Journal of Alzheimer's Disease - Volume 19, issue 2

Authors: Della Sala, Sergio | Cocchini, Gianna | Logie, Robert H. | Allerhand, Michael | MacPherson, Sarah E.

Article Type: Research Article

Abstract: Previous dual task studies have demonstrated minimal costs when healthy individuals simultaneously perform two tasks at their own individual ability levels. Conversely, Alzheimer's disease (AD) patients show dual task decrements, but it is unclear whether the problem arises at the encoding, maintenance, and/or retrieval phases of memory. Two experiments combined digit recall and visuo-motor tracking to investigate dual task effects during encoding, maintenance, and/or retrieval for AD patients compared with healthy adults. The demands of each single task were titrated for the ability of each participant. In Experiment 1, the dual task requirement was present throughout both encoding and retrieval …of digit recall and the differential dual task effects on a secondary tracking task were examined post-hoc. In Experiment 2, the impact of dual task during encoding only, during maintenance only, and during retrieval only was examined systematically. The findings suggest that the specific AD deficit reflects impairment of a cognitive function that supports the simultaneous performance of two tasks in the healthy brain, particularly during the encoding and retrieval phases of the memory task. Show more

Keywords: Alzheimer's disease, dual task, encoding, maintenance, retrieval, working memory

DOI: 10.3233/JAD-2010-1244

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 503-515, 2010

Authors: Vidoni, Eric D. | Honea, Robyn A. | Burns, Jeffrey M.

Article Type: Research Article

Abstract: Cognitive and physical decline are important predictors of functional independence in Alzheimer's disease (AD). However, little is known about AD-related neural change leading to decreased independence. We hypothesized that regional gray matter atrophy, including the medial frontal cortex, would be related to cognition, physical function, and functional independence. Individuals without dementia (n = 56) and subjects with early-stage AD (n = 58) underwent MRI and a comprehensive cognitive and physical function evaluation. The relationship of cognitive and physical function measures and independence performing complex daily activities was explored using correlation and mediation analysis. These results suggest that cognition had both …a strong direct effect and mediated the influence of physical function on independence for those with AD. We followed this with a voxel-based morphometric global conjunction analysis of imaging data within each group to identify neural substrates common to our function measures. Imaging evidence supported our mediation analysis results. Imaging evidence revealed that in AD, regional gray matter atrophy measures in medial frontal and temporo-parietal areas were related to decreased cognition, physical function, and independence. Loss of independence in early AD is closely related to impaired cognition associated with performing complex behaviors. People with early AD may have decreased gray matter volume in the medial frontal and temporal-parietal cortices that is associated with loss of independence in activities of daily living. These results are the first to identify regionally specific brain volume changes that may be related to functional dependence seen in early AD. Show more

Keywords: Activities of daily living, cognition, physical function, voxel-based morphometry

DOI: 10.3233/JAD-2010-1245

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 517-527, 2010

Authors: Cui, Jia | Chen, Qiuyue | Yue, Xiaojing | Jiang, Xuejun | Gao, George F. | Yu, Long-Chuan | Zhang, Yan

Article Type: Research Article

Abstract: Galanin and galanin receptors are upregulated in the brain regions associated with Alzheimer's disease (AD). However, the consequence of this overexpression is still unknown, particularly in human neurons. Here, we investigate the possible protective effects of galanin against intracellular amyloid-β (Aβ)1–42 toxicity, as well as other insults including staurosporine, etoposide, hydrogen peroxide, and serum depletion in cultured human primary neurons. The results show that galanin is protective against intracellular Aβ cytotoxicity and all of the above insults at sub-nanomolar physiological concentrations. The galanin protection may be mediated by galanin receptor 2 and down-regulation of Bax level. The data from …the present study provide a potential drug target for therapy or prevention of neurodegenerative diseases, including AD. Show more

Keywords: Alzheimer's disease, galanin, human primary neurons, neuronal loss

DOI: 10.3233/JAD-2010-1246

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 529-544, 2010

Authors: Coppus, Antonia M.W. | Evenhuis, Heleen M. | Verberne, Gert-Jan | Visser, Frank E. | Eikelenboom, Piet | van Gool, Willem A. | Janssens, A. Cecile J.W. | van Duijn, Cornelia M.

