Effects of forkhead transcription factor O1 and piglitazone on glucose consumption of HepG-2 cell line

Objective To study the effect and mechanism of forkhead transcription factor (FoxO1) and pioglitazone on the glucose utilization in HepG-2 cell line induced by high-level insulin. Methods HepG-2 cells were induced by exposure to 1×10-6 mol/L insulin for 24 hours. HepG-2 cells were divided into control group, blank plasmid group, FoxO1 small interfering RNA(siRNA) vector group, and pioglitazone medium group. The blank control group was cultured with normal medium. At 37 ℃, 5% CO2 for 24 hours, the glucose consumption was detected by glucose oxidase method, the expression levels of FoxO1 mRNA and peroxisome proliferator-activated receptors-gamma(PPAR-γ) mRNA were analyzed by RT-PCR, and the protein expression of PPAR-γ was determined by Western blot.Single factor analysis of variance and SNK or Dunnet's test were used for statistic analysis. Results Compared with blank control group, the glucose consumption((1.36 ± 0.03)vs(2.93 ± 0.05)mmol/L, P 0.05). After inhibiting FoxO1 by small interference RNA or induced by pioglitazone, these indices were closed to the indices of blank control group. The expressions of FoxO1 mRNA, PPAR-γ mRNA and PPAR-γ protein were highly correlated with the glucose consumption. Conclusions Inhibiting and increasing the expression of FoxO1 could produce adverse effects on glucose metabolism. Up-regulation PPAR-γ expression could improve insulin sensitivity. Key words: Forkhead transcription factors; Peroxisome proliferator activated receptors; Pioglitazone; HepG-2 cell line