Abstract：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 staining. 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 visceral adipose tissue. Free fatty acids increased the expression of IFN-γ in 3T3-L1 adipocytes through TLR2 signaling. Conclusion: TLR2/ IFN-γ adipocytes may be involved in high-fat-induced insulin resistance by inducing IFN-γ expression in visceral adipose tissue.
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