Article Type: Research Article

Abstract: In a prospective longitudinal cohort study of dementia and mortality in persons with Down syndrome aged 45 years and older, 85 postmenopausal women were followed for a mean follow-up time of 4.3 years (range 0.0 to 7.4 years). The effect of age at menopause on age at diagnosis of dementia and survival was estimated using correlation analysis and Cox Proportional Hazard Model. We found a significant correlation between age at menopause and age at diagnosis of dementia (ρ = 0.52; p < 0.001), and between age at menopause and age at death (ρ = 0.49; p = 0.01). Early age …at menopause is associated with a 1.8 fold increased risk of dementia: Hazard Ratio (HR): 1.82 (95%Confidence Interval (CI): 1.31–2.52) and with risk of death: HR: 2.05 (95%CI: 1.33–3.16). Our study suggests that age at menopause in women with Down syndrome is a determinant of age at onset of dementia and mortality. Show more

Keywords: Alzheimer's disease, APOE genotype, Down syndrome, menopause, mortality

DOI: 10.3233/JAD-2010-1247

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 545-550, 2010

Authors: Listì, Florinda | Caruso, Calogero | Lio, Domenico | Colonna-Romano, Giuseppina | Chiappelli, Martina | Licastro, Federico | Candore, Giuseppina

Article Type: Research Article

Abstract: Alzheimer's disease (AD) is a neurodegenerative disorder clinically characterized by cognitive deficit with progressive worsening of memory. Recent data indicate that neurons, as well as other brain cells, can express enzymes such as cyclooxygenases (COXs) and 5-lipoxygenase (5-LO) which are considered important in inflammatory cells. Moreover, it has been demonstrated that COX-2 and 5-LO enzymes play a considerable role in the pathophysiology of AD. In order to assess the possible role of COX-2 and 5-LO single nucleotide polymorphisms (SNPs) in AD, we examined their distribution in 341 AD patients and 190 controls from Northern Italy. A significant difference was observed …in the distribution of the −765G COX-2 and −1708A 5-LO alleles between AD cases and controls (p = 0.03 for −765G/C COX-2 SNP; and p = 0.007 for −1708G/A 5-LO SNP). Hence, COX-2 −765G and 5-LO −1708A alleles were overrepresented in AD patients and underrepresented in controls. Our data suggest that these alleles of COX-2 and 5-LO could be risk factors for AD. These results seem of some importance for a pharmacogenomic approach. Show more

Keywords: Alzheimer's disease, COX-2, 5-LO, pharmacogenomics

DOI: 10.3233/JAD-2010-1260

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 551-557, 2010

Authors: Ciaramella, Antonio | Bizzoni, Federica | Salani, Francesca | Vanni, Diego | Spalletta, Gianfranco | Sanarico, Nunzia | Vendetti, Silvia | Caltagirone, Carlo | Bossù, Paola

