Hyperoside Alleviates High Glucose-Induced Proliferation of Mesangial Cells through the Inhibition of the ERKCREBmiRNA-34a Signaling Pathway

Abstract EN

Purpose.

Hyperoside, a flavonoid isolated from conventional medicinal herbs, has been demonstrated to exert a significant protective effect in diabetic nephropathy.

This study aimed to determine the underlying mechanisms, by which hyperoside inhibits high glucose-(HG-) induced proliferation in mouse renal mesangial cells.

Methods.

Mouse glomerular mesangial cells line (SV40-MES13) was used to study the inhibitory effect of hyperoside on cell proliferation induced by 30 mM glucose, which was used to simulate a diabetic condition.

Viable cell count was assessed using the Cell Counting Kit-8 and by the 5-ethynyl-20-deoxyuridine incorporation assay.

The underlying mechanism involving miRNA-34a was further investigated by quantitative RT-PCR and transfection with miRNA-34a agomir.

The phosphorylation levels of extracellular signal-regulated kinases (ERKs) and cAMP-response element-binding protein (CREB) were measured by Western blotting.

The binding region and the critical binding sites of CREB in the miRNA-34a promoter were investigated by the chromatin immunoprecipitation assay and luciferase reporter assay, respectively.

Results.

We found that hyperoside could significantly decrease HG-induced proliferation of SV40-MES13 cells in a dose-dependent manner, without causing obvious cell death.

In addition, hyperoside inhibited the activation of ERK pathway and phosphorylation of its downstream transcriptional factor CREB, as well as the miRNA-34a expression.

We further confirmed that CREB-mediated regulation of miRNA-34a is dependent on the direct binding to specific sites in the promoter region of miRNA-34a.

Conclusion.

Our cumulative results suggested that hyperoside inhibits the proliferation of SV40-MES13 cells through the suppression of the ERK/CREB/miRNA-34a signaling pathway, which provides new insight to the current investigation on therapeutic strategies for diabetic nephropathy.