Watanabe H, Tisdale A S, Gipson I K
Cornea Unit, Schepens Eye Research Institute, Boston, Massachusetts 02114.
Invest Ophthalmol Vis Sci. 1993 Feb;34(2):327-38.
We previously characterized a monoclonal antibody against a glycoprotein of rat ocular surface glycocalyx (ROSG). This monoclonal antibody recognizes a carbohydrate epitope on a glycoprotein expressed in apical cells of the differentiated ocular surface epithelium. Our goal was to determine the developmental appearance of the ROSG glycoprotein.
We localized the antigen immunohistochemically and immunocytochemically in newborn (day 1) rats and in rats 2-5, 7, and 11-15 days after birth.
Before eyelid opening (days 12-14), the ROSG antigen was localized in the palpebral conjunctiva near the lid margin. The binding extended to layers of the subapical flattened cells. However, the antigen was not found in the corneal epithelium while the eyelid remained closed. In contrast, at the first day of eyelid opening (days 12-15), the antigen was present contiguously in several cell layers from the eyelid margin along the entire ocular surface, including the corneal epithelium. Thus, the binding pattern seen upon eyelid opening was similar to that of adult rats. The phenomenon of appearance of the glycoprotein upon eyelid opening was further demonstrated in rats with asynchronous eyelid opening. Artificial, premature eyelid opening at days 8-11 also induced the expression of the antigen along the entire ocular surface epithelium, similar to the binding in naturally opened eyes.
Eyelid opening may induce glycosylation or expression of a glycocalyx component that we hypothesize to be involved in mucin spread.
我们之前鉴定了一种针对大鼠眼表糖萼（ROSG）糖蛋白的单克隆抗体。这种单克隆抗体识别在分化的眼表上皮顶端细胞中表达的糖蛋白上的碳水化合物表位。我们的目标是确定ROSG糖蛋白的发育出现情况。
我们通过免疫组织化学和免疫细胞化学方法，在新生（第1天）大鼠以及出生后2 - 5天、7天和11 - 15天的大鼠中定位抗原。
在眼睑张开前（第12 - 14天），ROSG抗原定位于睑缘附近的睑结膜。结合延伸至顶端下扁平细胞层。然而，在眼睑仍闭合时，角膜上皮中未发现该抗原。相比之下，在眼睑张开的第一天（第12 - 15天），抗原沿着整个眼表从睑缘连续存在于几个细胞层中，包括角膜上皮。因此，眼睑张开时观察到的结合模式与成年大鼠相似。在眼睑异步张开的大鼠中进一步证明了眼睑张开时糖蛋白出现的现象。在第8 - 11天人工过早张开眼睑也诱导了抗原沿整个眼表上皮的表达，类似于自然张开眼睛中的结合情况。
眼睑张开可能诱导一种糖萼成分的糖基化或表达，我们推测其参与黏蛋白扩散。
