Development of heart valve leaflets and supporting apparatus in chicken and mouse embryos
Development of heart valve leaflets and supporting apparatus in chicken and mouse embryos
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DOI：
10.1002/dvdy.20051
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发表时间：
2004-06-01
影响因子：
2.5
通讯作者：
Yutzey, KE
中科院分区：
文献类型：
--
作者：
Lincoln, J;Alfieri, CM;Yutzey, KE
瓣膜间隔发育异常在很大程度上导致先天性心脏缺陷，但其潜在原因复杂且知之甚少。早期心脏调节基因在瓣膜间隔发育过程中差异表达，与鸡和小鼠胚胎心腔形成过程中的新功能一致。根据细胞外基质分子的限制表达，在小叶、肌腱和与乳头肌的肌腱连接中发现了不同的瓣膜细胞谱系。这些结构中的特定细胞类型表现出软骨形成和肌腱发育的特征，通过硬化症、II型胶原和肌腱蛋白的表达来鉴定。在鸡胚中，瓣膜重塑和成熟伴随着有丝分裂指数的下降，这表明溴脱氧尿苷掺入减少。对Tie2-cre x ROSA26R小鼠的分析表明，成熟的瓣膜结构，包括房室和流出道半月瓣叶、肌腱以及连接二尖瓣和三尖瓣隔叶的纤维连续性，来自心内膜垫层的内皮细胞。总之，这些研究为了解发育中的脊椎动物心脏成熟瓣膜结构的起源和细胞谱系多样性提供了新的见解。(C)2004年Wiley-Liss公司
Abnormalities in valvuloseptal development significantly contribute to congenital heart defects, yet the underlying causes are complex and poorly understood. Early cardiac regulatory genes are differentially expressed during valvuloseptal development, consistent with novel functions during heart chamber formation in chicken and mouse embryos. Distinct valve cell lineages were identified in the leaflets, chordae tendineae, and myotendinous junctions with the papillary muscles based on restricted expression of extracellular matrix molecules. Specific cell types within these structures demonstrate characteristics of chondrogenesis and tendon development, identified by scleraxis, type II collagen, and tenascin expression. In chicken embryos, valve remodeling and maturation accompanies a decrease in mitotic index indicated by reduced bromodeoxyuridine incorporation. Analysis of Tie2-cre x ROSA26R mice demonstrates that mature valve structures, including the atrioventricular and outflow tract semilunar valve leaflets, chordae tendineae, and the fibrous continuity that connects the septal leaflets of mitral and tricuspid valves, arise from endothelial cells of the endocardial cushions. Together, these studies provide novel insights into the origins and cell lineage diversity of mature valve structures in the developing vertebrate heart. (C) 2004 Wiley-Liss, Inc.