Journal of Alzheimer's Disease - Volume 31, issue 1

Authors: Capsoni, Simona | Carucci, Nicola Maria | Cattaneo, Antonino

Article Type: Short Communication

Abstract: Several studies suggest that systemic infection occurring during aging and chronic neurodegenerative diseases can evoke an exaggerated immune response that contributes to the progression of neurodegeneration and cognitive decline. However, studies directly addressing the relationship between microbial environment and the onset of neurodegeneration in Alzheimer's disease animal models are lacking. Here we show that the onset of neurodegeneration that transgenic mice develop when raised in conventional husbandry slows down when raising anti-nerve growth factor transgenic mice in a murine pathogen free condition.

Keywords: Amyloid-β, deprivation, interleukin-6, microglia, murine pathogen free, nerve growth factor, phosphorylated tau, systemic inflammation

DOI: 10.3233/JAD-2012-120427

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 1-6, 2012

Authors: Testi, Silvia | Fabrizi, Gian Maria | Pompanin, Sara | Cagnin, Annachiara

Article Type: Short Communication

Abstract: Mutations in the Presenilin 2 gene (PSEN2) represent the less frequent genetic cause of familial Alzheimer's disease (FAD). Only eight PSEN2 mutations, reported in approximately 27 families, satisfied strict criteria of pathogenicity. We reported a patient with early-onset FAD and the PSEN2 p.Met239Ile mutation, presenting with severe executive dysfunction and myoclonic tremor, associated with memory loss. Brain SPECT study showed an early hypoperfusion of the frontal cortex. We confirmed the pathogenicity of PSEN2 p.Met239Ile mutation and its heterogeneous phenotypic expression. The modulating effect of the Apolipoprotein E and Prion Protein gene polymorphisms on the phenotypic variability was not confirmed.

Keywords: Alzheimer's disease, familial, frontal lobe, mutation, Presenilin 2

DOI: 10.3233/JAD-2012-120280

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 7-11, 2012

Authors: Perret-Liaudet, Armand | Pelpel, Mathieu | Tholance, Yannick | Dumont, Benoit | Vanderstichele, Hugo | Zorzi, Willy | ElMoualij, Benaissa | Schraen, Susanna | Moreaud, Olivier | Gabelle, Audrey | Thouvenot, Eric | Thomas-Anterion, Catherine | Touchon, Jacques | Krolak-Salmon, Pierre | Kovacs, Gabor G. | Coudreuse, Arnaud | Quadrio, Isabelle | Lehmann, Sylvain

Article Type: Research Article

Abstract: Tau proteins and amyloid-β (Aβ) peptides are the current recognized cerebrospinal fluid (CSF) biomarkers used as an aid in the diagnosis of Alzheimer's disease (AD). However, there is no consensus on their clinical use due to non-qualified cut-off values, probably related to the observed high pre-analytical and analytical variability. Standardized pre-analytical protocols have therefore been proposed. Importantly, these recommend the use of polypropylene collection/sampling tubes while, to date, no broad comparison of these types of tubes has been conducted. In this study, we first compared, as part of a real clinical workflow, the impact of four different collection tubes on …the CSF concentration of Aβ peptides (Aβ42 , Aβ40 ) and total (hTau) and phosphorylated (P-Tau181P) tau proteins measured using routine ELISA kits. We then extended this study to 11 polypropylene tubes used by different clinical laboratories, and investigated their plastic polymer composition using differential scanning calorimetry and Fourier Transformed Infrared spectroscopy. Significant concentration variations linked solely to the use of different types of tubes were observed. This was particularly marked for Aβ peptides, with >50% disparity occurring in less than five minutes. Polymer composition analysis revealed that most polypropylene tubes were in fact copolymers with at least polyethylene. There was no clear correlation between tube composition and pre-analytical behavior. Our results show that the use of polypropylene tubes does not guarantee satisfactory pre-analytical behavior. They also point to collection/sampling tubes being a major pre-analytical source of variability that could impact the significance of AD biological diagnosis. Show more

Keywords: Alzheimer's disease, cerebrospinal fluid, collection tubes, standardization

DOI: 10.3233/JAD-2012-120361

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 13-20, 2012

Authors: Eckert, Schamim H. | Eckmann, Janett | Renner, Kathrin | Eckert, Gunter P. | Leuner, Kristina | Muller, Walter E.

