Immune Netw.  2006 Sep;6(3):123-127. 10.4110/in.2006.6.3.123.

Ectopic Expression of Caveolin-1 Induces COX-2 Expression in Rabbit Articular Chondrocytes via MAP Kinase Pathway

• Kim SJ

• KMID: 1808156
• DOI: http://doi.org/10.4110/in.2006.6.3.123

Abstract

BACKGROUND: Caveolin-1 is a principal component of caveolae membranes in vivo. Although expression of caveolae structure and expression of caveolin family, caveolin-1, -2 and -3, was known in chondrocytes, the functional role of caveolae and caveolins in chondrocytes remains unknown. In this study, we investigated the role of caveolin-1 in articular chondrocytes.
METHODS
Rabbit articular chondrocytes were prepared from cartilage slices of 2-week-old New Zealand white rabbits by enzymatic digestion. Caveolin-1 cDNA was transfected to articular chondrocytes using LipofectaminePLUS. The cyclooxygenase-2 (COX-2) expression levels were determined by immunoblot analysis, immunostaining, immunohistochemistry, and prostaglandin E2 (PGE2) assay was used to measure the COX-2 activity.
RESULTS
Ectopic expression of caveolin-1 induced COX-2 expression and activity, as indicated by immunoblot analysis and PGE2 assay. And also, overexpression of caveolin-1 stimulated activation of p38 kinase and ERK-1/ -2. Inhibition of p38 kinase and ERK-1/-2 with SB203580 and PD98059, respectively, led to a dose-dependent decrease COX-2 expression and PGE2 production in caveolin-1-transfected cells.
CONCLUSION
Taken together, our data suggest that ectopic expression of caveolin-1 contributes to the expression and activity of COX-2 in articular chondrocytes through MAP kinase pathway.

Keyword

Caveolin-1; COX-2; prostaglandin E2; p38 kinase

MeSH Terms

Cartilage
Caveolae
Caveolin 1*
Caveolins
Chondrocytes*
Cyclooxygenase 2
Digestion
Dinoprostone
DNA, Complementary
Humans
Immunohistochemistry
Membranes
Phosphotransferases*
Rabbits
Caveolin 1
Caveolins
Cyclooxygenase 2
DNA, Complementary
Dinoprostone
Phosphotransferases