载脂蛋白E基因多态性与阿尔茨海默病

利用PCR RFLP方法分析了中国汉族人群中 16 0例散发性阿尔茨海默病 (Alzheimerdisease,AD)患者和 195例正常对照老年人中载脂蛋白E(APOE)基因多态性分布的差异。结果表明 ,APOE 3种等位基因ε2、ε3和ε4的频率在AD组和对照组分别为 0 0 5 6、0 713、0 2 31和 0 0 82、0 84 4、0 0 74。APOEε4等位基因携带个体患AD的危险为非携带个体的 3 82倍 (χ2 =2 8 7,P <0 0 0 1)。 6 5岁以上APOEε4携带个体患AD的危险为非携带个体的 5 38倍(χ2 =2 9 8,P <0 0 0 1) ,说明年龄因素可能影响ε4与AD间的相互作用。APOE等位基因和基因型频率在轻、中和重度痴呆病人间的分布无明显差异 (P >0 0 5 ) ,提示APOE基因多态性可能与AD患者的痴呆程度无关联。APOEε4基因型频率在女性AD病人中的分布略高于男性AD病人 (4 3 0 %对 36 5 % ) ,女性ε4携带个体患AD的危险也高于男性ε4携带个体 (4 3倍对 3 3倍 ) ,但统计学分析未检测到这些差异的显著性 (P >0 0 5 )。ε2等位基因频率在AD患者男性亚组明显低于女性亚组 ,也低于对照人群的男性亚组 (P <0 0 5 ) ,提示ε2等位基因可能降低中国汉族男性人群AD发病的危险     

Heart Rate Variation, Age, and Behavior in Subjects with Senile Dementia of Alzheimer Type

Minute-by-minute heart rate (HR) recordings over a period of 24 h were obtained once for 30 elderly subjects diagnosed as having senile dementia of Alzheimer type (SDAT). Twenty-one of the subjects were studied in a hospital ward setting, and nine were studied in their own homes. Twelve were men and 18 were women. Eleven took some form of sedative medication; 10 took no medication. Thirty-minute mean values were unmasked to take account of the effects of activity and sleep on HR. Results indicate that the masked HR circadian rhythm of SDAT may be more often unimodal than that of normal subjects of similar age, and that phase shift of the endogenous, clock-mediated component of the rhythm (with higher HR at night) is to be expected in a proportion of individuals with SDAT.     

The role of apolipoprotein E in neurodegeneration and cardiovascular disease

Apolipoprotein E (ApoE) is an abundant plasma protein that interacts with low density lipoprotein receptors and other proteins, participating in the transport of cholesterol and lipids. Research has revealed many other roles for this multifunctional protein. ApoE is polymorphic and exists in three major isoforms: ApoE2, ApoE3 (the most common isoform) and ApoE4, which differ by only one amino acid, at positions 112 and 158. The altered binding to lipids and receptors by ApoE isoforms E2 and E4 results in an elevated risk for neurological, cerebrovascular and cardiovascular pathologies. Most notably, ApoE4 is associated with an elevated risk (relative to E3) for Alzheimer’s disease. The application of mass spectrometry for genotyping and also direct measurement of ApoE protein isoforms is a recent development and is well suited to high-throughput applications. The precise quantification of protein isoforms will allow better characterization of effects resulting from heterozygous APOE genotypes.     

Sortilin,a novel APOE receptor implicated in Alzheimer disease

In the brain, apolipoprotein E (APOE) delivers cholesterol-rich lipoproteins to neurons to support synaptogenesis and maintenance of synaptic connections. Three APOE alleles exist in the human population with ε4 being an Alzheimer disease (AD) risk gene and ε2 being protective relative to the common ε3 variant. Many hypotheses have been advanced concerning allele-specific effects of APOE on neurodegeneration including effects on Aβ clearance, synaptic transmission, or neurotoxicity. Central to most proposed APOE functions is its interaction with receptors that mediate cellular uptake of this ligand. Several members of the LDL receptor gene family have been implicated as APOE receptors in the (patho)physiology of APOE in the brain, yet their specific modes of action in AD remain controversial. Recently, the pro-neurotrophin receptor sortilin has been identified as a novel APOE receptor in neurons. Ablation of sortilin expression in mice results in accumulation of APOE and Aβ in the brain. Moreover, primary neurons lacking sortilin exhibit significantly impaired uptake of APOE/Aβ complexes. Despite increased brain APOE levels, sortilin-deficient animals recapitulate anomalies in brain lipid homeostasis seen in APOE null mice, indicating functional deficiency in APOE uptake pathways. Taken together, these findings suggest a link between Aβ catabolism and pro-neurotrophin signaling converging on this receptor pathway.     

