Extracellular matrix (ECM) is widely considered to be integral to the function of skeletal muscle, providing mechanical support, transmitting force, and contributing to passive stiffness. Many functions and dysfunctions attributed to ECM are thought to stem from its mechanical properties, yet there are few data describing the mechanics of intact ECM. Such measurements require isolating intact ECM from the muscle cells it surrounds. The objectives of this study were to quantify the efficiency of three techniques for this purpose: Triton, Triton with sodium dodecyl sulfate, and latrunculin B; and to determine their impact on properties of the remaining ECM. Efficiency was quantified by DNA content and evaluation of western blot intensities for myosin and actin. The properties of ECM were quantified by collagen content and uniaxial tensile testing. We found that latrunculin B was the most efficient method for removing skeletal muscle cells, reducing DNA content to less than 10% of that seen in control muscles, and substantially reducing the myosin and actin to 15% and 23%, respectively; these changes were larger than for the competing methods. Collagen content after decellularization was not significantly different from control muscles for all methods. Only the stiffness of the muscles decellularized with latrunculin B differed significantly from control, having a Young’s modulus reduced by 47% compared to the other methods at matched stresses. Our results suggest that latrunculin B is the most efficient method for decellularizing skeletal muscle and that the remaining ECM accounts for approximately half of the stiffness in passive muscle.

细胞外基质 (ECM) 被广泛认为是骨骼肌功能不可或缺的一部分，提供机械支撑、传递力并有助于被动僵硬。归因于 ECM 的许多功能和功能障碍被认为源于其机械特性，但描述完整 ECM 力学的数据很少。这种测量需要从它周围的肌肉细胞中分离出完整的 ECM。本研究的目的是量化用于此目的的三种技术的效率：Triton、含有十二烷基硫酸钠的 Triton 和 latrunculin B；并确定它们对剩余 ECM 特性的影响。通过 DNA 含量和对肌球蛋白和肌动蛋白的蛋白质印迹强度的评估来量化效率。ECM 的特性通过胶原含量和单轴拉伸测试进行量化。我们发现 latrunculin B 是去除骨骼肌细胞的最有效方法，将 DNA 含量降低到对照肌肉的 10% 以下，并将肌球蛋白和肌动蛋白分别显着降低到 15% 和 23%；这些变化比竞争方法更大。脱细胞后的胶原蛋白含量与所有方法的对照肌肉没有显着差异。只有用 latrunculin B 去细胞的肌肉的刚度与对照显着不同，在匹配的应力下，与其他方法相比，杨氏模量降低了 47%。我们的结果表明 latrunculin B 是使骨骼肌脱细胞的最有效方法，剩余的 ECM 约占被动肌肉僵硬度的一半。