miR-216a-5p promotes mesangial cell proliferation by targeting FoxO1 in diabetic nephropathy.

BACKGROUND

Diabetic nephropathy (DN) is a leading cause of end-stage renal disease worldwide. microRNAs (miRNAs) have been reported to play essential roles in DN progression. However, the mechanism of miR-216a-5p on DN progression is still unclear.

METHODS

A DN model was established in human mesangial cells (HMC) by high glucose treatment. Cell proliferation was investigated using the cell counting kit-8 (CCK-8) assay. The cell cycle was measured through a propidium iodide (PI) cell cycle kit with flow cytometry. The interaction between miR-216a-5p and forkhead boxO1 (FoxO1) was probed by a bioinformatics analysis and luciferase activity assay. The expression of miR-216a-5p was detected using a quantitative real-time polymerase chain reaction (qRT-PCR). The abundances of FoxO1 and cell cycle-related cyclinD1, cyclin-dependent kinase 4 (CDK4), CDK6 and p27 were examined by qRT-PCR and Western blots (WB).

RESULTS

miR-216a-5p was up-regulated while FoxO1 was down-regulated in DN tissues. Moreover, miR-216a-5p promoted cell proliferation by regulating the cell cycle in high glucose-treated HMC cells. Notably, FoxO1 was a direct target and negatively correlated with miR-216a-5p. In addition, miR-216a induced cyclinD1, CDK4 and CDK6 but inhibited p27 expressions at the mRNA and protein levels. Furthermore, FoxO1 restoration reversed the regulatory effect of miR-216a on the cell cycle by regulating cyclinD1, CDK4, CDK6 and p27 abundances at the mRNA and protein levels.

CONCLUSION

miR-216a-5p is ectopic in DN and it promotes cell proliferation through regulating the cell cycle by targeting FoxO1 in high glucose-stimulated HMC cells, indicating it may serve as a novel biomarker for DN treatment.