Martin Meghan, Chen Chih-Ying, McCowan Timothy, Wells Sarah
School of Biomedical Engineering, Dalhousie University, Halifax, NS B3H 4R2, Canada.
Medical Sciences Program, Faculties of Science and Medicine, Dalhousie University, Halifax, NS B3H 4R2, Canada.
J Cardiovasc Dev Dis. 2024 Mar 29;11(4):106. doi: 10.3390/jcdd11040106.
There is increasing evidence that some adult mitral valve pathologies may have developmental origins involving errors in cell signaling and protein deposition during valvulogenesis. While early and late gestational stages are well-documented in zebrafish, chicks, and small mammalian models, longitudinal studies in large mammals with a similar gestational period to humans are lacking. Further, the mechanism of chordae tendineae formation and multiplication remains unclear. The current study presents a comprehensive examination of mitral anterior leaflet and chordae tendineae development in a bovine model (a large mammal with the same gestational period as humans). Remarkably distinct from small mammals, bovine development displayed early branched chordae, with increasing attachments only until birth, while the anterior leaflet grew both during gestation and postnatally. Chordae also exhibited accelerated collagen deposition, maturation, and crimp development during gestation. These findings suggest that the bovine anterior leaflet and chordae tendineae possess unique processes of development despite being a continuous collagenous structure and could provide greater insight into human valve development.
越来越多的证据表明，一些成人二尖瓣病变可能具有发育起源，涉及瓣膜发生过程中细胞信号传导和蛋白质沉积的错误。虽然斑马鱼、小鸡和小型哺乳动物模型对妊娠早期和晚期阶段有充分记录，但缺乏对与人类妊娠期相似的大型哺乳动物的纵向研究。此外，腱索形成和增殖的机制仍不清楚。当前的研究全面检查了牛模型（一种与人类妊娠期相同的大型哺乳动物）中二尖瓣前叶和腱索的发育情况。与小型哺乳动物明显不同，牛的发育显示出早期分支的腱索，仅在出生前附着增加，而前叶在妊娠期和出生后都生长。腱索在妊娠期也表现出胶原沉积、成熟和卷曲发育加速。这些发现表明，尽管牛的前叶和腱索是连续的胶原结构，但它们具有独特的发育过程，并且可以为人类瓣膜发育提供更多见解。
