Insulin Regulates Glucose Consumption and Lactate Production through Reactive Oxygen Species and Pyruvate Kinase M2
Figure 4
Knockdown of PKM2 is sufficient to inhibit insulin-induced glucose consumption, lactate production, and cell proliferation. (a) HepG2 and Bel7402 cells were transfected with siRNA against PKM2 (siPKM2) or scramble control (siSCR) for 48 h. The protein levels of PKM2 were analyzed by immunoblotting. (b) Relative densities of PKM2/GAPDH from three independent experiments were normalized to those of control and presented as mean ± SD. *** indicate significant difference when compared to scramble control at . (c) and (d) HepG2 and Bel7402 cells were transfected with siRNA against PKM2 (siPKM2) or scramble control (siSCR) for 24 h, followed by starving in serum-free medium for 24 h. Then, cells were stimulated with insulin (200 nM) for 12 h. Cells were trypsinized and counted, while the medium was collected. The glucose consumption and lactate production levels were analyzed. Data were mean ± SD from three independent experiments. ** significant difference when compared to cell treated with siSCR; # and ## significant difference compared to cell treated with siSCR and insulin. (e) HepG2 and Bel7402 cells were transfected with siRNA against PKM2 (siPKM2) or scramble control (siSCR) for 24 h. The cells were then trypsinized and resuspended. Cells at 3000 cells per well in a 96-well plate. The cell proliferation was measured at 12 h, 24 h, 48 h, 72 h, and 96 h. Values represent means ± SD. * and ** Compared to scramble control ( and ).
