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蛛网膜挛缩症相关的心血管异常分别与微纤维ECM蛋白原纤维蛋白1和原纤维蛋白2在遗传和生化上有关。除了眼部和骨骼异常外，这些疾病的患者还表现为主动脉根扩张、主动脉不全和二尖瓣脱垂。新生儿形式的马凡氏综合征会导致严重的心血管缺陷，并在第一年导致死亡。荧光显微镜显示，纤原蛋白-1和-2阳性原纤维存在于禽类胚胎的心外膜、背心系膜和心包垫组织/瓣膜原始区，并包围着正在形成的双侧背主动脉；提示纤原蛋白参与心血管形态发生。这些微纤维可以赋予这些区域稳定性或提供可扩展的特性，这些区域受到应力/应变的影响。为了研究纤原蛋白在早期心血管发育过程中的功能，我们将使用延迟成像、纤原蛋白标记抗体和计算分析来记录正常胚胎中双侧心脏形成组织、心内膜垫/瓣膜原基和主要胚胎血管中纤原蛋白的组装/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。同样，我们将监测改变心血管（CV）形态发生（在组织水平上）对原蛋白组装的影响。最后，我们将使用一个互补的小鼠外植体培养系统来动态监测正常和转基因CV组织中的原纤维蛋白组装。我们假设动态微纤维组装是正常心脏发育的关键，而有序组装的破坏会导致心血管畸形。检查原纤维蛋白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.