Desmin integrates the three-dimensional mechanical properties of muscles
Desmin integrates the three-dimensional mechanical properties of muscles
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DOI：
10.1152/ajpcell.2001.280.1.c46
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发表时间：
2001-01-01
影响因子：
5.5
通讯作者：
Tidball, JG
中科院分区：
文献类型：
--
作者：
Boriek, AM;Capetanaki, Y;Tidball, JG
横纹肌是一个线性电机，其属性已被定义为单轴结构。这里要解决的问题是什么样的贡献是由extramyofilament细胞骨架结构，不与肌丝平行排列的电机的性能。这个问题产生的观察，横向负荷增加肌肉生产的隔膜，但不是在后肢肌肉，从而表明存在的结构，耦合的纵向和横向特性的肌肉。此外，我们发现，细胞骨架蛋白结蛋白的无效突变体的隔膜显示1）纵向和横向特性之间的耦合显着减少，首次表明特定蛋白质在整合肌肉的三维力学特性中的作用，2）肌肉的刚度和粘弹性显着减少，和3）强直力产生显着增加。因此，结蛋白通过在三维结构网络中对被动刚度和粘弹性以及对主动力产生的调制做出贡献而在膈肌中起到复杂的机械功能。我们的发现通过将我们对细胞骨架功能的理解置于肌肉结构和机械复杂性的背景下，改变了细胞之间力传递的范式。
Striated muscle is a linear motor whose properties have been defined in terms of uniaxial structures. The question addressed here is what contribution is made to the properties of this motor by extramyofilament cytoskeletal structures that are not aligned in parallel with the myofilaments. This question arose from observations that transverse loads increase muscle force production in diaphragm but not in the hindlimb muscle, thereby indicating the presence of structures that couple longitudinal and transverse properties of diaphragmatic muscle. Furthermore, we find that the diaphragms of null mutants for the cytoskeletal protein desmin show 1) significant reductions in coupling between the longitudinal and transverse properties, indicating for the first time a role for a specific protein in integrating the three-dimensional mechanical properties of muscle, 2) significant reductions in the stiffness and viscoelasticity of muscle, and 3) significant increases in tetanic force production. Thus desmin serves a complex mechanical function in diaphragm muscle by contributing both to passive stiffness and viscoelasticity and to modulation of active force production in a three-dimensional structural network. Our finding changes the paradigm of force transmission among cells by placing our understanding of the function of the cytoskeleton in the context of the structural and mechanical complexity of muscles.