Renalase Protects against Contrast-Induced Nephropathy in Sprague-Dawley Rats

Background Contrast-induced nephropathy (CIN) is the third leading cause of hospital-acquired acute renal failure. Oxidative stress, apoptosis and inflammation play crucial roles in CIN. Renalase is a newly discovered monoamine oxidase from the kidney. We hypothesize that renalase could protect against CIN through anti-oxidation, anti-inflammation and anti-apoptosis pathways. Methods We tested our hypothesis in vivo with a rat model of Ioversol-induced CIN and in vitro . Sprague-Dawley rats were divided into 4 groups (n = 6 per group): control group, Ioversol group (rats subjected to Ioversol-induced CIN), Ioversol plus vehicle group (CIN rats pretreated with vehicle) and Ioversol plus renalase group (CIN rats pretreated with 2 mg/kg recombinant renalase). HK2 cells were treated with Ioversol or H 2 O 2 . Results The results showed that pretreatment with renalase attenuated the deterioration of renal function, tubular necrosis, oxidative stress, apoptosis and inflammation ( P<0.05 ). Furthermore, renalase protected HK2 cells against the cytotoxicity of Ioversol and suppressed Caspase-3 activity, oxidative stress and apoptosis induced by H 2 O 2 . Conclusion Recombinant renalase protected CIN in rats through anti-oxidation, anti-apoptosis and anti-inflammation mechanisms.