0.07#), and FIBRONECTIN (250 µM: 2.6 ± 0.5*; 250 µM + TGFβ1: 4.4 ± 0.8##). GPR84 mRNA was significantly elevated by LA in basal (250 µM: 6.9 ± 1.5**) and pro-fibrotic (250 µM: 5.1 ± 1.0##) conditions. No changes were observed for COLA1A or SNAI1 expression in CoEpi cells. Conclusion LA exhibits a dual role in colonic epithelial and fibroblast cells, showing context-dependent effects that can offer therapeutic benefits or pose challenges. Its interaction with GPR84 underscores a complex regulatory function that requires further study. References Bauset C, Carda-Diéguez M, Cejudo-Garcés A, Buetas E, Seco-Cervera M, Macias-Ceja DC, Navarro-Vicente F, Esplugues JV, Calatayud S, Mira Á, Ortiz-Masiá D, Barrachina MD, Cosín-Roger J. A disturbed metabolite-GPCR axis is associated with microbial dysbiosis in IBD patients: Potential role of GPR109A in macrophages. Biochim Biophys Acta Mol Basis Dis. 2024 Dec;1870(8):167489. doi: 10.1016/j.bbadis.2024.167489. Epub 2024 Sep 2. PMID: 39233260.

Akkermansia muciniphila and its metabolite propionic acid maintains neuronal mitochondrial division and autophagy homeostasis during Alzheimer’s disease pathologic process via GPR41 and GPR43

BackgroundAlzheimer’s disease (AD) is a prevalent neurodegenerative disease (ND). In recent years, multiple clinical and animal studies have shown that mitochondrial dysfunction may be involved in the pathogenesis of AD. In addition, short-chain fatty acids (SCFA) produced by intestinal microbiota metabolism have been considered to be important factors affecting central nervous system (CNS) homeostasis. Among the main mediators of host-microbe interactions, volatile fatty acids play a crucial role. Nevertheless, the influence and pathways of microorganisms and their metabolites on Alzheimer’s disease (AD) remain uncertain.ResultsIn this study, we present distinctions in blood and fecal SCFA levels and microbiota composition between healthy individuals and those diagnosed with AD. We found that AD patients showed a decrease in the abundance of Akkermansia muciniphila and a decrease in propionic acid both in fecal and in blood. In order to further reveal the effects and the mechanisms of propionic acid on AD prevention, we systematically explored the effects of propionic acid administration on AD model mice and cultured hippocampal neuronal cells. Results showed that oral propionate supplementation ameliorated cognitive impairment in AD mice. Propionate downregulated mitochondrial fission protein (DRP1) via G-protein coupled receptor 41 (GPR41) and enhanced PINK1/PARKIN-mediated mitophagy via G-protein coupled receptor 43 (GPR43) in AD pathophysiology which contribute to maintaining mitochondrial homeostasis both in vivo and in vitro. Administered A. muciniphila to AD mice before disease onset showed improved cognition, mitochondrial division and mitophagy in AD mice.ConclusionsTaken together, our results demonstrate that A. muciniphila and its metabolite propionate protect against AD-like pathological events in AD mouse models by targeting mitochondrial homeostasis, making them promising therapeutic candidates for the prevention and treatment of AD.2Eefw-diaDYPDEcqvaR2iqVideo

Genistein-3'-sodium sulfonate suppresses NLRP3-mediated cell pyroptosis after cerebral ischemia.

