Bmx Tyrosine Kinase Signaling in Cardiac Protection

Bmx 酪氨酸激酶信号传导在心脏保护中的作用

• 批准号: 7581041
• 负责人: Sarah Franklin
• 金额: $ 4.72万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-29 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7581041
• 关键词: Biochemistry; Cardiac; Cardiac Myocytes; Cell Death; Cell Survival; Cells; Confocal Microscopy; Family; Goals; Heart; Heart Block; Hindlimb; Injury; Ischemia; Ischemic Preconditioning; Knock-out; Knockout Mice; Link; Maps; Measures; Methods; Mitochondria; Mitochondrial Proteins; Molecular; Mus; Myocardial Ischemia; Nitric Oxide; Nitric Oxide Donors; Organelles; Permeability; Pharmaceutical Preparations; Phenotype; Phosphorylation Site; Physiology; Prevention; Protein Tyrosine Kinase; Proteins; Proteomics; Receptor Protein-Tyrosine Kinases; Reperfusion Injury; Reporting; Role; Signal Transduction; Skeletal Muscle; Testing; Tissues; Tyrosine Kinase Inhibitor; base; insight; mitochondrial dysfunction; myocardial infarct sizing; prevent; protein expression; response

DESCRIPTION (provided by applicant): Ischemic preconditioning is the most potent and consistently reproducible method of preventing heart tissue from undergoing irreversible ischemic damage. Induction of this phenomenon can be recapitulated in lieu of ischemia by drugs such as nitric oxide (NO) donors, which significantly reduce myocardial infarct size. Cardiac cell death in ischemia/reperfusion injury is known to centrally involve malfunction of the mitochondria (mitochondrial permeability transition [MPT]), and protection thus requires prevention of MPT. Although the signaling mechanisms which prevent mitochondrial dysfunction in cardiac protection are unknown, tyrosine kinase signaling has been implicated based on the ability of tyrosine kinase inhibitors to block cardiac protection. The non-receptor tyrosine kinase, Bmx, which has an established role in cytoprotective signaling in non-cardiac cells, was recently identified in cardiac tissue. This protein has been shown to be activated by PI3-K and Src in non-cardiac cells, although how it is activated in the cardiomyocyte is completely unknown. Our preliminary results have shown that the hearts of Bmx knockout (KO) mice cannot be protected with NO donors, thereby implicating Bmx as a previously unrecognized necessary component of protective signaling. Because of these observations, we hypothesize that Bmx signaling is activated in cardiomyocytes in response to cardiac protection and promotes cell survival, at least in part, by regulating mitochondrial function. We propose two Aims that combine biochemistry, proteomic analysis, confocal microscopy and cell/organelle physiology to test this hypothesis: First, we will characterize Bmx activation in mouse cardiomyocytes during NO donor induced protection by determining the role of PI3-K and Src, identifying activators of Bmx and mapping the phosphorylation sites necessary for cardiac protective signaling. Second, we will evaluate the role of Bmx signaling in NO donor induced cardiac protection by measuring mitochondrial function in Bmx KO mice, identifying Bmx associated proteins at this organelle, and determining Bmx-dependent changes in mitochondrial protein expression. Determining Bmx signaling mechanisms will establish the first insights into a newly discovered family of tyrosine kinases in the heart and allow a better understanding of the protective phenotype with the goal of developing molecular approaches to treat ischemic heart disease.

描述（由申请人提供）：缺血性预处理是防止心脏组织遭受不可逆性缺血性损害的最有效且始终可再现的方法。可以通过一氧化氮（NO）供体等药物来概括这种现象，以代替缺血，从而大大降低心肌梗死的大小。众所周知，缺血/再灌注损伤中的心脏细胞死亡涉及线粒体故障（线粒体通透性转变[MPT]），因此需要预防MPT。尽管尚不清楚心脏保护中线粒体功能障碍的信号传导机制，但基于酪氨酸激酶抑制剂阻断心脏保护的能力，酪氨酸激酶信号传导已与之牵涉。最近在心脏组织中鉴定出非受体酪氨酸激酶BMX在非心脏细胞中具有确定的作用在非心脏细胞的细胞保护信号传导中。尽管在心肌细胞中如何激活该蛋白在非心脏细胞中被PI3-K和SRC激活，但完全未知。我们的初步结果表明，BMX敲除（KO）小鼠的心脏不能在没有供体的情况下受到保护，从而暗示BMX是先前未知的保护信号传导的必要组成部分。由于这些观察结果，我们假设BMX信号在响应心脏保护方面激活了心肌细胞，并通过调节线粒体功能至少部分地促进细胞存活。 We propose two Aims that combine biochemistry, proteomic analysis, confocal microscopy and cell/organelle physiology to test this hypothesis: First, we will characterize Bmx activation in mouse cardiomyocytes during NO donor induced protection by determining the role of PI3-K and Src, identifying activators of Bmx and mapping the phosphorylation sites necessary for cardiac protective signaling.其次，我们将通过测量BMX KO小鼠的线粒体功能，鉴定该细胞器上的BMX相关蛋白，并确定线粒体蛋白表达的BMX依赖性变化，从而评估BMX信号传导在无供体诱导心脏保护中的作用。确定BMX信号传导机制将在心脏中对新发现的酪氨酸激酶家族建立第一批见解，并以开发分子方法来治疗缺血性心脏病的目的更好地了解保护性表型。