Journal of Alzheimer's Disease - Volume 54, issue 4

Authors: Qiu, Tiantian | Luo, Xiao | Shen, Zhujing | Huang, Peiyu | Xu, Xiaojun | Zhou, Jiong | Zhang, Minming | for the Alzheimer’s Disease Neuroimaging Initiative

Article Type: Research Article

Abstract: Mild cognitive impairment (MCI) is a heterogeneous condition associated with a high risk of progressing to Alzheimer’s disease (AD). Although functional brain network alterations have been observed in progressive MCI (pMCI), the underlying pathological mechanisms of network alterations remain unclear. In the present study, we evaluated neuropsychological, imaging, and cerebrospinal fluid (CSF) data at baseline across a cohort of: 21 pMCI patients, 33 stable MCI (sMCI) patients, and 29 normal controls. Fast eigenvector centrality mapping (fECM) based on resting-state functional MRI (rsfMRI) was used to investigate brain network organization differences among these groups, and we further assessed its relation to …cognition and AD-related pathology. Our results demonstrated that pMCI had decreased eigenvector centrality (EC) in left temporal pole and parahippocampal gyrus, and increased EC in left middle frontal gyrus compared to sMCI. In addition, compared to normal controls, patients with pMCI showed decreased EC in right hippocampus and bilateral parahippocampal gyrus, and sMCI had decreased EC in right middle frontal gyrus and superior parietal lobule. Correlation analysis showed that EC in the left temporal pole was related to Wechsler Memory Scale-Revised Logical Memory (WMS-LM) delay score (r  = 0.467, p  = 0.044) and total tau (t-tau) level in CSF (r  = –0.509, p  = 0.026) in pMCI. Our findings implicate EC changes of different brain network nodes in the prognosis of pMCI and sMCI. Importantly, the association between decreased EC of brain network node and pathological changes may provide a deeper understanding of the underlying pathophysiology of pMCI. Show more

Keywords: Alzheimer’s disease, brain network organization, cerebrospinal fluid, cognition, mild cognitive impairment, pathophysiology

DOI: 10.3233/JAD-160403

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1483-1493, 2016

Authors: Mazzeo, Salvatore | Santangelo, Roberto | Bernasconi, Maria Paola | Cecchetti, Giordano | Fiorino, Agnese | Pinto, Patrizia | Passerini, Gabriella | Falautano, Monica | Comi, Giancarlo | Magnani, Giuseppe

Article Type: Research Article

Abstract: Background: Correctly diagnosing Alzheimer’s disease (AD) in prodromal phases would allow the adoption of experimental therapeutic strategies that could selectively interrupt the pathogenetic process before neuronal damage becomes irreversible. Therefore, great efforts have been aimed at finding early reliable disease markers. Objective: The aim of this study was to identify a simple, cost effective, and reliable diagnostic algorithm to predict conversion from mild cognitive impairment (MCI) to AD. Methods: 96 consecutive MCI patients admitted to the Neurology department of San Raffaele Hospital in Milan between January 2009 and January 2015 were included. All patients underwent …neuropsychological assessment and lumbar puncture with CSF analysis of amyloid-β 42 (Aβ42 ), total tau (t-tau), and phosphorylated tau (p-tau) levels. Each patient underwent clinical and neuropsychological follow-up, in order to identify a possible progression from MCI to AD. The mean follow up time was 36.73 months. Results: 37 out of 96 MCI converted to AD during follow up. CSF analysis and neuropsychological assessment reliably detected MCI patients who developed AD. In a subsample of 43 subjects, a Composite Cognitive Score (CCS) was calculated including episodic memory, executive function, and verbal fluency tests. Combining together CSF biomarkers and CCS increased the accuracy of the single predictors, correctly classifying 86% of patients with a specificity of 96% and a Positive Predictive Value of 93%. Discussion: Even if preliminary, our data seem to suggest that CSF analysis and neuropsychological assessment could detect MCI patients who will convert to AD with high confidence. Their relative low cost and availability could make them worldwide essential tools in future clinical trials. Show more

Keywords: Amyloid-β42, composite cognitive score, diagnostic algorithm, mild cognitive impairment, neuropsychological tests, tau protein

