Activation of diacylglycerol O-acyltransferase 1 gene results in increased tumor necrosis factor-α gene expression in 3T3-L1 adipocytes

The tumor necrosis factor-α (TNF-α) expression has been reported to be largely dependent on the size of adipocytes. We herein investigated the gene regulation of diacylglycerol O-acyltransferase (DGAT) in order to clarify the mechanism of TNF-α expression induced in large adipocytes. 3T3-L1 cells were cultured in the presence of 5 mM or 25 mM glucose to generate adipocytes from which the triglyceride content differs. The expression of TNF-α, DGAT1, and DGAT2 were upregulated in adipocytes cultured with 25 mM glucose. Furthermore, knockdown of DGAT1 gene significantly inhibited the TNF-α expression. Finally, the DGAT1 expression levels were closely related to the TNF-α level in 3T3-L1 adipocytes.