Insulin Regulates Glucose Consumption and Lactate Production through Reactive Oxygen Species and Pyruvate Kinase M2
Figure 3
miR-145 and miR-128 are suppressed by insulin and involved in insulin-induced PKM2 expression. (a) HepG2 cells and Bel7402 cells were cultured overnight and switched to serum-free medium for 20 h. The starved cells were pretreated with catalase (1500 U/mL) for 1 h. Insulin (200 nM) was added and the cells were incubated for 6 h. Total RNAs were extracted and used for real-time RT-PCR for detecting the expression levels of miR-145, miR-128, and U6. * and ** Significant difference compared to control ( and ); ## significant difference compared to treatment with insulin alone (). (b) HepG2 cells and Bel7402 cells were transfected with miR-145, miR-128, or miRNA scrambled control precursor. After transfection for 24 h, cells were cultured in serum-free medium for 20 h and treated without or with insulin (200 nM) for 6 h. Protein expression levels of p70S6K1, HIF-1α, PKM2, and GAPDH were determined by immunoblotting. (c), (d), and (e) Relative protein densities were quantified using ImageJ software. Results are presented as mean ± SD from three independent experiments. * and ** Significant difference compared to the value of the scramble control ( and ); # and ## significant difference compared to that treated with insulin alone ( and ).
