Inhibition of microRNA-218 reduces HIF-1α by targeting on Robo1 in mice aortic endothelial cells under intermittent hypoxia

Abstract

ObjectiveTo investigate the effects of miR-218 on expression of hypoxia-inducible factors 1α (HIF-1α), vascular endothelial growth factor (VEGF) and cell apoptosis in normal mice aortic endothelial cells under intermittent hypoxia (IH) condition.MethodsAnti-miR-218 inhibitor, miR-negative control and miR-218 mimic were used to tranfect the cells in different groups under IH condition. Both RT-PCR and Western blot were used to determine the expressions of HIF-1α and VEGF. Akt, p-Akt and cell apoptosis related proteins bcl-2, bax and caspase-3 and roundabout 1 (Robo1) were measured using Western blot. Cell apoptosis was evaluated by flow cytometry. Statistical analysis was performed using SPSS 18.0.ResultsExpression of miR-218 was significantly up-regulated in the IH group and was significantly inhibited when cells were transfected with miR-218 inhibitor. Down regulation of miR-218 could reduce the expression of HIF-1α and VEGF under intermittent hypoxia condition. In cells transfected with miR-218 mimic, expression of HIF-1α and VEGF significantly increased compared with the control. However, when treated with LY294002, the expression of HIF-1α and VEGF both decreased. Apoptosis assay showed that down regulation of miR-218 could inhibit intermittent hypoxia induced cell apoptosis, decrease expression of caspase-3 and bax and increase expression of bcl-2 under intermittent hypoxia condition. At last, silencing Robo1 could significantly enhance the expression of HIF-1α under IH condition.ConclusionInhibition of miR-218 could reduce the expression of HIF-1α and protect against IH-induced apoptosis in mice aortic endothelial cells. The effects were associated with PI3K/AKT pathway and might through targeting of Robo1.

Downregulation of microRNA-218 is cardioprotective against cardiac fibrosis and cardiac function impairment in myocardial infarction by binding to MITF

“…Another study reported by Fish et al hypothesized that a Slit/miR-218/Robo regulatory loop is clearly required for the heart tube formation in zebrafish [20]. Expression of miR-218 was observed to be significantly increased in aortic endothelial cells of mice under intermittent hypoxia [39].…”

Sustained Intermittent Hypoxemia Induces Adiponectin Oligomers Redistribution and a Tissue-Specific Modulation of Adiponectin Receptor in Mice

“…Moreover, as we did not detect any modification of AdipoR expression at the mRNA level, our results suggest that hypoxemia could modulate AdipoR protein abundance through post-transcriptional or post-traductional modifications. Indeed, the microRNA 218 was previously found to decrease AdipoR2 protein level (Du et al, 2015) and reported to be induced in hypoxic condition (Liu et al, 2017). Another mechanism could be an increased lysosomal degradation of AdipoR.…”

Intermittent Hypoxia Activates Duration-Dependent Protective and Injurious Mechanisms in Mouse Lung Endothelial Cells

“…Finally, a forced downregulation of mmu-mir-218 has been shown to protect against intermittent hypoxia-induced apoptosis (Liu et al, 2017). Though, the authors describe upregulation of this miRNA as a response to IH in mice.…”