A novel role for Twist-1 in pulp homeostasis.
The molecular mechanisms that maintain the equilibrium of odontoblast progenitor cells in dental pulp are unknown. Here we tested whether homeostasis in dental pulp is modulated by Twist-1, a nuclear protein that partners with Runx2 during osteoblast differentiation. Our analysis of Twist-1(+/-) mice revealed phenotypic changes that involved an earlier onset of dentin matrix formation, increased alkaline phosphatase activity, and pulp stones within the pulp. RT-PCR analyses revealed Twist-1 expression in several adult organs, including pulp. Decreased levels of Twist-1 led to higher levels of type I collagen and Dspp gene expression in perivascular cells associated with the pulp stones. In mice heterozygous for both Twist-1 and Runx2 inactivation, the phenotype of pulp stones appeared completely rescued. These findings suggest that Twist-1 plays a key role in restraining odontoblast differentiation, thus maintaining homeostasis in dental pulp. Furthermore, Twist-1 functions in dental pulp are dependent on its interaction with Runx2.
Galler
K M
KM
Department of Biomedical Sciences, Texas A&M University Health Science Center, Baylor College of Dentistry, 3302 Gaston Avenue, Dallas, TX 75246, USA.
Yasue
A
A
Cavender
A C
AC
Bialek
P
P
Karsenty
G
G
D'Souza
R N
RN
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D024042:Collagen Type I / Q000096:biosynthesis; D050659:Core Binding Factor Alpha 1 Subunit / Q000037:antagonists & inhibitors / Q000502:physiology*; D003782:Dental Pulp / Q000166:cytology*; D003784:Dental Pulp Calcification / Q000503:physiopathology; D016326:Extracellular Matrix Proteins; D006706:Homeostasis / Q000502:physiology; D051379:Mice; D008817:Mice, Mutant Strains; D009687:Nuclear Proteins / Q000502:physiology*; D009804:Odontoblasts / Q000166:cytology / Q000378:metabolism; D010750:Phosphoproteins; D011498:Protein Precursors / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins; D051879:Twist-Related Protein 1 / Q000502:physiology*; D000099311:Dentin Sialophosphoprotein
D024042:Collagen Type I; D050659:Core Binding Factor Alpha 1 Subunit; D016326:Extracellular Matrix Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011498:Protein Precursors; D012795:Sialoglycoproteins; D051879:Twist-Related Protein 1; D000099311:Dentin Sialophosphoprotein; C493716:Runx2 protein, mouse; C067250:Twist1 protein, mouse