Article Type: Research Article

Abstract: Due to their role in producing energy, as major sources of free radicals, and as critical regulators of apoptosis, mitochondria play a dominant role in the central nervous system (CNS). Mitochondrial dysfunction represents one major pathomechanism of Alzheimer's disease (AD), including impaired function of mitochondrial respiratory chain complexes and deficits of mitochondrial dynamics, such as impaired balance between fission and fusion mechanisms and reduced mitochondrial trafficking. Major consequences are enhanced depletion of mitochondria in axons and dendrites, synaptic dysfunction, and finally neuronal loss. Interfering with impaired mitochondrial dynamics has been proposed as novel strategy for antidementia drugs. Dimebon has been …shown to improve cognition in animal models and seems to be beneficial in AD patients. Regardless of the final proof of Dimebon's clinical efficacy, it might specifically interfere with mechanisms relevant for the cognitive decline, especially by improving impaired mitochondrial function and/or dynamics in AD. Herein, we tested the effects of Dimebon on mitochondrial function and dynamics in a cellular model, overexpressing neurotoxic Aβ peptides, one of the hallmarks of AD. Dimebon exerted pronounced effects on mitochondrial morphology, respiratory chain complex activities, and enlarged mitochondrial mass. In summary, form and function of mitochondria are altered in the Aβ overexpressing cell model and precisely those changes are restored by nanomolar Dimebon treatment. Our findings support the idea that Dimebon improves mitochondrial function and that these “disease specific” effects might be relevant for interpretation and planning of future clinical trials. Show more

Keywords: Alzheimer's disease, amyloid-β, AβPP mutation, Dimebon, latrepirdine, mitochondrial dynamics, mitochondrial dysfunction, mitochondrial mass, mitochondrial morphology, mitochondrial respiratory complexes, OXPHOS

DOI: 10.3233/JAD-2012-120310

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 21-32, 2012

Authors: Mak, Henry K.F. | Chan, Queenie | Zhang, Zhipeng | Petersen, Esben T. | Qiu, Deqiang | Zhang, Linda | Yau, Kelvin K.W. | Chu, Leung-Wing | Golay, Xavier

Article Type: Research Article

Abstract: QUASAR arterial spin labeling (ASL) was used to investigate the role of vascular impairment in Alzheimer's disease (AD). We hypothesized that the hemodynamic parameters monitoring cerebrovascular integrity, i.e., cerebral blood flow (CBF), arterial blood volume (aBV), and arterial transit time (aTT), would be affected. 13 AD patients and 15 healthy control (HC) subjects underwent 3T MRI scanning. Two separate blood flow acquisitions were obtained with 1 slice overlap for whole brain coverage. CBF, aBV, and aTT maps were calculated using in-house software. Preprocessing and statistical analyses were performed on SPM5. Region-of-interest (ROI) studies of ten selected cerebral regions were also …conducted. There were significant differences in Mini Mental Status Exam (MMSE) (AD: 16.3 ± 4.55, HC: 28.5 ± 2.00) and Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) scores (AD: 25.25 ± 9.64, HC: 5.51 ± 2.62) between the 2 groups (p < 0.001) but none in age (p = 0.068). CBF decreased significantly (p < 0.01) in AD compared to controls in the right middle cingulate, left cuneus, left inferior and middle frontal, right superior frontal, left inferior parietal, and right supramarginal gyri. ROI studies confirmed significant hemodynamic impairments in AD compared to HC (p < 0.05): CBF in middle and posterior cingulate, aBV in left superior temporal, right inferior parietal, and posterior cingulate, and aTT in left inferior frontal and middle cingulate gyri. CBF correlated positively while aTT correlated negatively to MMSE, and vice versa for ADAS-cog. Using QUASAR ASL, we found patterns of regional hemodynamic impairment typical of moderate AD, suggesting underlying vascular abnormality. As potential biomarkers, these hemodynamic parameters could differentiate patients from volunteers, and possibly indicate the conversion from healthy aging to mild cognitive impairment to AD. Show more

Keywords: Alzheimer's disease, arterial blood volume, arterial spin labeling, arterial transit time, cerebral blood flow, magnetic resonance imaging, mild cognitive impairment, QUASAR

DOI: 10.3233/JAD-2012-111877

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 33-44, 2012

Authors: Squarzoni, Paula | Tamashiro-Duran, Jaqueline | Souza Duran, Fabio Luiz | Santos, Luciana Cristina | Vallada, Homero Pinto | Menezes, Paulo Rossi | Scazufca, Marcia | Filho, Geraldo Busatto | Alves, Tania Correa Toledo de Ferraz

