23, Number 3, February 2011
Marianna Mazza, Giuseppe Marano, Gianandrea Traversi, Pietro Bria, Salvatore Mazza
Primary Cerebral Blood Flow Deficiency and Alzheimer’s Disease: Shadows and Lights
Abstract: Alzheimer’s disease (AD) is a degenerative disorder characterized by a decreased regional cerebral blood flow (CBF). It is most likely that a reduction in CBF could displace a pathway leading to AD genesis, in so far neuron death explains a sustained reduction in the supply of oxygen, glucose, and nutrients. Nevertheless, the concept of secondary CBF deficiency cannot explain the critical stages of early memory loss while, on the other hand, the picture of progressive ischemia due to primary CBF decline sheds light on the course of AD in a most persuasive manner. The concept of primary CBF deficiency is even more strengthened by the lack of correlation between degree of dementia and amount of CBF. Vascular abnormalities, frequently observed to co-occur with AD, might play a critical role in the initiation and aggravation of AD pathology given that the elimination of amyloid-β (Aβ) through a vascular route is an important brain Aβ clearance mechanism and its failure leads to formation of vascular amyloidosis and dense-core plaques. The goal of this review is to provide scientists comprehensive knowledge of the state-of the art influence vascular damage and reduced perfusion have on the final development of AD and to hopefully stimulate more research in this area of neuroscience.
Yuan-HanYang, Shey-Lin Wu, Mei-Chuan Chou, Chiou-Lian Lai, Su-Hwei Chen, Ching-Kuan Liu
Plasma concentration of donepezil to the therapeutic response of Alzheimer’s disease in Taiwanese
Abstract: Donepezil has been approved for the treatment for mild-to-moderate Alzheimer’s disease (AD), but the therapeutic response rate varies from 20 to 60%. A higher oral dosage was suggested to have a better therapeutic response in reported results, but the plasma concentration of donepezil was not examined with respect to the therapeutic outcomes in those studies. Therefore, we analyzed the therapeutic responses, measured by neuropsychological assessments, among 70 newly diagnosed AD patients taking donepezil (5 mg daily) in relation to their plasma concentration of donepezil, apolipoprotein E genotype, and demographic characteristics. Our results have showed 60% of recruited AD patients improved in cognition, measured by Mini-Mental Status Examination (MMSE), and 57.1% in global status, by Clinical Dementia Rating Scale (CDR) sum of boxes (CDR-SB). In cognition, compared to the improving group, the clinically worsening group had a significantly higher donepezil concentration [p=0.022, odds ratio (OR) =1.024, 95% CI=1.003-1.045] and higher initial MMSE score (p=0.007, OR=1.330, 95% CI=1.080-1.639). In global status, initially higher CDR-SB (p=0.028, OR=2.318, 95% CI=1.096-4.903) and initially higher MMSE (p=0.036, OR=1.201, 95% CI=1.012-1.425), not donepezil concentration (p=0.883), were significantly associated with clinical worsening. Our results have indicated that the dosage of donepezil should be reconsidered for AD patients, especially those clinically worsening in cognition.
Elizabeth Head, Eric Doran, Mihaela Nistor, MaryAnn Hill, Frederick A. Schmitt, Richard J. Haier, Ira T. Lott
Plasma Amyloid-β as a Function of Age, Level of Intellectual Disability, and Presence of Dementia in Down syndrome
Abstract: Adults with Down syndrome (DS) are at risk for developing Alzheimer’s disease (AD). While plasma amyloid-β (Aβ) is known to be elevated in DS, its relationship to cognitive functioning is unknown. To assess this relationship, samples from two groups of subjects were used. In the first group, nondemented adults with DS were compared to: 1) a group of young and old individuals without DS and 2) to a group of patients with AD. Compared to these controls, there were significantly higher levels of plasma Aβ in nondemented adults with DS while AD patients showed lower levels of plasma Aβ. A larger second group included demented and nondemented adults with DS, in order to test the hypothesis that plasma Aβ may vary as a function of dementia and Apolipoprotein E (ApoE) genotype. Plasma Aβ levels alone did not dissociate DS adults with and without dementia. However, in demented adults with DS, ApoE4 was associated with higher Aβ40 but not Aβ42. After controlling for level of intellectual disability (mild, moderate, severe) and the presence or absence of dementia, there was an improved prediction of neuropsychological scores by plasma Aβ. In summary, plasma Aβ can help predict cognitive function in adults with DS independently of the presence or absence of dementia.
