Extracellular Matrix in Hypertensive Heart Disease & Transition to Heart Failure

高血压心脏病中的细胞外基质

• 批准号: 9100853
• 负责人: Michael R Zile
• 金额: $ 37.5万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9100853
• 关键词: Biopsy; Cardiac; Chronic; Collagen; Congestive Heart Failure; Development; EFRAC; Equilibrium; European; Event; Extracellular Matrix; Fibrillar Collagen; Fibroblasts; Functional disorder; Goals; Guidelines; Health; Healthcare; Heart failure; Human; Hypertension; In Vitro; Knock-out; Knockout Mice; Lead; Matrix Metalloproteinase Inhibitor; Matrix Metalloproteinases; Measurement; Measures; Methods; Microdialysis; Microfilaments; Modeling; Molecular; Morbidity - disease rate; Mus; Myocardial; Patients; Peptide Hydrolases; Peptides; Phenotype; Play; Property; Proteins; RNA Interference; Role; Stress; Surgical Models; Tamoxifen; Techniques; Testing; Time; Tissues; Transfection; Transgenic Model; Ventricular Remodeling; base; care burden; clinically relevant; connectin; constriction; effective therapy; hypertensive heart disease; in vivo; indexing; interstitial; mortality; mouse model; novel; outcome forecast; pressure; prevent

 DESCRIPTION (provided by applicant): The development of myocardial remodeling and abnormal diastolic function is a critical event in patients with hypertensive heart disease (HHD). The mechanisms that contribute to the development of abnormal diastolic function and progression to heart failure with a preserved ejection fraction (HFpEF) are poorly defined. This proposal will examine the causal contribution made by changes in fibrillar collagen. We hypothesized that 1- the stoichiometric balance between matrix metalloproteinases (MMPs) and endogenous tissue inhibitors of MMPs (TIMPs) is a primary determinant of diastolic stiffness and collagen content, 2- there is a critical change in this stoichiometric balance in HHD patients that develop HFpEF, 3- HFpEF patients have an increase in TIMP-1 that results in decreased interstitial protease activity, decreased collagen degradation, increased collagen content and increased collagen-dependent stiffness, 4- changes in TIMP-1 and interstitial MMP activity reflect a change in fibroblast function; fibroblasts shift to a more profibrotic phenotype in HHD patients that develop HFpEF, and 5- TIMP-1 deletion will prevent and reverse TIMP-1 dependent effects of pressure overload. We developed novel methods that allow, for the first time, in vivo measurements of aggregate interstitial protease activity (using microdialysis and a quenched fluorogenic peptide substrate) and measurement of collagen-dependent myocardial diastolic stiffness (myocardial stress vs. strain measured in LV biopsies treated with sequential extraction techniques). These methods will be applied to both patients with HHD and novel murine surgical and transgenic models of clinically relevant pressure-overload (transverse aortic constriction in tamoxifen-inducible, fibroblast-specific, TIMP-1 knock-out mice). Specific Aim One: Demonstrate that in patients with hypertensive heart disease, the transition to heart failure is characterized by an increase in TIMP-1 and a decrease in in vivo interstitial protease activation leading to an increase in collagen content and an increase in collagen-dependent stiffness. Specific Aim Two: Demonstrate in vitro, using primary fibroblast cultures that fundamental changes in cardiac fibroblast function occur in patients with HFpEF that result from a TIMP-1 induced decrease in protease activation and decreased collagen degradation. Specific Aim Three: Determine in vivo whether there is a cause and effect relationship between a change in TIMP-1 expression/abundance, interstitial protease activity, and the development of increased collagen- dependent stiffness in a murine model of pressure-overload induced heart failure.

 描述（由适用提供）：心肌重塑和异常舒张功能的发展是高血压心脏病（HHD）患者的关键事件。有助于舒张功能异常的发育和通过保留的射血分数（HFPEF）发展为心力衰竭的机制。该提案将检查原纤维胶原蛋白的变化所做的因果贡献。我们假设1- MMPS（TIMP）（TIMP）之间基质金属蛋白酶（MMP）和内源性组织抑制剂之间的化学计量平衡是对舒张僵硬和胶原蛋白含量的主要确定，2-在HHD患者中，HHD患者中有3- hfppps的相互措施的较大变化，这是3-- hfppef的范围。蛋白酶活性，胶原蛋白降解降低，胶原蛋白含量增加并增加胶原蛋白依赖性刚度，4- TIMP-1的变化和间质MMP活性反映了成纤维细胞功能的变化；成纤维细胞转移到发展HFPEF的HHD患者中的更纤维化表型，5-TIMP-1删除将预防和逆转TIMP-1依赖性压力过载的影响。我们开发了新的方法，该方法首次允许在体内测量间质蛋白酶活性（使用微透析和淬灭荧光肽底物）和测量胶原蛋白依赖性心肌舒张僵硬度（心肌压力与sequ​​ipies precoppies precoppies precique sequestials sequesique celeceique）。这些方法将应用于HHD和新型鼠类外科手术和转基因模型的临床相关压力越过负荷的患者（他莫昔芬可诱导的，成纤维细胞特异性的TIMP-1敲除小鼠的横向主动脉缩减）。具体目标：证明，在患有高血压心脏病的患者中，对心力衰竭的过渡的特征是TIMP-1的增加，体内间质蛋白酶激活的减少，导致胶原蛋白含量的增加和胶原蛋白依赖性刚度的增加。具体目标二：在体外证明，使用原发性成纤维细胞培养物在HFPEF患者中发生心脏成纤维细胞功能的基本变化，这是由于TIMP-1引起的蛋白酶激活降低和胶原蛋白降解增加的降低。特定目标三：确定体内TIMP-1表达/丰度变化，间质蛋白酶活性的变化与增加胶原蛋白依赖性刚度的变化之间是否存在原因和作用关系。