神经生长因子对兔合并局部神经损伤的下颌骨骨折愈合中BMP-2表达的影响

The effect of nerve growth factor on the expression of BMP-2 in the healing of rabbits′mandibular fracture with partial nerve injury

目的:通过鼠神经生长因子(NGF)在兔合并局部神经损伤的下颌骨骨折模型的局部应用,观察NGF对BMP-2表达的影响,初步探讨NGF促进合并局部神经损伤的下颌骨骨折愈合的分子机制。方法:将48只新西兰大白兔随机分为实验组(下颌骨骨折+切断神经束+以明胶海绵为载体的NGF)、对照组(下颌骨骨折+切断神经束+以明胶海绵为载体的NS)、空白组(下颌骨骨折+切断神经束)和完整组(下颌骨骨折+保留神经束)。手术建模后分别于2、4、6、8周每组各处死实验动物3只,苏木精-伊红染色观察下颌骨骨折愈合情况,荧光定量PCR检测BMP-2表达的改变。结果:苏木精-伊红染色观察到骨折区成骨现象:实验组较对照组明显,完整组较空白组明显,对照组与空白组相近。PCR早期结果差异有统计学意义,BMP-2表达在2周时达到最高峰后在中后期均呈下降趋势且下降幅度随时间减小。结论:局部应用NGF能够促使BMP-2在合并局部神经损伤的下颌骨骨折愈合的早期表达升高,这可能是NGF促进下颌骨骨折愈合的分子机制之一。

Objective：To observe the effect of NGF on the expression of BMP-2in rabbit model and explore the molecular mechanism of NGF which might promote the healing of mandibular fracture with nerve injury.Method：The 48New-Zealand white rabbits were randomly divided into the experimental group（mandibular fracture＋to cut off the nerve bundle＋NGF by GS）,the control group（mandibular fracture＋to cut off the nerve bundle＋NS by GS）,the blank group（mandibular fracture＋to cut off the nerve bundle）and the full-set group（mandibular fracture＋retains the nerve bundle）.After 2weeks,4weeks,6weeks and 8weeks,3rabbits were sacrificed in each group for HE staining and RT-PCR,respectively.Result：HE staining showed the osteogenesis phenomenon：the experimental group was clearer than control group,the full-set group was clearer than the blank group and the control group is similarly to the blank group.RT-PCR results revealed that there was a statistically significance in the early stage.The expression of BMP-2peaked in 2weeks and decreased later with time.Conclusion：The local application of NGF can prompt BMP-2expression in the early stages of the mandibular fracture with partial nerve injury healing and this may be one of the molecular mechanisms.