GPR116 promotes ferroptosis in sepsis-induced liver injury by suppressing system Xc-/GSH/GPX4.

The disease sepsis is caused by an infection that damages organs. Liver injury, with ferroptosis playing a key role, is an early sign of sepsis. G protein-coupled receptor 116 (GPR116) is essential in the maintenance of functional homeostasis in various systems of the body and has been proven to play a protective role in septic lung injury. However, it's role in septic liver injury remains unclear. In this study, we found that hepatic ferroptosis during sepsis was accompanied by GPR116 upregulation. Hepatocyte-specific GPR116 gene deletion can prevent hepatic ferroptosis, thereby alleviating sepsis-induced liver dysfunction and improving mouse survival, which was verified in vivo. Mechanistically, GPR116 aggravated mitochondrial damage and lipid peroxidation in hepatocytes by inhibiting system Xc-/GSH/GPX4 in overexpression experiments. In conclusion, we have identified GPR116 as a vital mediator of ferroptosis in sepsis-induced liver injury. It is thus an attractive therapeutic target in sepsis.

Adhesion-GPCR Gpr116 (ADGRF5) expression inhibits renal acid secretion.

The diversity and near universal expression of G protein-coupled receptors (GPCR) reflects their involvement in most physiological processes. The GPCR superfamily is the largest in the human genome, and GPCRs are common pharmaceutical targets. Therefore, uncovering the function of understudied GPCRs provides a wealth of untapped therapeutic potential. We previously identified an adhesion-class GPCR, Gpr116, as one of the most abundant GPCRs in the kidney. Here, we show that Gpr116 is highly expressed in specialized acid-secreting A-intercalated cells (A-ICs) in the kidney using both imaging and functional studies, and we demonstrate in situ receptor activation using a synthetic agonist peptide unique to Gpr116. Kidney-specific knockout (KO) of Gpr116 caused a significant reduction in urine pH (i.e., acidification) accompanied by an increase in blood pH and a decrease in pCO2 compared to WT littermates. Additionally, immunogold electron microscopy shows a greater accumulation of V-ATPase proton pumps at the apical surface of A-ICs in KO mice compared to controls. Furthermore, pretreatment of split-open collecting ducts with the synthetic agonist peptide significantly inhibits proton flux in ICs. These data suggest a tonic inhibitory role for Gpr116 in the regulation of V-ATPase trafficking and urinary acidification. Thus, the absence of Gpr116 results in a primary excretion of acid in KO mouse urine, leading to mild metabolic alkalosis ("renal tubular alkalosis"). In conclusion, we have uncovered a significant role for Gpr116 in kidney physiology, which may further inform studies in other organ systems that express this GPCR, such as the lung, testes, and small intestine.

In silico molecular docking and physicochemical property studies on effective phytochemicals targeting GPR116 for breast cancer treatment.

G protein-coupled receptor 116 (GPR116), an orphan adhesion receptor, found an important role in cell adhesion and migration in eukaryotes. Abnormal expression of GPCR identified in various cancers turns focus of research community towards GPCR to identify the targeting drug against GPCR. Though GPR116 role was studied in progression of metastasis in triple-negative breast cancer (TNBC), unfortunately, still no drugs targeting GPR116 were identified. TNBC is a hormone-negative aggressive breast cancer found even in young women. Since TNBC has no target receptor for therapy, it would be desirable to target GPR116. Currently, chemotherapy is the only promising option for TNBC; however, these drugs cause chemoresistance. Hence this current study concentrated on finding drugable natural phytochemical ligands targeting GPR116 using in silico approach. Best docked ligand with target and active binding site amino acids were identified in molecular docking study. Pharmacokinetic properties (ADME) were assessed by Qikprop. Result showed that pharmacokinetics properties of natural phytochemicals were as good as existing chemotherapeutic cancer drugs. This study indicates that phytochemicals could be a promising target for GPR116. This in silico analysis facilitates further research to design the drug targeting GPR116 for treatment of TNBC.

Loss of the adhesion G-protein coupled receptor ADGRF5 in mice induces airway inflammation and the expression of CCL2 in lung endothelial cells.

