鼠趾钻孔再生模型中巨噬细胞对骨退化和再生作用研究

Terminal phalangeal bone (Phalange3, P3) of human finger and murine digit is capable of a regenerative response, The regeneration of digit amputation is a classic experimental model for human fingertip regeneration. Drilling hole in mice digit P3, results in a large amount of bone resorption and subsequent bone regrowth. Regeneration of hole drilling digit is a brand new mouse model of bone regeneration of human fingertip regeneration, which is operable and repeatable. In our previous study, the kinetic expression of macrophage mature marker F4/80 and type 2 macrophage factor CD206 closely involved bone degradation and regeneration process in drilling hole digit regeneration model. But the role of macrophages in hole drilling digit regeneration model is still unclear. M-CSF, a myeloid proliferation and differentiation factor, promotes bone marrow cell proliferation and migration, especially macrophages and osteoclasts. In the following project, we will establish mouse hole drilling digit model and which applied a single M-CSF binding bead to discover the M1/M2 polarization and factors related to drilling hole digit regeneration, and the effects of macrophages on blastema formation marker genes and cell proliferation. To further explore roles of macrophages in bone degradation and bone regrowth and remodeling associated with regeneration response in drilling hole digit model, we will validate effects of macrophage on osteoclast activity associated factor in bone degradation, and effects on osteoblast differentiation related molecules in bone regrowth by using mouse drilling hole digit, drilling hole digit applied M-CSF binding bead and drilling hole digit accompanied with macrophage depletion model. The results of this project would be a higher steps towards understanding the limitations of human regeneration ability and as well，for the developments of therapies of enhancing this amusing response in human finger injury.

人指和鼠趾的末节骨（Phalange3，P3)有一定的再生能力，鼠趾尖切除再生为人指再生的经典实验模型。我们发现在小鼠P3趾钻孔，可引发大量的骨吸收（退化）及骨再生，此模型是全新的动物模型。我们的前期工作表明，小鼠趾钻孔骨再生中巨噬细胞标记F4/80、M2型巨噬细胞CD206的表达与P3骨的退化和再生过程相关，但巨噬细胞在其中的作用还不清楚。 M-CSF可促进巨噬细胞、破骨细胞的迁移、增殖和存活，增强骨愈合。本研究利用鼠趾钻孔及埋入M-CSF微粒，研究巨噬细胞在鼠趾钻孔再生模型中M1/M2表型及相关转录因子的变化；研究巨噬细胞对芽基形成、细胞增殖和迁移的影响。为探明巨噬细胞对骨退化和骨再生的作用，本项目利用鼠趾钻孔、M-CSF处理钻孔鼠趾和去巨噬细胞钻孔鼠趾模型，研究巨噬细胞对破骨细胞激活相关因子的作用，以及对成骨细胞分化相关因子的作用。本研究对人指损伤后临床治疗有参考价值。

鼠趾钻孔模型是在鼠的趾甲上转孔，引发显著的骨退化，以及骨退化后骨再生的模型。该模型是美国A&M大学发现的，至今尚未公开。在研究中我们发现，鼠趾钻孔模型的骨退化程度与钻孔位置相关：近端钻孔不退化，远端钻孔退化。本项目完成了近端钻孔/远端钻孔模型中巨噬细胞的分布、巨噬细胞的极化，以及外援性巨噬细胞集落因子（macrophage colony stimulating factor, M-CSF）对骨退化的作用等内容。以上内容的论文草稿已完成，等待美国方面公开鼠趾钻孔模型的研究后再投稿。. 我们发现将细胞外基质（extracellular matrix，ECM）置于断离式切除鼠趾的残端，可使残端趾骨延长，实现鼠趾的骨性再生（但不能再生关节）。ECM中添加骨形态蛋白（bone morphogenetic protein，BMP）等成分，可提高再生组织量，实现过量的骨性再生（再生后的长度可大于切除前原趾的长度）。相关内容的专利申请处于审查答辩阶段。. 我们还在关节炎和皮肤炎模型中进行了中药提取物的药理作用研究(包括巨噬细胞极化和骨退化方面的内容)。以上内容发表论文2篇，其中第一/第二标注各一篇。