Background: GWAS has revealed that rs738409 C>G patatin-like phospholipase domain-containing 3(PNPLA3) is strongly associated with nonalcoholic fatty liver disease(NAFLD), but the mechanism remains obscure. Our study aims to investigate differences in mechanism for genotypes of PNPLA3 I148M in palmitate-induced inflammation and apoptosis.
Method: We constructed point mutation PNPLA3 148 I/I,148 I/M 148 M/M HepG2 cell lines via CRISPR-associated (Cas) 9 system. Cells were exposed to palmitate to induce lipid accumulation. Oil red O staining was used to explore the lipid deposition. Levels of inflammatory and apoptotic factors were determined by real-time PCR and western blotting.
Result: Lipid accumulation was remarkably increased in cells induced by PA, it is remarkably higher in 148M/M cell than in 148I/I HepG2 cell (P<0.05 PA vs. BSA). Expression of apoptotic and inflammatory markers BIP, p-PERK, CHOP, p-JNK increased significantly in 148M/M and 148I/M hepG2 cells (P<0.05). Compared with 148I/I cells, The mRNA expression of TNF-α and IL-8 was higher in 148M/M hepG2 cells induced by palmitate.
Conclusion: Different genotypes of PNPLA3 I148M have different effects on PA-induced lipid deposition, PNPLA3 148M may play an important role in pathogenesis of NAFLD through ER stress CHOP and IRE1α-JNK pathway.
Y. Chen: None. H. Liang: None. X. Yan: None. X. Xu: None.