Department of Oral Growth & Development, Division of Clinical Dentistry, Fukuoka Dental College, Fukuoka, Japan.
Connect Tissue Res. 2012;53(1):14-20. doi: 10.3109/03008207.2011.602767. Epub 2011 Aug 18.
The ciliary zonule, also known as Zinn's zonule, is composed of oxytalan fibers. However, the mechanism by which epithelial cells in the ciliary body form these fibers in not fully understood. We examined human nonpigmented ciliary epithelial cells to determine the appearance and amount of oxytalan fibers in terms of positivity for their major components, fibrillin-1 and fibrillin-2. Examination of fibrillin-1 and fibrillin-2 expression by immunofluorescence revealed that thin fibers positive for fibrillin-1 on Day 2 changed to thick fibers by Day 8. The fibers positive for fibrillin-2 appeared on the thick fibrillin-1-positive fibers after Day 4. Northern blot analysis revealed that the level of fibrillin-1 did not change markedly, while induction of fibrillin-2 gene was evident on Day 5. Western blot analysis showed that fibrillin-1 deposition increased gradually, while that of fibrillin-2 increased markedly from Day 5 to Day 8. Fibrillin-1 suppression did not lead to the formation of fibrillin-2-positive thick fibers, whereas fibrillin-2 suppression led to the formation of fibrillin-1-positive thin fibers, but not thick fibers. These results suggest that both fibrillin-1 and fibrillin-2 are essential for the formation of thick oxytalan fibers in the ciliary zonule and are informative for clarifying the mechanism of homeostasis of the ocular matrix.
睫状小带，也称为津恩氏小带，由弹性蛋白纤维组成。然而，睫状体上皮细胞形成这些纤维的机制尚不完全清楚。我们检查了人类非色素睫状上皮细胞，以确定主要成分原纤维蛋白 1 和原纤维蛋白 2 阳性的弹性蛋白纤维的外观和数量。免疫荧光检查显示，第 2 天对原纤维蛋白 1 呈阳性的细纤维在第 8 天变为粗纤维。第 4 天后，在厚的原纤维蛋白 1 阳性纤维上出现对原纤维蛋白 2 呈阳性的纤维。Northern blot 分析显示，原纤维蛋白 1 的水平没有明显变化，而原纤维蛋白 2 基因的诱导在第 5 天明显。Western blot 分析显示，原纤维蛋白 1 的沉积逐渐增加，而原纤维蛋白 2 的沉积从第 5 天到第 8 天显著增加。原纤维蛋白 1 抑制不会导致形成原纤维蛋白 2 阳性的粗纤维，而原纤维蛋白 2 抑制会导致形成原纤维蛋白 1 阳性的细纤维，但不会形成粗纤维。这些结果表明，原纤维蛋白 1 和原纤维蛋白 2 对于睫状小带中厚弹性蛋白纤维的形成都是必不可少的，并且有助于阐明眼部基质的动态平衡机制。