Article Type: Research Article

Abstract: Alzheimer's disease (AD) is characterized by abnormal accumulation of amyloid-β peptide (Aβ) into extracellular fibrillar deposits, paralleled by chronic neuroinflammatory processes. Although Aβ seems to be causative in AD brain damage, the role of the immune system and its mechanisms still remain to be clarified. We have recently shown that normal monocyte-derived dendritic cells (MDDCs), when differentiated in the presence of Aβ1–42 , acquire an inflammatory phenotype and a reduced antigen presenting ability. Here we studied MDDCs derived from AD patients in comparison with MDDCs obtained from healthy control subjects (HC). MDDCs from AD patients, at variance with HC-derived cells, …were characterized by an augmented cell recovery, a consistent increase in the expression of the pro-inflammatory ICAM-1 molecule, a decrease in the expression of the co-stimulatory CD40 molecule, and an impaired ability to induce T cell proliferation. Furthermore, MDDCs from AD produced higher amounts of IL-6 than HC-derived cells, confirming the more pronounced pro-inflammatory features of these cells in AD patients. Consistent results have been also obtained with monocytes, the MDDC precursors. In fact, while unstimulated monocytes do not appear to be different in AD and HC, after stimulation with lipopolysaccharide, AD monocytes overexpressed ICAM-1 with respect to controls, suggesting that common pathways of monocyte activation and MDDC differentiation are altered in AD. Overall, these findings show that AD-linked dysregulated immune mechanisms exist, which lead to dendritic cell-mediated over-activation of inflammation and impaired antigen presentation, thus supporting the view that immune cell activation could play an important role in AD pathogenesis. Show more

Keywords: Alzheimer's disease, innate immune cells, inflammation, monocyte-derived dendritic cells, monocytes

DOI: 10.3233/JAD-2010-1257

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 559-572, 2010

Authors: Rojo, Leonel E. | Alzate-Morales, Jans | Saavedra, Iván N. | Davies, Peter | Maccioni, Ricardo B.

Article Type: Research Article

Abstract: We describe the interactions of two benzimidazole derivatives, astemizole (AST) and lansoprazole (LNS), with anomalous aggregates of tau protein (neurofibrillary tangles). Interestingly, these compounds, with important medical applications in the treatment of allergies and gastrointestinal disorders respectively, specifically bind to aggregated variants of tau protein and to paired helical filaments isolated from brains of Alzheimer's disease (AD) patients. These ligands appear to be a powerful tool to tag brain-isolated tau-aggregates and heparin-induced polymers of recombinant tau. The interactions of AST and LNS with tau aggregates were assessed by classical radioligand assays, surface plasmon resonance, and bioinformatic approaches. The affinity of …AST and LNS for tau aggregates was comparatively higher than that for amyloid-β polymers according to our data. This is relevant since senile plaques are also abundant but are not pathognomonic in AD patients. Immunochemical studies on paired helical filaments from brains of AD patients and surface plasmon resonance studies confirm these findings. The capacity of these drugs to penetrate the blood-brain barrier was evaluated: i) in vitro by parallel artificial membrane permeability assay followed by experimental Log P determinations; and ii) in vivo by pharmacokinetic studies comparing distribution profiles in blood and brain of mice using HPLC/UV. Importantly, our studies indicate that the brain/blood concentration ratios for these compounds were suitable for their use as PET radiotracers. Since neurofibrillary tangles are positively correlated with cognitive impairment, we concluded that LNS and AST have a great potential in PET neuroimaing for in vivo early detection of AD and in reducing the formation of neurofibrillary tangles. Show more

Keywords: Alzheimer's disease, benzimidazoles, neurofibrillary tangles, neuroimaging, radiotracers, surface plasmon resonance, tangles, tau aggregates

DOI: 10.3233/JAD-2010-1262

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 573-589, 2010

Authors: Stellos, Konstantinos | Panagiota, Victoria | Sachsenmaier, Saskia | Trunk, Theresia | Straten, Guido | Leyhe, Thomas | Seizer, Peter | Geisler, Tobias | Gawaz, Meinrad | Laske, Christoph

