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Sait AM, Day PJR. Interconnections between the Gut Microbiome and Alzheimer's Disease: Mechanisms and Therapeutic Potential. Int J Mol Sci 2024; 25:8619. [PMID: 39201303 PMCID: PMC11354889 DOI: 10.3390/ijms25168619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 07/23/2024] [Accepted: 08/06/2024] [Indexed: 09/02/2024] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that is known to accumulate amyloid-β (Aβ) and tau protein. Clinical studies have not identified pathogenesis mechanisms or produced an effective cure for AD. The Aβ monoclonal antibody lecanemab reduces Aβ plaque formation for the treatment of AD, but more studies are required to increase the effectiveness of drugs to reduce cognitive decline. The lack of AD therapy targets and evidence of an association with an acute neuroinflammatory response caused by several bacteria and viruses in some individuals has led to the establishment of the infection hypothesis during the last 10 years. How pathogens cross the blood-brain barrier is highly topical and is seen to be pivotal in proving the hypothesis. This review summarizes the possible role of the gut microbiome in the pathogenesis of AD and feasible therapeutic approaches and current research limitations.
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Affiliation(s)
- Ahmad M. Sait
- Medical Laboratory Science, Faculty of Applied Medical Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
- Regenerative Medicine Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Philip J. R. Day
- Division of Evolution and Genomic Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PL, UK
- Department of Medicine, University of Cape Town, Cape Town 7925, South Africa
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Stark SM, Kirwan CB, Stark CEL. Mnemonic Similarity Task: A Tool for Assessing Hippocampal Integrity. Trends Cogn Sci 2019; 23:938-951. [PMID: 31597601 DOI: 10.1016/j.tics.2019.08.003] [Citation(s) in RCA: 141] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 12/25/2022]
Abstract
The hippocampus is critical for learning and memory, relying in part on pattern separation processes supported by the dentate gyrus (DG) to prevent interference from overlapping memory representations. In 2007, we designed the Mnemonic Similarity Task (MST), a modified object recognition memory task, to be highly sensitive to hippocampal function by placing strong demands on pattern separation. The MST is now a widely used behavioral task, repeatedly shown to be sensitive to age-related memory decline, hippocampal connectivity, and hippocampal function, with specificity to the DG. Here, we review the utility of the MST, its relationship to hippocampal function, its utility in detecting hippocampal-based memory alterations across the lifespan, and impairments associated with clinical pathology from a variety of disorders.
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Affiliation(s)
- Shauna M Stark
- Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - C Brock Kirwan
- Department of Psychology, Neuroscience Center, Brigham Young University, Provo, UT, USA
| | - Craig E L Stark
- Department of Neurobiology and Behavior, University of California, Irvine, CA, USA.
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Oleson S, Murphy C. Olfactory Dysfunction in ApoE ɛ4/4 Homozygotes with Alzheimer's Disease. J Alzheimers Dis 2016; 46:791-803. [PMID: 25869786 DOI: 10.3233/jad-150089] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive memory impairment and the presence of amyloid plaques and neurofibrillary tangles. The associated neuropathology originates in brain areas responsible for olfaction, which makes olfactory tasks potentially useful for assessing AD. The strongest genetic risk factor for AD is the apolipoprotein E (ApoE) ɛ4 allele that has been associated with increased cognitive and olfactory deficits. While individuals carrying one ɛ4 allele of the ApoE gene are at increased risk for AD relative to non-carriers, those with two copies of the ɛ4 allele demonstrate an even higher risk for developing AD. Furthermore, homozygous ApoE ɛ4/4 individuals diagnosed with AD are known to have heightened amyloid burden and a more rapid rate of cognitive decline relative to heterozygous ɛ3/4 ApoE carriers. All of these factors suggest there are differences in severity and progression of AD as a function of possessing one versus two ɛ4 alleles. The current study investigated olfactory functioning in homozygous ɛ4/4 older adults diagnosed with probable AD. Compared to demographically matched ɛ3/3 and ɛ3/4 individuals, ɛ4/4 individuals showed deficits in odor identification and remote odor memory as measured by odor familiarity ratings. The current findings suggest that these particular domains of olfactory functioning may be more impaired in AD ɛ4/4 homozygotes compared to ɛ3/4 heterozygotes and ɛ3/3 homozygotes. These deficits give insight into how the presence of two ɛ4 alleles may differentially affect the progression of AD and suggest the usefulness of odor tasks in detecting those at risk for AD.
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Affiliation(s)
- Stephanie Oleson
- Department of Psychology, San Diego State University, San Diego, CA, USA
| | - Claire Murphy
- Department of Psychology, San Diego State University, San Diego, CA, USA.,San Diego State University/University of California San Diego, Joint Doctoral Program in Clinical Psychology, San Diego, CA, USA.,Department of Surgery, Division of Head and Neck Surgery, University of California, San Diego, CA, USA
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Sheppard DP, Graves LV, Holden HM, Delano-Wood L, Bondi MW, Gilbert PE. Spatial pattern separation differences in older adult carriers and non-carriers for the apolipoprotein E epsilon 4 allele. Neurobiol Learn Mem 2015; 129:113-9. [PMID: 25957133 DOI: 10.1016/j.nlm.2015.04.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 04/13/2015] [Accepted: 04/23/2015] [Indexed: 12/24/2022]
Abstract
We examined the performance of healthy young (n=57) and older adults (n=43) genotyped as apolipoprotein E-ε4 (APOE-ε4) carriers or APOE-ε4 non-carriers on a delayed match-to-sample task involving varying degrees of spatial interference hypothesized to assess spatial pattern separation. Older adult ε4 carriers were further divided into "impaired" and "unimpaired" groups based on their performance on a standardized test of verbal memory. We found that performance on the spatial pattern separation test increased as a function of decreased spatial interference across all groups. The older ε4 carriers in the impaired group performed significantly worse (p<.05) than unimpaired ε4 carriers, ε4 non-carriers, and young adults. The data suggest that spatial pattern separation may be less efficient in a subset of healthy older adults with subtle memory decline who are carriers of the ε4 allele. However, pattern separation performance may be comparable to that of young adults in a subset of older adult ε4 carriers and more broadly among non-carriers. Our findings offer additional evidence that pattern separation may vary in older adults, and they provide novel insight into pattern separation efficiency in ε4-positive older adults.