BACKGROUND: Adhesion G-protein coupled receptor F5 (ADGRF5) was recently identified as an essential regulator of pulmonary surfactant homeostasis in alveolar type II cells. We previously showed that in addition to abnormal surfactant accumulation, Adgrf5-deficient (Adgrf5-/-) mice exhibit emphysema-like signs, suggesting a possible role for ADGRF5 in immune regulation. Here, we extended the phenotypic analysis of Adgrf5-/- mice to help understand its biological role in the lung, and especially in immune regulation. METHODS: Histological features of lungs were evaluated by Alcian blue and Masson's trichrome staining. Quantitative real-time PCR (qPCR) and western blot analyses were performed to analyze the differential expression of genes/proteins related to airway inflammation in lungs between wildtype and Adgrf5-/- mice. Acid-base status was assessed by performing blood gas tests and urine pH measurements. Inflammatory cell counting was performed using Giemsa-stained bronchoalveolar lavage cells. Serum IgE concentrations were determined by enzyme-linked immunosorbent assay. The expression of Ccl2, S100a8, S100a9, and Saa3 in primary lung endothelial cells (ECs) was determined by qPCR and/or western blotting. Finally, the effect of administrating RS504393 to 2-week-old Adgrf5-/- mice on gene expression in the lungs was analyzed by qPCR. RESULTS: Adgrf5-/- mice exhibited several features of chronic airway inflammation (mucous cell metaplasia, mucus hyperproduction, subepithelial fibrosis, respiratory acidosis, high serum IgE, mast cell accumulation, and neutrophilia) in parallel with elevated expression of genes involved in mucous cell metaplasia (Muc5ac, Muc5b, Slc26a4, and Clca1), fibrosis (Tgfb1, Col1a1, Fn1, and Tnc), and type 2 immune response (Il4, Il5, Il13, IL-25, and IL-33) at 12 and/or 30 weeks of age. In contrast, mRNA expression of Ccl2, S100a8, and S100a9 was upregulated in embryonic or neonatal Adgrf5-/- lungs as well as in lung ECs of Adgrf5-/- mice at 1 week of age. RS504393 treatment suppressed the upregulation of S100a8, S100a9, Slc26a4, and Il5 in Adgrf5-/- lungs. CONCLUSIONS: Targeted disruption of ADGRF5 results in the development of airway inflammation, which is likely mediated by the type 2 immune response and possibly CCL2-mediated inflammation. ADGRF5 also has a potential role in the regulation of genes encoding CCL2 in lung ECs, thereby maintaining immune homeostasis.

GPR116 receptor regulates the antitumor function of NK cells via Gαq/HIF1α/NF-κB signaling pathway as a potential immune checkpoint.

BACKGROUND: NK cell is one of innate immune cells and can protect the body from cancer-initiating cells. It has been reported that GPR116 receptor is involved in inflammation and tumors. However, the effect of GPR116 receptor on the NK cells remains largely unclear. RESULTS: We discovered that GPR116-/- mice could efficiently eliminate pancreatic cancer through enhancing the proportion and function of NK cells in tumor. Moreover, the expression of GPR116 receptor was decreased upon the activation of the NK cells. Besides, GPR116-/- NK cells showed higher cytotoxicity and antitumor activity in vitro and in vivo by producing more GzmB and IFNγ than wild-type (WT) NK cells. Mechanistically, GPR116 receptor regulated the function of NK cells via Gαq/HIF1α/NF-κB signaling pathway. Furthermore, downregulation of GPR116 receptor promoted the antitumor activity of NKG2D-CAR-NK92 cells against pancreatic cancer both in vitro and in vivo. CONCLUSIONS: Our data indicated that GPR116 receptor had a negatively effect on NK cell function and downregulation of GPR116 receptor in NKG2D-CAR-NK92 cells could enhance the antitumor activity, which provides a new idea to enhance the antitumor efficiency of CAR NK cell therapy.

The clinical relevance of the adhesion G protein-coupled receptor F5 for human diseases and cancers.

Among the numerous adhesion G protein-coupled receptors (GPCRs), adhesion G protein-coupled estrogen receptor F5 (ADGRF5) contains unique domains in the long N-terminal tail which can determine cell-cell and cell-matrix interaction as well as cell adhesion. Nevertheless, the biology of ADGRF5 is complex and still poorly explored. Accumulating evidence suggests that the ADGRF5 activity is fundamental in health and disease. For instance, ADGRF5 is essential in the proper function of lungs and kidney as well as the endocrine system, and its signification in vascularization and tumorigenesis has been demonstrated. The most recent studies have provided findings about the diagnostic potential of ADGRF5 in osteoporosis and cancers, and ongoing studies suggest other diseases as well. Here, we elaborate on the current state of knowledge about the ADGRF5 in the physiology and pathophysiology of human diseases and highlight its high potential as a novel target in various therapeutic areas.

The adhesion G-protein-coupled receptor Gpr116 is essential to maintain the skeletal muscle stem cell pool.

Skeletal muscle is populated with a reservoir of quiescent muscle stem cells (MuSCs), which regenerate the tissue after injury. Here, we show that the adhesion G-protein-coupled receptor Gpr116 is essential for long-term maintenance of the MuSC pool. Quiescent MuSCs express high levels of Gpr116, which is rapidly downregulated upon MuSC activation. MuSCs deficient for Gpr116 exhibit progressive depletion over time and are defective in self-renewal. Adhesion G-protein-coupled receptors contain an agonistic peptide sequence, called the "Stachel" sequence, within their long N-terminal ectodomains. Stimulation of MuSCs with the GPR116 Stachel peptide delays MuSC activation and differentiation. Stachel peptide stimulation of GPR116 leads to strong interaction with ß-arrestins. Stimulation of GPR116 increases the nuclear localization of ß-arrestin1, where it interacts with cAMP response element binding protein to regulate gene expression. Altogether, we propose a model by which GPR116 maintains the MuSC pool via nuclear functions of ß-arrestin1.

