LncRNA MALAT1 Promotes OGD-Induced Apoptosis of Brain Microvascular Endothelial Cells by Sponging miR-126 to Repress PI3K/Akt Signaling Pathway.

Ischemic stroke (IS) is a common disease that seriously endangers human health. Patients with IS present with increased death of brain microvascular endothelial cells (BMECs). MALAT1 is found to be upregulated in IS patients. However, the function of MALAT1 in IS pathogenesis still remains unclear. This study aimed to investigate the role of MALAT1 in IS in vitro model and the related molecular mechanisms. The expressions of MALAT1 and miR-126 were detected by qPCR. The in vitro IS model was established by treating BMECs with oxygen-glucose deprivation (OGD). Cell viability and cell apoptosis were assessed by MTT assay and flow cytometry, respectively. Luciferase assay was conducted to examine the interplay between MALAT1 and miR-126. Western blotting was used to determine the protein levels of apoptosis-associated proteins (e.g. caspase 3, Bax and Bcl-2) and PI3K/Akt pathway-related proteins (e.g. PI3K, Akt, p-PI3K, p-Akt). OGD induced upregulation of MALAT1 and downregulation of miR-126 in HBMECs. MALAT1 knockdown promoted the proliferation of HBMECs and reduced the proportion of apoptotic HBMECs by regulating the expression of apoptosis-related proteins. MALAT1 targeted and negatively regulated miR-126 expression. Overexpression of miR-126 activated the PI3K/Akt pathway, which in turn affected the proliferation and apoptosis of HBMECs. MALAT1 negatively regulated PI3K/Akt pathway. MALAT1 inhibited the proliferation and induced the apoptosis of OGD-induced HBMECs through suppressing PI3K/AKT pathway by sponging miR-126, providing a potential therapeutic target for IS.