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Bae J, Logan PE, Acri DJ, Bharthur A, Nho K, Saykin AJ, Risacher SL, Nudelman K, Polsinelli AJ, Pentchev V, Kim J, Hammers DB, Apostolova LG. A simulative deep learning model of SNP interactions on chromosome 19 for predicting Alzheimer's disease risk and rates of disease progression. Alzheimers Dement 2023; 19:5690-5699. [PMID: 37409680 PMCID: PMC10770299 DOI: 10.1002/alz.13319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 04/25/2023] [Accepted: 05/12/2023] [Indexed: 07/07/2023]
Abstract
BACKGROUND Identifying genetic patterns that contribute to Alzheimer's disease (AD) is important not only for pre-symptomatic risk assessment but also for building personalized therapeutic strategies. METHODS We implemented a novel simulative deep learning model to chromosome 19 genetic data from the Alzheimer's Disease Neuroimaging Initiative and the Imaging and Genetic Biomarkers of Alzheimer's Disease datasets. The model quantified the contribution of each single nucleotide polymorphism (SNP) and their epistatic impact on the likelihood of AD using the occlusion method. The top 35 AD-risk SNPs in chromosome 19 were identified, and their ability to predict the rate of AD progression was analyzed. RESULTS Rs561311966 (APOC1) and rs2229918 (ERCC1/CD3EAP) were recognized as the most powerful factors influencing AD risk. The top 35 chromosome 19 AD-risk SNPs were significant predictors of AD progression. DISCUSSION The model successfully estimated the contribution of AD-risk SNPs that account for AD progression at the individual level. This can help in building preventive precision medicine.
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Affiliation(s)
- Jinhyeong Bae
- Department of Neurology, School of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Paige E. Logan
- Department of Neurology, School of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Dominic J. Acri
- Department of Medical and Molecular Genetics, School of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Apoorva Bharthur
- Department of Neurology, School of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Kwangsik Nho
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Andrew J. Saykin
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Shannon L. Risacher
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Kelly Nudelman
- Department of Medical and Molecular Genetics, School of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Angelina J. Polsinelli
- Department of Neurology, School of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Valentin Pentchev
- Department of Information Technology, Indiana University Network Science Institute, Bloomington, IN, 47408, United States
| | - Jungsu Kim
- Department of Medical and Molecular Genetics, School of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Dustin B. Hammers
- Department of Neurology, School of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Liana G. Apostolova
- Department of Neurology, School of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
- Department of Medical and Molecular Genetics, School of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
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TOMM40 Genetic Variants Cause Neuroinflammation in Alzheimer's Disease. Int J Mol Sci 2023; 24:ijms24044085. [PMID: 36835494 PMCID: PMC9962462 DOI: 10.3390/ijms24044085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/10/2023] [Accepted: 02/15/2023] [Indexed: 02/22/2023] Open
Abstract
Translocase of outer mitochondrial membrane 40 (TOMM40) is located in the outer membrane of mitochondria. TOMM40 is essential for protein import into mitochondria. TOMM40 genetic variants are believed to increase the risk of Alzheimer's disease (AD) in different populations. In this study, three exonic variants (rs772262361, rs157581, and rs11556505) and three intronic variants (rs157582, rs184017, and rs2075650) of the TOMM40 gene were identified from Taiwanese AD patients using next-generation sequencing. Associations between the three TOMM40 exonic variants and AD susceptibility were further evaluated in another AD cohort. Our results showed that rs157581 (c.339T > C, p.Phe113Leu, F113L) and rs11556505 (c.393C > T, p.Phe131Leu, F131L) were associated with an increased risk of AD. We further utilized cell models to examine the role of TOMM40 variation in mitochondrial dysfunction that causes microglial activation and neuroinflammation. When expressed in BV2 microglial cells, the AD-associated mutant (F113L) or (F131L) TOMM40 induced mitochondrial dysfunction and oxidative stress-induced activation of microglia and NLRP3 inflammasome. Pro-inflammatory TNF-α, IL-1β, and IL-6 released by mutant (F113L) or (F131L) TOMM40-activated BV2 microglial cells caused cell death of hippocampal neurons. Taiwanese AD patients carrying TOMM40 missense (F113L) or (F131L) variants displayed an increased plasma level of inflammatory cytokines IL-6, IL-18, IL-33, and COX-2. Our results provide evidence that TOMM40 exonic variants, including rs157581 (F113L) and rs11556505 (F131L), increase the AD risk of the Taiwanese population. Further studies suggest that AD-associated mutant (F113L) or (F131L) TOMM40 cause the neurotoxicity of hippocampal neurons by inducing the activation of microglia and NLRP3 inflammasome and the release of pro-inflammatory cytokines.
