组织中的细胞形状受到细胞之间的生物物理相互作用的影响。组织力可以影响特定的细胞特征,例如细胞几何形状和细胞表面积。这里,我们检查了二维形状,尺寸,和胸膜上皮细胞在不同肺容积的周长。我们证明了与剩余肺容量相比,总肺容量的二维细胞表面积增加了1.53倍,细胞周长增加了1.43倍。与以前的结果一致,胸膜的紧密检查显示,在所有肺容积处,胸膜上皮细胞之间呈波浪状褶皱。为了研究波状褶皱的潜在解释,我们开发了D'ArcyThompson在《论生长和形态》中提出的物理模拟物。模拟物表明,波浪状褶皱是多余的细胞膜无法收缩的结果。为了检验这个假设,我们开发了一个数值模拟来评估二维细胞表面积和细胞周长的增加对细胞-细胞界面形状的影响。我们的模拟表明,细胞周长的增加,而不是二维细胞表面积的增加,对波状褶皱的存在有最直接的影响。我们得出的结论是,胸膜上皮细胞之间的波浪状褶皱反映了由于适应内脏器官扩张所必需的过量细胞周长而引起的屈曲力。
Cell shapes in tissues are affected by the biophysical interaction between cells. Tissue forces can influence specific cell features such as cell geometry and cell surface area. Here, we examined the 2-dimensional shape, size, and perimeter of pleural epithelial cells at various lung volumes. We demonstrated a 1.53-fold increase in 2-dimensional cell surface area and a 1.43-fold increase in cell perimeter at total lung capacity compared to residual lung volume. Consistent with previous results, close inspection of the pleura demonstrated wavy folds between pleural epithelial cells at all lung volumes. To investigate a potential explanation for the wavy folds, we developed a physical simulacrum suggested by D\'Arcy Thompson in On Growth and Form. The simulacrum suggested that the wavy folds were the result of redundant cell membranes unable to contract. To test this hypothesis, we developed a numerical simulation to evaluate the impact of an increase in 2-dimensional cell surface area and cell perimeter on the shape of the cell-cell interface. Our simulation demonstrated that an increase in cell perimeter, rather than an increase in 2-dimensional cell surface area, had the most direct impact on the presence of wavy folds. We conclude that wavy folds between pleural epithelial cells reflects buckling forces arising from the excess cell perimeter necessary to accommodate visceral organ expansion.