Adenosine Mediated Modulation of Cardiac Fibrosis

腺苷介导的心脏纤维化调节

• 批准号: 6758583
• 负责人: Francisco J Villarreal
• 金额: $ 34.2万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-15 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6758583
• 关键词: adenosine; adenosine kinase; angiotensin receptor; cell proliferation; collagen; cyclic AMP; cyclic GMP; echocardiography; extracellular matrix; fibroblasts; fibrogenesis; fibrosis; genetic transcription; green fluorescent proteins; heart cell; heart failure; heart function; kinase inhibitor; laboratory mouse; laboratory rat; myocardial infarction; myocardium disorder; protein biosynthesis; purinergic receptor; scars; tumor necrosis factor alpha

Myocardial fibrosis can contribute to diastolic dysfunction and the development of heart failure. Preliminary results indicate that adenosine (ADO) can inhibit cardiac fibroblast (CF) function. These effects appear mediated via ADO A2b receptors. We will test the hypothesis that: "The enhancement of myocardial adenosine levels reduces the synthesis of cardiac collagens and associated fibrosis through the stimulation of cardiac fibroblast adenosine A2b receptors". We will examine the following aims: AIM 1: Enhanced myocardial ADO levels in the setting of myocardial infarction (MI) inhibits the deposition of cardiac collagens. We will induce the acute deposition of cardiac collagens in rats via MI induced scar formation. To enhance tissue ADO levels we will use the ADO kinase inhibitor compound GP515. We will assess for the functional consequences of the inhibition of scar formation in control untreated and treated MI rats by determining passive and active structure-function and by analysis of the microstructural properties of the scar. AIM 2: Enhanced myocardial ADO levels in the setting of MI reduces in vivo cardiac fibroblast proliferation and type I collagen gene transcription. We will use MI to induce cardiac fibroblast proliferation and collagen deposition in transgenic mice that link the expression of the marker green fluorescent protein (GFP) to collagen type I (CI- GFP) gene expression. Myocardial ADO levels will be enhanced as in aim 1. In vivo CF proliferation, type I gene expression and cardiac function, scarring/remodeling will be assessed at predetermined time points. AIM 3: The absence of A2b receptors in the MI mouse heart impairs the ability of ADO to diminish cardiac collagen synthesis yielding enhanced scar deposition. We will use mice null (-/-) for A2b receptors. We will induce the acute deposition of cardiac collagens in wild type and in A2b receptor null mice by using MI. Tissue ADO levels will be enhanced as in aim 1. Cardiac passive and active structure- function will be assessed at predetermined time points. The effects of enhanced ADO levels will also be examined in vitro using cultured CF from A2b (-/-) mice and assessing for ADO modulation of cell function. AIM 4: ADO inhibits TNF-alpha release and cardiac fibroblast function through the stimulation of A2b receptors and associated increases in cAMP and/or cGMP levels. We will assess for adenosine A2b receptor mediated induced inhibition of CF function and for the role of intracellular cAMP and/or cGMP in mediating ADO induced alterations in CF function.

心肌纤维化会导致舒张功能障碍和心力衰竭的发展。 初步结果表明腺苷（ADO）可以抑制心脏成纤维细胞（CF）功能。 这些作用通过ADO A2B受体介导。 我们将检验以下假设：“心肌腺苷水平的增强可以通过刺激心脏成纤维细胞腺苷A2B受体来降低心脏胶原蛋白的合成和相关的纤维化”。 我们将研究以下目的：目标1：在心肌梗塞（MI）的环境中增强的心肌ADO水平抑制心脏胶原的沉积。 我们将通过MI诱导的疤痕形成在大鼠中诱导心脏胶原蛋白的急性沉积。 为了提高组织ADO水平，我们将使用ADO激酶抑制剂化合物GP515。 我们将通过确定被动和主动的结构功能以及分析疤痕的微结构特性，评估未处理和处理过的MI大鼠在未处理和处理过的MI大鼠中抑制疤痕形成的功能后果。 AIM 2：在MI降低体内心脏成纤维细胞增殖和I型胶原基因转录的MI降低时，心肌ADO水平增强。 我们将使用MI在转基因小鼠中诱导心脏成纤维细胞增殖和胶原蛋白沉积，将标记绿色荧光蛋白（GFP）与胶原蛋白I型（CI-GFP）基因表达联系起来。 在AIM 1中，心肌ADO水平将得到增强。体内CF增殖，I型基因表达和心脏功能，疤痕/重塑将在预定时间点进行评估。 AIM 3：MI小鼠心脏中没有A2B受体会损害ADO减少心脏胶原蛋白合成的能力，从而增强了疤痕沉积。 我们将使用null（ - / - ）用于A2B受体。 我们将使用MI诱导野生型和A2B受体无效小鼠中心脏胶原蛋白的急性沉积。 与AIM 1一样，组织ADO水平将得到增强。心脏被动和主动结构功能将在预定时间点进行评估。 使用A2b（ - / - ）小鼠的培养的CF以及评估细胞功能的ADO调节，还将在体外检查增强的ADO水平的效果。 AIM 4：ADO通过刺激A2B受体和CAMP和/或CGMP水平的刺激来抑制TNF-Alpha释放和心脏成纤维细胞功能。 我们将评估腺苷A2B受体介导的CF功能抑制作用以及细胞内CAMP和/或CGMP在介导ADO诱导的CF功能改变中的作用。