WTAP-mediated N(6)-methyladenosine modification of NLRP3 mRNA in kidney injury of diabetic nephropathy

BACKGROUND: Diabetic nephropathy (DN) is prevalent in patients with diabetes. N(6)-methyladenosine (m(6)A) methylation has been found to cause modification of nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing (NLRP) 3, which is involved in cell pyroptosis and inflammation. WTAP is a key gene in modulating NLRP3 m(6)A. METHODS: In this study, WTAP was silenced or overexpressed in high glucose (HG)-treated HK-2 cells to determine its influence on pyroptosis, NLRP3 inflammasome-related proteins, and the release of pro-inflammatory cytokines. NLRP3 expression and m(6)A levels were assessed in the presence of WTAP shRNA (shWTAP). WTAP expression in HK-2 cells was examined with the introduction of C646, a histone acetyltransferase p300 inhibitor. RESULTS: We found that WTAP expression was enhanced in patients with DN and in HG-treated HK-2 cells. Knockdown of WTAP attenuated HG-induced cell pyroptosis and NLRP3-related pro-inflammatory cytokines in both HK-2 cells and db/db mice, whereas WTAP overexpression promoted these cellular processes in HK-2 cells. WTAP mediated the m(6)A of NLRP3 mRNA that was stabilized by insulin-like growth factor 2 mRNA binding protein 1. Histone acetyltransferase p300 regulated WTAP expression. WTAP mRNA levels were positively correlated with NLRP3 inflammasome components and pro-inflammatory cytokines. CONCLUSION: Taken together, WTAP promotes the m(6)A methylation of NLRP3 mRNA to upregulate NLRP3 inflammasome activation, which further induces cell pyroptosis and inflammation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s11658-022-00350-8.