Varanda Raquel Veloso, Kumari Jyoti, van Rheden René E M, Cuijpers Vincent M J I, Bloemen Marjon, Göllesch Fleur, Von den Hoff Johannes W, Henneman Sjoerd, Xie Rui, Wagener Frank A D T G, Suttorp C Maarten
Department of Dentistry-Orthodontics and Craniofacial Biology, Research Institute for Medical Innovation, Radboud university medical center, Philips van Leydenlaan 25, Nijmegen 6525 EX, the Netherlands.
Department of Dentistry-Orthodontics and Craniofacial Biology, Research Institute for Medical Innovation, Radboud university medical center, Philips van Leydenlaan 25, Nijmegen 6525 EX, the Netherlands; Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, Nijmegen 6525 AJ, the Netherlands.
Arch Oral Biol. 2025 Apr;172:106173. doi: 10.1016/j.archoralbio.2025.106173. Epub 2025 Jan 6.
To investigate in vivo whether myofibroblasts formed in the PDL after exposure to short-term high experimental orthodontic forces in rats survive. To study in vitro whether human PDL fibroblasts can differentiate into myofibroblasts and survive when chemical or mechanical stimuli are removed.
Nine 6-week-old male Wistar rats were used in this experiment. Rat molars were exposed to high but rapidly decreasing experimental orthodontic forces by applying a rubber band and analyzed for the presence of myofibroblasts using ASMA staining. In vitro, human periodontal ligament (PDL) fibroblasts were exposed to transforming growth factor β1 (TGFβ1) and/or mechanical stress and monitored for myofibroblast formation and survival after these stimuli were abrogated.
In vivo exposure to orthodontic forces strongly induced myofibroblast formation in the stretched regions of the PDL. Furthermore, many PDL myofibroblasts remained present 6 days after exposure to these short-term high orthodontic forces. Human PDL fibroblasts were shown to differentiate into myofibroblasts after 2 days of TGFβ1 exposure and survive for at least 2 more days after removing chemical stimuli (TGFβ1) or mechanical strain. Under in vitro conditions, both TGFβ1 and mechanical strain for 3 days promoted (myo)fibroblast formation, and these cells persisted for 3 more days after the removal of both stimuli.
PDL myofibroblasts survive after the removal of mechanical strain in vivo and in vitro. This supports the hypothesis that myofibroblasts, which form in response to mechanical strain and chemical cues in the periodontal ligament (PDL), play a role in relapse following orthodontic tooth movement.
研究大鼠在短期承受高实验性正畸力后，牙周膜中形成的肌成纤维细胞在体内是否存活。研究体外条件下，当化学或机械刺激去除后，人牙周膜成纤维细胞能否分化为肌成纤维细胞并存活。
本实验使用9只6周龄雄性Wistar大鼠。通过施加橡皮筋使大鼠磨牙承受高但迅速衰减的实验性正畸力，并用抗平滑肌肌动蛋白（ASMA）染色分析肌成纤维细胞的存在情况。在体外，使人牙周膜（PDL）成纤维细胞暴露于转化生长因子β1（TGFβ1）和/或机械应力，并在这些刺激消除后监测肌成纤维细胞的形成和存活情况。
体内暴露于正畸力强烈诱导了牙周膜拉伸区域的肌成纤维细胞形成。此外，在暴露于这些短期高正畸力6天后，许多牙周膜肌成纤维细胞仍然存在。人牙周膜成纤维细胞在暴露于TGFβ1 2天后显示分化为肌成纤维细胞，并在去除化学刺激（TGFβ1）或机械应变后至少再存活2天。在体外条件下，TGFβ1和机械应变3天均促进（肌）成纤维细胞形成，并且在去除两种刺激后这些细胞又持续存在3天。
体内和体外去除机械应变后，牙周膜肌成纤维细胞仍存活。这支持了以下假设：牙周膜中响应机械应变和化学信号而形成的肌成纤维细胞在正畸牙齿移动后的复发中起作用。
