Post-Synthetic Procollagen Processing in Load-Induced Left Ventricular Remodeling

负荷诱导左心室重构中的合成后原胶原加工

基本信息

批准号：
7923984
负责人：
Amy D Bradshaw
金额：
$ 36.88万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-01 至 2011-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7923984
关键词：
Address Adhesives Anabolism Binding Binding Proteins Binding Sites Biochemistry C-terminal Cardiac Cardiac Myocytes Cardiovascular system Catheterization Cell surface Cessation of life Chronic Cleaved cell Clinical Collagen Collagen Fibril Complementary DNA Cysteine Data Deposition Development Diagnosis Disintegrins DsRed Echocardiography Enhancers Equilibrium Extracellular Matrix Extracellular Space Fibrillar Collagen Fibroblasts Functional disorder Heart failure Histology Hospitalization Hypertrophy In Vitro Incidence Infection Integral Membrane Protein Integrins Label Lead Left Left Ventricular Remodeling Left ventricular structure Length Location Measurement Measures Metabolic Metalloproteases Methods Molecular Chaperones Mus Mutate Myocardial Myocardium N-terminal Patients Play Prevalence Process Procollagen Proline Property Protein-Lysine 6-Oxidase Proteins Role Scanning Transmission Electron Microscopy Procedures Series Small Interfering RNA Staining method Stains Structure Subfamily lentivirinae Techniques Testing Time Transgenic Mice United States National Institutes of Health Ventricular Ventricular Remodeling Wild Type Mouse constriction crosslink design human MMP14 protein in vivo light microscopy papillary muscle pressure procollagen C-endopeptidase prototype receptor research study

项目摘要

After biosynthesis within the fibroblast, a procollagen molecule is secreted into the extracellular space where it must undergo a series of very ordered, time sensitive, and location sensitive sequential post-synthetic processing steps in order to become a mature cross-linked insoluble structural collagen fibril. We hypothesized that one fundamental independent mechanism by which chronic pressure overload (PO) increases myocardial fibrillar collagen content, causes the development of abnormal diastolic function and chronic heart failure is an alteration in post-synthetic procollagen processing. This overall hypothesis will be tested using 2 specific aims. Specific Aim 1: determine whether PO changes the balance between procollagen processing into mature cross-linked collagen fibrils vs. procollagen degradation. Specific Aim 2: determine in vitro, using murine primary cardiac fibroblast culture studies, whether a change in SPARC (Secreted Protein Acidic and Rich in Cysteine) expression or procollagen binding results in an isolated change in procollagen processing and fibrillar collagen deposition. PO will be produced by transverse aortic constriction (TAC) in mice. We will examine LV structure & function with echocardiography & catheterization, myocardial function with isolated papillary muscles studies, collagen content, composition and morphometric structure with histology & biochemistry, and procollagen synthesis, procollagen processing, and fibrillar collagen degradation rates with metabolic 14C and 3H proline labeling techniques. The mechanism by which TAC and SPARC alter post-synthetic procollagen processing will be examined using in vitro primary cardiac fibroblast culture studies. Thus, this project will examine whether alteration in SPARC-dependent procollagen processing is a fundamental mechanism by which PO increases myocardial fibrillar collagen content and causes diastolic dysfunction.

在成纤维细胞内生物合成后，将胶原蛋白分子分泌到细胞外空间必须经历一系列非常有序的，对时间敏感和位置敏感的顺序序列后处理步骤，以成为一个成熟的交联无溶性结构胶原原纤维。我们假设一个慢性压力超负荷（PO）的基本独立机制增加心肌原纤维胶原蛋白含量，导致异常发展舒张功能和慢性心力衰竭是合成后的改变 Procollagen处理。该总体假设将使用2个特定目的进行检验。特定目标1：确定PO是否会改变procollagen之间的平衡加工成成熟的交联胶原原纤维与降解。具体的 AIM 2：使用鼠类原发性心脏成纤维细胞培养研究确定体外，确定 SPARC（分泌蛋白质酸性和富含半胱氨酸）表达的变化是否变化或procollagen的约束性会导致procollagen处理的孤立变化和纤维胶原沉积。 PO将通过横向主动脉收缩（TAC）产生在老鼠中。我们将通过超声心动图和带有孤立乳头肌肉研究的导管插入术，心肌功能，胶原蛋白与组织学和生物化学的内容，组成和形态计量结构，以及 Procollagen合成，Procollagen加工和原纤维胶原蛋白降解率具有代谢14C和3H脯氨酸标记技术。 TAC的机制和SPARC ALTER合成后的Procollagen加工将使用体外检查原发性心脏成纤维细胞培养研究。因此，该项目将检查是否依赖SPARC的Procollagen加工的改变是一种基本机制 PO会增加心肌纤维胶原蛋白含量并导致舒张期功能障碍。