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Genetic Variants and Haplotypes of TOMM40, APOE, and APOC1 are Related to the Age of Onset of Late-onset Alzheimer Disease in a Colombian Population. Alzheimer Dis Assoc Disord 2022; 36:29-35. [PMID: 35149606 DOI: 10.1097/wad.0000000000000477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 08/04/2021] [Indexed: 11/01/2022]
Abstract
BACKGROUND The Apolipoprotein E (APOE) gene is the main risk factor for late-onset Alzheimer disease (LOAD). Genetic variants and haplotypes in regions near the APOE locus may be associated with LOAD in the Colombian population. OBJECTIVE We evaluated frequencies and risk of genetic variants and haplotypes in APOE, TOMM40, and APOC1 promoters, also in putative regulatory enhancer elements (TOMM40 IVS2-4 and TOMM40 IVS6), and in cis-regulatory elements (ME1 and BCR). MATERIALS AND METHODS Our case-control association study was carried out in 50 patients with LOAD and 50 controls. We determined frequencies and odd ratios for genetic variants and haplotypes. RESULTS We found a significant association between LOAD and genetic variants at the TOMM40 promoter, at TOMM40 IVS2-4 and TOMM40 IVS6 regulatory enhancer elements, and at the APOC1 promoter. Particularly, variants of Poly-T and APOC1 promoter could anticipate the age of onset of LOAD in our population. We identified three risk haplotypes in TOMM40 (ACGGAG, ACGGGG, and ATAGGC) related to LOAD's age of onset. We also found other risk or protection haplotypes at the TOMM40 and APOE promoters, at TOMM40 IVS2-4, TOMM40 IVS6 regulatory enhancer elements, and at ME1. CONCLUSION Genetic variants and haplotypes near the APOE locus are related to LOAD risk and accelerated onset of LOAD in the Colombian population.
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Gockley J, Montgomery KS, Poehlman WL, Wiley JC, Liu Y, Gerasimov E, Greenwood AK, Sieberts SK, Wingo AP, Wingo TS, Mangravite LM, Logsdon BA. Multi-tissue neocortical transcriptome-wide association study implicates 8 genes across 6 genomic loci in Alzheimer's disease. Genome Med 2021; 13:76. [PMID: 33947463 PMCID: PMC8094491 DOI: 10.1186/s13073-021-00890-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 04/17/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is an incurable neurodegenerative disease currently affecting 1.75% of the US population, with projected growth to 3.46% by 2050. Identifying common genetic variants driving differences in transcript expression that confer AD risk is necessary to elucidate AD mechanism and develop therapeutic interventions. We modify the FUSION transcriptome-wide association study (TWAS) pipeline to ingest gene expression values from multiple neocortical regions. METHODS A combined dataset of 2003 genotypes clustered to 1000 Genomes individuals from Utah with Northern and Western European ancestry (CEU) was used to construct a training set of 790 genotypes paired to 888 RNASeq profiles from temporal cortex (TCX = 248), prefrontal cortex (FP = 50), inferior frontal gyrus (IFG = 41), superior temporal gyrus (STG = 34), parahippocampal cortex (PHG = 34), and dorsolateral prefrontal cortex (DLPFC = 461). Following within-tissue normalization and covariate adjustment, predictive weights to impute expression components based on a gene's surrounding cis-variants were trained. The FUSION pipeline was modified to support input of pre-scaled expression values and support cross validation with a repeated measure design arising from the presence of multiple transcriptome samples from the same individual across different tissues. RESULTS Cis-variant architecture alone was informative to train weights and impute expression for 6780 (49.67%) autosomal genes, the majority of which significantly correlated with gene expression; FDR < 5%: N = 6775 (99.92%), Bonferroni: N = 6716 (99.06%). Validation of weights in 515 matched genotype to RNASeq profiles from the CommonMind Consortium (CMC) was (72.14%) in DLPFC profiles. Association of imputed expression components from all 2003 genotype profiles yielded 8 genes significantly associated with AD (FDR < 0.05): APOC1, EED, CD2AP, CEACAM19, CLPTM1, MTCH2, TREM2, and KNOP1. CONCLUSIONS We provide evidence of cis-genetic variation conferring AD risk through 8 genes across six distinct genomic loci. Moreover, we provide expression weights for 6780 genes as a valuable resource to the community, which can be abstracted across the neocortex and a wide range of neuronal phenotypes.
