Effect of ALDH2 on accumulation of 4-HNE protein adducts. 4-HNE protein adducts were determined after tunicamycin (TN) exposure. (A) 4-HNE adducts were accumulated by TN, which was mitigated by ALDH2 vector and aggravated by ALDH2 siRNA. (B) Time course of GRP78 expression and Akt phosphorylation in cardiomyocytes incubated with 4-HNE (20 µmol/L). All values for given protein expression were normalized to that of GAPDH. The data (presented as percentages of control) are means ± SEM of three separate experiments. *p < 0.05 versus control; #p < 0.05 versus TN group.