Common genetic and environmental contributions to post-traumatic stress disorder and alcohol dependence in young women.

PubMed

Sartor, C E; McCutcheon, V V; Pommer, N E; Nelson, E C; Grant, J D; Duncan, A E; Waldron, M; Bucholz, K K; Madden, P A F; Heath, A C

2011-07-01

The few genetically informative studies to examine post-traumatic stress disorder (PTSD) and alcohol dependence (AD), all of which are based on a male veteran sample, suggest that the co-morbidity between PTSD and AD may be attributable in part to overlapping genetic influences, but this issue has yet to be addressed in females.MethodData were derived from an all-female twin sample (n=3768) ranging in age from 18 to 29 years. A trivariate genetic model that included trauma exposure as a separate phenotype was fitted to estimate genetic and environmental contributions to PTSD and the degree to which they overlap with those that contribute to AD, after accounting for potential confounding effects of heritable influences on trauma exposure. Additive genetic influences (A) accounted for 72% of the variance in PTSD; individual-specific environmental (E) factors accounted for the remainder. An AE model also provided the best fit for AD, for which heritability was estimated to be 71%. The genetic correlation between PTSD and AD was 0.54. The heritability estimate for PTSD in our sample is higher than estimates reported in earlier studies based almost exclusively on an all-male sample in which combat exposure was the precipitating traumatic event. However, our findings are consistent with the absence of evidence for shared environmental influences on PTSD and, most importantly, the substantial overlap in genetic influences on PTSD and AD reported in these investigations. Additional research addressing potential distinctions by gender in the relative contributions of genetic and environmental influences on PTSD is merited.

Linking brain imaging and genomics in the study of Alzheimer's disease and aging.

PubMed

Reiman, Eric M

2007-02-01

My colleagues and I have been using positron emission tomography (PET) and magnetic resonance imaging (MRI) to detect and track the brain changes associated with Alzheimer's disease (AD) and normal brain aging in cognitively normal persons with two copies, one copy, and no copies of the apolipoprotein E (APOE) epsilon4 allele, a common AD susceptibility gene. In this review article, I consider how brain imaging techniques could be used to evaluate putative AD prevention therapies in cognitively normal APOE epsilon4 carriers and putative age-modifying therapies in cognitively normal APOE epsilon4 noncarriers, how they could help investigate the individual and aggregate effects of putative AD risk modifiers, and how they could help guide the investigation of a molecular mechanism associated with AD vulnerability and normal neurological aging. I suggest how high-resolution genome-wide genetic and transcriptomic studies could further help in the scientific understanding of AD, aging, and other common and genetically complex phenotypes, such as variation in normal human memory performance, and in the discovery and evaluation of promising treatments for these phenotypes. Finally, I illustrate the push-pull relationship between brain imaging, genomics research, and other neuroscientific research in the study of AD and aging.

Dissecting Alzheimer disease in Down syndrome using mouse models

PubMed Central

Choong, Xun Yu; Tosh, Justin L.; Pulford, Laura J.; Fisher, Elizabeth M. C.

2015-01-01

Down syndrome (DS) is a common genetic condition caused by the presence of three copies of chromosome 21 (trisomy 21). This greatly increases the risk of Alzheimer disease (AD), but although virtually all people with DS have AD neuropathology by 40 years of age, not all develop dementia. To dissect the genetic contribution of trisomy 21 to DS phenotypes including those relevant to AD, a range of DS mouse models has been generated which are trisomic for chromosome segments syntenic to human chromosome 21. Here, we consider key characteristics of human AD in DS (AD-DS), and our current state of knowledge on related phenotypes in AD and DS mouse models. We go on to review important features needed in future models of AD-DS, to understand this type of dementia and so highlight pathogenic mechanisms relevant to all populations at risk of AD. PMID:26528151

Dissecting Alzheimer disease in Down syndrome using mouse models.

PubMed

Choong, Xun Yu; Tosh, Justin L; Pulford, Laura J; Fisher, Elizabeth M C

2015-01-01

Down syndrome (DS) is a common genetic condition caused by the presence of three copies of chromosome 21 (trisomy 21). This greatly increases the risk of Alzheimer disease (AD), but although virtually all people with DS have AD neuropathology by 40 years of age, not all develop dementia. To dissect the genetic contribution of trisomy 21 to DS phenotypes including those relevant to AD, a range of DS mouse models has been generated which are trisomic for chromosome segments syntenic to human chromosome 21. Here, we consider key characteristics of human AD in DS (AD-DS), and our current state of knowledge on related phenotypes in AD and DS mouse models. We go on to review important features needed in future models of AD-DS, to understand this type of dementia and so highlight pathogenic mechanisms relevant to all populations at risk of AD.

Genetic variation affecting exon skipping contributes to brain structural atrophy in Alzheimer's disease.

PubMed

Lee, Younghee; Han, Seonggyun; Kim, Dongwook; Kim, Dokyoon; Horgousluoglu, Emrin; Risacher, Shannon L; Saykin, Andrew J; Nho, Kwangsik

2018-01-01

Genetic variation in cis-regulatory elements related to splicing machinery and splicing regulatory elements (SREs) results in exon skipping and undesired protein products. We developed a splicing decision model to identify actionable loci among common SNPs for gene regulation. The splicing decision model identified SNPs affecting exon skipping by analyzing sequence-driven alternative splicing (AS) models and by scanning the genome for the regions with putative SRE motifs. We used non-Hispanic Caucasians with neuroimaging, and fluid biomarkers for Alzheimer's disease (AD) and identified 17,088 common exonic SNPs affecting exon skipping. GWAS identified one SNP (rs1140317) in HLA-DQB1 as significantly associated with entorhinal cortical thickness, AD neuroimaging biomarker, after controlling for multiple testing. Further analysis revealed that rs1140317 was significantly associated with brain amyloid-f deposition (PET and CSF). HLA-DQB1 is an essential immune gene and may regulate AS, thereby contributing to AD pathology. SRE may hold potential as novel therapeutic targets for AD.

Genetically engineering adenoviral vectors for gene therapy.

PubMed

Coughlan, Lynda

2014-01-01

Adenoviral (Ad) vectors are commonly used for various gene therapy applications. Significant advances in the genetic engineering of Ad vectors in recent years has highlighted their potential for the treatment of metastatic disease. There are several methods to genetically modify the Ad genome to incorporate retargeting peptides which will redirect the natural tropism of the viruses, including homologous recombination in bacteria or yeast. However, homologous recombination in yeast is highly efficient and can be achieved without the need for extensive cloning strategies. In addition, the method does not rely on the presence of unique restriction sites within the Ad genome and the reagents required for this method are widely available and inexpensive. Large plasmids containing the entire adenoviral genome (~36 kbp) can be modified within Saccharomyces cerevisiae yeast and genomes easily rescued in Escherichia coli hosts for analysis or amplification. A method for two-step homologous recombination in yeast is described in this chapter.

Joint association discovery and diagnosis of Alzheimer's disease by supervised heterogeneous multiview learning.

PubMed

Zhe, Shandian; Xu, Zenglin; Qi, Yuan; Yu, Peng

2014-01-01

A key step for Alzheimer's disease (AD) study is to identify associations between genetic variations and intermediate phenotypes (e.g., brain structures). At the same time, it is crucial to develop a noninvasive means for AD diagnosis. Although these two tasks-association discovery and disease diagnosis-have been treated separately by a variety of approaches, they are tightly coupled due to their common biological basis. We hypothesize that the two tasks can potentially benefit each other by a joint analysis, because (i) the association study discovers correlated biomarkers from different data sources, which may help improve diagnosis accuracy, and (ii) the disease status may help identify disease-sensitive associations between genetic variations and MRI features. Based on this hypothesis, we present a new sparse Bayesian approach for joint association study and disease diagnosis. In this approach, common latent features are extracted from different data sources based on sparse projection matrices and used to predict multiple disease severity levels based on Gaussian process ordinal regression; in return, the disease status is used to guide the discovery of relationships between the data sources. The sparse projection matrices not only reveal the associations but also select groups of biomarkers related to AD. To learn the model from data, we develop an efficient variational expectation maximization algorithm. Simulation results demonstrate that our approach achieves higher accuracy in both predicting ordinal labels and discovering associations between data sources than alternative methods. We apply our approach to an imaging genetics dataset of AD. Our joint analysis approach not only identifies meaningful and interesting associations between genetic variations, brain structures, and AD status, but also achieves significantly higher accuracy for predicting ordinal AD stages than the competing methods.

Molecular genetics of Alzheimer disease.

PubMed

St George-Hyslop, P H

1999-01-01

Epidemiological and individual case studies indicate that genetic factors play a significant role in the genesis of Alzheimer Disease (AD). To date, molecular genetic studies in families multiply affected with AD have identified three genes (Presenilin 1-PS1, Presenilin 2-PS2, and beta-amyloid precursor protein--betaAPP) associated with highly penetrant early onset AD, and one gene (Apolipoprotein E) associated with late onset AD. A fifth potential AD susceptibility locus has been mapped to a broad region of chromosome 12, but the responsible gene defect has not yet been identified. Case-control studies comparing the frequency of alleles in numerous other candidate genes have identified a number of additional potential AD genes. However, methodological difficulties and conflicting results in follow-up studies, make it unclear whether allelic variations in these genes are truly pathogenic. Nevertheless, analysis of the biochemical effects of mutations in PS1, PS2, betaAPP at least, suggest a common biochemical effect-namely disturbances in the processing of betaAPP protein. In addition to utility in defining potential therapeutic targets, in some circumstances these genes can also potentially be used as adjunctives in clinical presymptomatic, symptomatic or pharmacogenomic diagnosis.

The genetics of Alzheimer disease: back to the future.

PubMed

Bertram, Lars; Lill, Christina M; Tanzi, Rudolph E

2010-10-21

Three decades of genetic research in Alzheimer disease (AD) have substantially broadened our understanding of the pathogenetic mechanisms leading to neurodegeneration and dementia. Positional cloning led to the identification of rare, disease-causing mutations in APP, PSEN1, and PSEN2 causing early-onset familial AD, followed by the discovery of APOE as the single most important risk factor for late-onset AD. Recent genome-wide association approaches have delivered several additional AD susceptibility loci that are common in the general population, but exert only very small risk effects. As a result, a large proportion of the heritability of AD continues to remain unexplained by the currently known disease genes. It seems likely that much of this "missing heritability" may be accounted for by rare sequence variants, which, owing to recent advances in high-throughput sequencing technologies, can now be assessed in unprecedented detail. Copyright © 2010 Elsevier Inc. All rights reserved.

Behavioral comparisons in autistic individuals from multiplex and singleton families.

PubMed

Cuccaro, Michael L; Shao, Yujun; Bass, Meredyth P; Abramson, Ruth K; Ravan, Sarah A; Wright, Harry H; Wolpert, Chantelle M; Donnelly, Shannon L; Pericak-Vance, Margaret A

2003-02-01

Autistic disorder (AD) is a complex neurodevelopmental disorder. The role of genetics in AD etiology is well established, and it is postulated that anywhere from 2 to 10 genes could be involved. As part of a larger study to identify these genetic effects we have ascertained a series of AD families: Sporadic (SP, 1 known AD case per family and no known history of AD) and multiplex (MP, > or = 2 cases per family). The underlying etiology of both family types is unknown. It is possible that MP families may constitute a unique subset of families in which the disease phenotype is more likely due to genetic factors. Clinical differences between the two family types could represent underlying genetic heterogeneity. We examined ADI-R data for 69 probands from MP families and 88 from SP families in order to compare and contrast the clinical phenotypes for each group as a function of verbal versus nonverbal status. Multivariate analysis controlling for covariates of age at examination, gender, and race (MANCOVA) revealed no differences between either the verbal or nonverbal MP and SP groups for the three ADI-R area scores: social interaction, communication, and restricted/repetitive interests or behaviors. These data failed to find clinical heterogeneity between MP and SP family types. This supports previous work that indicated that autism features are not useful as tools to index genetic heterogeneity. Thus, although there may be different underlying etiologic mechanisms in the SP and MP probands, there are no distinct behavioral patterns associated with probands from MP families versus SP families. These results suggests the possibility that common etiologic mechanisms, either genetic and/or environmental, could underlie all of AD.

Mitochondrial dysfunction: the missing link between aging and sporadic Alzheimer's disease.

PubMed

Grimm, Amandine; Friedland, Kristina; Eckert, Anne

2016-04-01

Alzheimer's disease (AD) is a progressive neurodegenerative disease that represents the most common form of dementia among the elderly. Despite the fact that AD was studied for decades, the underlying mechanisms that trigger this neuropathology remain unresolved. Since the onset of cognitive deficits occurs generally within the 6th decade of life, except in rare familial case, advancing age is the greatest known risk factor for AD. To unravel the pathogenesis of the disease, numerous studies use cellular and animal models based on genetic mutations found in rare early onset familial AD (FAD) cases that represent less than 1 % of AD patients. However, the underlying process that leads to FAD appears to be distinct from that which results in late-onset AD. As a genetic disorder, FAD clearly is a consequence of malfunctioning/mutated genes, while late-onset AD is more likely due to a gradual accumulation of age-related malfunction. Normal aging and AD are both marked by defects in brain metabolism and increased oxidative stress, albeit to varying degrees. Mitochondria are involved in these two phenomena by controlling cellular bioenergetics and redox homeostasis. In the present review, we compare the common features observed in both brain aging and AD, placing mitochondrial in the center of pathological events that separate normal and pathological aging. We emphasize a bioenergetic model for AD including the inverse Warburg hypothesis which postulates that AD is a consequence of mitochondrial deregulation leading to metabolic reprogramming as an initial attempt to maintain neuronal integrity. After the failure of this compensatory mechanism, bioenergetic deficits may lead to neuronal death and dementia. Thus, mitochondrial dysfunction may represent the missing link between aging and sporadic AD, and represent attractive targets against neurodegeneration.

From Common to Rare Variants: The Genetic Component of Alzheimer Disease.

PubMed

Nicolas, Gaël; Charbonnier, Camille; Campion, Dominique

2016-01-01

Alzheimer disease (AD) is a remarkable example of genetic heterogeneity. Extremely rare variants in the APP, PSEN1, or PSEN2 genes, or duplications of the APP gene cause autosomal dominant forms, generally with complete penetrance by the age of 65 years. Nonautosomal dominant forms are considered as a complex disorder with a high genetic component, whatever the age of onset. Although genetically heterogeneous, AD is defined by the same neuropathological criteria in all configurations. According to the amyloid cascade hypothesis, the Aβ peptide, which aggregates in AD brains, is a key player. APP, PSEN1, or PSEN2 gene mutations increase the production of more aggregation-prone forms of the Aβ peptide, triggering the pathological process. Several risk factors identified in association studies hit genes involved in Aβ production/secretion, aggregation, clearance, or toxicity. Among them, the APOE ε4 allele is a rare example of a common allele with a large effect size, the ORs ranging from 4 to 11-14 for heterozygous and homozygous carriers, respectively. In addition, genome-wide association studies have identified more than two dozen loci with a weak but significant association, the OR of the at-risk allele ranging from 1.08 to 1.30. Recently, the use of massive parallel sequencing has enabled the analysis of rare variants in a genome-wide manner. Two rare variants have been nominally associated with AD risk or protection (TREM2 p.R47H, MAF approximately 0.002, OR approximately 4 and APP p.A673T, MAF approximately 0.0005, OR approximately 0.2). Association analyses at the gene level identified rare loss-of-function and missense, predicted damaging, variants (MAF <0.01) in the SORL1 and ABCA7 genes associated with a moderate relative risk (OR approximately 5 and approximately 2.8, respectively). Although the latter analyses revealed association signals with moderately rare variants by collapsing them, the power to detect genes hit by extremely rare variants is still limited. An alternative approach is to consider the de novo paradigm, stating that de novo variants may contribute to AD genetics in sporadic patients. Here, we critically review AD genetics reports with a special focus on rare variants. © 2016 S. Karger AG, Basel.

Alzheimer's Disease in the Latino Community: Intersection of Genetics and Social Determinants of Health.

PubMed

Vega, Irving E; Cabrera, Laura Y; Wygant, Cassandra M; Velez-Ortiz, Daniel; Counts, Scott E

2017-01-01

Alzheimer's disease (AD) is the most common type of dementia among individuals 65 or older. There are more than 5 million diagnosed cases in the US alone and this number is expected to triple by 2050. Therefore, AD has reached epidemic proportions with significant socioeconomic implications. While aging in general is the greatest risk factor for AD, several additional demographic factors that have contributed to the rise in AD in the US are under study. One such factor is associated with the relatively fast growth of the Latino population. Several reports indicate that AD is more prevalent among blacks and Latinos. However, the reason for AD disparity among different ethnic groups is still poorly understood and highly controversial. The Latino population is composed of different groups based on nationality, namely South and Central America, Mexico, and Caribbean Hispanics. This diversity among the Latino population represents an additional challenge since there are distinct characteristics associated with AD and comorbidities. In this review, we aim to bring attention to the intersection between social determinants of health and genetic factors associated with AD within the Latino community. We argue that understanding the interplay between identified social determinants of health, co-morbidities, and genetic factors could lead to community empowerment and inclusiveness in research and healthcare services, contributing to improved diagnosis and treatment of AD patients. Lastly, we propose that inserting a neuroethics perspective could help understand key challenges that influence healthcare disparities and contribute to increased risk of AD among Latinos.

Utility of genetic and non-genetic risk factors in prediction of type 2 diabetes: Whitehall II prospective cohort study.

PubMed

Talmud, Philippa J; Hingorani, Aroon D; Cooper, Jackie A; Marmot, Michael G; Brunner, Eric J; Kumari, Meena; Kivimäki, Mika; Humphries, Steve E

2010-01-14

To assess the performance of a panel of common single nucleotide polymorphisms (genotypes) associated with type 2 diabetes in distinguishing incident cases of future type 2 diabetes (discrimination), and to examine the effect of adding genetic information to previously validated non-genetic (phenotype based) models developed to estimate the absolute risk of type 2 diabetes. Workplace based prospective cohort study with three 5 yearly medical screenings. 5535 initially healthy people (mean age 49 years; 33% women), of whom 302 developed new onset type 2 diabetes over 10 years. Non-genetic variables included in two established risk models-the Cambridge type 2 diabetes risk score (age, sex, drug treatment, family history of type 2 diabetes, body mass index, smoking status) and the Framingham offspring study type 2 diabetes risk score (age, sex, parental history of type 2 diabetes, body mass index, high density lipoprotein cholesterol, triglycerides, fasting glucose)-and 20 single nucleotide polymorphisms associated with susceptibility to type 2 diabetes. Cases of incident type 2 diabetes were defined on the basis of a standard oral glucose tolerance test, self report of a doctor's diagnosis, or the use of anti-diabetic drugs. A genetic score based on the number of risk alleles carried (range 0-40; area under receiver operating characteristics curve 0.54, 95% confidence interval 0.50 to 0.58) and a genetic risk function in which carriage of risk alleles was weighted according to the summary odds ratios of their effect from meta-analyses of genetic studies (area under receiver operating characteristics curve 0.55, 0.51 to 0.59) did not effectively discriminate cases of diabetes. The Cambridge risk score (area under curve 0.72, 0.69 to 0.76) and the Framingham offspring risk score (area under curve 0.78, 0.75 to 0.82) led to better discrimination of cases than did genotype based tests. Adding genetic information to phenotype based risk models did not improve discrimination and provided only a small improvement in model calibration and a modest net reclassification improvement of about 5% when added to the Cambridge risk score but not when added to the Framingham offspring risk score. The phenotype based risk models provided greater discrimination for type 2 diabetes than did models based on 20 common independently inherited diabetes risk alleles. The addition of genotypes to phenotype based risk models produced only minimal improvement in accuracy of risk estimation assessed by recalibration and, at best, a minor net reclassification improvement. The major translational application of the currently known common, small effect genetic variants influencing susceptibility to type 2 diabetes is likely to come from the insight they provide on causes of disease and potential therapeutic targets.

HLA similarities indicate shared genetic risk in 21-hydroxylase autoantibody positive South African and United States Addison's disease.

PubMed

Ross, I L; Babu, S; Armstrong, T; Zhang, L; Schatz, D; Pugliese, A; Eisenbarth, G; Baker Ii, P

2014-10-01

Genetic similarities between patients from the United States and South African (SA) Addison's Disease (AD) strengthen evidence for genetic association. SA-AD (n = 73), SA healthy controls (N = 78), and US-AD patients (N = 83) were genotyped for DQA1, DQB1, DRB1, and HLA-B alleles. Serum was tested for the quantity of 21OH-AA and IFNα-AA at the Barbara Davis Center. Although not as profound as in US-AD, in SA-AD 21OH-AA + subjects the predominantly associated risk haplotypes were DRB1*0301-DQB1*0201 (DR3), DRB1*04xx-DQB1*0302 (DR4), and the combined DR3/4 genotype. DQB1*0302 associated DRB1*04xx haplotypes conferred higher risk than those DRB1*04xx haplotypes associated with other DQB1 alleles. We found negative association in 21OH-AA + SA-AD for DQA1*0201-DQB1*0202 and DQA1*0101-DQB1*0501 vs SA controls, and positive association for DQA1*0401-DQB1*0402 vs US-AD. Apart from the class II DR3 haplotype, HLA-B8 did not have an independent effect; however together DR3 and HLA-B8 conferred the highest risk vs 21OH-AA negative SA-AD and SA-controls. HLA-B7 (often with DR4) conferred novel risk in 21OH-AA + SA-AD vs controls. This study represents the first comparison between South African and United States AD populations utilizing genotyping and serology performed at the same center. SA-AD and US-AD 21OH-AA + patients share common HLA risk haplotypes including DR4 (with HLA-B7) and DR3 (with HLA-B8), strengthening previously described HLA associations and implicating similar genetic etiology. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

No genetic effect of {alpha}{sub 1}-antichymotrypsin in Alzheimer disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haines, J.L.; Pritchard, M.L.; Saunders, A.M.

1996-04-01

Alzheimer disease (AD) is the most common neurodegenerative disorder for individuals over the age of 40.AD has a complex etiology, and it is likely that multiple genes, acting independently and/or interacting, affect the risk of developing AD. Several genes involved with AD have been described already, but only the APOE gene on chromosome 19q has been shown to affect the risk of the common late onset form of AD. {alpha}{sub 1}-Antichymotrypsin (AACT) is a major component of the amyloid plaques found in the brains of AD patients, and an allele in its gene has been proposed to increase the riskmore » of developing AD when also associated with the APOE-4 allele. We have examined the role of this AACT polymorphism in a large set of families and sporadic cases, and do not see any effect, either alone or in combination with the APOE-4 allele. 18 refs., 3 tabs.« less

Mutations, associated with early-onset Alzheimer’s disease, discovered in Asian countries

PubMed Central

Bagyinszky, Eva; Youn, Young Chul; An, Seong Soo A; Kim, SangYun

2016-01-01

Alzheimer’s disease (AD), the most common form of senile dementia, is a genetically complex disorder. In most Asian countries, the population and the number of AD patients are growing rapidly, and the genetics of AD has been extensively studied, except in Japan. However, recent studies have been started to investigate the genes and mutations associated with AD in Korea, the People’s Republic of China, and Malaysia. This review describes all of the known mutations in three early-onset AD (EOAD) causative genes (APP, PSEN1, and PSEN2) that were discovered in Asian countries. Most of the EOAD-associated mutations have been detected in PSEN1, and several novel PSEN1 mutations were recently identified in patients from various parts of the world, including Asia. Until 2014, no PSEN2 mutations were found in Asian patients; however, emerging studies from Korea and the People’s Republic of China discovered probably pathogenic PSEN2 mutations. Since several novel mutations were discovered in these three genes, we also discuss the predictions on their pathogenic nature. This review briefly summarizes genome-wide association studies of late-onset AD and the genes that might be associated with AD in Asian countries. Standard sequencing is a widely used method, but it has limitations in terms of time, cost, and efficacy. Next-generation sequencing strategies could facilitate genetic analysis and association studies. Genetic testing is important for the accurate diagnosis and for understanding disease-associated pathways and might also improve disease therapy and prevention. PMID:27799753

Alzheimer's Disease and Autistic Spectrum Disorder: Is there any Association?

PubMed

Khan, Sarah A; Khan, Shahida A; Narendra, A R; Mushtaq, Gohar; Zahran, Solafa A; Khan, Shahzad; Kamal, Mohammad A

2016-01-01

Autism spectrum disorder (ASD) and Alzheimer's disease (AD) are neurodevelopmental and neurodegenerative disorders respectively, with devastating effects not only on the individual but also the society. Collectively, a number of factors contribute to the expression of ASD and AD. It is of utmost curiosity that these disorders express at different stages of life and there is an involvement of certain susceptible genes. This genetic basis makes the background of common associations like memory deficits, cognition changes, demyelination, oxidative stress and inflammation, an integral part of both disorders. Modern technology resulting in genetically modified crops and increase in gadgets emitting electromagnetic frequencies have resulted in enhanced risks for neurological dysfunctions and disorders like ASD and AD. Subsequent advances in the psychological, pharmacological, biochemical and nutritional aspects of the disorders have resulted in the development of newer therapeutic approaches. The common clinical features like language impairment, executive functions, and motor problems have been discussed along with the patho-physiological changes, role of DNA methylation, myelin development, and heavy metals in the expression of these disorders. Psychopharmacological and nutritional approaches towards the reduction and management of risk factors have gained attention from the researchers in recent years. Current major therapies either target the inflammatory pathways or reduce cellular oxidative stress. This contribution focuses on the commonalities of the two disorders.

Diagnosis of Atopic Dermatitis: Mimics, Overlaps, and Complications

PubMed Central

Siegfried, Elaine C.; Hebert, Adelaide A.

2015-01-01

Atopic dermatitis (AD) is one of the most common skin diseases affecting infants and children. A smaller subset of adults has persistent or new-onset AD. AD is characterized by pruritus, erythema, induration, and scale, but these features are also typical of several other conditions that can mimic, coexist with, or complicate AD. These include inflammatory skin conditions, infections, infestations, malignancies, genetic disorders, immunodeficiency disorders, nutritional disorders, graft-versus-host disease, and drug eruptions. Familiarity of the spectrum of these diseases and their distinguishing features is critical for correct and timely diagnosis and optimal treatment. PMID:26239454

Let Food Be Thy Medicine: Diet, Nutrition, and Biomarkers’ Risk of Alzheimer’s Disease

PubMed Central

Mosconi, Lisa; McHugh, Pauline F.

2015-01-01

Epidemiological evidence linking diet—one of the most important modifiable lifestyle factors—and risk of Alzheimer’s disease (AD)—the most common cause of dementia—is rapidly increasing. However, the biological mechanisms underlying the relationship between dietary nutrients, brain aging, and risk of AD are largely unexplored. Recent studies using brain imaging and biological markers of AD have begun to clarify how diet and nutrition modulate risk of AD in cognitively normal individuals, especially those at increased genetic risk. Such knowledge is critical prior to implementing dietary recommendations for prevention and treatment of disease. PMID:26167396

Genome-wide association meta-analysis of neuropathologic features of Alzheimer's disease and related dementias.

PubMed

Beecham, Gary W; Hamilton, Kara; Naj, Adam C; Martin, Eden R; Huentelman, Matt; Myers, Amanda J; Corneveaux, Jason J; Hardy, John; Vonsattel, Jean-Paul; Younkin, Steven G; Bennett, David A; De Jager, Philip L; Larson, Eric B; Crane, Paul K; Kamboh, M Ilyas; Kofler, Julia K; Mash, Deborah C; Duque, Linda; Gilbert, John R; Gwirtsman, Harry; Buxbaum, Joseph D; Kramer, Patricia; Dickson, Dennis W; Farrer, Lindsay A; Frosch, Matthew P; Ghetti, Bernardino; Haines, Jonathan L; Hyman, Bradley T; Kukull, Walter A; Mayeux, Richard P; Pericak-Vance, Margaret A; Schneider, Julie A; Trojanowski, John Q; Reiman, Eric M; Schellenberg, Gerard D; Montine, Thomas J

2014-09-01

Alzheimer's disease (AD) and related dementias are a major public health challenge and present a therapeutic imperative for which we need additional insight into molecular pathogenesis. We performed a genome-wide association study and analysis of known genetic risk loci for AD dementia using neuropathologic data from 4,914 brain autopsies. Neuropathologic data were used to define clinico-pathologic AD dementia or controls, assess core neuropathologic features of AD (neuritic plaques, NPs; neurofibrillary tangles, NFTs), and evaluate commonly co-morbid neuropathologic changes: cerebral amyloid angiopathy (CAA), Lewy body disease (LBD), hippocampal sclerosis of the elderly (HS), and vascular brain injury (VBI). Genome-wide significance was observed for clinico-pathologic AD dementia, NPs, NFTs, CAA, and LBD with a number of variants in and around the apolipoprotein E gene (APOE). GalNAc transferase 7 (GALNT7), ATP-Binding Cassette, Sub-Family G (WHITE), Member 1 (ABCG1), and an intergenic region on chromosome 9 were associated with NP score; and Potassium Large Conductance Calcium-Activated Channel, Subfamily M, Beta Member 2 (KCNMB2) was strongly associated with HS. Twelve of the 21 non-APOE genetic risk loci for clinically-defined AD dementia were confirmed in our clinico-pathologic sample: CR1, BIN1, CLU, MS4A6A, PICALM, ABCA7, CD33, PTK2B, SORL1, MEF2C, ZCWPW1, and CASS4 with 9 of these 12 loci showing larger odds ratio in the clinico-pathologic sample. Correlation of effect sizes for risk of AD dementia with effect size for NFTs or NPs showed positive correlation, while those for risk of VBI showed a moderate negative correlation. The other co-morbid neuropathologic features showed only nominal association with the known AD loci. Our results discovered new genetic associations with specific neuropathologic features and aligned known genetic risk for AD dementia with specific neuropathologic changes in the largest brain autopsy study of AD and related dementias.

Forensic STR loci reveal common genetic ancestry of the Thai-Malay Muslims and Thai Buddhists in the deep Southern region of Thailand.

PubMed

Kutanan, Wibhu; Kitpipit, Thitika; Phetpeng, Sukanya; Thanakiatkrai, Phuvadol

2014-12-01

Among the people living in the five deep Southern Thai provinces, Thai-Malay Muslims (MUS) constitute the majority, while the remaining are Thai Buddhists (BUD). Cultural, linguistic and religious differences between these two populations have been previously reported. However, their biological relationship has never been investigated. In this study, we aimed to reveal the genetic structure and genetic affinity between MUS and BUD by analyzing 15 autosomal short tandem repeats. Both distance and model-based clustering methods showed significant genetic homogeneity between these two populations, suggesting a common biological ancestry. After Islamization in this region during the fourteenth century AD, gradual albeit nonstatistically significant genetic changes occurred within these two populations. Cultural barriers possibly influenced these genetic changes. MUS have closer admixture to Malaysian-Malay Muslims than BUD countrywide. Admixture proportions also support certain degree of genetic dissimilarity between the two studied populations, as shown by the unequal genetic contribution from Malaysian-Malay Muslims. Cultural transformation and recent minor genetic admixture are the likely processes that shaped the genetic structure of both MUS and BUD.

A Partial E3 Deletion in Replication-Defective Adenoviral Vectors Allows for Stable Expression of Potentially Toxic Transgene Products.

PubMed

Haut, Larissa H; Gill, Amanda L; Kurupati, Raj K; Bian, Ang; Li, Yan; Giles-Davis, Wynetta; Xiang, Zhiquan; Zhou, Xiang Yang; Ertl, Hildegund C J

2016-10-01

Adenovirus (Ad) is used extensively for construction of viral vectors, most commonly with deletion in its E1 and/or E3 genomic regions. Previously, our attempts to insert envelope proteins (Env) of HIV-1 into such vectors based on chimpanzee-derived Ad (AdC) viruses were thwarted. Here, we describe that genetic instability of an E1- and E3-deleted AdC vector of serotype C6 expressing Env of HIV-1 can be overcome by reinsertion of E3 sequences with anti-apoptotic activities. This partial E3 deletion presumably delays premature death of HEK-293 packaging cell lines due to Env-induced cell apoptosis. The same partial E3 deletion also allows for the generation of stable glycoprotein 140 (gp140)- and gp160-expressing Ad vectors based on AdC7, a distinct AdC serotype. Env-expressing AdC vectors containing the partial E3 deletion are genetically stable upon serial cell culture passaging, produce yields comparable to those of other AdC vectors, and induce transgene product-specific antibody responses in mice. A partial E3 deletion thereby allows expansion of the repertoire of transgenes that can be expressed by Ad vectors.

Association between oxytocin and receptor genetic polymorphisms and aggression in a northern Chinese Han population with alcohol dependence.

PubMed

Yang, Ling; Wang, Fan; Wang, Meiling; Han, Mei; Hu, Lufeng; Zheng, Minghua; Ma, Ji; Kang, Yimin; Wang, Pengxiang; Sun, Hongqiang; Zuo, Wei; Xie, Longteng; Wang, Aiju; Yu, Dongsheng; Liu, Yanlong

2017-01-01

Alcohol dependence (AD) is a common chronic brain disorder precipitated by complex interactions between biological, genetic, and environmental risk factors. Aggression often occurs in the context of AD. Previous studies have shown that Oxytocin (OXT) and OXT receptor (OXTR) are involved in the regulation of aggression. The present study investigated whether variations and interactions of OXT and OXTR genes were associated with AD-related aggression in a genetically homogeneous northern Chinese Han population. Three hundred and twenty-four male AD patients and 510 male healthy controls (HCs) were recruited. A Chinese version of the Buss-Perry Aggression Questionnaire was used as a subjective measurement of aggressive behavior. Three variations, rs2254298, rs53576, and rs6133010 were genotyped using TaqMan and ligase detection reaction for all subjects. Generalized Multifactor Dimensionality Reduction was used to detect interactions between genetic attributes and environmental attributes. The frequencies of alleles and genotypes of rs6133010 were significantly different between AD patients and HCs (p<0.001). In HCs, the effect of genotype GG of rs53576 on hostility aggression was significantly stronger than that of genotype AA and AG (p=0.001 and p=0.004, respectively), and the subjects with the interaction combination of rs6133010AA×rs2254298GG×rs53576AG exhibited significant effect on physical aggression (p=0.0107). The present study found that rs6133010 in the OXT gene is associated with AD in the northern Chinese Han population. The polymorphisms of OXT/R may play a key role in the susceptibility of AD-related aggression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Mathematical modeling of atopic dermatitis reveals "double-switch" mechanisms underlying 4 common disease phenotypes.

PubMed

Domínguez-Hüttinger, Elisa; Christodoulides, Panayiotis; Miyauchi, Kosuke; Irvine, Alan D; Okada-Hatakeyama, Mariko; Kubo, Masato; Tanaka, Reiko J

2017-06-01

The skin barrier acts as the first line of defense against constant exposure to biological, microbial, physical, and chemical environmental stressors. Dynamic interplay between defects in the skin barrier, dysfunctional immune responses, and environmental stressors are major factors in the development of atopic dermatitis (AD). A systems biology modeling approach can yield significant insights into these complex and dynamic processes through integration of prior biological data. We sought to develop a multiscale mathematical model of AD pathogenesis that describes the dynamic interplay between the skin barrier, environmental stress, and immune dysregulation and use it to achieve a coherent mechanistic understanding of the onset, progression, and prevention of AD. We mathematically investigated synergistic effects of known genetic and environmental risk factors on the dynamic onset and progression of the AD phenotype, from a mostly asymptomatic mild phenotype to a severe treatment-resistant form. Our model analysis identified a "double switch," with 2 concatenated bistable switches, as a key network motif that dictates AD pathogenesis: the first switch is responsible for the reversible onset of inflammation, and the second switch is triggered by long-lasting or frequent activation of the first switch, causing irreversible onset of systemic T H 2 sensitization and worsening of AD symptoms. Our mathematical analysis of the bistable switch predicts that genetic risk factors decrease the threshold of environmental stressors to trigger systemic T H 2 sensitization. This analysis predicts and explains 4 common clinical AD phenotypes from a mild and reversible phenotype through to severe and recalcitrant disease and provides a mechanistic explanation for clinically demonstrated preventive effects of emollient treatments against development of AD. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

A founder mutation in presenilin 1 causing early-onset Alzheimer disease in unrelated Caribbean Hispanic families.

PubMed

Athan, E S; Williamson, J; Ciappa, A; Santana, V; Romas, S N; Lee, J H; Rondon, H; Lantigua, R A; Medrano, M; Torres, M; Arawaka, S; Rogaeva, E; Song, Y Q; Sato, C; Kawarai, T; Fafel, K C; Boss, M A; Seltzer, W K; Stern, Y; St George-Hyslop, P; Tycko, B; Mayeux, R

2001-11-14

Genetic determinants of Alzheimer disease (AD) have not been comprehensively examined in Caribbean Hispanics, a population in the United States in whom the frequency of AD is higher compared with non-Hispanic whites. To identify variant alleles in genes related to familial early-onset AD among Caribbean Hispanics. Family-based case series conducted in 1998-2001 at an AD research center in New York, NY, and clinics in the Dominican Republic. Among 206 Caribbean Hispanic families with 2 or more living members with AD who were identified, 19 (9.2%) had at least 1 individual with onset of AD before the age of 55 years. The entire coding region of the presenilin 1 gene and exons 16 and 17 of the amyloid precursor protein gene were sequenced in probands from the 19 families and their living relatives. A G-to-C nucleotide change resulting in a glycine-alanine amino acid substitution at codon 206 (Gly206Ala) in exon 7 of presenilin 1 was observed in 23 individuals from 8 (42%) of the 19 families. A Caribbean Hispanic individual with the Gly206Ala mutation and early-onset familial disease was also found by sequencing the corresponding genes of 319 unrelated individuals in New York City. The Gly206Ala mutation was not found in public genetic databases but was reported in 5 individuals from 4 Hispanic families with AD referred for genetic testing. None of the members of these families were related to one another, yet all carriers of the Gly206Ala mutation tested shared a variant allele at 2 nearby microsatellite polymorphisms, indicating a common ancestor. No mutations were found in the amyloid precursor protein gene. The Gly206Ala mutation was found in 8 of 19 unrelated Caribbean Hispanic families with early-onset familial AD. This genetic change may be a prevalent cause of early-onset familial AD in the Caribbean Hispanic population.

Genetic and environmental influences on Anxious/Depression during childhood: a study from the Netherlands Twin Register.

PubMed

Boomsma, D I; van Beijsterveldt, C E M; Hudziak, J J

2005-11-01

For a large sample of twin pairs from the Netherlands Twins Register who were recruited at birth and followed through childhood, we obtained parental ratings of Anxious/Depression (A/D). Maternal ratings were obtained at ages 3 years (for 9025 twin pairs), 5 years (9222 pairs), 7 years (7331 pairs), 10 years (4430 pairs) and 12 years (2363 pairs). For 60-90% of the pairs, father ratings were also available. Multivariate genetic models were used to test for rater-independent and rater-specific assessments of A/D and to determine the genetic and environmental influences on individual differences in A/D at different ages. At all ages, monozygotic twins resembled each other more closely for A/D than dizygotic twins, implying genetic influences on variation in A/D. Opposite sex twin pairs resembled each other to same extent as same-sex dizygotic twins, suggesting that the same genes are expressed in boys and girls. Heritability estimates for rater-independent A/D were high in 3-year olds (76%) and decreased in size as children grew up [60% at age 5, 67% at age 7, 53% at age 10 (60% in boys) and 48% at age 12 years]. The decrease in genetic influences was accompanied by an increase in the influence of the shared family environment [absent at ages 3 and 7, 16% at age 5, 20% at age 10 (5% in boys) and 18% at age 12 years]. The agreement between parental A/D ratings was between 0.5 and 0.7, with somewhat higher correlations for the youngest group. Disagreement in ratings between the parents was not merely the result of unreliability or rater bias. Both the parents provided unique information from their own perspective on the behavior of their children. Significant influences of genetic and shared environmental factors were found for the unique parental views. At all ages, the contribution of shared environmental factors to variation in rater-specific views was higher for father ratings. Also, at all ages except age 12, the heritability estimates for the rater-specific phenotype were higher for mother ratings (59% at age 3 and decreasing to 27% at age 12 years) than for father ratings (between 14 and 29%). Differences between children, even as young as 3 years, in A/D are to a large extent due to genetic differences. As children grow up, the variation in A/D is due in equal parts to genetic and environmental influences. Anxious/Depression, unlike many other common childhood psychopathologies, is influenced by the shared family environment. These findings may provide support for why certain family therapeutic approaches are effective in the A/D spectrum of illnesses.

A rare duplication on chromosome 16p11.2 is identified in patients with psychosis in Alzheimer's disease.

PubMed

Zheng, Xiaojing; Demirci, F Yesim; Barmada, M Michael; Richardson, Gale A; Lopez, Oscar L; Sweet, Robert A; Kamboh, M Ilyas; Feingold, Eleanor

2014-01-01

Epidemiological and genetic studies suggest that schizophrenia and autism may share genetic links. Besides common single nucleotide polymorphisms, recent data suggest that some rare copy number variants (CNVs) are risk factors for both disorders. Because we have previously found that schizophrenia and psychosis in Alzheimer's disease (AD+P) share some genetic risk, we investigated whether CNVs reported in schizophrenia and autism are also linked to AD+P. We searched for CNVs associated with AD+P in 7 recurrent CNV regions that have been previously identified across autism and schizophrenia, using the Illumina HumanOmni1-Quad BeadChip. A chromosome 16p11.2 duplication CNV (chr16: 29,554,843-30,105,652) was identified in 2 of 440 AD+P subjects, but not in 136 AD subjects without psychosis, or in 593 AD subjects with intermediate psychosis status, or in 855 non-AD individuals. The frequency of this duplication CNV in AD+P (0.46%) was similar to that reported previously in schizophrenia (0.46%). This duplication CNV was further validated using the NanoString nCounter CNV Custom CodeSets. The 16p11.2 duplication has been associated with developmental delay, intellectual disability, behavioral problems, autism, schizophrenia (SCZ), and bipolar disorder. These two AD+P patients had no personal of, nor any identified family history of, SCZ, bipolar disorder and autism. To the best of our knowledge, our case report is the first suggestion that 16p11.2 duplication is also linked to AD+P. Although rare, this CNV may have an important role in the development of psychosis.

Atopic Dermatitis in Children: Clinical Features, Pathophysiology and Treatment

PubMed Central

Lyons, Jonathan J.; Milner, Joshua D.; Stone, Kelly D.

2014-01-01

Atopic dermatitis (AD) is a chronic, relapsing, highly pruritic skin condition resulting from disruption of the epithelial barrier and associated immune dysregulation in the skin of genetically predisposed hosts. AD generally develops in early childhood, has a characteristic age-dependent distribution and is commonly associated with elevated IgE, peripheral eosinophilia and other allergic diseases. Staphylococcus aureus colonization is common and may contribute to disease progression and severity. Targeted therapies to restore both impaired skin barrier and control inflammation are required for optimal outcomes for patients with moderate to severe disease. Pruritus is universal among patients with AD and has a dominant impact on diminishing quality of life. Medications such as anti-histamines have demonstrated poor efficacy in controlling AD-associated itch. Education of patients regarding the primary underlying defects and provision of a comprehensive skin care plan is essential for disease maintenance and management of flares. PMID:25459583

The effect of genetic bottlenecks and inbreeding on the incidence of two major autoimmune diseases in standard poodles, sebaceous adenitis and Addison's disease.

PubMed

Pedersen, Niels C; Brucker, Lynn; Tessier, Natalie Green; Liu, Hongwei; Penedo, Maria Cecilia T; Hughes, Shayne; Oberbauer, Anita; Sacks, Ben

2015-01-01

Sebaceous adenitis (SA) and Addison's disease (AD) increased rapidly in incidence among Standard Poodles after the mid-twentieth century. Previous attempts to identify specific genetic causes using genome wide association studies and interrogation of the dog leukocyte antigen (DLA) region have been non-productive. However, such studies led us to hypothesize that positive selection for desired phenotypic traits that arose in the mid-twentieth century led to intense inbreeding and the inadvertent amplification of AD and SA associated traits. This hypothesis was tested with genetic studies of 761 Standard, Miniature, and Miniature/Standard Poodle crosses from the USA, Canada and Europe, coupled with extensive pedigree analysis of thousands more dogs. Genome-wide diversity across the world-wide population was measured using a panel of 33 short tandem repeat (STR) loci. Allele frequency data were also used to determine the internal relatedness of individual dogs within the population as a whole. Assays based on linkage between STR genomic loci and DLA genes were used to identify class I and II haplotypes and disease associations. Genetic diversity statistics based on genomic STR markers indicated that Standard Poodles from North America and Europe were closely related and reasonably diverse across the breed. However, genetic diversity statistics, internal relatedness, principal coordinate analysis, and DLA haplotype frequencies showed a marked imbalance with 30 % of the diversity in 70 % of the dogs. Standard Poodles with SA and AD were strongly linked to this inbred population, with dogs suffering with SA being the most inbred. No single strong association was found between STR defined DLA class I or II haplotypes and SA or AD in the breed as a whole, although certain haplotypes present in a minority of the population appeared to confer moderate degrees of risk or protection against either or both diseases. Dogs possessing minor DLA class I haplotypes were half as likely to develop SA or AD as dogs with common haplotypes. Miniature/Standard Poodle crosses being used for outcrossing were more genetically diverse than Standard Poodles and genetically distinguishable across the genome and in the DLA class I and II region. Ancestral genetic polymorphisms responsible for SA and AD entered Standard Poodles through separate lineages, AD earlier and SA later, and were increasingly fixed by a period of close linebreeding that was related to popular bloodlines from the mid-twentieth century. This event has become known as the midcentury bottleneck or MCB. Sustained positive selection resulted in a marked imbalance in genetic diversity across the genome and in the DLA class I and II region. Both SA and AD were concentrated among the most inbred dogs, with genetic outliers being relatively disease free. No specific genetic markers other than those reflecting the degree of inbreeding were consistently associated with either disease. Standard Poodles as a whole remain genetically diverse, but steps should be taken to rebalance diversity using genetic outliers and if necessary, outcrosses to phenotypically similar but genetically distinct breeds.

Genetic variants of ABCA1 modify Alzheimer disease risk and quantitative traits related to beta-amyloid metabolism.

PubMed

Katzov, Hagit; Chalmers, Katy; Palmgren, Juni; Andreasen, Niels; Johansson, Boo; Cairns, Nigel J; Gatz, Margaret; Wilcock, Gordon K; Love, Seth; Pedersen, Nancy L; Brookes, Anthony J; Blennow, Kaj; Kehoe, Patrick G; Prince, Jonathan A

2004-04-01

Linkage studies have provided evidence that one or more loci on chromosome 9q influence Alzheimer disease (AD). The gene encoding the ATP-binding cassette A1 transporter (ABCA1) resides within proximity of previously identified linkage peaks and represents a plausible biological candidate for AD due to its central role in cellular lipid homeostasis. Several single nucleotide polymorphisms (SNPs) spanning ABCA1 have been genotyped and haplotype-based association analyses performed in four independent case-control samples, consisting of over 1,750 individuals from three European populations representing both early and late-onset AD. Prominent effects were observed for a common (H2) and rarer haplotype (H5) that were enriched in AD cases across studied populations (odds ratio [OR] 1.59, 95% confidence interval [CI] 1.36-1.82; P<0.00001 and OR 2.90; 95% CI 2.54-3.27; P<0.00001, respectively). Two other common haplotypes in the studied region (H1 and H3) were significantly under-represented in AD cases, suggesting that they may harbor alleles that decrease disease risk (OR 0.79, 95% CI 0.64-0.94; P=0.0065 and OR 0.70, 95% CI 0.46-0.93; P=0.011, respectively). While findings were significant in both early and late-onset samples, haplotype effects were more distinct in early-onset materials. For late-onset samples, ancillary evidence was obtained that both single marker alleles and haplotypes of ABCA1 contribute to variable cerebrospinal fluid tau and beta amyloid (Abeta42) protein levels, and brain Abeta load. Results indicate that variants of ABCA1 may affect the risk of AD, providing further support for a genetic link between AD and cholesterol metabolism. Copyright 2004 Wiley-Liss, Inc.

Prevalence of neutralising antibodies against adenoviruses in lizards and snakes.

PubMed

Ball, Inna; Ofner, Sabine; Funk, Richard S; Griffin, Chris; Riedel, Ulf; Möhring, Jens; Marschang, Rachel E

2014-10-01

Adenoviruses (AdVs) are relatively common in lizards and snakes, and several genetically distinct AdVs have been isolated in cell culture. The aims of this study were to examine serological relationships among lizard and snake AdVs and to determine the frequency of AdV infections in these species. Isolates from a boa constrictor (Boa constrictor), a corn snake (Pantherophis gutattus) and a central bearded dragon (Pogona vitticeps), and two isolates from helodermatid lizards (Heloderma horridum and H. suspectum) were used in neutralisation tests for the detection of antibodies in plasma from 263 lizards from seven families (including 12 species) and from 141 snakes from four families (including 28 species) from the USA and Europe. Most lizard and snake samples had antibodies against a range of AdV isolates, indicating that AdV infection is common among these squamates. Neutralisation tests with polyclonal antibodies raised in rabbits demonstrated serological cross-reactivity between both helodermatid lizard isolates. However, squamate plasma showed different reactions to each of these lizard isolates in neutralisation tests. Copyright © 2014 Elsevier Ltd. All rights reserved.

Alzheimer’s disease is not “brain aging”: neuropathological, genetic, and epidemiological human studies

PubMed Central

Head, Elizabeth; Schmitt, Frederick A.; Davis, Paulina R.; Neltner, Janna H.; Jicha, Gregory A.; Abner, Erin L.; Smith, Charles D.; Van Eldik, Linda J.; Kryscio, Richard J.; Scheff, Stephen W.

2011-01-01

Human studies are reviewed concerning whether “aging”-related mechanisms contribute to Alzheimer’s disease (AD) pathogenesis. AD is defined by specific neuropathology: neuritic amyloid plaques and neocortical neurofibrillary tangles. AD pathology is driven by genetic factors related not to aging per se, but instead to the amyloid precursor protein (APP). In contrast to genes involved in APP-related mechanisms, there is no firm connection between genes implicated in human “accelerated aging” diseases (progerias) and AD. The epidemiology of AD in advanced age is highly relevant but deceptively challenging to address given the low autopsy rates in most countries. In extreme old age, brain diseases other than AD approximate AD prevalence while the impact of AD pathology appears to peak by age 95 and decline thereafter. Many distinct brain diseases other than AD afflict older human brains and contribute to cognitive impairment. Additional prevalent pathologies include cerebrovascular disease and hippocampal sclerosis, both high-morbidity brain diseases that appear to peak in incidence later than AD chronologically. Because of these common brain diseases of extreme old age, the epidemiology differs between clinical “dementia” and the subset of dementia cases with AD pathology. Additional aging-associated mechanisms for cognitive decline such as diabetes and synapse loss have been linked to AD and these hypotheses are discussed. Criteria are proposed to define an “aging-linked” disease, and AD fails all of these criteria. In conclusion, it may be most fruitful to focus attention on specific pathways involved in AD rather than attributing it to an inevitable consequence of aging. PMID:21516511

Revision of the OECD Genetox Test Guidelines

EPA Science Inventory

The OECD Test Guidelines (TG) on genetic toxicology were initially prepared and adopted between 1981 and 1986. In 1997 the most commonly used guidelines were updated, and the in vivo UDS test (TG 486) was added. More recently, in 2010 and 2011, two new guidelines were adopted: th...

Prediction of breast cancer risk by genetic risk factors, overall and by hormone receptor status.

PubMed

Hüsing, Anika; Canzian, Federico; Beckmann, Lars; Garcia-Closas, Montserrat; Diver, W Ryan; Thun, Michael J; Berg, Christine D; Hoover, Robert N; Ziegler, Regina G; Figueroa, Jonine D; Isaacs, Claudine; Olsen, Anja; Viallon, Vivian; Boeing, Heiner; Masala, Giovanna; Trichopoulos, Dimitrios; Peeters, Petra H M; Lund, Eiliv; Ardanaz, Eva; Khaw, Kay-Tee; Lenner, Per; Kolonel, Laurence N; Stram, Daniel O; Le Marchand, Loïc; McCarty, Catherine A; Buring, Julie E; Lee, I-Min; Zhang, Shumin; Lindström, Sara; Hankinson, Susan E; Riboli, Elio; Hunter, David J; Henderson, Brian E; Chanock, Stephen J; Haiman, Christopher A; Kraft, Peter; Kaaks, Rudolf

2012-09-01

There is increasing interest in adding common genetic variants identified through genome wide association studies (GWAS) to breast cancer risk prediction models. First results from such models showed modest benefits in terms of risk discrimination. Heterogeneity of breast cancer as defined by hormone-receptor status has not been considered in this context. In this study we investigated the predictive capacity of 32 GWAS-detected common variants for breast cancer risk, alone and in combination with classical risk factors, and for tumours with different hormone receptor status. Within the Breast and Prostate Cancer Cohort Consortium, we analysed 6009 invasive breast cancer cases and 7827 matched controls of European ancestry, with data on classical breast cancer risk factors and 32 common gene variants identified through GWAS. Discriminatory ability with respect to breast cancer of specific hormone receptor-status was assessed with the age adjusted and cohort-adjusted concordance statistic (AUROC(a)). Absolute risk scores were calculated with external reference data. Integrated discrimination improvement was used to measure improvements in risk prediction. We found a small but steady increase in discriminatory ability with increasing numbers of genetic variants included in the model (difference in AUROC(a) going from 2.7% to 4%). Discriminatory ability for all models varied strongly by hormone receptor status. Adding information on common polymorphisms provides small but statistically significant improvements in the quality of breast cancer risk prediction models. We consistently observed better performance for receptor-positive cases, but the gain in discriminatory quality is not sufficient for clinical application.

EVALUATION OF CHEMICALS USED FOR DRINKING WATER DISINFECTION FOR PRODUCTION OF CHROMOSOMAL DAMAGE AND SPERM-HEAD ABNORMALITIES IN MICE

EPA Science Inventory

Chemical oxidants are commonly added during water treatment for disinfection purposes. These chemicals have not been tested previously for their ability to induce genetic damage in vivo. Chlorine (hypochlorite and hypochlorous acid), monochloramine, chlorine dioxide, sodium chlor...

Microglial Dysfunction in Brain Aging and Alzheimer’s Disease

PubMed Central

Mosher, Kira Irving; Wyss-Coray, Tony

2014-01-01

Microglia, the immune cells of the central nervous system, have long been a subject of study in the Alzheimer’s disease (AD) field due to their dramatic responses to the pathophysiology of the disease. With several large-scale genetic studies in the past year implicating microglial molecules in AD, the potential significance of these cells has become more prominent than ever before. As a disease that is tightly linked to aging, it is perhaps not entirely surprising that microglia of the AD brain share some phenotypes with aging microglia. Yet the relative impacts of both conditions on microglia are less frequently considered in concert. Furthermore, microglial “activation” and “neuroinflammation” are commonly analyzed in studies of neurodegeneration but are somewhat ill-defined concepts that in fact encompass multiple cellular processes. In this review, we have enumerated six distinct functions of microglia and discuss the specific effects of both aging and AD. By calling attention to the commonalities of these two states, we hope to inspire new approaches for dissecting microglial mechanisms. PMID:24445162

Association of HSP70 and its co-chaperones with Alzheimer’s Disease

PubMed Central

Broer, Linda; Ikram, Mohammad Arfan; Schuur, Maaike; DeStefano, Anita L.; Bis, Joshua C.; Liu, Fan; Rivadeneira, Fernando; Uitterlinden, Andre G.; Beiser, Alexa S.; Longstreth, William T.; Hofman, Albert; Aulchenko, Yurii; Seshadri, Sudha; Fitzpatrick, Annette L.; Oostra, Ben A.; Breteler, Monique M.B.; van Duijn, Cornelia M.

2012-01-01

The heat shock protein (HSP) 70 family has been implicated in the pathology of Alzheimer’s disease (AD). In this study, we examined common genetic variations in the 80 genes encoding HSP70 and its co-chaperones. We conducted a study in a series of 462 patients and 5238 unaffected participants derived from the Rotterdam Study, a population-based study including 7983 persons aged 55 years and older. We genotyped a total of 12,053 Single Nucleotide Polymorphisms (SNPs) using the HumanHap550K Genotyping BeadChip from Illumina. Replication was performed in two independent cohort studies, the Framingham Heart study (FHS; N=806) and Cardiovascular Health Study (CHS; N=2150). When adjusting for multiple testing, we found a small but consistent, though not significant effect of rs12118313 located 32kb from PFDN2, with an OR of 1.19 (p-value from meta-analysis =0.003). However this SNP was in the intron of another gene, suggesting it is unlikely this SNP reflects the effect of PFDN2. In a formal pathway analysis we found nominally significant evidence for an association of BAG, DNAJA and prefoldin with AD. These findings corroborate with those of a study of 2032 AD patients and 5328 controls, in which several members of the prefoldin family showed evidence for association to AD. Our study did not reveal evidence for a genetic variant if the HSP70 family with a major effect on AD. However, our findings of the single SNP analysis and pathway analysis suggest that multiple genetic variants in prefoldin are associated with AD. PMID:21403392

Impaired activity-dependent neural circuit assembly and refinement in autism spectrum disorder genetic models

PubMed Central

Doll, Caleb A.; Broadie, Kendal

2014-01-01

Early-use activity during circuit-specific critical periods refines brain circuitry by the coupled processes of eliminating inappropriate synapses and strengthening maintained synapses. We theorize these activity-dependent (A-D) developmental processes are specifically impaired in autism spectrum disorders (ASDs). ASD genetic models in both mouse and Drosophila have pioneered our insights into normal A-D neural circuit assembly and consolidation, and how these developmental mechanisms go awry in specific genetic conditions. The monogenic fragile X syndrome (FXS), a common cause of heritable ASD and intellectual disability, has been particularly well linked to defects in A-D critical period processes. The fragile X mental retardation protein (FMRP) is positively activity-regulated in expression and function, in turn regulates excitability and activity in a negative feedback loop, and appears to be required for the A-D remodeling of synaptic connectivity during early-use critical periods. The Drosophila FXS model has been shown to functionally conserve the roles of human FMRP in synaptogenesis, and has been centrally important in generating our current mechanistic understanding of the FXS disease state. Recent advances in Drosophila optogenetics, transgenic calcium reporters, highly-targeted transgenic drivers for individually-identified neurons, and a vastly improved connectome of the brain are now being combined to provide unparalleled opportunities to both manipulate and monitor A-D processes during critical period brain development in defined neural circuits. The field is now poised to exploit this new Drosophila transgenic toolbox for the systematic dissection of A-D mechanisms in normal versus ASD brain development, particularly utilizing the well-established Drosophila FXS disease model. PMID:24570656

Genetic association between Alzheimer disease and the alpha-synuclein gene.

PubMed

Matsubara, M; Yamagata, H; Kamino, K; Nomura, T; Kohara, K; Kondo, I; Miki, T

2001-01-01

alpha-Synuclein has been isolated as a component of amyloid in addition to the major A beta peptide in Alzheimer disease (AD). However, there are conflicting reports regarding the association of alpha-synuclein gene polymorphism with AD. Using a novel and common polymorphism in intron 3, we examined the relationship between AD and alpha-synuclein and apolipoprotein E (ApoE) genes in 183 Japanese AD patients and 210 controls. Carriers of the alpha-synuclein deletion (D) allele had a 2.2-fold increased risk of developing AD than noncarriers in women. The odds ratio for the ApoE epsilon 4 and the alpha-synuclein D allele was 11.4 in women. The results showed that the alpha-synuclein gene is associated with sporadic AD in women, independent of ApoE epsilon 4 status. Copyright 2001 S. Karger AG, Basel

Evidence for major gene inheritance of Alzheimer disease in families of patients with and without Apolipoprotein E {epsilon}4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, V.S.; Auerbach, S.A.; Farrer, L.A.

1996-09-01

Apolipoprotein E (APOE) genotype is the single most important determinant to the common form of Alzheimer disease (AD) yet identified. Several studies show that family history of AD is not entirely accounted for by APOE genotype. Also, there is evidence for an interaction between APOE genotype and gender. We carried out a complex segregation analysis in 636 nuclear families of consecutively ascertained and rigorously diagnosed probands in the Multi-Institutional Research in Alzheimer Genetic Epidemiology study in order to derive models of disease transmission which account for the influences of APOE genotype of the proband and gender. In the total groupmore » of families, models postulating sporadic occurrence, no major gene effect, random environmental transmission, and Mendelian inheritance were rejected. Transmission of AD in families of probands with at least one {epsilon}4 allele best fit a dominant model. Moreover, single gene inheritance best explained clustering of the disorder in families of probands lacking E4, but a more complex genetic model or multiple genetic models may ultimately account for risk in this group of families. Our results also suggest that susceptibility to AD differs between men and women regardless of the proband`s APOE status. Assuming a dominant model, AD appears to be completely penetrant in women, whereas only 62%-65% of men with predisposing genotypes develop AD. However, parameter estimates from the arbitrary major gene model suggests that AD is expressed dominantly in women and additively in men. These observations, taken together with epidemiologic data, are consistent with the hypothesis of an interaction between genes and other biological factors affecting disease susceptibility. 76 refs., 4 tabs.« less

Immunotoxicological evaluation of wheat genetically modified with TaDREB4 gene on BALB/c mice.

PubMed

Liang, Chun Lai; Zhang, Xiao Peng; Song, Yan; Jia, Xu Dong

2013-08-01

To evaluate the immunotoxicological effects of genetically modified wheat with TaDREB4 gene in female BALB/c mice. Female mice weighing 18-22 g were divided into five groups (10 mice/group), which were set as negative control group, common wheat group, parental wheat group, genetically modified wheat group and cyclophosphamide positive control group, respectively. Mice in negative control group and positive control group were fed with AIN93G diet, mice in common wheat group, non-genetically modified parental wheat group and genetically modified wheat group were fed with feedstuffs added corresponding wheat (the proportion is 76%) for 30 days, then body weight, absolute and relative weight of spleen and thymus, white blood cell count, histological examination of immune organ, peripheral blood lymphocytes phenotyping, serum cytokine, serum immunoglobulin, antibody plaque-forming cell, serum half hemolysis value, mitogen-induced splenocyte proliferation, delayed-type hypersensitivity reaction and phagocytic activities of phagocytes were detected. No immunotoxicological effects related to the consumption of the genetically modified wheat were observed in BALB/c mice when compared with parental wheat group, common wheat group and negative control group. From the immunotoxicological point of view, results from this study demonstrate that genetically modified wheat with TaDREB4 gene is as safe as the parental wheat. Copyright © 2013 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Alzheimer’s in 3D culture: Challenges and perspectives

PubMed Central

D'Avanzo, Carla; Aronson, Jenna; Kim, Young Hye; Choi, Se Hoon; Tanzi, Rudolph E.; Kim, Doo Yeon

2015-01-01

Summary Alzheimer’s disease (AD) is the most common cause of dementia, and there is currently no cure. The “β-amyloid cascade hypothesis” of AD is the basis of current understanding of AD pathogenesis and drug discovery. However, no AD models have fully validated this hypothesis. We recently developed a human stem cell culture model of AD by cultivating genetically modified human neural stem cells in a three-dimensional (3D) cell culture system. These cells were able to recapitulate key events of AD pathology including β-amyloid plaques and neurofibrillary tangles. In this review, we will discuss the progress and current limitations of AD mouse models and human stem cell models as well as explore the breakthroughs of 3D cell culture systems. We will also share our perspective on the potential of dish models of neurodegenerative diseases for studying pathogenic cascades and therapeutic drug discovery. PMID:26252541

A common biological mechanism in cancer and Alzheimer’s disease?

PubMed Central

Behrens, Maria I; Lendon, Corinne; Roe, Catherine M.

2009-01-01

Cancer and Alzheimer’s disease (AD) are two common disorders for which the final pathophysiological mechanism is not yet clearly defined. In a prospective longitudinal study we have previously shown an inverse association between AD and cancer, such that the rate of developing cancer in general with time was significantly slower in participants with AD, while participants with a history of cancer had a slower rate of developing AD. In cancer, cell regulation mechanisms are disrupted with augmentation of cell survival and/or proliferation, whereas conversely, AD is associated with increased neuronal death, either caused by, or concomitant with, beta amyloid (Aβ) and tau deposition. The possibility that perturbations of mechanisms involved in cell survival/death regulation could be involved in both disorders is discussed. Genetic polymorphisms, DNA methylation or other mechanisms that induce changes in activity of molecules with key roles in determining the decision to “repair and live”- or “die” could be involved in the pathogenesis of the two disorders. As examples, the role of p53, Pin1 and the Wnt signaling pathway are discussed as potential candidates that, speculatively, may explain inverse associations between AD and cancer. PMID:19519301

Transgenic animal models of neurodegeneration based on human genetic studies

PubMed Central

Richie, Christopher T.; Hoffer, Barry J.; Airavaara, Mikko

2011-01-01

The identification of genes linked to neurodegenerative diseases such as Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD) and Parkinson's disease (PD) has led to the development of animal models for studying mechanism and evaluating potential therapies. None of the transgenic models developed based on disease-associated genes have been able to fully recapitulate the behavioral and pathological features of the corresponding disease. However, there has been enormous progress made in identifying potential therapeutic targets and understanding some of the common mechanisms of neurodegeneration. In this review, we will discuss transgenic animal models for AD, ALS, HD and PD that are based on human genetic studies. All of the diseases discussed have active or complete clinical trials for experimental treatments that benefited from transgenic models of the disease. PMID:20931247

Modeling the Diagnostic Criteria for Alcohol Dependence with Genetic Animal Models

PubMed Central

Kendler, Kenneth S.; Hitzemann, Robert J.

2012-01-01

A diagnosis of alcohol dependence (AD) using the DSM-IV-R is categorical, based on an individual’s manifestation of three or more symptoms from a list of seven. AD risk can be traced to both genetic and environmental sources. Most genetic studies of AD risk implicitly assume that an AD diagnosis represents a single underlying genetic factor. We recently found that the criteria for an AD diagnosis represent three somewhat distinct genetic paths to individual risk. Specifically, heavy use and tolerance versus withdrawal and continued use despite problems reflected separate genetic factors. However, some data suggest that genetic risk for AD is adequately described with a single underlying genetic risk factor. Rodent animal models for alcohol-related phenotypes typically target discrete aspects of the complex human AD diagnosis. Here, we review the literature derived from genetic animal models in an attempt to determine whether they support a single-factor or multiple-factor genetic structure. We conclude that there is modest support in the animal literature that alcohol tolerance and withdrawal reflect distinct genetic risk factors, in agreement with our human data. We suggest areas where more research could clarify this attempt to align the rodent and human data. PMID:21910077

Novel autosomal dominant mandibulofacial dysostosis with ptosis: clinical description and exclusion of TCOF1.

PubMed

Hedera, P; Toriello, H V; Petty, E M

2002-07-01

Treacher Collins syndrome (TCS), the most common type of mandibulofacial dysostosis (MFD), is genetically homogeneous. Other types of MFD are less common and, of these, only the Bauru type of MFD has an autosomal dominant (AD) mode of inheritance established. Here we report clinical features of a kindred with a unique AD MFD with the exclusion of linkage to the TCS locus (TCOF1) on chromosome 5q31-q32. Six affected family members underwent a complete medical genetics physical examination and two affected subjects had skeletal survey. All available medical records were reviewed. Linkage analysis using the markers spanning the TCOF1 locus was performed. One typically affected family member had a high resolution karyotype. Affected subjects had significant craniofacial abnormalities without any significant acral changes and thus had a phenotype consistent with a MFD variant. Distinctive features included hypoplasia of the zygomatic complex, micrognathia with malocclusion, auricular abnormalities with conductive hearing loss, and ptosis. Significantly negative two point lod scores were obtained for markers spanning the TCOF1 locus, excluding the possibility that the disease in our kindred is allelic with TCS. High resolution karyotype was normal. We report a kindred with a novel type of MFD that is not linked to the TCOF1 locus and is also clinically distinct from other types of AD MFD. Identification of additional families will facilitate identification of the gene causing this type of AD MFD and further characterisation of the clinical phenotype.

Heritability of Nociception IV: Neuropathic pain assays are genetically distinct across methods of peripheral nerve injury

PubMed Central

Young, Erin E.; Costigan, Michael; Herbert, Teri A.; Lariviere, William R.

2013-01-01

Prior genetic correlation analysis of 22 heritable behavioral measures of nociception and hypersensitivity in the mouse identified five genetically distinct pain types. In the present study, we reanalyzed that dataset and included the results of an additional nine assays of nociception and hypersensitivity to: 1) replicate the previously identified five pain types; 2) test whether any of the newly added pain assays represent novel genetically distinct pain types; 3) test the level of genetic relatedness among nine commonly employed neuropathic pain assays. Multivariate analysis of pairwise correlations between assays shows that the newly added zymosan-induced heat hypersensitivity assay does not conform to the two previously identified groups of heat hypersensitivity assays and cyclophosphamide-induced cystitis, the first organ-specific visceral pain model examined, is genetically distinct from other inflammatory assays. The four included mechanical hypersensitivity assays are genetically distinct, and do not comprise a single pain type as previously reported. Among the nine neuropathic pain assays including autotomy, chemotherapy, nerve ligation and spared nerve injury assays, at least four genetically distinct types of neuropathic sensory abnormalities were identified, corresponding to differences in nerve injury method. In addition, two itch assays and Comt genotype were compared to the expanded set of nociception and hypersensitivity assays. Comt genotype was strongly related only to spontaneous inflammatory nociception assays. These results indicate the priority for continued investigation of genetic mechanisms in several assays newly identified to represent genetically distinct pain types. PMID:24071598

Alpha-2 macroglobulin is genetically associated with Alzheimer disease.

PubMed

Blacker, D; Wilcox, M A; Laird, N M; Rodes, L; Horvath, S M; Go, R C; Perry, R; Watson, B; Bassett, S S; McInnis, M G; Albert, M S; Hyman, B T; Tanzi, R E

1998-08-01

Alpha-2-macroglobulin (alpha-2M; encoded by the gene A2M) is a serum pan-protease inhibitor that has been implicated in Alzheimer disease (AD) based on its ability to mediate the clearance and degradation of A beta, the major component of beta-amyloid deposits. Analysis of a deletion in the A2M gene at the 5' splice site of 'exon II' of the bait region (exon 18) revealed that inheritance of the deletion (A2M-2) confers increased risk for AD (Mantel-Haenzel odds ratio=3.56, P=0.001). The sibship disequilibrium test (SDT) also revealed a significant association between A2M and AD (P=0.00009). These values were comparable to those obtained for the APOE-epsilon4 allele in the same sample, but in contrast to APOE-epsilon4, A2M-2 did not affect age of onset. The observed association of A2M with AD did not appear to account for the previously published linkage of AD to chromosome 12, which we were unable to confirm in this sample. A2M, LRP1 (encoding the alpha-2M receptor) and the genes for two other LRP ligands, APOE and APP (encoding the amyloid beta-protein precursor), have now all been genetically linked to AD, suggesting that these proteins may participate in a common neuropathogenic pathway leading to AD.

Recent advances in engineering propionyl-CoA metabolism for microbial production of value-added chemicals and biofuels.

PubMed

Srirangan, Kajan; Bruder, Mark; Akawi, Lamees; Miscevic, Dragan; Kilpatrick, Shane; Moo-Young, Murray; Chou, C Perry

2017-09-01

Diminishing fossil fuel reserves and mounting environmental concerns associated with petrochemical manufacturing practices have generated significant interests in developing whole-cell biocatalytic systems for the production of value-added chemicals and biofuels. Although acetyl-CoA is a common natural biogenic precursor for the biosynthesis of numerous metabolites, propionyl-CoA is unpopular and non-native to most organisms. Nevertheless, with its C3-acyl moiety as a discrete building block, propionyl-CoA can serve as another key biogenic precursor to several biological products of industrial importance. As a result, engineering propionyl-CoA metabolism, particularly in genetically tractable hosts with the use of inexpensive feedstocks, has paved an avenue for novel biomanufacturing. Herein, we present a systematic review on manipulation of propionyl-CoA metabolism as well as relevant genetic and metabolic engineering strategies for microbial production of value-added chemicals and biofuels, including odd-chain alcohols and organic acids, bio(co)polymers and polyketides. [Formula: see text].

The Relationship Between the Genetic and Environmental Influences on Common Externalizing Psychopathology and Mental Wellbeing

PubMed Central

Kendler, Kenneth S.; Myers, John M.; Keyes, Corey L. M.

2012-01-01

To determine the relationship between the genetic and environmental risk factors for externalizing psychopathology and mental wellbeing, we examined detailed measures of emotional, social and psychological wellbeing, and a history of alcohol-related problems and smoking behavior in the last year in 1,386 individual twins from same-sex pairs from the MIDUS national US sample assessed in 1995. Cholesky decomposition analyses were performed with the Mx program. The best fit model contained one highly heritable common externalizing psychopathology factor for both substance use/abuse measures, and one strongly heritable common factor for the three wellbeing measures. Genetic and environmental risk factors for externalizing psychopathology were both negatively associated with levels of mental wellbeing and accounted for, respectively, 7% and 21% of its genetic and environmental influences. Adding internalizing psychopathology assessed in the last year to the model, genetic risk factors unique for externalizing psychopathology were now positively related to levels of mental wellbeing, although accounting for only 5% of the genetic variance. Environmental risk factors unique to externalizing psychopathology continued to be negatively associated with mental wellbeing, accounting for 26% of the environmental variance. When both internalizing psychopathology and externalizing psychopathology are associated with mental wellbeing, the strongest risk factors for low mental wellbeing are genetic factors that impact on both internalizing psychopathology and externalizing psychopathology, and environmental factors unique to externalizing psychopathology. In this model, genetic risk factors for externalizing psychopathology predict, albeit weakly, higher levels of mental wellbeing. PMID:22506307

BCHE and CYP2D6 genetic variation in Alzheimer's disease patients treated with cholinesterase inhibitors.

PubMed

Chianella, Caterina; Gragnaniello, Daniela; Maisano Delser, Pierpaolo; Visentini, Maria Francesca; Sette, Elisabetta; Tola, Maria Rosaria; Barbujani, Guido; Fuselli, Silvia

2011-11-01

Cholinesterase inhibitors are commonly prescribed to patients with Alzheimer's disease (AD) to enhance cholinergic neurotransmission. Differential response to these treatments has been observed, and claims have been made that individual genetic variants may influence the pharmacokinetic and pharmacodynamic properties of these drugs. Here we assess the effects of genetic variation at two loci involved in the activity of cholinesterase inhibitors on longitudinal clinical change in AD patients being treated with donepezil, galantamine, and rivastigmine. This was an open study in which 171 Italian AD patients treated with donepezil (n = 92), galantamine (n = 33), or rivastigmine (n = 46) were enrolled. Response to treatment was quantified by grading the patient's cognitive state (Mini-Mental State Examination) and the patient's ability to perform normal daily activities (Activities of Daily Living, Instrumental Activities of Daily Living) at baseline and after 6 and 12 months of treatment. Genetic variation was comprehensively characterized and analyzed at two loci: CYP2D6, which is involved in donepezil and galantamine metabolism, and BCHE, which codes for an enzyme (butyrylcholinesterase) which is both target and metabolizer of rivastigmine. APOE (coding for apolipoprotein E), which is associated with the risk of AD and inefficacy of specific AD treatments, was genotyped to control for patient stratification. The influence of the CYP2D6 and BCHE genotype on clinical changes after 12 months was evaluated by several tests of association. After 1 year of treatment, 29, 12, and 12 of the patients receiving donepezil, galantamine, and rivastigmine, respectively, showed a cognitive decrement, while eight patients interrupted the therapy before 12 months of treatment. No significant differences between the three treatments were observed in terms of response and tolerability. Non-responders show a higher proportion of BCHE and CYP2D6 mutated alleles, but genetic variation at the two loci was not a reliable predictor of clinical changes in AD patients treated with cholinesterase inhibitors. Individualized therapy based on CYP2D6 and BCHE genotypes is unlikely to be beneficial for treating Alzheimer's disease patients in routine clinical practice.

Air Pollution, Oxidative Stress, and Alzheimer's Disease

PubMed Central

Moulton, Paula Valencia; Yang, Wei

2012-01-01

Alzheimer's disease (AD) is the most common form of dementia affecting millions of people worldwide and will continue to affect millions more with population aging on the rise. AD causality is multifactorial. Known causal factors include genetic predisposition, age, and sex. Environmental toxins such as air pollution (AP) have also been implicated in AD causation. Exposure to AP can lead to chronic oxidative stress (OS), which is involved in the pathogenesis of AD. Whereas AP plays a role in AD pathology, the epidemiological evidence for this association is limited. Given the significant prevalence of AP exposure combined with increased population aging, epidemiological evidence for this link is important to consider. In this paper, we examine the existing evidence supporting the relationship between AP, OS, and AD and provide recommendations for future research on the population level, which will provide evidence in support of public health interventions. PMID:22523504

A genome-wide association study of atopic dermatitis identifies loci with overlapping effects on asthma and psoriasis.

PubMed

Weidinger, Stephan; Willis-Owen, Saffron A G; Kamatani, Yoichiro; Baurecht, Hansjörg; Morar, Nilesh; Liang, Liming; Edser, Pauline; Street, Teresa; Rodriguez, Elke; O'Regan, Grainne M; Beattie, Paula; Fölster-Holst, Regina; Franke, Andre; Novak, Natalija; Fahy, Caoimhe M; Winge, Mårten C G; Kabesch, Michael; Illig, Thomas; Heath, Simon; Söderhäll, Cilla; Melén, Erik; Pershagen, Göran; Kere, Juha; Bradley, Maria; Lieden, Agne; Nordenskjold, Magnus; Harper, John I; McLean, W H Irwin; Brown, Sara J; Cookson, William O C; Lathrop, G Mark; Irvine, Alan D; Moffatt, Miriam F

2013-12-01

Atopic dermatitis (AD) is the most common dermatological disease of childhood. Many children with AD have asthma and AD shares regions of genetic linkage with psoriasis, another chronic inflammatory skin disease. We present here a genome-wide association study (GWAS) of childhood-onset AD in 1563 European cases with known asthma status and 4054 European controls. Using Illumina genotyping followed by imputation, we generated 268 034 consensus genotypes and in excess of 2 million single nucleotide polymorphisms (SNPs) for analysis. Association signals were assessed for replication in a second panel of 2286 European cases and 3160 European controls. Four loci achieved genome-wide significance for AD and replicated consistently across all cohorts. These included the epidermal differentiation complex (EDC) on chromosome 1, the genomic region proximal to LRRC32 on chromosome 11, the RAD50/IL13 locus on chromosome 5 and the major histocompatibility complex (MHC) on chromosome 6; reflecting action of classical HLA alleles. We observed variation in the contribution towards co-morbid asthma for these regions of association. We further explored the genetic relationship between AD, asthma and psoriasis by examining previously identified susceptibility SNPs for these diseases. We found considerable overlap between AD and psoriasis together with variable coincidence between allergic rhinitis (AR) and asthma. Our results indicate that the pathogenesis of AD incorporates immune and epidermal barrier defects with combinations of specific and overlapping effects at individual loci.

A genome-wide association study of atopic dermatitis identifies loci with overlapping effects on asthma and psoriasis

PubMed Central

Weidinger, Stephan; Willis-Owen, Saffron A.G.; Kamatani, Yoichiro; Baurecht, Hansjörg; Morar, Nilesh; Liang, Liming; Edser, Pauline; Street, Teresa; Rodriguez, Elke; O'Regan, Grainne M.; Beattie, Paula; Fölster-Holst, Regina; Franke, Andre; Novak, Natalija; Fahy, Caoimhe M.; Winge, Mårten C.G.; Kabesch, Michael; Illig, Thomas; Heath, Simon; Söderhäll, Cilla; Melén, Erik; Pershagen, Göran; Kere, Juha; Bradley, Maria; Lieden, Agne; Nordenskjold, Magnus; Harper, John I.; Mclean, W.H. Irwin; Brown, Sara J.; Cookson, William O.C.; Lathrop, G. Mark; Irvine, Alan D.; Moffatt, Miriam F.

2013-01-01

Atopic dermatitis (AD) is the most common dermatological disease of childhood. Many children with AD have asthma and AD shares regions of genetic linkage with psoriasis, another chronic inflammatory skin disease. We present here a genome-wide association study (GWAS) of childhood-onset AD in 1563 European cases with known asthma status and 4054 European controls. Using Illumina genotyping followed by imputation, we generated 268 034 consensus genotypes and in excess of 2 million single nucleotide polymorphisms (SNPs) for analysis. Association signals were assessed for replication in a second panel of 2286 European cases and 3160 European controls. Four loci achieved genome-wide significance for AD and replicated consistently across all cohorts. These included the epidermal differentiation complex (EDC) on chromosome 1, the genomic region proximal to LRRC32 on chromosome 11, the RAD50/IL13 locus on chromosome 5 and the major histocompatibility complex (MHC) on chromosome 6; reflecting action of classical HLA alleles. We observed variation in the contribution towards co-morbid asthma for these regions of association. We further explored the genetic relationship between AD, asthma and psoriasis by examining previously identified susceptibility SNPs for these diseases. We found considerable overlap between AD and psoriasis together with variable coincidence between allergic rhinitis (AR) and asthma. Our results indicate that the pathogenesis of AD incorporates immune and epidermal barrier defects with combinations of specific and overlapping effects at individual loci. PMID:23886662

ASSOCIATION BETWEEN GAB2 HAPLOTYPE AND HIGHER GLUCOSE METABOLISM IN ALZHEIMER'S DISEASE-AFFECTED BRAIN REGIONS IN COGNITIVELY NORMAL APOEε4 CARRIERS

PubMed Central

Liang, Winnie S.; Chen, Kewei; Lee, Wendy; Sidhar, Kunal; Corneveaux, Jason J.; Allen, April N.; Myers, Amanda; Villa, Stephen; Meechoovet, Bessie; Pruzin, Jeremy; Bandy, Daniel; Fleisher, Adam S.; Langbaum, Jessica B.S.; Huentelman, Matthew J.; Jensen, Kendall; Dunckley, Travis; Caselli, Richard J.; Kaib, Susan; Reiman, Eric M.

2010-01-01

In a genome-wide association study (GWAS) of late-onset Alzheimer's disease (AD), we found an association between common haplotypes of the GAB2 gene and AD risk in carriers of the apolipoprotein E (APOE) ε4 allele, the major late-onset AD susceptibility gene. We previously proposed the use of fluorodeoxyglucose positron emission tomography (FDG-PET) measurements as a quantitative presymptomatic endophenotype, more closely related to disease risk than the clinical syndrome itself, to help evaluate putative genetic and non-genetic modifiers of AD risk. In this study, we examined the relationship between the presence or absence of the relatively protective GAB2 haplotype and PET measurements of regional-to-whole brain FDG uptake in several AD-affected brain regions in 158 cognitively normal late-middle-aged APOEε4 homozygotes, heterozygotes, and non-carriers. GAB2 haplotypes were characterized using Affymetrix Genome-Wide Human SNP 6.0 Array data from each of these subjects. As predicted, the possibly protective GAB2 haplotype was associated with higher regional-to-whole brain FDG uptake in AD-affected brain regions in APOEε4 carriers. While additional studies are needed, this study supports the association between the possibly protective GAB2 haplotype and the risk of late-onset AD in APOEε4 carriers. It also supports the use of brain-imaging endophenotypes to help assess possible modifiers of AD risk. PMID:20888920

Pathways and barriers to genetic testing and screening: Molecular genetics meets the high-risk family. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duster, T.

The proliferation of genetic screening and testing is requiring increasing numbers of Americans to integrate genetic knowledge and interventions into their family life and personal experience. This study examines the social processes that occur as families at risk for two of the most common autosomal recessive diseases, sickle cell disease (SC) and cystic fibrosis (CF), encounter genetic testing. Each of these diseases is found primarily in a different ethnic/racial group (CF in Americans of North European descent and SC in Americans of West African descent). This has permitted them to have a certain additional lens on the role of culturemore » in integrating genetic testing into family life and reproductive planning. A third type of genetic disorder, the thalassemias was added to the sample in order to extent the comparative frame and to include other ethnic and racial groups.« less

Estrogen receptor β in Alzheimer's disease: From mechanisms to therapeutics.

PubMed

Zhao, Liqin; Woody, Sarah K; Chhibber, Anindit

2015-11-01

Alzheimer's disease (AD) disproportionally affects women and men. The female susceptibility for AD has been largely associated with the loss of ovarian sex hormones during menopause. This review examines the current understanding of the role of estrogen receptor β (ERβ) in the regulation of neurological health and its implication in the development and intervention of AD. Since its discovery in 1996, research conducted over the last 15-20 years has documented a great deal of evidence indicating that ERβ plays a pivotal role in a broad spectrum of brain activities from development to aging. ERβ genetic polymorphisms have been associated with cognitive impairment and increased risk for AD predominantly in women. The role of ERβ in the intervention of AD has been demonstrated by the alteration of AD pathology in response to treatment with ERβ-selective modulators in transgenic models that display pronounced plaque and tangle histopathological presentations as well as learning and memory deficits. Future studies that explore the potential interactions between ERβ signaling and the genetic isoforms of human apolipoprotein E (APOE) in brain aging and development of AD-risk phenotype are critically needed. The current trend of lost-in-translation in AD drug development that has primarily been based on early-onset familial AD (FAD) models underscores the urgent need for novel models that recapitulate the etiology of late-onset sporadic AD (SAD), the most common form of AD representing more than 95% of the current human AD population. Combining the use of FAD-related models that generally have excellent face validity with SAD-related models that hold more reliable construct validity would together increase the predictive validity of preclinical findings for successful translation into humans. Copyright © 2015 Elsevier B.V. All rights reserved.

Advertisement scheduling on commercial radio station using genetics algorithm

NASA Astrophysics Data System (ADS)

Purnamawati, S.; Nababan, E. B.; Tsani, B.; Taqyuddin, R.; Rahmat, R. F.

2018-03-01

On the commercial radio station, the advertising schedule is done manually, which resulted in ineffectiveness of ads schedule. Playback time consists of two types such as prime time and regular time. Radio Ads scheduling will be discussed in this research is based on ad playback schedule between 5am until 12am which rules every 15 minutes. It provides 3 slots ads with playback duration per ads maximum is 1 minute. If the radio broadcast time per day is 12 hours, then the maximum number of ads per day which can be aired is 76 ads. The other is the enactment of rules of prime time, namely the hours where the common people (listeners) have the greatest opportunity to listen to the radio, namely between the hours and hours of 4 am - 8 am, 6 pm - 10 pm. The number of screenings of the same ads on one day are limited to prime time ie 5 times, while for regular time is 8 times. Radio scheduling process is done using genetic algorithms which are composed of processes initialization chromosomes, selection, crossover and mutation. Study on chromosome 3 genes, each chromosome will be evaluated based on the value of fitness calculated based on the number of infractions that occurred on each individual chromosome. Where rule 1 is the number of screenings per ads must not be more than 5 times per day and rule 2 is there should never be two or more scheduling ads delivered on the same day and time. After fitness value of each chromosome is acquired, then the do the selection, crossover and mutation. From this research result, the optimal advertising schedule with schedule a whole day and ads data playback time ads with this level of accuracy: the average percentage was 83.79%.

Polygenic Scores for Major Depressive Disorder and Risk of Alcohol Dependence.