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Affiliation(s)
| | | | | | | | - Yue Liu
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Ekaterina Gerasimov
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | | | | | - Aliza P Wingo
- Division of Mental Health, Atlanta VA Medical Center, Decatur, GA, USA
- Department of Psychiatry, Emory University School of Medicine, Atlanta, GA, USA
| | - Thomas S Wingo
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | | | - Benjamin A Logsdon
- Cajal Neuroscience, 1616 Eastlake Avenue East, Suite 208, Seattle, WA, 98102, USA.
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Ye Q, Su F, Shu H, Gong L, Xie C, Zhang Z, Bai F. The apolipoprotein E gene affects the three-year trajectories of compensatory neural processes in the left-lateralized hippocampal network. Brain Imaging Behav 2018; 11:1446-1458. [PMID: 27734307 DOI: 10.1007/s11682-016-9623-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Previous cross-sectional studies that investigated the effects of apolipoprotein E (ApoE) ε4 status on hippocampal networks have shown inconsistent results. Aging is a well-known risk factor for Alzheimer's disease (AD) and could strongly interact with ApoE-related vulnerabilities to affect AD risk. However, no longitudinal data have been published regarding the interaction of the ApoE genotype and aging on hippocampal networks. Fifty-one patients with amnestic-type mild cognitive impairment (aMCI) and 64 matched cognitively normal elderly subjects underwent resting-state fMRI scans and neuropsychological tests at baseline and at a 35-month follow-up. Hippocampal resting-state functional connectivity (FC) data were analyzed utilizing a mixed analysis of covariance with ApoE genotype, time points and disease as fixed factors, controlling for age, sex and years of education. The notable finding was that the FC between the left hippocampus and right frontal regions for ε4 carriers longitudinally increased in the normal subjects, but decreased in aMCI patients, whereas the FC for non-carriers was maintained in normal subjects but increased in aMCI patients. Specifically, the longitudinal increases in hippocampal FC with the right inferior frontal gyrus were positively correlated with the changes in episodic memory test scores in non-carriers with aMCI. The interaction between the ApoE genotype, aging and disease suggested that aging should be considered a key regulator of the impact of the ApoE genotype on the phenotypic variants of AD. These findings also demonstrated that compensatory neural processes were accelerated in genetically high risk individuals, but could be subsequently exhausted with the onset of cognitive impairment.
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Affiliation(s)
- Qing Ye
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Fan Su
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Hao Shu
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Liang Gong
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Chunming Xie
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Zhijun Zhang
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Feng Bai
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, 210009, China.
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Tzeng NS, Chung CH, Lin FH, Chiang CP, Yeh CB, Huang SY, Lu RB, Chang HA, Kao YC, Yeh HW, Chiang WS, Chou YC, Tsao CH, Wu YF, Chien WC. Anti-herpetic Medications and Reduced Risk of Dementia in Patients with Herpes Simplex Virus Infections-a Nationwide, Population-Based Cohort Study in Taiwan. Neurotherapeutics 2018; 15:417-429. [PMID: 29488144 PMCID: PMC5935641 DOI: 10.1007/s13311-018-0611-x] [Citation(s) in RCA: 215] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
This retrospective cohort study is to investigate the association between herpes simplex virus (HSV) infections and dementia, and the effects of anti-herpetic medications on the risk involved, using Taiwan's National Health Insurance Research Database (NHIRD). We enrolled a total of 33,448 subjects, and identified 8362 with newly diagnosed HSV infections and 25,086 randomly selected sex- and age-matched controls without HSV infections in a ratio of 1:3, selected from January 1, to December 31, 2000. A multivariable Cox proportional hazards regression model was used to evaluate the risk of developing dementia in the HSV cohort. This analysis revealed an adjusted hazard ratio of 2.564 (95% CI: 2.351-2.795, P < 0.001) for the development of dementia in the HSV-infected cohort relative to the non-HSV cohort. Thus, patients with HSV infections may have a 2.56-fold increased risk of developing dementia. A risk reduction of dementia development in patients affected by HSV infections was found upon treatment with anti-herpetic medications (adjusted HR = 0.092 [95% CI 0.079-0.108], P < 0.001). The usage of anti-herpetic medications in the treatment of HSV infections was associated with a decreased risk of dementia. These findings could be a signal to clinicians caring for patients with HSV infections. Further research is, therefore, necessary to explore the underlying mechanism(s) of these associations.
