Department of Orthodontics, Sri Sankara Dental College, Trivandrum, Kerala, India.
Eur J Orthod. 2021 Dec 1;43(6):690-696. doi: 10.1093/ejo/cjab025.
The response of periodontal ligament cells (PDLC) from adult subjects in comparison to those obtained from younger ones to mechanical forces has been a matter of interest recently because of induced senescent changes. This study evaluated and compared cell surface changes and activity, integrin beta 1, and β-actin mRNA fold changes as well as klotho protein secretion capabilities of PDLC from young and adult donors before and after subjecting to orthodontic forces.
A total of 40 subjects with bimaxillary dentoalveolar protrusion requiring extraction of first premolars for orthodontic treatment were selected and divided into two groups. Force ranging from 80 to 90 g was applied to maxillary first premolars and extraction was carried out at two different time periods-pre-treatment (control group) and 28 days after force application (experimental group). Periodontal ligament was obtained, and cell surface changes and activity were observed with atomic force microscopy (AFM) and fluorescent tagging. mRNA fold change of integrin beta-1 and β-actin mRNA, as well as beta-galactosidase assay, was performed, and levels of klotho protein were evaluated.
AFM nanoindentation and fluorescent tagging indicated increased surface morphological changes in younger cells compared to adult ones. We observed a decrease in integrin beta 1 but an increase in β-actin mRNA levels in PDLC obtained from younger subjects compared to adults, while an increase was observed in SA-β-GAL from adult cells. The level of klotho protein was lower in adult cells in comparison to younger ones.
Large sample studies are required to find out a variation in aging characteristics between young and adult PDLC.
The study observed significant differences between PDLC obtained from younger and adult subjects in response to orthodontic force application.
牙周韧带细胞（PDLC）对机械力的反应，尤其是与年轻人相比，由于诱导的衰老变化，最近成为人们关注的焦点。本研究评估和比较了正畸力作用前后年轻和成年供体 PDLC 的细胞表面变化和活性、整合素β 1 和β-肌动蛋白 mRNA 倍数变化以及 klotho 蛋白分泌能力。
选择 40 名双颌牙槽前突患者，需拔除第一前磨牙进行正畸治疗，分为两组。上颌第一前磨牙施加 80-90g 的力，分别在治疗前（对照组）和力应用 28 天后（实验组）进行拔牙。获取牙周韧带，采用原子力显微镜（AFM）和荧光标记观察细胞表面变化和活性。进行整合素β-1 和β-肌动蛋白 mRNA 的倍数变化以及β-半乳糖苷酶测定，并评估 klotho 蛋白水平。
AFM 纳米压痕和荧光标记表明，与成年细胞相比，年轻细胞的表面形态变化更大。与成年供体相比，我们观察到年轻供体 PDLC 中的整合素β 1 减少，但β-肌动蛋白 mRNA 水平增加，而成年细胞中的 SA-β-GAL 增加。与年轻细胞相比，成年细胞的 klotho 蛋白水平较低。
需要进行大规模样本研究，以确定年轻和成年 PDLC 之间衰老特征的差异。
该研究观察到年轻和成年供体 PDLC 对正畸力应用的反应存在显著差异。
