美国哈佛医学院Clifford J. Tabin研究组发现肠平滑肌发育的遗传和机械调节机制。该研究于2019年9月19日发表于《细胞》。

研究发现Hedgehog通过Bmp来调控环向取向的内部肌肉层的位置，而局部Bmp抑制对于形成后期纵向取向的外层是至关重要的。因为这些层在不同的发育阶段形成，所以肌肉细胞暴露于引导其排列的独特机械刺激。早期肠管内的差异生长产生沿环向定向第一层的残余应变，并且当第一层形成后，该层的自发收缩对准纵向定向的第二层。该研究将基于形态发生的模式化与机械控制的平滑肌细胞排列相关联，并为了解各种管状器官中的平滑肌组成提供了机制背景。

研究人员表示，胃肠道由同心和正交排列的平滑肌层包裹。然而，对这些肌肉如何在胚胎中形成规则的模式和排列的机制仍是未知。

附：英文原文

Title: Genetic and Mechanical Regulation of Intestinal Smooth Muscle Development

Author: Tyler R. Huycke, Bess M. Miller, Hasreet K. Gill, Nandan L. Nerurkar, David Sprinzak, L. Mahadevan, Clifford J. Tabin

Issue&Volume: Volume 179 Issue 1

Summary: 

The gastrointestinal tract is enveloped by concentric and orthogonally aligned layers of smooth muscle; however, an understanding of the mechanisms by which these muscles become patterned and aligned in the embryo has been lacking. We find that Hedgehog acts through Bmp to delineate the position of the circumferentially oriented inner muscle layer, whereas localized Bmp inhibition is critical for allowing formation of the later-forming, longitudinally oriented outer layer. Because the layers form at different developmental stages, the muscle cells are exposed to unique mechanical stimuli that direct their alignments. Differential growth within the early gut tube generates residual strains that orient the first layer circumferentially, and when formed, the spontaneous contractions of this layer align the second layer longitudinally. Our data link morphogen-based patterning to mechanically controlled smooth muscle cell alignment and provide a mechanistic context for potentially understanding smooth muscle organization in a wide variety of tubular organs.

DOI: 10.1016/j.cell.2019.08.041

Source: https://www.cell.com/cell/fulltext/S0092-8674(19)30960-2