Paracrine Effect Of Mesenchymal Stem Cells Against Renal Ischemia-reperfusion Injury

Objective: To observe the protective effect of mesenchymal stem cells derived conditioned medium(MSC-CM)against mice renal ischemia-reperfusion injury(IRI).Methods: C57 mice bone marrow MSC was isolated and purified.Its morphology was observed.Cell surface markers were detected by flow cytometry and their multilineage differentiation was tested.Mice renal ischemia-reperfusion injury(IRI)model was established by clamping bilateral renal pedicles for 30 minutes.The experimental group was intraperitoneal injected 500 ul MSC-CM 3 hours after reperfusion and ischemia group,sham operation group and fibroblast culture media group were set.Postoperative serum creatinine and urea nitrogen level were detected at different time points and different groups.At 24 hours postoperation,the renal pathological changes and renal tubular epithelial cell apoptosis were observed;Western Blot was used to detect the expression level of apoptosis related proteins in renal tissue;Mouse cytokine array was used to detect serum cytokines in the different groups and cytokines in MSC and fibroblast culture media.In vitro hypoxia/reoxygenation model of mice renal tubular epithelial cells was established,the experimental group was co-cultured with MSC-CM after reoxygenation,the hypoxia group and control group were set.Results: At 24 hours postoperation,the degree of ischemia-reperfusion injury was the heaviest.At this time,the infusion of MSC-CM improved renal function,reduced kidney pathological damage,and reduced the apoptosis of renal cells markedly than control group(P<0.05).Western blot showed the level of three apoptosis related proteins increased in ischemia group than the control group,and after MSC-CM intervention,the protein levels significantly decreased(P<0.05).Mouse cytokine array showed various inflammatory and adhesion cytokines significantly increased in ischemia group,which significantly decreased in MSC-CM group(P<0.05).Three cytokines are more abundant in MSC-CM than fibroblasts culture media.In vitro model confirmed MSC-CM intervention can significantly reduce the apoptosis caused by hypoxia/reoxygenation.Conclusion: MSC-CM infusion can significantly reduce mice renal damage induced by ischemia-reperfusion,which may result from reducing inflammation and inhibiting renal tubular cell apoptosis and the specific molecular mechanism remains to be further researched.