Age-Related Adaptation of Bone-PDL-Tooth Complex: Rattus-Norvegicus as a Model System
Age-Related Adaptation of Bone-PDL-Tooth Complex: Rattus-Norvegicus as a Model System
复制标题
DOI：
10.1371/journal.pone.0035980
复制
发表时间：
2012-04-30
期刊：
影响因子：
3.7
通讯作者：
Ho, Sunita P.
中科院分区：
文献类型：
--
作者：
Leong, Narita L.;Hurng, Jonathan M.;Ho, Sunita P.
器官的功能负荷通过在细胞水平将机械能转化为化学能来诱导组织适应。细胞的转导能力改变组织的物理化学性质，形成通常被认为是形式-功能关系的正反馈。在这项研究中，通过识别 1.5 至 15 个月大的大鼠的生物分子表达并将其与物理化学特性相关联，绘制了骨-牙齿复合体中的器官和组织适应图。然而，未来对相关年龄组使用硬粮和软粮的研究将使功能相关影响与衰老影响脱钩。使用显微 X 射线计算机断层扫描观察到远端牙根逐渐弯曲并增加牙根吸收。使用抗酒石酸酸性磷酸酶 (TRAP) 治疗 6 个月之前，吸收与磨牙远端多核破骨细胞活性的增加相关。有趣的是，在老年大鼠中观察到 PDL 脉管系统内的单核 TRAP 阳性细胞。使用阿尔新蓝染色在 PDL 骨和 PDL 牙骨质附着处鉴定出较高水平的糖胺聚糖。使用免疫组织化学观察到从冠状区到顶端区的生化梯度下降，特别是可以诱导成骨（双糖链蛋白聚糖）和纤维形成（纤维调节蛋白、核心蛋白聚糖）表型的生物分子，以及矿化的 PDL 特异性负调节剂（阿孢菌素）。通过能量色散X射线分析，发现牙槽骨中Ca和P的分布不均匀，且附着点的含量相对较低。使用显微压头观察到年龄与牙槽骨显微硬度（0.7 +/- 0.1 至 0.9 +/- 0.2 GPa）和牙骨质（0.6 +/- 0.1 至 0.8 +/- 0.3 GPa）之间没有相关性。然而，任何给定年龄的牙骨质和牙槽骨的硬度都存在显着差异（P
Functional loads on an organ induce tissue adaptations by converting mechanical energy into chemical energy at a cell-level. The transducing capacity of cells alters physico-chemical properties of tissues, developing a positive feedback commonly recognized as the form-function relationship. In this study, organ and tissue adaptations were mapped in the bone-tooth complex by identifying and correlating biomolecular expressions to physico-chemical properties in rats from 1.5 to 15 months. However, future research using hard and soft chow over relevant age groups would decouple the function related effects from aging affects. Progressive curvature in the distal root with increased root resorption was observed using micro X-ray computed tomography. Resorption was correlated to the increased activity of multinucleated osteoclasts on the distal side of the molars until 6 months using tartrate resistant acid phosphatase (TRAP). Interestingly, mononucleated TRAP positive cells within PDL vasculature were observed in older rats. Higher levels of glycosaminoglycans were identified at PDL-bone and PDL-cementum entheses using alcian blue stain. Decreasing biochemical gradients from coronal to apical zones, specifically biomolecules that can induce osteogenic (biglycan) and fibrogenic (fibromodulin, decorin) phenotypes, and PDL-specific negative regulator of mineralization (asporin) were observed using immunohistochemistry. Heterogeneous distribution of Ca and P in alveolar bone, and relatively lower contents at the entheses, were observed using energy dispersive X-ray analysis. No correlation between age and microhardness of alveolar bone (0.7 +/- 0.1 to 0.9 +/- 0.2 GPa) and cementum (0.6 +/- 0.1 to 0.8 +/- 0.3 GPa) was observed using a microindenter. However, hardness of cementum and alveolar bone at any given age were significantly different (P