Objective To investigate the effect of triptolide (TP) on the expression of hypoxia inducible factor 1 alpha (HIF1α) and vascular endothelial growth factor (VEGF) in the human umbilical vein endothelial cells (HUVECs) under hypoxia. Methods (1) HUVECs were treated with 0, 40, 80, 160 and 320 nmol/L TP (named with hypoxia group, TP40 group, TP80 group, TP160 group and TP320 group, respectively) under the hypoxic condition (37℃, 5%CO2, 1%O2, 94%N2) for culturing 12 hours. Meanwhile, cells cultured under normoxia condition (without TP added) were set as the normoxia group. Western blot assay was used to detect the expression of HIF1αin each group. (2) The cells were divided into normal control group, hypoxia group and TP80 group. The immunofluorescence method was performed to detect the localization of HIF1α in cells. (3) Expressions of VEGF were detected by Western blot assay in TP80 group and hypoxia group. (4) The cells were divided into hypoxia group, TP80 group, TP80+KF20 group (80 nmol/L TP and 20μmol/L KC7F2), and TP80+KF30 group (80 nmol/L TP and 30 μmol/L KC7F2). After 12-hour culturing, Western blot assay was used to detect the expressions of HIF1α and VEGF in each group. Results (1) Under the normoxia condition, no HIF1α was detected in HUVECs. The expression level of HIF1αwas significantly increased in TP80 group than that in hypoxia group (P<0.05), while there was no significant change in expression of hypoxia HIF1αin TP160 group and TP320 group compared with that of hypoxic group. (2) The immunofluorescence result showed that HIF1α was mainly expressed in the nucleus. (3) The expression of VEGF was significantly increased in TP80 group than that in hypoxia group (P < 0.05). (4) After the intervention of KC7F2, HIF1αand VEGF expression levels were significantly decreased in the TP80+KF20 group and the TP80+KF30 group than those in the TP80 group (P<0.05). Conclusion TP can improve the expression of HIF1αand VEGF to accelerate the proliferation of endothelial cells under hypoxia condition.%目的 探讨缺氧环境下雷公藤甲素(TP)对人脐静脉内皮细胞(HUVECs)中缺氧诱导因子1α(HIF1α)和血管内皮生长因子(VEGF)表达的影响.方法 (1)HUVECs加入0、40、80、160、320 nmol/L的TP(分别为缺氧组,TP40组、TP80组、TP160组、TP320组)在缺氧条件下(37℃、5%CO2、1%O2、94%N2)培养12 h,同时设常氧组(不加TP)作为对照,Western blot检测各组HIF1α蛋白表达.(2)细胞设TP80组、缺氧组和常氧组,免疫荧光法检测HIF1α在细胞中的表达定位.(3)设TP80组和缺氧组,处理结束后Western blot检测VEGF蛋白表达水平.(4)设缺氧组、TP80组,TP80+KF20组(80 nmol/L TP和20μmol/L KC7F2)、TP80+KF30组(80 nmol/L TP和30μmol/L KC7F2),处理12 h后Western blot检测各组HIF1α、VEGF蛋白表达.结果 (1)常氧条件下HUVECs不表达HIF1α;缺氧条件下,TP80组HIF1α表达水平较缺氧组明显升高(P<0.05),TP160组和TP320组HIF1α表达水平与缺氧组相比无明显变化.(2)细胞免疫荧光结果显示HIF1α主要表达于细胞核.(3)TP80组VEGF表达水平较缺氧组升高(P<0.05).(4)经KC7F2干预后,TP80+KF20组和TP80+KF30组HIF1α、VEGF表达水平较TP80组明显降低(P<0.05).结论 缺氧环境下TP可通过提高HIF1α和VEGF表达来促进内皮细胞的增殖.
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