BALB/c小鼠胶原诱导关节炎模型的建立方法及特征分析

Establishment and characteristics analysis of the arthritis model induced by collagen in BALB/c mice

目的:建立BALB/c小鼠胶原诱导关节炎CIA(Collagen-induced Arthritis)模型及主要特征评价方法。方法 :鸡Ⅱ型胶原溶于0.1 M冰醋酸中,使其终浓度2 mg/ml,4度过夜,次日,取鸡Ⅱ型胶原与等体积完全弗氏佐剂充分乳化,将乳化后浓度为1mg/mlⅡ型胶原50μl注射于BLAB/c鼠足跖皮内进行初次免疫。第15天,在相同部位将1mg/mlⅡ型胶原25μl进行再次免疫。采用临床症状评分评价小鼠关节肿胀外观,测量小鼠肿胀厚度和小鼠体重并计算脾脏指数。对踝关节进行病理切片,采用HE染色观察滑膜增生,炎性细胞浸润及血管翳形成情况,甲苯胺蓝染色观察软骨损伤状况并评分,TRAP染色观察破骨细胞对骨侵蚀的影响。免疫组化法检测踝关节CD68蛋白的表达并计算平均光密度。结果:初次免疫第3天关节出现轻微肿胀,第18天肿胀最为明显,模型组小鼠体重下降,脾脏指数增加。病理学结果显示:模型组出现滑膜增生,炎性细胞浸润,血管翳形成,软骨损伤等一系列典型RA特征,模型组CD68高表达。结论:采用BALB/c小鼠在其足趾皮内注射鸡II型胶原可成功建立CIA模型,重现性好,周期短。病理学分析和临床症状评分评价了该模型具有典型的RA特征。

Objective： To establish CIA（ Collagen-induced arthritis） model in BALB/c mice and evaluate its main characteristics. Chicken typeⅡcollagen was dissolved in the 0. 1 M glacial acetic acid at a concentration 2 mg/ml,4℃ overnight. The solution was emulsified with equal volume complete freund＇s adjuvant. For the primary immune,50 μl of chicken type Ⅱcollagen was injected into the subplantar of BLAB/c mice＇s both hind paws. On day 15,a booster injection of 25μl chicken type Ⅱ collagen（ 1 mg/ml） was given in the same place. Clinical symptom score was evaluated,and the degree of paw swelling,body and spleen weights were measured. The ankle slice was examined by HE staining to observe synovial hyperplasia,inflammatory cell infiltration and pannus formation. Toluidine blue and TRAP staining were conducted to observe the cartilage injury and osteoclast erosion respectively. Immunohistochemical staining was used to detect the ankle CD68 protein expression. Results： On the third day after the primary immune,mice paws showed a slight swelling in joints,obvious swelling appeared on day 18（ P〈0. 01）,Weight loss and spleen index in model group increased. Pathological results showed that synovial hyperplasia,inflammatory cell infiltration,pannus formation and cartilage injury occurred in the model group. Higher CD68 expression was found in the model group. Conclusion： CIA model can be successfully established by intradermal injection of chicken type II collagen into the paw of BALB/c mice. This model has the good reproducibility and is short-term. Pathological analysis including clinical symptom scores and evaluation of the model proved the typical characteristics of RA.