Mechanical force modulates macrophage proliferation via Piezo1‐AKT‐Cyclin D1 axis

Abstract

Orthodontic tooth movement (OTM) is induced by biomechanical stimuli and facilitated by periodontal tissue remodeling, where multiple immune cells participate in this progression. It has been demonstrated that macrophage is essential for mechanical force‐induced tissue remodeling. In this study, we first found that mechanical force significantly induced macrophage proliferation in human periodontal samples and murine OTM models. Yet, how macrophages perceive mechanical stimuli and thereby modulate their biological behaviors remain elusive. To illustrate the mechanisms of mechanical force‐induced macrophage proliferation, we subsequently identified Piezo1, a novel mechanosensory ion channel, to modulate macrophage response subjected to mechanical stimuli. Mechanical force upregulates Piezo1 expression in periodontal tissues and cultured bone‐marrow‐derived macrophages (BMDMs). Remarkably, suppressing Piezo1 with GsMTx4 retarded OTM through reduced macrophage proliferation. Moreover, knockdown of Piezo1 effectively inhibited mechanical force‐induced BMDMs proliferation. RNA sequencing was further performed to dissect the underlying mechanisms of Piezo1‐mediated mechanotransduction utilizing mechanical stretch system. We revealed that Piezo1‐activated AKT/GSK3β signaling was closely associated with macrophage proliferation upon mechanical stimuli. Importantly, Cyclin D1 (Ccnd1) was authenticated as a critical downstream factor of Piezo1 that facilitated proliferation by enhancing Rb phosphorylation. We generated genetically modified mice in which Ccnd1 could be deleted in macrophages in an inducible manner. Conditional ablation of Ccnd1 inhibited periodontal macrophage proliferation and therefore delayed OTM. Overall, our findings highlight that proliferation driven by mechanical force is a key process by which macrophages infiltrate in periodontal tissue during OTM, where Piezo1‐AKT‐Ccnd1 axis plays a pivotal role.

Piezo1‐mediated M2 macrophage mechanotransduction enhances bone formation through secretion and activation of transforming growth factor‐β1

“…Mice were given the TGF‐β receptor I, II inhibitor (LY‐364947, Med Chem Express) intraperitoneally at a dose of 10 mg/kg body weight in a solution of 200 μL of 5% DMSO and 95% sunflower seed oil (Vehicle). GsMTx4 (Med Chem Express) was previously dissolved in ddH 2 O and then administered to mice as a 10 μL (5 μM) intraperitoneal injection 20 . Following the mice's exercise, drugs were given once every 2 days.…”

“…In accordance with the manufacturer's recommendations, RAW 264.7 cells were transiently transfected in six‐well plates with Piezo1 siRNA at a final concentration of 100 nM using Opti‐MEM (Gibco) supplemented with Lipofectamine 2000 Reagent (Invitrogen). We refer to the sequences of other subject groups 20 : Piezo1‐siRNA, 5′‐AGGAAGAAGCCAGAAGCUAATT‐3′ and 5′‐UUAGCUUCUGGCUCUUCCUTT‐3′, negative control (NC)‐siRNA, 5′‐UUCUCCGAACGUGUCACGUTT‐3′ and 5′‐ACGUGACACGUUCGGAGAATT‐3′.…”

“…GsMTx4 (Med Chem Express) was previously dissolved in ddH 2 O and then administered to mice as a 10 μL (5 μM) intraperitoneal injection. 20 Following the mice's exercise, drugs were given once every 2 days.…”

Mechanosensitive Piezo1 and Piezo2 ion channels in craniofacial development and dentistry: Recent advances and prospects

“…Bone marrow-derived macrophages express high levels of Piezo1, which can be activated by mechanical stimulation to trigger a proinflammatory response (Solis et al, 2019). Using both human PDL samples and OTM mouse models, a recent study found that mechanical force induces macrophage proliferation via the Piezo1-AKT-cyclin D1 axis (Xu et al, 2022). Moreover, inhibition of Piezo1 by GsMTx4 effectively inhibits tensile stressinduced macrophage proliferation and thus suppresses OTM.…”

“…Piezo1 and Piezo2 have also been reported to affect the skeletal system, and Piezo1 deficiency has been shown to impair bone anabolism and induce abnormal responses to external forces (Li et al, 2019;Sun et al, 2019;Wang et al, 2020;Zhou et al, 2020). Furthermore, emerging evidence indicates that Piezo1 and Piezo2 help to regulate dental pain and participate in signaling transduction in dental-derived stem cells, periodontal bone remodeling and orthodontic tooth movement (OTM) (Gao et al, 2017;Sugimoto et al, 2017;Won et al, 2017;Jiang et al, 2021;Cho et al, 2022;Xu et al, 2022).…”