纤粘连蛋白-成骨生长肽复合涂层材料通过Ephb4-Ephrinb2信号通路调控糖尿病牙槽骨稳态的分子机制研究

The limitation of implant prosthesis because of diabetic alveolar resorption is common in clinical, which has a severe impact on living quality. We previously found Fibronectin-Osteogenic growth peptide biomaterials (FN-OGP biomaterials) could promote osteoblast differentiation by Ephb4 up-regulation under high glucose. With the combination on Ephrinb2, Ephb4 could suppress the expression of c-Fos and NATc1, which could inhibit the osteoclast differentiation, while the specific molecular mechanism is unclear. Therefore, our project will discuss the proliferative and differentiative ability of osteoblasts and osteoclasts stimulated by high glucose, in order to demonstrate the affect of Ephb4 and Ephrinb2 on diabetic bone imbalance. Besides, we will find the effect of Ephb4-Ephrinb2 in the process of promoting osteoblastic differentiation and suppressing osteoclastic differentiation induced by FN-OGP biomaterials under high glucose, and illustrate the molecular mechanism of diabetic alveolar bone dynamic balance regulated by Ephb4-Ephrinb2 signal pathway on FN-OGP biomaterials to meet the clinical needs of osteanagenesis and bone defect repair among diabetic patients.

临床上因糖尿病牙槽骨稳态失衡导致无法种植修复的现象十分常见，严重影响患者生活质量，尚无良好解决方法。本课题前期工作发现，纤粘连蛋白-成骨生长肽（FN-OGP）复合涂层材料可以通过上调Ephb4表达促进高糖状态成骨细胞分化，通过与其配体Ephrinb2结合，抑制破骨细胞c-Fos、NATc1表达，影响破骨细胞分化，但具体机制不详。本项目旨在探讨高糖对成骨、破骨细胞增殖及分化能力的影响，确定Ephb4和Ephrinb2在糖尿病骨稳态失衡中的作用；阐述Ephb4-Ephrinb2信号通路在FN-OGP复合涂层材料在促进高糖状态成骨细胞分化，抑制破骨细胞分化过程中的关键作用，通过检测FN-OGP涂层材料修复糖尿病牙槽骨缺损能力，进一步明确其通过Ephb4-Ephrinb2信号通路调控糖尿病牙槽骨稳态的分子机制，为未来FN-OGP涂层材料的研发提供理论依据，更好地满足糖尿病患者修复骨缺损的临床需要。

本项目针对种植体表面改性涂层材料促进间充质干细胞成骨分化的现象，发现Ephb4-Ephrinb2参与到牙槽骨稳态动态平衡。课题组近而利用GO-PLL多聚物成功负载FN和OGP生物活性分子，我们制备了合适粒径大小的 GO-PLL负载系统，可以通过静电吸附作用固定多种生物活性分子，并实现可控序列释放。GO-PLL负载系统复合无细胞SF/BCP多孔支架，通过可控释放FN和OGPs显著促进BMSCs的粘附、增殖和成骨分化，具有良好的生物相容性和成骨诱导活性，为修复骨缺损和引导骨再生提供理论依据。 接下来，在高糖环境下，将过表达Ephb4的BMSCs与GO-PLL/FN+OGP/SF/TCP支架共培养后可以显著提高BMSC的粘附增殖和分化，反过来加入Ephb4的抑制剂后BMSCs的生物活性均下降，初步探讨了FN+OGP复合支架材料在高糖环境下通过Ephb4-Ephrinb2信号通路促进成骨分化的分子机制。此外课题组制备兔子颅骨缺损模型，将Ephb4过表达和Ephb4沉默的BMSCs复合到水凝胶里，发现过表达Ephb4的支架材料可以有效修复骨缺损。