Presence of ED-A containing fibronectin in human articular cartilage from patients with osteoarthritis and rheumatoid arthritis.
OBJECTIVE
To determine whether normal (fetal and adult) and osteoarthritic (OA) and rheumatoid arthritic (RA) cartilage express a specific isoform of fibronectin, the extra domain A (ED-A) containing fibronectin (EDA+Fn).


METHODS
Presence of fibronectin (EDA+Fn and native molecule) in cartilage matrix was studied using immunohistochemical assays with specific monoclonal antibodies. Fibronectins were identified by Western blots, in synovial fluids (SF) and cartilage extracts.


RESULTS
EDA+Fn was either moderately present in the surface zone or undetectable in normal cartilage, while it was increased in OA cartilage surface. In one OA cartilage sample, EDA+Fn was localized in the matrix distant from the cartilage surface (patches of staining) and its presence was confirmed by immunoblotting. In RA cartilage EDA+Fn was present in the pericellular areas of the different layers. By Western blots, the presence of EDA+Fn was confirmed in OA SF (2/3) and RA SF (3/3) (with different patterns of fragmentation).


CONCLUSIONS
EDA+Fn generally accumulates in the surface zone of OA cartilage, where it may play a role in extracellular matrix remodelling. Its presence was more abundant in SF and in cartilage from patients with RA.
Chevalier
X
X
Department of Rheumatology, Hopital Henri-Mondor, Creteil, France.
Claudepierre
P
P
Groult
N
N
Zardi
L
L
Hornebeck
W
W
D000368:Aged; D000911:Antibodies, Monoclonal; D001172:Arthritis, Rheumatoid / Q000378:metabolism* / Q000473:pathology; D001344:Autopsy; D015153:Blotting, Western; D002358:Cartilage, Articular / Q000378:metabolism*; D005260:Female; D005333:Fetus; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000378:metabolism; D008297:Male; D010003:Osteoarthritis / Q000378:metabolism* / Q000473:pathology; D010446:Peptide Fragments / Q000032:analysis; D013582:Synovial Fluid / Q000737:chemistry
D000911:Antibodies, Monoclonal; D005353:Fibronectins; D007375:Interleukin-1; D010446:Peptide Fragments