Cerebral ischemia-induced pyroptosis contributes to the dissemination of neuroinflammation, and Nod-like receptor protein-3 (NLRP3) inflammasome plays a key role in this process. Previous studies have indicated that Genistein-3'-sodiumsulfonate (GSS) can inhibit neuroinflammation caused by cerebral ischemia, exert cerebroprotective effects, but its specific mechanism has not been comprehensively understood. The aim of this study was to explore the effect of GSS on ischemic stroke-induced cell pyroptosis. SD rats were randomly assigned to Sham group, transient middle cerebral artery occlusion (tMCAO) group, and tMCAO + GSS group. The open field test (OFT) was utilized to assess animals' spontaneous movement and anxiety-like behavior. Immunofluorescence was adopted to observe nod-like receptor pyrin domain containing 3 (NLRP3)/neuronal nuclei (NeuN) double-positive cells in the ischemic penumbra of each group. Western blot (WB) was conducted to detect levels of NLRP3 inflammasomes and pyroptosis-related proteins in the ischemic cortex tissue. Furthermore, the G protein-coupled estrogen receptor 1 (GPER1) inhibitor G15 was administered to monitor tMCAO rats' motor function, emotional state, and NLRP3 inflammasome activation. Compared with the Sham group, rats in the tMCAO group exhibited significant motor dysfunction and anxiety, increased NLRP3+/NeuN+ co-expressing cells in the ischemic penumbra, and elevated levels of NLRP3, apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC), pro-cysteinyl aspartate specific proteinase-1 (pro-caspase-1), cleaved-cysteinyl aspartate specific proteinase-1 (cleaved-caspase-1), gasdermin D (GSDMD), GSDMD-N-terminal domain (GSDMD-N), interleukin (IL)-1β, and IL-18 in the ischemic cortex. Treatment with GSS reversed these trends. Additionally, post G15 treatment, the therapeutic effects of GSS were reversed. GSS may inhibit NLRP3 inflammasome activation via GPER1, reducing membrane perforation and pro-inflammatory cytokine secretion, suppressing cell pyroptosis, and mitigating neuroinflammation, thereby improving chronic motor dysfunction and anxiety in tMCAO rats. Our study uncovers a potential novel mechanism for GSS treatment in ischemic stroke and provides new ideas for the treatment of ischemic stroke.

Synthetic GPR84 Agonists in Colorectal Cancer: Effective in THP-1 Cells but Ineffective in BMDMs and MC38 Mouse Tumor Models.

Tumor-associated macrophages (TAMs) in the colorectal cancer (CRC) microenvironment promote tumor progression but can be reprogrammed into a pro-inflammatory state with anti-cancer properties. Activation of the G protein-coupled receptor 84 (GPR84) is associated with pro-inflammatory macrophage polarization, making it a potential target for CRC therapy. This study evaluates the effects of the GPR84 agonists 6-OAU and ZQ-16 on macrophage activation and anti-cancer efficacy. GPR84 expression on THP-1 macrophages and murine BMDMs was analyzed using flow cytometry. Macrophages were treated with 6-OAU or ZQ-16, and pro-inflammatory cytokine levels, reactive oxygen species (ROS) production, and phagocytosis were assessed using qPCR and functional assays. Anti-cancer effects were tested in a subcutaneous MC38 tumor model, with oral or intraperitoneal agonist administration. Pharmacokinetics and compound stability were also evaluated. In THP-1 macrophages, 6-OAU increased pro-inflammatory cytokines and ROS production, with ZQ-16 showing similar effects. However, neither agonist induced pro-inflammatory responses, ROS production, or phagocytosis in murine macrophages. In vivo, both agonists failed to inhibit tumor growth in the MC38 model despite systemic exposure. Current GPR84 agonists lack efficacy in promoting anti-cancer macrophage activity, limiting their potential as CRC therapies.

Mycobacteria Exploit Host GPR84 to Dampen Pro-Inflammatory Responses and Promote Infection in Macrophages.

Tuberculosis (TB) remains the major cause of mortality and morbidity, causing approximately 1.3 million deaths annually. As a highly successful pathogen, Mycobacterium tuberculosis (Mtb) has evolved numerous strategies to evade host immune responses, making it essential to understand the interactions between Mtb and host cells. G-protein-coupled receptor 84 (GPR84), a member of the G-protein-coupled receptor family, contributes to the regulation of pro-inflammatory reactions and the migration of innate immune cells, such as macrophages. Its role in mycobacterial infection, however, has not yet been explored. We found that GPR84 is induced in whole blood samples from tuberculosis patients and Mycobacterium marinum (Mm)-infected macrophage models. Using a Mm-wasabi infection model in mouse tails, we found that GPR84 is an important determinant of the extent of tissue damage. Furthermore, from our studies in an in vitro macrophage Mm infection model, it appears that GPR84 inhibits pro-inflammatory cytokines expression and increases intracellular lipid droplet (LD) accumulation, thereby promoting intracellular bacterial survival. Our findings suggest that GPR84 could be a potential therapeutic target for host-directed anti-TB therapeutics.

