NYGGF4 homologous gene expression in 3T3-L1 adipocytes: regulation by FFA and adipokines.

NYGGF4 is a novel gene that is abundantly expressed in the adipose tissue of obese subjects and is involved in insulin resistance. In the present study, the mRNA expression of NYGGF4 homologous genes was examined in the 3T3-L1 cell line. The NYGGF4 mRNAs were expressed at low levels in the 3T3-L1 preadipocytes. During the conversion of 3T3-L1 preadipocytes to adipocytes, the expression of NYGGF4 mRNA was upregulated. On the 8th day after induction of differentiation, the NYGGF4 mRNA levels peaked and remained high. Free fatty acids (FFA) and tumor necrosis factor-α (TNFα) could upregulate NYGGF4 mRNA expression in 3T3-L1 adipocytes, while interleukin-6 (IL-6), leptin, and resistin exerted an inhibitory effect. The results suggest that the expression of NYGGF4 mRNA is affected by a variety of factors that are related to insulin sensitivity. It is likely that NYGGF4 may be an important mediator in the development of obesity-related insulin resistance.