Stearoyl-CoA desaturase (SCD) is a key regulatory enzyme in the synthesis of unsaturated fatty acids which is encoded by two genes SCD1 and SCD2. Induction of SCD1 expression by carbohydrates has been demonstrated in the liver, however it is unknown whether similar regulation occurs in adipose cells. To address this question we treated 3T3-L1 adipocytes with various carbohydrates to determine the time course and dose-response of SCD1 to these nutrients. Differentiated 3T3-L1 cells were incubated overnight in glucose-free, serum-free medium then treated with the carbohydrates. We report no induction of the SCD1 mRNA upon treatment with 25mM fructose, 2-Deoxy-Glucose or 3-O-Methylglucose for 48 hours. Adipocytes treated with 5mM or 25mM glucose exhibited a 3-fold increase in SCD1 mRNA content compared to cells treated with no glucose or with 1mM pyruvate. This induction was maximal after 3 hours of glucose treatment. Using run on assay, we demonstrate that this upregulation of SCD1 mRNA by glucose was due to transcriptional activation of the SCD1 gene. Future studies will elucidate the mechanism responsible for the transcriptional regulation of SCD1 by glucose.
|State||Published - 1997|