淫黄葛复合剂对阿尔茨海默病小鼠行为学和海马解聚素金属蛋白酶10表达的影响

目的 探讨淫羊藿、黄芪、葛根有效组分复方对阿尔茨海默病（AD）模型小鼠行为学和海马CA3区解聚素金属蛋白酶10（ADAM10）表达的影响。方法 10月的雄性APPswe/PS1dE9双转基因模型小鼠30只随机分为复方组、模型组和去铁斯诺(DFX)组,10月龄的雄性C57BL/6 J小鼠10只作为正常对照组。用药结束后,采用Morris水迷宫检测各组小鼠学习记忆能力,并于水迷宫后取出小鼠的脑组织,应用免疫荧光、Real-time PCR和Western blotting方法检测各组小鼠海马CA3区ADAM10的表达。结果 水迷宫实验结果显示,与正常对照组小鼠相比,模型组小鼠的逃避潜伏期、游泳距离和游泳时间均明显延长(P＜0.05),穿越平台区域次数和平台区域停留时间明显减少(P＜0.05),首次穿越平台的逃避潜伏期明显延长(P＜0.05);与模型组小鼠相比,复方组和DFX组逃避潜伏期、游泳距离和游泳时间明显缩短(P＜0.05),穿越平台区域次数和平台区域停留时间明显增多(P＜0.05),首次穿越平台的逃避潜伏期明显缩短;复方组和DFX组相比,逃避潜伏期、游泳距离和游泳时间及跨台次数差异无显著性 (P＞0.05),穿越平台区域次数、平台区域停留时间和首次穿越平台的逃避潜伏期差异无显著性 (P＞0.05)。与正常对照组小鼠相比,模型组小鼠海马CA3区ADAM10的表达增高(P＜0.05);与模型组相比,复方组和DFX组小鼠海马CA3区DAM10的表达降低(P＜0.05);复方组和DFX组相比,ADAM10表达水平差异无显著性 (P＞0.05)。结论 应用淫羊藿、黄芪、葛根有效组分复方可以改善APPswe/PS1dE9双转基因AD模型小鼠的学习记忆能力,其机制可能与下调ADAM10的表达减少神经元的损伤和死亡有关。     

阿尔茨海默病转基因小鼠海马结构NIX的变化

目的观察阿尔茨海默病转基因小鼠海马结构NIX的变化。方法以Morris水迷宫检测野生型和突变型转基因小鼠学习记忆能力,免疫组织化学和共聚焦激光扫描显微技术观察转基因小鼠海马结构促凋亡蛋白NIX的变化结果野生型和突变型小鼠逃避潜伏期中位数分别为29.00 s和38.00 s,差异无统计学意义,P>0.05;野生型和突变型小鼠搜索策略相比,突变型较野生型使用的搜索策略减少,差异有统计学意义,P<0.05;野生型和突变型小鼠NIX免疫反应阳性物灰度值中位数分别为103.83和128.85,差异有统计学意义,P<0.05;野生型和突变型小鼠海马结构NIX平均荧光强度分别为92.18±7.81和103.07±14.94,差异有统计学意义,P<0.05;野生型和突变型小鼠海马结构NIX与线粒体共定位的数目分别为240.94±169.48和544.18±336.44,差异有统计学意义,P<0.05。结论阿尔茨海默病转基因小鼠出现学习记忆障碍,海马结构促凋亡蛋白NIX的量增多,且NIX与线粒体共定位的量增多,提示NIX在阿尔茨海默病病理改变过程中可能起到一定的作用。     

