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Fibrin binds to collagen and provides a bridge for αVβ3 integrin-dependent contraction of collagen gels.

Reyhani V, Seddigh P, Guss B, Gustafsson R, Rask L, Rubin K - Biochem. J. (2014)

Bottom Line: This allowed murine myoblast C2C12 cells to contract the collagenous composite gel via αVβ3 integrin.A specific competitive inhibitor blocking the Col-I-binding site for fibrinogen abolished the organization of fibrin into discernable fibrils, as well as the C2C12-mediated contraction of Col I gels.Our data show that fibrin can function as a linkage protein between Col I fibres and cells, and suggest that fibrin at inflammatory sites indirectly connects αVβ3 integrins to Col I fibres and thereby promotes cell-mediated contraction of collagenous tissue structures.

View Article: PubMed Central - PubMed

Affiliation: *Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, BMC Box 582, SE-751 23 Uppsala, Sweden.

ABSTRACT
The functional significance of fibrin deposits typically seen in inflammatory lesions, carcinomas and in healing wounds is not fully understood. In the present study, we demonstrate that fibrinogen/fibrin specifically bound to native Col I (collagen type I) and used the Col I fibre network as a base to provide a functional interface matrix that connects cells to the Col I fibres through αVβ3 integrins. This allowed murine myoblast C2C12 cells to contract the collagenous composite gel via αVβ3 integrin. We show that fibrinogen specifically bound to immobilized native Col I at the site known to bind matrix metalloproteinase-1, discoidin domain receptor-2 and fibronectin, and that binding had no effect on Col I fibrillation. A specific competitive inhibitor blocking the Col-I-binding site for fibrinogen abolished the organization of fibrin into discernable fibrils, as well as the C2C12-mediated contraction of Col I gels. Our data show that fibrin can function as a linkage protein between Col I fibres and cells, and suggest that fibrin at inflammatory sites indirectly connects αVβ3 integrins to Col I fibres and thereby promotes cell-mediated contraction of collagenous tissue structures.

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Immunogold staining of the fibrinogen/fibrin in fibrin/Col I gels(A–C) The presence of fibrinogen/fibrin in composite gels of fibrin/Col I was confirmed using immunogold SEM, as described in the Experimental section. Anti-fibrinogen IgG bound to fibrin/fibrinogen was detected by gold-conjugated Protein A (15 nm gold particles). Gold particles were visualized using back-scattered SEM (white spots in B or black spots in the inverted image in C). (D–F) Representative micrographs of pure Col I gels treated and analysed with the same procedure as used for immunogold staining of fibrin/Col I composite gels. No bound gold particles were detected in these gels.
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Figure 7: Immunogold staining of the fibrinogen/fibrin in fibrin/Col I gels(A–C) The presence of fibrinogen/fibrin in composite gels of fibrin/Col I was confirmed using immunogold SEM, as described in the Experimental section. Anti-fibrinogen IgG bound to fibrin/fibrinogen was detected by gold-conjugated Protein A (15 nm gold particles). Gold particles were visualized using back-scattered SEM (white spots in B or black spots in the inverted image in C). (D–F) Representative micrographs of pure Col I gels treated and analysed with the same procedure as used for immunogold staining of fibrin/Col I composite gels. No bound gold particles were detected in these gels.

Mentions: The presence of fibrin in composite gels was confirmed by immunogold staining of the composite fibrin/collagen gels. Fibrin was observed only in the composite gels, but not in pure Col I gels that were treated identically (Figure 7). These results provide morphological support for a direct association of fibrin with collagen fibres.


Fibrin binds to collagen and provides a bridge for αVβ3 integrin-dependent contraction of collagen gels.

Reyhani V, Seddigh P, Guss B, Gustafsson R, Rask L, Rubin K - Biochem. J. (2014)

Immunogold staining of the fibrinogen/fibrin in fibrin/Col I gels(A–C) The presence of fibrinogen/fibrin in composite gels of fibrin/Col I was confirmed using immunogold SEM, as described in the Experimental section. Anti-fibrinogen IgG bound to fibrin/fibrinogen was detected by gold-conjugated Protein A (15 nm gold particles). Gold particles were visualized using back-scattered SEM (white spots in B or black spots in the inverted image in C). (D–F) Representative micrographs of pure Col I gels treated and analysed with the same procedure as used for immunogold staining of fibrin/Col I composite gels. No bound gold particles were detected in these gels.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109839&req=5

Figure 7: Immunogold staining of the fibrinogen/fibrin in fibrin/Col I gels(A–C) The presence of fibrinogen/fibrin in composite gels of fibrin/Col I was confirmed using immunogold SEM, as described in the Experimental section. Anti-fibrinogen IgG bound to fibrin/fibrinogen was detected by gold-conjugated Protein A (15 nm gold particles). Gold particles were visualized using back-scattered SEM (white spots in B or black spots in the inverted image in C). (D–F) Representative micrographs of pure Col I gels treated and analysed with the same procedure as used for immunogold staining of fibrin/Col I composite gels. No bound gold particles were detected in these gels.
Mentions: The presence of fibrin in composite gels was confirmed by immunogold staining of the composite fibrin/collagen gels. Fibrin was observed only in the composite gels, but not in pure Col I gels that were treated identically (Figure 7). These results provide morphological support for a direct association of fibrin with collagen fibres.

Bottom Line: This allowed murine myoblast C2C12 cells to contract the collagenous composite gel via αVβ3 integrin.A specific competitive inhibitor blocking the Col-I-binding site for fibrinogen abolished the organization of fibrin into discernable fibrils, as well as the C2C12-mediated contraction of Col I gels.Our data show that fibrin can function as a linkage protein between Col I fibres and cells, and suggest that fibrin at inflammatory sites indirectly connects αVβ3 integrins to Col I fibres and thereby promotes cell-mediated contraction of collagenous tissue structures.

View Article: PubMed Central - PubMed

Affiliation: *Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, BMC Box 582, SE-751 23 Uppsala, Sweden.

ABSTRACT
The functional significance of fibrin deposits typically seen in inflammatory lesions, carcinomas and in healing wounds is not fully understood. In the present study, we demonstrate that fibrinogen/fibrin specifically bound to native Col I (collagen type I) and used the Col I fibre network as a base to provide a functional interface matrix that connects cells to the Col I fibres through αVβ3 integrins. This allowed murine myoblast C2C12 cells to contract the collagenous composite gel via αVβ3 integrin. We show that fibrinogen specifically bound to immobilized native Col I at the site known to bind matrix metalloproteinase-1, discoidin domain receptor-2 and fibronectin, and that binding had no effect on Col I fibrillation. A specific competitive inhibitor blocking the Col-I-binding site for fibrinogen abolished the organization of fibrin into discernable fibrils, as well as the C2C12-mediated contraction of Col I gels. Our data show that fibrin can function as a linkage protein between Col I fibres and cells, and suggest that fibrin at inflammatory sites indirectly connects αVβ3 integrins to Col I fibres and thereby promotes cell-mediated contraction of collagenous tissue structures.

Show MeSH
Related in: MedlinePlus