高龄小鼠沉默信息调节因子1基因敲除后膝骨关节炎模型的建立

Construction of elderly SIRT1 gene knockout mouse models of knee osteoarthritis

背景:国内外学者对骨关节炎的发病机制和治疗方法进行了大量的研究,近期发现沉默信息调节因子1(SIRT1)基因在骨关节炎的发病中有着重要的意义,但对其研究尚少,用于该基因研究的骨关节炎模型也鲜有报道。目的:建立特异性的高龄SIRT1基因敲除小鼠膝骨关节炎模型,以期为骨关节炎的研究提供便利条件。方法:采用随机对照分组的方法,将小鼠分为4组,即SIRT1^(+/+)小鼠假手术组(A组)、SIRT1^(+/+)小鼠骨关节炎模型组(B组)、SIRT1^(-/-)小鼠假手术组(C组)及SIRT1^(-/-)小鼠骨关节炎模型组(D组),每组6只。行单侧膝关节前交叉韧带横断加内侧半月板切除建立骨关节炎模型,荧光定量聚合酶链反应检测SIRT1基因敲除情况;苏木精-伊红染色、番红O-固绿双染色观察膝关节软骨形态结构改变,Mankin评分评价膝骨关节炎程度。结果与结论:SIRT1^(-/-)小鼠SIRT1 mRNA表达量明显低于SIRT1^(+/+)小鼠(P<0.01),说明SIRT1基因敲除成功。染色结果显示,B、D两组膝关节软骨破坏明显,Mankin评分明显高于A、C两组(P<0.01),并且SIRT1基因敲除后Mankin评分升高更明显(P<0.05)。提示软骨组织特异性SIRT1基因敲除膝骨关节炎小鼠动物模型建立成功。

BACKGROUND： Scholars in China and countries outside China conducted a lot of researches on the pathogenesis and treatment of osteoarthritis, and recently found that SIRT1 gene has an important significance in the pathogenesis of osteoarthritis. However, little is reported on SIRT1 gene, and there are few studies on animal models of knee osteoarthritis used for SIRT1 research.OBJECTIVE： To establish specific SIRT1 gene knockout mouse models of knee osteoarthritis, in order to provide favorable conditions for the study of osteoarthritis. METHODS： Mice were randomly divided into four groups according to the method of randomized controlled grouping： SIRT1^＋/＋ control group（Group A, n=6）; SIRT1^＋/＋ osteoarthritis model group（Group B, n=6）; SIRT1^-/-control group（Group C, n=6）; SIRT1^-/- osteoarthritis model group（Group D, n=6）. Unilateral knee anterior cruciate ligament transection and medial meniscectomy were conducted to establish mouse models of osteoarthritis. SIRT1 gene knockout was determined by quantitative fluorescence polymerase chain reaction. Knee cartilage morphological changes were observed by hematoxylin-eosin and safranin O-fast green double staining. The degree of knee osteoarthritis was evaluated by Mankin score.RESULTS AND CONCLUSION： The expression of SIRT1 mRNA in SIRT1^-/- mice was significantly lower than that in SIRT1^＋/＋ mice（P〈 0.01）, which indicated that SIRT1 gene knockout was successful. Hematoxylin-eosin staining and safranin O-fast green staining showed that the cartilage damage of the knee joint in Group B and Group D was obvious. Mankin scores in the Group B and Group D were significantly higher than those in the Group A and Group C（P〈0.01）. The Mankin scores were increased more obviously after SIRT1 gene knockout（P 〈0.05）. These results suggest that cartilage tissue-specific SIRT1 knockout mouse models of knee osteoarthritis were successfully established.