Related Experiment Video
Updated: Feb 21, 2026
Mesenchymal Stem Cell Regulation of Macrophage Phagocytosis; Quantitation and Imaging
Published on: July 16, 2021
M2 macrophage-derived migrasomes enhance bone regeneration by directing osteogenic differentiation of bone marrow
Mengci Wang1, Siyu Zhang2, Abudurexiti Kutibiding3
1Department of Histology and Embryology, School of Basic Medical Sciences, Xinjiang Medical University,(Xinjiang key Laboratory of Molecular Biology of Endemic Diseases) Xinjiang Uyghur Autonomous Region, 830000, China.
Objective:
While M2 macrophage-mediated immunoregulation is critical for bone regeneration, the role of migrasomes-a newly identified organelle-remains unexplored. This study aims to investigate the effect of M2 macrophage-derived migrasomes on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs).
Methods:
Macrophages were polarized to the M2 phenotype using IL-4. Migrasomes were subsequently isolated and characterized by electron microscopy and Western blotting (WB).In vivo, murine femoral fracture models treated with 100 μg/mL M2 macrophage-derived migrasomes were analyzed for fracture healing via X-ray, microcomputed tomography (microCT), and immunofluorescence.In vitro, bone marrow mesenchymal stem cells (BMSCs) were co-cultured with 60 ng/mL migrasomes. Cell migration was assessed by wound healing assay at 24 h; expression of RUNX2, ALP, OCN, and Bmp-2 was detected via quantitative real-time polymerase chain reaction (qRT-PCR) and WB at 72 h; osteogenic activity was evaluated by ALP and alizarin red S (ARS) staining at 14 and 21 days, respectively.
Results:
Increased Arg-1 and CD206 expression confirmed successful induction of M2 macrophages (P < 0.01, P < 0.0001). Transmission electron microscopy and Western blotting (WB) verified successful isolation and purification of M2 macrophage-derived migrasomes. X-ray and microcomputed tomography analyses demonstrated that migrasomes treatment significantly enhanced fracture healing. qRT-PCR showed migrasomes effectively upregulated mRNA levels of BMP-2, RUNX2, ALP, and OCN in BMSCs (P < 0.05, P < 0.01); WB revealed elevated protein levels of osteogenic markers (BMP-2, RUNX2, ALP) in the M2 migrasomes-treated group (P < 0.05).
Conclusion:
M2 macrophage-derived migrasomes promote fracture healing by inducing osteogenic differentiation of BMSCs.