PubMed

Andersen, Allan M; Pietrzak, Robert H; Kranzler, Henry R; Ma, Li; Zhou, Hang; Liu, Xiaoming; Kramer, John; Kuperman, Samuel; Edenberg, Howard J; Nurnberger, John I; Rice, John P; Tischfield, Jay A; Goate, Alison; Foroud, Tatiana M; Meyers, Jacquelyn L; Porjesz, Bernice; Dick, Danielle M; Hesselbrock, Victor; Boerwinkle, Eric; Southwick, Steven M; Krystal, John H; Weissman, Myrna M; Levinson, Douglas F; Potash, James B; Gelernter, Joel; Han, Shizhong

2017-11-01

Major depressive disorder (MDD) and alcohol dependence (AD) are heritable disorders with significant public health burdens, and they are frequently comorbid. Common genetic factors that influence the co-occurrence of MDD and AD have been sought in family, twin, and adoption studies, and results to date have been promising but inconclusive. To examine whether AD and MDD overlap genetically, using a polygenic score approach. Association analyses were conducted between MDD polygenic risk score (PRS) and AD case-control status in European ancestry samples from 4 independent genome-wide association study (GWAS) data sets: the Collaborative Study on the Genetics of Alcoholism (COGA); the Study of Addiction, Genetics, and Environment (SAGE); the Yale-Penn genetic study of substance dependence; and the National Health and Resilience in Veterans Study (NHRVS). Results from a meta-analysis of MDD (9240 patients with MDD and 9519 controls) from the Psychiatric Genomics Consortium were applied to calculate PRS at thresholds from P < .05 to P ≤ .99 in each AD GWAS data set. Association between MDD PRS and AD. Participants analyzed included 788 cases (548 [69.5%] men; mean [SD] age, 38.2 [10.8] years) and 522 controls (151 [28.9.%] men; age [SD], 43.9 [11.6] years) from COGA; 631 cases (333 [52.8%] men; age [SD], 35.0 [7.7] years) and 756 controls (260 [34.4%] male; age [SD] 36.1 [7.7] years) from SAGE; 2135 cases (1375 [64.4%] men; age [SD], 39.4 [11.5] years) and 350 controls (126 [36.0%] men; age [SD], 43.5 [13.9] years) from Yale-Penn; and 317 cases (295 [93.1%] men; age [SD], 59.1 [13.1] years) and 1719 controls (1545 [89.9%] men; age [SD], 64.5 [13.3] years) from NHRVS. Higher MDD PRS was associated with a significantly increased risk of AD in all samples (COGA: best P = 1.7 × 10-6, R2 = 0.026; SAGE: best P = .001, R2 = 0.01; Yale-Penn: best P = .035, R2 = 0.0018; and NHRVS: best P = .004, R2 = 0.0074), with stronger evidence for association after meta-analysis of the 4 samples (best P = 3.3 × 10-9). In analyses adjusted for MDD status in 3 AD GWAS data sets, similar patterns of association were observed (COGA: best P = 7.6 × 10-6, R2 = 0.023; Yale-Penn: best P = .08, R2 = 0.0013; and NHRVS: best P = .006, R2 = 0.0072). After recalculating MDD PRS using MDD GWAS data sets without comorbid MDD-AD cases, significant evidence was observed for an association between the MDD PRS and AD in the meta-analysis of 3 GWAS AD samples without MDD cases (best P = .007). These results suggest that shared genetic susceptibility contributes modestly to MDD and AD comorbidity. Individuals with elevated polygenic risk for MDD may also be at risk for AD.

Genetic heterogeneity and Alzheimer`s disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schellenberg, G.D.; Wijsman, E.M.; Bird, T.D.

1994-09-01

In some early-onset Alzheimer`s disease (AD) families, inheritance is autosomal dominant. (Early-onset AD is arbitarily defined as onset at {le} 60 years.) Two loci have been identified which are causative for early-onset familial AD (FAD). One is the amyloid precursor protein gene in which specific mutation have been identified. The second is a locus at 14q24.3 (AD3) which has been localized by linkage analysis; the gene and specific mutations have not been identified. Linkage studies place this locus between D14S61 and D14S63. These 2 loci, however, do not account for all early-onset FAD. The Volga German (VG) kindreds are descendantsmore » of families which emigrated from Germany to the Volga river region of Russia and subsequently to the US; AD in these families is hypothesized to be the result of a common genetic founder. The average age-at-onset in these families is 57 years. Linkage analysis for this group has been negative for the APP gene and for chromosome 14 markers. Thus, there is at least 1 other early-onset FAD locus. Recently, the {epsilon}4 allele of apolipoprotein E (ApoE) was identified as a risk-factor for late-onset AD. In a series of 53 late-onset kindreds, a strong genetic association was observed between the ApoE {epsilon}4 allele and AD. However, when linkage analysis was performed using a highly polymorphic locus at the ApoCII gene, which is within 30 kb of ApoE, significant evidence for co-segregation was not observed. This and other data suggests that while ApoE is an age-at-onset modifying locus, another gene(s), located elsewhere, contribute(s) to late-onset AD. Thus, there is probably at least 1 other late-onset locus. Once the VG locus is identified, it will be possible to determine whether an allelic variant of this locus is responsible for late-onset FAD.« less

Deletion of Late Cornified Envelope 3B and 3C genes is not associated with atopic dermatitis.

PubMed

Bergboer, Judith G M; Zeeuwen, Patrick L J M; Irvine, Alan D; Weidinger, Stephan; Giardina, Emiliano; Novelli, Giuseppe; Den Heijer, Martin; Rodriguez, Elke; Illig, Thomas; Riveira-Munoz, Eva; Campbell, Linda E; Tyson, Jess; Dannhauser, Emma N; O'Regan, Gráinne M; Galli, Elena; Klopp, Norman; Koppelman, Gerard H; Novak, Natalija; Estivill, Xavier; McLean, W H Irwin; Postma, Dirkje S; Armour, John A L; Schalkwijk, Joost

2010-08-01

Atopic dermatitis (AD) and psoriasis are common skin diseases characterized by cutaneous inflammation and disturbed epidermal differentiation. Genome-wide analyses have shown overlapping susceptibility loci, such as the epidermal differentiation complex on chromosome 1q21. Recently, a deletion on 1q21 (LCE3C_LCE3B-del), comprising LCE3B and LCE3C, two members of the late cornified envelope (LCE) gene cluster, was found to be associated with psoriasis. Although the mechanistic role of LCE proteins in psoriasis has not been identified, these proteins are putatively involved in skin barrier formation and repair. Considering the potential genetic overlap between the two diseases and the recent finding that mutations in the skin barrier protein filaggrin are associated with AD, we investigated a possible association between LCE3C_LCE3B-del and AD. Evaluation of four different cohorts of European ancestry, containing a total of 1075 AD patients and 1658 controls, did not provide evidence for such an association. Subgroup analysis did not reveal an association with concomitant asthma. Our data suggest that the potential roles of skin barrier defects in the pathogenesis of AD and psoriasis are based on distinct genetic causes.

Behavioral assays with mouse models of Alzheimer’s disease: practical considerations and guidelines

PubMed Central

Puzzo, Daniela; Lee, Linda; Palmeri, Agostino; Calabrese, Giorgio; Arancio, Ottavio

2014-01-01

In Alzheimer’s disease (AD) basic research and drug discovery, mouse models are essential resources for uncovering biological mechanisms, validating molecular targets and screening potential compounds. Both transgenic and non-genetically modified mouse models enable access to different types of AD-like pathology in vivo. Although there is a wealth of genetic and biochemical studies on proposed AD pathogenic pathways, as a disease that centrally features cognitive failure, the ultimate readout for any interventions should be measures of learning and memory. This is particularly important given the lack of knowledge on disease etiology – assessment by cognitive assays offers the advantage of targeting relevant memory systems without requiring assumptions about pathogenesis. A multitude of behavioral assays are available for assessing cognitive functioning in mouse models, including ones specific for hippocampal-dependent learning and memory. Here we review the basics of available transgenic and non-transgenic AD mouse models and detail three well-established behavioral tasks commonly used for testing hippocampal-dependent cognition in mice – contextual fear conditioning, radial arm water maze and Morris water maze. In particular, we discuss the practical considerations, requirements and caveats of these behavioral testing paradigms. PMID:24462904

Common biological networks underlie genetic risk for alcoholism in African- and European-American populations.

PubMed

Kos, M Z; Yan, J; Dick, D M; Agrawal, A; Bucholz, K K; Rice, J P; Johnson, E O; Schuckit, M; Kuperman, S; Kramer, J; Goate, A M; Tischfield, J A; Foroud, T; Nurnberger, J; Hesselbrock, V; Porjesz, B; Bierut, L J; Edenberg, H J; Almasy, L

2013-07-01

Alcohol dependence (AD) is a heritable substance addiction with adverse physical and psychological consequences, representing a major health and economic burden on societies worldwide. Genes thus far implicated via linkage, candidate gene and genome-wide association studies (GWAS) account for only a small fraction of its overall risk, with effects varying across ethnic groups. Here we investigate the genetic architecture of alcoholism and report on the extent to which common, genome-wide SNPs collectively account for risk of AD in two US populations, African-Americans (AAs) and European-Americans (EAs). Analyzing GWAS data for two independent case-control sample sets, we compute polymarker scores that are significantly associated with alcoholism (P = 1.64 × 10(-3) and 2.08 × 10(-4) for EAs and AAs, respectively), reflecting the small individual effects of thousands of variants derived from patterns of allelic architecture that are population specific. Simulations show that disease models based on rare and uncommon causal variants (MAF < 0.05) best fit the observed distribution of polymarker signals. When scoring bins were annotated for gene location and examined for constituent biological networks, gene enrichment is observed for several cellular processes and functions in both EA and AA populations, transcending their underlying allelic differences. Our results reveal key insights into the complex etiology of AD, raising the possibility of an important role for rare and uncommon variants, and identify polygenic mechanisms that encompass a spectrum of disease liability, with some, such as chloride transporters and glycine metabolism genes, displaying subtle, modifying effects that are likely to escape detection in most GWAS designs. © 2013 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Association Between Genetic Traits for Immune-Mediated Diseases and Alzheimer Disease.

PubMed

Yokoyama, Jennifer S; Wang, Yunpeng; Schork, Andrew J; Thompson, Wesley K; Karch, Celeste M; Cruchaga, Carlos; McEvoy, Linda K; Witoelar, Aree; Chen, Chi-Hua; Holland, Dominic; Brewer, James B; Franke, Andre; Dillon, William P; Wilson, David M; Mukherjee, Pratik; Hess, Christopher P; Miller, Zachary; Bonham, Luke W; Shen, Jeffrey; Rabinovici, Gil D; Rosen, Howard J; Miller, Bruce L; Hyman, Bradley T; Schellenberg, Gerard D; Karlsen, Tom H; Andreassen, Ole A; Dale, Anders M; Desikan, Rahul S

2016-06-01

Late-onset Alzheimer disease (AD), the most common form of dementia, places a large burden on families and society. Although epidemiological and clinical evidence suggests a relationship between inflammation and AD, their relationship is not well understood and could have implications for treatment and prevention strategies. To determine whether a subset of genes involved with increased risk of inflammation are also associated with increased risk for AD. In a genetic epidemiology study conducted in July 2015, we systematically investigated genetic overlap between AD (International Genomics of Alzheimer's Project stage 1) and Crohn disease, ulcerative colitis, rheumatoid arthritis, type 1 diabetes, celiac disease, and psoriasis using summary data from genome-wide association studies at multiple academic clinical research centers. P values and odds ratios from genome-wide association studies of more than 100 000 individuals were from previous comparisons of patients vs respective control cohorts. Diagnosis for each disorder was previously established for the parent study using consensus criteria. The primary outcome was the pleiotropic (conjunction) false discovery rate P value. Follow-up for candidate variants included neuritic plaque and neurofibrillary tangle pathology; longitudinal Alzheimer's Disease Assessment Scale cognitive subscale scores as a measure of cognitive dysfunction (Alzheimer's Disease Neuroimaging Initiative); and gene expression in AD vs control brains (Gene Expression Omnibus data). Eight single-nucleotide polymorphisms (false discovery rate P < .05) were associated with both AD and immune-mediated diseases. Of these, rs2516049 (closest gene HLA-DRB5; conjunction false discovery rate P = .04 for AD and psoriasis, 5.37 × 10-5 for AD, and 6.03 × 10-15 for psoriasis) and rs12570088 (closest gene IPMK; conjunction false discovery rate P = .009 for AD and Crohn disease, P = 5.73 × 10-6 for AD, and 6.57 × 10-5 for Crohn disease) demonstrated the same direction of allelic effect between AD and the immune-mediated diseases. Both rs2516049 and rs12570088 were significantly associated with neurofibrillary tangle pathology (P = .01352 and .03151, respectively); rs2516049 additionally correlated with longitudinal decline on Alzheimer's Disease Assessment Scale cognitive subscale scores (β [SE], 0.405 [0.190]; P = .03). Regarding gene expression, HLA-DRA and IPMK transcript expression was significantly altered in AD brains compared with control brains (HLA-DRA: β [SE], 0.155 [0.024]; P = 1.97 × 10-10; IPMK: β [SE], -0.096 [0.013]; P = 7.57 × 10-13). Our findings demonstrate genetic overlap between AD and immune-mediated diseases and suggest that immune system processes influence AD pathogenesis and progression.

Association Between Genetic Traits for Immune-Mediated Diseases and Alzheimer Disease

PubMed Central

Yokoyama, Jennifer S.; Wang, Yunpeng; Schork, Andrew J.; Thompson, Wesley K.; Karch, Celeste M.; Cruchaga, Carlos; McEvoy, Linda K.; Witoelar, Aree; Chen, Chi-Hua; Holland, Dominic; Brewer, James B.; Franke, Andre; Dillon, William P.; Wilson, David M.; Mukherjee, Pratik; Hess, Christopher P.; Miller, Zachary; Bonham, Luke W.; Shen, Jeffrey; Rabinovici, Gil D.; Rosen, Howard J.; Miller, Bruce L.; Hyman, Bradley T.; Schellenberg, Gerard D.; Karlsen, Tom H.; Andreassen, Ole A.; Dale, Anders M.; Desikan, Rahul S.

2016-01-01

IMPORTANCE Late-onset Alzheimer disease (AD), the most common form of dementia, places a large burden on families and society. Although epidemiological and clinical evidence suggests a relationship between inflammation and AD, their relationship is not well understood and could have implications for treatment and prevention strategies. OBJECTIVE To determine whether a subset of genes involved with increased risk of inflammation are also associated with increased risk for AD. DESIGN, SETTING, AND PARTICIPANTS In a genetic epidemiology study conducted in July 2015, we systematically investigated genetic overlap between AD (International Genomics of Alzheimer’s Project stage 1) and Crohn disease, ulcerative colitis, rheumatoid arthritis, type 1 diabetes, celiac disease, and psoriasis using summary data from genome-wide association studies at multiple academic clinical research centers. P values and odds ratios from genome-wide association studies of more than 100 000 individuals were from previous comparisons of patients vs respective control cohorts. Diagnosis for each disorder was previously established for the parent study using consensus criteria. MAIN OUTCOMES AND MEASURES The primary outcome was the pleiotropic (conjunction) false discovery rate P value. Follow-up for candidate variants included neuritic plaque and neurofibrillary tangle pathology; longitudinal Alzheimer’s Disease Assessment Scale cognitive subscale scores as a measure of cognitive dysfunction (Alzheimer’s Disease Neuroimaging Initiative); and gene expression in AD vs control brains (Gene Expression Omnibus data). RESULTS Eight single-nucleotide polymorphisms (false discovery rate P < .05) were associated with both AD and immune-mediated diseases. Of these, rs2516049 (closest gene HLA-DRB5; conjunction false discovery rate P = .04 for AD and psoriasis, 5.37 × 10−5 for AD, and 6.03 × 10−15 for psoriasis) and rs12570088 (closest gene IPMK; conjunction false discovery rate P = .009 for AD and Crohn disease, P = 5.73 × 10−6 for AD, and 6.57 × 10−5 for Crohn disease) demonstrated the same direction of allelic effect between AD and the immune-mediated diseases. Both rs2516049 and rs12570088 were significantly associated with neurofibrillary tangle pathology (P = .01352 and .03151, respectively); rs2516049 additionally correlated with longitudinal decline on Alzheimer’s Disease Assessment Scale cognitive subscale scores (β [SE], 0.405 [0.190]; P = .03). Regarding gene expression, HLA-DRA and IPMK transcript expression was significantly altered in AD brains compared with control brains (HLA-DRA: β [SE], 0.155 [0.024]; P = 1.97 × 10−10; IPMK: β [SE], −0.096 [0.013]; P = 7.57 × 10−13). CONCLUSIONS AND RELEVANCE Our findings demonstrate genetic overlap between AD and immune-mediated diseases and suggest that immune system processes influence AD pathogenesis and progression. PMID:27088644

Molecular Genetic of Atopic dermatitis: An Update

PubMed Central

Al-Shobaili, Hani A.; Ahmed, Ahmed A.; Alnomair, Naief; Alobead, Zeiad Abdulaziz; Rasheed, Zafar

2016-01-01

Atopic dermatitis (AD) is a chronic multifactorial inflammatory skin disease. The pathogenesis of AD remains unclear, but the disease results from dysfunctions of skin barrier and immune response, where both genetic and environmental factors play a key role. Recent studies demonstrate the substantial evidences that show a strong genetic association with AD. As for example, AD patients have a positive family history and have a concordance rate in twins. Moreover, several candidate genes have now been suspected that play a central role in the genetic background of AD. In last decade advanced procedures similar to genome-wide association (GWA) and single nucleotide polymorphism (SNP) have been applied on different population and now it has been clarified that AD is significantly associated with genes of innate/adaptive immune systems, human leukocyte antigens (HLA), cytokines, chemokines, drug-metabolizing genes or various other genes. In this review, we will highlight the recent advancements in the molecular genetics of AD, especially on possible functional relevance of genetic variants discovered to date. PMID:27004062

Blood Ammonia as a Possible Etiological Agent for Alzheimer’s Disease

PubMed Central

Jin, Yan Yan; Singh, Parul; Chung, Hea-Jong; Hong, Seong-Tschool

2018-01-01

Alzheimer’s disease (AD), characterized by cognitive decline and devastating neurodegeneration, is the most common age-related dementia. Since AD is a typical example of a complex disease that is affected by various genetic and environmental factors, various factors could be involved in preventing and/or treating AD. Extracellular accumulation of beta-amyloid peptide (Aβ) and intracellular accumulation of tau undeniably play essential roles in the etiology of AD. However, interestingly enough, medications targeting Aβ or tau all failed and the only clinically efficient medications for AD are drugs targeting the cholinergic pathway. Also, a very intriguing discovery in AD is that the Mediterranean diet (MeDi), containing an unusually large quantity of Lactobacilli, is very effective in preventing AD. Based on recently emerging findings, it is our opinion that the reduction of blood ammonia levels by Lactobacilli in MeDi is the therapeutic agent of MeDi for AD. The recent evidence of Lactobacilli lowering blood ammonia level not only provides a link between AD and MeDi but also provides a foundation of pharmabiotics for hyperammonemia as well as various neurological diseases. PMID:29734664

Blood Ammonia as a Possible Etiological Agent for Alzheimer's Disease.

PubMed

Jin, Yan Yan; Singh, Parul; Chung, Hea-Jong; Hong, Seong-Tschool

2018-05-04

Alzheimer’s disease (AD), characterized by cognitive decline and devastating neurodegeneration, is the most common age-related dementia. Since AD is a typical example of a complex disease that is affected by various genetic and environmental factors, various factors could be involved in preventing and/or treating AD. Extracellular accumulation of beta-amyloid peptide (Aβ) and intracellular accumulation of tau undeniably play essential roles in the etiology of AD. However, interestingly enough, medications targeting Aβ or tau all failed and the only clinically efficient medications for AD are drugs targeting the cholinergic pathway. Also, a very intriguing discovery in AD is that the Mediterranean diet (MeDi), containing an unusually large quantity of Lactobacilli, is very effective in preventing AD. Based on recently emerging findings, it is our opinion that the reduction of blood ammonia levels by Lactobacilli in MeDi is the therapeutic agent of MeDi for AD. The recent evidence of Lactobacilli lowering blood ammonia level not only provides a link between AD and MeDi but also provides a foundation of pharmabiotics for hyperammonemia as well as various neurological diseases.

Redirecting adenovirus tropism by genetic, chemical, and mechanical modification of the adenovirus surface for cancer gene therapy.

PubMed

Yoon, A-Rum; Hong, Jinwoo; Kim, Sung Wan; Yun, Chae-Ok

2016-06-01

Despite remarkable advancements, clinical evaluations of adenovirus (Ad)-mediated cancer gene therapies have highlighted the need for improved delivery and targeting. Genetic modification of Ad capsid proteins has been extensively attempted. Although genetic modification enhances the therapeutic potential of Ad, it is difficult to successfully incorporate extraneous moieties into the capsid and the engineering process is laborious. Recently, chemical modification of the Ad surface with nanomaterials and targeting moieties has been found to enhance Ad internalization into the target by both passive and active mechanisms. Alternatively, external stimulus-mediated targeting can result in selective accumulation of Ad in the tumor and prevent dissemination of Ad into surrounding nontarget tissues. In the present review, we discuss various genetic, chemical, and mechanical engineering strategies for overcoming the challenges that hinder the therapeutic efficacy of Ad-based approaches. Surface modification of Ad by genetic, chemical, or mechanical engineering strategies enables Ad to overcome the shortcomings of conventional Ad and enhances delivery efficiency through distinct and unique mechanisms that unmodified Ad cannot mimic. However, although the therapeutic potential of Ad-mediated gene therapy has been enhanced by various surface modification strategies, each strategy still possesses innate limitations that must be addressed, requiring innovative ideas and designs.

Does a medical history of hypertension influence disclosing genetic testing results of the risk for salt-sensitive hypertension, in primary care?

PubMed

Okayama, Masanobu; Takeshima, Taro; Harada, Masanori; Ae, Ryusuke; Kajii, Eiji

2016-01-01

Disclosing genetic testing results may contribute to the prevention and management of many common diseases. However, whether the presence of a disease influences these effects is unclear. This study aimed to clarify the difference in the effects of disclosing genetic testing results of the risk for developing salt-sensitive hypertension on the behavioral modifications with respect to salt intake in hypertensive and nonhypertensive patients. A cross-sectional study using a self-administered questionnaire was conducted for outpatients aged >20 years (N=2,237) at six primary care clinics and hospitals in Japan. The main factors assessed were medical histories of hypertension, salt preferences, reduced salt intakes, and behavior modifications for reducing salt intake. Behavioral modifications of participants were assessed using their behavior stages before and after disclosure of the hypothetical genetic testing results. Of the 2,237 participants, 1,644 (73.5%) responded to the survey. Of these respondents, 558 (33.9%) patients were hypertensive and 1,086 (66.1%) were nonhypertensive. After being notified of the result "If with genetic risk", the nonhypertensive participants were more likely to make positive behavioral modifications compared to the hypertensive patients among all participants and in those aged <65 years (adjusted relative ratio [ad-RR], 1.76; 95% confidence interval, 1.12-2.76 and ad-RR, 1.99; 1.11-3.57, respectively). In contrast, no difference in negative behavioral modifications between hypertensive and nonhypertensive patients was detected after being notified of the result "If without genetic risk" (ad-RR, 1.05; 95% confidence interval, 0.70-1.57). The behavior of modifying salt intake after disclosure of the genetic testing results differed between hypertensive and nonhypertensive patients. Disclosing a genetic risk for salt-sensitive hypertension was likely to cause nonhypertensive patients, especially those aged <65 years, to improve their behavior regarding salt intake. We conclude that disclosing genetic testing results could help prevent hypertension, and that the doctor should communicate the genetic testing results to those patients with a medical history of hypertension, or those who are at risk of developing hypertension.

Parents' Decisions to Screen Their Newborn for Fragile X Syndrome. FPG Snapshot #63

ERIC Educational Resources Information Center

FPG Child Development Institute, 2011

2011-01-01

State newborn screening (NBS) programs have expanded in recent years, and more tests may be added in the future. The expansion of neonatal screening raises ethical, legal, and social questions. The questions surrounding NBS for fragile X syndrome (FXS) typify these concerns. FXS is an X-linked genetic condition that is the most common inherited…

A large early-onset Alzheimer`s disease pedigree linked to chromosome 14q24.3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hannequin, D.; Campion, D.; Brice, A.

1994-09-01

A large French pedigree including 34 subjects with early-onset progressive dementia was identified. In patients, the mean age-at-onset was 46 {plus_minus} 3.5 (SD) years and the mean age at death 52.6 {plus_minus} 5.7 (SD) years. No evidence for anticipation or genetic imprinting was found. Twelve patients were clinically diagnosed as probable Alzheimer`s disease (AD) according to the NINCDS-ADRDA criteria. Myoclonus and extrapyramidal signs were common and seizures were found in all affected subjects. At autopsy, neuropathological changes typical of AD were present in two brains. A significant lod score of 5.38 was observed at a recombination fraction of {theta} =more » 0.0 with the genetic marker D14S43, thereby establishing that the responsible gene was located on chromosome 14q24.3. Furthermore, no obligate recombinant was observed with markers D14S77 and D14S71. Typing other genetic markers in this region will allow us to localize more precisely the pathological gene.« less

Atherogenic dyslipidemia in children: evaluation of clinical, biochemical and genetic aspects.

PubMed

Montali, Anna; Truglio, Gessica; Martino, Francesco; Ceci, Fabrizio; Ferraguti, Giampiero; Ciociola, Ester; Maranghi, Marianna; Gianfagna, Francesco; Iacoviello, Licia; Strom, Roberto; Lucarelli, Marco; Arca, Marcello

2015-01-01

The precursors of atherogenic dyslipidemia (AD) are not well defined. Therefore, we investigated 62 non-obese, non-diabetic AD and 221 normolipemic children. Anthropometric parameters, blood pressure and biochemical measures were obtained in index children, their parents and all available siblings. The heritability (h(2)) of anthropometric and biochemical traits was estimated by SOLAR. Rare and common variants in APOA1 and LPL genes were screened by re-sequencing. Compared to normolipemic, AD children showed increased body mass index, waist circumference, plasma glucose, insulin, ApoB, HOMA-IR, hs-CRP and lower adiponectin (p<0.001 for all). Metabolic syndrome was present in 40% of AD while absent in controls. All traits (except adiponectin and hs-CRP) showed a strong familial aggregation, with plasma glucose having the highest heritability (89%). Overall, 4 LPL loss-of-function mutations were detected (p.Asp9Asn, p.Ser45Asn, p.Asn291Ser, p.Leu365Val) and their cumulative prevalence was higher in AD than in control children (0.073 vs. 0.026; P=0.038). The LPL p.S447* gain-of-function mutation, resulted to be less frequent in AD than in control children (0.064 vs. 0.126; P=0.082). No variant in the APOA1 gene was found. Our data indicate that AD is a rather common dyslipidemia in childhood; it associates with metabolic abnormalities typical of insulin resistant state and shows a strong familial aggregation. LPL variants may contribute to the development of AD phenotype.

Identification of genetic risk factors in the Chinese population implicates a role of immune system in Alzheimer's disease pathogenesis.

PubMed

Zhou, Xiaopu; Chen, Yu; Mok, Kin Y; Zhao, Qianhua; Chen, Keliang; Chen, Yuewen; Hardy, John; Li, Yun; Fu, Amy K Y; Guo, Qihao; Ip, Nancy Y

2018-02-20

Alzheimer's disease (AD) is a leading cause of mortality among the elderly. We performed a whole-genome sequencing study of AD in the Chinese population. In addition to the variants identified in or around the APOE locus (sentinel variant rs73052335, P = 1.44 × 10 -14 ), two common variants, GCH1 (rs72713460, P = 4.36 × 10 -5 ) and KCNJ15 (rs928771, P = 3.60 × 10 -6 ), were identified and further verified for their possible risk effects for AD in three small non-Asian AD cohorts. Genotype-phenotype analysis showed that KCNJ15 variant rs928771 affects the onset age of AD, with earlier disease onset in minor allele carriers. In addition, altered expression level of the KCNJ15 transcript can be observed in the blood of AD subjects. Moreover, the risk variants of GCH1 and KCNJ15 are associated with changes in their transcript levels in specific tissues, as well as changes of plasma biomarkers levels in AD subjects. Importantly, network analysis of hippocampus and blood transcriptome datasets suggests that the risk variants in the APOE , GCH1 , and KCNJ15 loci might exert their functions through their regulatory effects on immune-related pathways. Taking these data together, we identified common variants of GCH1 and KCNJ15 in the Chinese population that contribute to AD risk. These variants may exert their functional effects through the immune system. Copyright © 2018 the Author(s). Published by PNAS.

Polygenic risk of Alzheimer disease is associated with early- and late-life processes.

PubMed

Mormino, Elizabeth C; Sperling, Reisa A; Holmes, Avram J; Buckner, Randy L; De Jager, Philip L; Smoller, Jordan W; Sabuncu, Mert R

2016-08-02

To examine associations between aggregate genetic risk and Alzheimer disease (AD) markers in stages preceding the clinical symptoms of dementia using data from 2 large observational cohort studies. We computed polygenic risk scores (PGRS) using summary statistics from the International Genomics of Alzheimer's Project genome-wide association study of AD. Associations between PGRS and AD markers (cognitive decline, clinical progression, hippocampus volume, and β-amyloid) were assessed within older participants with dementia. Associations between PGRS and hippocampus volume were additionally examined within healthy younger participants (age 18-35 years). Within participants without dementia, elevated PGRS was associated with worse memory (p = 0.002) and smaller hippocampus (p = 0.002) at baseline, as well as greater longitudinal cognitive decline (memory: p = 0.0005, executive function: p = 0.01) and clinical progression (p < 0.00001). High PGRS was associated with AD-like levels of β-amyloid burden as measured with florbetapir PET (p = 0.03) but did not reach statistical significance for CSF β-amyloid (p = 0.11). Within the younger group, higher PGRS was associated with smaller hippocampus volume (p = 0.05). This pattern was evident when examining a PGRS that included many loci below the genome-wide association study (GWAS)-level significance threshold (16,123 single nucleotide polymorphisms), but not when PGRS was restricted to GWAS-level significant loci (18 single nucleotide polymorphisms). Effects related to common genetic risk loci distributed throughout the genome are detectable among individuals without dementia. The influence of this genetic risk may begin in early life and make an individual more susceptible to cognitive impairment in late life. Future refinement of polygenic risk scores may help identify individuals at risk for AD dementia. © 2016 American Academy of Neurology.

Genetic susceptibility for Alzheimer disease neuritic plaque pathology.

PubMed

Shulman, Joshua M; Chen, Kewei; Keenan, Brendan T; Chibnik, Lori B; Fleisher, Adam; Thiyyagura, Pradeep; Roontiva, Auttawut; McCabe, Cristin; Patsopoulos, Nikolaos A; Corneveaux, Jason J; Yu, Lei; Huentelman, Matthew J; Evans, Denis A; Schneider, Julie A; Reiman, Eric M; De Jager, Philip L; Bennett, David A

2013-09-01

While numerous genetic susceptibility loci have been identified for clinical Alzheimer disease (AD), it is important to establish whether these variants are risk factors for the underlying disease pathology, including neuritic plaques. To investigate whether AD susceptibility loci from genome-wide association studies affect neuritic plaque pathology and to additionally identify novel risk loci for this trait. Candidate analysis of single-nucleotide polymorphisms and genome-wide association study in a joint clinicopathologic cohort, including 725 deceased subjects from the Religious Orders Study and the Rush Memory and Aging Project (2 prospective, community-based studies), followed by targeted validation in an independent neuroimaging cohort, including 114 subjects from multiple clinical and research centers. A quantitative measure of neuritic plaque pathologic burden, based on assessments of silver-stained tissue averaged from multiple brain regions. Validation based on β-amyloid load by immunocytochemistry, and replication with fibrillar β-amyloid positron emission tomographic imaging with Pittsburgh Compound B or florbetapir. Besides the previously reported APOE and CR1 loci, we found that the ABCA7 (rs3764650; P = .02) and CD2AP (rs9349407; P = .03) AD susceptibility loci are associated with neuritic plaque burden. In addition, among the top results of our genome-wide association study, we discovered a novel variant near the amyloid precursor protein gene (APP, rs2829887) that is associated with neuritic plaques (P = 3.3 × 10-6). This polymorphism was associated with postmortem β-amyloid load as well as fibrillar β-amyloid in 2 independent cohorts of adults with normal cognition. These findings enhance understanding of AD risk factors by relating validated susceptibility alleles to increased neuritic plaque pathology and implicate common genetic variation at the APP locus in the earliest, presymptomatic stages of AD.

Polygenic risk of Alzheimer disease is associated with early- and late-life processes

PubMed Central

Sperling, Reisa A.; Holmes, Avram J.; Buckner, Randy L.; De Jager, Philip L.; Smoller, Jordan W.; Sabuncu, Mert R.

2016-01-01

Objective: To examine associations between aggregate genetic risk and Alzheimer disease (AD) markers in stages preceding the clinical symptoms of dementia using data from 2 large observational cohort studies. Methods: We computed polygenic risk scores (PGRS) using summary statistics from the International Genomics of Alzheimer's Project genome-wide association study of AD. Associations between PGRS and AD markers (cognitive decline, clinical progression, hippocampus volume, and β-amyloid) were assessed within older participants with dementia. Associations between PGRS and hippocampus volume were additionally examined within healthy younger participants (age 18–35 years). Results: Within participants without dementia, elevated PGRS was associated with worse memory (p = 0.002) and smaller hippocampus (p = 0.002) at baseline, as well as greater longitudinal cognitive decline (memory: p = 0.0005, executive function: p = 0.01) and clinical progression (p < 0.00001). High PGRS was associated with AD-like levels of β-amyloid burden as measured with florbetapir PET (p = 0.03) but did not reach statistical significance for CSF β-amyloid (p = 0.11). Within the younger group, higher PGRS was associated with smaller hippocampus volume (p = 0.05). This pattern was evident when examining a PGRS that included many loci below the genome-wide association study (GWAS)–level significance threshold (16,123 single nucleotide polymorphisms), but not when PGRS was restricted to GWAS-level significant loci (18 single nucleotide polymorphisms). Conclusions: Effects related to common genetic risk loci distributed throughout the genome are detectable among individuals without dementia. The influence of this genetic risk may begin in early life and make an individual more susceptible to cognitive impairment in late life. Future refinement of polygenic risk scores may help identify individuals at risk for AD dementia. PMID:27385740

Associations between self-referral and health behavior responses to genetic risk information.

PubMed

Christensen, Kurt D; Roberts, J Scott; Zikmund-Fisher, Brian J; Kardia, Sharon Lr; McBride, Colleen M; Linnenbringer, Erin; Green, Robert C

2015-01-01

Studies examining whether genetic risk information about common, complex diseases can motivate individuals to improve health behaviors and advance planning have shown mixed results. Examining the influence of different study recruitment strategies may help reconcile inconsistencies. Secondary analyses were conducted on data from the REVEAL study, a series of randomized clinical trials examining the impact of genetic susceptibility testing for Alzheimer's disease (AD). We tested whether self-referred participants (SRPs) were more likely than actively recruited participants (ARPs) to report health behavior and advance planning changes after AD risk and APOE genotype disclosure. Of 795 participants with known recruitment status, 546 (69%) were self-referred and 249 (31%) had been actively recruited. SRPs were younger, less likely to identify as African American, had higher household incomes, and were more attentive to AD than ARPs (all P < 0.01). They also dropped out of the study before genetic risk disclosure less frequently (26% versus 41%, P < 0.001). Cohorts did not differ in their likelihood of reporting a change to at least one health behavior 6 weeks and 12 months after genetic risk disclosure, nor in intentions to change at least one behavior in the future. However, interaction effects were observed where ε4-positive SRPs were more likely than ε4-negative SRPs to report changes specifically to mental activities (38% vs 19%, p < 0.001) and diets (21% vs 12%, p = 0.016) six weeks post-disclosure, whereas differences between ε4-positive and ε4-negative ARPs were not evident for mental activities (15% vs 21%, p = 0.413) or diets (8% versus 16%, P = 0.190). Similarly, ε4-positive participants were more likely than ε4-negative participants to report intentions to change long-term care insurance among SRPs (20% vs 5%, p < 0.001), but not ARPs (5% versus 9%, P = 0.365). Individuals who proactively seek AD genetic risk assessment are more likely to undergo testing and use results to inform behavior changes than those who respond to genetic testing offers. These results demonstrate how the behavioral impact of genetic risk information may vary according to the models by which services are provided, and suggest that how participants are recruited into translational genomics research can influence findings. ClinicalTrials.gov NCT00089882 and NCT00462917.

Deciphering the Complexities of Atopic Dermatitis: Shifting Paradigms in Treatment Approaches

PubMed Central

Leung, Donald Y. M.; Guttman-Yassky, Emma

2014-01-01

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease. It often precedes the development of food allergy and asthma. Recent insights into AD reveal abnormalities in terminal differentiation of the epidermal epithelium leading to a defective stratum corneum, which allows enhanced allergen penetration and systemic IgE sensitization. Atopic skin is also predisposed to colonization or infection by pathogenic microbes, most notably Staphylococcus aureus and herpes simplex virus (HSV). Causes of this abnormal skin barrier are complex and driven by a combination of genetic, environmental and immunologic factors. These factors likely account for the heterogeneity of AD onset, severity and natural history of this skin disease. Recent studies suggest prevention of AD can be achieved by early interventions protecting the skin barrier. Onset of lesional AD requires effective control of local and systemic immune activation for optimal management. Early intervention may improve long term outcomes for AD and reduce the systemic allergen sensitization leading to associated allergic diseases in the gastrointestinal and respiratory tract. PMID:25282559

Anesthesia and Tau Pathology

PubMed Central

Whittington, Robert A.; Bretteville, Alexis; Dickler, Maya F.; Planel, Emmanuel

2013-01-01

Alzheimer’s disease (AD) is the most common form of dementia and remains a growing worldwide health problem. As life expectancy continues to increase, the number of AD patients presenting for surgery and anesthesia will steadily rise. The etiology of sporadic AD is thought to be multifactorial, with environmental, biological and genetic factors interacting together to influence AD pathogenesis. Recent reports suggest that general anesthetics may be such a factor and may contribute to the development and exacerbation of this neurodegenerative disorder. Intra-neuronal neurofibrillary tangles (NFT), composed of hyperphosphorylated and aggregated tau protein are one of the main neuropathological hallmarks of AD. Tau pathology is important in AD as it correlates very well with cognitive dysfunction. Lately, several studies have begun to elucidate the mechanisms by which anesthetic exposure might affect the phosphorylation, aggregation and function of this microtubule-associated protein. Here, we specifically review the literature detailing the impact of anesthetic administration on aberrant tau hyperphosphorylation as well as the subsequent development of neurofibrillary pathology and degeneration. PMID:23535147

Molecular mechanisms of the genetic risk factors in pathogenesis of Alzheimer disease.

PubMed

Kanatsu, Kunihiko; Tomita, Taisuke

2017-01-01

Alzheimer disease (AD) is a neurodegenerative disease characterized by the extensive deposition of senile plaques and neurofibrillary tangles. Until recently, only the APOE gene had been known as a genetic risk factor for late-onset AD (LOAD), which accounts for more than 95% of all AD cases. However, in addition to this well-established genetic risk factor, genome-wide association studies have identified several single nucleotide polymorphisms as genetic risk factors of LOAD, such as PICALM and BIN1 . In addition, whole genome sequencing and exome sequencing have identified rare variants associated with LOAD, including TREM2 . We review the recent findings related to the molecular mechanisms by which these genetic risk factors contribute to AD, and our perspectives regarding the etiology of AD for the development of therapeutic agents.

Loss of Neuroprotective Factors in Neurodegenerative Dementias: The End or the Starting Point?

PubMed Central

Benussi, Luisa; Binetti, Giuliano; Ghidoni, Roberta

2017-01-01

Recent clinical, genetic and biochemical experimental evidences highlight the existence of common molecular pathways underlying neurodegenerative diseases. In this review, we will explore a key common pathological mechanism, i.e., the loss of neuroprotective factors, across the three major neurodegenerative diseases leading to dementia: Alzheimer's disease (AD), Frontotemporal dementia (FTD) and Lewy body dementia (LBD). We will report evidences that the Brain Derived Neurotrophic Factor (BDNF), the most investigated and characterized brain neurotrophin, progranulin, a multi-functional adipokine with trophic and growth factor properties, and cystatin C, a neuroprotective growth factor, are reduced in AD, FTD, and LBD. Moreover, we will review the molecular mechanism underlying the loss of neuroprotective factors in neurodegenerative diseases leading to dementia, with a special focus on endo-lysosomal pathway and intercellular communication mediated by extracellular vesicles. Exploring the shared commonality of disease mechanisms is of pivotal importance to identify novel potential therapeutic targets and to develop treatments to delay, slow or block disease progression. PMID:29249935

Early Environmental Origins of Neurodegenerative Disease in Later Life

PubMed Central

Landrigan, Philip J.; Sonawane, Babasaheb; Butler, Robert N.; Trasande, Leonardo; Callan, Richard; Droller, Daniel

2005-01-01

Parkinson disease (PD) and Alzheimer disease (AD), the two most common neurodegenerative disorders in American adults, are of purely genetic origin in a minority of cases and appear in most instances to arise through interactions among genetic and environmental factors. In this article we hypothesize that environmental exposures in early life may be of particular etiologic importance and review evidence for the early environmental origins of neurodegeneration. For PD the first recognized environmental cause, MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), was identified in epidemiologic studies of drug abusers. Chemicals experimentally linked to PD include the insecticide rotenone and the herbicides paraquat and maneb; interaction has been observed between paraquat and maneb. In epidemiologic studies, manganese has been linked to parkinsonism. In dementia, lead is associated with increased risk in chronically exposed workers. Exposures of children in early life to lead, polychlorinated biphenyls, and methylmercury have been followed by persistent decrements in intelligence that may presage dementia. To discover new environmental causes of AD and PD, and to characterize relevant gene–environment interactions, we recommend that a large, prospective genetic and epidemiologic study be undertaken that will follow thousands of children from conception (or before) to old age. Additional approaches to etiologic discovery include establishing incidence registries for AD and PD, conducting targeted investigations in high-risk populations, and improving testing of the potential neurologic toxicity of chemicals. PMID:16140633

Unravelling the genetic basis of simplex Retinitis Pigmentosa cases

PubMed Central

Bravo-Gil, Nereida; González-del Pozo, María; Martín-Sánchez, Marta; Méndez-Vidal, Cristina; Rodríguez-de la Rúa, Enrique; Borrego, Salud; Antiñolo, Guillermo

2017-01-01

Retinitis Pigmentosa (RP) is the most common form of inherited retinal dystrophy (IRD) characterized ultimately by photoreceptors degeneration. Exhibiting great clinical and genetic heterogeneity, RP can be inherited as an autosomal dominant (ad), autosomal recessive (ar) and X-linked (xl) disorder. Although the relative prevalence of each form varies somewhat between populations, a major proportion (41% in Spain) of patients represent simplex cases (sRP) in which the mode of inheritance is unknown. Molecular genetic diagnostic is crucial, but also challenging, for sRP patients because any of the 81 RP genes identified to date may be causative. Herein, we report the use of a customized targeted gene panel consisting of 68 IRD genes for the molecular characterization of 106 sRP cases. The diagnostic rate was 62.26% (66 of 106) with a proportion of clinical refinements of 30.3%, demonstrating the high efficiency of this genomic approach even for clinically ambiguous cases. The high number of patients diagnosed here has allowed us to study in detail the genetic basis of the sRP. The solved sRP cohort is composed of 62.1% of arRP cases, 24.2% of adRP and 13.6% of xlRP, which implies consequences for counselling of patients and families. PMID:28157192

[Current status of the predictive genetic testing for hereditary neurological diseases in Shinshu University Hospital].

PubMed

Tanaka, Keiko; Sekijima, Yoshiki; Yoshida, Kunihiro; Mizuuchi, Asako; Yamashita, Hiromi; Tamai, Mariko; Ikeda, Shu-ichi; Fukushima, Yoshimitsu

2013-01-01

The current status of predictive genetic testing for late-onset hereditary neurological diseases in Japan is largely unknown. In this study, we analyzed data from 73 clients who visited the Division of Clinical and Molecular Genetics, Shinshu University Hospital, for the purpose of predictive genetic testing. The clients consisted of individuals with family histories of familial amyloid polyneuropathy (FAP; n=30), Huntington's disease (HD; n=16), spinocerebellar degeneration (SCD; n=14), myotonic dystrophy type 1 (DM1; n=9), familial amyotrophic lateral sclerosis type 1 (ALS1; n=3), and Alzheimer's disease (AD; n=1). Forty-nine of the 73 (67.1%) clients were in their twenties or thirties. Twenty-seven of the 73 (37.0%) clients visited a medical institution within 3 months after becoming aware of predictive genetic testing. The most common reason for requesting predictive genetic testing was a need for certainty or to reduce uncertainty and anxiety. The decision-making about marriage and having a child was also a main reason in clients in the twenties and thirties. The numbers of clients who actually underwent predictive genetic testing was 22 of 30 (73.3%) in FAP, 3 of 16 (18.8%) in HD, 6 of 10 (60.0%) in SCD, 7 of 9 (77.8%) in DM1, and 0 of 3 (0%) in ALS1 (responsible gene of the disease was unknown in 4 SCD patients and an AD patient). The percentage of test usage was lower in untreatable diseases such as HD and SCD than that in FAP, suggesting that many clients changed their way of thinking on the significance of testing through multiple genetic counseling sessions. In addition, it was obvious that existence of disease-modifying therapy promoted usage of predictive genetic testing in FAP. Improvement of genetic counseling system to manage predictive genetic testing is necessary, as consultation concerning predictive genetic testing is the main motivation to visit genetic counseling clinic in many at-risk clients.

Genetic association of ubiquilin with Alzheimer's disease and related quantitative measures.

PubMed

Kamboh, M I; Minster, R L; Feingold, E; DeKosky, S T

2006-03-01

The gene coding for ubiquilin 1 (UBQLN1) is located near a linkage peak on chromosome 9q22.2 and it also impacts the function of presenilin proteins involved in early-onset Alzheimer's disease (AD). Recently, genetic variation in UBQLN1 has been shown to affect the risk of AD in two independent family-based samples. The purpose of this study was to confirm the reported association in a large case-control sample and to also examine the association of UBQLN1 SNPs with quantitative measures of AD progression, namely age-at-onset (AAO), disease duration and Mini-Mental State Examination (MMSE) score. We examined the associations of three SNPs in the UBQLN1 gene (intron 6/A>C, intron 8/T>C and intron 9/A>G) in up to 978 LOAD cases and 808 controls. All SNPs were in significant linkage disequilibrium (P<0.0001). While modest significant associations were observed in the single-site regression analysis, 3-site haplotype analysis revealed significant associations (P<0.0001 for overall haplotype analysis). One common haplotype (H4) defined by intron 6/A-intron 8/C-intron 9/G alleles was associated with AD risk and one less common haplotype (H5) defined by intron 6/C-intron 8/C-intron 9/A alleles was associated with protection. The adjusted odds ratios with potentially one and two copies of risk haplotype H4 were 1.5 (95% CI: 0.99-2.26; P=0.054) and 3.66 (95% CI: 1.43-9.39; P=0.007), respectively, and odds ratio for haplotype H5 carriers was 0.31 (95% CI: 0.10-0.95; P=0.0398). In addition to disease risk, the homozygosity of the risk haplotype was also associated with older AAO, longer disease duration and lower MMSE score. In summary, our data from a large case-control cohort indicate that genetic variation in the UBQLN1 gene has a modest effect on risk, AAO and disease duration of AD. Our haplotype data suggest the presence of additional putative functional variants either in the UBQLN1 gene or nearby genes and provide strong justification for additional work in this region on chromosome 9.

Familial occurrence of cervical artery dissection--coincidence or sign of familial predisposition?

PubMed

Grond-Ginsbach, Caspar; de Freitas, Gabriel R; Campos, Cynthia R; Thie, Andreas; Caso, Valeria; Machetanz, Jochen; Kloss, Manja

2012-01-01

BACKGROUNDAND PURPOSE: The etiology of spontaneous cervical artery dissection (CeAD) is poorly understood in most patients. Mild cervical trauma preceding the dissection event is a common finding, but many CeAD occur spontaneously. It is likely that genetic factors may increase the risk for CeAD. However, familial cases are excedingly rare. Familial clustering of CeAD may be accidental or associated with genetic or environmental risk factors shared between affected relatives. In this explorative study, we aim to show that specific risk factors for familial CeAD exist. Age of onset, sex, affected artery and number of recurrent CeAD were documented for familial patients and compared with published findings from patients with sporadic CeAD. Concordance of age, sex and dissected artery within the families was analyzed by correlation analysis and by analysis of variance or Kruskal-Wallis testing. The study sample consisted of 9 new patients with a family history of CeAD enrolled in the Neurology Department of the University of Heidelberg or referred to Heidelberg from other centers. The study sample also included published findings from another 23 patients, in total 32 patients. The mean age of the patients with familial CeAD at their first dissections was 38.4 ± 13.3 years. Twenty (62.5%) patients were female and 12 patients (37.5%) suffered multiple dissections. Four patients (12.5%) presented with recurrent dissections after >1 year. Patients with a familial history of CeAD were younger (p = 0.023) and presented more often with multiple dissections (p = 0.024) and recurrent dissections (p = 0.018). Age at the first event (correlation analysis p = 0.026; analysis of variance p = 0.029) and site of the dissection (correlation analysis p = 0.032; Kruskal-Wallis test p = 0.018) differed between the families, and there was no concordance of gender of affected family members (correlation analysis p = 0.500; Kruskal-Wallis test p = 0.211). The high prevalence of multiple dissection events and of long-term (>1 year) recurrent dissections in patients with a familial history of CeAD indicates that a specific predisposition for familial CeAD exists. Since age of onset and affected vessel differ between families, the risk profile for familial CeAD is heterogeneous. A large-scale (whole exome) sequencing analysis of 14 patients from 7 of the analyzed families is currently being performed in order to identify causative genetic variants. Copyright © 2012 S. Karger AG, Basel.

Sigma receptor type 1 gene variation in a group of Polish patients with Alzheimer's disease and mild cognitive impairment.

PubMed

Maruszak, Aleksandra; Safranow, Krzysztof; Gacia, Magdalena; Gabryelewicz, Tomasz; Słowik, Agnieszka; Styczyńska, Maria; Pepłońska, Beata; Golan, Maciej P; Zekanowski, Cezary; Barcikowska, Maria

2007-01-01

The sigma-1 receptor (SIGMAR1) is a subtype of a nonopioid sigma receptor family and is implicated in numerous functions connected with Alzheimer's disease (AD). Two common genetic variants were identified in SIGMAR1: GC-241 -240TT and Q2P (A61C). It was suggested that the TT-C haplotype is a protective factor for AD. We decided to investigate a putative link between the variants of SIGMAR1 and AD in a group of Polish patients with late-onset AD, in patients with mild cognitive impairment, and in a control group. We observed no significant differences for the SIGMAR1 allele, genotype, haplotype, and diplotype distributions between the studied groups. Multivariate logistic regression analysis showed no interaction between the APOE4 and SIGMAR1 polymorphisms. Further studies using data from different populations are required to elucidate the effect of SIGMAR1 polymorphisms on AD.

A mitocentric view of Alzheimer's disease suggests multi-faceted treatments.

PubMed

Gibson, Gary E; Shi, Qingli

2010-01-01

Alzheimer's disease (AD) is defined by senile plaques made of amyloid-beta peptide (Abeta), neurofibrillary tangles made of hyperphosphorylated tau proteins, and memory deficits. Thus, the events initiating the cascade leading to these end points may be more effective therapeutic targets than treating each facet individually. In the small percentage of cases of AD that are genetic (or animal models that reflect this form of AD), the factor initiating AD is clear (e.g., genetic mutations lead to high Abeta1-42 or hyperphosphorylated tau proteins). In the vast majority of AD cases, the cause is unknown. Substantial evidence now suggests that abnormalities in glucose metabolism/mitochondrial function/oxidative stress (GMO) are an invariant feature of AD and occur at an early stage of the disease process in both genetic and non-genetic forms of AD. Indeed, decreases in brain glucose utilization are diagnostic for AD. Changes in calcium homeostasis also precede clinical manifestations of AD. Abnormal GMO can lead to plaques, tangles, and the calcium abnormalities that accompany AD. Abnormalities in GMO diminish the ability of the brain to adapt. Therapies targeting mitochondria may ameliorate abnormalities in plaques, tangles, calcium homeostasis, and cognition that comprise AD.

Nature Versus Nurture: Does Proteostasis Imbalance Underlie the Genetic, Environmental, and Age-Related Risk Factors for Alzheimer's Disease?

PubMed

Kikis, Elise A

2017-08-22

Aging is a risk factor for a number of "age-related diseases", including Alzheimer's disease (AD). AD affects more than a third of all people over the age of 85, and is the leading cause of dementia worldwide. Symptoms include forgetfulness, memory loss, and cognitive decline, ultimately resulting in the need for full-time care. While there is no cure for AD, pharmacological approaches to alleviate symptoms and target underlying causes of the disease have been developed, albeit with limited success. This review presents the age-related, genetic, and environmental risk factors for AD and proposes a hypothesis for the mechanistic link between genetics and the environment. In short, much is known about the genetics of early-onset familial AD (EO-FAD) and the central role played by the Aβ peptide and protein misfolding, but late-onset AD (LOAD) is not thought to have direct genetic causes. Nonetheless, genetic risk factors such as isoforms of the protein ApoE have been identified. Additional findings suggest that air pollution caused by the combustion of fossil fuels may be an important environmental risk factor for AD. A hypothesis suggesting that poor air quality might act by disrupting protein folding homeostasis (proteostasis) is presented.

Modifying dementia risk and trajectories of cognitive decline in aging: the Cache County Memory Study.

PubMed

Welsh-Bohmer, Kathleen A; Breitner, John C S; Hayden, Kathleen M; Lyketsos, Constantine; Zandi, Peter P; Tschanz, Joann T; Norton, Maria C; Munger, Ron

2006-07-01

The Cache County Study of Memory, Health, and Aging, more commonly referred to as the "Cache County Memory Study (CCMS)" is a longitudinal investigation of aging and Alzheimer's disease (AD) based in an exceptionally long-lived population residing in northern Utah. The study begun in 1994 has followed an initial cohort of 5,092 older individuals (many over age 84) and has examined the development of cognitive impairment and dementia in relation to genetic and environmental antecedents. This article summarizes the major contributions of the CCMS towards the understanding of mild cognitive disorders and AD across the lifespan, underscoring the role of common health exposures in modifying dementia risk and trajectories of cognitive change. The study now in its fourth wave of ascertainment illustrates the role of population-based approaches in informing testable models of cognitive aging and Alzheimer's disease.

Characterization of pathogenic SORL1 genetic variants for association with Alzheimer’s disease: a clinical interpretation strategy

PubMed Central

Holstege, Henne; van der Lee, Sven J; Hulsman, Marc; Wong, Tsz Hang; van Rooij, Jeroen GJ; Weiss, Marjan; Louwersheimer, Eva; Wolters, Frank J; Amin, Najaf; Uitterlinden, André G; Hofman, Albert; Ikram, M Arfan; van Swieten, John C; Meijers-Heijboer, Hanne; van der Flier, Wiesje M; Reinders, Marcel JT; van Duijn, Cornelia M; Scheltens, Philip

2017-01-01

Accumulating evidence suggests that genetic variants in the SORL1 gene are associated with Alzheimer disease (AD), but a strategy to identify which variants are pathogenic is lacking. In a discovery sample of 115 SORL1 variants detected in 1908 Dutch AD cases and controls, we identified the variant characteristics associated with SORL1 variant pathogenicity. Findings were replicated in an independent sample of 103 SORL1 variants detected in 3193 AD cases and controls. In a combined sample of the discovery and replication samples, comprising 181 unique SORL1 variants, we developed a strategy to classify SORL1 variants into five subtypes ranging from pathogenic to benign. We tested this pathogenicity screen in SORL1 variants reported in two independent published studies. SORL1 variant pathogenicity is defined by the Combined Annotation Dependent Depletion (CADD) score and the minor allele frequency (MAF) reported by the Exome Aggregation Consortium (ExAC) database. Variants predicted strongly damaging (CADD score >30), which are extremely rare (ExAC-MAF <1 × 10−5) increased AD risk by 12-fold (95% CI 4.2–34.3; P=5 × 10−9). Protein-truncating SORL1 mutations were all unknown to ExAC and occurred exclusively in AD cases. More common SORL1 variants (ExAC-MAF≥1 × 10−5) were not associated with increased AD risk, even when predicted strongly damaging. Findings were independent of gender and the APOE-ε4 allele. High-risk SORL1 variants were observed in a substantial proportion of the AD cases analyzed (2%). Based on their effect size, we propose to consider high-risk SORL1 variants next to variants in APOE, PSEN1, PSEN2 and APP for personalized risk assessments in clinical practice. PMID:28537274

Molecular Mechanisms of Cutaneous Inflammatory Disorder: Atopic Dermatitis

PubMed Central

Kim, Jung Eun; Kim, Jong Sic; Cho, Dae Ho; Park, Hyun Jeong

2016-01-01

Atopic dermatitis (AD) is a multifactorial inflammatory skin disease resulting from interactions between genetic susceptibility and environmental factors. The pathogenesis of AD is poorly understood, and the treatment of recalcitrant AD is still challenging. There is accumulating evidence for new gene polymorphisms related to the epidermal barrier function and innate and adaptive immunity in patients with AD. Newly-found T cells and dendritic cell subsets, cytokines, chemokines and signaling pathways have extended our understanding of the molecular pathomechanism underlying AD. Genetic changes caused by environmental factors have been shown to contribute to the pathogenesis of AD. We herein present a review of the genetics, epigenetics, barrier dysfunction and immunological abnormalities in AD with a focus on updated molecular biology. PMID:27483258

Recent Progress in Alzheimer’s Disease Research, Part 2: Genetics and Epidemiology

PubMed Central

Robinson, Morgan; Lee, Brenda Y.; Hane, Francis T.

2017-01-01

This is the second part of a three-part review series reviewing the most important advances in Alzheimer’s disease (AD) research since 2010. This review covers the latest research on genetics and epidemiology. Epidemiological and genetic studies are revealing important insights into the etiology of, and factors that contribute to AD, as well as areas of priority for research into mechanisms and interventions. The widespread adoption of genome wide association studies has provided compelling evidence of the genetic complexity of AD with genes associated with such diverse physiological function as immunity and lipid metabolism being implicated in AD pathogenesis. PMID:28211812

Endo-lysosomal and autophagic dysfunction: a driving factor in Alzheimer's disease?

PubMed

Whyte, Lauren S; Lau, Adeline A; Hemsley, Kim M; Hopwood, John J; Sargeant, Timothy J

2017-03-01

Alzheimer's disease (AD) is the most common cause of dementia, and its prevalence will increase significantly in the coming decades. Although important progress has been made, fundamental pathogenic mechanisms as well as most hereditary contributions to the sporadic form of the disease remain unknown. In this review, we examine the now substantial links between AD pathogenesis and lysosomal biology. The lysosome hydrolyses and processes cargo delivered by multiple pathways, including endocytosis and autophagy. The endo-lysosomal and autophagic networks are central to clearance of cellular macromolecules, which is important given there is a deficit in clearance of amyloid-β in AD. Numerous studies show prominent lysosomal dysfunction in AD, including perturbed trafficking of lysosomal enzymes and accumulation of the same substrates that accumulate in lysosomal storage disorders. Examination of the brain in lysosomal storage disorders shows the accumulation of amyloid precursor protein metabolites, which further links lysosomal dysfunction with AD. This and other evidence leads us to hypothesise that genetic variation in lysosomal genes modifies the disease course of sporadic AD. © 2016 International Society for Neurochemistry.

Disclosing Pleiotropic Effects during Genetic Risk Assessment for Alzheimer’s Disease: A Randomized, Controlled Trial

PubMed Central

Christensen, Kurt D.; Roberts, J. Scott; Whitehouse, Peter J.; Royal, Charmaine D. M.; Obisesan, Thomas O.; Cupples, L. Adrienne; Vernarelli, Jacqueline A.; Bhatt, Deepak L.; Linnenbringer, Erin; Butson, Melissa B.; Fasaye, Grace-Ann; Uhlmann, Wendy R.; Hiraki, Susan; Wang, Na; Cook-Deegan, Robert; Green, Robert C.

2016-01-01

Background Increasing use of genetic testing raises questions about disclosing secondary findings, including pleiotropic information. Objective To determine the safety and behavioral impact of disclosing modest associations between APOE genotype and coronary artery disease (CAD) risk during APOE-based genetic risk assessments for Alzheimer’s disease (AD). Design Randomized, multicenter equivalence clinical trial Setting Four teaching hospitals Participants 257 asymptomatic adults enrolled, 69% with one AD-affected first degree relative Intervention Disclosing AD and CAD genetic risk information (AD+CAD) versus disclosing only AD genetic risk (AD-only) Measurements Co-primary outcomes were Beck Anxiety Index (BAI) and Center for Epidemiologic Studies Depression Scale (CES-D) scores at 12 months. Secondary outcomes included test-related distress at 12 months, all measures at 6 weeks and 6 months, and health behavior changes at 12 months. Results 12 months after disclosure, mean BAI scores were 3.5 and 3.5 in AD-only and AD+CAD arms (Δ=0.0, 95%CI: −1.0 to 1.0), and mean CES-D scores were 6.4 and 7.1 in AD-only and AD+CAD arms (Δ=0.7, 95%CI: −1.0 to 2.4). Both confidence bounds fell within the equivalence margin of +/−5 points. Among ε4-positive participants, distress was lower in AD+CAD arms than AD-only arms (Δ=−4.8, 95%CI: −8.6 to −1.0) (p=0.031 for disclosure arm x APOE genotype). AD+CAD participants also reported more health behavior changes, regardless of APOE genotype. Limitations Outcomes were self-reported from volunteers without severe anxiety, severe depression, or cognitive problems. Analyses omitted 33 randomized participants. Conclusion Disclosing pleiotropic information did not increase anxiety or depression, and may have decreased distress among those at increased risk for two conditions. Providing risk modification information regarding CAD improved health behaviors. Findings highlight potential benefits of secondary genetic findings disclosure when options exist for decreasing risk. PMID:26810768

Autosomal recessive Charcot-Marie-Tooth neuropathy.

PubMed

Espinós, Carmen; Calpena, Eduardo; Martínez-Rubio, Dolores; Lupo, Vincenzo

2012-01-01

Charcot-Marie-Tooth (CMT) disease, a hereditary motor and sensory neuropathy that comprises a complex group of more than 50 diseases, is the most common inherited neuropathy. CMT is generally divided into demyelinating forms, axonal forms and intermediate forms. CMT is also characterized by a wide genetic heterogeneity with 29 genes and more than 30 loci involved. The most common pattern of inheritance is autosomal dominant (AD), although autosomal recessive (AR) forms are more frequent in Mediterranean countries. In this chapter we give an overview of the associated genes, mechanisms and epidemiology of AR-CMT forms and their associated phenotypes.

The Autoimmune Ecology.

PubMed

Anaya, Juan-Manuel; Ramirez-Santana, Carolina; Alzate, Maria A; Molano-Gonzalez, Nicolas; Rojas-Villarraga, Adriana

2016-01-01

Autoimmune diseases (ADs) represent a heterogeneous group of disorders that affect specific target organs or multiple organ systems. These conditions share common immunopathogenic mechanisms (i.e., the autoimmune tautology), which explain the clinical similarities they have among them as well as their familial clustering (i.e., coaggregation). As part of the autoimmune tautology, the influence of environmental exposure on the risk of developing ADs is paramount (i.e., the autoimmune ecology). In fact, environment, more than genetics, shapes immune system. Autoimmune ecology is akin to exposome, that is all the exposures - internal and external - across the lifespan, interacting with hereditary factors (both genetics and epigenetics) to favor or protect against autoimmunity and its outcomes. Herein, we provide an overview of the autoimmune ecology, focusing on the immune response to environmental agents in general, and microbiota, cigarette smoking, alcohol and coffee consumption, socioeconomic status (SES), gender and sex hormones, vitamin D, organic solvents, and vaccines in particular. Inclusion of the autoimmune ecology in disease etiology and health will improve the way personalized medicine is currently conceived and applied.

Assessment of gene order computing methods for Alzheimer's disease

PubMed Central

2013-01-01

Background Computational genomics of Alzheimer disease (AD), the most common form of senile dementia, is a nascent field in AD research. The field includes AD gene clustering by computing gene order which generates higher quality gene clustering patterns than most other clustering methods. However, there are few available gene order computing methods such as Genetic Algorithm (GA) and Ant Colony Optimization (ACO). Further, their performance in gene order computation using AD microarray data is not known. We thus set forth to evaluate the performances of current gene order computing methods with different distance formulas, and to identify additional features associated with gene order computation. Methods Using different distance formulas- Pearson distance and Euclidean distance, the squared Euclidean distance, and other conditions, gene orders were calculated by ACO and GA (including standard GA and improved GA) methods, respectively. The qualities of the gene orders were compared, and new features from the calculated gene orders were identified. Results Compared to the GA methods tested in this study, ACO fits the AD microarray data the best when calculating gene order. In addition, the following features were revealed: different distance formulas generated a different quality of gene order, and the commonly used Pearson distance was not the best distance formula when used with both GA and ACO methods for AD microarray data. Conclusion Compared with Pearson distance and Euclidean distance, the squared Euclidean distance generated the best quality gene order computed by GA and ACO methods. PMID:23369541

Genetically Predicted Body Mass Index and Alzheimer’s Disease Related Phenotypes in Three Large Samples: Mendelian Randomization Analyses

PubMed Central

Mukherjee, Shubhabrata; Walter, Stefan; Kauwe, John S.K.; Saykin, Andrew J.; Bennett, David A.; Larson, Eric B.; Crane, Paul K.; Glymour, M. Maria

2015-01-01

Observational research shows that higher body mass index (BMI) increases Alzheimer’s disease (AD) risk, but it is unclear whether this association is causal. We applied genetic variants that predict BMI in Mendelian Randomization analyses, an approach that is not biased by reverse causation or confounding, to evaluate whether higher BMI increases AD risk. We evaluated individual level data from the AD Genetics Consortium (ADGC: 10,079 AD cases and 9,613 controls), the Health and Retirement Study (HRS: 8,403 participants with algorithm-predicted dementia status) and published associations from the Genetic and Environmental Risk for AD consortium (GERAD1: 3,177 AD cases and 7,277 controls). No evidence from individual SNPs or polygenic scores indicated BMI increased AD risk. Mendelian Randomization effect estimates per BMI point (95% confidence intervals) were: ADGC OR=0.95 (0.90, 1.01); HRS OR=1.00 (0.75, 1.32); GERAD1 OR=0.96 (0.87, 1.07). One subscore (cellular processes not otherwise specified) unexpectedly predicted lower AD risk. PMID:26079416

Early neurotrophic pharmacotherapy rescues developmental delay and Alzheimer’s-like memory deficits in the Ts65Dn mouse model of Down syndrome

PubMed Central

Kazim, Syed Faraz; Blanchard, Julie; Bianchi, Riccardo; Iqbal, Khalid

2017-01-01

Down syndrome (DS), caused by trisomy 21, is the most common genetic cause of intellectual disability and is associated with a greatly increased risk of early-onset Alzheimer’s disease (AD). The Ts65Dn mouse model of DS exhibits several key features of the disease including developmental delay and AD-like cognitive impairment. Accumulating evidence suggests that impairments in early brain development caused by trisomy 21 contribute significantly to memory deficits in adult life in DS. Prenatal genetic testing to diagnose DS in utero, provides the novel opportunity to initiate early pharmacological treatment to target this critical period of brain development. Here, we report that prenatal to early postnatal treatment with a ciliary neurotrophic factor (CNTF) small-molecule peptide mimetic, Peptide 021 (P021), rescued developmental delay in pups and AD-like hippocampus-dependent memory impairments in adult life in Ts65Dn mice. Furthermore, this treatment prevented pre-synaptic protein deficit, decreased glycogen synthase kinase-3beta (GSK3β) activity, and increased levels of synaptic plasticity markers including brain derived neurotrophic factor (BNDF) and phosphorylated CREB, both in young (3-week-old) and adult (~ 7-month-old) Ts65Dn mice. These findings provide novel evidence that providing neurotrophic support during early brain development can prevent developmental delay and AD-like memory impairments in a DS mouse model. PMID:28368015

Strong evidence for a genetic contribution to late-onset Alzheimer's disease mortality: a population-based study.

PubMed

Kauwe, John S K; Ridge, Perry G; Foster, Norman L; Cannon-Albright, Lisa A

2013-01-01

Alzheimer's disease (AD) is an international health concern that has a devastating effect on patients and families. While several genetic risk factors for AD have been identified much of the genetic variance in AD remains unexplained. There are limited published assessments of the familiality of Alzheimer's disease. Here we present the largest genealogy-based analysis of AD to date. We assessed the familiality of AD in The Utah Population Database (UPDB), a population-based resource linking electronic health data repositories for the state with the computerized genealogy of the Utah settlers and their descendants. We searched UPDB for significant familial clustering of AD to evaluate the genetic contribution to disease. We compared the Genealogical Index of Familiality (GIF) between AD individuals and randomly selected controls and estimated the Relative Risk (RR) for a range of family relationships. Finally, we identified pedigrees with a significant excess of AD deaths. The GIF analysis showed that pairs of individuals dying from AD were significantly more related than expected. This excess of relatedness was observed for both close and distant relationships. RRs for death from AD among relatives of individuals dying from AD were significantly increased for both close and more distant relatives. Multiple pedigrees had a significant excess of AD deaths. These data strongly support a genetic contribution to the observed clustering of individuals dying from AD. This report is the first large population-based assessment of the familiality of AD mortality and provides the only reported estimates of relative risk of AD mortality in extended relatives to date. The high-risk pedigrees identified show a true excess of AD mortality (not just multiple cases) and are greater in depth and width than published AD pedigrees. The presence of these high-risk pedigrees strongly supports the possibility of rare predisposition variants not yet identified.

Pathology supported genetic testing and treatment of cardiovascular disease in middle age for prevention of Alzheimer's disease.

PubMed

Kotze, Maritha J; van Rensburg, Susan J

2012-09-01

Chronic, multi-factorial conditions caused by a complex interaction between genetic and environmental risk factors frequently share common disease mechanisms, as evidenced by an overlap between genetic risk factors for cardiovascular disease (CVD) and Alzheimer's disease (AD). Single nucleotide polymorphisms (SNPs) in several genes including ApoE, MTHFR, HFE and FTO are known to increase the risk of both conditions. The E4 allele of the ApoE polymorphism is the most extensively studied risk factor for AD and increases the risk of coronary heart disease by approximately 40%. It furthermore displays differential therapeutic responses with use of cholesterol-lowering statins and acetylcholinesterase inhibitors, which may also be due to variation in the CYP2D6 gene in some patients. Disease expression may be triggered by gene-environment interaction causing conversion of minor metabolic abnormalities into major brain disease due to cumulative risk. A growing body of evidence supports the assessment and treatment of CVD risk factors in midlife as a preventable cause of cognitive decline, morbidity and mortality in old age. In this review, the concept of pathology supported genetic testing (PSGT) for CVD is described in this context. PSGT combines DNA testing with biochemical measurements to determine gene expression and to monitor response to treatment. The aim is to diagnose treatable disease subtypes of complex disorders, facilitate prevention of cumulative risk and formulate intervention strategies guided from the genetic background. CVD provides a model to address the lifestyle link in most chronic diseases with a genetic component. Similar preventative measures would apply for optimisation of heart and brain health.

Are Genetic Tests for Atherosclerosis Ready for Routine Clinical Use?

PubMed

Paynter, Nina P; Ridker, Paul M; Chasman, Daniel I

2016-02-19

In this review, we lay out 3 areas currently being evaluated for incorporation of genetic information into clinical practice related to atherosclerosis. The first, familial hypercholesterolemia, is the clearest case for utility of genetic testing in diagnosis and potentially guiding treatment. Already in use for confirmatory testing of familial hypercholesterolemia and for cascade screening of relatives, genetic testing is likely to expand to help establish diagnoses and facilitate research related to most effective therapies, including new agents, such as PCSK9 inhibitors. The second area, adding genetic information to cardiovascular risk prediction for primary prevention, is not currently recommended. Although identification of additional variants may add substantially to prediction in the future, combining known variants has not yet demonstrated sufficient improvement in prediction for incorporation into commonly used risk scores. The third area, pharmacogenetics, has utility for some therapies today. Future utility for pharmacogenetics will wax or wane depending on the nature of available drugs and therapeutic strategies. © 2016 American Heart Association, Inc.

Management of Charcot–Marie–Tooth disease: improving long-term care with a multidisciplinary approach

PubMed Central

McCorquodale, Donald; Pucillo, Evan M; Johnson, Nicholas E

2016-01-01

Charcot–Marie–Tooth (CMT) disease is the most common inherited neuropathy and one of the most common inherited diseases in humans. The diagnosis of CMT is traditionally made by the neurologic specialist, yet the optimal management of CMT patients includes genetic counselors, physical and occupational therapists, physiatrists, orthotists, mental health providers, and community resources. Rapidly developing genetic discoveries and novel gene discovery techniques continue to add a growing number of genetic subtypes of CMT. The first large clinical natural history and therapeutic trials have added to our knowledge of each CMT subtype and revealed how CMT impacts patient quality of life. In this review, we discuss several important trends in CMT research factors that will require a collaborative multidisciplinary approach. These include the development of large multicenter patient registries, standardized clinical instruments to assess disease progression and disability, and increasing recognition and use of patient-reported outcome measures. These developments will continue to guide strategies in long-term multidisciplinary efforts to maintain quality of life and preserve functionality in CMT patients. PMID:26855581

A genetic screen of the mutations in the Korean patients with early-onset Alzheimer’s disease

PubMed Central

An, Seong Soo; Park, Sun Ah; Bagyinszky, Eva; Bae, Sun Oh; Kim, Yoon-Jeong; Im, Ji Young; Park, Kyung Won; Park, Kee Hyung; Kim, Eun-Joo; Jeong, Jee Hyang; Kim, Jong Hun; Han, Hyun Jeong; Choi, Seong Hye; Kim, SangYun

2016-01-01

Early-onset Alzheimer’s disease (EOAD) has distinct clinical characteristics in comparison to late-onset Alzheimer’s disease (LOAD). The genetic contribution is suggested to be more potent in EOAD. However, the frequency of causative mutations in EOAD could be variable depending on studies. Moreover, no mutation screening study has been performed yet employing large population in Korea. Previously, we reported that the rate of family history of dementia in EOAD patients was 18.7% in a nationwide hospital-based cohort study, the Clinical Research Center for Dementia of South Korea (CREDOS) study. This rate is much lower than in other countries and is even comparable to the frequency of LOAD patients in our country. To understand the genetic characteristics of EOAD in Korea, we screened the common Alzheimer’s disease (AD) mutations in the consecutive EOAD subjects from the CREDOS study from April 2012 to February 2014. We checked the sequence of APP (exons 16–17), PSEN1 (exons 3–12), and PSEN2 (exons 3–12) genes. We identified different causative or probable pathogenic AD mutations, PSEN1 T116I, PSEN1 L226F, and PSEN2 V214L, employing 24 EOAD subjects with a family history and 80 without a family history of dementia. PSEN1 T116I case demonstrated autosomal dominant trait of inheritance, with at least 11 affected individuals over 2 generations. However, there was no family history of dementia within first-degree relation in PSEN1 L226F and PSEN2 V214L cases. Approximately, 55.7% of the EOAD subjects had APOE ε4 allele, while none of the mutation-carrying subjects had the allele. The frequency of genetic mutation in this study is lower compared to the studies from other countries. The study design that was based on nationwide cohort, which minimizes selection bias, is thought to be one of the contributors to the lower frequency of genetic mutation. However, the possibility of the greater likeliness of earlier onset of sporadic AD in Korea cannot be excluded. We suggest early AD onset and not carrying APOE ε4 allele are more reliable factors for predicting an induced genetic mutation than the presence of the family history in Korean EOAD population. PMID:28008242

A Rapid Systematic Review of Outcomes Studies in Genetic Counseling.

PubMed

Madlensky, Lisa; Trepanier, Angela M; Cragun, Deborah; Lerner, Barbara; Shannon, Kristen M; Zierhut, Heather

2017-06-01

As healthcare reimbursement is increasingly tied to value-of-service, it is critical for the genetic counselor (GC) profession to demonstrate the value added by GCs through outcomes research. We conducted a rapid systematic literature review to identify outcomes of genetic counseling. Web of Science (including PubMed) and CINAHL databases were systematically searched to identify articles meeting the following criteria: 1) measures were assessed before and after genetic counseling (pre-post design) or comparisons were made between a GC group vs. a non-GC group (comparative cohort design); 2) genetic counseling outcomes could be assessed independently of genetic testing outcomes, and 3) genetic counseling was conducted by masters-level genetic counselors, or non-physician providers. Twenty-three papers met the inclusion criteria. The majority of studies were in the cancer genetic setting and the most commonly measured outcomes included knowledge, anxiety or distress, satisfaction, perceived risk, genetic testing (intentions or receipt), health behaviors, and decisional conflict. Results suggest that genetic counseling can lead to increased knowledge, perceived personal control, positive health behaviors, and improved risk perception accuracy as well as decreases in anxiety, cancer-related worry, and decisional conflict. However, further studies are needed to evaluate a wider array of outcomes in more diverse genetic counseling settings.

Genetic Restoration of Plasma ApoE Improves Cognition and Partially Restores Synaptic Defects in ApoE-Deficient Mice

PubMed Central

Wong, Wen Mai; Durakoglugil, Murat S.; Wasser, Catherine R.; Jiang, Shan; Xian, Xunde

2016-01-01

Alzheimer's disease (AD) is the most common form of dementia in individuals over the age of 65 years. The most prevalent genetic risk factor for AD is the ε4 allele of apolipoprotein E (ApoE4), and novel AD treatments that target ApoE are being considered. One unresolved question in ApoE biology is whether ApoE is necessary for healthy brain function. ApoE knock-out (KO) mice have synaptic loss and cognitive dysfunction; however, these findings are complicated by the fact that ApoE knock-out mice have highly elevated plasma lipid levels, which may independently affect brain function. To bypass the effect of ApoE loss on plasma lipids, we generated a novel mouse model that expresses ApoE normally in peripheral tissues, but has severely reduced ApoE in the brain, allowing us to study brain ApoE loss in the context of a normal plasma lipid profile. We found that these brain ApoE knock-out (bEKO) mice had synaptic loss and dysfunction similar to that of ApoE KO mice; however, the bEKO mice did not have the learning and memory impairment observed in ApoE KO mice. Moreover, we found that the memory deficit in the ApoE KO mice was specific to female mice and was fully rescued in female bEKO mice. Furthermore, while the AMPA/NMDA ratio was reduced in ApoE KO mice, it was unchanged in bEKO mice compared with controls. These findings suggest that plasma lipid levels can influence cognition and synaptic function independent of ApoE expression in the brain. SIGNIFICANCE STATEMENT One proposed treatment strategy for Alzheimer's disease (AD) is the reduction of ApoE, whose ε4 isoform is the most common genetic risk factor for the disease. A major concern of this strategy is that an animal model of ApoE deficiency, the ApoE knock-out (KO) mouse, has reduced synapses and cognitive impairment; however, these mice also develop dyslipidemia and severe atherosclerosis. Here, we have shown that genetic restoration of plasma ApoE to wild-type levels normalizes plasma lipids in ApoE KO mice. While this does not rescue synaptic loss, it does completely restore learning and memory in the mice, suggesting that both CNS and plasma ApoE are independent parameters that affect brain health. PMID:27683909

The BiolAD-DB system : an informatics system for clinical and genetic data.

PubMed

Nielsen, David A; Leidner, Marty; Haynes, Chad; Krauthammer, Michael; Kreek, Mary Jeanne

2007-01-01

The Biology of Addictive Diseases-Database (BiolAD-DB) system is a research bioinformatics system for archiving, analyzing, and processing of complex clinical and genetic data. The database schema employs design principles for handling complex clinical information, such as response items in genetic questionnaires. Data access and validation is provided by the BiolAD-DB client application, which features a data validation engine tightly coupled to a graphical user interface. Data integrity is provided by the password-protected BiolAD-DB SQL compliant server and database. BiolAD-DB tools further provide functionalities for generating customized reports and views. The BiolAD-DB system schema, client, and installation instructions are freely available at http://www.rockefeller.edu/biolad-db/.

Impact of Gene Patents and Licensing Practices on Access to Genetic Testing for Alzheimer’s Disease

PubMed Central

Skeehan, Katie; Heaney, Christopher; Cook-Deegan, Robert

2010-01-01

Genetic testing for Alzheimer’s disease (AD) includes genotyping for apolipoprotein E, for late-onset AD, and three rare autosomal dominant, early-onset forms of AD associated with different genes (APP, PSEN1 and PSEN2). According to researchers, patents have not impeded research in the field, nor were patents an important consideration in the quest for the genetic risk factors. Athena Diagnostics holds exclusive licenses from Duke University for three “method” patents covering APOE genetic testing. Athena offers tests for APOE and genes associated with early onset, autosomal dominant AD. One of those presenilin genes is patented and exclusively licensed to Athena; the other presenilin gene was patented but the patent was allowed to lapse; and one (APP) is patented only as a research tool and patent claims do not cover diagnostic use. Direct-to-consumer testing is available for some AD-related genes, apparently without a license. Athena Diagnostics consolidated its position in the market for AD genetic testing by collecting exclusive rights to patents arising from university research. Duke University also used its licenses to Athena to enforce adherence to clinical guidelines, including elimination of the service from Smart Genetics, which was offering direct-to-consumer risk assessment based on APOE genotyping. PMID:20393312

Bio Warfare and Terrorism: Toxins and Other Mid-Spectrum Agents

DTIC Science & Technology

2005-01-01

biotechnology, toxicogenomics, toxin, tetrodotoxin, and others. Once an agent has and proteomics may also help to open the door to the 276 Bio Warfare...also interferon gamma, interleukin-6, and tumor alsointrfern gmma intrlekin6, ad tmor by the mold Aspergillus flavus and commonly conta- necrosis factor...as bullets. No the new sciences of genomics and proteomics to alter toxoid or antitoxin is available, genetic code and to affect the expression of

Genetically-Predicted Adult Height and Alzheimer's Disease.

PubMed

Larsson, Susanna C; Traylor, Matthew; Burgess, Stephen; Markus, Hugh S

2017-01-01

Observational studies have linked increased adult height with better cognitive performance and reduced risk of Alzheimer's disease (AD). It is unclear whether the associations are due to shared biological processes that influence height and AD or due to confounding by early life exposures or environmental factors. To use a genetic approach to investigate the association between adult height and AD. We selected 682 single nucleotide polymorphisms (SNPs) associated with height at genome-wide significance (p < 5×10-8) in the Genetic Investigation of ANthropometric Traits (GIANT) consortium. Summary statistics for each of these SNPs on AD were obtained from the International Genomics of Alzheimer's Project (IGAP) of 17,008 individuals with AD and 37,154 controls. The estimate of the association between genetically predicted height and AD was calculated using the inverse-variance weighted method. The odds ratio of AD was 0.91 (95% confidence interval, 0.86-0.95; p = 9.8×10-5) per one standard deviation increase (about 6.5 cm) in genetically predicted height based on 682 SNPs, which were clustered in 419 loci. In an analysis restricted to one SNP from each height-associated locus (n = 419 SNPs), the corresponding OR was 0.92 (95% confidence interval, 0.86-0.97; p = 4.8×10-3). This finding suggests that biological processes that influence adult height may have a role in the etiology of AD.

Atherosclerosis and Alzheimer - diseases with a common cause? Inflammation, oxysterols, vasculature

PubMed Central

2014-01-01

Background Aging is accompanied by increasing vulnerability to pathologies such as atherosclerosis (ATH) and Alzheimer disease (AD). Are these different pathologies, or different presentations with a similar underlying pathoetiology? Discussion Both ATH and AD involve inflammation, macrophage infiltration, and occlusion of the vasculature. Allelic variants in common genes including APOE predispose to both diseases. In both there is strong evidence of disease association with viral and bacterial pathogens including herpes simplex and Chlamydophila. Furthermore, ablation of components of the immune system (or of bone marrow-derived macrophages alone) in animal models restricts disease development in both cases, arguing that both are accentuated by inflammatory/immune pathways. We discuss that amyloid β, a distinguishing feature of AD, also plays a key role in ATH. Several drugs, at least in mouse models, are effective in preventing the development of both ATH and AD. Given similar age-dependence, genetic underpinnings, involvement of the vasculature, association with infection, Aβ involvement, the central role of macrophages, and drug overlap, we conclude that the two conditions reflect different manifestations of a common pathoetiology. Mechanism Infection and inflammation selectively induce the expression of cholesterol 25-hydroxylase (CH25H). Acutely, the production of ‘immunosterol’ 25-hydroxycholesterol (25OHC) defends against enveloped viruses. We present evidence that chronic macrophage CH25H upregulation leads to catalyzed esterification of sterols via 25OHC-driven allosteric activation of ACAT (acyl-CoA cholesterol acyltransferase/SOAT), intracellular accumulation of cholesteryl esters and lipid droplets, vascular occlusion, and overt disease. Summary We postulate that AD and ATH are both caused by chronic immunologic challenge that induces CH25H expression and protection against particular infectious agents, but at the expense of longer-term pathology. PMID:24656052

Atherosclerosis and Alzheimer--diseases with a common cause? Inflammation, oxysterols, vasculature.

PubMed

Lathe, Richard; Sapronova, Alexandra; Kotelevtsev, Yuri

2014-03-21

Aging is accompanied by increasing vulnerability to pathologies such as atherosclerosis (ATH) and Alzheimer disease (AD). Are these different pathologies, or different presentations with a similar underlying pathoetiology? Both ATH and AD involve inflammation, macrophage infiltration, and occlusion of the vasculature. Allelic variants in common genes including APOE predispose to both diseases. In both there is strong evidence of disease association with viral and bacterial pathogens including herpes simplex and Chlamydophila. Furthermore, ablation of components of the immune system (or of bone marrow-derived macrophages alone) in animal models restricts disease development in both cases, arguing that both are accentuated by inflammatory/immune pathways. We discuss that amyloid β, a distinguishing feature of AD, also plays a key role in ATH. Several drugs, at least in mouse models, are effective in preventing the development of both ATH and AD. Given similar age-dependence, genetic underpinnings, involvement of the vasculature, association with infection, Aβ involvement, the central role of macrophages, and drug overlap, we conclude that the two conditions reflect different manifestations of a common pathoetiology. Infection and inflammation selectively induce the expression of cholesterol 25-hydroxylase (CH25H). Acutely, the production of 'immunosterol' 25-hydroxycholesterol (25OHC) defends against enveloped viruses. We present evidence that chronic macrophage CH25H upregulation leads to catalyzed esterification of sterols via 25OHC-driven allosteric activation of ACAT (acyl-CoA cholesterol acyltransferase/SOAT), intracellular accumulation of cholesteryl esters and lipid droplets, vascular occlusion, and overt disease. We postulate that AD and ATH are both caused by chronic immunologic challenge that induces CH25H expression and protection against particular infectious agents, but at the expense of longer-term pathology.

Buying time: a rationale for examining the use of circadian rhythm and sleep interventions to delay progression of mild cognitive impairment to Alzheimer's disease.

