Saika Shizuya, Miyamoto Takeshi, Ishida Iku, Barbour Walid K, Ohnishi Yoshitaka, Ooshima Akira
Departments of Ophthalmology, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-0012, Japan.
Exp Eye Res. 2004 Aug;79(2):147-56. doi: 10.1016/j.exer.2004.03.003.
Thrombospondin-1 (TSP-1) is a glycoprotein involved in activation of latent transforming growth factor beta (TGFbeta) expression. We examined changes in its expression pattern during human capsular opacification (PCO) and anterior subcapsular cataractogenesis (ASC), as well as in a healing injured mouse lens. Its expression pattern was also compared in a mouse embryonic lens with that in an adult lens. Based on immunohistochemistry under light microscopy, TSP-1 expression and other matrix components were evident in the anterior epithelium of an uninjured human lens, whereas fiber-differentiating cells in the equator of human lens lack TSP-1 immunoreactivity. In contrast, in post-operative human lens epithelial or fibroblastic cells, there was TSP-1 immunoreactivity, whereas it decreased in fiber-differentiating cells in PCO. Matrix components accumulated on the healing capsule also labeled with anti-TSP-1 antibody like antibodies against collagen I, IV, V and laminin. In uninjured, injured mouse lens epithelial cells and its matrix, there was TSP-1 expression. Embryonic lens cells in the posterior pole, undergoing differentiation to fiber cells, began to express TSP-1 protein at embryonic day (E) 11.5 whereas anterior epithelial cells started to express it at E13.5 in association with marked expression in central fiber cells. At E16.5, TSP-1 was detected in fibers just beneath the anterior epithelium, but the fiber mass showed minimal expression. At E18.5 and post-natally day 1, lens fiber TSP-1 expression was no longer seen. On the other hand, it was evident in both intact human anterior epithelial and dispersed mouse cells. The results indicate that there is TSP-1 expression in uninjured human and mouse lens epithelial cells and their fibrous tissue. In contrast, in post-operative lens cells differentiating to fiber cells, its expression levels decline. Further study is needed to clarify the roles of TSP-1 in modulating lens cell phenotype expression.
血小板反应蛋白-1（TSP-1）是一种糖蛋白，参与潜伏转化生长因子β（TGFβ）表达的激活过程。我们研究了其在人类晶状体后囊膜混浊（PCO）和前囊下白内障形成（ASC）过程中以及在受伤小鼠晶状体愈合过程中的表达模式变化。还比较了小鼠胚胎晶状体和成年晶状体中其表达模式。基于光学显微镜下的免疫组织化学，未受伤人类晶状体的前上皮细胞中有TSP-1表达及其他基质成分，而人类晶状体赤道部的纤维分化细胞缺乏TSP-1免疫反应性。相反，在术后人类晶状体上皮细胞或成纤维细胞中存在TSP-1免疫反应性，而在PCO中纤维分化细胞中的TSP-1免疫反应性降低。愈合囊膜上积累的基质成分也像抗I、IV、V型胶原和层粘连蛋白抗体一样，被抗TSP-1抗体标记。在未受伤、受伤的小鼠晶状体上皮细胞及其基质中，存在TSP-1表达。后极部正在分化为纤维细胞的胚胎晶状体细胞在胚胎第（E）11.5天开始表达TSP-1蛋白，而前上皮细胞在E13.5天开始表达，同时中央纤维细胞中有明显表达。在E16.5天，在前上皮下方的纤维中检测到TSP-1，但纤维团块表达极少。在E18.5天和出生后第1天，晶状体纤维中不再有TSP-1表达。另一方面，在完整的人类前上皮细胞和分散的小鼠细胞中均很明显。结果表明，未受伤的人类和小鼠晶状体上皮细胞及其纤维组织中有TSP-1表达。相反，在术后向纤维细胞分化的晶状体细胞中，其表达水平下降。需要进一步研究以阐明TSP-1在调节晶状体细胞表型表达中的作用。