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Affiliation(s)
- Nian-Sheng Tzeng
- Department of Psychiatry, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
- Student Counseling Center, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Chi-Hsiang Chung
- Taiwanese Injury Prevention and Safety Promotion Association, Taipei, Taiwan, Republic of China
- School of Public Health, National Defense Medical Center, Taipei, Taiwan, Republic of China
- Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, 7115R, No.325, Section 2, Cheng-Kung Road, Neihu District, Taipei City, 11490, Taiwan, Republic of China
| | - Fu-Huang Lin
- School of Public Health, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Chien-Ping Chiang
- Department of Dermatology, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Chin-Bin Yeh
- Department of Psychiatry, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - San-Yuan Huang
- Department of Psychiatry, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Ru-Band Lu
- Department of Psychiatry, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
- Division of Clinical Psychology, Institute of Allied Health Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, Republic of China
- Department of Psychiatry, College of Medicine, National Cheng Kung University, Tainan, Taiwan, Republic of China
- Institute of Behavioral Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan, Republic of China
- Department of Psychiatry, National Cheng Kung University Hospital, Tainan, Taiwan, Republic of China
- Center for Neuropsychiatric Research, National Health Research Institute, Zhunan, Miaoli County, Taiwan, Republic of China
| | - Hsin-An Chang
- Department of Psychiatry, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
- Student Counseling Center, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Yu-Chen Kao
- Department of Psychiatry, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
- Department of Psychiatry, Tri-Service General Hospital, Song-Shan Branch, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Hui-Wen Yeh
- Department of Psychiatry, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Wei-Shan Chiang
- Department of Psychiatry, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
- Department and Institute of Mathematics, Tamkang University, New Taipei City, Taiwan, Republic of China
| | - Yu-Ching Chou
- School of Public Health, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Chang-Huei Tsao
- Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, 7115R, No.325, Section 2, Cheng-Kung Road, Neihu District, Taipei City, 11490, Taiwan, Republic of China
| | - Yung-Fu Wu
- Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, 7115R, No.325, Section 2, Cheng-Kung Road, Neihu District, Taipei City, 11490, Taiwan, Republic of China
| | - Wu-Chien Chien
- School of Public Health, National Defense Medical Center, Taipei, Taiwan, Republic of China.
- Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, 7115R, No.325, Section 2, Cheng-Kung Road, Neihu District, Taipei City, 11490, Taiwan, Republic of China.
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Ye Q, Bai F, Zhang Z. Shared Genetic Risk Factors for Late-Life Depression and Alzheimer's Disease. J Alzheimers Dis 2017; 52:1-15. [PMID: 27060956 DOI: 10.3233/jad-151129] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Considerable evidence has been reported for the comorbidity between late-life depression (LLD) and Alzheimer's disease (AD), both of which are very common in the general elderly population and represent a large burden on the health of the elderly. The pathophysiological mechanisms underlying the link between LLD and AD are poorly understood. Because both LLD and AD can be heritable and are influenced by multiple risk genes, shared genetic risk factors between LLD and AD may exist. OBJECTIVE The objective is to review the existing evidence for genetic risk factors that are common to LLD and AD and to outline the biological substrates proposed to mediate this association. METHODS A literature review was performed. RESULTS Genetic polymorphisms of brain-derived neurotrophic factor, apolipoprotein E, interleukin 1-beta, and methylenetetrahydrofolate reductase have been demonstrated to confer increased risk to both LLD and AD by studies examining either LLD or AD patients. These results contribute to the understanding of pathophysiological mechanisms that are common to both of these disorders, including deficits in nerve growth factors, inflammatory changes, and dysregulation mechanisms involving lipoprotein and folate. Other conflicting results have also been reviewed, and few studies have investigated the effects of the described polymorphisms on both LLD and AD. CONCLUSION The findings suggest that common genetic pathways may underlie LLD and AD comorbidity. Studies to evaluate the genetic relationship between LLD and AD may provide insights into the molecular mechanisms that trigger disease progression as the population ages.
