Crosstalk Of Macrophages-Ecs Promotes Angiogenesis In Corticotomy-Accelerated Otm

To explore the underlying molecular mechanism of crosstalk between macrophages and endothelial cells via VEGFA-VEGFR1 signaling axis in regulating angiogenesis in corticotomy-accelerated OTM. Based on previous single-cell sequencing data, we firstly employed RT-qPCR, ELISA, and immunohistochemical staining to investigate alterations in the VEGFA-VEGFR1 signaling axis and its subsequent effects on macrophages and angiogenesis during corticotomy-accelerated orthodontic tooth movement (OTM).To assess the role of VEGFR1 and angiogenesis and to confirm the interaction between macrophages and endothelial cells,we performed macrophage ablation in alveolar bone using Clodronate liposomes (Clo-clip) and evaluated changes of VEGFR1 expression and vascularization in animal models.Morever,THP-1 monocytes overexpressing VEGFA (via lentiviral transduction) were co-cultured with human umbilical vein endothelial cells (HUVECs) to elucidate the mechanistic interplay between VEGFA-VEGFR1 signaling and cellular crosstalk, concluding scratching assay,CCK8 assay, RT-qPCR, Western blot and immunohistochemical staining. Following corticotomy, the VEGFA-VEGFR1 signaling axis was significantly upregulated in OTM, accompanied by enhanced angiogenesis and pronounced macrophage enrichment in the surrounding periodontal ligament (PDL) of the first molar furcation.Upon macrophage clearance, VEGFR1 expression was downregulated in corticotomy-accelerated OTM, leading to a significant reduction in angiogenesis.Futhermore,THP-1 monocytes overexpressing VEGFA markedly promoted HUVECs’ migration, proliferation, and VEGFR1 expression, resulting in a significant increase in angiogenic capacity. Macrophages and endothelial cells synergistically accelerate angiogenesis in corticotomy-accelerated OTM mediated by VEGFA-VEGFR1 signaling axis.