内质网应激条件下血管内皮细胞生长因子在人脑微血管内皮细胞中的表达

为观察内质网应激条件下血管内皮细胞生长因子的表达情况，用不同浓度的衣霉素处理体外培养的人脑微血管内皮细胞，建立内质网应激模型，采用RT—PCR、蛋白质免疫印迹以及免疫细胞化学的方法检测了细胞内血管内皮细胞生长因子的表达。结果发现血管内皮细胞生长因子在人脑微血管内皮细胞中存在一定的表达；内质网应激可诱导血管内皮细胞生长因子表达升高，随着衣霉素浓度的增高，血管内皮细胞生长因子的表达逐渐增加，与mRNA水平相比，血管内皮细胞生长因子蛋白量的增加更明显。实验结果提示人脑微血管内皮细胞中存在血管内皮细胞生长因子自分泌，血管内皮细胞生长因子可能是内质网应激的靶基因。

Response of VEGF Expression in Human Brain Microvascular Endothelial Cell to the Inducer of Endoplasmic Reticulum Stress

To reveal the expression of vascular endothelial growth factor (VEGF) under conditions that cause endoplasmic reticulum (ER) stress, human brain microvascular endothelial cells (HBMEC) were treated with tunicamycin at different concentration in vitro. RT-PCR, Western blot and immunocytochemisty analyses were used to measure intracellular levels of VEGF. The result showed that there was a basal expression of VEGF in HBMEC. Conditions known to active ER stress response could increase the expression of VEGF, and the level of VEGF mRNA was not correlated with that of VEGF under all conditions. Compared with GRP94, the increase of VEGF in response to tunicamycin at different concentrations was rapid. These results indicated that VEGF was an ER stress responsive gene and suggested that the expression of VEGF was regulated by unfolded protein response.