MicroRNA let 7i regulates DCs maturation targeting IL-10 via JAK1-STAT3 signal pathway subsequently induces prolonged cardiac allograft survival in rats

Abstract

Abstract Objective In this study, we investigated whether microRNA (MiR) let 7i regulates DCs maturation targeting IL-10 via JAK1-STAT3 signal pathway subsequently prolongs rat cardiac allograft survival. Methods QRT-PCR, ELISA, dual luciferase assay were performed to verify whether IL-10 was the target of let 7i. Tregs were assessed by flow cytometry and immunohistochemical study, and JAK1, STAT3 and pSTAT3 expressions were detected by western bolt. Lewis recipients of DA heart were transfused with PBS, LPS-mDCs, or let 7i inhibitor-mDCs. Allograft survival times were recorded, and histologic study were performed. Results Expression of IL-10 mRNA level and production of IL-10 were increased in let 7i inhibitor-mDCs as compared to LPS-mDCs. Luciferase activity showed that the translational level of the IL-10 luciferase reporter was decreased by let 7i mimic, but increased by let 7i inhibitor. MiR let 7i inhibitor suppressed DC maturation by depressing CD80 and CD86, however， pretreatment of IL-10 SiRNA attenuated the suppression. Expressions of JAK1, STAT3, and pSTAT3 in mDCs were suppressed by let 7i mimic and pretreatment of IL-10 SiRNA, however up regulated by let 7i inhibitor. Lewis recipients transfused with let 7i inhibitor-mDCs significantly prolonged DA cardiac allograft survival. The allografts transfused with let 7i inhibitor-mDCs showed slight cell infiltration and significantly preserved graft structure. Inhibition of let 7i increased Tregs and modulated cytokine profiles both in vivo and in vitro. Conclusion MiR let 7i regulated DCs maturation and function targeting the IL-10 through JAK1-STAT3 pathway. Moreover, transfusion of let 7i inhibitor-mDCs induced prolonged cardiac allograft survival and generated Tregs.