TLR2 Mediates High-Fat Diet-Induced IFN-γ Secretion and Insulin Resistance in 3T3L1 Adipocytes
Objective:To explore the mechanism of insulin resistance induced by high-fat diet,and to understand the phenotypic changes of adipocytes induced by high-fat diet.Methods:Male C57 BL/6 J mice were fed with normal diet or high-fat diet.Epididymal adipose tissue was isolated from mice fed with normal diet or high-fat diet for 2 weeks.The expression of interferon-γ(IFN-γ)and toll-like receptor 2(TLR2)mRNA was detected by real-time fluorescence quantitative RT-PCR.Flow cytometry was used to detect the number of adipocytes expressing TLR2 or IFN-γ.Pancreatic tissue was analyzed by hematoxylin-eosin stai-ning.The expression of TLR2 and IFN-γ in adipose tissue was analyzed by immunohistochemistry.3T3-L1 adipocytes were treated with FFA or Zymosan A,and the expression of IFN-γ and TLR2 mRNA was detected by real-time fluorescence quantitative RT-PCR.Results:Analysis of gene expression profiles in adipocytes showed that high-fat intake induced increased expression of IFN-γ and TLR2.Flow cytometry analysis showed that there were adipocytes co-expressing TLR2 and IFN-γ(TLR2/IFN-γ adipocytes).Compared with subcutaneous adipose tissue,high fat intake increased the number of TLR2/IFN-γ adipocytes in viscer-al adipose tissue.Free fatty acids increased the expression of IFN-γ in 3T3-L1 adipocytes through TLR2 sig-naling.Conclusion:TLR2/IFN-γ adipocytes may be involved in high-fat-induced insulin resistance by in-ducing IFN-γ expression in visceral adipose tissue.
万方数据
维普
