摘要目的 探讨电穿孔介导的基因治疗对兔下颌骨牵引成骨过程中碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)表达的影响.方法 新西兰大白兔双侧下颌骨截骨,术后3d开始以0.8 mm/d速度行下颌骨牵引,连续牵引7d,将实验动物分为:A、B、C、D、E5组.分别在牵引区注射2μg重组质粒pIRES-hVEGF165-hBMP2、pIRES-hBMP2、pIRES-hVEGF165、空质粒pIRES及生理盐水.各组实验动物均施加电穿孔刺激.各组分别于固定期第7、14、28天处死动物取材行免疫组织化学检查bFGF的表达,并利用病理图像分析系统进行分析.结果 bFGF在肉芽中的成纤维细胞、单核巨噬细胞、多核巨噬细胞、间质细胞、成骨细胞和骨细胞中表达:1周时以C组表达较强,2、4周时以A、B、C组表达仍较强,A、B、C组与D、E组相比差异有统计学意义(P＜0.01).结论 电穿孔介导的基因治疗能使bFGF在牵引区的表达增强和表达时限延长,发挥其生理作用,促进细胞的分裂增殖与分化及牵引区细胞基质的形成和新骨生成.这可能是基因治疗促进牵引区新骨生成的机制之一.

abstractsObjective To investigate the effect of gene therapy which was mediated by electroporation on the expression of basic fibroblast growth factor (bFGF) duning mandible distraction.Methods Bilateral mandibular osteotomies were performed in New-Zealand rabbit.After a latency of 3 days,the mandibles were elongated using distractors with a rate of 0.8 mm/d for 7 days.The rabbits were randomly divided into 5 groups:2 μtg recombinant plasmids pIRES-hVEGF165-hBMP2,pIRES-hBMP2,pIRES-hVEGF165,pIRES and normal saline (NS) were injected into the distraction area of groups A,B,C,D and E,after completion of distraction,respectively.The lengthened mandibles were harvested and processed for immunohistochemical detection of bFGF,and the mean optic densities and integral optical density of bFGF positive cells were measured by computerized image analyzer.Results bFGF mainly located in fibroblasts,giant monocytes,polynuclear phagocytes,osetocytes,and osetoblasts in the connective tissue around bone tissue.The strongest expression was observed at the 7th day,and weakened at 14th day of consolidation stage,there were no significant difference among groups A,B and C,at the 7th day of consolidation.However,there were significant differences between gene therapy groups (A,B and C) and control groups (D and E) (P＜0.01).Conclusions Gene therapy can enhance and prolong the expression of bFGF in distraction gap,which promotes the cell differentiation and proliferation,extracellular matrix synthesis and new bone formation during distraction osteogenesis.This is probably one of the molecular mechanisms of the gene therapy promoting new bone formation in distraction gap.