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Apolipoprotein ε4 is associated with lower brain volume in cognitively normal Chinese but not white older adults. PLoS One 2015; 10:e0118338. [PMID: 25738563 PMCID: PMC4349764 DOI: 10.1371/journal.pone.0118338] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 01/14/2015] [Indexed: 12/12/2022] Open
Abstract
Studying ethnically diverse groups is important for furthering our understanding of biological mechanisms of disease that may vary across human populations. The ε4 allele of apolipoprotein E (APOE ε4) is a well-established risk factor for Alzheimer's disease (AD), and may confer anatomic and functional effects years before clinical signs of cognitive decline are observed. The allele frequency of APOE ε4 varies both across and within populations, and the size of the effect it confers for dementia risk may be affected by other factors. Our objective was to investigate the role APOE ε4 plays in moderating brain volume in cognitively normal Chinese older adults, compared to older white Americans. We hypothesized that carrying APOE ε4 would be associated with reduced brain volume and that the magnitude of this effect would be different between ethnic groups. We performed whole brain analysis of structural MRIs from Chinese living in America (n = 41) and Shanghai (n = 30) and compared them to white Americans (n = 71). We found a significant interaction effect of carrying APOE ε4 and being Chinese. The APOE ε4xChinese interaction was associated with lower volume in bilateral cuneus and left middle frontal gyrus (Puncorrected<0.001), with suggestive findings in right entorhinal cortex and left hippocampus (Puncorrected<0.01), all regions that are associated with neurodegeneration in AD. After correction for multiple testing, the left cuneus remained significantly associated with the interaction effect (PFWE = 0.05). Our study suggests there is a differential effect of APOE ε4 on brain volume in Chinese versus white cognitively normal elderly adults. This represents a novel finding that, if verified in larger studies, has implications for how biological, environmental and/or lifestyle factors may modify APOE ε4 effects on the brain in diverse populations.
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Apolipoprotein E, amyloid-beta, and neuroinflammation in Alzheimer's disease. Neurosci Bull 2014; 30:317-30. [PMID: 24652457 DOI: 10.1007/s12264-013-1422-z] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 01/23/2014] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by the accumulation and deposition of amyloid-beta (Aβ) peptides in the brain. Neuroinflammation occurs in the AD brain and plays a critical role in the neurodegenerative pathology. Particularly, Aβ evokes an inflammatory response that leads to synaptic dysfunction, neuronal death, and neurodegeneration. Apolipoprotein E (ApoE) proteins are involved in cholesterol transport, Aβ binding and clearance, and synaptic functions in the brain. The ApoE4 isoform is a key risk factor for AD, while the ApoE2 isoform has a neuroprotective effect. However, studies have reached different conclusions about the roles of the isoforms; some show that both ApoE3 and ApoE4 have anti-inflammatory effects, while others show that ApoE4 causes a predisposition to inflammation or promotes an inflammatory response following lipopolysaccharide treatment. These discrepancies may result from the differences in models, cell types, experimental conditions, and inflammatory stimuli used. Further, little was known about the role of ApoE isoforms in the Aβ-induced inflammatory response and in the neuroinflammation of AD. Our recent work showed that ApoE isoforms differentially regulate and modify the Aβ-induced inflammatory response in neural cells, with ApoE2 suppressing and ApoE4 promoting the response. In this article, we review the roles, mechanisms, and interrelations among Aβ, ApoE, and neuroinflammation in AD.
