Mechanosensitive Piezo1 in Periodontal Ligament Cells Promotes Alveolar Bone Remodeling During Orthodontic Tooth Movement.

Yukun Jiang,Yuzhe Guan,Yuanchen Lan,Zhiai Hu,Tiancheng Li,Qingsong Ye,Shuo Chen,Shujuan Zou

doi:10.3389/fphys.2021.767136

Abstract

Orthodontic tooth movement (OTM) is a process depending on the remodeling of periodontal tissues surrounding the roots. Orthodontic forces trigger the conversion of mechanical stimuli into intercellular chemical signals within periodontal ligament (PDL) cells, activating alveolar bone remodeling, and thereby, initiating OTM. Recently, the mechanosensitive ion channel Piezo1 has been found to play pivotal roles in the different types of human cells by transforming external physical stimuli into intercellular chemical signals. However, the function of Piezo1 during the mechanotransduction process of PDL cells has rarely been reported. Herein, we established a rat OTM model to study the potential role of Piezo1 during the mechanotransduction process of PDL cells and investigate its effects on the tension side of alveolar bone remodeling. A total of 60 male Sprague-Dawley rats were randomly assigned into three groups: the OTM + inhibitor (INH) group, the OTM group, and the control (CON) group. Nickel-titanium orthodontic springs were applied to trigger tooth movement. Mice were sacrificed on days 0, 3, 7, and 14 after orthodontic movement for the radiographic, histological, immunohistochemical, and molecular biological analyses. Our results revealed that the Piezo1 channel was activated by orthodontic force and mainly expressed in the PDL cells during the whole tooth movement period. The activation of the Piezo1 channel was essential for maintaining the rate of orthodontic tooth movement and facilitation of new alveolar bone formation on the tension side. Reduced osteogenesis-associated transcription factors such as Runt-related transcription factor 2 (RUNX2), Osterix (OSX), and receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) ratio were examined when the function of Piezo1 was inhibited. In summary, Piezo1 plays a critical role in mediating both the osteogenesis and osteoclastic activities on the tension side during OTM.

Highlights

IntroductionOrthodontic tooth movement (OTM) is a process depending on the remodeling of periodontal tissues (mainly alveolar bone, periodontal ligament, and cementum) surrounding the roots (Kumar et al, 2015)
Induced by mechanical loading, orthodontic tooth movement (OTM) is a process depending on the remodeling of periodontal tissues surrounding the roots (Kumar et al, 2015)
Our results showed that Piezo1 was mainly expressed in the periodontal ligament (PDL), while it is rarely found in the alveolar bone

Summary

Introduction

Orthodontic tooth movement (OTM) is a process depending on the remodeling of periodontal tissues (mainly alveolar bone, periodontal ligament, and cementum) surrounding the roots (Kumar et al, 2015). PDL cells have multiple functions locally including forming and maintaining periodontal ligaments, mediating alveolar bone and cementum repair, and periodontal tissue regeneration (Liu et al, 2018; Maeda, 2020). PDL cells can sense mechanical stress, transform mechanical stimuli into biochemical signals, and eventually regulate alveolar bone remodeling by secreting multiple factors (Yang et al, 2018). During OTM, the specific mechanism by which PDL cells perceive the mechanical stimulus, transfer it into biological signals, and contribute to alveolar bone remodeling remains unclear

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Results

Conclusion