The effect of CHOP inactivation on renal IRI. CHOP^−/− and wild-type mice were subjected to right nephrectomy, followed by IR (left kidney) or sham-operation.

Serum creatinine (A) and BUN (B) concentrations at 24 h after the initiation of reperfusion were shown (n = 8 per group). (C) Survival of WT and CHOP−/− mice after renal IR operations (n = 20 per group). CHOP knockout led to a significant survival advantage by Kaplan-Meier analysis (log-rank test, P<0.05). (D) Representative PAS-stained sections from post-ischemic kidneys harvested at 24 h (original magnification, ×200). (E) Representative renal MPO staining (original magnification, ×200). (F) TUNEL assay (original magnification, ×400). (G) Representative immunoblotting results of the non-IR right kidneys and the operated left kidneys (6 hours after reperfusion). (H–I) Quantitative analyses of the relative levels of protein expression. Cleaved caspase-3 and CHOP protein bands were quantified and normalized to β-actin. The mean value obtained from non-IR WT kidneys was arbitrarily defined as 1. There were 6 mice in each group and data were expressed as mean ± SD. *P<0.05 vs. WT/IR group.