砷是一种自然环境中广泛存在的非金属元素[1]。人类在自然环境和工业活动中长期接触受砷污染的水、空气和食物而中毒,造成组织器官损伤、甚至癌变。此外,砷引起神经系统损害也受到人们越来越多的关注[2]。但目前砷引起神经损伤的具体机...砷是一种自然环境中广泛存在的非金属元素[1]。人类在自然环境和工业活动中长期接触受砷污染的水、空气和食物而中毒,造成组织器官损伤、甚至癌变。此外,砷引起神经系统损害也受到人们越来越多的关注[2]。但目前砷引起神经损伤的具体机制仍不是十分明确。Hippo信号通路是一条在进化上高度保守的激酶级联信号通路,主要控制器官大小、组织稳态和组织再生[3]。本课题组已经证实,NaAsO_(2)可通过激活Hippo信号通路,诱导PC12细胞凋亡。突触后致密蛋白95(post synaptic density protein,PSD95)、突触素蛋白(synaptophysin,SYN)作为神经突触功能相关蛋白,其表达和缺失在神经系统疾病中十分重要[4]。因此,本实验在前期研究的基础上探讨Hippo通路是否参与NaAsO_(2)对PC12细胞活性、形态以及PSD95、SYN神经突触相关蛋白表达的影响。展开更多
Neuronal nitric oxide synthase （nNOS） is mainly expressed in neurons,to some extent in astrocytes and neuronal stem cells.The alternative splicing of nNOS mRNA generates 5 isoforms of nNOS,including nNOS-,nNOS-,nNOS...Neuronal nitric oxide synthase （nNOS） is mainly expressed in neurons,to some extent in astrocytes and neuronal stem cells.The alternative splicing of nNOS mRNA generates 5 isoforms of nNOS,including nNOS-,nNOS-,nNOS-,nNOS-and nNOS-2.Monomer of nNOS is inactive,and dimer is the active form.Dimerization requires tetrahydrobiopterin （BH 4）,heme and L-arginine binding.Regulation of nNOS expression relies largely on cAMP response element-binding protein （CREB） activity,and nNOS activity is regulated by heat shock protein 90 （HSP90）/HSP70,calmodulin （CaM）,phosphorylation and dephosphorylation at Ser847 and Ser1412,and the protein inhibitor of nNOS （PIN）.There are primarily 9 nNOS-interacting proteins,including post-synaptic density protein 95 （PSD95）,clathrin assembly lymphoid leukemia （CALM）,calcium/calmodulindependent protein kinase II alpha （CAMKIIA）,Disks large homolog 4 （DLG4）,DLG2,6-phosphofructokinase,muscle type （PFK-M）,carboxy-terminal PDZ ligand of nNOS （CAPON） protein,syntrophin and dynein light chain （LC）.Among them,PSD95,CAPON and PFK-M are important nNOS adapter proteins in neurons.The interaction of PSD95 with nNOS controls synapse formation and is implicated in N-methyl-D-aspartic acid-induced neuronal death.nNOS-derived NO is implicated in synapse loss-mediated early cognitive/motor deficits in several neuropathological states,and negatively regulates neurogenesis under physiological and pathological conditions.展开更多
文摘砷是一种自然环境中广泛存在的非金属元素[1]。人类在自然环境和工业活动中长期接触受砷污染的水、空气和食物而中毒,造成组织器官损伤、甚至癌变。此外,砷引起神经系统损害也受到人们越来越多的关注[2]。但目前砷引起神经损伤的具体机制仍不是十分明确。Hippo信号通路是一条在进化上高度保守的激酶级联信号通路,主要控制器官大小、组织稳态和组织再生[3]。本课题组已经证实,NaAsO_(2)可通过激活Hippo信号通路,诱导PC12细胞凋亡。突触后致密蛋白95(post synaptic density protein,PSD95)、突触素蛋白(synaptophysin,SYN)作为神经突触功能相关蛋白,其表达和缺失在神经系统疾病中十分重要[4]。因此,本实验在前期研究的基础上探讨Hippo通路是否参与NaAsO_(2)对PC12细胞活性、形态以及PSD95、SYN神经突触相关蛋白表达的影响。
文摘目的:观察天智颗粒对血管性痴呆(vascular dementia,VD)模型大鼠认知功能障碍及神经元突触可塑性的影响。方法:采用双侧颈总动脉永久性结扎法制备VD模型,将造模成功大鼠按体质量分为模型组、多奈哌齐组(0.45 mg·kg^(-1))及天智颗粒低(0.66 g·kg^(-1))、中(1.32 g·kg^(-1))、高(2.65 g·kg^(-1))剂量组,另设假手术组,每组12只。灌胃给药8周后,Morris水迷宫检测大鼠的学习记忆能力;HE染色观察海马CA1区神经元损伤情况;透射电子显微镜观察海马CA1神经元突触结构改变情况;Western Blot检测海马组织突触素(synaptophysin,SYN)、突触后致密蛋白95(postsynaptic density protein 95,PSD95)的蛋白表达水平。结果:与模型组比较,天智颗粒组大鼠逃避潜伏期明显缩短(P<0.05),平台所在象限时间占比和平台穿越次数明显增多(P<0.05),海马神经元突触间隙宽度显著减小(P<0.01),海马组织SYN、PSD95蛋白表达水平显著升高(P<0.05);HE染色及透射电镜观察显示,天智颗粒可明显改善VD大鼠海马CA1区神经元排列紊乱和突触超微结构损伤。结论:天智颗粒能明显改善VD模型大鼠认知障碍,机制可能与其修复神经元及突触超微结构损伤、提高SYN、PSD95蛋白表达水平从而改善突触可塑性有关。
基金supported by the National Natural Science Foundation of China(No. 30971021,81030023 and 30901550)
文摘Neuronal nitric oxide synthase （nNOS） is mainly expressed in neurons,to some extent in astrocytes and neuronal stem cells.The alternative splicing of nNOS mRNA generates 5 isoforms of nNOS,including nNOS-,nNOS-,nNOS-,nNOS-and nNOS-2.Monomer of nNOS is inactive,and dimer is the active form.Dimerization requires tetrahydrobiopterin （BH 4）,heme and L-arginine binding.Regulation of nNOS expression relies largely on cAMP response element-binding protein （CREB） activity,and nNOS activity is regulated by heat shock protein 90 （HSP90）/HSP70,calmodulin （CaM）,phosphorylation and dephosphorylation at Ser847 and Ser1412,and the protein inhibitor of nNOS （PIN）.There are primarily 9 nNOS-interacting proteins,including post-synaptic density protein 95 （PSD95）,clathrin assembly lymphoid leukemia （CALM）,calcium/calmodulindependent protein kinase II alpha （CAMKIIA）,Disks large homolog 4 （DLG4）,DLG2,6-phosphofructokinase,muscle type （PFK-M）,carboxy-terminal PDZ ligand of nNOS （CAPON） protein,syntrophin and dynein light chain （LC）.Among them,PSD95,CAPON and PFK-M are important nNOS adapter proteins in neurons.The interaction of PSD95 with nNOS controls synapse formation and is implicated in N-methyl-D-aspartic acid-induced neuronal death.nNOS-derived NO is implicated in synapse loss-mediated early cognitive/motor deficits in several neuropathological states,and negatively regulates neurogenesis under physiological and pathological conditions.
