Puerarin attenuates LPS-induced inflammatory injury in gastric epithelial cells by repressing NLRP3 inflammasome-mediated apoptosis

Abstract

The NLRP3 inflammasome plays a crucial role in microbially induced gastric epithelial injury, but the underlying mechanisms remain unclear. Here, we aimed to assess the impacts of puerarin on LPS-induced inflammatory damage and the involvement of the AMPK/SIRT1/NLRP3 signaling pathways in this process in GES-1 cells. Cell viability and cytotoxicity were determined using CCK-8 and lactate dehydrogenase assay kits. Apoptosis was measured using annexin staining followed by flow cytometry. Cytokine levels were detected by ELISA, and protein expression was analyzed using western blotting. Protein overexpression was achieved by transfection with relevant pcDNA3.1 vectors, and protein knockdown was achieved by transfection with relevant siRNAs. Puerarin ameliorated LPS-induced cytotoxicity and apoptosis, while repressing LPS-stimulated NLRP3 inflammasome-mediated pyroptosis in GES-1 cells, as evidenced by significantly decreased expression of NLRP3, ASC, cleaved caspase-1, IL-1β and IL-18. NLRP3 knockdown efficiently repressed LPS-induced inflammatory injury in GES-1 cells. Puerarin activated the AMPK/SIRT1 pathway in LPS-treated GES-1 cells, and knockdown of both AMPK and SIRT1 reversed the protective effects of puerarin against LPS-induced inflammatory damage. AMPK overexpression strengthened, while AMPK knockdown weakened, the ability of puerarin to inhibit NLRP3-mediated inflammatory injury in LPS-treated GES-1 cells. Our findings suggest that puerarin may ameliorate LPS-induced inflammatory injury in GES-1 cells by activating the AMPK/SIRT1 signaling pathway and thereby repressing NLRP3 inflammasome-mediated apoptosis.

Keywords: AMP-activated protein kinase; Gastric epithelial cells; NLRP3 inflammasome; Puerarin; Sirtuin 1.