miR-25-3p promotes proliferation and inhibits autophagy of renal cells in polycystic kidney mice by regulating ATG14-Beclin 1.

MicroRNAs are involved in the regulation of the autophagy and proliferation in several diseases. This study aims to verify the role of miR-25-3p in the proliferation and autophagy of renal cells in polycystic kidney disease (PKD). We found that kidney to body weight and blood urea content were increased in PKD mice. Cystic dilations were increased in kidney tissue from PKD mice, and autophagy-related protein ULK1 and the ratio of LC3-II/LC3-I were decreased, indicating autophagy was inhibited in PKD mice. In addition, miR-25-3p was upregulated in PKD mice, and inhibition of miR-25-3p decreased cystic dilations in kidney tissues, increased ULK1 expression and the ratio of LC3-II/LC3-I, indicating inhibition of miR-25-3p enhanced the autophagy in PKD. Besides, inhibition of miR-25-3p suppressed the proliferation of renal cells and downregulated E2F-1 and PCNA expressions. Importantly, miR-25-3p targetedly suppressed ATG14 expression in PKD cells. Finally, silencing ATG14 abolished the inhibition effect of miR-25-3p inhibitor on renal cell proliferation, and reversed the inhibition effect of miR-25-3p inhibitor on E2F-1 and PCNA expressions in in vitro and in vivo experiments, which suggested that ATG14 was involved in the regulation of miR-25-3p-mediated kidney cell proliferation. Therefore, inhibition of miR-25-3p promoted cell autophagy and suppressed cell proliferation in PKD mice through regulating ATG14.

Ellagic acid inhibits high glucose-induced injury in rat mesangial cells via the PI3K/Akt/FOXO3a signaling pathway.

The pathological damage of mesangial cells serves an important role in the occurrence and development of diabetic nephropathy. Ellagic acid has been reported to possess antioxidant, antitumor, antiviral and anti-inflammatory properties in several diseases, but the roles of ellagic acid in diabetic nephropathy are unclear. The main aim of the present study was to investigate the effect of ellagic acid on high glucose-induced mesangial cell damage. The results revealed that high glucose could induce the hyperproliferation of mesangial cells, decrease the activity of superoxide dismutase, increase the malondialdehyde content, the level of reactive oxygen species, the secretion of inflammatory factors (TNF-α, IL-1ß and IL-6) and the synthesis of extracellular matrix (Fibronectin, MMP-9 and TIMP-1) and activate the PI3K/Akt/FOXO3a signaling pathway. Ellagic acid could attenuate the injury of mesangial cells induced by high glucose in a concentration-dependent manner and its effect was consistent with that of a PI3K inhibitor (LY294002). Moreover, a PI3K agonist (740Y-P) reversed the protective effect of ellagic acid on mesangial cells induced by high glucose. In conclusion, ellagic acid protected mesangial cells from high glucose-induced injury in a concentration-dependent manner. The mechanism may be associated with ellagic acid inhibiting the activation of the PI3K/Akt signaling pathway and reducing the expression levels of downstream transcription factor FOXO3a.