Endothelial cell migration in stable gradients of vascular endothelial growth factor a and fibroblast growth factor 2 - Effects on chemotaxis and chemokinesis
Endothelial cell migration in stable gradients of vascular endothelial growth factor a and fibroblast growth factor 2 - Effects on chemotaxis and chemokinesis
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DOI：
10.1074/jbc.m704917200
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发表时间：
2008-05-16
影响因子：
4.8
通讯作者：
Kreuger, Johan
中科院分区：
文献类型：
--
作者：
Barkefors, Irmeli;Le Jan, Sebastien;Kreuger, Johan
在正常和病理性血管生成过程中，分泌的信号蛋白的前体引导生长的血管。然而，内皮细胞整合和响应趋化因子的分级分布的机制仍然知之甚少。在这项研究中，我们研究了血管内皮生长因子A（VEGFA）和成纤维细胞生长因子2（FGF 2）使用一种新的微流控趋化室（MCC）的丘陵形梯度的内皮细胞迁移。使用延时显微镜在单个细胞的水平上对细胞迁移进行评分。在400 μ m的距离上，范围为0 - 50 ng/ml的稳定梯度的VEGFA 165显示出强烈诱导不同血管来源的内皮细胞的趋化性。VEGFA 121，不能结合蛋白聚糖和神经纤毛蛋白共受体，也显示在这种设置诱导趋化性。此外，FGF 2的梯度能够吸引小静脉内皮细胞，但不能吸引动脉内皮细胞，尽管不如VEGFA 165有效。值得注意的是，恒定水平的VEGFA 165，而不是FGF 2，显示有效地减少趋化作用。系统地探索不同的梯度形状导致识别有效的细胞引导所需的最小梯度陡度。最后，对所施加梯度的不同区域中的细胞迁移的分析表明，当细胞达到梯度的高端时，趋化性降低。我们的研究结果表明，趋化生长因子梯度可能会指示内皮细胞向非迁移表型时，接近生长因子源。
Gradients of secreted signaling proteins guide growing blood vessels during both normal and pathological angiogenesis. However, the mechanisms by which endothelial cells integrate and respond to graded distributions of chemotactic factors are still poorly understood. We have in this study investigated endothelial cell migration in response to hill-shaped gradients of vascular endothelial growth factor A (VEGFA) and fibroblast growth factor 2 (FGF2) using a novel microfluidic chemotaxis chamber (MCC). Cell migration was scored at the level of individual cells using time-lapse microscopy. A stable gradient of VEGFA165 ranging from 0 to 50 ng/ml over a distance of 400 mu m was shown to strongly induce chemotaxis of endothelial cells of different vascular origin. VEGFA121, unable to bind proteoglycan and neuropilin coreceptors, was also shown to induce chemotaxis in this setup. Furthermore, a gradient of FGF2 was able to attract venular but not arterial endothelial cells, albeit less efficiently than VEGFA165. Notably, constant levels of VEGFA165, but not of FGF2, were shown to efficiently reduce chemokinesis. Systematic exploration of different gradient shapes led to the identification of a minimal gradient steepness required for efficient cell guidance. Finally, analysis of cell migration in different regions of the applied gradients showed that chemotaxis is reduced when cells reach the high end of the gradient. Our findings suggest that chemotactic growth factor gradients may instruct endothelial cells to shift toward a nonmigratory phenotype when approaching the growth factor source.