Proteolytic processing of laminin-5 by MT1-MMP in tissues and its effects on epithelial cell morphology
Proteolytic processing of laminin-5 by MT1-MMP in tissues and its effects on epithelial cell morphology
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DOI：
10.1096/fj.03-0584fje
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发表时间：
2004-02-01
期刊：
影响因子：
4.8
通讯作者：
Quaranta, Vito
中科院分区：
文献类型：
--
作者：
Koshikawa, Naohiko;Schenk, Susann;Quaranta, Vito
细胞外基质大分子层粘连蛋白-5（Ln-5）在体外被基质金属蛋白酶（MMP）MT 1-MMP和MMP-2转化为促迁移底物。我们现在报告说，切割的Ln-5 MT 1-MMP发生在体内，影响上皮组织的组织和可能的Ln-5营业额。在MT 1-MMP敲除（KO）小鼠中，肾脏显示总Ln-5.2亚基水平增加，但γ 2 '（γ 2的氨基末端截短蛋白水解形式）的量显著减少。KO动物的肾小管上皮细胞分化不良，这是一种令人联想到人类先天性混合性发育不良/发育不良疾病的表型。为了在Ln-5蛋白水解裂解和上皮形态之间建立更好的联系，通过将MT 1-MMP转染到Ln-5阳性、MT 1-MMP缺陷的上皮细胞系中来重建MT 1-MMP表达。MT 1-MMP转染子表现出加工的Ln-5 γ 2链水平的增加和对Ln-5的扩展增强，但不是纤连蛋白。重组MT 1-MMP在体外在已知的体内γ 2 γ 2'加工位点切割γ 2构建体。这些结果有力地表明，Ln-5是MT 1 MMP在体内的生理底物。MT 1-MMP对γ 2亚基的蛋白水解加工可能影响上皮基底膜中Ln-5的周转，从而影响上皮的形态发生。
The extracellular matrix macromolecule laminin-5 (Ln-5) is converted by matrix metalloproteinases (MMP) MT1-MMP and MMP-2 into a migration-promoting substrate in vitro. We now report that cleavage of Ln-5 by MT1-MMP occurs in vivo and affects epithelial tissue organization and probably Ln-5 turnover. In MT1-MMP knockout (KO) mice, the kidneys showed increased levels of total Ln-5.2 subunit, but significantly reduced amounts of gamma 2', an amino-terminal truncated proteolytic form of gamma 2. The kidney tubular epithelia of KO animals were poorly differentiated, a phenotype reminiscent of human congenital mixed hypoplastic/dysplastic disorders. To establish a better link between Ln-5 proteolytic cleavage and epithelial morphology, MT1-MMP expression was reconstituted by transfection of MT1-MMP into a Ln-5 positive, MT1-MMP deficient epithelial cell line. MT1-MMP transfectants demonstrated increased levels of processed Ln-5 gamma 2 chain and enhanced spreading on Ln-5, but not fibronectin. Recombinant MT1-MMP cleaved gamma 2 constructs in vitro at a known in vivo gamma 2 gamma 2' processing site. These results strongly indicate that Ln-5 is a physiological substrate of MT1MMP in vivo. Proteolytic processing of gamma 2 subunit by MT1-MMP may influence Ln-5 turnover in epithelial basement membranes and affect epithelial morphogenesis.