静止性脑梗死与血管性痴呆相关性的病例对照分析

目的　探讨静止性脑梗死 (SCI)与血管性痴呆 (VD)的关系。　方法　采用病例对照的方法对 1 2 6例血管性痴呆病人和 1 2 6例非痴呆病人进行 CT或 MRI检查 ,比较两组 SCI的发生状况。　结果　1 2 6例 VD中发现 SCI5 3例 (4 2 .1 % ) ,1 2 6例非痴呆病人中发现 SCI2 2例 (1 7.5 % ) ,两组比较有高度显著性差异 (P <0 .0 1 )。　结论　 SCI与 VD密切相关     

Polymorphism of the Apolipoprotein E Gene and Risk of Myocardial Infarction

The apolipoprotein E (ApoE) gene polymorphism resulting from nucleotide substitutions in exon 4 was analyzed in Russian and Tatar patients with myocardial infarction (MI) from Bashkortostan. Alleles 2, 3, and 4 were identified by PCR. The genotype frequency distribution proved to be age-dependent in healthy Russians, genotype 2/3 increasing in frequency in subjects over 45. Russians who suffered MI under 45 had lower frequencies of genotype E3/3 (50.00% vs. 75.47% in controls of the same age, = 0.013, OR = 0.33) and allele 3 (72.12% vs. 85.85%, = 0.020, OR = 0.43) and a higher frequency of allele 4 (22.12% vs. 10.38%, = 0.030, OR = 2.45). Russians who suffered MI complicated by cardiogenic shock (CS) had a significantly higher frequency of genotype 3/4 and lower frequencies of genotype 3/3 and allele 3 as compared with MI patients without CS. In Tatars, genotype 4/4 occurred at a frequency of 14.29% in patients who suffered MI under 45, and was not detected in healthy subjects of the same age ( = 0.024, OR = 17.85). Thus, the ApoE polymorphism was associated with higher risk of MI in Russians and Tatars under 45.     

Apolipoprotein E Is a Ligand for Triggering Receptor Expressed on Myeloid Cells 2 (TREM2)

Several heterozygous missense mutations in the triggering receptor expressed on myeloid cells 2 (TREM2) have recently been linked to risk for a number of neurological disorders including Alzheimer disease (AD), Parkinson disease, and frontotemporal dementia. These discoveries have re-ignited interest in the role of neuroinflammation in the pathogenesis of neurodegenerative diseases. TREM2 is highly expressed in microglia, the resident immune cells of the central nervous system. Along with its adaptor protein, DAP12, TREM2 regulates inflammatory cytokine release and phagocytosis of apoptotic neurons. Here, we report apolipoprotein E (apoE) as a novel ligand for TREM2. Using a biochemical assay, we demonstrated high-affinity binding of apoE to human TREM2. The functional significance of this binding was highlighted by increased phagocytosis of apoE-bound apoptotic N2a cells by primary microglia in a manner that depends on TREM2 expression. Moreover, when the AD-associated TREM2-R47H mutant was used in biochemical assays, apoE binding was vastly reduced. Our data demonstrate that apoE-TREM2 interaction in microglia plays critical roles in modulating phagocytosis of apoE-bound apoptotic neurons and establish a critical link between two proteins whose genes are strongly linked to the risk for AD.     

Effect of homocysteine and nitric oxide levels on specific Computed Axial Tomography measurements in Alzheimer disease

The present study was undertaken to examine the effect of Homocysteine (Hcy) and nitric oxide (NO) levels on specific Computed Axial Tomography (CAT) measurements, as global brain atrophy and brain vascular lesion in Alzheimer Disease (AD) and in Vascular Dementia (VD) patients. We have analysed serum Hcy and NO levels in AD patients and compared the findings with those in VD patients and control subjects. Moreover we have studied the correlation of Hcy and NO levels with cognitive impairment and brain atrophy determined by Computed Axial Tomography. Hcy serum levels significantly increased in all demented patients compared to control group, independently from the dementia type. On the contrary, no differences were observed in NO serum levels between groups. Moreover, we found significant correlation between Hcy and brain atrophy in both demented groups; whereas NO levels correlated only in AD, but not in VD patients. The pathogenic effect of Hcy either in AD and VD patients appears to confirm a definitive vascular component in AD. As regards NO, our results highlight the role of NO as a beneficial molecule in AD and support the use of NO mimetics as an antineurodegenerative therapy for AD patients.     

