Cartilage Oligomeric Matrix Protein/Thrombospondin 5 Supports Chondrocyte Attachment through Interaction with Integrins
Chen, Faye Hui
Thomas, Ashby O.
Hecht, Jacqueline T.
Goldring, Mary B.
MetadataShow full item record
CitationChen, Faye Hui, Ashby O. Thomas, Jacqueline T. Hecht, Mary B. Goldring, and Jack Lawler. 2005. “Cartilage Oligomeric Matrix Protein/Thrombospondin 5 Supports Chondrocyte Attachment through Interaction with Integrins.” Journal of Biological Chemistry 280 (38): 32655–61. https://doi.org/10.1074/jbc.m504778200.
AbstractCartilage oligomeric matrix protein/ thrombospondin 5 ( COMP/ TSP5) is a major component of the extracellular matrix of the musculoskeletal system. Although COMP/ TSP5 abnormalities are associated with several pathological conditions, its normal function remains unclear. This study was undertaken to delineate the function( s) of COMP/ TSP5 in cartilage, especially regarding its interaction with chondrocytes. We show that COMP/ TSP5 can support chondrocyte attachment and that the RGD sequence in COMP/ TSP5 and the integrin receptors alpha 5 beta 1 and alpha V beta 3 on the chondrocytes are involved in mediating this attachment. The interactions of COMP/ TSP5 with the integrins are dependent on COMP/ TSP5 conformation. Chondrocyte attachment to COMP/ TSP5 in the calcium- replete conformation was inhibited by function- blocking integrin alpha 5 and beta 1 antibodies, suggesting the involvement of the alpha 5 beta 1 integrin. Under this condition, a function- blocking antibody against alpha V beta 3 did not have any effect on cell attachment. On the other hand, chondrocyte attachment to reduced COMP/ TSP5 was instead sensitive to alpha V beta 3 function- blocking antibodies, suggesting that COMP/ TSP5 mediates attachment through chondrocyte alpha V beta 3 integrin under this condition. Cell attachment to reduced COMP/ TSP5 was not inhibited by beta 1 antibodies. These data indicate that COMP/ TSP5 in different conformations can utilize different integrin receptors. These results are the first to demonstrate that COMP/ TSP5 can mediate chondrocyte attachment through interactions with integrins. Through these interactions, COMP/ TSP5 may be able to regulate cellular activities and respond to environment in the surrounding cartilage matrix.
Citable link to this pagehttp://nrs.harvard.edu/urn-3:HUL.InstRepos:41483164
- HMS Scholarly Articles