FoxO1转录因子介导巨噬细胞极化调控糖尿病小鼠种植体周血管化的机制研究

Diabetes has an inhibitory role on angiogenesis in wound healing, while little is reported how diabetes influences early vascularization around implant. Macrophage polarization has a regulative role in angiogenesis, recent research showed that M2 macrophage could promote angiogenesis while M1 macrophage inhibited it. FoxO1 transcription factor promotes M1 macrophage polarization in high glucose, while M2 macrophage is inhibited, but the mechanism is not clear. Our previous experiment results showed more M2 macrophage distributed around new formed vascular around implant. In co-culture system of endothelial cell and macrophage on titanium plates, angiogenesis and M2 macrophage were both inhibited in high glucose, while FoxO1 silence reversed this process. This study aimed to set up diabetic model in FoxO1 gene knockout mice, and insert implants into femurs. We try to explore how FoxO1 play an influence on macrophage polarization in high glucose, and how this process then regulates vascularization around implant. We also try to explain the mechanism of PI3K/Akt/FoxO1 signaling pathway in mediating macrophage polarization through regulating CCR2. This experiment provides a theoretical basis for research on how diabetes influence early vascularization around implant, and a gene target for promoting early vascularization around implant of diabetic patient.

糖尿病对种植体周早期血管化的影响相对较少。巨噬细胞极化对血管新生具有调控作用，其中M2型巨噬细胞促进血管新生，M1型则有抑制作用。高糖环境下FoxO1转录因子促进M1型，抑制M2型的极化，但机制并不明确。本课题预实验发现种植体植入早期新生血管周围分布较多的M2型巨噬细胞，将内皮细胞与巨噬细胞在钛表面共培养，经高糖刺激后，成血管能力减弱，M2型巨噬细胞的极化也受到抑制，而沉默FoxO1后二者的表达均有所恢复。因此本课题拟建立FoxO1基因敲除小鼠模型并诱发糖尿病，于股骨内植入种植体，利用体内外实验观察糖尿病对种植体周早期血管化的影响，探索高糖环境下FoxO1如何调控巨噬细胞极化进而影响钛表面血管新生，阐明PI3K/Akt/FoxO1信号通路调节CCR2的表达在巨噬细胞极化中的作用和机制，为阐明糖尿病如何影响种植体周早期血管化奠定理论基础，也为提高糖尿病患者种植体周血管化提供新的基因治疗靶点。

糖尿病对种植体周早期血管化影响的相关研究相对较少。巨噬细胞极化对血管新生具有调控作用，而高糖环境下FoxO1转录因子介导巨噬细胞极化调控血管化的机制并不明确。本课题实验结果发现FoxO1在LPS刺激型巨噬细胞的极化中表达相对稳定。正常状态下，FoxO1在LPS刺激型巨噬细胞中的表达下降，巨噬细胞的促炎能力降低，抗炎能力增强，同时巨噬细胞与内皮细胞共培养下，成血管能力增加，而经高糖刺激后，FoxO1在LPS刺激型巨噬细胞中的表达升高，巨噬细胞促炎能力增强，抗炎能力减弱，共培养体系中成血管能力减弱，沉默FoxO1后抗炎能力和成血管能力有所恢复。信号通路研究表明高糖环境下FoxO1调控巨噬细胞极化进而影响血管新生受到PI3K/Akt/FoxO1信号通路调节，这一结果为阐明体内环境下糖尿病如何影响种植体周早期血管化提供基础理论，也为提高糖尿病患者种植体周血管化提供新的基因治疗靶点。