Bestrophin and Retinal Disease

卵黄蛋白和视网膜疾病

• 批准号: 6824859
• 负责人: ALAN D MARMORSTEIN
• 金额: $ 37.63万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2009-08-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6824859
• 关键词: autosomal dominant trait; calcium channel; chloride channels; clinical research; disease /disorder model; electrical conductance; electroretinography; gene expression; gene mutation; genetically modified animals; histopathology; human tissue; intracellular transport; laboratory mouse; laboratory rat; macular degeneration; membrane proteins; model design /development; protein structure function; retinal pigment epithelium; tissue /cell culture; visual photosensitivity; voltage /patch clamp; voltage gated channel

DESCRIPTION (provided by applicant): Best Macular Dystrophy (BMD) is an inherited autosomal dominant disorder that exhibits symptoms and histopathology reminiscent of age-related macular degeneration (AMD,) the leading cause of blindness in the western world. Best disease results from mutations in the VMD2 gene, encoding the protein bestrophin. The only fully penetrant symptom of Best disease is a depressed light peak (LP) in the electrooculogram (EOG) in the absence of abnormalities in the clinical electroretinogram (ERG). The LP is generated by a Ca++ dependent CI conductance across the basolateral plasma membrane of the RPE cell. Consistent with the origin of the LP, our data suggest that bestrophin, the protein product of the VMD2 gene, is a regulator of voltage dependence and response kinetics of L-type voltage gated Ca++ channels. Based on data obtained in the previously funded period, we hypothesize that bestrophin functions to regulate the gain of the LP, by regulating the Ca++ dependent stimulation of a CI conductance. The studies proposed herein are designed to investigate this novel hypothesis in the only system in which it can be properly studied; the RPE cell. The goals of this study are to determine how bestrophin is involved in regulating or generating the LP, to explain the physiological consequences of bestrophin dysfunction in the eye, and to identify potential avenues for therapeutic intervention aimed at reducing or eliminating the loss of vision associated with Best disease. This will be accomplished via 3 specific aims. In the first aim a rat model of BMD in which adenovirus is used to overexpress bestrophin mutants will be used to assess the effects of bestrophin mutations on the LP via DC-electroretinography. In specific aim 2 we will assess the electrophysiological and histopathological phenotype of mice in which the vmd2 gene has been "knocked-out", or in which BMD associated mutations have been "knocked-in". In the third specific aim we will use a novel human RPE culture system to perform studies in Ussing chambers to assess the cellular consequences of bestrophin dysfunction.

描述（由申请人提供）：最佳黄斑营养不良（BMD）是一种遗传性常染色体显性遗传病，其症状和组织病理学表现令人联想到年龄相关性黄斑变性（AMD），AMD是西方世界失明的主要原因。最好的疾病是由VMD 2基因突变引起的，VMD 2基因编码蛋白质雌激素。Best病的唯一完全外显症状是眼电图（EOG）中的低光峰（LP），而临床视网膜电图（ERG）无异常。LP是由跨越RPE细胞的基底外侧质膜的Ca++依赖性Cl电导产生的。与LP的起源一致，我们的数据表明，VMD 2基因的蛋白质产物斑萎蛋白是L型电压门控Ca++通道的电压依赖性和响应动力学的调节剂。基于在先前资助期间获得的数据，我们假设，雌激素的功能，以调节增益的LP，通过调节钙++依赖刺激的CI电导。本文提出的研究旨在研究这一新的假设，在唯一的系统中，它可以适当地研究; RPE细胞。本研究的目的是确定雌激素是如何参与调节或产生LP，解释眼内雌激素功能障碍的生理后果，并确定旨在减少或消除与Best疾病相关的视力丧失的治疗干预的潜在途径。这将通过三个具体目标来实现。在第一个目标中，将使用其中腺病毒用于过表达雌激素突变体的BMD大鼠模型通过DC-视网膜电图来评估雌激素突变对LP的影响。在具体目标2中，我们将评估其中vmd 2基因已被“敲除”或其中BMD相关突变已被“敲入”的小鼠的电生理学和组织病理学表型。在第三个具体目标中，我们将使用一种新的人类RPE培养系统在Ussing室中进行研究，以评估雌激素功能障碍的细胞后果。