title: Hyaluronan induces odontoblastic differentiation of dental pulp stem cells via CD44.
abstract: Dental pulp tissue contains many undifferentiated mesenchymal cells, which retain the ability to differentiate into mature cells. Induced pluripotent stem cells have been developed from various cell sources, including dental pulp-derived stem cells, and evaluated for potential application to regenerative therapy. Dental pulp tissues overexpress CD44, a cell-adhesion factor involved in the induction of mineralization. In this study, we investigated the effects of hyaluronan-a known CD44 ligand-on dental pulp stem cells (DPSCs).
  
  
  
  DPSC CD44 expression was analyzed using immunofluorescence staining, flow cytometry, and western blotting. Cell proliferation was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Effects of hyaluronan on the cell cycle were analyzed by flow cytometry. Alkaline phosphatase activity was employed as marker of mineralization and measured by fluorometric quantification and western blotting. Bone morphogenetic protein (BMP)-2, BMP-4, dentin sialophosphoprotein (DSPP), and dentin matrix acidic phosphoprotein 1 (DMP-1) levels were measured using real-time polymerase chain reaction. Odontoblastic differentiation and the close cell signaling examination of DPSC differentiation were determined using western blotting.
  
  
  
  Hyaluronan induced expression of the odontoblastic differentiation markers DMP-1 and DSPP. Moreover, the odontoblastic differentiation induced by hyaluronan was mediated by CD44-but not by Akt, Smad1 or MAPK signaling.
  
  
  
  Our results indicate that hyaluronan induces odontoblastic differentiation of DPSCs via CD44. This suggests that hyaluronan plays a crucial role in the induction of odontoblastic differentiation from DPSCs. Our findings may aid the development of new, inexpensive, and effective conservative treatments for dental pulp repair.
authors.affiliation: Division of Pharmacology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 350-0283, Japan. umemura@dent.asahi-u.ac.jp.|Department of Oral Biochemistry, Asahi University School of Dentistry, Gifu, 501-0296, Japan. umemura@dent.asahi-u.ac.jp.
authors.forename: Naoki
authors.identifier: 0000-0002-3249-782X
authors.initials: N
authors.lastname: Umemura
authors.affiliation: Department of Natural Products Chemistry, Faculty of Pharmaceutical Science, Aomori University, Aomori, 030-0943, Japan.
authors.forename: Emika
authors.initials: E
authors.lastname: Ohkoshi
authors.affiliation: Division of Pharmacology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 350-0283, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Tajima
authors.affiliation: Division of Endodontics, Department of Restorative and Biomaterials Sciences, Meikai University School of Dentistry, Saitama, 350-0283, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Kikuchi
authors.affiliation: Division of Operative Dentistry, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, 350-0283, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Katayama
authors.affiliation: Division of Pharmacology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 350-0283, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakagami
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics / Q000378:metabolism; D055415:Bone Morphogenetic Protein 4 / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D003782:Dental Pulp / Q000166:cytology / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics* / Q000378:metabolism; D006820:Hyaluronic Acid / Q000494:pharmacology*; D008024:Ligands; D009804:Odontoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D012795:Sialoglycoproteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000099311:Dentin Sialophosphoprotein
chemical_list: D000469:Alkaline Phosphatase; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D016326:Extracellular Matrix Proteins; D018960:Hyaluronan Receptors; D006820:Hyaluronic Acid; D008024:Ligands; D010750:Phosphoproteins; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein; C525718:BMP2 protein, human; C525809:BMP4 protein, human; C497483:CD44 protein, human; C513309:DMP1 protein, human
keywords: Bone mineralization; DMP-1 protein; DSPP protein; Dental pulp calcification; Dental pulp capping; Smad1 protein