Effects Of Recombinant Human Erythropoietin With Bone Marrow Mesenchymal Stem Cells Transplantation On Renal Inflammatory Response Following Cardiopulmonary Bypass

Cardiopulmonary bypass(CPB)plays a very important role in open heart surgery.Despite the continuous improvement of surgical technique?surgical instruments and the continuous progress of CPB technology,kidney injury acute(AKI)is still a serious complication,and the mortality rate is very high.Various kinds of inflammatory mediators are produced and the complement system is activated after CPB,which causes a series of inflammatory reactions,kidney damage,and finally the development of AKI.It is still the main problem faced by clinicians.Therefore,new methods to prevent and reduce the postoperative renal injury need to be tested.Erythropoietin(EPO)is a hematopoietic cytokine produced mainly by the kidney,which can promote the maturation of erythroid progenitor cells.In recent years,studies have shown that they can protective renal injury by inhibiting systemic inflammatory response,promote angiogenesis.Bone mesenchymalstem cells(BMSCs)are nonhematopoietic stem cells with the ability of multilineage differentiation and proliferation,that with immune regulation,tissue repair and anti-inflammatory effects.There are some protective effects on renal injury.Their role in extracorporeal circulation kidney inflammation in unknown.In this study,the effects of recombinant human erythropoietin combined with bone marrow mesenchymal stem cells transplantation on renal inflammatory response following cardiopulmonary bypass were studied.Part1:The experimental of renal inflammatory response in a rat cardiopulmonary bypass modelObjectiveThe study was designed to explore the possible mechanism of CPB-induced renal inflammatory injury in a rat model.Materials and methodsMale Sprague-Dawley rats were randomly divided into two groups(n=8):Sham group and CPB group.The animals underwent CPB for 60 minutes with flow rate at 100ml/kg/min in CPB group.Blood samples were collected for determination of the level of creatinine(Cr)and urea nitro(BUN);Renal tissure was stained with hematoxylin-eosin to examine pathological changes;The level of serum interleukin 6(IL-6),interleukin 10(IL-10)was tested with ELISA and expression of Tumor necrosis factor(TNF-a),insulin-like growth factor 1(IGF-1)was analyzed with Western Blot.Statistical analyses were performed by using SPSS19.0.A= 0.05 for the test,A value of P<0.05 was considered statistically significant.Results:Comparing with the sham group,in CPB group the level of Cr,BUN,IL-6 and expression of TNF-a were increased,while the level of IL-10 and expression of IGF-1 were decreased.HE staining showed that therewas no obvious abnormality in the glomerular and tubular structures in Sham group.In CPB group,there were some vacuoles in the renal tubular epithelial cells,some of which were found in the renal tubular epithelial cells,and there were interstitial edema with inflammatory cell infiltration specially neutrophil.Conclusions:Our experiment showed that CPB would induce severe renal injury in a rat model,which is confirmed by both biochemical indices and morphology examinations.CPB-induced renal injury is mainly caused by inflammatory response.Part2:Effects of recombinant human erythropoietin with bone marrow mesenchymal stem cells transplantation on renal inflammatory response following cardiopulmonary bypassObjectiveTo study the effects of recombinant human erythropoietin with bone marrow mesenchymal stem cells transplantation on renal inflammation response following cardiopulmonary bypass.Materials and methodsForty sprague-Dawley rate were randomly divided into five groups(n = 8).The animals underwent CPB for 60 minutes with flow rate at 100ml/kg/min in CPB group.The EPO(3000IU/kg)and BMSCs(1.5×106)was infused via right jugular vein after CPB in EPO and BMSCs group respectively.Whle combination of EPO with BMSCs was infused in EPO+BMSCs group.Animals were sacrificed at24 hours after CPB terminated.Blood sanples were collected for determination of the level of creatinine(Cr)and urea nitro(BUN);Renal tissure was stained with hematoxylin ?eosin to examine pathological changes;The level of serum interleukin 6(IL-6),interleukin 10(IL-10)was tested with ELISA and expression of Tumor necrosis factor(TNF-?),insulin-like growth factor 1(IGF-1)was analyzed with Western Blot.Results:In CPB group,the level of Cr,BUN,IL-6 and expression of TNF-a were increased,while the level of IL-10 and expression of IGF-1 were decreased.Pathologic examination showed obvious renal injury fllowing CPB.EPO and BMSCs provided protective effects on CPB-induced renal injury,in which the level of Cr,BUN,IL-6 and expression of TNF-a were decreased and the level of IL-10 and expression of IGF-1 were increased.Meanwhile,the decrease of renal injury was observed on pathologic finding.Furthermore,the protective effects were substantially improved with the EPO and BMSCs combined.Conclusions:EPO and BMSCs could have protective effects on renal injury following CPB in rats,the protective effects were substentially improved while the EPO and BMSCs were combined.Anti-inflammatory effect of EPO and BMSCs may account for the protective machnism.