Knockdown of CHOP reduced apoptosis in HR-confronted HUVECs.

HUVECs were transfected with a scramble (control) or CHOP-specific siRNA at a final concentration of 80 nmol/l. 36 h later, cells were exposed to 4 h of hypoxia, followed by 6 h of reoxygenation. Then cells were collected and subjected to western blot analysis. Representative images of 6 separate experiments were shown (A). Quantitative analyses of the protein levels. Cleaved caspase-3 (B) and CHOP (C) protein bands were quantified and normalized to β-actin. The mean value obtained from the control was arbitrarily defined as 1. (D) The percentage of LDH release in the supernatant. Data were expressed as mean ± SD from 4–6 separate experiments. *P<0.05 vs. the control siRNA-transfected cells with HR treatment.