Gene expression profile of periodontal ligament during tooth movement, using microarray analysis

研究了大鼠上颌第一磨牙运动过程中牙周韧带（PDL）基因的表达谱。用固定矫治器舌移大鼠上颌第一磨牙6小时和5天，在磨牙区域制备未固定、未钙化的冷冻切片。对牙周膜切片进行显微解剖，从样品中分离RNA，用cDNA芯片进行分析。将微阵列数据与对照组（牙周韧带无牙齿运动数据）进行比较。激光捕获显微解剖所采集样品的质量和数量足以进行微阵列分析。在牙齿开始运动后6 h，在PDL扩展区，2506个基因的表达量比对照高2倍，2722个基因的表达量比对照低一半。在PDL压缩区，2960个基因的表达量比对照高2倍，2978个基因的表达量比对照低一半。在牙齿开始运动后5 d，在PDL延伸区，3762个基因的表达量比对照高2倍，2722个基因的表达量比对照低一半。在PDL压缩区，4239个基因的表达量比对照高2倍，2849个基因的表达量比对照低一半。PDL扩展区样品中与成骨相关的基因表达上调，PDL压缩区样品中与凋亡和骨吸收相关的基因表达上调。这些结果表明，PDL细胞改变其基因表达以适应牙齿移动引起的新环境，这些变化使牙齿在牙槽骨中移动成为可能。

Gene expression profile of the periodontal ligament (PDL) was examined in rat maxillary first molar during tooth movement. Rat maxillary first molars were moved lingually with fixed appliance for 6 hours and 5 days, and unfixed, undecalcified frozen sections was prepared from the molar areas. The periodontal ligament was microdissected from the sections and the RNA was isolated from the sample, and analyzed using cDNA microarray. The data from the microarray was compared with the data from the control (data of periodontal ligament without tooth movement).The quality and quantity of the sample collected with laser capture microdissection was enough for microarray analysis. 6 hours after initiation of tooth movement, in the extended zone of the PDL, 2506 genes were expressed 2 fold higher than those in the control and 2722 genes were expressed half lower than the control. In the compressed zone of the PDL, 2960 genes were expressed 2 fold higher than those in the control and 2978 genes were expressed half lower than the control. 5 days after initiation of tooth movement, in the extended zone of the PDL, 3762 genes were expressed 2 fold higher than those in the control and 2722 genes were expressed half lower than the control. In the compressed zone of the PDL, 4239 genes were expressed 2 fold higher than those in the control and 2849 genes were expressed half lower than the control. The genes related to osteogenesis were up-regulated in the sample of the extended zone of PDL, and the genes related to apoptosis and bone resorption were also up-regulated in the sample of the compressed zone of PDL.These results suggest that the PDL cells change their gene expression to adapt to new environment caused by tooth movement, and these change make it possible to move the tooth in the alveolar bone.