HOMEBOX GENES IN CARDIAC DEVELOPMENT AND FUNCTION

Homebox 基因在心脏发育和功能中的作用

• 批准号: 2464937
• 负责人: MICHAEL J KERN
• 金额: $ 11.45万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-04-10 至 2002-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2464937
• 关键词: 3T3 cells; SDS polyacrylamide gel electrophoresis; collagen; developmental genetics; fluorescent in situ hybridization; gene expression; genetic mapping; genetic regulation; genetically modified animals; growth /development; heart; heart disorder; heart function; homeobox genes; human genetic material tag; human tissue; immunocytochemistry; molecular cloning; northern blottings; polymerase chain reaction; scanning electron microscopy; single strand conformation polymorphism; stress; tissue /cell culture; transfection; western blottings

Heart disease is a major cause of morbidity and mortality; care for pediatric and adult heart patients represents a significant portion of the health care dollars spent in this country. Understanding the genetic processes of heart development and function will enhance future treatments for cardiac pathologies. Our work focuses on the Prx2 homeobox gene, a regulatory gene which encodes a DNA binding transcription factor. Prx2 is highly expressed in the embryonic heart, but decreases markedly at birth. The developing limbs and craniofacial mesenchyme also express Prx2. Gene targeting experiments have demonstrated that Prx2 is critical for correct limb and craniofacial morphogenesis as well as normal adult cardiac function. We have recently shown that the Prx2 mutant heart has defined alterations in cardiac contractility and action potential at the organ and cellular level. Thus the Prx2 gene targeted mouse is an excellent model to examine developmental gene regulation that is critical for normal cardiac function. The cardiac deficiencies in the Prx2 mutant may result from altered gene expression established during cardiac development and/or altered expression in the adult heart. Based on our data we hypothesize that Prx2 regulation of collagen expression in the primary mechanism whereby Prx2 is critical for normal cardiac development and function. Specific Aim Number 1 Test the hypothesis that mutations in Prx2 are implicated in human cardiovascular disease. Clone and chromosomally localize the human Prx2 gene to determine if it maps to any regions implicated in cardiovascular disease. Interbreed the Prx2 mutant allele onto different genetic strains of mice. Specific Aim Number 2 Test the hypothesis that collagen expression is regulated by Prx2 in the heart. Determine the pattern and level of collagen expression in the Prx2 mutant heart. Define when in development the Prx2 regulation of collagen begins. Establish and utilize two cell culture systems to examine the Prx2 regulation of collagen in vitro: cardiac fibroblastic cells from the mutant and wild type heart as well as NIH3T3 cells that are stably transfected with sense or antisense constructs of Prx2. Specific Aim Number 3 Evaluate the physiological parameters of altered cardiac function in the Prx2 mutant. Exercise and perform aortic banding of the Prx2 mice to assess cardiac function under stress. Evaluate the beta-adrenergic signalling pathway in the Prx2 mutant heart.

心脏病是发病和死亡的主要原因；照顾 儿童和成人心脏病患者占很大一部分 在这个国家花费的医疗保健费用。了解遗传 心脏发育和功能的过程将增强未来 心脏病的治疗。我们的工作重点是 Prx2 同源框基因，编码 DNA 结合的调节基因 转录因子。 Prx2 在胚胎心脏中高表达， 但在出生时明显减少。 正在发育的四肢和颅面 间质也表达 Prx2。 基因打靶实验已 证明 Prx2 对于正确的肢体和颅面至关重要 形态发生以及正常成人心脏功能。 我们有 最近表明，Prx2 突变体心脏已定义了改变 器官和细胞的心肌收缩力和动作电位 等级。 因此，Prx2 基因靶向小鼠是一个很好的模型 检查对正常发育至关重要的发育基因调控 心脏功能。 Prx2 突变体的心脏缺陷可能 心脏过程中建立的基因表达改变的结果 成人心脏的发育和/或表达改变。基于我们的 根据数据，我们假设 Prx2 对胶原表达的调节 Prx2 对正常心脏至关重要的主要机制 发育和功能。 具体目标 1 检验假设 Prx2 的突变与人类心血管疾病有关。 克隆并对人类 Prx2 基因进行染色体定位以确定它是否 映射到与心血管疾病有关的任何区域。 杂种 Prx2突变等位基因转移到不同遗传品系的小鼠上。 具体的 目标 2 检验胶原蛋白表达受到调节的假设 通过Prx2在心里。 确定胶原蛋白的模式和水平 Prx2 突变体心脏中的表达。 定义何时开发 Prx2 对胶原蛋白的调节开始。 建立并利用两个细胞 用于体外检查 Prx2 对胶原蛋白调节的培养系统： 来自突变型和野生型心脏的心脏成纤维细胞 作为用有义或反义稳定转染的 NIH3T3 细胞 Prx2 的构建体。具体目标 3 评估生理状况 Prx2突变体中心脏功能改变的参数。 锻炼和 对 Prx2 小鼠进行主动脉结扎以评估心脏功能 压力。 评估 Prx2 中的 β-肾上腺素信号通路 突变的心。