Article Type: Research Article

Abstract: The presence of cognitive impairment is a frequent complaint among elderly individuals in the general population. This study aimed to investigate the relationship between aging-related regional gray matter (rGM) volume changes and cognitive performance in healthy elderly adults. Morphometric magnetic resonance imaging (MRI) measures were acquired in a community-based sample of 170 cognitively-preserved subjects (66 to 75 years). This sample was drawn from the “São Paulo Ageing and Health” study, an epidemiological study aimed at investigating the prevalence and risk factors for Alzheimer's disease in a low income region of the city of São Paulo. All subjects underwent cognitive testing …using a cross-culturally battery validated by the Research Group on Dementia 10/66 as well as the SKT (applied on the day of MRI scanning). Blood genotyping was performed to determine the frequency of the three apolipoprotein E allele variants (APOE ε2/ε3/ε4) in the sample. Voxelwise linear correlation analyses between rGM volumes and cognitive test scores were performed using voxel-based morphometry, including chronological age as covariate. There were significant direct correlations between worse overall cognitive performance and rGM reductions in the right orbitofrontal cortex and parahippocampal gyrus, and also between verbal fluency scores and bilateral parahippocampal gyral volume (p < 0.05, familywise-error corrected for multiple comparisons using small volume correction). When analyses were repeated adding the presence of the APOE ε4 allele as confounding covariate or excluding a minority of APOE ε2 carriers, all findings retained significance. These results indicate that rGM volumes are relevant biomarkers of cognitive deficits in healthy aging individuals, most notably involving temporolimbic regions and the orbitofrontal cortex. Show more

Keywords: Cognitive decline, healthy aging, structural MRI, voxel-based morphometry

DOI: 10.3233/JAD-2012-111124

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 45-58, 2012

Authors: Hasegawa, Tohru | Ichiba, Masayoshi | Matsumoto, Shin-ei | Kasanuki, Koji | Hatano, Taku | Fujishiro, Hiroshige | Iseki, Eizo | Hattori, Nobutaka | Yamada, Tatsuo | Tabira, Takeshi

Article Type: Research Article

Abstract: Homocysteic acid (HA) has been suggested as a pathogen in a mouse model of Alzheimer's disease (AD), 3xTg-AD. However, it is not established whether HA is involved in humans. We investigated the relationship between urinary HA levels and Mini-Mental State Examination (MMSE) scores in AD patients (n = 70) and non-AD controls (n = 34). We found a positive, statistically significant relationship between the two variables (the urinary HA level and MMSE score) (r = 0.31, p = 0.0008, n = 70). This relationship was stronger in females than males (r = 0.43, p = 0.005, n = 44 in …females; r = 0.48, p = 0.02, n = 22 in males). The urinary HA levels were significantly different in AD patients than controls (AD: 8.7 ± 7.5, n = 70; non-dementia control: 13.3 ± 9.4, n = 34, p < 0.01). In addition, aging and smoking were found as lowering factors for urinary HA levels. Our preliminary study showed a negative, statistically significant relationship between blood HA (micromole) and urine HA levels (r = −0.6, p = 0.007, n = 19), and between blood HA levels and MMSE scores (r = −0.79, p = 0.0000518, n = 19). On the basis of these results, we speculate that reduced urinary excretion induces elevated HA levels in blood, resulting in cognitive dysfunctions. This study also suggests that HA may be a candidate of neurotoxins for uremic encephalopathy. Since amyloid-β increases HA toxicity and HA is an agonist of N-methyl-D-aspartic acid (NMDA) receptor, we speculate that elevated blood HA affects the brain cognitive function through NMDA receptor-mediated toxicity in AD. Show more

Keywords: Aging, Alzheimer disease, homocysteic acid, MMSE, smoking, uremia

DOI: 10.3233/JAD-2012-120022

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 59-64, 2012

Authors: Farías, Gonzalo | Pérez, Patricio | Slachevsky, Andrea | Maccioni, Ricardo B.

Article Type: Research Article

Abstract: Platelets are major reservoirs of circulating amyloid-β and amyloid-β protein precursor (AβPP) and have been postulated as a reliable source for biological markers of Alzheimer's disease (AD). We have recently demonstrated that tau is also present in platelets, and that there are differences in the electrophoretic patterns of platelet tau forms in AD subjects with respect to controls. Here, we demonstrate that modifications in platelet tau forms occur independently of age in a broad population of 104 neurologically healthy individuals. More interesting, a strong correlation of platelet markers with the degree of cognitive impairment was evidenced in a group of …47 AD patients in comparison with 19 cognitive healthy subjects. In our series, platelet tau forms ratio had a sensitivity of 75.7% and specificity of 73.7%, respectively. We also found that platelet tau displays a significantly higher correlation with the presence of AD than the analyses of platelet AβPP. Show more

Keywords: Alzheimer's disease, cognitive impairment, human platelets, tau biomarker

DOI: 10.3233/JAD-2012-120304

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 65-69, 2012

Authors: Bengtsson, Sara K. | Johansson, Maja | Bäckström, Torbjörn | Wang, Mingde

