N-Cadherin Regulates the Odontogenic Differentiation of Dental Pulp Stem Cells via β-Catenin Activity

Abstract

Dental pulp stem cell (DPSC) transplantation has shown new prospects in dental pulp regeneration, and is of great significance in the treatment of pulpitis and pulp necrosis. The fate and regenerative potential of stem cells are dependent, to a great extent, on their microenvironment, which is composed of various tissue components, cell populations, and soluble factors. N-cadherin-mediated cell–cell interaction has been implicated as an important factor in controlling the cell-fate commitment of mesenchymal stem cells. In this study, the effect of N-cadherin on odontogenic differentiation of DPSCs and the potential underlying mechanisms, both in vitro and in vivo, was investigated using a cell culture model and a subcutaneous transplantation mouse model. It was found that the expression of N-cadherin was reversely related to the expression of odontogenic markers (dentin sialophosphoprotein, DSPP, and runt-related transcription factor 2, Runx2) during the differentiation process of DPSCs. Specific shRNA-mediated knockdown of N-cadherin expression in DPSCs significantly increased the expression of DSPP and Runx2, alkaline phosphatase (ALP) activity, and the formation of mineralized nodules. Notably, N-cadherin silencing promoted nucleus translocation and accumulation of β-catenin. Inhibition of β-catenin by a specific inhibitor XAV939, reversed the facilitating effects of N-cadherin downregulation on odontogenic differentiation of DPSCs. In addition, knockdown of N-cadherin promoted the formation of odontoblast-like cells and collagenous matrix in β-tricalcium phosphate/DPSCs composites transplanted into mice. In conclusion, N-cadherin acted as a negative regulator via regulating β-catenin activity during odontogenic differentiation of DPSCs. These data may help to guide DPSC behavior by tuning the N-cadherin-mediated cell–cell interactions, with implications for pulp regeneration.

Dental Pulp Stem Cells Derived From Adult Human Third Molar Tooth: A Brief Review

“…Dental pulp stem cells are located within a heterogenic niche. Homeostatic regulation of the DPSCs niche, DPSCs’ proliferation and differentiation implicate a complex network of bioactive molecules, growth factors, ECM, and key signaling pathways ( Scheller et al, 2008 ; Mitsiadis et al, 2011 ; Tsutsui, 2020 ; Deng et al, 2021 ). Nevertheless, the signals that regulate DPSC fate are not only the biochemical cues, but also the biophysical cues (mechanical signals) that play a crucial role in influencing DPSC fate since orthodontic mechanical tension or stresses are exerted to teeth and transmitted into the dental pulp tissue by jaw movement during the process of normal mastication ( Tatullo et al, 2016 ).…”

BMP Signaling Pathway in Dentin Development and Diseases

“…BMP–MAPKs, –PI3K/Akt, –PKA, –PKC, and –Smad signaling pathways act synergistically, controlling dentin development. Besides Smad-dependent and Smad-independent pathways, the coordinated activities of TGF-β, transcriptional factors, and other factors are also essential for dentin development and formation [ 5 , 226 , 326 , 327 , 328 , 329 , 330 , 331 , 332 , 333 ].…”

A critical analysis of research methods and biological experimental models to study pulp regeneration

“…Alternatively, osteogenic induction media (OM) have commonly been used to convert dental stem cells into odontoblast‐like cells. The OM cocktail can increase the expression of RUNX2 and DSSP by DPSC as early as within three days of treatment (Deng et al, 2021). Many cellular pathways are involved in OM‐induced odontoblastic differentiation, including increased β‐catenin activity and the activation of RUNX2, a transcriptional factor that regulates osteoblastic differentiation (Deng et al, 2021; Han et al, 2014).…”

“…The OM cocktail can increase the expression of RUNX2 and DSSP by DPSC as early as within three days of treatment (Deng et al, 2021). Many cellular pathways are involved in OM‐induced odontoblastic differentiation, including increased β‐catenin activity and the activation of RUNX2, a transcriptional factor that regulates osteoblastic differentiation (Deng et al, 2021; Han et al, 2014). The RUNX2 is likely to be involved in odontoblastic differentiation during reparative dentine formation through a mechanism that involves β‐catenin activation (Han et al, 2014).…”