Journal of Alzheimer's Disease - Volume 19, issue 4

Authors: Li, Yazhou | Duffy, Kara B. | Ottinger, Mary Ann | Ray, Balmiki | Bailey, Jason A. | Holloway, Harold W. | Tweedie, David | Perry, TracyAnn | Mattson, Mark P. | Kapogiannis, Dimitrios | Sambamurti, Kumar | Lahiri, Debomoy K. | Greig, Nigel H.

Article Type: Research Article

Abstract: Type 2 (T2) diabetes mellitus (DM) has been associated with an increased incidence of neurodegenerative disorders, including Alzheimer's disease (AD). Several pathological features are shared between diabetes and AD, including dysfunctional insulin signaling and a dysregulation of glucose metabolism. It has therefore been suggested that not only may the two conditions share specific molecular mechanisms but also that agents with proven efficacy in one may be useful against the other. Hence, the present study characterized the effects of a clinically approved long-acting analogue, exendin-4 (Ex-4), of the endogenous insulin releasing incretin, glucagon-like peptide-1 (GLP-1), on stress-induced toxicity in neuronal cultures …and on amyloid-β protein (Aβ) and tau levels in triple transgenic AD (3xTg-AD) mice with and without streptozocin (STZ)-induced diabetes. Ex-4 ameliorated the toxicity of Aβ and oxidative challenge in primary neuronal cultures and human SH-SY5Y cells in a concentration-dependent manner. When 11 to 12.5 month old female 3xTg AD mice were challenged with STZ or saline, and thereafter treated with a continuous subcutaneous infusion of Ex-4 or vehicle, Ex-4 ameliorated the diabetic effects of STZ in 3xTg-AD mice, elevating plasma insulin and lowering both plasma glucose and hemoglobin A1c (HbA1c) levels. Furthermore, brain levels of Aβ protein precursor and Aβ, which were elevated in STZ 3xTg-AD mice, were significantly reduced in Ex-4 treated mice. Brain tau levels were unaffected following STZ challenge, but showed a trend toward elevation that was absent following Ex-4 treatment. Together, these results suggest a potential value of Ex-4 in AD, particularly when associated with T2DM or glucose intolerance. Show more

Keywords: 3xTg-AD mice, Alzheimer's disease, amyloid-β peptide, amyloid-β protein precursor, dementia, diabetes, extendin-4, glucagon-like peptide-1, neuroprotection, streptozocin, tau

DOI: 10.3233/JAD-2010-1314

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1205-1219, 2010

Authors: Qian, Wei | Shi, Jianhua | Yin, Xiaomin | Iqbal, Khalid | Grundke-Iqbal, Inge | Gong, Cheng-Xin | Liu, Fei

Article Type: Research Article

Abstract: Abnormal hyperphosphorylation of tau appears to be crucial in neurofibrillary degeneration in Alzheimer's disease (AD). Previous studies suggest that a down-regulation of protein phosphatase 2A (PP2A), the major tau phosphatase in human brain, contributes to tau hyperphosphorylation in AD. However, the effects of PP2A down-regulation on site-specific tau hyperphosphorylation is not well understood. In the present study, we showed that PP2A dephosphorylated tau at several phosphorylation sites with different efficiencies. Among the sites studied, Thr205, Thr212, Ser214, and Ser262 were the most favorable sites, and Ser199 and Ser404 were the least favorable sites for PP2A in vitro. Inhibition of PP2A …with okadaic acid in metabolically active rat brain slices caused inhibition of glycogen synthase kinase-3β (GSK-3β) via an increase in its phosphorylation at Ser9. GSK-3β phosphorylated tau at many sites, with Ser199, Thr205, and Ser396 being the most favorable sites in cells. The overall alterations in tau phosphorylation induced by PP2A inhibition were the result of the combined effects of both reduced tau dephosphorylation due to PP2A inhibition directly and reduced phosphorylation by GSK-3β due to its inhibition. Because the impacts of tau phosphorylation on its biological activity and on neurofibrillary degeneration are site-specific, this study provides a new insight into the role of PP2A down-regulation in neurofibrillary degeneration in AD. Show more

