ABSTRACT
Objective:To investigate the mechanism of invariant natural killer T (iNKT)2 cell improving hepatic fat deposition in nonalcoholic fatty liver (NAFL).Methods:NAFL model was established by feeding C57BL/6J mice with high fat diet. The levels of serum total cholesterol, triglyceride, high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in the peripheral blood of mice were analyzed using automatic biochemical analyzer. The pathological changes of liver were observed with HE staining. The cell frequencies of iNKT, iNKT1, and iNKT2 in liver were detected by flow cytometry. Western blotting was used to detect the expression of sterol regulatory element binding protein 1c (SREBP-1c), peroxisome proliferator activated receptor (PPAR)-α, and nuclear factor-κB (NF-κB) in liver tissues.Results:Compared with control group, the body weight of NAFL mice increased, the levels of total cholesterol, HDL-C, LDL-C, ALT, and liver fat deposition increased, the protein expression of SREBP-1c and PPAR-α in liver increased as well as the the protein phosphorylation level of NF-κB. After intraperitoneal injection of α-galactosylceramide (α-GalCer), the levels of total cholesterol, HDL-C, and LDL-C, liver fat deposition decreased, liver SREBP-1c was down-regulated, PPAR-α expression was up-regulated, and the proportion of liver iNKT2 subgroup increased in NAFL mice.Conclusion:iNKT2 cells improve NAFL liver fat deposition, which is related to the down-regulation of SREBP-1c and up-regulation of PPAR-α.