淫羊藿、黄芪、葛根有效组分复方介导铁调素干预AD细胞模型ADAM10表达的研究

目的:探讨淫羊藿、黄芪、葛根有效组分复方介导铁调素(hepcidin,HAMP)对阿尔茨海默病(Alzheimer disease,AD)细胞模型淀粉样前体蛋白水解中关键酶去整合素金属蛋白酶10(a disintegrin and metalloproteinase 10,ADAM10)表达的影响。方法:体外培养小鼠海马神经元细胞系HT22,随机分为7组:正常对照组、Aβ组(Aβ25-35诱导HT22细胞建立AD细胞模型)、RNAi组(沉默HAMP基因)、Aβ+RNAi组(建立AD细胞模型并沉默HAMP基因)和Aβ+TCM组(建立AD细胞模型并应用淫羊藿、黄芪、葛根有效组分复方处理)、RNAi+TCM组(沉默HAMP基因并应用淫羊藿、黄芪、葛根有效组分复方处理)、Aβ+RNAi+TCM组(建立AD细胞模型沉默HAMP基因并应用淫羊藿、黄芪、葛根有效组分复方处理)。应用qPCR和Western blot检测HAMP的沉默效率应用免疫荧光、qPCR和Western blot检测各组ADAM10的表达情况。结果:与正常对照组比较,Aβ组、RNAi组和Aβ+RNAi组中的ADAM10表达显著降...     

中药复方CHPⅡ对PDAPPV717I转基因小鼠脑组织病变的影响

目的研究中药复方(CHPⅡ)对PDAPP^V717I转基因小鼠脑组织内病理改变的影响。方法通过免疫组织化学染色检测CHPⅡ对PDAPP^V717I转基因小鼠脑组织内淀粉样蛋白沉淀和反应性星形胶质细胞活化程度的影响。结果CHPⅡ治疗组PDAPP^V717I转基因小鼠脑组织内淀粉样蛋白沉淀的水平明显低于对照组和脑复康组,反应性星形胶质细胞的活化程度也明显降低。结论CHPⅡ能够明显降低PDAPP^V717I转基因小鼠脑组织内淀粉样蛋白沉淀,降低脑组织内的神经炎症反应。     

淫羊藿苷对化疗后小鼠骨髓和细胞免疫抑制作用的影响

目的:观察淫羊藿苷(ICA)对环磷酰胺(Cy)所致小鼠骨髓和免疫抑制作用的影响,探讨ICA促进化疗后小鼠造血功能和免疫功能的作用及机制。方法:将小鼠随机分为6组:正常对照组,模型组,阳性对照组,ICA高、中、低剂量组。除正常对照组小鼠外,其余各组小鼠均腹腔注射Cy(200mg/kg)。第2天开始,对ICA高、中、低剂量的实验组小鼠灌胃不同剂量的ICA(150、80、40mg/kg.d),阳性对照组小鼠尾静脉注射参芪扶正注射液(1mL/d),模型对照组给予等量生理盐水,连续给予10d。经HE染色后观察小鼠胸腺组织结构的变化。用MTT比色法检测脾淋巴细胞的增殖率。用乳酸脱氢酶(LDH)法检测腹腔巨噬细胞对肿瘤细胞的杀伤能力。用ELISA试剂盒检测混合细胞培养上清中TNF-α和IL-12的含量。用全自动血液分析仪检测外周血红细胞、白细胞和血小板数量的变化;外周血和股骨骨髓涂片经瑞氏-吉姆萨染色后,光镜下计数单根股骨骨髓细胞(BMC)的数量。结果:ICA具有保护小鼠胸腺、骨髓免受Cy损伤的作用。不同剂量的ICA组小鼠的脾淋巴细胞增殖能力增加,巨噬细胞吞噬能力和分泌细胞因子的能力均增强,外周血红细胞、白细胞和血小板数量均明显上升。结论:ICA可逆转Cy化疗后小鼠骨髓造血和免疫功能的抑制状况。     

