To investigate the changes in local iron ion levels following mandibular bone defects and evaluate the effect of desferrioxamine (DFO) on bone defect repair, as well as to preliminarily explore the underlying mechanism by which DFO promotes osteogenic differentiation.

A mouse mandibular bone defect model was established. Local iron deposition was evaluated by Prussian blue staining and tissue iron content assay. DFO was locally administered, and bone defect repair was assessed using Micro-CT. An iron overload microenvironment was established in vitro using ferric ammonium citrate (FAC). Cell viability was assessed by CCK-8 assay. Osteogenic differentiation was evaluated by real-time quantitative polymerase chain reaction (RT-qPCR), Western blotting, alkaline phosphatase (ALP) staining, and alizarin red S staining. The expression of hypoxia-inducible factor-1α (HIF-1α) and mitophagy-related molecules was detected by immunofluorescence staining, RT-qPCR, and Western blotting. Small interfering RNA (siRNA)-mediated HIF-1α knockdown and the mitophagy inhibitor 3-methyladenine (3-MA) were used to further investigate the underlying mechanism.

Increased local iron deposition and significantly elevated tissue iron content were observed following mandibular bone defects in mice. Local administration of DFO promoted new bone formation and improved bone microarchitectural parameters in the defect area. In vitro, the iron overload microenvironment suppressed the expression of osteogenesis-related genes and proteins, reduced ALP activity, and inhibited mineralized nodule formation, whereas DFO partially reversed these effects. Furthermore, DFO upregulated the expression of HIF-1α and mitophagy-related molecules. The promotive effect of DFO on osteogenic differentiation was markedly attenuated after HIF-1α knockdown or treatment with 3-MA.

Iron ion levels are elevated in the bone defect area. Iron overload impairs osteogenic differentiation, while DFO counteracts this inhibition via mitophagy-mediated enhancement of osteogenesis.

探究小鼠下颌骨骨缺损后局部铁离子水平的变化及铁离子螯合剂去铁胺（desferrioxamine，DFO）对骨缺损修复的影响，并初步阐明其促进成骨分化的分子机制。

建立小鼠下颌骨骨缺损模型，通过普鲁士蓝染色及组织铁含量检测评价骨缺损局部铁沉积情况；局部注射DFO，通过Micro-CT观察骨缺损修复情况。体外采用枸橼酸铁铵（ferric ammonium citrate，FAC）建立高铁微环境模型，CCK-8法检测细胞活力，实时定量聚合酶链反应（real-time quantitative polymerase chain reaction，RT-qPCR）、蛋白质印迹法、碱性磷酸酶（alkaline phosphatase，ALP）染色及茜素红S染色评价其成骨分化能力；采用免疫荧光染色、RT-qPCR及蛋白质印迹法检测低氧诱导因子-1α（hypoxia-inducible factor-1α，HIF-1α）及线粒体自噬相关分子表达，并结合HIF-1α小干扰RNA（small interfering RNA，siRNA）及线粒体自噬抑制剂3-甲基腺嘌呤（3-methyladenine，3-MA）进一步验证其作用机制。

小鼠下颌骨骨缺损后，局部铁沉积增加，组织铁含量明显升高。局部应用DFO可促进骨缺损区新骨形成，改善骨组织形态学参数。体外实验显示，高铁微环境抑制成骨相关基因和蛋白表达，降低ALP活性及矿化结节形成，而DFO可部分逆转上述变化。进一步的研究发现，DFO上调HIF-1α及线粒体自噬相关分子的表达；沉默HIF-1α或应用3-MA后，DFO促进成骨分化的作用明显减弱。

骨缺损区铁离子水平增高，铁离子水平增高可以抑制细胞成骨分化的能力，DFO可以通过线粒体自噬促进细胞成骨分化能力。