低强度脉冲超声对牙本质损伤修复过程中TGF-β1/Smads表达的作用  

Effect of low intensity pulsed ultrasound on expression of TGF-β1 and Smads during dentin injury and repair

作　　者：王飞[1] 左静 李月恒[1] 杨正艳[1] 罗俊[1] WANG Fei ZUO Jing LI Yueheng YANG Zhengyan LUO Jun(Department of Preventive Dentisity, College of Stomatology, Chongqing Medical University, Chongqing Key Laboratory for Oral Diseases and Biomedical Science, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing 401147, China)

机构地区：[1]重庆医科大学附属口腔医学院预防科口腔疾病与生物医学重庆市重点实验室重庆市高校市级口腔生物医学工程重点实验室,重庆401147

出　　处：《中南大学学报（医学版）》2017年第9期1030-1036,共7页Journal of Central South University ：Medical Science

基　　金：重庆市卫生局重点科研项目(2013-1-032);重庆高校创新团队建设计划(CXTDG201602006);重庆市科委基础与前沿研究计划(cstc2016jcyj A0202)~~

摘　　要：目的:观察低强度脉冲超声(low intensity pulsed ultrasound,LIPUS)对牙本质牙髓复合体损伤修复模型中TGF-β1/Smads信号通路的影响。方法:25只Sprague-Dawley大鼠随机选择5只大鼠作为空白对照组,不予任何处理。剩余20只于双侧上颌第一磨牙采用改良备洞法备洞,建立牙本质牙髓损伤修复模型,右侧为LIPUS组,予以LIPUS辐照(强度为30 m W/cm2,频率为1.5 MHz,调制信号波宽为200μs,重复率为1 k Hz,20 min/d);左侧为备洞组,予以超声假照处理。分别在辐照1,3,5,7,14 d后处死大鼠,运用免疫组织化学法及图像分析技术检测TGF-β1,Smad 2和3在牙髓组织中的动态表达和定位情况。结果:TGF-β1,Smad 2,3蛋白在正常牙髓组织中均呈弱阳性表达,而在牙本质损伤后出现不同程度的表达增加。备洞组TGF-β1蛋白表达在1 d时增加,在5 d时TGF-β1表达最强,在14 d时表达减弱接近正常水平;与备洞组相比,LIPUS组在3和5 d时表达明显升高(均P<0.05)。Smad 2,3在LIPUS组及备洞组牙髓中表达均呈现逐步升高的基本变化,其中LIPUS组升高更明显(P<0.05)。结论:TGF-β1/Smad 2,3信号通路可能参与了牙本质损伤的修复过程,LIPUS在牙本质损伤修复早期可上调TGF-β1,Smad 2,3的表达,可能参与并促进了牙本质牙髓复合体的损伤修复过程。Objective： To explore the effect of low intensity pulsed ultrasound （LIPUS） on TGF-β1/Smad 2,3 signal pathway during the dentin injury and repair. Methods： Among 25 Sprague-Dawley rats, 5 rats served as a blank control group without treatment. The remaining 20 rats received modified caries preparation inbilateral maxillary first molars to establish a model of dentin-pulp injury and repair. The right maxillary first molars served as a LIPUS groupj which received LIPUS irradiation （frequency： 1.5 MHz, pulse width： 200 μs, pulse repetition frequency： 1 kHz, spatial averaged temporal averaged intensity： 30 mW/cm2, 20 min/d）, and the left maxillary first molars served as a cavity-prepared group, which received fake LIPUS irradiation. The rats were sacrificed at 1, 3, 5, 7 and 14 days after LIPUS irradiation. Immunohistochemical staining and Image-pro plus 6.0 were applied to detect the expression and distribution of transforming growth factor-beta1 （TGF-β1） and small mothers against decapentaplegic 2/3（Smad 2 and Smad 3）. Results： Immunohistochemical staining showed that the expression of TGF-β1 and Smad 2, 3 were low innormal pulp, but they were increased in different degree after dentin injury. The result of image analysis showed that the expression of TGF-β1 in the cavity-prepared group gradually increased at the first day and peaked at day 5, and then it returned to normal level at day 14. However, the expression of TGF-β1 in the LIPUS group were significantly higher than that in the cavity-prepared group at day 3 and 5 （both P〈0.05）. The expressions of Smad 2,3 in both the LIPUS group and the cavity-prepared group were consistently increased all the way, but the expressions in the LIPUS group were higher compared with that in the cavity-prepared group （P〈0.05）. Conclusion： The TGF-β1/Smad 2, 3 signal pathway can be activated during the dentin injury and repair. LIPUS can up-regulate the expression of TGF-β1 and Smad 2, 3 in the early period, which may take part

关 键 词：低强度脉冲超声 牙本质牙髓复合体 转化生长因子 SMAD 2 SMAD 3 

分 类 号：R781.2[医药卫生—口腔医学]