Evidence for Cyclooxygenase-2 Association with Caveolin-3 in Primary Cultured Rat Chondrocytes.
10.3346/jkms.2006.21.1.100
- Author:
Jin Oh KWAK
1
;
Woon Kyu LEE
;
Hyun Woo KIM
;
Sun Mi JUNG
;
Kwang Jin OH
;
Sang Yong JUNG
;
Yang Hoon HUH
;
Seok Ho CHA
Author Information
1. Department of Pharmacology and Toxicology, College of Medicine, Inha University, Incheon, Korea. shcha@inha.ac.kr
- Publication Type:Original Article
- Keywords:
Chondrocytes;
Cyclooxygenase 2;
Caveolins;
Microscopy, Confocal;
Microscopy, El
- MeSH:
Animals;
Animals, Newborn;
Blotting, Western;
Cadmium Chloride/pharmacology;
Caveolae/drug effects/metabolism/ultrastructure;
Caveolin 3/*genetics/metabolism;
Cell Membrane/drug effects/metabolism;
Cells, Cultured;
Chondrocytes/cytology/drug effects/*metabolism;
Cyclooxygenase 2/*genetics/metabolism;
Gene Expression;
Immunoprecipitation;
Microscopy, Confocal;
Microscopy, Electron;
RNA, Messenger/genetics/metabolism;
Rats;
Reverse Transcriptase Polymerase Chain Reaction
- From:Journal of Korean Medical Science
2006;21(1):100-106
- CountryRepublic of Korea
- Language:English
-
Abstract:
The purpose of this study was to demonstrate the cellular localization of cyclooxygenase-2 (COX-2) and caveolin-3 (Cav-3) in primarily cultured rat chondrocytes. In normal rat chondrocytes, we observed relatively high levels of Cav-3 and a very low level of COX-2 mRNA and protein. Upon treating the chondrocytes with 5 microM of CdCl2 (Cd) for 6 hr, the expressions of COX-2 mRNA and protein were increased with the decreased Cav-3 mRNA and protein expressions. The detergent insoluble caveolae-rich membranous fractions that were isolated from the rat chondrocytes and treated with Cd contained the both proteins of both COX-2 and Cav-3 in a same fraction. The immuno-precipitation experiments showed complex formation between the COX-2 and Cav-3 in the rat chondrocytes. Purified COX-2 with glutathione S-transferase-fused COX-2 also showed complex formation with Cav-3. Confocal and electron microscopy also demonstrated the co-localization of COX-2 and Cav-3 in the plasma membrane. The results from our current study show that COX-2 and Cav-3 are co-localized in the caveolae of the plasma membrane, and they form a protein-protein complex. The co-localization of COX-2 with Cav-3 in the caveolae suggests that the caveolins might play an important role for regulating the function of COX-2.