Article Type: Research Article

Abstract: The endogenous neurosteroid allopregnanolone alters neuronal excitability via modulation of the GABAA receptor and causes decreased neurotransmission. In Alzheimer's disease (AD), neurotransmission seems to alter the levels of toxic intracellular amyloid-β (Aβ) oligomers, which are implicated in AD pathogenesis and cause cognitive decline. Inhibition of synaptic activity has been shown to increase levels of intracellular Aβ. Allopregnanolone at endogenous stress levels inhibits synaptic activity and could have similar effects. By using a transgenic AβPPSwe PSEN1ΔE9 mouse model for AD, we observed that chronic allopregnanolone treatment for three months with stress levels of allopregnanolone impaired learning in the Morris …water maze. The learning impairment was seen one month after the end of treatment. Chronic allopregnanolone treatment also led to increased levels of soluble Aβ in the brain, which could be a sign of advanced pathogenesis. Since the learning and memory of wild-type mice was not affected by the treatment, we propose that chronic allopregnanolone treatment accelerates the pathogenesis of AD. However, further studies are required in order to determine the underlying mechanism. Show more

Keywords: Allopregnanolone, Alzheimer's disease, amyloid-β, amyloid-β1-40, amyloid-β1-42, cognition, physiological stress

DOI: 10.3233/JAD-2012-120268

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 71-84, 2012

Authors: Pluta, John | Yushkevich, Paul | Das, Sandhitsu | Wolk, David

Article Type: Research Article

Abstract: The measurement of hippocampal volumes using MRI is a useful in-vivo biomarker for detection and monitoring of early Alzheimer's disease (AD), including during the amnestic mild cognitive impairment (a-MCI) stage. The pathology underlying AD has regionally selective effects within the hippocampus. As such, we predict that hippocampal subfields are more sensitive in discriminating prodromal AD (i.e., a-MCI) from cognitively normal controls than whole hippocampal volumes, and attempt to demonstrate this using a semi-automatic method that can accurately segment hippocampal subfields. High-resolution coronal-oblique T2-weighted images of the hippocampal formation were acquired in 45 subjects (28 controls and 17 a-MCI (mean age: …69.5 ± 9.2; 70.2 ± 7.6)). CA1, CA2, CA3, and CA4/DG subfields, along with head and tail regions, were segmented using an automatic algorithm. CA1 and CA4/DG segmentations were manually edited. Whole hippocampal volumes were obtained from the subjects' T1-weighted anatomical images. Automatic segmentation produced significant group differences in the following subfields: CA1 (left: p = 0.001, right: p = 0.038), CA4/DG (left: p = 0.002, right: p = 0.043), head (left: p = 0.018, right: p = 0.002), and tail (left: p = 0.019). After manual correction, differences were increased in CA1 (left: p < 0.001, right: p = 0.002), and reduced in CA4/DG (left: p = 0.029, right: p = 0.221). Whole hippocampal volumes significantly differed bilaterally (left: p = 0.028, right: p = 0.009). This pattern of atrophy in a-MCI is consistent with the topography of AD pathology observed in postmortem studies, and corrected left CA1 provided stronger discrimination than whole hippocampal volume (p = 0.03). These results suggest that semi-automatic segmentation of hippocampal subfields is efficient and may provide additional sensitivity beyond whole hippocampal volumes. Show more

Keywords: Automatic segmentation, CA1, hippocampal subfields, mild cognitive impairment, magnetic resonance imaging

DOI: 10.3233/JAD-2012-111931

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 85-99, 2012

Authors: Liu, Yanyong | Aisa, Haji Akber | Ji, Chao | Yang, Nan | Zhu, Haibo | Zuo, Pingping

Article Type: Research Article

Abstract: Aging-associated cognitive impairment is an important health care issue since individuals with mild cognitive impairment are more likely to develop Alzheimer’s disease. In the present study, the protective effect of Gossypium herbaceam extracts (GHE) on learning and memory impairment associated with aging were examined in vivo using Morris water maze and step through task. Furthermore, the antioxidant activity and neuroprotective effect of GHE was investigated with methods of histochemistry and biochemistry. These data showed that oral administration with GHE at the doses of 35, 70, and 140 mg/kg exerted an improved effect on the learning and memory impairment in …aged rats. Subsequently, GHE afforded a beneficial action on eradication of free radicals without influence on the activity of glutathione peroxidase and superoxide dismutase. GHE treatment enhanced the expression levels of nerve growth factor. Meanwhile, proliferation of neural progenitor cells was elevated in hippocampus after treatment with GHE. Taken together, neurogenic niche improvement could be involved in the mechanism underlying neuroprotection of GHE against aging-associated cognitive impairment. These findings suggested that GHE might be a potential agent as cognitive-enhancing drugs that delay or halt mild cognitive impairment progression to Alzheimer’s disease or treatment of aging-associated cognitive impairment. Show more

Keywords: Aging, Alzheimer’s disease, mild cognitive impairment, oxidative stress

DOI: 10.3233/JAD-2012-112153

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 101-111, 2012

Authors: Saiz-Sanchez, Daniel | Ubeda-Bañon, Isabel | De la Rosa-Prieto, Carlos | Martinez-Marcos, Alino