Keywords: GSK-3β, phosphorylation, PP2A, tau

DOI: 10.3233/JAD-2010-1317

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1221-1229, 2010

Authors: Lee, Soon-Tae | Chu, Kon | Jung, Keun-Hwa | Jeon, Daejong | Bahn, Jae-Jun | Kim, Jin-Hee | Kun Lee, Sang | Kim, Manho | Roh, Jae-Kyu

Article Type: Research Article

Abstract: Vascular senescence contributes to the progression of Alzheimer's disease (AD) and circulating angiogenic cells (CACs) participate in the maintenance of the endothelium. As a step toward the development endothelial regeneration therapies for AD, we investigated the functional characteristics of CACs in AD patients. We enrolled AD patients and non-demented risk factor control subjects after matching for age, sex, and Framingham risk score. CACs were cultured from peripheral blood samples taken from subjects and used for various ex vivo assays. CACs from AD patients showed reduced chemotaxis, increased senescence, reduced paracrine angiogenic activity, and altered gene expression patterns compared to CACs …from risk factor (RF) controls. Addition of high concentration Aβ1–42 (200, 2000 ng/mL) to the CAC culture reduced CAC counts and endothelial nitric oxide synthase/Akt phosphorylation and induced apoptosis. However, lower concentration of Aβ1–42 (2, 20 ng/mL) failed to reduce the CAC counts. CACs from AD patients were more susceptible to the cytotoxic effect of Aβ1–42 than CACs from RF controls. In summary, AD patients have intrinsic dysfunctions of CACs which provides an extended understanding of vascular endothelial pathogenesis in AD. Show more

Keywords: Alzheimer's disease, amyloid-β, angiogenesis, circulating angiogenic cells, endothelial

DOI: 10.3233/JAD-2010-1315

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1231-1240, 2010

Authors: Sadowski, Martin J.

Article Type: Article Commentary

DOI: 10.3233/JAD-2010-01343

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1241-1243, 2010

Authors: Perucho, Juan | Rubio, Isabel | Casarejos, Maria J. | Gomez, Ana | Rodriguez-Navarro, Jose A. | Solano, Rosa M. | De Yébenes, Justo Garcia | Mena, Maria A.

Article Type: Research Article

Abstract: There is a great interest in the environmental and genetic factors which modify the risk of Alzheimer's disease since the manipulation of these factors could help to change the prevalence and natural course of this disease. Among the first group, anesthesia and surgery have been considered as risk enhancers, based mostly on “in vitro” experiments and epidemiological studies. We have investigated the effects of repetitive anesthesia, twice a week, for 3 months, from 7 to 10 months of age, with isoflurane on survival, behavior, apoptosis in hippocampal cells, amyloid-β (Aβ) peptide and tau patterns, chaperones and autophagy in WT and …AβPPswe mice. We have found that AβPPswe mice treated with isoflurane have increased mortality, less responsiveness after anesthesia, long lasting reduced exploratory behavior, increased number of TUNEL+ apoptotic cells, and increased ratio of pro-apoptotic proteins in hippocampus, reduced astroglial and increased microglial responses, increased Aβ aggregates and high molecular weight peptides, abnormal chaperone responses and reduced autophagy. These effects were not present in WT mice, suggesting that the deleterious impact of isoflurane on behavior, survival, neuronal cell death, and processing of proteins involved in neurodegeneration is restricted to subjects with increased susceptibility but does not affect normal subjects. Show more

Keywords: AβPPswe mice, amyloid pathology, apoptotic cell death, autophagy, chaperones, cognitive deficits, glial cells, isoflurane

DOI: 10.3233/JAD-2010-1318

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1245-1257, 2010

Authors: Eckenhoff, Maryellen F. | Eckenhoff, Roderic G.

Article Type: Article Commentary

DOI: 10.3233/JAD-2010-1324

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1259-1260, 2010

Authors: Perucho, Juan | Rubio, Isabel | Casarejos, Maria J. | Gomez, Ana | Rodriguez-Navarro, Jose A. | Solano, Rosa M. | De Yébenes, Justo Garcia | Mena, Maria A.

