The role of lncRNA MSTRG.2249.1 and miR-540-3p in regulation of angiogenesis in cerebral ischemia

Cerebral ischemia is a prevalent cerebrovascular disease. Although angiogenesis has been confirmed in improving blood supply to brain tissue and promoting neurological recovery, lncRNA MSTRG.2249.1 and underlying mechanism in regulating angiogenesis remains unclear in cerebral ischemia. A rat model of permanent focal middle cerebral artery occlusion (pMCAO) was successfully established. Immunohistochemical techniques were employed to detect expression of von Willebrand factor (vWF) for evaluation of angiogenesis. Subsequently, the expression profiles of lncRNA MSTRG.2249.1, MGAT5B, and miR-540-3p were quantitatively analyzed using real-time quantitative PCR (RT-qPCR) and Western blot techniques. Furthermore, the interaction between miR-540-3p & MSTRG.2249.1, as well as between miR-540-3p & MGAT5B was investigated using a dual-luciferase reporter gene system. Under hypoxic conditions, a hypoxia model of human umbilical vein endothelial cells (HUVECs) with MSTRG.2249.1 overexpression was constructed to further study the impact of MSTRG.2249.1, MGAT5B, and miR-540-3p on angiogenic capacity and their underlying regulatory mechanisms. The results showed that in the successfully established pMCAO model, the expressions of MSTRG.2249.1 and MGAT5B were decreased, while the expression of miR-540-3p was increased, which was consistent with results of RT-qPCR and Western blot. Bioinformatics analysis predicted the interaction between miR-540-3p and MSTRG.2249.1, as well as between miR-540-3p and MGAT5B, and their direct interaction relationships were confirmed by the dual-luciferase reporter gene system. Under hypoxic conditions, it was evaluated that cell proliferation, cell migration, and angiogenic abilities of HUVECs significantly reduced, nevertheless, the MSTRG.2249.1 overexpression model demonstrated that MSTRG.2249.1 could positively regulate the expression of MGAT5B and improve the angiogenic capacity of HUVECs under hypoxic conditions. This study reveals a novel functional role of lncRNA MSTRG.2249.1 and underlying molecular mechanism of lncRNA MSTRG.2249.1 suppressing miR-540-3p to upregulate MGAT5B expression to improve HUVECs mediated angiogenesis in cerebral ischemia, which could offer a novel therapeutic strategy for the treatment of cerebral ischemia.