Studies demonstrate that microRNA-126 plays a critical role in promoting angiogenesis. However, its effects on angiogenesis following ischemic stroke are unclear. Here, we explored the effect of microRNA-126-3p and microRNA-126-5p on angiogenesis and neurogenesis after brain ischemia. We demonstrated that both microRNA (miRNA)-126-3p and microRNA-126-5p increased the proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) compared with the scrambled miRNA control (p < 0.05). Transferring microRNA-126 into a mouse middle cerebral artery occlusion model via lentivirus, we found that microRNA-126 overexpression increased the number of CD31 + /BrdU + (5-bromo-2′-deoxyuridine-positive) proliferating endothelial cells and DCX + /BrdU + neuroblasts in the ischemic mouse brain, improved neurobehavioral outcomes (p < 0.05), and reduced brain atrophy volume (p < 0.05) compared with control mice. Western blot results showed that AKT and ERK signaling pathways were activated in the lentiviral-microRNA-126-treated group (p < 0.05). Both PCR and western blot results demonstrated that tyrosine-protein phosphatase non-receptor type 9 (PTPN9) was decreased in the lentiviral-microRNA-126-treated group (p < 0.05). Dual-luciferase gene reporter assay also showed that PTPN9 was the direct target of microRNA-126-3p and microRNA-126-5p in the ischemic brain. We demonstrated that microRNA-126-3p and microRNA-126-5p promoted angiogenesis and neurogenesis in ischemic mouse brain, and further improved neurobehavioral outcomes. Our mechanistic study further showed that microRNA-126 mediated angiogenesis through directly inhibiting its target PTPN9 and activating AKT and ERK signaling pathways.
Qu, M., Pan, J., Wang, L., Zhou, P., Song, Y., Wang, S., … Yang, G. Y. (2019). MicroRNA-126 Regulates Angiogenesis and Neurogenesis in a Mouse Model of Focal Cerebral Ischemia. Molecular Therapy - Nucleic Acids, 16, 15–25. https://doi.org/10.1016/j.omtn.2019.02.002