DDX3和CK1ε在SOD1-G93A突变的ALS转基因小鼠纹状体的表达

目的:检测DDX3和CK1ε在SOD1-G93A突变的ALS转基因小鼠纹状体的表达变化,探讨其在ALS纹状体病变中的作用,为ALS研究提供新的实验依据。方法:将发病早期、中期和晚期(即95 d、108 d和122 d)的成年野生型小鼠和SOD1-G93A突变型ALS转基因小鼠分别处死取材,运用免疫荧光技术对小鼠纹状体内DDX3和CK1ε的表达水平进行检测,运用RT-PCR技术对小鼠纹状体内DDX3和CK1ε的m RNA水平进行检测,运用Western Blot行蛋白水平变化检测。结果:野生型小鼠和SOD1-G93A突变型转基因小鼠纹状体中均可检测到DDX3和CK1ε阳性细胞。DDX3和CK1ε在神经元表达,但在星形胶质细胞不表达。在发病的中期和晚期,DDX3在ALS转基因小鼠纹状体中的m RNA和蛋白表达与野生型鼠相比均升高。CK1εm RNA在ALS发病的早期不变化,在中期、晚期较野生型鼠降低;而在ALS发病的早期转基因小鼠纹状体中CK1ε蛋白表达量较野生型鼠升高,在中期、晚期降低。结论:DDX3和CK1ε在SOD1-G93A突变的ALS转基因小鼠纹状体中表达异常与ALS纹状体的病变密切相关。     

DEAD-box RNA解旋酶5和转录因子12与肌萎缩侧索硬化症的关系

目的 通过检测DEAD-box RNA解旋酶5(DDX2)和转录因子12(TCF12)在SOD1-G93A突变型肌萎缩侧索硬化症(ALS)转基因小鼠海马中表达情况及其相互作用关系,揭示DDX5和TCF12表达改变与ALS海马病变的关系.方法 将42对SOD 1-G93A突变型ALS转基因小鼠和野生型小鼠,按照95 d龄(发病早期)、108 d龄(发病中期)和122 d龄(发病晚期)分为3组,通过RT-PCR、Western blotting和免疫荧光双标记技术,检测DDX5和TCF12在海马中的表达情况,通过免疫共沉淀技术检测DDX5和TCF12蛋白之间是否具有相互作用.结果 与同龄野生型小鼠相比,在SOD 1-G93A突变型ALS转基因小鼠海马中DDX5和TCF12 mRNA无明显变化,而蛋白在95 d、108 d和122 d表达均上调,差异均有统计学意义.海马齿状回和海马本部均可见DDX5和TCF12阳性细胞,且DDX5和TCF12在海马神经元中表达.SOD1-G93A突变型ALS转基因小鼠海马中DDX5和TCF12免疫阳性反应均较同龄野生型小鼠增强.免疫共沉淀实验检测发现,DDX5和TCF12蛋白质之间存在相互作用.结论 DDX5和TCF12蛋白在SOD1-G93A突变型ALS转基因小鼠海马组织中表达上调,DDX5和TCF12表达异常与ALS海马组织病变有关.     

RhoA和ROCK2在SOD1-G93A转基因小鼠脊髓中的表达

目的:通过研究RhoA和ROCK2在SOD1-G93A转基因小鼠脊髓内的表达变化以阐明Rho/ROCK信号通路在肌萎缩侧索硬化症(ALS)病程中的作用。方法:饲养SOD1-G93A转基因小鼠和同窝野生型小鼠至发病早期、中期和晚期,部分小鼠冰上剥离新鲜脊髓组织,利用RT-PCR方法检测RhoA和ROCK2 mRNA的表达,利用Western Blot方法检测RhoA和ROCK2蛋白的表达;部分小鼠行心脏灌注并剥离其脊髓组织制成冰冻切片,利用免疫组织化学染色方法检测RhoA和ROCK2蛋白的表达。结果:在SOD1-G93A鼠发病的早期、中期和晚期,转基因小鼠脊髓中RhoA和ROCK2的mRNA及蛋白表达均上调。免疫组织化学染色实验结果显示,野生型小鼠脊髓中RhoA和ROCK2弥散分布于胞质和突起中,阳性染色浅,SOD1-G93A转基因小鼠脊髓中RhoA和ROCK2阳性染色深,大量聚集在细胞膜及细胞质。结论:RhoA和ROCK2在SOD1-G93A转基因小鼠脊髓中异常高水平表达与ALS脊髓区病变密切相关,可能参与ALS疾病进程。     

