Collinsworth Amy M, Zhang Sarah, Kraus William E, Truskey George A
Department of Biomedical Engineering, 136 Hudson Hall, Duke University, Durham, NC 27708, USA.
Am J Physiol Cell Physiol. 2002 Oct;283(4):C1219-27. doi: 10.1152/ajpcell.00502.2001.
The effect of differentiation on the transverse mechanical properties of mammalian myocytes was determined by using atomic force microscopy. The apparent elastic modulus increased from 11.5 +/- 1.3 kPa for undifferentiated myoblasts to 45.3 +/- 4.0 kPa after 8 days of differentiation (P < 0.05). The relative contribution of viscosity, as determined from the normalized hysteresis area, ranged from 0.13 +/- 0.02 to 0.21 +/- 0.03 and did not change throughout differentiation. Myosin expression correlated with the apparent elastic modulus, but neither myosin nor beta-tubulin were associated with hysteresis. Microtubules did not affect mechanical properties because treatment with colchicine did not alter the apparent elastic modulus or hysteresis. Treatment with cytochalasin D or 2,3-butanedione 2-monoxime led to a significant reduction in the apparent elastic modulus but no change in hysteresis. In summary, skeletal muscle cells exhibited viscoelastic behavior that changed during differentiation, yielding an increase in the transverse elastic modulus. Major contributors to changes in the transverse elastic modulus during differentiation were actin and myosin.
通过使用原子力显微镜确定分化对哺乳动物肌细胞横向力学性能的影响。未分化的成肌细胞的表观弹性模量为11.5±1.3 kPa，分化8天后增加到45.3±4.0 kPa（P<0.05）。由归一化滞后面积确定的粘度相对贡献范围为0.13±0.02至0.21±0.03，并且在整个分化过程中没有变化。肌球蛋白表达与表观弹性模量相关，但肌球蛋白和β-微管蛋白均与滞后无关。微管不影响力学性能，因为用秋水仙碱处理不会改变表观弹性模量或滞后。用细胞松弛素D或2,3-丁二酮单肟处理导致表观弹性模量显著降低，但滞后没有变化。总之，骨骼肌细胞表现出在分化过程中发生变化的粘弹性行为，导致横向弹性模量增加。分化过程中横向弹性模量变化的主要贡献者是肌动蛋白和肌球蛋白。
