Long non-coding RNA XIST regulates hyperglycemia-associated apoptosis and migration in human retinal pigment epithelial cells

Abstract

ObjectivePatients with chronic hyperglycemia are at high risk of developing diabetic retinopathy. In this study, we investigated the functional role of long-noncoding RNA (lncRNA) X-inactive specific transcript (XIST) in anin vitro model of diabetic hyperglycemia in human retinal pigment epithelial ARPE-19 cells. MethodARPE-19 cells were cultured in normal glucose (NG) and high-glucose (HG) conditions to mimic hyperglycemia-associated cell apoptosis, migration and XIST expression. XIST was overexpressed in ARPE-19 cells to examine its functions in HG-induced cell apoptosis and migration. The downstream competing target of XIST, human mature microRNA-21-5p (hsa-miR-21-5p) was assessed by dual-luciferase assay and qRT-PCR. Hsa-miR-21-5p was upregulated in XIST-overexpressed ARPE-19 cells to further assess the functional correlation between XIST and hsa-miR-21-5p in hyperglycemia-associated cell apoptosis and migration. ResultsHG insult increased apoptosis, reduced migration and downregulated XIST in ARPE-19 cells. XIST overexpression significantly protected HG insult in ARPE-19 cells, by reducing apoptosis and restoring migration capability. XIST directly bound and inhibited hsa-miR-21-5p expression in HG-insulted ARPE-19 cells. Furthermore, hsa-miR-21-5p upregulation reversed the protective effects of XIST in HG-insulted ARPE-19 cells. ConclusionXIST, likely through competitive binding of hsa-miR-21-5p, provides protection against hyperglycemia-associated injury in human retinal pigment epithelial cells.