Article Type: Research Article

Abstract: Impaired olfaction is an early symptom of Alzheimer's disease (AD). Neuroanatomical changes underlying this deficit in the olfactory system are largely unknown. Cell neurodegeneration is known to involve, among others, somatostatin (SST)- and calcium-binding protein-positive cells. We report here quantitative analysis of temporal changes in the distribution of interneuron cell populations in the olfactory cortex of an AβPP/PS1 double-transgenic mouse model of AD and its correlation with amyloid-β pathology. To investigate early stages of pathology, the piriform and lateral entorhinal cortices were analyzed in groups of homozygous AβPP/PS1 and control animals at 2, 4, 6, and 8 months of age. …There was a significant increase in brain levels of aggregated amyloid-β peptide with age, accompanied by an early and marked fall in numbers of SST- and calretinin-positive interneurons; a later and less pronounced decrease in levels of calbindin- and parvalbumin-positive cells was also observed. In addition, double-labeling experiments indicated high levels of co-localization of SST-positive cells with amyloid-β expression in olfactory areas. These observations argue that SST-positive cells are vulnerable to amyloid-β neuropathy in the olfactory cortex during the early stages of AD. These data may cast light on the neural basis of hyposmia associated with this disorder and on the mechanisms of cell vulnerability to neurodegeneration. Show more

Keywords: Alzheimer's disease, amyloid, calcium-binding protein, entorhinal cortex, interneuron, piriform cortex, somatostatin, transgenic

DOI: 10.3233/JAD-2012-111889

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 113-129, 2012

Authors: Yang, Ling | Ye, Chun-yan | Huang, Xiao-tian | Tang, Xi-can | Zhang, Hai-yan

Article Type: Research Article

Abstract: A number of recent discoveries indicate that huperzine A, an active herbal medicine employed for the treatment of Alzheimer's disease (AD) in China, can afford neuroprotection on in vitro and in vivo models related to mitochondrial dysfunction. However, it is an intricate and highly debated research topic about whether another pharmacological mechanism is involved in the beneficial profiles of huperzine A, independent of its well-recognized potent acetycholinesterase (AChE) inhibitory effect. As an extension, this study for the first time verified the co-occurrence of the beneficial effects of huperzine A on mitochondrial dysfunction and memory deficits in AβPP/PS1 double transgenic mice, …at a time point that AChE was not inhibited. Moreover, using isolated brain cortical mitochondria, we confirmed the ameliorating effect of huperzine A on oligomeric Aβ1-42 -induced ATP reduction and mitochondrial swelling, as well as a decrease in the enzymatic activities of respiratory chain complexes, especially complex II-III and complex IV, which may be attributed to the blockage of oligomeric Aβ1-42 from penetrating into mitochondria. These results shed more light on a potential direct target of huperzine A on isolated mitochondria, which may be largely different from its specific inhibition on AChE. This work describes a novel mechanism of neuroprotection by huperzine A and provides important clues for discovering novel therapeutic strategy for AD. Show more

Keywords: Alzheimer's disease, amyloid-β peptide, huperzine A, mitochondrial dysfunction, oligomer

DOI: 10.3233/JAD-2012-120274

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 131-142, 2012

Authors: Chow, Tiffany W. | Fridhandler, Jonathan D. | Binns, Malcolm A. | Lee, Albert | Merrilees, Jennifer | Rosen, Howie J. | Ketelle, Robin | Miller, Bruce L.

Article Type: Research Article

Abstract: Predicting the progression of dementia is a challenge for clinicians yet this information is highly valued by patients' families. An informally observed 4-stage model of dementia can be helpful in educating caregivers and preparing them for what lies ahead. In the behavioral variant of frontotemporal dementia (bvFTD), this model describes the evolution of behavioral disturbances and is characterized by an inflection point between stage 2 (progressively severe behavioral aberration) and stage 3 (increasing apathy and remission of behavior problems). In this study, we sought evidence for this model using a database of serial Neuropsychiatric Inventory (NPI) scores for 45 patients …with FTD and 47 patients with Alzheimer's disease (AD). We transformed the NPI scores into a single variable for each participant that represented the yearly rate of change in total NPI score and used this as the dependent variable in a multivariate linear regression. Age at onset of dementia, NPI score at initial visit, and duration of illness at first NPI all contributed significantly to the regression model in the bvFTD group. Participants with an initial NPI acquired before 6 years of disease duration tended to have a more positive rate of change in NPI total score (representing worsening behavioral disturbances) than those with an initial NPI performed after 6 years. None of the aforementioned variables were significantly associated with yearly change in NPI total score in the AD group. These results support a crescendo-decrescendo trajectory of behavioral symptoms in bvFTD but do not suggest that there is a similar pattern in AD, and further longitudinal data collection is necessary. Show more

