Analysis Of Related Factors Affecting The Prognosis Of Allogeneic Kidney Transplantation And The Mechanism Of Renal Ischemia Reperfusion Injury

Background: With advances in technology and immunosuppressants,kidney transplantation(KT)is preferred for the recovery of renal function and the improvement of life quality.Methods for accurately predict and improve the prognosis of KT are in great need.The effect of pretransplant peritoneal dialysis(PD)or hemodialysis(HD)modality on outcomes of KT or end-stage renal disease(ESRD)is debatable.Circular RNAs(circ RNAs)have important roles in several cellular processes.No study has established the pathophysiological role for circ RNAs in the renal ischemic diseases.Finding the ideal biomarker and effectively predicting post-transplant outcomes are important for improving the prognosis of KT.Objective: Compare the effects of pretransplant HD vs PD on outcomes of renal function,post-transplant complications,graft as well as patient survival of first KT from Donor after cardiac death(DCD).Find ideal biomarkers to effectively predict the prognosis of KT including the delayed graft failure(DGF)and graft failure.Study the pathophysiological role for circ RNAs in the pyroptotic cell death of renal tubular epithelial cells and renal ischemia reperfusion injury(IRI).Methods: A cohort of 251 patients on HD,PD or pre-emptive who underwent first KT from DCD between January 2014 and December 2016 were prospectively analyzed to compare for outcomes on recovery of renal function,complications as well as patient and graft survival.The patients were followed till August 2017.Data on 104 HD and 98 PD were available for final comparative outcome analysis,5 pre-emptive were analyzed as the control group.Then a cohort of 144 patients who underwent first KT from DCD between September 2014 and December 2016 were prospectively analyzed to find ideal biomarkers to effectively predict the prognosis of KT including the DGF and graft failure.The cohort was divided into functional delayed graft function(f DGF)group(n=21)and immediate graft function(IGF)group(n=91)according to creatinine recovery.The baseline data and clinical follow-up information of the two groups were statistically analyzed.To study the pathophysiological role for circ RNAs in the pyroptotic cell death of renal tubular epithelial cells and renal IRI,both vitro and vivo experiments were carried out.In primary renal epithelial cells,the c SLC45A4 was knocked down to find its effects on the H/R induced pyroptosis.In vivo,the c SLC45A4 knockdown was mediated via adenovirus associated virus to find its influences on renal IRI and the parameters of pyroptotic cell death.Furthermore,we explored the interaction between c SLC45A4 and GSDMD by RIP,biotin-labeled RNA pull down,immunostaining and fluorescence in situ hybridization.Results: Pretransplant dialysis modality has no effect on outcomes of KT.Post-transplant renal functions between the two groups showed no differences.Complications of DGF,acute rejection,infections were comparable between the groups.The patient survival,graft survival and death-censored graft survival were similar for HD and PD patients.The level of urinary AIM one day before the opration has good predictive value for f DGF((AUC=0.841,95%CI,0.673-1.000,P<0.05)and serum IL-18 levels on one day after operation also can predict it(AUC=0.675,95%CI,0.526-0.825,P<0.05).However,IGFBP7 fails from predicting the outcomes of kidney transplantation.We found that an elevated circ RNA c SLC45A4(generated from solute carrier family 45 member 4)regulates the pyroptotic cell death,but not apoptosis and necroptosis,in the kidney by assisting the GSDMD membrane pore formation and the cytokines secretion.In primary renal epithelial cells,we found that c SLC45A4 knockdown attenuates the H/R induced pyroptosis.In vivo,adenovirus associated virus mediated c SLC45A4 knockdown was also found to be protective against renal ischemia reperfusion injury and reduce the parameters of pyroptotic cell death.Furthermore,we determined the interaction between c SLC45A4 and GSDMD and revealed the co-localization.Conclusions: The outcomes of first KT from DCD is not affected by pretransplant dialysis modality of PD or HD in aspects of recovery of renal function,complications as well as patient and graft survival.The urinary AMI one-day before the transplantation and serum IL-18 on the third day postoperative have better predictive value for the long-term prognosis of renal transplantation.An elevated circ RNA c SLC45A4 regulates the pyroptotic cell death,but not apoptosis and necroptosis,in the kidney by assisting the GSDMD membrane pore formation and the cytokines secretion.