Abstract：
Ischemic stroke rapidly increases the expression level of vascular endothelial growth factor (VEGF), which promotes neovascularization during hypoxia. However, the effect and mechanism of VEGF intervention on cerebrovascular formation remain unclear. Therefore, our research discussed the protective effect of exogenous VEGF on cells in hypoxia environment in cerebral microvascular endothelial cells, simulating ischemic stroke in hypoxic environment. Firstly, we detected the proliferation and apoptosis of cerebral microvascular endothelial cells under hypoxia environment, as well the expression levels of VEGF-E, vascular endothelial growth factor re-ceptor-2 (VEGFR-2), BCL2, PRKCE and PINK1. Moreover, immunofluorescence and western blotting were used to verify the regulation of exogenous VEGF-E on VEGFR-2 expression in hypoxic or normal oxygen environment. Lastly, we manipulated the concentration of VEGF-E in the culture medium to investigate its impact on phospholipase Cγ1 (PLCγ1)/extracellular signaling regulatory protein kinase (ERK) -1/2 and protein kinase B (AKT) pathways. Additionally, we employed a PLCγ1 inhibitor (U73122) to investigate its impact on proliferation and PLCγ1/ERK pathways. The results show that hypoxia inhibited the proliferation of cerebral microvascular endothelial cells, promoted cell apoptosis, significantly up-regulated the expression of VEGF-E, VEGFR-2, PRKCE and PINK1, but down-regulated the expression of BCL2. Interference from exogenous VEGF-E activated PLCγ1/ERK-1/2 and AKT pathways, promoting cell proliferation and inhibiting apoptosis of hypoxic brain microvascular endothelial cells. In summary, exogenous VEGF-E prevents hypoxia-induced damage to cerebral microvascular endothelial cells by activating the PLCγ1/ERK and AKT pathways. This action inhibits the apoptosis pathway in hypoxic cerebral microvascular endothelial cells, thereby safeguarding the blood-brain barrier and the nervous system.
摘要：
缺血性卒中迅速增加血管内皮生长因子(VEGF)的表达水平,在缺氧期间促进新生血管形成。然而,VEGF干预脑血管形成的作用及机制尚不清楚。因此,探讨外源性VEGF对脑微血管内皮细胞缺氧环境下细胞的保护作用,模拟缺氧环境下的缺血性卒中。首先,检测缺氧环境下脑微血管内皮细胞的增殖和凋亡,以及VEGF-E的表达水平，血管内皮生长因子受体2（VEGFR-2），BCL2、PRKCE和PINK1。此外，免疫荧光法和免疫印迹法验证外源性VEGF-E在低氧或常氧环境中对VEGFR-2表达的调节作用。最后,我们操纵培养基中VEGF-E的浓度，以研究其对磷脂酶Cγ1（PLCγ1）/细胞外信号调节蛋白激酶（ERK）-1/2和蛋白激酶B（AKT）通路的影响。此外,我们使用PLCγ1抑制剂(U73122)研究其对增殖和PLCγ1/ERK通路的影响.结果表明，缺氧抑制脑微血管内皮细胞的增殖，促进细胞凋亡，显著上调VEGF-E的表达,VEGFR-2、PRKCE和PINK1,但下调BCL2的表达。外源性VEGF-E激活的PLCγ1/ERK-1/2和AKT通路的干扰,促进细胞增殖，抑制缺氧脑微血管内皮细胞凋亡。总之,外源性VEGF-E通过激活PLCγ1/ERK和AKT通路防止缺氧诱导的脑微血管内皮细胞损伤。这种作用抑制了缺氧脑微血管内皮细胞的凋亡途径，从而保护血脑屏障和神经系统。
