APP17肽对快速老化小鼠SAMP10学习、记忆功能和海马神经 细胞线粒体氧化应激水平的影响

目的：观察APP17肽(β-Amyloid precursop protein,APP,319-335肽段)对快速老化小鼠SAMP10（senescence accelerated mouse/pr one 10）学习、记忆功能及海马神经细胞线粒体氧化应激的影响。方法:4月龄的SAMP10小鼠随机分为模型组和APP17肽治疗组，正常对照组采用抗快速老化小鼠SAM R1(senescence accelerated mouse/resistance 1)。APP17肽治疗组给予皮下注射APP17肽 ，每只每次0.34 μg，每周3次；模型组和正常对照给予等量的生理盐水；28周后成模。应 用水迷宫试验观察小鼠学习、记忆功能的变化，应用羟胺法和硫代巴比妥酸（TBA）比色法 分析海马神经细胞线粒体氧化应激反应水平。结果:(1)水迷宫结果显示 ，模型组小鼠存在明显的学习和记忆功能障碍，其游完全程的时间和错误反应次数均较正常 对照组增多（P<0.05）;APP17肽治疗组小鼠的行为学障碍明显轻于模型组，其上述 的水迷宫检测结果与正常对照组比较无显著差异。(2)模型组小鼠海马神经细胞线粒体SOD活 性明显低于正常对照组（P<0.01），MDA含量显著高于正常对照组（P<0.01）；A PP17肽治疗组检测结果与正常对照组接近，SOD活性高于模型组（P<0.05），而MDA含 量低于模型组（P<0.01）。结论:快速老化小鼠SAMP10存在学习和 记忆功能障碍；而且其海马神经细胞线粒体氧化应激反应明显加剧。APP17肽具有清除自由 基和抑制氧化应激反应的作用，从而提高脑组织的抗氧化能力，保护学习、记忆功能。     

SCN2b mRNA在快速老化小鼠额叶和海马中的表达及变化

本实验目的在于探讨SCN2bmRNA在快速老化小鼠SAMP8的不同生长发育阶段海马和额叶中的表达及变化。按月龄将SAMP8小鼠分为3组:2周龄组、8月龄组和13月龄组,每组5只;并分别以8月龄和13月龄SAMR1小鼠为对照组,每组5只。运用RT-PCR技术,观察SCN2bmRNA在各组额叶和海马内的表达及变化。结果显示:SCN2bmRNA在各组小鼠海马和额叶中均有表达,但仅额叶内SCN2bmRNA的表达在SAMP8小鼠2周龄组分别与8月龄组和13月龄组的比较有统计学差异(P<0.05)。以上结果提示,SCN2b参与了海马和额叶正常生理功能的维持,其在额叶随月龄增加的表达变化可能与衰老、认知记忆功能的减退有关。     

电针对阿尔茨海默病小鼠海马神经元突触损伤及对CREB/BDNF信号通路的影响

目的探讨电针对APP/PS-1转基因小鼠海马神经元突触损伤及对CREB/BDNF信号通路的影响。方法将7月龄APP/PS-1转基因小鼠随机分为模型组、电针组及药物组,每组10只;另取10只同龄C57BL/6小鼠作为对照组。电针组针刺百合、印堂穴,并接入电针仪,20 min/次/天,共治疗15天;药物组给予盐酸多奈哌齐灌胃治疗;对照组及模型组不予以治疗。Morris水迷宫检测各组小鼠学习记忆能力;筑巢实验检测小鼠智力改变;尼式染色检测各组小鼠海马尼氏体变化;Western blot检测小鼠海马区SYN、PSD95、GAP43、CREB、pCREB及BDNF蛋白表达。结果 Morris水迷宫结果显示,与对照组相比,模型组小鼠逃避潜伏期增加,穿越平台次数减少,在目标象限停留时间减少;电针及药物组小鼠逃避潜伏期减少,穿越平台次数增加,在目标象限停留时间延长。模型组筑巢分数较对照组明显降低,电针及药物组小鼠筑巢分数明显增加。电针及药物组小鼠海马区神经元排列整齐且尼氏体数量增加,SYN、PSD95及GAP43蛋白表达增加。电针及药物组小鼠海马区pCREB及BDNF蛋白表达较模型组增加。结论电针减轻小鼠海马神经元突触损伤,改善APP/PS-1转基因小鼠的学习记忆能力,可能与调控CREB/BDNF信号通路相关蛋白表达有关。     

