Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA; Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
Exp Eye Res. 2020 Nov;200:108228. doi: 10.1016/j.exer.2020.108228. Epub 2020 Sep 10.
In vivo, corneal keratocytes reside within a complex 3D extracellular matrix (ECM) consisting of highly aligned collagen lamellae, growth factors, and other extracellular matrix components, and are subjected to various mechanical stimuli during developmental morphogenesis, fluctuations in intraocular pressure, and wound healing. The process by which keratocytes convert changes in mechanical stimuli (e.g. local topography, applied force, ECM stiffness) into biochemical signaling is known as mechanotransduction. Activation of the various mechanotransductive pathways can produce changes in cell migration, proliferation, and differentiation. Here we review how corneal keratocytes respond to and integrate different biochemical and biophysical factors. We first highlight how growth factors and other cytokines regulate the activity of Rho GTPases, cytoskeletal remodeling, and ultimately the mechanical phenotype of keratocytes. We then discuss how changes in the mechanical properties of the ECM have been shown to regulate keratocyte behavior in sophisticated 2D and 3D experimental models of the corneal microenvironment. Finally, we discuss how ECM topography and protein composition can modulate cell phenotypes, and review the different methods of fabricating in vitro mimics of corneal ECM topography, novel approaches for examining topographical effects in vivo, and the impact of different ECM glycoproteins and proteoglycans on keratocyte behavior.
在体内,角膜基质细胞存在于由高度排列的胶原板层、生长因子和其他细胞外基质成分组成的复杂 3D 细胞外基质 (ECM) 中,并且在发育形态发生、眼内压波动和伤口愈合过程中受到各种机械刺激。基质细胞将机械刺激(例如局部形貌、施加的力、ECM 硬度)的变化转化为生化信号的过程称为机械转导。各种机械转导途径的激活可导致细胞迁移、增殖和分化的变化。在这里,我们回顾了角膜基质细胞如何响应和整合不同的生化和生物物理因素。我们首先强调了生长因子和其他细胞因子如何调节 Rho GTPases 的活性、细胞骨架重塑,最终调节基质细胞的机械表型。然后,我们讨论了 ECM 力学性质的变化如何在角膜微环境的复杂 2D 和 3D 实验模型中调节基质细胞的行为。最后,我们讨论了 ECM 形貌和蛋白质组成如何调节细胞表型,并回顾了体外模拟角膜 ECM 形貌的不同方法、体内研究形貌影响的新方法以及不同 ECM 糖蛋白和蛋白聚糖对基质细胞行为的影响。