摘要
目的 探讨肌苷对中枢神经再生的影响。方法 分离并制作均匀的视网膜神经节细胞 (RGC)悬液 ,采用 2 4孔培养皿培养 ,观察嘌呤类物质对RGC轴突生长及细胞存活的影响。结果 ( 1)肌苷促使RGC轴突生长 ;腺苷只有水解脱氨生成肌苷才能促使轴突生长。 ( 2 )肌苷与 6 硫鸟嘌呤 ( 6 TG)可能竞争性作用于蛋白激酶N(PKN)调节轴突生长。( 3 )肌苷刺激RGC致GAP 43表达增强。 ( 4 )肌苷的细胞内信息传递通路可能通过有丝分裂原激活蛋白激酶 (MAPK)、磷脂酰肌醇激酶 (PI3K)两条途径起作用。结论 肌苷在RGC神经再生中起积极的调节作用。
ObjectiveTo investigate the involvement of purine in the development and regeneration of neurons.MethodsGoldfish were dark adapted,and their retinas were dissected.Retinas were dissociated by gentle trituration.Repeated cycles of trituration and sedimentation yielded cultures nearly homogeneous in ganglion cells.Low density cells in 24 well culture dishes were maintained in a serum free.Axonal outgrowth and survival of retinal ganglion cells (RGC) in response to purine were evaluated.Results(1) Inosine stimulated axon outgrowth from RGC.Adenosine must be hydrolyzed to inosine via adenosine deaminase to stimulate RGC outgrowth.In the presence of aenosine deaminase inhibitor (deoxycoformycin),adenosine not only failed to stimulate growth,but also cause (RGC) to die.(2) 6 Thioguanine 10?μmol/L completely arrested axon outgrowth stimulated by AF 1 though not affecting cell survival.Inosine 100?μmol/L reversed the inhibitory effects of 6 thioguanine on AF 1 cometitively and may stimulate growth by direct activation of protein kinase N.(3) Inosine increased expression of GAP 43 in RGC.(4)In signaling transduction studying,PD 98059 and LY 294002,specific inhibitors to MAPKK and PI3K respectively,either alone blocked 50% of growth by inosine,blocked 100% growth by inosine if combined together.Inosine may therefore stimulate growth via MEK 1/2 and PI3K pathways.ConclusionInosine plays an important role in the development and regeneration of RGC.It suggests the possibility of a clinically therapeutic opportunity to be explored further in central nervous system neuron diseases.
出处
《眼科研究》
CSCD
2000年第3期221-223,共3页
Chinese Ophthalmic Research
