Figure 5.

ATP depletion mediates myostatin-induced VDAC1 upregulation, which contributes to apoptosis. (a, b) HeLa cells cultured in low glucose (5.5 mM) DMEM were treated with vehicle, 8 mM, 16 mM or 32 mM 2DG for 24 h. Cells were harvested for the ATP assay (a) and western blotting analysis (b). (c) HeLa cells pre-incubated with or without 2DG (32 mM) for 30 min were treated with PBS or myostatin for 24 h, followed by Annexin V/PI staining. (d) HeLa cells were incubated in glucose-free DMEM in the presence or absence of sodium pyruvate (10 mM) or inosine (20 mM), followed by treatment with myostatin (500 ng/ml) for 6 h. Cellular ATP levels were examined (n=3). (e) HeLa cells were treated as in (d), and cells lysates were subjected to western blotting analysis with anti-VDAC1 antibody. (f) HeLa cells were treated as in (d) with extended myostatin treatment for 12 h, followed by Annexin V and PI double staining