Inhibition of miR-30d-5p promotes mitochondrial autophagy and alleviates high glucose-induced injury in podocytes.

Abstract

To study the role of microRNA (miR)-30d-5p in high glucose-induced podocyte injury. Podocyte cells were hyperglycated with 30 mmol/L glucose, miR-30d-5p inhibitor and mimic were transfected into podocyte cells, and then podocyte cells were treated with 1 mg/mL 3-methyladenine (3-MA). The transfection efficiency of miR-30d-5p was detected by quantitative reverse transcription PCR. Cell apoptosis was detected by flow cytometry. The expressions of nephrin, microtubule-associated protein light chain 3 (LC3)Ⅱ/LC3Ⅰ, P62, autophagy-related gene 5 (ATG5), PTEN induced putative kinase 1 (PINK1) and PARK2 were detected by Western blotting. The mito-chondrial membrane potential was detected by JC-1 as a fluorescent probe, and adenosine triphosphate (ATP) content in cells was detected by relevant kits. In the high glucose-induced podocytes, miR-30d-5p and P62 expressions were upregulated, nephrin, ATG5, PINK1, PARK2 and LC3Ⅱ/LC3Ⅰ expression levels were decreased (all P<0.01). MiR-30d-5p inhibitor reversed the effect of high glucose on the expression of ATG5, PINK1, PARK2, nephrin, LC3Ⅱ/LC3Ⅰ and P62 (all P<0.01). High glucose induced loss of mitochondrial membrane potential and ATP content in podocytes, while inhibition of miR-30d-5p increased membrane potential and ATP content in podocytes. Autophagy inhibitors 3-MA and miR-30d-5p mimics reversed the effects of miR-30d-5p inhibition on apoptosis, autophagy and mitochondrial function of podocytocytes induced by high glucose (all P<0.05). Inhibition of miR-30d-5p may promote mitochondrial autophagy by promoting the expression of ATG5, PINK1, PARK2, resulting in alleviating high glucose-induced podocyte damage.