激活素A促进鸡胚背根神经节神经突起生长作用及其机制研究

发布时间：2018-02-12 18:37

本文关键词： 激活素A 神经生长因子神经突起 5-羟色胺一氧化氮　出处：《吉林大学》2008年博士论文　论文类型：学位论文

【摘要】： 激活素A(Activin A)属于转化生长因子-β(TGF-β)超家族的多功能生长和分化因子,新的研究揭示,Activin A具有神经营养和神经保护作用。但是,Activin A能否促进背根神经节(Dorsal root ganglia,DRG)神经突起生长、长时间维持DRG神经元存活以及抑制DRG胶质细胞增生作用至今仍不清楚。本研究采用8日龄鸡胚背根神经节,体外原代培养法,研究Activin A对鸡胚DRG神经突起生长的影响作用。结果显示Activin A能够刺激DRG神经突起生长(Neurite outgrowth),通过甲苯胺蓝染色尼氏小体和双重免疫组织化学染色证实Activin A还可以长时间维持体外培养DRG神经元存活以及抑制DRG胶质细胞增生。研究发现激活素结合蛋白——卵泡抑素(Follistatin, FS)可以阻断Activin A促进DRG神经突起生长和维持DRG神经元存活作用,但FS不能阻断NGF的作用。同时发现Activin A与NGF可以协同促进DRG神经元神经突起生长和维持DRG神经元存活。为了进一步探讨Activin A作用机制,实验采用半定量PCR、液相-质谱联用仪等,检测了激活素II型受体(ActRII)、CGRP、VIP、iNOS mRNA表达及5-羟色胺和NO释放情况。结果显示,Activin A具有促进ActRIIA、CGRP mRNA表达和神经递质5-羟色胺释放以及抑制NO分泌和iNOS mRNA表达作用,对ActRIIB及VIP mRNA表达无影响。CGRP具有神经保护、5-羟色胺具有促进神经突起作用,而NO过度分泌可以诱导神经细胞凋亡。上述资料提示Activin A刺激DRG神经突起生长和维持神经元存活作用,可能与其调控NO、5-羟色胺释放及ActRIIA、CGRP表达有关。Activin A不仅具有维持神经元存活和促进神经突起生长作用,还可以通过抑制胶质细胞活性改善神经组织重构、减少瘢痕组织的形成。本研究为Activin A治疗神经元损伤及变性疾病的应用提供了新的数据和实验依据。
[Abstract]:Activin A is a multifunctional growth and differentiation factor of transforming growth factor- 尾 (TGF- 尾) superfamily. New studies have shown that Activin A has neurotrophic and neuroprotective effects. It is still unclear to maintain the survival of DRG neurons for a long time and to inhibit the proliferation of DRG glial cells. In this study, the dorsal root ganglion (DRG) of 8-day-old chicken embryo was cultured in vitro. The effect of Activin A on the growth of DRG neurite in chicken embryo was studied. The results showed that Activin A could stimulate the growth of DRG neurite. It was proved by toluidine blue staining and double immunohistochemical staining that Activin A could also grow. The survival of DRG neurons was maintained in vitro and the proliferation of DRG glial cells was inhibited. It was found that the activin-binding protein Follistatin (FSA) could block the growth of DRG neurites and maintain the survival of DRG neurons. However, FS could not block the effect of NGF. It was also found that Activin A and NGF could promote the neurite growth of DRG neurons and maintain the survival of DRG neurons. In order to further study the mechanism of Activin A, semi-quantitative Activin and liquid-mass spectrometry were used in the experiment. The expression of iNOS mRNA and the release of 5-hydroxytryptamine and no were detected in ActRII receptor (ActRII). The results showed that Activin A could promote the expression of CGRP mRNA, release of neurotransmitter 5-hydroxytryptamine and inhibit the secretion of no and iNOS mRNA. CGRP has no effect on the expression of ActRIIB and VIP mRNA. CGRP has neuroprotective effects on neuronal processes, while no overexpression can induce neuronal apoptosis. These data suggest that Activin A stimulates the growth of DRG neurites and maintains the survival of neurons. Activin A may be related to the regulation of NO5-HT release and the expression of CGRP in ActRIIAA. Activin A can not only maintain the survival of neurons and promote neurite growth, but also improve the neural tissue remodeling by inhibiting the activity of glial cells. This study provides new data and experimental evidence for the treatment of neuronal injury and degeneration by Activin A.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2008
【分类号】：R392

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