Document Detail


Shox2 is required for chondrocyte proliferation and maturation in proximal limb skeleton.
MedLine Citation:
PMID:  17481601     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Mutations in the short stature homeobox gene SHOX lead to growth retardation associated with Turner, Leri-Weill dyschondrosteosis, and Langer mesomelic dysplasia syndromes, which marked the shortening of the forearms and lower legs. We report here that in contrast to the SHOX mutations in humans, Shox2 deficiency in mice leads to a virtual elimination of the stylopod in the developing limbs, while the zeugopod and autopod appear relatively normal. This phenotype is consistent with the restriction of the Shox2 expression to the proximal mesenchyme in the limb bud and later to chondrocytes associated with the forming stylopod. In the Shox2(-/-) embryo, the mesenchymal condensation for the stylopod initiates normally but the cartilaginous element subsequently fails in growth, chondrogenesis and endochondral ossification. A dramatic down-regulation of Runx2 and Runx3 could account for the lack of chondrocyte hypertrophy, while a down-regulation of Ihh expression may be responsible for a significant reduction in chondrocyte proliferation in the mutant stylopod. We further demonstrate that an enhanced and ectopic Bmp4 expression in the proximal limb of the Shox2 embryo may underlie the down-regulation of Runx2, as ectopically applied exogenous BMP4 represses Runx2 expression in the early limb bud. Moreover, we show that mouse Shox2, similar to human SHOX, can perform opposite roles on gene expression: either as a transcription activator or a repressor in different cell types. Our results establish a key role for Shox2 in regulating the growth of stylopod by controlling chondrocyte maturation via Runx2 and Runx3.
Authors:
Ling Yu; Hongbing Liu; Mingquan Yan; Jing Yang; Fanxin Long; Ken Muneoka; YiPing Chen
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2007-04-01
Journal Detail:
Title:  Developmental biology     Volume:  306     ISSN:  0012-1606     ISO Abbreviation:  Dev. Biol.     Publication Date:  2007 Jun 
Date Detail:
Created Date:  2007-06-11     Completed Date:  2007-08-01     Revised Date:  2011-06-08    
Medline Journal Info:
Nlm Unique ID:  0372762     Medline TA:  Dev Biol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  549-59     Citation Subset:  IM    
Affiliation:
Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70117, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Bone Morphogenetic Protein 4
Bone Morphogenetic Proteins / metabolism
Cell Proliferation
Chondrocytes / cytology*
Core Binding Factor Alpha 1 Subunit / genetics*
Core Binding Factor Alpha 3 Subunit / genetics*
Extremities / embryology*
Homeodomain Proteins / genetics*,  physiology*
Humans
Mice
Mice, Inbred C57BL
Mice, Mutant Strains
Mice, Transgenic
Mutation*
Transcription, Genetic
Grant Support
ID/Acronym/Agency:
R01 DE012329-10/DE/NIDCR NIH HHS; R01 DE014044-05/DE/NIDCR NIH HHS; R01 HD043277-02/HD/NICHD NIH HHS
Chemical
Reg. No./Substance:
0/BMP4 protein, human; 0/Bmp4 protein, mouse; 0/Bone Morphogenetic Protein 4; 0/Bone Morphogenetic Proteins; 0/Core Binding Factor Alpha 1 Subunit; 0/Core Binding Factor Alpha 3 Subunit; 0/Homeodomain Proteins; 0/Runx2 protein, mouse; 0/Runx3 protein, mouse; 0/Shox2 protein, mouse
Comments/Corrections

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