冷冻异体神经移植应用转化生长因子β_1质粒的研究

EFFECT OF TRANSFORMING GROWTH FACTOR β_1 PLASMID ON FROSTED ALLOGENIC NERVE TRANSPLANTATION

目的 探讨对经反复冻融处理的冷藏异体神经移植 ,局部使用转化生长因子β1 (transforming growthfactorβ1 ,TGF-β1 )质粒的效果。 方法 健康成年不同窝 Wistar大鼠 4 0只随机分为两组 ,每组 2 0只 ,将坐骨神经在梨状肌孔下 5 mm处切除 2 .0 cm,神经缺损用预制反复冻融于 - 196℃冷冻的异体神经 2 .0 cm移植修复。实验组在局部肌肉及神经两断端注射 TGF-β1 质粒 ,对照组注射等量生理盐水。分别于 6周和 12周对每组 10只大鼠取材 ,切片、染色并进行轴索计数和统计学分析。 结果 6周时实验组轴索间基本无水肿 ,再生神经数量接近正常 ;对照组神经移植段轴索间有轻度水肿 ,再生神经较少。 12周时实验组整个神经移植段基本被再生轴突充满 ,有髓纤维排列整齐 ,轴突和髓鞘发育良好 ,再生轴突数为 98.6± 4 .8/μm2 ;对照组神经纤维排列整齐 ,轴突和髓鞘发育较实验组差 ,轴突数为 75 .8±5 .1/ μm2 ,差异有统计学意义 (P<0 .0 1)。 结论 反复冻融冷藏保存的异体神经其抗原性降低 ,具有修复神经缺损的可能性。局部使用 TGF- β1 质粒可发挥免疫抑制作用 。

Objective To study the effect of transforming growth factor β_1 (TGF-β_1) plasmid on poly frosted-defrosted allogenic nerve transplantation. Methods Forty Wistar rats were randomly divided into two groups equally. A 2.0 cm sciatic nerve segment, 5 mm away from infrapiriformis muscle space, was removed and the defect was repaired with poly frosted-defrosted allogenic nerve. The TGF-β_1 plasmids were injected into the nerve anastomosis and adjacent muscles in the experimental group, normal saline in the control group. The nerve specimens were sectioned for staining in the 6th and 12th weeks . Axonal count and statistical analyses were done. Results The grafted and distal nerve segments showed regenerated fibers in both groups. In the experimental group, less edema and more nerve fibers were observed in the 6th week. The grafted nerve segment was filled with regeneration axons, the myelinated nerve fibers arranged regularly, and the axons and the myelin sheaths developed well in the 12th week. There was significant difference in the number of regenerating axons between the experimental group 98.6±4.8/μm 2 and control group (75.8±5.1/μm 2) (P<0.01). Conclusion Multiple frost-defrost of allogenic nerve can reduce its antigenicity and increase its usefulness in repairing nerve defects. Local use of TGF-β_1 plasmid can enhance immunosuppression to reduce immuno rejection.