BACKGROUND: Ischemia-reperfusion (I/R) leads to kidney injury. Renal I/R frequently occurs in kidney transplantations and acute kidney injuries. Recent studies reported that miR-30 stimulated immune responses and reductions in renal I/R related to anti-inflammation. Our study investigated the effects of miR-30c-5p on renal I/R and the relationship among miR-30c-5p, renal I/R, and macrophages.
MATERIAL AND METHODS: Sprague Dawley rats received intravenous tail injections of miR-30c-5p agomir. Then a renal I/R model were established by removing the left kidney and clamping the right renal artery. Serum creatinine (Cr) was analyzed using a serum Cr assay kit, and serum neutrophil gelatinase associated lipocalin (NGAL) was measured using a NGAL ELISA (enzyme-linked immunosorbent assay) kit. Rat kidney tissues were analyzed using hematoxylin and eosin staining. THP-1 cells treated with miR-30c-5p agomir and miR-30c-5p antagomir were measured with quantitative reverse transcription-polymerase chain reaction. Protein levels were analyzed by western blot.
RESULTS: MiR-30c-5p agomir reduced serum Cr, serum NGAL, and renal I/R injury. MiR-30c-5p agomir inhibited the expression of CD86 (M1 macrophage marker), inducible nitric oxide synthase (iNOS), and tumor necrosis factor-alpha (TNF-alpha) and promoted the expression of CD206 (M2 macrophage marker), interleukin (IL)-4, and IL-10 in rat kidneys. MiR-30c-5p agomir reduced the expression of CD86 and iNOS, and increased the expression of CD206 and IL-10 in THP-1 cells.
CONCLUSIONS: We preliminarily demonstrated that miR-30c-5p agomir might decrease renal I/R through transformation of M1 macrophages to M2 macrophages and resulted in changes in inflammatory cytokines.

Keywords: M2 Macrophage, M1 Macrophage, miR-30c-5p, Inflammation, Renal Ischemia-Reperfusion