基于三元调控理论探讨骨碎补总黄酮促进牵张成骨早中期成骨效能的机制研究

Distraction osteogenesis is an important technique for the reconstruction of the limbs in the orthopedics, and traditional Chinese medicine plays an important role in the process of distraction osteogenesis.Our previous study shows that BMP-Smad pathway is an important signaling during the early-to-mid distraction osteogenesis.The total flavonoids of Rhizoma Drynariae has a positive role in promoting osteogenesis quality in early distraction.But the expression of BMP2, BMP4, BMPR1A, Smad1 and other genes were not consistent with the protein expression,this suggests that there are other regulatory mechanisms involved during this process.The latest research on the ternary regulation theory indicates that the changes of microenvironment and angiogenesis in bone have important roles in osteogenesis.The total flavonoids of Rhizoma Drynariae can improve the local circulation, but the relationship between osteogenic and vascular formation in bone has not very clearly.Therefore, in this study, we established the DO model of SD rat in vivo and the co-culture system of endothelial and osteoblasts cells in vitro, and intervention with total flavones of Rhizoma Drynaria.The effect of Rhizoma Drynaria on vascular endothelial cell,osteoblast,vascular formation and osteogenesis will be clarified by historymorphology, radiography and molecular biology, in order to further investigate the mechanism of Rhizoma Drynaria in the process of distraction osteogenesis.

牵张成骨是骨科肢体重建的重要技术，中药在牵张成骨过程中有重要的作用。我们前期研究表明，BMP-Smad通路是牵张成骨早中期的重要信号调节通路，骨碎补总黄酮对牵张早中期成骨质量有正向促进作用，但在骨碎补总黄酮的干预下，BMP2、BMP4、BMPR1A、Smad1等基因表达与蛋白表达量并不一致，这表明该干预过程中有其他的调控机制参与。最新的三元调控理论研究表明，骨内血管形成和微环境的改变在骨形成中有重要调控作用，而骨碎补总黄酮有明确的改善成骨局部循环的作用，在牵张成骨过程中骨内血管形成与成骨效能之间的关系尚未见相关研究。因此，本研究通过建立SD大鼠牵张成骨模型及体外血管内皮细胞-成骨细胞共育系，给予骨碎补总黄酮干预，从组织形态学、影像学和分子生物学角度，阐明在牵张成骨过程中，骨碎补总黄酮对血管内皮细胞、成骨细胞、骨内血管生成以及成骨效能的影响，进一步探讨骨碎补总黄酮在牵张成骨技术中的干预机制。

前期研究表明，BMP-Smad通路是牵张成骨早中期的重要信号调节通路，骨碎补总黄酮对牵张早中期成骨质量有正向促进作用，但在干预过程中干预过程中有其他的调控机制参与。最新的三元调控理论研究表明，骨内血管形成和微环境的改变在骨形成中有重要调控作用，而骨碎补总黄酮有明确的改善成骨局部循环的作用，骨碎补总黄酮对牵张成骨中H血管生成及成血管-成骨耦联有明显的促进作用；牵张应力可明显促进H血管生成，但H血管生成具有明显的时效性，在牵张成骨模型中H血管丰度在牵张期较高，在固化期H血管生成降低。实验通过建立大鼠牵张模型等，观察动物牵张模型中47、41、55天等标志性时刻骨结构恢复情况，同时在给药干预情况下，从机制层面探究骨碎补总黄酮对于牵张模型的影响。实验采用牵张技术治疗大段骨缺损骨临床效果满意，但存在新骨钙化缓慢、治疗周期过长等问题。骨碎补总黄酮干预可协同牵张应力进一步促进H血管生成，H血管表达的高低与牵张过程中血管生成和骨生成效果强弱表现协同一致性。潜在的机制可能是骨碎补总黄酮上调 PDGF-BB 因子水平，激活 PDGF-BB/PDGFR-β信号通路，促进 H 血管的表达，继而增强牵张过程中成血管-成骨耦联作用，促进骨修复重建。