Keywords: Agitation, Alzheimer's disease, apathy, behavioral symptoms, disease progression, frontotemporal dementia, longitudinal study, neurobehavioral manifestations

DOI: 10.3233/JAD-2012-111916

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 143-149, 2012

Authors: Qosa, Hisham | Abuznait, Alaa H. | Hill, Ronald A. | Kaddoumi, Amal

Article Type: Research Article

Abstract: Rifampicin and caffeine are widely used drugs with reported protective effect against Alzheimer's disease (AD). However, the mechanism underlying this effect is incompletely understood. In this study, we have hypothesized that enhanced amyloid-β (Aβ) clearance from the brain across the blood-brain barrier (BBB) of wild-type mice treated with rifampicin or caffeine is caused by both drugs potential to upregulate low-density lipoprotein receptor related protein-1 (LRP1) and/or P-glycoprotein (P-gp) at the BBB. Expression studies of LRP1 and P-gp in brain endothelial cells and isolated mice brain microvessels following treatment with rifampicin or caffeine demonstrated both drugs as P-gp inducers, and only …rifampicin as an LRP1 inducer. Also, brain efflux index (BEI%) studies conducted on C57BL/6 mice treated with either drug to study alterations in Aβ clearance demonstrated the BEI% of Aβ in rifampicin (82.4 ± 4.3%) and caffeine (80.4 ± 4.8%) treated mice were significantly higher than those of control mice (62.4 ± 6.1%, p < 0.01). LRP1 and P-gp inhibition studies confirmed the importance of both proteins to the clearance of Aβ, and that enhanced clearance following drugs treatment was caused by LRP1 and/or P-gp upregulation at the mouse BBB. Furthermore, our results provided evidence for the presence of a yet to be identified transporter/receptor that plays significant role in Aβ clearance and is upregulated by caffeine and rifampicin. In conclusion, our results demonstrated the upregulation of LRP1 and P-gp at the BBB by rifampicin and caffeine enhanced brain Aβ clearance, and this effect could explain, at least in part, the protective effect of rifampicin and caffeine against AD. Show more

Keywords: Alzheimer's disease, amyloid-β, caffeine, LRP1, P-gp, rifampicin

DOI: 10.3233/JAD-2012-120319

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 151-165, 2012

Authors: Joshi, Yash B. | Chu, Jin | Praticò, Domenico

Article Type: Research Article

Abstract: Several studies have linked stress with Alzheimer's disease (AD) vulnerability; however, the mechanism remains to be fully elucidated. In the current paper, we investigated the role of glucocortitcoids on the AD-like phenotype. We administered the glucocorticoid dexamethasone to Tg2576 mice for 4 weeks and then investigated its effect on memory, amyloid-β and tau levels, and metabolism. At the end of the treatment period, we observed that mice receiving dexamethasone had a significant impairment in the fear conditioning paradigm compared with controls. Dexamethasone-treated animals showed a significant increase in the amount of brain soluble Aβ40 levels, but no alteration in …the steady state levels of its precursor protein, AβPP, or in the major protease enzymes involved in its metabolism (i.e., ADAM-10, BACE-1, or γ-secretase complex). While total tau protein levels were unaltered between the two groups, we found that dexamethasone significantly reduced tau phosphorylation at specific sites that were mediated by decreases in glycogen synthase kinase-3β protein level activity. Finally, we observed a direct correlation between memory impairments and tau phosphorylation levels. Our study highlights the significant role that glucocorticoids play in exacerbating AD-like cognitive impairments via alteration of tau protein phosphorylation state. Show more

Keywords: Alzheimer's disease, transgenic animal model, stress, glucocorticoid

DOI: 10.3233/JAD-2012-120328

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 167-176, 2012

Authors: Realmuto, Sabrina | Cinturino, Antonio | Arnao, Valentina | Mazzola, Maria Antonietta | Cupidi, Chiara | Aridon, Paolo | Ragonese, Paolo | Savettieri, Giovanni | D'Amelio, Marco