中西医结合治疗血管性痴呆的临床观察

目的：探讨中西医结合治疗血管性痴呆的临床疗效。方法：120例脑中风伴痴呆的患者随机分为2组,每组60例,治疗组采用一般治疗和哈伯因片200μg/d及中草药口服治疗8周,对照组采用一般治疗和哈伯因200μg/d口服8周,用长谷川痴呆量表和ADL Batthel指数来评定治疗前后痴呆和神经功能缺损情况。结果：治疗组治疗后智能缺损评分升高显著（P＜0．01）,总有效率为83．3％,对照组治疗后智能缺损评分也有明显好转（P＜0．05）,总有效率为65％,治疗组智力明显改善优于对照组（P＜0．01）。两组ADL Barthel指数治疗前无明显变化（P＞0．05）,两组均无死亡。结论：中西医结合疗法能显著提高血管性痴呆的认知能力。     

载脂蛋白E基因多态性与持续性植物状态的关系及其意义

研究载脂蛋白E(ApoE)基因多态性与持续性植物状态 (PVS)之间的关系 ,探讨PVS发生的遗传背景及其对血脂水平的影响。以 6 2名PVS患者为研究对象 ,5 5名正常人为对照 ,采用聚合酶链反应和限制性片段长度多态性(PCR RFLP)方法 ,分析了载脂蛋白E基因多态性 :血脂水平按常规酶法进行测定并进行统计学处理。ApoE基因多态分析表明 ,在PVS患者和正常人中观察到 5种ApoE基因型 ,分别为E3/ 3、E3/ 4、E2 / 2、E2 / 3及E4 / 2。PVS患者组ApoE3/ 4基因型频率高于对照组 (χ2 =14 .2 36 ,P <0 .0 0 1) ;而E3/ 3基因型频率较对照组显著降低 (χ2 =5 .348,P <0 .0 5 )。PVS患者的ε4等位基因频率显著高于对照组 (χ2 =10 .5 33,P <0 .0 0 1) ;而ε3等位基因频率显著低于对照组 (χ2 =7.0 2 2 ,P <0 .0 1)。两组ApoE基因型E2 / 2 ,E2 / 4 ,E2 / 3,E3/ 4的低密度脂蛋白胆固醇 (LDL C)水平之间存在统计学差异 (P <0 .0 5 ,P <0 .0 5 ,P <0 .0 5 ,P <0 .0 1)。ApoE基因多态性与PVS有关联 ,并影响患者的血脂水平。ApoE基因多态性可能与PVS的发生和预后有关     

用激光共聚焦显微镜观察纳络酮防治血管性痴呆大鼠对海马锥体细胞内钙离子的影响

目的:观察纳络酮预防性治疗血管性痴呆大鼠对海马锥体神经细胞内钙离子的影响。方法:将30只大鼠随机分为假手术组、模型组、防治组。利用钙离子敏感探针Fluo 3与钙离子络合后被激发产生荧光的特点,应用激光共聚焦显微镜观察海马锥体细胞内钙离子的荧光强度,应用图像分析技术记性处理。结果:荧光像素平均值假手术组为135.05±29.14;模型组为484.05±298.72较假手术组明显升高(P<0.01);防治组为139.39±30.74,较模型组明显降低(P<0.01)。结论:纳络酮防治血管性痴呆大鼠与其抑制钙离子内流保护海马神经元有关。     

Tyrosine Hydroxylase, Tryptophan Hydroxylase, Biopterin, and Neopterin in the Brains of Normal Controls and Patients with Senile Dementia of Alzheimer Type

The activities of tyrosine hydroxylase and tryptophan hydroxylase, and the concentrations of the biopterin cofactor and the precursor neopterin were measured in 14 regions of postmortem brains from four histologically verified patients of senile dementia of the Alzheimer type (SDAT) and eight histologically normal controls. Neopterin concentrations were measured in the human brain for the first time. The activities of tyrosine hydroxylase and tryptophan hydroxylase in the brains of patients with SDAT were significantly reduced in the substantia nigra and in the lateral segment of the globus pallidus, locus ceruleus, and substantia nigra, respectively. The concentrations of total biopterin in the brains of patients with SDAT were significantly reduced in the putamen and substantia nigra, but the total neopterin concentrations did not change significantly. These results suggest that the reduction in biogenic amines in SDAT might be related to reductions in biosynthetic enzymes associated with biogenic amines, due to destruction of monoaminergic neurons.     