Vasco Dos Santos1, Philipp A. Thomann1, Torsten Wüstenberg, Ulrich Seidl, Marco Essig, Johannes Schröder 1These authors contributed equally to this work.
Morphological cerebral correlates of CERAD test performance in mild cognitive impairment and Alzheimer’s disease
Abstract: The objective of this study was to investigate the associations between structural cerebral changes and neuropsychological deficits in mild cognitive impairment (MCI) and Alzheimer’s disease (AD). 60 patients with MCI, 34 patients with mild to moderate AD, and 32 healthy controls underwent both extensive neuropsychological assessment (CERAD test battery) and high-resolution structural magnetic resonance imaging. We used optimized voxel based morphometry to investigate (i) differences in gray matter density between the three aforementioned groups and (ii) the putative relations of CERAD test performance with atrophic brain changes. When compared to the healthy controls, the AD patients and, to a lesser extent, patients with MCI showed significant density losses predominantly in the medial temporal lobe. Deficits in verbal fluency and word finding were significantly correlated with left fronto-temporal and left temporal (including the hippocampus) changes, respectively. Decreased scores in immediate and delayed recall and in delayed recognition were associated with several cortical and subcortical sites including the parahippocampal and posterior cinguli gyri, the right thalamus, and the right hippocampus, whereas deficits in constructional praxis and constructional praxis recall referred to sites in the left thalamus and cerebellum, and the temporal cortices (bilaterally), respectively. Our findings lend further support for medial temporal lobe degeneration in MCI and AD and demonstrate that cognitive deficits as assessed on the CERAD do not simply refer to specific changes in discrete cerebral sites but rather reflect morphological alterations in widespread networks.
Federico Licastro, Martina Chiappelli, Claudio Marcello Caldarera, Elisa Porcellini, Ilaria Carbone, Calogero Caruso, Domenico Lio, Elizabeth H. Corder
Sharing Pathogenetic Mechanisms Between Acute Myocardial Infarction and Alzheimer’s Disease as Shown by Partially Overlapping of Gene Variant Profiles
Abstract: Gene variants that promote inflammation and cholesterol metabolism have been associated with acute myocardial infarction (AMI) and Alzheimer’s disease (AD). We investigated a panel of relevant polymorphisms to distinguish genetic backgrounds for AMI and AD: IL10 -1082G/A, IL6 -174G/C, TNF -308G/A, IFNG +874T/A, SERPINA3 -51G/T, HMGCR -911C/A, APOE ε2/3/4 (280 AMI cases, 257 AD cases, and 1307 population controls, all Italian (presumed risk alleles are shown in bold). Six genetic risk sets I to VI were identified by fuzzy latent classification: I had low risk; II and III had low risk before age 65 (II, III); low risk sets lacked pro-inflammatory alleles for HMGCR-TNF-APOE. Pro-inflammatory alleles for SERPINA3-IL10-IFNG were found for high risk sets IV to VI. Set IV ‘AMI < age 40, AD < age 65’ included risk alleles for HMGCR. Set V ‘AMI over a broad range of age’ included risk alleles for TNF+IL6. Set VI ‘AMI at ages 40 to 55, AD ages 65+’ included APOE ε4. Close resemblance to the high risk sets, as indicated by membership scores close to one, defined wide relative risks. We conclude that AMI and AD share genetic backgrounds involving cholesterol metabolism and the upregulation of inflammation and that gene-gene interactions in relevant sets of genes may be useful in defining inherited risk for common disorders.
Po H. Lu, Paul M. Thompson, Alex Leow, Grace J. Lee, Agatha Lee, Igor Yanovsky, Neelroop Parikshak, Theresa Khoo, Stephanie Wu, Daniel Geschwind, George Bartzokis
Apolipoprotein E Genotype is Associated with Temporal and Hippocampal Atrophy Rates in Healthy Elderly Adults: A Tensor-Based Morphometry Study
Abstract: Apolipoprotein (APOE) ε4 genotype is a strong risk factor for developing Alzheimer’s disease (AD). Conversely, the presence of the ε2 allele has been shown to mitigate cognitive decline. Tensor-based morphometry (TBM), a novel computational approach for visualizing longitudinal progression of brain atrophy, was used to determine whether cognitively intact elderly participants with the ε4 allele demonstrate greater volume reduction than those with the ε2 allele. Healthy “younger elderly” volunteers, aged 55-75, were recruited from the community and hospital staff. They were evaluated with a baseline and follow-up MRI scan (mean scan interval = 4.72 years, sd = 0.55) and completed APOE genotyping. Twenty-seven participants were included in the study of which 16 had the ε4 allele (all heterozygous ε3ε4 genotype) and 11 had the ε2ε3 genotype. The two groups did not differ significantly on any demographic characteristics and all subjects were cognitively “normal” at both baseline and follow-up time points. TBM was used to create 3D maps of local brain tissue atrophy rates for individual participants; these spatially detailed 3D maps were compared between the two ApoE groups. Regional analyses were performed and the ε4 group demonstrated significantly greater annual atrophy rates in the temporal lobes (p=0.048) and hippocampus (p=0.016); greater volume loss was observed in the right hippocampus than the left. TBM appears to be useful in tracking longitudinal progression of brain atrophy in cognitively asymptomatic adults. Possession of the ε4 allele is associated with greater temporal and hippocampal volume reduction well before the onset of cognitive deficits.
Angela L. Jefferson, Susan Lambe, Christine Chaisson, Joseph Palmisano, Kathy Horvath, Jason Karlawish (Handling Associate Editor: Peter Whitehouse)
Clinical research participation among aging adults enrolled in an Alzheimer’s Disease Center research registry
Abstract: In light of our limited understanding of what motivates older adults to participate in clinical studies of Alzheimer’s disease (AD), the current study examines incentives and barriers to participating in AD clinical research among older adults. 235 participants enrolled in the Boston University Alzheimer’s Disease Center research registry (75 ± 8 years, range 58-99 years, 60% female), a longitudinal registry from which individuals are recruited into other clinical studies, completed a survey assessing registry participation satisfaction, religiousness, trust in healthcare institutions, and medical research attitudes. Most participants reported initially enrolling in the registry for societal benefit. Insufficient time was a commonly endorsed barrier to enrolling in other Center-approved studies, particularly among younger participants. Driving and a lack of transportation to the medical facility were also barriers, particularly for older participants. Transportation was the most popular incentive, followed by home-based visits (particularly for older participants and participants with less formal education) and compensation (particularly among respondents from racial/ethnic minority groups). Participation interest in other studies was associated with favorable medical research attitudes (r=0.34, p=0.00003) but not religiousness (r=-0.09, p=0.21), or trust in healthcare institutions (r=0.09, p=0.17). Among older adults, societal benefit is a motivating factor for registry enrollment; however, participation in additional studies is hindered by insufficient time among younger participants and transportation barriers among older participants. Providing transportation, home-based visits, and modest compensation may improve participation rates. Furthermore, favorable attitudes toward medical research are strongly associated with interest in enrolling in additional studies and may serve as a beneficial outreach triage technique.