Article Type: Research Article

Abstract: Cerebrovascular dysfunction is a common finding in patients with Alzheimer's disease (AD) and may contribute to cognitive decline. Abundant evidence suggests that vascular and neuronal repair mechanisms are mediated by circulating progenitor cells in vivo. Whether CD34+ and, specifically, CD34+ /CD133+ progenitor cells are involved in the pathophysiology of AD is poorly understood so far. In the present study, peripheral blood concentrations of circulating CD34+ /CD133+ and CD34+ progenitor cells were measured in 45 AD patients and in 30 healthy elderly controls by flow cytometry. The severity of dementia was assessed by Mini-Mental Status Examination and …Clinical Dementia Rating scale. AD patients were stratified into two groups showing mild (n = 17) and moderate to severe (n = 28) dementia. In the present study, AD patients with moderate to severe dementia, but not those with mild dementia, showed significantly increased circulating CD34+ /CD133+ and CD34+ progenitor cells compared to healthy elderly controls independent of cardiovascular risk factors and medication. In addition, the number of circulating CD34+ /CD133+ progenitor cells in AD patients was significantly inversely correlated with cognitive function, age, and plasma levels of SDF-1, the most potent chemokine for progenitor cells. Our findings suggest a stage-dependent upregulation of circulating CD34+ /CD133+ and CD34+ progenitor cells in AD patients, which could take part in tissue healing processes of the brain in AD. Show more

Keywords: Alzheimer's disease, CD133, CD34, dementia, SDF-1

DOI: 10.3233/JAD-2010-1261

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 591-600, 2010

Authors: Coduras, Alicia | Rabasa, Isabel | Frank, Ana | Bermejo-Pareja, Felix | López-Pousa, Secundino | López-Arrieta, Jesús-María | Del Llano, Juan | León, Teresa | Rejas, Javier

Article Type: Research Article

Abstract: In this study, we analyzed the economic impact of one-year healthcare and non-healthcare resources utilization by patients with dementia of Alzheimer's disease (AD) under usual medical practice in Spain. A one-year, prospective, naturalistic, multicenter cohort study was designed to recruit patients with mild, moderate to severe, and severe AD according to Clinical Dementia Rating scale: the ECO study. Healthcare resources (medical visits, drugs and concomitant treatments, complementary and diagnostic tests, institutionalization and use of home-nursing facilities) and non-healthcare resources (inventory materials, consumables, professional and non-professional caregivers' time for care and supervision) were recorded and valued at 2006 prices. A total …of 560 patients with possible/probable AD by DSM-IV-NINCDS-ADRDA criteria were included in the study: 68% women, 77 ± 6 years old, 29% treatment naïve. Monthly average cost per patient was EURO1,425.73, and increased 10.08% at the end of the study (baseline monthly cost; EURO1,316.22). Non-healthcare costs EURO1059.00, 74.30% of total cost) decreased EURO4.30/month (0.40%) at the end of the year, while healthcare costs, which presented a total average of EURO366.66, grew by EURO136.94 in the period (54.06%), mainly due to cost of drugs, nursing home utilization, and institutionalization. The 87.26% of the overall cost (EURO1,244.22) was not financed by National Health Service (NHS), and the majority of this cost corresponded to caregiver-associated cost. The caregiver's total burden represented 70.86% of the overall cost-of-illness. In conclusion, monthly overall mean cost of dementia of AD type was high in Spain (EURO1,412.73). Almost 88% of the cost-of-illness is funded by the patient's own family, adding a financial burden to the suffering of these families. Show more

Keywords: Costs, dementia of Alzheimer type, healthcare resources utilization, non-healthcare resources, prospective, Spain

