lncRNA GAPLINC regulates vascular endothelial cell apoptosis in atherosclerosis.

INTRODUCTION: In this study, we investigated the role of the long non-coding RNA GAPLINC in atherosclerosis under oxidized low-density lipoprotein (ox-LDL) treatment.

MATERIAL AND METHODS: We utilized ox-LDL exposed human aortic endothelial cells as an in-vitro model. The expression level of GAPLINC was quantified by qPCR in different times and concentrations of ox-LDL treatment conditions. Cell apoptosis rate and cell cycle profiles were assessed by flow cytometry and TUNEL assay. The target association was confirmed using a luciferase reporter assay and Western blot.

RESULTS: We found that GAPLINC expression was induced by ox-LDL treatment, but cell proliferation ability was significantly inhibited. We further confirmed that overexpressing of lncRNA GAPLINC in ox-LDL-exposed HAECs decreased cell proliferation by increasing cell apoptosis and arresting cell cycle in G2/M and S phase. Importantly, the detailed mechanistic analysis elucidated that LncRNA GAPLINC acts as a decoy to sequester miR-183-5p to prevent it from binding to target PDCD4. MiR-183-5p targets GAPLINC, and PDCD4 is a downstream target of miR-183-5p, and the cellular effects of this direct interaction were confirmed by a rescue assay experiment.

CONCLUSIONS: The present study demonstrates that upregulation of lncRNA GAPLINC represses the binding of miR-183-5p to the PDCD4 promoter region and then promotes PDCD4 expression, thereby inducing cell apoptosis and suppressing endothelial cell proliferation.