Lisbeth Marner, Gitte M. Knudsen, Karine Madsen, Søren Holm, William Baaré, Steen G. Hasselbalch
The Reduction of Baseline Serotonin 2A Receptors in Mild Cognitive Impairment is stable at Two-year Follow-up
Abstract: We previously demonstrated a 20-30% reduction in cortical 5-HT2A receptor binding in patients with mild cognitive impairment (MCI) as compared to healthy subjects. Here we present a two-year follow-up of 14 patients and 12 healthy age-matched subjects. Baseline and follow-up partial volume corrected levels of 5-HT2A in four neocortical lobes and the posterior cingulate gyrus were investigated using [18F]altanserin positron emission tomography with a bolus-infusion approach. In the two-year follow-up period, 8 of 14 patients with MCI had progressed to fulfill diagnostic criteria for probable Alzheimer’s disease (AD). In both patients and healthy subjects, no significant change in 5-HT2A receptor binding was found as compared to baseline values. In MCI patients, the average BPP in neocortex ranged from 1.49 to 2.45 at baseline and 1.38 to 2.29 at two-year follow-up; and in healthy subjects BPP ranged from 1.85 to 3.10 at baseline and 1.81 to 2.98 at two-year follow-up. The BPP of the patients that converted to AD during the follow-up period did not differ significantly from the patients that had not (yet) converted, neither at baseline, nor at follow-up. We conclude that the reduced levels of 5-HT2A receptor binding in MCI patients decrease only slowly and non-significantly, even in patients who convert to AD. Our finding suggests that profoundly reduced cortical 5-HT2A receptor binding is an early feature in MCI whereas the clinical progression from MCI to AD is less associated with further decrease in binding.
Lina Keller, Weili Xu, Hui-Xin Wang, Bengt Winblad, Laura Fratiglioni, Caroline Graff
The obesity related gene, FTO, interacts with APOE, and is associated with Alzheimer’s disease risk: A prospective cohort study
Abstract: The FTO gene has been shown to have a small but robust effect on body mass index (BMI) and to increase the risk for diabetes. Both high BMI and diabetes are vascular risk factors that might play a role in the development of Alzheimer’s disease (AD) and dementia. Thus, our aim was to explore the impact of FTO on AD and dementia risk. Nine years of follow-up data was gathered from the Kungsholmen project, a prospective population-based study on 1,003 persons without dementia. Cox-regression models were used to assess the relative risks of developing AD and dementia (DSM-III-R criteria) according to FTO genotypes (rs9939609), taking into account APOE, physical inactivity, BMI, diabetes, and cardiovascular disease (CVD). Compared to carriers of the FTO TT-genotype, AA-carriers had a higher risk for AD (RR 1.58, 95% CI: 1.11-2.24) and for dementia (RR 1.48, 95% CI: 1.09-2.02) after adjustment for age, gender, education, and APOE genotype. This effect remained after additional adjustment for physical inactivity, BMI, diabetes, and CVD. An interaction between FTO and APOE was found, with increased risk for dementia for those carrying both FTO-AA and APOE ε4 (RR 2.01, 95% CI: 1.03-3.92). Importantly, the effect of the AA-genotype on dementia/AD risk seems to act mostly through the interaction with APOE ε4. Our findings suggest that the FTO AA-genotype increases the risk for dementia, and in particular AD, independently of physical inactivity, BMI, diabetes, and CVD measured at baseline. Our results are in line with the recently reported association between FTO and reduced brain volume in cognitively healthy subjects.
