MAPK mediates Hsp25 signaling in incisor development

Abstract

Rodent incisors are continuously growing teeth that include all stages of amelogenesis. Understanding amelogenesis requires investigations of the genes and their gene products control the ameloblast phenotype. One of the mechanisms related to tooth differentiation is mitogen-activated protein kinase (MAPK) signaling. The extracellular-signal regulated kinase (ERK)/mitogen-activated protein kinase kinase (MEK) cascade is associated with mechanisms that control the cell cycle and cell survival. However, the roles of cascades in incisor development remain to be determined. In this study, we investigated incisor development and growth in the mouse based on MAPK signaling. Moreover, heat-shock protein (Hsp)-25 is well known to be a useful marker of odontoblast differentiation. We used anisomycin (a protein-synthesis inhibitor that activates MAPKs) and U0126 (a MAPK inhibitor that blocks ERK1/2 phosphorylation) to examine the role of MAPKs in Hsp25 signaling in the development of the mouse incisor. We performed immunohistochemistry and in vitro culture using incisor tooth germ, and found that phospho-ERK (pERK), pMEK, and Hsp25 localized in developing incisor ameloblasts and anisomycin failed to produce incisor development. In addition, Western blotting results showed that anisomycin stimulated the phosphorylation of ERK, MEK, and Hsp25, and that some of these proteins were blocked by the U0126. These findings suggest that MAPK signals play important roles in incisor formation, differentiation, and development by mediating Hsp25 signaling.

Natural Mineralized Scaffolds Promote the Dentinogenic Potential of Dental Pulp Stem Cells Via the Mitogen-Activated Protein Kinase Signaling Pathway

“…Moreover, the identification of molecular mechanisms by which the scaffolds direct odonto-progenitors into odontogenic differentiation is of great interest to scientists in this field. 14,15 In this study, we compared the efficacy of five kinds of scaffolds for DPSC proliferation and odontogenic differentiation in vitro and the regeneration of dentin-like hard tissue in vivo. We further investigated how these scaffolds regulate odontogenic differentiation of DPSC through signaling pathways.…”

“…12 Recent studies have found that MAPK signaling is involved during dental pulp cell differentiation and tooth development. [13][14][15] However, whether the MAPK signaling pathways play an important role in the dentinogenic capacity of DPSCs and whether scaffolds could affect the MAPK signaling pathways of DPSCs have not been assessed.…”

Immunohistochemical analysis of pulpal regeneration by nestin expression in replanted teeth

“…For the immunohistochemical staining, a modification of a previously described method (Lee et al. 2009) was used.…”

“…For the immunohistochemical staining, a modification of a previously described method (Lee et al 2009) was used. In brief, the tissue section was blocked in 3% hydrogen peroxide for 15 min, pre-treated by boiling in 10 mmol L )1 citrate buffer (pH 6.0) for 5 min and cooled at room temperature.…”

Extending the knowledge in histochemistry and cell biology

“…In their recent work, Lee et al (2009) explored mitogen-activated protein kinase (MAPK) signaling during incisor development and growth in the mouse. By using pharmaceutical activation and inhibition of MAPKs in in vitro cultures, important functions of MAPKs for amelogenesis were found, which were partly involving Hsp25 signaling activated by phosphorylated ERK and MEK.…”