Role Of PKC-Nrf2/HO-1 Signal Transduction Pathway In Endotoxic Shock-induced Acute Renal Injury In Rabbits

Background and Objective: Acute kidney injury is a common clinical critical disease,which is notorious for its high mortality.There are a lot of factors cause AKI,mainly including renal ischemia/reperfusion injury,drug renal toxicity,sepsis.Previous studies mainly focus on ischemia/reperfusion injury AKI induced AKI.But for sepsis induced AKI,our research is relatively scarce.A number of survey datas show that severe sepsis and septic shock is the most common reason of AKI.In addition to the renal replacement therapy,there is no clear clinical treatment scheme or measures to prevent septic AKI occurred or effectively shorten the course of disease.In recent years,the theory of oxidative stress has become a new research direction in endotoxic shock resulting in the pathogenesis of organ damage.Nrf2 is the main transcription factor released in oxidative stress.Nrf2 can regulate the activation of a variety of antioxidant genes,and play a protective role in organ damage.Our research group in previous research found that there was the abnormal expression of Nrf2 in endotoxin shock induced lung injury model.We can refer the previous research experience,establish the rabbit endotoxic shock induced renal injury model,and research the role and possible mechanism of PKC-Nrf2/HO-1 signal transduction pathway in Endotoxic Shock induced Acute Renal Injury.Methods: Select 40 male healthy New Zealand white rabbits in same months of age,randomly divided into four groups,with 10 rats in each group,named for the CON group,AKI group,CHA group and PMA group.CHA group of rabbits were injected PKC inhibitor chelerythrine 5mg/kg,PMA group of rabbits were injected PKC agonist phorbol ester 5 g/kg,CON group and AKI group were respectively injected 1% DMSO 0.5ml.After 30 min,AKI group,PMA group and CHA group were injected with lipopolysaccharide(LPS)5mg/kg(soluble in 2mL saline),CON group was given equal volume saline.Wait until 6 hours.Blood urea nitrogen(BUN)and creatinine(Cr)concentrations were measured.Then killed those rabbits and took out double kidney.Left kidney was put in 4% paraformaldehyde,and right kidney was frozen in liquid nitrogen tank in-80℃.To observe the changes of renal pathology in the left kidney by HE staining,and evaluating renal injury score.A part of right kidney was detected the RNA level of Nrf2 and HO-1 by RT-PCR.Another part of right kidney was detected the difference in expression of PKC protein,Nrf2 protein,HO-1 protein by using Western blot.Results: 1.In the histopathological level,compared with CON group,renal injury score in AKI group,CHA group and PMA group all increased significantly(P<0.05).Compared with AKI group,renal injury score of CHA group was increased,renal injury score of PMA group was decreased,their differences were statistically significant(P<0.05).2.In serum levels,compared with CON group,The serum BUN,Cr concentrations of AKI group,CHA group and PMA group were statistically significant rise(P<0.05).Compared with AKI group,serum BUN,Cr concentration of CHA group were increased,PMA group were decreased,their differences were statistically significant(P<0.05).3.At the level of nucleic acid,compared with the CON group,the expression of mRNA Nrf2 and mRNA HO-1 in AKI group,CHA group and PMA group all showed different degrees of increase(P<0.05).Compared with the AKI group,the expression of mRNA Nrf2 and mRNA HO-1 in CHA group were all decreased(P<0.05),and the expression of Nrf2 mRNA and HO-1 mRNA in PMA group were all up-regulated(P<0.05).4.In terms of protein expression,compared with CON group,the expression of PKC protein,Nrf2 protein and HO-1 protein of AKI group,CHA group and PMA group were all increased(P<0.05).Compared with AKI group,with the decrease of PKC protein in CHA group down-regulation of Nrf2 protein and HO-1 protein were not statistically significance(P>0.05),and with elevated PKC protein in PMA group,the expression of Nrf2 protein and HO-1 protein showed statistically significant increase(P<0.05).Conclusion: The activation of Nrf2/HO-1 pathway may be a mechanism of adaptive regulation for toxin shock AKI,which is regulated by PKC.