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Function of alphaB-crystallin in brain development and neurodegeneration

αB-晶状体蛋白在大脑发育和神经退行性变中的功能

基本信息

批准号：
06454694
负责人：
IWAKI Toru
金额：
$ 3.58万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

It has been shown by immunohistochemical studies that alphaB-crystallin accumulated in the reactive and neoplastic glial cells in a variety of pathologic situations. We investigated the phenotypic effects of selectively altering the levels of alphaB-crystallin in cultured glial cells by genetic manipulation. Glioma cells were transfected with a rat alphaB-crystallin sense cDNA or an antisense cDNA to alter cellular levels of alphaB-crystallin. The anti-sense strategy resulted in decreased alphaB-crystallin levels, as revealed by Western blot and immunocytochemical analyzes. The reduced alphaBj-crystallin expression was accompanied by alterations in cellular phenotyp :(1)a reduction of cell size and/or a slender cell mophology ; (2)a disorganized microfilament network ; and (3)a reduction of cell adhesiveness. Like HSP27, the presence of additional alphaB-crystallin protein confer a thermoresistant phenotype to stable transfectants. Thus, alphaB-crystallin inglioma cells plays a role in their thermal resistance and maycontribute to the stability of cytoskeletal organization. Next we investigated the influence of elevated extracellular K^+ on th expression of alphaB-crystallin in glial cells. The treatment of the glioma cells with augmented K^+ in the cultrue media induced an accumulation of alphaB-crystallin mRNA in a dose-dependent manner and an accumulation of the alphaB-crystallin as well. Furthermore, an overexpression of alphaB-crystallin in the transformant transfected with a rat alphaB-crystallin cDNA conferred a resistant phenotype against the insult of elevated extracellular K^+ on the glioma cells. Thus, alphaB-crystallin may contribute to the survival of reactive glia in the presence of a high extracellular K^+ concentration.

免疫组织化学研究表明，在各种病理情况下，α -晶体蛋白在反应性和肿瘤性胶质细胞中积累。我们研究了通过基因操作选择性改变α -晶体蛋白水平在培养的神经胶质细胞中的表型效应。用大鼠α -结晶蛋白正义cDNA或反义cDNA转染胶质瘤细胞，改变细胞α -结晶蛋白水平。Western blot和免疫细胞化学分析显示，反义策略导致α -晶体蛋白水平下降。α bj -晶体蛋白表达的降低伴随着细胞表型的改变：(1)细胞大小的减小和/或细胞形态的细长；(2)无序的微丝网络；(3)细胞粘附性降低。像HSP27一样，额外的α -晶体蛋白的存在赋予了稳定的转染物耐热表型。因此，α -晶体蛋白胶质瘤细胞在其耐热性中发挥作用，并可能有助于细胞骨架组织的稳定性。接下来，我们研究了细胞外K^+升高对胶质细胞α -晶体蛋白表达的影响。在培养介质中增强K^+处理胶质瘤细胞诱导α -晶体蛋白mRNA以剂量依赖的方式积累，α -晶体蛋白也积累。此外，在转染了大鼠α -晶体蛋白cDNA的转化体中，α -晶体蛋白的过表达赋予了抗细胞外K^+对胶质瘤细胞的损伤的抗性表型。因此，在高细胞外K^+浓度的情况下，α -晶体蛋白可能有助于反应性胶质细胞的存活。