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Affiliation(s)
- David P Sheppard
- Department of Psychology, San Diego State University, San Diego, CA, USA; Department of Psychology, University of Houston, Houston, TX, USA.
| | - Lisa V Graves
- San Diego State University/University of California San Diego Joint Doctoral Program in Clinical Psychology, San Diego, CA, USA.
| | - Heather M Holden
- San Diego State University/University of California San Diego Joint Doctoral Program in Clinical Psychology, San Diego, CA, USA.
| | - Lisa Delano-Wood
- VA San Diego Healthcare System, La Jolla, CA, USA; Department of Psychiatry, University of California San Diego, School of Medicine, La Jolla, CA, USA.
| | - Mark W Bondi
- VA San Diego Healthcare System, La Jolla, CA, USA; Department of Psychiatry, University of California San Diego, School of Medicine, La Jolla, CA, USA.
| | - Paul E Gilbert
- Department of Psychology, San Diego State University, San Diego, CA, USA; San Diego State University/University of California San Diego Joint Doctoral Program in Clinical Psychology, San Diego, CA, USA.
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5
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Alzheimer's disease--a panorama glimpse. Int J Mol Sci 2014; 15:12631-50. [PMID: 25032844 PMCID: PMC4139864 DOI: 10.3390/ijms150712631] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 06/26/2014] [Accepted: 07/10/2014] [Indexed: 01/05/2023] Open
Abstract
The single-mutation of genes associated with Alzheimer's disease (AD) increases the production of Aβ peptides. An elevated concentration of Aβ peptides is prone to aggregation into oligomers and further deposition as plaque. Aβ plaques and neurofibrillary tangles are two hallmarks of AD. In this review, we provide a broad overview of the diverses sources that could lead to AD, which include genetic origins, Aβ peptides and tau protein. We shall discuss on tau protein and tau accumulation, which result in neurofibrillary tangles. We detail the mechanisms of Aβ aggregation, fibril formation and its polymorphism. We then show the possible links between Aβ and tau pathology. Furthermore, we summarize the structural data of Aβ and its precursor protein obtained via Nuclear Magnetic Resonance (NMR) or X-ray crystallography. At the end, we go through the C-terminal and N-terminal truncated Aβ variants. We wish to draw reader's attention to two predominant and toxic Aβ species, namely Aβ4-42 and pyroglutamate amyloid-beta peptides, which have been neglected for more than a decade and may be crucial in Aβ pathogenesis due to their dominant presence in the AD brain.
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Abstract
Alzheimer's disease (AD), the most common cause of dementia in aged populations, is believed to be caused by both environmental factors and genetic variations. Extensive linkage and association studies have established that a broad range of loci are associated with AD, including both causative and susceptibility (risk factor) genes. So far, at least three genes, APP, PS1, and PS2, have been identified as causative genes. Mutations in these genes have been found to cause mainly early-onset AD. On the other hand, APOE has been identified to be the most common high genetic risk factor for late-onset AD. Polymorphisms in the coding region, intron, and promoter region of certain genes constitute another kind of genetic variation associated with AD. A number of other genes or loci have been reported to have linkage with AD, but many show only a weak linkage or the results are not well reproduced. Currently, the measurable genetic associations account for about 50% of the population risk for AD. It is believed that more new loci will be found to associate with AD, either as causative genes or genetic risk factors, and that eventually the understanding of genetic factors in the pathogenesis of AD will be important for our efforts to cure this illness.
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Affiliation(s)
- Ya-Ping Tang
- Department of Psychiatry, The University of Chicago, 5841 S Maryland Avenue, Chicago, III, USA
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Morgan CD, Murphy C. Individuals at risk for Alzheimer's disease show differential patterns of ERP brain activation during odor identification. BEHAVIORAL AND BRAIN FUNCTIONS : BBF 2012; 8:37. [PMID: 22849610 PMCID: PMC3542023 DOI: 10.1186/1744-9081-8-37] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Accepted: 06/15/2012] [Indexed: 11/17/2022]
Abstract
BACKGROUND Studies suggest that older adults at risk of developing Alzheimer's disease may show olfactory processing deficits before other signs of dementia appear. METHODS We studied 60 healthy non-demented individuals, half of whom were positive for the genetic risk factor the Apolipoprotein E ε4 allele, in three different age groups. Event-related potentials to visual and olfactory identification tasks were recorded and analyzed for latency and amplitude differences, and plotted via topographical maps. RESULTS Varying patterns of brain activation were observed over the post-stimulus epoch for ε4- versus ε4+ individuals on topographical maps. Individuals with the ε4 allele demonstrated different ERP peak latencies during identification of olfactory but not visual stimuli. High correct ApoE classification rates were obtained utilizing the olfactory ERP. CONCLUSIONS Olfactory ERPs demonstrate functional decline in individuals at risk for Alzheimer's disease at much earlier ages than previously observed, suggesting the potential for pre-clinical detection of AD at very early stages.
