The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform

E Ruoslahti - One of the best experts on this subject based on the ideXlab platform.

  • A Fibronectin self-assembly site involved in Fibronectin matrix assembly: reconstruction in a synthetic peptide.
    The Journal of cell biology, 1992
    Co-Authors: Alex Morla, E Ruoslahti
    Abstract:

    The active form of Fibronectin is its extracellular matrix form, which allows for the attachment of cells and influences both the growth and migration of cells. The matrix form is assembled by cells; however, many cells are defective in this regard. Several regions within Fibronectin have been shown to play a role in matrix assembly by cells. One such region has been localized into the first type III repeat of Fibronectin (Chernousov, M. A., F. J. Fogerty, V. E. Koteliansky, and D. F. Mosher. J. Biol. Chem. 266:10851-10858). We have identified this site as a Fibronectin-Fibronectin binding site and reproduced it as a synthetic peptide. This site is contained in a 14-kD fragment that corresponds to portions of the first two type III repeats. The 14-kD fragment was found to bind to cell monolayers and to inhibit Fibronectin matrix assembly. The 14-kD fragment only slightly reduced the binding of Fibronectin to cell surfaces but it significantly inhibited the subsequent incorporation of Fibronectin into the extracellular matrix. The 14-kD fragment also bound to purified Fibronectin and inhibited Fibronectin-Fibronectin binding. A synthetic 31-amino acid peptide (P1) representing a segment of the 14-kD fragment retained the ability to inhibit Fibronectin-Fibronectin binding. Peptide P1 specifically bound Fibronectin from plasma in affinity chromatography, whereas a column containing another peptide from the 14-kD fragment did not. These results define a Fibronectin-Fibronectin binding site that appears to promote matrix assembly by allowing the assembly of Fibronectin molecules into nascent fibrils. The 14-kD fragment and the P1 peptide that contain this site inhibit matrix assembly by competing for the Fibronectin-Fibronectin binding.

Karin Wang - One of the best experts on this subject based on the ideXlab platform.

  • Fibronectin in development and wound healing
    Advanced drug delivery reviews, 2020
    Co-Authors: Jennifer Patten, Karin Wang
    Abstract:

    Fibronectin structure and composition regulate contextual cell signaling. Recent advances have been made in understanding Fibronectin and its role in tissue organization and repair. This review outlines Fibronectin splice variants and their functions, evaluates potential therapeutic strategies targeting or utilizing Fibronectin, and concludes by discussing potential future directions to modulate Fibronectin function in development and wound healing.

Alex Morla - One of the best experts on this subject based on the ideXlab platform.

  • The alpha v beta 1 integrin functions as a Fibronectin receptor but does not support Fibronectin matrix assembly and cell migration on Fibronectin
    The Journal of cell biology, 1993
    Co-Authors: Zhuohua Zhang, R. L. Juliano, Alex Morla, Kristiina Vuori, Jeffrey S. Bauer, Erkki Ruoslahti
    Abstract:

    The Fibronectin receptor, alpha 5 beta 1, has been shown to be required for Fibronectin matrix assembly and plays an important role in cell migration on Fibronectin. However, it is not clear whether other Fibronectin binding integrins can take the place of alpha 5 beta 1 during matrix assembly and cell migration. To test this, we expressed the human alpha v subunit in the CHO cell line CHO-B2 that lacks the alpha 5 subunit. We found that the human alpha v combined with CHO cell beta 1 to form the integrin alpha v beta 1. Cells that expressed alpha v beta 1 attached to and spread well on Fibronectin-coated dishes, but did so less well on vitronectin-coated dishes. This, along with other data, indicated that alpha v beta 1 functions as a Fibronectin receptor in CHO-B2 cells. The alpha v beta 1-expressing cells failed to produce a Fibronectin matrix or to migrate on Fibronectin, although the same cells transfected with alpha 5 do produce a matrix and migrate on Fibronectin. The affinity of the alpha v beta 1-expressing cells for Fibronectin was fourfold lower than that of the alpha 5 beta 1-expressing cells. In addition, alpha v beta 1 was distributed diffusely throughout the cell surface, whereas alpha 5 beta 1 was localized to focal adhesions when cells were seeded onto Fibronectin-coated surfaces. Thus, of the two Fibronectin receptors, alpha v beta 1 and alpha 5 beta 1, only alpha 5 beta 1 supports Fibronectin matrix assembly and promotes cell migration on Fibronectin in the CHO-B2 cells. Possible reasons for this difference in the activities of alpha v beta 1 and alpha 5 beta 1 include the lower affinity of alpha v beta 1 for Fibronectin and the failure of this integrin to localize in adhesion plaques on a Fibronectin substrate. These results show that two integrins with similar ligand specificities and cell attachment functions may be quite different in their ability to support Fibronectin matrix assembly and cell motility on Fibronectin.