Nrf2/HO-1在肌萎缩侧索硬化症转基因小鼠脊髓中的表达变化

目的:检测不同疾病阶段肌萎缩侧索硬化症(ALS)转基因小鼠脊髓内Nrf2及HO-1表达变化,以探究抗氧化应激能力变化与ALS发病的关系。方法:应用免疫荧光双重标记和Western Blot技术检测Nrf2及其下游调节蛋白HO-1在ALS发病早期(95 d)、发病晚期(122 d)脊髓中的表达差异。结果:与同窝别野生型鼠相比较,免疫荧光双重标记结果显示:95 d、122 d ALS鼠脊髓腰段内Nrf2~+/GFAP~+星形胶质细胞增多;虽与同时间点同窝别野生型鼠比较,ALS转基因鼠脊髓中Nrf2蛋白表达略有升高,但差异无统计学意义。HO-1蛋白表达在ALS早期95 d趋势与Nrf2相同,前角神经元内表达较多;至122 d转基因鼠脊髓内HO-1~+表达多集中于星形胶质细胞内,且脊髓内HO-1蛋白总量较同窝别野生型鼠显著升高(P0.05)。结论:ALS运动神经元退变可能与星形胶质细胞激活后Nrf2及HO-1参与的氧化应激机制有关。     

转录因子12在SOD1-G93A转基因小鼠大脑皮层和纹状体中的表达与定位研究

目的:检测转录因子12(TCF12)在SOD1-G93A转基因小鼠不同年龄阶段大脑皮层和纹状体中的表达情况。方法:采用成年SOD1-G93A转基因小鼠和野生型(WT)小鼠,分别在转基因小鼠肌萎缩性侧索硬化症(ALS)发病的早(95 d)、中(108 d)、晚(122 d)期取材制备标本。使用real time RT-PCR技术检测TCF12的mRNA表达情况,使用Western Blot技术检测TCF12蛋白表达情况,使用免疫荧光双标记技术检测TCF12在大脑皮层和纹状体的表达分布以及细胞类型分布。结果:在SOD1-G93A转基因小鼠和WT小鼠的大脑皮层和纹状体中均检测到了TCF12分布,TCF12在神经元表达;在ALS发病早、中、晚期SOD1-G93A转基因小鼠大脑皮层中的TCF12 mRNA和蛋白表达较WT小鼠显著升高(P 0. 05,P 0. 01);在发病中、晚期SOD1-G93A转基因小鼠纹状体中的TCF12 mRNA和蛋白水平表达相较于WT小鼠显著升高(P 0. 01)。结论:TCF12在SOD1-G93A转基因小鼠发病中晚期大脑皮层和纹状体中表达升高,提示TCF12分子参与大鼠了ALS发病中、晚期神经元的退变进程。     

突变SOD1导致星形胶质细胞对氧化应激的易损性

目的研究突变SOD1G93A星形胶质细胞是否表现了对氧化应激的易损性。方法原代突变SOD1星形胶质细胞和野生型SOD1星形胶质细胞体外培养。实验细胞分为突变型组和野生型组;突变组和野生型组又分为对照组、血清剥夺组和EGCG干预组;使用5和10μmol/L EGCG分别干预;用MTT检测细胞的增殖能力;激光共聚焦检测ROS;用Western blot检测细胞中Nrf2及其介导的HO1和NQO1的表达。结果与正常星形胶质细胞相比,含有突变SOD1星形胶质细胞MTT显著下降(P<0.01)。细胞中Nrf2表达下降了44%(P<0.01)。Nrf2介导的HO1和NQO1的表达水平也分别下降了43%(P<0.01)和40%(P<0.05)。5和10μmol/L EGCG使NQO1的表达水平分别升高了1.5和2.5倍(P<0.05),也升高了Nrf2的表达并促进了Nrf2向细胞核中转移。结论突变SOD1造成了星形胶质细胞对氧化应激的易受损性。     

脊髓神经干细胞对小鼠视网膜移植的研究

目的　研究原代培养的脊髓神经干细胞在小鼠视网膜的整合和分化情况。　方法　利用细胞培养和体内移植技术 ,将原代脊髓神经干细胞 (NSC)移植到不同年龄小鼠的视网膜 ,并对移植后细胞的整合及分化情况进行了免疫组织化学分析。　结果　 1 移植的NSC对组织的整合能力随宿主年龄的增加而降低 ;2 移植的NSC在宿主视网膜内可以分化为星形胶质细胞、少突胶质细胞和神经元。　结论　脊髓原代NSC移植到小鼠视网膜后的整合和分化均受内外因素的调控 ,为NSC的体内分化研究提供了新的证据     