DOI: 10.3233/JAD-2010-1258

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 601-615, 2010

Authors: Wimo, Anders

Article Type: Article Commentary

DOI: 10.3233/JAD-2010-1268

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 617-619, 2010

Authors: Cheng, Xin | Yang, Libang | He, Ping | Li, Rena | Shen, Yong

Article Type: Research Article

Abstract: We reported that tumor necrosis factor receptor I (TNFRI) is required for neuronal death induced by amyloid-β protein in the Alzheimer's disease (AD) brain. However, whether TNF receptor subtypes are expressed and activated differentially in AD brains compared to non-demented brains remains unclear. Our studies on Western blot and ELISA measurements demonstrated that TNFRI levels are increased whereas TNFRII levels are decreased in AD brains compared to non-demented brains (p < 0.05). Immunohistochemical results demonstrated that both TNFRI and TNFRII are expressed in neurons in AD and non-demented brains. However, in situ hybridization studies showed little change in the mRNA …levels of either type of TNF receptor in the neurons of AD brains compared to non-demented brains. To examine whether different levels of TNF receptors in AD brains are correlated with the alteration of functional binding of TNF receptors, by using 125 I-TNF-α binding technique, we found that, in AD brains, 125 I-TNF-α binding affinity to TNFRI is increased, whereas binding affinity to TNFRII is decreased (p < 0.01). These studies reveal a novel observation of abnormal TNF receptor activation in AD brains. Differential TNF receptor protein levels and binding affinities suggest distinct pathogenic mechanisms of neurodegeneration in the AD brain. Show more

Keywords: Alzheimer's disease, amyloid-β, neurodegeneration, receptor binding, TNF-α, TNFRI, TNFRII

DOI: 10.3233/JAD-2010-1253

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 621-630, 2010

Authors: Cocks, Graham | Wilde, Jonathan I. | Graham, Simon J | Bousgouni, Vicky | Virley, David | Lovestone, Simon | Richardson, Jill

Article Type: Research Article

Abstract: In a recent clinical study, the thiazolidinedione (TZD) pioglitazone (Actos™ was reported to preserve cognitive function in patients with mild to moderate Alzheimer's disease and type II diabetes mellitus. TZDs are agonists of the nuclear hormone receptor peroxisome proliferator-activated receptor-γ (PPARγ), are peripheral insulin sensitizers, and have recently been reported to increase mitochondrial biogenesis in the central nervous system and dendritic spine density. We report a transcriptional profile of the TZD pioglitazone and the non-TZD PPARγ agonist GW347845 in primary cortical culture. We observed that pioglitazone, but not GW347845, increased cholesterol biosynthetic and lipogenic gene expression after 6 h, and …the expression of the cholesterol efflux transporters Abca1 and Abcg1 after 24 h. Co-treatment of pioglitazone with the PPARγ antagonist GW9662 did not significantly reduce these effects, suggesting a PPARγ-independent mechanism. These findings suggest a novel effect of TZDs in neurons that may be of relevance as a novel approach against Alzheimer's disease. Show more

Keywords: ABCA1, Alzheimer's disease, cholesterol biosynthesis, thiazolidinediones

DOI: 10.3233/JAD-2010-1266

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 631-646, 2010

Authors: Kim, WonHee | Lee, Sangmook | Jung, Cheolwha | Ahmed, Ambar | Lee, Gloria | Hall, Garth F.

Article Type: Research Article

Abstract: The mechanisms by which tau-containing lesions are propagated between adjacent and synaptically interconnected parts of the brain are a potentially important but poorly understood component of human tauopathies such as Alzheimer's disease, Pick's disease, and corticobasal degeneration. Since the utility of currently available transgenic models for studying intercellular aspects of tauopathy is limited by their broad patterns of tau expression in the central nervous system, we used an in situ tauopathy model that replicates tau-induced cytodegeneration in identified neurons on a tau-negative background to determine whether tau secretion or interneuronal transfer might play a role in lesion propagation. We found …that the N-terminal half of tau is required for tau secretion and is efficiently exported to the extracellular space and adjacent neurons at relatively low levels of overexpression. By contrast, full-length tau is secreted by a separate mechanism that is correlated with phosphorylation of tau at tyrosine 18 and dendritic degeneration, is exacerbated by tauopathy mutations, and blocked by mutations that inhibit tau:tau interactions. Anterograde transneuronal tau movement occurred with the expression of tau containing the P301L tauopathy mutant, but not with wild type tau isoforms. Our results are consistent with recent studies suggesting a role for molecular “templating” in the propagation of neurofibrillary lesions and provide a novel conceptual and experimental basis for studying the mechanisms of interneuronal propagation and toxicity in human neurodegenerative disease. Show more

Keywords: Pseudophosphorylation, secretion, tau, tauopathy, transneuronal tau movement, tyrosine phosphorylation

DOI: 10.3233/JAD-2010-1273

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 647-664, 2010

Authors: Hernandez, Santiago | McClendon, McKee J. | Zhou, Xiao-Hua Andrew | Sachs, Michael | Lerner, Alan J.

