title: Lymphocyte enhancer-binding factor 1: an essential factor in odontoblastic differentiation of dental pulp cells enzymatically isolated from rat incisors.
abstract: Lymphocyte enhancer-binding factor 1 (Lef1), a HMG-domain protein, is thought to play important roles in inductive tissue interaction during tooth development. Lef1 knockdown in mice causes arrest at the bud stage in tooth development. As this gene participates in the regulation of a large and diverse set of peptide growth factors in ectomesenchymal cell differentiation of dental papilla, Lef1 appears to be a key factor in odontoblast differentiation. However, the relationship between Lef1 and odontoblast differentiation is still unclear. To analyze the biological roles of Lef1 in regulating odontoblast differentiation, we transiently overexpressed or suppressed Lef1 in cultured dental pulp cells. Lef1-overexpressing cells expressed higher levels of dentin sialoprotein (DSPP), osteocalcin and alkaline phosphatase (ALP) mRNA and formed larger numbers of mineralized nodules compared to control cells. However, Msx-1 expression or cell proliferation was unaffected by overexpression of Lef1. To further examine the role of Lef1 in dental pulp cells, we knocked down Lef1 expression in dental pulp cells using short interfering RNA (siRNA). Transient expression of siRNA against Lef1 markedly reduced Lef1 mRNA levels, and Lef1-suppressed cells expressed lower levels of DSPP, osteocalcin and ALP mRNA compared to control cells. Furthermore, the formation of mineralized nodules was inhibited by siRNA against Lef1; however, neither Msx-1 expression or cell proliferation was inhibited by siRNA against Lef1. These results outline the role of Lef1 in accelerating odontoblast differentiation by regulating DSP and osteocalcin mRNA expression in dental pulp cells, confirming that Lef1 is a key factor for odontoblast differentiation.
authors.affiliation: Division of Operative Dentistry, Department of Conservative Dentistry, School of Dentistry, Ohu University, 31-1 Misumido, Tomitamachi, Koriyama, Fukushima, Japan. s-yokose@den.ohu-u.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yokose
authors.forename: Takahiro
authors.initials: T
authors.lastname: Naka
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D003782:Dental Pulp / Q000166:cytology / Q000378:metabolism*; D003810:Dentinogenesis; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D020868:Gene Silencing; D017930:Genes, Reporter; D007180:Incisor; D051821:Lymphoid Enhancer-Binding Factor 1 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009804:Odontoblasts / Q000166:cytology / Q000378:metabolism*; D015675:Osteocalcin / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering; D051381:Rats; D017207:Rats, Sprague-Dawley; D012795:Sialoglycoproteins / Q000235:genetics / Q000378:metabolism; D014074:Tooth Calcification; D000099311:Dentin Sialophosphoprotein
chemical_list: D000469:Alkaline Phosphatase; D016326:Extracellular Matrix Proteins; D051821:Lymphoid Enhancer-Binding Factor 1; D015675:Osteocalcin; D010750:Phosphoproteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein; C497575:Lef1 protein, rat