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Affiliation(s)
- Charlie D Morgan
- Department of Psychology, San Diego State University, San Diego, CA, 92120, USA
| | - Claire Murphy
- Department of Psychology, San Diego State University, San Diego, CA, 92120, USA
- University of California San Diego Medical Center, San Diego, CA, 92120, USA
- SDSU/UCSD Joint Doctoral Program, 6363 Alvarado Ct., Suite 101, San Diego, CA, 92120-4913, USA
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Chen C, Zhou Z, Li M, Qu M, Ma Q, Zhong M, Zhang Y, Yu Z. Presenilin-2 polymorphisms and risk of sporadic AD: evidence from a meta-analysis. Gene 2012; 503:194-9. [PMID: 22580083 DOI: 10.1016/j.gene.2012.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Revised: 04/19/2012] [Accepted: 05/02/2012] [Indexed: 12/31/2022]
Abstract
Association studies of presenilin-2 (PSEN2) polymorphisms and sporadic Alzheimer's disease (AD) have yielded inconsistent results, possibly because single studies often lack sufficient statistical power. In this study, we performed a meta-analysis to evaluate the association of the two most extensively studied PSEN2 polymorphisms, rs8383 and 5'indel, with the risk of sporadic AD. We systematically reviewed relevant studies retrieved by Medline, Pubmed, Embase, AlzGene, and CNKI. Data were analyzed using the Stata (v11.0) software package. The fixed effects model or random-effects model were applied depending on between-study heterogeneity. Publication bias was evaluated using Egger's test and Begg's funnel plots. Overall, the meta-analysis included 6 case-control studies for each polymorphism with 2186 confirmed AD cases and 2507 healthy controls in total. Analysis suggested a significant association between SNP rs8383 polymorphism and AD risk with no evidence of between-study heterogeneity or publication bias. In contrast, we found no evidence for an association between the 5'indel polymorphism and AD risk. Further stratified analyses by apolipoprotein ε4 status or ethnicity also failed to reveal a statistically significant association between the 5'indel polymorphism of PSEN2 and AD risk. Our analysis supports the hypothesis that the PSEN2 rs8383 polymorphism is associated with an enlarged risk of sporadic AD. However, larger scale association studies are necessary to further validate the association of PSEN2 polymorphisms with sporadic AD risk and to define potential gene-gene interactions.
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Affiliation(s)
- Chunhai Chen
- Department of Occupational Health, Faculty of Preventive Medicine, Third Military Medical University, Chongqing 400038, China
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Willhite CC, Ball GL, McLellan CJ. Total allowable concentrations of monomeric inorganic aluminum and hydrated aluminum silicates in drinking water. Crit Rev Toxicol 2012; 42:358-442. [DOI: 10.3109/10408444.2012.674101] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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10
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Corby K, Morgan CD, Murphy C. Abnormal event-related potentials in young and middle-aged adults with the ApoE ε4 allele. Int J Psychophysiol 2012; 83:276-81. [PMID: 22100309 PMCID: PMC4343300 DOI: 10.1016/j.ijpsycho.2011.11.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Revised: 06/23/2011] [Accepted: 11/03/2011] [Indexed: 11/23/2022]
Abstract
The largest genetic susceptibility factor for Alzheimer's disease is the Apolipoprotein E (ApoE) ε4 allele. Cognitive decline and olfactory impairment are greater in those positive for the ε4 allele. This study sought to determine if the olfactory event-related potential (OERP), compared to the visual ERP, would be sensitive to these subtle declines. Participants included 40 individuals from two age groups, half of each group were ε4 allele positive and half were ε4 negative. Visual ERPs did not demonstrate significant differences between ApoE groups. OERPs demonstrated robust age by ApoE interactions. P3 latencies were significantly longer in ε4 young and middle age participants. These findings suggest that very early olfactory and cognitive changes related to ApoE status are detectible via the OERP.
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Affiliation(s)
- Krystin Corby
- San Diego State University, Department of Psychology, San Diego, CA, 92120, USA
| | - Charlie D. Morgan
- San Diego State University, Department of Psychology, San Diego, CA, 92120, USA
| | - Claire Murphy
- San Diego State University, Department of Psychology, San Diego, CA, 92120, USA
- University of California Medical Center, San Diego, CA, 92120, USA
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11
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Moraes CF, Lins TC, Carmargos EF, Naves JOS, Pereira RW, Nóbrega OT. Lessons from genome-wide association studies findings in Alzheimer's disease. Psychogeriatrics 2012; 12:62-73. [PMID: 22416831 DOI: 10.1111/j.1479-8301.2011.00378.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder with a complex genetic background. Recent genome-wide association studies (GWAS) have placed important new contributors into the genetic framework of early- and late-onset forms of this dementia. Besides confirming the major role of classic allelic variants (e.g. apolipoprotein E) in the development of AD, GWAS have thus far implicated over 20 single nucleotide polymorphisms in AD. In this review, we summarize the findings of 16 AD-based GWAS performed to date whose public registries are available at the National Human Genome Research Institute, with an emphasis on understanding whether the polymorphic markers under consideration support functional implications to the pathophysiological role of the major genetic risk factors unraveled by GWAS.
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Affiliation(s)
- Clayton F Moraes
- Geriatric Service, Hospital of the Catholic University of Brasília, Graduate Program in Medical Sciences, University of Brasília, Brasília - DF, Brazil
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12
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Zamani M, Mehri M, Kollaee A, Yenki P, Ghaffarpor M, Harirchian MH, Shahbazi M. Pharmacogenetic Study on the Effect of Rivastigmine on PS2 and APOE Genes in Iranian Alzheimer Patients. Dement Geriatr Cogn Dis Extra 2011; 1:180-9. [PMID: 22163243 PMCID: PMC3199882 DOI: 10.1159/000329514] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background/Aims Alzheimer disease (AD) is a complex and genetically heterogeneous disorder, and certain genes such as PS2 and APOE4 contribute to the development of AD. Due to its heterogeneity, AD-predisposing genes could vary in different populations. Moreover, not all AD patients will respond to the same therapy. We specifically investigated the effect ofrivastigmine (Exelon) on PS2 and APOE genes in Iranian AD patients. Methods A total of 100 AD patients, 67 patients with sporadic AD (SAD) and 33 patients with familial AD (FAD), receiving rivastigmine therapy and 100 healthy controls were studied. PCR-RFLP was used for genotyping of PS2 and APOE. Results We found a positive association between the PS2 –A allele and SAD patients (pc = 0.01), and the PS2 +A/–A genotype was significantly more frequent in SAD than FAD patients (pc = 0.009). The APOE4 allele was associated with total AD, SAD and FAD (pc = 0.000002). Patients with the PS2 +A/–A genotype and bigenic genotypes of +A/–A·∊3/∊3 and +A/–A·∊3/∊4 were the best responders to Exelon therapy, and those with the PS2 +A/+A and APOE ∊3/∊4 genotypes were the worst responders. Conclusion Our findings suggest that the PS2 and APOE4 alleles and genotypes affect both AD risk and response to rivastigmine therapy.
