Department of Biomedical Engineering, Boston University, Engineering Research Building Rm 502, 44 Cummington Mall, Boston, MA 02215, USA.
Integr Biol (Camb). 2014 Mar;6(3):357-65. doi: 10.1039/c3ib40127h. Epub 2014 Jan 17.
Cellular traction forces are important quantitative measures in cell biology as they have provided much insight into cell behavior in contexts such as cellular migration, differentiation, and disease progression. However, the complex environment in vivo permits application of cell traction forces through multiple types of cell adhesion molecules. Currently available approaches to differentiate traction forces among multiple cell adhesion molecules are limited to specialized approaches to decouple cell-cell from cell-extracellular matrix (ECM) tractions. Here, we present a technique which uses indirect micropatterning onto a polyacrylamide gel to pattern multiple, spatially distinct fluorescently labeled ECM proteins, specifically gelatin and fibronectin (Fn), and confine the area to which cells can adhere. We found that cells interacting with both gelatin and Fn altered their traction forces significantly in comparison to cells on Fn-only substrates. This crosstalk interaction resulted in a decrease in overall traction forces on dual-patterned substrates as compared to cells on Fn-only substrates. This illustrates the unique need to study such interactions and demonstrates great potential in future studies in multi-ligand environments. Current micropatterning techniques on glass can easily be adapted to present other protein classes, such as cadherins, while maintaining control of adhesion spacing, cell spread area, and stiffness, each of which are important regulators of cell mechanobiology.
细胞牵引力是细胞生物学中的重要定量指标，因为它们为细胞在细胞迁移、分化和疾病进展等情况下的行为提供了很多深入的了解。然而，体内复杂的环境允许通过多种细胞黏附分子应用细胞牵引力。目前区分多种细胞黏附分子牵引力的方法仅限于将细胞-细胞与细胞-细胞外基质（ECM）牵引力解耦的专门方法。在这里，我们提出了一种使用间接微图案化到聚丙烯酰胺凝胶上以图案化多种空间上不同的荧光标记 ECM 蛋白（特别是明胶和纤维连接蛋白（Fn））并限制细胞可以附着的区域的技术。我们发现，与仅在 Fn 上的细胞相比，与明胶和 Fn 相互作用的细胞显著改变了它们的牵引力。这种串扰相互作用导致与仅在 Fn 上的基底相比，双图案化基底上的总牵引力降低。这说明了研究这种相互作用的独特需求，并在未来的多配体环境研究中展示了巨大的潜力。目前在玻璃上的微图案化技术可以很容易地适应呈现其他蛋白质类，如钙黏蛋白，同时保持对粘附间距、细胞扩展面积和刚度的控制，这些都是细胞机械生物学的重要调节剂。