DOI: 10.3233/JAD-160360

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1495-1508, 2016

Authors: Brody, Mark | Liu, Enchi | Di, Jianing | Lu, Ming | Margolin, Richard A. | Werth, John L. | Booth, Kevin | Shadman, Anna | Brashear, H. Robert | Novak, Gerald

Article Type: Research Article

Abstract: Background: Bapineuzumab, a humanized monoclonal antibody, targets amyloid-β (Aβ1-40/1 -42 ) that is believed to play a key role in the pathogenesis of Alzheimer disease (AD). Objectives: To assess the effects of monthly subcutaneous (SC) bapineuzumab versus placebo on cerebral amyloid signal in amyloid-positive patients with mild to moderate AD. The incidence of amyloid-related imaging abnormalities–edema/effusion (ARIA-E), pharmacokinetics, pharmacodynamics, immunogenicity, and other safety aspects of bapineuzumab were also evaluated. Methods: In this multicenter, double-blind study, 146 patients were randomized (1 : 1:1 : 1) to SC bapineuzumab 2, 7, or 20 mg/month or placebo. Lack of efficacy of intravenous (IV) bapineuzumab …in Phase III studies led to truncation of the treatment duration from 24 months to 12 months. Primary endpoint: change from baseline to month 12 in brain amyloid signal as measured by standardized uptake value ratio (SUVR) using florbetapir positron emission tomography (PET). Results: Florbetapir PET SUVR decreased significantly (p  = 0.038) from baseline to month 12 for the bapineuzumab 7 mg/month group only; reductions versus placebo were not significant for any dosage. One patient each in bapineuzumab 2 mg/month and 20 mg/month groups had ARIA-E. The percentages of patients with treatment-emergent adverse events were similar in placebo (77.8%) and bapineuzumab 2 mg/month (78.4%) group, but higher in 7 mg/month (94.4%) and 20 mg/month (89.2%) groups. Conclusion: Bapineuzumab SC once-monthly did not demonstrate significant treatment difference over placebo on cerebral amyloid signal at one year but was well-tolerated. There was less ARIA-E than had been expected based on prior experience with comparable exposure on IV bapineuzumab. Show more

Keywords: Alzheimer’s disease, amyloid burden, bapineuzumab, biomarker, pharmacokinetics

DOI: 10.3233/JAD-160369

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1509-1519, 2016

Authors: Mead, Emma | Kestoras, Dimitra | Gibson, Yolanda | Hamilton, Lucy | Goodson, Ross | Jones, Sophie | Eversden, Sarah | Davies, Peter | O’Neill, Michael | Hutton, Michael | Szekeres, Philip | Wolak, Joanna

Article Type: Research Article

Abstract: Intracellular neurofibrillary tangles (NFTs) are the hallmark of Alzheimer’s disease and other tauopathies in which tau, a microtubule-associated protein, loses its ability to stabilize microtubules. Several post-translational modifications including phosphorylation and truncation increase tau’s propensity to aggregate thus forming NFTs; however, the mechanisms underlying tau conformational change and aggregation still remain to be defined. Caspase activation and subsequent proteolytic cleavage of tau is thought to be a potential trigger of this disease-related pathological conformation. The aim of this work was to investigate the link between caspase activation and a disease-related conformational change of tau in a neuroblastoma cell-based model of …spontaneous tau aggregation. We demonstrated that caspase induction initiates proteolytic cleavage of tau and generation of conformationally altered and aggregated tau recognized by the MC1 conformational antibody. Most importantly, these events were shown to be attenuated with caspase inhibitors. This implies that therapeutics aimed at inhibiting caspase-mediated tau cleavage may prove beneficial in slowing cleavage and aggregation, thus potentially halting tau pathology and disease progression. Show more

Keywords: Alzheimer’s disease, caspases, neurodegenerative diseases, protein aggregation, tau proteins, tauopathies

DOI: 10.3233/JAD-150960

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1521-1538, 2016

Authors: Mueller, Kimberly Diggle | Koscik, Rebecca L. | Turkstra, Lyn S. | Riedeman, Sarah K. | LaRue, Asenath | Clark, Lindsay R. | Hermann, Bruce | Sager, Mark A. | Johnson, Sterling C.