APP17肽对D-半乳糖性脑老化模型小鼠学习、记忆功能和海马神经元NT-3、NGF表达的影响

目的与方法:用D-半乳糖(D-gal)复制脑老化模型,给模型小鼠皮下注射β-淀粉样肽前体蛋白319-335肽段(APP17p),8周后应用水迷宫实验、神经免疫组化法,观察APP17肽对D-gal脑老化模型小鼠学习、记忆功能及海马神经元中神经营养因子3(NT-3)、神经生长因子(NGF)表达的影响。结果:(1)水迷宫实验D-gal组小鼠游完全程时间及错误反应次数明显高于对照组;APP17肽组小鼠游完全程时间及错误反应次数明显低于对照组和D-gal组。(2)APP17肽组海马神经元NT-3、NGF表达高于C组和D-gal组(P＜0.01)。结论:D-半乳糖性脑老化模型小鼠存在学习、记忆功能障碍,其海马神经元NT-3、NGF表达降低;APP17肽有保护模型小鼠学习、记忆功能的作用,并能促进其海马神经元NT-3、NGF表达的增加。     

β-蜕皮甾酮对APP/PS-1转基因小鼠学习记忆能力及海马Bcl-2、Bax蛋白表达的影响

目的观察β-蜕皮甾酮对APP/PS-1转基因小鼠学习记忆能力及海马Bcl-2、Bax蛋白表达的影响。方法取C57小鼠6只及APP/PS-1转基因小鼠12只,C57小鼠为对照组(Control)、APP/PS-1小鼠12只随机分为模型组(APP/PS-1)和实验组(APP/PS-1+20HE),实验组APP/PS-1转基因小鼠按14.4mg/kg的剂量灌胃β-蜕皮甾酮,每日一次,对照组及模型组小鼠灌胃等量蒸馏水,连续灌胃8周,Morris水迷宫检测小鼠学习记忆能力,尼氏染色观察各组小鼠海马组织病理学变化,免疫组化法观察海马Bcl-2和Bax蛋白表达的变化。结果模型组小鼠与对照组小鼠相比,认知能力明显下降(P<0.01),海马Bcl-2和Bax蛋白表达均增加。实验组与模型组相比,学习记忆能力明显改善(P<0.01),Bcl-2蛋白的表达增加,Bax蛋白的表达减少。结论β-蜕皮甾酮能够改善转基因小鼠的学习记忆能力,可能与促进海马Bcl-2蛋白表达和抑制Bax蛋白表达有关。     

六味地黄汤及其拆方对正常小鼠和SAMP8胸腺淋巴细胞分化相关基因表达的影响

目的:研究六味地黄汤及其"三补(SB)"、"三泻(SX)"拆方对正常小鼠和快速老化模型小鼠(SAMP8)胸腺淋巴细胞分化相关的Notch信号转导通路基因表达的影响.方法:以荧光实时定量PCR方法检测Notch1、PS1、PS2、HES1等基因表达的变化.结果:口服LW(5、10、20 s/kg)可明显促进正常小鼠胸腺细胞PS2、HES1基因的表达;口服LW(10g/kg)及其SB、SX拆方,可不同程度地降低SAMP8的PS2、HES1基因表达水平.结论:LW可增强正常的小鼠胸腺细胞Notch信号强度;对免疫老化的SAMP8,LW能够降低胸腺细胞Notch信号强度.     

APP17肽和救脑益智胶囊水提液对D-半乳糖脑老化小鼠海马PP-1表达的影响

为探讨 APP17肽及救脑益智胶囊水提液对 D-半乳糖脑老化小鼠海马蛋白磷酸酯酶 -1( PP-1)表达的影响。本研究将昆明小鼠随机分为 5组 :正常对照组、D-半乳糖对照组、APP17肽治疗组、小剂量中药治疗组、大剂量中药治疗组 ,每组动物 8只。用 D-半乳糖制备脑老化模型 ,并皮下注射 APP17肽或救脑益智胶囊水提液灌胃对 D-半乳糖脑老化小鼠进行治疗 ,3个月后取脑组织做 PP-1免疫组织化学染色。结果显示 :D-半乳糖小鼠和大剂量救脑益智胶囊水提液治疗组小鼠海马 PP-1阳性细胞数目少 ,染色淡 ;而正常小鼠、APP17肽保护和救脑益智胶囊水提液小剂量治疗的 D-半乳糖小鼠海马阳性反应神经元数目多 ,胞浆与突起深染。结果提示 :抑制凋亡的 PP-1在 D-半乳糖小鼠海马表达降低。 APP17肽和小剂量救脑益智胶囊水提液治疗能影响 D-半乳糖脑病小鼠脑内 PP-1的表达 ,使之接近正常。而大剂量救脑益智胶囊水提液治疗无此作用     

表没食子儿茶素没食子酸酯对APP/PS1双转基因小鼠神经元突触可塑性和神经细胞黏附分子表达的影响

目的 观察表没食子儿茶素没食子酸酯 (EGCG) 对淀粉样前体蛋白（APP）/早老素1(PS1)双转基因小鼠空间学习记忆能力、海马 CA1 区突触超微结构和神经细胞黏附分子表达的影响。方法 选用 8 周龄雄性APP/PS1双转基因小鼠随机分为模型组、EGCG组、盐酸多奈哌齐组,另以同窝阴性小鼠设立正常组,每组 12 只。连续灌胃给药 6 个月后进行相关指标检测。采用 Morris 水迷宫实验观测APP/PS1转基因小鼠空间学习记忆能力;透射电子显微镜观察小鼠海马CA1区突触超微结构; 分别采用免疫荧光法及免疫印迹法检测APP/PS1转基因小鼠海马CA1区神经细胞黏附分子（NCAM）和唾液酸转移酶（ST8Sia Ⅱ）的蛋白表达。结果 与正常组比较,模型组逃避潜伏期延长;与模型组比较,EGCG组、盐酸多奈哌齐组小鼠逃避潜伏期下降 (P＜0.05)。电子显微镜结果显示,与模型组比较,EGCG组和盐酸多奈哌齐组突触界面曲率变化不明显;突触间隙宽度变窄,突触后致密物厚度增加（P＜0.05）。免疫荧光结果显示,海马CA1区NCAM、ST8Sia Ⅱ蛋白表达在神经元的胞体内,EGCG组和盐酸多奈哌齐组NCAM、ST8Sia Ⅱ蛋白表达明显增加 (P＜0.05),免疫印迹实验发现其含量亦呈高表达水平(P＜0.05)。结论 EGCG对 APP/PS1 转基因小鼠的空间学习记忆功能具有改善作用,其机制可能与影响小鼠海马突触结构,提高小鼠海马神经黏附分子表达有关。     

电针干预阿尔茨海默病模型小鼠海马神经元和少突胶质细胞的增殖分化

背景：电针对阿尔茨海默病模型小鼠海马少突胶质细胞增殖分化的影响尚不清楚，而与少突胶质细胞有关的脱髓鞘反应却是阿尔茨海默病的常见病理反应。目的：探讨电针刺激阿尔茨海默病模型小鼠“百会”“风府”和双侧“肾俞”对内源性神经干细胞向神经元和少突胶质细胞增殖分化的影响及机制。方法：将6周龄清洁级APP/PS1转基因雄性阿尔茨海默病模型小鼠40只随机分为电针穴位组(n=20)和阿尔茨海默病模型组(n=20)，另以同鼠龄的健康C57BL/6J雄性小鼠作为正常对照组(n=20)。电针穴位组小鼠电针“百会”“风府”和双侧“肾俞”穴位16周后(每天20 min，每周6 d)，水迷宫检测其学习记忆功能；免疫组化染色检测海马齿状回β-淀粉样蛋白老年斑表达；免疫荧光双标检测海马齿状回Brd U/Neu N和Brd U/GALC的表达；免疫印迹检测海马神经元特异性蛋白Nestin和少突胶质细胞特异性蛋白GALC的表达水平；实时荧光定量PCR和免疫印迹检测海马Notch1和Hes1的m RNA及蛋白水平。结果与结论：(1)相对于正常对照组，模型组小鼠学习记忆能力明显下降；海马齿状回β-淀粉样蛋白老年斑明显增多(P&...     

