|
KMID : 0620920080400060721
|
|
Experimental & Molecular Medicine
2008 Volume.40 No. 6 p.721 ~ p.727
|
|
|
Ectopic expression of cyclooxygenase-2-induced dedifferentiation in articular chondrocytes
|
|
Lee Won-Kil
Kim Song-Ja
Yu Seon-Mi
Sonn Jong-Kyung
Cheong Seon-Woo
|
|
|
Abstract
|
|
|
|
Cyclooxygenase-2 (COX-2) is known to modulate bone metabolism, including bone formation and resorption. Because cartilage serves as a template for endochondral bone formation and because cartilage development is initiated by the differentiation of mesenchymal cells into chondrocytes (Ahrens et al., 1977; Sandell and Adler, 1999; Solursh, 1989), it is of interest to know whether COX-2 expression affect chondrocyte differentiation. Therefore, we investigated the effects of COX-2 protein on differentiation in rabbit articular chondrocyte and chick limb bud mesenchymal cells. Overexpression of COX-2 protein was induced by the COX-2 cDNA transfection. Ectopic expression of COX-2 was sufficient to causes dedifferentiation in articular chondrocytes as determined by the expression of type II collagen via Alcian blue staining and Western blot. Also, COX-2 overexpression caused suppression of SOX-9 expression, a major transcription factor that regulates type II collagen expression, as indicated by the Western blot and RT-PCR. We further examined ectopic expression of COX-2 in chondrifying mesenchymal cells. As expected, COX-2 cDNA transfection blocked cartilage nodule formation as determined by Alcian blue staining. Our results collectively suggest that COX-2 overexpression causes dedifferentiation in articular chondrocytes and inhibits chondrogenic differentiation of mesenchymal cells.
|
|
|
KEYWORD
|
|
|
chondrocytes, cyclooxygenase 2, cell dedifferentiation, cell differentiation, collagen type II, mesenchymal cells
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
    
|
|