补肾中药有效成分对大鼠骨损伤愈合及血液流变学的影响

背景：补肾中药为骨伤科常用药,但对不同有效成分用于骨愈合的比较研究尚缺乏。 目的：观察不同补肾中药有效成分对骨损伤大鼠骨愈合及血液流变学的影响。 方法：建立大鼠股骨干骨折模型并分别用提取的骨碎补总黄酮、淫羊藿总黄酮、菟丝子总黄酮、柚皮甙、槲皮素,以及橙皮甙对造模大鼠进行灌胃治疗。21 d后取血及骨标本,检测大鼠骨愈合程度和血液流变学指标。 结果与结论：不同补肾中药有效成分均对骨愈合有益,且骨碎补总黄酮、淫羊藿总黄酮效果优于其他4种药物。骨碎补总黄酮和淫羊藿总黄酮可有效抑制低剪切速下大鼠的血液黏度,降低红细胞聚集指数及血小板聚集性和黏附性(P < 0.05),但对红细胞变形性无显著作用。说明补肾中药有效成分可促进骨损伤的愈合,且对血液流变学有一定作用,以骨碎补总黄酮效果最佳。     

雌激素对app/ps1双转基因阿尔茨海默病模型小鼠海马老年斑形成的抑制作用

目的：用无偏性体视学定量研究雌激素对app／ps1双转基因(app／ps1 dtg)AD模型小鼠海马β-淀粉样蛋白(Aβ)沉积及老年斑形成的抑制作用。方法：雌性app／ps1 dtg小鼠行双侧卵巢切除,于颈部皮下植入可持续释放60d的17β-雌二醇片剂(17-β pestradiol,E2);60d后取脑行冰冻切片,6E10免疫组化染色显示沉积于海马的Aβ,刚果红组织学染色显示老年斑,无偏性体视学测量海马内Aβ斑及老年斑的总体积。结果：E2抑制Aβ在海马内沉积,降低海马内Aβ斑的总体积,并抑制老年斑的形成。结论：E2防治阿尔茨海默病可能与E2抑制Aβ在脑内沉积并聚集形成老年斑有关。     

淫羊藿甙对脑缺血再灌损伤小鼠的保护作用

目的：探讨淫羊覆甙对脑缺血再灌损伤小鼠的保护作用及其机制。方法：采用双侧颈总动脉夹闭合并取血降压再灌注的方法建立小鼠脑缺血再灌损伤模型，随机分为假手术组、模型组、淫羊藿甙防治组，检测各组行为学、总抗氧化能力、超氧化物歧化酶(superoxide dismutase，SOD)、丙二醛(malondialdehyde,MDA)、ATPase酶活性的变化。结果：(1)模型组小鼠学习记忆能力减退．淫羊藿甙(10、30、100mg／kg)灌胃可不同程度的提高小鼠学习记忆成绩。     

淫羊藿苷(ICA)对化疗后免疫抑制小鼠的免疫促进作用

目的:通过观察淫羊藿苷(ICA)对化疗药环磷酰胺(Cy)所致免疫抑制小鼠免疫功能的影响,探讨ICA促进免疫功能的作用及机理.方法:除正常组小鼠外,所有小鼠经腹腔注射Cy(300 mg/kg);第二天开始给予实验组小鼠灌胃不同剂量的ICA[150、80、40 mg/(kg·d)],阳性对照组小鼠尾静脉注射参芪扶正注射液(1 ml/d),模型组给予等量生理盐水,连续干预10天.所有小鼠均于末次给药12小时后处死,计算胸腺指数(TI)和脾指数(SI),光镜下计数外周血和脾淋巴细胞数量.MTT法检测小鼠脾淋巴细胞增殖反应.ELISA法检测TNF-α的含量.乳酸脱氢酶实验(LDH)检测小鼠脾脏NK和CTL细胞的活性.流式细胞术(FACS)检测脾淋巴细胞中NKT和CD3+T细胞的比例.结果:模型组小鼠以上各项免疫指标均有所下降.ICA处理组小鼠脾脏指数和胸腺指数均升高(P<0.01),脾淋巴细胞数量显著增加(P<0.01),但未达到正常对照组水平;ICA明显提高小鼠脾淋巴细胞的增殖反应,促进了小鼠脾NK和CTL细胞对肿瘤细胞的杀伤活性(P<0.01),提高了小鼠脾细胞TNF-α的产生(P<0.01).ICA处理组小鼠脾细胞中CD3+T、NKT细胞比例明显增加(P<0.01).结论:ICA能促进小鼠免疫功能,具有逆转化疗后小鼠免疫抑制状态的作用.     

