Novel Xin Protein in Cardiac Development and Function

心脏发育和功能中的新型 Xin 蛋白

• 批准号: 6989777
• 负责人: Jim Jung-Ching Lin
• 金额: $ 32.41万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6989777
• 关键词: DNA binding protein; biological signal transduction; cardiogenesis; cell adhesion; gene deletion mutation; gene expression; genetically modified animals; heart function; in situ hybridization; laboratory mouse; molecular cloning; northern blottings; phenotype; proline; protein protein interaction; ventricular hypertrophy; western blottings

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand the role of a novel cardiac protein, Xin, in development and cardiac function. Xin encodes a proline-rich protein located in adherens junctions of the intercalated discs of adult hearts. Xin antisense oligonucleotide treatment of chick embryos results in disruption of cardiac morphogenesis. Xin protein is co-localized and associated with the N-cadherin/beta-catenin complex suggesting that Xin is a component of adherens junctions of cardiac muscle and may play a vital role in the N-cadherin signaling during cardiac development and function. A mouse knockout to delete the first Xin (mXinalpha) gene has been generated. The knockout mice appear to develop normally. However, further analysis reveals that hearts from adult mXinalpha -/- mice appear to be hypertrophied. Fibrosis and thrombi are occasionally found within the ventricular myocardium of the mXinalpha -/- heart. Furthermore, introduction of pathophysiological stress in a form of pressure-overload to the mXinaalpha -/- mice results in an accelerated rate of hypertrophy. We have also discovered a second mXinbeta gene (mXinbeta, which is upregulated in the mXinalpha knockout hearts. This finding supports the idea that mXinbeta may partially compensate for loss of the mXinalpha gene during development. Our working hypothesis is that mXina and mXina are essential for normal heart development and function and may act by integrating adhesion and signaling. The specific aims are: (1) To further characterize the mXinalpha knockout mice by introducing pathophysiological stress and physiological exercise; (2) To clone and characterize mXinalpha interacting proteins; (3) To clone and characterize the second mXinbeta gene; and (4) To generate and characterize mXinbeta knockout and mXinalpha/mXinbeta double knockout mice. These studies should help provide the basic understanding of mXin protein function in normal cardiac development and function. Only through understanding normal development and cardiac function can intervention strategies be developed to alleviate cardiac defects.

描述（由申请人提供）：该项目的长期目标是了解新型心脏蛋白 Xin 在发育和心脏功能中的作用。 Xin 编码一种富含脯氨酸的蛋白质，位于成人心脏闰盘的粘附连接处。 Xin 反义寡核苷酸处理鸡胚胎会导致心脏形态发生破坏。 Xin 蛋白与 N-钙粘蛋白/β-连环蛋白复合物共定位并相关，表明 Xin 是心肌粘附连接的组成部分，并且可能在心脏发育和功能过程中的 N-钙粘蛋白信号传导中发挥重要作用。已生成删除第一个 Xin (mXinalpha) 基因的小鼠基因敲除。基因敲除小鼠似乎发育正常。然而，进一步的分析表明，成年 mXinalpha -/- 小鼠的心脏似乎肥大。 mXinalpha -/- 心脏的心室肌内偶尔会发现纤维化和血栓。此外，以压力超载的形式向 mXinaalpha -/- 小鼠引入病理生理应激会导致肥大速度加快。我们还发现了第二个 mXinbeta 基因（mXinbeta，在 mXinalpha 敲除心脏中表达上调。这一发现支持 mXinbeta 可能部分补偿发育过程中 mXinalpha 基因损失的观点。我们的工作假设是，mXina 和 mXina 对于发育过程中 mXinbeta 基因的缺失至关重要。正常的心脏发育和功能，并可能通过整合粘附和信号传导来发挥作用，具体目标是：（1）通过引入病理生理应激和生理运动来进一步表征 mXinalpha 基因敲除小鼠； (2) 克隆和表征 mXinalpha 相互作用蛋白；(3) 克隆和表征第二个 mXinbeta 基因；以及 (4) 生成和表征 mXinbeta 敲除小鼠和 mXinalpha/mXinbeta 双敲除小鼠。 mXin蛋白在正常心脏发育和功能中的作用只有了解正常发育和心脏功能才能制定干预策略来缓解心脏缺陷。