Cardiomyocyte Apoptosis and Cardioprotective Actions of Estrogen

心肌细胞凋亡与雌激素的心脏保护作用

基本信息

批准号：
9211365
负责人：
Jin Kyung Kim
金额：
$ 38.63万
依托单位：
UNIVERSITY OF CALIFORNIA-IRVINE
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-02-01 至 2019-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9211365
关键词：
Age Animal Model Apoptosis Apoptotic Biological Biological Preservation Biology Cardiac Cardiac Myocytes Cell Culture System Cell Death Cell Fate Control Cell Survival Cell physiology Cells Cellular Structures Coronary artery Cytoprotection Data Echocardiography Estradiol Estrogen Receptors Estrogens Feedback Female Gender Goals Heart Heart failure Hormones In Situ In Vitro Injury Investigation Ischemia Knowledge Ligation MAPK14 gene Mediating Mediator of activation protein Mitochondria Myocardial Infarction Myocardial Ischemia Nature Null Lymphocytes Organ Oxidative Regulation Oxidative Stress Pathway interactions Phosphotransferases Play Post-Translational Protein Processing Premenopause Protein Isoforms Protein p53 Rattus Receptor Signaling Regulation Reperfusion Injury Role Signal Transduction Stress TP53 gene Testing Therapeutic Translating Ursidae Family Woman cell type estrophilin gender difference in vivo Model insight men mitogen-activated protein kinase p38 mortality novel public health relevance therapy development

项目摘要

DESCRIPTION (provided by applicant): Ischemic heart disease (IHD) is the leading cause of mortality in this nation. Studies have shown that more premenopausal women are protected from IHD than age-matched men. However, the mechanisms underlying the gender difference are not clear. Scientific data show that the endogenous female hormone, 17-betaestradiol (E2) may be responsible for protecting heart muscle cells (cardiomyocytes). Our goal is to determine how E2 protects cardiomyocytes under ischemic stress. We hypothesize that estrogen signals to several important regulators of cell fate in ischemic stress - cardiac p38 mitogen-activated protein kinases (p38 MAPKs) and p53, a well-known mediator of apoptosis - to protect the cardiomyocyte. We will investigate how E2 mediates the novel relationship between cardiac p38 MAPKs and p53 in mitochondria-driven cell death, the dominant pathway of cardiac apoptosis. In Specific Aim 1, we will establish the role of E2 in cardiac p38 MAPK regulation. The p38 MAPK subtypes, p38� and p38�, possess distinct independent functions, with the former participating in apoptosis and the latter in preservation of cellular structure. We will subject cultured rat cardiomyocytes to simulated ischemia-reperfusion injury (I/R) and [A] examine the effect of E2 on each p38 isoform; [B] correlate the E2-specific effects on each kinase to mitochondria-centered apoptosis; and [C] identify the target(s) of p38� and p38� in the mitochondria. We will correlate data from cells to an in-vivo model of I/R in female ovariectomized rats with or without E2 supplement and examine p38�, p38�, cardiac apoptosis in situ, and cardiac function by echocardiography. In Specific Aim 2, we will investigate how E2 mediates p38 MAPKs - p53 interaction. p53 is a substrate of pro-apoptotic p38� in different cell types. We will [A] establish that p53 is phosphorylated by the p38� in cardiomyocytes; and [B] detail the nature of the posttranslational modification with respect to p38�-mediated cell death. We will also [A] investigate if p38� phosphorylates p53, and if so, what biological significance such a relationship bears in I/R-triggered apoptosis; [B] explore a possibility of a feedback mechanism between p53 and p38�; [C] determine how E2 modulates the dynamic between p53 and p38�; and [D] translate and confirm findings in a whole animal model of I/R injury by detailing p53-specific changes in cardiac p38 expression and activation at the organ level. In Specific Aim 3, we will define the role of estrogen receptor (ER) subtypes in cardiomyocyte protection. We suspect that both ER subtypes (ER� and ER�) are necessary for full cytoprotection from mitochondria-centered apoptosis. We will [A] delineate how each receptor signals to p38� and subsequent regulation of oxidative stress in mitochondria [B] identify and characterize endogenous ER �/� heterodimers in cardiomyocyte mitochondria, and [C] express a fusion ER �/� protein in ER-null cells and compare with ER homodimers in its ability to regulate apoptosis, mitochondrial p53 and p38 function.

描述（由申请人提供）：缺血性心脏病 (IHD) 是该国死亡的主要原因。研究表明，与年龄匹配的男性相比，更多绝经前女性免受 IHD 的影响。然而，性别差异背后的机制却并非如此。科学数据表明，内源性雌性激素 17-β 雌二醇 (E2) 可能负责保护心肌细胞（心肌细胞）。我们的目标是确定 E2 如何保护心肌细胞。我们探索了雌激素向缺血应激中细胞命运的几个重要调节因子 - 心脏 p38 丝裂原激活蛋白激酶 (p38 MAPK) 和 p53（众所周知的细胞凋亡介质）发出信号，以保护心肌细胞。 E2 如何介导心脏 p38 MAPK 和 p53 在线粒体驱动的细胞死亡（心脏细胞凋亡的主要途径）中的新关系。在特定目标 1 中，我们将确定 E2 的作用。 E2 在心脏 p38 MAPK 调节中的作用。p38 MAPK 亚型 p38� 和 p38� 具有不同的独立功能，前者参与细胞凋亡，后者维持细胞结构。我们将对培养的大鼠心肌细胞进行模拟缺血再灌注损伤。 (I/R) 和 [A] 检查 E2 对每种 p38 同工型的影响；[B] 将 E2 对每种激酶的特异性影响与以线粒体为中心的细胞凋亡相关联； [C] 确定线粒体中 p38� 和 p38� 的靶点我们将把细胞数据与补充或不补充 E2 的雌性卵巢切除大鼠体内 I/R 模型相关联，并检查 p38�、p38。在特定目标 2 中，我们将研究 E2 如何介导 p38 MAPK - p53 的相互作用。我们将 [A] 确定 p53 在心肌细胞中被 p38° 磷酸化；并且 [B] 详细说明 p38° 介导的细胞死亡的翻译后修饰的性质。 [A] p38� 是否磷酸化 p53，如果是，这种关系在 I/R 触发的细胞凋亡研究中具有什么生物学意义 [B] 探索反馈的可能性； p53 和 p38� 之间的机制；[C] 确定 E2 如何调节 p53 和 p38� 之间的动态；以及 [D] 通过详细说明心脏 p38 表达的 p53 特异性变化，转化并确认 I/R 损伤的整个动物模型中的发现在具体目标 3 中，我们将定义雌激素受体 (ER) 亚型在心肌细胞保护中的作用。对于以线粒体为中心的细胞凋亡的完全细胞保护是必需的。我们将 [A] 描述每个受体如何向 p38� 发出信号以及随后对线粒体氧化应激的调节 [B] 识别和表征心肌细胞线粒体中的内源 ER �/� 异二聚体，以及 [C] 在心肌细胞线粒体中表达融合 ER �/� 蛋白ER 缺失细胞并与 ER 同二聚体比较其调节细胞凋亡、线粒体 p53 和 p38 功能的能力。