Article Type: Article Commentary

DOI: 10.3233/JAD-2010-1325

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1261-1261, 2010

Authors: Oliveira Jr., Pedro Paulo de Magalhães | Nitrini, Ricardo | Busatto, Geraldo | Buchpiguel, Carlos | Sato, João Ricardo | Amaro Jr., Edson

Article Type: Research Article

Abstract: Here, we examine morphological changes in cortical thickness of patients with Alzheimer's disease (AD) using image analysis algorithms for brain structure segmentation and study automatic classification of AD patients using cortical and volumetric data. Cortical thickness of AD patients (n = 14) was measured using MRI cortical surface-based analysis and compared with healthy subjects (n = 20). Data was analyzed using an automated algorithm for tissue segmentation and classification. A Support Vector Machine (SVM) was applied over the volumetric measurements of subcortical and cortical structures to separate AD patients from controls. The group analysis showed cortical thickness reduction in the …superior temporal lobe, parahippocampal gyrus, and enthorhinal cortex in both hemispheres. We also found cortical thinning in the isthmus of cingulate gyrus and middle temporal gyrus at the right hemisphere, as well as a reduction of the cortical mantle in areas previously shown to be associated with AD. We also confirmed that automatic classification algorithms (SVM) could be helpful to distinguish AD patients from healthy controls. Moreover, the same areas implicated in the pathogenesis of AD were the main parameters driving the classification algorithm. While the patient sample used in this study was relatively small, we expect that using a database of regional volumes derived from MRI scans of a large number of subjects will increase the SVM power of AD patient identification. Show more

Keywords: Alzheimer's disease, FreeSurfer, magnetic resonance imaging, support vector machine, surface based methods

DOI: 10.3233/JAD-2010-1322

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1263-1272, 2010

Authors: Cherubini, Andrea | Péran, Patrice | Spoletini, Ilaria | Di Paola, Margherita | Di Iulio, Fulvia | Hagberg, Gisela Elizabeth | Sancesario, Giuseppe | Gianni, Walter | Bossù, Paola | Caltagirone, Carlo | Sabatini, Umberto | Spalletta, Gianfranco

Article Type: Research Article

Abstract: The aim of this work was to investigate the hypothesis that multimodal MRI is able to detect the progressive disruption of volume and microstructure of subcortical structures in patients with amnestic mild cognitive impairment (a-MCI) and mild Alzheimer's disease (AD) in comparison with healthy controls (CTRL). We combined volumetric and diffusion tensor imaging (DTI) techniques in a cross-sectional study including 30 a-MCI, 30 AD patients, and 30 age-matched CTRL. We employed a fully automated model-based segmentation algorithm on 3 Tesla MRI anatomical images and accurate coregistration of DTI to anatomical images to extract regional values of DTI parameters. Both the …hippocampi significantly and progressively decreased in volume from CTRL through MCI to AD. Both the thalami showed a progressive and significant decrease in volume from CTRL to AD. Mean diffusivity (MD) values increased progressively across the three groups in the bilateral hippocampus, amygdala, and in the right caudate. No differences in fractional anisotropy (FA) values were found. Two distinct but overlapping patterns of progression of structural (i.e., atrophy) and microstructural (i.e., MD increase) damage were observed. Particularly, the pattern of atrophy was mirrored by the increasing value of the averaged MD, which provided a further indicator of subtle tissue disruption in the hippocampal structure in mild AD patients. Combining different MRI modalities can allow identifying sensitive indicators of the subtle pathogenic mechanisms that occur in subcortical areas of AD patients. Show more

Keywords: Alzheimer's disease, diffusion tensor imaging, mild cognitive impairment, MRI, subcortical areas

