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素。与结缔组织疾病、马凡综合征和先天性先天性蛛网膜炎相关的心血管异常在遗传和生化上分别与微纤维ECM蛋白原纤维蛋白1和纤维蛋白2有关。除眼部和骨骼异常外，患有这些疾病的患者还表现为主动脉根部扩张、主动脉瓣关闭不全和二尖瓣脱垂。一种新生儿形式的马凡综合征会导致严重的心血管缺陷，并导致第一年内死亡。荧光显微镜观察显示，鸡胚心外膜、心背系膜、心包膜垫组织/瓣膜原基内均有纤维蛋白-1和-2阳性纤维分布，且分布于形成的双侧背主动脉周围，提示纤维蛋白参与了心血管的形态发生。这些微纤维可以赋予这些易受应力/应变影响的区域稳定性或提供可伸展特性。为了探讨纤维蛋白在早期心血管发育中的作用(S)，我们将使用延时成像、纤维蛋白标记物抗体和计算分析来证明纤维蛋白在禽类胚胎双侧心脏形成组织、心内膜垫/瓣膜原基和正常胚胎中的主要胚胎血管中的组装/重组和运动。此外，我们建议监测实验上干扰微原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)对纤维蛋白组装的影响。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，有序组装的破坏会导致心血管畸形。检查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.