Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan.
Department of Life Sciences & Institute of Genome Sciences, National Yang-Ming University, Taipei, 11221, Taiwan.
Sci Rep. 2017 Aug 22;7(1):9068. doi: 10.1038/s41598-017-09618-y.
Cell membrane roughness has been proposed as a sensitive feature to reflect cellular physiological conditions. In order to know whether membrane roughness is associated with the substrate properties, we employed the non-interferometric wide-field optical profilometry (NIWOP) technique to measure the membrane roughness of living mouse embryonic fibroblasts with different conditions of the culture substrate. By controlling the surface density of fibronectin (FN) coated on the substrate, we found that cells exhibited higher membrane roughness as the FN density increased in company with larger focal adhesion (FA) sizes. The examination of membrane roughness was also confirmed with atomic force microscopy. Using reagents altering actin or microtubule cytoskeletons, we provided evidence that the dynamics of actin filaments rather than that of microtubules plays a crucial role for the regulation of membrane roughness. By changing the substrate rigidity, we further demonstrated that the cells seeded on compliant gels exhibited significantly lower membrane roughness and smaller FAs than the cells on rigid substrate. Taken together, our data suggest that the magnitude of membrane roughness is modulated by way of actin dynamics in cells responding to substrate properties.
细胞膜粗糙度已被提出作为反映细胞生理状态的敏感特征。为了了解膜粗糙度是否与基底性质有关，我们采用非干涉式宽场光学轮廓术（NIWOP）技术测量了不同基底条件下活的小鼠胚胎成纤维细胞的膜粗糙度。通过控制基底上涂覆的纤连蛋白（FN）的表面密度，我们发现随着 FA 大小的增大，细胞表现出更高的膜粗糙度，同时 FN 密度也增加。原子力显微镜的检查也证实了膜粗糙度的变化。使用改变肌动蛋白或微管细胞骨架的试剂，我们提供的证据表明，肌动蛋白丝的动力学而不是微管的动力学对于调节膜粗糙度起着至关重要的作用。通过改变基底的刚性，我们进一步证明，与在刚性基底上的细胞相比，接种在顺应性凝胶上的细胞表现出显著更低的膜粗糙度和更小的 FA。总之，我们的数据表明，在细胞对基底性质做出反应时，膜粗糙度的大小是通过肌动蛋白动力学来调节的。
