Effects of histone deacetylase inhibitors on
regenerative cell responses in human dental pulp
, Z. Wang
, N. Liu
, B. Liu
, H. Duncan
& P. Cooper
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
Department of Operative Dentistry and Endodontics, School of Stomatology, The Guizhou Medical
Department of Stomatology, the Lishilu out-patient Department of the Chinese PLA Second Artillery
Corps, Beijing, China;
Division of Restorative Dentistry and Periodontology, Dublin Dental University Hospital, Dublin, Ireland;
Oral Biology, School of Dentistry, University of Birmingham, Birmingham, UK
Luo Z, Wang Z, He X, Liu N, Liu B, Sun L, Wang J,
Ma F, Duncan H, He W, Cooper P.
Effects of histone
deacetylase inhibitors on regenerative cell responses in
human dental pulp cells. International Endodontic Journal, 51,
Aim To investigate the growth, migratory and adhe-
sive effects of trichostatin A (TSA) and valproic acid
(VPA), two histone deacetylase inhibitors (HDACis),
on human dental pulp stem cells (hDPSCs).
Methodology To verify that TSA or VPA functions
as an HDAC inhibitor, the expressions of histones H3
and H4 were examined using Western blotting analy-
sis. hDPSC growth and metabolic activity was evalu-
ated 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 heal-
ing 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
followed by the
Student–Newman–Keuls test using SPSS software.
Results Trichostatin A and VPA enhanced acetyla-
tion 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
) or VPA (1 and 10 mmol L
numbers were not signiﬁcantly affected at the concen-
tration of TSA (0.2–10 nmol L
) or VPA (0.01–
100 mmol L
) 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
TSA and 1 mmol L
VPA (P < 0.05).
Higher TSA or VPA concentrations induced apoptosis
in hDPSCs in the cell count and apoptosis experi-
ments (P < 0.05). Moreover, TSA and VPA signiﬁ-
cantly 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
TSA or 1 mmol L
VPA (P < 0.05).
Conclusions Histone deacetylase inhibitors at speci-
ﬁc concentrations promoted proliferation, migration and
adhesion of hDPSCs, which may contribute to novel
regenerative therapies for pulpal disease treatment.
Keywords: cell adhesion, cell growth, cell migra-
tion, histone deacetylase inhibitors, human dental
pulp stem cells.
Received 9 May 2015; accepted 30 March 2017
Correspondence: Wenxi He, 145 Chang-le Xi Road, Xian
710032, China (Tel.: +86 29 84776476;
Fax: +86 29 84776476; e-mail: firstname.lastname@example.org).
These authors contributed equally to this work.
International Endodontic Journal
, 51, 767–778, 2018
© 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd