激素性股骨头坏死股骨头内Runx2、Osterix及AJ18的动态表达  

Dynamic expression of Runx2, Osterix and A J18 in the femoral head of steroid-induced osteonecrosis in rats

作　　者：马信龙[1,2] 刘泽朋[2] 马剑雄[2] 张华峰[2] 张园[2] 王志钢[2] 王涛[2] 杨阳[2] 

机构地区：[1]天津医院,300211 [2]天津医科大学总医院骨科

出　　处：《中华骨科杂志》2010年第1期67-72,共6页Chinese Journal of Orthopaedics

基　　金：天津市自然科学基金（043111411和993607711）;天津市卫生局科研基金（05KYZ69）

摘　　要：目的研究股骨头坏死股骨头内Runx2（runt-related transcription factor-2）、Osterix及AJ18基因表达和蛋白合成的动态变化。方法Wistar成年大鼠共40只，采用完全随机的方法分为正常对照组10只，模型组30只。模型组动物，按20mg／kg体重剂量交替经大鼠双侧臀大肌肌内注射地塞米松，每周一次；注射地塞米松后放在实验动物跑台上每周训练两次，共8周，诱导大鼠激素性股骨头坏死动物模型。HE染色确定模型诱导成功后，分为模型8、10和12周组，每组10只，按时段提取大鼠股骨头内总RNA及总蛋白，行实时荧光定量PCR及Westernblot检测，研究股骨头内Runx2、Osterix及AJ18基因表达、蛋白合成的动态变化。结果造模8、10、12周时，模型组大鼠股骨头内Runx2和Osterix的基因表达、蛋白合成较对照组减少，两者mRNA的表达量分别为正常组的0．9621、0．3259、0．0512和0．9661、0．2026、0．0194，随时间推移两者的基因表达、蛋白合成呈下降趋势。模型组大鼠股骨头内AJ18的基因表达、蛋白合成较对照组增多，AJ18mRNA的表达在造模后8、10、12周分别为正常组的3．5487、3．6303、3．7576。结论在激素性股骨头坏死发病过程中，糖皮质激素可能通过下调Runx2、OsterixmRNA和上调AJ18mRNA来抑制成骨细胞活性，促进骨吸收，导致骨质疏松和股骨头坏死。Objective To study the dynamic changes of gene expression and protein synthesis of runt-related transcription factor-2 （Runx2）, Osterix and A J18 in the femoral head in rats with steroid-induced osteonecrosis. Methods Forty mature Wistar rats were randomly divided into model group （30 rats） and control group （10 rats）. Early rat model of femoral head necrosis was made with alternate injection of dexam- ethasone （20 mg/kg） bilateral gluteus maximus once a week and twice-weekly training on laboratory animal treadmill after 8 weeks. The establishment of the model was determined by HE staining. The rats in model group were divided into 8 weeks, 10 weeks and 12 weeks groups, each group including 10 animals. Total RNA and total protein were extracted from the femoral head. Real-time quantitative polymerase chain reac- tion （PCR）, and Western blot were performed to detect the dynamic changes of the Runx2, Osterix and A J18. Results At the 8th, lOth and 12th week, the, proteins synthesis of the Runx2 and Osterix genes in model group reduced obviously. The volume of mRNA of Runx2 and Osterix were respectively equivalent to 0.9621, 0.3259, 0.0512 and 0.9661, 0.2026, 0.0194 times of those in control group. Transcription and expressions of Runx2 and Osterix had a downward trend with the passage of time. The expression of the AJ18 in model group was extremely higher than those in control group at 8th, lOth and 12th week. The volume of mRNA expression were 3.5487, 3.6303, 3.7576 times of those in control group. Conclusion These observations indicate that glueocortieoids down-regulated mRNA and protein expressions of Runx2, Osterix and up-regu- lated AJ18. In this way, glucocorticoids may inhibit the activity of osteoblast and promdte bone resorption, leading to osteoporosis and femoral head necrosis.

关 键 词：股骨头坏死 转录因子 糖皮质激素类 

分 类 号：R681.8[医药卫生—骨科学] R681[医药卫生—外科学]