模拟失重条件下小鼠骨组织尿卟啉原Ⅲ合酶通过增加破骨细胞活性促进骨量流失  

Uroporphyrinogen Ⅲ synthase promotes bone loss by increasing osteoclast activity in mouse bone tissue under weightlessness

作　　者：佟凡 刘明秋 丁祎 吴正升[1] 崔春萍 TONG Fan;LIU Mingqiu;DING Yi;WU Zhengsheng;CUI Chunping(School of Basic Medicine,Anhui Medical University,Hefei 230032,China;State Key Laboratory of Proteomics,Institute of Lifeomics,Academy of Military Medical Sciences,Academy of Military Sciences,Beijing 100850,China)

机构地区：[1]安徽医科大学基础医学院,合肥230032 [2]军事科学院军事医学研究院生命组学研究所,蛋白质组学国家重点实验室,北京100850

出　　处：《军事医学》2024年第3期166-171,共6页Military Medical Sciences

基　　金：国家自然科学基金重大项目(82192881)。

摘　　要：目的 探究尿卟啉原Ⅲ合酶(UROS)对失重性骨丢失的影响。方法 将8只C57BL/6J雄性小鼠(9周龄)分为对照组和尾吊组(HLU),每组4只。小鼠尾吊28 d后,取小鼠后肢分别进行Micro CT和力学实验检测。利用旋转式细胞培养系统(RCCS)建立失重的破骨细胞模型,通过实时定量PCR(qPCR)和抗酒石酸酸性磷酸酶(TRAP)染色明确失重导致破骨细胞活性的变化,qPCR和Western印迹检测UROS表达水平变化;构建UROS敲除RAW264.7稳定株,通过qPCR和TRAP染色进一步明确UROS缺失后破骨细胞活性的变化。结果 小鼠尾吊后骨组织骨量流失明显,UROS的蛋白表达水平显著上调;破骨细胞失重处理后,UROS的蛋白表达水平上调,并且破骨分化基质金属蛋白酶9、抗酒石酸酸性磷酸酶等表达水平上调。敲低UROS后,破骨细胞分化相关标志物表达水平显著下调。结论 失重应激条件下,破骨细胞中UROS表达水平上调,进而导致破骨细胞活性增强,骨吸收大于骨形成,从而导致骨量流失。Objective To investigate the impact of uroporphyrinogenⅢsynthase(UROS)on bone loss induced by weightlessness.Methods Eight male C57BL/6J mice aged 9 weeks were randomly assigned to a control group and a tail suspension group,with four mice in each.Following a 28-day period of tail suspension,the hind limbs of the mice underwent micro-CT and mechanical testing,respectively.A microgravity osteoclast model was established using the cell cyclotron device(RCCS).Changes in osteoclast differentiation activity induced by microgravity were assessed via real-time quantitative PCR(qPCR)and tartrate-resistant acid phosphatase(TRAP)staining.Additionally,alterations in UROS expression levels were detected using qPCR and Western blotting analysis.The protein expression of UROS was also determined via Western blotting.A UROS knockout RAW264.7 stable strain was generated.qPCR and TRAP staining were employed to confirm the downregulation of osteoclast differentiation activity upon UROS deficiency.Results After hindlimb unloading in mice,a marked decrease in bone mass was observed in the bone tissue,which was accompanied by a pronounced upregulation of UROS protein expression.Upon exposure to microgravity,osteoclasts exhibited an upregulation of UROS protein expression,along with increased levels of osteoclast differentiation markers including matrix metalloproteinase 9(MMP-9)and tartrate-resistant acid phosphatase(TRAP).Knockdown of UROS significantly downregulated the expression levels of osteoclast differentiation-related markers,indicating its crucial role in osteoclast differentiation and bone metabolism.Conclusion Under weightlessness stress,the expression level of UROS in osteoclasts is upregulated,leading to enhanced osteoclast activity and an imbalance between bone resorption and bone formation,with bone resorption exceeding bone formation,which ultimately results in bone loss.

关 键 词：尿卟啉原Ⅲ合酶 小鼠 失重 破骨细胞 骨丢失 

分 类 号：Q5[生物学—生物化学]