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

The tumor necrosis factor-alpha (TNF-alpha) 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-alpha 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-alpha, DGAT1, and DGAT2 were upregulated in adipocytes, cultured with 25 mM glucose. Furthermore, knockdown of DGAT1 gene significantly inhibited the TNF-alpha expression. Finally, the DGAT1 expression levels were closely related to the TNF-alpha level in 3T3-L1 adipocytes. (c) 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.