Mouse Snail family transcription repressors regulate chondrocyte, extracellular matrix, type II collagen, and aggrecan.
Snail family genes are conserved among species during evolution and encode transcription factors expressed at different stages of development in different tissues. These genes are involved in a broad spectrum of biological functions: cell differentiation, cell motility, cell cycle regulation, and apoptosis. However, little is known about the target genes involved in these functions. Here we show that mouse Snail family members, Snail (Sna) and Slug (Slugh), are involved in chondrocyte differentiation by controlling the expression of type II collagen (Col2a1) and aggrecan. In situ hybridization analysis of developing mouse limb demonstrated that Snail and Slug mRNAs were highly expressed in hypertrophic chondrocytes. Inversely, the expression of collagen type II mRNA disappeared during hypertrophic differentiation. Snail and Slug mRNA expression was down-regulated during differentiation of the mouse chondrogenic cell line ATDC5 and overexpression of exogenous Snail or Slug in ATDC5 cells inhibited expression of collagen type II and aggrecan mRNA. Reporter analysis revealed Snail and Slug suppressed the promoter activity of Col2a1, and the E-boxes in the promoter region were the responsible element. Gel shift assay demonstrated the binding of Snail to the E-box. Because type II collagen and aggrecan are major functional components of extracellular matrix in cartilage, these results suggest an important role for Snail-related transcription repressors during chondrocyte differentiation.
Seki
Kenji
K
Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA. kseki@anat1.med.kyoto-u.ac.jp
Fujimori
Toshihiko
T
Savagner
Pierre
P
Hata
Akiko
A
Aikawa
Tomonao
T
Ogata
Naoshi
N
Nabeshima
Yoichi
Y
Kaechoong
Lee
L
D053674:Aggrecans; D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D024043:Collagen Type II / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000502:physiology*; D024721:E-Box Elements; D004622:Embryo, Mammalian; D005109:Extracellular Matrix; D016326:Extracellular Matrix Proteins; D018507:Gene Expression Regulation, Developmental; D037181:Lectins, C-Type; D051379:Mice; D011401:Promoter Regions, Genetic; D011509:Proteoglycans; D012333:RNA, Messenger / Q000032:analysis; D012097:Repressor Proteins / Q000502:physiology; D000071250:Snail Family Transcription Factors; D013977:Tibia; D014157:Transcription Factors / Q000502:physiology*
C508320:Acan protein, mouse; D053674:Aggrecans; D024043:Collagen Type II; D004268:DNA-Binding Proteins; D016326:Extracellular Matrix Proteins; D037181:Lectins, C-Type; D011509:Proteoglycans; D012333:RNA, Messenger; D012097:Repressor Proteins; C000604449:Snai2 protein, mouse; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors