|
KMID : 0620920020340060426
|
|
Experimental & Molecular Medicine
2002 Volume.34 No. 6 p.426 ~ p.433
|
|
|
Spatio-temporal expression patterns of Runx2 isoforms in early skeletogenesis
|
|
Hyun Mo Ryoo/Kang Young Choi
Sang Won Lee/Mi Hyun Park/Yong Chul Bae/Hong In Shin/Soon Hyeun Nam/Young Jin Kim/Hyun Jung Kim/Hyun Mo Ryoo
|
|
|
Abstract
|
|
|
|
Skeletogenesis occurs through either intramembranous or endochondral ossification. In addition, some parts of the skeletal components maintain their cartilaginous characteristics throughout life without mineralization. Runx2 is known to be a pivotal transcription factor for all skeletogenic processes. In this study, we examined the expression patterns of two major isoforms of Runx2 in early skeletogenesis. During intramembranous bone formation, Runx2-type I (Runx2-I) was widely expressed in osteoprogenitor cells and active osteoblasts, while Runx2-type II (Runx2-II) expression was stringently restricted to cells lining mineralized bones. Cells in permanent cartilage expressed collagen type II (Col-II) but never expressed Runx2 or Col-X. These permanent cartilages were well circumscribed by Runx2-I positive cells, in which Runx2-II was negative. In endochondral bone formation, Runx2 expression temporarily disappeared in Col-II-positive proliferating chondrocytes, but a secondary surge of Runx2-I expression occurred in the prehypertrophic zone before the mineralization of cartilage. Collectively, both Runx2 isoforms showed very similar expression patterns in active bone forming areas; however, Runx2-I has an exclusive role in the early commitment stage of intramembranous or endochondral bone forming processes or in cells surrounding permanent cartilage.
|
|
|
KEYWORD
|
|
|
chondrocytes, chondrogenesis, collagen type-Ⅱ, osteoblasts, osteogenesis, transcription factors,
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
    
|
|