SysCODE Heart Valve Design and Engineering

从遗传缺陷到进行性钙化性动脉粥样硬化对半月瓣病变的影响 狭窄是巨大的，并且随着这些曾经致命的先天性疾病存活率的增加而继续升级 反常现象和迅速增长的老龄化人口。组织工程瓣膜置换术提供了一种 对儿童和成人都有诱人的潜在治疗和干预作用。然而，最终的成功是 这些战略将取决于它们能在多大程度上概括以下关键过程 正常的主、肺动脉瓣个体发育。我们假设半月瓣的发育需要 精心策划的心内膜菌遗传亚群的转化！单元格到 提供独特的瓣膜间质细胞(VIC)，可重塑已定义的细胞外基质并 维持瓣膜内环境平衡，以应对退行性刺激。利用开发的遗传试剂 在我们的实验室以及SysCODE财团的卓越专业知识和资源下，我们建议 制定成功组织所需的瓣膜发育和成熟的分子蓝图 工程学。我们的策略是在瓣膜形态发生的关键阶段干扰离散的途径 揭露基本的动态平衡相互作用。具体来说，我们建议：1)确定主要监管机构 流出道心内膜垫中启动瓣膜形成的途径 (EDC)。心内膜特异的Alk3等位基因缺失将被用来干扰BMP信号转导作为模型 减薄上皮间充质转化(EMT)和NFATd缺陷型小鼠将被用作 加强了急救。激光捕获显微解剖(LCM)和成像质谱学(IMS)将 用来比较组织特异的基因和蛋白质表达谱。2)定义关键的监管 表征胚胎晚期和出生后瓣膜重塑和内稳态的途径 半月瓣。一种新的心内膜前瓣膜特异性Cre将用于删除Tie1等位基因 这会导致瓣膜增生型。APOE-/-小鼠将被用作进展性主动脉模型 瓣膜狭窄。。将评估小鼠的瓣叶变薄、主动脉进展的变化 钙化。3)描述重述瓣膜所需的合成矩阵的基本成分 体外发育。根据获得的信息，我们将确定所需的关键组件 诱导EMT和ECM重塑透明质酸(HA)水凝胶体外培养体系。的有效性 基质操作将通过a)诱导心内膜细胞转化的能力进行分析，在 由于TGFBR2受体的缺失和b)重塑瓣膜的能力，转化生长因子信号已经减弱 FACS分选的ES细胞来源的心内膜细胞通过指定和转化形成。

The impact of semilunar valve pathology ranging from genetic defects to progressive calcific arotic stenosis is enormous and continues to escalate with the increased survival of these once fatal congenital abnormalities and the burgeoning aging population. Valve replacement by tissue engineering presents an attractive potential therapeutic, intervention for both children and adults. However, the ultimate success of these strategies will be determined by the degree to which they can recapitulate the critical processes of normal aortic and pulmonary valve ontogeny. We hypothesize semilunar valve development requires the carefully orchestrated transformation of a genetically distinct subpopulation of endocardia! cells to provide unique valvular interstitial cells (VICs) that remodel a defined extracellular matrix and maintain valve homeostasis in response to degenerative stimuli. Using the genetic reagents developed in our laboratory and the exceptional expertise and resources of the SysCode consortium, we propose to develop a molecular blueprint of valve development and maturation required for successful tissue engineering. Our strategy is to disrupt a discrete pathway at critical stages of valve morphogenesis to expose essential homeostatic interactions. Specifically, we propose to: 1) Determine the major regulatory pathways that are essential for initiation of valve formation in the outflow tract endocardial cushions (EDC). Endocardial specific deletion of a floxed Alk3 allele will be used to perturb BMP signaling as a model of attenuated epitheliahmesenchymal transformation (EMT) and NFATd null mice will be used as model of accentuated EMT. Laser Capture Microdissection (LCM) and Imaging Mass Spectrometry (IMS) will be employed to compare tissue specific gene and protein expression profiles. 2) Define the critical regulatory pathways that characterize valve remodeling and homeostasis in late embryonic and postnatal semilunar valve. A novel pro-valvar endocardial specific Cre will be used to delete a floxed Tie1 allele which results in a hyperplastic valve phenotype. ApoE-/- mice will be used as a model of progressive aortic valve stenosis. . Mice will be evaluated for alterations in valve leaflet thinning, progression of aortic calcification. 3) Delineate the essential components of a synthetic matrix required to recapitulate valve development in vitro. Based; on information obtained we will determine the key components required to induce EMT and ECM remodeling an in vitro Hyaluronic Acid (HA) Hydrogel culture system. Effectiveness of matrix manipulations will be assayed by a)the ability to induce transformation of endocardial cells in which TGF¿ signaling has been attenuated by deletion of the Tgfbr2 receptor and b) the ability to recapitulate valve formation via specification and transformation of FACS sorted ES cell derived endocardial cells.