Lam Kevin H, Shihabeddin Tarik Z, Awkal Jacob A, Najjar Alex M, Miron-Mendoza Miguel, Maruri Daniel P, Varner Victor D, Petroll W Matthew, Schmidtke David W
Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA.
Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
J Funct Biomater. 2023 Apr 13;14(4):217. doi: 10.3390/jfb14040217.
During corneal wound healing, corneal keratocytes are exposed to both biophysical and soluble cues that cause them to transform from a quiescent state to a repair phenotype. How keratocytes integrate these multiple cues simultaneously is not well understood. To investigate this process, primary rabbit corneal keratocytes were cultured on substrates patterned with aligned collagen fibrils and coated with adsorbed fibronectin. After 2 or 5 days of culture, keratocytes were fixed and stained to assess changes in cell morphology and markers of myofibroblastic activation by fluorescence microscopy. Initially, adsorbed fibronectin had an activating effect on the keratocytes as evidenced by changes in cell shape, stress fiber formation, and expression of alpha-smooth muscle actin (α-SMA). The magnitude of these effects depended upon substrate topography (i.e., flat substrate vs aligned collagen fibrils) and decreased with culture time. When keratocytes were simultaneously exposed to adsorbed fibronectin and soluble platelet-derived growth factor-BB (PDGF-BB), the cells elongated and had reduced expression of stress fibers and α-SMA. In the presence of PDGF-BB, keratocytes plated on the aligned collagen fibrils elongated in the direction of the fibrils. These results provide new information on how keratocytes respond to multiple simultaneous cues and how the anisotropic topography of aligned collagen fibrils influences keratocyte behavior.
在角膜伤口愈合过程中，角膜基质细胞会受到生物物理和可溶性信号的影响，这些信号会使它们从静止状态转变为修复表型。目前对于基质细胞如何同时整合这些多种信号的了解还不够深入。为了研究这个过程，将原代兔角膜基质细胞培养在有排列的胶原纤维图案并吸附有纤连蛋白的底物上。培养2天或5天后，固定并染色基质细胞，通过荧光显微镜评估细胞形态变化和肌成纤维细胞活化标志物。最初，吸附的纤连蛋白对基质细胞有激活作用，这可通过细胞形状变化、应力纤维形成以及α-平滑肌肌动蛋白（α-SMA）的表达来证明。这些作用的程度取决于底物的拓扑结构（即平坦底物与排列的胶原纤维），并随培养时间而降低。当基质细胞同时暴露于吸附的纤连蛋白和可溶性血小板衍生生长因子-BB（PDGF-BB）时，细胞伸长，应力纤维和α-SMA的表达减少。在PDGF-BB存在的情况下，接种在排列的胶原纤维上的基质细胞会沿纤维方向伸长。这些结果为基质细胞如何对多种同时存在的信号作出反应以及排列的胶原纤维的各向异性拓扑结构如何影响基质细胞行为提供了新信息。