app/ps1双转基因阿尔茨海默病模型小鼠脑内胶质细胞的激活及iNOS的表达

目的研究10～12月龄雌性app／ps1双转基因阿尔茨海默病(AD)模型小鼠(app／ps1,dtg)脑内小胶质细胞和星形胶质细胞的激活,以及诱导型一氧化氮合酶(inducible nitric oxide,iNOS)的表达。方法免疫组织化学结合刚果红组织学染色,普通光学显微镜观察。结果在app／ps1 dtg小鼠皮质和海马内有广泛的神经炎斑形成,围绕在神经炎斑周围的小胶质细胞和星形胶质细胞处于活化状态,且活化的星形胶质细胞表达iNOS。结论app／ps1 dtg小鼠能够模拟AD病人脑内的主要病理过程。神经胶质细胞的激活及iNOS的表达在app／ps1 dtg小鼠和AD脑内病理过程中具有重要的作用。     

Cortical atrophy and hypoperfusion in a transgenic mouse model of Alzheimer's disease

Magnetic resonance imaging studies have revealed distinct patterns of cortical atrophy and hypoperfusion in patients with Alzheimer's disease. The relationship between these in vivo imaging measures and the corresponding underlying pathophysiological changes, however, remains elusive. Recently, attention has turned to neuroimaging of mouse models of Alzheimer's disease in which imaging-pathological correlations can be readily performed. In this study, anatomical and arterial spin labeling perfusion magnetic resonance imaging scans of amyloid precursor protein transgenic and age-matched wild-type mice were acquired at 3, 12, and 18 months of age. Fully-automated image processing methods were used to derive quantitative measures of cortical thickness and perfusion. These studies revealed increased regional cortical thickness in young transgenic mice relative to age-matched wild-type mice. However, the transgenic mice generally demonstrated a greater rate of cortical thinning over 15 months. Cortical perfusion was significantly reduced in young transgenic mice in comparison with wild-type mice across most brain regions. Previously unreported regional genotype differences and age-related changes in cortical thickness and cerebral perfusion were identified in amyloid precursor protein transgenic and wild-type mice.     

Transthyretin accelerates vascular Abeta deposition in a mouse model of Alzheimer's disease

Transthyretin (TTR) binds amyloid-β (Aβ) and prevents Aβ fibril formation in vitro . It was reported that the lack of neurodegeneration in a transgenic mouse model of Alzheimer's disease (AD) (Tg2576 mouse) was associated with increased TTR level in the hippocampus, and that chronic infusion of anti-TTR antibody into the hippocampus of Tg2576 mice led to increased local Aβ deposits, tau hyperphosphorylation and apoptosis. TTR is, therefore, speculated to prevent Aβ pathology in AD. However, a role for TTR in Aβ deposition is not yet known. To investigate the relationship between TTR and Aβ deposition, we generated a mouse line carrying a null mutation at the endogenous TTR locus and the human mutant amyloid precursor protein cDNA responsible for familial AD (Tg2576 /TTR ^−/− mouse) by crossing Tg2576 mice with TTR-deficient mice. We asked whether Aβ deposition was accelerated in Tg2576/ TTR ^−/− mice relative to the heterozygous mutant Tg2576 (Tg2576/ TTR ^+/−) mice. Contrary to our expectations, the degree of total and vascular Aβ burdens in the aged Tg2576/ TTR ^−/− mice was significantly reduced relative to the age-matched Tg2576/ TTR ^+/− mice. Our experiments present, for the first time, compelling evidence that TTR does not suppress but rather accelerates vascular Aβ deposition in the mouse model of AD.     

