title: Effects of histone deacetylase inhibitors on regenerative cell responses in human dental pulp cells.
abstract: OBJECTIVE
  To investigate the growth, migratory and adhesive effects of trichostatin A (TSA) and valproic acid (VPA), two histone deacetylase inhibitors (HDACis), on human dental pulp stem cells (hDPSCs).
  
  
  METHODS
  To verify that TSA or VPA functions as an HDAC inhibitor, the expressions of histones H3 and H4 were examined using Western blotting analysis. hDPSC growth and metabolic activity was evaluated by MTT viability analysis at different time-points and by cell count experiments. The expression of cell cycle regulatory proteins and apoptosis-associated proteins was examined by Western blot analysis. Migration effects were investigated using wound healing and transwell migration assays. An adhesion assay was also performed in the presence and absence of HDACis. The levels of chemokines and adhesion molecules relevant to repair in hDPSCs were also assessed by qRT-PCR and Western blot analysis. The data were analysed, where appropriate, using Student's t-test or one-way anova followed by the Student-Newman-Keuls test using SPSS software.
  
  
  RESULTS
  Trichostatin A and VPA enhanced acetylation of histones H3 and H4 (P < 0.05). Significant increases (P < 0.05) in MTT levels in hDPSCs were observed after treatment with TSA (2 and 20 nmol L-1) or VPA (1 and 10 mmol L-1). Cell numbers were not significantly affected at the concentration of TSA (0.2-10 nmol L-1) or VPA (0.01-100 mmol L-1) applied compared with the control at 3, 5 or 7 days (P > 0.05). At the same time, the expression of Cdx2 and cyclin A was upregulated by 2 nmol L-1TSA and 1 mmol L-1VPA (P < 0.05). Higher TSA or VPA concentrations induced apoptosis in hDPSCs in the cell count and apoptosis experiments (P < 0.05). Moreover, TSA and VPA significantly depressed the expression of Cdx2 and cyclin A (P < 0.05), whilst it significantly improved the level of p21 (P < 0.05). TSA and VPA promoted migration and adhesion of hDPSCs (P < 0.05). The levels of chemokines and adhesion molecules were significantly upregulated after exposure of hDPSCs to 20 nmol L-1TSA or 1 mmol L-1VPA (P < 0.05).
  
  
  CONCLUSIONS
  Histone deacetylase inhibitors at specific concentrations promoted proliferation, migration and adhesion of hDPSCs, which may contribute to novel regenerative therapies for pulpal disease treatment.
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shanxi Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, China.|Department of Operative Dentistry and Endodontics, School of Stomatology, The Guizhou Medical University, Guiyang, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shanxi Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shanxi Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, China.
authors.forename: X
authors.initials: X
authors.lastname: He
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shanxi Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, China.
authors.forename: N
authors.initials: N
authors.lastname: Liu
authors.affiliation: Department of Stomatology, the Lishilu out-patient Department of the Chinese PLA Second Artillery Corps, Beijing, China.
authors.forename: B
authors.initials: B
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shanxi Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, China.
authors.forename: L
authors.initials: L
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shanxi Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, China.
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shanxi Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, China.
authors.forename: F
authors.initials: F
authors.lastname: Ma
authors.affiliation: Division of Restorative Dentistry and Periodontology, Dublin Dental University Hospital, Dublin, Ireland.
authors.forename: H
authors.identifier: http://orcid.org/0000-0001-8690-2379
authors.initials: H
authors.lastname: Duncan
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shanxi Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, China.
authors.forename: W
authors.identifier: http://orcid.org/0000-0002-6841-5021
authors.initials: W
authors.lastname: He
authors.affiliation: Oral Biology, School of Dentistry, University of Birmingham, Birmingham, UK.
authors.forename: P
authors.initials: P
authors.lastname: Cooper
mesh_terms: D000293:Adolescent; D015153:Blotting, Western; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003782:Dental Pulp / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006655:Histone Deacetylases / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D012038:Regeneration / Q000187:drug effects*; D013234:Stem Cells / Q000187:drug effects / Q000502:physiology; D014635:Valproic Acid / Q000494:pharmacology; D055815:Young Adult
chemical_list: D056572:Histone Deacetylase Inhibitors; D006657:Histones; D006877:Hydroxamic Acids; C012589:trichostatin A; D014635:Valproic Acid; D006655:Histone Deacetylases
keywords: cell adhesion; cell growth; cell migration; histone deacetylase inhibitors; human dental pulp stem cells