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Association between APOC1 polymorphism and Alzheimer's disease: a case-control study and meta-analysis. PLoS One 2014; 9:e87017. [PMID: 24498013 PMCID: PMC3909044 DOI: 10.1371/journal.pone.0087017] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 12/03/2013] [Indexed: 01/25/2023] Open
Abstract
Background Previous association studies examining the relationship between the APOC1 polymorphism and susceptibility to Alzheimer’s disease (AD) have shown conflicting results, and it is not clear if an APOC1 variant acts as a genetic risk factor in AD etiology across multiple populations. Methods To confirm the risk association between APOC1 and AD, we designed a case-control study and also performed a meta-analysis of previously published studies. Results Seventy-nine patients with AD and one hundred fifty-six unrelated controls were included in case-control study. No association was found between the variation of APOC1 and AD in stage 1 of our study. However, our meta-analysis pooled a total of 2092 AD patients and 2685 controls. The APOC1 rs11568822 polymorphism was associated with increased AD risk in Caucasians, Asians and Caribbean Hispanics, but not in African Americans. APOE ε4 carriers harboring the APOC1 insertion allele, were more prevalent in AD patients than controls (χ2 = 119.46, OR = 2.79, 95% CI = 2.31–3.36, P<0.01). Conclusions The APOC1 insertion allele, in combination with APOE ε4, likely serves as a potential risk factor for developing AD.
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Use of a modified spatial-context memory test to detect amnestic mild cognitive impairment. PLoS One 2013; 8:e57030. [PMID: 23468906 PMCID: PMC3585255 DOI: 10.1371/journal.pone.0057030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 01/18/2013] [Indexed: 11/19/2022] Open
Abstract
In this study we sought to differentiate participants with amnestic mild cognitive impairment (a-MCI) from those with mild dementia of Alzheimer’s type (m-DAT) and normal controls by modifying an existing test of spatial context memory (SCMT) designed so as to evaluate the function of brain regions affected in early m-DAT. We found that participants with a-MCI had better total scores on our modified SCMT than those with m-DAT. Furthermore, the locational memory subtest was able to discriminate between those with a-MCI and m-DAT. Additionally, compared with other screening tests, our spatial context memory test showed high sensitivity and specificity in discerning those with a-MCI from the normal population but, was relatively ineffective in discriminating a-MCI patients from those with m-DAT. We conclude that our modified test of SCMT is an effective tool for discriminating a-MCI from m-DAT and does so by detecting differences in locational memory.
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Lucatelli JF, Barros AC, Silva VKD, Machado FDS, Constantin PC, Dias AAC, Hutz MH, de Andrade FM. Genetic influences on Alzheimer's disease: evidence of interactions between the genes APOE, APOC1 and ACE in a sample population from the South of Brazil. Neurochem Res 2011; 36:1533-9. [PMID: 21533863 DOI: 10.1007/s11064-011-0481-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/18/2011] [Indexed: 10/18/2022]
Abstract
Alzheimer's disease is a complex neurodegenerative disorder. Several genes have been suggested as Alzheimer's susceptibility factors, the apolipoprotein E (APOE) gene being an established susceptibility gene and the genes coding angiotensin-converting enzyme (ACE) and apolipoprotein C1 (APOC1) being considered possible candidate genes for the disease. The objective of this study was to investigate the association of ACE and APOC1 gene polymorphisms with susceptibility to Alzheimer's disease and dementia in general, both alone and combined with the APOE gene. Forty-seven patients with dementia in general (35 of them with Alzheimer's disease) and 85 controls were investigated. The haplotypes E*3/-317*ins and E*4/-317*ins of APOE/APOC1 genes were significantly more frequent in the groups with Alzheimer's disease and dementia in general (P < 0.001). The frequency of the ACE*ins allele was also greater in the groups with Alzheimer's disease and dementia in general (P = 0.022; P = 0.045), but genotype frequencies were only different in groups without the E*4/-317*ins haplotype (P = 0.012 for Alzheimer's disease; P = 0.04 for dementia). Our data point to important genetic interactions involved in these diseases.
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Affiliation(s)
- Juliana Fagion Lucatelli
- Health Science Institute, Pró-Reitoria de Pesquisa e Inovação, PROPI Sala 201 F, Universidade Feevale, RS 239, No. 2755, B. Vila Nova, Novo Hamburgo, RS, 93352-000, Brazil
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