Article Type: Research Article

Abstract: Existing research shows differences in medication use for Alzheimer's disease (AD) based on demographics such as race, ethnicity, and geographical location. To determine individual and community characteristics associated with differences in acetylcholinesterase inhibitor (AChEI) and memantine use in AD, 3,049 AD subjects were drawn from 30 centers and evaluated using the Uniform data set (UDS). Cases were evaluated at the individual level within the context of 31 communities (one center encompassed two separate geographical regions). Multivariate analysis was used to determine the significance of individual variables on medication use. Compared to non-Hispanic Whites, Blacks were less likely to use AChEI …and memantine with odds ratios (OR) of 0.59 (95% CI 0.46–0.76) and 0.43 (95% CI 0.32–0.57), respectively. Compared to non-Hispanic Whites, non-Black Hispanics were less likely to use memantine (OR = 0.69 (95% CI 0.49–0.98)). No association was found between the proportion of Blacks or non-Black Hispanics versus non-Hispanic Whites at an Alzheimer Disease Center and individual use of AChEI or memantine. Other significant variables include gender, age, marital status, dementia severity, source of referral, AChEI use, and education. Education and age somewhat mitigated disparity. Significant racial and ethnic differences in AChEI and memantine use exist at the individual level regardless of the racial and ethnic composition of the individual's community. Research and initiatives at the societal level may be an important consideration toward addressing these differences. Show more

Keywords: Acetylcholinesterase inhibitor, Alzheimer's disease, disparity, ethnicity, memantine, race

DOI: 10.3233/JAD-2010-1269

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 665-672, 2010

Authors: van Dijk, Marie | van Bezu, Jan | Poutsma, Ankie | Veerhuis, Robert | Rozemuller, Annemieke J. | Scheper, Wiep | Blankenstein, Marinus A. | Oudejans, Cees B.

Article Type: Research Article

Abstract: Pre-eclampsia and late-onset Alzheimer's disease (LOAD) share no clinical features. In contrast to these clinical dissimilarities, striking parallels exist between the (epi)genetic features associated with pre-eclampsia and LOAD for the genes located on 10q22. The parallels in identity between the 10q22 genes involved and active in the organs (placenta, brain) primarily affected in the respective diseases led us to explore, if the pre-eclampsia susceptibility gene STOX1 is functionally involved in LOAD. We demonstrate that isoform A of STOX1 is abundantly expressed in the brain, correlates with severity of disease, and selectively transactivates LRRTM3 in neural cells with increased amyloid-β protein …precursor processing. Similar in vitro results were seen in trophoblast. Our data indicate that STOX1 controls a conserved pathway shared between placenta and brain with overexpression in LOAD. Show more

Keywords: Alzheimer's disease, amyloid-β protein precursor processing, LRRTM3, neuron, pre-eclampsia, STOX1, trophoblast

DOI: 10.3233/JAD-2010-1265

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 673-679, 2010

Authors: Dosanjh, Laura E. | Brown, Marishka K. | Rao, Gautam | Link, Christopher D. | Luo, Yuan

Article Type: Research Article

Abstract: Alzheimer's disease (AD) is rapidly reaching epidemic proportions in the United States, currently affecting more than 5 million individuals and predicted to affect 14 million by 2050. Despite a general consensus that the amyloid-β (Aβ) protein plays a significant role in disease progression, the underlying pathology of the disease is not entirely clear. Caenorhabditis elegans is a simple organism that has been used as a model for basic mechanistic studies on the underlying pathological processes involved in AD. Previous studies from our labs demonstrated that transgenic C. elegans with muscle specific expression of human Aβ undergo rapid paralysis, and worms …with neuronal expression of Aβ show deficits in chemotaxis to volatile chemicals. In this study, we evaluate the effect of neuron specific expression of Aβ on multiple neuronally controlled behaviors in a transgenic C. elegans. These worms demonstrate deficits in odorant preference associative learning behavior, and the serotonin-controlled behaviors experience-dependent learning and egg laying. These newly identified learning-deficit behavioral phenotypes in the neuronal Aβ C. elegans suggest that the model may be used to elucidate underlying pathological events related to development of AD and for pharmaceutical intervention. Show more