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Affiliation(s)
- M Zamani
- Department of Neurogenetics, Iranian Center of Neurological Research, Gorgan, Iran
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Chua SM, Ng BY, Lee TS. Genetic and Genomic Aspects of Alzheimer's Disease. PROCEEDINGS OF SINGAPORE HEALTHCARE 2010. [DOI: 10.1177/201010581001900408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Alzheimer's disease (AD) is the most common chronic neurodegenerative disease today, afflicting 35 million people worldwide. Age is the major risk factor. The heritability of AD is estimated to be around 60%. Less than 5% of AD cases are familial with early-onset of disease caused by specific gene mutations. Genetic studies over the past 2 decades have provided invaluable insights into this complex disease. Here we review AD from the latest genome-wide association studies (GWAS), and a brief review of the transcriptomics, proteomics, metabolomics and epigenetics. Ultimately, a system-wide approach is essential to integrating the diverse and complicated findings into a meaningful understanding of AD.
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Affiliation(s)
- Sze-Ming Chua
- Department of Psychiatry, Singapore General Hospital, Singapore
| | - Beng-Yeong Ng
- Department of Psychiatry, Singapore General Hospital, Singapore
| | - Tih-Shih Lee
- Department of Psychiatry, Singapore General Hospital, Singapore
- Duke University Medical School, Durham, North Carolina, USA
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14
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Wang M, Jia J. The interleukin-6 gene −572C/G promoter polymorphism modifies Alzheimer's risk in APOE ɛ4 carriers. Neurosci Lett 2010; 482:260-3. [DOI: 10.1016/j.neulet.2010.07.051] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 07/19/2010] [Accepted: 07/19/2010] [Indexed: 10/19/2022]
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Zhong L, Dong-hai Q, Hong-ying L, Qing-feng L. Analysis of the nicastrin promoter rs10752637 polymorphism and its association with Alzheimer's disease. Eur J Neurosci 2009; 30:1831-6. [PMID: 19840113 DOI: 10.1111/j.1460-9568.2009.06942.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alzheimer's disease (AD) is a common, degenerative form of dementia characterized by the accumulation of plaques containing amyloid beta-peptides (A beta). Nicastrin (NCSTN) is a type I trans-membrane glycoprotein and an essential component of gamma-secretase, a multiprotein complex required for the production of the mature form of A beta. Overexpression of wild-type NCSTN increases A beta production, indicating that the strict regulation of NCSTN expression may play a fundamental role in the pathogenesis of AD. In this study we investigated the effect of a single-nucleotide polymorphism (SNP; rs10752637), located in the promoter region of the NCSTN gene, on NCSTN promoter activity. First, the rs10752637 genotypes were determined in a Chinese population consisting of 462 patients with sporadic AD and 470 normal control subjects. The distributions of the rs10752637 genotypes and allele frequencies were significantly different between the AD and control groups, with the -922T allele significantly associated with the occurrence of AD. Reporter assays indicated that the rs10752637 -922T allele had a significantly increased promoter activity relative to the -922G allele. Furthermore, gel shift assays demonstrated that the -922T allele preferentially bound to components of nuclear extracts. Overall, our results indicate that the rs10752637 SNP can likely influence the expression of NCSTN, and that this may be an influencing factor during the pathogenesis of AD.
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Affiliation(s)
- Li Zhong
- Department of Neurology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.
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16
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Trends in the molecular pathogenesis and clinical therapeutics of common neurodegenerative disorders. Int J Mol Sci 2009; 10:2510-2557. [PMID: 19582217 PMCID: PMC2705504 DOI: 10.3390/ijms10062510] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Revised: 04/28/2009] [Accepted: 05/05/2009] [Indexed: 12/11/2022] Open
Abstract
The term neurodegenerative disorders, encompasses a variety of underlying conditions, sporadic and/or familial and are characterized by the persistent loss of neuronal subtypes. These disorders can disrupt molecular pathways, synapses, neuronal subpopulations and local circuits in specific brain regions, as well as higher-order neural networks. Abnormal network activities may result in a vicious cycle, further impairing the integrity and functions of neurons and synapses, for example, through aberrant excitation or inhibition. The most common neurodegenerative disorders are Alzheimer’s disease, Parkinson’s disease, Amyotrophic Lateral Sclerosis and Huntington’s disease. The molecular features of these disorders have been extensively researched and various unique neurotherapeutic interventions have been developed. However, there is an enormous coercion to integrate the existing knowledge in order to intensify the reliability with which neurodegenerative disorders can be diagnosed and treated. The objective of this review article is therefore to assimilate these disorders’ in terms of their neuropathology, neurogenetics, etiology, trends in pharmacological treatment, clinical management, and the use of innovative neurotherapeutic interventions.
