Endothelial cell traction forces on RGD-derivatized polyacrylamide substrata
Endothelial cell traction forces on RGD-derivatized polyacrylamide substrata
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DOI：
10.1021/la026142j
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发表时间：
2003-03-04
期刊：
影响因子：
3.9
通讯作者：
Hammer, DA
中科院分区：
文献类型：
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作者：
Reinhart-King, CA;Dembo, M;Hammer, DA
受体介导的粘附涉及细胞-基质界面处发生的机械和化学信号。使用一种称为牵引力显微镜的相对较新的技术，测量内皮细胞在 RGD 肽衍生的水凝胶基质上施加的机械力的大小、方向和空间位置。我们构建了一个含有 RGD 的细胞粘附九肽密度受控的表面，它可以连接内皮细胞整合素受体并诱导细胞扩散。增加 RGD 肽的浓度会增加细胞在聚丙烯酰胺非粘附表面上的铺展，并且细胞面积是肽浓度的单调递增函数。将细胞施加的力与细胞面积相关联表明，力是细胞面积的线性递增函数，细胞力的平均增量为 10(4) dyn/cm(2) 细胞面积。此外，我们发现内皮细胞施加的牵引力集中在伪足的末端，而在细胞核下几乎可以忽略不计。这些结果表明，内皮细胞可能具有在细胞延伸尖端内的集中位置处接触并拉动基底的内部结构，并且粘附强度随着细胞铺展而增加。
Receptor-mediated adhesion involves both mechanical and chemical signals occurring at the cell-substrate interface. Using a relatively new technique called traction force microscopy, the magnitude, direction, and spatial location of mechanical forces exerted by endothelial cells on a RGD-peptide-derivatized hydrogel substrate were measured. We constructed a surface with a controlled density of cell adhesion nonapeptide containing RGD, which can ligate endothelial cell integrin receptors and induce cell spreading. Increasing the concentration of the RGD peptide increases cell spreading on an otherwise nonadhesive surface of polyacrylamide, and cell area is a monotonically increasing function of peptide concentration. Correlating the force exerted by the cell to the cell area reveals that force is a linear, increasing function of cell area, with a mean increase in cell force of 10(4) dyn/cm(2) cell area. Additionally, we have found that tractions exerted by endothelial cells are concentrated at the ends of pseudopodia and are almost negligible under the nucleus. These results indicate that endothelial cells may have an internal structure that contacts and pulls on the substrate at concentrated locations within the tips of cell extensions and that the strength in adhesion increases with cell spreading.