Article Type: Research Article

Abstract: Connected language is often impaired among people with Alzheimer’s disease (AD), yet little is known about when language difficulties first emerge on the path to a clinical diagnosis. The objective of this study was to determine whether individuals with psychometric (preclinical) evidence of amnestic mild cognitive impairment (pMCI) showed deficits in connected language measures. Participants were 39 pMCI and 39 cognitively healthy (CH) adults drawn from the Wisconsin Registry for Alzheimer’s Prevention, who were matched for age, literacy, and sex. Participants completed a connected language task in which they described the Cookie Theft picture from the Boston Diagnostic Aphasia Examination. …Language samples were analyzed across three language domains: content, syntactic complexity, and speech fluency. Paired t -tests were used to compare CH and pMCI groups on all variables, and Cohen’s d effect sizes were calculated for each comparison. The CH and pMCI groups differed significantly on measures of content (e.g., CH group produced more semantic units, more unique words and had larger idea density, on average, than the pMCI group). The picture description findings are consistent with previous retrospective studies showing semantic language differences in adults with autopsy-confirmed AD. Given that these comparisons are between cognitively healthy and pMCI individuals (before a clinical MCI diagnosis), these findings may represent subtle language difficulty in spontaneous speech, and may be predictive of larger language changes over time. Show more

Keywords: Alzheimer’s disease, dementia, discourse, language disorders, linguistics, mild cognitive impairment, semantics, speech

DOI: 10.3233/JAD-160252

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1539-1550, 2016

Authors: Turró-Garriga, Oriol | Garre-Olmo, Josep | Reñé-Ramírez, Ramon | Calvó-Perxas, Laia | Gascón-Bayarri, Jordi | Conde-Sala, Josep-Lluís

Article Type: Research Article

Abstract: Background : Anosognosia is common in patients with Alzheimer’s disease (AD) and it is frequently related to an increase in time of care demand. Objective : The aim of the study was to examine the effect of anosognosia on the total costs of informal care in patients with AD. Methods : This was a prospective longitudinal study with community-dwelling AD patients. Anosognosia, time of informal care, and the use of support services (e.g., day care centers) were recorded at baseline and after 24 months. The cost of informal caregiving was calculated as ‘market price’. Results : At …baseline, the prevalence of anosognosia was 54.3% (n  = 221), and 43.9% were classified as mild-AD. The average time of care was 5 h/day±2.4 (IADL: 1.3 h/day±1.4 and BADL: 3.6 h/day±1.5). Thirty percent of the patients used home care services, and 25.1% attended a day care center. Patients with anosognosia received more time of care and were more likely to use support services than did their no-anosognosia peers, including institutionalization. The mean cost of support services was 490.4€ /month (SD = 413.1€; range = 25–2,212.38€), while the overall cost of care (support services plus informal care) was 1,787€ /month (SD = 972.4€), ranging from 834.1€ in mild-AD without anosognosia patients, to 2,424.8€ in severe-AD with incident anosognosia patients. Conclusions : Anosognosia was associated with an increased number of hours of informal care, and a greater use of support services, regardless of the severity of the dementia, which lead to an increase of the total family-care costs. Show more

Keywords: Alzheimer’s disease, anosognosia, cost of illness, dementia, health care costs, longitudinal studies

DOI: 10.3233/JAD-160419

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1551-1560, 2016

Authors: Lazarou, Ioulietta | Karakostas, Anastasios | Stavropoulos, Thanos G. | Tsompanidis, Theodoros | Meditskos, Georgios | Kompatsiaris, Ioannis | Tsolaki, Magda

