Protective effect of MiR-146 on renal injury following cardiopulmonary bypass in rats through mediating NF-κB signaling pathway

Abstract

The mechanism of renal injury after cardiopulmonary bypass is not clear, and the protective effect of microRNA-146 through mediating NF KB signaling pathway needs to be verified. The study intends to establish a rat model of cardiopulmonary bypass (CPB). MiR-146 is silenced or overexpressed by lentivirus transfection. It is divided into miR-146 inhibitors group (inhibitors), miR-146 mimics group (mimics) and sham group. It is found that the contents of Cr, bun and MDA in blood = , serum IL-1, IL-6 and TNF in mimics group are higher than those in the other two groups- α Content, apoptosis rate, ICAM-1, TNF- α, NF- κ B mRNA and NF- κ B protein decreased significantly (P < 0.05), while the content of SOD in kidney increased significantly (P < 0.05). In the inhibitors group, the above indicators showed the opposite results. Double luciferase assay showed that NF-kB was the target gene of miR-146. It can be seen that the expression of miR-146 inhibits inflammatory factors, apoptosis, oxidative stress and NF- κ the activation of B pathway promotes the repair of renal injury in CPB rats.

Keywords: MiR-146; NF KB signaling pathway; cardiopulmonary bypass; protective effect; rat; renal injury.

Figure 1.

Transfection effect of MIR-146b the expression of MIR-146 in the Mimics group increased, and the content in the inhibitors group decreased (P < 0.05) **P < 0.05.

Figure 2.

HE staining, glomerular damage, glomerular hypertrophy and proximal tubule damage in the Inhibitors group. Then the kidney cells were damaged (Figure A 20X). The glomeruli and tubules in the Mimics group were in normal shape, and no pathological changes were observed (Figure B 20X).

Figure 3.

Gene expression results During the development of renal injury, the expression of important genes ICAM-1, inflammation gene TNF-α and pathway gene NF-KB were significantly reduced in the Mimics group (P < 0.05). Oxidative antioxidant gene SOD increased significantly (P < 0.05), a means P < 0.05 VS Sham; b means P < 0.05 VS Inhibitors.

Figure 4.

TUNEL staining. No obvious positive cells were seen in the Sham group. The apoptosis rate in the Inhibitors group was significantly higher than that in the Sham group (P < 0.05), and the apoptosis rate in the Mimics group was significantly reduced (P < 0.05).

Figure 5.

The expression level of the pathway protein NF-κB declines obviously in Mimics group (p < 0.05). ^ap<0.05 vs. Sham group, ^bp<0.05 vs. Inhibitors group. (a) Western blot result. (b) Quantification analysis of Western blot result.