Serosal mast cells maintain their viability and promote the metabolism of cartilage proteoglycans when cocultured with chondrocytes.
OBJECTIVE
To determine the consequences of mast cell (MC)-chondrocyte interactions.


METHODS
Cocultured cells were analyzed histochemically, morphologically, biochemically, and functionally.


RESULTS
Cocultured MC adhered to the chondrocytes and remained viable. Chondrocytes cocultured with nonactivated MC produced more proteoglycans than did chondrocytes cultured alone, and these proteoglycans possessed an intact hyaluronic acid-binding region. In contrast, most of the proteoglycans produced by chondrocytes cocultured with activated MC were degraded.


CONCLUSIONS
These studies indicate that a complex interaction occurs in which the nonactivated MC stimulates biosynthesis and the activated MC degrades cartilage proteoglycans.
Stevens
R L
RL
Department of Medicine, Harvard Medical School, Boston, MA 02115.
Somerville
L L
LL
Sewell
D
D
Swafford
J R
JR
Caulfield
J P
JP
Levi-Schaffer
F
F
Hubbard
J R
JR
Dayton
E T
ET
D000818:Animals; D002358:Cartilage, Articular / Q000166:cytology* / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured / Q000648:ultrastructure; D002813:Chondrosarcoma / Q000473:pathology; D008407:Mast Cells / Q000166:cytology*; D011509:Proteoglycans / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013462:Sulfur Radioisotopes; D013997:Time Factors; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
D011509:Proteoglycans; D013462:Sulfur Radioisotopes; D003189:p-Methoxy-N-methylphenethylamine