LAUSR

Nephrolithiasis is a very common disease in which cell–crystal adhesion is an essential mechanism for kidney stone formation. This study has explored the anti-adhesion function of the microRNA, miR-34a, by targeting CD44, a cell surface receptor, in human renal epithelial (HK-2) cells. The expression of CD44 was monitored by qPCR and western blot. A luciferase assay validated the target of miR-34a in CD44 3′ UTR. Immunofluorescence staining under confocal microscopy was used to detect the cell–crystal adhesion effects in vitro. Pizzolato staining was performed to examine the adhesion role of miR-34a in vivo. In HK-2 cells, miR-34a was down-regulated and CD44 was up-regulated when exposed to calcium oxalate monohydrate crystals. Moreover, miR-34a negatively regulated the expression of CD44. According to the luciferase report assay, miR-34a direct targeted a binding site in the CD44 3′UTR. In vitro experiments, miR-34a overexpression inhibited CD44 expression and cell–crystals adhesion; whereas CD44 overexpression showed reversed results. Furthermore, miR-34a suppressed cell–crystals adhesion and stone formation in vivo. These findings indicate that miR-34a targets CD44 in HK-2 cells and inhibits cell–crystal adhesion both in vitro and in vivo. Based on these results, miR-34a may be a potential therapeutic target for renal stone disease.