Piezo 1/PI3K/AKT axis mediates the mechanical response of macrophages to promote bone regeneration

TAO Di-hao; CHENG Jia-yu; YANG Jian-hua; HE Xiao-ning; LI Bei

doi:10.15956/j.cnki.chin.j.conserv.dent.2024.11.002

Abstract：AIM:To explore how the viscoelastic properties of the extracellular matrix(ECM)influence macrophage(M φ)behavior,thereby facilitating cranial bone regeneration.METHODS:Viscoelastic hydrogels with varying relaxation rates were developed using an alginate-calcium ion crosslinking system.Bone marrow-derived macrophages(BMDMs)were cultured on these hydrogels,and the hydrogel-Mφconstructs were then implanted into mouse cranial defects to evaluate bone regeneration through Micro-CT and histological analysis.RT-qPCR was used to identify mechanosensitive ion channels involved in cellular sensing of ECM mechanics,with agonists and inhibitors to confirm their roles.RNA sequencing(RNA-seq)on M φ s cultured on both hydrogel types aimed to elucidate the mechanisms by which ion channels modulate M φ function in response to ECM viscoelasticity changes.RESULTS:The hydrogels with fast and slow relaxation properties demonstrated equivalent compressive moduli and high biocompatibility.The implantation of the fast relaxation hydrogel-M φ complex led to effective cranial defect repair.RT-qPCR revealed that Piezo 1 ion channel expression was elevated in M φ s,with reduced levels in the fast relaxation group.Modulating Piezo 1 activity with GsMTx-4 or Yoda1 altered Mφfunction accordingly.KEGG and GSEA analyses indicated an enhanced PI3K/AKT signaling pathway in the fast relaxation group.Modulating Piezo 1 activity also affected PI3K/AKT-related protein expression in Mφs.CONCLUSION:The Piezo 1/PI3K/AKT pathway is crucial for macrophage-mediated mechanical responses that promote cranial bone regeneration,offering a novel therapeutic approach for bone defects in clinical settings.