Impact of sex hormones on pheochromocytomas, paragangliomas, and gastroenteropancreatic neuroendocrine tumors

Abstract Objective The effects of sex hormones remain largely unexplored in pheochromocytomas and paragangliomas (PPGLs) and gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Methods We evaluated the effects of estradiol, progesterone, Dehydroepiandrosterone sulfate (DHEAS), and testosterone on human patient-derived PPGL/GEP-NET primary culture cell viability (n = 38/n = 12), performed next-generation sequencing and immunohistochemical hormone receptor analysis in patient-derived PPGL tumor tissues (n = 36). Results In PPGLs, estradiol and progesterone (1 µm) demonstrated overall significant antitumor effects with the strongest efficacy in PPGLs with NF1 (cluster 2) pathogenic variants. Estrogen receptor alpha (ERα) positivity was detected in 11/36 PPGLs, including 4/4 head-and-neck paragangliomas (HNPGLs). ERα–positive tumors responded with a significant cell viability decrease to estradiol. DHEAS and testosterone (1 µm) displayed no effects, but higher doses of testosterone (10 µm) demonstrated significant antitumor effects, including a pheochromocytoma lung metastasis with strong androgen receptor positivity (30%). Driven by the antitumor effects of estrogen, we evaluated G-protein-coupled estrogen receptor (GPER) agonist G-1 as a potential therapeutic option for PPGLs and found strong significant antitumor potential, with the strongest efficacy in tumors with NF1 pathogenic variants. Moreover, we detected sex-related differences—tumors from male patients showed significantly stronger responsivity to G-1 compared with tumors from female patients. In GEP-NETs, sex hormones showed overall no effects, especially no tumor growth-promoting effects. Conclusion We provide novel data on the effects of elevated sex hormone levels, potentially seen during pregnancy or hormone replacement therapy, on PPGL/GEP-NET tumor growth. G-1 might offer a novel therapeutic approach for some PPGLs depending on patient’s sex and the individual tumor’s genetic/molecular background. All HNPGLs showed ERα positivity.

A comprehensive review of GPR84: A novel player in pathophysiology and treatment.

G protein-coupled receptor 84 (GPR84), a member of the highly conserved rhodopsin-like superfamily, represents a promising target for therapeutic drug development. Its distinctive expression profiles in adipocytes, gut endocrine cells, and various myeloid immune cells underscore its critical roles in fundamental physiological processes, particularly in metabolic regulation and immune responses. Over the past two decades, emerging research has demonstrated that GPR84 regulates immune cell chemotaxis, phagocytosis, and inflammatory responses, playing a pivotal role in metabolic disorders, inflammatory diseases, and organ fibrosis. However, the precise molecular mechanisms by which GPR84 is involved in these diseases remain largely uncharacterized, highlighting a significant gap in our understanding. Medium-chain fatty acids (MCFAs) are considered potential endogenous ligands for GPR84. Furthermore, the development of synthetic agonists and antagonists have provided valuable pharmacological tools for analyzing the ligand-GPR84 complex structure and investigating the extensive biological functions of GPR84. Ongoing preclinical and clinical studies highlight the potential of targeting GPR84 in molecular therapies, although concerns regarding drug safety and specificity require further investigation.

Epigenetic Modulation of Estrogen Receptor Signaling in Ovarian Cancer.

Ovarian cancer remains one of the leading causes of cancer-related deaths in women. There are several processes that are described to have a causal relationship in ovarian cancer development, progression, and metastasis formation, that occur both at the genetic and epigenetic level. One of the mechanisms involved in its pathogenesis and progression is estrogen signaling. Estrogen receptors (ER) α, ERβ, and G-protein coupled estrogen receptor 1 (GPER1), in concert with various coregulators and pioneer transcription factors, mediate the effects of estrogens primarily by the transcriptional regulation of estrogen responsive genes, thereby exerting pleiotropic effects including the regulation of cellular proliferation and apoptosis. The expression and activity of estrogen receptors and their coregulators have been demonstrated to be regulated by epigenetic mechanisms like histone modifications and DNA methylation. Here, we intend to summarize and to provide an update on the current understanding of epigenetic mechanisms regulating estrogen signaling and their role in ovarian cancer. For this purpose, we reviewed publications on this topic listed in the PubMed database. Finally, we assess to which extent drugs acting on the epigenetic level might be suitable for the treatment of ovarian cancer.

