MiRNA-148b targeted AMPKα1 mediates high glucose-induced apoptosis in human renal tubular epithelial cells via oxidative stress

Objective To investigate the expression and mechanism of microRNA-148b (miRNA-148b) in high glucose-induced renal tubular injury. Method HK-2 cells cultured in vitro were divided into normal glucose group, mannitol hypertonic control group and high glucose group. After 48 hours of culture, the expression of miRNA-148b was detected by real-time quantitative PCR. 2',7'-Dichlorodihydrofluorescein diacetate (DCFH-DA) was used for detecting production of ROS and observed under fluorescence microscope for analysis; The expression of AMPKα1, Bcl-2, NOX2, NOX4, activated caspase3 (cleaved-caspase3) were detected by Western blotting. Results Compared with the normal glucose group, the expression of miRNA-148b was up-regulated in HK-2 cells in high glucose group and hypertonic group (P<0.01), and the production of ROS increased (P<0.01). The expression of NOX2 and NOX4 was increased, AMPKα1 and Bcl-2 decreased, and cleaved caspase-3 was increased (all P<0.01). Conclusions HG up-regulated miRNA-148b expression and down-regulated its target gene AMPKα1 which promotes the expression of NOX2 and NOX4 in HK-2 cells. MiRNA-148b promotes apoptosis of HK-2 cells via increasing production of ROS and enhancing cleaved-caspase3 for Bcl-2 insufficiency. The tubular toxicity of high glucose is partly due to osmotic pressure. MiRNA-148b may be involved in the pathological injury of diabetic nephropathy and is expected to become a new therapeutic target for diabetic nephropathy. Key words: Diabetic nephropathy; Oxidative stress; Renal tubular epithelial cells; MiRNA-148b; AMPKα1