Intrinsic mechanical properties of the extracellular matrix affect the behavior of pre-osteoblastic MC3T3-E1 cells
Intrinsic mechanical properties of the extracellular matrix affect the behavior of pre-osteoblastic MC3T3-E1 cells
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DOI：
10.1152/ajpcell.00455.2005
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发表时间：
2006-06-01
影响因子：
5.5
通讯作者：
Putnam, AJ
中科院分区：
文献类型：
--
作者：
Khatiwala, CB;Peyton, SR;Putnam, AJ
存在于ECM中的机械线索已被假设为提供指示细胞行为的指导性信号。我们通过在具有可调机械性能的I型胶原改性水凝胶表面上培养MC 3 T3-E1细胞来探索成骨细胞中的这一假设，并评估其增殖、迁移和分化。在用低I型胶原蛋白密度功能化的凝胶上，在聚苯乙烯上培养的MC 3 T3-E1细胞的增殖速度是在最软基质上培养的细胞的两倍。定量延时视频显微镜分析显示，随机运动速度显着延迟最软的基板（0.25 +/- 0.01 μ m/min），在聚苯乙烯基板上的最大速度（0.42 +/- 0.04 μ m/min）相反。在用高I型胶原密度功能化的凝胶上，迁移速度表现出对ECM顺应性的双相依赖性，在中等硬度的凝胶上观察到最大速度（0.34 +/-0.02 μ m/min），而最小速度（0.24 +/-0.03 μ m/min）出现在最软和最硬的凝胶上（即，聚苯乙烯）基材。不成熟的焦点接触和组织不良的肌动蛋白细胞骨架中观察到的细胞培养在最软的基板上，而那些更刚性的基板组装成熟的焦点粘连和强大的肌动蛋白应力纤维。与此同时，粘着斑激酶（FAK）活性（通过检测pY 397-FAK评估）的依从性的影响，与最大的活动发生在聚苯乙烯上培养的细胞。最后，MC 3 T3-E1细胞的矿物质沉积也受到ECM顺应性的影响，从而得出这样的结论，即改变ECM的机械性质可能会影响各种MC 3 T3-E1细胞功能，并可能最终影响其分化的表型。
Mechanical cues present in the ECM have been hypothesized to provide instructive signals that dictate cell behavior. We probed this hypothesis in osteoblastic cells by culturing MC3T3-E1 cells on the surface of type I collagen-modified hydrogels with tunable mechanical properties and assessed their proliferation, migration, and differentiation. On gels functionalized with a low type I collagen density, MC3T3-E1 cells cultured on polystyrene proliferated twice as fast as those cultured on the softest substrate. Quantitative time-lapse video microscopic analysis revealed random motility speeds were significantly retarded on the softest substrate (0.25 +/- 0.01 mu m/min), in contrast to maximum speeds on polystyrene substrates (0.42 +/- 0.04 mu m/min). On gels functionalized with a high type I collagen density, migration speed exhibited a biphasic dependence on ECM compliance, with maximum speeds (0.34 +/- 0.02 mu m/min) observed on gels of intermediate stiffness, whereas minimum speeds (0.24 +/- 0.03 mu m/min) occurred on both the softest and most rigid (i.e., polystyrene) substrates. Immature focal contacts and a poorly organized actin cytoskeleton were observed in cells cultured on the softest substrates, whereas those on more rigid substrates assembled mature focal adhesions and robust actin stress fibers. In parallel, focal adhesion kinase (FAK) activity ( assessed by detecting pY397-FAK) was influenced by compliance, with maximal activity occurring in cells cultured on polystyrene. Finally, mineral deposition by the MC3T3-E1 cells was also affected by ECM compliance, leading to the conclusion that altering ECM mechanical properties may influence a variety of MC3T3-E1 cell functions, and perhaps ultimately, their differentiated phenotype.