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Gupta M, Kaur H, Grover S, Kukreti R. Pharmacogenomics and treatment for dementia induced by Alzheimer’s disease. Pharmacogenomics 2008; 9:895-903. [DOI: 10.2217/14622416.9.7.895] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Pharmacogenomics is the study of interindividual genetic variability, which plays a significant role in defining drug response and toxicity. As research has graduated from studying single candidate genes to whole-genome scans, pharmacogenomics is beginning to make its impact on the therapeutics of complex CNS disorders, such as schizophrenia, Parkinson’s disease and Alzheimer’s disease. Alzheimer’s disease is a progressive complex disorder, where genetic predisposition interacts with environmental factors. With conventional therapeutics only providing symptomatic treatment, the current focus of the pharmaceutical industry is on novel strategies with an etiopathogenic orientation. In this review, we have summarized the current knowledge of pathogenetic mechanisms of Alzheimer’s disease, with a focus on the known relevant molecules and the potential of pharmacogenomics in translating this knowledge of human genome variability into efficacious and safer therapeutics.
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Affiliation(s)
- Meenal Gupta
- Functional Genomics Unit, Institute of Genomics & Integrative Biology (Council of Scientific and Industrial Research), Mall Road, Delhi 110 007, India
| | - Harpreet Kaur
- Functional Genomics Unit, Institute of Genomics & Integrative Biology (Council of Scientific and Industrial Research), Mall Road, Delhi 110 007, India
| | - Sandeep Grover
- Functional Genomics Unit, Institute of Genomics & Integrative Biology (Council of Scientific and Industrial Research), Mall Road, Delhi 110 007, India
| | - Ritushree Kukreti
- Functional Genomics Unit, Institute of Genomics & Integrative Biology (Council of Scientific and Industrial Research), Mall Road, Delhi 110 007, India
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Llorca J, Rodríguez-Rodríguez E, Dierssen-Sotos T, Delgado-Rodríguez M, Berciano J, Combarros O. Meta-analysis of genetic variability in the beta-amyloid production, aggregation and degradation metabolic pathways and the risk of Alzheimer's disease. Acta Neurol Scand 2008; 117:1-14. [PMID: 17854420 DOI: 10.1111/j.1600-0404.2007.00899.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Variants in genes encoding enzymes involved in production, aggregation or degradation of beta-amyloid are potential risk factors for sporadic Alzheimer's disease (AD). METHODS Meta-analyses on AD association with BACE1 exon 5, BACE1 intron 5, FE65 intron 13, CYP46 intron 2, alpha(1)-antichymotrypsine Ala17Thr, bleomycin hydrolase I443V, lectin-like oxidized low-density lipoprotein receptor (OLR1) 3'-UTR (+1071) and (+1073), and very-low-density lipoprotein receptor (VLDLR) 5'-UTR (CGG-repeat) polymorphisms. RESULTS In BACE1 exon 5, genotype CC+CT acts as a protective factor in Apolipoprotein E (ApoE) epsilon 4 carriers [odds ratio (OR) = 0.57; 95% confidence interval (CI): 0.38-0.88], and as a risk factor in ApoE epsilon 4 non-carriers (OR = 1.33; 95% CI: 1.00-1.78). OLR1 3'-UTR (+1073) allele C is associated with increased risk (OR = 1.23; 95% CI: 1.01-1.50). VLDLR 5'-UTR genotype 2 is associated with increased risk (OR = 1.70; 95% CI: 1.09-2.63) in the Asian population and is protective (OR = 0.48; 95% CI: 0.26-0.86) in the non-Asian population. Other studied polymorphisms are not associated with AD. CONCLUSIONS The overall impact on AD risk of the genes for which meta-analyses are now available is rather limited. Additional meta-analyses of other different genes encoding for A beta production, aggregation and degradation mediators might help in determining the risk profile for AD.
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Affiliation(s)
- J Llorca
- Division of Epidemiology and Computational Biology, University of Cantabria School of Medicine, Santander, Spain.
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19
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Abstract
OBJECTIVE Episodic recognition memory for odors and visual was assessed in apolipoprotein E (ApoE) epsilon4-positive and epsilon4-negative men and women diagnosed with Alzheimer disease (AD) and a healthy age- and gender-matched comparison group. METHODS A total of 38 AD patients and 38 age- and gender-matched healthy older adults completed a recognition memory task involving three categories of stimuli: odors, faces, and symbols. RESULTS In the healthy comparison group, men who were epsilon4 negative outperformed epsilon4-positive men in recognition memory for odors and committed fewer false-positive errors. However, there were no significant differences between epsilon4-negative and epsilon4-positive women in the comparison group. No significant gender or ApoE status differences were detected in recognition memory for faces or symbols in the comparison group. In patients with AD, epsilon4-negative women outperformed epsilon4-positive women in recognition memory for odors and committed significantly fewer false-positive errors. However, there were no significant differences between epsilon4-positive and epsilon4-negative men. There were no significant gender or ApoE status differences in recognition memory for faces or symbols in AD patients. CONCLUSION The results demonstrate that recognition memory for olfactory stimuli may be particularly impaired in healthy older men with the epsilon4 allele. In patients with AD, odor memory impairments may be less severe in women who are negative for the epsilon4 allele. The results offer new insight into how recognition memory is affected by gender, the epsilon4 allele, and the modality of the stimulus to be remembered in healthy older adults and patients with AD.