PubMed

Landry, Glenn J; Liu-Ambrose, Teresa

2014-01-01

As of 2010, the worldwide economic impact of dementia was estimated at $604 billion USD; and without discovery of a cure or effective interventions to delay disease progression, dementia's annual global economic impact is expected to surpass $1 trillion USD as early as 2030. Alzheimer's disease (AD) is the leading cause of dementia accounting for over 75% of all cases. Toxic accumulation of amyloid beta (Aβ), either by overproduction or some clearance failure, is thought to be an underlying mechanism of the neuronal cell death characteristic of AD-though this amyloid hypothesis has been increasingly challenged in recent years. A compelling alternative hypothesis points to chronic neuroinflammation as a common root in late-life degenerative diseases including AD. Apolipoprotein-E (APOE) genotype is the strongest genetic risk factor for AD: APOE-ε4 is proinflammatory and individuals with this genotype accumulate more Aβ, are at high risk of developing AD, and almost half of all AD patients have at least one ε4 allele. Recent studies suggest a bidirectional relationship exists between sleep and AD pathology. Sleep may play an important role in Aβ clearance, and getting good quality sleep vs. poor quality sleep might reduce the AD risk associated with neuroinflammation and the ε4 allele. Taken together, these findings are particularly important given the sleep disruptions commonly associated with AD and the increased burden disrupted sleep poses for AD caregivers. The current review aims to: (1) identify individuals at high risk for dementia who may benefit most from sleep interventions; (2) explore the role poor sleep quality plays in exacerbating AD type dementia; (3) examine the science of sleep interventions to date; and (4) provide a road map in pursuit of comprehensive sleep interventions, specifically targeted to promote cognitive function and delay progression of dementia.

Genetic genealogy comes of age: perspectives on the use of deep-rooted pedigrees in human population genetics.

PubMed

Larmuseau, M H D; Van Geystelen, A; van Oven, M; Decorte, R

2013-04-01

In this article, we promote the implementation of extensive genealogical data in population genetic studies. Genealogical records can provide valuable information on the origin of DNA donors in a population genetic study, going beyond the commonly collected data such as residence, birthplace, language, and self-reported ethnicity. Recent studies demonstrated that extended genealogical data added to surname analysis can be crucial to detect signals of (past) population stratification and to interpret the population structure in a more objective manner. Moreover, when in-depth pedigree data are combined with haploid markers, it is even possible to disentangle signals of temporal differentiation within a population genetic structure during the last centuries. Obtaining genealogical data for all DNA donors in a population genetic study is a labor-intensive task but the vastly growing (genetic) genealogical databases, due to the broad interest of the public, are making this job more time-efficient if there is a guarantee for sufficient data quality. At the end, we discuss the advantages and pitfalls of using genealogy within sampling campaigns and we provide guidelines for future population genetic studies. Copyright © 2013 Wiley Periodicals, Inc.

Genetic counseling and testing for Alzheimer disease: joint practice guidelines of the American College of Medical Genetics and the National Society of Genetic Counselors.

PubMed

Goldman, Jill S; Hahn, Susan E; Catania, Jennifer Williamson; LaRusse-Eckert, Susan; Butson, Melissa Barber; Rumbaugh, Malia; Strecker, Michelle N; Roberts, J Scott; Burke, Wylie; Mayeux, Richard; Bird, Thomas

2011-06-01

Alzheimer disease is the most common cause of dementia. It occurs worldwide and affects all ethnic groups. The incidence of Alzheimer disease is increasing due, in part, to increased life expectancy and the aging baby boomer generation. The average lifetime risk of developing Alzheimer disease is 10-12%. This risk at least doubles with the presence of a first-degree relative with the disorder. Despite its limited utility, patients express concern over their risk and, in some instances, request testing. Furthermore, research has demonstrated that testing individuals for apolipoprotein E can be valuable and safe in certain contexts. However, because of the complicated genetic nature of the disorder, few clinicians are prepared to address the genetic risks of Alzheimer disease with their patients. Given the increased awareness in family history thanks to family history campaigns, the increasing incidence of Alzheimer disease, and the availability of direct to consumer testing, patient requests for information is increasing. This practice guideline provides clinicians with a framework for assessing their patients' genetic risk for Alzheimer disease, identifying which individuals may benefit from genetic testing, and providing the key elements of genetic counseling for AD.

Eugenics: some lessons from the past.

PubMed

Galton, D J

2005-03-01

Eugenics was first debated by the ancient Greeks, particularly Plato and Aristotle, developed in the nineteenth century by Francis Galton and Charles Darwin, and then abused in the twentieth century by right-wing politicians. With the new methods of assisted conception combined with the use of genetic markers, all the old problems of eugenics have resurfaced. Gender selection, embryo selection, preimplantation genetic diagnosis of common disease, and gene replacement techniques (somatic cells) have added greatly to the power of the modern eugenicist. How are these procedures to be monitored and regulated? What is the role of the State compared with individual families for the implementation of the new methodologies? Some of these issues will be discussed.

Experimental optimization of directed field ionization

NASA Astrophysics Data System (ADS)

Liu, Zhimin Cheryl; Gregoric, Vincent C.; Carroll, Thomas J.; Noel, Michael W.

2017-04-01

The state distribution of an ensemble of Rydberg atoms is commonly measured using selective field ionization. The resulting time resolved ionization signal from a single energy eigenstate tends to spread out due to the multiple avoided Stark level crossings atoms must traverse on the way to ionization. The shape of the ionization signal can be modified by adding a perturbation field to the main field ramp. Here, we present experimental results of the manipulation of the ionization signal using a genetic algorithm. We address how both the genetic algorithm and the experimental parameters were adjusted to achieve an optimized result. This work was supported by the National Science Foundation under Grants No. 1607335 and No. 1607377.

Modeling Alzheimer’s disease in transgenic rats

PubMed Central

2013-01-01

Alzheimer’s disease (AD) is the most common form of dementia. At the diagnostic stage, the AD brain is characterized by the accumulation of extracellular amyloid plaques, intracellular neurofibrillary tangles and neuronal loss. Despite the large variety of therapeutic approaches, this condition remains incurable, since at the time of clinical diagnosis, the brain has already suffered irreversible and extensive damage. In recent years, it has become evident that AD starts decades prior to its clinical presentation. In this regard, transgenic animal models can shed much light on the mechanisms underlying this “pre-clinical” stage, enabling the identification and validation of new therapeutic targets. This paper summarizes the formidable efforts to create models mimicking the various aspects of AD pathology in the rat. Transgenic rat models offer distinctive advantages over mice. Rats are physiologically, genetically and morphologically closer to humans. More importantly, the rat has a well-characterized, rich behavioral display. Consequently, rat models of AD should allow a more sophisticated and accurate assessment of the impact of pathology and novel therapeutics on cognitive outcomes. PMID:24161192

Alzheimer disease in women: a clinical and genetics perspective.

PubMed

Gies, Cheryl; Lessick, Mira

2009-08-01

Upon completion of this activity, the learner will be able to: 1. Identify clinical and genetic characteristics and considerations associated with Alzheimer disease (AD). 2. Describe assessment and management strategies for AD. 3. Describe nursing implications for women and families with, or at risk for, AD.

Susceptibility to neurofibrillary tangles: role of the PTPRD locus and limited pleiotropy with other neuropathologies.

PubMed

Chibnik, L B; White, C C; Mukherjee, S; Raj, T; Yu, L; Larson, E B; Montine, T J; Keene, C D; Sonnen, J; Schneider, J A; Crane, P K; Shulman, J M; Bennett, D A; De Jager, P L

2017-03-21

Tauopathies, including Alzheimer's disease (AD) and other neurodegenerative conditions, are defined by a pathological hallmark: neurofibrillary tangles (NFTs). NFT accumulation is thought to be closely linked to cognitive decline in AD. Here, we perform a genome-wide association study for NFT pathologic burden and report the association of the PTPRD locus (rs560380, P=3.8 × 10 -8 ) in 909 prospective autopsies. The association is replicated in an independent data set of 369 autopsies. The association of PTPRD with NFT is not dependent on the accumulation of amyloid pathology. In contrast, we found that the ZCWPW1 AD susceptibility variant influences NFT accumulation and that this effect is mediated by an accumulation of amyloid β plaques. We also performed complementary analyses to identify common pathways that influence multiple neuropathologies that coexist with NFT and found suggestive evidence that certain loci may influence multiple different neuropathological traits, including tau, amyloid β plaques, vascular injury and Lewy bodies. Overall, these analyses offer an evaluation of genetic susceptibility to NFT, a common end point for multiple different pathologic processes.Molecular Psychiatry advance online publication, 21 March 2017; doi:10.1038/mp.2017.20.

Buying time: a rationale for examining the use of circadian rhythm and sleep interventions to delay progression of mild cognitive impairment to Alzheimer’s disease

PubMed Central

Landry, Glenn J.; Liu-Ambrose, Teresa

2014-01-01

As of 2010, the worldwide economic impact of dementia was estimated at $604 billion USD; and without discovery of a cure or effective interventions to delay disease progression, dementia’s annual global economic impact is expected to surpass $1 trillion USD as early as 2030. Alzheimer’s disease (AD) is the leading cause of dementia accounting for over 75% of all cases. Toxic accumulation of amyloid beta (Aβ), either by overproduction or some clearance failure, is thought to be an underlying mechanism of the neuronal cell death characteristic of AD—though this amyloid hypothesis has been increasingly challenged in recent years. A compelling alternative hypothesis points to chronic neuroinflammation as a common root in late-life degenerative diseases including AD. Apolipoprotein-E (APOE) genotype is the strongest genetic risk factor for AD: APOE-ε4 is proinflammatory and individuals with this genotype accumulate more Aβ, are at high risk of developing AD, and almost half of all AD patients have at least one ε4 allele. Recent studies suggest a bidirectional relationship exists between sleep and AD pathology. Sleep may play an important role in Aβ clearance, and getting good quality sleep vs. poor quality sleep might reduce the AD risk associated with neuroinflammation and the ε4 allele. Taken together, these findings are particularly important given the sleep disruptions commonly associated with AD and the increased burden disrupted sleep poses for AD caregivers. The current review aims to: (1) identify individuals at high risk for dementia who may benefit most from sleep interventions; (2) explore the role poor sleep quality plays in exacerbating AD type dementia; (3) examine the science of sleep interventions to date; and (4) provide a road map in pursuit of comprehensive sleep interventions, specifically targeted to promote cognitive function and delay progression of dementia. PMID:25538616

A canine model of Alzheimer's disease generated by overexpressing a mutated human amyloid precursor protein.

PubMed

Lee, Geun-Shik; Jeong, Yeon Woo; Kim, Joung Joo; Park, Sun Woo; Ko, Kyeong Hee; Kang, Mina; Kim, Yu Kyung; Jung, Eui-Man; Moon, Changjong; Hyun, Sang Hwan; Hwang, Kyu-Chan; Kim, Nam-Hyung; Shin, Taeyoung; Jeung, Eui-Bae; Hwang, Woo Suk

2014-04-01

Canines are considered the most authentic model for studying multifactorial human diseases, as these animals typically share a common environment with man. Somatic cell nuclear transfer (SCNT) technology along with genetic engineering of nuclear donor cells provides a unique opportunity for examining human diseases using transgenic canines. In the present study, we generated transgenic canines that overexpressed the human amyloid precursor protein (APP) gene containing well-characterized familial Alzheimer's disease (AD) mutations. We successfully obtained five out of six live puppies by SCNT. This was confirmed by observing the expression of green fluorescence protein in the body as a visual transgenic marker and the overexpression of the mutated APP gene in the brain. The transgenic canines developed AD-like symptoms, such as enlarged ventricles, an atrophied hippocampus, and β-amyloid plaques in the brain. Thus, the transgenic canines we created can serve as a novel animal model for studying human AD.

Genetic compendium of 1511 human brains available through the UK Medical Research Council Brain Banks Network Resource.

PubMed

Keogh, Michael J; Wei, Wei; Wilson, Ian; Coxhead, Jon; Ryan, Sarah; Rollinson, Sara; Griffin, Helen; Kurzawa-Akanbi, Marzena; Santibanez-Koref, Mauro; Talbot, Kevin; Turner, Martin R; McKenzie, Chris-Anne; Troakes, Claire; Attems, Johannes; Smith, Colin; Al Sarraj, Safa; Morris, Chris M; Ansorge, Olaf; Pickering-Brown, Stuart; Ironside, James W; Chinnery, Patrick F

2017-01-01

Given the central role of genetic factors in the pathogenesis of common neurodegenerative disorders, it is critical that mechanistic studies in human tissue are interpreted in a genetically enlightened context. To address this, we performed exome sequencing and copy number variant analysis on 1511 frozen human brains with a diagnosis of Alzheimer's disease (AD, n = 289), frontotemporal dementia/amyotrophic lateral sclerosis (FTD/ALS, n = 252), Creutzfeldt-Jakob disease (CJD, n = 239), Parkinson's disease (PD, n = 39), dementia with Lewy bodies (DLB, n = 58), other neurodegenerative, vascular, or neurogenetic disorders (n = 266), and controls with no significant neuropathology (n = 368). Genomic DNA was extracted from brain tissue in all cases before exome sequencing (Illumina Nextera 62 Mb capture) with variants called by FreeBayes; copy number variant (CNV) analysis (Illumina HumanOmniExpress-12 BeadChip); C9orf72 repeat expansion detection; and APOE genotyping. Established or likely pathogenic heterozygous, compound heterozygous, or homozygous variants, together with the C9orf72 hexanucleotide repeat expansions and a copy number gain of APP, were found in 61 brains. In addition to known risk alleles in 349 brains (23.9% of 1461 undergoing exome sequencing), we saw an association between rare variants in GRN and DLB. Rare CNVs were found in <1.5% of brains, including copy number gains of PRPH that were overrepresented in AD. Clinical, pathological, and genetic data are available, enabling the retrieval of specific frozen brains through the UK Medical Research Council Brain Banks Network. This allows direct access to pathological and control human brain tissue based on an individual's genetic architecture, thus enabling the functional validation of known genetic risk factors and potentially pathogenic alleles identified in future studies. © 2017 Keogh et al.; Published by Cold Spring Harbor Laboratory Press.

Review: Pathogenesis of canine atopic dermatitis: skin barrier and host-micro-organism interaction.

PubMed

Santoro, Domenico; Marsella, Rosanna; Pucheu-Haston, Cherie M; Eisenschenk, Melissa N C; Nuttall, Tim; Bizikova, Petra

2015-04-01

Canine atopic dermatitis (AD) is a common, genetically predisposed, inflammatory and pruritic skin disease. The pathogenesis of canine AD is incompletely understood. The aim of this review is to provide an in-depth update on the involvement of skin barrier and host-microbiome interaction in the pathogenesis of canine AD. Online citation databases and abstracts from international meetings were searched for publications related to skin barrier and host-microbiome interaction (e.g. bacteria, yeast, antimicrobial peptides). A total of 126 publications were identified. This review article focuses on epidermal barrier dysfunction and the interaction between cutaneous microbes (bacteria and yeasts) and the host (antimicrobial peptides). Epidemiological updates on the presence of pathogenic organisms and canine AD are also provided. Major advances have been made in the investigation of skin barrier dysfunction in canine AD, although many questions still remain. Skin barrier dysfunction and host-microbiome interactions are emerging as primary alterations in canine AD. Based on this review, it is clear that future studies focused on the development of drugs able to restore the skin barrier and increase the natural defences against pathogenic organisms are needed. © 2015 ESVD and ACVD.

Roles of vascular and metabolic components in cognitive dysfunction of Alzheimer disease: short- and long-term modification by non-genetic risk factors.

PubMed

Sato, Naoyuki; Morishita, Ryuichi

2013-11-05

It is well known that a specific set of genetic and non-genetic risk factors contributes to the onset of Alzheimer disease (AD). Non-genetic risk factors include diabetes, hypertension in mid-life, and probably dyslipidemia in mid-life. This review focuses on the vascular and metabolic components of non-genetic risk factors. The mechanisms whereby non-genetic risk factors modify cognitive dysfunction are divided into four components, short- and long-term effects of vascular and metabolic factors. These consist of (1) compromised vascular reactivity, (2) vascular lesions, (3) hypo/hyperglycemia, and (4) exacerbated AD histopathological features, respectively. Vascular factors compromise cerebrovascular reactivity in response to neuronal activity and also cause irreversible vascular lesions. On the other hand, representative short-term effects of metabolic factors on cognitive dysfunction occur due to hypoglycemia or hyperglycemia. Non-genetic risk factors also modify the pathological manifestations of AD in the long-term. Therefore, vascular and metabolic factors contribute to aggravation of cognitive dysfunction in AD through short-term and long-term effects. β-amyloid could be involved in both vascular and metabolic components. It might be beneficial to support treatment in AD patients by appropriate therapeutic management of non-genetic risk factors, considering the contributions of these four elements to the manifestation of cognitive dysfunction in individual patients, though all components are not always present. It should be clarified how these four components interact with each other. To answer this question, a clinical prospective study that follows up clinical features with respect to these four components: (1) functional MRI or SPECT for cerebrovascular reactivity, (2) MRI for ischemic lesions and atrophy, (3) clinical episodes of hypoglycemia and hyperglycemia, (4) amyloid-PET and tau-PET for pathological features of AD, would be required.

Retargeting of adenovirus vectors through genetic fusion of a single-chain or single-domain antibody to capsid protein IX.

PubMed

Poulin, Kathy L; Lanthier, Robert M; Smith, Adam C; Christou, Carin; Risco Quiroz, Milagros; Powell, Karen L; O'Meara, Ryan W; Kothary, Rashmi; Lorimer, Ian A; Parks, Robin J

2010-10-01

Adenovirus (Ad) vectors are the most commonly used system for gene therapy applications, due in part to their ability to infect a wide array of cell types and tissues. However, many therapies would benefit from the ability to target the Ad vector only to specific cells, such as tumor cells for cancer gene therapy. In this study, we investigated the utility of capsid protein IX (pIX) as a platform for the presentation of single-chain variable-fragment antibodies (scFv) and single-domain antibodies (sdAb) for virus retargeting. We show that scFv can be displayed on the capsid through genetic fusion to native pIX but that these molecules fail to retarget the virus, due to improper folding of the scFv. Redirecting expression of the fusion protein to the endoplasmic reticulum (ER) results in correct folding of the scFv and allows it to recognize its epitope; however, ER-targeted pIX-scFv was incorporated into the Ad capsid at a very low level which was not sufficient to retarget virus infection. In contrast, a pIX-sdAb construct was efficiently incorporated into the Ad capsid and enhanced virus infection of cells expressing the targeted receptor. Taken together, our data indicate that pIX is an effective platform for presentation of large targeting polypeptides on the surface of the virus capsid, but the nature of the ligand can significantly affect its association with virions.

Genome-wide association studies in Alzheimer disease.

PubMed

Waring, Stephen C; Rosenberg, Roger N

2008-03-01

The genetics of Alzheimer disease (AD) to date support an age-dependent dichotomous model whereby earlier age of disease onset (< 60 years) is explained by 3 fully penetrant genes (APP [NCBI Entrez gene 351], PSEN1 [NCBI Entrez gene 5663], and PSEN2 [NCBI Entrez gene 5664]), whereas later age of disease onset (> or = 65 years) representing most cases of AD has yet to be explained by a purely genetic model. The APOE gene (NCBI Entrez gene 348) is the strongest genetic risk factor for later onset, although it is neither sufficient nor necessary to explain all occurrences of disease. Numerous putative genetic risk alleles and genetic variants have been reported. Although all have relevance to biological mechanisms that may be associated with AD pathogenesis, they await replication in large representative populations. Genome-wide association studies have emerged as an increasingly effective tool for identifying genetic contributions to complex diseases and represent the next frontier for furthering our understanding of the underlying etiologic, biological, and pathologic mechanisms associated with chronic complex disorders. There have already been success stories for diseases such as macular degeneration and diabetes mellitus. Whether this will hold true for a genetically complex and heterogeneous disease such as AD is not known, although early reports are encouraging. This review considers recent publications from studies that have successfully applied genome-wide association methods to investigations of AD by taking advantage of the currently available high-throughput arrays, bioinformatics, and software advances. The inherent strengths, limitations, and challenges associated with study design issues in the context of AD are presented herein.

Genome-wide analysis of genetic correlation in dementia with Lewy bodies, Parkinson's and Alzheimer's diseases

PubMed Central

Guerreiro, Rita; Escott-Price, Valentina; Darwent, Lee; Parkkinen, Laura; Ansorge, Olaf; Hernandez, Dena G.; Nalls, Michael A.; Clark, Lorraine; Honig, Lawrence; Marder, Karen; van der Flier, Wiesje; Holstege, Henne; Louwersheimer, Eva; Lemstra, Afina; Scheltens, Philip; Rogaeva, Ekaterina; St George-Hyslop, Peter; Londos, Elisabet; Zetterberg, Henrik; Ortega-Cubero, Sara; Pastor, Pau; Ferman, Tanis J.; Graff-Radford, Neill R.; Ross, Owen A.; Barber, Imelda; Braae, Anne; Brown, Kristelle; Morgan, Kevin; Maetzler, Walter; Berg, Daniela; Troakes, Claire; Al-Sarraj, Safa; Lashley, Tammaryn; Compta, Yaroslau; Revesz, Tamas; Lees, Andrew; Cairns, Nigel J.; Halliday, Glenda M.; Mann, David; Pickering-Brown, Stuart; Powell, John; Lunnon, Katie; Lupton, Michelle K.; Dickson, Dennis; Hardy, John; Singleton, Andrew; Bras, Jose

2016-01-01

The similarities between dementia with Lewy bodies (DLB) and both Parkinson's disease (PD) and Alzheimer's disease (AD) are many and range from clinical presentation, to neuropathological characteristics, to more recently identified, genetic determinants of risk. Because of these overlapping features, diagnosing DLB is challenging and has clinical implications since some therapeutic agents that are applicable in other diseases have adverse effects in DLB. Having shown that DLB shares some genetic risk with PD and AD, we have now quantified the amount of sharing through the application of genetic correlation estimates, and show that, from a purely genetic perspective, and excluding the strong association at the APOE locus, DLB is equally correlated to AD and PD. PMID:26643944

Limited Associations of Dopamine System Genes With Alcohol Dependence and Related Traits in the Irish Affected Sib Pair Study of Alcohol Dependence (IASPSAD)

PubMed Central

Hack, Laura M.; Kalsi, Gursharan; Aliev, Fazil; Kuo, Po-Hsiu; Prescott, Carol A.; Patterson, Diana G.; Walsh, Dermot; Dick, Danielle M.; Riley, Brien P.; Kendler, Kenneth S.

2012-01-01

Background Over 50 years of evidence from research has established that the central dopaminergic reward pathway is likely involved in alcohol dependence (AD). Additional evidence supports a role for dopamine (DA) in other disinhibitory psychopathology, which is often comorbid with AD. Family and twin studies demonstrate that a common genetic component accounts for most of the genetic variance in these traits. Thus, DA-related genes represent putative candidates for the genetic risk that underlies not only AD but also behavioral disinhibition. Many linkage and association studies have examined these relationships with inconsistent results, possibly because of low power, poor marker coverage, and/or an inappropriate correction for multiple testing. Methods We conducted an association study on the products encoded by 10 DA-related genes (DRD1-D5, SLC18A2, SLC6A3, DDC, TH, COMT) using a large, ethnically homogeneous sample with severe AD (n = 545) and screened controls (n = 509). We collected genotypes from linkage disequilibrium (LD)-tagging single nucleotide polymorphisms (SNPs) and employed a gene-based method of correction. We tested for association with AD diagnosis in cases and controls and with a variety of alcohol-related traits (including age-at-onset, initial sensitivity, tolerance, maximum daily drinks, and a withdrawal factor score), disinhibitory symptoms, and a disinhibitory factor score in cases only. A total of 135 SNPs were genotyped using the Illumina GoldenGate and Taqman Assays-on-Demand protocols. Results Of the 101 SNPs entered into standard analysis, 6 independent SNPs from 5 DA genes were associated with AD or a quantitative alcohol-related trait. Two SNPs across 2 genes were associated with a disinhibitory symptom count, while 1 SNP in DRD5 was positive for association with the general disinhibitory factor score. Conclusions Our study provides evidence of modest associations between a small number of DA-related genes and AD as well as a range of alcohol-related traits and measures of behavioral disinhibition. While we did conduct gene-based correction for multiple testing, we did not correct for multiple traits because the traits are correlated. However, false-positive findings remain possible, so our results must be interpreted with caution. PMID:21083670

Population genetic structure and gene flow of Adélie penguins (Pygoscelis adeliae) breeding throughout the western Antarctic Peninsula

USGS Publications Warehouse

Gorman, Kristen B.; Talbot, Sandra L.; Sonsthagen, Sarah A.; Sage, George K.; Gravley, Megan C.; Fraser, William R.; Williams, Tony D.

2017-01-01

Adélie penguins (Pygoscelis adeliae) are responding to ocean–climate variability throughout the marine ecosystem of the western Antarctic Peninsula (WAP) where some breeding colonies have declined by 80%. Nuclear and mitochondrial DNA (mtDNA) markers were used to understand historical population genetic structure and gene flow given relatively recent and continuing reductions in sea ice habitats and changes in numbers of breeding adults at colonies throughout the WAP. Genetic diversity, spatial genetic structure, genetic signatures of fluctuations in population demography and gene flow were assessed in four regional Adélie penguin colonies. The analyses indicated little genetic structure overall based on bi-parentally inherited microsatellite markers (FST =-0.006–0.004). No significant variance was observed in overall haplotype frequency (mtDNA ΦST =0.017; P=0.112). Some comparisons with Charcot Island were significant, suggestive of female-biased philopatry. Estimates of gene flow based on a two-population coalescent model were asymmetrical from the species’ regional core to its northern range. Breeding Adélie penguins of the WAP are a panmictic population and hold adequate genetic diversity and dispersal capacity to be resilient to environmental change.

The Autoimmune Ecology

PubMed Central

Anaya, Juan-Manuel; Ramirez-Santana, Carolina; Alzate, Maria A.; Molano-Gonzalez, Nicolas; Rojas-Villarraga, Adriana

2016-01-01

Autoimmune diseases (ADs) represent a heterogeneous group of disorders that affect specific target organs or multiple organ systems. These conditions share common immunopathogenic mechanisms (i.e., the autoimmune tautology), which explain the clinical similarities they have among them as well as their familial clustering (i.e., coaggregation). As part of the autoimmune tautology, the influence of environmental exposure on the risk of developing ADs is paramount (i.e., the autoimmune ecology). In fact, environment, more than genetics, shapes immune system. Autoimmune ecology is akin to exposome, that is all the exposures – internal and external – across the lifespan, interacting with hereditary factors (both genetics and epigenetics) to favor or protect against autoimmunity and its outcomes. Herein, we provide an overview of the autoimmune ecology, focusing on the immune response to environmental agents in general, and microbiota, cigarette smoking, alcohol and coffee consumption, socioeconomic status (SES), gender and sex hormones, vitamin D, organic solvents, and vaccines in particular. Inclusion of the autoimmune ecology in disease etiology and health will improve the way personalized medicine is currently conceived and applied. PMID:27199979

Genetics of Aggression in Alzheimer’s Disease (AD)

PubMed Central

Lukiw, Walter J.; Rogaev, Evgeny I.

2017-01-01

Alzheimer’s disease (AD) is a terminal, age-related neurological syndrome exhibiting progressive cognitive and memory decline, however AD patients in addition exhibit ancillary neuropsychiatric symptoms (NPSs) and these include aggression. In this communication we provide recent evidence for the mis-regulation of a small family of genes expressed in the human hippocampus that appear to be significantly involved in expression patterns common to both AD and aggression. DNA array- and mRNA transcriptome-based gene expression analysis and candidate gene association and/or genome-wide association studies (CGAS, GWAS) of aggressive attributes in humans have revealed a surprisingly small subset of six brain genes that are also strongly associated with altered gene expression patterns in AD. These genes encoded on five different chromosomes (chr) include the androgen receptor (AR; chrXq12), brain-derived neurotrophic factor (BDNF; chr11p14.1), catechol-O-methyl transferase (COMT; chr22q11.21), neuronal specific nitric oxide synthase (NOS1; chr12q24.22), dopamine beta-hydroxylase (DBH chr9q34.2) and tryptophan hydroxylase (TPH1, chr11p15.1 and TPH2, chr12q21.1). Interestingly, (i) the expression of three of these six genes (COMT, DBH, NOS1) are highly variable; (ii) three of these six genes (COMT, DBH, TPH1) are involved in DA or serotonin metabolism, biosynthesis and/or neurotransmission; and (iii) five of these six genes (AR, BDNF, COMT, DBH, NOS1) have been implicated in the development, onset and/or propagation of schizophrenia. The magnitude of the expression of genes implicated in aggressive behavior appears to be more pronounced in the later stages of AD when compared to MCI. These recent genetic data further indicate that the extent of cognitive impairment may have some bearing on the degree of aggression which accompanies the AD phenotype. PMID:28443016

Scientific feuds, polemics, and ad hominem arguments in basic and special-interest genetics.

PubMed

Carlson, Elof Axel

Scientific disputes are commonly presented and settled in journal publications. Most are resolved by a weighing of evidence and new findings. In some cases the arguments are personal and in the form of ad hominem attacks on the personality or integrity of an author of a journal article. Many famous scientists (e.g., Galileo, Newton, and Hooke) used ad hominem arguments in responding to their critics. William Bateson, W.F.R. Weldon, William Castle, and H.J. Muller used ad hominem arguments in their publications until the end of World War I, when editorial policy of journals changed. Motivating some of the attacks are philosophic differences (such as holistic or reductionist approaches to science), ideological differences (such as Marxist or Capitalist outlooks), politics (such as Cold War depictions by East and West on fallout from nuclear testing), or conflicts of interest (which can be professional or financial such as the debates over nontraditional and orthodox medicine or over tobacco smoking and health). Most of the time, the disputes are motivated by honest disagreements over the interpretation of the data. A recent surge (2009-2016) of ad hominem attacks by Edward Calabrese has appeared disparaging H. J. Muller, E. B. Lewis, other twentieth-century contributors to radiation genetics, and the National Academy of Sciences. They address the mutational effects of low-dose radiation exposure. Calabrese's attacks have led to responses by geneticists in the field of mutagenesis, by agencies criticized by Calabrese, and by students and colleagues of those who have been accused of deception by Calabrese. This article reviews some of the history of ad hominem arguments in science and the background to the attacks by Calabrese. I argue that Calabrese's characterization of Muller and his supporters is unjust, misleading, and hurtful. I also propose some methods for dealing with or preventing ad hominem attacks in professional journals. Copyright © 2017. Published by Elsevier B.V.

Auditory hedonic phenotypes in dementia: A behavioural and neuroanatomical analysis

PubMed Central

Fletcher, Phillip D.; Downey, Laura E.; Golden, Hannah L.; Clark, Camilla N.; Slattery, Catherine F.; Paterson, Ross W.; Schott, Jonathan M.; Rohrer, Jonathan D.; Rossor, Martin N.; Warren, Jason D.

2015-01-01

Patients with dementia may exhibit abnormally altered liking for environmental sounds and music but such altered auditory hedonic responses have not been studied systematically. Here we addressed this issue in a cohort of 73 patients representing major canonical dementia syndromes (behavioural variant frontotemporal dementia (bvFTD), semantic dementia (SD), progressive nonfluent aphasia (PNFA) amnestic Alzheimer's disease (AD)) using a semi-structured caregiver behavioural questionnaire and voxel-based morphometry (VBM) of patients' brain MR images. Behavioural responses signalling abnormal aversion to environmental sounds, aversion to music or heightened pleasure in music (‘musicophilia’) occurred in around half of the cohort but showed clear syndromic and genetic segregation, occurring in most patients with bvFTD but infrequently in PNFA and more commonly in association with MAPT than C9orf72 mutations. Aversion to sounds was the exclusive auditory phenotype in AD whereas more complex phenotypes including musicophilia were common in bvFTD and SD. Auditory hedonic alterations correlated with grey matter loss in a common, distributed, right-lateralised network including antero-mesial temporal lobe, insula, anterior cingulate and nucleus accumbens. Our findings suggest that abnormalities of auditory hedonic processing are a significant issue in common dementias. Sounds may constitute a novel probe of brain mechanisms for emotional salience coding that are targeted by neurodegenerative disease. PMID:25929717

Genetic counseling and testing for Alzheimer disease: Joint practice guidelines of the American College of Medical Genetics and the National Society of Genetic Counselors

PubMed Central

Goldman, Jill S.; Hahn, Susan E.; Catania, Jennifer Williamson; LaRusse-Eckert, Susan; Butson, Melissa Barber; Rumbaugh, Malia; Strecker, Michelle N.; Roberts, J. Scott; Burke, Wylie; Mayeux, Richard; Bird, Thomas

2012-01-01

Alzheimer disease is the most common cause of dementia. It occurs worldwide and affects all ethnic groups. The incidence of Alzheimer disease is increasing due, in part, to increased life expectancy and the aging baby boomer generation. The average lifetime risk of developing Alzheimer disease is 10–12%. This risk at least doubles with the presence of a first-degree relative with the disorder. Despite its limited utility, patients express concern over their risk and, in some instances, request testing. Furthermore, research has demonstrated that testing individuals for apoli-poprotein E can be valuable and safe in certain contexts. However, because of the complicated genetic nature of the disorder, few clinicians are prepared to address the genetic risks of Alzheimer disease with their patients. Given the increased awareness in family history thanks to family history campaigns, the increasing incidence of Alzheimer disease, and the availability of direct to consumer testing, patient requests for information is increasing. This practice guideline provides clinicians with a framework for assessing their patients’ genetic risk for Alzheimer disease, identifying which individuals may benefit from genetic testing, and providing the key elements of genetic counseling for AD. PMID:21577118

Genome-wide analysis of genetic correlation in dementia with Lewy bodies, Parkinson's and Alzheimer's diseases.

PubMed

Guerreiro, Rita; Escott-Price, Valentina; Darwent, Lee; Parkkinen, Laura; Ansorge, Olaf; Hernandez, Dena G; Nalls, Michael A; Clark, Lorraine; Honig, Lawrence; Marder, Karen; van der Flier, Wiesje; Holstege, Henne; Louwersheimer, Eva; Lemstra, Afina; Scheltens, Philip; Rogaeva, Ekaterina; St George-Hyslop, Peter; Londos, Elisabet; Zetterberg, Henrik; Ortega-Cubero, Sara; Pastor, Pau; Ferman, Tanis J; Graff-Radford, Neill R; Ross, Owen A; Barber, Imelda; Braae, Anne; Brown, Kristelle; Morgan, Kevin; Maetzler, Walter; Berg, Daniela; Troakes, Claire; Al-Sarraj, Safa; Lashley, Tammaryn; Compta, Yaroslau; Revesz, Tamas; Lees, Andrew; Cairns, Nigel J; Halliday, Glenda M; Mann, David; Pickering-Brown, Stuart; Powell, John; Lunnon, Katie; Lupton, Michelle K; Dickson, Dennis; Hardy, John; Singleton, Andrew; Bras, Jose

2016-02-01

The similarities between dementia with Lewy bodies (DLB) and both Parkinson's disease (PD) and Alzheimer's disease (AD) are many and range from clinical presentation, to neuropathological characteristics, to more recently identified, genetic determinants of risk. Because of these overlapping features, diagnosing DLB is challenging and has clinical implications since some therapeutic agents that are applicable in other diseases have adverse effects in DLB. Having shown that DLB shares some genetic risk with PD and AD, we have now quantified the amount of sharing through the application of genetic correlation estimates, and show that, from a purely genetic perspective, and excluding the strong association at the APOE locus, DLB is equally correlated to AD and PD. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

GEMINI: Integrative Exploration of Genetic Variation and Genome Annotations

PubMed Central

Paila, Umadevi; Chapman, Brad A.; Kirchner, Rory; Quinlan, Aaron R.

2013-01-01

Modern DNA sequencing technologies enable geneticists to rapidly identify genetic variation among many human genomes. However, isolating the minority of variants underlying disease remains an important, yet formidable challenge for medical genetics. We have developed GEMINI (GEnome MINIng), a flexible software package for exploring all forms of human genetic variation. Unlike existing tools, GEMINI integrates genetic variation with a diverse and adaptable set of genome annotations (e.g., dbSNP, ENCODE, UCSC, ClinVar, KEGG) into a unified database to facilitate interpretation and data exploration. Whereas other methods provide an inflexible set of variant filters or prioritization methods, GEMINI allows researchers to compose complex queries based on sample genotypes, inheritance patterns, and both pre-installed and custom genome annotations. GEMINI also provides methods for ad hoc queries and data exploration, a simple programming interface for custom analyses that leverage the underlying database, and both command line and graphical tools for common analyses. We demonstrate GEMINI's utility for exploring variation in personal genomes and family based genetic studies, and illustrate its ability to scale to studies involving thousands of human samples. GEMINI is designed for reproducibility and flexibility and our goal is to provide researchers with a standard framework for medical genomics. PMID:23874191

The Genetics of Infertility: Current Status of the Field

PubMed Central

Zorrilla, Michelle; Yatsenko, Alexander N

2013-01-01

Infertility is a relatively common health condition, affecting nearly 7% of all couples. Clinically, it is a highly heterogeneous pathology with a complex etiology that includes environmental and genetic factors. It has been estimated that nearly 50% of infertility cases are due to genetic defects. Hundreds of studies with animal knockout models convincingly showed infertility to be caused by gene defects, single or multiple. However, despite enormous efforts, progress in translating basic research findings into clinical studies has been challenging. The genetic causes remain unexplained for the vast majority of male or female infertility patients. A particular difficulty is the huge number of candidate genes to be studied; there are more than 2,300 genes expressed in the testis alone, and hundreds of those genes influence reproductive function in humans and could contribute to male infertility. At present, there are only a handful of genes or genetic defects that have been shown to cause, or to be strongly associated with, primary infertility. Yet, with completion of the human genome and progress in personalized medicine, the situation is rapidly changing. Indeed, there are 10-15 new gene tests, on average, being added to the clinical genetic testing list annually. PMID:24416713

Impact of direct-to-consumer advertising for hereditary breast cancer testing on genetic services at a managed care organization: a naturally-occurring experiment.

PubMed

Mouchawar, Judy; Hensley-Alford, Sharon; Laurion, Suzanne; Ellis, Jennifer; Kulchak-Rahm, Alanna; Finucane, Melissa L; Meenan, Richard; Axell, Lisen; Pollack, Rebecca; Ritzwoller, Debra

2005-03-01

To describe the impact of Myriad Genetics, Inc.'s direct-to-consumer advertising (DTC-ad) campaign on cancer genetic services within two Managed Care Organizations, Kaiser Permanente Colorado (KPCO), Denver, Colorado, where the ad campaign occurred, and Henry Ford Health System (HFHS), Detroit, Michigan, where there were no advertisements. The main outcome measures were the changes in number and pretest mutation probability of referrals approved for cancer genetic services at KPCO and HFHS during the campaign versus the year prior, and mutation probability of those undergoing testing. At KPCO, referrals increased 244% during the DTC-ad compared to the same time period a year earlier (P value<0.001). The proportion of referrals at high pretest probability of a mutation (10% or greater) dropped from 69% the previous year to 48% during the campaign (P value<0.001). There was no significant change in pretest mutation probability among women who underwent testing between the two time periods. HFHS reported no significant change between the two time periods for numbers or mutation probability of referrals, or for mutation probability of women tested. The DTC-ad caused significant increase in demand for cancer genetic services. In the face of potential future DTC-ad for inherited cancer risk, providers and payers need to consider the delivery of genetic services and genetic education for persons of all risk levels.

Inflammation in Alzheimer's Disease and Molecular Genetics: Recent Update.

PubMed

Zhang, Zhi-Gang; Li, Yan; Ng, Cheung Toa; Song, You-Qiang

2015-10-01

Alzheimer's disease (AD) is a complex age-related neurodegenerative disorder of the central nervous system. Since the first description of AD in 1907, many hypotheses have been established to explain its causes. The inflammation theory is one of them. Pathological and biochemical studies of brains from AD individuals have provided solid evidence of the activation of inflammatory pathways. Furthermore, people with long-term medication of anti-inflammatory drugs have shown a reduced risk to develop the disease. After three decades of genetic study in AD, dozens of loci harboring genetic variants influencing inflammatory pathways in AD patients has been identified through genome-wide association studies (GWAS). The most well-known GWAS risk factor that is responsible for immune response and inflammation in AD development should be APOE ε4 allele. However, a growing number of other GWAS risk AD candidate genes in inflammation have recently been discovered. In the present study, we try to review the inflammation in AD and immunity-associated GWAS risk genes like HLA-DRB5/DRB1, INPP5D, MEF2C, CR1, CLU and TREM2.

Alpha-1-antichymotrypsin (ACT or SERPINA3) polymorphism may affect age-at-onset and disease duration of Alzheimer's disease.

PubMed

Kamboh, M Ilyas; Minster, Ryan L; Kenney, Margaret; Ozturk, Ayla; Desai, Purnima P; Kammerer, Candace M; DeKosky, Steven T

2006-10-01

In addition to genetic effects on disease risk, age-at-onset (AAO) of Alzheimer's disease (AD) is also genetically controlled. Using AAO as a covariate, a linkage signal for AD has been detected on chromosome 14q32 near the alpha1-antichymotrypsin (ACT) gene. Previously, a signal peptide polymorphism (codon -17A>T) in the ACT gene has been suggested to affect AD risk, but with inconsistent findings. Given that a linkage signal for AAO has been detected near ACT, we hypothesized that ACT genetic variation affects AAO rather than disease risk and this may explain the previous inconsistent findings between ACT genetic variation and AD risk. We examined the impact of the ACT signal peptide polymorphism on mean AAO in 909 AD cases. The ACT polymorphism was significantly associated with AAO and this effect was independent of the APOE polymorphism. Mean AAO among ACT/AA homozygotes was significantly lower than that in the combined AT+TT genotype group (p = 0.019) and this difference was confined to male AD patients (p = 0.002). Among male AD patients, the ACT/AA genotype was also associated with shorter disease duration before death as compared to the ACT/AT+TT genotypes (p = 0.012). These data suggest that the ACT gene may affect AAO and disease duration of AD.

Alpha-1-antichymotrypsin (ACT or SERPINA3) polymorphism may affect age-at-onset and disease duration of Alzheimer’s disease

PubMed Central

Kamboh, M. Ilyas; Minster, Ryan L.; Kenney, Margaret; Ozturk, Ayla; Desai, Purnima P.; Kammerer, Candace M.; DeKosky, Steven T.

2006-01-01

In addition to genetic effects on disease risk, age-at-onset (AAO) of Alzheimer’s disease (AD) is also genetically controlled. Using AAO as a covariate, a linkage signal for AD has been detected on chromosome 14q32 near the a1-antichymotrypsin (ACT) gene. Previously, a signal peptide polymorphism (codon -17A>T) in the ACT gene has been suggested to affect AD risk, but with inconsistent findings. Given that a linkage signal for AAO has been detected near ACT, we hypothesized that ACT genetic variation affects AAO rather than disease risk and this may explain the previous inconsistent findings between ACT genetic variation and AD risk. We examined the impact of the ACT signal peptide polymorphism on mean AAO in 909 AD cases. The ACT polymorphism was significantly associated with AAO and this effect was independent of the APOE polymorphism. Mean AAO among ACT/AA homozygotes was significantly lower than that in the combined AT+TT genotype group (p=0.019) and this difference was confined to male AD patients (p=0.002). Among male AD patients, the ACT/AA genotype was also associated with shorter disease duration before death as compared to the ACT/AT + TT genotypes (p=0.012). These data suggest that the ACT gene may affect AAO and disease duration of AD. PMID:16137793

Association of Alzheimer's disease GWAS loci with MRI markers of brain aging.

PubMed

Chauhan, Ganesh; Adams, Hieab H H; Bis, Joshua C; Weinstein, Galit; Yu, Lei; Töglhofer, Anna Maria; Smith, Albert Vernon; van der Lee, Sven J; Gottesman, Rebecca F; Thomson, Russell; Wang, Jing; Yang, Qiong; Niessen, Wiro J; Lopez, Oscar L; Becker, James T; Phan, Thanh G; Beare, Richard J; Arfanakis, Konstantinos; Fleischman, Debra; Vernooij, Meike W; Mazoyer, Bernard; Schmidt, Helena; Srikanth, Velandai; Knopman, David S; Jack, Clifford R; Amouyel, Philippe; Hofman, Albert; DeCarli, Charles; Tzourio, Christophe; van Duijn, Cornelia M; Bennett, David A; Schmidt, Reinhold; Longstreth, William T; Mosley, Thomas H; Fornage, Myriam; Launer, Lenore J; Seshadri, Sudha; Ikram, M Arfan; Debette, Stephanie

2015-04-01

Whether novel risk variants of Alzheimer's disease (AD) identified through genome-wide association studies also influence magnetic resonance imaging-based intermediate phenotypes of AD in the general population is unclear. We studied association of 24 AD risk loci with intracranial volume, total brain volume, hippocampal volume (HV), white matter hyperintensity burden, and brain infarcts in a meta-analysis of genetic association studies from large population-based samples (N = 8175-11,550). In single-SNP based tests, AD risk allele of APOE (rs2075650) was associated with smaller HV (p = 0.0054) and CD33 (rs3865444) with smaller intracranial volume (p = 0.0058). In gene-based tests, there was associations of HLA-DRB1 with total brain volume (p = 0.0006) and BIN1 with HV (p = 0.00089). A weighted AD genetic risk score was associated with smaller HV (beta ± SE = -0.047 ± 0.013, p = 0.00041), even after excluding the APOE locus (p = 0.029). However, only association of AD genetic risk score with HV, including APOE, was significant after multiple testing correction (including number of independent phenotypes tested). These results suggest that novel AD genetic risk variants may contribute to structural brain aging in nondemented older community persons. Copyright © 2015 Elsevier Inc. All rights reserved.

Human Genetics and Islam: Scientific and Medical Aspects

PubMed Central

Ghareeb, Bilal A.A.

2011-01-01

Objective: To relate diverse aspects of genetics and its applications to concepts in the Glorious Qur’an and the ḥadīth. Study Design: The author compared passages from the Glorious Qur’an and ḥadīth with modern concepts in genetics, such as recessive inheritance, genetic counseling, genetic variation, cytoplasmic inheritance, sex chromosomes, genetics-environment interactions, gender determination, and the hypothesis of “pairing in the universe.” Conclusions: A fresh understanding of Islamic scripture reveals references to principles of genetics that predate contemporary discoveries. This highlights the need for further exploration of possible links between science and religion. PMID:23610491

Association of tagSNPs in the urokinase-plasminogen activator (PLAU) gene with Alzheimer's disease and associated quantitative traits.

PubMed

Ozturk, Ayla; Minster, Ryan L; DeKosky, Steven T; Kamboh, M Ilyas

2007-01-05

The gene coding for urokinase-plasminogen activator (PLAU) is a strong biological and positional candidate gene for Alzheimer's disease (AD). Previously some studies have examined the role of common variation in the PLAU gene with AD risk but the results have been inconsistent and this inconsistency could have been due to the use of relatively small sample sizes. In this study we evaluated the distribution of four tagSNPs (rs2227562 in intron 5, rs2227564 in exon 6, rs2227571 in intron 9, and rs4065 in 3'UTR) in the PLAU gene in a large case-control study consisting of up to 1,000 AD patients and 697 white control subjects. We examined the role of these tagSNPs with AD risk and quantitative traits of AD, including age-at-onset (AAO), disease duration, and mini-mental state examination (MMSE) scores. The 3'UTR SNP revealed modest significant association with risk (OR = 0.71, 95% CI: 0.53-0.95; P = 0.02), AAO (P = 0.036) and disease duration (P = 0.04) of AD. In addition, the intron 9 SNP also revealed a significant association with AAO (P = 0.01) and disease duration (P = 0.006). Our data on a large number of AD cases and controls suggest that genetic variation in PLAU may affect the risk and AAO of AD.

Genetic assessment of age-associated Alzheimer disease risk: Development and validation of a polygenic hazard score

PubMed Central

Cupples, L. Adrienne; Thompson, Wesley K.; Besser, Lilah; Kukull, Walter A.; Holland, Dominic; Chen, Chi-Hua; Brewer, James B.; Karow, David S.; Kauppi, Karolina; Bonham, Luke W.; Rosen, Howard J.; Miller, Bruce L.; Dillon, William P.; Wilson, David M.; Pericak-Vance, Margaret; Haines, Jonathan L.; Farrer, Lindsay A.; Mayeux, Richard; Hardy, John; Goate, Alison M.; Schellenberg, Gerard D.; Andreassen, Ole A.

2017-01-01

Background Identifying individuals at risk for developing Alzheimer disease (AD) is of utmost importance. Although genetic studies have identified AD-associated SNPs in APOE and other genes, genetic information has not been integrated into an epidemiological framework for risk prediction. Methods and findings Using genotype data from 17,008 AD cases and 37,154 controls from the International Genomics of Alzheimer’s Project (IGAP Stage 1), we identified AD-associated SNPs (at p < 10−5). We then integrated these AD-associated SNPs into a Cox proportional hazard model using genotype data from a subset of 6,409 AD patients and 9,386 older controls from Phase 1 of the Alzheimer’s Disease Genetics Consortium (ADGC), providing a polygenic hazard score (PHS) for each participant. By combining population-based incidence rates and the genotype-derived PHS for each individual, we derived estimates of instantaneous risk for developing AD, based on genotype and age, and tested replication in multiple independent cohorts (ADGC Phase 2, National Institute on Aging Alzheimer’s Disease Center [NIA ADC], and Alzheimer’s Disease Neuroimaging Initiative [ADNI], total n = 20,680). Within the ADGC Phase 1 cohort, individuals in the highest PHS quartile developed AD at a considerably lower age and had the highest yearly AD incidence rate. Among APOE ε3/3 individuals, the PHS modified expected age of AD onset by more than 10 y between the lowest and highest deciles (hazard ratio 3.34, 95% CI 2.62–4.24, p = 1.0 × 10−22). In independent cohorts, the PHS strongly predicted empirical age of AD onset (ADGC Phase 2, r = 0.90, p = 1.1 × 10−26) and longitudinal progression from normal aging to AD (NIA ADC, Cochran–Armitage trend test, p = 1.5 × 10−10), and was associated with neuropathology (NIA ADC, Braak stage of neurofibrillary tangles, p = 3.9 × 10−6, and Consortium to Establish a Registry for Alzheimer’s Disease score for neuritic plaques, p = 6.8 × 10−6) and in vivo markers of AD neurodegeneration (ADNI, volume loss within the entorhinal cortex, p = 6.3 × 10−6, and hippocampus, p = 7.9 × 10−5). Additional prospective validation of these results in non-US, non-white, and prospective community-based cohorts is necessary before clinical use. Conclusions We have developed a PHS for quantifying individual differences in age-specific genetic risk for AD. Within the cohorts studied here, polygenic architecture plays an important role in modifying AD risk beyond APOE. With thorough validation, quantification of inherited genetic variation may prove useful for stratifying AD risk and as an enrichment strategy in therapeutic trials. PMID:28323831

Genetic assessment of age-associated Alzheimer disease risk: Development and validation of a polygenic hazard score.

PubMed

Desikan, Rahul S; Fan, Chun Chieh; Wang, Yunpeng; Schork, Andrew J; Cabral, Howard J; Cupples, L Adrienne; Thompson, Wesley K; Besser, Lilah; Kukull, Walter A; Holland, Dominic; Chen, Chi-Hua; Brewer, James B; Karow, David S; Kauppi, Karolina; Witoelar, Aree; Karch, Celeste M; Bonham, Luke W; Yokoyama, Jennifer S; Rosen, Howard J; Miller, Bruce L; Dillon, William P; Wilson, David M; Hess, Christopher P; Pericak-Vance, Margaret; Haines, Jonathan L; Farrer, Lindsay A; Mayeux, Richard; Hardy, John; Goate, Alison M; Hyman, Bradley T; Schellenberg, Gerard D; McEvoy, Linda K; Andreassen, Ole A; Dale, Anders M

2017-03-01

Identifying individuals at risk for developing Alzheimer disease (AD) is of utmost importance. Although genetic studies have identified AD-associated SNPs in APOE and other genes, genetic information has not been integrated into an epidemiological framework for risk prediction. Using genotype data from 17,008 AD cases and 37,154 controls from the International Genomics of Alzheimer's Project (IGAP Stage 1), we identified AD-associated SNPs (at p < 10-5). We then integrated these AD-associated SNPs into a Cox proportional hazard model using genotype data from a subset of 6,409 AD patients and 9,386 older controls from Phase 1 of the Alzheimer's Disease Genetics Consortium (ADGC), providing a polygenic hazard score (PHS) for each participant. By combining population-based incidence rates and the genotype-derived PHS for each individual, we derived estimates of instantaneous risk for developing AD, based on genotype and age, and tested replication in multiple independent cohorts (ADGC Phase 2, National Institute on Aging Alzheimer's Disease Center [NIA ADC], and Alzheimer's Disease Neuroimaging Initiative [ADNI], total n = 20,680). Within the ADGC Phase 1 cohort, individuals in the highest PHS quartile developed AD at a considerably lower age and had the highest yearly AD incidence rate. Among APOE ε3/3 individuals, the PHS modified expected age of AD onset by more than 10 y between the lowest and highest deciles (hazard ratio 3.34, 95% CI 2.62-4.24, p = 1.0 × 10-22). In independent cohorts, the PHS strongly predicted empirical age of AD onset (ADGC Phase 2, r = 0.90, p = 1.1 × 10-26) and longitudinal progression from normal aging to AD (NIA ADC, Cochran-Armitage trend test, p = 1.5 × 10-10), and was associated with neuropathology (NIA ADC, Braak stage of neurofibrillary tangles, p = 3.9 × 10-6, and Consortium to Establish a Registry for Alzheimer's Disease score for neuritic plaques, p = 6.8 × 10-6) and in vivo markers of AD neurodegeneration (ADNI, volume loss within the entorhinal cortex, p = 6.3 × 10-6, and hippocampus, p = 7.9 × 10-5). Additional prospective validation of these results in non-US, non-white, and prospective community-based cohorts is necessary before clinical use. We have developed a PHS for quantifying individual differences in age-specific genetic risk for AD. Within the cohorts studied here, polygenic architecture plays an important role in modifying AD risk beyond APOE. With thorough validation, quantification of inherited genetic variation may prove useful for stratifying AD risk and as an enrichment strategy in therapeutic trials.

Improving Memory and Cognition in Individuals with Down Syndrome.

PubMed

Rafii, Michael S

2016-07-01

Down syndrome (DS), often due to trisomy 21, is the most common genetic cause of intellectual disability (ID). In addition, virtually all individuals with DS develop the neuropathology of Alzheimer's disease (AD) by the age of 40 years and almost 60 % will manifest symptoms of AD dementia by the age of 65 years. Currently, there are no pharmacological treatments available for ID in individuals with DS and only limited symptomatic treatments for AD dementia. Advances in our understanding in both the molecular basis of ID and the pathogenesis of AD have created opportunities to study potential therapeutic targets. Recent studies in animal models of DS continue to provide a rational basis for translating specific compounds into human clinical trials. However, target and compound selection are only initial steps in the drug development pathway. Other necessary considerations include appropriate study designs to assess efficacy in the DS population, as well as operational aspects specifically tailored to assess cognition in this population. We discuss recent progress in the development of compounds for both ID and AD in individuals with DS, as well as concepts for the design and conduct of clinical trials with such compounds.

Pharmacogenetics: A strategy for personalized medicine for autoimmune diseases.

PubMed

Tavakolpour, S; Darvishi, M; Ghasemiadl, M

2018-03-01

For many years, a considerable number of patients with autoimmune diseases (ADs) have suffered from a lack of drug response and drug-related toxicity. Despite the emergence of new therapeutic options such as biological agents, patients continue to struggle with these problems. Unfortunately, new challenges, including the paradoxical effects of biological drugs, have complicated the situation. In recent decades, efforts have been made to predict drug response as well as drug-related side effects. Thanks to the many advances in genetics, evaluation of markers to predict drug response/toxicity before the initiation of treatment may be an avenue toward personalizing treatments. Implementing pharmacogenetics and pharmacogenomics in the clinic could improve clinical care; however, obstacles remain to effective personalized medicine for ADs. The present study attempted to clarify the concept of pharmacogenetics/pharmacogenomics for ADs. After an overview on the pathogenesis of the most common types of treatments, this paper focuses on pharmacogenetic studies related to the selected ADs. Bridging the gap between pharmacogenetics and personalized medicine is also discussed. Moreover, the advantages, disadvantages and recommendations related to making personalized medicine practical for ADs have been addressed. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Genetics Home Reference: fibrodysplasia ossificans progressiva

MedlinePlus

... Glaser DL, LeMerrer M, Morhart R, Rogers JG, Smith R, Triffitt JT, Urtizberea JA, Zasloff M, Brown ... added]; Morhart, Rolf [added]; Rogers, John G [added]; Smith, Roger [added]; Triffitt, James T [added]; Urtizberea, J ...

Can Alzheimer disease be prevented by amyloid-β immunotherapy?

PubMed Central

Lemere, Cynthia A.; Masliah, Eliezer

2010-01-01

Alzheimer disease (AD) is the most common form of dementia. The amyloid-β (Aβ) peptide has become a major therapeutic target in AD on the basis of pathological, biochemical and genetic evidence that supports a role for this molecule in the disease process. Active and passive Aβ immunotherapies have been shown to lower cerebral Aβ levels and improve cognition in animal models of AD. In humans, dosing in the phase II clinical trial of the AN1792 Aβ vaccine was stopped when ~6% of the immunized patients developed meningoencephalitis. However, some plaque clearance and modest clinical improvements were observed in patients following immunization. As a result of this study, at least seven passive Aβ immunotherapies are now in clinical trials in patients with mild to moderate AD. Several second-generation active Aβ vaccines are also in early clinical trials. On the basis of preclinical studies and the limited data from clinical trials, Aβ immunotherapy might be most effective in preventing or slowing the progression of AD when patients are immunized before or in the very earliest stages of disease onset. Biomarkers for AD and imaging technology have improved greatly over the past 10 years and, in the future, might be used to identify presymptomatic, at-risk individuals who might benefit from Aβ immunization. PMID:20140000

Association between the APOE ε4 Allele and Late-Onset Alzheimer's Disease in an Ecuadorian Mestizo Population

PubMed Central

Calero, Cristian; Vinueza, Rodrigo; Correa, Patricio; Carrera-Gonzalez, Andrea; Villegas, Franklin; Moreta, Germania; Paredes, Rosario

2017-01-01

Alzheimer's disease (AD) is the most common neurodegenerative disease. It has two main pathological hallmarks: amyloid plaques and neurofibrillary tangles. The APOE ε4 allele has been recognized as the strongest genetic risk factor for late-onset Alzheimer's disease (LOAD) in several populations worldwide, yet the risk varies by region and ethnicity. The aims of this study were to describe APOE allele and genotype frequencies and examine the relationship between the APOE ε4 allele and LOAD risk in an Ecuadorian Mestizo population. We carried out a case-control study comprising 56 individuals clinically diagnosed with probable AD (≥65 years of age) and 58 unrelated healthy control subjects (≥65 years of age). Genotyping was performed using the real-time PCR method. Our data showed that allelic and genotypic frequencies follow the trends observed in most worldwide populations. We also found a high-risk association between APOE ε4 allele carriers and LOAD (OR = 7.286; 95% CI = 2.824–18.799; p < 0.001). Therefore, we concluded that APOE ε4 must be considered an important genetic risk factor for LOAD in the Ecuadorian Mestizo population. Additionally, we suggest that in mixed populations the effects of admixture and ethnic identity should be differentiated when evaluating genetic contributions to Alzheimer's disease risk. PMID:29348964

Added value measures in education show genetic as well as environmental influence.

PubMed

Haworth, Claire M A; Asbury, Kathryn; Dale, Philip S; Plomin, Robert

2011-02-02

Does achievement independent of ability or previous attainment provide a purer measure of the added value of school? In a study of 4000 pairs of 12-year-old twins in the UK, we measured achievement with year-long teacher assessments as well as tests. Raw achievement shows moderate heritability (about 50%) and modest shared environmental influences (25%). Unexpectedly, we show that for indices of the added value of school, genetic influences remain moderate (around 50%), and the shared (school) environment is less important (about 12%). The pervasiveness of genetic influence in how and how much children learn is compatible with an active view of learning in which children create their own educational experiences in part on the basis of their genetic propensities.

Discovery of gene-gene interactions across multiple independent data sets of late onset Alzheimer disease from the Alzheimer Disease Genetics Consortium.

PubMed

Hohman, Timothy J; Bush, William S; Jiang, Lan; Brown-Gentry, Kristin D; Torstenson, Eric S; Dudek, Scott M; Mukherjee, Shubhabrata; Naj, Adam; Kunkle, Brian W; Ritchie, Marylyn D; Martin, Eden R; Schellenberg, Gerard D; Mayeux, Richard; Farrer, Lindsay A; Pericak-Vance, Margaret A; Haines, Jonathan L; Thornton-Wells, Tricia A

2016-02-01

Late-onset Alzheimer disease (AD) has a complex genetic etiology, involving locus heterogeneity, polygenic inheritance, and gene-gene interactions; however, the investigation of interactions in recent genome-wide association studies has been limited. We used a biological knowledge-driven approach to evaluate gene-gene interactions for consistency across 13 data sets from the Alzheimer Disease Genetics Consortium. Fifteen single nucleotide polymorphism (SNP)-SNP pairs within 3 gene-gene combinations were identified: SIRT1 × ABCB1, PSAP × PEBP4, and GRIN2B × ADRA1A. In addition, we extend a previously identified interaction from an endophenotype analysis between RYR3 × CACNA1C. Finally, post hoc gene expression analyses of the implicated SNPs further implicate SIRT1 and ABCB1, and implicate CDH23 which was most recently identified as an AD risk locus in an epigenetic analysis of AD. The observed interactions in this article highlight ways in which genotypic variation related to disease may depend on the genetic context in which it occurs. Further, our results highlight the utility of evaluating genetic interactions to explain additional variance in AD risk and identify novel molecular mechanisms of AD pathogenesis. Copyright © 2016 Elsevier Inc. All rights reserved.

Mosaic Loss of Chromosome Y in Blood Is Associated with Alzheimer Disease.

PubMed

Dumanski, Jan P; Lambert, Jean-Charles; Rasi, Chiara; Giedraitis, Vilmantas; Davies, Hanna; Grenier-Boley, Benjamin; Lindgren, Cecilia M; Campion, Dominique; Dufouil, Carole; Pasquier, Florence; Amouyel, Philippe; Lannfelt, Lars; Ingelsson, Martin; Kilander, Lena; Lind, Lars; Forsberg, Lars A

2016-06-02

Men have a shorter life expectancy compared with women but the underlying factor(s) are not clear. Late-onset, sporadic Alzheimer disease (AD) is a common and lethal neurodegenerative disorder and many germline inherited variants have been found to influence the risk of developing AD. Our previous results show that a fundamentally different genetic variant, i.e., lifetime-acquired loss of chromosome Y (LOY) in blood cells, is associated with all-cause mortality and an increased risk of non-hematological tumors and that LOY could be induced by tobacco smoking. We tested here a hypothesis that men with LOY are more susceptible to AD and show that LOY is associated with AD in three independent studies of different types. In a case-control study, males with AD diagnosis had higher degree of LOY mosaicism (adjusted odds ratio = 2.80, p = 0.0184, AD events = 606). Furthermore, in two prospective studies, men with LOY at blood sampling had greater risk for incident AD diagnosis during follow-up time (hazard ratio [HR] = 6.80, 95% confidence interval [95% CI] = 2.16-21.43, AD events = 140, p = 0.0011). Thus, LOY in blood is associated with risks of both AD and cancer, suggesting a role of LOY in blood cells on disease processes in other tissues, possibly via defective immunosurveillance. As a male-specific risk factor, LOY might explain why males on average live shorter lives than females. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

ApoE -491A/T promoter polymorphism is not an independent risk factor, but associated with the epsilon4 allele in Hungarian Alzheimer's dementia population.

PubMed

Juhász, Anna; Palotás, András; Janka, Zoltán; Rimanóczy, Agnes; Palotás, Miklós; Bódi, Nikoletta; Boda, Krisztina; Zana, Marianna; Vincze, Gábor; Kálmán, János

2005-05-01

Apolipoprotein E gene (Apo(epsilon)) has three common alleles (epsilon2, epsilon3, and epsilon4), of which epsilon4 has been shown to be associated with an increased risk for Alzheimer's disease (AD). Possible additional genetic factors, like the -491A variant of ApoE promoter may modify the development of AD, independently of the ApoE allele status. The objective of this study was to investigate whether A/T allelic polymorphism at site-491 of the ApoE promoter is associated with AD in a Hungarian population. The genomic DNA isolated from peripheral blood lymphocytes of 52 late-onset AD and 53 control individuals was used as a template for the two examined polymorphisms and PCR assay was applied. The epsilon4 allele was significantly over-represented in the AD group (28%) as compared with the control population (7%). No significant differences have been found between the control and the AD populations regarding the occurrence of the promoter A allele frequencies (control: 77%, AD: 70%). However, the AA genotype was more frequent in the AD group (48%) than in the control (10%) when the presence of epsilon4 allele was also considered. It is unlikely therefore that the -491A variant of the ApoE promoter gene is an independent risk factor in the Hungarian AD population, but a linkage disequilibrium exists between the two examined mutations.

Alcoholic Marriage: Later Start, Sooner End

PubMed Central

Waldron, Mary; Heath, Andrew C.; Lynskey, Michael T.; Bucholz, Kathleen K.; Madden, Pamela A. F.; Martin, Nicholas G.

2010-01-01

Background Although associations between drinking behavior and marital status are well documented, timing of marital transitions as a function of alcohol use or disorder has received limited empirical attention. Methods We examine the relationship between lifetime history of alcohol dependence (AD) and timing and survival of first marriages in a sample of 3575 female and 1845 male adult Australian twins born mostly between 1940 and 1964. Survival analyses were conducted using Cox proportional hazards regression models. Results Results indicate moderate delays in marriage associated with AD for both women and men. Among ever married respondents, AD was strongly predictive of early separation, with similar effects observed for women and men. Heritable sources of covariation were also documented. For women, genetic influences shared between early-onset AD and marital timing were found. Genetic influences shared between AD and marital survival were observed for women without regard to onset and for men with later-onset AD. Conclusions Results confirm the importance of AD as a predictor of both timing and survival of first marriages, with genetic influences contributing to observed associations. PMID:21244438

CDK5RAP2 gene and tau pathophysiology in late-onset sporadic Alzheimer's disease.

PubMed

Miron, Justin; Picard, Cynthia; Nilsson, Nathalie; Frappier, Josée; Dea, Doris; Théroux, Louise; Poirier, Judes

2018-06-01

Because currently known Alzheimer's disease (AD) single-nucleotide polymorphisms only account for a small fraction of the genetic variance in this disease, there is a need to identify new variants associated with AD. Our team performed a genome-wide association study in the Quebec Founder Population isolate to identify novel protective or risk genetic factors for late-onset sporadic AD and examined the impact of these variants on gene expression and AD pathology. The rs10984186 variant is associated with an increased risk of developing AD and with a higher CDK5RAP2 mRNA prevalence in the hippocampus. On the other hand, the rs4837766 variant, which is among the best cis-expression quantitative trait loci in the CDK5RAP2 gene, is associated with lower mild cognitive impairment/AD risk and conversion rate. The rs10984186 risk and rs4837766 protective polymorphic variants of the CDK5RAP2 gene might act as potent genetic modifiers for AD risk and/or conversion by modulating the expression of this gene. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Genetic overlap between Alzheimer’s disease and Parkinson’s disease at the MAPT locus

PubMed Central

Desikan, Rahul S.; Schork, Andrew J.; Wang, Yunpeng; Witoelar, Aree; Sharma, Manu; McEvoy, Linda K.; Holland, Dominic; Brewer, James B.; Chen, Chi-Hua; Thompson, Wesley K.; Harold, Denise; Williams, Julie; Owen, Michael J.; O’Donovan, Michael C.; Pericak-Vance, Margaret A.; Mayeux, Richard; Haines, Jonathan L.; Farrer, Lindsay A.; Schellenberg, Gerard D.; Heutink, Peter; Singleton, Andrew B.; Brice, Alexis; Wood, Nicolas W.; Hardy, John; Martinez, Maria; Choi, Seung Hoi; DeStefano, Anita; Ikram, M. Arfan; Bis, Joshua C.; Smith, Albert; Fitzpatrick, Annette L.; Launer, Lenore; van Duijn, Cornelia; Seshadri, Sudha; Ulstein, Ingun Dina; Aarsland, Dag; Fladby, Tormod; Djurovic, Srdjan; Hyman, Bradley T.; Snaedal, Jon; Stefansson, Hreinn; Stefansson, Kari; Gasser, Thomas; Andreassen, Ole A.; Dale, Anders M.

2015-01-01

We investigated genetic overlap between Alzheimer’s disease (AD) and Parkinson’s disease (PD). Using summary statistics (p-values) from large recent genomewide association studies (GWAS) (total n = 89,904 individuals), we sought to identify single nucleotide polymorphisms (SNPs) associating with both AD and PD. We found and replicated association of both AD and PD with the A allele of rs393152 within the extended MAPT region on chromosome 17 (meta analysis p-value across 5 independent AD cohorts = 1.65 × 10−7). In independent datasets, we found a dose-dependent effect of the A allele of rs393152 on intra-cerebral MAPT transcript levels and volume loss within the entorhinal cortex and hippocampus. Our findings identify the tau-associated MAPT locus as a site of genetic overlap between AD and PD and extending prior work, we show that the MAPT region increases risk of Alzheimer’s neurodegeneration. PMID:25687773

Synopsis on the linkage of Alzheimer's and Parkinson's disease with chronic diseases.

PubMed

Jabir, Nasimudeen R; Firoz, Chelapram K; Baeesa, Saleh S; Ashraf, Ghulam Md; Akhtar, Suhail; Kamal, Warda; Kamal, Mohammad A; Tabrez, Shams

2015-01-01

Neurodegeneration is the progressive loss of neuronal structure and function, which ultimately leads to neurological disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis, and Huntington's disease. Even after the recent significant advances in neurobiology, the above-mentioned disorders continue to haunt the global population. Several studies have suggested the role of specific environmental and genetic risk factors associated with these disorders. However, the exact mechanism associated with the progression of these disorders still needs to be elucidated. In the recent years, sophisticated research has revealed interesting association of prominent neurodegenerative disorders such as AD and PD with chronic diseases such as cancer, diabetes, and cardiovascular diseases. Several common molecular mechanisms such as generation of free radicals, oxidative DNA damage, aberrations in mitochondrial DNA, and dysregulation of apoptosis have been highlighted as possible points of connection. The present review summarizes the possible mechanism of coexistence of AD and PD with other chronic diseases. © 2014 John Wiley & Sons Ltd.

Genetic Targeting of an Adenovirus Vector via Replacement of the Fiber Protein with the Phage T4 Fibritin

PubMed Central

Krasnykh, Victor; Belousova, Natalya; Korokhov, Nikolay; Mikheeva, Galina; Curiel, David T.

2001-01-01

The utility of adenovirus (Ad) vectors for gene therapy is restricted by their inability to selectively transduce disease-affected tissues. This limitation may be overcome by the derivation of vectors capable of interacting with receptors specifically expressed in the target tissue. Previous attempts to alter Ad tropism by genetic modification of the Ad fiber have had limited success due to structural conflicts between the fiber and the targeting ligand. Here we present a strategy to derive an Ad vector with enhanced targeting potential by a radical replacement of the fiber protein in the Ad capsid with a chimeric molecule containing a heterologous trimerization motif and a receptor-binding ligand. Our approach, which capitalized upon the overall structural similarity between the human Ad type 5 (Ad5) fiber and bacteriophage T4 fibritin proteins, has resulted in the generation of a genetically modified Ad5 incorporating chimeric fiber-fibritin proteins targeted to artificial receptor molecules. Gene transfer studies employing this novel viral vector have demonstrated its capacity to efficiently deliver a transgene payload to the target cells in a receptor-specific manner. PMID:11287567

Interactions Among Polymorphisms of Susceptibility Loci for Alzheimer’s Disease or Depressive Disorder

PubMed Central

Kitzlerová, Eva; Lelková, Petra; Jirák, Roman; Zvěřová, Martina; Hroudová, Jana; Manukyan, Ada; Martásek, Pavel; Raboch, Jiří

2018-01-01

Background Several genetic susceptibility loci for major depressive disorder (MDD) or Alzheimer’s disease (AD) have been described. Interactions among polymorphisms are thought to explain the differences between low- and high-risk groups. We tested for the contribution of interactions between multiple functional polymorphisms in the risk of MDD or AD. Material/Methods A genetic association case-control study was performed in 68 MDD cases, 84 AD cases (35 of them with comorbid depression), and 90 controls. The contribution of 7 polymorphisms from 5 genes (APOE, HSPA1A, SLC6A4, HTR2A, and BDNF) related to risk of MDD or AD development was analyzed. Results Significant associations were found between MDD and interactions among polymorphisms in HSPA1A, SLC6A4, and BDNF or HSPA1A, BDNF, and APOE genes. For polymorphisms in the APOE gene in AD, significant differences were confirmed on the distributions of alleles and genotype rates compared to the control or MDD. Increased probability of comorbid depression was found in patients with AD who do not carry the ɛ4 allele of APOE. Conclusions Assessment of the interactions among polymorphisms of susceptibility loci in both MDD and AD confirmed a synergistic effect of genetic factors influencing inflammatory, serotonergic, and neurotrophic pathways at these heterogenous complex diseases. The effect of interactions was greater in MDD than in AD. A presence of the ɛ4 allele was confirmed as a genetic susceptibility factor in AD. Our findings indicate a role of APOE genotype in onset of comorbid depression in a subgroup of patients with AD who are not carriers of the APOE ɛ4 allele. PMID:29703883

Atopic dermatitis: Interaction between genetic variants of GSTP1, TNF, TLR2, and TLR4 and air pollution in early life.

PubMed

Hüls, Anke; Klümper, Claudia; MacIntyre, Elaina A; Brauer, Michael; Melén, Erik; Bauer, Mario; Berdel, Dietrich; Bergström, Anna; Brunekreef, Bert; Chan-Yeung, Moira; Fuertes, Elaine; Gehring, Ulrike; Gref, Anna; Heinrich, Joachim; Standl, Marie; Lehmann, Irina; Kerkhof, Marjan; Koppelman, Gerard H; Kozyrskyj, Anita L; Pershagen, Göran; Carlsten, Christopher; Krämer, Ursula; Schikowski, Tamara

2018-04-06

Associations between traffic-related air pollution (TRAP) and childhood atopic dermatitis (AD) remain inconsistent, possibly due to unexplored gene-environment interactions. The aim of this study was to examine whether a potential effect of TRAP on AD prevalence in children is modified by selected single nucleotide polymorphisms (SNPs) related to oxidative stress and inflammation. Doctor-diagnosed AD up to age 2 years and at 7-8 years, as well as AD symptoms up to age 2 years, was assessed using parental-reported questionnaires in six birth cohorts (N = 5685). Associations of nitrogen dioxide (NO 2 ) estimated at the home address of each child at birth and nine SNPs within the GSTP1, TNF, TLR2, or TLR4 genes with AD were examined. Weighted genetic risk scores (GRS) were calculated from the above SNPs and used to estimate combined marginal genetic effects of oxidative stress and inflammation on AD and its interaction with TRAP. GRS was associated with childhood AD and modified the association between NO 2 and doctor-diagnosed AD up to the age of 2 years (P(interaction) = .029). This interaction was mainly driven by a higher susceptibility to air pollution in TNF rs1800629 minor allele (A) carriers. TRAP was not associated with the prevalence of AD in the general population. The marginal genetic association of a weighted GRS from GSTP1, TNF, TLR2, and TLR4SNPs and its interaction with air pollution supports the role of oxidative stress and inflammation in AD. © 2018 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

PICALM gene rs3851179 polymorphism contributes to Alzheimer's disease in an Asian population.

PubMed

Liu, Guiyou; Zhang, Shuyan; Cai, Zhiyou; Ma, Guoda; Zhang, Liangcai; Jiang, Yongshuai; Feng, Rennan; Liao, Mingzhi; Chen, Zugen; Zhao, Bin; Li, Keshen

2013-06-01

PICALM gene rs3851179 polymorphism was reported to an Alzheimer's disease (AD) susceptibility locus in a Caucasian population. However, recent studies reported consistent and inconsistent results in an Asian population. Four studies indicated no association between rs3851179 and AD in a Chinese population and one study reported weak association in a Japanese population. We consider that the failure to replicate the significant association between rs3851179 and AD may be caused by at least two reasons. The first reason may be the genetic heterogeneity in AD among different populations, and the second may be the relatively small sample size compared with large-scale GWAS in Caucasian ancestry. In order to confirm this view, in this research, we first evaluated the genetic heterogeneity of rs3851179 polymorphism in Caucasian and Asian populations. We then investigated rs3851179 polymorphism in an Asian population by a pooled analysis method and a meta-analysis method. We did not observe significant genetic heterogeneity of rs3851179 in the Caucasian and Asian populations. Our results indicate that rs3851179 polymorphism is significantly associated with AD in the Asian population by both pooled analysis and meta-analysis methods. We believe that our findings will be very useful for future genetic studies in AD.

GACD: Integrated Software for Genetic Analysis in Clonal F1 and Double Cross Populations.

PubMed

Zhang, Luyan; Meng, Lei; Wu, Wencheng; Wang, Jiankang

2015-01-01

Clonal species are common among plants. Clonal F1 progenies are derived from the hybridization between 2 heterozygous clones. In self- and cross-pollinated species, double crosses can be made from 4 inbred lines. A clonal F1 population can be viewed as a double cross population when the linkage phase is determined. The software package GACD (Genetic Analysis of Clonal F1 and Double cross) is freely available public software, capable of building high-density linkage maps and mapping quantitative trait loci (QTL) in clonal F1 and double cross populations. Three functionalities are integrated in GACD version 1.0: binning of redundant markers (BIN); linkage map construction (CDM); and QTL mapping (CDQ). Output of BIN can be directly used as input of CDM. After adding the phenotypic data, the output of CDM can be used as input of CDQ. Thus, GACD acts as a pipeline for genetic analysis. GACD and example datasets are freely available from www.isbreeding.net. © The American Genetic Association. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Construction of a reference genetic linkage map for carnation (Dianthus caryophyllus L.)

PubMed Central

2013-01-01

Background Genetic linkage maps are important tools for many genetic applications including mapping of quantitative trait loci (QTLs), identifying DNA markers for fingerprinting, and map-based gene cloning. Carnation (Dianthus caryophyllus L.) is an important ornamental flower worldwide. We previously reported a random amplified polymorphic DNA (RAPD)-based genetic linkage map derived from Dianthus capitatus ssp. andrezejowskianus and a simple sequence repeat (SSR)-based genetic linkage map constructed using data from intraspecific F2 populations; however, the number of markers was insufficient, and so the number of linkage groups (LGs) did not coincide with the number of chromosomes (x = 15). Therefore, we aimed to produce a high-density genetic map to improve its usefulness for breeding purposes and genetic research. Results We improved the SSR-based genetic linkage map using SSR markers derived from a genomic library, expression sequence tags, and RNA-seq data. Linkage analysis revealed that 412 SSR loci (including 234 newly developed SSR loci) could be mapped to 17 linkage groups (LGs) covering 969.6 cM. Comparison of five minor LGs covering less than 50 cM with LGs in our previous RAPD-based genetic map suggested that four LGs could be integrated into two LGs by anchoring common SSR loci. Consequently, the number of LGs corresponded to the number of chromosomes (x = 15). We added 192 new SSRs, eight RAPD, and two sequence-tagged site loci to refine the RAPD-based genetic linkage map, which comprised 15 LGs consisting of 348 loci covering 978.3 cM. The two maps had 125 SSR loci in common, and most of the positions of markers were conserved between them. We identified 635 loci in carnation using the two linkage maps. We also mapped QTLs for two traits (bacterial wilt resistance and anthocyanin pigmentation in the flower) and a phenotypic locus for flower-type by analyzing previously reported genotype and phenotype data. Conclusions The improved genetic linkage maps and SSR markers developed in this study will serve as reference genetic linkage maps for members of the genus Dianthus, including carnation, and will be useful for mapping QTLs associated with various traits, and for improving carnation breeding programs. PMID:24160306

Construction of a reference genetic linkage map for carnation (Dianthus caryophyllus L.).

PubMed

Yagi, Masafumi; Yamamoto, Toshiya; Isobe, Sachiko; Hirakawa, Hideki; Tabata, Satoshi; Tanase, Koji; Yamaguchi, Hiroyasu; Onozaki, Takashi

2013-10-26

Genetic linkage maps are important tools for many genetic applications including mapping of quantitative trait loci (QTLs), identifying DNA markers for fingerprinting, and map-based gene cloning. Carnation (Dianthus caryophyllus L.) is an important ornamental flower worldwide. We previously reported a random amplified polymorphic DNA (RAPD)-based genetic linkage map derived from Dianthus capitatus ssp. andrezejowskianus and a simple sequence repeat (SSR)-based genetic linkage map constructed using data from intraspecific F2 populations; however, the number of markers was insufficient, and so the number of linkage groups (LGs) did not coincide with the number of chromosomes (x = 15). Therefore, we aimed to produce a high-density genetic map to improve its usefulness for breeding purposes and genetic research. We improved the SSR-based genetic linkage map using SSR markers derived from a genomic library, expression sequence tags, and RNA-seq data. Linkage analysis revealed that 412 SSR loci (including 234 newly developed SSR loci) could be mapped to 17 linkage groups (LGs) covering 969.6 cM. Comparison of five minor LGs covering less than 50 cM with LGs in our previous RAPD-based genetic map suggested that four LGs could be integrated into two LGs by anchoring common SSR loci. Consequently, the number of LGs corresponded to the number of chromosomes (x = 15). We added 192 new SSRs, eight RAPD, and two sequence-tagged site loci to refine the RAPD-based genetic linkage map, which comprised 15 LGs consisting of 348 loci covering 978.3 cM. The two maps had 125 SSR loci in common, and most of the positions of markers were conserved between them. We identified 635 loci in carnation using the two linkage maps. We also mapped QTLs for two traits (bacterial wilt resistance and anthocyanin pigmentation in the flower) and a phenotypic locus for flower-type by analyzing previously reported genotype and phenotype data. The improved genetic linkage maps and SSR markers developed in this study will serve as reference genetic linkage maps for members of the genus Dianthus, including carnation, and will be useful for mapping QTLs associated with various traits, and for improving carnation breeding programs.

Changing Paradigms in Down Syndrome: The First International Conference of the Trisomy 21 Research Society.

PubMed

Delabar, Jean-Maurice; Allinquant, Bernadette; Bianchi, Diana; Blumenthal, Tom; Dekker, Alain; Edgin, Jamie; O'Bryan, John; Dierssen, Mara; Potier, Marie-Claude; Wiseman, Frances; Guedj, Faycal; Créau, Nicole; Reeves, Roger; Gardiner, Katheleen; Busciglio, Jorge

2016-10-01

Down syndrome (DS) is the most common genetic cause of intellectual disability (ID) in humans with an incidence of ∼1:1,000 live births worldwide. It is caused by the presence of an extra copy of all or a segment of the long arm of human chromosome 21 (trisomy 21). People with DS present with a constellation of phenotypic alterations involving most organs and organ systems. ID is present in all people with DS, albeit with variable severity. DS is also the most frequent genetic cause of Alzheimer's disease (AD), and ∼50% of those with DS will develop AD-related dementia. In the last few years, significant progress has been made in understanding the crucial genotype-phenotype relationships in DS, in identifying the alterations in molecular pathways leading to the various clinical conditions present in DS, and in preclinical evaluations of potential therapies to improve the overall health and well-being of individuals with DS. In June 2015, 230 scientists, advocates, patients, and family members met in Paris for the 1st International Conference of the Trisomy 21 Research Society. Here, we report some of the most relevant presentations that took place during the meeting.

Clinical-genetic model predicts incident impulse control disorders in Parkinson's disease.

PubMed

Kraemmer, Julia; Smith, Kara; Weintraub, Daniel; Guillemot, Vincent; Nalls, Mike A; Cormier-Dequaire, Florence; Moszer, Ivan; Brice, Alexis; Singleton, Andrew B; Corvol, Jean-Christophe

2016-10-01

Impulse control disorders (ICD) are commonly associated with dopamine replacement therapy (DRT) in patients with Parkinson's disease (PD). Our aims were to estimate ICD heritability and to predict ICD by a candidate genetic multivariable panel in patients with PD. Data from de novo patients with PD, drug-naïve and free of ICD behaviour at baseline, were obtained from the Parkinson's Progression Markers Initiative cohort. Incident ICD behaviour was defined as positive score on the Questionnaire for Impulsive-Compulsive Disorders in PD. ICD heritability was estimated by restricted maximum likelihood analysis on whole exome sequencing data. 13 candidate variants were selected from the DRD2, DRD3, DAT1, COMT, DDC, GRIN2B, ADRA2C, SERT, TPH2, HTR2A, OPRK1 and OPRM1 genes. ICD prediction was evaluated by the area under the curve (AUC) of receiver operating characteristic (ROC) curves. Among 276 patients with PD included in the analysis, 86% started DRT, 40% were on dopamine agonists (DA), 19% reported incident ICD behaviour during follow-up. We found heritability of this symptom to be 57%. Adding genotypes from the 13 candidate variants significantly increased ICD predictability (AUC=76%, 95% CI (70% to 83%)) compared to prediction based on clinical variables only (AUC=65%, 95% CI (58% to 73%), p=0.002). The clinical-genetic prediction model reached highest accuracy in patients initiating DA therapy (AUC=87%, 95% CI (80% to 93%)). OPRK1, HTR2A and DDC genotypes were the strongest genetic predictive factors. Our results show that adding a candidate genetic panel increases ICD predictability, suggesting potential for developing clinical-genetic models to identify patients with PD at increased risk of ICD development and guide DRT management. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Lower Prevalence of Alzheimer's Disease among Tibetans: Association with Religious and Genetic Factors.

PubMed

Huang, Fukai; Shang, Ying; Luo, Yuandai; Wu, Peng; Huang, Xue; Tan, Xiaohui; Lu, Xingyi; Zhen, Lifang; Hu, Xianda

2016-01-01

The prevalence of dementia differs among racial groups, the highest prevalence being in Latin America (8.5%) compared to sub-Saharan African regions (2-4%). The most common type of dementia is Alzheimer's disease (AD). To estimate the prevalence of AD in the Qinghai-Tibet plateau and to investigate the related factors. This was a cross-sectional, multistage cluster sampling design survey. Data was collected from May 2014 to September 2014 from 4,060 Tibetan aged >60 years. Participants underwent clinical examinations and neuropsychological evaluations. MALDI-TOF was used to test the genotypes of CLU, TFAM, TP53INP1, IGHV1-67, CR1, ApoE, and BIN1. Logistic regression models were used to ascertain the associations with AD. The prevalence of AD among Tibetan individuals aged >60 years was 1.33% (95% CI: 0.98-1.69). The CLU haplotypes AA+GA (odds ratio (OR) = 4.483; 95% CI: 1.069-18.792) of rs2279590 was correlated with AD. The CLU haplotypes GG+GC (OR = 0.184; 95% CI: 0.038-0.888) of rs9331888 and kowtow (OR = 0.203; 95% CI 0.046-0.896) were negatively correlated with AD. A low prevalence of AD was found in Tibetans from the Qinghai-Tibet plateau. Multivariate analysis might suggest that regular "mind-body" religious meditative activities may be negatively associated with AD in this population, as well as the CLU genotype at rs9331888.

