Petroll W M, Cavanagh H D, Jester J V
Department of Ophthalmology, University of Texas Southwestern Medical Center at Dallas, Texas, USA.
Scanning. 1998 Mar;20(2):74-82. doi: 10.1002/sca.1998.4950200202.
Radial keratotomy (RK) is a refractive surgical procedure in which partial thickness incisions are made in the cornea in order to alter its shape. Previous studies suggest that RK wounds undergo changes in wound gape in response to the ingrowth of myofibroblasts which mediate subsequent wound contraction and may modulate changes in corneal curvature seen after RK. A recent quantitative analysis of f-actin organization in full-thickness incisional wounds in the rabbit demonstrated that microfilament bundles (stress fibers) present in myofibroblasts align parallel to the long axis of the wound during wound contraction. To investigate whether the same pattern of alignment occurs after RK, a similar analysis of f-actin organization was undertaken using the cat RK model. Radial keratotomy wounds were studied from 10 to 28 days after surgery using en block staining with fluorescein isothiocyanate (FITC) phalloidin, and three-dimensional (3-D) datasets (z-series of en face optical sections) were collected using laser confocal microscopy at various regions within the wound. In addition, conventional en face sections were double-labeled using combinations of phalloidin and antibodies to fibronectin and alpha 5 beta 1 integrin. Myofibroblast ingrowth started in the bottom of the wound and progressed anteriorly. At 10 to 14 days, f-actin was predominantly distributed in long, thick bundles (stress fibers) within the wound. These fibers appeared to be randomly oriented anteriorly, but became progressively more aligned with the long axis of the wound posteriorly. At 21 days, the stress fibers were predominantly oriented parallel to the long axis of the wound at all levels. F-actin, fibronectin and integrin were coaligned at both the 14 and 21 day time points. Since the majority of wound closure occurs between 14 and 28 days after surgery, we conclude that parallel alignment of the actin filament-fibronectin-integrin assembly in the cat RK model is associated with wound contraction.
放射状角膜切开术（RK）是一种屈光性外科手术，通过在角膜上制作部分厚度的切口来改变其形状。先前的研究表明，RK伤口会随着肌成纤维细胞的长入而发生伤口间隙变化，肌成纤维细胞介导随后的伤口收缩，并可能调节RK后观察到的角膜曲率变化。最近对兔全层切口伤口中f-肌动蛋白组织的定量分析表明，肌成纤维细胞中存在的微丝束（应力纤维）在伤口收缩过程中与伤口的长轴平行排列。为了研究RK后是否会出现相同的排列模式，使用猫RK模型对f-肌动蛋白组织进行了类似分析。在手术后10至28天，使用异硫氰酸荧光素（FITC）鬼笔环肽进行整块染色研究放射状角膜切开术伤口，并使用激光共聚焦显微镜在伤口内的各个区域收集三维（3-D）数据集（正面光学切片的z系列）。此外，使用鬼笔环肽与抗纤连蛋白和α5β1整合素抗体的组合对传统的正面切片进行双重标记。肌成纤维细胞从伤口底部开始长入并向前推进。在10至14天时，f-肌动蛋白主要分布在伤口内长而粗的束（应力纤维）中。这些纤维在伤口前部似乎是随机取向的，但在伤口后部逐渐与伤口的长轴更加对齐。在21天时，应力纤维在所有层面上主要与伤口的长轴平行取向。在第14天和第21天时间点，f-肌动蛋白、纤连蛋白和整合素是共线的。由于大部分伤口闭合发生在手术后14至28天之间，我们得出结论，猫RK模型中肌动蛋白丝-纤连蛋白-整合素组装的平行排列与伤口收缩有关。
