The Histone Deacetylase Inhibitor (MS-275) Promotes Differentiation of Human Dental Pulp Stem Cells into Odontoblast-Like Cells Independent of the MAPK Signaling System

Abstract

The role of dental pulp stem cells (DPSCs) in dental tissue regeneration is gaining attention because DPSCs can differentiate into odontoblasts and other specialized cell types. Epigenetic modification has been found to play an important role in cell differentiation and regulation, among which histone deacetylase (HDAC) is involved in suppressing genes by removing histone acetyl groups. The use of HDAC inhibitor to control this is increasing and has been widely studied by many researchers. This study aimed to induce differentiation by causing epigenetic changes in odontoblast-related genes and the MAPK signaling pathway in human dental pulp stem cells. Western blot and immunofluorescence staining showed increased expression of DMP-1, ALP, DSPP, and RUNX2 compared to the control. However, activation of the MAPK signaling system was similar to but slightly different from the expression of odontoblast-related proteins. After 3 days, as shown by MTT and LDH assays, proliferation decreased overall, but cytotoxicity decreased at only a specific concentration. We confirmed that there was no change in mRNA expression of caspase 3 or 9 using real-time PCR. In addition, flow cytometry analysis confirmed that differentiation occurred due to the decrease in the expression of the CD73 and CD146. Although overall proliferation was reduced due to the G2/M inhibition of the cell cycle, the expression of BCL-2 protected the cells from cell death. Overall, cell proliferation decreased in response to MS-275, but it did not induce cytotoxicity in 5 nM and 10 nM concentration and induces differentiation into odontoblast-like cells.

The Selective Histone Deacetylase Inhibitor MI192 Enhances the Osteogenic Differentiation Efficacy of Human Dental Pulp Stromal Cells

“…MI192 substantially enhanced extracellular matrix collagen deposition and mineralisation compared to the untreated hDPSCs, correlating with the increased mineralisation observed in MI192 pre-treated ADSCs [ 28 ]. These findings clearly indicate that MI192 effects in stimulating hDPSCs efficacy for bone formation is not limited to enhancing osteogenic differentiation but also the mineralisation of its extracellular matrix, consistent with observations in the literature [ 32 , 56 ]. Moreover, the enhanced collagen production and calcium deposition observed in this study indicate the efficacy of MI192 pre-treatment in promoting hDPSCs mineralisation, likely due to the slow-binding kinetics of this HDACi [ 26 ].…”

“…HDPSCs have garnered growing interest for use in bone tissue engineering, due to their ease of procurement, increased proliferation rate and osteogenic capacity [ 13 , 32 ]. Therefore, the combination of this stem cell source with HDACi treatment could further accelerate the fracture healing process which would have a tremendous impact in the clinical practice.…”

Epigenetic regulation of dental pulp stem cells and its potential in regenerative endodontics

“…Cytotoxicity can be avoided at a concentration of 20 nmol/L. The MAPK signaling system was barely activated under MS-275 stimulation, suggesting that MS-275 induces odontogenesis independent of MAPK signaling[ 126 ]. The pro-odontogenic potential of MS-275 was also tested on a murine odontoblast-like cell line, MDPC-23.…”

Key Markers and Epigenetic Modifications of Dental-Derived Mesenchymal Stromal Cells

“…HDACs are downregulated during the osteogenic differentiation of dental-derived MSCs [ 160 , 161 ]. The use of HDAC inhibitors effectively increases the acetylation of H3K9K14 (histone H3, lysines 9 and 14) and promotes the expression of bone-related genes [ 162 , 163 ]. Valproic acid (VPA), a short-chain fatty acid, can inhibit class II HDACs.…”