Osteoarthritic cartilage fibrillation is associated with a decrease in chondrocyte adhesion to fibronectin.
OBJECTIVE
Cartilage destruction in osteoarthritis (OA) is generally accepted as a failed repair process. Cell adhesion is implicated in tissue repair. Therefore, adhesion of OA chondrocytes to extracellular matrix proteins was investigated.


METHODS
Using chondrocytes from human OA femoral head cartilage, adhesion to fibronectin and type II collagen of cells from distinct areas showing an intact cartilage surface or a fibrillated cartilage surface was studied. Modulation of chondrocyte adhesion by both protein kinase C (PKC) inhibitors and glucosamine sulfate (GS) was also investigated.


RESULTS
A significant (P < 0.05) decrease in adhesion to fibronectin of chondrocytes from fibrillated cartilage, relative to those from grossly normal OA cartilage, was demonstrated. Adhesion to type II collagen was not modified by the chondrocyte origins (either from normal or fibrillated OA cartilage). Adhesion to fibronectin of cells from grossly intact cartilage was decreased by the addition of PKC and calmodulin-dependent kinase inhibitors, W7 and sphingosine, to the cell culture. Adhesion to fibronectin of chondrocytes from fibrillated cartilage was significantly (P < 0.05) increased after glucosamine sulfate treatment.


CONCLUSIONS
Fibrillation of cartilage from OA femoral head is associated with a defective adhesion of chondrocytes to fibronectin. The process is suggested to be dependent of PKC and/or calmodulin-dependent kinases and potentially reversible. Conceivably, it could play a role in OA cartilage destruction.
Piperno
M
M
Claude Bernard University, Centre Hospitalier Lyon Sud, Pierre Bénite, France.
Reboul
P
P
Hellio le Graverand
M P
MP
Peschard
M
M
Annefeld
M
M
Richard
M
M
Vignon
E
E
D000368:Aged; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D003094:Collagen / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005353:Fibronectins / Q000378:metabolism*; D005944:Glucosamine / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism / Q000473:pathology*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D013110:Sphingosine / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology
D004791:Enzyme Inhibitors; D005353:Fibronectins; D013449:Sulfonamides; C096190:glucosamine 2-sulfate; C017967:W 7; D003094:Collagen; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D005944:Glucosamine; D013110:Sphingosine