Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, California 95616, USA.
J Biomed Mater Res A. 2013 Apr;101(4):1069-79. doi: 10.1002/jbm.a.34417. Epub 2012 Sep 11.
The basement membrane of the corneal epithelium presents biophysical cues in the form of topography and compliance that can modulate cytoskeletal dynamics, which, in turn, can result in altering cellular and nuclear morphology and alignment. In this study, the effect of topographic patterns of alternating ridges and grooves on nuclear and cellular shape and alignment was determined. Primary corneal epithelial cells were cultured on either planar or topographically patterned (400-4000 nm pitch) substrates. Alignment of individual cell body was correlated with respective nucleus for the analysis of orientation and elongation. A biphasic response in alignment was observed. Cell bodies preferentially aligned perpendicular to the 800 nm pitch; and with increasing pitch, cells increasingly aligned parallel to the substratum. Nuclear orientation largely followed this trend with the exception of those on 400 nm. On this biomimetic size scale, some nuclei oriented perpendicular to the topography while their cytoskeleton elements aligned parallel. Both nuclei and cell bodies were elongated on topography compared to those on flat surfaces. Our data demonstrate that nuclear orientation and shape are differentially altered by topographic features that are not mandated by alignment of the cell body. This novel finding suggests that nuanced differences in alignment of the nucleus versus the cell body exist and that these differences could have consequences on gene and protein regulation that ultimately regulate cell behaviors. A full understanding of these mechanisms could disclose novel pathways that would better inform evolving strategies in cell, stem cell, and tissue engineering as well as the design and fabrication of improved prosthetic devices.
角膜上皮的基底膜以形貌和顺应性的形式呈现出生物物理线索,这些线索可以调节细胞骨架动力学,进而导致细胞和核形态及排列的改变。在这项研究中,确定了交替脊和槽的形貌模式对核和细胞形状及排列的影响。原代角膜上皮细胞培养在平面或形貌图案(400-4000nm 节距)基底上。对每个细胞体的排列与相应的细胞核进行相关性分析,以确定取向和伸长。观察到对齐的双相反应。细胞体优先垂直于 800nm 节距排列;随着节距的增加,细胞越来越平行于基底排列。细胞核的取向大致遵循这一趋势,但 400nm 除外。在这种仿生尺寸范围内,一些细胞核垂直于形貌取向,而其细胞骨架元素平行于形貌排列。与在平面上相比,细胞在形貌上的细胞核和细胞体都被拉长了。与在平面上相比,细胞在形貌上的细胞核和细胞体都被拉长了。我们的数据表明,核的取向和形状被形貌特征以不同于细胞体对齐的方式改变。这一新颖的发现表明,细胞核与细胞体的对齐存在细微差异,这些差异可能对基因和蛋白质调节产生影响,最终调节细胞行为。对这些机制的全面理解可以揭示新的途径,从而为细胞、干细胞和组织工程以及改进的假体设计和制造提供更好的信息。