Department of Ophthalmology, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
Invest Ophthalmol Vis Sci. 2012 Sep 21;53(10):6495-503. doi: 10.1167/iovs.12-9684.
A timely regression of the hyaloid vascular system (HVS) is required for the normal ocular development. Although macrophages have a critical role in this process, the exact mechanism remains undetermined. Periostin is a matricellular protein involved in tissue and vascular remodeling. The purpose of our study was to determine whether periostin is involved in the HVS regression.
We used wild type (WT) and periostin knockout (KO) mice. Indocyanine green angiography and immunohistochemistry with isolectin B4 were used to evaluate the HVS regression. TUNEL-labeling was used to quantify the number of apoptotic hyaloid vascular endothelial cells. F4/80 and Iba-1 staining was performed to determine the number and location of macrophages in the vitreous. The location of periostin also was investigated by immunohistochemistry. To determine the functional role of periostin, the degree of adhesion of human monocytes to fibronectin was measured by an adhesion assay.
The HVS regression and peak in the number of TUNEL-positive apoptotic endothelial cells were delayed in periostin KO mice. The number of F4/80 positive cells in the vitreous was higher in periostin KO mice. Only a small number of Iba-1-positive cells near the hyaloid vessels was co-stained with periostin, and peripheral blood monocytes were not stained with periostin. Adhesion assay showed that periostin increased the degree of attachment of monocytes to fibronectin.
These results suggest that periostin, which is secreted by the intraocular macrophages, enhances the HVS regression by intensifying the adhesion of macrophages to hyaloid vessels.
玻璃血管系统（HVS）的及时退化对于正常的眼球发育是必需的。尽管巨噬细胞在这个过程中起着关键作用，但确切的机制仍未确定。纤连蛋白是一种参与组织和血管重塑的细胞外基质蛋白。我们研究的目的是确定纤连蛋白是否参与了 HVS 的退化。
我们使用了野生型（WT）和纤连蛋白敲除（KO）小鼠。吲哚菁绿血管造影和异硫氰酸荧光素结合大豆凝集素 B4 的免疫组化用于评估 HVS 的退化。TUNEL 标记用于定量凋亡的玻璃血管内皮细胞的数量。F4/80 和 Iba-1 染色用于确定玻璃体内巨噬细胞的数量和位置。纤连蛋白的位置也通过免疫组化进行了研究。为了确定纤连蛋白的功能作用，通过粘附试验测量了人单核细胞与纤维连接蛋白的粘附程度。
HVS 的退化和 TUNEL 阳性凋亡内皮细胞数量的峰值在纤连蛋白 KO 小鼠中延迟。玻璃体内 F4/80 阳性细胞的数量在纤连蛋白 KO 小鼠中更高。只有一小部分位于玻璃血管附近的 Iba-1 阳性细胞与纤连蛋白共染色，外周血单核细胞不与纤连蛋白染色。粘附试验表明，纤连蛋白增加了单核细胞与纤维连接蛋白的附着程度。
这些结果表明，由眼内巨噬细胞分泌的纤连蛋白通过增强巨噬细胞与玻璃血管的粘附来增强 HVS 的退化。
