Hyaluronan induces odontoblastic differentiation of dental pulp stem cells via CD44

Abstract

BackgroundDental 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).MethodsDPSC 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.ResultsHyaluronan 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.ConclusionsOur 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s13287-016-0399-8) contains supplementary material, which is available to authorized users.

The Antimicrobial Peptide LL-37 as a Possible Adjunct for the Proliferation and Differentiation of Dental Pulp Stem Cells

“…A greater number of cells were observed in the G0/G1 phase, which was demonstrated in previous studies of the cell cycle in DPSCs (11,12). DPSC proliferation provides an appropriate number of cells for cell differentiation (28).…”

“…Soares et al (35) observed that the biomembrane composed of chitosan/matrix of collagen incorporated with calcium aluminate microparticles increased the expression of these genes in DPSCs after 28 days. However, previous studies also demonstrated that DPSCs increased the expression of DSPP and DMP-1 genes depending on the stimulus without the use of mineralizing-inducing agents (11,12), and this methodology was successfully adopted in the present work. Wang et al (12) observed that the expression of DSPP and DMP-1 genes increased after treatment with ATP for 24 and 48 hours.…”

“…Wang et al (12) observed that the expression of DSPP and DMP-1 genes increased after treatment with ATP for 24 and 48 hours. Umemura et al (11) observed an increased expression of these genes and their respective proteins after 24 hours of hyaluronic acid treatment without mineralizing-inducing agents. We demonstrated that 10 mg/mL of LL-37 increased the expression of the DSSP gene and protein in a dose-dependent manner, which indicates that this peptide plays a role in the differentiation of stem cells into odontoblasts.…”

“…These cells are promising for the regeneration of the dentin-pulp complex because these cells are accessible and offer small chances of immunological rejection and pathogen transmission (10). Some studies demonstrated that DPSCs differentiate into odontoblast-like cells when in contact with some substances (11,12).…”

Effects of substrate stiffness on dental pulp stromal cells in culture

“…For instance, previous research has shown that cells isolated from human dental pulp can form a structure analogous to the dentin‐pulp complex . DPSCs have also been reported to be strongly influenced by their external chemical environment …”