Endothelial Progenitor Cells Enhance the Migration and Osteoclastic Differentiation of Bone Marrow-Derived Macrophages in vitro and in a Mouse Femur Fracture Model through Talin-1
Endothelial Progenitor Cells Enhance the Migration and Osteoclastic Differentiation of Bone Marrow-Derived Macrophages in vitro and in a Mouse Femur Fracture Model through Talin-1
复制标题
内皮祖细胞通过 Talin-1 在体外和小鼠股骨骨折模型中增强骨髓源性巨噬细胞的迁移和破骨细胞分化
DOI：
10.1159/000492993
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发表时间：
2018-01-01
影响因子：
--
通讯作者：
Wu, Xuehui
中科院分区：
文献类型：
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作者：
Cui, Yigong;Fu, Shenglong;Wu, Xuehui
背景/目的：破骨细胞介导的骨吸收在骨愈合中起重要作用。内皮祖细胞（EPCs）通过刺激新生血管和成骨促进骨修复。然而，EPCs在破骨细胞形成和功能中的作用尚未明确。本研究旨在阐明EPCs在破骨细胞形成和功能中的作用机制。方法：在体外共培养系统中，研究EPCs对小鼠原代骨髓源性巨噬细胞（BMMs）增殖、迁移和破骨分化的影响。我们还在小鼠骨折模型中评估了EPC共移植对移植bmm归巢和破骨分化的影响。采用免疫荧光、免疫组织化学、western blot、Rt-PCR、细胞共培养、Transwell等技术。结果：EPCs在EPCs - bmm共培养培养基中分泌TGF-β1， Talin-1在共培养的bmm中表达增加。TGF-β1中和抗体或Talin-1沉默治疗BMM完全抑制BMM在共培养系统中的破骨细胞分化。这些结果表明EPCs的破骨作用是通过TGF-β1介导的Talin-1在BMMs中的表达介导的。在股骨骨折模型中，与单独移植相比，骨髓基质与EPCs共移植在骨折部位的植入和破骨细胞分化增强。EPC-BMM联合移植小鼠骨折部位新生血管增加，骨折愈合速度加快。结论：EPCs通过增强破骨细胞前体的募集和分化来促进骨修复。
Background/Aims: Bone resorption mediated by osteoclasts plays an important role in bone healing. Endothelial progenitor cells (EPCs) promote bone repair by stimulating neovascularization and osteogenesis. However, the role of EPCs in osteoclast formation and function is not well defined. The aim of this study was to elucidate mechanisms of EPCs in osteoclast formation and function. Methods: In this study, we examined the effects of EPCs on the proliferation, migration and osteoclastic differentiation of primary mouse bone marrow-derived macrophages (BMMs) in a co-culture system in vitro. We also evaluated the effects of EPC co-transplantation on the homing and osteoclastic differentiation of transplanted BMMs in a mouse bone fracture model in vivo. The technology of immunofluorescence, immunohistochemical, western blot, Rt-PCR, cell co-culture and Transwell were used in this study. Results: EPCs secreted TGF-β1 in the EPC-BMM co-culture medium and increased Talin-1 expression in the co-cultured BMMs. Treatment with a TGF-β1 neutralizing antibody or Talin-1 silencing in BMMs completely inhibited BMM osteoclastic differentiation in the co-culture system. These results indicated that the osteoclastogenic effects of EPCs were mediated by TGF-β1-mediated Talin-1 expression in BMMs. In the femur fracture model, BMMs co-transplanted with EPCs exhibited enhanced engraftment into the fracture site and osteoclastic differentiation compared with those transplanted alone. Mice treated with EPC-BMM co-transplantation exhibited increased neovascularization at the fracture site and accelerated fracture healing compared with those treated with BMMs alone. Conclusion: Taken together, the results suggest that EPCs can promote bone repair by enhancing recruitment and differentiation of osteoclast precursors.