Mechanism of hypoxia-induced factor 1α expression in endothelial cells of the human umbilical vein and its induction of apoptosis
Mechanism of hypoxia-induced factor 1α expression in endothelial cells of the human umbilical vein and its induction of apoptosis
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DOI：
10.1007/s11033-007-9083-5
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发表时间：
2008-09
影响因子：
2.8
通讯作者：
Chan Yanyan;Qi Guoxian;Guo Yang;Wang Leting
中科院分区：
文献类型：
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作者：
Chan Yanyan;Qi Guoxian;Guo Yang;Wang Leting
目的探讨缺氧诱导因子1α（hypoxia induced factor 1α，HIF 1α）在人脐静脉内皮细胞（ECV 30 4）中的表达及其诱导凋亡的机制。方法采用体外模型，应用透射电镜、流式细胞术、RT-PCR和Western blot等技术，研究缺氧诱导因子1 α（hypoxia induced factor 1 α，HIF 1α）在ECV 30 4细胞中的转录和蛋白表达，以及HIF 1α对细胞周期的阻断作用。增殖抑制和诱导凋亡。将细胞分为常氧组和缺氧2、4、8、12、24、48 h组。缺氧4、8、12、24和48 h后HIF-1α mRNA表达均显著增加，以24和48 h最为显著，灰度值分别为（71 ± 1.81）和（70 ± 2.02），与对照组比较有显著性差异缺氧后4、8、12、24、48 h，HIF-1α蛋白表达也明显增加（P< 0.01），尤以24、48 h为显著（P< 0.01）（83 ± 0.15）和（98 ± 0.10）（P< 0.01），与其他组比较差异有显著性（P< 0.01）。对照组缺氧后0 h有少量HIF-1α的转录和蛋白表达。缺氧处理后，细胞周期各时相的HIF-1α表达均增加。24和48 h时，G1期细胞数百分比显著增加，分别为66.335 ± 2.144和58.890 ± 5.128; S期细胞数分别为36.215 ± 1.582和39.826 ± 5.097，与对照组比较，0 h时的值分别为43.903 ± 6.506和60.571 ± 24.026，差异有显著性（P< 0.05）。当细胞周期被阻滞在G2/S期时，细胞凋亡率显著增加，与各对照组相比分别为9.24 ± 1.828和30.735 ± 11.38。结论缺氧可使细胞周期阻滞于G1/S期，HIF-1α表达增加。HIF-1α的持续表达可抑制细胞增生，促进损伤细胞的凋亡，对内皮细胞提供保护。
ObjectivesApproach to mechanism of hypoxia-induced factor 1α expression in endothelial cells of human umbilical vein and its induction of apoptosisMethodsIn vitro models, and such techniques as transmission electron microscopy, flow cytometry, RT-PCR and Western blot, were applied to investigate the transcription and protein expression of HIF-1α mRNA in ECV 304 cells and the action of HIF-1α on cell cycle blocking, proliferation inhibition and induction of apoptosis. Cells were divided into two groups: normal oxygen and hypoxic for various time periods (2, 4, 8, 12, 24 and 48 h).ResultsWe observed that the expression level of HIF-1α mRNA and its protein were correlated with the degree of hypoxia. The expression of HIF-1α mRNA notably increased after 4, 8, 12, 24 and 48 h of hypoxia, particularly at 24 and 48 h with a gray scale of (71 ± 1.81) and (70 ± 2.02) respectively, differing significantly from the control group (P< 0.01), The protein expression of HIF-1α also increased 4, 8, 12, 24 and 48 h after hypoxia, particularly at 24 and 48 h, with gray scale (83 ± 0.15) and (98 ± 0.10) respectively (P< 0.01), indicating an increase of HIF-1α protein expression significantly different from the other groups (P< 0.01). In the control group, there was slight transcription and protein expression of HIF-1α at 0 h after hypoxia. Meanwhile, each phase of the cell cycle was detected to have increased expression of HIF-1α in response to oxygen-deficient treatment. At times of 24 and 48 h, the number percentage of cells in G1 significantly increased with values of 66.335 ± 2.144 and 58.890 ± 5.128; however, the number cells in S phase decreased to 36.215 ± 1.582 and 39.826 ± 5.097, significantly different compared to the control group at 0 h with values of 43.903 ± 6.506 and 60.571 ± 24.026—(P< 0.05). When the cell cycle was blocked in the G2/S phase, the cell apoptosis ratio significantly increased by 9.24 ± 1.828 and 30.735 ± 11.38, compared to each control group—(P< 0.01).ConclusionsBy induction of hypoxia, the cell cycle was dramatically blocked in G1/S phase, and the expression of HIF-1α also increased Therefore, sustained expression of HIF-1α can inhibit cell hyperplasia, and the apoptosis promotion of injured cells as well as provide protection of endothelial cells.