DOI: 10.3233/JAD-2010-091186

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1273-1282, 2010

Authors: Xin, Xiao-Yu | Ding, Jian-Qing | Chen, Sheng-Di

Article Type: Research Article

Abstract: Apolipoprotein E (APOE) promoter polymorphisms have long been linked to Alzheimer disease (AD) susceptibility, although the established data remains controversial. Using meta-analysis, our study aimed to clarify the nature of the genetic risks contributed by the three polymorphisms for developing AD. Medline, Embase, and Alzgene search identified 40 studies with 9,662 cases and 9.696 controls. Both -491A/T polymorphism (AA vs AT + TT: OR = 1.49, 95% CI = 1.29–1.72) and -219T/G polymorphism (TT vs TG + GG: OR = 1.30, 95% CI = 1.10–1.55) showed a significant association with AD susceptibility; however, significant association was not identified in the …analysis for -427T/C polymorphism (TT vs TC + CC: OR = 1.03, 95% CI = 0.82–1.30). Among the APOE ε 4} carriers, the -491A homozygotes were at higher risk to develop AD compared with the -491T carriers (OR = 1.42, 95% CI = 1.15–1.76). For subjects carrying the -491AA genotype, the presence of the APOE ε4 allele increased the risk of AD 4.37-fold (95% CI = 3.43–5.56). Subgroup analysis restricted to the late-onset or the Caucasian individuals revealed a similar association as that identified without restriction regarding -491A/T polymorphism. Our results confirm a significant but modest association between APOE promoter -491A/T and -219T/G polymorphisms and AD susceptibility. Show more

Keywords: Alzheimer's disease, APOE promoter, meta-analysis, -491A/T, -427T/C, -219T/G

DOI: 10.3233/JAD-2010-1329

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1283-1294, 2010

Authors: Michel, Tanja Maria | Gsell, Wieland | Käsbauer, Ludwig | Tatschner, Thomas | Sheldrick, Abigail Jane | Neuner, Irene | Schneider, Frank | Grünblatt, Edna | Riederer, Peter

Article Type: Research Article

Abstract: For decades, it has been acknowledged that oxidative stress due to free radical species contributes to the pathophysiology of aging and neurodegenerative diseases. Aldehyde dehydrogenases (ALDH) not only transform aldehydes to acids but also act as antioxidant enzymes. However, little is known about the implications of the enzymatic family of ALDH in the context of neurodegenerative processes such as Alzheimer's disease (AD). We therefore examined the enzymatic activity of the mitochondrial ALDH-isoform in different regions of the postmortem brain tissue isolated from patients with AD and controls. We found that the mitochondrial ALDH activity was significantly increased only in the …putamen of patients suffering from AD compared to controls. This is of particular interest since mediators of oxidative stress, such as iron, are increased in the putamen of patients with AD. This study adds to the body of evidence that suggests that oxidative stress as well as aldehyde toxicity play a role in AD. Show more

Keywords: Aging, aldehydehydrogenase, Alzheimer's disease, dementia, free radicals, mitochondria, oxidative stress

DOI: 10.3233/JAD-2010-1326

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1295-1301, 2010

Authors: del Valle, Jaume | Duran-Vilaregut, Joaquim | Manich, Gemma | Casadesús, Gemma | Smith, Mark A. | Camins, Antoni | Pallàs, Mercè | Pelegrí, Carme | Vilaplana, Jordi

Article Type: Research Article

Abstract: Late-onset Alzheimer's disease (AD) is the most common form of AD appearing after 65 years of age. To date, however, there are no non-genetically manipulated rodent models that develop a similar sporadic onset of AD with age-related amyloid-β (Aβ) deposition. Although the senescence accelerated mouse prone 8 (SAMP8) mice have been proposed as a model of AD, the presence of Aβ deposits remains controversial. In this study, we describe the time course of Aβ deposition in SAMP8 mice as well as in control SAMR1 and ICR-CD1 strains of mice. From as early as 6 months onward, SAMP8 mice show Aβ …deposition in the hippocampus that increase in number and extent with age. These deposits are comprised of by clustered granules that contain Aβ42 , Aβ40 , and other Aβ protein precursor fragments. By marked contrast, control mice show only low numbers of Aβ clusters that do not develop until 15 months of age. The demonstration that SAMP8 mice present with amyloid deposits in their hippocampus makes this animal model a useful tool to understand the mechanisms involved in Aβ deposition in AD. Show more