Jason Lockrow, Heather Boger, Greg Gerhardt, David Bachman, Ann-Charlotte Granholm
A Noradrenergic Lesion Exacerbates Neurodegeneration in a Down Syndrome Mouse Model
Abstract: Individuals with Down syndrome (DS) acquire Alzheimer’s-like dementia (AD) and associated neuropathology earlier and at significantly greater rates than age-matched normosomic individuals. However, biological mechanisms have not been discovered and there is currently limited therapy for either DS- or AD-related dementia. Segmental trisomy 16 (Ts65Dn) mice provide a useful model for many of the degenerative changes which occur with age in DS including cognitive deficits, neuroinflammation, and degeneration of basal forebrain cholinergic neurons. Loss of noradrenergic locus coeruleus (LC) neurons is an early event in AD and in DS, and may contribute to the neuropathology. We report that Ts65Dn mice exhibit progressive loss of norepinephrine (NE) phenotype in LC neurons. In order to determine whether LC degeneration contributes to memory loss and neurodegeneration in Ts65Dn mice, we administered the noradrenergic neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4; 2 doses of 50 mg/kg, i.p.) to Ts65Dn mice at four months of age, prior to working memory loss. At eight months of age, Ts65Dn mice treated with DSP-4 exhibited an 80% reduction in hippocampal NE, coupled with a marked increase in hippocampal neuroinflammation. Noradrenergic depletion also resulted in accelerated cholinergic neuron degeneration and a further impairment of memory function in Ts65Dn mice. In contrast, DSP-4 had minimal effects on normosomic littermates, suggesting a disease-modulated vulnerability to NE loss in the DS mouse model. These data suggest that noradrenergic degeneration may play a role in the progressive memory loss, neuroinflammation, and cholinergic loss occurring in DS individuals, providing a possible therapeutic avenue for future clinical studies.
Seema Briyal, Tina Philip, Anil Gulati
Endothelin-A receptor antagonists prevent amyloid-β-induced increase in ETA receptor expression, oxidative stress, and cognitive impairment
Abstract: Alzheimer’s disease is a neurodegenerative disorder associated with abnormal accumulation of amyloid-β (Aβ) which can release endothelin (ET). The present study was conducted to investigate the effect of ET antagonists on Aβ-induced changes in ETA and ETB receptor expression, oxidative stress, and cognitive impairment. Male Sprague-Dawley rats were treated with Aβ1-40 in the lateral cerebral ventricles and were administered vehicle or ET antagonists for 14 days. Aβ treatment produced an increase in ETA receptor expression in the cerebral cortex, hippocampus, and brain stem by 72%, 85%, and 90%, respectively. No change in ETB receptor expression was observed. There was an increase in malondialdehyde (MDA) and decrease in reduced glutathione (GSH) and superoxide dismutase (SOD) levels in Aβ-treated rats. In the Morris swim task, Aβ treated rats showed a significant impairment in spatial memory. ET receptor antagonists, BQ123, BMS182874, and TAK-044, significantly decreased Aβ-induced increase in ETA expression in the cortex, hippocampus, and brain stem. Rats treated with ET antagonists showed significant attenuation of Aβ-induced changes in the brain MDA, GSH, and SOD levels. Rats treated with specific ETA receptor antagonists, BQ123 and BMS182874, significantly reduced the cognitive impairment induced by Aβ. However, nonspecific ETA/ETB receptor antagonist TAK-044 did not show any improvement in the learning and memory parameter. This study demonstrates that ETA receptor antagonists are effective in preventing cognitive impairment, changes in ETA expression and oxidative stress induced by Aβ. It is concluded that ETA receptor antagonists may be useful in improving cognitive impairment due to Alzheimer’s disease.
Barbara Borroni, Carlo Cerini, Silvana Archetti, Enrico Premi, Maura Cosseddu, Maria Ferrari, Giuseppe Bellelli, Roberto Gasparotti, Luigi Caimi, Monica Di Luca, Alessandro Padovani
Cerebrospinal Fluid Tau in Frontotemporal Lobar Degeneration: Clinical, Neuroimaging, and Prognostic Correlates
Abstract: Frontotemporal lobar degeneration (FTLD) refers to heterogeneous clinical and biological conditions. In FTLD, cerebrospinal fluid (CSF) tau levels have been reported highly variable. The aim of the present study was to evaluate whether CSF tau might be the hallmark of a distinct FTLD phenotype. Fifty-five FTLD patients, who underwent CSF analysis, were considered in the present study. In each patient, a wide standardized neuropsychological evaluation, and CSF tau, phospho-tau, and amyloid-β (Aβ) dosages were performed. Each patient was followed-up to five years, and outcomes carefully recorded. In a subgroup of patients (n=24), magnetic resonance imaging scanning was performed, by using voxel-based morphometry, for grey matter investigation. The higher the CSF tau levels, the worse the neuropsychological and neuroimaging pattern, mainly characterized by greater language disturbances and left temporal grey matter loss. The same pattern, even if less significant, was associated with CSF phospho-tau, while CSF Aβ levels did not play any influence on FTLD phenotype. FTLD patients with high CSF tau showed poor prognosis compared to those with low CSF tau (p=0.031). In FTLD, CSF tau levels might be considered a marker of neurodegeneration, associated with a specific clinical and neuroimaging picture, and significantly related to poor outcome. Further studies aimed at defining the biological underpinnings of these findings are warranted.
