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.

研究表明，microRNA-126在促进血管生成中起关键作用。但是，它对缺血性中风后血管生成的影响尚不清楚。在这里，我们探讨了microRNA-126-3p和microRNA-126-5p对脑缺血后血管生成和神经发生的影响。我们证明，与混乱的miRNA对照相比，microRNA（miRNA）-126-3p和microRNA-126-5p均能增加人脐静脉内皮细胞（HUVEC）的增殖，迁移和管形成（p <0.05）。通过慢病毒将microRNA-126转移到小鼠大脑中动脉闭塞模型中，我们发现microRNA-126过表达增加了CD31 ⁺ / BrdU ⁺（5-溴2'-脱氧尿苷阳性）增殖内皮细胞和DCX ^+的数量与对照小鼠相比，缺血性小鼠大脑中的/ BrdU ⁺成神经细胞，改善了神经行为学结果（p <0.05），并减少了脑萎缩体积（p <0.05）。蛋白质印迹结果表明，慢病毒-microRNA-126治疗组的AKT和ERK信号通路被激活（p <0.05）。PCR和Western印迹结果均表明，慢病毒microRNA-126治疗组的酪氨酸蛋白磷酸酶非受体9型（PTPN9）减少（p <0.05）。双荧光素酶基因报告基因检测还显示PTPN9是缺血性脑中microRNA-126-3p和microRNA-126-5p的直接靶标。我们证明了microRNA-126-3p和microRNA-126-5p促进缺血小鼠大脑中的血管生成和神经发生，并进一步改善了神经行为学结果。我们的机理研究进一步表明，microRNA-126通过直接抑制其靶标PTPN9并激活AKT和ERK信号通路来介导血管生成。