电针刺激足三里在金黄葡萄球菌小鼠骨髓炎模型中的作用研究

The effect of electroacupuncture stimulation at acupoint Zusanli on the model of Staphylococcus aureus osteomyelitis

目的探究电针刺激(ES)足三里(ST36)在金黄葡萄球菌(SA)小鼠骨髓炎模型中能否抑制SA感染所致的骨量丢失并探究其机制。方法将12只10~12周龄雄性C57BL/6小鼠随机均分为2组(n=6):SA+ES组和SA组。在进行骨髓炎造模并行ES 4周后于股骨及胫骨取材。行Micro-CT重建以检测骨小梁体积分数(BV/TV)、骨小梁数量(Tb.N)、骨小梁厚度(Tb.Th)、骨小梁间距(Tb.Sp)、连接密度(Conn.Dn)等参数用于分析骨量变化;行瘦素受体(LEPR)免疫荧光染色以检测成骨细胞;行抗酒石酸磷酸酶(TRAP)染色用于检测破骨细胞变化;并通过酶联免疫吸附实验(ELISA)检测血浆炎症因子变化情况。结果Micro-CT结果显示:SA+ES组较SA组目标区域松质骨的BV/TV、Tb.N、Tb.Th、Conn.Dn均升高,LEPR免疫荧光结果提示:SA+ES组较SA组的成骨前体细胞增多,血清ELISA提示:SA+ES组血液中炎症因子较SA组减少,以上项目两组间比较差异均有统计学意义(P<0.05)。TRAP染色中两组骨小梁表面破骨细胞数量差异无统计学意义(P>0.05)。结论ES可通过抑制SA感染诱发的炎症反应及诱导间充质干细胞向骨小梁的聚集和分化来减缓感染性骨质破坏。

Objective To explore whether the electroacupunture stimulation(ES)at acupoint Zusanli(ST36)can inhibit the bone loss caused by Staphylococcus aureus(SA)infection and its mechanism in a model of SA osteomyelitis.Methods Twelve male C57 BL/6 mice aged 10 to 12 weeks were randomly divided into 2 even groups(n=6)for SA infection+ES or SA infection only.After ES at ST36 was conducted for 4 weeks in the model of SA osteomyelitis,samples were harvested from the femora and tibiae.Micro-CT reconstruction was performed to detect trabecular bone volume fraction(BV/TV),trabecular number(Tb.N),trabecular thickness(Tb.Th),trabecular separation(Tb.Sp),connectivity density(Conn.Dn)to analyze changes in bone mass.Leptin receptor(LEPR)staining was performed to detect osteoblasts.Tartrate resistant acid phosphatase(TRAP)staining was used to detect the changes in osteoclasts.The changes in plasma inflammatory factors were detected by enzyme-linked immunosorbent assay(ELISA).Results Micro-CT results showed that the BV/TV,Tb.N,Tb.Th,and Conn.Dn in the cancellous bone in the target areas in the SA+ES group were all higher than those in the SA group,LEPR immunofluorescence results indicated that the number of osteogenic precursor cells in the ES group was larger than that in the SA group,and serum ELISA indicated a decrease in inflammatory factors in the blood in the SA+ES group compared with the SA group.There were significant differences in the comparisons above(P<0.05).There was no significant difference in the number of osteoclasts on the surface of trabecular bone between the 2 groups in TRAP staining.Conclusion ES may slow down infectious bone destruction by inhibiting the inflammatory response induced by SA infection and by inducing aggregation and differentiation of mesenchymal stem cells into trabecular bone.