Keywords: Aβ40, Aβ42, AβPP, aging, Alzheimer's disease, amyloid-β, hippocampus, SAMP8, SAMR1, senescence

DOI: 10.3233/JAD-2010-1321

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1303-1315, 2010

Authors: Cantoni, Claudia | Fenoglio, Chiara | Cortini, Francesca | Venturelli, Eliana | Villa, Chiara | Clerici, Francesca | Marcone, Alessandra | Benussi, Luisa | Ghidoni, Roberta | Gallone, Salvatore | Scalabrini, Diego | Franceschi, Massimo | Cappa, Stefano | Binetti, Giuliano | Mariani, Claudio | Rainero, Innocenzo | Giordana, Maria Teresa | Bresolin, Nereo | Scarpini, Elio | Galimberti, Daniela

Article Type: Research Article

Abstract: Two hundred and fifty one Italian patients with sporadic frontotemporal lobar degeneration (FTLD) and 259 age-matched controls were tested for association with the tagging single nucleotide polymorphisms (SNPs) rs741810 and rs1052352 in the fused in sarcoma/translated in liposarcoma gene (FUS/TLS). Only patients negative for GRN mutations were included. Considering each SNP alone, no differences in either allelic or genotypic frequencies between patients and controls were found (P > 0.05), even stratifying according to gender or the presence of concomitant motor neuron disease. Haplotype analysis failed to detect haplotypes associated with FTLD. According to these results, FUS/TLS is not a susceptibility …factor for the development of sporadic FTLD. Show more

Keywords: Frontotemporal lobar degeneration (FTLD), fused in sarcoma/translated in liposarcoma (FUS/TLS), polymorphism, risk factor, variability

DOI: 10.3233/JAD-2010-1328

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1317-1322, 2010

Authors: Innocenti, Massimo | Salvietti, Emanuele | Guidotti, Martina | Casini, Angela | Bellandi, Silvano | Foresti, Maria Luisa | Gabbiani, Chiara | Pozzi, Andrea | Zatta, Paolo | Messori, Luigi

Article Type: Research Article

Abstract: Formation of amyloid-β (Aβ)1–42 amyloid fibrils, a characteristic feature of Alzheimer's disease (AD), was monitored in situ through atomic force microscopy (AFM). Well-structured amyloid fibrils slowly formed in solution within 24 hours for which high quality AFM pictures could be obtained. Remarkably, addition of either copper(II) or zinc(II) ions to the incubation medium, even at extremely low molar ratios, dramatically changed the Aβ1–42 aggregation profile and prevented fibril formation. Aggregates of different morphology appeared in accordance with previous observations: small globular aggregates upon addition of zinc; ill-structured micro-aggregates in the case of copper. The implications of these AFM …results are discussed in the context of current concepts for AD metallobiology. Show more

Keywords: Alzheimer's disease, amyloid-β, atomic force microscopy, metal ions

DOI: 10.3233/JAD-2010-1338

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1323-1329, 2010

Authors: Bowman, Gene L. | Shannon, Jackilen | Frei, Balz | Kaye, Jeffrey A. | Quinn, Joseph F.