Notch1在肌萎缩侧索硬化症转基因鼠动物模型和细胞模型中的表达变化

目的:观察Notch1在肌萎缩侧索硬化症(ALS)转基因鼠动物模型和细胞模型中的表达情况。方法:应用免疫荧光、免疫印迹、RT-PCR,检测Notch1在95、108、122 d ALS转基因鼠脊髓中的表达变化;检测转染pEGFP-wt-SOD1和pEGFPG93A-SOD1的NSC34细胞模型中Notch1的表达变化。结果:Notch1可与β-tubulinⅢ共表达,与GFAP无明显共表达。较同窝野生型鼠,Notch1于蛋白水平和mRNA水平上的表达在95 d ALS转基因鼠脊髓中无明显变化,在108 d和122 d ALS转基因鼠脊髓中明显升高;与转染pEGFP-wt-SOD的NSC34细胞相比,转染pEGFP-G93A-SOD1的NSC34细胞中Notch1蛋白和mRNA表达增多。结论:Notch1在ALS转基因鼠动物模型和细胞模型中表达增多,提示Notch1信号通路可能与ALS相关。     

抑制水通道蛋白4可降低脊髓后角胶质细胞细胞外调节蛋白激酶信号的活化改善坐骨神经损伤导致的神经病理性疼痛

目的 探讨腰椎间盘突出引起的坐骨神经痛中,抑制水通道蛋白4（AQP4）对脊髓胶质细胞以及丝裂原活化蛋白激酶（MAPK）信号通路活化的影响。 方法 取8周龄雄性SD大鼠90只,分为假手术组18只,坐骨神经慢性压迫损伤(CCI)+DMSO组36只, CCI+TGN-020组（AQP4抑制剂）36只。CCI模型应用动物行为学,Western blotting方法,免疫荧光（双重染色）等方法检测。 结果 Western blotting显示,细胞外调节蛋白激酶（ERK）、c-Jun氨基末端激酶（JNK）、 p38MAPK信号通路及星形胶质细胞在神经损伤之后活化;免疫荧光在AQP4的表达被TGN-020抑制之后,胶质细胞及ERK、JNK、p38MAPK信号通路的活化被削弱,p-ERK和胶质纤维酸性蛋白（GFAP）共定位的细胞数量在损伤后明显增多,而TGN-020可减少之。 结论 抑制AQP4可抑制坐骨神经损伤引发的脊髓后角星形胶质细胞活化及MAPK信号通路活化,且可以通过抑制脊髓后角ERK通路的活化来抑制星形胶质细胞的活化,从而改善坐骨神经损伤所致神经病理性疼痛。     

DDX3和酪蛋白激酶1ε在肌萎缩侧索硬化症转基因鼠脑干中的表达变化

目的 检测DDX3和酪蛋白激酶1ε(CK1ε)在肌萎缩侧索硬化症(ALS)转基因鼠脑干中的表达变化,探讨DDX3和CK1ε在ALS脑干运动神经元变性中的作用。 方法 选取ALS转基因鼠33只,分别于发病早期（95d）、中期（108d）和晚期（122d）3个时间点剥离脑干,应用RT-PCR、Western blotting和免疫荧光染色技术分别检测ALS转基因鼠脑干组织中DDX3和CK1ε的表达规律,在脑干运动核团舌下神经（12N）和面神经（7N）中阳性细胞的分布特点及细胞定位,每组均选择相同数量的同窝野生型鼠作为对照。 结果 RT-PCR和Western blotting结果显示,与同窝野生型鼠相比,ALS转基因鼠脑干组织中DDX3和CK1εmRNA于95 d、108d、122d表达均无明显变化,DDX3和CK1ε蛋白在95d和108d表达上调,122d表达下调(P<0.01, P<0.001)。免疫荧光结果显示,在ALS鼠和野生型鼠脑干的12N和7N区域均可检测到DDX3和CK1ε阳性细胞,DDX3和CK1ε表达在神经元,在星形胶质细胞不表达。ALS鼠和野生型鼠DDX3和CK1ε免疫反应性具有差异。 结论 DDX3和CK1ε在脑干中的表达异常与ALS发病密切相关。     