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Togsverd M, Werge TM, Tankó LB, Bagger YZ, Qin GG, Hansen T, Christiansen C, Rasmussen HB. Cognitive performance in elderly women: significance of the 19bp insertion/deletion polymorphism in the 5' flank of the dopamine beta-hydroxylase gene, educational level, body fat measures, serum triglyceride, alcohol consumption and age. Int J Geriatr Psychiatry 2007; 22:883-9. [PMID: 17200925 DOI: 10.1002/gps.1756] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Genetic and environmental factors influence cognitive aging. The gene encoding dopamine beta-hydroxylase (DBH) could be one such factor since this hydroxylase converts dopamine to norepinephrine both of which are involved in cognition regulation. OBJECTIVE To assess the effect of the 19bp insertion/deletion polymorphism in the 5' flank of the DBH gene on cognitive performance in elderly women relative to other factors of cognitive aging. METHODS We examined a cross-sectional sample of 1371 postmenopausal women. Cognitive abilities were assessed by the 6-item orientation-memory-concentration test. The 19bp insertion/deletion polymorphism of the DBH gene was genotyped and apolipoprotein E (APOE) epsilon4 allele status was determined. In addition blood pressure, body fat mass and blood lipids were measured. Information was also obtained by personal interviews. Data were analyzed by regression analysis. RESULTS Cognition was univariately associated with DBH genotype (p = 0.04). A univariate association of borderline significance was observed for APOE epsilon4 allele status (p = 0.07). Exclusion of women with severe cognition impairment did not alter the strength of the association with the DBH gene polymorphism markedly (p = 0.06) but obliterated the weak association between APOE epsilon4 allele status and cognition. The association of the DBH gene polymorphism with cognition persisted after adjustment for other variables (p = 0.03). CONCLUSIONS The 19bp insertion/deletion polymorphism of the DBH gene influences cognition in elderly women and might have a stronger effect than APOE epsilon4 allele status on mild cognitive impairment. Both genetic polymorphisms had a significantly smaller impact on cognition than age, education, alcohol consumption and body fat measures.
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Affiliation(s)
- Mads Togsverd
- Research Institute of Biological Psychiatry, H:S Sct. Hans Hospital, Roskilde, Copenhagen University, Denmark
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21
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Jeong BH, Lee KH, Jeong YE, Hwang KA, Lee YJ, Carp RI, Ju YR, Kim YS. Polymorphisms at codons 129 and 219 of the prion protein gene (PRNP) are not associated with sporadic Alzheimer's disease in the Korean population. Eur J Neurol 2007; 14:621-6. [PMID: 17539938 DOI: 10.1111/j.1468-1331.2007.01786.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Polymorphisms of prion protein gene (PRNP) at codons 129 and 219 play an important role in the susceptibility to Creutzfeldt-Jakob disease (CJD). Alzheimer's disease (AD) and prion diseases, such as CJD, are both characterized by the accumulation of abnormally folded proteins in the brain. An association between sporadic AD and the PRNP polymorphism at codon 129 has been reported in several studies, but other studies have failed to confirm an association. To investigate whether PRNP polymorphisms are associated with an increased risk for developing sporadic AD in the Korean population, we compared the genotype, allele, and haplotype frequencies of PRNP polymorphisms in 271 sporadic AD patients with those in 236 healthy Koreans. Our study does not show a significant difference in PRNP genotype, allele, and haplotype frequency at codons 129 and 219 between sporadic AD and normal controls. Analyses stratifying by age at disease onset, and gender also failed to reveal any association between these polymorphisms and sporadic AD. These results indicate that these PRNP polymorphisms have no direct influence on the susceptibility to sporadic AD in the Korean population.
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Affiliation(s)
- B-H Jeong
- Ilsong Institute of Life Science, Hallym University, Gwanyang-dong, Dongan-gu, Anyang, Kyounggi-do, South Korea
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22
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Coon KD, Siegel AM, Yee SJ, Dunckley TL, Mueller C, Nagra RM, Tourtellotte WW, Reiman EM, Papassotiropoulos A, Petersen FF, Stephan DA, Kirsch WM. Preliminary demonstration of an allelic association of the IREB2 gene with Alzheimer's disease. J Alzheimers Dis 2006; 9:225-33. [PMID: 16914832 PMCID: PMC1555623 DOI: 10.3233/jad-2006-9301] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The role of iron metabolism in Alzheimer's disease (AD) is well documented. Regulation of the proteins that maintain cellular iron metabolism is mediated by two cytoplasmic RNA-binding proteins, the Iron Regulatory Proteins (IRP1 and IRP2), that function through post-transcriptional interactions with RNA stem loop structures called iron-responsive elements. As the primary mediator of iron homeostasis in neuronal cells, IRP2 is a strong candidate for polymorphisms that could impact AD pathogenesis. Thus, we performed a pilot study to assess polymorphisms in the gene encoding IRP2 (IREB2) on clinically well-characterized, post-mortem samples (50 AD and 50 controls). DNA sequence analysis of the IREB2 gene region revealed 14 polymorphisms. Two (rs2656070 and rs13180) showed statistically significant skewing of allelic and genotypic distributions between AD patients and controls. In silico analyses revealed that rs2656070 lies within a probable promoter and disrupts the binding sites of at least two known transcription factors. Though silent and likely not functionally relevant, rs13180 is in complete LD with rs2656070 (D' > 0.999), creating an IREB2-haplotype that is significantly associated with AD. Confirmation of this association in a larger cohort of cases and controls would further support the role of iron regulation in the pathogenesis of this catastrophic and increasingly common neurodegenerative disorder.
