Ochrietor J D, Moroz T M, Kadomatsu K, Muramatsu T, Linser P J
The Whitney Laboratory of the University of Florida, St. Augustine, FL 32080, USA.
Exp Eye Res. 2001 Apr;72(4):467-77. doi: 10.1006/exer.2000.0974.
5A11/Basigin is a member of the immunoglobulin gene superfamily which plays an important role in cell-cell interactions in the developing neural retina. These studies were initiated to investigate the distribution of 5A11/Basigin within the mouse retina, as well as the cytoarchitectural and biochemical effects on the retina after the inactivation of the 5A11/Basigin gene in a mouse strain. Immunocytochemical analyses indicated that mouse 5A11/Basigin is located on the surface of Müller cells, the apical and basal surfaces of the retinal pigmented epithelium, and blood vessels. Lower expression levels were found on photoreceptor cell bodies and a portion of the inner segments. Inactivation of the 5A11/Basigin gene in mice resulted in the failure of photoreceptor cells to fully mature. This failed development eventually lead to the degeneration, death and removal of most of the photoreceptors several months after birth. Biochemical analyses indicated that expression of Müller cell specific proteins, including glutamine synthetase and carbonic anhydrase-II, was not effected; however, opsin protein expression never achieved normal adult levels in the 5A11/Basigin null mice. Also, 5A11/Basigin null retinas were considered 'reactive' based on elevated glial fibrillary acidic protein expression. The results presented here suggest that 5A11/Basigin expression on Müller cells and/or the retinal pigmented epithelium is necessary for photoreceptor outer segment biochemical development and structural maintenance. However, the exact role that 5A11/Basigin plays during retinal development remains to be determined.
5A11/基底膜蛋白是免疫球蛋白基因超家族的成员，在发育中的神经视网膜的细胞间相互作用中起重要作用。开展这些研究是为了调查5A11/基底膜蛋白在小鼠视网膜中的分布，以及在一个小鼠品系中5A11/基底膜蛋白基因失活后对视网膜的细胞结构和生化影响。免疫细胞化学分析表明，小鼠5A11/基底膜蛋白位于Müller细胞表面、视网膜色素上皮的顶端和基底表面以及血管上。在光感受器细胞体和部分内节上发现较低的表达水平。小鼠中5A11/基底膜蛋白基因的失活导致光感受器细胞无法完全成熟。这种发育失败最终导致出生后几个月大多数光感受器发生退化、死亡并被清除。生化分析表明，包括谷氨酰胺合成酶和碳酸酐酶-II在内的Müller细胞特异性蛋白的表达没有受到影响；然而，在5A11/基底膜蛋白基因敲除小鼠中，视蛋白的表达从未达到正常成年水平。此外，基于胶质纤维酸性蛋白表达升高，5A11/基底膜蛋白基因敲除的视网膜被认为具有“反应性”。此处呈现的结果表明，Müller细胞和/或视网膜色素上皮上的5A11/基底膜蛋白表达对于光感受器外节的生化发育和结构维持是必要的。然而，5A11/基底膜蛋白在视网膜发育过程中的确切作用仍有待确定。
