摘要： 【目的】 研究间断性低剂量应用重组人甲状旁腺素（1-34）[rhPTH (1-34) ]在骨折愈合的早期过程中与成骨基因Runx2表达的相关性。 【方法】 应用60只2月龄雄性Sprague-Dawley大鼠建立单侧闭合性股骨骨折内固定模型，随机分为甲状旁腺素治疗组和对照组，术后分别皮下注射重组人甲状旁腺素（1-34）10g/kg/d或等剂量安慰剂，分别于术后2天、4天、7天、14天和21天取双侧股骨标本，提取组织RNA和蛋白质，分别行实时荧光定量PCR和Western-blotting，以检测Runx2的mRNA表达和蛋白质水平。 【结果】 甲状旁腺素组较对照组，骨折端Runx2的mRNA表达水平于骨折术后第14、21天有明显升高（分别为2.6倍和3.8倍，P＜0.05），同时骨折端Runx2的蛋白质水平也于术后第14、21天时有明显增加。 【结论】间断性低剂量应用重组人甲状旁腺素（1-34）在骨折愈合的早期过程中，可上调成骨基因Runx2的mRNA表达和蛋白质水平，促进骨折的愈合。
Intermittent low-dose administration of recombinant human parathyroid hormone (1-34) promotes the expression of Runx2 during early stage of fracture healing
LI Ning, WANG Man-yi, HE Liang*
Abstract: [Objective] Aim to study the correlation of intermittent low-dose administration of recombinant human parathyroid hormone (1-34) [rhPTH (1-34) ] and the expression of Runx2 during early stage of fracture healing. [Method] 60 2-month old male Sprague-Dawley rats were used. Close unilateral femoral fractures were generated, and intramedullary nail fixtions were performed. They were randomly divided into treatment group and control group. Recombinant human parathyroid hormone (1-34) 10g/kg/d or same dose vehicle was injected subcutaneously immediately after the operation. Bilateral femoral specimens were collected on day 2, 4, 7, 14, 21. Tissue RNA and protein were extracted. And the levels of Runx2 mRNA expression and protein were evaluated through real time quantitative PCR and Western-blotting. [Result] Compared with control group, the expression levels of Runx2 mRNA of fractured fumers in rhPTH(1-34) group increased significantly on day 14 and day 21 after the operation (2.6 folds and 3.8 folds respectively, P<0.05).The levels of proteins also increased significantly on day 14 and day 21 after the operation. [Conclusion] Intermittent low-dose administration of recombinant human parathyroid hormone (1-34) could up-regulate the levels of osteogenesis-specific Runx2 mRNA expression and protein to accelerate the fracture healing during early stage of fracture healing.
Key words: Parathyroid hormones; Fracture healing; Osteoblasts; Gene expression
Authors′unit: Department of Traumatology and Orthopaedics, The Fourth Hospital of Peking University (Beijing Jishuitan Hospital), Beijing, 100035, China
*Corresponding author: HE Liang