Article Type: Research Article

Abstract: Studies reporting an inverse association between Alzheimer's disease (AD) and cancer are scant. Available data are mostly based on ancillary findings of mortality data or obtained from studies evaluating frequency of neoplasms in AD patients independently if they occurred before or after AD. Moreover, some studies estimated frequencies of neoplasms in demented individuals, who were not necessarily AD patients. We estimated frequency of tumors preceding the onset of AD in AD patients and compared it to that of age- and gender-matched AD-free individuals. Occurrence of tumors preceding AD onset was assessed through a semi-structured questionnaire. Tumors were categorized as benign, …malignant, or of uncertain classification and as endocrine-related or not. Odds ratios (OR), used as measure of the association between the two diseases, were adjusted for tumor categories and known risk factors for AD and tumors. We included 126 AD patients and 252 matched controls. Tumor frequency before AD onset was 18.2% among cases and 24.2% among controls. There was a suggestive trend of an overall inverse association between the two diseases (adjusted OR 0.6; 95% CI 0.4–1.1; p = 0.11). Risk for neoplasms was significantly reduced only for women (adjusted OR, 0.5; 95% CI 0.3–0.9; p = 0.03) and for endocrine related tumors (adjusted OR, 0.5; 95% CI 0.2–1; p = 0.04). Our study confirms the inverse association reported in previous epidemiological studies. Though our findings might be explained by processes playing an opposite role in tumors development and neurodegeneration, they are also suggestive for a possible role of estrogen. Show more

Keywords: Aging, Alzheimer's disease, case-control, estrogen, neurodegeneration, tumors

DOI: 10.3233/JAD-2012-120184

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 177-182, 2012

Authors: Calderón-Garcidueñas, Lilian | Mora-Tiscareño, Antonieta | Styner, Martin | Gómez-garza, Gilberto | Zhu, Hongtu | Torres-Jardón, Ricardo | Carlos, Esperanza | Solorio-López, Edelmira | Medina-Cortina, Humberto | Kavanaugh, Michael | D'Angiulli, Amedeo

Article Type: Research Article

Abstract: Air pollution exposures are linked to neuroinflammation and neuropathology in young urbanites. Forty percent of exposed children and young adults exhibit frontal tau hyperphosphorylation and 51% have amyloid-β diffuse plaques compared to 0% in low pollution controls. In older adults, white matter hyperintensities (WMH) are associated with cognitive deficits while inflammatory markers correlate with greater atrophy than expected for age. We investigated patterns of WMH, magnetic resonance imaging (MRI) volume growth, blood inflammatory mediators, and cognition in matched children from two urban cohorts: one severely and one minimally exposed to air pollution. Baseline and one year follow-up measurements of cognitive …abilities, brain MRI volumes, and blood were collected in 20 Mexico City (MC) children (10 with WMH+ , and 10 without WMH− ) and 10 matched controls (WMH− ). MC WMH− children display the profile of classical pro-inflammatory defensive responses: high interleukin 12, production of powerful pro-inflammatory cytokines, and low concentrations of key cytokines and chemokines associated with neuroprotection. MC WMH+ children exhibit a response involved in resolution of inflammation, immunoregulation, and tissue remodeling. The MC WMH+ group responded to the air pollution-associated brain volumetric alterations with white and grey matter volume increases in temporal, parietal, and frontal regions and better cognitive performance compared to MC WMH− . We conclude that complex modulation of cytokines and chemokines influences children's central nervous system structural and volumetric responses and cognitive correlates resulting from environmental pollution exposures. Identification of biomarkers associating systemic inflammation to brain growth is critical for detecting children at higher risk for cognitive deficits and neurodegeneration, thereby warranting early implementation of neuroprotective measures. Show more

Keywords: Air pollution, Alzheimer's disease risk, biomarkers, chemokines, children, cognition, cytokines, fine particulate matter, MRI volumes, systemic inflammation, white matter hyperintensities

DOI: 10.3233/JAD-2012-120610

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 183-191, 2012

Authors: Wang, Shu | Qaisar, Uzma | Yin, Xiangling | Grammas, Paula

Article Type: Research Article

Abstract: The enigma that is Alzheimer's disease (AD) continues to present daunting challenges for effective therapeutic intervention. The lack of disease-modifying therapies may, in part, be attributable to the narrow research focus employed to understand this complex disease. Most studies into disease pathogenesis are based on a priori assumptions about the role of AD lesion-associated proteins such as amyloid-β and tau. However, the complex disease processes at work may not be amenable to single-target therapeutic approaches. Genome-wide expression studies provide an unbiased approach for investigating the pathogenesis of complex diseases like AD. A growing literature suggests a role for cerebrovascular contributions …to the pathogenesis of AD. The objective of the current study is to examine human brain microvessels isolated from AD patients and controls by microarray analysis. Differentially expressed genes with more than 2-fold change are used for further data analysis. Gene ontology analysis and pathway analysis algorithms within GeneSpringGX are employed to understand the regulatory networks of differentially expressed genes. Twelve matched pairs of AD and control brain microvessel samples are hybridized to Agilent Human 4 × 44 K arrays in replication. We document that more than 2,000 genes are differentially altered in AD microvessels and that a large number of these genes map to pathways associated with immune and inflammatory response, signal transduction, and nervous system development and function categories. These data may help elucidate heretofore unknown molecular alterations in the AD cerebromicrovasculature. Show more

Keywords: Alzheimer's disease, brain, gene expression profile, microarray, microvessel

