高糖环境下硅酸盐生物活性陶瓷对骨髓间充质干细胞增殖及成骨分化影响的研究

Epidemiological studies showed that there are close to 90% in diabetes patients is type 2 diabetes, and symptoms of type 2 diabetes is hyperglycemia which inhibit or delay bone defects reparation. In our previously study, we found that silicate bioactive ceramic could enhance the osteogenic differentiation of bone mesenchymal stem cells（BMSCs）, however, under the circumstances of high glucose microenvironment and silicate bioactive ceramic whether the BMSCs could still differentiate into osteoblast lineage, there are no reports about that until now. The project is proposed on the basis of previous researches, first, we imitate the hyperglycemia microenvironment of patients with diabetes in vitro, analyze the influence on the proliferation and osteogenic differentiation of BMSCs with or without silicate bioactive ceramic respectively. Designing silicate bioactive ceramic composites, which could reduced the influence of hyperglycemia microenvironment on the BMSCs, on the contrary, promoting the proliferation and osteogenic differentiation of BMSCs under the condition of three dimensional. Using the combined system of silicate bioactive ceramics and growth factor to restrain high glucose microenvironment and reduce the damage of new bone, analyze the molecular mechanism of the combined system. Explore and design the best three-dimensional scaffold under the complex system of silicate bioactive ceramics, which can be used as the BMSCs carrier in the reparation of diabetes animal bone defect model. The project will lay the foundation for application of bone tissue engineering on the bone defects in patients with diabetes.

流行病研究结果显示糖尿病患者中接近90%是2型糖尿病，而2型糖尿病大多存在高血糖症状，高血糖导致牙周炎症反应又抑制或延迟骨缺损修复。前期研究已证实硅酸盐生物活性陶瓷促进骨髓间充质干细胞（BMSCs）成骨分化，但高糖环境下硅酸盐生物活性陶瓷对BMSCs增殖及成骨分化影响还未见报道，本项目拟在前期研究基础上首先研究体外高糖微环境对BMSCs增殖及成骨分化的影响机理，进一步研究硅酸盐生物活性陶瓷离子微环境联合高糖环境对BMSCs增殖及成骨分化的影响。最终研究设计硅酸盐生物活性陶瓷减弱高糖环境对BMSCs的影响进而促进BMSCs三维条件下成骨。利用硅酸盐生物活性陶瓷体系及其微环境减弱高糖环境对新生骨的损害，研究体系分子机制，设计最佳硅酸盐生物活性陶瓷三维支架，最终联合BMSCs体内修复糖尿病动物骨缺损，为骨组织工程在糖尿病患者骨缺损疾病应用奠定基础。

人骨髓干细胞(hBMSCs) 常被用于骨组织工程的各种研究，主要用作种子细胞。但是，高血糖(HG)环境对hBMSC的增殖和成骨分化具有负面影响，因此减少了糖尿病患者的骨形成。在我们以前的研究工作中，我们发现从硅酸盐基生物陶瓷中提取的硅（Si）离子能够在正常培养条件下刺激hBMSC的增殖和成骨分化。这项研究旨在调查硅离子是否可以阻止HG诱导的hBMSCs增殖和成骨抑制。我们发现，在HG条件下，浓度为2.59 ppm的Si离子可促进hBMSC的增殖。碱性磷酸酶（ALP）活性测定，茜素红S染色和成骨基因（BMP2，RUNX2，ALP，COL1和OCN）的定量实时PCR分析结果表明，浓度为15.92 ppm的Si离子可防止HG诱导的抑制作用hBMSC的成骨分化。此外，硅离子的应用降低了经HG处理的hBMSCs中活性氧的含量。在经过15.92 ppm Si离子作用的HG处理的hBMSC中，检测到BMP2 / SMAD信号通路的激活，同时发现BMP2受体及其下游基因如SMAD1，SMAD4和SMAD5的表达增加。我们研究的结果表明，特定浓度的Si离子可通过抗氧化剂作用和BMP2 / SMAD途径的调节来补偿HG诱导的hBMSCs增殖和成骨分化的抑制。最后，基于硅酸盐的生物陶瓷可能是用于糖尿病患者骨组织工程应用的良好支架生物材料。