GPR126 is a member of the adhesion G protein-coupled receptors (aGPCRs) that is essential for the normal development of diverse tissues, and its mutations are implicated in various pathological processes. Here, through screening 34 steroid hormones and their derivatives for cAMP production, we found that progesterone (P4) and 17-hydroxyprogesterone (17OHP) could specifically activate GPR126 and trigger its downstream Gi signaling by binding to the ligand pocket in the seven-transmembrane domain of the C-terminal fragment of GPR126. A detailed mutagenesis screening according to a computational simulated structure model indicated that K1001ECL2 and F1012ECL2 are key residues that specifically recognize 17OHP but not progesterone. Finally, functional analysis revealed that progesterone-triggered GPR126 activation promoted cell growth in vitro and tumorigenesis in vivo, which involved Gi-SRC pathways in a triple-negative breast cancer model. Collectively, our work identified a membrane receptor for progesterone/17OHP and delineated the mechanisms by which GPR126 participated in potential tumor progression in triple-negative breast cancer, which will enrich our understanding of the functions and working mechanisms of both the aGPCR member GPR126 and the steroid hormone progesterone.
Chengcheng Xiao,Peng Wang,Yayun Wang,Jiaxi Zhu,Hai Zhu,Xin Li,Renhe Wang
Ethnopharmacological relevance Acute kidney injury (AKI) is a growing worldwide health concern. Danggui Shaoyao San (DGSYS) was an frequently-used representative prescription to "promote blood and water and harmonize the body" in traditional Chinese medicine, and its underlying mechanism against AKI remains to be elucidated. Aim of the study To investigate the protective effect and potential molecular mechanism of DGSYS in alleviating AKI by network pharmacology and experiment validation. Materials and methods DGSYS was analyzed and separated by UHPLC. Network pharmacology, molecular docking and molecular dynamics simulation were used to screen the active ingredient-target pathway of DGSYS for AKI treatment. Meanwhile, the predictions were experimentally validated both in vivo and in vitro . Results 30 bioactive compounds and 821 non-repetitive targets were screened for DGSYS, and 292 potential DGSYS-AKI intersection targets were identified. According to the protein–protein interaction results and GO and KEGG analyses, we found that apoptosis mediated by SRC pathway exerted a vital role in DGSYS against AKI. In vivo experiments indicated that DGSYS mitigated I/R-induced kidney injury by suppressing SRC signaling pathway. Molecular docking and molecular dynamics simulation revealed that paeoniflorin (PF) have good binding affinity to SRC. Subsequently, in vitro experiments suggested that PF was the key bioactive compound against AKI from DGSYS by inhibiting SRC/ERK1/2 signaling pathway. Conclusion We exhibited the promising anti-AKI mechanism of DGSYS, and our findings also opened up an avenue for future basic experimental validation, indicating a novel research direction.
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