Article Type: Research Article

Abstract: Oxidative damage is a consistent finding in a number of central nervous system (CNS) disorders. Uric acid (UA) is a potent hydrophilic antioxidant that is modified by diet and drug. Several lines of evidence suggest that plasma UA may modulate outcomes in neurologic disease, but little attention has been paid to CNS levels of UA. Our objective was to test the hypothesis that cerebrospinal fluid (CSF) UA is determined by plasma UA, modified by blood-brain barrier (BBB) integrity and associated with rate of cognitive decline in Alzheimer's disease (AD). Also, since UA and ascorbic acid may act as antioxidants for …one another, we also explored a potential interaction between them in the brain. Thirty-two patients with mild to moderate AD (Mini-Mental Status Exam 19 ± 5) participated in a longitudinal biomarker study for one year involving standardized clinical assessments. CSF and blood were collected at baseline for UA, ascorbic acid, and albumin. Cognitive measures were collected at baseline and again one year later. CSF UA was independent of age, gender, and AD severity. CSF and plasma UA were positively correlated (r = 0.669, p = 0.001) and BBB impairment was associated with higher CSF levels of UA (p = 0.028). Neither plasma nor CSF UA reached significant association with rates of cognitive decline over 1 year. CSF UA and CSF ascorbic acid were positively correlated (r = 0.388, p = 0.001). The hypothesis that CSF UA is determined by plasma UA and BBB integrity is supported, as is the hypothesis that UA and ascorbic acid are associated in CSF but not plasma. Adequately powered prospective studies would help assess any role for UA in primary and secondary prevention of AD. Show more

Keywords: Alzheimer's disease, ascorbic acid, blood-brain barrier, cerebrospinal fluid, uric acid

DOI: 10.3233/JAD-2010-1330

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1331-1336, 2010

Authors: Spitsin, Sergei | Koprowski, Hilary

Article Type: Article Commentary

DOI: 10.3233/JAD-2010-1336

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1337-1338, 2010

Authors: Doehner, Jana | Madhusudan, Amrita | Konietzko, Uwe | Fritschy, Jean-Marc | Knuesel, Irene

Article Type: Research Article

Abstract: Reelin is a large extracellular glycoprotein required for proper neuronal positioning during development. In the adult brain, Reelin plays a crucial modulatory role in the induction of synaptic plasticity and successful formation of long-term memory. Recently, alterations in Reelin-mediated signaling have been suggested to contribute to neuronal dysfunction associated with Alzheimer's disease (AD). We previously reported that aging in several species is characterized by a decline in Reelin-expressing interneurons and concomitant accumulation in amyloid-like plaques in the hippocampal formation, significantly correlating with cognitive impairments. In transgenic AD mice, we detected Reelin in oligomeric amyloid-β aggregates and in tight association with …fibrillary plaques. Here, we used immunohistochemistry at the light and electron microscopy level to characterize further the morphology, temporal and spatial progression, as well as the potential of Reelin-positive plaques to sequester murine amyloid-β peptides in wild-type mice. We developed a new immunohistochemical protocol involving a stringent protease pretreatment which markedly enhanced Reelin-immunoreactivity and allowed specific detection of variable shapes of murine anti-amyloid-β protein precursor-immunoreactivity in plaques in the hippocampus, likely representing N-terminal fragments and amyloid-β species. Ultrastructural investigations confirmed the presence of Reelin in extracellular space, somata of interneurons in young and aged wild-type mice. In aged mice, Reelin- and amyloid-β-immunoreactivity was detected in extracellular, spherical deposits, likely representing small intermediates or fragments of amyloid fibrils. Our results suggest that Reelin itself aggregates into abnormal oligomeric or protofibrillary deposits during aging, potentially creating a precursor condition for fibrillary amyloid-β plaque formation. Show more

Keywords: Amyloid-β plaques, AβPP, electron microscopy, hippocampus, immunohistochemistry, Mus musculus, non-transgenic, pepsin treatment, pre-fibrillary oligomers, sporadic Alzheimer's disease, stratum lacunosum-moleculare, ultrastructure

DOI: 10.3233/JAD-2010-1333

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1339-1357, 2010

Authors: Guo, Jian-Ping | Yu, Sheng | McGeer, Patrick L.