人骨髓间质干细胞治疗肌萎缩侧索硬化症模型小鼠的行为学和病理学研究

目的:研究静脉移植人骨髓间质干细胞对肌萎缩侧索硬化症(ALS)模型小鼠生存期和病理变化的影响。方法:体外培养扩增人骨髓间质干细胞(hMSCs),流式细胞仪鉴定hMSCs的性质及纯度,微量尾静脉血提取模型小鼠DNA,PCR扩增鉴定肌萎缩侧索硬化症模型小鼠(SOD1-G93A阳性小鼠)。将3×106个第5代hM-SCs尾静脉移植入预放疗8周的SOD1-G93A阳性小鼠,用Weyd4分法进行评定移植小鼠和未治疗小鼠的生存期、发病时间,尼氏染色计数脊髓前角运动神经元,组织DNA提取、PCR检测人特异性基因β-globin基因来验证hMSCs在受体小鼠中的植入。结果:生存分析显示尾静脉移植hMSCs的ALS模型小鼠生存期比未治疗小鼠延长18d,延缓发病14d;尼氏染色显示在16周、20周移植小鼠脊髓前角大运动神经元计数多于未治疗小鼠;终末期hMSCs移植小鼠中,在中枢神经系统可检测到人特异性该基因。结论:hMSCs可经过尾静脉移植在ALS小鼠中长期植入,延长生存期,减少脊髓前角运动神经元的丢失,有一定的治疗作用。     

Mutation of SOD1 in ALS: a gain of a loss of function

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease caused by motoneuron loss. Some familial cases (fALS) are linked to mutations of superoxide dismutase type-1 (SOD1), an antioxidant enzyme whose activity is preserved in most mutant forms. Owing to the similarities in sporadic and fALS forms, mutant SOD1 animal and cellular models are a useful tool to study the disease. In transgenic mice expressing either wild-type (wt) human SOD1 or mutant G93A-SOD1, we found that wtSOD1 was present in cytoplasm and in nuclei of motoneurons, whereas mutant SOD1 was mainly cytoplasmic. Similar results were obtained in immortalized motoneurons (NSC34 cells) expressing either wtSOD1 or G93A-SOD1. Analyzing the proteasome activity, responsible for misfolded protein clearance, in the two subcellular compartments, we found proteasome impairment only in the cytoplasm. The effect of G93A-SOD1 exclusion from nuclei was then analyzed after oxidative stress. Cells expressing G93A-SOD1 showed a higher DNA damage compared with those expressing wtSOD1, possibly because of a loss of nuclear protection. The toxicity of mutant SOD1 might, therefore, arise from an initial misfolding (gain of function) reducing nuclear protection from the active enzyme (loss of function in the nuclei), a process that may be involved in ALS pathogenesis.     

Overexpression of neurofilament subunit NF-L and NF-H extends survival of a mouse model for amyotrophic lateral sclerosis

Mutations in superoxide dismutase 1 (SOD1) cause amyotrophic lateral sclerosis (ALS) in a subset of patients. Neurofilaments (NFs), the most abundant protein in motoneurons, may play a role in motoneuron degeneration. To investigate this role, we crossed transgenic mice expressing SOD1 mutant G93A (G93A mice) with mice overexpressing mouse neurofilament subunit H (H mice) or L (L mice). G93A mice overexpressing either NF-L or NF-H developed ALS later and survived longer than the G93A mice on a wild type background. These results illustrate a beneficial role of neurofilaments in ALS and call into question of several hypotheses regarding the role of neurofilaments in the development of ALS.     

Focal transplantation-based astrocyte replacement is neuroprotective in a model of motor neuron disease

Cellular abnormalities in amyotrophic lateral sclerosis (ALS) are not limited to motor neurons. Astrocyte dysfunction also occurs in human ALS and transgenic rodents expressing mutant human SOD1 protein (SOD1(G93A)). Here we investigated focal enrichment of normal astrocytes using transplantation of lineage-restricted astrocyte precursors, called glial-restricted precursors (GRPs). We transplanted GRPs around cervical spinal cord respiratory motor neuron pools, the principal cells whose dysfunction precipitates death in ALS. GRPs survived in diseased tissue, differentiated efficiently into astrocytes and reduced microgliosis in the cervical spinal cords of SOD1(G93A) rats. GRPs also extended survival and disease duration, attenuated motor neuron loss and slowed declines in forelimb motor and respiratory physiological functions. Neuroprotection was mediated in part by the primary astrocyte glutamate transporter GLT1. These findings indicate the feasibility and efficacy of transplantation-based astrocyte replacement and show that targeted multisegmental cell delivery to the cervical spinal cord is a promising therapeutic strategy for slowing focal motor neuron loss associated with ALS.     

