Induction of three-dimensional assembly and increase in apoptosis of human endothelial cells by simulated microgravity: Impact of vascular endothelial growth factor
Induction of three-dimensional assembly and increase in apoptosis of human endothelial cells by simulated microgravity: Impact of vascular endothelial growth factor
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DOI：
10.1007/s10495-006-5697-7
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发表时间：
2006-05-01
期刊：
影响因子：
7.2
通讯作者：
Grimm, D.
中科院分区：
文献类型：
--
作者：
Infanger, M.;Kossmehl, P.;Grimm, D.
内皮细胞在许多疾病的发病机制中起着至关重要的作用，并且对低重力条件高度敏感。我们利用三维随机定位仪(回转器)研究了模拟失重对人EA.hy926细胞株(4、12、24、48和72小时)的影响，并探讨了血管内皮生长因子(10 ng/ml)的影响。模拟微重力导致细胞外基质蛋白(ECMP)增加，并改变了细胞骨架成分，如微管(α-微管蛋白)和中间丝(细胞角蛋白)。在最初的4h内，模拟微重力和单独的血管内皮生长因子均可促进ECMP(I型胶原、纤维连接蛋白、骨桥蛋白、层粘连蛋白)和Flk-1蛋白的表达。微重力与血管内皮细胞生长因子之间未见协同作用。微重力作用12h后，上述蛋白质均进一步增强。DAPI染色、原位末端标记法、流式细胞仪和电子显微镜显示血管内皮细胞在4h后出现凋亡的形态和生化征象，72h后进一步增强，血管内皮生长因子显著抑制细胞的凋亡。Caspase-3、Bax、Fas和85-kDa的凋亡相关切割片段明显减少。72 h后，大部分存活的内皮细胞已组装成三维管状结构。模拟失重可诱导细胞凋亡，增加ECMP的含量。血管内皮生长因子对暴露在模拟微重力下的内皮细胞产生细胞保护作用。
Endothelial cells play a crucial role in the pathogenesis of many diseases and are highly sensitive to low gravity conditions. Using a three-dimensional random positioning machine (clinostat) we investigated effects of simulated weightlessness on the human EA.hy926 cell line (4, 12, 24, 48 and 72 h) and addressed the impact of exposure to VEGF (10 ng/ml). Simulated microgravity resulted in an increase in extracellular matrix proteins (ECMP) and altered cytoskeletal components such as microtubules (alpha-tubulin) and intermediate filaments (cytokeratin). Within the initial 4 h, both simulated microgravity and VEGF, alone, enhanced the expression of ECMP (collagen type I, fibronectin, osteopontin, laminin) and flk-1 protein. Synergistic effects between microgravity and VEGF were not seen. After 12 h, microgravity further enhanced all proteins mentioned above. Moreover, clinorotated endothelial cells showed morphological and biochemical signs of apoptosis after 4 h, which were further increased after 72 h. VEGF significantly attenuated apoptosis as demonstrated by DAPI staining, TUNEL flow cytometry and electron microscopy. Caspase-3, Bax, Fas, and 85-kDa apoptosis-related cleavage fragments were clearly reduced by VEGF. After 72 h, most surviving endothelial cells had assembled to three-dimensional tubular structures. Simulated weightlessness induced apoptosis and increased the amount of ECMP. VEGF develops a cell-protective influence on endothelial cells exposed to simulated microgravity.