  • A Fibronectin self-assembly site involved in Fibronectin matrix assembly: reconstruction in a synthetic peptide.
    The Journal of cell biology, 1992
    Co-Authors: Alex Morla, E Ruoslahti
    Abstract:

    The active form of Fibronectin is its extracellular matrix form, which allows for the attachment of cells and influences both the growth and migration of cells. The matrix form is assembled by cells; however, many cells are defective in this regard. Several regions within Fibronectin have been shown to play a role in matrix assembly by cells. One such region has been localized into the first type III repeat of Fibronectin (Chernousov, M. A., F. J. Fogerty, V. E. Koteliansky, and D. F. Mosher. J. Biol. Chem. 266:10851-10858). We have identified this site as a Fibronectin-Fibronectin binding site and reproduced it as a synthetic peptide. This site is contained in a 14-kD fragment that corresponds to portions of the first two type III repeats. The 14-kD fragment was found to bind to cell monolayers and to inhibit Fibronectin matrix assembly. The 14-kD fragment only slightly reduced the binding of Fibronectin to cell surfaces but it significantly inhibited the subsequent incorporation of Fibronectin into the extracellular matrix. The 14-kD fragment also bound to purified Fibronectin and inhibited Fibronectin-Fibronectin binding. A synthetic 31-amino acid peptide (P1) representing a segment of the 14-kD fragment retained the ability to inhibit Fibronectin-Fibronectin binding. Peptide P1 specifically bound Fibronectin from plasma in affinity chromatography, whereas a column containing another peptide from the 14-kD fragment did not. These results define a Fibronectin-Fibronectin binding site that appears to promote matrix assembly by allowing the assembly of Fibronectin molecules into nascent fibrils. The 14-kD fragment and the P1 peptide that contain this site inhibit matrix assembly by competing for the Fibronectin-Fibronectin binding.

Jean E Schwarzbauer - One of the best experts on this subject based on the ideXlab platform.

  • Fibronectin fibrillogenesis, a cell-mediated matrix assembly process
    Matrix Biology, 2005
    Co-Authors: Yong Mao, Jean E Schwarzbauer
    Abstract:

    The extracellular matrix provides a framework for cell adhesion, supports cell movement, and serves to compartmentalize tissues into functional units. Fibronectin is a core component of many extracellular matrices where it regulates a variety of cell activities through direct interactions with cell surface integrin receptors. Fibronectin is synthesized by many adherent cells which then assemble it into a fibrillar network. The assembly process is integrin-dependent and Fibronectin-integrin interactions initiate a step-wise process involving conformational activation of Fibronectin outside and organization of the actin cytoskeleton inside. During assembly, Fibronectin undergoes conformational changes that expose Fibronectin-binding sites and promote intermolecular interactions needed for fibril formation. In this review, the main steps of Fibronectin assembly are described and recent studies on Fibronectin conformational changes are discussed.

  • Analysis of Fibronectin matrix assembly.
    Current protocols in cell biology, 2004
    Co-Authors: Iwona Wierzbicka-patynowski, Yong Mao, Jean E Schwarzbauer
    Abstract:

    The extracellular matrix acts as a framework for tissue architecture and dynamically regulates many cellular functions. Fibronectin is a ubiquitous extracellular matrix component that plays critical roles in matrix structure and in directing cell behaviors. Fibronectin is synthesized and secreted by many cell types including fibroblasts, endothelial cells, myoblasts, and astrocytes. Upon secretion, cells assemble Fibronectin into a fibrillar network. During assembly, Fibronectin is initially organized into fine cell-associated fibrils and, through continued accumulation of Fibronectin, these fibrils are converted into a dense network of detergent-insoluble fibrils. Differential solubility in the detergent deoxycholate is the principle for biochemical fractionation of Fibronectin matrix. Fibril assembly and organization can also be examined by immunofluorescence staining. In this unit, basic methods of detection, quantification, and visualization of fibrillar Fibronectin matrix are described.

Toru Hayakawa - One of the best experts on this subject based on the ideXlab platform.

  • Role of Fibronectin-stimulated tumor cell migration in glioma invasion in vivo: clinical significance of Fibronectin and Fibronectin receptor expressed in human glioma tissues.
    Clinical & experimental metastasis, 1998
    Co-Authors: Takanori Ohnishi, Shoju Hiraga, Shuichi Izumoto, Hirotaka Matsumura, Yonehiro Kanemura, Norio Arita, Toru Hayakawa
    Abstract:

    In order to clarify the role of Fibronectin in glioma invasion in vivo, we analyzed the relationship between Fibronectin-stimulated cell migration and adhesion in 14 primary glioma cells and the expression of Fibronectin and the Fibronectin receptor in the corresponding tumor tissues. The tumors comprised nine glioblastomas (GB) and five anaplastic gliomas (AG) consisting of two astrocytomas, two oligoastrocytomas and one ependymoma. All glioma cells tested in the primary cell culture were found to migrate to Fibronectin in a dose-dependent manner. The extent of cell migration to Fibronectin was not significantly different for the GB and AG groups. On the other hand, cell adhesion to Fibronectin in the AG was much stronger than that in the GB group. Immunohistochemistry demonstrated that Fibronectin positively stained in the extra-cellular matrix (ECM) in eight cases and that the Fibronectin receptor was positive in tumor cell membranes in 10 cases. In addition, cellular Fibronectin isoforms containing ED-A and ED-B sequences were found to be immunolocalized in the tumor cells and the ECM of GB. These isoforms were also specifically expressed in tumor vessels within tumor tissues, but not in those within normal brain tissues. Cell migration tended to be expressed more strongly by glioma cells derived from tumor tissues in which Fibronectin was posi-tively immunolocalized in the ECM than from tissues with negative Fibronectin in the ECM. Four glioma cells derived from GB whose tumor cells did not positively stain for Fibronectin receptors migrated much less extensively to Fibronectin than other glioma cells whose tissues showed positive staining for the Fibronectin receptor. Of these four GB, two had loss of heterozygosity in the locus of Fibronectin receptor b1 gene. These results suggest that Fibronectin deposited in the extracellular matrix of tumors, which can be derived from both plasma and the tumor cell itself, strongly promotes the migration of glioma cells, and that expression of the Fibronectin receptor may play a critical role in the biological behavior of the tumor cells, particularly in Fibronectin-stimulated cell migration in vivo.© Kluwer Academic Publishers 1998