Modulation of miRNAs by vitamin C in H2O2‑exposed human umbilical vein endothelial cells.

Vitamin C plays a protective role in oxidative damage by blocking the effects of free radicals. The present study investigated the mechanisms through which vitamin C partly mediates anti‑apoptotic and antioxidant functions via the regulation of microRNAs (miRNAs or miRs). For this purpose, a global miRNA expression analysis on human umbilical vein endothelial cells (HUVECs) treated with vitamin C was conducted using microarrays containing human precursor and mature miRNA probes. The results revealed that there were 42 identical miRNAs among the differentially expressed miRNAs in the HUVEC group and H2O2 + vitamin C‑treated HUVEC group compared to the H2O2‑exposed HUVEC group, including 41 upregulated miRNAs and 1 down‑regulated miRNA. Using bioinformatics analysis, differentially expressed miRNAs were investigated to identify novel target mRNAs and signaling pathways. Pathway enrichment analyses revealed that apoptosis, the mitogen‑activated protein kinase (MAPK) signaling pathway, phosphoinositide 3‑kinase (PI3K)/Akt signaling pathway and oxidative phosphorylation were significantly enriched. The results from western blot analysis demonstrated that the interleukin (IL)10, matrix metalloproteinase (MMP)2, cAMP‑response element binding protein (CREB) and p‑CREB protein expression levels in HUVECs transfected with hsa‑miR‑3928‑5p and induced by H2O2 were significantly downregulated; the MAPK9, caspase‑3 (CASP3) and p‑CASP3 protein expression levels in HUVECs transfected with hsa‑miR‑323a‑5p and induced by H2O2 were significantly downregulated. The present study therefore demonstrates that vitamin C partly exerts protective effects on HUVECs through the regulation of miRNA/mRNA axis expression.