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Affiliation(s)
- Keith D. Coon
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004
| | - Andrew M. Siegel
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004
| | - Stephanie J. Yee
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004
| | - Travis L. Dunckley
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004
| | - Claudius Mueller
- Neurosurgery Center for Research, Training and Education, Loma Linda University, Loma Linda, CA, 92350
- Free University of Berlin, Berlin, Germany
| | - Rashed M. Nagra
- Human Brain and Spinal Fluid Resource Center, Los Angeles, CA, 90073
| | | | - Eric M. Reiman
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004
- PET Center, Banner Good Samaritan Medical Center, Department of Psychiatry, University of Arizona
- The Arizona Disease Consortium, Phoenix, AZ, USA
| | - Andreas Papassotiropoulos
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004
- Division of Psychiatry Research, University of Zurich, Zurich, Switzerland
| | - Floyd F. Petersen
- Neurosurgery Center for Research, Training and Education, Loma Linda University, Loma Linda, CA, 92350
| | - Dietrich A. Stephan
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004
- *To whom correspondence should be addressed: Director, Neurogenomics Division, TGen, The Translational Genomics Research Institute, 400 N. Fifth Street, Suite 1600, Phoenix, AZ, 85004 602-343-8727 (phone), 602-343-8740 (fax), www.tgen.org,
| | - Wolff M. Kirsch
- Neurosurgery Center for Research, Training and Education, Loma Linda University, Loma Linda, CA, 92350
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Del Bo R, Scarlato M, Ghezzi S, Martinelli-Boneschi F, Fenoglio C, Galimberti G, Galbiati S, Virgilio R, Galimberti D, Ferrarese C, Scarpini E, Bresolin N, Comi GP. Is M129V of PRNP gene associated with Alzheimer's disease? A case-control study and a meta-analysis. Neurobiol Aging 2006; 27:770.e1-770.e5. [PMID: 16099550 DOI: 10.1016/j.neurobiolaging.2005.05.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2005] [Revised: 05/12/2005] [Accepted: 05/23/2005] [Indexed: 11/28/2022]
Abstract
The methionine/valine (M/V) polymorphism at codon 129 within the prion protein gene (PRNP) represents a known risk factor for Creutzfeldt-Jakob disease (CJD). Few authors reported also the effects of this polymorphism on the risk of Alzheimer's disease (AD), although with controversial results. To better clarify this issue, we performed a novel case-control study and a meta-analysis of published association studies between PRNP and AD. Our findings argue against PRNP as a susceptibility gene for developing AD in the Italian population but support the hypothesis that the V allele influences cognitive performances. The meta-analysis, revealed that Caucasian subjects homozygous at codon 129 had a 1.3-fold increased risk [95% CI: 1.0-1.6, p = 0.05] of developing AD compared to heterozygous individuals. We also observed that MM genotype and M allele represent a risk factor for AD, independently from the ethnic background, providing a significant but modest association between this polymorphism and AD.
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Affiliation(s)
- Roberto Del Bo
- Dino Ferrari Centre, Department of Neurological Sciences, University of Milan and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Padiglione Ponti, Milano, Italy.
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BEYER KATRIN, LAO JOSÉI, LATORRE PILAR, ARIZA AURELIO. Age at Onset: An Essential Variable for the Definition of Genetic Risk Factors for Sporadic Alzheimer's Disease. Ann N Y Acad Sci 2006. [DOI: 10.1111/j.1749-6632.2005.tb06138.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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25
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Kazama H, Ruberu NN, Murayama S, Saito Y, Nakahara KI, Kanemaru K, Nagura H, Arai T, Sawabe M, Yamanouchi H, Orimo H, Hosoi T. Association of estrogen receptor alpha gene polymorphisms with neurofibrillary tangles. Dement Geriatr Cogn Disord 2005; 18:145-50. [PMID: 15211069 DOI: 10.1159/000079194] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/19/2003] [Indexed: 11/19/2022] Open
Abstract
Estrogen receptor alpha (ERalpha) may be implicated in the pathogenesis of Alzheimer's disease (AD). The aim of this study was to clarify the association between ERalpha gene polymorphisms and AD-related pathologic changes. The staging of neurofibrillary tangles (NFT) and senile plaques (SP) was performed according to the method by Braak and Braak and two polymorphisms, PvuII (P or p) and XbaI (X or x), of the ERalpha gene were typed in 551 Japanese cadavers (294 men and 257 women; mean age, 80.8 years). Distributions of the NFT and SP stages significantly correlated with age (NFT: r = 0.306, p < 0.0001; SP: r = 0.237, p < 0.0001) and were significantly higher in patients with the apolipoprotein E epsilon4 allele (p < 0.0001). Possession of the P allele showed a trend to be associated with a more serious NFT stage, but had no relationship with the SP stage. In men, a significant association between PvuII polymorphism and the NFT stage (p = 0.002) was found, revealing a gene- dose effect of the P allele. Similar results were obtained in the men without the epsilon4 allele (p = 0.011). Multiple regression analyses demonstrated that age was the strongest determinant of the NFT stage, possession of the epsilon4 allele was the next strongest, and PvuII polymorphism was the third strongest (p < 0.0001, R(2) = 0.144). The XbaI polymorphism did affect neither the NFT stage nor the SP stage. In conclusion, the PvuII polymorphism of the ERalpha gene is associated with Braak NFT stages and possession of the P allele may act as a risk factor for AD in Japanese men, especially in those without the epsilon4 allele.
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Affiliation(s)
- Hirohito Kazama
- Department of Endocrinology, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
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26
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Del Bo R, Scarlato M, Ghezzi S, Martinelli Boneschi F, Fenoglio C, Galbiati S, Virgilio R, Galimberti D, Galimberti G, Crimi M, Ferrarese C, Scarpini E, Bresolin N, Comi GP. Vascular endothelial growth factor gene variability is associated with increased risk for AD. Ann Neurol 2005; 57:373-80. [PMID: 15732116 DOI: 10.1002/ana.20390] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Converging evidence points to a pivotal role of vascular endothelial growth factor (VEGF) in neuronal protection and a lack of its activity in neurodegenerative disorders. To investigate this possible association, we screened the VEGF gene promoter for various well-known single-nucleotide polymorphisms in a series of 249 consecutively recruited Italian patients with sporadic Alzheimer's disease (AD). Genetic analysis indicated different distributions of two single-nucleotide polymorphisms in the AD population compared with healthy control subjects. In particular, the frequencies of -2578A/A and -1198C/T genotypes were significantly greater in AD patients than in control subjects (23.7 vs 14.7% and 2.8 vs 0%, respectively). The -2578A/A genotype was associated with an increased risk for disease, independently of apolipoprotein E genotype. The risk was significantly increased with respect to various VEGF genotype combinations. In contrast, no difference in serum VEGF levels was detected comparing 96 patients and 49 control subjects. These findings suggest that polymorphisms within the promoter region of the VEGF gene confer greater risk for AD, probably by reducing its neuroprotective effect, and confirm the biological role of VEGF in neurodegenerative processes.