Article Type: Research Article

Abstract: Compounds that will inhibit buildup of amyloid-β(Aβ) deposits in Alzheimer's disease (AD) brain are potential therapeutic agents. Here we report the development of two simple in vitro screening assays to identify such agents. We use these assays to evaluate the relative potency of some possible candidates. One assay is based on binding of fluorescence-tagged Aβ1–42 to synthetic Aβ1–42 plated in wells of fluorescent black-wall microplates. Fluorescence-tagged Aβ1–42 solutions with and without blockers are then added to the plates, and the amount of bound fluorescence is measured. Another is a tissue type assay, where sections of unfixed AD …or AD model transgenic mouse brains are mounted on glass slides. The same solutions assayed in the microplate test are then added to tissue sections. Binding of fluorescence-tagged Aβ1–42 to the Aβ deposits in AD or transgenic brain tissue is detected with a fluorescence microscope. Good agreement is obtained between the two methods. Most of the tested agents have too low an affinity for Aβ1–42 to be effective clinically. Agents that may have marginal affinity according to these tests include 1,2,3,4,6-penta-O-galloyl-b-D-glucopyranose (PGG), S-diclofenac, epigallocatechin gallate (EGCG), resveratrol, and extracts of spirulina, ginger, rhubarb, cinnamon, blueberries, and turmeric. Compounds which failed to show binding include scyllo-inositol, myo-inositol, rhamnose, ginkgolide A, emodin, rhein, caryophellene, curcumin, valproic acid, tramiprosate, and garlic extract. Show more

Keywords: Blueberry, cinnamon, Congo red, epigallocatechin gallate, garlic, ginger, resveratrol, rhubarb, spirulina, S-diclofenac, senile plaques, turmeric

DOI: 10.3233/JAD-2010-1331

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1359-1370, 2010

Authors: Kim, Insub | Lee, Junhee | Hong, Hyun Joo | Jung, Eun Sun | Ku, Yun Hyi | Jeong, In Kyong | Cho, Young Min | So, Insuk | Park, Kyong Soo | Mook-Jung, Inhee

Article Type: Research Article

Abstract: Increasing evidence suggests that type 2 diabetes mellitus (T2DM) is strongly correlated with Alzheimer's disease (AD). To examine the relationship between T2DM and AD, autoantibodies against amyloid-Aβ were measured in the serum of T2DM patients and age-matched controls. Levels of Aβ autoantibody were measured by ELISA in serum samples of T2DM patients (n = 92) and age-matched control group (n = 106). Aβ autoantibody levels were increased in T2DM compared with age-matched controls by 45.4 ± 8.1% (p < 0.001). Females had higher Aβ autoantibody levels than males in both T2DM and control group. Aβ autoantibody levels in the T2DM …group were positively correlated with the levels of cholesterol (p = 0.011), low density lipoprotein cholesterol (p = 0.020), and triglycerides (p = 0.039). In conclusion, the level of Aβ autoantibody is dramatically elevated in patient serum of T2DM, and, as such, might be used as a possible biomarker for T2DM. Show more

Keywords: Aβ autoantibody, Alzheimer's disease, biomarker, cholesterol, type 2 diabetes mellitus

DOI: 10.3233/JAD-2010-1332

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1371-1376, 2010

Authors: Yenjerla, Mythili | LaPointe, Nichole E. | Lopus, Manu | Cox, Corey | Jordan, Mary Ann | Feinstein, Stuart C. | Wilson, Leslie

Article Type: Research Article

Abstract: NAP (Asn-Ala-Pro-Val-Ser-Ile-Pro-Gln) is a neuroprotective peptide that shows cognitive protection in patients with amnestic mild cognitive impairment, a precursor to Alzheimer's disease. NAP exhibits potent neuroprotective properties in several in vivo and cellular models of neural injury. While NAP has been found in many studies to affect microtubule assembly and/or stability in neuronal and glial cells at fM concentrations, it has remained unclear whether NAP acts directly or indirectly on tubulin or microtubules. We analyzed the effects of NAP (1 fM-1 μM) on the assembly of reconstituted bovine brain microtubules in vitro and found that it did not significantly (p …< 0.05) alter polymerization of either purified tubulin or of a mixture of tubulin and unfractionated microtubule-associated proteins. NAP also had no significant effect (p < 0.05) on the growing and shortening dynamics of steady-state microtubules at their plus ends, nor did it alter the polymerization or dynamics of microtubules assembled in the presence of 3-repeat or 4-repeat tau. Thus, the neuroprotective activity of NAP does not appear to involve a direct action on the polymerization or dynamics of purified tubulin or microtubules. Show more

Keywords: Microtubule dynamics, NAP, tau, tubulin polymerization

DOI: 10.3233/JAD-2010-1335

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1377-1386, 2010

Authors: Smith, Danielle G. | Ciccotosto, Giuseppe D. | Tew, Deborah J. | Perez, Keyla | Curtain, Cyril C. | Boas, John F. | Masters, Colin L. | Cappai, Roberto | Barnham, Kevin J.

