Gyoneva Lazarina, Hovell Carley B, Pewowaruk Ryan J, Dorfman Kevin D, Segal Yoav, Barocas Victor H
Department of Biomedical Engineering , University of Minnesota , 7-105 Nils Hasselmo Hall, 312 Church Street SE, Minneapolis, MN 55455 , USA.
Department of Chemical Engineering and Materials Science , University of Minnesota , 151 Amundson Hall, 421 Washington Ave SE, Minneapolis, MN 55455 , USA.
Interface Focus. 2016 Feb 6;6(1):20150069. doi: 10.1098/rsfs.2015.0069.
The importance of tissue remodelling is widely accepted, but the mechanism by which the remodelling process occurs remains poorly understood. At the tissue scale, the concept of tensional homeostasis, in which there exists a target stress for a cell and remodelling functions to move the cell stress towards that target, is an important foundation for much theoretical work. We present here a theoretical model of a cell in parallel with a network to study what factors of the remodelling process help the cell move towards mechanical stability. The cell-network system was deformed and kept at constant stress. Remodelling was modelled by simulating strain-dependent degradation of collagen fibres and four different cases of collagen addition. The model did not lead to complete tensional homeostasis in the range of conditions studied, but it showed how different expressions for deposition and removal of collagen in a fibre network can interact to modulate the cell's ability to shield itself from an imposed stress by remodelling the surroundings. This study also showed how delicate the balance between deposition and removal rates is and how sensitive the remodelling process is to small changes in the remodelling rules.
组织重塑的重要性已得到广泛认可，但重塑过程发生的机制仍知之甚少。在组织尺度上，张力稳态的概念是许多理论工作的重要基础，即细胞存在一个目标应力，重塑功能是使细胞应力朝着该目标移动。我们在此提出一个细胞与网络并行的理论模型，以研究重塑过程中的哪些因素有助于细胞趋向机械稳定性。细胞 - 网络系统发生变形并保持恒定应力。通过模拟胶原纤维的应变依赖性降解和四种不同的胶原添加情况对重塑进行建模。在所研究的条件范围内，该模型并未导致完全的张力稳态，但它展示了纤维网络中胶原沉积和去除的不同表达式如何相互作用，通过重塑周围环境来调节细胞抵御施加应力的能力。这项研究还表明沉积和去除速率之间的平衡是多么微妙，以及重塑过程对重塑规则的微小变化是多么敏感。