芍药苷对APP/PS1小鼠的神经细胞保护作用及机制研究

目的:探讨芍药苷(paeoniflorin,PF)通过抑制细胞凋亡通路而产生神经细胞保护作用的机制。方法:分别选用15只5月龄雄性APP/PS1非显性小鼠作为正常对照组,15只5月龄雄性APP/PS1双转基因小鼠为模型组和15只5月龄雄性APP/PS1双转基因小鼠为给药组(5 mg/kg的PF腹腔注射)。采用水迷宫实验检测各组小鼠的学习和记忆能力。采用TUNEL荧光染色法检测脑内神经细胞凋亡情况。采用Western Blot检测脑内皮层及海马区PI3K、Akt、p-PI3K、p-Akt、caspase-3、caspase-9、Bcl-2和Bax的蛋白表达水平,并用免疫组化分析caspase-3和caspase-9的蛋白表达水平及分布情况。结果:(1)与正常对照组相比,APP/PS1模型组小鼠的学习和记忆能力明显下降;与APP/PS1模型组相比,PF明显改善小鼠的学习和记忆能力。(2)与正常对照组相比,APP/PS1模型组小鼠脑内神经细胞凋亡明显增多,分布区域较广,而PF给药组小鼠凋亡细胞明显减少。(3)与APP/PS1模型组相比,PF给药组能显著下调促凋亡因子caspase-3、caspase-9和Bax的表达水平(P0.05),同时上调抑凋亡因子pPI3K、p-Akt和Bcl-2的表达水平(P0.05)。结论:PF可能通过激活PI3K/Akt通路而上调Bcl-2,下调caspase-9、caspase-3和Bax的蛋白表达水平,从而抑制神经细胞凋亡和保护神经细胞,以治疗神经退行性疾病。     

六味地黄汤现代药理学及化学的初步研究

六味地黄汤（LW）是传统中医“滋补肾阴”的经典代表名方,由宋朝名医钱乙取《金匮要略》中的肾气丸去桂附,变“温补肾阳”为“滋补肾阴”,在《小儿药证直诀》中首创。本方由熟地、山茱萸、山药、泽泻、牡丹皮及茯苓所组成,用于“滋补肾阴”、“填补肾精”,主治肝肾阴虚、腰膝酸软、头晕目眩、耳鸣耳聋、遗精、消渴、盗汗、骨蒸潮热、小便淋沥等肾阴不足之证,被认为是大补元阴的代表方剂。“元阴者其在肾”,因此本方功专于肾,是“滋阴补肾”之首方,近千年来在中医临床广为应用。在近代临床医疗中,LW 仍被广泛应用于神经衰弱帕金…     

神经元型一氧化氮合酶在快速衰老小鼠额叶皮质中的增龄性改变

为了观察快速衰老小鼠(senescence accelerated mouse,SAM)衰老过程中大脑额叶皮质中nNOS的分布和表达变化,探讨NO/nNOS在中枢神经系统衰老中的作用。采用雄性快速衰老亚系8小鼠(senescence accelerated mouse/prone8,SAMP8)及抗快速衰老亚系1小鼠(senescence accelerated mouse/resistance1,SAMR1)为研究对象,其中SAMP8为实验组,SAMR1为对照组,每组动物再分为青年组(2月龄)和老年组(10月龄)两组。用免疫组织化学方法观察SAM额叶皮质中的nNOS神经元的形态和分布,并计数nNOS阳性神经元在额叶皮质中的数量;用RT-PCR法检测额叶皮质中nNOS mRNA表达水平。结果显示:SAMP8老年组与青年组相比,额叶皮质中nNOS阳性神经元的数量显著增加(15.8±6.3vs8.0±4.9,P<0.05);SAMP8与SAMR1比较,青年组额叶皮质nNOS阳性神经元的数量差异无统计学意义,老年组额叶皮质nNOS阳性神经元的数量显著增加(15.8±6.3vs7.5±5.3,P<0.05)。SAMP8老年组额叶皮质nNOS mRNA水平明显高于SAMP8青年组(1.00±0.17vs0.67±0.13,P<0.01)和老年组SAMR1(1.00±0.17vs0.67±0.11,P<0.01)。以上结果提示:额叶皮质中nNOS神经元的数量增加可能产生过量NO,NO可能参与了SAMP8快速衰老的过程。本研究的结果为通过调节额叶皮质NO产量来延缓衰老及衰老相关功能障碍提供了依据。     

Sleep wake profile and EEG spectral power in young or old senescence accelerated mice

Changes occurring with age in cortical EEG and sleep-wake states architecture were examined in senescence accelerated prone (SAMP8) or senescence resistant (SAMR1) mice (age: 2 and 12 months) under baseline conditions or after a 4 h sleep deprivation (SD). In baseline conditions, an increase in slow wave sleep (SWS) amount (21-24%) occurs at the expense of the wakefulness (W) in old SAMP8 and SAMR1 mice versus young animals. In these conditions, SWS latency is reduced (67-72%). Moreover, in SAMP8 and SAMR1 mice, aging deteriorates paradoxical sleep (PS) architecture with more pronounced changes in SAMP8 (amount: -63%; episode duration: -44%; latency: +286%; circadian component loss; and EEG theta (theta) peak frequency (TPF): -1 Hz). During the 4 h recovery subsequent to a 4 h sleep deprivation, old SAMP8 mice exhibit an enhanced sensitivity resulting in SWS (+62%) and PS (+120%) rebounds, a characteristic of this inbred strain. Results obtained are discussed in line with the age-related learning and memory impairments existing in SAMP8 animals. In particular, the reduced cognitive performances described in old SAMP8 might be linked to the TPF deterioration during PS.     

