MT01对成/破骨细胞TLR9激活的抑制及其对牙槽骨吸收的影响

MT01, an oligodeoxynucleotide designed based on the sequence of human mitochondrial DNA, was demonstrated capable of inhibiting the alveolar bone resorption in periodontitis rats in our previous work. MT01 can target and block TLR9 activation, and reduce the inflammation injury of tissues. Upon these, we plan to study whether MT01 can inhibit the alveolar bone resorption by antagonizing TLR9 activation in osteoblast/osteoclast. In the proposed project, we will build a periodontitis model using TLR9 gene knockout mice to observe the alveolar bone resorption in TLR9+/+ and TLR9-/- mice treated with MT01; test whether MT01 can regulate the production of proinflammatory cytokines and bone-associated factors from osteoblast/osteoclast stimulated with DNA isolated from periodontal- pathogenic -bacteria, or stimulated with DNA isolated from the injury tissues of the patients with periodontitis. The novelty of the proposed project is to study the effect of TLR9-mediated innate immune response on alveolar bone resorption and to establish an experimental basis for developing MT01, a self designed and developed oligodeoxynucleotide, into an agent with efficacies of inhibiting or delaying alveolar bone resorption.

在我们的前期工作中发现，MT01(一种根据人线粒体DNA序列设计的寡脱氧核苷酸) 能在牙周炎模型大鼠中抑制牙槽骨吸收。MT01可以靶向阻断TLR9的激活，减轻组织的炎症性损伤。基于以上工作，我们拟研究MT01抑制成骨/破骨细胞TLR9的激活及其和牙槽骨吸收的关系。主要研究内容是：建立TLR9基因敲除小鼠牙周炎动物模型，观察MT01对TLR9 (+/+) 和TLR9(-/-) 小鼠牙槽骨吸收的影响；探讨MT01对牙周致病菌DNA刺激成骨/破骨细胞表达致炎细胞因子以及成骨/破骨相关因子的影响；提取牙周炎患者自身细胞DNA，检测MT01是否可调控患者自体DNA刺激成骨/破骨细胞内致炎细胞因子以及成骨/破骨相关因子的表达。该工作的新颖性在于，以TLR9激活为主线研究固有免疫应答对牙周炎牙槽骨吸收的影响，为自行设计研制的MT01可能成为抑制牙槽骨吸收的制剂奠定实验基础。

本课题研究ODN MT01(一种根据人线粒体DNA序列设计的寡脱氧核苷酸)可以抑制成骨/破骨细胞TLR9的激活及其和牙槽骨吸收的关系，为MT01作为抑制牙槽骨吸收的制剂奠定实验基础。在获得面上项目资助后，进展顺利，已完成项目计划内容。证实了MT01可以抑制由细菌和牙周炎患者组织DNA所导致的炎症反应，促进成骨细胞的增殖与分化。此外，我们利用PEI的衍生物PEN构建了PEN/MT01复合物，实现MT01的高效递送；针对实验中的一些问题，我们又对另外11条不同序列的ODN进行了进一步检测，筛选出2条具有骨改建作用的ODN；此外将miR-34a引入到我们的相关研究中，证实了其促进健康状态下成骨细胞成骨分化，抑制感染状态下成骨细胞成骨分化；并且在正畸牙移动过程中促进骨组织分化。