Department of Food Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Cell Biol Int. 2010 Apr 21;34(6):587-91. doi: 10.1042/CBI20090096.
The current study was designed to investigate whether the activities of TGC (total gelatinase and collagenase) as well as MMP-9 (matrix metalloproteinase-9, gelatinase B) secreted by the cultured fibroblasts and myoblasts were influenced by the specific extracellular substrates and by cyclic mechanical strain. Fibroblasts (Rat 2) and myoblasts (C2C12) were cultured with either fibronectin, laminin or collagen type I for 24 h and applied with or without a biaxial deformation at 1 Hz using the Flexcell FX-4000 system. MMP-9 activity was increased in fibroblasts when the cells were in contact with fibronectin and laminin, while in myoblasts, enhanced activity of the secreted enzyme was only observed when collagen was present. TGC activity expressed from myoblasts was increased in cells growing on all three types of extracellular proteins in response to the mechanical stimulation, but in fibroblasts, such an increase was only observed in cells grown on the laminin coating. In summary, our data demonstrate that the activities of MMP-9 synthesized by fibroblasts tend to be regulated by the specific extracellular protein the cells are in contact with, whereas the gelatinolytic actions of proteases produced by myoblasts are more responsive to the mechanical deformation.
本研究旨在探讨培养的成纤维细胞和肌母细胞分泌的 TGC（总明胶酶和胶原酶）以及 MMP-9（基质金属蛋白酶-9，明胶酶 B）的活性是否受到特定细胞外基质和周期性机械应变的影响。将成纤维细胞（Rat 2）和肌母细胞（C2C12）分别用纤连蛋白、层粘连蛋白或 I 型胶原培养 24 小时，并使用 Flexcell FX-4000 系统以 1 Hz 的频率进行双轴变形。当细胞与纤连蛋白和层粘连蛋白接触时，成纤维细胞中 MMP-9 的活性增加，而在肌母细胞中，只有当存在胶原时，分泌酶的活性才增强。对机械刺激的反应，在所有三种细胞外蛋白上生长的肌母细胞表达的 TGC 活性增加，但在成纤维细胞中，这种增加仅发生在层粘连蛋白包被的细胞中。总之，我们的数据表明，成纤维细胞合成的 MMP-9 活性倾向于受到细胞接触的特定细胞外蛋白的调节，而肌母细胞产生的明胶酶的凝胶酶活性对机械变形更敏感。