Mapping the Alzheimer’s Brain with Connectomics

PubMed Central

Xie, Teng; He, Yong

2012-01-01

Alzheimer’s disease (AD) is the most common form of dementia. As an incurable, progressive, and neurodegenerative disease, it causes cognitive and memory deficits. However, the biological mechanisms underlying the disease are not thoroughly understood. In recent years, non-invasive neuroimaging and neurophysiological techniques [e.g., structural magnetic resonance imaging (MRI), diffusion MRI, functional MRI, and EEG/MEG] and graph theory based network analysis have provided a new perspective on structural and functional connectivity patterns of the human brain (i.e., the human connectome) in health and disease. Using these powerful approaches, several recent studies of patients with AD exhibited abnormal topological organization in both global and regional properties of neuronal networks, indicating that AD not only affects specific brain regions, but also alters the structural and functional associations between distinct brain regions. Specifically, disruptive organization in the whole-brain networks in AD is involved in the loss of small-world characters and the re-organization of hub distributions. These aberrant neuronal connectivity patterns were associated with cognitive deficits in patients with AD, even with genetic factors in healthy aging. These studies provide empirical evidence to support the existence of an aberrant connectome of AD. In this review we will summarize recent advances discovered in large-scale brain network studies of AD, mainly focusing on graph theoretical analysis of brain connectivity abnormalities. These studies provide novel insights into the pathophysiological mechanisms of AD and could be helpful in developing imaging biomarkers for disease diagnosis and monitoring. PMID:22291664

Investigating the genetic relationship between Alzheimer's disease and cancer using GWAS summary statistics.

PubMed

Feng, Yen-Chen Anne; Cho, Kelly; Lindstrom, Sara; Kraft, Peter; Cormack, Jean; Liang, Liming; Driver, Jane A

2017-10-01

Growing evidence from both epidemiology and basic science suggest an inverse association between Alzheimer's disease (AD) and cancer. We examined the genetic relationship between AD and various cancer types using GWAS summary statistics from the IGAP and GAME-ON consortia. Sample size ranged from 9931 to 54,162; SNPs were imputed to the 1000 Genomes European panel. Our results based on cross-trait LD Score regression showed a significant positive genetic correlation between AD and five cancers combined (colon, breast, prostate, ovarian, lung; r g  = 0.17, P = 0.04), and specifically with breast cancer (ER-negative and overall; r g  = 0.21 and 0.18, P = 0.035 and 0.034) and lung cancer (adenocarcinoma, squamous cell carcinoma and overall; r g  = 0.31, 0.38 and 0.30, P = 0.029, 0.016, and 0.006). Estimating the genetic correlation in specific functional categories revealed mixed positive and negative signals, notably stronger at annotations associated with increased enhancer activity. This suggests a role of gene expression regulators in the shared genetic etiology between AD and cancer, and that some shared variants modulate disease risk concordantly while others have effects in opposite directions. Due to power issues, we did not detect cross-phenotype associations at individual SNPs. This genetic overlap is not likely driven by a handful of major loci. Our study is the first to examine the co-heritability of AD and cancer leveraging large-scale GWAS results. The functional categories highlighted in this study need further investigation to illustrate the details of the genetic sharing and to bridge between different levels of associations.

Three new genetic loci (R1210C in CFH, variants in COL8A1 and RAD51B) are independently related to progression to advanced macular degeneration.

PubMed

Seddon, Johanna M; Reynolds, Robyn; Yu, Yi; Rosner, Bernard

2014-01-01

To assess the independent impact of new genetic variants on conversion to advanced stages of AMD, controlling for established risk factors, and to determine the contribution of genes in predictive models. In this prospective longitudinal study of 2765 individuals, 777 subjects progressed to neovascular disease (NV) or geographic atrophy (GA) in either eye over 12 years. Recently reported genetic loci were assessed for their independent effects on incident advanced AMD after controlling for 6 established loci in 5 genes, and demographic, behavioral, and macular characteristics. New variants which remained significantly related to progression were then added to a final multivariate model to assess their independent effects. The contribution of genes to risk models was assessed using reclassification tables by determining risk within cross-classified quintiles for alternative models. THREE NEW GENETIC VARIANTS WERE SIGNIFICANTLY RELATED TO PROGRESSION: rare variant R1210C in CFH (hazard ratio (HR) 2.5, 95% confidence interval [CI] 1.2-5.3, P = 0.01), and common variants in genes COL8A1 (HR 2.0, 95% CI 1.1-3.5, P = 0.02) and RAD51B (HR 0.8, 95% CI 0.60-0.97, P = 0.03). The area under the curve statistic (AUC) was significantly higher for the 9 gene model (.884) vs the 0 gene model (.873), P = .01. AUC's for the 9 vs 6 gene models were not significantly different, but reclassification analyses indicated significant added information for more genes, with adjusted odds ratios (OR) for progression within 5 years per one quintile increase in risk score of 2.7, P<0.001 for the 9 vs 6 loci model, and OR 3.5, P<0.001 for the 9 vs. 0 gene model. Similar results were seen for NV and GA. Rare variant CFH R1210C and common variants in COL8A1 and RAD51B plus six genes in previous models contribute additional predictive information for advanced AMD beyond macular and behavioral phenotypes.

Three New Genetic Loci (R1210C in CFH, Variants in COL8A1 and RAD51B) Are Independently Related to Progression to Advanced Macular Degeneration

PubMed Central

Seddon, Johanna M.; Reynolds, Robyn; Yu, Yi; Rosner, Bernard

2014-01-01

Objectives To assess the independent impact of new genetic variants on conversion to advanced stages of AMD, controlling for established risk factors, and to determine the contribution of genes in predictive models. Methods In this prospective longitudinal study of 2765 individuals, 777 subjects progressed to neovascular disease (NV) or geographic atrophy (GA) in either eye over 12 years. Recently reported genetic loci were assessed for their independent effects on incident advanced AMD after controlling for 6 established loci in 5 genes, and demographic, behavioral, and macular characteristics. New variants which remained significantly related to progression were then added to a final multivariate model to assess their independent effects. The contribution of genes to risk models was assessed using reclassification tables by determining risk within cross-classified quintiles for alternative models. Results Three new genetic variants were significantly related to progression: rare variant R1210C in CFH (hazard ratio (HR) 2.5, 95% confidence interval [CI] 1.2–5.3, P = 0.01), and common variants in genes COL8A1 (HR 2.0, 95% CI 1.1–3.5, P = 0.02) and RAD51B (HR 0.8, 95% CI 0.60–0.97, P = 0.03). The area under the curve statistic (AUC) was significantly higher for the 9 gene model (.884) vs the 0 gene model (.873), P = .01. AUC’s for the 9 vs 6 gene models were not significantly different, but reclassification analyses indicated significant added information for more genes, with adjusted odds ratios (OR) for progression within 5 years per one quintile increase in risk score of 2.7, P<0.001 for the 9 vs 6 loci model, and OR 3.5, P<0.001 for the 9 vs. 0 gene model. Similar results were seen for NV and GA. Conclusions Rare variant CFH R1210C and common variants in COL8A1 and RAD51B plus six genes in previous models contribute additional predictive information for advanced AMD beyond macular and behavioral phenotypes. PMID:24498017

Review of Amyotrophic Lateral Sclerosis, Parkinson's and Alzheimer's diseases helps further define pathology of the novel paradigm for Alzheimer's with heavy metals as primary disease cause.

PubMed

Cavaleri, Franco

2015-12-01

Pathologies of neurological diseases are increasingly recognized to have common structural and molecular events that can fit, sometimes loosely, into a central pathological theme. A better understanding of the genetic, proteomic and metabolic similarities between three common neurodegenerative diseases - Amyotrophic Lateral Sclerosis (ALS), Parkinson's disease (PD) and Alzheimer's disease (AD) - and how these similarities relate to their unique pathological features may shed more light on the underlying pathology of each. These are complex multigenic neuroinflammatory diseases caused by a combined action by multiple genetic mutations, lifestyle factors and environmental elements including a proposed contribution by transition metals. This comprehensive dynamic makes disease decoding and treatment difficult. One case of ALS, for example, can manifest from a very different pool of genetic mutations than another. In the case of ALS multiple genes in addition to SOD1 are implicated in the pathogenesis of both sporadic and familial variants of the disease. These genes play different roles in the processing and trafficking of signalling, metabolic and structural proteins. However, many of these genetic mutations or the cellular machinery they regulate can play a role in one form or another in PD and AD as well. In addition, the more recent understanding of how TREM-2 mutations factor into inflammatory response has shed new light on how chronic inflammatory activity can escalate to uncontrolled systemic levels in a variety of inflammatory diseases from neurodegenerative, auto-inflammatory and autoimmune diseases. TREM-2 mutations represent yet another complicating element in these multigenic disease pathologies. This review takes us one step back to discuss basic pathological features of these neurodegenerative diseases known to us for some time. However, the objective is to discuss the possibility of related or linked mechanisms that may exist through these basic disease hallmarks that we often classify as absolute signatures of one disease. These new perspectives will be discussed in the context of a new paradigm for Alzheimer's disease that implicates heavy metals as a primary cause. Plausible links between these distinctly different pathologies are presented showing intersections of their distinct pathologies that hinge on metal interactions.

Development and validation of a 48-target analytical method for high-throughput monitoring of genetically modified organisms.

PubMed

Li, Xiaofei; Wu, Yuhua; Li, Jun; Li, Yunjing; Long, Likun; Li, Feiwu; Wu, Gang

2015-01-05

The rapid increase in the number of genetically modified (GM) varieties has led to a demand for high-throughput methods to detect genetically modified organisms (GMOs). We describe a new dynamic array-based high throughput method to simultaneously detect 48 targets in 48 samples on a Fludigm system. The test targets included species-specific genes, common screening elements, most of the Chinese-approved GM events, and several unapproved events. The 48 TaqMan assays successfully amplified products from both single-event samples and complex samples with a GMO DNA amount of 0.05 ng, and displayed high specificity. To improve the sensitivity of detection, a preamplification step for 48 pooled targets was added to enrich the amount of template before performing dynamic chip assays. This dynamic chip-based method allowed the synchronous high-throughput detection of multiple targets in multiple samples. Thus, it represents an efficient, qualitative method for GMO multi-detection.

Development and Validation of A 48-Target Analytical Method for High-throughput Monitoring of Genetically Modified Organisms

PubMed Central

Li, Xiaofei; Wu, Yuhua; Li, Jun; Li, Yunjing; Long, Likun; Li, Feiwu; Wu, Gang

2015-01-01

The rapid increase in the number of genetically modified (GM) varieties has led to a demand for high-throughput methods to detect genetically modified organisms (GMOs). We describe a new dynamic array-based high throughput method to simultaneously detect 48 targets in 48 samples on a Fludigm system. The test targets included species-specific genes, common screening elements, most of the Chinese-approved GM events, and several unapproved events. The 48 TaqMan assays successfully amplified products from both single-event samples and complex samples with a GMO DNA amount of 0.05 ng, and displayed high specificity. To improve the sensitivity of detection, a preamplification step for 48 pooled targets was added to enrich the amount of template before performing dynamic chip assays. This dynamic chip-based method allowed the synchronous high-throughput detection of multiple targets in multiple samples. Thus, it represents an efficient, qualitative method for GMO multi-detection. PMID:25556930

miRNAs Expressions and Interaction with Biological Systems in Patients with Alzheimer`s Disease. Using miRNAs as a Diagnosis and Prognosis Biomarker.

PubMed

Negoita, Silvius I; Sandesc, Dorel; Rogobete, Alexandru F; Dutu, Madalina; Bedreag, Ovidiu H; Papurica, Marius; Ercisli, Muhammed F; Popovici, Sonia E; Dumache, Raluca; Sandesc, Mihai; Dinu, Anca; Sas, Adriana M; Serban, Denis; Corneci, Dan

2017-09-01

A high percentage of patients develop Alzheimer`s disease (AD). The main signs are loss of memory and cognitive functions which have a significant impact on lifestyle. Numerous studies have been conducted to identify new biomarkers for early diagnosis of patients with AD. An ideal biomarker is represented by the expression of miRNAs. In this paper, we want to summarize expressions miRNAs in AD. We also want to present the pathophysiological and genetic interactions of miRNAs with protein systems in these patients. For the study, we examined available studies in scientific databases, such as PubMed and Scopus. The studies were searched using the keywords "miRNAs expression", "Alzheimer`s disease", "genetic polymorphisms", and "genetic biomarkers". For the assessment and monitoring of patients with AD, the expression of miRNAs can be used successfully due to increased specificity and selectivity. Moreover, the expression of miRNAs can provide important answers regarding possible genetic interactions and genetic therapeutic regimens. For the evaluation and non-invasive monitoring of patients with Alzheimer`s disease the expression of miRNAs can be successfully used.

Skin Prick Test in Patients with Chronic Allergic Skin Disorders

PubMed Central

Bains, Pooja; Dogra, Alka

2015-01-01

Background: Chronic allergic skin disorders are the inflammatory and proliferative conditions in which both genetic and environmental factors play important roles. Chronic idiopathic urticaria (CIU) and atopic dermatitis (AD) are among the most common chronic allergic skin disorders. These can be provoked by various food and aeroallergens. Skin prick tests (SPTs) represent the cheapest and most effective method to diagnose type I hypersensitivity. Positive skin tests with a history suggestive of clinical sensitivity strongly incriminate the allergen as a contributor to the disease process. Aims and Objectives: To determine the incidence of positive SPT in patients with chronic allergic skin disorders and to identify the various allergens implicated in positive SPT. Methods: Fifty patients of chronic allergic disorders were recruited in this study. They were evaluated by SPT with both food and aeroallergens. Results: In our study, SPT positivity in patients of CIU was 63.41% and in AD was 77.78%. Out of the 41 patients of CIU, the most common allergen groups showing SPT positivity were dust and pollen, each comprising 26.83% patients. SPT reaction was positive with food items (21.6%), insects (17.07%), fungus (12.20%), and Dermatophagoides farinae, that is, house dust mite (HDM) (7.32%). The allergen which showed maximum positivity was grain dust wheat (19.51%). Among nine patients of AD, maximum SPT positivity was seen with Dermatophagoides farinae, pollen Amaranthus spinosus, grain dust wheat, and cotton mill dust; each comprising 22.22% of patients. Conclusion: Our study showed that a significant number of patients of CIU and AD showed sensitivity to dust, pollen, insects, Dermatophagoides farinae, and fungi on SPT. Thus, it is an important tool in the diagnosis of CIU and AD. PMID:25814704

Non-Ceruloplasmin Copper Distincts Subtypes in Alzheimer's Disease: a Genetic Study of ATP7B Frequency.

PubMed

Squitti, Rosanna; Ventriglia, Mariacarla; Gennarelli, Massimo; Colabufo, Nicola A; El Idrissi, Imane Ghafir; Bucossi, Serena; Mariani, Stefania; Rongioletti, Mauro; Zanetti, Orazio; Congiu, Chiara; Rossini, Paolo M; Bonvicini, Cristian

2017-01-01

Meta-analyses show that serum copper non-bound-to-ceruloplasmin (non-Cp-Cu) is higher in patients with Alzheimer's disease (AD). ATP7B gene variants associate with AD, modulating the size of non-Cp-Cu pool. However, a dedicated genetic study comparing AD patients after stratification for a copper biomarker to demonstrate the existence of a copper subtype of AD has not yet been carried out. An independent patient sample of 287 AD patients was assessed for non-Cp-Cu serum concentrations, rs1801243, rs1061472, and rs732774 ATP7B genetic variants and the APOE4 genotype. Patients were stratified into two groups based on a non-Cp-Cu cutoff (1.9 μM). Single-locus and haplotype-group analyses were performed to define their frequencies in dependence of the non-Cp-Cu group. The two AD subgroups did not differ regarding age, sex, MMSE score, or APOE4 frequency allele, while they did differ regarding non-Cp-Cu concentrations in serum, allele, genotype, and haplotype frequencies of rs1061472 A > G and rs732774 C > T after multiple testing corrections. AD patients with a GG genotype had a 1.76-fold higher risk of having a non-Cp-Cu higher than 1.9 μmol/L (p = 0.029), and those with a TT genotype for rs732774 C > T of 1.8-fold (p = 0.018). After 100,000 permutations for multiple testing corrections, the haplotype containing the AC alleles appeared more frequently in AD patients with normal non-Cp-Cu [43 vs. 33 %; Pm = 0.03], while the haplotype containing the GT risk alleles appeared more frequently in the higher non-Cp-Cu AD (66 vs. 55 %; Pm = 0.01). Genetic heterogeneity sustains a copper AD metabolic subtype; non-Cp-Cu is a marker of this copper AD.

Genomic stability of adipogenic human adenovirus 36.

PubMed

Nam, J-H; Na, H-N; Atkinson, R L; Dhurandhar, N V

2014-02-01

Human adenovirus Ad36 increases adiposity in several animal models, including rodents and non-human primates. Importantly, Ad36 is associated with human obesity, which has prompted research to understand its epidemiology and to develop a vaccine to prevent a subgroup of obesity. For this purpose, understanding the genomic stability of Ad36 in vivo and in vitro infections is critical. Here, we examined whether in vitro cell passaging over a 14-year period introduced any genetic variation in Ad36. We sequenced the whole genome of Ad36-which was plaque purified in 1998 from the original strain obtained from American Type Culture Collection, and passaged approximately 12 times over the past 14 years (Ad36-2012). This DNA sequence was compared with a previously published sequence of Ad36 likely obtained from the same source (Ad36-1988). Compared with Ad36-1988, only two nucleotides were altered in Ad36-2012: a T insertion at nucleotide 1862, which may induce early termination of the E1B viral protein, and a T➝C transition at nucleotide 26 136. Virus with the T insertion (designated Ad36-2012-T6) was mixed with wild-type virus lacking the T insertion (designated Ad36-2012-T5) in the viral stock. The transition at nucleotide 26 136 does not change the encoded amino acid (aspartic acid) in the pVIII viral protein. The rate of genetic variation in Ad36 is ∼2.37 × 10(-6) mutations/nucleotide/passage. Of particular importance, there were no mutations in the E4orf1 gene, the critical gene for producing obesity. This very-low-variation rate should reduce concerns about genetic variability when developing Ad36 vaccines or developing assays for detecting Ad36 infection in populations.

CHOLESTEROL-RELATED GENETIC RISK SCORES ARE ASSOCIATED WITH HYPOMETABOLISM IN ALZHEIMER’S-AFFECTED BRAIN REGIONS

PubMed Central

Reiman, Eric M.; Chen, Kewei; Caselli, Richard J.; Alexander, Gene E.; Bandy, Daniel; Adamson, Jennifer L.; Lee, Wendy; Cannon, Ashley; Stephan, Elizabeth A.; Stephan, Dietrich A.; Papassotiropoulos, Andreas

2008-01-01

We recently implicated a cluster of nine single nucleotide polymorphisms from seven cholesterol-related genes in the risk of Alzheimer’s disease (AD) in a European cohort, and we proposed calculating an aggregate cholesterol-related genetic score (CREGS) to characterize a person’s risk. In a separate study, we found that apolipoprotein E (APOE) ε4 gene dose, an established AD risk factor, was correlated with fluorodeoxyglucose (FDG) positron emission tomography (PET) measurements of hypometabolism in AD-affected brain regions in a cognitively normal American cohort, and we proposed using PET as a presymptomatic endophenotype to help assess putative modifiers of AD risk. Thus, the objective in the present study is to determine whether CREGS is related to PET measurements of hypometabolism in AD-affected brain regions. DNA and PET data from 141 cognitively normal late middle-aged APOE ε4 homozygotes, heterozygotes and non-carriers were analyzed to evaluate the relationship between CREGS and regional PET measurements. Cholesterol-related genetic risk scores were associated with hypometabolism in AD-affected brain regions, even when controlling for the effects of APOE ε4 gene dose. The results support the role of cholesterol-related genes in the predisposition to AD, and support the value of neuroimaging in the presymptomatic assessment of putative modifiers of AD risk. PMID:18280754

Apolipoprotein E and Alzheimer disease: risk, mechanisms and therapy.

PubMed

Liu, Chia-Chen; Liu, Chia-Chan; Kanekiyo, Takahisa; Xu, Huaxi; Bu, Guojun

2013-02-01

Apolipoprotein E (Apo-E) is a major cholesterol carrier that supports lipid transport and injury repair in the brain. APOE polymorphic alleles are the main genetic determinants of Alzheimer disease (AD) risk: individuals carrying the ε4 allele are at increased risk of AD compared with those carrying the more common ε3 allele, whereas the ε2 allele decreases risk. Presence of the APOE ε4 allele is also associated with increased risk of cerebral amyloid angiopathy and age-related cognitive decline during normal ageing. Apo-E-lipoproteins bind to several cell-surface receptors to deliver lipids, and also to hydrophobic amyloid-β (Aβ) peptide, which is thought to initiate toxic events that lead to synaptic dysfunction and neurodegeneration in AD. Apo-E isoforms differentially regulate Aβ aggregation and clearance in the brain, and have distinct functions in regulating brain lipid transport, glucose metabolism, neuronal signalling, neuroinflammation, and mitochondrial function. In this Review, we describe current knowledge on Apo-E in the CNS, with a particular emphasis on the clinical and pathological features associated with carriers of different Apo-E isoforms. We also discuss Aβ-dependent and Aβ-independent mechanisms that link Apo-E4 status with AD risk, and consider how to design effective strategies for AD therapy by targeting Apo-E.

Apolipoprotein E and Alzheimer disease: risk, mechanisms, and therapy

PubMed Central

Liu, Chia-Chen; Kanekiyo, Takahisa; Xu, Huaxi; Bu, Guojun

2013-01-01

Apolipoprotein E (ApoE) is a major cholesterol carrier that supports lipid transport and injury repair in the brain. APOE polymorphic alleles are the main genetic determinants of Alzheimer disease (AD) risk: individuals carrying the ε4 allele are at increased risk of AD compared with those carrying the more common ε3 allele, whereas the ε2 allele decreases risk. Presence of the APOE ε4 allele is also associated with increased risk for cerebral amyloid angiopathy and age-related cognitive decline during normal ageing. ApoE–lipoproteins bind to several cell-surface receptors to deliver lipids and also to hydrophobic amyloid-β (Aβ) peptide, which is thought to initiate toxic events that lead to synaptic dysfunction and neurodegeneration in AD. ApoE isoforms differentially regulate Aβ aggregation and clearance in the brain, and have distinct functions in regulating brain lipid transport, glucose metabolism, neuronal signalling, neuroinflammation, and mitochondrial function. In this Review, we describe current knowledge on ApoE in the CNS, with a particular emphasis on the clinical and pathological features associated with carriers of different ApoE isoforms. We also discuss Aβ-dependent and Aβ-independent mechanisms that link ApoE4 status with AD risk, and consider how to design effective strategies for AD therapy by targeting ApoE. PMID:23296339

Pharmacological approaches to improving cognitive function in Down syndrome: current status and considerations

PubMed Central

Gardiner, Katheleen J

2015-01-01

Down syndrome (DS), also known as trisomy 21, is the most common genetic cause of intellectual disability (ID). Although ID can be mild, the average intelligence quotient is in the range of 40–50. All individuals with DS will also develop the neuropathology of Alzheimer’s disease (AD) by the age of 30–40 years, and approximately half will display an AD-like dementia by the age of 60 years. DS is caused by an extra copy of the long arm of human chromosome 21 (Hsa21) and the consequent elevated levels of expression, due to dosage, of trisomic genes. Despite a worldwide incidence of one in 700–1,000 live births, there are currently no pharmacological treatments available for ID or AD in DS. However, over the last several years, very promising results have been obtained with a mouse model of DS, the Ts65Dn. A diverse array of drugs has been shown to rescue, or partially rescue, DS-relevant deficits in learning and memory and abnormalities in cellular and electrophysiological features seen in the Ts65Dn. These results suggest that some level of amelioration or prevention of cognitive deficits in people with DS may be possible. Here, we review information from the preclinical evaluations in the Ts65Dn, how drugs were selected, how efficacy was judged, and how outcomes differ, or not, among studies. We also summarize the current state of human clinical trials for ID and AD in DS. Lastly, we describe the genetic limitations of the Ts65Dn as a model of DS, and in the preclinical testing of pharmacotherapeutics, and suggest additional targets to be considered for potential pharmacotherapies. PMID:25552901

The pathogenic implication of abnormal interaction between apolipoprotein E isoforms, amyloid-beta peptides, and sulfatides in Alzheimer's disease.

PubMed

Han, Xianlin

2010-06-01

Alzheimer's disease (AD) is the most common cause of dementia in the aging population. Prior work has shown that the epsilon4 allele of apolipoprotein E (apoE4) is a major risk factor for "sporadic" AD, which accounts for >99% of AD cases without a defined underlying mechanism. Recently, we have demonstrated that sulfatides are substantially and specifically depleted at the very early stage of AD. To identify the mechanism(s) of sulfatide loss concurrent with AD onset, we have found that: (1) sulfatides are specifically associated with apoE-associated particles in cerebrospinal fluid (CSF); (2) apoE modulates cellular sulfatide levels; and (3) the modulation of sulfatide content is apoE isoform dependent. These findings not only lead to identification of the potential mechanisms underlying sulfatide depletion at the earliest stages of AD but also serve as mechanistic links to explain the genetic association of apoE4 with AD. Moreover, our recent studies further demonstrated that (1) apoE mediates sulfatide depletion in amyloid-beta precursor protein transgenic mice; (2) sulfatides enhance amyloid beta (Abeta) peptides binding to apoE-associated particles; (3) Abeta42 content notably correlates with sulfatide content in CSF; (4) sulfatides markedly enhance the uptake of Abeta peptides; and (5) abnormal sulfatide-facilitated Abeta uptake results in the accumulation of Abeta in lysosomes. Collectively, our studies clearly provide a link between apoE, Abeta, and sulfatides in AD and establish a foundation for the development of effective therapeutic interventions for AD.

Is the urea cycle involved in Alzheimer's disease?

PubMed

Hansmannel, Franck; Sillaire, Adeline; Kamboh, M Ilyas; Lendon, Corinne; Pasquier, Florence; Hannequin, Didier; Laumet, Geoffroy; Mounier, Anais; Ayral, Anne-Marie; DeKosky, Steven T; Hauw, Jean-Jacques; Berr, Claudine; Mann, David; Amouyel, Philippe; Campion, Dominique; Lambert, Jean-Charles

2010-01-01

Since previous observations indicated that the urea cycle may have a role in the Alzheimer's disease (AD) process, we set out to quantify the expression of each gene involved in the urea cycle in control and AD brains and establish whether these genes could be genetic determinants of AD. We first confirmed that all the urea cycle enzyme genes are expressed in the AD brain. The expression of arginase 2 was greater in the AD brain than in the control brain. The presence of the rare arginase 2 allele rs742869 was associated with an increase in the risk of AD in men and with an earlier age-at-onset for both genders. None of the other genes in the pathway appeared to be differentially expressed in the AD brain or act as genetic determinants of the disease.

Is the urea cycle involved in Alzheimer’s disease?

PubMed Central

Hansmannel, Franck; Sillaire, Adeline; Kamboh, M. Ilyas; Lendon, Corinne; Pasquier, Florence; Hannequin, Didier; Laumet, Geoffroy; Mounier, Anais; Ayral, Anne-Marie; DeKosky, Steven T.; Hauw, Jean-Jacques; Berr, Claudine; Mann, David; Amouyel, Philippe; Campion, Dominique; Lambert, Jean-Charles

2010-01-01

Since previous observations indicated that the urea cycle may have a role in the Alzheimer’s disease (AD) process, we set out to quantify the expression of each gene involved in the urea cycle in control and AD brains and establish whether these genes could be genetic determinants of AD. We first confirmed that all the urea cycle enzyme genes are expressed in the AD brain. The expression of arginase 2 was greater in the AD brain than in the control brain. The presence of the rare arginase 2 allele rs742869 was associated with an increase in the risk of AD in men and with an earlier age at onset for both genders. None of the other genes in the pathway appeared to be differentially expressed in the AD brain or act as genetic determinants of the disease. PMID:20693631

Analysis of functional polymorphisms in three synaptic plasticity-related genes (BDNF, COMT AND UCHL1) in Alzheimer's disease in Colombia.

PubMed

Forero, Diego A; Benítez, Bruno; Arboleda, Gonzalo; Yunis, Juan J; Pardo, Rodrigo; Arboleda, Humberto

2006-07-01

In recent years, it has been proposed that synaptic dysfunction may be an important etiological factor for Alzheimer's disease (AD). This hypothesis has important implications for the analysis of AD genetic risk in case-control studies. In the present work, we analyzed common functional polymorphisms in three synaptic plasticity-related genes (brain-derived neurotrophic factor, BDNF Val66Met; catechol-O-methyl transferase, COMT Val158; ubiquitin carboxyl-terminal hydroxylase, UCHL1 S18Y) in a sample of 102 AD cases and 168 age and sex matched controls living in Bogotá, Colombia. There was not association between UCHL1 polymorphism and AD in our sample. We have found an initial association with BDNF polymorphism in familial cases and with COMT polymorphism in male and sporadic patients. These initial associations were lost after Bonferroni correction for multiple testing. Unadjusted results may be compatible with the expected functional effect of variations in these genes on pathological memory and cognitive dysfunction, as has been implicated in animal and cell models and also from neuropsychological analysis of normal subjects carriers of the AD associated genotypes. An exploration of functional variants in these and in other synaptic plasticity-related genes (a synaptogenomics approach) in independent larger samples will be important to discover new genes associated with AD.

Common variation in PHACTR1 is associated with susceptibility to cervical artery dissection.

PubMed

Debette, Stéphanie; Kamatani, Yoichiro; Metso, Tiina M; Kloss, Manja; Chauhan, Ganesh; Engelter, Stefan T; Pezzini, Alessandro; Thijs, Vincent; Markus, Hugh S; Dichgans, Martin; Wolf, Christiane; Dittrich, Ralf; Touzé, Emmanuel; Southerland, Andrew M; Samson, Yves; Abboud, Shérine; Béjot, Yannick; Caso, Valeria; Bersano, Anna; Gschwendtner, Andreas; Sessa, Maria; Cole, John; Lamy, Chantal; Medeiros, Elisabeth; Beretta, Simone; Bonati, Leo H; Grau, Armin J; Michel, Patrik; Majersik, Jennifer J; Sharma, Pankaj; Kalashnikova, Ludmila; Nazarova, Maria; Dobrynina, Larisa; Bartels, Eva; Guillon, Benoit; van den Herik, Evita G; Fernandez-Cadenas, Israel; Jood, Katarina; Nalls, Michael A; De Leeuw, Frank-Erik; Jern, Christina; Cheng, Yu-Ching; Werner, Inge; Metso, Antti J; Lichy, Christoph; Lyrer, Philippe A; Brandt, Tobias; Boncoraglio, Giorgio B; Wichmann, Heinz-Erich; Gieger, Christian; Johnson, Andrew D; Böttcher, Thomas; Castellano, Maurizio; Arveiler, Dominique; Ikram, M Arfan; Breteler, Monique M B; Padovani, Alessandro; Meschia, James F; Kuhlenbäumer, Gregor; Rolfs, Arndt; Worrall, Bradford B; Ringelstein, Erich-Bernd; Zelenika, Diana; Tatlisumak, Turgut; Lathrop, Mark; Leys, Didier; Amouyel, Philippe; Dallongeville, Jean

2015-01-01

Cervical artery dissection (CeAD), a mural hematoma in a carotid or vertebral artery, is a major cause of ischemic stroke in young adults although relatively uncommon in the general population (incidence of 2.6/100,000 per year). Minor cervical traumas, infection, migraine and hypertension are putative risk factors, and inverse associations with obesity and hypercholesterolemia are described. No confirmed genetic susceptibility factors have been identified using candidate gene approaches. We performed genome-wide association studies (GWAS) in 1,393 CeAD cases and 14,416 controls. The rs9349379[G] allele (PHACTR1) was associated with lower CeAD risk (odds ratio (OR) = 0.75, 95% confidence interval (CI) = 0.69-0.82; P = 4.46 × 10(-10)), with confirmation in independent follow-up samples (659 CeAD cases and 2,648 controls; P = 3.91 × 10(-3); combined P = 1.00 × 10(-11)). The rs9349379[G] allele was previously shown to be associated with lower risk of migraine and increased risk of myocardial infarction. Deciphering the mechanisms underlying this pleiotropy might provide important information on the biological underpinnings of these disabling conditions.

Alzheimer,s Disease Risk and Progression: The Role of Nutritional Supplements and their Effect on Drug Therapy Outcome

PubMed Central

Giulietti, A.; Vignini, A.; Nanetti, L.; Mazzanti, L.; Primio, R. Di; Salvolini, E.

2016-01-01

Alzheimer's disease (AD) is the most common neurodegenerative disease in the elderly population. Despite significant advancements in understanding the genetic and molecular basis of AD, the pathology still lacks treatments that can slow down or reverse the progression of cognitive deterioration. Recently, the relationship between nutrient deficiency and dementia onset has been highlighted. AD is in fact a multifactorial pathology, so that a multi-target approach using combinations of micronutrients and drugs could have beneficial effects on cognitive function in neurodegenerative brain disorders leading to synaptic degeneration. Primarily, this review examines the most recent literature regarding the effects of nutrition on the risk/progression of the disease, focusing attention mostly on antioxidants agents, polyunsaturated fatty acids and metals. Secondly, it aims to figure out if nutritional supplements might have beneficial effects on drug therapy outcome. Even if nutritional supplements showed contrasting evidence of a likely effect of decreasing the risk of AD onset that could be studied more deeply in other clinical trials, no convincing data are present about their usefulness in combination with drug therapies and their effectiveness in slowing down the disease progression. PMID:26415975

Locus-Specific Mutation Databases for Neurodegenerative Brain Diseases

PubMed Central

Cruts, Marc; Theuns, Jessie; Van Broeckhoven, Christine

2012-01-01

The Alzheimer disease and frontotemporal dementia (AD&FTLD) and Parkinson disease (PD) Mutation Databases make available curated information of sequence variations in genes causing Mendelian forms of the most common neurodegenerative brain disease AD, frontotemporal lobar degeneration (FTLD), and PD. They are established resources for clinical geneticists, neurologists, and researchers in need of comprehensive, referenced genetic, epidemiologic, clinical, neuropathological, and/or cell biological information of specific gene mutations in these diseases. In addition, the aggregate analysis of all information available in the databases provides unique opportunities to extract mutation characteristics and genotype–phenotype correlations, which would be otherwise unnoticed and unexplored. Such analyses revealed that 61.4% of mutations are private to one single family, while only 5.7% of mutations occur in 10 or more families. The five mutations with most frequent independent observations occur in 21% of AD, 43% of FTLD, and 48% of PD families recorded in the Mutation Databases, respectively. Although these figures are inevitably biased by a publishing policy favoring novel mutations, they probably also reflect the occurrence of multiple rare and few relatively common mutations in the inherited forms of these diseases. Finally, with the exception of the PD genes PARK2 and PINK1, all other genes are associated with more than one clinical diagnosis or characteristics thereof. Hum Mutat 33:1340–1344, 2012. © 2012 Wiley Periodicals, Inc. PMID:22581678

MAC Protocol for Ad Hoc Networks Using a Genetic Algorithm

PubMed Central

Elizarraras, Omar; Panduro, Marco; Méndez, Aldo L.

2014-01-01

The problem of obtaining the transmission rate in an ad hoc network consists in adjusting the power of each node to ensure the signal to interference ratio (SIR) and the energy required to transmit from one node to another is obtained at the same time. Therefore, an optimal transmission rate for each node in a medium access control (MAC) protocol based on CSMA-CDMA (carrier sense multiple access-code division multiple access) for ad hoc networks can be obtained using evolutionary optimization. This work proposes a genetic algorithm for the transmission rate election considering a perfect power control, and our proposition achieves improvement of 10% compared with the scheme that handles the handshaking phase to adjust the transmission rate. Furthermore, this paper proposes a genetic algorithm that solves the problem of power combining, interference, data rate, and energy ensuring the signal to interference ratio in an ad hoc network. The result of the proposed genetic algorithm has a better performance (15%) compared to the CSMA-CDMA protocol without optimizing. Therefore, we show by simulation the effectiveness of the proposed protocol in terms of the throughput. PMID:25140339

Classifying Alzheimer's disease with brain imaging and genetic data using a neural network framework.

PubMed

Ning, Kaida; Chen, Bo; Sun, Fengzhu; Hobel, Zachary; Zhao, Lu; Matloff, Will; Toga, Arthur W

2018-08-01

A long-standing question is how to best use brain morphometric and genetic data to distinguish Alzheimer's disease (AD) patients from cognitively normal (CN) subjects and to predict those who will progress from mild cognitive impairment (MCI) to AD. Here, we use a neural network (NN) framework on both magnetic resonance imaging-derived quantitative structural brain measures and genetic data to address this question. We tested the effectiveness of NN models in classifying and predicting AD. We further performed a novel analysis of the NN model to gain insight into the most predictive imaging and genetics features and to identify possible interactions between features that affect AD risk. Data were obtained from the AD Neuroimaging Initiative cohort and included baseline structural MRI data and single nucleotide polymorphism (SNP) data for 138 AD patients, 225 CN subjects, and 358 MCI patients. We found that NN models with both brain and SNP features as predictors perform significantly better than models with either alone in classifying AD and CN subjects, with an area under the receiver operating characteristic curve (AUC) of 0.992, and in predicting the progression from MCI to AD (AUC=0.835). The most important predictors in the NN model were the left middle temporal gyrus volume, the left hippocampus volume, the right entorhinal cortex volume, and the APOE (a gene that encodes apolipoprotein E) ɛ4 risk allele. Furthermore, we identified interactions between the right parahippocampal gyrus and the right lateral occipital gyrus, the right banks of the superior temporal sulcus and the left posterior cingulate, and SNP rs10838725 and the left lateral occipital gyrus. Our work shows the ability of NN models to not only classify and predict AD occurrence but also to identify important AD risk factors and interactions among them. Copyright © 2018 Elsevier Inc. All rights reserved.

Late-onset Alzheimer disease genetic variants in posterior cortical atrophy and posterior AD.

PubMed

Carrasquillo, Minerva M; Khan, Qurat ul Ain; Murray, Melissa E; Krishnan, Siddharth; Aakre, Jeremiah; Pankratz, V Shane; Nguyen, Thuy; Ma, Li; Bisceglio, Gina; Petersen, Ronald C; Younkin, Steven G; Dickson, Dennis W; Boeve, Bradley F; Graff-Radford, Neill R; Ertekin-Taner, Nilüfer

2014-04-22

To investigate association of genetic risk factors for late-onset Alzheimer disease (LOAD) with risk of posterior cortical atrophy (PCA), a syndrome of visual impairment with predominant Alzheimer disease (AD) pathology in posterior cortical regions, and with risk of "posterior AD" neuropathology. We assessed 81 participants with PCA diagnosed clinically and 54 with neuropathologic diagnosis of posterior AD vs 2,523 controls for association with 11 significant single nucleotide polymorphisms (SNPs) from published LOAD risk genome-wide association studies. There was highly significant association with APOE ε4 and increased risk of PCA (p = 0.0003, odds ratio [OR] = 3.17) and posterior AD (p = 1.11 × 10(-17), OR = 6.43). No other locus was significant after corrections for multiple testing, although rs11136000 near CLU (p = 0.019, OR = 0.60) and rs744373 near BIN1 (p = 0.025, OR = 1. 63) associated nominally significantly with posterior AD, and rs3851179 at the PICALM locus had significant association with PCA (p = 0.0003, OR = 2.84). ABCA7 locus SNP rs3764650, which was also tested under the recessive model because of Hardy-Weinberg disequilibrium, also had nominally significant association with PCA risk. The direction of association at APOE, CLU, and BIN1 loci was the same for participants with PCA and posterior AD. The effects for all SNPs, except rs3851179, were consistent with those for LOAD risk. We identified a significant effect for APOE and nominate CLU, BIN1, and ABCA7 as additional risk loci for PCA and posterior AD. Our findings suggest that at least some of the genetic risk factors for LOAD are shared with these atypical conditions and provide effect-size estimates for their future genetic studies.

Improving coeliac disease risk prediction by testing non-HLA variants additional to HLA variants.

PubMed

Romanos, Jihane; Rosén, Anna; Kumar, Vinod; Trynka, Gosia; Franke, Lude; Szperl, Agata; Gutierrez-Achury, Javier; van Diemen, Cleo C; Kanninga, Roan; Jankipersadsing, Soesma A; Steck, Andrea; Eisenbarth, Georges; van Heel, David A; Cukrowska, Bozena; Bruno, Valentina; Mazzilli, Maria Cristina; Núñez, Concepcion; Bilbao, Jose Ramon; Mearin, M Luisa; Barisani, Donatella; Rewers, Marian; Norris, Jill M; Ivarsson, Anneli; Boezen, H Marieke; Liu, Edwin; Wijmenga, Cisca

2014-03-01

The majority of coeliac disease (CD) patients are not being properly diagnosed and therefore remain untreated, leading to a greater risk of developing CD-associated complications. The major genetic risk heterodimer, HLA-DQ2 and DQ8, is already used clinically to help exclude disease. However, approximately 40% of the population carry these alleles and the majority never develop CD. We explored whether CD risk prediction can be improved by adding non-HLA-susceptible variants to common HLA testing. We developed an average weighted genetic risk score with 10, 26 and 57 single nucleotide polymorphisms (SNP) in 2675 cases and 2815 controls and assessed the improvement in risk prediction provided by the non-HLA SNP. Moreover, we assessed the transferability of the genetic risk model with 26 non-HLA variants to a nested case-control population (n=1709) and a prospective cohort (n=1245) and then tested how well this model predicted CD outcome for 985 independent individuals. Adding 57 non-HLA variants to HLA testing showed a statistically significant improvement compared to scores from models based on HLA only, HLA plus 10 SNP and HLA plus 26 SNP. With 57 non-HLA variants, the area under the receiver operator characteristic curve reached 0.854 compared to 0.823 for HLA only, and 11.1% of individuals were reclassified to a more accurate risk group. We show that the risk model with HLA plus 26 SNP is useful in independent populations. Predicting risk with 57 additional non-HLA variants improved the identification of potential CD patients. This demonstrates a possible role for combined HLA and non-HLA genetic testing in diagnostic work for CD.

Maternal DNA lineages at the gate of Europe in the 10th century AD

PubMed Central

Modi, Alessandra; Vai, Stefania; Pilli, Elena; Mircea, Cristina; Radu, Claudia; Urduzia, Claudia; Pinter, Zeno Karl; Bodolică, Vitalie; Dobrinescu, Cătălin; Hervella, Montserrat; Popescu, Octavian; Lari, Martina; Caramelli, David; Kelemen, Beatrice

2018-01-01

Given the paucity of archaeogenetic data available for medieval European populations in comparison to other historical periods, the genetic landscape of this age appears as a puzzle of dispersed, small, known pieces. In particular, Southeastern Europe has been scarcely investigated to date. In this paper, we report the study of mitochondrial DNA in 10th century AD human samples from Capidava necropolis, located in Dobruja (Southeastern Romania, Southeastern Europe). This geographical region is particularly interesting because of the extensive population flux following diverse migration routes, and the complex interactions between distinct population groups during the medieval period. We successfully amplified and typed the mitochondrial control region of 10 individuals. For five of them, we also reconstructed the complete mitochondrial genomes using hybridization-based DNA capture combined with Next Generation Sequencing. We have portrayed the genetic structure of the Capidava medieval population, represented by 10 individuals displaying 8 haplotypes (U5a1c2a, V1a, R0a2’3, H1, U3a, N9a9, H5e1a1, and H13a1a3). Remarkable for this site is the presence of both Central Asiatic (N9a) and common European mtDNA haplotypes, establishing Capidava as a point of convergence between East and West. The distribution of mtDNA lineages in the necropolis highlighted the existence of two groups of two individuals with close maternal relationships as they share the same haplotypes. We also sketch, using comparative statistical and population genetic analyses, the genetic relationships between the investigated dataset and other medieval and modern Eurasian populations. PMID:29538439

The evolution of adenoviral vectors through genetic and chemical surface modifications.

PubMed

Capasso, Cristian; Garofalo, Mariangela; Hirvinen, Mari; Cerullo, Vincenzo

2014-02-17

A long time has passed since the first clinical trial with adenoviral (Ad) vectors. Despite being very promising, Ad vectors soon revealed their limitations in human clinical trials. The pre-existing immunity, the marked liver tropism and the high toxicity of first generation Ad (FG-Ad) vectors have been the main challenges for the development of new approaches. Significant effort toward the development of genetically and chemically modified adenoviral vectors has enabled researchers to create more sophisticated vectors for gene therapy, with an improved safety profile and a higher transduction ability of different tissues. In this review, we will describe the latest findings in the high-speed, evolving field of genetic and chemical modifications of adenoviral vectors, a field in which different disciplines, such as biomaterial research, virology and immunology, co-operate synergistically to create better gene therapy tools for modern challenges.

Environmental effects on molecular and phenotypic variation in populations of Eruca sativa across a steep climatic gradient

PubMed Central

Westberg, Erik; Ohali, Shachar; Shevelevich, Anatoly; Fine, Pinchas; Barazani, Oz

2013-01-01

Abstract In Israel Eruca sativa has a geographically narrow distribution across a steep climatic gradient that ranges from mesic Mediterranean to hot desert environments. These conditions offer an opportunity to study the influence of the environment on intraspecific genetic variation. For this, we combined an analysis of neutral genetic markers with a phenotypic evaluation in common-garden experiments, and environmental characterization of populations that included climatic and edaphic parameters, as well as geographic distribution. A Bayesian clustering of individuals from nine representative populations based on amplified fragment length polymorphism (AFLP) divided the populations into a southern and a northern geographic cluster, with one admixed population at the geographic border between them. Linear mixed models, with cluster added as a grouping factor, revealed no clear effects of environment or geography on genetic distances, but this may be due to a strong association of geography and environment with genetic clusters. However, environmental factors accounted for part of the phenotypic variation observed in the common-garden experiments. In addition, candidate loci for selection were identified by association with environmental parameters and by two outlier methods. One locus, identified by all three methods, also showed an association with trichome density and herbivore damage, in net-house and field experiments, respectively. Accordingly, we propose that because trichomes are directly linked to defense against both herbivores and excess radiation, they could potentially be related to adaptive variation in these populations. These results demonstrate the value of combining environmental and phenotypic data with a detailed genetic survey when studying adaptation in plant populations. This article describes the use of several types of data to estimate the influence of the environment on intraspecific genetic variation in populations originating from a steep climatic gradient. In addition to molecular marker data, we made use of phenotypic evaluation from common garden experiments, and a broad GIS based environmental data with edaphic information gathered in the field. This study, among others, lead to the identification of an outlier locus with an association to trichome formation and herbivore defense, and its ecological adaptive value is discussed. PMID:24567822

Genetics of psychosis of Alzheimer disease.

PubMed

Shah, Chintan; DeMichele-Sweet, Mary Ann A; Sweet, Robert A

2017-01-01

Psychotic symptoms, comprised of delusions and hallucinations, occur in about half of individuals with Alzheimer disease (AD with psychosis, AD+P). These individuals have greater agitation, aggression, depression, functional impairment, and mortality than individuals without psychosis (AD-P). Although the exact etiopathogenesis of AD+P is unclear, the rapidly developing field of genomics continues to expand our understanding of this disease. Several independent studies have demonstrated familial aggregation and heritability of AD+P. Linkage studies have been suggestive of loci on several chromosomes associated with AD+P. Association studies examining apolipoprotein E gene, the best established genetic risk factor for late-onset AD, did not find any significant association of this gene with AD+P. Other candidate gene studies focusing on monoamine neurotransmitter systems have yielded equivocal results. A genome-wide association study and studies examining copy number variations recently have detected suggestive associations, but have been underpowered. Approaches to increase sizes of AD+P samples for genome wide association studies are discussed. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Genetics of Psychosis in Alzheimer Disease.

PubMed

DeMichele-Sweet, Mary Ann A; Sweet, Robert A

2014-03-01

Psychosis occurs in approximately half of patients with Alzheimer disease (AD with psychosis, AD+P). AD+P patients have more rapid cognitive decline, greater behavioral symptoms, and higher mortality than do AD patients without psychosis. Studies in three independent cohorts have shown that psychosis in AD aggregates in families, with estimated heritability of 29.5 - 60.8%. These findings have motivated studies to investigate and uncover the genes responsible for the development of psychosis, with the ultimate goal of identifying potential biologic mechanisms that may serve as leads to specific therapies. Linkage analyses have implicated loci on chromosomes 2, 6, 7, 8, 15, and 21 with AD+P. Association studies of APOE do not support it as a risk gene for psychosis in AD. No other candidate genes, such as neurodegenerative and monoamine genes, show conclusive evidence of association with AD+P. However, a recent genome-side association study has produced some promising leads, including among them genes that have been associated with schizophrenia. This review summarizes the current knowledge of the genetic basis of AD+P.

Comparison of the levels of intra-specific genetic variation within Giardia muris and Giardia intestinalis.

PubMed

Andrews, R H; Monis, P T; Ey, P L; Mayrhofer, G

1998-08-01

The extent of intra-specific genetic variation between isolates of Giardia muris was assessed by allozyme electrophoresis. Additionally, the levels of allozymic variation detected within G. muris were compared with those observed between members of the two major assemblages of the morphologically distinct species Giardia intestinalis. Four isolates of G. muris were analysed. Three (Ad-120, -150, -151) were isolated from mice in Australia, while the fourth (R-T) was isolated from a golden hamster in North America. The 11 isolates of G. intestinalis (Ad-1, -12, -2, -62, representing genetic Groups I and II of Assemblage A and BAH-12, BRIS/87/HEPU/694, Ad-19, -22, -28, -45, -52, representing genetic Groups III and IV of Assemblage B) were from humans in Australia. Intra-specific genetic variation was detected between G. muris isolates at four of the 23 enzyme loci examined. Similar levels of variation were found within the genetic groups that comprise Assemblages A and B of G. intestinalis. These levels of intra-specific variation are similar to those observed within other morphologically-distinct species of protozoan parasites. We suggest that the magnitude of the genetic differences detected within G. muris provides an indication of the range of genetic variation within other species of Giardia and that this can be used as a model to delineate morphologically similar but genetically distinct (cryptic) species within this genus.

Neuropathologic assessment of dementia markers in identical and fraternal twins

PubMed Central

Iacono, Diego; Volkman, Inga; Nennesmo, Inger; Pedersen, Nancy L.; Fratiglioni, Laura; Johansson, Boo; Karlsson, David; Winblad, Bengt; Gatz, Margaret

2014-01-01

Twin studies are an incomparable source of investigation to shed light on genetic and non-genetic components of neurodegenerative diseases, as Alzheimer’s disease (AD). Detailed clinicopathologic correlations using twin longitudinal data and postmortem examinations are mostly missing. We describe clinical and pathologic findings of 7 monozygotic (MZ) and dizygotic (DZ) twin pairs. Our findings show good agreement between clinical and pathologic diagnoses in the majority of the twin pairs, with greater neuropathologic concordance in MZ than DZ twins. Greater neuropathologic concordance was found for β-amyloid than tau pathology within the pairs. ApoE4 was associated with higher β-amyloid and earlier dementia onset, and importantly, higher frequency of other co-occurring brain pathologies, regardless of the zygosity. Dementia onset, dementia duration, difference between twins in age at dementia onset and at death, did not correlate with AD pathology. These clinicopathologic correlations of older identical and fraternal twins support the relevance of genetic factors in AD, but not their sufficiency to determine the pathology, and consequently the disease, even in monozygotic twins. It is the interaction among genetic and non-genetic risks which plays a major role in influencing, or probably determining, the degeneration of those brain circuits associated with pathology and cognitive deficits in AD. PMID:24450926

New era of biologic therapeutics in atopic dermatitis.

PubMed

Guttman-Yassky, Emma; Dhingra, Nikhil; Leung, Donald Y M

2013-04-01

Atopic dermatitis (AD) is a common inflammatory skin disease regulated by genetic and environmental factors. Both skin barrier defects and aberrant immune responses are believed to drive cutaneous inflammation in AD. Existing therapies rely largely on allergen avoidance, emollients and topical and systemic immune-suppressants, some with significant toxicity and transient efficacy; no specific targeted therapies are in clinical use today. As our specific understanding of the immune and molecular pathways that cause different subsets of AD increases, a variety of experimental agents, particularly biologic agents that target pathogenic molecules bring the promise of safe and effective therapeutics for long-term use. This paper discusses the molecular pathways characterizing AD, the contributions of barrier and immune abnormalities to its pathogenesis, and development of new treatments that target key molecules in these pathways. In this review, we will discuss a variety of biologic therapies that are in development or in clinical trials for AD, perhaps revolutionizing treatment of this disease. Biologic agents in moderate to severe AD offer promise for controlling a disease that currently lacks good and safe therapeutics posing a large unmet need. Unfortunately, existing treatments for AD aim to decrease cutaneous inflammation, but are not specific for the pathways driving this disease. An increasing understanding of the immune mechanisms underlying AD brings the promise of narrow targeted therapies as has occurred for psoriasis, another inflammatory skin disease, for which specific biologic agents have been demonstrated to both control the disease and prevent occurrence of new skin lesions. Although no biologic is yet approved for AD, these are exciting times for active therapeutic development in AD that might lead to revolutionary therapeutics for this disease.

Hand stereotypies distinguish Rett syndrome from autism disorder.

PubMed

Goldman, Sylvie; Temudo, Teresa

2012-07-01

Rett syndrome (RTT) and autism disorder (AD) are 2 neurodevelopmental disorders of early life that share phenotypic features, one being hand stereotypies. Distinguishing RTT from AD often represents a challenge, and given their distinct long-term prognoses, this issue may have far-reaching implications. With the advances in genetic testing, the contribution of clinical manifestations in distinguishing RTT from AD has been overlooked. A comparison of hand stereotypies in 20 children with RTT and 20 with AD was performed using detailed analyses of videotaped standardized observations. Striking differences are observed between RTT and AD children. In RTT, hand stereotypies are predominantly complex, continuous, localized to the body midline, and involving mouthing. Conversely, in AD children, hand stereotypies are simple, bilateral, intermittent, and often involving objects. These results provide important clinical signs useful to the differential diagnosis of RTT versus AD, especially when genetic testing for RTT is not an option. Copyright © 2012 Movement Disorder Society.

Genetic factors contribute to bleeding after cardiac surgery.

PubMed

Welsby, I J; Podgoreanu, M V; Phillips-Bute, B; Mathew, J P; Smith, P K; Newman, M F; Schwinn, D A; Stafford-Smith, M

2005-06-01

Postoperative bleeding remains a common, serious problem for cardiac surgery patients, with striking inter-patient variability poorly explained by clinical, procedural, and biological markers. We tested the hypothesis that genetic polymorphisms of coagulation proteins and platelet glycoproteins are associated with bleeding after cardiac surgery. Seven hundred and eighty patients undergoing aortocoronary surgery with cardiopulmonary bypass were studied. Clinical covariates previously associated with bleeding were recorded and DNA isolated from preoperative blood. Matrix Assisted Laser Desorption/Ionization, Time-Of-Flight (MALDI-TOF) mass spectroscopy or polymerase chain reaction were used for genotype analysis. Multivariable linear regression modeling, including all genetic main effects and two-way gene-gene interactions, related clinical and genetic predictors to bleeding from the thorax and mediastinum. Nineteen candidate polymorphisms were assessed; seven [GPIaIIa-52C>T and 807C>T, GPIb alpha 524C>T, tissue factor-603A>G, prothrombin 20210G>A, tissue factor pathway inhibitor-399C>T, and angiotensin converting enzyme (ACE) deletion/insertion] demonstrate significant association with bleeding (P < 0.01). Adding genetic to clinical predictors results improves the model, doubling overall ability to predict bleeding (P < 0.01). We identified seven genetic polymorphisms associated with bleeding after cardiac surgery. Genetic factors appear primarily independent of, and explain at least as much variation in bleeding as clinical covariates; combining genetic and clinical factors double our ability to predict bleeding after cardiac surgery. Accounting for genotype may be necessary when stratifying risk of bleeding after cardiac surgery.

Predictive accuracy of combined genetic and environmental risk scores.

PubMed

Dudbridge, Frank; Pashayan, Nora; Yang, Jian

2018-02-01

The substantial heritability of most complex diseases suggests that genetic data could provide useful risk prediction. To date the performance of genetic risk scores has fallen short of the potential implied by heritability, but this can be explained by insufficient sample sizes for estimating highly polygenic models. When risk predictors already exist based on environment or lifestyle, two key questions are to what extent can they be improved by adding genetic information, and what is the ultimate potential of combined genetic and environmental risk scores? Here, we extend previous work on the predictive accuracy of polygenic scores to allow for an environmental score that may be correlated with the polygenic score, for example when the environmental factors mediate the genetic risk. We derive common measures of predictive accuracy and improvement as functions of the training sample size, chip heritabilities of disease and environmental score, and genetic correlation between disease and environmental risk factors. We consider simple addition of the two scores and a weighted sum that accounts for their correlation. Using examples from studies of cardiovascular disease and breast cancer, we show that improvements in discrimination are generally small but reasonable degrees of reclassification could be obtained with current sample sizes. Correlation between genetic and environmental scores has only minor effects on numerical results in realistic scenarios. In the longer term, as the accuracy of polygenic scores improves they will come to dominate the predictive accuracy compared to environmental scores. © 2017 WILEY PERIODICALS, INC.

Predictive accuracy of combined genetic and environmental risk scores

PubMed Central

Pashayan, Nora; Yang, Jian

2017-01-01

ABSTRACT The substantial heritability of most complex diseases suggests that genetic data could provide useful risk prediction. To date the performance of genetic risk scores has fallen short of the potential implied by heritability, but this can be explained by insufficient sample sizes for estimating highly polygenic models. When risk predictors already exist based on environment or lifestyle, two key questions are to what extent can they be improved by adding genetic information, and what is the ultimate potential of combined genetic and environmental risk scores? Here, we extend previous work on the predictive accuracy of polygenic scores to allow for an environmental score that may be correlated with the polygenic score, for example when the environmental factors mediate the genetic risk. We derive common measures of predictive accuracy and improvement as functions of the training sample size, chip heritabilities of disease and environmental score, and genetic correlation between disease and environmental risk factors. We consider simple addition of the two scores and a weighted sum that accounts for their correlation. Using examples from studies of cardiovascular disease and breast cancer, we show that improvements in discrimination are generally small but reasonable degrees of reclassification could be obtained with current sample sizes. Correlation between genetic and environmental scores has only minor effects on numerical results in realistic scenarios. In the longer term, as the accuracy of polygenic scores improves they will come to dominate the predictive accuracy compared to environmental scores. PMID:29178508

Gene-based rare allele analysis identified a risk gene of Alzheimer's disease.

PubMed

Kim, Jong Hun; Song, Pamela; Lim, Hyunsun; Lee, Jae-Hyung; Lee, Jun Hong; Park, Sun Ah

2014-01-01

Alzheimer's disease (AD) has a strong propensity to run in families. However, the known risk genes excluding APOE are not clinically useful. In various complex diseases, gene studies have targeted rare alleles for unsolved heritability. Our study aims to elucidate previously unknown risk genes for AD by targeting rare alleles. We used data from five publicly available genetic studies from the Alzheimer's Disease Neuroimaging Initiative (ADNI) and the database of Genotypes and Phenotypes (dbGaP). A total of 4,171 cases and 9,358 controls were included. The genotype information of rare alleles was imputed using 1,000 genomes. We performed gene-based analysis of rare alleles (minor allele frequency≤3%). The genome-wide significance level was defined as meta P<1.8×10(-6) (0.05/number of genes in human genome = 0.05/28,517). ZNF628, which is located at chromosome 19q13.42, showed a genome-wide significant association with AD. The association of ZNF628 with AD was not dependent on APOE ε4. APOE and TREM2 were also significantly associated with AD, although not at genome-wide significance levels. Other genes identified by targeting common alleles could not be replicated in our gene-based rare allele analysis. We identified that rare variants in ZNF628 are associated with AD. The protein encoded by ZNF628 is known as a transcription factor. Furthermore, the associations of APOE and TREM2 with AD were highly significant, even in gene-based rare allele analysis, which implies that further deep sequencing of these genes is required in AD heritability studies.

Associations between Potentially Modifiable Risk Factors and Alzheimer Disease: A Mendelian Randomization Study.

PubMed

Østergaard, Søren D; Mukherjee, Shubhabrata; Sharp, Stephen J; Proitsi, Petroula; Lotta, Luca A; Day, Felix; Perry, John R B; Boehme, Kevin L; Walter, Stefan; Kauwe, John S; Gibbons, Laura E; Larson, Eric B; Powell, John F; Langenberg, Claudia; Crane, Paul K; Wareham, Nicholas J; Scott, Robert A

2015-06-01

Potentially modifiable risk factors including obesity, diabetes, hypertension, and smoking are associated with Alzheimer disease (AD) and represent promising targets for intervention. However, the causality of these associations is unclear. We sought to assess the causal nature of these associations using Mendelian randomization (MR). We used SNPs associated with each risk factor as instrumental variables in MR analyses. We considered type 2 diabetes (T2D, NSNPs = 49), fasting glucose (NSNPs = 36), insulin resistance (NSNPs = 10), body mass index (BMI, NSNPs = 32), total cholesterol (NSNPs = 73), HDL-cholesterol (NSNPs = 71), LDL-cholesterol (NSNPs = 57), triglycerides (NSNPs = 39), systolic blood pressure (SBP, NSNPs = 24), smoking initiation (NSNPs = 1), smoking quantity (NSNPs = 3), university completion (NSNPs = 2), and years of education (NSNPs = 1). We calculated MR estimates of associations between each exposure and AD risk using an inverse-variance weighted approach, with summary statistics of SNP-AD associations from the International Genomics of Alzheimer's Project, comprising a total of 17,008 individuals with AD and 37,154 cognitively normal elderly controls. We found that genetically predicted higher SBP was associated with lower AD risk (odds ratio [OR] per standard deviation [15.4 mm Hg] of SBP [95% CI]: 0.75 [0.62-0.91]; p = 3.4 × 10(-3)). Genetically predicted higher SBP was also associated with a higher probability of taking antihypertensive medication (p = 6.7 × 10(-8)). Genetically predicted smoking quantity was associated with lower AD risk (OR per ten cigarettes per day [95% CI]: 0.67 [0.51-0.89]; p = 6.5 × 10(-3)), although we were unable to stratify by smoking history; genetically predicted smoking initiation was not associated with AD risk (OR = 0.70 [0.37, 1.33]; p = 0.28). We saw no evidence of causal associations between glycemic traits, T2D, BMI, or educational attainment and risk of AD (all p > 0.1). Potential limitations of this study include the small proportion of intermediate trait variance explained by genetic variants and other implicit limitations of MR analyses. Inherited lifetime exposure to higher SBP is associated with lower AD risk. These findings suggest that higher blood pressure--or some environmental exposure associated with higher blood pressure, such as use of antihypertensive medications--may reduce AD risk.

Addison's disease: a survey on 633 patients in Padova.

PubMed

Betterle, Corrado; Scarpa, Riccardo; Garelli, Silvia; Morlin, Luca; Lazzarotto, Francesca; Presotto, Fabio; Coco, Graziella; Masiero, Stefano; Parolo, Anna; Albergoni, Maria Paola; Favero, Roberta; Barollo, Susi; Salvà, Monica; Basso, Daniela; Chen, Shu; Rees Smith, Bernard; Furmaniak, Jadwiga; Mantero, Franco

2013-12-01

Addison's disease (AD) is a rare endocrine condition. We aimed to evaluate clinical, immunologic, adrenal imaging, and genetic features in 633 Italian patients with AD followed up since 1967. Adrenal cortex autoantibodies, presence of other autoimmune and nonautoimmune diseases, nonadrenal autoantibodies, adrenal imaging, and genetic profile for HLA-DRB1 and AIRE were analyzed. A total of 492 (77.7%) patients were found to be affected by autoimmune AD (A-AD), 57 (9%) tuberculous AD, 29 (4.6%) genetic-associated AD, 10 (1.6%) adrenal cancer, six (0.94%) post-surgical AD, four (0.6%) vascular disorder-related AD, three (0.5%) post-infectious AD, and 32 (5.1%) were defined as idiopathic. Adrenal cortex antibodies were detected in the vast majority (88100%) of patients with recent onset A-AD, but in none of those with nonautoimmune AD. Adrenal imaging revealed normal/atrophic glands in all A-AD patients: 88% of patients with A-AD had other clinical or subclinical autoimmune diseases or were positive for nonadrenal autoantibodies. Based on the coexistence of other autoimmune disorders, 65.6% of patients with A-AD were found to have type 2 autoimmune polyendocrine syndrome (APS2), 14.4% have APS1, and 8.5% have APS4. Class II HLA alleles DRB1*03 and DRB1*04 were increased, and DRB1*01, DRB1*07, DRB1*013 were reduced in APS2 patients when compared with controls. Of the patients with APS1, 96% were revealed to have AIRE gene mutations. A-AD is the most prevalent form of adrenal insufficiency in Italy, and ∼90% of the patients are adrenal autoantibody-positive at the onset. Assessment of patients with A-AD for the presence of other autoimmune diseases should be helpful in monitoring and diagnosing APS types 1, 2, or 4 and improving patients' care.

An advanced analysis method of initial orbit determination with too short arc data

NASA Astrophysics Data System (ADS)

Li, Binzhe; Fang, Li

2018-02-01

This paper studies the initial orbit determination (IOD) based on space-based angle measurement. Commonly, these space-based observations have short durations. As a result, classical initial orbit determination algorithms give poor results, such as Laplace methods and Gauss methods. In this paper, an advanced analysis method of initial orbit determination is developed for space-based observations. The admissible region and triangulation are introduced in the method. Genetic algorithm is also used for adding some constraints of parameters. Simulation results show that the algorithm can successfully complete the initial orbit determination.

Modulation of beta-amyloid precursor protein trafficking and processing by the low density lipoprotein receptor family.

PubMed

Cam, Judy A; Bu, Guojun

2006-08-18

Amyloid-beta peptide (Abeta) accumulation in the brain is an early, toxic event in the pathogenesis of Alzheimer's disease (AD). Abeta is produced by proteolytic processing of a transmembrane protein, beta-amyloid precursor protein (APP), by beta- and gamma-secretases. Mounting evidence has demonstrated that alterations in APP cellular trafficking and localization directly impact its processing to Abeta. Recent studies have shown that members of the low-density lipoprotein receptor family, including LRP, LRP1B, SorLA/LR11, and apolipoprotein E (apoE) receptor 2, interact with APP and regulate its endocytic trafficking. Another common feature of these receptors is their ability to bind apoE, which exists in three isoforms in humans and the presence of the epsilon4 allele represents a genetic risk factor for AD. In this review, we summarize the current understanding of the function of these apoE receptors with a focus on their role in APP trafficking and processing. Knowledge of the interactions between these distinct low-density lipoprotein receptor family members and APP may ultimately influence future therapies for AD.

Current Concepts of Neurodegenerative Mechanisms in Alzheimer's Disease.

PubMed

Magalingam, Kasthuri Bai; Radhakrishnan, Ammu; Ping, Ng Shee; Haleagrahara, Nagaraja

2018-01-01

Neurodegenerative diseases are hereditary or sporadic conditions that result in the progressive loss of the structure and function of neurons as well as neuronal death. Although a range of diseases lie under this umbrella term, Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common neurodegenerative diseases that affect a large population around the globe. Alzheimer's disease is characterized by the abnormal accumulation of extracellular amyloid- β plaques and intraneuronal neurofibrillary tangles in brain regions and manifests as a type of dementia in aged individuals that results in memory loss, multiple cognitive abnormalities, and intellectual disabilities that interfere with quality of life. Since the discovery of AD, a wealth of new information has emerged that delineates the causes, mechanisms of disease, and potential therapeutic agents, but an effective remedy to cure the diseases has not been identified yet. This could be because of the complexity of the disease process, as it involves various contributing factors that include environmental factors and genetic predispositions. This review summarizes the current understanding on neurodegenerative mechanisms that lead to the emergence of the pathology of AD.

Genetic dissection of Alzheimer disease, a heterogeneous disorder.

PubMed

Schellenberg, G D

1995-09-12

The genetics of Alzheimer disease (AD) are complex and not completely understood. Mutations in the amyloid precursor protein gene (APP) can cause early-onset autosomal dominant AD. In vitro studies indicate that cells expressing mutant APPs overproduce pathogenic forms of the A beta peptide, the major component of AD amyloid. However, mutations in the APP gene are responsible for 5% or less of all early-onset familial AD. A locus on chromosome 14 is responsible for AD in other early-onset AD families and represents the most severe form of the disease in terms of age of onset and rate of decline. Attempts to identify the AD3 gene by positional cloning methods are underway. At least one additional early-onset AD locus remains to be located. In late-onset AD, the apolipoprotein E gene allele epsilon 4 is a risk factor for AD. This allele appears to act as a dose-dependent age-of-onset modifier. The epsilon 2 allele of this gene may be protective. Other late-onset susceptibility factors remain to be identified.

Genetic Contribution to Alcohol Dependence: Investigation of a Heterogeneous German Sample of Individuals with Alcohol Dependence, Chronic Alcoholic Pancreatitis, and Alcohol-Related Cirrhosis

PubMed Central

Treutlein, Jens; Streit, Fabian; Juraeva, Dilafruz; Degenhardt, Franziska; Rietschel, Liz; Forstner, Andreas J.; Ridinger, Monika; Dukal, Helene; Foo, Jerome C.; Soyka, Michael; Maier, Wolfgang; Gaebel, Wolfgang; Dahmen, Norbert; Scherbaum, Norbert; Müller-Myhsok, Bertram; Lucae, Susanne; Ising, Marcus; Stickel, Felix; Berg, Thomas; Roggenbuck, Ulla; Jöckel, Karl-Heinz; Scholz, Henrike; Zimmermann, Ulrich S.; Buch, Stephan; Sommer, Wolfgang H.; Spanagel, Rainer; Brors, Benedikt; Cichon, Sven; Mann, Karl; Kiefer, Falk; Hampe, Jochen; Rosendahl, Jonas; Nöthen, Markus M.; Rietschel, Marcella

2017-01-01

The present study investigated the genetic contribution to alcohol dependence (AD) using genome-wide association data from three German samples. These comprised patients with: (i) AD; (ii) chronic alcoholic pancreatitis (ACP); and (iii) alcohol-related liver cirrhosis (ALC). Single marker, gene-based, and pathway analyses were conducted. A significant association was detected for the ADH1B locus in a gene-based approach (puncorrected = 1.2 × 10−6; pcorrected = 0.020). This was driven by the AD subsample. No association with ADH1B was found in the combined ACP + ALC sample. On first inspection, this seems surprising, since ADH1B is a robustly replicated risk gene for AD and may therefore be expected to be associated also with subgroups of AD patients. The negative finding in the ACP + ALC sample, however, may reflect genetic stratification as well as random fluctuation of allele frequencies in the cases and controls, demonstrating the importance of large samples in which the phenotype is well assessed. PMID:28714907

Genetic aspect of Alzheimer disease: Results of complex segregation analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sadonvick, A.D.; Lee, I.M.L.; Bailey-Wilson, J.E.

1994-09-01

The study was designed to evaluate the possibility that a single major locus will explain the segregation of Alzheimer disease (AD). The data were from the population-based AD Genetic Database and consisted of 402 consecutive, unrelated probands, diagnosed to have either `probable` or `autopsy confirmed` AD and their 2,245 first-degree relatives. In this analysis, a relative was considered affected with AD only when there were sufficient medical/autopsy data to support diagnosis of AD being the most likely cause of the dementia. Transmission probability models allowing for a genotype-dependent and logistically distributed age-of-onset were used. The program REGTL in the S.A.G.E.more » computer program package was used for a complex segregation analysis. The models included correction for single ascertainment. Regressive familial effects were not estimated. The data were analyzed to test for single major locus (SML), random transmission and no transmission (environmental) hypotheses. The results of the complex segregation analysis showed that (1) the SML was the best fit, and (2) the non-genetic models could be rejected.« less

Genetic Contribution to Alcohol Dependence: Investigation of a Heterogeneous German Sample of Individuals with Alcohol Dependence, Chronic Alcoholic Pancreatitis, and Alcohol-Related Cirrhosis.

PubMed

Treutlein, Jens; Frank, Josef; Streit, Fabian; Reinbold, Céline S; Juraeva, Dilafruz; Degenhardt, Franziska; Rietschel, Liz; Witt, Stephanie H; Forstner, Andreas J; Ridinger, Monika; Strohmaier, Jana; Wodarz, Norbert; Dukal, Helene; Foo, Jerome C; Hoffmann, Per; Herms, Stefan; Heilmann-Heimbach, Stefanie; Soyka, Michael; Maier, Wolfgang; Gaebel, Wolfgang; Dahmen, Norbert; Scherbaum, Norbert; Müller-Myhsok, Bertram; Lucae, Susanne; Ising, Marcus; Stickel, Felix; Berg, Thomas; Roggenbuck, Ulla; Jöckel, Karl-Heinz; Scholz, Henrike; Zimmermann, Ulrich S; Buch, Stephan; Sommer, Wolfgang H; Spanagel, Rainer; Brors, Benedikt; Cichon, Sven; Mann, Karl; Kiefer, Falk; Hampe, Jochen; Rosendahl, Jonas; Nöthen, Markus M; Rietschel, Marcella

2017-07-17

The present study investigated the genetic contribution to alcohol dependence (AD) using genome-wide association data from three German samples. These comprised patients with: (i) AD; (ii) chronic alcoholic pancreatitis (ACP); and (iii) alcohol-related liver cirrhosis (ALC). Single marker, gene-based, and pathway analyses were conducted. A significant association was detected for the ADH1B locus in a gene-based approach ( p uncorrected = 1.2 × 10 -6 ; p corrected = 0.020). This was driven by the AD subsample. No association with ADH1B was found in the combined ACP + ALC sample. On first inspection, this seems surprising, since ADH1B is a robustly replicated risk gene for AD and may therefore be expected to be associated also with subgroups of AD patients. The negative finding in the ACP + ALC sample, however, may reflect genetic stratification as well as random fluctuation of allele frequencies in the cases and controls, demonstrating the importance of large samples in which the phenotype is well assessed.

Genetic instability in inherited and sporadic leukemias.

PubMed

Popp, Henning D; Bohlander, Stefan K

2010-12-01

Genetic instability due to increased DNA damage and altered DNA repair is of central significance in the initiation and progression of inherited and sporadic human leukemias. Although very rare, some inherited DNA repair insufficiency syndromes (e.g., Fanconi anemia, Bloom's syndrome) have added substantially to our understanding of crucial mechanisms of leukemogenesis in recent years. Conversely, sporadic leukemias account for the main proportion of leukemias and here DNA damaging reactive oxygen species (ROS) play a central role. Although the exact mechanisms of increased ROS production remain largely unknown and no single pathway has been detected thus far, some oncogenic proteins (e.g., the activated tyrosine kinases BCR-ABL1 and FLT3-ITD) seem to play a key role in driving genetic instability by increased ROS generation which influences the disease course (e.g., blast crisis in chronic myeloid leukemia or relapse in FLT3-ITD positive acute myeloid leukemia). Of course other mechanisms, which promote genetic instability in leukemia also exist. A newly emerging mechanism is the genome-wide alteration of epigenetic marks (e.g., hypomethylation of histone H3K79), which promotes chromosomal instability. Taken together genetic instability plays a critical role both in inherited and sporadic leukemias and emerges as a common theme in both inherited and sporadic leukemias. Beyond its theoretical impact, the analysis of genetic instability may lead the way to the development of innovative therapy strategies. © 2010 Wiley-Liss, Inc.

Can Genetic Analysis of Putative Blood Alzheimer’s Disease Biomarkers Lead to Identification of Susceptibility Loci?

PubMed Central

Huebinger, Ryan M.; Shewale, Shantanu J.; Koenig, Jessica L.; Mitchel, Jeffrey S.; O’Bryant, Sid E.; Waring, Stephen C.; Diaz-Arrastia, Ramon; Chasse, Scott

2015-01-01

Although 24 Alzheimer’s disease (AD) risk loci have been reliably identified, a large portion of the predicted heritability for AD remains unexplained. It is expected that additional loci of small effect will be identified with an increased sample size. However, the cost of a significant increase in Case-Control sample size is prohibitive. The current study tests whether exploring the genetic basis of endophenotypes, in this case based on putative blood biomarkers for AD, can accelerate the identification of susceptibility loci using modest sample sizes. Each endophenotype was used as the outcome variable in an independent GWAS. Endophenotypes were based on circulating concentrations of proteins that contributed significantly to a published blood-based predictive algorithm for AD. Endophenotypes included Monocyte Chemoattractant Protein 1 (MCP1), Vascular Cell Adhesion Molecule 1 (VCAM1), Pancreatic Polypeptide (PP), Beta2 Microglobulin (B2M), Factor VII (F7), Adiponectin (ADN) and Tenascin C (TN-C). Across the seven endophenotypes, 47 SNPs were associated with outcome with a p-value ≤1x10-7. Each signal was further characterized with respect to known genetic loci associated with AD. Signals for several endophenotypes were observed in the vicinity of CR1, MS4A6A/MS4A4E, PICALM, CLU, and PTK2B. The strongest signal was observed in association with Factor VII levels and was located within the F7 gene. Additional signals were observed in MAP3K13, ZNF320, ATP9B and TREM1. Conditional regression analyses suggested that the SNPs contributed to variation in protein concentration independent of AD status. The identification of two putatively novel AD loci (in the Factor VII and ATP9B genes), which have not been located in previous studies despite massive sample sizes, highlights the benefits of an endophenotypic approach for resolving the genetic basis for complex diseases. The coincidence of several of the endophenotypic signals with known AD loci may point to novel genetic interactions and should be further investigated. PMID:26625115

Can Genetic Analysis of Putative Blood Alzheimer's Disease Biomarkers Lead to Identification of Susceptibility Loci?

PubMed

Barber, Robert C; Phillips, Nicole R; Tilson, Jeffrey L; Huebinger, Ryan M; Shewale, Shantanu J; Koenig, Jessica L; Mitchel, Jeffrey S; O'Bryant, Sid E; Waring, Stephen C; Diaz-Arrastia, Ramon; Chasse, Scott; Wilhelmsen, Kirk C

2015-01-01

Although 24 Alzheimer's disease (AD) risk loci have been reliably identified, a large portion of the predicted heritability for AD remains unexplained. It is expected that additional loci of small effect will be identified with an increased sample size. However, the cost of a significant increase in Case-Control sample size is prohibitive. The current study tests whether exploring the genetic basis of endophenotypes, in this case based on putative blood biomarkers for AD, can accelerate the identification of susceptibility loci using modest sample sizes. Each endophenotype was used as the outcome variable in an independent GWAS. Endophenotypes were based on circulating concentrations of proteins that contributed significantly to a published blood-based predictive algorithm for AD. Endophenotypes included Monocyte Chemoattractant Protein 1 (MCP1), Vascular Cell Adhesion Molecule 1 (VCAM1), Pancreatic Polypeptide (PP), Beta2 Microglobulin (B2M), Factor VII (F7), Adiponectin (ADN) and Tenascin C (TN-C). Across the seven endophenotypes, 47 SNPs were associated with outcome with a p-value ≤1x10(-7). Each signal was further characterized with respect to known genetic loci associated with AD. Signals for several endophenotypes were observed in the vicinity of CR1, MS4A6A/MS4A4E, PICALM, CLU, and PTK2B. The strongest signal was observed in association with Factor VII levels and was located within the F7 gene. Additional signals were observed in MAP3K13, ZNF320, ATP9B and TREM1. Conditional regression analyses suggested that the SNPs contributed to variation in protein concentration independent of AD status. The identification of two putatively novel AD loci (in the Factor VII and ATP9B genes), which have not been located in previous studies despite massive sample sizes, highlights the benefits of an endophenotypic approach for resolving the genetic basis for complex diseases. The coincidence of several of the endophenotypic signals with known AD loci may point to novel genetic interactions and should be further investigated.

On the discovery of the genetic association of Apolipoprotein E genotypes and common late-onset Alzheimer disease.

PubMed

Roses, Allen D

2006-01-01

The association of Apolipoprotein E-4 with the age of onset of common late-onset Alzheimer's disease (AD) was originally reported in three 1993 papers from the Duke ADRC (Alzheimer's Disease Research Center) group. The Center was investigating two diverse experimental streams that led to this discovery. The first being a genetic linkage study performed in multiplex familial late-onset AD in which a linkage was discovered at chromosome 19q13. The 1991 multilocus analysis of linkage had been considered very controversial. The second stream came from a series of amyloid-beta binding studies in which a consistent protein "impurity" was present on gel separation analyses. After sequencing this "impurity" band, several tryptic peptide sequences were found to be identical for apoE which, at that time, had no known association with Alzheimer's disease. The flash of recognition was the knowledge that APOE was one of the first genes localized to chromosome 19 in the mid-1980's. Within a three week period in late 1992, a highly significant association was identified in clinical patients from multiplex families, in sporadic clinical patients, and in autopsy diagnosed series. Within the first two months of 1993, it was possible to clearly demonstrate that the APOE isoforms were associated with differing ages of onset, but the course of illness following diagnosis was related more to age than APOE genotype. The earliest submitted paper reported the familial association and amyloid-beta binding. The second reported the association with common sporadic late-onset, [not-known to be familial] AD patients. The third reported that APOE4 carriers had earlier rates of onset of clinical disease than APOE2 or APOE3 carriers. Subsequently, over more than a decade, the biological expression of apoE in human neurons was confirmed as distinct from rodent brain. Proteomic experiments and positron emission tomography data have led to a series of clinical trials with agents selected to increase glucose utilization. These agents also regulate inflammatory responses of neural cells. Rosiglitazone, a PPARgamma agonist which also leads to mitochondrial proliferation shown efficacy as a monotherapy in a Phase IIB clinical trial of 511 patients in an APOE allele-specific analysis.

The role of genetics in fisheries management under the E.U. common fisheries policy.

PubMed

Casey, J; Jardim, E; Martinsohn, J Th

2016-12-01

Exploitation of fish and shellfish stocks by the European Union fishing fleet is managed under the Common Fisheries Policy (CFP), which aims to ensure that fishing and aquaculture are environmentally, economically and socially sustainable and that they provide a source of healthy food for E.U. citizens. A notable feature of the CFP is its legally enshrined requirement for sound scientific advice to underpin its objectives. The CFP was first conceived in 1970 when it formed part of the Common Agricultural Policy. Its formal inception as a stand-alone regulation occurred in 1983 and since that time, the CFP has undergone reforms in 1992, 2002 and 2013, each time bringing additional challenges to the scientific advisory process as the scope of the advice increased in response to changing objectives arising from E.U. regulations and commitments to international agreements. This paper reviews the influence that genetics has had on fish stock assessments and the provision of management advice for European fisheries under successive reforms of the CFP. The developments in genetics since the inception of the CFP have given rise to a diverse and versatile set of genetic techniques that have the potential to provide significant added value to fisheries assessments and the scientific advisory process. While in some cases, notably Pacific salmon Oncorhynchus spp., genetics appear to be very well integrated into existing management schemes, it seems that for marine fishes, discussions on the use of genetics and genomics for fisheries management are often driven by the remarkable technological progress in this field, rather than imminent needs emerging from policy frameworks. An example is the recent suggestion to use environmental (e)DNA for monitoring purposes. While there is no denying that state-of-the-art genetic and genomic approaches can and will be of value to address a number of issues relevant for the management and conservation of marine renewable natural resources, a focus on technology rather than policy and management needs is prone to widen the gap between science and policy, governance and management, thereby further impeding the effective integration of genetic and genomic information into the fisheries management decision making process. Hence, rather than focusing on what is technically achievable, this review outlines suggestions as to which modern genetic and genomic approaches are likely to help address some of the most pressing fisheries management challenges under the CFP. © 2016 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

Meta-analysis of six genes (BDNF, DRD1, DRD3, DRD4, GRIN2B and MAOA) involved in neuroplasticity and the risk for alcohol dependence.

PubMed

Forero, Diego A; López-León, Sandra; Shin, Hyoung Doo; Park, Byung Lae; Kim, Dai-Jin

2015-04-01

Alcohol-related problems have a large impact on human health, accounting for around 4% of deaths and 4.5% of disability-adjusted life-years around the world. Genetic factors could explain a significant fraction of the risk for alcohol dependence (AD). Recent meta-analyses have found significant pooled odds ratios (ORs) for variants in the ADH1B, ADH1C, DRD2 and HTR2A genes. In the present study, we carried out a meta-analysis of common variants in 6 candidate genes involved in neurotransmission and neuroplasticity: BDNF, DRD1, DRD3, DRD4, GRIN2B and MAOA. We carried out a systematic search for published association studies that analyzed the genes of interest. Relevant articles were retrieved and demographic and genetic data were extracted. Pooled ORs were calculated using a random-effects model using the Meta-Analyst program. Dominant, recessive and allelic models were tested and analyses were also stratified by ethnicity. Forty two published studies were included in the current meta-analysis: BDNF-rs6265 (nine studies), DRD1-rs4532 (four studies), DRD3-rs6280 (eleven studies), DRD4-VNTR (seven studies), GRIN2B-rs1806201 (three studies) and MAOA-uVNTR (eight studies). We did not find significant pooled ORs for any of the six genes, under different models and stratifying for ethnicity. In terms of the number of candidate genes included, this is one of the most comprehensive meta-analyses for genetics of AD. Pooled ORs did not support consistent associations with any of the six candidate genes tested. Future studies of novel genes of functional relevance and meta-analyses of quantitative endophenotypes could identify further susceptibility molecular factors for AD. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

ADMultiImg: a novel missing modality transfer learning based CAD system for diagnosis of MCI due to AD using incomplete multi-modality imaging data

NASA Astrophysics Data System (ADS)

Liu, Xiaonan; Chen, Kewei; Wu, Teresa; Weidman, David; Lure, Fleming; Li, Jing

2018-02-01

Alzheimer's Disease (AD) is the most common cause of dementia and currently has no cure. Treatments targeting early stages of AD such as Mild Cognitive Impairment (MCI) may be most effective to deaccelerate AD, thus attracting increasing attention. However, MCI has substantial heterogeneity in that it can be caused by various underlying conditions, not only AD. To detect MCI due to AD, NIA-AA published updated consensus criteria in 2011, in which the use of multi-modality images was highlighted as one of the most promising methods. It is of great interest to develop a CAD system based on automatic, quantitative analysis of multi-modality images and machine learning algorithms to help physicians more adequately diagnose MCI due to AD. The challenge, however, is that multi-modality images are not universally available for many patients due to cost, access, safety, and lack of consent. We developed a novel Missing Modality Transfer Learning (MMTL) algorithm capable of utilizing whatever imaging modalities are available for an MCI patient to diagnose the patient's likelihood of MCI due to AD. Furthermore, we integrated MMTL with radiomics steps including image processing, feature extraction, and feature screening, and a post-processing for uncertainty quantification (UQ), and developed a CAD system called "ADMultiImg" to assist clinical diagnosis of MCI due to AD using multi-modality images together with patient demographic and genetic information. Tested on ADNI date, our system can generate a diagnosis with high accuracy even for patients with only partially available image modalities (AUC=0.94), and therefore may have broad clinical utility.

Redox proteomics analysis of HNE-modified proteins in Down syndrome brain: clues for understanding the development of Alzheimer disease.

PubMed

Di Domenico, Fabio; Pupo, Gilda; Tramutola, Antonella; Giorgi, Alessandra; Schininà, Maria Eugenia; Coccia, Raffaella; Head, Elizabeth; Butterfield, D Allan; Perluigi, Marzia

2014-06-01

Down syndrome (DS) is the most common genetic cause of intellectual disability, due to partial or complete triplication of chromosome 21. DS subjects are characterized by a number of abnormalities including premature aging and development of Alzheimer disease (AD) neuropathology after approximately 40 years of age. Several studies show that oxidative stress plays a crucial role in the development of neurodegeneration in the DS population. Increased lipid peroxidation is one of the main events causing redox imbalance within cells through the formation of toxic aldehydes that easily react with DNA, lipids, and proteins. In this study we used a redox proteomics approach to identify specific targets of 4-hydroxynonenal modifications in the frontal cortex from DS cases with and without AD pathology. We suggest that a group of identified proteins followed a specific pattern of oxidation in DS vs young controls, probably indicating characteristic features of the DS phenotype; a second group of identified proteins showed increased oxidation in DS/AD vs DS, thus possibly playing a role in the development of AD. The third group of comparison, DS/AD vs old controls, identified proteins that may be considered specific markers of AD pathology. All the identified proteins are involved in important biological functions including intracellular quality control systems, cytoskeleton network, energy metabolism, and antioxidant response. Our results demonstrate that oxidative damage is an early event in DS, as well as dysfunctions of protein-degradation systems and cellular protective pathways, suggesting that DS subjects are more vulnerable to oxidative damage accumulation that might contribute to AD development. Further, considering that the majority of proteins have been already demonstrated to be oxidized in AD brain, our results strongly support similarities with AD in DS. Copyright © 2014 Elsevier Inc. All rights reserved.