Article Type: Research Article

Abstract: Background: Assistive technology, in the form of a smart home environment, is employed to support people with dementia. Objectives: To propose a system for continuous and objective remote monitoring of problematic daily living activity areas and design personalized interventions based on system feedback and clinical observations for improving cognitive function and health-related quality of life. Methods: The assistive technology of the proposed system, including wearable, sleep, object motion, presence, and utility usage sensors, was methodically deployed at four different home installations of people with cognitive impairment. Detection of sleep patterns, physical activity, and activities of …daily living, based on the collected sensor data and analytics, was available at all times through comprehensive data visualization solutions. Combined with clinical observation, targeted psychosocial interventions were introduced to enhance the participants’ quality of life and improve their cognitive functions and daily functionality. Meanwhile, participants and their caregivers were able to visualize a reduced set of information tailored to their needs. Results: Overall, paired-sample t -test analysis of monitored qualities revealed improvement for all participants in neuropsychological assessment. Moreover, improvement was detected from the beginning to the end of the trial, in physical condition and in the domains of sleep. Detecting abnormalities via the system, for example in sleep quality, such as REM sleep, has proved to be critical to assess current status, drive interventions, and evaluate improvements in a reliable manner. Conclusion: It has been proved that the proposed system is suitable to support clinicians to reliably drive and evaluate clinical interventions toward quality of life improvement of people with cognitive impairment. Show more

Keywords: Adaptive interventions, ambient assisted living, assistive technology, dementia, remote monitoring, sensors, smart home

DOI: 10.3233/JAD-160348

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1561-1591, 2016

Authors: Portelius, Erik | Durieu, Emilie | Bodin, Marion | Cam, Morgane | Pannee, Josef | Leuxe, Charlotte | Mabondzo, Aloϊse | Oumata, Nassima | Galons, Hervé | Lee, Jung Yeol | Chang, Young-Tae | Stϋber, Kathrin | Koch, Philipp | Fontaine, Gaëlle | Potier, Marie-Claude | Manousopoulou, Antigoni | Garbis, Spiros D. | Covaci, Adrian | Van Dam, Debby | De Deyn, Peter | Karg, Frank | Flajolet, Marc | Omori, Chiori | Hata, Saori | Suzuki, Toshiharu | Blennow, Kaj | Zetterberg, Henrik | Meijer, Laurent

Article Type: Research Article

Abstract: Proteolytic cleavage of the amyloid-β protein precursor (AβPP) by secretases leads to extracellular release of amyloid-β (Aβ) peptides. Increased production of Aβ42 over Aβ40 and aggregation into oligomers and plaques constitute an Alzheimer’s disease (AD) hallmark. Identifying products of the ‘human chemical exposome’ (HCE) able to induce Aβ42 production may be a key to understanding some of the initiating causes of AD and to generate non-genetic, chemically-induced AD animal models. A cell model was used to screen HCE libraries for Aβ42 inducers. Out of 3500+ compounds, six triazine herbicides were found that induced a β- and …γ-secretases-dependent, 2–10 fold increase in the production of extracellular Aβ42 in various cell lines, primary neuronal cells, and neurons differentiated from human-induced pluripotent stem cells (iPSCs). Immunoprecipitation/mass spectrometry analyses show enhanced production of Aβ peptides cleaved at positions 42/43, and reduced production of peptides cleaved at positions 38 and lower, a characteristic of AD. Neurons derived from iPSCs obtained from a familial AD (FAD) patient (AβPP K724N) produced more Aβ42 versus Aβ40 than neurons derived from healthy controls iPSCs (AβPP WT). Triazines enhanced Aβ42 production in both control and AD iPSCs-derived neurons. Triazines also shifted the cleavage pattern of alcadeinα, another γ-secretase substrate, suggesting a direct effect of triazines on γ-secretase activity. In conclusion, several widely used triazines enhance the production of toxic, aggregation prone Aβ42 /Aβ43 amyloids, suggesting the possible existence of environmental “Alzheimerogens” which may contribute to the initiation and propagation of the amyloidogenic process in late-onset AD. Show more

Keywords: Alzheimer’s disease, alzheimerogen, amyloid-β, amyloid-β protein precursor, Aβ42/Aβ40 ratio, herbicides, human chemical exposome, triazines

DOI: 10.3233/JAD-160310

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1593-1605, 2016

Authors: Wijesinghe, Printha | Shankar, S.K. | Yasha, T.C. | Gorrie, Catherine | Amaratunga, Dhammika | Hulathduwa, Sanjayah | Kumara, K. Sunil | Samarasinghe, Kamani | Suh, Yoo-hun | Steinbusch, Harry W.M. | De Silva, K. Ranil D.

