^(99)Tc-MDP抑制胶原诱导性关节炎大鼠DKK1表达的研究

Expression of DKK1 in collagen-induced arthritis rats and the intervention of ^(99)Tc-MDP

目的:观察胶原诱导性关节炎(CIA)大鼠DKK1的表达及99锝-亚甲基二磷酸盐(99Tc-MDP,商品名:云克)对骨侵蚀的治疗作用,探讨云克治疗骨侵蚀的可能作用机制。方法:建立CIA大鼠模型,分为模型组、甲氨蝶呤(MTX)组、云克小剂量组、云克大剂量组;通过Larsen评分和病理组织形态学评分评价骨质破坏;ELISA法检测关节液和血清DKK1、肿瘤坏死因子(TNF)-α水平;免疫组化法检测踝关节区滑膜及软骨的DKK1、TNF-α表达;采用方差分析、t检验和相关分析进行统计学处理。结果:云克干预组和MTX组大鼠骨质破坏,血清和关节液DKK1、TNF-α水平,踝关节区滑膜及软骨DKK1、TNF-α表达均低于模型组(P<0.05);云克干预组骨质破坏、血清和关节液DKK1水平、踝关节区滑膜及软骨DKK1表达低于MTX组(P<0.05),但云克组间差异无统计学意义(P>0.05);云克干预组和MTX组血清和关节液TNF-α水平、踝关节区滑膜及软骨TNF-α表达组间差异无统计学意义(P>0.05);相关性分析显示模型组及药物干预组大鼠血清和关节液DKK1与TNF-α水平呈正相关(r=0.439,P<0.05)。结论:云克可以减轻CIA大鼠骨侵蚀,疗效优于MTX,可能是通过直接降低DKK1或通过抑制TNF-α间接下调DKK1,增强Wnt信号通路保护骨侵蚀。

Objective： To observe the expression of dickkopf-1（ DKKl） and the effects of99Tc-MDP on bone erosion in collagen-induced arthritis（ CIA） rats,and to explore the possible treatment mechanism of99Tc-MDP.Methods： The CIA models were established by subcutaneous injection with typeⅡ collagen and complete Freud＇s adjuvant to rats. CIA rats were randomly divided into 4 groups： model group,methotrexate（ MTX） group,low dose 99Tc-MDP group,and high dose99Tc- MDP group. Destruction of bone were assessed by Larsen score and histopathological score. The synovial fluid and serum levels of DKK1 and TNF-α were tested by ELISA. The synovium and cartilage of ankle joints expressions of DKK1 and TNF-α were tested by immunohistochemistry. T test,analysis of variance,and correlation analysis were used for statistic analysis. Results： Compared with model group,destruction of bone,synovial fluid and serum levels of DKK1 and TNF-α,and synovium and cartilage of ankle joints expressions of DKK1 and TNF-α in drugs intervention groups were significantly decreased（ P〉0. 05）.Destruction of bone,synovial fluid and serum levels of DKK1, and synovium and cartilage of ankle joints expressions of DKK1 in99Tc-MDP intervention groups were notably lower than those in MTX group（ P〈0. 05）,and the indexes in both99Tc-MDP groups illustrated no significant difference（ P〉0. 05）. Moreover,synovial fluid and serum levels of TNF-α,and synovium and cartilage of ankle joints expressions of TNF-α in MTX group and both99Tc-MDP groups demonstrated no significant differences（ P〉0. 05）. Correlation analysis showed that synovial fluid and serum levels of DKK1 and TNF-α in model and drugs intervention groups were positively correlated（ r =0. 439,P〈0. 05）. Conclusion：99Tc-MDP can reduce bone erosion of CIA rats,and the therapeutic effect is better than MTX,probably by reducing the DKK1 directly or inhibiting DKK1 to lower down TNF-α indirectly,thereby enhancing the wnt signaling pathway to protect bone erosion.