CFH Variants Affect Structural and Functional Brain Changes and Genetic Risk of Alzheimer's Disease.

PubMed

Zhang, Deng-Feng; Li, Jin; Wu, Huan; Cui, Yue; Bi, Rui; Zhou, He-Jiang; Wang, Hui-Zhen; Zhang, Chen; Wang, Dong; Kong, Qing-Peng; Li, Tao; Fang, Yiru; Jiang, Tianzi; Yao, Yong-Gang

2016-03-01

The immune response is highly active in Alzheimer's disease (AD). Identification of genetic risk contributed by immune genes to AD may provide essential insight for the prognosis, diagnosis, and treatment of this neurodegenerative disease. In this study, we performed a genetic screening for AD-related top immune genes identified in Europeans in a Chinese cohort, followed by a multiple-stage study focusing on Complement Factor H (CFH) gene. Effects of the risk SNPs on AD-related neuroimaging endophenotypes were evaluated through magnetic resonance imaging scan, and the effects on AD cerebrospinal fluid biomarkers (CSF) and CFH expression changes were measured in aged and AD brain tissues and AD cellular models. Our results showed that the AD-associated top immune genes reported in Europeans (CR1, CD33, CLU, and TREML2) have weak effects in Chinese, whereas CFH showed strong effects. In particular, rs1061170 (P(meta)=5.0 × 10(-4)) and rs800292 (P(meta)=1.3 × 10(-5)) showed robust associations with AD, which were confirmed in multiple world-wide sample sets (4317 cases and 16 795 controls). Rs1061170 (P=2.5 × 10(-3)) and rs800292 (P=4.7 × 10(-4)) risk-allele carriers have an increased entorhinal thickness in their young age and a higher atrophy rate as the disease progresses. Rs800292 risk-allele carriers have higher CSF tau and Aβ levels and severe cognitive decline. CFH expression level, which was affected by the risk-alleles, was increased in AD brains and cellular models. These comprehensive analyses suggested that CFH is an important immune factor in AD and affects multiple pathological changes in early life and during disease progress.

Genetic Ablation of Apolipoprotein A-IV Accelerates Alzheimer's Disease Pathogenesis in a Mouse Model

PubMed Central

Cui, Yujie; Huang, Mingwei; He, Yingbo; Zhang, Shuyan; Luo, Yongzhang

2011-01-01

The link between lipoprotein metabolism and Alzheimer's disease (AD) has been established. Apolipoprotein A-IV (apoA-IV), a component of lipoprotein particles similar to apolipoprotein E, has been suggested to play an important role in brain metabolism. Although there are clinical debates on the function of its polymorphism in AD, the pathologic role of apoA-IV in AD is still unknown. Here, we report that genetic ablation of apoA-IV is able to accelerate AD pathogenesis in mice. In a mouse model that overexpresses human amyloid precursor protein (APP) and presenilin 1, genetic reduction of apoA-IV augments extracellular amyloid-β peptide (Aβ) burden and aggravates neuron loss in the brain. In addition, genetic ablation of apoA-IV also accelerates spatial learning deficits and increases the mortality of mice. We have found that apoA-IV colocalizes within Aβ plaques in APP/presenilin 1 transgenic mice and binds to Aβ in vitro. Subsequent studies show that apoA-IV in this model facilitates Aβ uptake in the Aβ clearance pathway mediated by astrocytes rather than the amyloidogenic pathway of APP processing. Taken together, we conclude that apoA-IV deficiency increases Aβ deposition and results in cognitive damage in the mouse model. Enhancing levels of apoA-IV may have therapeutic potential in AD treatment. PMID:21356380

IL-1β-Induced Protection of Keratinocytes against Staphylococcus aureus-Secreted Proteases Is Mediated by Human β-Defensin 2.

PubMed

Wang, Bingjie; McHugh, Brian J; Qureshi, Ayub; Campopiano, Dominic J; Clarke, David J; Fitzgerald, J Ross; Dorin, Julia R; Weller, Richard; Davidson, Donald J

2017-01-01

Atopic dermatitis (AD) is a common chronic inflammatory skin disease that results in significant morbidity. A hallmark of AD is disruption of the critical barrier function of upper epidermal layers, causatively linked to environmental stimuli, genetics, and infection, and a critical current target for the development of new therapeutic and prophylactic interventions. Staphylococcus aureus is an AD-associated pathogen producing virulence factors that induce skin barrier disruption in vivo and contribute to AD pathogenesis. We show, using immortalized and primary keratinocytes, that S. aureus protease SspA/V8 is the dominant secreted factor (in laboratory and AD clinical strains of S. aureus) inducing barrier integrity impairment and tight junction damage. V8-induced integrity damage was inhibited by an IL-1β-mediated mechanism, independent of effects on claudin-1. Induction of keratinocyte expression of the antimicrobial/host defense peptide human β-defensin 2 (hBD2) was found to be the mechanism underpinning this protective effect. Endogenous hBD2 expression was required and sufficient for protection against V8 protease-mediated integrity damage, and exogenous application of hBD2 was protective. This modulatory property of hBD2, unrelated to antibacterial effects, gives new significance to the defective induction of hBD2 in the barrier-defective skin lesions of AD and indicates therapeutic potential. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Blood type gene locus has no influence on ACE association with Alzheimer's disease.

PubMed

Braae, Anne; Medway, Christopher; Carrasquillo, Minerva; Younkin, Steven; Kehoe, Patrick G; Morgan, Kevin

2015-04-01

The ABO blood group locus was recently found to contribute independently and via interactions with angiotensin-converting enzyme (ACE) gene variation to plasma levels of ACE. Variation in ACE has previously been not only implicated as individually conferring susceptibility for Alzheimer's disease (AD) but also proposed to confer risk via interactions with other as yet unknown genes. More recently, larger studies have not supported ACE as a risk factor for AD, whereas the role of ACE pathway in AD has come under increased levels of scrutiny with respect to various aspects of AD pathology and possible therapies. We explored the potential combined involvement of ABO and ACE variations in the genetic susceptibility of 2067 AD cases compared with 1376 nondemented elderly. Including the effects of ABO haplotype did not provide any evidence for the genetic association of ACE with AD. Copyright © 2015 Elsevier Inc. All rights reserved.

Insulin‐degrading enzyme is genetically associated with Alzheimer's disease in the Finnish population

PubMed Central

Vepsäläinen, Saila; Parkinson, Michele; Helisalmi, Seppo; Mannermaa, Arto; Soininen, Hilkka; Tanzi, Rudolph E; Bertram, Lars; Hiltunen, Mikko

2007-01-01

The gene for insulin‐degrading enzyme (IDE), which is located at chromosome 10q24, has been previously proposed as a candidate gene for late‐onset Alzheimer's disease (AD) based on its ability to degrade amyloid β‐protein. Genotyping of single nucleotide polymorphisms (SNPs) in the IDE gene in Finnish patients with AD and controls revealed SNPs rs4646953 and rs4646955 to be associated with AD, conferring an approximately two‐fold increased risk. Single locus findings were corroborated by the results obtained from haplotype analyses. This suggests that genetic alterations in or near the IDE gene may increase the risk for developing AD. PMID:17496198

Association of HLA-DRB1 genetic variants with the persistence of atopic dermatitis

PubMed Central

Margolis, David J.; Mitra, Nandita; Kim, Brian; Gupta, Jayanta; Hoffstad, Ole J; Papadopoulos, Maryte; Wubbenhorst, Bradley; Nathanson, Katherine L; Duke, Jamie L.; Monos, Dimtri.; Kamoun, Malek

2015-01-01

Atopic dermatitis (AD) is a waxing and waning illness of childhood that is likely caused by interactions between an altered skin barrier and immune dysregulation. The goal of our study was to evaluate the association of DRB1 genetic variants and the persistence of AD using whole exome sequencing and high resolution typing. DRB1 was interrogated based on previous reports that utilized high throughput techniques. We evaluated an ongoing nation-wide long-term cohort of children with AD in which patients are asked every 6 months about their medication use and their AD symptoms. In total, 87 African-American and 50 European-American children were evaluated. Genetic association analysis was performed using a software tool focusing on amino acid variable positions shared by HLA-DRB1 alleles covering the antigen presenting domain. Amino acid variations at position 9 (pocket 9), position 26, and position 78 (pocket 4) were marginally associated with the prevalence of AD. However, the odds ratio was 0.30 (0.14, 0.68; p=0.003) for residue 78, 0.27 (0.10, 0.69; p=0.006) for residue 26 and not significant for residue 9 with respect to the persistence of AD. In conclusion, amino acid variations at peptide-binding pockets of HLA-DRB1 were associated with the persistence of AD in African-American children. PMID:26307177

GAB2 as an Alzheimer disease susceptibility gene: follow-up of genomewide association results.

PubMed

Schjeide, Brit-Maren M; Hooli, Basavaraj; Parkinson, Michele; Hogan, Meghan F; DiVito, Jason; Mullin, Kristina; Blacker, Deborah; Tanzi, Rudolph E; Bertram, Lars

2009-02-01

Genomewide association (GWA) studies have recently implicated 4 novel Alzheimer disease (AD) susceptibility loci (GAB2, GOLM1, and 2 uncharacterized loci to date on chromosomes 9p and 15q). To our knowledge, these findings have not been independently replicated. To assess these GWA findings in 4 large data sets of families affected by AD. Follow-up of genetic association findings in previous studies. Academic research. More than 4000 DNA samples from almost 1300 families affected with AD. Genetic association analysis testing of 4 GWA signals (rs7101429 [GAB2], rs7019241 [GOLM1], rs10519262 [chromosome 15q], and rs9886784 [chromosome 9p]) using family-based methods. In the combined analyses, only rs7101429 in GAB2 yielded significant evidence of association with the same allele as in the original GWA study (P =.002). The results are in agreement with recent meta-analyses of this and other GAB2 polymorphisms suggesting approximately a 30% decrease in risk for AD among carriers of the minor alleles. None of the other 3 tested loci showed consistent evidence for association with AD across the investigated data sets. GAB2 contains genetic variants that may lead to a modest change in the risk for AD. Despite these promising results, more data from independent samples are needed to better evaluate the potential contribution of GAB2 to AD risk in the general population.

Neuroblastoma in children: Update on clinicopathologic and genetic prognostic factors.

PubMed

Ahmed, Atif A; Zhang, Lei; Reddivalla, Naresh; Hetherington, Maxine

2017-04-01

Neuroblastoma is the most common extracranial solid tumor in childhood accounting for 8-10% of all childhood malignancies. The tumor is characterized by a spectrum of histopathologic features and a heterogeneous clinical phenotype. Modern multimodality therapy results in variable clinical response ranging from cure in localized tumors to limited response in aggressive metastatic disease. Accurate clinical staging and risk assessment based on clinical, surgical, biologic and pathologic criteria are of pivotal importance in assigning prognosis and planning effective treatment approaches. Numerous studies have analyzed the presence of several clinicopathologic and biologic factors in association with the patient's prognosis and outcome. Although patient's age, tumor stage, histopathologic classification, and MYCN amplification are the most commonly validated prognostic markers, several new gene mutations have been identified in sporadic and familial neuroblastoma cases that show association with an adverse outcome. Novel molecular studies have also added data on chromosomal segmental aberrations in MYCN nonamplified tumors. In this review, we provide an updated summary of the clinical, serologic and genetic prognostic indicators in neuroblastoma including classic factors that have consistently played a role in risk stratification of patients as well as newly discovered biomarkers that may show a potential significance in patients' management.

Molecular genetics of early-onset Alzheimer's disease revisited.

PubMed

Cacace, Rita; Sleegers, Kristel; Van Broeckhoven, Christine

2016-06-01

As the discovery of the Alzheimer's disease (AD) genes, APP, PSEN1, and PSEN2, in families with autosomal dominant early-onset AD (EOAD), gene discovery in familial EOAD came more or less to a standstill. Only 5% of EOAD patients are carrying a pathogenic mutation in one of the AD genes or a apolipoprotein E (APOE) risk allele ε4, most of EOAD patients remain unexplained. Here, we aimed at summarizing the current knowledge of EOAD genetics and its role in ongoing approaches to understand the biology of AD and disease symptomatology as well as developing new therapeutics. Next, we explored the possible molecular mechanisms that might underlie the missing genetic etiology of EOAD and discussed how the use of massive parallel sequencing technologies triggered novel gene discoveries. To conclude, we commented on the relevance of reinvestigating EOAD patients as a means to explore potential new avenues for translational research and therapeutic discoveries. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Amyloid precursor protein and endosomal-lysosomal dysfunction in Alzheimer's disease: inseparable partners in a multifactorial disease.

PubMed

Nixon, Ralph A

2017-07-01

Abnormalities of the endosomal-lysosomal network (ELN) are a signature feature of Alzheimer's disease (AD). These include the earliest known cytopathology that is specific to AD and that affects endosomes and induces the progressive failure of lysosomes, each of which are directly linked by distinct mechanisms to neurodegeneration. The origins of ELN dysfunction and β-amyloidogenesis closely overlap, which reflects their common genetic basis, the established early involvement of endosomes and lysosomes in amyloid precursor protein (APP) processing and clearance, and the pathologic effect of certain APP metabolites on ELN functions. Genes that promote β-amyloidogenesis in AD (APP, PSEN1/2, and APOE4) have primary effects on ELN function. The importance of primary ELN dysfunction to pathogenesis is underscored by the mutations in more than 35 ELN-related genes that, thus far, are known to cause familial neurodegenerative diseases even though different pathogenic proteins may be involved. In this article, I discuss growing evidence that implicates AD gene-driven ELN disruptions as not only the antecedent pathobiology that underlies β-amyloidogenesis but also as the essential partner with APP and its metabolites that drive the development of AD, including tauopathy, synaptic dysfunction, and neurodegeneration. The striking amelioration of diverse deficits in animal AD models by remediating ELN dysfunction further supports a need to integrate APP and ELN relationships, including the role of amyloid-β, into a broader conceptual framework of how AD arises, progresses, and may be effectively therapeutically targeted.-Nixon, R. A. Amyloid precursor protein and endosomal-lysosomal dysfunction in Alzheimer's disease: inseparable partners in a multifactorial disease. © FASEB.

Mechanisms of AD neurodegeneration may be independent of Aβ and its derivatives.

PubMed

Robakis, Nikolaos K

2011-03-01

Alzheimer's disease (AD) is the most common cause of dementia in the aged population. Most cases are sporadic although a small percent are familial (FAD) linked to genetic mutations. AD is caused by severe neurodegeneration in the hippocampus and neocortical regions of the brain but the cause of this neuronal loss is unclear. A widely discussed theory posits that amyloid depositions of Aβ peptides or their soluble forms are the causative agents of AD. Extensive research in the last 20 years however, failed to produce convincing evidence that brain amyloid is the main cause of AD neurodegeneration. Moreover, a number of observations, including absence of correlations between amyloid deposits and cognition, detection in normal individuals of amyloid loads similar to AD, and animal models with behavioral abnormalities independent of amyloid, are inconsistent with this theory. Other theories propose soluble Aβ peptides or their oligomers as agents that promote AD. These peptides, however, are normal components of human CSF and serum and there is little evidence of disease-associated increases in soluble Aβ and oligomers. That mutants of amyloid precursor protein (APP) and presenilin (PS) promote FAD suggests these proteins play crucial roles in neuronal function and survival. Accordingly, PS regulates production of signaling peptides and cell survival pathways while APP functions in cell death and may promote endosomal abnormalities. Evidence that FAD mutations inhibit the biological functions of PS combined with absence of haploinsufficiency mutants, support a model of allelic interference where inactive FAD mutant alleles promote autosomal dominant neurodegeneration by also inhibiting the functions of wild type alleles. Copyright © 2011 Elsevier Inc. All rights reserved.

Loss of function of ATXN1 increases amyloid beta-protein levels by potentiating beta-secretase processing of beta-amyloid precursor protein.

PubMed

Zhang, Can; Browne, Andrew; Child, Daniel; Divito, Jason R; Stevenson, Jesse A; Tanzi, Rudolph E

2010-03-19

Alzheimer disease (AD) is a devastating neurodegenerative disease with complex and strong genetic inheritance. Four genes have been established to either cause familial early onset AD (APP, PSEN1, and PSEN2) or to increase susceptibility for late onset AD (APOE). To date approximately 80% of the late onset AD genetic variance remains elusive. Recently our genome-wide association screen identified four novel late onset AD candidate genes. Ataxin 1 (ATXN1) is one of these four AD candidate genes and has been indicated to be the disease gene for spinocerebellar ataxia type 1, which is also a neurodegenerative disease. Mounting evidence suggests that the excessive accumulation of Abeta, the proteolytic product of beta-amyloid precursor protein (APP), is the primary AD pathological event. In this study, we ask whether ATXN1 may lead to AD pathogenesis by affecting Abeta and APP processing utilizing RNA interference in a human neuronal cell model and mouse primary cortical neurons. We show that knock-down of ATXN1 significantly increases the levels of both Abeta40 and Abeta42. This effect could be rescued with concurrent overexpression of ATXN1. Moreover, overexpression of ATXN1 decreased Abeta levels. Regarding the underlying molecular mechanism, we show that the effect of ATXN1 expression on Abeta levels is modulated via beta-secretase cleavage of APP. Taken together, ATXN1 functions as a genetic risk modifier that contributes to AD pathogenesis through a loss-of-function mechanism by regulating beta-secretase cleavage of APP and Abeta levels.

Loss of Function of ATXN1 Increases Amyloid β-Protein Levels by Potentiating β-Secretase Processing of β-Amyloid Precursor Protein*

PubMed Central

Zhang, Can; Browne, Andrew; Child, Daniel; DiVito, Jason R.; Stevenson, Jesse A.; Tanzi, Rudolph E.

2010-01-01

Alzheimer disease (AD) is a devastating neurodegenerative disease with complex and strong genetic inheritance. Four genes have been established to either cause familial early onset AD (APP, PSEN1, and PSEN2) or to increase susceptibility for late onset AD (APOE). To date ∼80% of the late onset AD genetic variance remains elusive. Recently our genome-wide association screen identified four novel late onset AD candidate genes. Ataxin 1 (ATXN1) is one of these four AD candidate genes and has been indicated to be the disease gene for spinocerebellar ataxia type 1, which is also a neurodegenerative disease. Mounting evidence suggests that the excessive accumulation of Aβ, the proteolytic product of β-amyloid precursor protein (APP), is the primary AD pathological event. In this study, we ask whether ATXN1 may lead to AD pathogenesis by affecting Aβ and APP processing utilizing RNA interference in a human neuronal cell model and mouse primary cortical neurons. We show that knock-down of ATXN1 significantly increases the levels of both Aβ40 and Aβ42. This effect could be rescued with concurrent overexpression of ATXN1. Moreover, overexpression of ATXN1 decreased Aβ levels. Regarding the underlying molecular mechanism, we show that the effect of ATXN1 expression on Aβ levels is modulated via β-secretase cleavage of APP. Taken together, ATXN1 functions as a genetic risk modifier that contributes to AD pathogenesis through a loss-of-function mechanism by regulating β-secretase cleavage of APP and Aβ levels. PMID:20097758

Translational Research on the Way to Effective Therapy for Alzheimer Disease

PubMed Central

Rosenberg, Roger N.

2006-01-01

Context Alzheimer disease (AD) is a major public health issue with a prediction of 12 million Americans being affected by 2025 from the present 4 million. Molecular and genetic findings have provided significant insights into the roles that amyloid, tau, and apolipoprotein E isoforms have in the causation of AD. A central issue in AD pathogenesis is the amyloid cascade hypothesis. It states that abnormal amyloid processing and accumulation is the primary causative factor of AD and other associated neuropathologic abnormalities are of secondary consequence. It is presented to provide the rationale for novel drug and vaccination therapeutic strategies. Future research directed at prediction and prevention of AD through a genomic and proteomic analysis with identification of multiple polymorphic genes that interact, resulting in increased risk for late-onset AD, are the realistic and ultimate goals. A new approach for drug development is required, one that will emphasize a genomic and proteomic analysis to identify at-risk gene sets whose genetic expression is sufficient to cause late onset, sporadic AD. Prediction and prevention of disease prior to clinical signs and symptoms are the goals. Objective A review and analysis from electronic literature databases and subsequent reference searches of the molecular genetic data including pertinent genetic mutations and abnormal biochemical findings causal of AD, are cited. The amyloid cascade hypothesis, the contributions of apolipoprotein E, and hyperphosphorylated tau are discussed as to their roles in pathogenesis. Molecular targets for potential drug and vaccination therapies are cited from a critical assessment of the molecular and biomedical data. These data form the basis for rational, target-specific drug and vaccination therapies currently employed and planned for the near future. Phase 2 and 3 clinical trial results of drug and vaccination therapies are cited. Conclusions A new approach is needed as current pharmacologic therapy directed at symptomatic relief has proved to be marginally effective. The genomic and proteomic basis of AD will be defined in the near future, and corresponding molecular therapeutic targets will be identified. Genomic neurology has arrived and its application to resolving AD is our best hope. PMID:16275806

Translational research on the way to effective therapy for Alzheimer disease.

PubMed

Rosenberg, Roger N

2005-11-01

Alzheimer disease (AD) is a major public health issue with a prediction of 12 million Americans being affected by 2025 from the present 4 million. Molecular and genetic findings have provided significant insights into the roles that amyloid, tau, and apolipoprotein E isoforms have in the causation of AD. A central issue in AD pathogenesis is the amyloid cascade hypothesis. It states that abnormal amyloid processing and accumulation is the primary causative factor of AD and other associated neuropathologic abnormalities are of secondary consequence. It is presented to provide the rationale for novel drug and vaccination therapeutic strategies. Future research directed at prediction and prevention of AD through a genomic and proteomic analysis with identification of multiple polymorphic genes that interact, resulting in increased risk for late-onset AD, are the realistic and ultimate goals. A new approach for drug development is required, one that will emphasize a genomic and proteomic analysis to identify at-risk gene sets whose genetic expression is sufficient to cause late onset, sporadic AD. Prediction and prevention of disease prior to clinical signs and symptoms are the goals. A review and analysis from electronic literature databases and subsequent reference searches of the molecular genetic data. including pertinent genetic mutations and abnormal biochemical findings causal of AD, are cited. The amyloid cascade hypothesis, the contributions of apolipoprotein E, and hyperphosphorylated tau are discussed as to their roles in pathogenesis. Molecular targets for potential drug and vaccination therapies are cited from a critical assessment of the molecular and biomedical data. These data form the basis for rational, target-specific drug and vaccination therapies currently employed and planned for the near future. Phase 2 and 3 clinical trial results of drug and vaccination therapies are cited. A new approach is needed as current pharmacologic therapy directed at symptomatic relief has proved to be marginally effective. The genomic and proteomic basis of AD will be defined in the near future, and corresponding molecular therapeutic targets will be identified. Genomic neurology has arrived and its application to resolving AD is our best hope.

Evaluation of dogs with genetic hyperuricosuria and urate urolithiasis consuming a purine restricted diet: a pilot study.

PubMed

Westropp, Jodi L; Larsen, Jennifer A; Johnson, Eric G; Bannasch, Dannika; Fascetti, Andrea J; Biourge, Vincent; Queau, Yann

2017-02-08

Urate urolithiasis is a common problem in breed homozygous for the mutation that results in hyperuricosuria. Low purine diets have been recommended to reduce purine intake in these dogs. A higher protein, purine restricted diet with water added was evaluated in dogs with genetic hyperuricosuria and a history of clinical urate urolithiasis over a one year time period. Dogs were evaluated at baseline and 2, 6, and 12 months after initiating the test diet. Bloodwork, urinalysis, abdominal ultrasound, body composition, and 24-h urinary purine metabolite analyses were performed. Transient, mild, self-limited lower urinary tract signs were noted in only one dog on a single day, despite variable but usually mild and occasionally moderate amounts of echogenic bladder stones (<2-3 mm in size) in almost every dog at each visit. No significant differences were noted in urine specific gravity, urine pH, lean body condition score or body composition. Urinary uric acid concentration was lower on the test diet (p = 0.008), but 24-h uric acid excretions were similar (p = 0.220) compared to baseline. Significant differences between least squares mean plasma amino acid concentrations measured at the 0 and 12-month visits were found only for valine (p = 0.0119) and leucine (p = 0.0017). This study suggests the use of a low purine, higher protein diet with added water may be beneficial as part of the management of dogs with genetic hyperuricosuria and history of clinical urate urolithiasis.

Common variation in PHACTR1 is associated with susceptibility to cervical artery dissection

PubMed Central

Debette, Stéphanie; Kamatani, Yoichiro; Metso, Tiina M; Kloss, Manja; Chauhan, Ganesh; Engelter, Stefan T; Pezzini, Alessandro; Thijs, Vincent; Markus, Hugh S; Dichgans, Martin; Wolf, Christiane; Dittrich, Ralf; Touzé, Emmanuel; Southerland, Andrew M; Samson, Yves; Abboud, Shérine; Béjot, Yannick; Caso, Valeria; Bersano, Anna; Gschwendtner, Andreas; Sessa, Maria; Cole, John; Lamy, Chantal; Medeiros, Elisabeth; Beretta, Simone; Bonati, Leo H; Grau, Armin J; Michel, Patrik; Majersik, Jennifer J; Sharma, Pankaj; Kalashnikova, Ludmila; Nazarova, Maria; Dobrynina, Larisa; Bartels, Eva; Guillon, Benoit; van den Herik, Evita G; Fernandez-Cadenas, Israel; Jood, Katarina; Nalls, Michael A; De Leeuw, Frank-Erik; Jern, Christina; Cheng, Yu-Ching; Werner, Inge; Metso, Antti J; Lichy, Christoph; Lyrer, Philippe A; Brandt, Tobias; Boncoraglio, Giorgio B; Wichmann, Heinz-Erich; Gieger, Christian; Johnson, Andrew D; Böttcher, Thomas; Castellano, Maurizio; Arveiler, Dominique; Ikram, M Arfan; Breteler, Monique M B; Padovani, Alessandro; Meschia, James F; Kuhlenbäumer, Gregor; Rolfs, Arndt; Worrall, Bradford B; Ringelstein, Erich-Bernd; Zelenika, Diana; Tatlisumak, Turgut; Lathrop, Mark; Leys, Didier; Amouyel, Philippe; Dallongeville, Jean

2018-01-01

Cervical artery dissection (CeAD), a mural hematoma in a carotid or vertebral artery, is a major cause of ischemic stroke in young adults although relatively uncommon in the general population (incidence of 2.6/100,000 per year)1. Minor cervical traumas, infection, migraine and hypertension are putative risk factors1–3, and inverse associations with obesity and hypercholesterolemia are described3,4. No confirmed genetic susceptibility factors have been identified using candidate gene approaches5. We performed genome-wide association studies (GWAS) in 1,393 CeAD cases and 14,416 controls. The rs9349379[G] allele (PHACTR1) was associated with lower CeAD risk (odds ratio (OR) = 0.75, 95% confidence interval (CI) = 0.69–0.82; P = 4.46 × 10−10), with confirmation in independent follow-up samples (659 CeAD cases and 2,648 controls; P = 3.91 × 10−3; combined P = 1.00 × 10−11). The rs9349379[G] allele was previously shown to be associated with lower risk of migraine and increased risk of myocardial infarction6–9. Deciphering the mechanisms underlying this pleiotropy might provide important information on the biological underpinnings of these disabling conditions. PMID:25420145

Oncolytic Adenovirus: Strategies and Insights for Vector Design and Immuno-Oncolytic Applications

PubMed Central

Uusi-Kerttula, Hanni; Hulin-Curtis, Sarah; Davies, James; Parker, Alan L.

2015-01-01

Adenoviruses (Ad) are commonly used both experimentally and clinically, including oncolytic virotherapy applications. In the clinical area, efficacy is frequently hampered by the high rates of neutralizing immunity, estimated as high as 90% in some populations that promote vector clearance and limit bioavailability for tumor targeting following systemic delivery. Active tumor targeting is also hampered by the ubiquitous nature of the Ad5 receptor, hCAR, as well as the lack of highly tumor-selective targeting ligands and suitable targeting strategies. Furthermore, significant off-target interactions between the viral vector and cellular and proteinaceous components of the bloodstream have been documented that promote uptake into non-target cells and determine dose-limiting toxicities. Novel strategies are therefore needed to overcome the obstacles that prevent efficacious Ad deployment for wider clinical applications. The use of less seroprevalent Ad serotypes, non-human serotypes, capsid pseudotyping, chemical shielding and genetic masking by heterologous peptide incorporation are all potential strategies to achieve efficient vector escape from humoral immune recognition. Conversely, selective vector arming with immunostimulatory agents can be utilized to enhance their oncolytic potential by activation of cancer-specific immune responses against the malignant tissues. This review presents recent advantages and pitfalls occurring in the field of adenoviral oncolytic therapies. PMID:26610547

Polygenic Overlap Between C-Reactive Protein, Plasma Lipids, and Alzheimer Disease.

PubMed

Desikan, Rahul S; Schork, Andrew J; Wang, Yunpeng; Thompson, Wesley K; Dehghan, Abbas; Ridker, Paul M; Chasman, Daniel I; McEvoy, Linda K; Holland, Dominic; Chen, Chi-Hua; Karow, David S; Brewer, James B; Hess, Christopher P; Williams, Julie; Sims, Rebecca; O'Donovan, Michael C; Choi, Seung Hoan; Bis, Joshua C; Ikram, M Arfan; Gudnason, Vilmundur; DeStefano, Anita L; van der Lee, Sven J; Psaty, Bruce M; van Duijn, Cornelia M; Launer, Lenore; Seshadri, Sudha; Pericak-Vance, Margaret A; Mayeux, Richard; Haines, Jonathan L; Farrer, Lindsay A; Hardy, John; Ulstein, Ingun Dina; Aarsland, Dag; Fladby, Tormod; White, Linda R; Sando, Sigrid B; Rongve, Arvid; Witoelar, Aree; Djurovic, Srdjan; Hyman, Bradley T; Snaedal, Jon; Steinberg, Stacy; Stefansson, Hreinn; Stefansson, Kari; Schellenberg, Gerard D; Andreassen, Ole A; Dale, Anders M

2015-06-09

Epidemiological findings suggest a relationship between Alzheimer disease (AD), inflammation, and dyslipidemia, although the nature of this relationship is not well understood. We investigated whether this phenotypic association arises from a shared genetic basis. Using summary statistics (P values and odds ratios) from genome-wide association studies of >200 000 individuals, we investigated overlap in single-nucleotide polymorphisms associated with clinically diagnosed AD and C-reactive protein (CRP), triglycerides, and high- and low-density lipoprotein levels. We found up to 50-fold enrichment of AD single-nucleotide polymorphisms for different levels of association with C-reactive protein, low-density lipoprotein, high-density lipoprotein, and triglyceride single-nucleotide polymorphisms using a false discovery rate threshold <0.05. By conditioning on polymorphisms associated with the 4 phenotypes, we identified 55 loci associated with increased AD risk. We then conducted a meta-analysis of these 55 variants across 4 independent AD cohorts (total: n=29 054 AD cases and 114 824 healthy controls) and discovered 2 genome-wide significant variants on chromosome 4 (rs13113697; closest gene, HS3ST1; odds ratio=1.07; 95% confidence interval=1.05-1.11; P=2.86×10(-8)) and chromosome 10 (rs7920721; closest gene, ECHDC3; odds ratio=1.07; 95% confidence interval=1.04-1.11; P=3.38×10(-8)). We also found that gene expression of HS3ST1 and ECHDC3 was altered in AD brains compared with control brains. We demonstrate genetic overlap between AD, C-reactive protein, and plasma lipids. By conditioning on the genetic association with the cardiovascular phenotypes, we identify novel AD susceptibility loci, including 2 genome-wide significant variants conferring increased risk for AD. © 2015 American Heart Association, Inc.

Associations between Potentially Modifiable Risk Factors and Alzheimer Disease: A Mendelian Randomization Study

PubMed Central

Østergaard, Søren D.; Mukherjee, Shubhabrata; Sharp, Stephen J.; Proitsi, Petroula; Lotta, Luca A.; Day, Felix; Perry, John R. B.; Boehme, Kevin L.; Walter, Stefan; Kauwe, John S.; Gibbons, Laura E.; Larson, Eric B.; Powell, John F.; Langenberg, Claudia; Crane, Paul K.; Wareham, Nicholas J.; Scott, Robert A.

2015-01-01

Background Potentially modifiable risk factors including obesity, diabetes, hypertension, and smoking are associated with Alzheimer disease (AD) and represent promising targets for intervention. However, the causality of these associations is unclear. We sought to assess the causal nature of these associations using Mendelian randomization (MR). Methods and Findings We used SNPs associated with each risk factor as instrumental variables in MR analyses. We considered type 2 diabetes (T2D, N SNPs = 49), fasting glucose (N SNPs = 36), insulin resistance (N SNPs = 10), body mass index (BMI, N SNPs = 32), total cholesterol (N SNPs = 73), HDL-cholesterol (N SNPs = 71), LDL-cholesterol (N SNPs = 57), triglycerides (N SNPs = 39), systolic blood pressure (SBP, N SNPs = 24), smoking initiation (N SNPs = 1), smoking quantity (N SNPs = 3), university completion (N SNPs = 2), and years of education (N SNPs = 1). We calculated MR estimates of associations between each exposure and AD risk using an inverse-variance weighted approach, with summary statistics of SNP–AD associations from the International Genomics of Alzheimer’s Project, comprising a total of 17,008 individuals with AD and 37,154 cognitively normal elderly controls. We found that genetically predicted higher SBP was associated with lower AD risk (odds ratio [OR] per standard deviation [15.4 mm Hg] of SBP [95% CI]: 0.75 [0.62–0.91]; p = 3.4 × 10−3). Genetically predicted higher SBP was also associated with a higher probability of taking antihypertensive medication (p = 6.7 × 10−8). Genetically predicted smoking quantity was associated with lower AD risk (OR per ten cigarettes per day [95% CI]: 0.67 [0.51–0.89]; p = 6.5 × 10−3), although we were unable to stratify by smoking history; genetically predicted smoking initiation was not associated with AD risk (OR = 0.70 [0.37, 1.33]; p = 0.28). We saw no evidence of causal associations between glycemic traits, T2D, BMI, or educational attainment and risk of AD (all p > 0.1). Potential limitations of this study include the small proportion of intermediate trait variance explained by genetic variants and other implicit limitations of MR analyses. Conclusions Inherited lifetime exposure to higher SBP is associated with lower AD risk. These findings suggest that higher blood pressure—or some environmental exposure associated with higher blood pressure, such as use of antihypertensive medications—may reduce AD risk. PMID:26079503

Association of MAOA gene functional promoter polymorphism with CSF dopamine turnover and atypical depression.

PubMed

Aklillu, Eleni; Karlsson, Sara; Zachrisson, Olof O; Ozdemir, Vural; Agren, Hans

2009-04-01

Monoamine oxidase-A (MAO-A) is a key mitochondrial enzyme that metabolizes biogenic amine neurotransmitters such as dopamine and serotonin. Individuals with atypical depression (AD) are particularly responsive to treatment with MAO inhibitors (MAOIs). Biomarker tests are essential for prompt diagnosis of AD, and to identify those with an altered brain neurotransmitter metabolism who may selectively respond to MAOI therapy. In a sample of 118 Scandinavian patients with treatment-resistant depression who are naive to MAOI therapy, we investigated the associations between a common MAOA functional promoter polymorphism (MAOA-uVNTR), cerebrospinal fluid (CSF) neurotransmitter metabolites, and AD susceptibility. The metabolites for dopamine (homovanillic acid, HVA), serotonin (5-hydroxyindoleacetic acid) and noradrenaline (3-methoxy-4-hydroxyphenylglycol) were measured in the CSF. AD was associated with the female sex and a higher HVA in CSF (P=0.008). The carriers of the MAOA-uVNTR short allele were significantly overrepresented among women with AD (P=0.005; odds ratio=4.76; 95% confidence interval=1.5-13.1; statistical power=80.0%). Moreover, the MAOA-uVNTR genotype significantly influenced the HVA concentration (P=0.01) and showed a strong trend in relation to 5-hydroxyindoleacetic acid concentration (P=0.057) in women. The mediational statistical analyses showed the CSF-HVA concentration as a key driver of the relationship between MAOA-uVNTR genotype and AD. The association of the MAOA-uVNTR with both susceptibility to AD and dopamine metabolite (HVA) concentration lends further biological plausibility for high MAO-A enzyme activity as a mechanistic factor for genetic predisposition to AD through altered dopamine turnover. Our observations provide new evidence on the in-vivo functional significance of the MAOA-uVNTR short allele as a high activity variant.

Alzheimer Disease

PubMed Central

Apostolova, Liana G.

2016-01-01

ABSTRACT Purpose of Review: This article discusses the recent advances in the diagnosis and treatment of Alzheimer disease (AD). Recent Findings: In recent years, significant advances have been made in the fields of genetics, neuroimaging, clinical diagnosis, and staging of AD. One of the most important recent advances in AD is our ability to visualize amyloid pathology in the living human brain. The newly revised criteria for diagnosis of AD dementia embrace the use for biomarkers as supportive evidence for the underlying pathology. Guidelines for the responsible use of amyloid positron emission tomography (PET) have been developed, and the clinical and economic implications of amyloid PET imaging are actively being explored. Summary: Our improved understanding of the clinical onset, progression, neuroimaging, pathologic features, genetics, and other risk factors for AD impacts the approaches to clinical diagnosis and future therapeutic interventions. PMID:27042902

Genome-wide Analysis of Genetic Loci Associated with Alzheimer’s Disease

PubMed Central

Seshadri, Sudha; Fitzpatrick, Annette L.; Arfan Ikram, M; DeStefano, Anita L.; Gudnason, Vilmundur; Boada, Merce; Bis, Joshua C.; Smith, Albert V.; Carassquillo, Minerva M.; Charles Lambert, Jean; Harold, Denise; Schrijvers, Elisabeth M. C.; Ramirez-Lorca, Reposo; Debette, Stephanie; Longstreth, W.T.; Janssens, A. Cecile J.W.; Shane Pankratz, V.; Dartigues, Jean François; Hollingworth, Paul; Aspelund, Thor; Hernandez, Isabel; Beiser, Alexa; Kuller, Lewis H.; Koudstaal, Peter J.; Dickson, Dennis W.; Tzourio, Christophe; Abraham, Richard; Antunez, Carmen; Du, Yangchun; Rotter, Jerome I.; Aulchenko, Yurii S.; Harris, Tamara B.; Petersen, Ronald C.; Berr, Claudine; Owen, Michael J.; Lopez-Arrieta, Jesus; Varadarajan, Badri N.; Becker, James T.; Rivadeneira, Fernando; Nalls, Michael A.; Graff-Radford, Neill R.; Campion, Dominique; Auerbach, Sanford; Rice, Kenneth; Hofman, Albert; Jonsson, Palmi V.; Schmidt, Helena; Lathrop, Mark; Mosley, Thomas H.; Au, Rhoda; Psaty, Bruce M.; Uitterlinden, Andre G.; Farrer, Lindsay A.; Lumley, Thomas; Ruiz, Agustin; Williams, Julie; Amouyel, Philippe; Younkin, Steve G.; Wolf, Philip A.; Launer, Lenore J.; Lopez, Oscar L.; van Duijn, Cornelia M.; Breteler, Monique M. B.

2010-01-01

Context Genome wide association studies (GWAS) have recently identified CLU, PICALM and CR1 as novel genes for late-onset Alzheimer’s disease (AD). Objective In a three-stage analysis of new and previously published GWAS on over 35000 persons (8371 AD cases), we sought to identify and strengthen additional loci associated with AD and confirm these in an independent sample. We also examined the contribution of recently identified genes to AD risk prediction. Design, Setting, and Participants We identified strong genetic associations (p<10−3) in a Stage 1 sample of 3006 AD cases and 14642 controls by combining new data from the population-based Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium (1367 AD cases (973 incident)) with previously reported results from the Translational Genomics Research Institute (TGEN) and Mayo AD GWAS. We identified 2708 single nucleotide polymorphisms (SNPs) with p-values<10−3, and in Stage 2 pooled results for these SNPs with the European AD Initiative (2032 cases, 5328 controls) to identify ten loci with p-values<10−5. In Stage 3, we combined data for these ten loci with data from the Genetic and Environmental Risk in AD consortium (3333 cases, 6995 controls) to identify four SNPs with a p-value<1.7×10−8. These four SNPs were replicated in an independent Spanish sample (1140 AD cases and 1209 controls). Main outcome measure Alzheimer’s Disease. Results We showed genome-wide significance for two new loci: rs744373 near BIN1 (OR:1.13; 95%CI:1.06–1.21 per copy of the minor allele; p=1.6×10−11) and rs597668 near EXOC3L2/BLOC1S3/MARK4 (OR:1.18; 95%CI1.07–1.29; p=6.5×10−9). Associations of CLU, PICALM, BIN1 and EXOC3L2 with AD were confirmed in the Spanish sample (p<0.05). However, CLU and PICALM did not improve incident AD prediction beyond age, sex, and APOE (improvement in area under receiver-operating-characteristic curve <0.003). Conclusions Two novel genetic loci for AD are reported that for the first time reach genome-wide statistical significance; these findings were replicated in an independent population. Two recently reported associations were also confirmed, but these loci did not improve AD risk prediction, although they implicate biological pathways that may be useful targets for potential interventions. PMID:20460622

The impact of direct-to-consumer marketing of cancer genetic testing on women according to their genetic risk.

PubMed

Lowery, Jan T; Byers, Tim; Axell, Lisen; Ku, Lisa; Jacobellis, Jillian

2008-12-01

To assess the impact of direct-to-consumer marketing for genetic testing among women of varying genetic risk for breast and ovarian cancer. Telephone surveys were conducted with 315 women in Denver, Colorado, one target audience for the Myriad BRACAnalysis ad campaign. Genetic risk was determined from personal and family history and grouped by probability of having a BRCA1/2 mutation (low <5%, moderate 5-<10%, high > or =10%). High-risk women were more knowledgeable about BRACAnalysis and more likely to recall the media ads than were low-risk women (60 vs. 39%, P < 0.01). After seeing the ads, about 40% of women were more interested in testing and about 10% expressed increased worry about developing breast or ovarian cancer. Women across all risk groups overstated the benefits and appropriateness of testing. An equal percentage of high- and low-risk women (51 and 60%) felt that they would benefit from genetic testing. The campaign effectively reached a large audience. Concern about breast cancer was not appreciably increased. A large percentage of low-risk women (not candidates for testing) expressed interest in testing, suggesting the campaign was too broad. A campaign targeted at high-risk women, who may benefit from testing might be preferred.

Clinical and neurocognitive aspects of hallucinations in Alzheimer's disease.

PubMed

El Haj, Mohamad; Roche, Jean; Jardri, Renaud; Kapogiannis, Dimitrios; Gallouj, Karim; Antoine, Pascal

2017-12-01

Due to their prevalence, hallucinations are considered as one of the most frequent psychotic symptoms in Alzheimer's disease (AD). These psychotic manifestations reduce patients' well-being, increase the burden of caregivers, contribute to early institutionalization, and are related with the course of cognitive decline in AD. Considering their consequences, we provide a comprehensive account of the current state of knowledge about the prevalence and characteristics of hallucinations in AD. We propose a comprehensive and testable theoretical model about hallucinations in AD: the ALZHA (ALZheimer and HAllucinations) model. In this model, neurological, genetic, cognitive, affective, and iatrogenic factors associated with hallucinations in AD are highlighted. According to the ALZHA model, hallucinations in AD first involve trait markers (i.e., cognitive deficits, neurological deficits, genetic predisposition and/or sensory deficits) to which state markers that may trigger these experiences are added (e.g., psychological distress and/or iatrogenic factors). Finally, we provide recommendations for assessment and management of these psychotic manifestations in AD, with the aim to benefit patients, caregivers, and health professionals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Citalopram for the Treatment of Agitation in Alzheimer Dementia: Genetic Influences.

PubMed

Peters, Matthew E; Vaidya, Vijay; Drye, Lea T; Devanand, Davangere P; Mintzer, Jacobo E; Pollock, Bruce G; Porsteinsson, Anton P; Rosenberg, Paul B; Schneider, Lon S; Shade, David M; Weintraub, Daniel; Yesavage, Jerome; Lyketsos, Constantine G; Avramopoulos, Dimitri

2016-03-01

To assess potential genetic influences on citalopram treatment efficacy for agitation in individuals with Alzheimer dementia (AD). Six functional genetic variants were studied in the following genes: serotonin receptor 2A (HTR2A-T102C), serotonin receptor 2C (HTR2C-Cys23Ser), serotonin transporter (5HTT-LPR), brain-derived neurotropic factor (BDNF-Val66Met), apolipoprotein E (ε2, ε3, ε4 variants), and cytochrome P450 (CYP2C19). Treatment response by genotype was measured by (1) the agitation domain of the Neurobehavioral Rating Scale, (2) the modified Alzheimer Disease Cooperative Study-Clinical Global Impression of Change scale (mADCS-CGIC), (3) the agitation domain of the Neuropsychiatric Inventory (NPI), and (4) the Cohen-Mansfield Agitation Inventory. We utilized data from the Citalopram for Agitation in Alzheimer's Disease (CitAD) database. CitAD was a 9-week randomized, double-blind, placebo-controlled multicenter clinical trial showing significant improvement in agitation and caregiver distress in patients treated with citalopram. Proportional odds logistic regression and mixed effects models were used to examine the above-mentioned outcome measures. Significant interactions were noted on the NPI agitation domain for HTR2A (likelihood ratio [LR] = 6.19, df = 2, P = .04) and the mADCS-CGIC for HTR2C (LR = 4.33, df = 2, P = .02) over 9 weeks. Treatment outcomes in CitAD showed modest, although statistically significant, influence of genetic variation at HTR2A and HTR2C loci. Future studies should continue to examine the interaction of known genetic variants with antidepressant treatment in patients with AD having agitation. © The Author(s) 2015.

Genome-editing applications of CRISPR–Cas9 to promote in vitro studies of Alzheimer’s disease

PubMed Central

Shim, Kyu Hwan; Bagyinszky, Eva

2018-01-01

Genetic variations play an important role in the clinical presentation and progression of Alzheimer’s disease (AD), especially early-onset Alzheimer’s disease. Hundreds of mutations have been reported with the majority resulting from alterations in β-amyloid precursor protein (APP), presenilin 1 (PSEN1), or presenilin 2 (PSEN2) genes. The roles of these mutations in the pathogenesis of AD have been classically confirmed or refuted through functional studies, where the mutations are cloned, inserted into cell lines, and monitored for changes in various properties including cell survival, amyloid production, or Aβ42/40 ratio. However, these verification studies tend to be expensive, time consuming, and inconsistent. Recently, the clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9 (CRISPR–Cas9) system was developed, which improves sequence-specific gene editing in cell lines, organs, and animals. CRISPR–Cas9 is a promising tool for the generation of models of human genetic diseases and could facilitate the establishment of new animal AD models and the observation of dynamic bioprocesses in AD. Here, we recapitulated the history of CRISPR technology, recent progress, and, especially, its potential applications in AD-related genetic, animal modeling, and functional studies. PMID:29445268

Translational research in genomics of Alzheimer's disease: a review of current practice and future perspectives.

PubMed

Mihaescu, Raluca; Detmar, Symone B; Cornel, Martina C; van der Flier, Wiesje M; Heutink, Peter; Hol, Elly M; Rikkert, Marcel G M Olde; van Duijn, Cornelia M; Janssens, A Cecile J W

2010-01-01

Alzheimer's disease (AD) is the most prevalent form of dementia and the number of cases is expected to increase exponentially worldwide. Three highly penetrant genes (AbetaPP, PSEN1, and PSEN2) explain only a small number of AD cases with a Mendelian transmission pattern. Many genes have been analyzed for association with non-Mendelian AD, but the only consistently replicated finding is APOE. At present, possibilities for prevention, early detection, and treatment of the disease are limited. Predictive and diagnostic genetic testing is available only in Mendelian forms of AD. Currently, APOE genotyping is not considered clinically useful for screening, presymptomatic testing, or clinical diagnosis of non-Mendelian AD. However, clinical management of the disease is expected to benefit from the rapid pace of discoveries in the genomics of AD. Following a recently developed framework for the continuum of translation research that is needed to move genetic discoveries to health applications, this paper reviews recent genetic discoveries as well as translational research on genomic applications in the prevention, early detection, and treatment of AD. The four phases of translation research include: 1) translation of basic genomics research into a potential health care application; 2) evaluation of the application for the development of evidence-based guidelines; 3) evaluation of the implementation and use of the application in health care practice; and 4) evaluation of the achieved population health impact. Most research on genome-based applications in AD is still in the first phase of the translational research framework, which means that further research is still needed before their implementation can be considered.

GAB2 as an Alzheimer Disease Susceptibility Gene

PubMed Central

Schjeide, Brit-Maren M.; Hooli, Basavaraj; Parkinson, Michele; Hogan, Meghan F.; DiVito, Jason; Mullin, Kristina; Blacker, Deborah; Tanzi, Rudolph E.; Bertram, Lars

2009-01-01

Background Genomewide association (GWA) studies have recently implicated 4 novel Alzheimer disease (AD) susceptibility loci (GAB2, GOLM1, and 2 uncharacterized loci to date on chromosomes 9p and 15q). To our knowledge, these findings have not been independently replicated. Objective To assess these GWA findings in 4 large data sets of families affected by AD. Design Follow-up of genetic association findings in previous studies. Setting Academic research. Participants More than 4000 DNA samples from almost 1300 families affected with AD. Main Outcome Measures Genetic association analysis testing of 4 GWA signals (rs7101429 [GAB2], rs7019241 [GOLM1], rs10519262 [chromosome 15q], and rs9886784 [chromosome 9p]) using family-based methods. Results In the combined analyses, only rs7101429 in GAB2 yielded significant evidence of association with the same allele as in the original GWA study (P = .002). The results are in agreement with recent meta-analyses of this and other GAB2 polymorphisms suggesting approximately a 30% decrease in risk for AD among carriers of the minor alleles. None of the other 3 tested loci showed consistent evidence for association with AD across the investigated data sets. Conclusions GAB2 contains genetic variants that may lead to a modest change in the risk for AD. Despite these promising results, more data from independent samples are needed to better evaluate the potential contribution of GAB2 to AD risk in the general population. PMID:19204163

Hypothermia and Alzheimer's disease neuropathogenic pathways.

PubMed

Whittington, R A; Papon, M-A; Chouinard, F; Planel, E

2010-12-01

Alzheimer's disease (AD) remains a major health problem, and accounts for 50 to 60% of all cases of dementia. The two histopathological hallmarks of AD are senile plaques, composed of the β-amyloid peptide (Aβ), and intraneuronal neurofibrillary tangles composed of abnormally hyperphosphorylated tau protein. Only a small proportion of AD is due to mutations in the genome of patients, the large majority of cases being of late onset and sporadic in origin. The relative contribution of genetics and environment to the sporadic cases is unclear, but they are accepted to be of multifactorial origin. This means that genetic and environmental factors can interact together to induce or accelerate the disease. Among environmental factors, studies suggest that hypothermia may contribute to the development and exacerbation AD. Here, we review the preclinical data involving hypothermia with tau and Aβ, as well as clinical evidence implicating hypothermia in the development of AD.

Interactions of Mitochondria/Metabolism and Calcium Regulation in Alzheimer’s Disease - A Calcinist Point of View

PubMed Central

Gibson, Gary E.; Thakkar, Ankita

2017-01-01

Decades of research suggest that alterations in calcium are central to the pathophysiology of Alzheimer’s Disease (AD). Highly reproducible changes in calcium dynamics occur in cells from patients with both genetic and non-genetic forms of AD relative to controls. The most robust change is an exaggerated release of calcium from internal stores. Detailed analysis of these changes in animal and cell models of the AD-causing presenilin mutations reveal robust changes in ryanodine receptors, inositol tris-phosphate receptors, calcium leak channels and store activated calcium entry. Similar anomalies in calcium result when AD-like changes in mitochondrial enzymes or oxidative stress are induced experimentally. The calcium abnormalities can be directly linked to the altered tau phosphorylation, amyloid precursor protein processing and synaptic dysfunction that are defining features of AD. A better understanding of these changes is required before using calcium abnormalities as therapeutic targets. PMID:28181072

Interactions of Mitochondria/Metabolism and Calcium Regulation in Alzheimer's Disease: A Calcinist Point of View.

PubMed

Gibson, Gary E; Thakkar, Ankita

2017-06-01

Decades of research suggest that alterations in calcium are central to the pathophysiology of Alzheimer's Disease (AD). Highly reproducible changes in calcium dynamics occur in cells from patients with both genetic and non-genetic forms of AD relative to controls. The most robust change is an exaggerated release of calcium from internal stores. Detailed analysis of these changes in animal and cell models of the AD-causing presenilin mutations reveal robust changes in ryanodine receptors, inositol tris-phosphate receptors, calcium leak channels and store activated calcium entry. Similar anomalies in calcium result when AD-like changes in mitochondrial enzymes or oxidative stress are induced experimentally. The calcium abnormalities can be directly linked to the altered tau phosphorylation, amyloid precursor protein processing and synaptic dysfunction that are defining features of AD. A better understanding of these changes is required before using calcium abnormalities as therapeutic targets.

Atopic dermatitis in diverse racial and ethnic groups-Variations in epidemiology, genetics, clinical presentation and treatment.

PubMed

Kaufman, Bridget P; Guttman-Yassky, Emma; Alexis, Andrew F

2018-04-01

Atopic dermatitis (AD) is a chronic inflammatory skin condition that affects diverse ethnic groups with varying prevalence. Despite a predominance of studies in individuals of European ancestry, AD has been found to occur more frequently in Asian and Black individuals than Whites. Therefore, an understanding of the unique clinical features of AD in diverse ethnic groups, as well as the differences in genetic polymorphisms that influence susceptibility to AD and response to current therapies, is paramount for management of an increasingly diverse patient population. In this article, we review key nuances in the epidemiology, pathophysiology, clinical presentation and treatment of AD in non-White ethnic groups, which are largely underappreciated in the literature. We highlight the need for studies evaluating the tissue molecular and cellular phenotypes of AD in non-White patients, as well as greater inclusion of minority groups in clinical trials, to develop targeted treatments for a multi-ethnic population. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Insights to the Genetics of Diabetic Nephropathy through a Genome-wide Association Study of the GoKinD Collection

PubMed Central

Pezzolesi, Marcus G.; Skupien, Jan; Krolewski, Andrzej S.

2010-01-01

The Genetics of Kidneys in Diabetes (GoKinD) study was initiated to facilitate research aimed at identifying genes involved in diabetic nephropathy (DN) in type 1 diabetes (T1D). In this review, we present on overview of this study and the various reports that have utilized its collection. At the forefront of these efforts is the recent genome-wide association (GWA) scan implemented on the GoKinD collection. We highlight the results from our analysis of these data and describe compelling evidence from animal models that further support the potential role of associated loci in the susceptibility of DN. To enhance our analysis of genetic associations in GoKinD, using genome-wide imputation (GWI), we expanded our analysis of this collection to include genotype data from more than 2.4 million common SNPs. We illustrate the added utility of this enhanced dataset through the comprehensive fine-mapping of candidate genomic regions previously linked with DN and the targeted investigation of genes involved in candidate pathway implicated in its pathogenesis. Collectively, GWA and GWI data from the GoKinD collection will serve as a springboard for future investigations into the genetic basis of DN in T1D. PMID:20347642

Heritable Variation, With Little or No Maternal Effect, Accounts for Recurrence Risk to Autism Spectrum Disorder in Sweden.

PubMed

Yip, Benjamin Hon Kei; Bai, Dan; Mahjani, Behrang; Klei, Lambertus; Pawitan, Yudi; Hultman, Christina M; Grice, Dorothy E; Roeder, Kathryn; Buxbaum, Joseph D; Devlin, Bernie; Reichenberg, Abraham; Sandin, Sven

2018-04-01

Autism spectrum disorder (ASD) has both genetic and environmental origins, including potentially maternal effects. Maternal effects describe the association of one or more maternal phenotypes with liability to ASD in progeny that are independent of maternally transmitted risk alleles. While maternal effects could play an important role, consistent with association to maternal traits such as immune status, no study has estimated maternal, additive genetic, and environmental effects in ASD. Using a population-based sample consisting of all children born in Sweden from 1998 to 2007 and their relatives, we fitted statistical models to family data to estimate the variance in ASD liability originating from maternal, additive genetic, and shared environmental effects. We calculated sibling and cousin family recurrence risk ratio as a direct measure of familial, genetic, and environmental risk factors and repeated the calculations on diagnostic subgroups, specifically autistic disorder (AD) and spectrum disorder (SD), which included Asperger's syndrome and/or pervasive developmental disorder not otherwise specified. The sample consisted of 776,212 children of whom 11,231 had a diagnosis of ASD: 4554 with AD, 6677 with SD. We found support for large additive genetic contribution to liability; heritability (95% confidence interval [CI]) was estimated to 84.8% (95% CI: 73.1-87.3) for ASD, 79.6% (95% CI: 61.2-85.1) for AD, and 76.4% (95% CI: 63.0-82.5) for SD. There was modest, if any, contribution of maternal effects to liability for ASD, including subtypes AD and SD, and there was no support for shared environmental effects. These results show liability to ASD arises largely from additive genetic variation. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Gad67 haploinsufficiency reduces amyloid pathology and rescues olfactory memory deficits in a mouse model of Alzheimer's disease.

PubMed

Wang, Yue; Wu, Zheng; Bai, Yu-Ting; Wu, Gang-Yi; Chen, Gong

2017-10-10

Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder, affecting millions of people worldwide. Although dysfunction of multiple neurotransmitter systems including cholinergic, glutamatergic and GABAergic systems has been associated with AD progression the underlying mechanisms remain elusive. We and others have recently found that GABA content is elevated in AD brains and linked to cognitive deficits in AD mouse models. The glutamic acid decarboxylase 67 (GAD67) is the major enzyme converting glutamate into GABA and has been implied in a number of neurological disorders such as epilepsy and schizophrenia. However, whether Gad67 is involved in AD pathology has not been well studied. Here, we investigate the functional role of GAD67 in an AD mouse model with Gad67 haploinsufficiency that is caused by replacing one allele of Gad67 with green fluorescent protein (GFP) gene during generation of GAD67-GFP mice. To genetically reduce GAD67 in AD mouse brains, we crossed the Gad67 haploinsufficient mice (GAD67-GFP +/- ) with 5xFAD mice (harboring 5 human familial AD mutations in APP and PS1 genes) to generate a new line of bigenic mice. Immunostaining, ELISA, electrophysiology and behavior test were applied to compare the difference between groups. We found that reduction of GAD67 resulted in a significant decrease of amyloid β production in 5xFAD mice. Concurrently, the abnormal astrocytic GABA and tonic GABA currents, as well as the microglial reactivity were significantly reduced in the 5xFAD mice with Gad67 haploinsufficiency. Importantly, the olfactory memory deficit of 5xFAD mice was rescued by Gad67 haploinsufficiency. Our results demonstrate that GAD67 plays an important role in AD pathology, suggesting that GAD67 may be a potential drug target for modulating the progress of AD.

Cardiovascular Involvement in Autoimmune Diseases

PubMed Central

Amaya-Amaya, Jenny

2014-01-01

Autoimmune diseases (AD) represent a broad spectrum of chronic conditions that may afflict specific target organs or multiple systems with a significant burden on quality of life. These conditions have common mechanisms including genetic and epigenetics factors, gender disparity, environmental triggers, pathophysiological abnormalities, and certain subphenotypes. Atherosclerosis (AT) was once considered to be a degenerative disease that was an inevitable consequence of aging. However, research in the last three decades has shown that AT is not degenerative or inevitable. It is an autoimmune-inflammatory disease associated with infectious and inflammatory factors characterized by lipoprotein metabolism alteration that leads to immune system activation with the consequent proliferation of smooth muscle cells, narrowing arteries, and atheroma formation. Both humoral and cellular immune mechanisms have been proposed to participate in the onset and progression of AT. Several risk factors, known as classic risk factors, have been described. Interestingly, the excessive cardiovascular events observed in patients with ADs are not fully explained by these factors. Several novel risk factors contribute to the development of premature vascular damage. In this review, we discuss our current understanding of how traditional and nontraditional risk factors contribute to pathogenesis of CVD in AD. PMID:25177690

DEVELOPMENT OF A DNA ARCHIVE FOR GENETIC MONITORING OF FISH POPULATIONS

EPA Science Inventory

Analysis of intraspecific genetic diversity provides a potentially powerful tool to estimate the impacts of environmental stressors on populations. Genetic responses of populations to novel stressors include dramatic shifts in genotype frequencies at loci under selection (i.e. ad...

76 FR 69146 - Common or Usual Name for Raw Meat and Poultry Products Containing Added Solutions-Reopening of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-08

.... FSIS-2010-0012] RIN 0583-AD41 Common or Usual Name for Raw Meat and Poultry Products Containing Added... for 60 days the comment period for the proposed rule, ``Common or Usual Name for Raw Meat and Poultry..., FSIS published the proposed rule ``Common or Usual Name for Raw Meat and Poultry Products Containing...

Reversal of fragile X phenotypes by manipulation of AβPP/Aβ levels in Fmr1KO mice.

PubMed

Westmark, Cara J; Westmark, Pamela R; O'Riordan, Kenneth J; Ray, Brian C; Hervey, Crystal M; Salamat, M Shahriar; Abozeid, Sara H; Stein, Kelsey M; Stodola, Levi A; Tranfaglia, Michael; Burger, Corinna; Berry-Kravis, Elizabeth M; Malter, James S

2011-01-01

Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and the leading known genetic cause of autism. Fragile X mental retardation protein (FMRP), which is absent or expressed at substantially reduced levels in FXS, binds to and controls the postsynaptic translation of amyloid β-protein precursor (AβPP) mRNA. Cleavage of AβPP can produce β-amyloid (Aβ), a 39-43 amino acid peptide mis-expressed in Alzheimer's disease (AD) and Down syndrome (DS). Aβ is over-expressed in the brain of Fmr1(KO) mice, suggesting a pathogenic role in FXS. To determine if genetic reduction of AβPP/Aβ rescues characteristic FXS phenotypes, we assessed audiogenic seizures (AGS), anxiety, the ratio of mature versus immature dendritic spines and metabotropic glutamate receptor (mGluR)-mediated long-term depression (LTD) in Fmr1(KO) mice after removal of one App allele. All of these phenotypes were partially or completely reverted to normal. Plasma Aβ(1-42) was significantly reduced in full-mutation FXS males compared to age-matched controls while cortical and hippocampal levels were somewhat increased, suggesting that Aβ is sequestered in the brain. Evolving therapies directed at reducing Aβ in AD may be applicable to FXS and Aβ may serve as a plasma-based biomarker to facilitate disease diagnosis or assess therapeutic efficacy.

Epstein-Barr virus and its association with rheumatoid arthritis and oral lichen planus.

PubMed

Adtani, Pooja; Malathi, Narasimhan

2015-01-01

Pathogenesis of autoimmune diseases (AD) is one of a multifactorial milieu. A genetic predisposition, an immune system failure, hormonal imbalance and environmental factors play important roles. Among the many environmental factors, the role of infection is gaining importance in the pathogenesis of various autoimmune disorders; among them, Epstein-Barr virus (EBV) plays a pivotal role. Literature states an association of various AD with EBV namely multiple sclerosis, autoimmune thyroiditis, systemic lupus erythematous, oral lichen planus (OLP), rheumatoid arthritis (RA), autoimmune hepatitis, Sjögren's syndrome and Kawasaki disease; among these, the most commonly occurring are OLP and RA. Considering the frequency of occurrences, our aim was to perform a qualitative analysis of EBV viral capsid antigen (EBV VCA) IgG in the sera of patients with RA, OLP and establish a comparison with normal. In-vitro experiment in a research laboratory. Five-milliliter blood sample was collected from 25 patients diagnosed with RA and OLP. Serum was separated and EBV VCA IgG antibody titer was detected using NovaTec EBV VCA IgG ELISA kit. Chi-square test. Six out of 25 subjects with RA and 4 out of 25 subjects with OLP tested positive for EBV VCA IgG. Both environmental and genetic factors are important contributory components for autoimmune conditions. Screening for viral etiology would improve the efficacy of conventional treatment and reduce the risk of relapses.

Computational Prediction of Alzheimer’s and Parkinson’s Disease MicroRNAs in Domestic Animals

PubMed Central

Wang, Hai Yang; Lin, Zi Li; Yu, Xian Feng; Bao, Yuan; Cui, Xiang-Shun; Kim, Nam-Hyung

2016-01-01

As the most common neurodegenerative diseases, Alzheimer’s disease (AD) and Parkinson’s disease (PD) are two of the main health concerns for the elderly population. Recently, microRNAs (miRNAs) have been used as biomarkers of infectious, genetic, and metabolic diseases in humans but they have not been well studied in domestic animals. Here we describe a computational biology study in which human AD- and PD-associated miRNAs (ADM and PDM) were utilized to predict orthologous miRNAs in the following domestic animal species: dog, cow, pig, horse, and chicken. In this study, a total of 121 and 70 published human ADM and PDM were identified, respectively. Thirty-seven miRNAs were co-regulated in AD and PD. We identified a total of 105 unrepeated human ADM and PDM that had at least one 100% identical animal homolog, among which 81 and 54 showed 100% sequence identity with 241 and 161 domestic animal miRNAs, respectively. Over 20% of the total mature horse miRNAs (92) showed perfect matches to AD/PD-associated miRNAs. Pigs, dogs, and cows have similar numbers of AD/PD-associated miRNAs (63, 62, and 59). Chickens had the least number of perfect matches (34). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses suggested that humans and dogs are relatively similar in the functional pathways of the five selected highly conserved miRNAs. Taken together, our study provides the first evidence for better understanding the miRNA-AD/PD associations in domestic animals, and provides guidance to generate domestic animal models of AD/PD to replace the current rodent models. PMID:26954182

Genome-wide alteration of 5-hydroxymenthylcytosine in a mouse model of Alzheimer's disease.

PubMed

Shu, Liqi; Sun, Wenjia; Li, Liping; Xu, Zihui; Lin, Li; Xie, Pei; Shen, Hui; Huang, Luoxiu; Xu, Qi; Jin, Peng; Li, Xuekun

2016-05-20

Alzheimer's disease (AD) is the most common form of neurodegenerative disorder that leads to a decline in cognitive function. In AD, aggregates of amyloid β peptide precede the accumulation of neurofibrillary tangles, both of which are hallmarks of the disease. The great majority (>90 %) of the AD cases are not originated from genetic defects, therefore supporting the central roles of epigenetic modifications that are acquired progressively during the life span. Strong evidences have indicated the implication of epigenetic modifications, including histone modification and DNA methylation, in AD. Recent studies revealed that 5-hydroxymethylcytosine (5hmC) is dynamically regulated during neurodevelopment and aging. We show that amyloid peptide 1-42 (Aβ1-42) could significantly reduce the overall level of 5hmC in vitro. We found that the level of 5hmC displayed differential response to the pathogenesis in different brain regions, including the cortex, cerebellum, and hippocampus of APP-PSEN1 double transgenic (DTg) mice. We observed a significant decrease of overall 5hmC in hippocampus, but not in cortex and cerebellum, as the DTg mice aged. Genome-wide profiling identified differential hydroxymethylation regions (DhMRs) in DTg mice, which are highly enriched in introns, exons and intergenic regions. Gene ontology analyses indicated that DhMR-associated genes are highly enriched in multiple signaling pathways involving neuronal development/differentiation and neuronal function/survival. 5hmC-mediated epigenetic regulation could potentially be involved in the pathogenesis of AD.

Microorganism-induced exacerbations in atopic dermatitis: a possible preventive role for vitamin D?

PubMed

Benetti, Cecilia; Piacentini, Giorgio L; Capristo, Carlo; Boner, Attilio L; Peroni, Diego G

2015-01-01

Atopic dermatitis (AD) is a common skin disease characterized by a complex pathogenesis not completely understood despite numerous studies to date. The clinical patterns result from interactions between genetic disorders determining abnormalities in the epidermis differentiation complex, modification of the cutaneous barrier, and dysfunction of immune responses. Several studies have shown that an alteration of the skin barrier combined with immune dysfunction is important for the onset, maintenance, and risk of exacerbations of the disease. In recent years, new aspects regarding the pathogenesis of the disease, such as the effects of vitamin D (VD) on immunity at the skin level and the role of certain microorganisms (particularly Staphylococcus and Malassezia species) on eczema exacerbations, have been evaluated. This article provides an overview of the evidences supporting the link between VD (deficiency) and microorganisms (skin colonization/sensitization) in AD pathogenesis, based on comprehensive review of the literature. By considering different aspects of disease, it might be possible to improve our understanding, particularly in those patients refractory to conventional treatments. An electronic research strategy was used to search in Medline Pub-Med Library using as research words AD, exacerbation, VD, Staphylococcus aureus (SA), and Malassezia. The results were downloaded and analyzed for systematic review. Few studies actually consider the relationship between VD deficiency (VDD), AD, and SA and Malassezia, but many suggest a correlation between these factors. VDs play a major role against microorganisms in the development of AD and should be considered when treating patients.

Cognitive Impairment, Neuroimaging, and Alzheimer Neuropathology in Mouse Models of Down Syndrome

PubMed Central

Hamlett, Eric D.; Boger, Heather A.; Ledreux, Aurélie; Kelley, Christy M.; Mufson, Elliott J.; Falangola, Maria F.; Guilfoyle, David N.; Nixon, Ralph A.; Patterson, David; Duval, Nathan; Granholm, Ann-Charlotte E.

2016-01-01

Down syndrome (DS) is the most common non-lethal genetic condition that affects approximately 1 in 700 births in the United States of America. DS is characterized by complete or segmental chromosome 21 trisomy, which leads to variable intellectual disabilities, progressive memory loss, and accelerated neurodegeneration with age. During the last three decades, people with DS have experienced a doubling of life expectancy due to progress in treatment of medical comorbidities, which has allowed this population to reach the age when they develop early onset Alzheimer’s disease (AD). Individuals with DS develop cognitive and pathological hallmarks of AD in their fourth or fifth decade, and are currently lacking successful prevention or treatment options for dementia. The profound memory deficits associated with DS-related AD (DS-AD) have been associated with degeneration of several neuronal populations, but mechanisms of neurodegeneration are largely unexplored. The most successful animal model for DS is the Ts65Dn mouse, but several new models have also been developed. In the current review, we discuss recent findings and potential treatment options for the management of memory loss and AD neuropathology in DS mouse models. We also review age-related neuropathology, and recent findings from neuroimaging studies. The validation of appropriate DS mouse models that mimic neurodegeneration and memory loss in humans with DS can be valuable in the study of novel preventative and treatment interventions, and may be helpful in pinpointing gene-gene interactions as well as specific gene segments involved in neurodegeneration. PMID:26391050

Neurobiology of Alzheimer’s Disease: Integrated Molecular, Physiological, Anatomical, Biomarker, and Cognitive Dimensions

PubMed Central

Raskin, Joel; Cummings, Jeffrey; Hardy, John; Schuh, Kory; Dean, Robert A.

2015-01-01

Background: Alzheimer’s disease (AD), the most common form of dementia, is a progressive neurodegenerative disorder with interrelated molecular, physiological, anatomical, biomarker, and cognitive dimensions. Methods: This article reviews the biological changes (genetic, molecular, and cellular) underlying AD and their correlation with the clinical syndrome. Results: Dementia associated with AD is related to the aberrant production, processing, and clearance of beta-amyloid and tau. Beta-amyloid deposition in brain follows a distinct spatial progression starting in the basal neocortex, spreading throughout the hippocampus, and eventually spreading to the rest of the cortex. The spread of tau pathology through neural networks leads to a distinct and consistent spatial progression of neurofibrillary tangles, beginning in the transentorhinal and hippocampal region and spreading superolaterally to the primary areas of the neocortex. Synaptic dysfunction and cell death is shown by progressive loss of cerebral metabolic rate for glucose and progressive brain atrophy. Decreases in synapse number in the dentate gyrus of the hippocampus correlate with declining cognitive function. Amyloid changes are detectable in cerebrospinal fluid and with amyloid imaging up to 20 years prior to the onset of symptoms. Structural atrophy may be detectable via magnetic resonance imaging up to 10 years before clinical signs appear. Conclusion: This review highlights the progression of biological changes underlying AD and their association with the clinical syndrome. Many changes occur before overt symptoms are evident and biomarkers provide a means to detect AD pathology even in patients without symptoms. PMID:26412218

Cerebral metabolic and cognitive decline in persons at genetic risk for Alzheimer's disease

PubMed Central

Small, Gary W.; Ercoli, Linda M.; Silverman, Daniel H. S.; Huang, S.-C.; Komo, Scott; Bookheimer, Susan Y.; Lavretsky, Helen; Miller, Karen; Siddarth, Prabha; Rasgon, Natalie L.; Mazziotta, John C.; Saxena, Sanjaya; Wu, H. M.; Mega, Michael S.; Cummings, Jeffrey L.; Saunders, Ann M.; Pericak-Vance, Margaret A.; Roses, Allen D.; Barrio, Jorge R.; Phelps, Michael E.

2000-01-01

The major known genetic risk for Alzheimer's disease (AD), apolipoprotein E-4 (APOE-4), is associated with lowered parietal, temporal, and posterior cingulate cerebral glucose metabolism in patients with a clinical diagnosis of AD. To determine cognitive and metabolic decline patterns according to genetic risk, we investigated cerebral metabolic rates by using positron emission tomography in middle-aged and older nondemented persons with normal memory performance. A single copy of the APOE-4 allele was associated with lowered inferior parietal, lateral temporal, and posterior cingulate metabolism, which predicted cognitive decline after 2 years of longitudinal follow-up. For the 20 nondemented subjects followed longitudinally, memory performance scores did not decline significantly, but cortical metabolic rates did. In APOE-4 carriers, a 4% left posterior cingulate metabolic decline was observed, and inferior parietal and lateral temporal regions demonstrated the greatest magnitude (5%) of metabolic decline after 2 years. These results indicate that the combination of cerebral metabolic rates and genetic risk factors provides a means for preclinical AD detection that will assist in response monitoring during experimental treatments. PMID:10811879

[Hybrids of human and monkey adenoviruses (adeno-adeno hybrids) that can reproduce in monkey cells: biological and molecular genetic peculiarities].

PubMed

Grinenko, N F; Savitskaia, N V; Pashvykina, G V; Al'tshteĭn, A D

2003-06-01

A highly oncogenic monkey adenovirus SA7(C8) facilitates the reproduction of human adenovirus type 2 (Ad2) in monkey cells. Upon mixed infection of monkey cells with both viruses, these viruses recombine producing defective adeno-adeno hybrids Ad2C8 serologically identical to Ad2 and capable of assisting Ad2 to reproduce in monkey cells. Ad2C8 and Ad2 form an intercomplementary pair inseparable in monkey cells. Unlike oncogenic SA7(C8), Ad2C8 is a nononcogenic virus for hamsters but is able to induce tumor antigens of this virus (T and TSTA). Molecular genetic analysis of 68 clones of adeno-adeno hybrids revealed that the left part of their genome consists of Ad2 DNA, and the right part contains no less than 40% of the viral SA7(C8) genome where E2A, E3, and E4 genes are located. Apparently, the products of these genes contribute to the composition of adenoviral tumor antigens, while the E4 gene is involved in complementation of monkey and human adenoviruses and makes a contribution to host range determination of these viruses.

Public understanding of genetics and Alzheimer disease.

PubMed

Stockdale, A

1999-01-01

It is generally thought that public understanding of science is inadequate. The definitions of "the public," "understanding," and "science" all need careful consideration in this formulation, with a greater focus on who should understand what and for what purposes. Improved public understanding depends on experts being reflective about the limits of their own expertise and the different needs of the many potential consumers of genetic knowledge. Media coverage of genetic discoveries has been extensive in recent years, but this coverage is often not useful and may even be misleading to families at risk for genetic disease. The Internet provides an alternative source of information as well as an interactive forum, one that has been widely used by persons interested in Alzheimer disease (AD). Internet-based activities hold great promise for providing interested members of the public with useful information and facilitating more substantive dialogue among physicians, researches, and laypersons regarding the genetic aspects of AD.

Genetic Code Expansion of Mammalian Cells with Unnatural Amino Acids.

PubMed

Brown, Kalyn A; Deiters, Alexander

2015-09-01

The expansion of the genetic code of mammalian cells enables the incorporation of unnatural amino acids into proteins. This is achieved by adding components to the protein biosynthetic machinery, specifically an engineered aminoacyl-tRNA synthetase/tRNA pair. The unnatural amino acids are chemically synthesized and supplemented to the growth medium. Using this methodology, fundamental new chemistries can be added to the functional repertoire of the genetic code of mammalian cells. This protocol outlines the steps necessary to incorporate a photocaged lysine into proteins and showcases its application in the optical triggering of protein translocation to the nucleus. Copyright © 2015 John Wiley & Sons, Inc.

Toward precision medicine in Alzheimer's disease.

PubMed

Reitz, Christiane

2016-03-01

In Western societies, Alzheimer's disease (AD) is the most common form of dementia and the sixth leading cause of death. In recent years, the concept of precision medicine, an approach for disease prevention and treatment that is personalized to an individual's specific pattern of genetic variability, environment and lifestyle factors, has emerged. While for some diseases, in particular select cancers and a few monogenetic disorders such as cystic fibrosis, significant advances in precision medicine have been made over the past years, for most other diseases precision medicine is only in its beginning. To advance the application of precision medicine to a wider spectrum of disorders, governments around the world are starting to launch Precision Medicine Initiatives, major efforts to generate the extensive scientific knowledge needed to integrate the model of precision medicine into every day clinical practice. In this article we summarize the state of precision medicine in AD, review major obstacles in its development, and discuss its benefits in this highly prevalent, clinically and pathologically complex disease.

Analyzing the genes related to Alzheimer's disease via a network and pathway-based approach.

PubMed

Hu, Yan-Shi; Xin, Juncai; Hu, Ying; Zhang, Lei; Wang, Ju

2017-04-27

Our understanding of the molecular mechanisms underlying Alzheimer's disease (AD) remains incomplete. Previous studies have revealed that genetic factors provide a significant contribution to the pathogenesis and development of AD. In the past years, numerous genes implicated in this disease have been identified via genetic association studies on candidate genes or at the genome-wide level. However, in many cases, the roles of these genes and their interactions in AD are still unclear. A comprehensive and systematic analysis focusing on the biological function and interactions of these genes in the context of AD will therefore provide valuable insights to understand the molecular features of the disease. In this study, we collected genes potentially associated with AD by screening publications on genetic association studies deposited in PubMed. The major biological themes linked with these genes were then revealed by function and biochemical pathway enrichment analysis, and the relation between the pathways was explored by pathway crosstalk analysis. Furthermore, the network features of these AD-related genes were analyzed in the context of human interactome and an AD-specific network was inferred using the Steiner minimal tree algorithm. We compiled 430 human genes reported to be associated with AD from 823 publications. Biological theme analysis indicated that the biological processes and biochemical pathways related to neurodevelopment, metabolism, cell growth and/or survival, and immunology were enriched in these genes. Pathway crosstalk analysis then revealed that the significantly enriched pathways could be grouped into three interlinked modules-neuronal and metabolic module, cell growth/survival and neuroendocrine pathway module, and immune response-related module-indicating an AD-specific immune-endocrine-neuronal regulatory network. Furthermore, an AD-specific protein network was inferred and novel genes potentially associated with AD were identified. By means of network and pathway-based methodology, we explored the pathogenetic mechanism underlying AD at a systems biology level. Results from our work could provide valuable clues for understanding the molecular mechanism underlying AD. In addition, the framework proposed in this study could be used to investigate the pathological molecular network and genes relevant to other complex diseases or phenotypes.

Joint SOGC-CCMG Opinion for Reproductive Genetic Carrier Screening: An Update for All Canadian Providers of Maternity and Reproductive Healthcare in the Era of Direct-to-Consumer Testing.

PubMed

Wilson, R Douglas; De Bie, Isabelle; Armour, Christine M; Brown, Richard N; Campagnolo, Carla; Carroll, June C; Okun, Nan; Nelson, Tanya; Zwingerman, Rhonda; Audibert, Francois; Brock, Jo-Ann; Brown, Richard N; Campagnolo, Carla; Carroll, June C; De Bie, Isabelle; Johnson, Jo-Ann; Okun, Nan; Pastruck, Melanie; Vallée-Pouliot, Karine; Wilson, R Douglas; Zwingerman, Rhonda; Armour, Christine; Chitayat, David; De Bie, Isabelle; Fernandez, Sara; Kim, Raymond; Lavoie, Josee; Leonard, Norma; Nelson, Tanya; Taylor, Sherry; Van Allen, Margot; Van Karnebeek, Clara

2016-08-01

This guideline was written to update Canadian maternity care and reproductive healthcare providers on pre- and postconceptional reproductive carrier screening for women or couples who may be at risk of being carriers for autosomal recessive (AR), autosomal dominant (AD), or X-linked (XL) conditions, with risk of transmission to the fetus. Four previous SOGC- Canadian College of Medical Geneticists (CCMG) guidelines are updated and merged into the current document. All maternity care (most responsible health provider [MRHP]) and paediatric providers; maternity nursing; nurse practitioner; provincial maternity care administrator; medical student; and postgraduate resident year 1-7. Fertile, sexually active females and their fertile, sexually active male partners who are either planning a pregnancy or are pregnant (preferably in the first trimester of pregnancy, but any gestational age is acceptable). Women and their partners will be able to obtain appropriate genetic carrier screening information and possible diagnosis of AR, AD, or XL disorders (preferably pre-conception), thereby allowing an informed choice regarding genetic carrier screening and reproductive options (e.g., prenatal diagnosis, preimplantation genetic diagnosis, egg or sperm donation, or adoption). Informed reproductive decisions related to genetic carrier screening and reproductive outcomes based on family history, ethnic background, past obstetrical history, known carrier status, or genetic diagnosis. SOGC REPRODUCTIVE CARRIER SCREENING SUMMARY STATEMENT (2016): Pre-conception or prenatal education and counselling for reproductive carrier screening requires a discussion about testing within the three perinatal genetic carrier screening/diagnosis time periods, which include pre-conception, prenatal, and neonatal for conditions currently being screened for and diagnosed. This new information should be added to the standard reproductive carrier screening protocols that are already being utilized by the most responsible maternity provider through the informed consent process with the patient. (III-A; GRADE low/moderate) SOGC OVERVIEW OF RECOMMENDATIONS QUALITY AND GRADE: There was a strong observational/expert opinion (quality and grade) for the genetic carrier literature with randomized controlled trial evidence being available only for the invasive testing. Both the Canadian Task Force on Preventive Health Care quality and classification and the GRADE evidence quality and grade are provided. MEDLINE; PubMed; government neonatal screening websites; key words/common reproductive genetic carrier screened diseases/previous SOGC Guidelines/medical academic societies (Society of Maternal-Fetal Medicine [SMFM]; American College of Medical Genetics and Genomics; American College of Obstetricians and Gynecologists [ACOG]; CCMG; Royal College Obstetrics and Gynaecology [RCOG] [UK]; American Society of Human Genetics [ASHG]; International Society of Prenatal Diagnosis [ISPD])/provincial neonatal screening policies and programs; search terms (carrier screening, prenatal screening, neonatal genetic/metabolic screening, cystic fibrosis (CF), thalassemia, hemoglobinopathy, hemophilia, Fragile X syndrome (FXS), spinal muscular atrophy, Ashkenazi Jewish carrier screening, genetic carrier screening protocols, AR, AD, XL). 10 years (June 2005-September 2015); initial search dates June 30, 2015 and September 15, 2015; completed final search January 4, 2016. Validation of articles was completed by primary authors RD Wilson and I De Bie. Benefits are to provide an evidenced based reproductive genetic carrier screening update consensus based on international opinions and publications for the use of Canadian women, who are planning a pregnancy or who are pregnant and have been identified to be at risk (personal or male partner family or reproductive history) for the transmission of a clinically significant genetic condition to their offspring with associated morbidity and/or mortality. Harm may arise from having counselling and informed testing of the carrier status of the mother, their partner, or their fetus, as well as from declining to have this counselling and informed testing or from not having the opportunity for counselling and informed testing. Costs will ensue both from the provision of opportunities for counselling and testing, as well as when no such opportunities are offered or are declined and the birth of a child with a significant inherited condition and resulting morbidity/mortality occurs; these comprise not only the health care costs to the system but also the social/financial/psychological/emotional costs to the family. These recommendations are based on expert opinion and have not been subjected to a health economics assessment and local or provincial implementation will be required. This guideline is an update of four previous joint SOGC-CCMG Genetic Screening Guidelines dated 2002, 2006, 2008, and 2008 developed by the SOGC Genetic Committee in collaboration with the CCMG Prenatal Diagnosis Committee (now Clinical Practice Committee). 2016 CARRIER SCREENING RECOMMENDATIONS. Copyright © 2016 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.

Integration of Multilocus Genetic Risk into the Default Mode Network Longitudinal Trajectory during the Alzheimer's Disease Process.

PubMed

Su, Fan; Shu, Hao; Ye, Qing; Xie, Chunming; Yuan, Baoyu; Zhang, Zhijun; Bai, Feng

2017-01-01

The aim of the study was to investigate the cognitive significance of the changes in default mode network (DMN) during the process of Alzheimer's disease (AD) and the genetic basis that drives the alteration. Eighty-seven subjects with mild cognitive impairment (MCI) and 131 healthy controls (HC) were employed at baseline, and they had the genetic risk scores (GRS) based on the GWAS-validated AD-related top loci. Eleven MCIs who converted to AD (c-MCIs), 32 subjects who remained stable (nc-MCIs), and 56 HCs participated in the follow-up analyses after an average of 35 months. Decreased functional connectivity (FC) within temporal cortex was identified for MCIs at baseline, which was partially determined by the GRS; moreover, compensations may occur within the frontal-parietal brain to maintain relatively intact cognition. During the follow-ups, c-MCIs exhibited more FC declines within the prefrontal-parietal lobes and parahippocampal gyrus/hippocampus than the HCs and nc-MCIs. The GRS did not significantly vary among the three groups, whereas associations were identified at risky alleles and FC declines in all AD spectra. Interestingly, the influence of APOEɛ4 varied as the disease progressed; APOEɛ4 was associated with longitudinal FC decreases only for HCs in the single variance-based analyses and deteriorated DMN integration in nc-MCIs by combining the effects of other loci. However, the GRS without APOEɛ4 predicted FC decline for converters. It is suggested that the integration of multilocus genetic risk predicted the longitudinal trajectory of DMN and may be used as a clinical strategy to track AD progression.

Protective effect of the APOE-e3 allele in Alzheimer's disease

PubMed Central

de-Almada, B.V.P.; de-Almeida, L.D.; Camporez, D.; de-Moraes, M.V.D.; Morelato, R.L.; Perrone, A.M.S.; Belcavello, L.; Louro, I.D.; de-Paula, F.

