Interference with GPR4 inactivates NLRP3 inflammasome signaling by inhibiting LPAR1 expression to ameliorate oxygen-glucose deprivation/reoxygenation-induced inflammation and apoptosis of cardiomyocytes

• Published in: Prostaglandins & other lipid mediators 2024-10, Vol.174, p.106863, Article 106863
• Main Authors: He, Hanlong, Su, Huiren, Chen, Xinjian, Chen, Xiaohong, Yang, Shaoze
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis; Cell Line; Glucose - deficiency; Glucose - metabolism; GPR4; Inflammasomes - metabolism; Inflammation; Inflammation - metabolism; Inflammation - pathology; Ischemic heart disease; Myocardial Reperfusion Injury - genetics; Myocardial Reperfusion Injury - metabolism; Myocardial Reperfusion Injury - pathology; Myocytes, Cardiac - metabolism; Myocytes, Cardiac - pathology; NLR Family, Pyrin Domain-Containing 3 Protein - genetics; NLR Family, Pyrin Domain-Containing 3 Protein - metabolism; NLRP3 inflammasome signaling; Oxygen - metabolism; Rats; Receptors, G-Protein-Coupled - genetics; Receptors, G-Protein-Coupled - metabolism; Receptors, Lysophosphatidic Acid - genetics; Receptors, Lysophosphatidic Acid - metabolism; Signal Transduction
• ISSN: 1098-8823
• DOI: 10.1016/j.prostaglandins.2024.106863

Myocardial ischemia/reperfusion (MI/R) injury is a detrimental disease with high mortality worldwide. We aimed to explore the role of G protein-coupled receptor 4 (GPR4) and lysophosphatidic acid receptor 1 (LPAR1) in MI/R injury in vitro. H9c2 cells were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) conditions to simulate the MI/R injury and GPR4 expression was detected. Then, GPR4 was knocked down and cell viability was examined with a CCK-8 assay. The activities of LDH, CK and CK-MB were detected to evaluate the damage of OGD/R-induced H9c2 cells. ELISA kits and TUNEL staining were used to examine the inflammation and apoptosis of H9c2 cells exposed to OGD/R conditions. Western blot was employed to detect the expression of proteins related to apoptosis and NLRP3 inflammasome signaling. Additionally, Co-IP analyzed the binding between GPR4 and LPAR1. Finally, LPAR1 was overexpressed to conduct the rescue experiments. Results revealed that GPR4 was upregulated in OGD/R-treated H9c2 cells and GPR4 knockdown attenuated the damage of H9c2 cells. OGD/R induced inflammation and apoptosis were markedly inhibited by GPR4 silencing, as evidenced by the decreased TNF-α, IL-6 and IL-8 levels as well as the elevated Bcl-2 expression and reduced Bax and cleaved caspase3 expression. Moreover, GPR4 bound to LPAR1 and upregulated LPAR1 expression. Interference with GPR4 inactivated the NLRP3 inflammasome signaling. Besides, LPAR1 overexpression abrogated the effects of GPR4 silencing on the damage, inflammation and apoptosis of H9c2 cells induced by OGD/R. Particularly, LPAR1 upregulation promoted the activation of NLRP3 inflammasome signaling in GPR4-silenced H9c2 cells induced by OGD/R. To be concluded, GPR4 deficiency inactivates NLRP3 inflammasome signaling by inhibiting LPAR1 expression to ameliorate OGD/R -induced inflammation and apoptosis of cardiomyocytes. •GPR4 was upregulated in OGD/R-treated H9c2 cells and GPR4 knockdown attenuated the damage of H9c2 cells.•GPR4 knockdown alleviated the inflammation and apoptosis of H9c2 cells exposed to OGD/R conditions.•GPR4 knockdown inactivated NLRP3 inflammasome signaling in OGD/R-treated H9c2 cells.•GPR4 bound to LPAR1 and upregulated LPAR1 expression in H9c2 cells exposed to OGD/R conditions.•LPAR1 overexpression restored the activation of NLRP3 inflammasome signaling in GPR4-silenced H9c2 cells induced by OGD/R.