CELL-CELL INTERACTIONS--DYSPLASTIC RETINAL MORPHOGENESIS

本申请中提出的研究将检验以下假设： 细胞-细胞相互作用在正常视网膜形态发生中是重要的。的 主要目标是确定细胞表面糖蛋白的作用， 细胞粘附分子在发育不良视网膜玫瑰花结形成中的作用。具体 提出的目标将是：l）确定是否操纵细胞 表面成分会改变发育中视网膜的图案形成; 2)为了确定视网膜玫瑰花结形成的程度， 受细胞表面糖蛋白或粘附作用的影响 分子。实验旨在从以下方面接近这些目标： 几个不同的方面。 这项工作将使用三个实验 方法：l）玻璃体内注射到胚胎小鸡中， 新生大鼠的特定酶或代谢抑制已知修改 细胞表面粘附分子或糖蛋白作为激发试验， 膜扰动; 2）器官培养的鸟类和哺乳动物视网膜将 更严格地评估和操纵视网膜细胞表面， 在更受控的环境中的粘附现象; 3）体外 解离视网膜的再聚集研究将集中在 玫瑰花结的形成以及如何通过修饰 细胞表面。将完成细胞表面的修饰 使用对糖部分特异的酶如神经内氨酸酶， 对神经细胞粘附分子上的聚唾液酸具有特异性，或 其他糖基化酶作用于其他糖基。细胞表面 糖蛋白组分也将使用代谢抑制剂改变 对N-连接糖基化或糖蛋白加工位点具有特异性。 这些操作将通过形态学和形态测量学进行评价 视网膜的分析进一步的研究将确定细胞的变化， 糖蛋白和粘附分子，使用凝集素组织化学， 细胞粘附分子的免疫组织化学定位。 这些 研究对于理解正常和异常的 视网膜发育过程以及了解一个主要的 实验性视网膜移植的并发症（玫瑰花结形成）。 它们在一般的发育神经生物学和基本的 理解细胞间的识别

The studies proposed in this application will test the hypothesis that cell-cell interactions are important in normal retinal morphogenesis. The primary goal is to determine the role of cell surface glycoproteins and cell adhesion molecules in dysplastic retinal rosette formation. Specific objectives addressed will be: l) to determine if manipulation of cell surface components will alter the pattern formation of developing retina; 2) to determine the degree to which retinal rosette formation can be affected by manipulation of cell surface glycoproteins or adhesion molecules. Experiments are designed to approach these objectives from several different aspects. The work will use three experimental approaches: l) intravitreal injections into embryonating chicks and neonatal rats of specific enzymes or metabolic inhibitions known to modify cell surface adhesion molecules or glycoproteins as provocative tests of membrane perturbation; 2) organ cultured avian and mammalian retina will more critically evaluate and manipulate the retinal cell surface and adhesion phenomena in a more controlled environment; 3) in vitro reaggregation studies of dissociated retina will focus on the process of rosette formation and how reaggregation can be affected by modification of the cell surface. Modification of the cell surface will be accomplished using enzymes specific for sugar moieties such as endoneuraminidase which is specific for polysialic acid on neural cell adhesion molecules, or other glycosidases acting at other sugar sties. The cell surface glycoprotein components will also be altered using metabolic inhibitors specific for N-linked glycosylation or sites of glycoprotein processing. These manipulations will be evaluated by morphological and morphometric analysis of the retina. Additional studies will determine changes in cell glycoproteins and adhesion molecules using lectin histochemistry and immunohistochemical localization of cell adhesion molecules. These studies have important implications in understanding normal and aberrant retinal developmental processes as well as understanding one of the major complications of experimental retinal transplantation (rosette formation). They have implications in general developmental neurobiology and the basic understanding of cell-cell recognition.