2011-01-01

Although several alleles of susceptibility to Alzheimer's disease (AD) have been studied in the last decades, few polymorphisms have been considered as risk factors for the disease. Among them, the APOE-e4 allele appears to be the major genetic risk factor for the onset of the disease. However, it is important to confirm the potential susceptibility of these genetic variants in different populations in order to establish a genetic profile for the disease in specific communities. This study analyzed the APOE polymorphisms regarding susceptibility to AD in a sample of 264 individuals (primarily Caucasians; 82 cases and 182 controls) in the population from Vitória, ES, Brazil, by PCR restriction fragment length polymorphism (PCR-RFLP) methods. The patients were selected according to clinical criteria for probable AD. Whereas the e4 allele showed statistically significant positive association with susceptibility to AD (OR = 3.01, 95%CI = 1.96-4.61; P < 0.0001), the e2 allele did not. The results of the e4 allele confirm the role of this polymorphism as a risk factor for AD in the sample studied as observed in other populations. Although the e3 allele has been considered neutral in several studies, our results suggest that it acts as a protective factor against AD in the population studied (OR = 0.46, 95%CI = 0.30-0.67; P < 0.0001). This study may provide a new insight into the role of the APOE-e3 allele in the etiology of AD and might help to estabilish a profile of risk for AD in the population from Vitória, ES. PMID:22068907

Genetic Retargeting of Adenovirus: Novel Strategy Employing “Deknobbing” of the Fiber

PubMed Central

Magnusson, Maria K.; Hong, Saw See; Boulanger, Pierre; Lindholm, Leif

2001-01-01

For efficient and versatile use of adenovirus (Ad) as an in vivo gene therapy vector, modulation of the viral tropism is highly desirable. In this study, a novel method to genetically alter the Ad fiber tropism is described. The knob and the last 15 shaft repeats of the fiber gene were deleted and replaced with an external trimerization motif and a new cell-binding ligand, in this case the integrin-binding motif RGD. The corresponding recombinant fiber retained the basic biological functions of the natural fiber, i.e., trimerization, nuclear import, penton formation, and ligand binding. The recombinant fiber bound to integrins but failed to react with antiknob antibody. For virus production, the recombinant fiber gene was rescued into the Ad genome at the exact position of the wild-type (WT) fiber to make use of the native regulation of fiber expression. The recombinant virus Ad5/FibR7-RGD yielded plaques on 293 cells, but the spread through the monolayer was two to three times delayed compared to WT, and the ratio of infectious to physical particles was 20 times lower. Studies on virus tropism showed that Ad5/FibR7-RGD was able to infect cells which did not express the coxsackie-adenovirus receptor (CAR), but did express integrins. Ad5/FibR7-RGD virus infectivity was unchanged in the presence of antiknob antibody, which neutralized the WT virus. Ad5/FibR7-RGD virus showed an expanded tropism, which is useful when gene transfer to cells not expressing CAR is needed. The described method should also make possible the construction of Ad genetically retargeted via ligands other than RGD. PMID:11462000

Shared Genetics and Couple-Associated Environment Are Major Contributors to the Risk of Both Clinical and Self-Declared Depression.

PubMed

Zeng, Yanni; Navarro, Pau; Xia, Charley; Amador, Carmen; Fernandez-Pujals, Ana M; Thomson, Pippa A; Campbell, Archie; Nagy, Reka; Clarke, Toni-Kim; Hafferty, Jonathan D; Smith, Blair H; Hocking, Lynne J; Padmanabhan, Sandosh; Hayward, Caroline; MacIntyre, Donald J; Porteous, David J; Haley, Chris S; McIntosh, Andrew M

2016-12-01

Both genetic and environmental factors contribute to risk of depression, but estimates of their relative contributions are limited. Commonalities between clinically-assessed major depressive disorder (MDD) and self-declared depression (SDD) are also unclear. Using data from a large Scottish family-based cohort (GS:SFHS, N=19,994), we estimated the genetic and environmental variance components for MDD and SDD. The components representing the genetic effect associated with genome-wide common genetic variants (SNP heritability), the additional pedigree-associated genetic effect and non-genetic effects associated with common environments were estimated in a linear mixed model (LMM). Both MDD and SDD had significant contributions from components representing the effect from common genetic variants, the additional genetic effect associated with the pedigree and the common environmental effect shared by couples. The estimate of correlation between SDD and MDD was high (r=1.00, se=0.20) for common-variant-associated genetic effect and lower for the additional genetic effect from the pedigree (r=0.57, se=0.08) and the couple-shared environmental effect (r=0.53, se=0.22). Both genetics and couple-shared environmental effects were major factors influencing liability to depression. SDD may provide a scalable alternative to MDD in studies seeking to identify common risk variants. Rarer variants and environmental effects may however differ substantially according to different definitions of depression. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Using an Alzheimer Disease Polygenic Risk Score to Predict Memory Decline in Black and White Americans Over 14 Years of Follow-up.

PubMed

Marden, Jessica R; Mayeda, Elizabeth R; Walter, Stefan; Vivot, Alexandre; Tchetgen Tchetgen, Eric J; Kawachi, Ichiro; Glymour, M Maria

2016-01-01

Evidence on whether genetic predictors of Alzheimer disease (AD) also predict memory decline is inconsistent, and limited data are available for African ancestry populations. For 8253 non-Hispanic white (NHW) and non-Hispanic black (NHB) Health and Retirement Study participants with memory scores measured 1 to 8 times between 1998 and 2012 (average baseline age=62), we calculated weighted polygenic risk scores [AD Genetic Risk Score (AD-GRS)] using the top 22 AD-associated loci, and an alternative score excluding apolipoprotein E (APOE) (AD-GRSexAPOE). We used generalized linear models with AD-GRS-by-age and AD-GRS-by-age interactions (age centered at 70) to predict memory decline. Average NHB decline was 26% faster than NHW decline (P<0.001). Among NHW, 10% higher AD-GRS predicted faster memory decline (linear β=-0.058 unit decrease over 10 y; 95% confidence interval,-0.074 to -0.043). AD-GRSexAPOE also predicted faster decline for NHW, although less strongly. Among NHB, AD-GRS predicted faster memory decline (linear β=-0.050; 95% confidence interval, -0.106 to 0.006), but AD-GRSexAPOE did not. Our nonsignificant estimate among NHB may reflect insufficient statistical power or a misspecified AD-GRS among NHB as an overwhelming majority of genome-wide association studies are conducted in NHW. A polygenic score based on previously identified AD loci predicts memory loss in US blacks and whites.

Assessing controversial direct-to-consumer advertising for hereditary breast cancer testing: reactions from women and their physicians in a managed care organization.

PubMed

Mouchawar, Judy; Laurion, Suzanne; Ritzwoller, Debra P; Ellis, Jennifer; Kulchak-Rahm, Alanna; Hensley-Alford, Sharon

2005-10-01

To describe the impact on patients and physicians at a managed care organization (MCO) of a direct-to-consumer advertising (DTC-ad) campaign concerning testing for the BRCA1 and BRCA2 genes. Observational study. In 2003, we mailed a 30-item questionnaire to 750 randomly chosen female members of Kaiser Permanente Colorado (KPCO) aged 25 to 54 years, and 100 female KPCO members with a history of breast cancer genetic referral. We mailed a 7-item questionnaire to 180 randomly chosen KPCO primary care providers. Of 394 patient respondents, 245 (62%) reported exposure to the DTC-ad of whom 63% reported that the DTC-ad caused no anxiety at all. A high level of perceived breast cancer risk and being of Hispanic ethnicity each were independently associated with reported anxiety due to the DTC-ad (adjusted odds ratio [OR] = 3.23, 95% confidence interval [CI] = 1.35, 7.73, and adjusted OR = 4.19, 95% CI = 1.48, 11.83, respectively). Greater knowledge was seen among respondents exposed to the DTC-ad than among those reporting no exposure (P = .015). Of the physician respondents, 84% reported that the DTC-ad caused no strain on the doctor-patient relationship, and nearly 80% reported no effect on daily clinical practice. Genetic referrals soared more than 200% compared with the prior year, when there was no advertising. The DTC-ad had a marked impact on genetic services, but little apparent negative impact on patients or primary care providers at an MCO.

The more from East-Asian, the better: risk prediction of colorectal cancer risk by GWAS-identified SNPs among Japanese.

PubMed

Abe, Makiko; Ito, Hidemi; Oze, Isao; Nomura, Masatoshi; Ogawa, Yoshihiro; Matsuo, Keitaro

2017-12-01

Little is known about the difference of genetic predisposition for CRC between ethnicities; however, many genetic traits common to colorectal cancer have been identified. This study investigated whether more SNPs identified in GWAS in East Asian population could improve the risk prediction of Japanese and explored possible application of genetic risk groups as an instrument of the risk communication. 558 Patients histologically verified colorectal cancer and 1116 first-visit outpatients were included for derivation study, and 547 cases and 547 controls were for replication study. Among each population, we evaluated prediction models for the risk of CRC that combined the genetic risk group based on SNPs from GWASs in European-population and a similarly developed model adding SNPs from GWASs in East Asian-population. We examined whether adding East Asian-specific SNPs would improve the discrimination. Six SNPs (rs6983267, rs4779584, rs4444235, rs9929218, rs10936599, rs16969681) from 23 SNPs by European-based GWAS and five SNPs (rs704017, rs11196172, rs10774214, rs647161, rs2423279) among ten SNPs by Asian-based GWAS were selected in CRC risk prediction model. Compared with a 6-SNP-based model, an 11-SNP model including Asian GWAS-SNPs showed improved discrimination capacity in Receiver operator characteristic analysis. A model with 11 SNPs resulted in statistically significant improvement in both derivation (P = 0.0039) and replication studies (P = 0.0018) compared with six SNP model. We estimated cumulative risk of CRC by using genetic risk group based on 11 SNPs and found that the cumulative risk at age 80 is approximately 13% in the high-risk group while 6% in the low-risk group. We constructed a more efficient CRC risk prediction model with 11 SNPs including newly identified East Asian-based GWAS SNPs (rs704017, rs11196172, rs10774214, rs647161, rs2423279). Risk grouping based on 11 SNPs depicted lifetime difference of CRC risk. This might be useful for effective individualized prevention for East Asian.

Prevalence of Drug Combinations Increasing Bleeding Risk Among Warfarin Users With and Without Alzheimer's Disease.

PubMed

Taipale, Heidi; Vuorikari, Hanna; Tanskanen, Antti; Koponen, Marjaana; Tiihonen, Jari; Kettunen, Raimo; Hartikainen, Sirpa

2015-11-01

The aim of this study was to analyse the prevalence and predictors of drug combinations increasing bleeding risk among warfarin users with and without Alzheimer's disease (AD). This retrospective observational study utilised data from the Finnish MEDALZ-2005 cohort. The MEDALZ-2005 study included all community-dwelling persons with a clinically verified diagnosis of AD at the end of 2005, and one comparison person without AD for each case. Data on drug use was collected from the Prescription Register. We included persons who were warfarin users during the study period 2006-2009. Drug combinations increasing bleeding risk with warfarin included selective serotonin reuptake inhibitors (SSRIs), non-steroidal anti-inflammatory agents (NSAIDs), other antithrombotic drugs and tramadol. Factors associated with combination use were investigated with logistic regression. During the follow-up, 3385 persons with AD and 4830 persons without AD used warfarin. Drug combinations increasing bleeding risk were more common in warfarin users with AD than without AD [35.9 and 30.5%, respectively (p < 0.0001)]. The most common combination was SSRIs and warfarin, which was more common among persons with AD (23.8%) than among persons without AD (10.9%). NSAIDs and warfarin combination was more common among persons without AD. Combination use was associated with AD, female gender, younger age, diabetes mellitus, rheumatoid arthritis and asthma/chronic obstructive pulmonary disease (COPD). Use of drug combinations increasing bleeding risk was more common among warfarin users with AD. Special attention should be paid to minimise the duration of concomitant use and to find safer alternatives without increased bleeding risk.

Pharmacogenetic studies in Alzheimer disease.

PubMed

Zúñiga Santamaría, T; Yescas Gómez, P; Fricke Galindo, I; González González, M; Ortega Vázquez, A; López López, M

2018-06-10

Alzheimer disease (AD) is the most common cause of dementia and is considered one of the main causes of disability and dependence affecting quality of life in elderly people and their families. Current pharmacological treatment includes acetylcholinesterase inhibitors (donepezil, galantamine, rivastigmine) and memantine; however, only one-third of patients respond to treatment. Genetic factors have been shown to play a role in this inter-individual variability in drug response. We review pharmacogenetic reports of AD-modifying drugs, the pharmacogenetic biomarkers included, and the phenotypes evaluated. We also discuss relevant methodological considerations for the design of pharmacogenetic studies into AD. A total of 33 pharmacogenetic reports were found; the majority of these focused on the variability in response to and metabolism of donepezil. Most of the patients included were from Caucasian populations, although some studies also include Korean, Indian, and Brazilian patients. CYP2D6 and APOE are the most frequently studied biomarkers. The associations proposed are controversial. Potential pharmacogenetic biomarkers for AD have been identified; however, it is still necessary to conduct further research into other populations and to identify new biomarkers. This information could assist in predicting patient response to these drugs and contribute to better treatment decision-making in a context as complex as aging. Copyright © 2018 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Biomarkers of aggression in dementia.

PubMed

Gotovac, Kristina; Nikolac Perković, Matea; Pivac, Nela; Borovečki, Fran

2016-08-01

Dementia is a clinical syndrome defined by progressive global impairment of acquired cognitive abilities. It can be caused by a number of underlying conditions. The most common types of dementia are Alzheimer's disease (AD), frontotemporal dementia (FTD), vascular cognitive impairment (VCI) and dementia with Lewy bodies (DLB). Despite the fact that cognitive impairment is central to the dementia, noncognitive symptoms, most commonly described nowadays as neuropsychiatric symptoms (NPS) exist almost always at certain point of the illness. Aggression as one of the NPS represents danger both for patients and caregivers and the rate of aggression correlates with the loss of independence, cognitive decline and poor outcome. Therefore, biomarkers of aggression in dementia patients would be of a great importance. Studies have shown that different genetic factors, including monoamine signaling and processing, can be associated with various NPS including aggression. There have been significant and multiple neurotransmitter changes identified in the brains of patients with dementia and some of these changes have been involved in the etiology of NPS. Aggression specific changes have also been observed in neuropathological studies. The current consensus is that the best approach for development of such biomarkers may be incorporation of genetics (polymorphisms), neurobiology (neurotransmitters and neuropathology) and neuroimaging techniques. Copyright © 2016 Elsevier Inc. All rights reserved.

Genetics and Common Disorders: Implications for Primary Care and Public Health Providers

DOE Office of Scientific and Technical Information (OSTI.GOV)

McInerney, Joseph D.; Greendale, Karen; Peay, Holly L.

We developed this program for primary care providers (PCPs) and public health professionals (PHPs) who are interested in increasing their understanding of the genetics of common chronic diseases and of the implications of genetics and genomics for their fields. The program differs from virtually all previous educational efforts in genetics for health professionals in that it focuses on the genetics of common chronic disease and on the broad principles that emerge when one views disease from the perspectives of variation and individuality, which are at the heart of thinking genetically. The CD-ROM introduces users to content that will improve theirmore » understanding of topics such as: • A framework for genetics and common disease; • Basic information on genetics, genomics, genetic medicine, and public health genetics, all in the context of common chronic disease; • The status of research on genetic contributions to specific common diseases, including a review of research methods; • Genetic/environmental interaction as the new “central dogma” of public health genetics; • The importance of taking and analyzing a family history; • The likely impact of potential gene discovery and genetic testing on genetic counseling and risk assessment and on the practices of PCPs and PHPs; • Stratification of populations into low-, moderate-, and high-risk categories; • The potential role of PCPs and PHPs in identifying high-risk individuals and families, in providing limited genetics services, and in referring to clinical genetics specialists; the potential for standard referral algorithms; • Implications of genetic insights for diagnosis and treatment; • Ethical, legal, and social issues that arise from genetic testing for common chronic diseases; and • Specific prevention strategies based on understanding of genetics and genetic/ environmental interactions. The interactive content – developed by experts in genetics, primary care, and public health – is organized around two case studies designed to appeal to primary care providers (thrombophilia) and public health professionals (development of a screening grogram for colorectal cancer). NCHPEG has distributed more than 0000 copies of the CD-ROM to NCHPEG member organizations and to other organizations and individuals in response to requests. The program also is available at www.nchpeg.org.« less

Functional analysis of regulatory single-nucleotide polymorphisms.

PubMed

Pampín, Sandra; Rodríguez-Rey, José C

2007-04-01

The identification of regulatory polymorphisms has become a key problem in human genetics. In the past few years there has been a conceptual change in the way in which regulatory single-nucleotide polymorphisms are studied. We revise the new approaches and discuss how gene expression studies can contribute to a better knowledge of the genetics of common diseases. New techniques for the association of single-nucleotide polymorphisms with changes in gene expression have been recently developed. This, together with a more comprehensive use of the old in-vitro methods, has produced a great amount of genetic information. When added to current databases, it will help to design better tools for the detection of regulatory single-nucleotide polymorphisms. The identification of functional regulatory single-nucleotide polymorphisms cannot be done by the simple inspection of DNA sequence. In-vivo techniques, based on primer-extension, and the more recently developed 'haploChIP' allow the association of gene variants to changes in gene expression. Gene expression analysis by conventional in-vitro techniques is the only way to identify the functional consequences of regulatory single-nucleotide polymorphisms. The amount of information produced in the last few years will help to refine the tools for the future analysis of regulatory gene variants.

Genetic risk factors for the posterior cortical atrophy variant of Alzheimer's disease.

PubMed

Schott, Jonathan M; Crutch, Sebastian J; Carrasquillo, Minerva M; Uphill, James; Shakespeare, Tim J; Ryan, Natalie S; Yong, Keir X; Lehmann, Manja; Ertekin-Taner, Nilufer; Graff-Radford, Neill R; Boeve, Bradley F; Murray, Melissa E; Khan, Qurat Ul Ain; Petersen, Ronald C; Dickson, Dennis W; Knopman, David S; Rabinovici, Gil D; Miller, Bruce L; González, Aida Suárez; Gil-Néciga, Eulogio; Snowden, Julie S; Harris, Jenny; Pickering-Brown, Stuart M; Louwersheimer, Eva; van der Flier, Wiesje M; Scheltens, Philip; Pijnenburg, Yolande A; Galasko, Douglas; Sarazin, Marie; Dubois, Bruno; Magnin, Eloi; Galimberti, Daniela; Scarpini, Elio; Cappa, Stefano F; Hodges, John R; Halliday, Glenda M; Bartley, Lauren; Carrillo, Maria C; Bras, Jose T; Hardy, John; Rossor, Martin N; Collinge, John; Fox, Nick C; Mead, Simon

2016-08-01

The genetics underlying posterior cortical atrophy (PCA), typically a rare variant of Alzheimer's disease (AD), remain uncertain. We genotyped 302 PCA patients from 11 centers, calculated risk at 24 loci for AD/DLB and performed an exploratory genome-wide association study. We confirm that variation in/near APOE/TOMM40 (P = 6 × 10(-14)) alters PCA risk, but with smaller effect than for typical AD (PCA: odds ratio [OR] = 2.03, typical AD: OR = 2.83, P = .0007). We found evidence for risk in/near CR1 (P = 7 × 10(-4)), ABCA7 (P = .02) and BIN1 (P = .04). ORs at variants near INPP5D and NME8 did not overlap between PCA and typical AD. Exploratory genome-wide association studies confirmed APOE and identified three novel loci: rs76854344 near CNTNAP5 (P = 8 × 10(-10) OR = 1.9 [1.5-2.3]); rs72907046 near FAM46A (P = 1 × 10(-9) OR = 3.2 [2.1-4.9]); and rs2525776 near SEMA3C (P = 1 × 10(-8), OR = 3.3 [2.1-5.1]). We provide evidence for genetic risk factors specifically related to PCA. We identify three candidate loci that, if replicated, may provide insights into selective vulnerability and phenotypic diversity in AD. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Lessons from a Rare Familial Dementia: Amyloid and Beyond

PubMed Central

Cantlon, Adam; Frigerio, Carlo Sala; Walsh, Dominic M.

2015-01-01

Here we review the similarities between a rare inherited disorder, familial British dementia (FBD), and the most common of all late-life neurological conditions, Alzheimer's diseases (AD). We describe the symptoms, pathology and genetics of FBD, the biology of the BRI2 protein and mouse models of FBD and familial Danish dementia. In particular, we focus on the evolving recognition of the importance of protein oligomers and aberrant processing of the amyloid β-protein precursor (APP) - themes that are common to both FBD and AD. The initial discovery that FBD is phenotypically similar to AD, but associated with the deposition of an amyloid peptide (ABri) distinct from the amyloid β-protein (Aβ) led many to assume that amyloid production alone is sufficient to initiate disease and that ABri is the molecular equivalent of Aβ. Parallel with work on Aβ, studies of ABri producing animal models and in vitro ABri toxicity experiments caused a revision of the amyloid hypothesis and a focus on soluble oligomers of Aβ and ABri. Contemporaneous other studies suggested that loss of the ABri precursor protein (BRI2) may underlie the cognitive deficits in FBD. In this regard it is important to note that BRI2 has been shown to interact with and regulate the processing of APP, and that mutant BRI2 leads to altered cleavage of APP. A synthesis of these results suggests that a “two-hit mechanism” better explains FBD than earlier toxic gain of function and toxic loss of function models. The lessons learned from the study of FBD imply that the molecular pathology of AD is also likely to involve both aberrant aggregation (in AD, Aβ) and altered APP processing. With regard to FBD, we propose that the C-terminal 11 amino acid of FBD-BRI2 interfere with both the normal function of BRI2 and promotes the production of cystine cross-linked toxic ABri oligomers. In this scenario, loss of BRI2 function leads to altered APP processing in as yet underappreciated ways. Given the similarities between FBD and AD it seems likely that study of the structure of ABri oligomers and FBD-induced changes in APP metabolites will further our understanding of AD. PMID:26405694

Nutritional and Genetic Determinants of Early Puberty

DTIC Science & Technology

2007-06-01

AD_________________ Award Number: W81XWH-04-1-0575 TITLE: Nutritional and Genetic Determinants...CONTRACT NUMBER Nutritional and Genetic Determinants of Early Puberty 5b. GRANT NUMBER W81XWH-04-1-0575 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR...later in life. Nutritional factors during childhood and puberty, and inherited genetic factors are suspected to interact in modulating these early

Genetic association between ghrelin polymorphisms and Alzheimer's disease in a Japanese population.

PubMed

Shibata, Nobuto; Ohnuma, Tohru; Kuerban, Bolati; Komatsu, Miwa; Arai, Heii

2011-01-01

Ghrelin has been reported to enter the hippocampus and to bind to the neurons of the hippocampal formation. This peptide also affects neuronal glucose uptake and decreases tau hyperphosphorylation. There is increasing evidence suggesting an association between ghrelin and Alzheimer's disease (AD) pathology. The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) of the ghrelin gene are associated with AD. The SNPs were genotyped using TaqMan technology and were analyzed using a case-control study design. Our case-control dataset consisted of 182 AD patients and 143 age-matched controls. Hardy-Weinberg equilibrium and linkage disequilibrium analyses suggest that the region in and around the gene is highly polymorphic. One SNP, rs4684677 (Leu90Gln), showed a marginal association with age of AD onset. We did not detect any association between the other SNPs of the ghrelin gene and AD. There have been few genetic studies on the relationship between circulating ghrelin and functional SNPs. Further multifactorial studies are needed to clarify the relationship between ghrelin and AD. Copyright © 2011 S. Karger AG, Basel.

Etiopathologic findings of canine hypothyroidism.

PubMed

Graham, Peter A; Refsal, Kent R; Nachreiner, Raymond F

2007-07-01

The causes of canine hypothyroidism are varied, but most cases result from irreversible acquired thyroid pathologic changes and only a small proportion arise from congenital anomalies of the thyroid gland or pituitary. Of primary thyroid failure, at least half is the result of immune-mediated thyroiditis. Recent research has focused on the genetics and immunology of canine thyroid disease, adding to what is known from experimental and human studies. Epidemiologic and diagnostic laboratory studies continue to provide information on contributing factors and raise questions for future research directions. Serum antibodies against thyroid components are common in thyroid pathologic conditions and dysfunction, and understanding their properties and frequency is important in the interpretation of thyroid diagnostic test results.

Phormidium animalis (Cyanobacteria: Oscillatoriaceae) supports larval development of Anopheles albimanus.

PubMed

Vázquez-Martínez, M Guadalupe; Rodríguez, Mario H; Arredondo-Jiménez, Juan I; Méndez-Sánchez, José D

2003-06-01

The capability of Phormidium animalis, a cyanobacterium commonly found in larval habitats of Anopheles albimanus in southern Mexico, to support larval development of this mosquito was investigated. First-stage larvae were reared under insectary conditions with P. animalis ad libitum and their development was compared with larvae fed with wheat germ. The time of pupation and adult mosquito size, assessed by wing length, were similar in both groups, but fewer adult mosquitoes were obtained from larvae fed with the cyanobacteria. Nevertheless, these observations indicate that P. animalis is ingested and assimilated by larval An. albimanus, making this cyanobacterium a good candidate for genetic engineering for the introduction of mosquitocidal toxins for malaria control in the region.

Identification of a rare coding variant in TREM2 in a Chinese individual with Alzheimer's disease.

PubMed

Bonham, Luke W; Sirkis, Daniel W; Fan, Jia; Aparicio, Renan E; Tse, Marian; Ramos, Eliana Marisa; Wang, Qing; Coppola, Giovanni; Rosen, Howard J; Miller, Bruce L; Yokoyama, Jennifer S

2017-02-01

Rare variation in the TREM2 gene is associated with a broad spectrum of neurodegenerative disorders including Alzheimer's disease (AD). TREM2 encodes a receptor expressed in microglia which is thought to influence neurodegeneration by sensing damage signals and regulating neuroinflammation. Many of the variants reported to be associated with AD, including the rare R47H variant, were discovered in populations of European ancestry and have not replicated in diverse populations from other genetic backgrounds. We utilized a cohort of elderly Chinese individuals diagnosed as cognitively normal, or with mild cognitive impairment or AD to identify a rare variant, A192T, present in a single patient diagnosed with AD. We characterized this variant using biochemical cell surface expression assays and found that it significantly altered cell surface expression of the TREM2 protein. Together these data provide evidence that the A192T variant in TREM2 could contribute risk for AD. This study underscores the increasingly recognized role of immune-related processes in AD and highlights the importance of including diverse populations in research to identify genetic variation that contributes risk for AD and other neurodegenerative disorders.

Psychological heterogeneity in AD/HD--a dual pathway model of behaviour and cognition.

PubMed

Sonuga-Barke, Edmund J S

2002-03-10

Psychological accounts have characterised attention-deficit/hyperactivity disorder (AD/HD) as either a neuro-cognitive disorder of regulation or a motivational style. Poor inhibitory control is thought to underpin AD/HD children's dysregulation while delay aversion is a dominant characteristic of their motivational style. A recent 'head to head' study of these two accounts suggest that delay aversion and poor inhibitory control are independent co-existing characteristics of AD/HD (combined type). In the present paper we build on these findings to propose a dual pathway model of AD/HD that recognises two quite distinct sub-types of the disorder. In one AD/HD is the result of the dysregulation of action and thought resulting from poor inhibitory control associated with the meso-cortical branch of the dopamine system projecting in the cortical control centres (e.g. pre-frontal cortex). In the other AD/HD is a motivational style characterised by an altered delay of reward gradient linked to the meso-limbic dopamine branch associated with the reward circuits (e.g. nucleus accumbens). The two pathways are further distinguished at the levels of symptoms, cognitive and motivation profiles and genetic and non-genetic origins.

Two rare AKAP9 variants are associated with Alzheimer disease in African Americans

PubMed Central

Logue, Mark W.; Schu, Matthew; Vardarajan, Badri N.; Farrell, John; Bennett, David A.; Buxbaum, Joseph D.; Byrd, Goldie S.; Ertekin-Taner, Nilufer; Evans, Denis; Foroud, Tatiana; Goate, Alison; Graff-Radford, Neill R.; Kamboh, M. Ilyas; Kukull, Walter A.; Manly, Jennifer J.; Haines, Jonathan L.; Mayeux, Richard; Pericak-Vance, Margaret A.; Schellenberg, Gerard D.; Lunetta, Kathryn L.; Baldwin, Clinton T.; Fallin, M. Daniele; Farrer, Lindsay A.

2014-01-01

Background Less is known about the genetic basis of Alzheimer disease (AD) in African Americans (AAs) than in non-Hispanic whites. Methods Whole exome sequencing (WES) was performed on seven AA AD cases. Disease association with potentially AD-related variants from WES was assessed in an AA discovery cohort of 422 cases and 394 controls. Replication was sought in an AA sample of 1,037 cases and 1,869 controls from the Alzheimer Disease Genetics Consortium (ADGC). Results Forty-four SNPs from WES passed filtering criteria and were successfully genotyped, Nominally significant (p<0.05) association to AD was observed with two African-descent specific AKAP9 SNPs in tight linkage disequilibrium: rs144662445 (p=0.014) and rs149979685 (p=0.037). These associations were replicated in the ADGC sample (rs144662445: p=0.0022, odds ratio [OR]=2.75; rs149979685: p=0.0022, OR=3.61). Conclusions Because AKAP9 was not previously linked to AD risk, this study indicates a potential new disease mechanism. PMID:25172201

Transethnic genome-wide scan identifies novel Alzheimer's disease loci.

PubMed

Jun, Gyungah R; Chung, Jaeyoon; Mez, Jesse; Barber, Robert; Beecham, Gary W; Bennett, David A; Buxbaum, Joseph D; Byrd, Goldie S; Carrasquillo, Minerva M; Crane, Paul K; Cruchaga, Carlos; De Jager, Philip; Ertekin-Taner, Nilufer; Evans, Denis; Fallin, M Danielle; Foroud, Tatiana M; Friedland, Robert P; Goate, Alison M; Graff-Radford, Neill R; Hendrie, Hugh; Hall, Kathleen S; Hamilton-Nelson, Kara L; Inzelberg, Rivka; Kamboh, M Ilyas; Kauwe, John S K; Kukull, Walter A; Kunkle, Brian W; Kuwano, Ryozo; Larson, Eric B; Logue, Mark W; Manly, Jennifer J; Martin, Eden R; Montine, Thomas J; Mukherjee, Shubhabrata; Naj, Adam; Reiman, Eric M; Reitz, Christiane; Sherva, Richard; St George-Hyslop, Peter H; Thornton, Timothy; Younkin, Steven G; Vardarajan, Badri N; Wang, Li-San; Wendlund, Jens R; Winslow, Ashley R; Haines, Jonathan; Mayeux, Richard; Pericak-Vance, Margaret A; Schellenberg, Gerard; Lunetta, Kathryn L; Farrer, Lindsay A

2017-07-01

Genetic loci for Alzheimer's disease (AD) have been identified in whites of European ancestry, but the genetic architecture of AD among other populations is less understood. We conducted a transethnic genome-wide association study (GWAS) for late-onset AD in Stage 1 sample including whites of European Ancestry, African-Americans, Japanese, and Israeli-Arabs assembled by the Alzheimer's Disease Genetics Consortium. Suggestive results from Stage 1 from novel loci were followed up using summarized results in the International Genomics Alzheimer's Project GWAS dataset. Genome-wide significant (GWS) associations in single-nucleotide polymorphism (SNP)-based tests (P < 5 × 10 -8 ) were identified for SNPs in PFDN1/HBEGF, USP6NL/ECHDC3, and BZRAP1-AS1 and for the interaction of the (apolipoprotein E) APOE ε4 allele with NFIC SNP. We also obtained GWS evidence (P < 2.7 × 10 -6 ) for gene-based association in the total sample with a novel locus, TPBG (P = 1.8 × 10 -6 ). Our findings highlight the value of transethnic studies for identifying novel AD susceptibility loci. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Genetic Techniques for Manipulation of the Phytosterol Biotransformation Strain Mycobacterium neoaurum NRRL B-3805.

PubMed

Loraine, Jessica K; Smith, Margaret C M

2017-01-01

Mycobacterium neoaurum is a saprophytic, soil-dwelling bacterium. The strain NRRL B-3805 converts phytosterols to androst-4-ene-3,17-dione (androstenedione; AD), a precursor of multiple C19 steroids of importance to industry. NRRL B-3805 itself is able to convert AD to other steroid products, including testosterone (Ts) and androst-1,4-diene-3,17-dione (androstadienedione; ADD). However to improve this strain for industrial use, genetic modification is a priority. In this chapter, we describe a range of genetic techniques that can be used for M. neoaurum NRRL B-3805. Methods for transformation, expression, and gene knockouts are presented as well as plasmid maintenance and stability.

The major types of added sugars and non-nutritive sweeteners in a sample of Australian packaged foods.

PubMed

Probst, Yasmine C; Dengate, Alexis; Jacobs, Jenny; Louie, Jimmy Cy; Dunford, Elizabeth K

2017-12-01

Limiting the intake of added sugars in the diet remains a key focus of global dietary recommendations. To date there has been no systematic monitoring of the major types of added sugars used in the Australian food supply. The present study aimed to identify the most common added sugars and non-nutritive sweeteners in the Australian packaged food supply. Secondary analysis of data from the Australian FoodSwitch database was undertaken. Forty-six added sugars and eight non-nutritive sweetener types were extracted from the ingredient lists of 5744 foods across seventeen food categories. Australia. Not applicable. Added sugar ingredients were found in 61 % of the sample of foods examined and non-nutritive sweetener ingredients were found in 69 %. Only 31 % of foods contained no added sugar or non-nutritive sweetener. Sugar (as an ingredient), glucose syrup, maple syrup, maltodextrin and glucose/dextrose were the most common sugar ingredient types identified. Most Australian packaged food products had at least one added sugar ingredient, the most common being 'sugar'. The study provides insight into the most common types of added sugars and non-nutritive sweeteners used in the Australian food supply and is a useful baseline to monitor changes in how added sugars are used in Australian packaged foods over time.

Association of GSK3B With Alzheimer Disease and Frontotemporal Dementia

PubMed Central

Schaffer, Barbara A. J.; Bertram, Lars; Miller, Bruce L.; Mullin, Kristina; Weintraub, Sandra; Johnson, Nancy; Bigio, Eileen H.; Mesulam, Marsel; Wiedau-Pazos, Martina; Jackson, George R.; Cummings, Jeffrey L.; Cantor, Rita M.; Levey, Allan I.; Tanzi, Rudolph E.; Geschwind, Daniel H.

2009-01-01

Background Deposits of abnormally hyperphosphorylated tau are a hallmark of several dementias, including Alzheimer disease (AD), and about 10% of familial frontotemporal dementia (FTD) cases are caused by mutations in the tau gene. As a known tau kinase, GSK3B is a promising candidate gene in the remaining cases of FTD and in AD, for which tau mutations have not been found. Objective To examine the promoter of GSK3B and all 12 exons, including the surrounding intronic sequence, in patients with FTD, patients with AD, and aged healthy subjects to identify single-nucleotide polymorphisms associated with disease. Design, Setting, and Participants Single-nucleotide polymorphism frequency was examined in a case-control cohort of 48 patients with probable AD, 102 patients with FTD, 38 patients with primary progressive aphasia, and 85 aged healthy subjects. Results were followed up in 2 independent AD family samples consisting of 437 multiplex families with AD (National Institute of Mental Health Genetics Initiative AD Study) or 150 sibships discordant for AD (Consortium on Alzheimer’s Genetics Study). Results Several rare sequence variants in GSK3B were identified in the case-control study. An intronic polymorphism (IVS2−68G>A) occurred at more than twice the frequency among patients with FTD (10.8%) and patients with AD (14.6%) than in aged healthy subjects (4.1%). The polymorphism showed association with disease in both follow-up samples independently, although only the Consortium on Alzheimer’s Genetics sample showed the same direction of association as the case-control sample. Conclusions To our knowledge, this is the first evidence that a gene known to be involved in tau phosphorylation, GSK3B, is associated with risk for primary neurodegenerative dementias. This supports previous work in animal models suggesting that such genes are therapeutic targets. PMID:18852354

Overrepresentation of glutamate signaling in Alzheimer's disease: network-based pathway enrichment using meta-analysis of genome-wide association studies.

PubMed

Pérez-Palma, Eduardo; Bustos, Bernabé I; Villamán, Camilo F; Alarcón, Marcelo A; Avila, Miguel E; Ugarte, Giorgia D; Reyes, Ariel E; Opazo, Carlos; De Ferrari, Giancarlo V

2014-01-01

Genome-wide association studies (GWAS) have successfully identified several risk loci for Alzheimer's disease (AD). Nonetheless, these loci do not explain the entire susceptibility of the disease, suggesting that other genetic contributions remain to be identified. Here, we performed a meta-analysis combining data of 4,569 individuals (2,540 cases and 2,029 healthy controls) derived from three publicly available GWAS in AD and replicated a broad genomic region (>248,000 bp) associated with the disease near the APOE/TOMM40 locus in chromosome 19. To detect minor effect size contributions that could help to explain the remaining genetic risk, we conducted network-based pathway analyses either by extracting gene-wise p-values (GW), defined as the single strongest association signal within a gene, or calculated a more stringent gene-based association p-value using the extended Simes (GATES) procedure. Comparison of these strategies revealed that ontological sub-networks (SNs) involved in glutamate signaling were significantly overrepresented in AD (p<2.7×10(-11), p<1.9×10(-11); GW and GATES, respectively). Notably, glutamate signaling SNs were also found to be significantly overrepresented (p<5.1×10(-8)) in the Alzheimer's disease Neuroimaging Initiative (ADNI) study, which was used as a targeted replication sample. Interestingly, components of the glutamate signaling SNs are coordinately expressed in disease-related tissues, which are tightly related to known pathological hallmarks of AD. Our findings suggest that genetic variation within glutamate signaling contributes to the remaining genetic risk of AD and support the notion that functional biological networks should be targeted in future therapies aimed to prevent or treat this devastating neurological disorder.

Systemic inflammation as a predictor of brain aging: Contributions of physical activity, metabolic risk, and genetic risk.

PubMed

Corlier, Fabian; Hafzalla, George; Faskowitz, Joshua; Kuller, Lewis H; Becker, James T; Lopez, Oscar L; Thompson, Paul M; Braskie, Meredith N

2018-05-15

Inflammatory processes may contribute to risk for Alzheimer's disease (AD) and age-related brain degeneration. Metabolic and genetic risk factors, and physical activity may, in turn, influence these inflammatory processes. Some of these risk factors are modifiable, and interact with each other. Understanding how these processes together relate to brain aging will help to inform future interventions to treat or prevent cognitive decline. We used brain magnetic resonance imaging (MRI) to scan 335 older adult humans (mean age 77.3 ± 3.4 years) who remained non-demented for the duration of the 9-year longitudinal study. We used structural equation modeling (SEM) in a subset of 226 adults to evaluate whether measures of baseline peripheral inflammation (serum C-reactive protein levels; CRP), mediated the baseline contributions of genetic and metabolic risk, and physical activity, to regional cortical thickness in AD-relevant brain regions at study year 9. We found that both baseline metabolic risk and AD risk variant apolipoprotein E ε4 (APOE4), modulated baseline serum CRP. Higher baseline CRP levels, in turn, predicted thinner regional cortex at year 9, and mediated an effect between higher metabolic risk and thinner cortex in those regions. A higher polygenic risk score composed of variants in immune-associated AD risk genes (other than APOE) was associated with thinner regional cortex. However, CRP levels did not mediate this effect, suggesting that other mechanisms may be responsible for the elevated AD risk. We found interactions between genetic and environmental factors and structural brain health. Our findings support the role of metabolic risk and peripheral inflammation in age-related brain decline. Copyright © 2018 Elsevier Inc. All rights reserved.

Overrepresentation of Glutamate Signaling in Alzheimer's Disease: Network-Based Pathway Enrichment Using Meta-Analysis of Genome-Wide Association Studies

PubMed Central

Villamán, Camilo F.; Alarcón, Marcelo A.; Avila, Miguel E.; Ugarte, Giorgia D.; Reyes, Ariel E.; Opazo, Carlos; De Ferrari, Giancarlo V.

2014-01-01

Genome-wide association studies (GWAS) have successfully identified several risk loci for Alzheimer's disease (AD). Nonetheless, these loci do not explain the entire susceptibility of the disease, suggesting that other genetic contributions remain to be identified. Here, we performed a meta-analysis combining data of 4,569 individuals (2,540 cases and 2,029 healthy controls) derived from three publicly available GWAS in AD and replicated a broad genomic region (>248,000 bp) associated with the disease near the APOE/TOMM40 locus in chromosome 19. To detect minor effect size contributions that could help to explain the remaining genetic risk, we conducted network-based pathway analyses either by extracting gene-wise p-values (GW), defined as the single strongest association signal within a gene, or calculated a more stringent gene-based association p-value using the extended Simes (GATES) procedure. Comparison of these strategies revealed that ontological sub-networks (SNs) involved in glutamate signaling were significantly overrepresented in AD (p<2.7×10−11, p<1.9×10−11; GW and GATES, respectively). Notably, glutamate signaling SNs were also found to be significantly overrepresented (p<5.1×10−8) in the Alzheimer's disease Neuroimaging Initiative (ADNI) study, which was used as a targeted replication sample. Interestingly, components of the glutamate signaling SNs are coordinately expressed in disease-related tissues, which are tightly related to known pathological hallmarks of AD. Our findings suggest that genetic variation within glutamate signaling contributes to the remaining genetic risk of AD and support the notion that functional biological networks should be targeted in future therapies aimed to prevent or treat this devastating neurological disorder. PMID:24755620

Clinical worthlessness of genetic prediction of common forms of diabetes mellitus and related chronic complications: A position statement of the Italian Society of Diabetology.

PubMed

Buzzetti, R; Prudente, S; Copetti, M; Dauriz, M; Zampetti, S; Garofolo, M; Penno, G; Trischitta, V

2017-02-01

We are currently facing several attempts aimed at marketing genetic data for predicting multifactorial diseases, among which diabetes mellitus is one of the more prevalent. The present document primarily aims at providing to practicing physicians a summary of available data regarding the role of genetic information in predicting diabetes and its chronic complications. Firstly, general information about characteristics and performance of risk prediction tools will be presented in order to help clinicians to get acquainted with basic methodological information related to the subject at issue. Then, as far as type 1 diabetes is concerned, available data indicate that genetic information and counseling may be useful only in families with many affected individuals. However, since no disease prevention is possible, the utility of predicting this form of diabetes is at question. In the case of type 2 diabetes, available data really question the utility of adding genetic information on top of well performing, easy available and inexpensive non-genetic markers. Finally, the possibility of using the few available genetic data on diabetic complications for improving our ability to predict them will also be presented and discussed. For cardiovascular complication, the addition of genetic information to models based on clinical features does not translate in a substantial improvement in risk discrimination. For all other diabetic complications genetic information are currently very poor and cannot, therefore, be used for improving risk stratification. In all, nowadays the use of genetic testing for predicting diabetes and its chronic complications is definitively of little value in clinical practice. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

Monoaminergic Neuropathology in Alzheimer's disease

PubMed Central

Šimić, Goran; Leko, Mirjana Babić; Wray, Selina; Harrington, Charles; Delalle, Ivana; Jovanov-Milošević, Nataša; Bažadona, Danira; Buée, Luc; de Silva, Rohan; Di Giovanni, Giuseppe; Wischik, Claude; Hof, Patrick R.

2016-01-01

None of the proposed mechanisms of Alzheimer’s disease (AD) fully explains the distribution patterns of the neuropathological changes at the cellular and regional levels, and their clinical correlates. One aspect of this problem lies in the complex genetic, epigenetic, and environmental landscape of AD: early-onset AD is often familial with autosomal dominant inheritance, while the vast majority of AD cases are late-onset, with the ε4 variant of the gene encoding apolipoprotein E (APOE) known to confer a 5–20 fold increased risk with partial penetrance. Mechanisms by which genetic variants and environmental factors influence the development of AD pathological changes, especially neurofibrillary degeneration, are not yet known. Here we review current knowledge of the involvement of the monoaminergic systems in AD. The changes in the serotonergic, noradrenergic, dopaminergic, histaminergic, and melatonergic systems in AD are briefly described. We also summarize the possibilities for monoamine-based treatment in AD. Besides neuropathologic AD criteria that include the noradrenergic locus coeruleus (LC), special emphasis is given to the serotonergic dorsal raphe nucleus (DRN). Both of these brainstem nuclei are among the first to be affected by tau protein abnormalities in the course of sporadic AD, causing behavioral and cognitive symptoms of variable severity. The possibility that most of the tangle-bearing neurons of the LC and DRN may release amyloid β as well as soluble monomeric or oligomeric tau protein trans-synaptically by their diffuse projections to the cerebral cortex emphasizes their selective vulnerability and warrants further investigations of the monoaminergic systems in AD. PMID:27084356

White matter hyperintensities are a core feature of Alzheimer's disease: Evidence from the dominantly inherited Alzheimer network.

PubMed

Lee, Seonjoo; Viqar, Fawad; Zimmerman, Molly E; Narkhede, Atul; Tosto, Giuseppe; Benzinger, Tammie L S; Marcus, Daniel S; Fagan, Anne M; Goate, Alison; Fox, Nick C; Cairns, Nigel J; Holtzman, David M; Buckles, Virginia; Ghetti, Bernardino; McDade, Eric; Martins, Ralph N; Saykin, Andrew J; Masters, Colin L; Ringman, John M; Ryan, Natalie S; Förster, Stefan; Laske, Christoph; Schofield, Peter R; Sperling, Reisa A; Salloway, Stephen; Correia, Stephen; Jack, Clifford; Weiner, Michael; Bateman, Randall J; Morris, John C; Mayeux, Richard; Brickman, Adam M

2016-06-01

White matter hyperintensities (WMHs) are areas of increased signal on T2-weighted magnetic resonance imaging (MRI) scans that most commonly reflect small vessel cerebrovascular disease. Increased WMH volume is associated with risk and progression of Alzheimer's disease (AD). These observations are typically interpreted as evidence that vascular abnormalities play an additive, independent role contributing to symptom presentation, but not core features of AD. We examined the severity and distribution of WMH in presymptomatic PSEN1, PSEN2, and APP mutation carriers to determine the extent to which WMH manifest in individuals genetically determined to develop AD. The study comprised participants (n = 299; age = 39.03 ± 10.13) from the Dominantly Inherited Alzheimer Network, including 184 (61.5%) with a mutation that results in AD and 115 (38.5%) first-degree relatives who were noncarrier controls. We calculated the estimated years from expected symptom onset (EYO) by subtracting the affected parent's symptom onset age from the participant's age. Baseline MRI data were analyzed for total and regional WMH. Mixed-effects piece-wise linear regression was used to examine WMH differences between carriers and noncarriers with respect to EYO. Mutation carriers had greater total WMH volumes, which appeared to increase approximately 6 years before expected symptom onset. Effects were most prominent for the parietal and occipital lobe, which showed divergent effects as early as 22 years before estimated onset. Autosomal-dominant AD is associated with increased WMH well before expected symptom onset. The findings suggest the possibility that WMHs are a core feature of AD, a potential therapeutic target, and a factor that should be integrated into pathogenic models of the disease. Ann Neurol 2016;79:929-939. © 2016 American Neurological Association.

Dystrophic neurites express C9orf72 in Alzheimer's disease brains

PubMed Central

2012-01-01

Introduction Chromosome 9 open reading frame 72 (C9orf72) is an evolutionarily conserved protein with unknown function, expressed at high levels in the brain. An expanded hexanucleotide GGGGCC repeat located in the first intron of the C9orf72 gene represents the most common genetic cause of familial frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Previous studies by immunohistochemistry with two different anti-C9orf72 antibodies named sc-138763 and HPA023873 showed that C9orf72 is expressed chiefly in the cytoplasm of neurons, and is concentrated in the synaptic terminals in the brains of FTD/ALS with or without C9orf72 repeat expansion as well as those of controls. At present, a pathological role of C9orf72 in the process of neurodegeneration remains unknown. Methods Using immunohistochemistry we studied C9orf72 expression in the frontal cortex and the hippocampus of six Alzheimer's disease (AD) and 13 control cases, including ALS, Parkinson's disease, multiple system atrophy, and non-neurological cases. Results The HPA023873 antibody showed a cross-reactivity to glial fibrillary acidic protein, and therefore stained intensely reactive astrocytes in AD and non-AD brains. Both sc-138763 and HPA023873 antibodies labeled the neuronal cytoplasm and the neuropil with variable intensities, and intensely stained a cluster of p62-negative, UBQLN1-positive swollen neurites, which were distributed in the CA1 region and the molecular layer in the hippocampus of both AD and non-AD brains. Most notably, both of these antibodies reacted strongly with dystrophic neurites accumulated on senile plaques in AD brains. Conclusion These results suggest a general role of C9orf72 in the process of neurodegeneration in a range of human neurodegenerative diseases. PMID:22898310

Gait dyspraxia as a clinical marker of cognitive decline in Down syndrome: A review of theory and proposed mechanisms.

PubMed

Anderson-Mooney, Amelia J; Schmitt, Frederick A; Head, Elizabeth; Lott, Ira T; Heilman, Kenneth M

2016-04-01

Down syndrome (DS) is the most common genetic cause of intellectual disability in children. With aging, DS is associated with an increased risk for Alzheimer's disease (AD). The development of AD neuropathology in individuals with DS can result in further disturbances in cognition and behavior and may significantly exacerbate caregiver burden. Early detection may allow for appropriate preparation by caregivers. Recent literature suggests that declines in gait may serve as an early marker of AD-related cognitive disorders; however, this relationship has not been examined in individuals with DS. The theory regarding gait dyspraxia and cognitive decline in the general population is reviewed, and potential applications to the population with individuals with DS are highlighted. Challenges and benefits in the line of inquiry are discussed. In particular, it appears that gait declines in aging individuals with DS may be associated with known declines in frontoparietal gray matter, development of AD-related pathology, and white matter losses in tracts critical to motor control. These changes are also potentially related to the cognitive and functional changes often observed during the same chronological period as gait declines in adults with DS. Gait declines may be an early marker of cognitive change, related to the development of underlying AD-related pathology, in individuals with DS. Future investigations in this area may provide insight into the clinical changes associated with development of AD pathology in both the population with DS and the general population, enhancing efforts for optimal patient and caregiver support and propelling investigations regarding safety/quality of life interventions and disease-modifying interventions. Copyright © 2016 Elsevier Inc. All rights reserved.

Neuronal pentraxin 1: A synaptic-derived plasma biomarker in Alzheimer's disease.

PubMed

Ma, Qiu-Lan; Teng, Edmond; Zuo, Xiaohong; Jones, Mychica; Teter, Bruce; Zhao, Evan Y; Zhu, Cansheng; Bilousova, Tina; Gylys, Karen H; Apostolova, Liana G; LaDu, Mary Jo; Hossain, Mir Ahamed; Frautschy, Sally A; Cole, Gregory M

2018-06-01

Synaptic neurodegeneration is thought to be an early event initiated by soluble β-amyloid (Aβ) aggregates that closely correlates with cognitive decline in Alzheimer disease (AD). Apolipoprotein ε4 (APOE4) is the most common genetic risk factor for both familial AD (FAD) and sporadic AD; it accelerates Aβ aggregation and selectively impairs glutamate receptor function and synaptic plasticity. However, its molecular mechanisms remain elusive and these synaptic deficits are difficult to monitor. AD- and APOE4-dependent plasma biomarkers have been proposed, but synapse-related plasma biomarkers are lacking. We evaluated neuronal pentraxin 1 (NP1), a potential CNS-derived plasma biomarker of excitatory synaptic pathology. NP1 is preferentially expressed in brain and involved in glutamate receptor internalization. NP1 is secreted presynaptically induced by Aβ oligomers, and implicated in excitatory synaptic and mitochondrial deficits. Levels of NP1 and its fragments were increased in a correlated fashion in both brain and plasma of 7-8 month-old E4FAD mice relative to E3FAD mice. NP1 was also found in exosome preparations and reduced by dietary DHA supplementation. Plasma NP1 was higher in E4FAD+ (APOE4 +/+ /FAD +/- ) relative to E4FAD- (non-carrier; APOE4 +/+ /FAD -/- ) mice, suggesting NP1 is modulated by Aβ expression. Finally, relative to normal elderly, plasma NP1 was also elevated in patients with mild cognitive impairment (MCI) and elevated further in the subset who progressed to early-stage AD. In those patients, there was a trend towards increased NP1 levels in APOE4 carriers relative to non-carriers. These findings indicate that NP1 may represent a potential synapse-derived plasma biomarker relevant to early alterations in excitatory synapses in MCI and early-stage AD. Copyright © 2018. Published by Elsevier Inc.

Sex-dependent Association of a Common Low Density Lipoprotein Receptor Polymorphism with RNA Splicing Efficiency in the Brain and Alzheimers Disease

PubMed Central

Zou, Fanggeng; Gopalraj, Rangaraj K.; Lok, Johann; Zhu, Haiyan; Ling, I-Fang; Simpson, James F.; Tucker, H. Michael; Kelly, Jeremiah F.; Younkin, Samuel G.; Dickson, Dennis W.; Petersen, Ronald C; Graff-Radford, Neill R.; Bennett, David A.; Crook, Julia E.; G.Younkin, Steven; Estus, Steven

2008-01-01

Since apoE allele status is the predominant Alzheimers disease (AD) genetic risk factor, functional single nucleotide polymorphisms (SNP)s in brain apoE receptors represent excellent candidates for association with AD. Recently, we identified a SNP, rs688, as modulating the splicing efficiency of low-density lipoprotein receptor (LDLR) exon 12 in the female human liver and in minigene transfected HepG2 cells. Moreover, the rs688T minor allele associated with significantly higher LDL and total cholesterol in women in the Framingham Offspring Study. Since LDLR is a major apoE receptor in the brain, we hypothesized that rs688 modulates LDLR splicing in neural tissues and associates with AD. To evaluate this hypothesis, we first transfected LDLR minigenes into SH-SY5Y neuroblastoma cells and found that rs688T reduces exon 12 inclusion in this neural model. We then evaluated rs688 association with exon 12 splicing efficiency in vivo by quantifying LDLR splicing in human anterior cingulate tissue obtained at autopsy; the rs688T allele associated with decreased LDLR exon 12 splicing efficiency in aged men but not women. Lastly, we evaluated whether rs688 associates with AD by genotyping DNA from 1,457 men and 2,055 women drawn from three case-control series. The rs688T/T genotype was associated with increased AD odds in males (recessive model, odds ratio (OR) of 1.49, 95% confidence interval (CI) of 1.13−1.97, uncorrected p=0.005), but not in females. In summary, these studies identify a functional apoE receptor SNP that is associated with AD in a sex-dependent fashion. PMID:18065781

Detection of novel mutations that cause autosomal dominant retinitis pigmentosa in candidate genes by long-range PCR amplification and next-generation sequencing

PubMed Central

Dias, Miguel de Sousa; Hernan, Imma; Pascual, Beatriz; Borràs, Emma; Mañé, Begoña; Gamundi, Maria José

2013-01-01

Purpose To devise an effective method for detecting mutations in 12 genes (CA4, CRX, IMPDH1, NR2E3, RP9, PRPF3, PRPF8, PRPF31, PRPH2, RHO, RP1, and TOPORS) commonly associated with autosomal dominant retinitis pigmentosa (adRP) that account for more than 95% of known mutations. Methods We used long-range PCR (LR-PCR) amplification and next-generation sequencing (NGS) performed in a GS Junior 454 benchtop sequencing platform. Twenty LR-PCR fragments, between 3,000 and 10,000 bp, containing all coding exons and flanking regions of the 12 genes, were obtained from DNA samples of patients with adRP. Sequencing libraries were prepared with an enzymatic (Fragmentase technology) method. Results Complete coverage of the coding and flanking sequences of the 12 genes assayed was obtained with NGS, with an average sequence depth of 380× (ranging from 128× to 1,077×). Five previous known mutations in the adRP genes were detected with a sequence variation percentage between 35% and 65%. We also performed a parallel sequence analysis of four samples, three of them new patients with index adRP, in which two novel mutations were detected in RHO (p.Asn73del) and PRPF31 (p.Ile109del). Conclusions The results demonstrate that genomic LR-PCR amplification together with NGS is an effective method for analyzing individual patient samples for mutations in a monogenic heterogeneous disease such as adRP. This approach proved effective for the parallel analysis of adRP and has been introduced as routine. Additionally, this approach could be extended to other heterogeneous genetic diseases. PMID:23559859

Targeted Deep Sequencing Identifies Rare ‘loss-of-function’ Variants in IFNGR1 for Risk of Atopic Dermatitis Complicated by Eczema Herpeticum

PubMed Central

Gao, Li; Rafaels, Nicholas M; Huang, Lili; Potee, Joseph; Ruczinski, Ingo; Beaty, Terri H.; Paller, Amy S.; Schneider, Lynda C.; Gallo, Rich; Hanifin, Jon M.; Beck, Lisa A.; Geha, Raif S.; Mathias, Rasika A.; Leung, Donald Y. M.

2015-01-01

Background A subset of atopic dermatitis (AD) is associated with increased susceptibility to eczema herpeticum (ADEH+). We previously reported that common single nucleotide polymorphisms (SNPs) in interferon-gamma (IFNG) and receptor 1 (IFNGR1) were associated with ADEH+ phenotype. Objective To interrogate the role of rare variants in IFN-pathway genes for risk of ADEH+. Methods We performed targeted sequencing of interferon-pathway genes (IFNG, IFNGR1, IFNAR1 and IL12RB1) in 228 European American (EA) AD patients selected according to their EH status and severity measured by Eczema Area and Severity Index (EASI). Replication genotyping was performed in independent samples of 219 EA and 333 African Americans (AA). Functional investigation of ‘loss-of-function’ variants was conducted using site-directed mutagenesis. Results We identified 494 single nucleotide variants (SNVs) encompassing 105kb of sequence, including 145 common, 349 (70.6%) rare (minor allele frequency (MAF) <5%) and 86 (17.4%) novel variants, of which 2.8% were coding-synonymous, 93.3% were non-coding (64.6% intronic), and 3.8% were missense. We identified six rare IFNGR1 missense including three damaging variants (Val14Met (V14M), Val61Ile and Tyr397Cys (Y397C)) conferring a higher risk for ADEH+ (P=0.031). Variants V14M and Y397C were confirmed to be deleterious leading to partial IFNGR1 deficiency. Seven common IFNGR1 SNPs, along with common protective haplotypes (2 to 7-SNPs) conferred a reduced risk of ADEH+ (P=0.015-0.002, P=0.0015-0.0004, respectively), and both SNP and haplotype associations were replicated in an independent AA sample (P=0.004-0.0001 and P=0.001-0.0001, respectively). Conclusion Our results provide evidence that both genetic variants in the gene encoding IFNGR1 are implicated in susceptibility to the ADEH+ phenotype. CAPSULE SUMMARY We provided the first evidence that rare functional IFNGR1 mutations contribute to a defective systemic IFN-γ immune response that accounts for the propensity of AD patients to disseminated viral skin infections. PMID:26343451

A Becn1 mutation mediates hyperactive autophagic sequestration of amyloid oligomers and improved cognition in Alzheimer's disease

PubMed Central

Rocchi, Altea; Yamamoto, Soh; Fan, Yuying; Sadleir, Katherine; Wang, Yigang; Zhang, Weiran; Huang, Sui; Vassar, Robert

2017-01-01

Impairment of the autophagy pathway has been observed during the pathogenesis of Alzheimer’s disease (AD), a neurodegenerative disorder characterized by abnormal deposition of extracellular and intracellular amyloid β (Aβ) peptides. Yet the role of autophagy in Aβ production and AD progression is complex. To study whether increased basal autophagy plays a beneficial role in Aβ clearance and cognitive improvement, we developed a novel genetic model to hyperactivate autophagy in vivo. We found that knock-in of a point mutation F121A in the essential autophagy gene Beclin 1/Becn1 in mice significantly reduces the interaction of BECN1 with its inhibitor BCL2, and thus leads to constitutively active autophagy even under non-autophagy-inducing conditions in multiple tissues, including brain. Becn1F121A-mediated autophagy hyperactivation significantly decreases amyloid accumulation, prevents cognitive decline, and restores survival in AD mouse models. Using an immunoisolation method, we found biochemically that Aβ oligomers are autophagic substrates and sequestered inside autophagosomes in the brain of autophagy-hyperactive AD mice. In addition to genetic activation of autophagy by Becn1 gain-of-function, we also found that ML246, a small-molecule autophagy inducer, as well as voluntary exercise, a physiological autophagy inducer, exert similar Becn1-dependent protective effects on Aβ removal and memory in AD mice. Taken together, these results demonstrate that genetically disrupting BECN1-BCL2 binding hyperactivates autophagy in vivo, which sequestrates amyloid oligomers and prevents AD progression. The study establishes new approaches to activate autophagy in the brain, and reveals the important function of Becn1-mediated autophagy hyperactivation in the prevention of AD. PMID:28806762

Genetically decreased vitamin D and risk of Alzheimer disease.

PubMed

Mokry, Lauren E; Ross, Stephanie; Morris, John A; Manousaki, Despoina; Forgetta, Vincenzo; Richards, J Brent

2016-12-13

To test whether genetically decreased vitamin D levels are associated with Alzheimer disease (AD) using mendelian randomization (MR), a method that minimizes bias due to confounding or reverse causation. We selected single nucleotide polymorphisms (SNPs) that are strongly associated with 25-hydroxyvitamin D (25OHD) levels (p < 5 × 10 -8 ) from the Study of Underlying Genetic Determinants of Vitamin D and Highly Related Traits (SUNLIGHT) Consortium (N = 33,996) to act as instrumental variables for the MR study. We measured the effect of each of these SNPs on 25OHD levels in the Canadian Multicentre Osteoporosis Study (CaMos; N = 2,347) and obtained the corresponding effect estimates for each SNP on AD risk from the International Genomics of Alzheimer's Project (N = 17,008 AD cases and 37,154 controls). To produce MR estimates, we weighted the effect of each SNP on AD by its effect on 25OHD and meta-analyzed these estimates using a fixed-effects model to provide a summary effect estimate. The SUNLIGHT Consortium identified 4 SNPs to be genome-wide significant for 25OHD, which described 2.44% of the variance in 25OHD in CaMos. All 4 SNPs map to genes within the vitamin D metabolic pathway. MR analyses demonstrated that a 1-SD decrease in natural log-transformed 25OHD increased AD risk by 25% (odds ratio 1.25, 95% confidence interval 1.03-1.51, p = 0.021). After sensitivity analysis in which we removed SNPs possibly influenced by pleiotropy and population stratification, the results were largely unchanged. Our results provide evidence supporting 25OHD as a causal risk factor for AD. These findings provide further rationale to understand the effect of vitamin D supplementation on cognition and AD risk in randomized controlled trials. © 2016 American Academy of Neurology.

Omega-3 Fatty Acid Docosahexaenoic Acid Increases SorLA/LR11, a Sorting Protein with Reduced Expression in Sporadic Alzheimer’s Disease (AD): Relevance to AD Prevention

PubMed Central

Ma, Qiu-Lan; Teter, Bruce; Ubeda, Oliver J.; Morihara, Takashi; Dhoot, Dilsher; Nyby, Michael D.; Tuck, Michael L.; Frautschy, Sally A.; Cole, Greg M.

2008-01-01

Environmental and genetic factors, notably ApoE4, contribute to the etiology of late-onset Alzheimer’s disease (LOAD). Reduced mRNA and protein for an apolipoprotein E (ApoE) receptor family member, SorLA (LR11) has been found in LOAD but not early-onset AD, suggesting that LR11 loss is not secondary to pathology. LR11 is a neuronal sorting protein that reduces amyloid precursor protein (APP) trafficking to secretases that generate β-amyloid (Aβ). Genetic polymorphisms that reduce LR11 expression are associated with increased AD risk. However these polymorphisms account for only a fraction of cases with LR11 deficits, suggesting involvement of environmental factors. Because lipoprotein receptors are typically lipid-regulated, we postulated that LR11 is regulated by docosahexaenoic acid (DHA), an essential ω-3 fatty acid related to reduced AD risk and reduced Aβ accumulation. In this study, we report that DHA significantly increases LR11 in multiple systems, including primary rat neurons, aged non-Tg mice and an aged DHA-depleted APPsw AD mouse model. DHA also increased LR11 in a human neuronal line. In vivo elevation of LR11 was also observed with dietary fish oil in young rats with insulin resistance, a model for type II diabetes, another AD risk factor. These data argue that DHA induction of LR11 does not require DHA-depleting diets and is not age dependent. Because reduced LR11 is known to increase Aβ production and may be a significant genetic cause of LOAD, our results indicate that DHA increases in SorLA/LR11 levels may play an important role in preventing LOAD. PMID:18160637

Fibrillar amyloid-β burden in cognitively normal people at 3 levels of genetic risk for Alzheimer's disease

PubMed Central

Reiman, Eric M.; Chen, Kewei; Liu, Xiaofen; Bandy, Daniel; Yu, Meixiang; Lee, Wendy; Ayutyanont, Napatkamon; Keppler, Jennifer; Reeder, Stephanie A.; Langbaum, Jessica B. S.; Alexander, Gene E.; Klunk, William E.; Mathis, Chester A.; Price, Julie C.; Aizenstein, Howard J.; DeKosky, Steven T.; Caselli, Richard J.

2009-01-01

Fibrillar amyloid-beta (Aβ) is found in the brains of many cognitively normal older people. Whether or not this reflects a predisposition to Alzheimer's disease (AD) is unknown. We used Pittsburgh Compound B (PiB) PET to characterize the relationship between fibrillar Aβ burden and this predisposition in cognitively normal older people at 3 mean levels of genetic risk for AD. Dynamic PiB PET scans, the Logan method, statistical parametric mapping, and automatically labeled regions of interest (ROIs) were used to characterize and compare cerebral-to-cerebellar PIB distribution volume ratios, reflecting fibrillar Aβ burden, in 28 cognitively normal persons (mean age, 64 years) with a reported family history of AD and 2 copies, 1 copy, and no copies of the apolipoprotein E (APOE) ε4 allele. The 8 ε4 homozygotes, 8 heterozygotes, and 12 noncarriers did not differ significantly in terms of age, sex, or cognitive scores. Fibrillar Aβ was significantly associated with APOE ε4 carrier status and ε4 gene dose in AD-affected mean cortical, frontal, temporal, posterior cingulate-precuneus, parietal, and basal ganglia ROIs, and was highest in an additional homozygote who had recently developed mild cognitive impairment. These findings suggest that fibrillar Aβ burden in cognitively normal older people is associated with APOE ε4 gene dose, the major genetic risk factor for AD. Additional studies are needed to track fibrillar Aβ accumulation in persons with different kinds and levels of AD risk; to determine the extent to which fibrillar Aβ, alone or in combination with other biomarkers and risk factors, predicts rates of cognitive decline and conversion to clinical AD; and to establish the role of fibrillar Aβ imaging in primary prevention trials. PMID:19346482

Adenovirus-based genetic vaccines for biodefense.

PubMed

Boyer, Julie L; Kobinger, Gary; Wilson, James M; Crystal, Ronald G

2005-02-01

The robust host responses elicited against transgenes encoded by (E1-)(E3-) adenovirus (Ad) gene transfer vectors can be used to develop Ad-based vectors as platform technologies for vaccines against potential bioterror pathogens. This review focuses on pathogens of major concern as bioterror agents and why Ad vectors are ideal as anti-bioterror vaccine platforms, providing examples from our laboratories of using Ad vectors as vaccines against potential bioterror pathogens and how Ad vectors can be developed to enhance vaccine efficacy in the bioterror war.

Allelic association but only weak evidence for linkage to the apolipoprotein E locus in late-onset Swedish Alzheimer families

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, L.; Forsell, C.; Lilius, L.

1996-05-31

An association between the {epsilon}4 allele of the apolipoprotein E gene (APOE) and late-onset Alzheimer`s disease (AD) was recently demonstrated. In order to confirm the association and to gauge the ability of standard genetic linkage methods to identify susceptibility genes, we investigated 15 Swedish late-onset AD families. We found an association of familial AD to the APOE {epsilon}4 allele (P = 0.01) but no indication of linkage to the APOE region using 2-point linkage analysis, and only weak evidence using the affected pedigree-member (APM) method. Our results confirm an APOE {epsilon}4 association with late-onset familial AD and indicate that susceptibilitymore » genes can easily be missed when using standard lod score and APM genetic linkage analysis. 19 refs., 1 fig., 4 tabs.« less

A short period of breastfeeding in infancy, excessive house cleaning, absence of older sibling, and passive smoking are related to more severe atopic dermatitis in children.

PubMed

Fotopoulou, Maria; Iordanidou, Maria; Vasileiou, Eleni; Trypsianis, Grigorios; Chatzimichael, Athanasios; Paraskakis, Emmanouil

2018-02-01

Atopic dermatitis (AD) is one of the most common, chronic or chronically relapsing inflammatory skin diseases that affect children. Multiple genetic and environmental factors appear to regulate the pathogenesis of AD. Our aim was to investigate the possible association between family, social, dieting, atopic and environmental factors and the severity of AD evaluated by SCORAD scores in children. The study group included 100 children with AD who attended a paediatric dermatology outpatient clinic with a median age of 18.5 months. The diagnosis of AD was established on the basis of the clinical criteria according to the American Dermatology Society, while the SCORAD score was used to evaluate disease severity. Multivariate linear regression analysis disclosed that excessive cleanliness (p<0.001), RAST level greater than 0.7 KU/l (p<0.001), breastfeeding for less than two months (p = 0.001), and the absence of an older sibling (p = 0.049) were statistically significant independent determinants for high SCORAD scores. Multivariate logistic regression analysis showed that excessive cleanliness (p<0.001) was the strongest independent risk factor for severe AD (SCORAD>36) (aOR: 59.4; 95% CI: 10.9-322.6). RAST level greater than 0.7 KU/l (aOR: 7.9; 95% CI: 1.5-41.0; p = 0.014) and severe passive smoking (aOR: 4.6; 95% CI: 1.0-22.1; p = 0.050) also showed a significant independent, but clearly weaker, association with severe AD. A short duration of breastfeeding, absence of older siblings, parental passive smoking, food allergens along with aeroallergens, and excessive cleanliness should be considered as negative prognostic factors, leading to a higher SCORAD score in children with AD.

Identification of microRNAs involved in Alzheimer’s progression using a rabbit model of the disease

PubMed Central

Liu, Qing Yan; Chang, Marilyn N Vera; Lei, Joy X; Koukiekolo, Roger; Smith, Brandon; Zhang, Dongling; Ghribi, Othman

2014-01-01

Alzheimer’s disease (AD) is the most common neurodegenerative disorder characterized by the presence of extracellular plaques of β-amyloid peptides and intracellular tangles of hyperphosphorylated tau proteins in the brain. The vast majority of cases are late onset AD (LOAD), which are genetically heterogeneous and occur sporadically. High blood cholesterol is suggested to be a risk factor for this disease. Several neuropathological changes of LOAD can be reproduced by supplementing a rabbit’s diet with 2% cholesterol for 12 weeks. Accumulating data in the literature suggest that microRNAs (miRNA) participate in the development of AD pathology. The present study focuses on the survey of changes of miRNA expression in rabbit brains during the progression of AD-like pathology using microarray followed by Taq-Man qRT-PCR analyses. Out of 1769 miRNA probes used in the experiments, 99 miRNAs were found to be present in rabbit brain, 57 were newly identified as miRNAs from rabbit brain. Eleven miRNAs showed significant changes over AD-like pathology progression. Among them, the changes of miR-125b, miR-98, miR-107, miR-30, along with 3 members of the let-7 family were similar to those observed in human AD samples, whereas the expression patterns of miR-15a, miR-26b, miR-9 and miR-576-3p were unique to this rabbit LOAD model. The significant up regulation of miR-26b is consistent with the decrease of leptin levels in the brains of cholesterol fed rabbit model for AD, confirming that miR-26b is indeed regulated by leptin and that both leptin and miR-26b may be involved in cholesterol induced AD-like pathology. PMID:24754001

Extinction, recolonization, and dispersal through time in a planktonic crustacean.

PubMed

Mergeay, Joachim; Vanoverbeke, Joost; Verschuren, Dirk; De Meester, Luc

2007-12-01

Dormant propagule banks are important reservoirs of biological and genetic diversity of local communities and populations and provide buffering mechanisms against extinction. Although dormant stages of various plant and animal species are known to remain viable for decades and even centuries, little is known about the effective influence of recolonization from such old sources on the genetic continuity of intermittent populations under natural conditions. Using recent and old dormant eggs recovered from a dated lake sediment core in Kenya, we traced the genetic composition of a local population of the planktonic crustacean Daphnia barbata through a sequence of extinction and recolonization events. This was combined with a phylogeographic and population-genetic survey of regional populations. Four successive populations, fully separated in time, inhabited Lake Naivasha from ca. 1330 to 1570 AD, from ca. 1610 to 1720 AD, from ca. 1840 to 1940 AD, and from 1995 to the present (2001 AD). Our results strongly indicate genetic continuity between the 1840-1940 and 1995-2001 populations, which are separated in time by at least 50 years, and close genetic relatedness of them both to the 1330-1580 population. A software tool (Colonize) was developed to find the most likely source population of the refounded 1995-2001 population and to test the number of colonists involved in the recolonization event. The results confirmed that the 1995-2001 population most probably developed out of a limited number of surviving local dormant eggs from the previous population, rather than out of individuals from regional (central and southern Kenya) or more distant (Ethiopia, Zimbabwe) populations that may have immigrated to Lake Naivasha through passive dispersal. These results emphasize the importance of prolonged dormancy for the natural long-term dynamics of crustacean zooplankton in fluctuating environments and suggest an important role of old local dormant egg banks in aquatic habitat restoration.

CR1 rs3818361 Polymorphism Contributes to Alzheimer's Disease Susceptibility in Chinese Population.

PubMed

Li, Yongning; Song, Dongjing; Jiang, Yongshuai; Wang, Jingwei; Feng, Rennan; Zhang, Liangcai; Wang, Guangyu; Chen, Zugen; Wang, Renzhi; Jiang, Qinghua; Liu, Guiyou

2016-08-01

Recent genome-wide association studies (GWAS) reported CR1 rs3818361 polymorphism to be an Alzheimer's disease (AD) susceptibility variant in European ancestry. Three independent studies investigated this association in Chinese population. However, these studies reported weak or no significant association. Here, we reinvestigated the association using all the samples from three independent studies in Chinese population (N = 4047, 1244 AD cases and 2803 controls). We also selected three independent studies in European ancestry population (N = 11787, 3939 AD cases and 7848 controls) to evaluate the effect of rs3818361 polymorphism on AD risk in different ethnic backgrounds. In Chinese population, we did not identified significant heterogeneity using additive, recessive, and dominant genetic models. Meta-analysis showed significant association between rs3818361 and AD with P = 6.00E-03 and P = 5.00E-03. We further identified no heterogeneity of rs3818361 polymorphism between Chinese and European populations. We found that rs3818361 polymorphism contributed to AD with similar genetic risk in Chinese and European populations. In summary, this is the first study to show significant association between rs3818361 polymorphism and AD in Chinese population by a meta-analysis method. Our findings indicate that the effect of CR1 rs3818361 polymorphism on AD risk in Chinese cohorts is consistent with the increased risk observed in European AD cohorts.

Magnetic resonance imaging traits in siblings discordant for Alzheimer disease.

PubMed

Cuenco, Karen T; Green, Robert C; Zhang, J; Lunetta, Kathryn; Erlich, Porat M; Cupples, L Adrienne; Farrer, Lindsay A; DeCarli, Charles

2008-07-01

Magnetic resonance imaging (MRI) can aid clinical assessment of brain changes potentially correlated with Alzheimer disease (AD). MRI traits may improve our ability to identify genes associated with AD-outcomes. We evaluated semi-quantitative MRI measures as endophenotypes for genetic studies by assessing their association with AD in families from the Multi-Institutional Research in Alzheimer Genetic Epidemiology (MIRAGE) Study. Discordant siblings from multiple ethnicities were ascertained through a single affected proband. Semi-quantitative MRI measures were obtained for each individual. The association between continuous/ordinal MRI traits and AD were analyzed using generalized estimating equations. Medical history and Apolipoprotein E (APOE)epsilon4 status were evaluated as potential confounders. Comparisons of 214 affected and 234 unaffected subjects from 229 sibships revealed that general cerebral atrophy, white matter hyperintensities (WMH), and mediotemporal atrophy differed significantly between groups (each at P < .0001) and varied by ethnicity. Age at MRI and duration of AD confounded all associations between AD and MRI traits. Among unaffected sibs, the presence of at least one APOEepsilon4 allele and MRI infarction was associated with more WMH after adjusting for age at MRI. The strong association between MRI traits and AD suggests that MRI traits may be informative endophenotypes for basic and clinical studies of AD. In particular, WMH may be a marker of vascular disease that contributes to AD pathogenesis.

Reversal of experimental colitis disease activity in mice following administration of an adenoviral IL-10 vector.

PubMed

Sasaki, Makoto; Mathis, J Michael; Jennings, Merilyn H; Jordan, Paul; Wang, Yuping; Ando, Tomoaki; Joh, Takashi; Alexander, J Steven

2005-10-31

Genetic deficiency in the expression of interleukin-10 (IL-10) is associated with the onset and progression of experimental inflammatory bowel disease (IBD). The clinical significance of IL-10 expression is supported by studies showing that immune-augmentation of IL-10 prevents inflammation and mucosal damage in animal models of colitis and in human colitis. Interleukin-10 (IL-10), an endogenous anti-inflammatory and immunomodulating cytokine, has been shown to prevent some inflammation and injury in animal and clinical studies, but the efficacy of IL-10 treatment remains unsatisfactory. We found that intra-peritoneal administration of adenoviral IL-10 to mice significantly reversed colitis induced by administration of 3% DSS (dextran sulfate), a common model of colitis. Adenoviral IL-10 (Ad-IL10) transfected mice developed high levels of IL-10 (394 +/- 136 pg/ml) within the peritoneal cavity where the adenovirus was expressed. Importantly, when given on day 4 (after the induction of colitis w/DSS), Ad-IL10 significantly reduced disease activity and weight loss and completely prevented histopathologic injury to the colon at day 10. Mechanistically, compared to Ad-null and DSS treated mice, Ad-IL10 and DSS-treated mice were able to suppress the expression of MAdCAM-1, an endothelial adhesion molecule associated with IBD. Our results suggest that Ad-IL10 (adenoviral IL-10) gene therapy of the intestine or peritoneum may be useful in the clinical treatment of IBD, since we demonstrated that this vector can reverse the course of an existing gut inflammation and markers of inflammation.

Reversal of experimental colitis disease activity in mice following administration of an adenoviral IL-10 vector

PubMed Central

Sasaki, Makoto; Mathis, J Michael; Jennings, Merilyn H; Jordan, Paul; Wang, Yuping; Ando, Tomoaki; Joh, Takashi; Alexander, J Steven

2005-01-01

Genetic deficiency in the expression of interleukin-10 (IL-10) is associated with the onset and progression of experimental inflammatory bowel disease (IBD). The clinical significance of IL-10 expression is supported by studies showing that immune-augmentation of IL-10 prevents inflammation and mucosal damage in animal models of colitis and in human colitis. Interleukin-10 (IL-10), an endogenous anti-inflammatory and immunomodulating cytokine, has been shown to prevent some inflammation and injury in animal and clinical studies, but the efficacy of IL-10 treatment remains unsatisfactory. We found that intra-peritoneal administration of adenoviral IL-10 to mice significantly reversed colitis induced by administration of 3% DSS (dextran sulfate), a common model of colitis. Adenoviral IL-10 (Ad-IL10) transfected mice developed high levels of IL-10 (394 +/- 136 pg/ml) within the peritoneal cavity where the adenovirus was expressed. Importantly, when given on day 4 (after the induction of colitis w/DSS), Ad-IL10 significantly reduced disease activity and weight loss and completely prevented histopathologic injury to the colon at day 10. Mechanistically, compared to Ad-null and DSS treated mice, Ad-IL10 and DSS-treated mice were able to suppress the expression of MAdCAM-1, an endothelial adhesion molecule associated with IBD. Our results suggest that Ad-IL10 (adenoviral IL-10) gene therapy of the intestine or peritoneum may be useful in the clinical treatment of IBD, since we demonstrated that this vector can reverse the course of an existing gut inflammation and markers of inflammation. PMID:16259632

Comparison of the Life Cycles of Genetically Distant Species C and Species D Human Adenoviruses Ad6 and Ad26 in Human Cells.

PubMed

Turner, Mallory A; Middha, Sumit; Hofherr, Sean E; Barry, Michael A

2015-12-01

Our understanding of adenovirus (Ad) biology is largely extrapolated from human species C Ad5. Most humans are immune to Ad5, so lower-seroprevalence viruses like human Ad6 and Ad26 are being tested as therapeutic vectors. Ad6 and Ad26 differ at the DNA level by 34%. To better understand how this might impact their biology, we examined the life cycle of the two viruses in human lung cells in vitro. Both viruses infected A549 cells with similar efficiencies, executed DNA replication with identical kinetics within 12 h, and began killing cells within 72 h. While Ad6-infected cells remained adherent until death, Ad26-infected cells detached within 12 h of infection but remained viable. Next-generation sequencing (NGS) of mRNA from infected cells demonstrated that viral transcripts constituted 1% of cellular mRNAs within 6 h and 8 to 16% within 12 h. Quantitative PCR and NGS revealed the activation of key early genes at 6 h and transition to late gene activation by 12 h by both viruses. There were marked differences in the balance of E1A and E1B activation by the two viruses and in the expression of E3 immune evasion mRNAs. Ad6 was markedly more effective at suppressing major histocompatibility complex class I (MHC I) display on the cell surface and in evading TRAIL-mediated apoptosis than was Ad26. These data demonstrate shared as well as divergent life cycles in these genetically distant human adenoviruses. An understanding of these differences expands the knowledge of alternative Ad species and may inform the selection of related Ads for therapeutic development. A burgeoning number of adenoviruses (Ads) are being harnessed as therapeutics, yet the biology of these viruses is generally extrapolated from Ad2 and Ad5. Here, we are the first to compare the transcriptional programs of two genetically distant Ads by mRNA next-generation sequencing (NGS). Species C Ad6 and Ad26 are being pursued as lower-seroprevalence Ad vectors but differ at the DNA level by 34%. Head-to-head comparison in human lung cells by NGS revealed that the two viruses generally conform to our general understanding of the Ad transcriptional program. However, fine mapping revealed subtle and strong differences in how these two viruses execute these programs, including differences in the balance of E1A and E1B mRNAs and in E3 immune evasion genes. This suggests that not all adenoviruses behave like Ad2 and Ad5 and that they may have unique strategies to infect cells and evade the immune system. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

76 FR 44855 - Common or Usual Name for Raw Meat and Poultry Products Containing Added Solutions

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-27

.... FSIS-2010-0012] RIN 0583-AD41 Common or Usual Name for Raw Meat and Poultry Products Containing Added... name for raw meat and poultry products that do not meet standard of identity regulations and to which... description of the raw meat or poultry component, the percentage of added solution incorporated into the raw...

Efficacy of severe acute respiratory syndrome vaccine based on a nonhuman primate adenovirus in the presence of immunity against human adenovirus.

PubMed

Zhi, Yan; Figueredo, Joanita; Kobinger, Gary P; Hagan, Heather; Calcedo, Roberto; Miller, James R; Gao, Guangping; Wilson, James M

2006-05-01

Replication-deficient human adenovirus type 5 (AdH5) vectors can induce strong transgene product-specific cellular and humoral responses. However, many adult humans have neutralizing antibodies (NAbs) against AdH5 as a result of natural infection with this virus. Therefore, a chimpanzee adenovirus C7 (AdC7) vector was developed to circumvent interference by preexisting immunity to AdH5. This study evaluated the impact of preexisting immunity to human adenovirus on the efficacy of adenovirus-based vaccines against the coronavirus that causes severe acute respiratory syndrome (SARS-CoV). Efficacy was assessed after intramuscular injection of the vector into mice and was measured as the frequency of SARS-CoV-specific T cells and NAbs against SARS-CoV. Immunogenicity of the AdH5-based vaccine was significantly attenuated or completely abolished when the preexisting anti-AdH5 NAb titer was higher than 40. Because 27% of human serum samples from the United States tested so far have an anti-AdH5 NAb titer higher than 40, our results suggested that a significant percentage of humans with preexisting anti-AdH5 immunity would not be candidates for vaccination with an AdH5-based genetic vaccine. In contrast, preexisting anti-AdH5 NAbs have a minimal effect on the potency of the AdC7-based genetic vaccine. Taken together, our studies warrant the further development of AdC7 as a vaccine carrier for human trials.

Biomarkers in Sporadic and Familial Alzheimer's Disease.

PubMed

Lista, Simone; O'Bryant, Sid E; Blennow, Kaj; Dubois, Bruno; Hugon, Jacques; Zetterberg, Henrik; Hampel, Harald

2015-01-01

Most forms of Alzheimer's disease (AD) are sporadic (sAD) or inherited in a non-Mendelian fashion, and less than 1% of cases are autosomal-dominant. Forms of sAD do not exhibit familial aggregation and are characterized by complex genetic and environmental interactions. Recently, the expansion of genomic methodologies, in association with substantially larger combined cohorts, has resulted in various genome-wide association studies that have identified several novel genetic associations of AD. Currently, the most effective methods for establishing the diagnosis of AD are defined by multi-modal pathways, starting with clinical and neuropsychological assessment, cerebrospinal fluid (CSF) analysis, and brain-imaging procedures, all of which have significant cost- and access-to-care barriers. Consequently, research efforts have focused on the development and validation of non-invasive and generalizable blood-based biomarkers. Among the modalities conceptualized by the systems biology paradigm and utilized in the "exploratory biomarker discovery arena", proteome analysis has received the most attention. However, metabolomics, lipidomics, transcriptomics, and epigenomics have recently become key modalities in the search for AD biomarkers. Interestingly, biomarker changes for familial AD (fAD), in many but not all cases, seem similar to those for sAD. The integration of neurogenetics with systems biology/physiology-based strategies and high-throughput technologies for molecular profiling is expected to help identify the causes, mechanisms, and biomarkers associated with the various forms of AD. Moreover, in order to hypothesize the dynamic trajectories of biomarkers through disease stages and elucidate the mechanisms of biomarker alterations, updated and more sophisticated theoretical models have been proposed for both sAD and fAD.

Evidence for a role of the rare p.A152T variant in MAPT in increasing the risk for FTD-spectrum and Alzheimer's diseases

PubMed Central

Coppola, Giovanni; Chinnathambi, Subashchandrabose; Lee, Jason JiYong; Dombroski, Beth A.; Baker, Matt C.; Soto-Ortolaza, Alexandra I.; Lee, Suzee E.; Klein, Eric; Huang, Alden Y.; Sears, Renee; Lane, Jessica R.; Karydas, Anna M.; Kenet, Robert O.; Biernat, Jacek; Wang, Li-San; Cotman, Carl W.; DeCarli, Charles S.; Levey, Allan I.; Ringman, John M.; Mendez, Mario F.; Chui, Helena C.; Le Ber, Isabelle; Brice, Alexis; Lupton, Michelle K.; Preza, Elisavet; Lovestone, Simon; Powell, John; Graff-Radford, Neill; Petersen, Ronald C.; Boeve, Bradley F.; Lippa, Carol F.; Bigio, Eileen H.; Mackenzie, Ian; Finger, Elizabeth; Kertesz, Andrew; Caselli, Richard J.; Gearing, Marla; Juncos, Jorge L.; Ghetti, Bernardino; Spina, Salvatore; Bordelon, Yvette M.; Tourtellotte, Wallace W.; Frosch, Matthew P.; Vonsattel, Jean Paul G.; Zarow, Chris; Beach, Thomas G.; Albin, Roger L.; Lieberman, Andrew P.; Lee, Virginia M.; Trojanowski, John Q.; Van Deerlin, Vivianna M.; Bird, Thomas D.; Galasko, Douglas R.; Masliah, Eliezer; White, Charles L.; Troncoso, Juan C.; Hannequin, Didier; Boxer, Adam L.; Geschwind, Michael D.; Kumar, Satish; Mandelkow, Eva-Maria; Wszolek, Zbigniew K.; Uitti, Ryan J.; Dickson, Dennis W.; Haines, Jonathan L.; Mayeux, Richard; Pericak-Vance, Margaret A.; Farrer, Lindsay A.; Ross, Owen A.; Rademakers, Rosa; Schellenberg, Gerard D.; Miller, Bruce L.; Mandelkow, Eckhard; Geschwind, Daniel H.