Androgens affect muscle,motor neuron,and survival in a mouse model of SOD1-related amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by selective loss of upper and lower motor neurons and skeletal muscle atrophy. Epidemiologic and experimental evidence suggest the involvement of androgens in ALS pathogenesis, but the mechanism through which androgens modify the ALS phenotype is unknown. Here, we show that androgen ablation by surgical castration extends survival and disease duration of a transgenic mouse model of ALS expressing mutant human SOD1 (hSOD1-G93A). Furthermore, long-term treatment of orchiectomized hSOD1-G93A mice with nandrolone decanoate (ND), an anabolic androgenic steroid, worsened disease manifestations. ND treatment induced muscle fiber hypertrophy but caused motor neuron death. ND negatively affected survival, thereby dissociating skeletal muscle pathology from life span in this ALS mouse model. Interestingly, orchiectomy decreased androgen receptor levels in the spinal cord and muscle, whereas ND treatment had the opposite effect. Notably, stimulation with ND promoted the recruitment of endogenous androgen receptor into biochemical complexes that were insoluble in sodium dodecyl sulfate, a finding consistent with protein aggregation. Overall, our results shed light on the role of androgens as modifiers of ALS pathogenesis via dysregulation of androgen receptor homeostasis.     

The BH4 domain of Bcl-X(L) rescues astrocyte degeneration in amyotrophic lateral sclerosis by modulating intracellular calcium signals

Collective evidence indicates that motor neuron degeneration in amyotrophic lateral sclerosis (ALS) is non-cell-autonomous and requires the interaction with the neighboring astrocytes. Recently, we reported that a subpopulation of spinal cord astrocytes degenerates in the microenvironment of motor neurons in the hSOD1(G93A) mouse model of ALS. Mechanistic studies in vitro identified a role for the excitatory amino acid glutamate in the gliodegenerative process via the activation of its inositol 1,4,5-triphosphate (IP(3))-generating metabotropic receptor 5 (mGluR5). Since non-physiological formation of IP(3) can prompt IP(3) receptor (IP(3)R)-mediated Ca(2+) release from the intracellular stores and trigger various forms of cell death, here we investigated the intracellular Ca(2+) signaling that occurs downstream of mGluR5 in hSOD1(G93A)-expressing astrocytes. Contrary to wild-type cells, stimulation of mGluR5 causes aberrant and persistent elevations of intracellular Ca(2+) concentrations ([Ca(2+)](i)) in the absence of spontaneous oscillations. The interaction of IP(3)Rs with the anti-apoptotic protein Bcl-X(L) was previously described to prevent cell death by modulating intracellular Ca(2+) signals. In mutant SOD1-expressing astrocytes, we found that the sole BH4 domain of Bcl-X(L), fused to the protein transduction domain of the HIV-1 TAT protein (TAT-BH4), is sufficient to restore sustained Ca(2+) oscillations and cell death resistance. Furthermore, chronic treatment of hSOD1(G93A) mice with the TAT-BH4 peptide reduces focal degeneration of astrocytes, slightly delays the onset of the disease and improves both motor performance and animal lifespan. Our results point at TAT-BH4 as a novel glioprotective agent with a therapeutic potential for ALS.     

In vivo imaging reveals rapid morphological reactions of astrocytes towards focal lesions in an ALS mouse model

Pathophysiology of the motoneuron disease amyotrophic lateral sclerosis (ALS) is non-cell-autonomous. In mouse models of familiar ALS, neurotoxicity is derived not only from mutant motor neurons but also from mutant neighbouring glial cells. In vivo imaging by two-photon laser-scanning microscopy was used to study rapid morphological reactions of astroglial cells towards laser-induced axonal transection in ALS-linked transgenic SOD1(G93A) mice. In the affected lateral spinal cord, mutated astroglial cells extended branches towards injured axons within a time frame of minutes to hours post lesion while in control animals astrocytes lack any rapid morphological alteration within the studied time frame. This suggests that astrocytes partially contribute to the rapid response of non-neuronal cells to acute axonal lesions in ALS mice.