Collagen type V enhances matrix contraction by human periodontal ligament fibroblasts seeded in three-dimensional collagen gels

Extracellular matrix components play an important role in modulating cellular activity. To study such capacities of the matrix, fibroblasts are frequently cultured in a three-dimensional gel and contraction is assessed as a measure of cellular activity. Since a connective tissue contains several types of collagen, we investigated the effect of gels composed of collagen I alone or in combination with 10% collagen III and/or 5% collagen V on contraction by human periodontal ligament fibroblasts. Gels containing collagen V contracted much faster than those without this type of collagen. Blocking of the integrin beta 1-subunit with an activity-blocking antibody delayed (gels with collagen V) or almost completely blocked (gels without collagen V) contraction. Use of an antibody directed against integrin alpha 2 beta 1 resulted in delay of gel contraction for gels both with and without collagen V Anti-integrin alpha v beta 3 or RGD peptides partially blocked contraction of gels containing collagen V but had no effect on gels consisting of collagen I alone. The beta 1-containing integrins are involved in the basal contraction by fibroblasts that bind to collagens I and III. The enhanced contraction, stimulated by collagen V, appears to be mediated by integrin alpha v beta 3. We conclude that collagen V may play an important modulating role in connective tissue contraction. Such a modulation may occur during the initial stages of wound healing and/or tissue regeneration. (c) 2006 Elsevier B.V./International Society of Matrix Biology. All rights reserved.