Cortical Substance P-Like Immunoreactivity in Cases of Alzheimer's Disease and Senile Dementia of the Alzheimer Type

Abstract: The concentration of substance P-like immunoreactive material (SPLI) and somatostatin-like immunoreactive material (SLI) and the activity of acetyl-CoA: choline- O -acetyltransferase (ChAT; EC 2.3.1.6.) were measured in eight brain regions of 13 normal patients and 12 patients with Alzheimer disease/senile dementia of the Alzheimer type (AD/SDAT). SPLI was significantly lower in five of eight regions in the patients with AD/SDAT. Younger patients with AD/SDAT had significantly lower SLI in the parietal cortex than older patients. ChAT activity and SPLI in the parietal cortex of the presenile patients with ADISDAT were not significantly different from values found in older patients.     

大鼠血管性痴呆动物模型的研究进展

本文综述了近年来大鼠血管性痴呆的造模方法和造模后大鼠行为学、组织形态学、神经生化指标及影像学等观测指标,为今后的实验研究提供相应的依据。     

Circadian rhythm in Alzheimer disease after trazodone use

A circadian rhythm is a cycle of approximately 24?h, responsible for many physiological adjustments, and ageing of the circadian clock contributes to cognitive decline. Rhythmicity is severely impaired in Alzheimer disease (AD) and few therapeutic attempts succeeded in improving sleep disorders in such context. This study evaluated sleep parameters by actigraphy in 30 AD patients before and after trazodone use for 2 weeks, and we show a significant improvement in relative rhythm amplitude (RRA), compatible with a more stable daytime behavioral pattern. So, trazodone appears to produce a stabilization of the circadian rhythms in individuals with AD.     

血管性痴呆动物模型制作方法的改良

目的对大鼠血管性痴呆双侧颈总动脉永久性结扎模型（permanent bilateral common carotid arteryocclusion,2VO）进行改良,以提高模型动物存活率。方法采取改良造模方法（间隔7d分2次结扎双侧颈总动脉）和传统的2VO方法（同时结扎双侧颈总动脉）建立血管性痴呆模型,观察并比较2种方法大鼠的存活率、学习记忆能力改变及病理形态学变化。结果术后7 d,改良模型组动物存活率（86.7%）明显高于传统模型组（40.0%）（P〈0.05）。术后8 w与12 w,与假手术组比较,两种方法模型组逃避潜伏期均明显延长（P〈0.05）,而改良法与传统法造模组之间相比较无显著性差异。HE染色显示：改良法与传统法造模组的大鼠海马区神经元有相似程度的明显变性、坏死和凋亡。结论 2VO改良造模法是降低大鼠血管性痴呆模型动物死亡率的成功方法,值得进一步研究、推广。     

Deletion of vitamin E enhances phenotype of Alzheimer disease model mouse

Increased oxidative damage is a prominent and early feature in Alzheimer disease (AD). However, whether it is a primary cause or merely a downstream consequence in AD pathology is still unknown. We previously generated alpha-tocopherol transfer protein knockout (Ttpa-/-) mice, in which lipid peroxidation in the brain was significantly increased by complete depletion of alpha-tocopherol (alpha-Toc). Here we crossed AD transgenic (APPsw) model mice (Tg2576) with Ttpa-/- mice. The resulting double-mutant (Ttpa-/- APPsw) mice showed earlier and more severe cognitive dysfunction in the Morris water maze, novel-object recognition, and contextual fear conditioning tests. They also showed increased amyloid beta-peptide (Abeta) deposits in the brain by immunohistochemical analysis, which was ameliorated with alpha-Toc supplementation. In this report we provide clear evidence indicating that chronic lipid peroxidation due to alpha-Toc depletion enhances AD phenotype in a mouse model.     

On the issue of transmissibility of Alzheimer disease

Results from recent experiments with rodents imply that Alzheimer disease might be inducible by seeding Aβ peptides into recipient animals. In respect to this new experimental data, public health aspects as well as epidemiological data have to be reevaluated. In this article, the available experimental and epidemiological data are reviewed.