title: Evidence for sequential utilization of fibronectin, vitronectin, and collagen during fibroblast-mediated collagen contraction.
abstract: Contraction plays a major role in wound healing and is inevitably mediated through the mechanical interaction of fibroblast cytoskeleton and integrins with their extracellular matrix ligands. Cell-matrix attachment is critical for such events. In human dermal fibroblasts most such interactions are mediated by the beta1-type integrins. This study investigated the role played by key components in this system, notably fibronectin, vitronectin, and integrin subcomponents alpha2 and alpha5, which recognize collagen and fibronectin. Inhibition of adhesion through these ligands was studied either by antibody blocking or with fibronectin and/or vitronectin depletion. Functional effects of inhibition were monitored as force generation in collagen-glycosaminoglycan (IntegraTM) sponges, over 20 hours using a culture force monitor. Dose and time-course inhibition studies indicated that initial attachment and force generation (approx. 0-5 hours postseeding) was through fibronectin receptors and this was followed by vitronectin ligand and receptor utilization (4 hours onward). Utilization of the collagen integrin subcomponent alpha2 appeared to be increasingly important between 6 and 16 hours and dominant thereafter. Additionally, there was evidence for functional interdependence between the three ligand systems fibronectin, vitronectin, and collagen. We propose that there is a short cascade of sequential integrin-ligand interactions as cells attach to, extend through, and eventually contract their matrix. (WOUND REP REG 2002;10:-408)
authors.affiliation: University College London, RFUCMS, Tissue Repair & Engineering Center, Institute of Orthopaedics, RNOH campus, Stanmore, United Kingdom.
authors.forename: Kamaljit K
authors.initials: KK
authors.lastname: Sethi
authors.forename: Ioannis V
authors.initials: IV
authors.lastname: Yannas
authors.forename: Vivek
authors.initials: V
authors.lastname: Mudera
authors.forename: Mark
authors.initials: M
authors.lastname: Eastwood
authors.forename: Clive
authors.initials: C
authors.lastname: McFarland
authors.forename: Robert A
authors.initials: RA
authors.lastname: Brown
mesh_terms: D001672:Biocompatible Materials; D002809:Chondroitin Sulfates; D003094:Collagen / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000502:physiology; D005347:Fibroblasts / Q000502:physiology*; D005353:Fibronectins / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D039421:Integrin alpha2 / Q000502:physiology; D039482:Integrin alpha5 / Q000502:physiology; D013500:Surface Tension; D013997:Time Factors; D000267:Tissue Adhesions / Q000503:physiopathology; D019096:Vitronectin / Q000502:physiology*; D014945:Wound Healing / Q000502:physiology*; D014950:Wounds, Penetrating / Q000503:physiopathology*
chemical_list: D001672:Biocompatible Materials; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D039421:Integrin alpha2; D039482:Integrin alpha5; D019096:Vitronectin; C114835:integra artificial skin; D002809:Chondroitin Sulfates; D003094:Collagen