| Renal Ischemia reperfusion injury(IRI)is a cascade of inflammation in the kidney triggered mainly by prerenal factors,resulting in tissue injury.Macrophages play an important role in IRI induced inflammatory response.At the initial stage of inflammation,M1-type macrophages dominate,releasing pro-inflammatory factors and chemokines to induce inflammatory response.In the middle and late stage of inflammation,macrophages transform into M2 type,releasing a large number of anti-inflammatory factors and a variety of growth factors to inhibit inflammation and promote tissue repair.Adipose-derived mesenchymal stem cells(ADMSC)are a type of pluripotent adult stem cells with the function of repairing tissue damage.Studies have found that the pro-repair effect of ADMSC mainly relies on the production and secretion of bioactive factors to interfere with the metabolism of damaged cells,among which Exosome(Exo)is one of the most valuable therapeutic factors.In addition,ADMSC-Exo has been reported to reduce renal injury caused by renal IRI in rats and mice.Therefore,this study aims to explore whether ADMSC-Exo has a protective effect on canine renal IRI by regulating macrophage polarization,so as to provide a theoretical basis for its application in clinical trials.Unilateral renal IRI model was established and divided into blank group(blank operation),model group(renal IRI model)and experimental group(ADMSC-Exo intervention)to observe the effects of ADMSC-Exo on inflammatory cell infiltration,inflammatory factor content and macrophage phenotype.Phenotypic changes of LPSinduced macrophages cocultured with ADMSC-Exo were detected by ELISA and q PCR in vitro.The mirnas in canine kidney tissues were detected by q PCR,and the mirnas that might be involved in the regulation of macrophage polarization were screened,and verified in vitro and in vivo.In vivo experimental results showed that ADMSC-Exo injection in renal cortex immediately after renal IRI could reduce inflammatory cell infiltration in renal tissue and significantly reduce the expression levels of pro-inflammatory factors IL-1β,IL-6 and TNF-α in serum and renal tissue(p < 0.05).And increased the content of anti-inflammatory factors IL-10 and TGF-β(p < 0.1),reduce the inflammatory response.At the same time,the expression level of i NOS in M1-type macrophages was significantly decreased(p < 0.05),and the expression level of Arg-1 in M2-type macrophages was increased(p < 0.05).In vitro experiments showed that ADMSC-Exo could promote the transformation of LPS-induced macrophages from M1 to M2,and affect the expression of inflammatory factors released by macrophages.After detection of mirnas in canine kidney tissues,it was found that the change of mi R-146 a was associated with M2 macrophages.mi RNA functional experiments confirmed that mi R-146 a could promote the transformation of macrophages from M1 to M2 induced by LPS.When mi R-146 a was inhibited in ADMSC-Exo,the effect of ADMSC-Exo on promoting macrophage polarization was weakened.Conclusions: ADMSC-Exo can regulate the polarization of macrophages through the transport of mi R-146 a,reduce the infiltration of inflammatory cells in renal tissues,reduce inflammatory response,and reduce canine renal IRI. |
