The Conditioned Medium of Calcined Tooth Powder Promotes the Osteogenic and Odontogenic Differentiation of Human Dental Pulp Stem Cells via MAPK Signaling Pathways.

Jintao Wu,Yuan Fan,Yin Pan,Na Li,Jinhua Yu,Yongchun Gu,Yanqiu Wang,Zehan Li,Zuomin Zhou,Gobin Romila

doi:10.1155/2019/4793518

Abstract

The calcined tooth powder (CTP), a type of allogeneic biomimetic mineralized material, has been confirmed that can promote new bone formation when obtained at high temperature. The aim of this study was to investigate effects of the conditioned medium of calcined tooth powder (CTP-CM) on the osteogenic and odontogenic differentiation of human dental pulp stem cells (hDPSCs) and the underlying mechanisms involved. First, ALP activity assay determined that 200 μg/mL was the optimal concentration of CTP-CM for the following experiments. CTP-CM had no significant effect on the proliferation of hDPSCs as indicated by CCK-8 and FCM analysis. Both the gene and protein (DSPP/DSPP, RUNX2/RUNX2, OCN/OCN, OSX/OSX, OPN/OPN, ALP/ALP, and COL-1/COL-1) expression levels increased in the CTP-CM-induced hDPSC group as compared with those in the control group at day 3 or 7, showing the positive regulation of CTP-CM on the osteo/odontogenic differentiation of hDPSCs. Mechanistically, MAPK signaling pathways were activated after the CTP-CM treatment, and the inhibitors targeting MAPK were identified which weakened the effects of CTM-CM on the committed differentiation of hDPSCs. These findings could lead to the creation of stem cell therapies for dental regeneration.

Highlights

The ultimate aim of tissue engineering is to research and develop biological substitutes, to rescue or/and restore various forms of damage and defect, and to maintain and enhance the function of tissues or organs [1]
Dental stem cells are thought to originate from the cranial neural crest and were documented, successfully isolated, and characterized, including human dental pulp stem cells (hDPSCs) [7], stem cells isolated from apical papilla (SCAPs) [8, 9], periodontal ligament stem cells [10], stem cells from human exfoliated deciduous teeth (SHED), stem cells isolated from dental follicle precursor cells (DFPCs), and stem cells from human gingiva
To explore whether MAPK signaling pathways are involved in the calcined tooth powder (CTP)-CM-mediated promotion odonto/osteogenic differentiation of hDPSCs, we evaluated the protein levels related to MAPK, such as p-P38, P38, p-ERK, ERK, p-JNK, and JNK by western blotting

Summary

Introduction

The ultimate aim of tissue engineering is to research and develop biological substitutes, to rescue or/and restore various forms of damage and defect, and to maintain and enhance the function of tissues or organs [1]. Stem cells and biomaterials and the interactions between them are the most important part of the development process of tissue engineering [2]. There is a considerable amount of data available that stem cells existed in various areas of the human body, such as bone marrow, skin, teeth, heart, liver, skeletal muscle, peripheral blood, and blood vessels [6]. The teeth and the surrounding tissues are an important source of stem cells. HDPSCs, which are successfully isolated from human third

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