Keywords: Amyloid toxicity, C. elegans, genotyping, neurological behavioral

DOI: 10.3233/JAD-2010-1267

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 681-690, 2010

Authors: Plaschke, Konstanze | Kopitz, Juergen | Siegelin, Markus | Schliebs, Reinhard | Salkovic-Petrisic, Melita | Riederer, Peter | Hoyer, Siegfried

Article Type: Research Article

Abstract: For studying rare hereditary Alzheimer's disease (AD), transgenic (Tg) animal models overexpressing amyloid-β protein precursor (AβPP) followed by increased amyloid-β (Aβ) formation are used. In contrast, sporadic AD has been proposed to start with an insulin-resistant brain state (IRBS). We investigated the effect of IRBS induced by intracerebroventricularly (icv) administered streptozotocin (STZ) on behavior, glycogen synthase kinase-3 (GSK)α/β content, and the formation of AD-like morphological hallmarks Aβ and tau protein in AβPP Tg2576 mice. Nine-month-old Tg mice were investigated 6 months after a single icv injection of STZ or placebo. Spatial cognition was analyzed using the Morris water maze test. …Soluble and aggregated Aβ40/42 fragments, total and phosphorylated tau protein, and GSK-3α/β were determined by ELISA. Cerebral (immuno)histological analyses were performed. In Tg mice, STZ treatment increased mortality, reduced spatial cognition, and increased cerebral aggregated Aβ fragments, total tau protein, and congophilic amyloid deposits. These changes were associated with decreased GSK-3α/β ratio (phosphorylated/total). A linear negative correlation was detected between Aβ42 and cognition, and between GSK-3α/β ratio and aggregated Aβ40+42 . No marked necrotic and apoptotic changes were observed. In conclusion, IRBS may aggravate AD-like changes such as behavioral and increase the formation of pathomorphological AD hallmarks via GSK-3α/β pathway in AβPP-overexpressing mice. Show more

Keywords: Amyloid-β, glycogen synthase kinase-3, insulin, sporadic Alzheimer's disease, streptozotocin, transgenic 2576 mice, tau

DOI: 10.3233/JAD-2010-1270

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 691-704, 2010

Authors: Leroy, Karelle | Ando, Kunie | Héraud, Céline | Yilmaz, Zehra | Authelet, Michèle | Boeynaems, Jean-Marie | Buée, Luc | De Decker, Robert | Brion, Jean-Pierre

Article Type: Research Article

Abstract: Neurofibrillary tangles (NFTs) made of phosphorylated tau proteins are a key lesion of Alzheimer's disease and other neurodegenerative diseases, and previous studies have indicated that lithium can decrease tau phosphorylation in tau transgenic models. In this study, we have reassessed the effectiveness of treatment per os with lithium on the prevention, the arrest, or the reversal of NFT development in a tau transgenic line (Tg30tau) developing severe neurofibrillary pathology in the brain and the spinal cord. Wild-type and Tgtau30 mice were treated per os with lithium carbonate or with natrium carbonate by chronic chow feeding for 8 months starting at …the age of 3 months (to test for a preventive effect on NFT formation) or by oral gavage for 1 month starting at the age of 9 months (after development of NFTs). In mice treated by oral gavage, a decrease of tau phosphorylation and of Sarkosyl-insoluble aggregated tau was observed in the brain and in the spinal cord. The density of NFTs identified by Gallyas staining in the hippocampus and in the spinal cord was also significantly reduced and was similar to that observed at the beginning of the lithium treatment. In these animals, the level of brain β-catenin was increased probably as a result of its stabilization by glycogen synthase kinase-3β inhibition. Despite this inhibitory effect of lithium on NFT development, the motor and working memory deficits were not significantly rescued in these aged animals. Chronic chow feeding with lithium did not alter the development of NFT. Nevertheless, this study indicates that even a relatively short-term per os treatment leading to high blood concentration of lithium is effective in arresting the formation of NFTs in the hippocampus and the spinal cord of a tau transgenic model. Show more

