电穿孔介导基因治疗下颌骨牵引过程中血管内皮细胞生长因子的表达

Effects of electroporation-mediated gene therapy on the expression of vascular endothelial growth factor during mandible distraction

背景:课题组前期实验已证明基因治疗能促进下颌骨牵引区新骨的生成。目的:探索电穿孔介导的基因治疗对兔下颌骨牵引成骨过程中血管内皮细胞生长因子表达的影响。方法:45只新西兰大白兔双侧下颌骨截骨,建立下颌骨牵引模型。牵引7d后将模型兔随机摸球法均分为pIRES-hVEGF165-hBMP2组、pIRES-hBMP2组、pIRES-hVEGF165组、空质粒载体pIRES组、生理盐水对照组,分别于牵引区注射相应质粒或生理盐水。各组动物均施加电穿孔刺激。结果与结论:血管内皮细胞生长因子主要在骨周围结缔组织成纤维细胞、血管内皮细胞、骨组织成骨细胞和骨细胞表达,也可见炎细胞如单核细胞表达。各组均在固定期第7天表达最强,14d下降,28d时表达较弱,但在各时点基因治疗组明显强于对照组。说明电穿孔介导的基因治疗能使血管内皮细胞生长因子持续表达,并使其表达时限延长,促进牵引区新生血管生成和新骨形成。

BACKGROUND：Our previous studies have proved the gene therapy can promote new bone formation in mandibular distraction area.OBJECTIVE：To investigate the effect of electroporation-mediated gene therapy on the expression of vascular endothelial growth factor（VEGF） in the distracted calluses during mandibular distraction osteogenesis in a rabbit model.METHODS：Bilateral mandibular osteotomies were performed in 50 New-Zeland rabbits.The mandibular distraction osteogenesis models were established.After the completion of distraction,the rabbits were randomly divided into five groups：group A：pIRES-hVEGF165-hBMP2;group B：pIRES-hBMP2;group C：pIRES-hVEGF165;group D：pIRES and group E：normal saline.All the animals were treated with electroporation stimulation.RESULTS AND CONCLUSION：VEGF staining was located in cytoplasm of endothelial cells,osteoblasts,fibroblasts,inflammatory cells and immature osteocytes.Their strongest expression was found at 7 days after the end of distraction,declined at 14 days,and weakened with maturation of the newly formed bone at 28 days.But in every point,the gene therapy group was stronger than the control group.It suggests that electroporation-mediated gene therapy can obtain continues expression of VEGF,and make the meaning extended time limit,which can promote angiogenesis during mandibular distraction,and new bone formation.