Rodrigo Lerchundi, Rodrigo Neira, Sharin Valdivia, Karin Vio, Margarita I. Concha, Angara Zambrano, Carola Otth (Handling Associate Editor: Elliott Mufson)
Tau Cleavage at D421 by Caspase-3 is Induced in Neurons and Astrocytes Infected with Herpes Simplex Virus Type 1 Abstract: Herpes Simplex Virus Type 1 (HSV-1) is ubiquitous, neurotropic, and the most common pathogenic causes of sporadic acute encephalitis in humans. Herpes simplex encephalitis is associated with a high mortality rate and significant neurological, neuropsychological, and neurobehavioral sequelae, which afflict patients for life. HSV-1 infects limbic system structures in the central nervous system and has been suggested as an environmental risk factor for Alzheimer’s disease. However, the possible mechanisms that link HSV-1 infection with the neurodegenerative process are still largely unknown. In a previous study we demonstrated that HSV-1 triggers hyperphosphorylation of tau epitopes serine202/threonine205 and serine396/serine404 in neuronal cultures, resembling what occurs in neurodegenerative diseases. Therefore, the aim of the present study was to evaluate at the cellular level if another event associated with neurodegeneration, such as caspase-3 induced cleavage of tau, could also be triggered by HSV-1infection in primary neuronal and astrocyte cultures. As expected, induction of caspase-3 activation and cleavage of tau protein at its specific site (aspartic acid 421) was observed by Western blot and immunofluorescence analyses in mice neuronal primary cultures infected with HSV-1. In agreement with our previous study on tau hyperphosphorylation, tau cleavage was also observed during the first 4 hours of infection, before neuronal death takes place. This tau processing has been previously demonstrated to increase the kinetics of tau aggregation in vitro and has also been observed in neurodegenerative pathologies. In conclusion, our findings support the idea that HSV-1 could contribute to induce neurodegenerative processes in age-associated pathologies such as Alzheimer’s disease.
Luis De Taboada, Jin Yu, Salim El-Amouri, Sebastiano Gattoni-Celli, Steve Richieri, Thomas McCarthy, Jackson Streeter, Mark S. Kindy
Transcranial laser therapy attenuates amyloid-β peptide neuropathology in amyloid-β protein precursor transgenic mice
Abstract: Transcranial laser therapy (TLT) was tested for efficacy in a mouse model of Alzheimer’s disease (AD) using a near-infrared energy laser system. TLT is thought to stimulate ATP production, increase mitochondrial activity, and help maintain neuronal function. Studies were performed to determine the effect of TLT in an amyloid-β protein precursor (AβPP) transgenic mouse model. TLT was administered 3 times/week at various doses, starting at 3 months of age, and was compared to a control group (no laser treatment). Treatment was continued for a total of six months. Animals were examined for amyloid load, inflammatory markers, brain amyloid-β (Aβ) levels, plasma Aβ levels, cerebrospinal fluid Aβ levels, soluble AβPP (sAβPP) levels, and behavioral changes. The numbers of Aβ plaques were significantly reduced in the brain with administration of TLT in a dose-dependent fashion. Administration of TLT was associated with a dose-dependent reduction in amyloid load. All TLT doses mitigated the behavioral effects seen with advanced amyloid deposition and reduce the expression of inflammatory markers in the AβPP transgenic mice. All TLT doses produced an increase in sAβPPα and a decrease in CTFβ levels consistent with inhibition of the β-secretase activity. In addition, TLT showed an increase in ATP levels, mitochondrial function, and c-fos suggesting an overall improvement in neurological function. These studies suggest that TLT is a potential candidate for treatment of AD.
