Morphoelastic control of gastro-intestinal organogenesis: Theoretical predictions and numerical insights
Morphoelastic control of gastro-intestinal organogenesis: Theoretical predictions and numerical insights
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DOI：
10.1016/j.jmps.2015.02.016
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发表时间：
2015-05-01
影响因子：
5.3
通讯作者：
Ciarletta, P.
中科院分区：
文献类型：
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作者：
Balbi, V.;Kuhl, E.;Ciarletta, P.
胃肠道长9米，不仅是我们最长的器官，也是我们结构最多样化的器官。在胚胎发育过程中，它演变为具有内胚层内衬和外中胚层的双层管。其内表面形态多样，与消化功能密切相关。然而，这些肠道模式的演变仍然知之甚少。在这里，我们表明几何和机械因素可以解释肠道模式的形成。利用力学的非线性场理论，将表面形态形成模型化为约束微分生长的不稳定问题。为了允许内部和外部扩张，我们用均匀的诺伊曼边界条件模拟胃肠道。为了在折叠开始时建立折叠模式的估计，我们进行了线性稳定性分析，并辅以微扰理论。为了预测后屈曲状态下的模式演变，我们进行了一系列非线性有限元模拟。我们的模型解释了为什么纵向褶皱出现在食管中，外层厚而硬，而空肠中圆周褶皱出现在外层薄而软。在中间区域，如猫的食道，纵向和周向褶皱同时出现。我们的模型可以作为一个有价值的工具来解释和预测由于发育障碍或某些消化系统疾病（包括食物过敏）导致的食管形态改变。(C) 2015 Elsevier Ltd.版权所有。
With nine meters in length, the gastrointestinal tract is not only our longest, but also our structurally most diverse organ. During embryonic development, it evolves as a bilayered tube with an inner endodermal lining and an outer mesodermal layer. Its inner surface displays a wide variety of morphological patterns, which are closely correlated to digestive function. However, the evolution of these intestinal patterns remains poorly understood. Here we show that geometric and mechanical factors can explain intestinal pattern formation. Using the nonlinear field theories of mechanics, we model surface morphogenesis as the instability problem of constrained differential growth. To allow for internal and external expansion, we model the gastrointestinal tract with homogeneous Neumann boundary conditions. To establish estimates for the folding pattern at the onset of folding, we perform a linear stability analysis supplemented by the perturbation theory. To predict pattern evolution in the post-buckling regime, we perform a series of nonlinear finite element simulations. Our model explains why longitudinal folds emerge in the esophagus with a thick and stiff outer layer, whereas circumferential folds emerge in the jejunum with a thinner and softer outer layer. In intermediate regions like the feline esophagus, longitudinal and circumferential folds emerge simultaneously. Our model could serve as a valuable tool to explain and predict alterations in esophageal morphology as a result of developmental disorders or certain digestive pathologies including food allergies. (C) 2015 Elsevier Ltd. All rights reserved.