The Expression Pattern of Adhesion G Protein-Coupled Receptor F5 Is Related to Cell Adhesion and Metastatic Pathways in Colorectal Cancer-Comprehensive Study Based on In Silico Analysis.

Adhesion G protein-coupled receptor F5 (ADGRF5) is involved inthe neoplastic transformation of some cancer types. However, the significance of ADGRF5 expression signature and the impact of signaling pathways mediated by ADGRF5 during neoplastic transformation of the colon and colorectal cancer (CRC) progression has been poorly examined. Using Gene Expression Omnibus and The Cancer Genome Atlas datasets, we showed that ADGRF5 is overexpressed in the colons of patients with CRC. In line, combined analysis of ADGRF5 expression with clinical characterization revealed an increased expression of ADGRF5 in patients with more advanced stages of CRC compared to patients with early stages of CRC. The Spearman correlation analysis documented numerous genes positively and negatively correlated with the expression pattern of ADGRF5 in the colon of patients with CRC. In the colon of CRC patients, the expression signature of ADGRF5 was associated with genes participating in phosphatidylinositol 3-kinase/Akt, focal adhesion, cell adhesion molecules, and ribosome signaling pathways. Of note, ADGRF5 expression correlated with the levels of tumor-infiltrating immune cells in the colon of CRC patients. Moreover, we found that CRC patients with high expression of ADGRF5 had a significantly lower probability of overall survival and disease-free survival. In conclusion, our results support the prognostic value of ADGRF5 and its potent therapeutic implication in CRC.

In silico structure prediction, molecular docking and dynamic simulation studies on G Protein-Coupled Receptor 116: a novel insight into breast cancer therapy.

G Protein-Coupled Receptor gains more importance in cancer research; because of their key role in several physiologic functions of cells. However, most of the GPCR's are orphan receptors, this hampers the finding of drugs against GPCR. G Protein-Coupled Receptor 116 is an adhesion orphan receptor that intensifies the invasion of cells in Triple-Negative Breast Cancer. In this study, existing FDA approved anticancer drugs were chosen as ligands and molecular docking was performed using in silico protein model of GPR116. Molecular interaction was analyzed carefully to identify the crucial amino acids present in binding pocket. Molecular dynamics simulations study executed to verify the structural and dynamic properties of Doxorubicin-GPR116 protein complex. The results have shown that Doxorubicin, Neratinib maleate, Epirubicin, and Lapatinib Ditosylate have good interaction with GPR116 binding site. Tyrosine 195 (Y195), Cysteine 196 (C196), Argenine 197 (R197), and Tryptophan 100 (W100) are commonly found in the majority of ligand-target interaction, hence based on the computational studies selective amino acids might be crucial for functional properties. Further to confirm crucial amino acids, computational mutation studies were executed. Molecular docking analysis with mutated GPR116 disclosed that significant variation in G score compared withligand-native protein interaction. Hence, the theoretical confirmatory structural properties changes support to prove selective crucial amino acids play the significant role in ligand binding. Molecular dynamic simulation results reveal that the interaction was stable throughout the MD simulation. To the best of our prognosis, GPR116 could be the best molecular target for breast cancer drug discovery.Communicated by Ramaswamy H. Sarma.

High expression of GPR116 indicates poor survival outcome and promotes tumor progression in colorectal carcinoma.

Previous studies have found that G-protein-coupled receptor 116 (GPR116) is a regulator of breast cancer metastasis. However, the role of GPR116 in colorectal carcinoma (CRC) carcinogenesis and progression is unknown. In this study, We found GPR116 expression was significantly up-regulated in CRC specimens compared with corresponding non-cancerous tissues. Increased GPR116 expression in CRC was correlated with histological differentiation and distant metastasis. In addition, high expression of GPR116 was significantly associated with poor overall survival of CRC patients, which was also confirmed by GSE14333, GSE17536 and GSE33113 datasets from the Gene Expression Omnibus (GEO). Furthermore, we demonstrated that the ability of proliferation and invasion of CRC cell lines HCT116 and LOVO was markedly reduced after transfected with siRNA-GPR116. Meanwhile, GPR116 may drive EMT in CRC cells through AKT/EKR signaling pathway, resulting in metastasis. Thus, GPR116 may be a novel reliable prognostic indicator and a risk factor in CRC progression.