脑源性神经营养因子对出生后大鼠周围神经髓鞘化的作用

目的:探讨脑源性神经营养因子(BDNF)对出生后大鼠周围神经髓鞘化的作用及其作用机制.方法:用光镜和电镜方法检测坐骨神经纤维的髓鞘化情况;用免疫印迹方法检测坐骨神经p75的表达;用免疫荧光方法检测坐骨神经雪旺细胞内核转录因子(NF-kB)的表达.结果:出生后3 d,与对照组相比,实验组坐骨神经髓鞘化的神经纤维数目减少,p75表达下调,雪旺细胞内NF-KB转移率下调;出生后14 d,与对照组相比,实验组坐骨神经出现较多的髓鞘化异常.结论:内源性BDNF影响出生后大鼠周围神经的髓鞘化,尤其在早期作用明显;内源性BDNF主要通过p75和NF-kB信号途径调节出生后大鼠周围神经的髓鞘化.

Effect of endogenous BDNF on peripheral nerve myelination and its mechanism in postnatal rats

Objective: To investigate the effect of endogenous brain-derived neurotrophic factor(BDNF) on the myelination of the postnatal peripheral nerve in rats.Methods: The myelination of the sciatic nerve was measured with light microscope and electron microscope;the expression of p75 in the sciatic nerve was measured by Western blot;the nuclear translocation of NF-kappa B in the sciatic nerve were showed by immunofluorescence.Results: At postnatal day 3(P3),the number of myelinating fibres,the p75 expression and the rate of NF-kappa B nuclear translocation in the sciatic nerve were reduced in the anti-BDNF group compared to those in the control group;at P14,the number of abnormal myelinating fibres in the sciatic nerve was increased in the anti-BDNF group compared to that in the control group.Conclusion: Endogenous BDNF affected myelination of postnatal peripheral nerve through p75 and NF-kappa B signal transduction pathway.