Fig. 4. ATP5A1 expression and ATP synthase activity in the hearts of hyperglycemic mice, in the heart following global I/R and in H9c2 cells following H/R.

a, b Adult Tg-mtCAST/tTA (TG) mice and their wild-type (WT) littermates were injected with STZ (50 mg ·kg⁻¹ ·d⁻¹, i.p.) for five consecutive days. Two months after STZ injection, heart tissues were collected. a The upper panel shows representative Western blots for ATP5A1 and GAPDH from two out of the six hearts, and the bottom panel shows the quantification of the ATP5A1/GAPDH ratio for all hearts. b ATP synthase activity was measured. The data are presented as the mean ± SD of six different heart tissues from each group. *P < 0.05 vs WT+sham and ^#P < 0.05 vs WT+STZ. c, d Hearts isolated from adult TG and WT mice were subjected to 45 min of global (zero-flow) ischemia and 30 min of reperfusion. c Upper panel: representative Western blots for ATP5A1 and GAPDH from two out of the five hearts. Lower panel: quantification of the ATP5A1/GAPDH ratio for all hearts. d ATP synthase activity was measured. The data are presented as the mean ± SD of five different heart tissues from each group. *P < 0.05 vs WT+sham and ^#P < 0.05 vs WT+I/R. e, f H9c2 cells were infected with Ad-mtCAST or Ad-gal for 24 h and then subjected to 24 h of hypoxia followed by 24 h of reoxygenation (H/R). e Upper panel: a representative Western blot for ATP5A1 and VDAC1 from three different experiments. Lower panel: quantitation of the ATP5A1/VDAC1 ratio. f ATP synthase activity was measured. The data are the mean ± SD of three different experiments. *P < 0.05 vs Ad-gal + sham and ^#P < 0.05 vs Ad-gal + H/R.