激活素促进鸡胚神经节神经突起生长作用

为了探讨激活素(activin)促进鸡胚背根神经节(dorsal root ganglia,DRG)突起生长、维持神经节细胞生存作用及其与一氧化氮(NO)释放的关系,实验采用8 d的鸡胚分离背根神经节,原代培养法,观察鸡胚背根神经节的体外生长情况。研究结果表明,添加激活素A培养的背根神经节有明显的神经突起生长,形成密集的网络,背根神经节可存活8~10 d;而阴性对照组几乎无神经突起生长,背根神经节可存活3~4 d。添加激活素A的背根神经节单层培养神经节细胞也可长期存活;而阴性对照组在培养第5 d几乎无神经节细胞生存。NO检测结果显示,添加激活素A培养的背根神经节上清NO分泌水平明显降低,与阴性对照组比较差异显著(P<0.05);激活素A与神经生长因子(nerve growth factor,NGF)具有协同抑制背根神经节NO分泌作用。激活素结合蛋白(follistatin)明显抑制激活素A诱导的背根神经节神经突起生长。研究结果提示,激活素可维持鸡胚神经节细胞存活并刺激神经突起生长,其作用与抑制神经损伤因子NO的释放有关。

Neurite Growth Stimulation by Activin in Dorsal Root Ganglia of Embryonic Chicken

To investigate the effect of activin on neurite growth in dorsal root ganglia(DRG) and the gangliocyte survival as well as the relationship between activin function with nitric oxide release,dorsal root ganglia were collected from E8 chicken embryos and the growth of cultured DRG in vitro was observed by primary culture method.The results showed that,stimulated by activin A,the cultured DRG showed evident growth of the nervous processes,which formed a dense network and survived for 8-10 days.However,almost no nervous process growth was found in the control group,in which DRG could survive for only 3-4 days.Monolayer-cultured DRG neurocytes also maintained long-time survival in the activin A group,while the control group almost had no neurocyte survived on the fifth day.The results of NO detection indicated that NO secretion level in the supernatant of cultured DRG decreased significantly in activin A group,compared to the control group(P<0.05);furthermore,activin A and NGF may synergistically inhibit NO secretion in DRG.Follistatin,an activin-binding protein,significantly inhibited neurite growth induced by activin A.All the above findings suggest that activin could maintain gangliocyte survival and stimulate neurite growth by inhibiting the release of the nerve injury factor NO.