Quantitative proteomics analysis of specific protein expression and oxidative modification in aged senescence-accelerated-prone 8 mice brain

The senescence-accelerated mouse (SAM) is a murine model of accelerated senescence that was established using phenotypic selection. The SAMP series includes nine substrains, each of which exhibits characteristic disorders. SAMP8 is known to exhibit age-dependent learning and memory deficits. In our previous study, we reported that brains from 12-month-old SAMP8 have greater protein oxidation, as well as lipid peroxidation, compared with brains from 4-month-old SAMP8 mice. In order to investigate the relation between age-associated oxidative stress on specific protein oxidation and age-related learning and memory deficits in SAMP8, we used proteomics to identify proteins that are expressed differently and/or modified oxidatively in aged SAMP8 brains. We report here that in 12 month SAMP8 mice brains the expressions of neurofilament triplet L protein, lactate dehydrogenase 2 (LDH-2), heat shock protein 86, and alpha-spectrin are significantly decreased, while the expression of triosephosphate isomerase (TPI) is increased compared with 4-month-old SAMP8 brains. We also report that the specific protein carbonyl levels of LDH-2, dihydropyrimidinase-like protein 2, alpha-spectrin and creatine kinase, are significantly increased in the brain of 12-month-old SAMP8 mice when compared with the 4-month-old SAMP8 brain. These findings are discussed in reference to the effect of specific protein oxidation and changes of expression on potential mechanisms of abnormal alterations in metabolism and neurochemicals, as well as to the learning and memory deficits in aged SAMP8 mice.     

Memantine combined with environmental enrichment improves spatial memory and alleviates Alzheimer’s disease-like pathology in senescence-accelerated prone-8(SAMP8) mice

Memantine is a N-methyl-D-aspartate(NMDA) receptor antagonist approved for the treatment of moderate to severe Alzheimer’s disease(AD).Environmental enrichment(EE) has shown significant beneficial effects on functional improvement in AD.In this study,we sought to determine whether combining these two distinct therapies would yield greater benefit than either drug used alone.We investigated the effect of memantine combined with EE on spatial learning and memory and AD-like pathology in a widely used AD model,the senescence-accelerated prone mice(SAMP8).The SAMP8 mice were randomly assigned to enriched housing(EH) or standard housing(SH),where either memantine(20 mg/kg) or saline was given by gastric lavage once daily continuously for eight weeks.Our results showed that,when provided separately,memantine and EE significantly improved spatial learning and memory by shortening escape latencies and increasing the frequency of entrance into the target quadrant.When combined,memantine and EE showed additive effect on learning and memory as evidenced by significant shorter escape latencies and higher frequency of target entrance than either drug alone.Consistent with the behavior results,pathological studies showed that both memantine and EE significantly reduced hippocampal CA1 neurofibrilliary tangles(NFTs) as well as amyloid beta precursor protein(APP) levels.Combining both therapies synergistically lessened NFTs and APP expression compared to either drug alone in SAMP8 mice,indicating that the combination of memantine with EE could offer a novel and efficient therapeutic strategy for the treatment of AD.     

Age-related difference in nociceptive behavior between SAMP6 and SAMR1 strains

Senescence accelerated prone mouse 6 (SAMP6) mice have been known to be a model for accelerated aging. Compared with the normal control senescence accelerated resistant mouse 1 (SAMR1) mice, although the SAMP6 mice have normal bone mass at 4 months, they exhibit a significantly lower bone mass at 8 months. It was recently reported that SAMP6 has memory deficit at 4 months of age, indicating that the change of nervous function might be already detected at 4 months of age. To assess whether SAMP6 mice exhibit an age-related abnormality of nociceptive transmission, we examined a battery of tests using the von Frey test for mechanically induced response, the hot plate test for thermally induced response, and the formalin paw test for chemically induced response. SAMP6 and SAMR1 showed similar response patterns in the von Frey test and the hot plate test. In the formalin paw test, 1-month-old SAMP6 and SAMR1 had similar responses, while 4-month-old SAMP6 exhibited attenuated phase 2 response, but normal phase 1 response. These findings indicate that onset of age-related phenotypes in SAMP6 differs in different tissues. SAMP6 could be useful to delineate the involvement of age-related nociceptive mechanisms.