DOI: 10.3233/JAD-2012-120454

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 193-205, 2012

Authors: Hwang, Sung Hee | Shin, Eun-Joo | Shin, Tae-Joon | Lee, Byung-Hwan | Choi, Sun-Hye | Kang, Jiyeon | Kim, Hyeon-Joong | Kwon, Seung-Hwan | Jang, Choon-Gon | Lee, Jun-Ho | Kim, Hyoung-Chun | Nah, Seung-Yeol

Article Type: Research Article

Abstract: Ginseng extracts show cognition-enhancing effects in Alzheimer's disease (AD) patients. However, little is known about the active components and molecular mechanisms of how ginseng exerts its effects. Recently, we isolated a novel lysophosphatidic acid (LPA) receptor-activating ligand from ginseng, gintonin. AD is caused by amyloid-β protein (Aβ) accumulation. Aβ is derived from amyloid-β protein precursors (AβPPs) through the amyloidogenic pathway. In contrast, non-amyloidogenic pathways produce beneficial, soluble AβPPα (sAβPPα). Here, we describe our investigations of the effect of gintonin on sAβPPα release, Aβ formation, Swedish-AβPP transfection-mediated neurotoxicity in SH-SY5Y neuroblastoma cells, and Aβ-induced neuropathy in mice. Gintonin promoted sAβPPα release …in a concentration- and time-dependent manner. Gintonin action was also blocked by the Ca2+ chelator BAPTA, α-secretase inhibitor TAPI-2, and protein-trafficking inhibitor brefeldin. Gintonin decreased Aβ1-42 release and attenuated Aβ1-40 -induced cytotoxicity in SH-SY5Y cells. Gintonin also rescued Aβ1-40 -induced cognitive dysfunction in mice. Moreover, in a transgenic mouse AD model, long-term oral administration of gintonin attenuated amyloid plaque deposition as well as short- and long-term memory impairment. In the present study, we demonstrated that gintonin mediated the promotion of non-amyloidogenic processing to stimulate sAβPPα release to restore brain function in mice with AD. Gintonin could be a useful agent for AD prevention or therapy. Show more

Keywords: Alzheimer's disease, amyloid-β protein precursor, memory, transgenic mice

DOI: 10.3233/JAD-2012-120439

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 207-223, 2012

Authors: Scheltens, Philip | Twisk, Jos W.R. | Blesa, Rafael | Scarpini, Elio | von Arnim, Christine A.F. | Bongers, Anke | Harrison, John | Swinkels, Sophie H.N. | Stam, Cornelis J. | de Waal, Hanneke | Wurtman, Richard J. | Wieggers, Rico L. | Vellas, Bruno | Kamphuis, Patrick J.G.H.

Article Type: Research Article

Abstract: Souvenaid aims to improve synapse formation and function. An earlier study in patients with Alzheimer's disease (AD) showed that Souvenaid increased memory performance after 12 weeks in drug-naïve patients with mild AD. The Souvenir II study was a 24-week, randomized, controlled, double-blind, parallel-group, multi-country trial to confirm and extend previous findings in drug-naïve patients with mild AD. Patients were randomized 1 : 1 to receive Souvenaid or an iso-caloric control product once daily for 24 weeks. The primary outcome was the memory function domain Z-score of the Neuropsychological Test Battery (NTB) over 24 weeks. Electroencephalography (EEG) measures served as secondary …outcomes as marker for synaptic connectivity. Assessments were done at baseline, 12, and 24 weeks. The NTB memory domain Z-score was significantly increased in the active versus the control group over the 24-week intervention period (p = 0.023; Cohen's d = 0.21; 95% confidence interval [−0.06]–[0.49]). A trend for an effect was observed on the NTB total composite z-score (p = 0.053). EEG measures of functional connectivity in the delta band were significantly different between study groups during 24 weeks in favor of the active group. Compliance was very high (96.6% [control] and 97.1% [active]). No difference between study groups in the occurrence of (serious) adverse events. This study demonstrates that Souvenaid is well tolerated and improves memory performance in drug-naïve patients with mild AD. EEG outcomes suggest that Souvenaid has an effect on brain functional connectivity, supporting the underlying hypothesis of changed synaptic activity. Show more

Keywords: Alzheimer's disease, dietary management, medical food, membrane phosphatide synthesis, nutritional intervention, randomized clinical trial, synapse formation, synaptic activity

DOI: 10.3233/JAD-2012-121189

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 225-236, 2012

Authors: Cummings, Jeffrey L.

Article Type: Research Article

DOI: 10.3233/JAD-2012-121297

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 237-238, 2012

Article Type: Other

DOI: 10.3233/JAD-2012-120245B

Citation: Journal of Alzheimer's Disease, vol. 31, no. 1, pp. 239-241, 2012