Early cerebrovascular inflammation in a transgenic mouse model of Alzheimer's disease

Amyloid plaques associated with Alzheimer's disease (AD) induce inflammatory responses associated with activated microglia and reactive astrocytes, which exacerbate neurodegeneration through release of inflammatory cytokines, reactive oxygen species, and other factors. Inflammation contributes to neurodegeneration at later stages of AD, but it may also play a role in early disease pathogenesis. We found that before plaque deposition, amyloid precursor protein (APP)/presenilin 1 (PSEN1) transgenic mice (PSAPP mice), a well-characterized model of AD, exhibit evidence of cerebrovascular inflammation. Expression of the endothelial cell-specific antigen MECA-32 (mouse endothelial cell antigen-32) was upregulated in the cerebrovasculature of young PSAPP mice (3 months old) and was similar to that observed in mice with experimental autoimmune encephalomyelitis, a model of multiple sclerosis characterized by neuroinflammation. MECA-32 is normally expressed in central and peripheral vasculature throughout development, but expression in the cerebrovasculature is downregulated on establishment of the blood-brain barrier (BBB). However, CNS inflammation triggers re-expression of MECA-32 in compromised cerebrovasculature. Our study indicates that MECA-32 may be a robust marker of cerebrovascular inflammation and compromised BBB integrity, triggered by soluble amyloid-β early in disease pathogenesis.     

Hypermetabolism in a triple-transgenic mouse model of Alzheimer's disease

A common feature of Alzheimer's disease (AD) is weight loss, even though there is often an increase in food intake in AD patients. The reasons for this weight loss are unknown, but may be due to increased energy expenditure (metabolic rate) or a reduction in energy intake. This was investigated in the present study, using a triple-transgenic (3xTgAD) mouse model of AD. Two-month-old 3xTgAD mice displayed greater food intake (17%) and body weight (34%) but no difference in metabolic rate, as compared with nontransgenic controls (non-Tg). At 12 months of age, 3xTgAD mice still consumed more food (30%), but their body weight was significantly lower (15%) than non-Tg controls. This reduction in body weight was accompanied by a significant rise in metabolic rate, indicated by greater oxygen consumption (24%) and carbon dioxide production (29%); the effects were also observed in 18-month-old 3xTgAD mice. These data demonstrate for the first time the existence of a hypermetabolic state in an experimental model of AD, but whether this can explain the weight loss observed in AD patients remains to be determined.     

Effects of demographic factors on cortical thickness in Alzheimer's disease

The aim of this study was to investigate the effect of demographic factors (age of onset, sex and years of education) on the distribution of cortical thickness in a large sample of patients with Alzheimer's disease (AD). The study participants consisted of 193 AD patients and 142 controls with no cognitive impairment (NCI) that were measured with cortical thickness across the entire brain. The effects of demographic factors on cortical thickness were analyzed by applying linear regression after controlling confounding factors. Older individuals in NCI group showed more cortical thinning in frontal, temporal association cortices and insula than younger participants. Early onset AD was associated with cortical thinning in the parietal lobe, whereas late onset AD was associated with cortical thinning in the medial temporal region. The NCI group demonstrated sex-related differences in cortical thickness, although those differences were not present in the AD group. While the education effect was absent in NCI individuals, high levels of education in the AD group correlated with cortical thinning in the frontal and temporoparietal association cortices. Our results show that AD with earlier onset and higher education had suffered more pronounced cortical atrophy in specific parts of the brain than their counterparts, which may be related to cognitive reserve theory.     

人参皂甙对Alzheimer病模型大鼠海马生长抑素mRNA表达的影响

目的：研究人参皂甙（GS）对Alzheimer病（AD）模型大鼠海马内生长抑素（SS）mRNA表达的影响。方法：本实验以D-半乳糖致衰老合并鹅膏蕈氨酸脑内Meynert核注射建立AD大鼠模型,运用原位杂交方法结合图像分析检测各组大鼠海马SSmRNA表达。结果：模型组大鼠海马各区SSmRNA表达阳性神经元平均灰度值比正常对照组明显升高,平均密度显著降低;而预防组、治疗组阳性神经元灰度值则比模型组显著降低,平均密度明显升高;正常对照组与人参皂甙对照组大鼠的CA4及DG区中,此两项指标差异显著。结论：GS对AD模型大鼠海马SSmRNA表达减弱有预防及治疗作用。     

