title: Interdependency of cell adhesion, force generation and extracellular proteolysis in matrix remodeling.
abstract: It is becoming increasingly evident that the micromechanics of cells and their environment determine cell fate and function as much as soluble molecular factors do. We hypothesized that extracellular matrix proteolysis by membrane type 1 matrix metalloproteinase (MT1-MMP) depends on adhesion, force generation and rigidity sensing of the cell. Melanoma cells (MV3 clone) stably transfected with MT1-MMP, or the empty vector as a control, served as the model system. α2β1 integrins (cell adhesion), actin and myosin II (force generation and rigidity sensing) were blocked by their corresponding inhibitors (α2β1 integrin antibodies, Cytochalasin D, blebbistatin). A novel, anisotropic matrix array of parallel, fluorescently labeled collagen-I fibrils was used. Cleavage and bundling of the collagen-I fibrils, and spreading and durotaxis of the cells on this matrix array could be readily discerned and quantified by a combined set-up for fluorescence and atomic force microscopy. In short, expression of the protease resulted in the generation of structural matrix defects, clearly indicated by gaps in the collagen lattice and loose fiber bundles. This key feature of matrix remodeling depended essentially on the functionality of α2β1 integrin, the actin filament network and myosin II motor activity. Interference with any of these negatively impacted matrix cleavage and three-dimensional matrix entanglement of cells.
authors.affiliation: German Cancer Research Center Heidelberg (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Kirmse
authors.forename: Hannes
authors.initials: H
authors.lastname: Otto
authors.forename: Thomas
authors.initials: T
authors.lastname: Ludwig
mesh_terms: D016880:Anisotropy; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D024042:Collagen Type I / Q000378:metabolism; D015638:Cytochalasin D / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D006801:Humans; D038982:Integrin alpha2beta1 / Q000378:metabolism; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D018625:Microscopy, Atomic Force / Q000379:methods; D008856:Microscopy, Fluorescence; D024462:Myosin Type II / Q000037:antagonists & inhibitors; D013314:Stress, Mechanical
chemical_list: D024042:Collagen Type I; D006576:Heterocyclic Compounds, 4 or More Rings; D038982:Integrin alpha2beta1; D061965:Matrix Metalloproteinase Inhibitors; C472645:blebbistatin; D015638:Cytochalasin D; D053511:Matrix Metalloproteinase 14; D024462:Myosin Type II