Sex-specific cardiovascular adaptations to simulated microgravity in Sprague-Dawley rats

Men and women have different cardiovascular responses to spaceflight; however, few studies have focused on direct comparisons between sexes. We investigated the mechanisms of aortic stiffening in socially and sexually mature 20-week-old male and female Sprague Dawley (SD) rats exposed to hindlimb unloading (HLU) for 14 days. Pulse wave velocity (PWV) was greater in the aortic arch of females after HLU versus control females (n = 6–8). HLU had no effect on aortic PWV in males (n = 5–6). Aortic α smooth muscle actin, myosin, collagen, elastin, and collagen-to-elastin ratio were not different in rats of either sex following HLU. The levels of G protein-coupled estrogen receptor (GPER) were lower in the aorta of SD females exposed to HLU compared with female controls but were not altered in males. HLU females also had lower aortic PPARγ, increased oxidative stress markers, and diastolic dysfunction compared with control females. GPER agonist G1 prevented the increase in PWV and 8-hydroxy-2’-deoxyguanosine without altering PPARγ or p47phox in HLU females (n = 4 in each group) suggesting that lower GPER may contribute to arterial stiffening in the setting of simulated microgravity. This study highlights sex-specific vascular adaptations to the state of simulated microgravity.

Roseburia intestinalis-derived butyrate alleviates neuropathic pain.

Approximately 20% of patients with shingles develop postherpetic neuralgia (PHN). We investigated the role of gut microbiota in shingle- and PHN-related pain. Patients with shingles or PHN exhibited significant alterations in their gut microbiota with microbial markers predicting PHN development among patients with shingles. Functionally, fecal microbiota transplantation from patients with PHN to mice heightened pain sensitivity. Administration of Roseburia intestinalis, a bacterium both depleted in patients with shingles and PHN, alleviated peripheral nerve injury-induced pain in mice. R.intestinalis enhanced vagal neurotransmission to the nucleus tractus solitarius (NTS) to suppress the central amygdala (CeA), a brain region involved in pain perception. R.intestinalis-generated butyrate activated vagal neurons through the receptor, G protein-coupled receptor 41 (GPR41). Vagal knockout of Gpr41 abolished the effects of R.intestinalis on the NTS-CeA circuit and reduced pain behaviors. Overall, we established a microbiota-based model for PHN risk assessment and identified R.intestinalis as a potential pain-alleviating probiotic.

G-protein-coupled receptor 41 in cardiomyocytes: Effect of butyrate on intracellular Ca2+ and sarcomere shortening.

G-protein-coupled receptor 41 (GPR41) is a Gαi-coupled receptor activated by short-chain fatty acids (SCFAs). Here, we tested that GPR41 is also expressed in cardiomyocytes and exerts a direct negative inotropic effect when activated by SCFA butyrate. Primary cardiomyocytes were isolated from wild-type (WT) and GPR41 knockout (GPR41-/-) adult mice and intracellular Ca2+ concentration and cell shortening were measured using the IonOptix system. RNA localization (RNAScope), quantitative real-time polymerase chain reaction (qRT-PCR), immunofluorescence staining, and western blot were used to examine the expression of GPR41 in adult primary cardiomyocytes of WT and GPR41-/- mice. The effect of butyrate on shortening and intracellular Ca2+ transient via GPR41 was also tested in cardiomyocytes. We demonstrated for the first time the presence of GPR41s on cardiomyocytes. Butyrate dose-dependently decreased cell shortening and the amplitude of intracellular Ca2+ transients in cardiomyocytes from WT but not GPR41-/- mice. In WT cardiomyocytes, butyrate decreased caffeine-mediated amplitudes of intracellular Ca2+ transients from the sarcoplasmic reticulum (SR). Moreover, the inhibitory effects of butyrate on cell shortening and intracellular Ca2+ were pertussis toxin (PTX)-sensitive. Finally, butyrate decreased the activity of sarcoendoplasmic reticulum Ca2+-ATPase (SERCA) and cellular 3'-5'-cyclic adenosine monophosphate (cAMP) content. In conclusion, GPR41 is expressed on cardiomyocytes. Butyrate, a known GPR41 agonist, reduces cardiomyocyte shortening and intracellular Ca2+ transient via decreasing Ca2+ content in the SR by inhibiting SERCA activity in a PTX-dependent manner. These findings establish that GPR41 is directly activated by SCFAs to decrease contraction and intracellular Ca2+ transient, highlighting the potential inhibitory role of GPR41 in cardiomyocytes.

The GPER is an important factor through which somatic cells regulate oocyte maternal mRNA translation and developmental competence.