Keywords: Lithium, neurofibrillary tangles, phosphorylation, tau, transgenic mouse, treatment

DOI: 10.3233/JAD-2010-1276

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 705-719, 2010

Authors: Tremblay, Matthew A. | Acker, Christopher M. | Davies, Peter

Article Type: Research Article

Abstract: Tau is a microtubule-associated protein and a main component of neurofibrillary tangles, one of the pathologic hallmarks of Alzheimer's disease. The paired helical filaments (PHF) that comprise neurofibrillary tangles contain an abnormally hyperphosphorylated form of tau. Historically, most of the tau phosphorylation sites that have been characterized are serine and threonine residues. Recent reports state that tau can be phosphorylated at tyrosine residues by kinases including Fyn, Syk, and c-abl (Abl). Proteomic analyses show that tau phosphorylated at tyrosine 394 (Y394) exists within PHF samples taken from Alzheimer's disease brains. This study also confirms phosphorylation of Y394 as an Alzheimer's …disease-specific event by immunohistochemistry. To date, only Abl is known to phosphorylate this particular site on tau. We report, for the first time, that Arg, the other member of the Abl family of tyrosine kinases, also phosphorylates tau at Y394 in a manner independent of Abl activity. Given the reported role of Arg in oxidative stress response and neural development, the ability to phosphorylate tau at Y394 implicates Arg as a potential player in the pathogenesis of Alzheimer's disease and other tauopathies. Show more

Keywords: Abl2, Alzheimer's disease, Arg, phosphorylation, tangle, tau, tyrosine

DOI: 10.3233/JAD-2010-1271

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 721-733, 2010

Authors: Yin, Yang-Yang | Liu, Hao | Cong, Xiao-Bin | Liu, Zhao | Wang, Qun | Wang, Jian-Zhi | Zhu, Ling-Qiang

Article Type: Research Article

Abstract: Tau hyperphosphorylation and memory deficit are characteristic alterations of Alzheimer's disease (AD). Protein phosphatases (PP) 2A plays a crucial role in AD-like lesions. Inhibition of PP2A through hippocampal injection of okadaic acid (OA) induces tau hyperphosphorylation and memory impairment of rats. By using this model, we explored in the present study the effects of acetyl-L-carnitine (ALCAR), a constituent of the inner mitochondrial membrane, on the memory retention, tau phosphorylation, and oxidative stress in rats. We found that pre-treatment of ALCAR (50 mg/d · rat, per os) for two weeks efficiently improved the OA-induced spatial memory retention impairment of the rats. …ALCAR antagonized tau hyperphosphorylation at multiple AD sites and it abated the OA-induced PP2A inhibition and oxidative stress. Our study provides the first in vivo evidence that ALCAR can attenuate AD-like PP2A inhibition, tau hyperphosphorylation, and spatial memory deficit of the rats. It suggests that ALCAR may hold potential in AD treatment. Show more

Keywords: Acetyl-L-carnitine, Alzheimer's disease, hyperphosphorylation, okadaic acid, spatial memory, tau

DOI: 10.3233/JAD-2010-1272

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 735-746, 2010

Authors: McCaffrey, Pat | Fagan, Tom | Landhuis, Esther

Article Type: Research Article

DOI: 10.3233/JAD-2010-1277

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 747-758, 2010

Article Type: Announcement

DOI: 10.3233/JAD-2010-1278

Citation: Journal of Alzheimer's Disease, vol. 19, no. 2, pp. 759-760, 2010