Intranasal deferoxamine reverses iron-induced memory deficits and inhibits amyloidogenic APP processing in a transgenic mouse model of Alzheimer's disease

Increasing evidence indicates that a disturbance of normal iron homeostasis and an amyloid-β (Aβ)-iron interaction may contribute to the pathology of Alzheimer's disease (AD), whereas iron chelation could be an effective therapeutic intervention. In the present study, transgenic mice expressing amyloid precursor protein (APP) and presenilin 1 and watered with high-dose iron served as a model of AD. We evaluated the effects of intranasal administration of the high-affinity iron chelator deferoxamine (DFO) on Aβ neuropathology and spatial learning and memory deficits created in this AD model. The effects of Fe, DFO, and combined treatments were also evaluated in vitro using SHSY-5Y cells overexpressing the human APP Swedish mutation. In vivo, no significant differences in the brain concentrations of iron, copper, or zinc were found among the treatment groups. We found that high-dose iron (deionized water containing 10 mg/mL FeCl₃) administered to transgenic mice increased protein expression and phosphorylation of APP695, enhanced amyloidogenic APP cleavage and Aβ deposition, and impaired spatial learning and memory. Chelation of iron via intranasal administration of DFO (200 mg/kg once every other day for 90 days) inhibited iron-induced amyloidogenic APP processing and reversed behavioral alterations. DFO treatment reduced the expression and phosphorylation of APP protein by shifting the processing of APP to the nonamyloidogenic pathway, and the reduction was accompanied by attenuating the Aβ burden, and then significantly promoted memory retention in APP/PS1 mice. The effects of DFO on iron-induced amyloidogenic APP cleavage were further confirmed in vitro. Collectively, the present data suggest that intranasal DFO treatment may be useful in AD, and amelioration of iron homeostasis is a potential strategy for prevention and treatment of this disease.     

携带淀粉样前体蛋白瑞典型突变基因转基因小鼠的制备及体内表达研究

目的 建立携带人类淀粉样前体蛋白瑞典型突变（Swedish mutation of amyloid precursor protein,APPSWE)基因的转基因小鼠模型。方法 采用受精卵原核显微注射法，将人类APPSWE转基因导入C57及昆明种小鼠受精卵内，然后将注射后保持完整的受精卵移植到假孕母鼠的输卵管内，然后应用聚合酶链反应（polymerase chain reaction,PCR)、荧光原位杂交及逆转录PCR分析子代小鼠中外源基因的整合及表达情况。结果 注射后卵的存活率和幼子出现率分别为76.62%和10.38%；外源基因整合率为35.29%；共获得6只首建小鼠，已稳定传3代，PCR检测共55只阳性；提取阳性小鼠心、脑、肝、肾组织及骨骼肌以人类APPSWE基因外显子特异的引物进行逆转录PCR分析，结果发现其心、脑组织及骨骼肌中具有人类APPSWE基因的表达。结论 说明携带淀粉样前体蛋白瑞典型突变基因的转基因小鼠模型已制备成功。     

Impaired long-trace eyeblink conditioning in a Tg2576 mouse model of Alzheimer's disease

Eyeblink conditioning has been used for assessing cognitive performance in cases of human neurodegenerative diseases including Alzheimer's disease (AD). Here, we tested and compared the delay and long-trace interval (TI = 500 ms) eyeblink conditionings in a Tg2576 mouse model of AD, at the age of 3, 6, and 12 months. Tg2576 mice exhibited significant impairment in trace conditioning at 6 months of age. In contrast, delay conditioning was not impaired in Tg2576 mice even at 12 months. These findings indicate that the long-TI eyeblink conditioning is more susceptible to age-related cognitive deterioration than delay conditioning in Tg2576 mice. The long-trace eyeblink conditioning could be a potential tool for detecting early cognitive deficits in AD mouse model.