The G protein-coupled estrogen receptor (GPER) plays a crucial role in various biological processes, but its regulation of oocyte meiosis remains unclear. In this study, we generated a Gper1 knockout in growing oocytes using Zp3-Cre, revealing that GPER is essential for oocyte maturation and embryo development. RNA-seq analysis indicated that GPER deficiency significantly altered the oocyte transcriptome and disrupted mRNA translation. Immunoprecipitation mass spectrometry revealed that GPER directly interacts with HSP90 and modulates the ERK1/2 and PI3K-AKT signaling pathways, which are vital for enhancing maternal mRNA translation and developmental potential. We also found that cumulus cell-derived GPER-positive vesicles and delivered to oocytes through a RAB11A-dependent pathway. RAB11A facilitates GPER recycling, preventing its degradation in late endosomes and promoting its plasma membrane localization. Moreover, epidermal growth factor (EGF) improves GPER expression in cumulus cells by upregulating RAB11A, thereby enhancing the exocytosis of recycling vesicles. Knockdown of Rab11a severely reduced GPER-positive vesicles in oocytes, impairing spindle morphogenesis and meiosis. Our findings highlight the critical role of somatic cell signals in regulating maternal mRNA translation and oocyte quality for embryonic development.

Microenvironmental G protein-coupled estrogen receptor-mediated glutamine metabolic coupling between cancer-associated fibroblasts and triple-negative breast cancer cells governs tumour progression.

Triple-negative breast cancer (TNBC) is a particularly aggressive type of breast cancer, known for its lack of effective treatments and unfavorable prognosis. The G protein-coupled estrogen receptor (GPER), a novel estrogen receptor, is linked to increased malignancy in various cancers. However, its involvement in the metabolic regulation of cancer-associated fibroblasts (CAFs), a key component in the tumour microenvironment, remains largely unexplored. This study investigates how GPER influences the metabolic interaction between CAFs and TNBC cells, aiming to identify potential therapeutic targets. The co-culture system is performed to examine the interaction between CAFs and TNBC cells, with a focus on GPER-mediated glutamine production and release by CAFs and its subsequent uptake and utilization by TNBC cells. The definite roles of microenvironmental GPER/cAMP/PKA/CREB signalling in regulating the expression of glutamine synthetase (GLUL) and lactate dehydrogenase B (LDHB) are further investigated. Our findings reveal that estrogen-activated GPER in CAFs significantly upregulates the expression of GLUL and LDHB, leading to increased glutamine production. This glutamine is then secreted into the extracellular matrix and absorbed by TNBC cells, enhancing their viability, motility, and chemoresistance both in vitro and in vivo. TNBC cells further metabolize the glutamine through the glutamine transporter (ASCT2) and glutaminase (GLS1) axes, which, in turn, promote mitochondrial activity and tumour progression. The study identifies GPER as a critical mediator of metabolic coupling between CAFs and TNBC cells, primarily through glutamine metabolism. Targeting the estrogen/GPER/glutamine signalling axis in CAFs offers a promising therapeutic strategy to inhibit TNBC progression and improve patient outcomes. This novel insight into the tumour microenvironment highlights the potential of metabolic interventions in treating TNBC. Estrogen-activated GPER in CAFs enhances GLUL and LDHB expression via the cAMP/PKA/CREB signalling, facilitating glutamine production and utilization. Microenvironmental GPER-induced glutamine serves as a crucial mediator of metabolic coupling between CAFs and TNBC cells, boosting tumour progression by enhancing mitochondrial function. Targeting the glutamine metabolic coupling triggered by estrogen/GPER/GLUL signalling in CAFs is a promising therapeutic strategy for TNBC treatment.

Eicosapentaenoic acid enhances intestinal stem cell-mediated colonic epithelial regeneration by activating the LSD1-WNT signaling pathway.

Inflammatory bowel disease (IBD) is often associated with impaired proliferation and differentiation of intestinal stem cells (ISCs). Eicosapentaenoic acid (EPA), which is predominantly found in fish oil, has been recognized for its intestinal health benefits, although the potential mechanisms are not well understood. This study aimed to investigate the regulatory role and mechanism of EPA in colonic epithelial regeneration, specifically from the perspective of ISCs. Wild-type mice whose diet was supplemented with 5% EPA-enriched fish oil were subjected to dextran sulfate sodium (DSS) to induce colitis. We utilized intestinal organoids, ISC-specific lysine-specific demethylase 1 (LSD1) knockout mice, and WNT inhibitor-treated mice to explore how EPA influences ISC proliferation and differentiation. ISC proliferation, differentiation and apoptosis were assessed using tdTomato and propidium iodide tracer testing, histological analyses, and immunofluorescence staining. EPA treatment significantly mitigated the symptoms of DSS-induced acute colitis, as evidenced by lower body weight loss and decreased disease activity index, histological scores and proinflammatory cytokine levels. Additionally, EPA increased the numbers of proliferative cells, absorptive cells, goblet cells, and enteroendocrine cells, which enhanced the regeneration of intestinal epithelium. Pretreatment with EPA increased ISC proliferation and differentiation, and protected against TNF-α-induced cell death in intestinal organoids. Mechanistically, EPA upregulated G protein-coupled receptor 120 (GPR120) to induce LSD1 expression, which facilitated ISC proliferation and differentiation in organoids. ISC-specific ablation of LSD1 negated the protective effect of EPA on DSS-induced colitis in mice. Moreover, EPA administration activated the WNT signaling pathway downstream of LSD1 in ISCs, while inhibiting WNT signaling abolished the beneficial effects of EPA. These findings demonstrate that EPA promotes ISC proliferation and differentiation, thereby enhancing colonic epithelial regeneration through the activation of LSD1-WNT signaling. Consequently, dietary supplementation with EPA represents a promising alternative therapeutic strategy for managing IBD.

