MMP inhibitors augment fibroblast adhesion through stabilization of focal adhesion contacts and up-regulation of cadherin function
MMP inhibitors augment fibroblast adhesion through stabilization of focal adhesion contacts and up-regulation of cadherin function
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DOI：
10.1074/jbc.m101647200
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发表时间：
2001-10-26
影响因子：
4.8
通讯作者：
Khokha, R
中科院分区：
文献类型：
--
作者：
Ho, AT;Voura, EB;Khokha, R
由于MMP（基质金属蛋白酶）和TIMP（金属蛋白酶的组织抑制剂）之间的不平衡而增加的细胞周围蛋白水解促进肿瘤发生的早期阶段。我们已经报道了TIMP-1下调赋予永生瑞士3 T3成纤维细胞致瘤性。在追求参与这种转变的机制，我们问是否MMP抑制剂调节接触抑制和细胞粘附，因为这些事件的失调是必不可少的细胞转化。使用遗传和生化手段，我们证明，MMP抑制剂调节成纤维细胞粘附。TIMP-1下调的细胞形成密集的多层集落，表明接触抑制的丧失。重组TIMP-1和合成MMP抑制剂（MMPi）恢复正常的细胞接触和密度，这些细胞在剂量依赖性的方式。因此，研究了MMP i对细胞-细胞外基质（ECM）和细胞-细胞粘附的影响。MMPi处理后，p125（FAK）重新分布，与黏着斑蛋白，细胞ECM接触点。此外，p125（FAK）的磷酸化恢复到与野生型相似的水平。同时，MMPi治疗增加了钙粘蛋白水平并稳定了钙粘蛋白介导的细胞-细胞接触。此外，增强的钙粘蛋白功能是明显的，因为钙依赖性细胞-细胞聚集增加以及钙粘蛋白和β-连环蛋白在细胞膜上的共定位。我们还获得了使用timp-1（-/-）小鼠胚胎成纤维细胞改变钙粘蛋白功能的独立证据。我们的数据提供了挑衅性的证据，增加细胞周围蛋白水解影响细胞粘附系统，以抵消正常的接触抑制，随后对细胞转化和肿瘤发生的影响。
Increased pericellular proteolysis due to an imbalance between MMPs (matrix metalloproteinases) and TIMPs (tissue inhibitors of metalloproteinases) promotes early stages of tumorigenesis. We have reported that TIMP-1 down-regulation confers tumorigenicity on immortal Swiss 3T3 fibroblasts. In pursuit of the mechanism involved in this transformation, we asked whether MMP inhibitors modulate contact inhibition and cell adhesion, because the dysregulation of these events is essential for cellular transformation. Using both genetic and biochemical means, we demonstrate that MMP inhibitors regulate fibroblast cell adhesion. TIMP-1 down-regulated cells formed dense, multilayered colonies, suggesting a loss of contact inhibition. Recombinant TIMP-1 and synthetic MMP inhibitors (MMPi) restored normal cell contact and density of these cells in a dose-dependent manner. Consequently, the effect of MMPi on both cell-extracellular matrix (ECM) and cell-cell adhesion were investigated. Upon MMPi treatment, p125(FAK) was redistributed, together with vinculin, to points of cell-ECM contact. Furthermore, phosphorylation of p125(FAK) was restored to levels similar to that of wild type. In parallel, MMPi treatment increased cadherin levels and stabilized cadherin-mediated cell-cell contacts. Moreover, enhanced cadherin function was evident as increased calcium-dependent cell-cell aggregation and co-localization of cadherin and beta -catenin at the cell membrane. We also obtained independent evidence of altered cadherin function using timp-1(-/-) mouse embryonic fibroblasts. Our data provide provocative evidence that increased pericellular proteolysis impacts cell adhesion systems to offset normal contact inhibition, with subsequent effects on cell transformation and tumorigenesis.