Isidro Ferrer, Ana Gómez, Margarita Carmona, Gema Huesa, Silvia Porta, Miquel Riera-Codina, Marta Biagioli, Stefano Gustincich, Ester Aso (Handling Associate Editor: Sigfrido Scarpa)
Neuronal hemoglobin is reduced in Alzheimer’s disease, argyrophilic grain disease, Parkinson’s disease, and Dementia with Lewy bodies
Abstract: Previous studies have demonstrated the presence of hemoglobin α-chain and β-chain in neurons of the rodent and human brain thus indicating that hemoglobin is a normal component of nerve cells and that hemoglobin may play a role in intraneuronal oxygen homeostasis. Progressing with these studies, hemoglobin expression has been examined in selected cell population in the brains of Alzheimer’s disease (AD), argyrophilic grain disease (AGD), Parkinson’s disease (PD) and Dementia with Lewy bodies (DLB). Double labeling immunofluorescence and confocal microscopy revealed reduced hemoglobin α-chain and β-chain in practically all neurons with small amounts of granular or punctuate hyperphosphorylated tau deposits and in neurons with tangles in the hippocampus and frontal cortex in AD and in the hippocampus in AGD; in ballooned neurons containing αB-crystallin in the amygdala in AD and AGD; and in about 80% of neurons with punctuate α-synuclein deposits and in neurons with Lewy bodies in the substantia nigra pars compacta and in vulnerable neurons of the medulla oblongata in PD and DLB; and in neurons with Lewy bodies in the frontal cortex in DLB. Hemoglobin immunoreactivity was also observed in the core of neuritic plaques and in diffuse plaques, but not in dystrophic neurites. Loss of hemoglobin was specific as neuroglobin was present equally in neurons with and without abnormal protein inclusions, and erythropoietin receptor was expressed equally in neurons without and in neurons with abnormal protein aggregates in AD, AGD, PD, and DLB.
Supplementary Data for Ferrer et al. article (PDF)
Ying Zhang*, Jin-Sheng He*, Xin Wang*, Jun Wang, Fu-Xiang Bao, Si-Yuan Pang, Fan Yin, Hong-Gang Hu, Xiang-Lei Peng, Wei-Min Sun, Yan-Peng Zheng, Ling-Ling Hou, Tao Hong *These authors contributed equally to this work.
Administration of Amyloid-β42 Oligomer-Specific Monoclonal Antibody Improved Memory Performance in SAMP8 Mice
Abstract: Amyloid-β peptide (Aβ) is recognized by many as the leading cause of Alzheimer’s disease (AD), and Aβ oligomers play a major role in the early-onset form of AD. Recently, the application of passive immunization targeting Aβ has been investigated as a potential method of AD immunotherapy. We used a strain of monoclonal antibody against Aβ42 oligomers, designated A8, as an Aβ inhibitor to suppress Aβ aggregation and Aβ-derived cell toxicity in vitro, and as a passive immunotherapy approach to treat SAMP8 (senescence accelerated mouse sub-line P8) mice, an animal model of AD, in vivo. First, our results showed that pre-incubation of A8 with Aβ oligomers inhibited both the maturation of Aβ fiber and Aβ oligomer toxicity on SH-SY5Y cells. Second, learning and memory was improved through intraperitoneal administration of A8 in SAMP8 mice. Third, Aβ pathology was ameliorated with decreased Aβ oligomers and phospho-tau levels in SAMP8 mice. Our data suggest that our monoclonal antibody A8 may be a candidate as a potential immunotherapeutic agent in AD.
Supplementary Data for Zhang et al. article (PDF)