[摘要] 目的：探讨大鼠颅骨缝成骨细胞在张应力作用下Ets1和Cbfa1基因表达的变化，以揭示骨缝牵张成骨的分子机制。方法：分离培养新生大鼠颅缝成骨样细胞，应用四点弯曲细胞加力装置对其施加单一周期的机械张力，并通过SYBR Green实时定量RT-PCR技术，对Ets1和Cbfa1的基因表达进行检测。结果：Ets1和Cbfa1的mRNA水平分别在机械张应力作用后6 h及12 h内显著增高，随后，mRNA水平逐渐恢复到对照组水平，Ets1先于Cbfa1表达，在加力后表达立即升高，并在0.5h达到最高水平，而Cbfa1则首先经历一个短暂的潜伏期，后表达逐渐升高，在6 h达到最高水平，Cbfa1的最高表达水平约为Ets1的2.58倍。结论：Ets1和Cbfa1在骨缝牵张中对成骨细胞合成分泌骨基质蛋白可能起着不同的调节作用，而它们的功能具有时序性。高频率的牵张 (>2次/24 h)更有利于Ets1和Cbfa1的最佳表达。

    [关键词] 骨缝牵张 成骨细胞 Ets1 Cbfa1 实时定量RT-PCR

    Expression Patterns of Ets1 and Cbfa1 in Rat Calvarial Sutural Osteoblast-like Cells after a Single Period of Mechanical Strain.

    ZOU Shu-juan, QI Meng-chun, HU Jing, et al.

    West China School of Stomatology, Sichuan University, Chengdu 610041

    [Abstract]Objective: Effects of a single period of mechanical strain on gene expression patterns of two osteogenic transcription factors, Ets1 and Cbfa1, in rat calvarial sutural osteoblast-like cells were studied in this study to elucidate the molecular mechanism of suture distraction. Methods: The cells were isolated and cultured in vitro, and subjected to a single 40 minutes mechanical strain using a four-point bending apparatus. The gene expression patterns of Ets1and Cbfa1 were examined by SYBR Green real-time RT-PCR. Results: Both mRNA levels of Ets1 and Cbfa1 increased significantly within 6 and 12 hours respectively after mechanical strain, and the increase returned to control level thereafter. However, Ets1and Cbfa1 exhibited different temporal expression patterns: Ets1 expressed immediately after the mechanical loading and reached the maximum transcription at 0.5h; whereas Cbfa1 experienced a latency period first, then increased slowly within 2 hours, and reached the maximum transcription at 6h. The maximum transcription of Cbfa1 was about 2.58 fold of that of Ets1. Conclusion: Ets1and Cbfa1 may play different roles in regulating bone matrix protein expressions in osteoblast-like cells during suture distraction and their function is time-dependent. High frequency distraction (>2times/24h) is favorable to the maximal expression of two genes. ......