*Purpose: In this study, we investigated the protective functions of miR-124 on renal I/R injury both in vivo and in vitro and explored its underlying mechanisms, focusing on the anti-ERS effect of miR-124 and the down-regulation of IRE-1α in renal I/R injury. This study provides a theoretical basis for the clinical study of renal I/R injury protection, thereby exploring the pathogenesis of AKI and providing clues for the development of new treatment strategies.

*Methods: To investigate the pathogenesis of the renal I/R injury, we used C57 mice to establish a renal I/R model and detected the expression of ERS-related genes in the renal I/R model. we examined the mRNA levels of ERS-related genes, including IRE-1α, XBP-1 and GRP78, were examined by RT-qPCR. Next, we explored the functions of miR-124 in vitro, and TCMK-1 cells were cultured in the hypoxia/reoxygenation condition to simulate I/R injury. Since ERS can induce apoptosis, we further explored the effect of miR-124 on ERS. Western blot analysis showed that miR-124 overexpression evidently inhibited the I/R-induced increase in the expressions of IRE-1α, XBP-1 and GRP78 proteins.To determine the underlying mechanisms, TargetScan was employed to predict the potential relationship between miR-124 and IRE-1α. Bioinformatics analysis revealed the miR-124 binding site in the 3’UTR of IRE-1α. To further explore whether the effects of miR-124 on I/R are dependent on IRE-1α, the cell viability of TCMK-1 cells was examined under hypoxia/reoxygenation condition after transfection with miR-124 mimic and IRE-1α.

*Results: The western blot results showed that the expression levels of ERS-relatedproteins IRE-1α, XBP-1 and glucose-regulated protein 78 (GRP78) were significantly increased in the I/R model group when compared with those in the control group. Meanwhile, qPCR results showed that miR-124 was decreased in the I/R injury model, and overexpression of miR-124 using miR-124 mimic effectively reduced the expression of ERS-related proteins and alleviated renal I/R injury. In addition, luciferase reporter assay was performed and the results showed that IRE-1α and miR-124 may have direct interaction. In conclusion, our data indicated that miR-124 was a negative regulator of ERS via binding to IRE-1α, ultimately conferring its protective effect on the kidney.

*Conclusions: In summary, in this study we investigated the roles of miR-124 in renal I/R injury and explored its possible underlying mechanism. Our results may provides a theoretical basis for the clinical study of renal I/R injury protection

« Back to 2020 American Transplant Congress