Uribe Pamela, Larsson Lena, Westerlund Anna, Ransjö Maria
Department of Orthodontics, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, PO Box 450, 405 30, Gothenburg, Sweden.
Department of Periodontology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Odontology. 2018 Oct;106(4):351-359. doi: 10.1007/s10266-018-0342-9. Epub 2018 Feb 12.
Animal studies suggest that the dental follicle (DF) plays a major role in tooth eruption. However, the role of the DF during tooth impaction and related root resorptions in adjacent teeth is not clear. The hypothesis for the present study is that expression of regulatory factors involved in the bone remodelling process necessary for tooth eruption may differ between dental follicles from teeth with different clinical situations. We have analysed the gene expression profiles in the DF obtained from impacted canines, with (N = 3) or without (N = 5) signs of root resorption, and from control teeth (normal erupting teeth, mesiodens) (N = 3). DF from 11 patients (mean age: 13 years) obtains at the time of surgical exposure of the tooth. Due to the surgical time point, all teeth were in a late developmental stage. Gene expression related to osteoblast activation/bone formation, osteoclast recruitment and activation was analysed by RTqPCR. Genes related to bone formation (RUNX2, OSX, ALP, OCN, CX43) were highly expressed in all the samples, but osteoclast recruitment/activation markers (OPG, RANKL, MCP-1, CSF-1) were negligible. No apparent patterns or significant differences in gene expression were found between impacted canines, with or without signs of root resorption, or when compared to control teeth. Our results suggest the DF regulation of osteoclastic activity is limited in the late pre-emergent stage of tooth development, irrespective if the tooth is normally erupting or impacted. We suggest that the follicle may have an important regulatory function for alveolar bone formation in the final eruption process and CX43-gap junction communication could be an important signalling pathway.
动物研究表明，牙囊（DF）在牙齿萌出过程中起主要作用。然而，牙囊在牙齿阻生及相邻牙齿相关牙根吸收过程中的作用尚不清楚。本研究的假设是，参与牙齿萌出所需骨重塑过程的调节因子的表达，在不同临床情况的牙齿的牙囊中可能存在差异。我们分析了从阻生犬牙获取的牙囊的基因表达谱，这些犬牙有（N = 3）或无（N = 5）牙根吸收迹象，以及来自对照牙齿（正常萌出牙齿、多生牙）（N = 3）的牙囊。11名患者（平均年龄：13岁）的牙囊在牙齿手术暴露时获取。由于手术时间点，所有牙齿均处于发育后期。通过RTqPCR分析与成骨细胞激活/骨形成、破骨细胞募集和激活相关的基因表达。与骨形成相关的基因（RUNX2、OSX、ALP、OCN、CX43）在所有样本中均高表达，但破骨细胞募集/激活标志物（OPG、RANKL、MCP - 1、CSF - 1）可忽略不计。在有或无牙根吸收迹象的阻生犬牙之间，或与对照牙齿相比，未发现明显的基因表达模式或显著差异。我们的结果表明，在牙齿发育的萌出前期后期，无论牙齿是正常萌出还是阻生，牙囊对破骨细胞活性的调节作用有限。我们认为，牙囊可能在最终萌出过程中对牙槽骨形成具有重要的调节功能，且CX43 - 缝隙连接通讯可能是一条重要的信号通路。
