Ruimin Li1, Chenglin Wang1, Juan Tong1, Yingying Su1, Yunfeng Lin1, Xuedong Zhou1, Ling Ye2. 1. State Key Laboratory of Oral Diseases West China School of Stomatology, Sichuan University, Chengdu, Sichuan, China. 2. State Key Laboratory of Oral Diseases West China School of Stomatology, Sichuan University, Chengdu, Sichuan, China. Electronic address: yeling@scu.edu.cn.
Abstract
INTRODUCTION: During the dental pulp repair process, human dental pulp cells (HDPCs) migrate to injury sites where they may differentiate into odontoblastlike cells. WNT6 plays a role in dental development and can activate a noncanonical pathway including the c-Jun N-terminal kinase (JNK) pathway. The mechanism of WNT6 in dental pulp repair is still unknown. The purpose of this study was to explore the potential role of the WNT6/JNK signaling pathway in the promotion of cell migration and the differentiation of HDPCs. METHODS: The third passage of HDPCs were cultured in vitro and treated with WNT6 conditioned medium with or without the pretreatment of JNK inhibitor SP600125. The activation of JNK was detected by Western blot, the expression of c-Jun was quantified by reverse-transcription polymerase chain reaction, the migration of HDPCs was determined by wound healing and transwell migration assays, and the differentiation of HDPCs was investigated using alkaline phosphatase staining and alizarin red staining. The expression of odontogenesis-related genes such as Runt-related transcription factor 2, dentin sialophosphoprotein, and dentin matrix protein 1 was quantified. RESULTS: WNT6 activates the JNK pathway in HDPCs and enhances cell migration, mineralization nodule formation, and alkaline phosphatase activation. WNT6 also increases the expression of Runt-related transcription factor 2, dentin sialophosphoprotein, and dentin matrix protein messenger RNA in HDPCs. Blockage of the JNK pathway in HDPCs decreases but does not completely abolish the cell migration and differentiation capacity induced by WNT6. CONCLUSIONS: WNT6 activates the JNK signaling pathway in HDPCs, leading to migration and differentiation.
INTRODUCTION: During the dental pulp repair process, human dental pulp cells (HDPCs) migrate to injury sites where they may differentiate into odontoblastlike cells. WNT6 plays a role in dental development and can activate a noncanonical pathway including the c-Jun N-terminal kinase (JNK) pathway. The mechanism of WNT6 in dental pulp repair is still unknown. The purpose of this study was to explore the potential role of the WNT6/JNK signaling pathway in the promotion of cell migration and the differentiation of HDPCs. METHODS: The third passage of HDPCs were cultured in vitro and treated with WNT6 conditioned medium with or without the pretreatment of JNK inhibitor SP600125. The activation of JNK was detected by Western blot, the expression of c-Jun was quantified by reverse-transcription polymerase chain reaction, the migration of HDPCs was determined by wound healing and transwell migration assays, and the differentiation of HDPCs was investigated using alkaline phosphatase staining and alizarin red staining. The expression of odontogenesis-related genes such as Runt-related transcription factor 2, dentin sialophosphoprotein, and dentin matrix protein 1 was quantified. RESULTS:WNT6 activates the JNK pathway in HDPCs and enhances cell migration, mineralization nodule formation, and alkaline phosphatase activation. WNT6 also increases the expression of Runt-related transcription factor 2, dentin sialophosphoprotein, and dentin matrix protein messenger RNA in HDPCs. Blockage of the JNK pathway in HDPCs decreases but does not completely abolish the cell migration and differentiation capacity induced by WNT6. CONCLUSIONS:WNT6 activates the JNK signaling pathway in HDPCs, leading to migration and differentiation.
Authors: Georgia Nikoloudaki; Sarah Brooks; Alexander P Peidl; Dylan Tinney; Douglas W Hamilton Journal: Int J Mol Sci Date: 2020-02-04 Impact factor: 5.923