Regulatory effects of G protein-coupled receptor 30 agonist on nucleotide oligomerization domain-like receptor family, pyrin domain containing 3 inflammasomes

Abstract

Objective To determine whether G protein-coupled receptor 30 (GPR30) agonist G-1 can inhibit the activation of nucleotide oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) inflammasomes and the maturation of interleukin-1β (IL-1β). Methods The peritoneal macrophages were extracted from C57BL/6, and then pretreated with 10, 30, 50 μmol/L G-1. After induction with 50 ng/ml lipopolysaccharide (LPS), macrophages were collected. Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to detect the mRNA expression of NLRP3, apoptosis-related microparticle protein (ASC), and IL-1β, and the expression levels of NLRP3, ASC and pro-cysteinyl aspartate-specific protease (Caspase)-1 proteins were detected by Western blotting. The macrophages were pretreated with 1, 5, 15, 30, 50 μmol/L G-1, and cells were induced with 50 ng/ml LPS and 5 mmol/L adenosine triphosphate (ATP). The levels of IL-1β and TNF-α in supernatants were determined by enzyme linked immunosorbent assay (ELISA). Results There was no significant difference in the expression of NLRP3, ASC and IL-1β mRNA in macrophages between LPS group and G-1 plus LPS group. There was no significant difference in the expression of NLRP3, ASC and pro-Caspase-1 proteins between LPS group and G-1 plus LPS group. The ELISA results showed that with the increase of G-1 concentration, the content of IL-1β (3 062.42±12.10, 1 709.29±25.31, 653.27±35.66, 144.23±4.18, 98.40±2.02) decreased gradually in G-1 plus LPS group as compared with the LPS+ ATP group (2 714.73±107.05), and the difference was statistically significant when G-1 concentration ≥5 μmol/L (P 0.05). Conclusion GPR30 agonist G-1 can specifically inhibit the activation of NLRP3 inflammasome and the maturation of IL-1β. Key words: G protein-coupled receptor 30; Nucleotide oligomerization domain-like receptor family, pyrin domain containing 3; Inflammasome; Interleukin-1β