骨桥蛋白在大鼠颅骨缝牵张成骨中表达变化的研究

Temporospatial Expression of Osteopontin during the Distraction Process of Cranial Sagittal Suture of rats in Vitro

目的:研究大鼠颅骨矢状缝体外牵张过程骨桥蛋白的时空表达变化,探索力刺激—整合素—骨桥蛋白合成之间的信号转导机制。方法:利用大鼠颅骨矢状缝体外牵张模型,通过免疫组织化学方法半定量分析不同受力时间点骨桥蛋白的时空表达变化,并在部分培养基中加入精氨酸-甘氨酸-天门冬氨酸-丝氨酸肽(RGDS),观察该整合素受体阻断剂对骨桥蛋白表达的影响。结果:颅骨缝受到张应力后骨桥蛋白表达明显高于对照组,呈现一定的时间分布规律。整合素受体阻断剂对加力的OPN上调效果有拮抗作用。结论:骨桥蛋白可能参与调控缝牵张成骨过程,整合素可能是力刺激-蛋白合成信号通路中的关键点。

Objective： To observe the temporospatial expression pattern of osteopontin involved in sutural distraction osteogenesis and the signal transduction process.Methods： The parietal bones with the midsagittal suture were removed from 14-day-old Sprague-Dawley rats,and divided into four groups.In the experimental groups,tensile force（0.3 g） was applied by helical springs to the midsagittal suture,whereas helical springs with no tension（0 g） were set in the control groups.After cultured for different time（1 h,6 h ,3 d ,7 d, 10 d, 14 d）, the immunohistochemical staining was committed to detect the temporospatial expression pattern of osteopontin. With parts of media contain Arg - Gly - Asp - Ser peptide, a block agent to integrin receptors, semiquantitative analysis was committed to detect the influence of Arg - Gly - Asp - Set peptide to osteopontin induction. Results ： The tensile force significantly increased the expression of osteopontin expression. It started to increase at day 3 , peaked at day 7, then decreased slowly, compared with the control. The osteopontin induction during suture distraction can be inhibited with addition of Arg - Gly - Asp - Ser peptide. Conclusion： Mechanical stress upregulates osteopontin expression in distracted sutures with some temporospatial pattern. Occupancy of integrin receptor clustering may be a prerequisite to the signal transduction process that leads to the induction of osteopontin expres-