Article Type: Research Article

Abstract: Background: Evidence from various consortia on vascular contributions has been inconsistent in determining the etiology of sporadic Alzheimer’s disease (AD). Objective: To investigate vascular risk factors and cerebrovascular pathologies associated in manifestation of AD-related neuropathological changes of an elderly population. Methods: Postmortem brain samples from 76 elderly subjects (≥50 years) were used to study genetic polymorphisms, intracranial atherosclerosis of the circle of Willis (IASCW), and microscopic infarcts in deep white matters. From this cohort, 50 brains (≥60 years) were subjected to neuropathological diagnosis using immunohistopathological techniques. Results: Besides the association with age, the …apolipoprotein E ɛ 4 allele was significantly and strongly associated with Thal amyloid-β phases ≥1 [odds ratio (OR) = 6.76, 95% confidence interval (CI) 1.37–33.45] and inversely with Braak neurofibrillary tangle (NFT) stages ≥III (0.02, 0.0–0.47). Illiterates showed a significant positive association for Braak NFT stages ≥IV (14.62, 1.21–176.73) and a significant negative association for microscopic infarcts (0.15, 0.03–0.71) in deep white matters. With respect to cerebrovascular pathologies, cerebral small vessel lesions (white matter hyperintensities and cerebral amyloid angiopathy) showed a higher degree of associations among them and with AD-related neuropathological changes (p  < 0.05) compared to large vessel pathology (IASCW), which showed a significant association only with Braak NFT stages ≥I (p  = 0.050). Conclusion: These findings suggest that besides age, education, and genetic factors, other vascular risk factors were not associated with AD-related neuropathological changes and urge prompt actions be taken against cerebral small vessel diseases since evidence for effective prevention is still lacking. Show more

Keywords: Alzheimer’s disease, apolipoprotein E, atherosclerosis, cerebral small vessel diseases, neuropathology

DOI: 10.3233/JAD-160425

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1607-1618, 2016

Authors: Tombini, Mario | Sicari, Maura | Pellegrino, Giovanni | Ursini, Francesca | Insardá, Pasqualina | Di Lazzaro, Vincenzo

Article Type: Research Article

Abstract: Background: Malnutrition is one of the most important conditions that negatively affects the health of elder people, particularly in patients with dementia. Objective: To provide an assessment of nutritional status of patients affected by Alzheimer’s disease (AD) living at home and of their caregivers by means of Mini Nutritional Assessment (MNA), and to explore the influence of different factors on nutrition. Methods: 90 patients affected by AD living at home and 90 age- and sex-matched caregivers were enrolled. Patients and caregivers, coming from an urban-rural fringe of Southern Italy, were assessed using full MNA, Mini-Mental …State Examination, Geriatric Depression Scale— short form, Activity of Daily Living, and Instrumental Activities of Daily Living scales. Results: Malnutrition was found with high prevalence in patients affected by AD of different severity (more than 95% of patients were malnourished or at risk of malnutrition), and associated with reduced functional status. An altered nutrition was also recognized with high rate in the group of caregivers (23.3% were malnourished and 41.1% at risk of malnutrition) and the worse nutritional condition was correlated with higher age and lower functional and cognitive status and education. A positive correlation between MNA score of AD patients and caregivers was found. Conclusion: Corrective measures should be taken in order to early identify nutritional deficiencies and risk of malnutrition observed with high rate in both groups of AD patients and their caregivers; in these subjects a nutrition education program and intervention policies are mandatory to restore nutritional status. Show more

Keywords: Alzheimer’s disease, caregivers, Mini Nutritional Assessment, nutrition

DOI: 10.3233/JAD-160261

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1619-1627, 2016

Authors: Parham, Christi L. | Shaw, Courtney | Auckland, Lisa D. | Dickeson, S. Kent | Griswold-Prenner, Irene | Bix, Gregory