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Affiliation(s)
- Roberto Del Bo
- Department of Neurological Sciences, Dino Ferrari Centre and Centre of Excellence on Neurodegenerative Diseases, University of Milan, I.R.C.C.S. Ospedale Maggiore Policlinico, Via F. Sforza 35, 20122 Milan, Italy.
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27
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Xiang W, Windl O, Wünsch G, Dugas M, Kohlmann A, Dierkes N, Westner IM, Kretzschmar HA. Identification of differentially expressed genes in scrapie-infected mouse brains by using global gene expression technology. J Virol 2004; 78:11051-60. [PMID: 15452225 PMCID: PMC521804 DOI: 10.1128/jvi.78.20.11051-11060.2004] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The pathogenesis of prion diseases, a class of transmissible fatal neurodegenerative diseases in humans and animals, is still unclear. The aim of this study was to identify the differentially regulated genes that correlate with the development of prion diseases for a better understanding of their pathological mechanisms. We employed Affymetrix Mouse Expression Arrays 430A containing >22,000 transcripts and compared the global gene expression profiles from brains of mice who were intracerebrally inoculated with scrapie strains ME7 and RML with those from brains of uninfected and mock-infected mice. The microarray data were analyzed by Significance Analysis of Microarrays, revealing 121 genes whose expression increased at least twofold in both ME7- and RML-infected mouse brains, with an estimated false discovery rate of < or =5%. These genes encode proteins involved in proteolysis, protease inhibition, cell growth and maintenance, the immune response, signal transduction, cell adhesion, and molecular metabolism. The time course of expression generally showed up-regulation of these genes from 120 days postinoculation (dpi) for ME7-inoculated mouse brains and from 90 dpi for RML-inoculated mouse brains. The onset of elevated expression correlated temporally with the onset of PrP(Sc) accumulation and the activation of glia, which may have contributed to neuronal cell death. Among the differentially regulated genes reported in the present study, the emergence of genes for several cathepsins and S100 calcium binding proteins was conspicuous. These and other genes reported here may represent novel potential diagnostic and therapeutic targets for prion disease.
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Affiliation(s)
- Wei Xiang
- Institute of Neuropathology, Department of Internal Medicine III, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 23, D-81377 Munich, Germany
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28
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Gilbert PE, Murphy C. Differences between recognition memory and remote memory for olfactory and visual stimuli in nondemented elderly individuals genetically at risk for Alzheimer's disease. Exp Gerontol 2004; 39:433-41. [PMID: 15036403 DOI: 10.1016/j.exger.2004.01.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2003] [Revised: 12/28/2003] [Accepted: 01/13/2004] [Indexed: 11/19/2022]
Abstract
Recognition and remote memory for olfactory and visual stimuli were assessed in nondemented elderly individuals positive for the apolipoprotein E 4 allele and in 4 negative controls to examine whether the 4 allele differentially affects recognition and/or remote memory depending on the modality of stimulus to be remembered. Compared to controls, 4 positive individuals committed more false positive recognition memory errors for olfactory but not visual stimuli suggesting that 4 positive individuals may show false positive errors for olfactory stimuli before deficits for other stimuli are detectable. There were no significant differences in familiarity ratings (a proposed measure of remote memory) suggesting that brain areas involved in remote memory are not affected in nondemented 4 positive individuals. The results suggest that neuropathological changes in nondemented individuals genetically at risk for Alzheimer's disease may differentially affect memory processes.
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Affiliation(s)
- Paul E Gilbert
- Department of Head and Neck Surgery, University of California San Diego, San Diego, CA 92103, USA
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29
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Helbecque N, Cottel D, Codron V, Berr C, Amouyel P. Paraoxonase 1 gene polymorphisms and dementia in humans. Neurosci Lett 2004; 358:41-4. [PMID: 15016430 DOI: 10.1016/j.neulet.2003.12.100] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2003] [Revised: 12/26/2003] [Accepted: 12/26/2003] [Indexed: 10/26/2022]
Abstract
Several clinical and epidemiological studies suggest that Alzheimer's disease (AD) and vascular dementia share common risk factors. Oxidative stress is one of these well recognized factors. It can result from an excess of free-radical activity and impaired antioxidant defenses. Paraoxonase (PON1), a component of high density lipoproteins, has antioxidative potential and was previously associated with an increased risk of cardiovascular diseases. The impact of two polymorphisms in PON1 (Gln192Arg associated with enzyme activity and T-107C associated with enzyme concentration) was examined in a case-control study. The two polymorphisms were independent risk factors for nonAD dementia, particularly in APOE-4 noncarriers. An at-'risk haplotype' could be constructed including the Gln192 and the T-107 alleles, suggesting that subjects at risk have lower plasma paraoxonase levels and this enzyme is less active.
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Affiliation(s)
- Nicole Helbecque
- INSERM U508, Institut Pasteur de Lille, 1 rue du Professeur Calmette, 59019 Lille Cedex, France
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30
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Nelson LM, Tanner CM, Van Den Eeden SK, McGuire VM. Alzheimer’s Disease and Vascular Dementia. Neuroepidemiology 2004. [DOI: 10.1093/acprof:oso/9780195133790.003.05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
This chapter explores the frequency with which dementing illnesses occur in populations, their distributions by personal characteristics, and what is known about their causes and potential protective factors. The primary focus is on the most common forms of dementia: Alzheimer's disease and vascular dementia. The chapter summarizes clinical and pathologic features of Alzheimer's disease and vascular dementia, and highlights recent theories of how risk factors affect brain reserve. With the evolution of the epidemiology of dementia from case-control studies to prospective cohort studies has come a new set of methodological challenges. These include identification of representative populations, enhancing subject participation and retention in studies, the need to include institutionalized as well as community-dwelling populations, the non-standardized use of cognitive tests to screen for dementia, and the complexities of the diagnostic process itself. Finally, the chapter summarizes risk and protective factors for disease expression, including cardiovascular risk factors, lifestyle factors, and factors that affect brain reserve.
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