2012-01-01

Rare mutations in the gene encoding for tau (MAPT, microtubule-associated protein tau) cause frontotemporal dementia-spectrum (FTD-s) disorders, including FTD, progressive supranuclear palsy (PSP) and corticobasal syndrome, and a common extended haplotype spanning across the MAPT locus is associated with increased risk of PSP and Parkinson's disease. We identified a rare tau variant (p.A152T) in a patient with a clinical diagnosis of PSP and assessed its frequency in multiple independent series of patients with neurodegenerative conditions and controls, in a total of 15 369 subjects. Tau p.A152T significantly increases the risk for both FTD-s (n = 2139, OR = 3.0, CI: 1.6–5.6, P = 0.0005) and Alzheimer's disease (AD) (n = 3345, OR = 2.3, CI: 1.3–4.2, P = 0.004) compared with 9047 controls. Functionally, p.A152T (i) decreases the binding of tau to microtubules and therefore promotes microtubule assembly less efficiently; and (ii) reduces the tendency to form abnormal fibers. However, there is a pronounced increase in the formation of tau oligomers. Importantly, these findings suggest that other regions of the tau protein may be crucial in regulating normal function, as the p.A152 residue is distal to the domains considered responsible for microtubule interactions or aggregation. These data provide both the first genetic evidence and functional studies supporting the role of MAPT p.A152T as a rare risk factor for both FTD-s and AD and the concept that rare variants can increase the risk for relatively common, complex neurodegenerative diseases, but since no clear significance threshold for rare genetic variation has been established, some caution is warranted until the findings are further replicated. PMID:22556362

Multivariate modelling of endophenotypes associated with the metabolic syndrome in Chinese twins.

PubMed

Pang, Z; Zhang, D; Li, S; Duan, H; Hjelmborg, J; Kruse, T A; Kyvik, K O; Christensen, K; Tan, Q

2010-12-01

The common genetic and environmental effects on endophenotypes related to the metabolic syndrome have been investigated using bivariate and multivariate twin models. This paper extends the pairwise analysis approach by introducing independent and common pathway models to Chinese twin data. The aim was to explore the common genetic architecture in the development of these phenotypes in the Chinese population. Three multivariate models including the full saturated Cholesky decomposition model, the common factor independent pathway model and the common factor common pathway model were fitted to 695 pairs of Chinese twins representing six phenotypes including BMI, total cholesterol, total triacylglycerol, fasting glucose, HDL and LDL. Performances of the nested models were compared with that of the full Cholesky model. Cross-phenotype correlation coefficients gave clear indication of common genetic or environmental backgrounds in the phenotypes. Decomposition of phenotypic correlation by the Cholesky model revealed that the observed phenotypic correlation among lipid phenotypes had genetic and unique environmental backgrounds. Both pathway models suggest a common genetic architecture for lipid phenotypes, which is distinct from that of the non-lipid phenotypes. The declining performance with model restriction indicates biological heterogeneity in development among some of these phenotypes. Our multivariate analyses revealed common genetic and environmental backgrounds for the studied lipid phenotypes in Chinese twins. Model performance showed that physiologically distinct endophenotypes may follow different genetic regulations.

Could Better Phenotyping Small Vessel Disease Provide New Insights into Alzheimer Disease and Improve Clinical Trial Outcomes?

PubMed

Marnane, Michael; Hsiung, Ging-Yuek R

2016-01-01

Alzheimer Disease (AD) is the most common primary cause of dementia with a burgeoning epidemic as life expectancy and general medical care improve worldwide. Recent data from pathologic studies has shown that the cooccurrence of other neurodegenerative and vascular pathologies is in fact the rule rather than the exception. In late onset AD, cerebral small vessel disease (SVD) is almost invariably co-existent to a greater or lesser extent and is known to promote cognitive deterioration. Previous observational studies and clinical trials have largely sought to divide dementia based on predominant neurodegenerative or vascular mechanisms. Given the high degree of overlap, findings from such studies may be difficult to interpret and apply to population cohorts. Additionally opportunities may be lost for uncovering novel interventions that target interactions between co-existent vascular and neurodegenerative pathologies. In the current review, we consider potential pathophysiologic mechanisms through which SVD may be associated with and promote AD pathology. In particular we explore shared environmental and genetic associations and how these may converge via neuroinflammatory pathways potentially providing novel therapeutic targets. SVD has heterogenous manifestations on cerebral imaging and at pathology. We discuss how studying SVD topography may enable us to better identify those at risk for more rapid cognitive decline and improve future clinical trial design.

HNE-modified proteins in Down syndrome: Involvement in development of Alzheimer disease neuropathology.

PubMed

Barone, Eugenio; Head, Elizabeth; Butterfield, D Allan; Perluigi, Marzia

2017-10-01

Down syndrome (DS), trisomy of chromosome 21, is the most common genetic form of intellectual disability. The neuropathology of DS involves multiple molecular mechanisms, similar to AD, including the deposition of beta-amyloid (Aβ) into senile plaques and tau hyperphosphorylationg in neurofibrillary tangles. Interestingly, many genes encoded by chromosome 21, in addition to being primarily linked to amyloid-beta peptide (Aβ) pathology, are responsible for increased oxidative stress (OS) conditions that also result as a consequence of reduced antioxidant system efficiency. However, redox homeostasis is disturbed by overproduction of Aβ, which accumulates into plaques across the lifespan in DS as well as in AD, thus generating a vicious cycle that amplifies OS-induced intracellular changes. The present review describes the current literature that demonstrates the accumulation of oxidative damage in DS with a focus on the lipid peroxidation by-product, 4-hydroxy-2-nonenal (HNE). HNE reacts with proteins and can irreversibly impair their functions. We suggest that among different post-translational modifications, HNE-adducts on proteins accumulate in DS brain and play a crucial role in causing the impairment of glucose metabolism, neuronal trafficking, protein quality control and antioxidant response. We hypothesize that dysfunction of these specific pathways contribute to accelerated neurodegeneration associated with AD neuropathology. Copyright © 2017 Elsevier Inc. All rights reserved.

Are allergic multimorbidities and IgE polysensitization associated with the persistence or re-occurrence of foetal type 2 signalling? The MeDALL hypothesis.

PubMed

Bousquet, J; Anto, J M; Wickman, M; Keil, T; Valenta, R; Haahtela, T; Lodrup Carlsen, K; van Hage, M; Akdis, C; Bachert, C; Akdis, M; Auffray, C; Annesi-Maesano, I; Bindslev-Jensen, C; Cambon-Thomsen, A; Carlsen, K H; Chatzi, L; Forastiere, F; Garcia-Aymerich, J; Gehrig, U; Guerra, S; Heinrich, J; Koppelman, G H; Kowalski, M L; Lambrecht, B; Lupinek, C; Maier, D; Melén, E; Momas, I; Palkonen, S; Pinart, M; Postma, D; Siroux, V; Smit, H A; Sunyer, J; Wright, J; Zuberbier, T; Arshad, S H; Nadif, R; Thijs, C; Andersson, N; Asarnoj, A; Ballardini, N; Ballereau, S; Bedbrook, A; Benet, M; Bergstrom, A; Brunekreef, B; Burte, E; Calderon, M; De Carlo, G; Demoly, P; Eller, E; Fantini, M P; Hammad, H; Hohman, C; Just, J; Kerkhof, M; Kogevinas, M; Kull, I; Lau, S; Lemonnier, N; Mommers, M; Nawijn, M; Neubauer, A; Oddie, S; Pellet, J; Pin, I; Porta, D; Saes, Y; Skrindo, I; Tischer, C G; Torrent, M; von Hertzen, L

2015-09-01

Allergic diseases [asthma, rhinitis and atopic dermatitis (AD)] are complex. They are associated with allergen-specific IgE and nonallergic mechanisms that may coexist in the same patient. In addition, these diseases tend to cluster and patients present concomitant or consecutive diseases (multimorbidity). IgE sensitization should be considered as a quantitative trait. Important clinical and immunological differences exist between mono- and polysensitized subjects. Multimorbidities of allergic diseases share common causal mechanisms that are only partly IgE-mediated. Persistence of allergic diseases over time is associated with multimorbidity and/or IgE polysensitization. The importance of the family history of allergy may decrease with age. This review puts forward the hypothesis that allergic multimorbidities and IgE polysensitization are associated and related to the persistence or re-occurrence of foetal type 2 signalling. Asthma, rhinitis and AD are manifestations of a common systemic immune imbalance (mesodermal origin) with specific patterns of remodelling (ectodermal or endodermal origin). This study proposes a new classification of IgE-mediated allergic diseases that allows the definition of novel phenotypes to (i) better understand genetic and epigenetic mechanisms, (ii) better stratify allergic preschool children for prognosis and (iii) propose novel strategies of treatment and prevention. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

An improved genetic map for Castanea mollissima/Castanea dentata and its relationship to the genetic map of Castanea sativa

Treesearch

P.H. Sisco; T.L. Kubisiak; M. Casasoli; T. Barreneche; A. Kremer; C. Clark; R.R. Sederoff; F.V. Hebard; F. Villani

2005-01-01

We have added 275 AFLP and 24 SSR markers and the 5SrDNA locus to a previously published genetic map based on a hybrid cross between Castanea mollissima and C. denata. The SSR markers, 5SrDNA locus, and one isozyme locus also permitted us to correlate the linkage groups in the published genetic map of C. sativa...

The CLU gene rs11136000 variant is significantly associated with Alzheimer's disease in Caucasian and Asian populations.

PubMed

Liu, Guiyou; Wang, Haiyang; Liu, Jiafeng; Li, Jingbo; Li, Hali; Ma, Guoda; Jiang, Yongshuai; Chen, Zugen; Zhao, Bin; Li, Keshen

2014-03-01

Large-scale genomewide association studies have reported that the CLU rs11136000 polymorphism is significantly associated with Alzheimer's disease (AD) in people of Caucasian ancestry. Recently, this association was investigated in Asian populations (Chinese, Japanese, and Korean). However, these studies reported either a weak association or no association between the rs11136000 polymorphism and AD. We believe that this discrepancy may be caused by the relatively small sample size of the previous studies and the genetic heterogeneity of the rs11136000 polymorphism in AD among different populations. For this study, we searched the PubMed and AlzGene databases. We selected 18 independent studies (6 studies of Asian populations and 12 of populations of Caucasian ancestry) that evaluated the association between the rs11136000 polymorphism and AD using a case-control experimental design. We evaluated the genetic heterogeneity of the rs11136000 polymorphism in Caucasian and Asian populations. We then investigated the rs11136000 polymorphism by a meta-analysis in Asian populations using allele, dominant, and recessive models. We identified a significant association between rs11136000 and AD with the allele model (P = 2.00 × 10(-4)) and the dominant model (P = 5.00 × 10(-3)). Meanwhile, a similar genetic risk of the rs11136000 polymorphism in AD was observed in Asian and Caucasian populations. Further meta-analysis in pooled Asian and Caucasian populations indicated a more significant association with the allele (P = 8.30 × 10(-24)), dominant (P = 4.46 × 10(-17)), and recessive (P = 3.92 × 10(-12)) models. Collectively, our findings from this meta-analysis indicate that the effect of the CLU rs11136000 polymorphism on AD risk in Asian cohorts (Chinese, Japanese, and Korean) is consistent with the protective effect observed in Caucasian AD cohorts.

Chronic type B aortic dissection in association with Hemolyticuremic syndrome in a child.

PubMed

Gera, D N; Ghuge, P P; Gandhi, S; Vanikar, A V; Shrimali, J D; Kute, V B; Trivedi, H L

2013-11-01

Aortic dissection (AD) is a potentially life-threatening medical emergency usually encountered in the elderly. Here, we report a 9-year-old child who was incidentally detected to have asymptomatic chronic type B dissecting aneurysm of aorta when he presented with relapse of Hemolytic uremic syndrome (HUS) without any genetic abnormalities like Marfan or Ehler-Danlos syndrome. To the best of our knowledge, this is the first case of AD associated with HUS in a child without any known associated genetic or inherited risk factors.

Chronic type B aortic dissection in association with Hemolyticuremic syndrome in a child

PubMed Central

Gera, D. N.; Ghuge, P. P.; Gandhi, S.; Vanikar, A. V.; Shrimali, J. D.; Kute, V. B.; Trivedi, H. L.

2013-01-01

Aortic dissection (AD) is a potentially life-threatening medical emergency usually encountered in the elderly. Here, we report a 9-year-old child who was incidentally detected to have asymptomatic chronic type B dissecting aneurysm of aorta when he presented with relapse of Hemolytic uremic syndrome (HUS) without any genetic abnormalities like Marfan or Ehler-Danlos syndrome. To the best of our knowledge, this is the first case of AD associated with HUS in a child without any known associated genetic or inherited risk factors. PMID:24339527

Two Alzheimer’s disease risk genes increase entorhinal cortex volume in young adults

PubMed Central

DiBattista, Amanda Marie; Stevens, Benson W.; Rebeck, G. William; Green, Adam E.

2014-01-01

Alzheimer’s disease (AD) risk genes alter brain structure and function decades before disease onset. Apolipoprotein E (APOE) is the strongest known genetic risk factor for AD, and a related gene, apolipoprotein J (APOJ), also affects disease risk. However, the extent to which these genes affect brain structure in young adults remains unclear. Here, we report that AD risk alleles of these two genes, APOE-ε4 and APOJ-C, cumulatively alter brain volume in young adults. Using voxel-based morphometry (VBM) in 57 individuals, we examined the entorhinal cortex, one of the earliest brain regions affected in AD pathogenesis. Apolipoprotein E-ε4 carriers exhibited higher right entorhinal cortex volume compared to non-carriers. Interestingly, APOJ-C risk genotype was associated with higher bilateral entorhinal cortex volume in non-APOE-ε4 carriers. To determine the combined disease risk of APOE and APOJ status per subject, we used cumulative odds ratios as regressors for volumetric measurements. Higher disease risk corresponded to greater right entorhinal cortex volume. These results suggest that, years before disease onset, two key AD genetic risk factors may exert influence on the structure of a brain region where AD pathogenesis takes root. PMID:25339884

Genome-wide copy number variation (CNV) in patients with autoimmune Addison's disease

PubMed Central

2011-01-01

Background Addison's disease (AD) is caused by an autoimmune destruction of the adrenal cortex. The pathogenesis is multi-factorial, involving genetic components and hitherto unknown environmental factors. The aim of the present study was to investigate if gene dosage in the form of copy number variation (CNV) could add to the repertoire of genetic susceptibility to autoimmune AD. Methods A genome-wide study using the Affymetrix GeneChip® Genome-Wide Human SNP Array 6.0 was conducted in 26 patients with AD. CNVs in selected genes were further investigated in a larger material of patients with autoimmune AD (n = 352) and healthy controls (n = 353) by duplex Taqman real-time polymerase chain reaction assays. Results We found that low copy number of UGT2B28 was significantly more frequent in AD patients compared to controls; conversely high copy number of ADAM3A was associated with AD. Conclusions We have identified two novel CNV associations to ADAM3A and UGT2B28 in AD. The mechanism by which this susceptibility is conferred is at present unclear, but may involve steroid inactivation (UGT2B28) and T cell maturation (ADAM3A). Characterization of these proteins may unravel novel information on the pathogenesis of autoimmunity. PMID:21851588

Chitinase-3-like 1 protein (CHI3L1) locus influences cerebrospinal fluid levels of YKL-40.

PubMed

Deming, Yuetiva; Black, Kathleen; Carrell, David; Cai, Yefei; Del-Aguila, Jorge L; Fernandez, Maria Victoria; Budde, John; Ma, ShengMei; Saef, Benjamin; Howells, Bill; Bertelsen, Sarah; Huang, Kuan-Lin; Sutphen, Courtney L; Tarawneh, Rawan; Fagan, Anne M; Holtzman, David M; Morris, John C; Goate, Alison M; Dougherty, Joseph D; Cruchaga, Carlos

2016-11-10

Alzheimer's disease (AD) pathology appears several years before clinical symptoms, so identifying ways to detect individuals in the preclinical stage is imperative. The cerebrospinal fluid (CSF) Tau/Aβ 42 ratio is currently the best known predictor of AD status and cognitive decline, and the ratio of CSF levels of chitinase-3-like 1 protein (CHI3L1, YKL-40) and amyloid beta (Aβ 42 ) were reported as predictive, but individual variability and group overlap inhibits their utility for individual diagnosis making it necessary to find ways to improve sensitivity of these biomarkers. We used linear regression to identify genetic loci associated with CSF YKL-40 levels in 379 individuals (80 cognitively impaired and 299 cognitively normal) from the Charles F and Joanne Knight Alzheimer's Disease Research Center. We tested correlations between YKL-40 and CSF Tau/Aβ 42 ratio, Aβ 42 , tau, and phosphorylated tau (ptau 181 ). We used studentized residuals from a linear regression model of the log-transformed, standardized protein levels and the additive reference allele counts from the most significant locus to adjust YKL-40 values and tested the differences in correlations with CSF Tau/Aβ 42 ratio, Aβ 42 , tau, and ptau 181 . We found that genetic variants on the CH13L1 locus were significantly associated with CSF YKL-40 levels, but not AD risk, age at onset, or disease progression. The most significant variant is a reported expression quantitative trait locus for CHI3L1, the gene which encodes YKL-40, and explained 12.74 % of the variance in CSF YKL-40 in our study. YKL-40 was positively correlated with ptau 181 (r = 0.521) and the strength of the correlation significantly increased with the addition of genetic information (r = 0.573, p = 0.006). CSF YKL-40 levels are likely a biomarker for AD, but we found no evidence that they are an AD endophenotype. YKL-40 levels are highly regulated by genetic variation, and by including genetic information the strength of the correlation between YKL-40 and ptau 181 levels is significantly improved. Our results suggest that studies of potential biomarkers may benefit from including genetic information.

A High-Density Genetic Map with Array-Based Markers Facilitates Structural and Quantitative Trait Locus Analyses of the Common Wheat Genome

PubMed Central

Iehisa, Julio Cesar Masaru; Ohno, Ryoko; Kimura, Tatsuro; Enoki, Hiroyuki; Nishimura, Satoru; Okamoto, Yuki; Nasuda, Shuhei; Takumi, Shigeo

2014-01-01

The large genome and allohexaploidy of common wheat have complicated construction of a high-density genetic map. Although improvements in the throughput of next-generation sequencing (NGS) technologies have made it possible to obtain a large amount of genotyping data for an entire mapping population by direct sequencing, including hexaploid wheat, a significant number of missing data points are often apparent due to the low coverage of sequencing. In the present study, a microarray-based polymorphism detection system was developed using NGS data obtained from complexity-reduced genomic DNA of two common wheat cultivars, Chinese Spring (CS) and Mironovskaya 808. After design and selection of polymorphic probes, 13,056 new markers were added to the linkage map of a recombinant inbred mapping population between CS and Mironovskaya 808. On average, 2.49 missing data points per marker were observed in the 201 recombinant inbred lines, with a maximum of 42. Around 40% of the new markers were derived from genic regions and 11% from repetitive regions. The low number of retroelements indicated that the new polymorphic markers were mainly derived from the less repetitive region of the wheat genome. Around 25% of the mapped sequences were useful for alignment with the physical map of barley. Quantitative trait locus (QTL) analyses of 14 agronomically important traits related to flowering, spikes, and seeds demonstrated that the new high-density map showed improved QTL detection, resolution, and accuracy over the original simple sequence repeat map. PMID:24972598

A high-density genetic map with array-based markers facilitates structural and quantitative trait locus analyses of the common wheat genome.

PubMed

Iehisa, Julio Cesar Masaru; Ohno, Ryoko; Kimura, Tatsuro; Enoki, Hiroyuki; Nishimura, Satoru; Okamoto, Yuki; Nasuda, Shuhei; Takumi, Shigeo

2014-10-01

The large genome and allohexaploidy of common wheat have complicated construction of a high-density genetic map. Although improvements in the throughput of next-generation sequencing (NGS) technologies have made it possible to obtain a large amount of genotyping data for an entire mapping population by direct sequencing, including hexaploid wheat, a significant number of missing data points are often apparent due to the low coverage of sequencing. In the present study, a microarray-based polymorphism detection system was developed using NGS data obtained from complexity-reduced genomic DNA of two common wheat cultivars, Chinese Spring (CS) and Mironovskaya 808. After design and selection of polymorphic probes, 13,056 new markers were added to the linkage map of a recombinant inbred mapping population between CS and Mironovskaya 808. On average, 2.49 missing data points per marker were observed in the 201 recombinant inbred lines, with a maximum of 42. Around 40% of the new markers were derived from genic regions and 11% from repetitive regions. The low number of retroelements indicated that the new polymorphic markers were mainly derived from the less repetitive region of the wheat genome. Around 25% of the mapped sequences were useful for alignment with the physical map of barley. Quantitative trait locus (QTL) analyses of 14 agronomically important traits related to flowering, spikes, and seeds demonstrated that the new high-density map showed improved QTL detection, resolution, and accuracy over the original simple sequence repeat map. © The Author 2014. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

A CT-rich haplotype in intron 4 of SNCA confers risk for Lewy body pathology in Alzheimer’s disease and affects SNCA expression

PubMed Central

Lutz, Michael W.; Saul, Robert; Linnertz, Colton; Glenn, Omolara-Chinue; Roses, Allen D.; Chiba-Falek, Ornit

2015-01-01

INTRODUCTION We recently showed that tagging-SNPs across the SNCA locus were significantly associated with increased risk for LB pathology in AD cases. However, the actual genetic variant(s) that underlie the observed associations remain elusive. METHODS We used a bioinformatics algorithm to catalogue Structural-Variants in a region of SNCA-intron4, followed by phased-sequencing. We performed a genetic-association analysis in autopsy series of LBV/AD cases compared with AD-only controls. We investigated the biological functions by expression analysis using temporal-cortex samples. RESULTS We identified four distinct haplotypes within a highly-polymorphic-low-complexity CT-rich region. We showed that a specific haplotype conferred risk to develop LBV/AD. We demonstrated that the CT-rich site acts as an enhancer element, where the risk haplotype was significantly associated with elevated levels of SNCA-mRNA. DISCUSSION We have discovered a novel haplotype in a CT-rich region in SNCA that contributes to LB pathology in AD patients, possibly via cis-regulation of the gene expression. PMID:26079410

Assessment of interbreeding and introgression of farm genes into a small Scottish Atlantic salmon Salmo salar stock: ad hoc samples - ad hoc results?

PubMed

Verspoor, E; Knox, D; Marshall, S

2016-12-01

An eclectic set of tissues and existing data, including purposely collected samples, spanning 1997-2006, was used in an ad hoc assessment of hybridization and introgression of farmed wild Atlantic salmon Salmo salar in the small Loch na Thull (LnT) catchment in north-west Scotland. The catchment is in an area of marine farm production and contains freshwater smolt rearing cages. The LnT S. salar stock was found to be genetically distinctive from stocks in neighbouring rivers and, despite regular reports of feral farm S. salar, there was no evidence of physical or genetic mixing. This cannot be completely ruled out, however, and low level mixing with other local wild stocks has been suggested. The LnT population appeared underpinned by relatively smaller effective number of breeders (N eb ) and showed relatively low levels of genetic diversity, consistent with a small effective population size. Small sample sizes, an incomplete farm baseline and the use of non-diagnostic molecular markers, constrain the power of the analysis but the findings strongly support the LnT catchment having a genetically distinct wild S. salar population little affected by interbreeding with feral farm escapes. © 2016 The Fisheries Society of the British Isles.

A molecular phylogenetic study on South Korean Tettigonia species (Orthoptera: Tettigoniidae) using five genetic loci: The possibility of multiple allopatric speciation.

PubMed

Kim, Tae-Kyu; Han, Taeman; Kim, Tae-Woo; Park, In Gyun; Kim, Seonghyun; Park, Haechul

2016-03-15

In Korea, members of the genus Tettigonia have been known as two species, T. ussuriana and T. dolichoptera dolichoptera. However, the taxonomic status of the Jeju Island population of T. ussuriana (JJ-TU) is in question, relative to the mainland population (ML-TU), because of their different body sizes and ratios of wing length. To clarify the relatedness of JJ-TU and ML-TU, we examined the genetic variation and phylogenetic relationships within and between T. ussuriana and related species collected in South Korea, using five genetic loci: three mitochondrial genes (cytochrome c oxidase subunit 1 [CO1], cytochrome c oxidase subunit 2 [CO2], NADH dehydrogenase 1 [ND1]) and two nuclear loci (second internal transcribed spacer [ITS2], and tubulin alpha-1 [TA1]). Unexpectedly, the JJ-TU population is explicitly sister to T. d. dolichoptera, with low genetic distance (0.76-1.22% in CO1), indicating no direct connection with the ML-TU population; this finding suggests a recent divergence involving rapid morphological change without gene flow between JJ-TU and mainland T. d. dolichoptera. The separation of these populations from their common ancestor was caused by geographical isolation during last glacial age. This finding indicates that the JJ-TU population should be elevated to the rank of subspecies, at the very least. Furthermore, the ML-TU population was also revealed to have four genetically divided groups (group A-D) from four localized populations, but no significant morphological differences exist among them. The genetic difference (range 3.19-4.10% in CO1) between group A + B and C + D was especially large, suggesting that cryptic speciation has widely occurred within the mainland areas, caused by allopatric isolations resulting from mountain barriers.

Docosahexaenoic Acid and the Aging Brain1–3

PubMed Central

Lukiw, Walter J.; Bazan, Nicolas G.

2008-01-01

The dietary essential PUFA docosahexaenoic acid [DHA; 22:6(n-3)] is a critical contributor to cell structure and function in the nervous system, and deficits in DHA abundance are associated with cognitive decline during aging and in neurodegenerative disease. Recent studies underscore the importance of DHA-derived neuroprotectin D1 (NPD1) in the homeostatic regulation of brain cell survival and repair involving neurotrophic, antiapoptotic and antiinflammatory signaling. Emerging evidence suggests that NPD1 synthesis is activated by growth factors and neurotrophins. Evolving research indicates that NPD1 has important determinant and regulatory interactions with the molecular-genetic mechanisms affecting β-amyloid precursor protein (βAPP) and amyloid beta (Aβ) peptide neurobiology. Deficits in DHA or its peroxidation appear to contribute to inflammatory signaling, apoptosis, and neuronal dysfunction in Alzheimer disease (AD), a common and progressive age-related neurological disorder unique to structures and processes of the human brain. This article briefly reviews our current understanding of the interactions of DHA and NPD1 on βAPP processing and Aβ peptide signaling and how this contributes to oxidative and pathogenic processes characteristic of aging and AD pathology. PMID:19022980

Does the cycad genotoxin MAM implicated in Guam ALS-PDC induce disease-relevant changes in mouse brain that includes olfaction?

PubMed

Kisby, Glen; Palmer, Valerie; Lasarev, Mike; Fry, Rebecca; Iordanov, Mihail; Magun, Eli; Samson, Leona; Spencer, Peter

2011-11-01

Western Pacific amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex (PDC), a prototypical neurodegenerative disease (tauopathy) affecting distinct genetic groups with common exposure to neurotoxic chemicals in cycad seed, has many features of Parkinson's and Alzheimer's diseases (AD), including early olfactory dysfunction. Guam ALS-PDC incidence correlates with cycad flour content of cycasin and its aglycone methylazoxymethanol (MAM), which produces persistent DNA damage (O(6)-methylguanine) in the brains of mice lacking O(6)-methylguanine methyltransferase (Mgmt(-/-)). We described in Mgmt(-/-)mice up to 7 days post-MAM treatment that brain DNA damage was linked to brain gene expression changes found in human neurological disease, cancer, and skin and hair development. This addendum reports 6 months post-MAM treatment- related brain transcriptional changes as well as elevated mitogen activated protein kinases and increased caspase-3 activity, both of which are involved in tau aggregation and neurofibrillary tangle formation typical of ALS-PDC and AD, plus transcriptional changes in olfactory receptors. Does cycasin act as a "slow (geno)toxin" in ALS-PDC?

Fine mapping of genetic variants in BIN1, CLU, CR1 and PICALM for association with cerebrospinal fluid biomarkers for Alzheimer's disease.

PubMed

Kauwe, John S K; Cruchaga, Carlos; Karch, Celeste M; Sadler, Brooke; Lee, Mo; Mayo, Kevin; Latu, Wayne; Su'a, Manti; Fagan, Anne M; Holtzman, David M; Morris, John C; Goate, Alison M

2011-02-09

Recent genome-wide association studies of Alzheimer's disease (AD) have identified variants in BIN1, CLU, CR1 and PICALM that show replicable association with risk for disease. We have thoroughly sampled common variation in these genes, genotyping 355 variants in over 600 individuals for whom measurements of two AD biomarkers, cerebrospinal fluid (CSF) 42 amino acid amyloid beta fragments (Aβ(42)) and tau phosphorylated at threonine 181 (ptau(181)), have been obtained. Association analyses were performed to determine whether variants in BIN1, CLU, CR1 or PICALM are associated with changes in the CSF levels of these biomarkers. Despite adequate power to detect effects as small as a 1.05 fold difference, we have failed to detect evidence for association between SNPs in these genes and CSF Aβ(42) or ptau(181) levels in our sample. Our results suggest that these variants do not affect risk via a mechanism that results in a strong additive effect on CSF levels of Aβ(42) or ptau(181).

Could adult female acne be associated with modern life?

PubMed

Albuquerque, R G R; Rocha, M A D; Bagatin, E; Tufik, S; Andersen, M L

2014-10-01

In recent years, the prevalence of adult female acne has increased, but the reason for this increase remains unclear. Acne is one of the most common skin disorders. It can be triggered or worsened by endogenous and exogenous factors, including genetic predisposition, hormone concentrations, diet, smoke and stress; although the interaction with this last factor is not well understood. Modern life presents many stresses including urban noises, socioeconomic pressures and light stimuli. Women are especially affected by stress during daily routine. The recent insertion in the labor market is added to the duties of the mother and wife. Women also have a higher risk of developing psychiatric disorders such as depression and anxiety. Sleep restriction is added to these factors, with several negative consequences on health, including on hormonal secretion and the immune system. This is further complicated by the natural variation in sleep architecture across the menstrual cycle. Recent studies have brought new data about the mechanisms and possible factors involved. This review aims to establish a connection between stress, sleep deprivation and adult female acne.

Reelin protects against amyloid β toxicity in vivo

PubMed Central

Lane-Donovan, Courtney; Philips, Gary T.; Wasser, Catherine R.; Durakoglugil, Murat S.; Masiulis, Irene; Upadhaya, Ajeet; Pohlkamp, Theresa; Coskun, Cagil; Kotti, Tiina; Steller, Laura; Hammer, Robert E.; Frotscher, Michael; Bock, Hans H.; Herz, Joachim

2015-01-01

Alzheimer's disease (AD) is a currently incurable neurodegenerative disorder and the most common form of dementia in people over the age of 65. The predominant genetic risk factor for AD is the ε4 allele encoding apolipoprotein E (ApoE4). The secreted glycoprotein Reelin, which is a physiological ligand for the multifunctional ApoE receptors Apolipoprotein E receptor 2 (Apoer2) and very low-density lipoprotein receptor (Vldlr), enhances synaptic plasticity. We have previously shown that the presence of ApoE4 renders neurons unresponsive to Reelin by impairing the recycling of the receptors, thereby decreasing its protective effects against amyloid β (Aβ) oligomer-induced synaptic toxicity in vitro. Here, we show that when Reelin was knocked out in adult mice, these mice behaved normally without overt learning or memory deficits. However, they were strikingly sensitive to amyloid-induced synaptic suppression, and had profound memory and learning disabilities at very low amounts of amyloid deposition. Our findings highlight the physiological importance of Reelin in protecting the brain against Aβ-induced synaptic dysfunction and memory impairment. PMID:26152694

Novel Genetic Models to Study the Role of Inflammation in Brain Injury-Induced Alzheimer’s Pathology

DTIC Science & Technology

2014-12-01

AD_________________ Award Number: W81XWH-12-1-0629 TITLE: Novel Genetic Models to Study the Role...CONTRACT NUMBER Novel Genetic Models to Study the Role of Inflammation in Brain Injury-Induced Alzheimer’s Pathology 5b. GRANT NUMBER W81XWH-12-1...However, our laboratories have recently performed pioneering studies using genetic labels regulated by these chemokine-receptor promoters to show

Map refinement of locus RP13 to human chromosome 17p13.3 in a second family with autosomal dominant retinitis pigmentosa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kojis, T.L.; Heinzmann, C.; Ngo, J.T.

1996-02-01

In order to elucidate the genetic basis of autosomal dominant retinitis pigmentosa (adRP) in a large eight-generation family (UCLA-RP09) of British descent, we assessed linkage between the UCLA-RP09 adRP gene and numerous genetic loci, including eight adRP candidate genes, five anonymous adRP-linked DNA loci, and 20 phenotypic markers. Linkage to the UCLA-RP09 disease gene was excluded for all eight candidate genes analyzed, including rhodopsin (RP4) and peripherin/RDS (RP7), for the four adRP loci RP1, RP9, RP10 and RP11, as well as for 17 phenotypic markers. The anonymous DNA marker locus D17S938, linked to adRP locus RP13 on chromosome 17p13.1, yieldedmore » a suggestive but not statistically significant positive lod score. Linkage was confirmed between the UCLA-RP09 adRP gene and markers distal to D17S938 in the chromosomal region 17p13.3. A reanalysis of the original RP13 data from a South African adRP family of British descent, in conjunction with our UCLA-RP09 data, suggests that only one adRP locus exists on 17p but that it maps to a more telomeric position, at band 17p13.3, than previously reported. Confirmation of the involvement of RP13 in two presumably unrelated adRP families, both of British descent, suggests that this locus is a distinct adRP gene in a proportion of British, and possibly other, adRP families. 39 refs., 4 figs., 3 tabs.« less

Genetic analyses of herding traits in the Border Collie using sheepdog trial data.

PubMed

Storteig Horn, S; Steinheim, G; Fjerdingby Olsen, H; Gjerjordet, H F; Klemetsdal, G

2017-04-01

The aim of this study was to evaluate the quality of the data provided from sheepdog trials in Norway, estimate heritabilities, repeatabilities and genetic correlations for the traits included in the trial and make recommendations on how sheepdog trials best can be utilized in the breeding of Border Collies in Norway. The analyses were based on test results from sheepdog trials carried out in Norway from 1993 to 2012. A total of 45 732 records from 3841 Border Collies were available, but after quality assurance only a third was left. The results demonstrated little information in the data. Heritabilities varied between 0.010 and 0.056 with standard errors ranging from 0.010 to 0.023, while repeatabilities ranged from 0.041 to 0.286. There is a need to assure the quality of data to improve the information in the test results. We recommend adding new traits based on the Herding Trait Characterization scheme evaluated in Sweden, and on traits from the predatory motor pattern, regarded as common for all dogs. These new traits may be scored across the elements that make up the current trial system, which should be kept in place to stimulate participation in the genetic evaluation scheme. © 2016 Blackwell Verlag GmbH.

Gene flow in a Yersinia pestis vector, Oropsylla hirsuta, during a plague epizootic.

PubMed

Jones, Philip H; Washburn, Leigh R; Britten, Hugh B

2011-09-01

Appreciating how Yersinia pestis, the etiological agent of plague, spreads among black - tailed prairie dog (Cynomys ludovicianus) colonies (BTPD), is vital to wildlife conservation programs in North American grasslands. A little - studied aspect of the system is the role of Y. pestis vectors, i.e. fleas, play in the spreading of plague in natural settings. We investigated the genetic structure and variability of a common prairie dog flea (Oropsylla hirsuta) in BTPD colonies in order to examine dispersal patterns. Given that this research took place during a widespread plague epizootic, there was the added advantage of gaining information on the dynamics of sylvatic plague. Oropsylla hirsuta were collected from BTPD burrows in nine colonies from May 2005 to July 2005, and eight polymorphic microsatellite markers were used to generate genotypic data from them. Gene flow estimates revealed low genetic differentiation among fleas sampled from different colonies. NestedPCR plague assays confirmed the presence of Y. pestis with the average Y. pestis prevalence across all nine colonies at 12%. No significant correlations were found between the genetic variability and gene flow of O. hirsuta and Y. pestis prevalence on a per -colony basis. Oropsylla hirsuta dispersal among BTPD colonies was high, potentially explaining the rapid spread of Y. pestis in our study area in 2005 and 2006.

Assessing the cost of implementing the 2011 Society of Obstetricians and Gynecologists of Canada and Canadian College of Medical Genetics practice guidelines on the detection of fetal aneuploidies.

PubMed

Lilley, Margaret; Hume, Stacey; Karpoff, Nina; Maire, Georges; Taylor, Sherry; Tomaszewski, Robert; Yoshimoto, Maisa; Christian, Susan

2017-09-01

The Society of Obstetricians and Gynecologists of Canada and the Canadian College of Medical Genetics published guidelines, in 2011, recommending replacement of karyotype with quantitative fluorescent polymerase chain reaction when prenatal testing is performed because of an increased risk of a common aneuploidy. This study's objective is to perform a cost analysis following the implementation of quantitative fluorescent polymerase chain reaction as a stand-alone test. A total of 658 samples were received between 1 April 2014 and 31 August 2015: 576 amniocentesis samples and 82 chorionic villi sampling. A chromosome abnormality was identified in 14% (93/658) of the prenatal samples tested. The implementation of the 2011 Society of Obstetricians and Gynecologists of Canada and the Canadian College of Medical Genetics guidelines in Edmonton and Northern Alberta resulted in a cost savings of $46 295.80. The replacement of karyotype with chromosomal microarray for some indications would be associated with additional costs. The implementation of new test methods may provide cost savings or added costs. Cost analysis is important to consider during the implementation of new guidelines or technologies. © 2017 John Wiley & Sons, Ltd. © 2017 John Wiley & Sons, Ltd.

Delineating genetic relationships among the Maya.

PubMed

Ibarra-Rivera, Lisa; Mirabal, Sheyla; Regueiro, Manuela M; Herrera, Rene J

2008-03-01

By 250 AD, the Classic Maya had become the most advanced civilization within the New World, possessing the only well-developed hieroglyphic writing system of the time and an advanced knowledge of mathematics, astronomy and architecture. Though only ruins of the empire remain, 7.5 million Mayan descendants still occupy areas of Mexico, Guatemala, Belize, El Salvador, and Honduras. Although they inhabit distant and distinct territories, speak more than 28 languages, and have been historically divided by warfare and a city-state-like political system, and they share characteristics such as rituals, artistic, architectural motifs that distinguish them as unequivocally Maya. This study was undertaken to determine whether these similarities among Mayan communities mirror genetic affinities or are merely a reflection of their common culture. Four Mayan populations were investigated (i.e., the K'iche and Kakchikel from Guatemala and the Campeche and Yucatan from Mexico) and compared with previously published populations across 15 autosomal STR loci. As a whole, the Maya emerge as a distinct group within Mesoamerica, indicating that they are more similar to each other than to other Mesoamerican groups. The data suggest that although geographic and political boundaries existed among Mayan communities, genetic exchanges between the different Mayan groups have occurred, supporting theories of extensive trading throughout the empire. 2007 Wiley-Liss, Inc.

GENETIC SUSCEPTIBILITY AND EXPERIMENTAL INDUCTION OF PULMONARY DISEASE

EPA Science Inventory

Genetic Susceptibility and Experimental Induction of Pulmonary Disease. UP Kodavanti, MC Schladweiler, AD Ledbetter, PS Gilmour, P Evansky, KR Smith*, WP Watkinson, DL Costa, KE Pinkerton*. ETD, NHEERL, ORD, US EPA, RTP, NC; *Univ California, Davis, CA, USA.
Conventional la...

New insights into the genetics of glioblastoma multiforme by familial exome sequencing

PubMed Central

Backes, Christina; Harz, Christian; Fischer, Ulrike; Schmitt, Jana; Ludwig, Nicole; Petersen, Britt-Sabina; Mueller, Sabine C.; Kim, Yoo-Jin; Wolf, Nadine M.; Katus, Hugo A.; Meder, Benjamin; Furtwängler, Rhoikos; Franke, Andre; Bohle, Rainer; Henn, Wolfram; Graf, Norbert; Keller, Andreas; Meese, Eckart

2015-01-01

Glioblastoma multiforme (GBM) is the most aggressive and malignant subtype of human brain tumors. While a family clustering of GBM has long been acknowledged, relevant hereditary factors still remained elusive. Exome sequencing of families offers the option to discover respective genetic factors. We sequenced blood samples of one of the rare affected families: while both parents were healthy, both children were diagnosed with GBM. We report 85 homozygous non-synonymous single nucleotide variations (SNVs) in both siblings that were heterozygous in the parents. Beyond known key players for GBM such as ERBB2, PMS2, or CHI3L1, we identified over 50 genes that have not been associated to GBM so far. We also discovered three accumulative effects potentially adding to the tumorigenesis in the siblings: a clustering of multiple variants in single genes (e.g. PTPRB, CROCC), the aggregation of affected genes on specific molecular pathways (e.g. Focal adhesion or ECM receptor interaction) and genomic proximity (e.g. chr22.q12.2, chr1.p36.33). We found a striking accumulation of SNVs in specific genes for the daughter, who developed not only a GBM at the age of 12 years but was subsequently diagnosed with a pilocytic astrocytoma, a common acute lymphatic leukemia and a diffuse pontine glioma. The reported variants underline the relevance of genetic predisposition and cancer development in this family and demonstrate that GBM has a complex and heterogeneous genetic background. Sequencing of other affected families will help to further narrow down the driving genetic causes for this disease. PMID:25537509

A gene-brain-cognition pathway for the effect of an Alzheimer׳s risk gene on working memory in young adults.

PubMed

Stevens, Benson W; DiBattista, Amanda M; William Rebeck, G; Green, Adam E

2014-08-01

Identifying pathways by which genetic Alzheimer׳s disease (AD) risk factors exert neurocognitive effects in young adults are essential for the effort to develop early interventions to forestall or prevent AD onset. Here, in a brain-imaging cohort of 59 young adults, we investigated effects of a variant within the clusterin (CLU) gene on working memory function and gray matter volume in cortical areas that support working memory. In addition, we investigated the extent to which effects of CLU genotype on working memory were independent of variation in the strongest AD risk factor gene apolipoprotein E (APOE). CLU is among the strongest genetic AD risk factors and, though it appears to share AD pathogenesis-related features with, APOE, it has been far less well studied. CLU genotype was associated with working memory performance in our study cohort. Notably, we found that variation in gray matter volume in a parietal region, previously implicated in maintenance of information for working memory, mediated the effect of CLU on working memory performance. APOE genotype did not affect working memory within our sample, and did not interact with CLU genotype. To our knowledge, this work represents the first evidence of a behavioral effect of CLU genotype in young people. In addition, this work identifies the first gene-brain-cognition mediation effect pathway for the transmission of the effect of an AD risk factor. Relative to conventional pairwise associations in cognitive neurogenetic research, gene-brain-cognition mediation modeling provides a more integrated understanding of how genetic effects transmit from gene to brain to cognitive function. Copyright © 2014 Elsevier Ltd. All rights reserved.

Intraspecific morphological and genetic variation of common species predicts ranges of threatened ones

PubMed Central

Fuller, Trevon L.; Thomassen, Henri A.; Peralvo, Manuel; Buermann, Wolfgang; Milá, Borja; Kieswetter, Charles M.; Jarrín-V, Pablo; Devitt, Susan E. Cameron; Mason, Eliza; Schweizer, Rena M.; Schlunegger, Jasmin; Chan, Janice; Wang, Ophelia; Schneider, Christopher J.; Pollinger, John P.; Saatchi, Sassan; Graham, Catherine H.; Wayne, Robert K.; Smith, Thomas B.

2013-01-01

Predicting where threatened species occur is useful for making informed conservation decisions. However, because they are usually rare, surveying threatened species is often expensive and time intensive. Here, we show how regions where common species exhibit high genetic and morphological divergence among populations can be used to predict the occurrence of species of conservation concern. Intraspecific variation of common species of birds, bats and frogs from Ecuador were found to be a significantly better predictor for the occurrence of threatened species than suites of environmental variables or the occurrence of amphibians and birds. Fully 93 per cent of the threatened species analysed had their range adequately represented by the geographical distribution of the morphological and genetic variation found in seven common species. Both higher numbers of threatened species and greater genetic and morphological variation of common species occurred along elevation gradients. Higher levels of intraspecific divergence may be the result of disruptive selection and/or introgression along gradients. We suggest that collecting data on genetic and morphological variation in common species can be a cost effective tool for conservation planning, and that future biodiversity inventories include surveying genetic and morphological data of common species whenever feasible. PMID:23595273

Genetic architecture of the Delis-Kaplan Executive Function System Trail Making Test: evidence for distinct genetic influences on executive function.

PubMed

Vasilopoulos, Terrie; Franz, Carol E; Panizzon, Matthew S; Xian, Hong; Grant, Michael D; Lyons, Michael J; Toomey, Rosemary; Jacobson, Kristen C; Kremen, William S

2012-03-01

To examine how genes and environments contribute to relationships among Trail Making Test (TMT) conditions and the extent to which these conditions have unique genetic and environmental influences. Participants included 1,237 middle-aged male twins from the Vietnam Era Twin Study of Aging. The Delis-Kaplan Executive Function System TMT included visual searching, number and letter sequencing, and set-shifting components. Phenotypic correlations among TMT conditions ranged from 0.29 to 0.60, and genes accounted for the majority (58-84%) of each correlation. Overall heritability ranged from 0.34 to 0.62 across conditions. Phenotypic factor analysis suggested a single factor. In contrast, genetic models revealed a single common genetic factor but also unique genetic influences separate from the common factor. Genetic variance (i.e., heritability) of number and letter sequencing was completely explained by the common genetic factor while unique genetic influences separate from the common factor accounted for 57% and 21% of the heritabilities of visual search and set shifting, respectively. After accounting for general cognitive ability, unique genetic influences accounted for 64% and 31% of those heritabilities. A common genetic factor, most likely representing a combination of speed and sequencing, accounted for most of the correlation among TMT 1-4. Distinct genetic factors, however, accounted for a portion of variance in visual scanning and set shifting. Thus, although traditional phenotypic shared variance analysis techniques suggest only one general factor underlying different neuropsychological functions in nonpatient populations, examining the genetic underpinnings of cognitive processes with twin analysis can uncover more complex etiological processes.

Integrating mRNA and miRNA Weighted Gene Co-Expression Networks with eQTLs in the Nucleus Accumbens of Subjects with Alcohol Dependence

PubMed Central

Blevins, Tana; Aliev, Fazil; Adkins, Amy; Hack, Laura; Bigdeli, Tim; D. van der Vaart, Andrew; Web, Bradley Todd; Bacanu, Silviu-Alin; Kalsi, Gursharan; Kendler, Kenneth S.; Miles, Michael F.; Dick, Danielle; Riley, Brien P.; Dumur, Catherine; Vladimirov, Vladimir I.

2015-01-01

Alcohol consumption is known to lead to gene expression changes in the brain. After performing weighted gene co-expression network analyses (WGCNA) on genome-wide mRNA and microRNA (miRNA) expression in Nucleus Accumbens (NAc) of subjects with alcohol dependence (AD; N = 18) and of matched controls (N = 18), six mRNA and three miRNA modules significantly correlated with AD were identified (Bonferoni-adj. p≤ 0.05). Cell-type-specific transcriptome analyses revealed two of the mRNA modules to be enriched for neuronal specific marker genes and downregulated in AD, whereas the remaining four mRNA modules were enriched for astrocyte and microglial specific marker genes and upregulated in AD. Gene set enrichment analysis demonstrated that neuronal specific modules were enriched for genes involved in oxidative phosphorylation, mitochondrial dysfunction and MAPK signaling. Glial-specific modules were predominantly enriched for genes involved in processes related to immune functions, i.e. cytokine signaling (all adj. p≤ 0.05). In mRNA and miRNA modules, 461 and 25 candidate hub genes were identified, respectively. In contrast to the expected biological functions of miRNAs, correlation analyses between mRNA and miRNA hub genes revealed a higher number of positive than negative correlations (χ2 test p≤ 0.0001). Integration of hub gene expression with genome-wide genotypic data resulted in 591 mRNA cis-eQTLs and 62 miRNA cis-eQTLs. mRNA cis-eQTLs were significantly enriched for AD diagnosis and AD symptom counts (adj. p = 0.014 and p = 0.024, respectively) in AD GWAS signals in a large, independent genetic sample from the Collaborative Study on Genetics of Alcohol (COGA). In conclusion, our study identified putative gene network hubs coordinating mRNA and miRNA co-expression changes in the NAc of AD subjects, and our genetic (cis-eQTL) analysis provides novel insights into the etiological mechanisms of AD. PMID:26381263

Genetic Evaluation for the Scoliosis Gene(s) in Patients with Neurofibromatosis 1 and Scoliosis

DTIC Science & Technology

2012-08-01

AD_________________ Award Number: W81XWH-10-1-0469 TITLE: Genetic Evaluation for the Scoliosis ...Gene(s) in Patients with Neurofibromatosis 1 and Scoliosis PRINCIPAL INVESTIGATOR: David W. Polly, Jr., M.D...2011 – 31 July 2012 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Genetic Evaluation for the Scoliosis Gene(s) in Patients with Neurofibromatosis 1

Sertraline for the treatment of depression in Alzheimer disease: genetic influences.

PubMed

Peters, Matthew E; Vaidya, Vijay; Drye, Lea T; Rosenberg, Paul B; Martin, Barbara K; Porsteinsson, Anton P; Frangakis, Constantine E; Mintzer, Jacobo; Weintraub, Daniel; Schneider, Lon S; Rabins, Peter V; Munro, Cynthia A; Meinert, Curtis L; Lyketsos, Constantine G; Avramopoulos, Dimitri; Dimitri, Avramopoulos

2011-12-01

To assess the potential for genetic influences on sertraline treatment efficacy for depression of Alzheimer disease (dAD). Four functional genetic variants were studied: 2 serotonin receptors (HTR2A-T102C and HTR2C-Cys23Ser), the serotonin transporter (5HTT-LPR), and brain-derived neurotrophic factor (BDNF-Val66Met). Treatment response by genotype was measured by (1) the modified Alzheimer's Disease Cooperative Study Clinical Global Impression of Change, (2) the Cornell scale for Depression in Dementia, and (3) remission of depression. We utilized data from the Depression in Alzheimer's Disease Study 2 (DIADS-2), a 24-week, randomized, multicenter trial showing no significant treatment effect of sertraline on dAD. Proportional odds logistic regression and mixed effects models were used to examine the above mentioned outcome measures. No significant interactions were seen between any of the genetic polymorphisms and the selected outcomes above at 12 or 24 weeks. Treatment outcomes in the DIADS-2 trial were not significantly influenced by genetic variation at the loci that were assessed. Future studies should continue to examine the interaction of depression-related genetic variants with antidepressant treatment in Alzheimer disease patients with depression.

Genomics of Alzheimer Disease: A Review.

PubMed

Rosenberg, Roger N; Lambracht-Washington, Doris; Yu, Gang; Xia, Weiming

2016-07-01

To provide a comprehensive review of knowledge of the genomics of Alzheimer disease (AD) and DNA amyloid β 42 (Aβ42) vaccination as a potential therapy. Genotype-phenotype correlations of AD are presented to provide a comprehensive appreciation of the spectrum of disease causation. Alzheimer disease is caused in part by the overproduction and lack of clearance of Aβ protein. Oligomer Aβ, the most toxic species of Aβ, causes direct injury to neurons, accompanied by enhanced neuroinflammation, astrocytosis and gliosis, and eventually neuronal loss. The strongest genetic evidence supporting this hypothesis derives from mutations in the amyloid precursor protein (APP) gene. A detrimental APP mutation at the β-secretase cleavage site linked to early-onset AD found in a Swedish pedigree enhances Aβ production, in contrast to a beneficial mutation 2 residues away in APP that reduces Aβ production and protects against the onset of sporadic AD. A number of common variants associated with late-onset AD have been identified including apolipoprotein E, BIN1, ABC7, PICALM, MS4A4E/MS4A6A, CD2Ap, CD33, EPHA1, CLU, CR1, and SORL1. One or 2 copies of the apolipoprotein E ε4 allele are a major risk factor for late-onset AD. With DNA Aβ42 vaccination, a Th2-type noninflammatory immune response was achieved with a downregulation of Aβ42-specific effector (Th1, Th17, and Th2) cell responses at later immunization times. DNA Aβ42 vaccination upregulated T regulator cells (CD4+, CD25+, and FoxP3+) and its cytokine interleukin 10, resulting in downregulation of T effectors. Mutations in APP and PS-1 and PS-2 genes that are associated with early-onset, autosomal, dominantly inherited AD, in addition to the at-risk gene polymorphisms responsible for late-onset AD, all indicate a direct and early role of Aβ in the pathogenesis of AD. A translational result of genomic research has been Aβ-reducing therapies including DNA Aβ42 vaccination as a promising approach to delay or prevent this disease.

Innovative Research Design Exploring the Effects of Physical Activity and Genetics on Cognitive Performance in Community-Based Older Adults

PubMed Central

Etnier, Jennifer L.; Labban, Jeffrey D.; Karper, William B.; Wideman, Laurie; Piepmeier, Aaron T.; Shih, Chia-Hao; Castellano, Michael; Williams, Lauren M.; Park, Se-Yun; Henrich, Vincent C.; Dudley, William N.; Rulison, Kelli L.

2015-01-01

Physical activity is predictive of better cognitive performance and lower risk of Alzheimer’s disease (AD). The apolipoprotein E gene (APOE) is a susceptibility gene for AD with the e4 allele being associated with a greater risk of AD. Cross-sectional and prospective research shows that physical activity is predictive of better cognitive performance for those at greater genetic risk for AD. However, the moderating role of APOE on the effects of a physical activity intervention on cognitive performance has not been examined. The purpose of this manuscript is to justify the need for such research and to describe the design, methods, and recruitment tactics used in the conductance of a study designed to provide insight as to the extent to which cognitive benefits resulting from an 8-month physical activity program are differentiated by ApoEe4 status. The effectiveness of the recruitment strategies and the feasibility of recruiting ApoE e4 carriers are discussed. PMID:25594264

Innovative Research Design Exploring the Effects of Physical Activity and Genetics on Cognitive Performance in Community-Based Older Adults.

PubMed

Etnier, Jennifer L; Labban, Jeffrey D; Karper, William B; Wideman, Laurie; Piepmeier, Aaron T; Shih, Chia-Hao; Castellano, Michael; Williams, Lauren M; Park, Se-Yun; Henrich, Vincent C; Dudley, William N; Rulison, Kelli L

2015-10-01

Physical activity is predictive of better cognitive performance and lower risk of Alzheimer's disease (AD). The apolipoprotein E gene (APOE) is a susceptibility gene for AD with the e4 allele being associated with a greater risk of AD. Cross-sectional and prospective research shows that physical activity is predictive of better cognitive performance for those at greater genetic risk for AD. However, the moderating role of APOE on the effects of a physical activity intervention on cognitive performance has not been examined. The purpose of this manuscript is to justify the need for such research and to describe the design, methods, and recruitment tactics used in the conductance of a study designed to provide insight as to the extent to which cognitive benefits resulting from an 8-month physical activity program are differentiated by APOE e4 status. The effectiveness of the recruitment strategies and the feasibility of recruiting APOE e4 carriers are discussed.

Precision medicine and drug development in Alzheimer's disease: The importance of sexual dimorphism and patient stratification.

PubMed

Hampel, Harald; Vergallo, Andrea; Giorgi, Filippo Sean; Kim, Seung Hyun; Depypere, Herman; Graziani, Manuela; Saidi, Amira; Nisticò, Robert; Lista, Simone

2018-06-12

Neurodegenerative diseases (ND) are among the leading causes of disability and mortality. Considerable sex differences exist in the occurrence of the various manifestations leading to cognitive decline. Alzheimer's disease (AD) exhibits substantial sexual dimorphisms and disproportionately affects women. Women have a higher life expectancy compared to men and, consequently, have more lifespan to develop AD. The emerging precision medicine and pharmacology concepts - taking into account the individual genetic and biological variability relevant for disease risk, prevention, detection, diagnosis, and treatment - are expected to substantially enhance our knowledge and management of AD. Stratifying the affected individuals by sex and gender is an important basic step towards personalization of scientific research, drug development, and care. We hypothesize that sex and gender differences, extending from genetic to psychosocial domains, are highly relevant for the understanding of AD pathophysiology, and for the conceptualization of basic/translational research and for clinical therapy trial design. Copyright © 2018 Elsevier Inc. All rights reserved.

The amyloid precursor protein locus and very-late-onset Alzheimer disease.

PubMed

Olson, J M; Goddard, K A; Dudek, D M

2001-10-01

Although mutations in the amyloid-beta precursor protein (APP) gene are known to confer high risk of Alzheimer disease (AD) to a small percentage of families in which it has early onset, convincing evidence of a major role for the APP locus in late-onset AD has not been forthcoming. In this report, we have used a covariate-based affected-sib-pair linkage method to analyze the chromosome 21 clinical and genetic data obtained on affected sibships by the National Institute of Mental Health Alzheimer Disease Genetics Initiative. The baseline model (without covariates) gave a LOD score of 0.02, which increases to 1.43 when covariates representing the additive effects of E2 and E4 are added. Larger increases in LOD scores were found when age at last examination/death (LOD score 5.54; P=.000002) or age at onset plus disease duration (LOD score 5.63; P=.000006) were included in the linkage model. We conclude that the APP locus may predispose to AD in the very elderly.

Bioinformatics Identification of Modules of Transcription Factor Binding Sites in Alzheimer's Disease-Related Genes by In Silico Promoter Analysis and Microarrays

PubMed Central

Augustin, Regina; Lichtenthaler, Stefan F.; Greeff, Michael; Hansen, Jens; Wurst, Wolfgang; Trümbach, Dietrich

2011-01-01

The molecular mechanisms and genetic risk factors underlying Alzheimer's disease (AD) pathogenesis are only partly understood. To identify new factors, which may contribute to AD, different approaches are taken including proteomics, genetics, and functional genomics. Here, we used a bioinformatics approach and found that distinct AD-related genes share modules of transcription factor binding sites, suggesting a transcriptional coregulation. To detect additional coregulated genes, which may potentially contribute to AD, we established a new bioinformatics workflow with known multivariate methods like support vector machines, biclustering, and predicted transcription factor binding site modules by using in silico analysis and over 400 expression arrays from human and mouse. Two significant modules are composed of three transcription factor families: CTCF, SP1F, and EGRF/ZBPF, which are conserved between human and mouse APP promoter sequences. The specific combination of in silico promoter and multivariate analysis can identify regulation mechanisms of genes involved in multifactorial diseases. PMID:21559189

The role of clusterin in Alzheimer's disease: pathways, pathogenesis, and therapy.

PubMed

Yu, Jin-Tai; Tan, Lan

2012-04-01

Genetic variation in clusterin gene, also known as apolipoprotein J, has been associated with Alzheimer's disease (AD) through replicated genome-wide studies, and plasma clusterin levels are associated with brain atrophy, baseline prevalence and severity, and rapid clinical progression in patients with AD, highlighting the importance of clusterin in AD pathogenesis. Emerging data suggest that clusterin contributes to AD through various pathways, including amyloid-β aggregation and clearance, lipid metabolism, neuroinflammation, and neuronal cell cycle control and apoptosis. Moreover, epigenetic regulation of the clusterin expression also seems to play an important role in the pathogenesis of AD. Emerging knowledge of the contribution of clusterin to the pathogenesis of AD presents new opportunities for AD therapy.

Molecular genetic contributions to socioeconomic status and intelligence

PubMed Central

Marioni, Riccardo E.; Davies, Gail; Hayward, Caroline; Liewald, Dave; Kerr, Shona M.; Campbell, Archie; Luciano, Michelle; Smith, Blair H.; Padmanabhan, Sandosh; Hocking, Lynne J.; Hastie, Nicholas D.; Wright, Alan F.; Porteous, David J.; Visscher, Peter M.; Deary, Ian J.

2014-01-01

Education, socioeconomic status, and intelligence are commonly used as predictors of health outcomes, social environment, and mortality. Education and socioeconomic status are typically viewed as environmental variables although both correlate with intelligence, which has a substantial genetic basis. Using data from 6815 unrelated subjects from the Generation Scotland study, we examined the genetic contributions to these variables and their genetic correlations. Subjects underwent genome-wide testing for common single nucleotide polymorphisms (SNPs). DNA-derived heritability estimates and genetic correlations were calculated using the ‘Genome-wide Complex Trait Analyses’ (GCTA) procedures. 21% of the variation in education, 18% of the variation in socioeconomic status, and 29% of the variation in general cognitive ability was explained by variation in common SNPs (SEs ~ 5%). The SNP-based genetic correlations of education and socioeconomic status with general intelligence were 0.95 (SE 0.13) and 0.26 (0.16), respectively. There are genetic contributions to intelligence and education with near-complete overlap between common additive SNP effects on these traits (genetic correlation ~ 1). Genetic influences on socioeconomic status are also associated with the genetic foundations of intelligence. The results are also compatible with substantial environmental contributions to socioeconomic status. PMID:24944428

Molecular genetic contributions to socioeconomic status and intelligence.

PubMed

Marioni, Riccardo E; Davies, Gail; Hayward, Caroline; Liewald, Dave; Kerr, Shona M; Campbell, Archie; Luciano, Michelle; Smith, Blair H; Padmanabhan, Sandosh; Hocking, Lynne J; Hastie, Nicholas D; Wright, Alan F; Porteous, David J; Visscher, Peter M; Deary, Ian J

2014-05-01

Education, socioeconomic status, and intelligence are commonly used as predictors of health outcomes, social environment, and mortality. Education and socioeconomic status are typically viewed as environmental variables although both correlate with intelligence, which has a substantial genetic basis. Using data from 6815 unrelated subjects from the Generation Scotland study, we examined the genetic contributions to these variables and their genetic correlations. Subjects underwent genome-wide testing for common single nucleotide polymorphisms (SNPs). DNA-derived heritability estimates and genetic correlations were calculated using the 'Genome-wide Complex Trait Analyses' (GCTA) procedures. 21% of the variation in education, 18% of the variation in socioeconomic status, and 29% of the variation in general cognitive ability was explained by variation in common SNPs (SEs ~ 5%). The SNP-based genetic correlations of education and socioeconomic status with general intelligence were 0.95 (SE 0.13) and 0.26 (0.16), respectively. There are genetic contributions to intelligence and education with near-complete overlap between common additive SNP effects on these traits (genetic correlation ~ 1). Genetic influences on socioeconomic status are also associated with the genetic foundations of intelligence. The results are also compatible with substantial environmental contributions to socioeconomic status.

Genome-wide association study of CSF levels of 59 alzheimer's disease candidate proteins: significant associations with proteins involved in amyloid processing and inflammation.

PubMed

Kauwe, John S K; Bailey, Matthew H; Ridge, Perry G; Perry, Rachel; Wadsworth, Mark E; Hoyt, Kaitlyn L; Staley, Lyndsay A; Karch, Celeste M; Harari, Oscar; Cruchaga, Carlos; Ainscough, Benjamin J; Bales, Kelly; Pickering, Eve H; Bertelsen, Sarah; Fagan, Anne M; Holtzman, David M; Morris, John C; Goate, Alison M

2014-10-01

Cerebrospinal fluid (CSF) 42 amino acid species of amyloid beta (Aβ42) and tau levels are strongly correlated with the presence of Alzheimer's disease (AD) neuropathology including amyloid plaques and neurodegeneration and have been successfully used as endophenotypes for genetic studies of AD. Additional CSF analytes may also serve as useful endophenotypes that capture other aspects of AD pathophysiology. Here we have conducted a genome-wide association study of CSF levels of 59 AD-related analytes. All analytes were measured using the Rules Based Medicine Human DiscoveryMAP Panel, which includes analytes relevant to several disease-related processes. Data from two independently collected and measured datasets, the Knight Alzheimer's Disease Research Center (ADRC) and Alzheimer's Disease Neuroimaging Initiative (ADNI), were analyzed separately, and combined results were obtained using meta-analysis. We identified genetic associations with CSF levels of 5 proteins (Angiotensin-converting enzyme (ACE), Chemokine (C-C motif) ligand 2 (CCL2), Chemokine (C-C motif) ligand 4 (CCL4), Interleukin 6 receptor (IL6R) and Matrix metalloproteinase-3 (MMP3)) with study-wide significant p-values (p<1.46×10-10) and significant, consistent evidence for association in both the Knight ADRC and the ADNI samples. These proteins are involved in amyloid processing and pro-inflammatory signaling. SNPs associated with ACE, IL6R and MMP3 protein levels are located within the coding regions of the corresponding structural gene. The SNPs associated with CSF levels of CCL4 and CCL2 are located in known chemokine binding proteins. The genetic associations reported here are novel and suggest mechanisms for genetic control of CSF and plasma levels of these disease-related proteins. Significant SNPs in ACE and MMP3 also showed association with AD risk. Our findings suggest that these proteins/pathways may be valuable therapeutic targets for AD. Robust associations in cognitively normal individuals suggest that these SNPs also influence regulation of these proteins more generally and may therefore be relevant to other diseases.

Comorbidity in Atopic Dermatitis.

PubMed

Simpson, Eric L

2012-03-01

The negative impact of atopic dermatitis (AD) often extends beyond the skin. Children with AD experience increased rates of infectious, mental health, and allergic diseases compared to their non-atopic peers. The mechanisms underlying these associations remain elusive. New insights from genetic and epidermal research pinpoint the skin barrier as a primary initiator of AD. Epicutaneous sensitization represents an intriguing new model which links a disrupted skin barrier to the later development of IgE-mediated diseases in patients with AD. Recent epidemiological studies have identified new comorbidities linked to AD as well, including several mental health disorders and obesity. This manuscript reviews the recent literature regarding both classic and newly described AD comorbidities.

Disease-related microglia heterogeneity in the hippocampus of Alzheimer's disease, dementia with Lewy bodies, and hippocampal sclerosis of aging.

PubMed

Bachstetter, Adam D; Van Eldik, Linda J; Schmitt, Frederick A; Neltner, Janna H; Ighodaro, Eseosa T; Webster, Scott J; Patel, Ela; Abner, Erin L; Kryscio, Richard J; Nelson, Peter T

2015-05-23

Neuropathological, genetic, and biochemical studies have provided support for the hypothesis that microglia participate in Alzheimer's disease (AD) pathogenesis. Despite the extensive characterization of AD microglia, there are still many unanswered questions, and little is known about microglial morphology in other common forms of age-related dementia: particularly, dementia with Lewy bodies (DLB) and hippocampal sclerosis of aging (HS-Aging). In addition, no prior studies have attempted to compare and contrast the microglia morphology in the hippocampus of various neurodegenerative conditions. Here we studied cases with pathologically-confirmed AD (n = 7), HS-Aging (n = 7), AD + HS-aging (n = 4), DLB (n = 12), and normal (cognitively intact) controls (NC) (n = 9) from the University of Kentucky Alzheimer's Disease Center autopsy cohort. We defined five microglia morphological phenotypes in the autopsy samples: ramified, hypertrophic, dystrophic, rod-shaped, and amoeboid. The Aperio ScanScope digital neuropathological tool was used along with two well-known microglial markers: IBA1 (a marker for both resting and activated microglia) and CD68 (a lysosomal marker in macrophages/microglia associated with phagocytic cells). Hippocampal staining analyses included studies of subregions within the hippocampal formation and nearby white matter. Using these tools and methods, we describe variation in microglial characteristics that show some degree of disease specificity, including, (1) increased microglia density and number in HS-aging and AD + HS-aging; (2) low microglia density in DLB; (3) increased number of dystrophic microglia in HS-aging; and (4) increased proportion of dystrophic to all microglia in DLB. We conclude that variations in morphologies among microglial cells, and cells of macrophage lineage, can help guide future work connecting neuroinflammatory mechanisms with specific neurodegenerative disease subtypes.

The Potential of Genetic Engineering in Agriculture to Affect Global Stability

DTIC Science & Technology

2013-04-17

manipulation in agriculture is thousands of years old, dating back to man’s first efforts of plant domestication. Over the last 200 years, and especially the...engineering.” In agriculture, genetic engineering describes the science of manipulating the genetic material (DNA) of plants by adding or taking...nature run its course. This paper does not delve into the science or even the raging safety debate over the use of genetic engineering in plants that

Ordered-subsets linkage analysis detects novel Alzheimer disease loci on chromosomes 2q34 and 15q22.

PubMed

Scott, William K; Hauser, Elizabeth R; Schmechel, Donald E; Welsh-Bohmer, Kathleen A; Small, Gary W; Roses, Allen D; Saunders, Ann M; Gilbert, John R; Vance, Jeffery M; Haines, Jonathan L; Pericak-Vance, Margaret A

2003-11-01

Alzheimer disease (AD) is a complex disorder characterized by a wide range, within and between families, of ages at onset of symptoms. Consideration of age at onset as a covariate in genetic-linkage studies may reduce genetic heterogeneity and increase statistical power. Ordered-subsets analysis includes continuous covariates in linkage analysis by rank ordering families by a covariate and summing LOD scores to find a subset giving a significantly increased LOD score relative to the overall sample. We have analyzed data from 336 markers in 437 multiplex (>/=2 sampled individuals with AD) families included in a recent genomic screen for AD loci. To identify genetic heterogeneity by age at onset, families were ordered by increasing and decreasing mean and minimum ages at onset. Chromosomewide significance of increases in the LOD score in subsets relative to the overall sample was assessed by permutation. A statistically significant increase in the nonparametric multipoint LOD score was observed on chromosome 2q34, with a peak LOD score of 3.2 at D2S2944 (P=.008) in 31 families with a minimum age at onset between 50 and 60 years. The LOD score in the chromosome 9p region previously linked to AD increased to 4.6 at D9S741 (P=.01) in 334 families with minimum age at onset between 60 and 75 years. LOD scores were also significantly increased on chromosome 15q22: a peak LOD score of 2.8 (P=.0004) was detected at D15S1507 (60 cM) in 38 families with minimum age at onset >/=79 years, and a peak LOD score of 3.1 (P=.0006) was obtained at D15S153 (62 cM) in 43 families with mean age at onset >80 years. Thirty-one families were contained in both 15q22 subsets, indicating that these results are likely detecting the same locus. There is little overlap in these subsets, underscoring the utility of age at onset as a marker of genetic heterogeneity. These results indicate that linkage to chromosome 9p is strongest in late-onset AD and that regions on chromosome 2q34 and 15q22 are linked to early-onset AD and very-late-onset AD, respectively.

[Genetics determination of wheat resistance to Puccinia graminis F. sp. tritici deriving from Aegilops cylindrica, Triticum erebuni and amphidiploid 4].

PubMed

Babaiants, O V; Babaiants, L T; Horash, A F; Vasil'ev, A A; Trackovetskaia, V A; Paliasn'iĭĭ, V A

2012-01-01

The lines of winter soft wheat developed in the Plant Breeding and Genetics Institute contain new effective introgressive Sr-genes. Line 85/06 possess SrAc1 gene, lines 47/06, 54/06, 82/06, 85/06, 87/06, 238/06, and 367/06 possess SrAc1 and SrAc2 derived from Aegilops cylindrica, line 352/06 - SrTe1 and SrTe2 from Triticum erebuni, line 12/86-04 - SrAd1 and SrAd2 from Amphidiploid 4 (Triticum dicoccoides x Triticum tauschii).

Deleterious ABCA7 mutations and transcript rescue mechanisms in early onset Alzheimer's disease.

PubMed

De Roeck, Arne; Van den Bossche, Tobi; van der Zee, Julie; Verheijen, Jan; De Coster, Wouter; Van Dongen, Jasper; Dillen, Lubina; Baradaran-Heravi, Yalda; Heeman, Bavo; Sanchez-Valle, Raquel; Lladó, Albert; Nacmias, Benedetta; Sorbi, Sandro; Gelpi, Ellen; Grau-Rivera, Oriol; Gómez-Tortosa, Estrella; Pastor, Pau; Ortega-Cubero, Sara; Pastor, Maria A; Graff, Caroline; Thonberg, Håkan; Benussi, Luisa; Ghidoni, Roberta; Binetti, Giuliano; de Mendonça, Alexandre; Martins, Madalena; Borroni, Barbara; Padovani, Alessandro; Almeida, Maria Rosário; Santana, Isabel; Diehl-Schmid, Janine; Alexopoulos, Panagiotis; Clarimon, Jordi; Lleó, Alberto; Fortea, Juan; Tsolaki, Magda; Koutroumani, Maria; Matěj, Radoslav; Rohan, Zdenek; De Deyn, Peter; Engelborghs, Sebastiaan; Cras, Patrick; Van Broeckhoven, Christine; Sleegers, Kristel

2017-09-01

Premature termination codon (PTC) mutations in the ATP-Binding Cassette, Sub-Family A, Member 7 gene (ABCA7) have recently been identified as intermediate-to-high penetrant risk factor for late-onset Alzheimer's disease (LOAD). High variability, however, is observed in downstream ABCA7 mRNA and protein expression, disease penetrance, and onset age, indicative of unknown modifying factors. Here, we investigated the prevalence and disease penetrance of ABCA7 PTC mutations in a large early onset AD (EOAD)-control cohort, and examined the effect on transcript level with comprehensive third-generation long-read sequencing. We characterized the ABCA7 coding sequence with next-generation sequencing in 928 EOAD patients and 980 matched control individuals. With MetaSKAT rare variant association analysis, we observed a fivefold enrichment (p = 0.0004) of PTC mutations in EOAD patients (3%) versus controls (0.6%). Ten novel PTC mutations were only observed in patients, and PTC mutation carriers in general had an increased familial AD load. In addition, we observed nominal risk reducing trends for three common coding variants. Seven PTC mutations were further analyzed using targeted long-read cDNA sequencing on an Oxford Nanopore MinION platform. PTC-containing transcripts for each investigated PTC mutation were observed at varying proportion (5-41% of the total read count), implying incomplete nonsense-mediated mRNA decay (NMD). Furthermore, we distinguished and phased several previously unknown alternative splicing events (up to 30% of transcripts). In conjunction with PTC mutations, several of these novel ABCA7 isoforms have the potential to rescue deleterious PTC effects. In conclusion, ABCA7 PTC mutations play a substantial role in EOAD, warranting genetic screening of ABCA7 in genetically unexplained patients. Long-read cDNA sequencing revealed both varying degrees of NMD and transcript-modifying events, which may influence ABCA7 dosage, disease severity, and may create opportunities for therapeutic interventions in AD.

Heterogeneity in the development of proactive and reactive aggression in childhood: Common and specific genetic - environmental factors

PubMed Central

Lacourse, Eric; Brendgen, Mara; Vitaro, Frank; Dionne, Ginette; Tremblay, Richard Ernest; Boivin, Michel

2017-01-01

Background Few studies are grounded in a developmental framework to study proactive and reactive aggression. Furthermore, although distinctive correlates, predictors and outcomes have been highlighted, proactive and reactive aggression are substantially correlated. To our knowledge, no empirical study has examined the communality of genetic and environmental underpinning of the development of both subtypes of aggression. The current study investigated the communality and specificity of genetic-environmental factors related to heterogeneity in proactive and reactive aggression’s development throughout childhood. Methods Participants were 223 monozygotic and 332 dizygotic pairs. Teacher reports of aggression were obtained at 6, 7, 9, 10 and 12 years of age. Joint development of both phenotypes were analyzed through a multivariate latent growth curve model. Set point, differentiation, and genetic maturation/environmental modulation hypotheses were tested using a biometric decomposition of intercepts and slopes. Results Common genetic factors accounted for 64% of the total variation of proactive and reactive aggression’s intercepts. Two other sets of uncorrelated genetic factors accounted for reactive aggression’s intercept (17%) on the one hand, and for proactive (43%) and reactive (13%) aggression’s slopes on the other. Common shared environmental factors were associated with proactive aggression’s intercept (21%) and slope (26%) and uncorrelated shared environmental factors were also associated with reactive aggression’s slope (14%). Common nonshared environmental factors explained most of the remaining variability of proactive and reactive aggression slopes. Conclusions A genetic differentiation hypothesis common to both phenotypes was supported by common genetic factors associated with the developmental heterogeneity of proactive and reactive aggression in childhood. A genetic maturation hypothesis common to both phenotypes, albeit stronger for proactive aggression, was supported by common genetic factors associated with proactive and reactive aggression slopes. A shared environment set point hypothesis for proactive aggression was supported by shared environmental factors associated with proactive aggression baseline and slope. Although there are many common features to proactive and reactive aggression, the current research underscores the advantages of differentiating them when studying aggression. PMID:29211810

Multi-gene panel testing in Korean patients with common genetic generalized epilepsy syndromes.

PubMed

Lee, Cha Gon; Lee, Jeehun; Lee, Munhyang

2018-01-01

Genetic heterogeneity of common genetic generalized epilepsy syndromes is frequently considered. The present study conducted a focused analysis of potential candidate or susceptibility genes for common genetic generalized epilepsy syndromes using multi-gene panel testing with next-generation sequencing. This study included patients with juvenile myoclonic epilepsy, juvenile absence epilepsy, and epilepsy with generalized tonic-clonic seizures alone. We identified pathogenic variants according to the American College of Medical Genetics and Genomics guidelines and identified susceptibility variants using case-control association analyses and family analyses for familial cases. A total of 57 patients were enrolled, including 51 sporadic cases and 6 familial cases. Twenty-two pathogenic and likely pathogenic variants of 16 different genes were identified. CACNA1H was the most frequently observed single gene. Variants of voltage-gated Ca2+ channel genes, including CACNA1A, CACNA1G, and CACNA1H were observed in 32% of variants (n = 7/22). Analyses to identify susceptibility variants using case-control association analysis indicated that KCNMA1 c.400G>C was associated with common genetic generalized epilepsy syndromes. Only 1 family (family A) exhibited a candidate pathogenic variant p.(Arg788His) on CACNA1H, as determined via family analyses. This study identified candidate genetic variants in about a quarter of patients (n = 16/57) and an average of 2.8 variants was identified in each patient. The results reinforced the polygenic disorder with very high locus and allelic heterogeneity of common GGE syndromes. Further, voltage-gated Ca2+ channels are suggested as important contributors to common genetic generalized epilepsy syndromes. This study extends our comprehensive understanding of common genetic generalized epilepsy syndromes.

Cellar-Associated Saccharomyces cerevisiae Population Structure Revealed High-Level Diversity and Perennial Persistence at Sauternes Wine Estates

PubMed Central

Börlin, Marine; Venet, Pauline; Claisse, Olivier; Salin, Franck

2016-01-01

ABSTRACT Three wine estates (designated A, B, and C) were sampled in Sauternes, a typical appellation of the Bordeaux wine area producing sweet white wine. From those wine estates, 551 yeast strains were collected between 2012 and 2014, added to 102 older strains from 1992 to 2011 from wine estate C. All the strains were analyzed through 15 microsatellite markers, resulting in 503 unique Saccharomyces cerevisiae genotypes, revealing high genetic diversity and a low presence of commercial yeast starters. Population analysis performed using Fst genetic distance or ancestry profiles revealed that the two closest wine estates, B and C, which have juxtaposed vineyard plots and common seasonal staff, share more related isolates with each other than with wine estate A, indicating exchange between estates. The characterization of isolates collected 23 years ago at wine estate C in relation to recent isolates obtained at wine estate B revealed the long-term persistence of isolates. Last, during the 2014 harvest period, a temporal succession of ancestral subpopulations related to the different batches associated with the selective picking of noble rotted grapes was highlighted. IMPORTANCE High genetic diversity of S. cerevisiae isolates from spontaneous fermentation on wine estates in the Sauternes appellation of Bordeaux was revealed. Only 7% of all Sauternes strains were considered genetically related to specific commercial strains. The long-term persistence (over 20 years) of S. cerevisiae profiles on a given wine estate is highlighted. PMID:26969698

Cellar-Associated Saccharomyces cerevisiae Population Structure Revealed High-Level Diversity and Perennial Persistence at Sauternes Wine Estates.

PubMed

Börlin, Marine; Venet, Pauline; Claisse, Olivier; Salin, Franck; Legras, Jean-Luc; Masneuf-Pomarede, Isabelle

2016-05-15

Three wine estates (designated A, B, and C) were sampled in Sauternes, a typical appellation of the Bordeaux wine area producing sweet white wine. From those wine estates, 551 yeast strains were collected between 2012 and 2014, added to 102 older strains from 1992 to 2011 from wine estate C. All the strains were analyzed through 15 microsatellite markers, resulting in 503 unique Saccharomyces cerevisiae genotypes, revealing high genetic diversity and a low presence of commercial yeast starters. Population analysis performed using Fst genetic distance or ancestry profiles revealed that the two closest wine estates, B and C, which have juxtaposed vineyard plots and common seasonal staff, share more related isolates with each other than with wine estate A, indicating exchange between estates. The characterization of isolates collected 23 years ago at wine estate C in relation to recent isolates obtained at wine estate B revealed the long-term persistence of isolates. Last, during the 2014 harvest period, a temporal succession of ancestral subpopulations related to the different batches associated with the selective picking of noble rotted grapes was highlighted. High genetic diversity of S. cerevisiae isolates from spontaneous fermentation on wine estates in the Sauternes appellation of Bordeaux was revealed. Only 7% of all Sauternes strains were considered genetically related to specific commercial strains. The long-term persistence (over 20 years) of S. cerevisiae profiles on a given wine estate is highlighted. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

IgA Vasculitis: Genetics and Clinical and Therapeutic Management.

PubMed

González-Gay, Miguel A; López-Mejías, Raquel; Pina, Trinitario; Blanco, Ricardo; Castañeda, Santos

2018-04-02

The purpose of the study is to perform an update on the current knowledge on genetics, clinical manifestations, and therapy in immunoglobulin A vasculitis (IgAV) (Henoch-Schönlein purpura). A strong genetic predisposition in individuals with IgAV was confirmed. It was due to the association with the HLA class II region that in people of European background is mainly related to HLA-DRB1*01 allele. Recent reports support the claim that kidney disease is more common in adults than in children with IgAV. The clinical spectrum and outcome of adults with IgAV depends on the age of onset. Relapses are not uncommon in IgAV. The presence of renal impairment or proteinuria excretion exceeding 1 g/24 h at the time of disease diagnosis and the degree of renal damage on the kidney biopsy are the best predictors of end-stage renal failure in adults with IgAV. The levels of urinary IgA at the onset of the disease may predict a poor renal outcome. The use of prednisone does not seem to prevent persistent kidney disease in children with IgAV. No additional benefit of adding cyclophosphamide to glucocorticoids in adults with IgAV was found. Rituximab seems to be a promising therapy in the management of adults with IgAV. In this overview, we focus on the genetics, clinical manifestations, and therapy of IgA vasculitis, emphasizing the main differences in the clinical expression of the disease between children and adults.

JavaGenes: Evolving Graphs with Crossover

NASA Technical Reports Server (NTRS)

Globus, Al; Atsatt, Sean; Lawton, John; Wipke, Todd

2000-01-01

Genetic algorithms usually use string or tree representations. We have developed a novel crossover operator for a directed and undirected graph representation, and used this operator to evolve molecules and circuits. Unlike strings or trees, a single point in the representation cannot divide every possible graph into two parts, because graphs may contain cycles. Thus, the crossover operator is non-trivial. A steady-state, tournament selection genetic algorithm code (JavaGenes) was written to implement and test the graph crossover operator. All runs were executed by cycle-scavagging on networked workstations using the Condor batch processing system. The JavaGenes code has evolved pharmaceutical drug molecules and simple digital circuits. Results to date suggest that JavaGenes can evolve moderate sized drug molecules and very small circuits in reasonable time. The algorithm has greater difficulty with somewhat larger circuits, suggesting that directed graphs (circuits) are more difficult to evolve than undirected graphs (molecules), although necessary differences in the crossover operator may also explain the results. In principle, JavaGenes should be able to evolve other graph-representable systems, such as transportation networks, metabolic pathways, and computer networks. However, large graphs evolve significantly slower than smaller graphs, presumably because the space-of-all-graphs explodes combinatorially with graph size. Since the representation strongly affects genetic algorithm performance, adding graphs to the evolutionary programmer's bag-of-tricks should be beneficial. Also, since graph evolution operates directly on the phenotype, the genotype-phenotype translation step, common in genetic algorithm work, is eliminated.

Highly polygenic architecture of antidepressant treatment response: Comparative analysis of SSRI and NRI treatment in an animal model of depression.

PubMed

Malki, Karim; Tosto, Maria Grazia; Mouriño-Talín, Héctor; Rodríguez-Lorenzo, Sabela; Pain, Oliver; Jumhaboy, Irfan; Liu, Tina; Parpas, Panos; Newman, Stuart; Malykh, Artem; Carboni, Lucia; Uher, Rudolf; McGuffin, Peter; Schalkwyk, Leonard C; Bryson, Kevin; Herbster, Mark

2017-04-01

Response to antidepressant (AD) treatment may be a more polygenic trait than previously hypothesized, with many genetic variants interacting in yet unclear ways. In this study we used methods that can automatically learn to detect patterns of statistical regularity from a sparsely distributed signal across hippocampal transcriptome measurements in a large-scale animal pharmacogenomic study to uncover genomic variations associated with AD. The study used four inbred mouse strains of both sexes, two drug treatments, and a control group (escitalopram, nortriptyline, and saline). Multi-class and binary classification using Machine Learning (ML) and regularization algorithms using iterative and univariate feature selection methods, including InfoGain, mRMR, ANOVA, and Chi Square, were used to uncover genomic markers associated with AD response. Relevant genes were selected based on Jaccard distance and carried forward for gene-network analysis. Linear association methods uncovered only one gene associated with drug treatment response. The implementation of ML algorithms, together with feature reduction methods, revealed a set of 204 genes associated with SSRI and 241 genes associated with NRI response. Although only 10% of genes overlapped across the two drugs, network analysis shows that both drugs modulated the CREB pathway, through different molecular mechanisms. Through careful implementation and optimisations, the algorithms detected a weak signal used to predict whether an animal was treated with nortriptyline (77%) or escitalopram (67%) on an independent testing set. The results from this study indicate that the molecular signature of AD treatment may include a much broader range of genomic markers than previously hypothesized, suggesting that response to medication may be as complex as the pathology. The search for biomarkers of antidepressant treatment response could therefore consider a higher number of genetic markers and their interactions. Through predominately different molecular targets and mechanisms of action, the two drugs modulate the same Creb1 pathway which plays a key role in neurotrophic responses and in inflammatory processes. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc.

Meta-analyses of four polymorphisms of lipoprotein lipase associated with the risk of Alzheimer's disease.

PubMed

Ren, Liang; Ren, Xingxing

2016-04-21

We evaluated the contributions of four polymorphisms of the lipoprotein lipase (LPL) gene to the risk of Alzheimer's disease (AD). Through a comprehensive literature search for genetic variants of LPL involved in AD association studies, we found four polymorphisms for the current meta-analyses. These polymorphisms were Asn291Ser(rs268), PvuII(rs285), HindIII(rs320) and Ser447Ter(rs328). In total, eight studies with 5064 cases and 5016 controls were retrieved for the meta-analyses of the four genetic variants. The analyses showed that Asn291Ser(rs268) (OR=2.34, 95% CI=1.05-5.25, P=0.04), HindIII(rs320) (OR=1.44, 95% CI=1.17-1.78, P=0.0006), and Ser447Ter(rs328) (OR=0.80, 95% CI=0.66-0.98, P=0.03) were significantly associated with a risk of AD. No association was found between the PvuII(rs285) polymorphism and the risk of AD. Our results showed that Asn291Ser(rs268), HindIII(rs320) and Ser447Ter(rs328) polymorphisms of LPL were associated with a risk of AD. Asn291Ser(rs268) and HindIII(rs320) were predisposing factors of AD, whereas Ser447Ter(rs328) showed a protective effect for AD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Genetic Architecture of the Delis-Kaplan Executive Function System Trail Making Test: Evidence for Distinct Genetic Influences on Executive Function

PubMed Central

Vasilopoulos, Terrie; Franz, Carol E.; Panizzon, Matthew S.; Xian, Hong; Grant, Michael D.; Lyons, Michael J; Toomey, Rosemary; Jacobson, Kristen C.; Kremen, William S.

