BDNF促进新生期视网膜神经细胞MAP-1B表达的实验研究

Study on effect of BDNF intervention on expression of MAP-1B in neonatal retinal nerve cells

目的研究脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)对视网膜神经细胞生长的影响及其可能机制,为治疗相关视网膜疾病提供依据。方法以新生小牛视网膜为研究对象,以细胞培养、神经营养因子药物诱导、PCR和免疫组化为研究手段,检测BDNF作用2d、5d、7d后,微管相关蛋白-1B(microtubule associated proteins-1B,MAP-1B)的表达情况,以明确BDNF对视网膜神经细胞生长和轴突延伸的影响。结果BDNF作用2d后,视网膜神经细胞贴壁迅速,PCR结果显示MAP-1B的cDNA表达含量增加,表达强度之比为0.338±0.010;BDNF作用5d后,视网膜神经细胞内MAP-1B基因表达量继续增加,表达强度之比为0.383±0.020;BDNF作用7d后,视网膜神经细胞内MAP-1B基因表达量仍继续增加,表达强度之比为0.474±0.030;均明显高于对照组。蛋白表达增多、密度增大和分布改变亦呈规律性,MAP-1B在生长比较旺盛的区域分布偏多。随时间推移,蛋白分布由核周向胞浆和突起部位扩展,呈极性分布。50μg·L-1的BDNF对神经细胞生长和轴突延伸起到促进作用。结论BDNF对小牛视网膜神经细胞生长有明显的促进作用,能加速细胞增生,增强细胞活性,并能促进突起延伸,增强轴突延伸的极性。

Objective To explore the effect of brain-derived neurotrophic factor（BDNF） on growth of neonatal retinal cells by detecting the expression of microtttbule associated protein-1B （MAP-1B） and it＇ s possible mechanism. Methods Neonatal bovine retinal nerve cells were treated with BDNF for 2 days ,5 days and 7 days. Polymerase chain reaction was used to evaluate the cell proliferation and DNA synthesis. Immunity histochemistry was used to study the distribution of MAP-1B in nerve cells. Results The proliferation of retinal cells was stimulated by the treatment of BDNF. It has been found that after treated with BDNF for 2 days,the expression of MAP-1B cDNA increased rapidly. The average value of expression ratio was 0.338 ± 0.010 ;After 5 days,the value was 0.383 ± 0.020 and after 7 days, the value was 0.474 ±0.030, increasing evidently in contrast to the group without BDNF. MAP-1B enclosed to cell nuclear at 2 days,lied in cytoplasm at 5 days and moved to the axon at 7 days. MAP-1B concentrated on the part grew rapidly. BDNF with 50 μg · L^-1 could promote the growth of neonatal retinal cells obviously. Conclusion BDNF can promote the growth of neonatal bovine retinal nerve cells, accelerate its proliferation and promote the development of axon.