A CRYSTALLIN MUTATION WITH ABNORMAL ASTROCYTES AND RETINAL VESSELS

晶状体蛋白突变导致星形胶质细胞和视网膜血管异常

• 批准号: 7350844
• 负责人: DEBASISH SINHA
• 金额: $ 41万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7350844
• 关键词: Address; Adult; Affect; Antibodies; Apoptosis; Astrocytes; Axon; Axonal Transport; Base Pairing; Binding; Biochemistry; Biological Assay; Biology; Blood Vessels; Blood flow; Bromodeoxyuridine; Cataract; Cell physiology; Cells; Chromosomes, Human, Pair 10; Coculture Techniques; Colchicine; Communication; Complement; Crystallins; Deposition; Development; Dyes; Electrical Resistance; Endothelial Cells; Endothelium; Evans blue stain; Exons; Eye; Genes; Genetic; Glial Cell Proliferation; Glial Fibrillary Acidic Protein; Goals; Growth; Heterozygote; Homozygote; Hour; Human; In Situ Nick-End Labeling; Injection of therapeutic agent; Intermediate Filaments; Label; Measures; Microaneurysm; Molecular; Mutation; Names; Neurons; Optic Nerve; Phenotype; Photography; Play; Process; Proteins; Rattus; Retina; Retinal; Retinal Ganglion Cells; Role; Signal Pathway; Sprague-Dawley Rats; Staining method; Stains; Structure; Surface; System; Techniques; Testing; Thick; Tight Junctions; Vascular Permeabilities; Vimentin; Yeasts; anterior chamber; base; cell motility; fetal; insight; migration; mutant; nestin protein; novel; research study; retina blood vessel structure; time use; tool; yeast two hybrid system

DESCRIPTION (provided by applicant): We have discovered a spontaneous mutation in the Sprague Dawley rat with an unusual eye phenotype that we have named Nuc1. The mutation behaves as a single semi-dominant locus with a viable homozygote and an intermediate phenotype in the heterozygotes. The mutation causing Nuc1 is a 27 base pair insertion in exon 6 of the ¿A3/A1 crystallin gene on chromosome 10. In addition to Nuc1 several human mutations in ¿A3/A1 crystallin are known, all of which cause dominant cataract. In homozygous Nuc1 rats the fetal intraocular vessels persist even after development of the retinal vessels. During early post-natal development these rats also have a much thicker retina than normal with an excess number of vessels. As the Nuc1 homozygote rat matures, we find evidence of microaneurysm formation, intravascular deposits and blockage of blood flow inside some vessels. We have found that in the retina, ¿A3/A1 is expressed only in astrocytes and that in the Nuc1 homozygotes the astrocytes are morphologically abnormal. The purpose of this study is to address the possibility that the normal functioning of the retinal astrocytes is compromised as a consequence of the Nuc1 mutation. It is now accepted that astrocytes play a major role in the establishment of a functional retinal vasculature, however, the cellular and molecular mechanisms involved in this process remain elusive. Establishing Nuc1 as a genetic tool will provide a unique system in which to study the biology of astrocytes, in particular their interactions with retinal ganglion and endothelial cells. Our goal for the proposed studies is to test our hypothesis that expression of mutant ¿A3/A1 crystallin affects astrocyte function, leading to improper organization and function of the retinal vasculature in the Nuc1 rat. To test this hypothesis, the following specific aims are proposed: SPECIFIC AIM 1: To characterize and compare the structure, sub-cellular localization and protein interactions of ¿A3/A1 crystallin protein in retinal astrocytes from Nuc1 and wild type rats. SPECIFIC AIM 2: To investigate if the proliferation or migration of astrocytes is disrupted by expression of mutant ¿A3/A1 crystallin SPECIFIC AIM 3: To demonstrate the effect of astrocytes expressing mutant ¿A3/A1 on retinal vasculature. Despite rapid progress made in understanding the development of the retinal vasculature, many questions remain to be answered about the mechanisms and signaling pathways regulating vascular development. We believe that studies on the Nuc1 rat will provide new insights into the cellular and molecular mechanisms that regulate vascular development including the molecular interactions among neurons, astrocytes and endothelial cells.

描述（由适用提供）：我们在Sprague Dawley大鼠中发现了一个具有不寻常的眼表型Nuc1的赞助突变。该突变的表现是一个半主导基因座，具有可行的纯合子和杂合子中的中间表型。引起的NUC1突变是10染色体上A3/A1晶体基因的外显子6中的27个碱基对插入。除了nuc1外，已知nuc1除nuc1外，还已知A3/A1晶体中的几种人突变，所有这些都会引起主要白内障。在纯合子NUC1中，即使在视网膜血管发展后，胎儿内血管也持续存在。在产后早期发育期间，这些大鼠的视网膜也比正常人厚得多，数量过多。随着NUC1纯合大鼠的成熟，我们发现了微型神经瘤形成，血管内沉积物和某些血管内血流的阻塞。我们发现，在视网膜中，A3/A1仅在星形胶质细胞中表达，而在NUC1纯合子中，星形胶质细胞在形态上是异常的。这项研究的目的是解决视网膜星形胶质细胞正常功能由于NUC1突变而受到损害的可能性。现在可以接受的是，星形胶质细胞在功能性视网膜脉管系统的建立中起着重要作用，但是，此过程中涉及的细胞和分子机制仍然难以捉摸。将NUC1作为遗传工具建立将提供一个独特的系统，以研究星形胶质细胞的生物学，特别是它们与视网膜神经节和内皮细胞的相互作用。我们提出的研究的目标是检验我们的假设，即突变体的表达�A3/A1结晶蛋白会影响星形胶质细胞功能，从而导致NUC1大鼠中视网膜脉管系统的组织和功能不当。为了检验这一假设，提出了以下特定目的：具体目的1：表征和比较nuc1和野生型大鼠的视网膜星形胶质细胞中的A3/A1结晶蛋白的结构，细胞亚定位和蛋白质相互作用。具体目的2：研究星形胶质细胞的增殖或迁移是否被突变体的表达``a3/a1 crystallin特异性目标3：证明表达突变体的星形胶质细胞对视网膜脉管系统的影响。尽管在理解视网膜脉管系统的发展方面取得了迅速的进展，但有关调节血管发育的机制和信号通路的许多问题仍有待解决。我们认为，对NUC1大鼠的研究将为调节血管发育的细胞和分子机制提供新的见解，包括神经元，星形胶质细胞和内皮细胞之间的分子相互作用。