Jaworowski A, Fang Z, Khong T F, Augusteyn R C
Russell Grimwade School of Biochemistry, University of Melbourne, Parkville, Australia.
Biochim Biophys Acta. 1995 Aug 17;1245(1):121-9. doi: 10.1016/0304-4165(95)00079-q.
Protein synthesis and secretion by post-natal sheep and calf retinal pigment epithelial (RPE) cells was investigated following labelling of choroidal pieces, isolated RPE cells and RPE cells in tissue culture with L-[U-14C] leucine. We show that RPE cells secrete a specific set of proteins that includes retinol binding protein (RBP) and transthyretin (TTR), which are both involved in retinol transport in blood. Using a two-chambered culture system we show that protein secretion by the post-natal RPE cells occurs predominantly across the apical pole of the cells, i.e., across the surface of the cells which, in vivo, faces the retina. In agreement with results of others using foetal RPE cells (Ong, D.E., Davis, J.T., O'Day, W.T. and Bok, D. (1994) Biochemistry 33, 1835-1842) we show that RBP and, to a lesser extent, TTR are also secreted predominantly across the apical pole of the cell. We have developed a cell culture model for the RPE that may be used as an in vitro model for studying transport across the blood-retinal barrier.
在用L-[U-¹⁴C]亮氨酸标记脉络膜组织块、分离的视网膜色素上皮（RPE）细胞以及组织培养中的RPE细胞后，对出生后绵羊和小牛的RPE细胞的蛋白质合成与分泌进行了研究。我们发现，RPE细胞分泌一组特定的蛋白质，其中包括视黄醇结合蛋白（RBP）和转甲状腺素蛋白（TTR），这两种蛋白都参与血液中的视黄醇运输。使用双室培养系统，我们发现出生后RPE细胞的蛋白质分泌主要发生在细胞的顶端极，即细胞在体内面向视网膜的表面。与其他使用胎儿RPE细胞的研究结果一致（Ong, D.E., Davis, J.T., O'Day, W.T.和Bok, D. (1994) Biochemistry 33, 1835 - 1842），我们发现RBP以及程度稍轻的TTR也主要通过细胞的顶端极分泌。我们已经开发出一种用于RPE的细胞培养模型，该模型可作为研究跨越血视网膜屏障运输的体外模型。