Downregulated Regucalcin Expression Induces a Cancer-like Phenotype in Non-Neoplastic Prostate Cells and Augments the Aggressiveness of Prostate Cancer Cells: Interplay with the G Protein-Coupled Oestrogen Receptor?

Regucalcin (RGN) is a calcium-binding protein and an oestrogen target gene, which has been shown to play essential roles beyond calcium homeostasis. Decreased RGN expression was identified in several cancers, including prostate cancer (PCa). However, it is unknown if the loss of RGN is a cause or a consequence of malignancy. Also, it needs confirmation if RGN oestrogenic regulation occurs through the G-protein-coupled oestrogen receptor (GPER). This study investigates how RGN knockdown affects prostate cell fate and metabolism and highlights the GPER/RGN interplay in PCa. Bioinformatic analysis assessed the relationship between RGN expression levels and patients' outcomes. RGN knockdown (siRNA) was performed in non-neoplastic prostate and castration-resistant PCa. Wild-type and RGN knockdown PCa cells were treated with the GPER agonist G1. Viability (MTT), proliferation (Ki-67 immunocytochemistry), apoptosis (caspase-3-like activity) and migration (Transwell assays) were evaluated. Spectrophotometric analysis was used to determine glucose consumption, lactate production and lactate dehydrogenase activity. Lipid content was assessed using the Oil Red assay. Bioinformatic analysis showed that the loss of RGN correlates with the development of metastatic PCa and poor survival outcomes. RGN knockdown induced a cancer-like phenotype in PNT1A cells, indicated by increased cell viability and proliferation and reduced apoptosis. In DU145 PCa cells, RGN knockdown augmented migration and enhanced the glycolytic profile, which indicates increased aggressiveness, in line with patients' data. GPER activation modulated RGN expression in PCa cells and RGN knockdown in DU145 cells influenced GPER actions, which highlighted an interplay between these molecular players with relevance for their potential use as biomarkers or therapeutic targets.

Attenuation of Hypertension and protection of vascular inflammation in hyperaldosteronism: GPER1 as potential therapeutic candidate when MR antagonist is less satisfying?

Hyperaldosteronism is an endocrine disorder leading to persistent and severe hypertension. G protein-coupled estrogen receptor 1(GPER1) is regarded as a potential receptor of aldosterone (ALDO). This study aimed to investigate the effects of GPER1 on aldosterone (ALDO)-induced hypertension and inflammation in mice. GPER1-knockout (KO) and wild-type (WT) C57BL/6j mice were divided into control (CON, normal saline treatment), ALDO (subcutaneous injections of 600 g/kg/d ALDO), and ALDO + eplerenone (EPL) (subcutaneous injections of 600 g/kg/d ALDO and 100 mg/kg/d EPL) groups (n = 5 per group). Fourteen days after drug administration, the heart rate and tail blood pressure of the mice in the different groups were measured. S100A8 and IL-1β protein expression in arterial tissues were detected by western blotting, NLRP3 expression was assessed using immunofluorescence, and CD68 expression was investigated using immunohistochemistry. GPER1 deficiency alleviated ALDO-induced diastolic blood pressure (P< 0.05). In addition, the protein expression levels of IL-1β, S100A8, and CD68 showed significant decreases in the arterial tissues of GPER1-KO mice after combination treatment with ALDO and EPL (all P < 0.05). We discovered attenuation of hypertension and vascular inflammation of GPER1 KO mice only on the basis of mineralocorticoid receptor (MR) blocking. Collectively, our study indicates that GPER1 might become a therapeutic target of hyperaldosteronism in controlling the residual risk of cardiovascular disease when MR antagonist alone is not satisfying.