Computational Study of Fibrillins in CV Morphogenesis

描述（由申请人提供）：细胞-细胞外基质（ECM）相互作用是发育形态发生事件的关键调节因子。与结缔组织疾病马凡氏综合征和先天性挛缩性蛛网膜下腔畸形相关的心血管异常已分别与微纤维ECM蛋白1和2在遗传和生物化学上相关联。除了眼部和骨骼异常外，患有这些疾病的患者还表现出主动脉根部扩张、主动脉瓣关闭不全和二尖瓣脱垂。马凡氏综合征的新生儿形式会导致严重的心血管缺陷，并导致在第一年内死亡。落射荧光显微镜观察表明，在鸡胚的心外膜、背侧中膜和心内膜垫组织/瓣膜原基中存在着cardiovascular-1和cardiovascular-2阳性原纤维，并围绕着正在形成的双侧背侧动脉，表明cardiovascular-2阳性原纤维参与了心血管的形态发生。这些微原纤维可赋予这些区域稳定性或为这些区域提供可延展性，这些区域经受应力/应变。为了解决在早期心血管发育的原纤维蛋白的功能（S），我们将使用时间推移成像，标记抗体，和计算分析，以记录在鸟类胚胎双侧心脏形成组织，内皮细胞垫/瓣膜原基，和正常胚胎中的主要胚胎血管中的标记蛋白的组装/重组和运动。此外，我们建议监测实验扰动微纤维组装对心血管发育的影响。类似地，我们将监测改变心血管（CV）形态发生（在组织水平）对血管生成素组装的影响。最后，我们将使用互补的小鼠外植体培养系统来动态监测正常和转基因CV组织中的微纤维组装。我们假设动态微纤维组装是正常心脏发育的关键，并且有序组装的破坏导致心血管畸形。研究结缔组织原纤维组装将有助于更好地了解结缔组织相关的心血管缺陷。

DESCRIPTION (provided by applicant): Cell-extracellular matrix (ECM) interactions are key regulators of developmental morphogenic events. Cardiovascular abnormalities associated with the connective tissue disorders Marfan syndrome and congenital contractural arachnodactyly have been linked genetically and biochemically to the microfibrillar ECM proteins fibrillin 1 and 2 respectively. In addition to ocular and skeletal abnormalities, patients with these disorders manifest aortic root dilatation, aortic insufficiency, and mitral valve prolapse. A neonatal form of Marfan syndrome causes severe cardiovascular defects and leads to death within the first year. Epifluorescence microscopy indicates fibrillin-1 and -2 positive fibrils are present in the epicardium, dorsal mesocardium, and enclocardial cushion tissue/valve primordial of avian embryos, and surround the forming bilateral dorsal aortae; implicating the fibrillins in cardiovascular morphogenesis. These microfibrils may impart stability or provide extensible properties to these regions, which are subject to stress/strain. To address the function(s) of fibrillins during early cardiovascular development we will use time-lapse imaging, fibrillin marker antibodies, and computational analyses to document fibrillin assembly/reorganization and motion in the avian embryo bilateral heart forming tissues, endocardial cushions/valve primordia, and major embryonic vessels in normal embryos. Further, we propose to monitor the effects of experimentally perturbing microfibril assembly on cardiovascular development. Similarly, we will monitor the effects of altering cardiovascular (CV) morphogenesis (at the tissue level) on fibrillin assembly. Finally, we will use a complementary mouse explant culture system to monitor dynamically fibrillin assembly in normal and transgenic CV tissue, We hypothesize that dynamic microfibril assembly is key for normal cardiac development, and that disruption of orderly assembly leads to cardiovascular malformations. Examining fibrillin fibril assembly will lead to a better understanding of connective tissue-related cardiovascular defects.