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Matrix accumulation by articular chondrocytes during mechanical stimulation is influenced by integrin‐mediated cell spreading
Author(s) -
Spiteri Caroline,
Raizman Igal,
Pilliar Robert M.,
Kandel Rita A.
Publication year - 2010
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.32706
Subject(s) - chondrocyte , integrin , mechanotransduction , materials science , microbiology and biotechnology , matrix (chemical analysis) , matrix metalloproteinase , biophysics , cartilage , extracellular matrix , biomedical engineering , cell , chemistry , anatomy , biology , biochemistry , medicine , composite material
Abstract We have shown previously that cyclic compression of newly forming bioengineered cartilage in vitro results in improved tissue formation via changes in expression of matrix metalloproteases, such as, MT1‐MMP (membrane type metalloprotease), and increased synthesis of matrix molecules. Several studies have suggested an association between MT1‐MMP and integrins, which are known to influence cell shape. Thus, the objectives of this study were to determine the effect of compressive mechanical stimulation on cell shape and the role of integrins and MT1‐MMP in mediating these changes and influencing matrix accumulation. Bovine articular chondrocytes were grown on the surface of a porous ceramic substrate for 72 h and then cyclically compressed for 30 min. Scanning electron microscopy and morphometric analysis demonstrated that compression induced a rapid, transient increase in chondrocyte spreading by 10 min, followed by a retraction to prestimulated size within 6 h. This was associated with increased accumulation of newly synthesized proteoglycans, as determined by quantification of radioisotope incorporation. Blocking the α5β1 integrin, or its β1 subunit, inhibited cell spreading and resulted in a partial inhibition of compression‐induced increase in matrix accumulation. Knockdown of MT1‐MMP expression partially inhibited cell retraction and resulted in a reduced matrix accumulation as well. These results suggest that chondrocyte spreading and retraction following cyclic compression in vitro regulates matrix accumulation. Understanding the mechanisms that regulate chondrocyte mechanotransduction may ultimately lead to the design of improved repair tissue for cartilage damage. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010