Article Type: Research Article

Abstract: Amyloid-β peptide (Aβ) toxicity is thought to be responsible for the neurodegeneration associated with Alzheimer's disease. While the mechanism(s) that modulate this toxicity are still widely debated, it has previously been demonstrated that modifications to the three histidine residues (6, 13, and 14) of Aβ are able to modulate the toxicity. Therefore to further elucidate the potential role of the histidine (H) residues in Aβ toxicity, we synthesized Aβ peptides with single alanine substitutions for each of the three histidine residues and ascertained how these substitutions affect peptide aggregation, metal binding, redox chemistry, and cell membrane interactions, factors which have …previously been shown to modulate Aβ toxicity. Aβ42 H13A and Aβ42 H6A modified peptides were able to induce significant cell toxicity in primary cortical cell cultures at levels similar to the wild-type peptide. However, Aβ42 H14A did not induce any measurable toxicity in the same cultures. This lack of toxicity correlated with the inability of the Aβ42 H14A to bind to cell membranes. The interaction of Aβ with cell membranes has previously been shown to be dependent on electrostatic interactions between Aβ and the negatively charged head group of phosphatidylserine. Our data suggests that it is the imidazole sidechain of histidine 14 that modulates this interaction and strategies inhibiting this interaction may have therapeutic potential for Alzheimer's disease. Show more

Keywords: Amyloid, cell membrane, neurotoxicity, phosphatidylserine

DOI: 10.3233/JAD-2010-1334

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1387-1400, 2010

Authors: Koedam, Esther L.G.E. | Lauffer, Vivian | van der Vlies, Annelies E. | van der Flier, Wiesje M. | Scheltens, Philip | Pijnenburg, Yolande A.L.

Article Type: Research Article

Abstract: Alzheimer's disease (AD) is the most common cause of dementia at older age. Although less prevalent before the age of 65 years, it is still the most frequent cause of early-onset dementia followed by frontotemporal dementia. The typical presentation of AD is memory dysfunction, however, presentations with prominent cognitive impairment in other domains besides memory, like prominent apraxia, language problems, or executive dysfunction, may occur and are relatively more common in early-onset AD. In this retrospective descriptive study, we determined the prevalence of non-memory presentations in a large sample of early-onset AD patients compared to late-onset AD. The clinical files …of 270 patients with AD starting before the age of 65 years and 90 patients with late-onset AD (⩾ 65 years) were reviewed to assess clinical characteristics. Patients were classified as memory presentation and non-memory presentation according to their clinical presentation. The mean age of the early-onset group was 56 ± 5 years and 74 ± 6 years for the late-onset group. A third of the early-onset AD group presented with non-memory symptoms compared to only 6% in the late-onset group (p < 0.001). Within the group with non-memory presentations, apraxia/visuospatial dysfunction was the most prevalent presenting symptom (12%). Patients with early-onset AD often present with a non-memory phenotype, of which apraxia/visuospatial dysfunction is the most common presenting symptom. Atypical presentations of AD should be considered in the clinical differential diagnosis of early-onset dementia. Show more

Keywords: Alzheimer's disease, clinical presentation, dementia, early onset

DOI: 10.3233/JAD-2010-1337

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1401-1408, 2010

Authors: Dance, Amber | Landhuis, Esther | Strobel, Gabrielle

Article Type: Editorial

DOI: 10.3233/JAD-2010-1323

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1409-1415, 2010

Article Type: Announcement

DOI: 10.3233/JAD-2010-1327

Citation: Journal of Alzheimer's Disease, vol. 19, no. 4, pp. 1417-1419, 2010