心脏左右侧的建立。
Establishment of Cardiac Laterality.
机构信息
Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
出版信息
Adv Exp Med Biol. 2024;1441:167-183. doi: 10.1007/978-3-031-44087-8_9.
Formation of the vertebrate heart with its complex arterial and venous connections is critically dependent on patterning of the left-right axis during early embryonic development. Abnormalities in left-right patterning can lead to a variety of complex life-threatening congenital heart defects. A highly conserved pathway responsible for left-right axis specification has been uncovered. This pathway involves initial asymmetric activation of a nodal signaling cascade at the embryonic node, followed by its propagation to the left lateral plate mesoderm and activation of left-sided expression of the Pitx2 transcription factor specifying visceral organ asymmetry. Intriguingly, recent work suggests that cardiac laterality is encoded by intrinsic cell and tissue chirality independent of Nodal signaling. Thus, Nodal signaling may be superimposed on this intrinsic chirality, providing additional instructive cues to pattern cardiac situs. The impact of intrinsic chirality and the perturbation of left-right patterning on myofiber organization and cardiac function warrants further investigation. We summarize recent insights gained from studies in animal models and also some human clinical studies in a brief overview of the complex processes regulating cardiac asymmetry and their impact on cardiac function and the pathogenesis of congenital heart defects.
脊椎动物心脏及其复杂的动脉和静脉连接的形成,在很大程度上取决于胚胎早期发育过程中左右轴的模式形成。左右模式形成的异常会导致各种复杂的危及生命的先天性心脏缺陷。一个高度保守的负责左右轴特化的途径已经被揭示。该途径涉及胚胎节点处的节点信号级联的初始非对称激活,随后传播到左侧侧板中胚层,并激活指定内脏器官不对称的 Pitx2 转录因子的左侧表达。有趣的是,最近的研究表明,心脏的左右侧是由内在细胞和组织手性决定的,与 Nodal 信号无关。因此,Nodal 信号可能叠加在这种内在手性上,为模式心脏 situs 提供额外的指导线索。内在手性和左右模式形成的扰动对肌纤维组织和心脏功能的影响值得进一步研究。我们总结了来自动物模型研究的最新见解,并简要概述了调节心脏不对称的复杂过程及其对心脏功能和先天性心脏缺陷发病机制的影响,以及一些人类临床研究。