Article Type: Research Article

Abstract: Alzheimer’s disease (AD) is characterized by neuronal death, neurofibrillary tangles, and senile plaques. Amyloid-beta (Aβ) is the major component of plaques and consists of two prominent isoforms, Aβ40 and Aβ42 . As many risk factors for AD are vascular in origin and blood vessel defects in clearing Aβ from the brain are a potential key component of AD pathology, we have focused on the neuron-blood vessel interface, and in particular, the vascular basement membrane, which coats blood vessels and physically separates them from neurons. A prominent component of the vascular basement membrane is the extracellular matrix proteoglycan perlecan. Domain …V (DV) is the C-terminal domain and is generated by perlecan proteolysis. DV interacts with the α2 integrin and Aβ is a ligand for both α2β1 and αvβ1. Due to the known interaction of DV with α2β1 and α2β1’s requirement for Aβ deposition and neurotoxicity, we hypothesized that DV and/or its C-terminal domain, LG3, might alter neurotoxic signaling pathways by directly blocking or otherwise interfering with α2β1 binding by Aβ. Our study suggests that α2β1 mediates Aβ-induced activation of c-Jun and caspase-3, key components of the neurotoxic pathway, in primary cortical and hippocampal neurons. We further demonstrate that DV and/or LG3 may therapeutically modulate these α2β1 mediated neurotoxic effects suggesting that they or other α2β1 integrin modulators could represent a novel approach to treat AD. Finally, our results suggest different neurotoxicity susceptibilities between cortical and hippocampal neurons to Aβ40 and Aβ42 as further underscored by differing neuroprotective potencies of LG3 in each cell type. Show more

Keywords: Amyloid-β, cortical neurons, extracellular matrix, hippocampal neurons, integrins, signaling

DOI: 10.3233/JAD-160290

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1629-1647, 2016

Authors: Bonanni, Laura | Franciotti, Raffaella | Nobili, Flavio | Kramberger, Milica G. | Taylor, John-Paul | Garcia-Ptacek, Sara | Falasca, N. Walter | Famá, Francesco | Cromarty, Ruth | Onofrj, Marco | Aarsland, Dag | on behalf of the E-DLB study group

Article Type: Research Article

Abstract: Quantitative EEG (QEEG) has demonstrated good discriminative capacity for dementia with Lewy bodies (DLB) diagnosis as compared to Alzheimer’s disease (AD) with a predictive value of 100% in a single cohort study. EEG in DLB was characterized by a dominant frequency (DF) in pre-alpha (5.5–7.5 Hz), theta, or delta bands and DF variability (DFV) >1.2 Hz, frequency prevalence (FP) pre-alpha in >40% and FP alpha in <32% of the epochs. To validate the aforementioned QEEG findings in independent cohorts of clinically diagnosed DLB versus AD patients, we analyzed EEG traces of 79 DLB and 133 AD patients (MMSE >20) collected from four …European Centers. EEG traces from 19 scalp derivations were acquired as at least 10 min continuous signals and epoched in off-setting as series of 2-second-long epochs, subsequently processed by Fast Fourier Transform (frequency resolution 0.5 Hz). DLB patients showed EEG specific abnormalities in posterior derivations characterized by DF <8 Hz FP pre-alpha >50%, FP alpha <25%. DFV was >0.5 Hz. AD patients displayed stable alpha DF, DFV <0.5 Hz, FP pre-alpha <30%, and FP alpha >55%. DLB and AD differed for DF (p  < 10–6 ), DFV (p  < 0.05), FP pre-alpha (p  < 10–12 ) and FP alpha (p  < 10–12 ). Discriminant analysis detected specific cut-offs for every EEG mathematical descriptor; DF = 8, DFV = 2.2 Hz, FP pre-alpha=33%, FP alpha = 41% for posterior derivations. If at least one of the cut-off values was met, the percentage of DLB and AD patients correctly classified was 90% and 64%, respectively. The findings in this multicenter study support the validity of QEEG analysis as a tool for diagnosis in DLB patients. Show more

