Overexpression of miR‑30c‑5p reduces cellular cytotoxicity and inhibits the formation of kidney stones through ATG5.

MicroRNAs (miRNAs or miRs) are critical regulators in various diseases. In the current study, the role of miR‑30c‑5p in the formation of sodium oxalate‑induced kidney stones was investigated. For this purpose, human renal tubular epithelial cells (HK‑2 cells) were incubated with sodium oxalate at the concentrations of 100, 250, 500, 750 and 1,000 µM. Cell viability and the miR‑30c‑5p expression level were respectively measured by CCK‑8 assay and RT‑qPCR. After separately transfecting miR‑30c‑5p mimic and inhibitor into the HK‑2 cells, the cell apoptotic rate, the levels of mitochondrial membrane potential (MMP) and ROS were determined by flow cytometry. The levels of oxidative stress indicators [lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT)] were determined using commercial kits. Crystal‑cell adhesion assay was performed to evaluate the crystal adhesion capacity in vitro. miR‑30c‑5p binding at autophagy related 5 (ATG5) was predicted by TargetScan7.2 and further verified by dual‑luciferase reporter assay. Rescue experiments were performed to confirm the molecular mechanisms underlying sodium oxalate‑induced kidney formation in HK‑2 cells. The results revealed that sodium oxalate decreased the viability of HK‑2 cells in a concentration‑dependent manner, and that miR‑30c‑5p expression was significantly downregulated by exposure to 750 µM sodium oxalate. In addition, the increase in cell apoptosis and crystal number, and the upregulated levels of LDH, MDA and ROS were reversed by the overexpression of miR‑30c‑5p. Moreover, the overexpression of miR‑30c‑5p upregulated the levels of SOD, CAT and MMP induced by sodium oxalate. ATG5 was directly regulated by miR‑30c‑5p, and the inhibition of cell cytotoxicity and crystal‑cell adhesion induced by miR‑30c‑5p mimic was blocked by ATG5. These data indicated that the overexpression of miR‑30c‑5p alleviated cell cytotoxicity and crystal‑cell adhesion induced by sodium oxalate through ATG5. Thus, the current study provides a better understanding of the role of miR‑30c‑5p in sodium oxalate‑induced kidney stones.