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.
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2017 Sep 28;42(9):1030-1036. doi: 10.11817/j.issn.1672-7347.2017.09.006.
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 group, 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 in the dentin-pulp complex injury and repair process.
探讨低强度脉冲超声（LIPUS）对牙本质损伤修复过程中TGF-β1/Smad 2、3信号通路的影响。方法：25只Sprague-Dawley大鼠中，5只作为未处理的空白对照组。其余20只大鼠双侧上颌第一磨牙行改良龋洞制备，建立牙本质-牙髓损伤修复模型。右侧上颌第一磨牙作为LIPUS组，接受LIPUS照射（频率：1.5 MHz，脉冲宽度：200 μs，脉冲重复频率：1 kHz，空间平均时间平均强度：30 mW/cm2，20 min/d），左侧上颌第一磨牙作为龋洞制备组，接受假LIPUS照射。LIPUS照射后1、3、5、7和14天处死大鼠。采用免疫组织化学染色及Image-pro plus 6.0检测转化生长因子-β1（TGF-β1）及小母亲抗五肢瘫蛋白2/3（Smad 2和Smad 3）的表达及分布。结果：免疫组织化学染色显示，正常牙髓中TGF-β1及Smad 2、3表达较低，但牙本质损伤后不同程度升高。图像分析结果显示，龋洞制备组TGF-β1表达在第1天逐渐升高，第5天达到峰值，然后在第14天恢复至正常水平。然而，LIPUS组在第3天和第5天TGF-β1表达显著高于龋洞制备组（均P<0.05）。LIPUS组和龋洞制备组Smad 2、3表达均持续升高，但LIPUS组表达高于龋洞制备组（P<0.05）。结论：牙本质损伤修复过程中TGF-β1/Smad 2、3信号通路可被激活。LIPUS可在早期上调TGF-β1及Smad 2、3表达，可能参与牙本质-牙髓复合体损伤修复过程。