Keywords: Dementia with Lewy bodies, quantitative EEG

DOI: 10.3233/JAD-160435

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1649-1657, 2016

Authors: Gourmaud, Sarah | Mouton-Liger, François | Abadie, Claire | Meurs, Eliane F. | Paquet, Claire | Hugon, Jacques

Article Type: Research Article

Abstract: In Alzheimer’s disease (AD), the amyloid cascade hypothesis proposes that amyloid-beta (Aβ) neurotoxicity leads to neuroinflammation, synaptic loss, and neuronal degeneration. In AD patients, anti-amyloid immunotherapies did not succeed because they were possibly administered late in AD progression. Modulating new targets associated with Aβ toxicity, such as PKR (double-stranded RNA dependent kinase), and JNK (c-Jun N-terminal kinase) is a major goal for neuroprotection. These two pro-apoptotic kinases are activated in AD brains and involved in Aβ production, tau phosphorylation, neuroinflammation, and neuronal death. In HEK cells transfected with siRNA directed against PKR, and in PKR knockout (PKR–/– ) mice neurons, …we showed that PKR triggers JNK activation. Aβ-induced neuronal apoptosis, measured by cleaved PARP (Poly ADP-ribose polymerase) and cleaved caspase 3 levels, was reduced in PKR–/– neurons. Two selective JNK inhibitory peptides also produced a striking reduction of Aβ toxicity. Finally, the dual inhibition of PKR and JNK nearly abolished Aβ toxicity in primary cultured neurons. These results reveal that dual kinase inhibition can afford neuroprotection and this approach is worth being tested in in vivo AD and oxidative stress models. Show more

Keywords: Alzheimer’s disease, amyloid-beta, JNK, neuronal death, PKR, therapeutic strategy

DOI: 10.3233/JAD-160509

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1659-1670, 2016

Authors: Musunuri, Sravani | Khoonsari, Payam Emami | Mikus, Maria | Wetterhall, Magnus | Häggmark-Mänberg, Anna | Lannfelt, Lars | Erlandsson, Anna | Bergquist, Jonas | Ingelsson, Martin | Shevchenko, Ganna | Nilsson, Peter | Kultima, Kim

Article Type: Research Article

Abstract: Background: Alzheimer’s disease (AD) is a chronic neurodegenerative disorder accounting for more than 50% of all dementia cases. AD neuropathology is characterized by the formation of extracellular plaques and intracellular neurofibrillary tangles consisting of aggregated amyloid-β and tau, respectively. The disease mechanism has only been partially elucidated and is believed to also involve many other proteins. Objective: This study intended to perform a proteomic profiling of post mortem AD brains and compare it with control brains as well as brains from other neurological diseases to gain insight into the disease pathology. Methods: Here we …used label-free shotgun mass spectrometry to analyze temporal neocortex samples from AD, other neurological disorders, and non-demented controls, in order to identify additional proteins that are altered in AD. The mass spectrometry results were verified by antibody suspension bead arrays. Results: We found 50 proteins with altered levels between AD and control brains. The majority of these proteins were found at lower levels in AD. Pathway analyses revealed that several of the decreased proteins play a role in exocytic and endocytic pathways, whereas several of the increased proteins are related to extracellular vesicles. Using antibody-based analysis, we verified the mass spectrometry results for five representative proteins from this group of proteins (CD9, HSP72, PI42A, TALDO, and VAMP2) and GFAP, a marker for neuroinflammation. Conclusions: Several proteins involved in exo-endocytic pathways and extracellular vesicle functions display altered levels in the AD brain. We hypothesize that such changes may result in disturbed cellular clearance and a perturbed cell-to-cell communication that may contribute to neuronal dysfunction and cell death in AD. Show more

Keywords: Alzheimer’s disease, endocytosis, exocytosis, exosomes, extracellular vesicles, immobilized, chemistry antibodies, mass spectrometry

DOI: 10.3233/JAD-160271

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1671-1686, 2016

Article Type: Other

DOI: 10.3233/JAD-160799

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1687-1690, 2016

Article Type: Other

DOI: 10.3233/JAD-160963

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1691-1702, 2016

Article Type: Other

Citation: Journal of Alzheimer's Disease, vol. 54, no. 4, pp. 1703-1720, 2016