Division of Molecular Virology and Oncology, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
Division of Molecular Virology and Oncology, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan; Department of Oral and Maxillofacial Surgery, Graduate School of Medical Science, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8641, Japan.
Biochem Biophys Res Commun. 2014 Jul 25;450(2):1016-20. doi: 10.1016/j.bbrc.2014.06.100. Epub 2014 Jun 26.
Fibronectin matrix formation requires the increased cytoskeletal tension generated by cadherin adhesions, and is suppressed by membrane-type 1 matrix metalloproteinase (MT1-MMP). In a co-culture of Rat1 fibroblasts and MT1-MMP-silenced HT1080 cells, fibronectin fibrils extended from Rat1 to cell-matrix adhesions in HT1080 cells, and N-cadherin adhesions were formed between Rat1 and HT1080 cells. In control HT1080 cells contacting with Rat1 fibroblasts, cell-matrix adhesions were formed in the side away from Rat1 fibroblasts, and fibronectin assembly and N-cadherin adhesions were not formed. The role of N-cadherin adhesions in fibronectin matrix formation was studied using MT1-MMP-silenced HT1080 cells. MT1-MMP knockdown promoted fibronectin matrix assembly and N-cadherin adhesions in HT1080 cells, which was abrogated by double knockdown with either integrin β1 or fibronectin. Conversely, inhibition of N-cadherin adhesions by its knockdown or treatment with its neutralizing antibody suppressed fibronectin matrix formation in MT1-MMP-silenced cells. These results demonstrate that fibronectin assembly initiated by MT1-MMP knockdown results in increase of N-cadherin adhesions, which are prerequisite for further fibronectin matrix formation.
纤连蛋白基质的形成需要黏附连接产生的细胞骨架张力增加，而这一过程受到膜型基质金属蛋白酶 1（MT1-MMP）的抑制。在 Rat1 成纤维细胞和沉默 MT1-MMP 的 HT1080 细胞的共培养物中，纤连蛋白纤维从 Rat1 延伸到 HT1080 细胞的细胞-基质黏附物上，并且 Rat1 和 HT1080 细胞之间形成了 N-钙黏蛋白黏附物。在与 Rat1 成纤维细胞接触的对照 HT1080 细胞中，细胞-基质黏附物形成在远离 Rat1 成纤维细胞的一侧，并且没有形成纤连蛋白组装和 N-钙黏蛋白黏附物。使用沉默 MT1-MMP 的 HT1080 细胞研究了 N-钙黏蛋白黏附在纤连蛋白基质形成中的作用。MT1-MMP 敲低促进了 HT1080 细胞中纤连蛋白基质的组装和 N-钙黏蛋白黏附，而用整合素 β1 或纤连蛋白的双重敲低则消除了这种作用。相反，N-钙黏蛋白黏附的抑制作用通过其敲低或用其中和抗体处理，抑制了 MT1-MMP 沉默细胞中的纤连蛋白基质形成。这些结果表明，由 MT1-MMP 敲低引发的纤连蛋白组装导致 N-钙黏蛋白黏附的增加，这是进一步纤连蛋白基质形成的必要条件。
