MiR-124a enhances therapeutic effects of bone marrow stromal cells transplant on diabetic nephropathy-related epithelial-to-mesenchymal transition and fibrosis.

Abstract

Epithelial-to-mesenchymal transition (EMT) has beengradually considered as one of the major pathways that causes the production of interstitial myofibroblasts in diseased kidneys. The study was done to investigate the effect of a bone marrow stromal cell(BMSCs) transplant on rat podocytes and diabetic nephropathy (DN) rats in high-glucose concentration, and to explore the effect of miR-124a on BMSCtherapy. High glucose-injured podocytes and streptozotocin-induced DN rats have beenrespectively used as injury models in in vitro and in vivo studies. Podocyte viability was measured using the Cell Counting Kit-8 assay. Renal pathological examination was observed by HE staining and Masson staining. The messenger RNA and protein levels were determined via real-time polymerase chain reaction and Western blotting, respectively. By mediating the activation of caveolin-1 (cav-1) and β-catenin and affecting the expression levels of EMT biomarkers including p-cadherin, synaptopodin, fibroblast-specific protein-1, α-smooth muscle actin and snail, our in vitro study confirmed that miR-124a played a significant role in the treatment of high glucose-induced podocyte injury by BMSCs. The therapeutic effects of the BMSCtransplant on DN rats were also proved to be further enhanced by miR-124a overexpression in BMSCs, and such a phenomenon was accompanied by the improvement of renal fibrosis and mitigation of DN-related kidney impairment. Regulation of fibronectin, collagen1, and EMT-related proteins was closely implicated with the mechanism, and the activation of cav-1 and β-catenin was also possibly involved. The study demonstrated thepivotal effect of miR-124a on BMSCtherapy for DN rats via mitigating EMT and fibrosis. Our results provide a novel insight into how therapeutic effects of BMSCs can be improved at theposttranscriptional level.