DE PEDIATRIC COBRE: EXTRACELLULAR MATRIX REMODELING IN CARDIOVASCULAR DISEASES

DE PEDIATRIC COBRE：心血管疾病中的细胞外基质重塑

• 批准号: 7382174
• 负责人: Takeshi Tsuda
• 金额: $ 17.96万
• 依托单位: ALFRED I. DU PONT HOSP FOR CHILDREN
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7382174
• 关键词: DE; PEDIATRIC; COBRE; EXTRACELLULAR; MATRIX

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The underlying mechanism of heart failure is not well understood. Fibulin-2 is an extracellular matrix (ECM) protein that marks epithelial-mesenchymal transformation during embryonic cardiovascular development but is significantly down-regulated in the postnatal life. Fibulin-2 expression is remarkably up-regulated in myocardial wound healing, indicating its possible role in myocardial fibrosis and ventricular remodeling. Our working hypothesis is that Fibulin-2 intermediates upstream signals to induce ventricular remodeling. To test this hypothesis, Fibulin-2 null mutant mice (Fbln2-/-) were generated by gene targeting technique. Fbln2-/- showed no obvious phenotypic abnormalities compared with the wild type (WT) littermates and showed normal life span and fertility. (1) In vivo animal experiments: Both Fbln2-/- and WT were subject to myocardial infarction (MI) to induce heart failure. Hemodynamic, biochemical, and histological studies were performed to assess the biological role of fibulin-2 in ventricular remodeling after myocardial infarction. (2) In vitro newborn rat ventricular myocyte cell culture experiments: Ventricular myocytes are co-cultured with myocardial fibroblasts and are stimulated with angiotensin-II (Ang-II). The effects of Ang-II over changes in ECM, morphology and proliferation of cells are examined. Then the intrinsic fibulin-2 activity is inhibited by the fibulin-2 antibody to examine whether the neutralizations block the effect of Ang-II in ECM and cells. To date we found that the following: (1) Fbln2-/- resulted in better survival rate than WT at 2 weeks after MI (Fbln2-/- 78%, WT 44%). Although both revealed comparable myocardial hypertrophy, diastolic function was significantly well preserved in Fbln2-/-. Systolic function was better in Fbln2-/- than in WT. The degree of fibrosis is substantially decreased in Fbln2-/- myocardium; and (2) Ang-II increased fibulin-2 expression in a dose-responsive manner at 24 and 48 hours. Antibody blocking experiments will follow. In summary, absence of fibulin-2 preserved ventricular compliance despite comparable hypertrophy after MI. Our data suggest that fibulin-2 intermediates Ang-II related pathways in the formation of myocardial fibrosis and ventricular remodeling.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子弹和调查员（PI）可能已经从其他NIH来源获得了主要资金，因此可以在其他清晰的条目中代表。列出的机构适用于该中心，这不一定是调查员的机构。心力衰竭的基本机制尚不清楚。 Fibulin-2是一种细胞外基质（ECM）蛋白，在胚胎心血管发育过程中标记上皮 - 间质转化，但在产后寿命中显着下调。在心肌伤口愈合中，斐杜蛋白-2的表达显着上调，表明其在心肌纤维化和心室重塑中可能作用。 我们的工作假设是，斐杜蛋白2中间信号诱导心室重塑。为了检验这一假设，通过基因靶向技术产生了斐杜蛋白-2 null突变小鼠（FBLN2 - / - ）。与野生型（WT）同窝仔相比，FBLN2 - / - 没有明显的表型异常，并且显示出正常的寿命和生育能力。 （1）体内动物实验：FBLN2 - / - 和WT均受到心肌梗塞（MI）的约束，以诱导心力衰竭。进行了血液动力学，生化和组织学研究，以评估腓蛋白-2在心肌梗塞后心室重塑中的生物学作用。 （2）体外新生大鼠心室心肌细胞培养实验：心室心肌细胞与心肌成纤维细胞共培养，并与血管紧张素II（ANG-II）刺激。研究了ANG-II对ECM变化，细胞形态和增殖的影响。然后，纤维蛋白-2抗体抑制了固有的斐杜蛋白-2活性，以检查中和是否阻止了ANG-II在ECM和细胞中的作用。迄今为止，我们发现以下几点：（1）FBLN2 - / - 在MI后2周（FBLN2 - / - 78％，WT 44％）时，与WT相比，生存率更好。尽管两者都显示出可比的心肌肥大，但舒张功能在FBLN2 - / - 中得到了明显保存。 FBLN2 - / - 的收缩功能比在wt中更好。 FBLN2 - / - 心肌的纤维化程度大大降低。 （2）ANG-II在24和48小时以剂量响应方式增加了纤维蛋白-2的表达。抗体阻断实验将进行。总而言之，尽管Mi后肥大，但缺乏腓蛋白-2保留的心室依从性。我们的数据表明，斐杜蛋白2中间在形成心肌纤维化和心室重塑的形成中与ANG-II相关的途径。