Role of miR-139-5p in relieving renal allograft ischemia-reperfusion injury by inhibiting c-Jun NH-terminal kinase (JNK) signaling pathway

Abstract

Renal ischemia-reperfusion injury cannot be avoided in the process of kidney transplants. In this study, the role of miR-139-5p in renal ischemia-reperfusion injury in mice was investigated. Hyperuricemia cells were detected using qPCR. The results confirm that the expression levels of miR-139-5p, Jun, and c-Jun were detected, and miR-139-5p was down-regulated in the ischemia-reperfusion injury after renal transplantation, while CDK4 and Jun were up-regulated. The levels of [Ca++]i and ROO were measured in HK-2 cells, and it was determined that overexpression of miR-139-5p reduced these levels to approach a normal state. After cell silencing of miR139-5p, the levels of [Ca++]i and ROO of the hyperuricemia cells increased significantly. After down-regulation of miR-139-5p via CCK-8 and clonal cell formation assays, it was determined that the survival rate and viability of hyperuricemia cells were decreased significantly. However, the addition of the agent anisomycin (JNK activation) improved the survival rate of hyperuricemia cells and increased their viability. The detection of the cycle of the hyperuricemia cells revealed that the up-regulation of miR-139-5p blocked a large number of cells in the G1 phase; however, the number of these cells significantly decreased after the addition of anisomycin. The expression levels of c-Jun and JNK in hyperuricemia cells were detected via immunofluorescence. In the hyperuricemia cells, the fluorescence intensity in the miR-139-5p overexpression group was higher compared to that in the control group. Moreover, the fluorescence intensity decreased significantly after the addition of anisomycin. Nano-magnetic beads were fabricated and used to extract high purity RNA. Scanning electron microscopy was used to confirm the efficacy of the nanoparticles in the extraction of RNA. The detection of the JNK pathway-related proteins of hyperuricemia cells using qPCR and Western blot revealed that the downregulation of miR-139-5p promoted the expression of JNK pathway-related proteins while the up-regulation of miR-139-5p inhibited the expression levels of c-jun, JNK, JNK 1, and JNK 2. The experimental results indicate that miR-139-5p alleviates renal–renal ischemia-reperfusion injury by targeting Jun-mediated JNK signaling pathways.