2012-01-01

Objective To examine how genes and environments contribute to relationships among Trail Making test conditions and the extent to which these conditions have unique genetic and environmental influences. Method Participants included 1237 middle-aged male twins from the Vietnam-Era Twin Study of Aging (VESTA). The Delis-Kaplan Executive Function System Trail Making test included visual searching, number and letter sequencing, and set-shifting components. Results Phenotypic correlations among Trails conditions ranged from 0.29 – 0.60, and genes accounted for the majority (58–84%) of each correlation. Overall heritability ranged from 0.34 to 0.62 across conditions. Phenotypic factor analysis suggested a single factor. In contrast, genetic models revealed a single common genetic factor but also unique genetic influences separate from the common factor. Genetic variance (i.e., heritability) of number and letter sequencing was completely explained by the common genetic factor while unique genetic influences separate from the common factor accounted for 57% and 21% of the heritabilities of visual search and set-shifting, respectively. After accounting for general cognitive ability, unique genetic influences accounted for 64% and 31% of those heritabilities. Conclusions A common genetic factor, most likely representing a combination of speed and sequencing accounted for most of the correlation among Trails 1–4. Distinct genetic factors, however, accounted for a portion of variance in visual scanning and set-shifting. Thus, although traditional phenotypic shared variance analysis techniques suggest only one general factor underlying different neuropsychological functions in non-patient populations, examining the genetic underpinnings of cognitive processes with twin analysis can uncover more complex etiological processes. PMID:22201299

Gender-specific association of ATP-binding cassette transporter 1 (ABCA1) polymorphisms with the risk of late-onset Alzheimer's disease.

PubMed

Sundar, Purnima Desai; Feingold, Eleanor; Minster, Ryan L; DeKosky, Steven T; Kamboh, M Ilyas

2007-06-01

Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder caused by a complex interaction of genetic and environmental factors. Increasing evidence highlights a potential role for cholesterol in the pathophysiology of AD. The ABCA1 gene, located in close vicinity to the 9q linkage peaks identified by genome-wide AD linkage studies, plays an important role in cellular cholesterol efflux, and is likely a good candidate gene. However, results from published genetic association studies between ABCA1 and AD are ambiguous. In the present study, we examined the role of two ABCA1 polymorphisms, R219K (rs2230806) and G-17C (rs2740483) in modifying the risk of late-onset AD (LOAD) in a large American white cohort of 992 AD cases and 699 controls. We observed significant gender x R219K interaction (p=0.00008). Female carriers of the 219K allele showed a 1.75-fold increased risk of developing AD compared to non-219K carrier females (95% CI 1.34-2.29; p=0.00004). The overall two-site haplotype distribution was also significant between female AD cases and controls (p=0.017). The risk associated with the R219K polymorphism was independent of the recently reported significant association in the ubiquilin (UBQLN1) gene in this region on chromosome 9q. Our data suggest a gender-specific and APOE and UBQLN1 independent association between the ABCA1/R219K polymorphism and LOAD.

MAPT H1 Haplotype is Associated with Late-Onset Alzheimer's Disease Risk in APOEɛ4 Noncarriers: Results from the Dementia Genetics Spanish Consortium.

PubMed

Pastor, Pau; Moreno, Fermín; Clarimón, Jordi; Ruiz, Agustín; Combarros, Onofre; Calero, Miguel; López de Munain, Adolfo; Bullido, Maria J; de Pancorbo, Marian M; Carro, Eva; Antonell, Anna; Coto, Eliecer; Ortega-Cubero, Sara; Hernandez, Isabel; Tárraga, Lluís; Boada, Mercè; Lleó, Alberto; Dols-Icardo, Oriol; Kulisevsky, Jaime; Vázquez-Higuera, José Luis; Infante, Jon; Rábano, Alberto; Fernández-Blázquez, Miguel Ángel; Valentí, Meritxell; Indakoetxea, Begoña; Barandiarán, Myriam; Gorostidi, Ana; Frank-García, Ana; Sastre, Isabel; Lorenzo, Elena; Pastor, María A; Elcoroaristizabal, Xabier; Lennarz, Martina; Maier, Wolfang; Rámirez, Alfredo; Serrano-Ríos, Manuel; Lee, Suzee E; Sánchez-Juan, Pascual

2016-01-01

The MAPT H1 haplotype has been linked to several disorders, but its relationship with Alzheimer's disease (AD) remains controversial. A rare variant in MAPT (p.A152T) has been linked with frontotemporal dementia (FTD) and AD. We genotyped H1/H2 and p.A152T MAPT in 11,572 subjects from Spain (4,327 AD, 563 FTD, 648 Parkinson's disease (PD), 84 progressive supranuclear palsy (PSP), and 5,950 healthy controls). Additionally, we included 101 individuals from 21 families with genetic FTD. MAPT p.A152T was borderline significantly associated with FTD [odds ratio (OR) = 2.03; p = 0.063], but not with AD. MAPT H1 haplotype was associated with AD risk (OR = 1.12; p = 0.0005). Stratification analysis showed that this association was mainly driven by APOE ɛ4 noncarriers (OR = 1.14; p = 0.0025). MAPT H1 was also associated with risk for PD (OR = 1.30; p = 0.0003) and PSP (OR = 3.18; p = 8.59 × 10-8) but not FTD. Our results suggest that the MAPT H1 haplotype increases the risk of PD, PSP, and non-APOE ɛ4 AD.

Dyslipidemia and dementia: current epidemiology, genetic evidence and mechanisms behind the associations

PubMed Central

Reitz, Christiane

2013-01-01

The role of cholesterol in the etiology of Alzheimer’s disease (AD) is still controversial. Some studies aiming to explore the association between lipids and/or lipid lowering treatment and AD indicate a harmful effect of dyslipidemia and a beneficial effect of statin therapy on AD risk. The findings are supported by genetic linkage and association studies that have clearly identified several genes involved in cholesterol metabolism or transport as AD susceptibility genes, including Apolipoprotein E (APOE), Apolipoprotein J (APOJ, CLU) and the sortilin-related receptor (SORL1). Functional cell biology studies support a critical involvement of lipid raft cholesterol in the modulation of AbetaPP processing by β- and γ-secretase resulting in altered Aβ production. Contradictory evidence comes from epidemiological studies showing no or controversial association between dyslipidemia and AD risk, cell biology studies suggesting that there is little exchange between circulating and brain cholesterol, that increased membrane cholesterol is protective by inhibiting loss of membrane integrity through amyloid cytotoxicity, and that cellular cholesterol inhibits co-localization of BACE1 and AbetaPP in non-raft membrane domains and thereby increasing generation of plasmin, an Aβ-degrading enzyme. The aim of this review is to summarize the findings of epidemiologic and cell biologic studies aiming to elucidate the role of cholesterol in AD etiology. PMID:21965313

Inhibition of AMP-Activated Protein Kinase Signaling Alleviates Impairments in Hippocampal Synaptic Plasticity Induced by Amyloid β

PubMed Central

Ma, Tao; Chen, Yiran; Vingtdeux, Valerie; Zhao, Haitian; Viollet, Benoit; Marambaud, Philippe

2014-01-01

The AMP-activated protein kinase (AMPK) is a Ser/Thr kinase that is activated in response to low-energy states to coordinate multiple signaling pathways to maintain cellular energy homeostasis. Dysregulation of AMPK signaling has been observed in Alzheimer's disease (AD), which is associated with abnormal neuronal energy metabolism. In the current study we tested the hypothesis that aberrant AMPK signaling underlies AD-associated synaptic plasticity impairments by using pharmacological and genetic approaches. We found that amyloid β (Aβ)-induced inhibition of long-term potentiation (LTP) and enhancement of long-term depression were corrected by the AMPK inhibitor compound C (CC). Similarly, LTP impairments in APP/PS1 transgenic mice that model AD were improved by CC treatment. In addition, Aβ-induced LTP failure was prevented in mice with genetic deletion of the AMPK α2-subunit, the predominant AMPK catalytic subunit in the brain. Furthermore, we found that eukaryotic elongation factor 2 (eEF2) and its kinase eEF2K are key downstream effectors that mediate the detrimental effects of hyperactive AMPK in AD pathophysiology. Our findings describe a previously unrecognized role of aberrant AMPK signaling in AD-related synaptic pathophysiology and reveal a potential therapeutic target for AD. PMID:25186765

Alzheimer's disease in people with Down's syndrome: the prospects for and the challenges of developing preventative treatments.

PubMed

Castro, Paula; Zaman, Shahid; Holland, Anthony

2017-04-01

People with Down's syndrome (DS) are at high risk for developing Alzheimer's disease (AD) at a relatively young age. This increased risk is not observed in people with intellectual disabilities for reasons other than DS and for this reason it is unlikely to be due to non-specific effects of having a neurodevelopmental disorder but, instead, a direct consequence of the genetics of DS (trisomy 21). Given the location of the amyloid precursor protein (APP) gene on chromosome 21, the amyloid cascade hypothesis is the dominant theory accounting for this risk, with other genetic and environmental factors modifying the age of onset and the course of the disease. Several potential therapies targeting the amyloid pathway and aiming to modify the course of AD are currently being investigated, which may also be useful for treating AD in DS. However, given that the neuropathology associated with AD starts many years before dementia manifests, any preventative treatment must start well before the onset of symptoms. To enable trials of such interventions, plasma, CSF, brain, and retinal biomarkers are being studied as proxy early diagnostic and outcome measures for AD. In this systematic review, we consider the prospects for the development of potential preventative treatments of AD in the DS population and their evaluation.

Genetic Comparison of Symptomatic and Asymptomatic Persons With Alzheimer Disease Neuropathology.

PubMed

Monsell, Sarah E; Mock, Charles; Fardo, David W; Bertelsen, Sarah; Cairns, Nigel J; Roe, Catherine M; Ellingson, Sally R; Morris, John C; Goate, Alison M; Kukull, Walter A

2017-01-01

The objective was to determine whether symptomatic and asymptomatic persons with Alzheimer disease (AD) neuropathology have different allele counts for single-nucleotide polymorphisms that have been associated with clinical late-onset AD. Data came from the National Alzheimer's Coordinating Center Uniform Data Set and Neuropathology Data Set, and the Alzheimer's Disease Genetics Consortium (ADGC). Participants had low to high AD neuropathologic change. The 22 known/suspected genes associated with late-onset AD were considered. "Symptomatic" was defined as Clinical Dementia Rating global score >0. Sixty-eight asymptomatic and 521 symptomatic participants met inclusion criteria. Single-nucleotide polymorphisms associated with ABCA7 [odds ratio (OR)=1.66; 95% confidence interval (CI), 1.03-2.85] and MAPT (OR=2.18; CI, 1.26-3.77) were associated with symptomatic status. In stratified analyses, loci containing CD2AP (OR=0.35; 95% CI, 0.16-0.74), ZCWPW1 (OR=2.98; 95% CI, 1.34-6.86), and MAPT (OR=3.73, 95% CI, 1.30-11.76) were associated with symptomatic status in APOE e4 carriers. These findings potentially explain some of the variation in whether a person with AD neuropathology expresses symptoms. Understanding why some people remain cognitively normal despite having AD neuropathology could identify pathways to disease heterogeneity and guide treatment trials.

Informed Choice in Direct-to-Consumer Genetic Testing for Alzheimer and Other Diseases: Lessons from Two Cases

PubMed Central

Messner, Donna A.

2011-01-01

Health-related direct-to-consumer (DTC) genetic testing has been a controversial practice. Especially problematic is predictive testing for Alzheimer disease (AD), since the disease is incurable, prevention is inconclusive, and testing does not definitively predict an individual’s future disease status. In this paper, I examine two contrasting cases of subjects who learn through genetic testing that they have an elevated risk of developing AD later in life. In these cases, the subject’s emotional response to the result is related to how well prepared she was for the real-life personal implications of possible test results. Analysis leads to the conclusion that when groups of health-related genetic tests are offered as packages by DTC companies, informed consumer choice is rendered impossible. Moreover, I argue, this marketing approach contravenes U.S. Federal Trade Commission policies for non-deceptive commercial communications. I conclude by suggesting ways to improve the prospects for informed consumer choice in DTC testing. PMID:21603253

Pharmacogenetics in Neurodegenerative Diseases: Implications for Clinical Trials.

PubMed

Tortelli, Rosanna; Seripa, Davide; Panza, Francesco; Solfrizzi, Vincenzo; Logroscino, Giancarlo

2016-01-01

Pharmacogenetics has become extremely important over the last 20 years for identifying individuals more likely to be responsive to pharmacological interventions. The role of genetic background as a predictor of drug response is a young and mostly unexplored field in neurodegenerative diseases. Mendelian mutations in neurodegenerative diseases have been used as models for early diagnosis and intervention. On the other hand, genetic polymorphisms or risk factors for late-onset Alzheimer's disease (AD) or other neurodegenerative diseases, probably influencing drug response, are hardly taken into account in randomized clinical trial (RCT) design. The same is true for genetic variants in cytochrome P450 (CYP), the principal enzymes influencing drug metabolism. A better characterization of individual genetic background may optimize clinical trial design and personal drug response. This chapter describes the state of the art about the impact of genetic factors in RCTs on neurodegenerative disease, with AD, frontotemporal dementia, Parkinson's disease, amyotrophic lateral sclerosis, and Huntington's disease as examples. Furthermore, a brief description of the genetic bases of drug response focusing on neurodegenerative diseases will be conducted. The role of pharmacogenetics in RCTs for neurodegenerative diseases is still a young, unexplored, and promising field. Genetic tools allow increased sophistication in patient profiling and treatment optimization. Pharmaceutical companies are aware of the value of collecting genetic data during their RCTs. Pharmacogenetic research is bidirectional with RCTs: efficacy data are correlated with genetic polymorphisms, which in turn define subjects for treatment stratification. © 2016 S. Karger AG, Basel.

Landscape genetics, adaptive diversity and population structure in Phaseolus vulgaris.

PubMed

Rodriguez, Monica; Rau, Domenico; Bitocchi, Elena; Bellucci, Elisa; Biagetti, Eleonora; Carboni, Andrea; Gepts, Paul; Nanni, Laura; Papa, Roberto; Attene, Giovanna

2016-03-01

Here we studied the organization of genetic variation of the common bean (Phaseolus vulgaris) in its centres of domestication. We used 131 single nucleotide polymorphisms to investigate 417 wild common bean accessions and a representative sample of 160 domesticated genotypes, including Mesoamerican and Andean genotypes, for a total of 577 accessions. By analysing the genetic spatial patterns of the wild common bean, we documented the existence of several genetic groups and the occurrence of variable degrees of diversity in Mesoamerica and the Andes. Moreover, using a landscape genetics approach, we demonstrated that both demographic processes and selection for adaptation were responsible for the observed genetic structure. We showed that the study of correlations between markers and ecological variables at a continental scale can help in identifying local adaptation genes. We also located putative areas of common bean domestication in Mesoamerica, in the Oaxaca Valley, and the Andes, in southern Bolivia-northern Argentina. These observations are of paramount importance for the conservation and exploitation of the genetic diversity preserved within this species and other plant genetic resources. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Do Health Professionals Need Additional Competencies for Stratified Cancer Prevention Based on Genetic Risk Profiling?

PubMed Central

Chowdhury, Susmita; Henneman, Lidewij; Dent, Tom; Hall, Alison; Burton, Alice; Pharoah, Paul; Pashayan, Nora; Burton, Hilary

2015-01-01

There is growing evidence that inclusion of genetic information about known common susceptibility variants may enable population risk-stratification and personalized prevention for common diseases including cancer. This would require the inclusion of genetic testing as an integral part of individual risk assessment of an asymptomatic individual. Front line health professionals would be expected to interact with and assist asymptomatic individuals through the risk stratification process. In that case, additional knowledge and skills may be needed. Current guidelines and frameworks for genetic competencies of non-specialist health professionals place an emphasis on rare inherited genetic diseases. For common diseases, health professionals do use risk assessment tools but such tools currently do not assess genetic susceptibility of individuals. In this article, we compare the skills and knowledge needed by non-genetic health professionals, if risk-stratified prevention is implemented, with existing competence recommendations from the UK, USA and Europe, in order to assess the gaps in current competences. We found that health professionals would benefit from understanding the contribution of common genetic variations in disease risk, the rationale for a risk-stratified prevention pathway, and the implications of using genomic information in risk-assessment and risk management of asymptomatic individuals for common disease prevention. PMID:26068647

Anxiety Disorders and Rapid Cycling Data From a Cohort of 8129 Youths With Bipolar Disorder

PubMed Central

Castilla-Puentes, Ruby; Sala, Regina; Ng, Bernardo; Galvez, Juan; Camacho, Alvaro

2014-01-01

Anxiety disorders (ADs) are common in youths with bipolar disorder (BD). We examine psychiatric comorbidity, hospitalization, and treatment in youths with versus without AD and rapid cycling (four or more cycles per year). Data from the Integrated Healthcare Information Services cohort were used and included 8129 youths (ages ≤18 years). Prevalence of AD, demographic, type of AD, hospitalization, and use of psychotropics were compared between rapid and nonrapid cycling. Overall, 51% of the youths met criteria for at least one comorbid AD; they were predominantly female and were between 12 and 17 years of age. The most common comorbid ADs were generalized ADs and separation ADs. In the patients with rapid cycling, 65.5%met criteria for comorbid AD. The BD youths with AD were more likely to have major depressive disorders and other comorbid ADs, to be given more psychotropics, and to be hospitalized for depression and medical conditions more often than were those without AD. PMID:24284641

Ancient DNA Analysis Suggests Negligible Impact of the Wari Empire Expansion in Peru’s Central Coast during the Middle Horizon

PubMed Central

Barreto Romero, María Inés; Flores Espinoza, Isabel; Cooper, Alan; Fehren-Schmitz, Lars

2016-01-01

The analysis of ancient human DNA from South America allows the exploration of pre-Columbian population history through time and to directly test hypotheses about cultural and demographic evolution. The Middle Horizon (650–1100 AD) represents a major transitional period in the Central Andes, which is associated with the development and expansion of ancient Andean empires such as Wari and Tiwanaku. These empires facilitated a series of interregional interactions and socio-political changes, which likely played an important role in shaping the region’s demographic and cultural profiles. We analyzed individuals from three successive pre-Columbian cultures present at the Huaca Pucllana archaeological site in Lima, Peru: Lima (Early Intermediate Period, 500–700 AD), Wari (Middle Horizon, 800–1000 AD) and Ychsma (Late Intermediate Period, 1000–1450 AD). We sequenced 34 complete mitochondrial genomes to investigate the potential genetic impact of the Wari Empire in the Central Coast of Peru. The results indicate that genetic diversity shifted only slightly through time, ruling out a complete population discontinuity or replacement driven by the Wari imperialist hegemony, at least in the region around present-day Lima. However, we caution that the very subtle genetic contribution of Wari imperialism at the particular Huaca Pucllana archaeological site might not be representative for the entire Wari territory in the Peruvian Central Coast. PMID:27248693

Ancient DNA Analysis Suggests Negligible Impact of the Wari Empire Expansion in Peru's Central Coast during the Middle Horizon.

PubMed

Valverde, Guido; Barreto Romero, María Inés; Flores Espinoza, Isabel; Cooper, Alan; Fehren-Schmitz, Lars; Llamas, Bastien; Haak, Wolfgang

2016-01-01

The analysis of ancient human DNA from South America allows the exploration of pre-Columbian population history through time and to directly test hypotheses about cultural and demographic evolution. The Middle Horizon (650-1100 AD) represents a major transitional period in the Central Andes, which is associated with the development and expansion of ancient Andean empires such as Wari and Tiwanaku. These empires facilitated a series of interregional interactions and socio-political changes, which likely played an important role in shaping the region's demographic and cultural profiles. We analyzed individuals from three successive pre-Columbian cultures present at the Huaca Pucllana archaeological site in Lima, Peru: Lima (Early Intermediate Period, 500-700 AD), Wari (Middle Horizon, 800-1000 AD) and Ychsma (Late Intermediate Period, 1000-1450 AD). We sequenced 34 complete mitochondrial genomes to investigate the potential genetic impact of the Wari Empire in the Central Coast of Peru. The results indicate that genetic diversity shifted only slightly through time, ruling out a complete population discontinuity or replacement driven by the Wari imperialist hegemony, at least in the region around present-day Lima. However, we caution that the very subtle genetic contribution of Wari imperialism at the particular Huaca Pucllana archaeological site might not be representative for the entire Wari territory in the Peruvian Central Coast.

Memory Resilience to Alzheimer's Genetic Risk: Sex Effects in Predictor Profiles.

PubMed

McDermott, Kirstie L; McFall, G Peggy; Andrews, Shea J; Anstey, Kaarin J; Dixon, Roger A

2017-10-01

Apolipoprotein E (APOE) ɛ4 and Clusterin (CLU) C alleles are risk factors for Alzheimer's disease (AD) and episodic memory (EM) decline. Memory resilience occurs when genetically at-risk adults perform at high and sustained levels. We investigated whether (a) memory resilience to AD genetic risk is predicted by biological and other risk markers and (b) the prediction profiles vary by sex and AD risk variant. Using a longitudinal sample of nondemented adults (n = 642, aged 53-95) we focused on memory resilience (over 9 years) to 2 AD risk variants (APOE, CLU). Growth mixture models classified resilience. Random forest analysis, stratified by sex, tested the predictive importance of 22 nongenetic risk factors from 5 domains (n = 24-112). For both sexes, younger age, higher education, stronger grip, and everyday novel cognitive activity predicted memory resilience. For women, 9 factors from functional, health, mobility, and lifestyle domains were also predictive. For men, only fewer depressive symptoms was an additional important predictor. The prediction profiles were similar for APOE and CLU. Although several factors predicted resilience in both sexes, a greater number applied only to women. Sex-specific mechanisms and intervention targets are implied. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Oxidative stress increases internal calcium stores and reduces a key mitochondrial enzyme.

PubMed

Gibson, Gary E; Zhang, Hui; Xu, Hui; Park, Larry C H; Jeitner, Thomas M

2002-03-16

Fibroblasts from patients with genetic and non-genetic forms of Alzheimer's disease (AD) show many abnormalities including increased bombesin-releasable calcium stores (BRCS), diminished activities of the mitochondrial alpha-ketoglutarate dehydrogenase complex (KGDHC), and an altered ability to handle oxidative stress. The link between genetic mutations (and the unknown primary event in non-genetic forms) and these other cellular abnormalities is unknown. To determine whether oxidative stress could be a convergence point that produces the other AD-related changes, these experiments tested in fibroblasts the effects of H(2)O(2), in the presence or absence of select antioxidants, on BRCS and KGDHC. H(2)O(2) concentrations that elevated carboxy-dichlorofluorescein (c-H(2)DCF)-detectable ROS increased BRCS and decreased KGDHC activity. These changes are in the same direction as those in fibroblasts from AD patients. Acute treatments with the antioxidants Trolox, or DMSO decreased c-H(2)DCF-detectable ROS by about 90%, but exaggerated the H(2)O(2)-induced increases in BRCS by about 4-fold and did not alter the reduction in KGDHC. Chronic pretreatments with Trolox more than doubled the BRCS, tripled KGDHC activities, and reduced the effects of H(2)O(2). Pretreatment with DMSO or N-acetyl cysteine diminished the BRCS and either had no effect, or exaggerated the H(2)O(2)-induced changes in these variables. The results demonstrate that BRCS and KGDHC are more sensitive to H(2)O(2) derived species than c-H(2)DCF, and that oxidized derivatives of the antioxidants exaggerate the actions of H(2)O(2). The findings support the hypothesis that select abnormalities in oxidative processes are a critical part of a cascade that leads to the cellular abnormalities in cells from AD patients.

Classification of Alzheimer's disease and prediction of mild cognitive impairment-to-Alzheimer's conversion from structural magnetic resource imaging using feature ranking and a genetic algorithm.

PubMed

Beheshti, Iman; Demirel, Hasan; Matsuda, Hiroshi

2017-04-01

We developed a novel computer-aided diagnosis (CAD) system that uses feature-ranking and a genetic algorithm to analyze structural magnetic resonance imaging data; using this system, we can predict conversion of mild cognitive impairment (MCI)-to-Alzheimer's disease (AD) at between one and three years before clinical diagnosis. The CAD system was developed in four stages. First, we used a voxel-based morphometry technique to investigate global and local gray matter (GM) atrophy in an AD group compared with healthy controls (HCs). Regions with significant GM volume reduction were segmented as volumes of interest (VOIs). Second, these VOIs were used to extract voxel values from the respective atrophy regions in AD, HC, stable MCI (sMCI) and progressive MCI (pMCI) patient groups. The voxel values were then extracted into a feature vector. Third, at the feature-selection stage, all features were ranked according to their respective t-test scores and a genetic algorithm designed to find the optimal feature subset. The Fisher criterion was used as part of the objective function in the genetic algorithm. Finally, the classification was carried out using a support vector machine (SVM) with 10-fold cross validation. We evaluated the proposed automatic CAD system by applying it to baseline values from the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset (160 AD, 162 HC, 65 sMCI and 71 pMCI subjects). The experimental results indicated that the proposed system is capable of distinguishing between sMCI and pMCI patients, and would be appropriate for practical use in a clinical setting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cerebral amyloid angiopathy in Down syndrome and sporadic and autosomal-dominant Alzheimer's disease.

PubMed

Carmona-Iragui, María; Balasa, Mircea; Benejam, Bessy; Alcolea, Daniel; Fernández, Susana; Videla, Laura; Sala, Isabel; Sánchez-Saudinós, María Belén; Morenas-Rodriguez, Estrella; Ribosa-Nogué, Roser; Illán-Gala, Ignacio; Gonzalez-Ortiz, Sofía; Clarimón, Jordi; Schmitt, Frederick; Powell, David K; Bosch, Beatriz; Lladó, Albert; Rafii, Michael S; Head, Elizabeth; Molinuevo, José Luis; Blesa, Rafael; Videla, Sebastián; Lleó, Alberto; Sánchez-Valle, Raquel; Fortea, Juan

2017-11-01

We aimed to investigate if cerebral amyloid angiopathy (CAA) is more frequent in genetically determined than in sporadic early-onset forms of Alzheimer's disease (AD) (early-onset AD [EOAD]). Neuroimaging features of CAA, apolipoprotein (APOE), and cerebrospinal fluid amyloid β (Aβ) 40 levels were studied in subjects with Down syndrome (DS, n = 117), autosomal-dominant AD (ADAD, n = 29), sporadic EOAD (n = 42), and healthy controls (n = 68). CAA was present in 31%, 38%, and 12% of cognitively impaired DS, symptomatic ADAD, and sporadic EOAD subjects and in 13% and 4% of cognitively unimpaired DS individuals and healthy controls, respectively. APOE ε4 genotype was borderline significantly associated with CAA in sporadic EOAD (P = .06) but not with DS or ADAD. There were no differences in Aβ040 levels between groups or between subjects with and without CAA. CAA is more frequently found in genetically determined AD than in sporadic EOAD. Cerebrospinal fluid Aβ40 levels are not a useful biomarker for CAA in AD. Copyright © 2017 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

CLU rs2279590 polymorphism contributes to Alzheimer's disease susceptibility in Caucasian and Asian populations.

PubMed

Zhang, Shuyan; Zhang, Donghui; Jiang, Yongshuai; Wu, Lina; Shang, Hong; Liu, Jiafeng; Feng, Rennan; Liao, Mingzhi; Zhang, Liangcai; Liu, Yong; Liu, Guiyou; Li, Keshen

2015-03-01

It is reported that CLU rs2279590 polymorphism is significantly associated with Alzheimer's disease (AD) in European ancestry. Recent studies investigated rs2279590 polymorphism in Asian population (Chinese, Japanese and Korean). Four studies showed negative association and two studies showed weak association between rs2279590 and AD. We believe that the weak association or no association may be caused by the relatively small sample size in Asian population. Here, we reinvestigated the association in Asian population. Meanwhile, to investigate the genetic heterogeneity of the rs2279590 polymorphism in Asian and Caucasian populations, we searched the PubMed and AlzGene databases and selected 11 independent studies (6 studies in Asian population and 5 studies in Caucasian population) including 20,655 individuals (8,605 cases and 12,050 controls) for meta-analysis. Our results showed significant association between rs2279590 polymorphism and AD in Asian population with P = 2.00E-04 and P = 2.00E-04 using additive and recessive models, respectively. We observed no significant heterogeneity between Asian and Caucasian populations. We believe that our results may be helpful to understand the mechanisms of CLU in AD pathogenesis and will be useful for future genetic studies in AD.

[Genetic counseling and testing for families with Alzheimer's disease].

PubMed

Kowalska, Anna

2004-01-01

With the identification of the genes responsible for autosomal dominant early-onset familial Alzheimer's disease (FAD genes), there is a considerable interest in the application of this genetic information in medical practice through genetic testing and counseling. Pathogenic mutations in the PSEN1 and PSEN2 genes encoding presenilin-1 and -2, and the APP gene encoding amyloid b precursor protein, account for 18-50% of familial EOAD cases with autosomal dominant pattern of inheritance. A clinical algorithm of genetic testing and counseling proposed for families with AD has been presented here. A screening for mutations in the APP, PSEN1, and PSEN2 genes is available to individuals with AD symptoms and at-risk children or siblings of patients with early-onset disease determined by a known mutation. In an early-onset family, a known mutation in an affected patient puts the siblings and children at a 50% risk of inheriting the same mutation. The goal of genetic testing is to identify at-risk individuals in order to facilitate early and effective treatments in the symptomatic person based on an individual's genotype and strategies to delay the onset of disease in the presymptomatic mutation carriers. However, there are several arguments against the use of genetic testing both presymptomatically (unpredictable psychological consequences of information about a genetic defect for family members) and as a diagnostic tool for the differential diagnosis of dementia in general practice (a risk of errors in an interpretation of mutation penetrance and its secondary effects on family members, especially for novel mutations; the possibility of coexistence of another form of dementia at the presence of a mutation). Currently, APOE genotyping for presymptomatic individuals with a family history of late-onset disease is not recommended. The APOE4 allele may only confer greater risk for disease, but its presence is not conclusive for the development of AD.

Osteoblastic differentiation of human and equine adult bone marrow-derived mesenchymal stem cells when BMP-2 or BMP-7 homodimer genetic modification is compared to BMP-2/7 heterodimer genetic modification in the presence and absence of dexamethasone.

PubMed

Carpenter, Ryan S; Goodrich, Laurie R; Frisbie, David D; Kisiday, John D; Carbone, Beth; McIlwraith, C Wayne; Centeno, Christopher J; Hidaka, Chisa

2010-10-01

Bone marrow-derived mesenchymal stem cells (BMDMSCs) have been targeted for use in enhancement of bone healing; and their osteogenic potential may be further augmented by genes encoding bone morphogenetic proteins (BMP's). The purpose of this study was to compare the effect of genetic modification of human and equine BMDMSCs with BMP-2 or -7 or BMP-2 and -7 on their osteoblastogenic differentiation in the presence or absence of dexamethasone. The BMDMSCs were harvested from the iliac crest of three human donors and tuber coxae of three equine donors. Monolayer cells were genetically modified using adenovirus vectors encoding BMP-2, -7 or both and cultured in the presence or absence of dexamethasone. Expression of BMPs was confirmed by enzyme linked immunosorbent assay (ELISA). To evaluate osteoblastic differentiation, cellular morphology was assessed every other day and expression and secretion of alkaline phosphatase (ALP), as well as expression levels of osteonectin (OSTN), osteocalcin (OCN), and runt-related transcription factor-2 (Runx2) were measured for up to 14 days. Human and equine BMDMSCs showed a capacity for osteogenic differentiation regardless of genetic modification or dexamethasone supplementation. Dexamethasone supplementation was more important for osteoblastogenic differentiation of equine BMDMSCs than human BMDMSCs. Genetic modification of BMDMSCs increased ALP secretion with AdBMP-2 homodimer having the greatest effect in both human and equine cells compared to AdBMP 7 or AdBMP 2/7. BMP protein elution rates reached their maximal concentration between day 4 and 8 and remained relatively stable thereafter, suggesting that genetically modified BMDMSCs could be useful for cell-based delivery of BMPs to a site of bone formation. Published by Wiley Periodicals, Inc. J Orthop Res 28:1330-1337, 2010.

Genotyping the factor VIII intron 22 inversion locus using fluorescent in situ hybridization.

PubMed

Sheen, Campbell R; McDonald, Margaret A; George, Peter M; Smith, Mark P; Morris, Christine M

2011-02-15

The factor VIII intron 22 inversion is the most common cause of hemophilia A, accounting for approximately 40% of all severe cases of the disease. Southern hybridization and multiplex long distance PCR are the most commonly used techniques to detect the inversion in a diagnostic setting, although both have significant limitations. Here we describe our experience establishing a multicolor fluorescent in situ hybridization (FISH) based assay as an alternative to existing methods for genetic diagnosis of the inversion. Our assay was designed to apply three differentially labelled BAC DNA probes that when hybridized to interphase nuclei would exhibit signal patterns that are consistent with the normal or the inversion locus. When the FISH assay was applied to five normal and five inversion male samples, the correct genotype was assignable with p<0.001 for all samples. When applied to carrier female samples the assay could not assign a genotype to all female samples, probably due to a lower proportion of informative nuclei in female samples caused by the added complexity of a second X chromosome. Despite this complication, these pilot findings show that the assay performs favourably compared to the commonly used methods. Copyright © 2010 Elsevier Inc. All rights reserved.

University Students' Knowledge and Attitude about Genetic Engineering

ERIC Educational Resources Information Center

Bal, Senol; Samanci, Nilay Keskin; Bozkurt, Orçun

2007-01-01

Genetic engineering and biotechnology made possible of gene transfer without discriminating microorganism, plant, animal or human. However, although these scientific techniques have benefits, they cause arguments because of their ethical and social impacts. The arguments about ethical ad social impacts of biotechnology made clear that not only…

Screening of Early and Late Onset Alzheimer's Disease Genetic Risk Factors in a Cohort of Dementia Patients from Liguria, Italy.

PubMed

Ferrari, Raffaele; Ferrara, Michela; Alinani, Anwar; Sutton, Roger Brian; Famà, Francesco; Picco, Agnese; Rodriguez, Guido; Nobili, Flavio; Momeni, Parastoo

2015-01-01

Cohorts from a defined geographical area enable ad hoc genotype-phenotype correlation studies providing novel and unique insight into disease. We analysed genetic risk factors associated with early and late onset Alzheimer's disease (EOAD and LOAD) in a population from Liguria (northern Italy), as part of an ongoing longitudinal study. We screened 37 AD, 8 mild cognitive impairment (MCI), 3 AD and CVD (cerebrovascular disease), 3 MCI and CVD, 8 frontotemporal dementia (FTD) and 2 progressive supranuclear palsy (PSP) patients, and 28 normal controls (NCs).We sequenced PSEN1, PSEN2 and APP (EOAD risk factors), as well as MAPT, GRN and TARDBP for all cases and NCs, and analysed the APOE, CLU, CR1 and PICALM genotypes as well as the MAPT and ACE haplotypes (LOAD risk factors) for the AD (n = 37) and AD + MCI (n = 45) cases and NCs (n = 28).We identified variants in PSEN1, PSEN2 and TARDBP across a range of phenotypes (AD, AD and CVD, FTD and PSP), suggesting that screening of all known candidate genes of Alzheimer's and non-Alzheimer's forms of dementias in all dementia cases might be warranted. The analysis of the LOAD risk factors revealed no association with AD or AD + MCI status after Bonferroni correction. Lack of association with APOE is supported by previous studies in the Italian population. Our data also evidenced: 1) a potentially protective haplotype at the PSEN2 locus; 2) a nominal association with the GWAS-risk allele A for rs3818361 in CR1 and; 3) a threefold prevalence of AD in the female population compared to men.Our results will need to be further assessed and confirmed in larger cohorts from this area. 

Genome-wide association study identifies two loci influencing plasma neurofilament light levels.

PubMed

Li, Jie-Qiong; Yuan, Xiang-Zhen; Li, Hai-Yan; Cao, Xi-Peng; Yu, Jin-Tai; Tan, Lan; Chen, Wei-An

2018-05-10

Plasma neurofilament light (NFL) is a promising biomarker for Alzheimer disease (AD), which increases in the early stage of AD and is associated with the progression of AD. We performed a genome-wide association study (GWAS) of plasma NFL in Alzheimer's Disease Neuroimaging Initiative 1 (ADNI-1) cohort to identify novel variants associated with AD. This study included 179 cognitively healthy controls (HC), 176 patients with mild cognitive impairment (MCI), and 172 patients with AD. All subjects were restricted to non-Hispanic Caucasian derived from the ADNI cohort and met all quality control (QC) criteria. Association of plasma NFL with the genetic variants was assessed using PLINK with an additive genetic model, i.e.dose-dependent effect of the minor alleles. The influence of a genetic variant associated with plasma NFL (rs7943454) on brain structure was further assessed using PLINK with a linear regression model. The minor allele (T) of rs7943454 in leucine zipper protein 2 gene (LUZP2) was associated with higher plasma NFL at suggestive levels (P = 1.39 × 10 - 6 ) in a dose-dependent fashion. In contrast, the minor allele (G) of rs640476 near GABRB2 was associated with lower plasma NFL at suggestive levels (P = 6.71 × 10 - 6 ) in a dose-dependent effect in all diagnostic groups except the MCI group. Furthermore, the minor allele (T) of rs7943454 within LUZP2 increased the onset risk of AD (odds ratio = 1.547, confidence interval 95% = 1.018-2.351) and was associated with atrophy of right middle temporal gyrus in the whole cohort in the longitudinal study (P = 0.0234). GWAS found the associations of two single nucleotide polymorphisms (rs7943454 and rs640476) with plasma NFL at suggestive levels. Rs7943454 in LUZP2 was associated with the onset risk of AD and atrophy of right middle temporal gyrusin the whole cohort. Using an endophenotype-based approach, we identified rs7943454 as a new AD risk locus.

Affinity Maturation of an Anti-V Antigen IgG Expressed In Situ Via Adenovirus Gene Delivery Confers Enhanced Protection Against Yersinia pestis Challenge

PubMed Central

Van Blarcom, Thomas J.; Sofer-Podesta, Carolina; Ang, John; Boyer, Julie L.; Crystal, Ronald G.; Georgiou, George

2013-01-01

Genetic transfer of neutralizing antibodies has been shown to confer strong and persistent protection against bacterial and viral infectious agents. While it is well established that for many exogenous neutralizing antibodies increased antigen affinity correlates with protection, the effect of antigen affinity on antibodies produced in situ following adenoviral gene transfer has not been examined. The mouse IgG2b monoclonal antibody 2C12.4 recognizes the Yersinia pestis Type III secretion apparatus protein LcrV (V antigen) and confers protection in mice when administered as an IgG intraperitoneally or, following genetic immunization with engineered, replication-defective serotype 5 human adenovirus (Ad) 1. 2C12.4 was expressed as a scFv fragment in E. coli and was shown to display a KD=3.5 nM by surface plasmon resonance (SPR) analysis. The 2C12.4 scFv was subjected to random mutagenesis and variants with increased affinity were isolated by flow cytometry using the Anchored Periplasmic Expression (APEx) bacterial display system. After a single round of mutagenesis, variants displaying up to 35-fold lower KD values (H8, KD=100 pM) were isolated. The variable domains of the H8 scFv were used to replace those of the parental 2C12.4 IgG encoded in the Ad vector, AdαV giving rise to AdαV.H8. The two adenoviral vectors resulted in similar titers of anti-V antigen antibodies 3 days post-immunization with 109, 1010 or 1011 particle units. Following intranasal challenge with 363 LD50Y. pestis CO92, 54% of the mice immunized with 1010 pu of AdαV.H8 survived at the 14 day end point compared to only 15% survivors for the group immunized with AdαV expressing the lower affinity 2C12.4 (P<0.04, AdαV versus AdαV.H8). These results indicate that affinity maturation of a neutralizing antibody delivered by genetic transfer may confer increased protection not only for Y. pestis challenge but possibly for other pathogens. PMID:20393511

Genetic and environmental influences on female sexual orientation, childhood gender typicality and adult gender identity.

PubMed

Burri, Andrea; Cherkas, Lynn; Spector, Timothy; Rahman, Qazi

2011-01-01

Human sexual orientation is influenced by genetic and non-shared environmental factors as are two important psychological correlates--childhood gender typicality (CGT) and adult gender identity (AGI). However, researchers have been unable to resolve the genetic and non-genetic components that contribute to the covariation between these traits, particularly in women. Here we performed a multivariate genetic analysis in a large sample of British female twins (N = 4,426) who completed a questionnaire assessing sexual attraction, CGT and AGI. Univariate genetic models indicated modest genetic influences on sexual attraction (25%), AGI (11%) and CGT (31%). For the multivariate analyses, a common pathway model best fitted the data. This indicated that a single latent variable influenced by a genetic component and common non-shared environmental component explained the association between the three traits but there was substantial measurement error. These findings highlight common developmental factors affecting differences in sexual orientation.

The role of ryanodine receptor type 3 in a mouse model of Alzheimer disease

PubMed Central

Liu, Jie; Supnet, Charlene; Sun, Suya; Zhang, Hua; Good, Levi; Popugaeva, Elena; Bezprozvanny, Ilya

2014-01-01

Dysregulated endoplasmic reticulum (ER) calcium (Ca2+) signaling is reported to play an important role in Alzheimer disease (AD) pathogenesis. The role of ER Ca2+ release channels, the ryanodine receptors (RyanRs), has been extensively studied in AD models and RyanR expression and activity are upregulated in the brains of various familial AD (FAD) models. The objective of this study was to utilize a genetic approach to evaluate the importance of RyanR type 3 (RyanR3) in the context of AD pathology. PMID:24476841

Complete genomic screen in late-onset familial Alzheimer disease. Evidence for a new locus on chromosome 12.

PubMed

Pericak-Vance, M A; Bass, M P; Yamaoka, L H; Gaskell, P C; Scott, W K; Terwedow, H A; Menold, M M; Conneally, P M; Small, G W; Vance, J M; Saunders, A M; Roses, A D; Haines, J L

1997-10-15

Four genetic loci have been identified as contributing to Alzheimer disease (AD), including the amyloid precursor protein gene, the presenilin 1 gene, the presenilin 2 gene, and the apolipoprotein E gene, but do not account for all the genetic risk for AD. To identify additional genetic risk factors for late-onset AD. A complete genomic screen was performed (N=280 markers). Critical values for chromosomal regional follow-up were a P value of .05 or less for affected relative pair analysis or sibpair analysis, a parametric lod score of 1.0 or greater, or both. Regional follow-up included analysis of additional markers and a second data set. Clinic populations in the continental United States. From a series of multiplex families affected with late-onset (> or =60 years) AD ascertained during the last 14 years (National Insititute of Neurological Disorders and Stroke-Alzheimer's Disease and Related Disorders Association diagnostic criteria) and for which DNA has been obtained, a subset of 16 families (135 total family members, 52 of whom were patients with AD) was used for the genomic screen. A second subset of 38 families (216 total family members, 89 of whom were patients with AD) was used for the follow-up analysis. Linkage analysis results generated using both genetic model-dependent (lod score) and model-independent methods. Fifteen chromosomal regions warranted initial follow-up. Follow-up analyses revealed 4 regions of continued interest on chromosomes 4, 6, 12, and 20, with the strongest results observed forchromosome 12. Peak 2-point affecteds-only lod scores (n=54) were 1.3, 1.6, 2.7, and 2.2 and affected relative pairs P values (n=54) were .04, .03, .14, and .04 for D12S373, D12S1057, D12S1042, and D12S390, respectively. Sibpair analysis (n=54) resulted in maximum lod scores (MLSs) of 1.5, 2.6, 3.2, and 2.3 for these markers, with a peak multipoint MLS of 3.5. A priori stratification by APOE genotype identified 27 families that had at least 1 member with AD whose genotype did not contain an APOE*4 allele. Analysis of these 27 families resulted in MLSs of 1.0, 2.4, 3.7, and 3.3 and a peak multipoint MLS of 3.9. A complete genomic screen in families affected with late-onset AD identified 4 regions of interest after follow-up. Chromosome 12 gave the strongest and most consistent results with a peak multipoint MLS of 3.5, suggesting that this region contains a new susceptibility gene for AD. Additional analyses are necessary to identify the chromosome 12 susceptibility gene for AD and to follow up the regions of interest on chromosomes 4, 6, and 20.

Maternal Genetic Ancestry and Legacy of 10th Century AD Hungarians

NASA Astrophysics Data System (ADS)

Csősz, Aranka; Szécsényi-Nagy, Anna; Csákyová, Veronika; Langó, Péter; Bódis, Viktória; Köhler, Kitti; Tömöry, Gyöngyvér; Nagy, Melinda; Mende, Balázs Gusztáv

2016-09-01

The ancient Hungarians originated from the Ural region in today’s central Russia and migrated across the Eastern European steppe, according to historical sources. The Hungarians conquered the Carpathian Basin 895-907 AD, and admixed with the indigenous communities. Here we present mitochondrial DNA results from three datasets: one from the Avar period (7th-9th centuries) of the Carpathian Basin (n = 31) one from the Hungarian conquest-period (n = 76) and a completion of the published 10th-12th century Hungarian-Slavic contact zone dataset by four samples. We compare these mitochondrial DNA hypervariable segment sequences and haplogroup results with published ancient and modern Eurasian data. Whereas the analyzed Avars represents a certain group of the Avar society that shows East and South European genetic characteristics, the Hungarian conquerors’ maternal gene pool is a mixture of West Eurasian and Central and North Eurasian elements. Comprehensively analyzing the results, both the linguistically recorded Finno-Ugric roots and historically documented Turkic and Central Asian influxes had possible genetic imprints in the conquerors’ genetic composition. Our data allows a complex series of historic and population genetic events before the formation of the medieval population of the Carpathian Basin, and the maternal genetic continuity between 10th-12th century and modern Hungarians.

Maternal Genetic Ancestry and Legacy of 10(th) Century AD Hungarians.

PubMed

Csősz, Aranka; Szécsényi-Nagy, Anna; Csákyová, Veronika; Langó, Péter; Bódis, Viktória; Köhler, Kitti; Tömöry, Gyöngyvér; Nagy, Melinda; Mende, Balázs Gusztáv

2016-09-16

The ancient Hungarians originated from the Ural region in today's central Russia and migrated across the Eastern European steppe, according to historical sources. The Hungarians conquered the Carpathian Basin 895-907 AD, and admixed with the indigenous communities. Here we present mitochondrial DNA results from three datasets: one from the Avar period (7(th)-9(th) centuries) of the Carpathian Basin (n = 31); one from the Hungarian conquest-period (n = 76); and a completion of the published 10(th)-12(th) century Hungarian-Slavic contact zone dataset by four samples. We compare these mitochondrial DNA hypervariable segment sequences and haplogroup results with published ancient and modern Eurasian data. Whereas the analyzed Avars represents a certain group of the Avar society that shows East and South European genetic characteristics, the Hungarian conquerors' maternal gene pool is a mixture of West Eurasian and Central and North Eurasian elements. Comprehensively analyzing the results, both the linguistically recorded Finno-Ugric roots and historically documented Turkic and Central Asian influxes had possible genetic imprints in the conquerors' genetic composition. Our data allows a complex series of historic and population genetic events before the formation of the medieval population of the Carpathian Basin, and the maternal genetic continuity between 10(th)-12(th) century and modern Hungarians.

Maternal Genetic Ancestry and Legacy of 10th Century AD Hungarians

PubMed Central

Csősz, Aranka; Szécsényi-Nagy, Anna; Csákyová, Veronika; Langó, Péter; Bódis, Viktória; Köhler, Kitti; Tömöry, Gyöngyvér; Nagy, Melinda; Mende, Balázs Gusztáv

2016-01-01

The ancient Hungarians originated from the Ural region in today’s central Russia and migrated across the Eastern European steppe, according to historical sources. The Hungarians conquered the Carpathian Basin 895–907 AD, and admixed with the indigenous communities. Here we present mitochondrial DNA results from three datasets: one from the Avar period (7th–9th centuries) of the Carpathian Basin (n = 31); one from the Hungarian conquest-period (n = 76); and a completion of the published 10th–12th century Hungarian-Slavic contact zone dataset by four samples. We compare these mitochondrial DNA hypervariable segment sequences and haplogroup results with published ancient and modern Eurasian data. Whereas the analyzed Avars represents a certain group of the Avar society that shows East and South European genetic characteristics, the Hungarian conquerors’ maternal gene pool is a mixture of West Eurasian and Central and North Eurasian elements. Comprehensively analyzing the results, both the linguistically recorded Finno-Ugric roots and historically documented Turkic and Central Asian influxes had possible genetic imprints in the conquerors’ genetic composition. Our data allows a complex series of historic and population genetic events before the formation of the medieval population of the Carpathian Basin, and the maternal genetic continuity between 10th–12th century and modern Hungarians. PMID:27633963

A safety review of the medications used to treat atopic dermatitis.

PubMed

Shukla, Shweta; Feldman, Steven R; Strowd, Lindsay C

2018-02-01

Atopic dermatitis (AD) is a common disease in children and adults which causes severe physical discomfort and psychosocial distress. Recently novel therapies for AD have been FDA approved for use which creates the need to review the safety surrounding current FDA approved AD medications. Areas covered: Published clinical studies involving topical and oral FDA approved medications for AD are included in this review. Authors used PubMed research database to search for clinical trials involving AD patients. Expert opinion: AD is a common disease which currently has limited FDA approved medications. Given the chronicity of this disease, medications are needed which control disease while minimizing side effects to allow for long term use. Newer approved medications show promise but safety data is limited given their relatively new utilization for AD.

Genetic interactions for heat stress and production level: predicting foreign from domestic data

USDA-ARS?s Scientific Manuscript database

Genetic by environmental interactions were estimated from U.S. national data by separately adding random regressions for heat stress (HS) and herd production level (HL) to the all-breed animal model to improve predictions of future records and rankings in other climate and production situations. Yie...

Defining the genetic connection linking amyotrophic lateral sclerosis (ALS) with frontotemporal dementia (FTD).

PubMed

Lattante, Serena; Ciura, Sorana; Rouleau, Guy A; Kabashi, Edor

2015-05-01

Several genetic causes have been recently described for neurological diseases, increasing our knowledge of the common pathological mechanisms involved in these disorders. Mutation analysis has shown common causative factors for two major neurodegenerative disorders, ALS and FTD. Shared pathological and genetic markers as well as common neurological signs between these diseases have given rise to the notion of an ALS/FTD spectrum. This overlap among genetic factors causing ALS/FTD and the coincidence of mutated alleles (including causative, risk and modifier variants) have given rise to the notion of an oligogenic model of disease. In this review we summarize major advances in the elucidation of novel genetic factors in these diseases which have led to a better understanding of the common pathogenic factors leading to neurodegeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stem Cell Technology for (Epi)genetic Brain Disorders.

PubMed

Riemens, Renzo J M; Soares, Edilene S; Esteller, Manel; Delgado-Morales, Raul

2017-01-01

Despite the enormous efforts of the scientific community over the years, effective therapeutics for many (epi)genetic brain disorders remain unidentified. The common and persistent failures to translate preclinical findings into clinical success are partially attributed to the limited efficiency of current disease models. Although animal and cellular models have substantially improved our knowledge of the pathological processes involved in these disorders, human brain research has generally been hampered by a lack of satisfactory humanized model systems. This, together with our incomplete knowledge of the multifactorial causes in the majority of these disorders, as well as a thorough understanding of associated (epi)genetic alterations, has been impeding progress in gaining more mechanistic insights from translational studies. Over the last years, however, stem cell technology has been offering an alternative approach to study and treat human brain disorders. Owing to this technology, we are now able to obtain a theoretically inexhaustible source of human neural cells and precursors in vitro that offer a platform for disease modeling and the establishment of therapeutic interventions. In addition to the potential to increase our general understanding of how (epi)genetic alterations contribute to the pathology of brain disorders, stem cells and derivatives allow for high-throughput drugs and toxicity testing, and provide a cell source for transplant therapies in regenerative medicine. In the current chapter, we will demonstrate the validity of human stem cell-based models and address the utility of other stem cell-based applications for several human brain disorders with multifactorial and (epi)genetic bases, including Parkinson's disease (PD), Alzheimer's disease (AD), fragile X syndrome (FXS), Angelman syndrome (AS), Prader-Willi syndrome (PWS), and Rett syndrome (RTT).

A SNP panel and online tool for checking genotype concordance through comparing QR codes.

PubMed

Du, Yonghong; Martin, Joshua S; McGee, John; Yang, Yuchen; Liu, Eric Yi; Sun, Yingrui; Geihs, Matthias; Kong, Xuejun; Zhou, Eric Lingfeng; Li, Yun; Huang, Jie

2017-01-01

In the current precision medicine era, more and more samples get genotyped and sequenced. Both researchers and commercial companies expend significant time and resources to reduce the error rate. However, it has been reported that there is a sample mix-up rate of between 0.1% and 1%, not to mention the possibly higher mix-up rate during the down-stream genetic reporting processes. Even on the low end of this estimate, this translates to a significant number of mislabeled samples, especially over the projected one billion people that will be sequenced within the next decade. Here, we first describe a method to identify a small set of Single nucleotide polymorphisms (SNPs) that can uniquely identify a personal genome, which utilizes allele frequencies of five major continental populations reported in the 1000 genomes project and the ExAC Consortium. To make this panel more informative, we added four SNPs that are commonly used to predict ABO blood type, and another two SNPs that are capable of predicting sex. We then implement a web interface (http://qrcme.tech), nicknamed QRC (for QR code based Concordance check), which is capable of extracting the relevant ID SNPs from a raw genetic data, coding its genotype as a quick response (QR) code, and comparing QR codes to report the concordance of underlying genetic datasets. The resulting 80 fingerprinting SNPs represent a significant decrease in complexity and the number of markers used for genetic data labelling and tracking. Our method and web tool is easily accessible to both researchers and the general public who consider the accuracy of complex genetic data as a prerequisite towards precision medicine.

A SNP panel and online tool for checking genotype concordance through comparing QR codes

PubMed Central

Du, Yonghong; Martin, Joshua S.; McGee, John; Yang, Yuchen; Liu, Eric Yi; Sun, Yingrui; Geihs, Matthias; Kong, Xuejun; Zhou, Eric Lingfeng; Li, Yun

2017-01-01

In the current precision medicine era, more and more samples get genotyped and sequenced. Both researchers and commercial companies expend significant time and resources to reduce the error rate. However, it has been reported that there is a sample mix-up rate of between 0.1% and 1%, not to mention the possibly higher mix-up rate during the down-stream genetic reporting processes. Even on the low end of this estimate, this translates to a significant number of mislabeled samples, especially over the projected one billion people that will be sequenced within the next decade. Here, we first describe a method to identify a small set of Single nucleotide polymorphisms (SNPs) that can uniquely identify a personal genome, which utilizes allele frequencies of five major continental populations reported in the 1000 genomes project and the ExAC Consortium. To make this panel more informative, we added four SNPs that are commonly used to predict ABO blood type, and another two SNPs that are capable of predicting sex. We then implement a web interface (http://qrcme.tech), nicknamed QRC (for QR code based Concordance check), which is capable of extracting the relevant ID SNPs from a raw genetic data, coding its genotype as a quick response (QR) code, and comparing QR codes to report the concordance of underlying genetic datasets. The resulting 80 fingerprinting SNPs represent a significant decrease in complexity and the number of markers used for genetic data labelling and tracking. Our method and web tool is easily accessible to both researchers and the general public who consider the accuracy of complex genetic data as a prerequisite towards precision medicine. PMID:28926565

Association of genetic polymorphisms with risk of renal injury after coronary bypass graft surgery.

PubMed

Stafford-Smith, Mark; Podgoreanu, Mihai; Swaminathan, Madhav; Phillips-Bute, Barbara; Mathew, Joseph P; Hauser, Elizabeth H; Winn, Michelle P; Milano, Carmelo; Nielsen, Dahlia M; Smith, Mike; Morris, Richard; Newman, Mark F; Schwinn, Debra A

2005-03-01

Post-cardiac surgery renal dysfunction is a common, serious, multifactorial disorder, with interpatient variability predicted poorly by preoperative clinical, procedural, and biological markers. Therefore, we tested the hypothesis that selected gene variants are associated with acute renal injury, reflected by a serum creatinine level increase after cardiac surgery. One thousand six hundred seventy-one patients undergoing aortocoronary surgery were studied. Clinical covariates were recorded. DNA was isolated from preoperative blood; mass spectrometry was used for genotype analysis. A model was developed relating clinical and genetic factors to postoperative acute renal injury. A race effect was found; therefore, Caucasians and African Americans were analyzed separately. Overall, clinical factors alone account poorly for postoperative renal injury, although more so in African Americans than Caucasians. When 12 candidate polymorphisms were assessed, 2 alleles (interleukin 6 -572C and angiotensinogen 842C) showed a strong association with renal injury in Caucasians (P < 0.0001; >50% decrease in renal filtration when they present together). Using less stringent criteria for significance (0.01 > P > 0.001), 4 additional polymorphisms are identified (apolipoproteinE 448C [4], angiotensin receptor1 1166C, and endothelial nitric oxide synthase [eNOS] 894T in Caucasians; eNOS 894T and angiotensin-converting enzyme deletion and insertion in African Americans). Adding genetic to clinical factors resulted in the best model, with overall ability to explain renal injury increasing approximately 4-fold in Caucasians and doubling in African Americans (P < 0.0005). In this study, we identify genetic polymorphisms that collectively provide 2- to 4-fold improvement over preoperative clinical factors alone in explaining post-cardiac surgery renal dysfunction. From a mechanistic perspective, most identified genetic variants are associated with increased renal inflammatory and/or vasoconstrictor responses.

Genetic influences on alcohol use behaviors have diverging developmental trajectories: a prospective study among male and female twins.

PubMed

Meyers, Jacquelyn L; Salvatore, Jessica E; Vuoksimaa, Eero; Korhonen, Tellervo; Pulkkinen, Lea; Rose, Richard J; Kaprio, Jaakko; Dick, Danielle M

2014-11-01

Both alcohol-specific genetic factors and genetic factors related to externalizing behavior influence problematic alcohol use. Little is known, however, about the etiologic role of these 2 components of genetic risk on alcohol-related behaviors across development. Prior studies conducted in a male cohort of twins suggest that externalizing genetic factors are important for predicting heavy alcohol use in adolescence, whereas alcohol-specific genetic factors increase in importance during the transition to adulthood. In this report, we studied twin brothers and sisters and brother-sister twin pairs to examine such developmental trajectories and investigate whether sex and cotwin sex effects modify these genetic influences. We used prospective, longitudinal twin data collected between ages 12 and 22 within the population-based FinnTwin12 cohort study (analytic n = 1,864). Our dependent measures of alcohol use behaviors included alcohol initiation (age 12), intoxication frequency (ages 14 and 17), and alcohol dependence criteria (age 22). Each individual's genetic risk of alcohol use disorders (AUD-GR) was indexed by his/her parents' and cotwin's DSM-IV Alcohol Dependence (AD) criterion counts. Likewise, each individual's genetic risk of externalizing disorders (EXT-GR) was indexed with a composite measure of parents' and cotwin's DSM-IV Conduct Disorder and Antisocial Personality Disorder criterion counts. EXT-GR was most strongly related to alcohol use behaviors during adolescence, while AUD-GR was most strongly related to alcohol problems in young adulthood. Further, sex of the twin and sex of the cotwin significantly moderated the associations between genetic risk and alcohol use behaviors across development: AUD-GR influenced early adolescent alcohol use behaviors in females more than in males, and EXT-GR influenced age 22 AD more in males than in females. In addition, the associations of AUD-GR and EXT-GR with intoxication frequency were greater among 14- and 17-year-old females with twin brothers. We found divergent developmental trajectories for alcohol-specific and externalizing behavior-related genetic influences on alcohol use behaviors; in early adolescence, genetic influences on alcohol use behaviors are largely nonspecific, and later in adolescence and young adulthood, alcohol-specific genetic influences on alcohol use are more influential. Importantly, within these overall trajectories, several interesting sex differences emerged. We found that the relationship between genetic risk and problematic drinking across development is moderated by the individual's sex and his/her cotwin's sex. AUD-GR influenced adolescent alcohol outcomes in females more than in males and by age 22, EXT-GR influenced AD criteria more for males than females. In addition, the association between genetic risk and intoxication frequency was greater among 14- and 17-year-old females with male cotwins. Copyright © 2014 by the Research Society on Alcoholism.

[An ADAA model and its analysis method for agronomic traits based on the double-cross mating design].

PubMed

Xu, Z C; Zhu, J

2000-01-01

According to the double-cross mating design and using principles of Cockerham's general genetic model, a genetic model with additive, dominance and epistatic effects (ADAA model) was proposed for the analysis of agronomic traits. Components of genetic effects were derived for different generations. Monte Carlo simulation was conducted for analyzing the ADAA model and its reduced AD model by using different generations. It was indicated that genetic variance components could be estimated without bias by MINQUE(1) method and genetic effects could be predicted effectively by AUP method; at least three generations (including parent, F1 of single cross and F1 of double-cross) were necessary for analyzing the ADAA model and only two generations (including parent and F1 of double-cross) were enough for the reduced AD model. When epistatic effects were taken into account, a new approach for predicting the heterosis of agronomic traits of double-crosses was given on the basis of unbiased prediction of genotypic merits of parents and their crosses. In addition, genotype x environment interaction effects and interaction heterosis due to G x E interaction were discussed briefly.

Sleep Modifies the Relation of APOE to the Risk of Alzheimer Disease and Neurofibrillary Tangle Pathology

PubMed Central

Lim, Andrew S.P.; Yu, Lei; Kowgier, Matthew; Schneider, Julie A.; Buchman, Aron S.; Bennett, David A.

2013-01-01

IMPORTANCE The Apolipoprotein E (APOE) ε4 allele is a common and well-established genetic risk factor for Alzheimer Disease (AD). Sleep consolidation is also associated with AD risk and previous work suggests that APOE genotype and sleep may interact to influence cognitive function. OBJECTIVE To determine whether better sleep consolidation attenuates the relation of the APOE genotype to the risk of incident AD and the burden of AD pathology. DESIGN Prospective longitudinal cohort study with up to 6 years of follow-up. SETTING Community-based. PARTICIPANTS We studied a volunteer sample of 698 community dwelling older adults without dementia (average age 81.7 years; 77% female) in the Rush Memory and Aging Project followed for up to 6 years. EXPOSURES We used up to 10 days of actigraphic recording to quantify the degree of sleep consolidation, and ascertained APOE genotype. MAIN OUTCOME MEASURES Subjects underwent annual evaluation for AD over a follow-up period of up to 6 years. Autopsies were performed on 201 deceased participants, and Aβ and neurofibrillary tangle (NFT) pathology were identified by immunohistochemistry and quantified. RESULTS Over a follow-up period, 98 individuals developed AD. In a series of Cox proportional hazards models, better sleep consolidation attenuated the effect of the ε4 allele on the risk of incident AD (HR 0.67 95%CI 0.46–0.97 p=0.036 per allele per 1SD increase in sleep consolidation). In a series of linear mixed effect models, better sleep consolidation also attenuated the effect of the ε4 allele on the annual rate of cognitive decline (interaction estimate +0.048 SE=0.012 p<0.001). In deceased individuals, better sleep consolidation attenuated the effect of the ε4 allele on NFT density (interaction estimate −0.42 SE=0.17 p=0.016), which accounted for the effect of sleep consolidation on the association between APOE genotype and cognition proximate to death. CONCLUSIONS AND RELEVANCE Better sleep consolidation attenuates the effect of APOE genotype on incident AD and NFT pathology. Assessment of sleep consolidation may identify APOE positive individuals at high risk for incident AD, and interventions to enhance sleep consolidation should be studied as potentially useful means to reduce the risk of AD and NFT pathology in APOE ε4+ individuals. PMID:24145819

Environmental risk factors and their role in the management of atopic dermatitis

PubMed Central

Kantor, Robert; Silverberg, Jonathan I.

2016-01-01

Introduction The etiology of atopic dermatitis (AD) is multifactorial with interaction between genetics, immune and environmental factors. Areas covered We review the role of prenatal exposures, irritants and pruritogens, pathogens, climate factors, including temperature, humidity, ultraviolet radiation, outdoor and indoor air pollutants, tobacco smoke exposure, water hardness, urban vs. rural living, diet, breastfeeding, probiotics and prebiotics on AD. Expert commentary The increased global prevalence of AD cannot be attributed to genetics alone, suggesting that evolving environmental exposures may trigger and/or flare disease in predisposed individuals. There is a complex interplay between different environmental factors, including individual use of personal care products and exposure to climate, pollution, food and other exogenous factors. Understanding these complex risk factors is crucial to developing targeted interventions to prevent the disease in millions. Moreover, patients require counseling on optimal regimens for minimization of exposure to irritants and pruritogens and other harmful exposures. PMID:27417220

Amyloid Precursor Protein Processing and Alzheimer’s Disease

PubMed Central

O’Brien, Richard J.; Wong, Philip C.

2011-01-01

Alzheimer’s disease (AD), the leading cause of dementia worldwide, is characterized by the accumulation of the β-amyloid peptide (Aβ) within the brain along with hyperphosphorylated and cleaved forms of the microtubule-associated protein tau. Genetic, biochemical, and behavioral research suggest that physiologic generation of the neurotoxic Aβ peptide from sequential amyloid precursor protein (APP) proteolysis is the crucial step in the development of AD. APP is a single-pass transmembrane protein expressed at high levels in the brain and metabolized in a rapid and highly complex fashion by a series of sequential proteases, including the intramembranous γ-secretase complex, which also process other key regulatory molecules. Why Aβ accumulates in the brains of elderly individuals is unclear but could relate to changes in APP metabolism or Aβ elimination. Lessons learned from biochemical and genetic studies of APP processing will be crucial to the development of therapeutic targets to treat AD. PMID:21456963

Environmental risk factors and their role in the management of atopic dermatitis.

PubMed

Kantor, Robert; Silverberg, Jonathan I

2017-01-01

The etiology of atopic dermatitis (AD) is multifactorial with interaction between genetics, immune and environmental factors. Areas covered: We review the role of prenatal exposures, irritants and pruritogens, pathogens, climate factors, including temperature, humidity, ultraviolet radiation, outdoor and indoor air pollutants, tobacco smoke exposure, water hardness, urban vs. rural living, diet, breastfeeding, probiotics and prebiotics on AD. Expert commentary: The increased global prevalence of AD cannot be attributed to genetics alone, suggesting that evolving environmental exposures may trigger and/or flare disease in predisposed individuals. There is a complex interplay between different environmental factors, including individual use of personal care products and exposure to climate, pollution, food and other exogenous factors. Understanding these complex risk factors is crucial to developing targeted interventions to prevent the disease in millions. Moreover, patients require counseling on optimal regimens for minimization of exposure to irritants and pruritogens and other harmful exposures.

Conditional Deletion of Prnp Rescues Behavioral and Synaptic Deficits after Disease Onset in Transgenic Alzheimer's Disease

PubMed Central

Kaufman, Adam C.; Herber, Charlotte S.; Haas, Laura T.; Robinson, Sophie; Lee, Michael K.

2017-01-01

Biochemical and genetic evidence implicate soluble oligomeric amyloid-β (Aβo) in triggering Alzheimer's disease (AD) pathophysiology. Moreover, constitutive deletion of the Aβo-binding cellular prion protein (PrPC) prevents development of memory deficits in APPswe/PS1ΔE9 mice, a model of familial AD. Here, we define the role of PrPC to rescue or halt established AD endophenotypes in a therapeutic disease-modifying time window after symptom onset. Deletion of Prnp at either 12 or 16 months of age fully reverses hippocampal synapse loss and completely rescues preexisting behavioral deficits by 17 months. In contrast, but consistent with a neuronal function for Aβo/PrPC signaling, plaque density, microgliosis, and astrocytosis are not altered. Degeneration of catecholaminergic neurons remains unchanged by PrPC reduction after disease onset. These results define the potential of targeting PrPC as a disease-modifying therapy for certain AD-related phenotypes after disease onset. SIGNIFICANCE STATEMENT The study presented here further elucidates our understanding of the soluble oligomeric amyloid-β–Aβo-binding cellular prion protein (PrPC) signaling pathway in a familial form of Alzheimer's disease (AD) by implicating PrPC as a potential therapeutic target for AD. In particular, genetic deletion of Prnp rescued several familial AD (FAD)-associated phenotypes after disease onset in a mouse model of FAD. This study underscores the therapeutic potential of PrPC deletion given that patients already present symptoms at the time of diagnosis. PMID:28842420

Organic Solvents as Risk Factor for Autoimmune Diseases: A Systematic Review and Meta-Analysis

PubMed Central

Barragán-Martínez, Carolina; Speck-Hernández, Cesar A.; Montoya-Ortiz, Gladis; Mantilla, Rubén D.; Anaya, Juan-Manuel; Rojas-Villarraga, Adriana

2012-01-01

Background Genetic and epigenetic factors interacting with the environment over time are the main causes of complex diseases such as autoimmune diseases (ADs). Among the environmental factors are organic solvents (OSs), which are chemical compounds used routinely in commercial industries. Since controversy exists over whether ADs are caused by OSs, a systematic review and meta-analysis were performed to assess the association between OSs and ADs. Methods and Findings The systematic search was done in the PubMed, SCOPUS, SciELO and LILACS databases up to February 2012. Any type of study that used accepted classification criteria for ADs and had information about exposure to OSs was selected. Out of a total of 103 articles retrieved, 33 were finally included in the meta-analysis. The final odds ratios (ORs) and 95% confidence intervals (CIs) were obtained by the random effect model. A sensitivity analysis confirmed results were not sensitive to restrictions on the data included. Publication bias was trivial. Exposure to OSs was associated to systemic sclerosis, primary systemic vasculitis and multiple sclerosis individually and also to all the ADs evaluated and taken together as a single trait (OR: 1.54; 95% CI: 1.25–1.92; p-value<0.001). Conclusion Exposure to OSs is a risk factor for developing ADs. As a corollary, individuals with non-modifiable risk factors (i.e., familial autoimmunity or carrying genetic factors) should avoid any exposure to OSs in order to avoid increasing their risk of ADs. PMID:23284705

Rarity and genetic diversity in Indo–Pacific Acropora corals

PubMed Central

Richards, Zoe T; Oppen, Madeleine J H

2012-01-01

Among various potential consequences of rarity is genetic erosion. Neutral genetic theory predicts that rare species will have lower genetic diversity than common species. To examine the association between genetic diversity and rarity, variation at eight DNA microsatellite markers was documented for 14 Acropora species that display different patterns of distribution and abundance in the Indo–Pacific Ocean. Our results show that the relationship between rarity and genetic diversity is not a positive linear association because, contrary to expectations, some rare species are genetically diverse and some populations of common species are genetically depleted. Our data suggest that inbreeding is the most likely mechanism of genetic depletion in both rare and common corals, and that hybridization is the most likely explanation for higher than expected levels of genetic diversity in rare species. A significant hypothesis generated from our study with direct conservation implications is that as a group, Acropora corals have lower genetic diversity at neutral microsatellite loci than may be expected from their taxonomic diversity, and this may suggest a heightened susceptibility to environmental change. This hypothesis requires validation based on genetic diversity estimates derived from a large portion of the genome. PMID:22957189

Concurrence of High Fat Diet and APOE Gene Induces Allele Specific Metabolic and Mental Stress Changes in a Mouse Model of Alzheimer's Disease.

PubMed

Segev, Yifat; Livne, Adva; Mints, Meshi; Rosenblum, Kobi

2016-01-01

Aging is the main risk factor for neurodegenerative diseases, including Alzheimer's disease (AD). However, evidence indicates that the pathological process begins long before actual cognitive or pathological symptoms are apparent. The long asymptomatic phase and complex integration between genetic, environmental and metabolic factors make it one of the most challenging diseases to understand and cure. In the present study, we asked whether an environmental factor such as high-fat (HF) diet would synergize with a genetic factor to affect the metabolic and cognitive state in the Apolipoprotein E (ApoE4) mouse model of AD. Our data suggest that a HF diet induces diabetes mellitus (DM)-like metabolism in ApoE4 mice, as well as changes in β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) protein levels between the two ApoE strains. Furthermore, HF diet induces anxiety in this AD mouse model. Our results suggest that young ApoE4 carriers are prone to psychological stress and metabolic abnormalities related to AD, which can easily be triggered via HF nutrition.

Estimating the probability for major gene Alzheimer disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farrer, L.A.; Cupples, L.A.

1994-02-01

Alzheimer disease (AD) is a neuropsychiatric illness caused by multiple etiologies. Prediction of whether AD is genetically based in a given family is problematic because of censoring bias among unaffected relatives as a consequence of the late onset of the disorder, diagnostic uncertainties, heterogeneity, and limited information in a single family. The authors have developed a method based on Bayesian probability to compute values for a continuous variable that ranks AD families as having a major gene form of AD (MGAD). In addition, they have compared the Bayesian method with a maximum-likelihood approach. These methods incorporate sex- and age-adjusted riskmore » estimates and allow for phenocopies and familial clustering of age on onset. Agreement is high between the two approaches for ranking families as MGAD (Spearman rank [r] = .92). When either method is used, the numerical outcomes are sensitive to assumptions of the gene frequency and cumulative incidence of the disease in the population. Consequently, risk estimates should be used cautiously for counseling purposes; however, there are numerous valid applications of these procedures in genetic and epidemiological studies. 41 refs., 4 figs., 3 tabs.« less

Application of Short Tandem Repeat markers in diagnosis of chromosomal aneuploidies and forensic DNA investigation in Pakistan.

PubMed

Chishti, Hafsah Muhammad; Ansar, Muhammad; Ajmal, Muhammad; Hameed, Abdul

2014-09-15

Short Tandem Repeat (STR) genetic markers hold great potential in forensic investigations, molecular diagnostics and molecular genetics research. AmpFlSTR® Identifiler™ PCR amplification kit is a multiplex system for co-amplification of 15 STR markers used worldwide in forensic investigations. This study attempts to assess forensic validity of these STRs in Pakistani population and to investigate its applicability in quick and simultaneous diagnosis and tracing parental source of common chromosomal aneuploidies. Samples from 554 healthy Pakistani individuals from 5 different ethnicities were analyzed for forensic parameters using Identifiler STRs and 74 patients' samples with different aneuploidies were evaluated for diagnostic strengths of these markers. All STRs hold sufficient forensic applicability in Pakistani population with paternity index between 1.5 and 3.5, polymorphic information content from 0.63 to 0.87 and discrimination power ≥0.9 (except TPOX locus). Variation from Hardy-Weinberg equilibrium was observed at some loci reflecting selective breeding and intermarriages trend in Pakistan. Among aneuploidic samples, all trisomies were precisely detectable while aneuploidies involving sex chromosomes or missing chromosomes were not clearly detectable using Identifiler STRs. Parental origin of aneuploidy was traceable in 92.54% patients. The studied STR markers are valuable tools for forensic application in Pakistan and utilizable for quick and simultaneous identification of some common trisomic conditions. Adding more sex chromosome specific STR markers can immensely increase the diagnostic and forensic potential of this system. Copyright © 2014 Elsevier B.V. All rights reserved.

HIGHER SERUM TOTAL CHOLESTEROL LEVELS IN LATE MIDDLE AGE ARE ASSOCIATED WITH GLUCOSE HYPOMETABOLISM IN BRAIN REGIONS AFFECTED BY ALZHEIMER’S DISEASE AND NORMAL AGING

PubMed Central

Reiman, Eric M.; Chen, Kewei; Langbaum, Jessica B.S.; Lee, Wendy; Reschke, Cole; Bandy, Daniel; Alexander, Gene E.; Caselli, Richard J.

2010-01-01

Epidemiological studies suggest that higher midlife serum total cholesterol levels are associated with an increased risk of Alzheimer’s disease (AD). Using fluorodeoxyglucose positron emission tomography (PET) in the study of cognitively normal late-middle-aged people, we demonstrated an association between apolipoprotein E (APOE) ε4 gene dose, the major genetic risk factor for late-onset AD, and lower measurements of the cerebral metabolic rate for glucose (CMRgl) in AD-affected brain regions, we proposed using PET as a presymptomatic endophenotype to evaluate other putative AD risk modifiers, and we then used it to support an aggregate cholesterol-related genetic risk score in the risk of AD. In the present study, we used PET to investigate the association between serum total cholesterol levels and cerebral metabolic rate for glucose metabolism (CMRgl) in 117 cognitively normal late middle-aged APOE ε4 homozygotes, heterozygotes and noncarriers. Higher serum total cholesterol levels were associated with lower CMRgl bilaterally in precuneus, parietotemporal and prefrontal regions previously found to be preferentially affected by AD, and in additional frontal regions previously found to be preferentially affected by normal aging. The associations were greater in APOE ε4 carriers than non-carriers in some of the AD-affected brain regions. We postulate the higher midlife serum total cholesterol levels accelerate brain processes associated with normal aging and conspire with other risk factors in the predisposition to AD. We propose using PET in proof-of-concept randomized controlled trials to rapidly evaluate the effects of midlife cholesterol-lowering treatments on the brain changes associated with normal aging and AD. PMID:19631758

Different demographic, genetic, and longitudinal traits in language versus memory Alzheimer's subgroups.

PubMed

Mez, Jesse; Cosentino, Stephanie; Brickman, Adam M; Huey, Edward D; Mayeux, Richard

2013-01-01

The study's objective was to compare demographics, APOE genotypes, and rate of rise over time in functional impairment in neuropsychologically defined language, typical, and memory subgroups of clinical Alzheimer's disease (AD). 1,368 participants from the National Alzheimer's Coordinating Center database with a diagnosis of probable AD (CDR 0.5-1.0) were included. A language subgroup (n = 229) was defined as having language performance >1 SD worse than memory performance. A memory subgroup (n = 213) was defined as having memory performance >1 SD worse than language performance. A typical subgroup (n = 926) was defined as having a difference in language and memory performance of <1 SD. Compared with the memory subgroup, the language subgroup was 3.7 years older and more frequently self-identified as African American (OR = 3.69). Under a dominant genetic model, the language subgroup had smaller odds of carrying at least one APOEε4 allele relative to the memory subgroup. While this difference was present for all ages, it was more striking at a younger age (OR = 0.19 for youngest tertile; OR = 0.52 for oldest tertile). Compared with the memory subgroup, the language subgroup rose 35% faster on the Functional Assessment Questionnaire and 44% faster on CDR sum of boxes over time. Among a subset of participants who underwent autopsy (n = 98), the language, memory, and typical subgroups were equally likely to have an AD pathologic diagnosis, suggesting that variation in non-AD pathologies across subtypes did not lead to the observed differences. The study demonstrates that a language subgroup of AD has different demographics, genetic profile, and disease course in addition to cognitive phenotype.

Candidate genes for alcohol dependence: A genetic association study from India.

PubMed

Malhotra, Savita; Basu, Debasish; Khullar, Madhu; Ghosh, Abhishek; Chugh, Neera

2016-11-01

Search for candidate genes for alcohol dependence (AD) has been inconsistent and inconclusive. Moreover, most of the research has been confined to a few specific ethnic groups. Hence, the aim of our study was to explore specific candidate genes for AD in north Indian male population. In this clinic-based genetic association study, 210 males with AD and 200 controls matched for age, gender and ethnicity were recruited from the clinic and the general population, respectively. Cases were diagnosed with Semi-structured Assessment for Genetics of Alcoholism-II (SSAGA-II). Single-nucleotide polymorphism genotyping was done by real-time quantitative-polymerase chain reaction (PCR) using Taq Man assay (ABI 7500) fast real-time PCR system. Both at the genotypic level and at allelic frequency, Met158 variant of catechol-O-methyl transferase (COMT) showed significant increase in cases as compared to controls. The frequency of heterozygous genotype (A/G) of gamma-aminobutyric acid receptor A1 (GABRA1) was significantly lower in cases as compared to controls. Likewise, for GABRA2, the frequency of homozygous recessive genotype (G/G) was significantly higher in the control group. With respect to the 5-hydroxytryptamine (5HT) transporter long promoter region (5HTTLPR), cholinergic receptor muscarinic (CHRM2) and alcohol dehydrogenase 1B (ADH1B) genes, there was no significant difference between the cases and the controls. Aldehyde dehydrogenase (ALDH2) gene was found to be monomorphic in our study population. Our study findings showed COMT polymorphism conferring risk and GABRA polymorphism as a protective genotype for Indian male with AD. Genes for alcohol metabolism, serotonin transporter and cholinergic receptor gene polymorphism were perhaps not contributory to AD for Indian population.

Genetic influences on schizophrenia and subcortical brain volumes: large-scale proof-of-concept and roadmap for future studies

PubMed Central

Anttila, Verneri; Hibar, Derrek P; van Hulzen, Kimm J E; Arias-Vasquez, Alejandro; Smoller, Jordan W; Nichols, Thomas E; Neale, Michael C; McIntosh, Andrew M; Lee, Phil; McMahon, Francis J; Meyer-Lindenberg, Andreas; Mattheisen, Manuel; Andreassen, Ole A; Gruber, Oliver; Sachdev, Perminder S; Roiz-Santiañez, Roberto; Saykin, Andrew J; Ehrlich, Stefan; Mather, Karen A; Turner, Jessica A; Schwarz, Emanuel; Thalamuthu, Anbupalam; Shugart, Yin Yao; Ho, Yvonne YW; Martin, Nicholas G; Wright, Margaret J

2016-01-01

Schizophrenia is a devastating psychiatric illness with high heritability. Brain structure and function differ, on average, between schizophrenia cases and healthy individuals. As common genetic associations are emerging for both schizophrenia and brain imaging phenotypes, we can now use genome-wide data to investigate genetic overlap. Here we integrated results from common variant studies of schizophrenia (33,636 cases, 43,008 controls) and volumes of several (mainly subcortical) brain structures (11,840 subjects). We did not find evidence of genetic overlap between schizophrenia risk and subcortical volume measures either at the level of common variant genetic architecture or for single genetic markers. The current study provides proof-of-concept (albeit based on a limited set of structural brain measures), and defines a roadmap for future studies investigating the genetic covariance between structural/functional brain phenotypes and risk for psychiatric disorders. PMID:26854805

Genetic influences on schizophrenia and subcortical brain volumes: large-scale proof of concept.

PubMed

Franke, Barbara; Stein, Jason L; Ripke, Stephan; Anttila, Verneri; Hibar, Derrek P; van Hulzen, Kimm J E; Arias-Vasquez, Alejandro; Smoller, Jordan W; Nichols, Thomas E; Neale, Michael C; McIntosh, Andrew M; Lee, Phil; McMahon, Francis J; Meyer-Lindenberg, Andreas; Mattheisen, Manuel; Andreassen, Ole A; Gruber, Oliver; Sachdev, Perminder S; Roiz-Santiañez, Roberto; Saykin, Andrew J; Ehrlich, Stefan; Mather, Karen A; Turner, Jessica A; Schwarz, Emanuel; Thalamuthu, Anbupalam; Shugart, Yin Yao; Ho, Yvonne Yw; Martin, Nicholas G; Wright, Margaret J; O'Donovan, Michael C; Thompson, Paul M; Neale, Benjamin M; Medland, Sarah E; Sullivan, Patrick F

2016-03-01

Schizophrenia is a devastating psychiatric illness with high heritability. Brain structure and function differ, on average, between people with schizophrenia and healthy individuals. As common genetic associations are emerging for both schizophrenia and brain imaging phenotypes, we can now use genome-wide data to investigate genetic overlap. Here we integrated results from common variant studies of schizophrenia (33,636 cases, 43,008 controls) and volumes of several (mainly subcortical) brain structures (11,840 subjects). We did not find evidence of genetic overlap between schizophrenia risk and subcortical volume measures either at the level of common variant genetic architecture or for single genetic markers. These results provide a proof of concept (albeit based on a limited set of structural brain measures) and define a roadmap for future studies investigating the genetic covariance between structural or functional brain phenotypes and risk for psychiatric disorders.

Learning from Job: A Rare Genetic Disease and Lessons of Biblical Proportions.

PubMed

Milner, Joshua D

2018-01-29

Dominant negative mutations in STAT3, a critical signaling molecule and transcription factor in multiple organ systems, lead to a rare monogenic disease called the STAT3 loss-of-function, autosomal dominant hyper-IgE syndrome (STAT3LOF AD-HIES). The original name for this syndrome, Job's syndrome, was derived from the observation that patients had a propensity to develop skin boils, reminiscent of the affliction cast upon the biblical Job. Many fascinating observations have been made regarding the pathogenesis of the disease and the role STAT3 plays in human health and disease. Additionally, quite a few phenotypic descriptions from the Book of Job are similar to those seen in patients with STAT3LOF AD-HIES, beyond just the boils. This complex multisystem genetic disorder is a challenge clinically and scientifically, but it also brings into question how we approach genetic syndromes beyond just the technical aspects of research and treatment.

Genome-wide association analysis of age-at-onset in Alzheimer’s disease

PubMed Central

Kamboh, M. Ilyas; Barmada, M. Michael; Demirci, F. Yesim; Minster, Ryan L.; Carrasquillo, Minerva M.; Pankratz, V. Shane; Younkin, Steven G.; Saykin, Andrew J.; Sweet, Robert A.; Feingold, Eleanor; DeKosky, Steven T.; Lopez, Oscar L.

2011-01-01

The risk of Alzheimer’s disease (AD) is strongly determined by genetic factors and recent genome-wide association studies (GWAS) have identified several genes for the disease risk. In addition to the disease risk, age-at-onset (AAO) of AD has also strong genetic component with an estimated heritability of 42%. Identification of AAO genes may help to understand the biological mechanisms that regulate the onset of the disease. Here we report the first GWAS focused on identifying genes for the AAO of AD. We performed a genome-wide meta analysis on 3 samples comprising a total of 2,222 AD cases. A total of ~2.5 million directly genotyped or imputed SNPs were analyzed in relation to AAO of AD. As expected, the most significant associations were observed in the APOE region on chromosome 19 where several SNPs surpassed the conservative genome-wide significant threshold (P<5E-08). The most significant SNP outside the APOE region was located in the DCHS2 gene on chromosome 4q31.3 (rs1466662; P=4.95E-07). There were 19 additional significant SNPs in this region at P<1E-04 and the DCHS2 gene is expressed in the cerebral cortex and thus is a potential candidate for affecting AAO in AD. These findings need to be confirmed in additional well-powered samples. PMID:22005931

Genome-wide association analysis of age-at-onset in Alzheimer's disease.

PubMed

Kamboh, M I; Barmada, M M; Demirci, F Y; Minster, R L; Carrasquillo, M M; Pankratz, V S; Younkin, S G; Saykin, A J; Sweet, R A; Feingold, E; DeKosky, S T; Lopez, O L

2012-12-01

The risk of Alzheimer's disease (AD) is strongly determined by genetic factors and recent genome-wide association studies (GWAS) have identified several genes for the disease risk. In addition to the disease risk, age-at-onset (AAO) of AD has also strong genetic component with an estimated heritability of 42%. Identification of AAO genes may help to understand the biological mechanisms that regulate the onset of the disease. Here we report the first GWAS focused on identifying genes for the AAO of AD. We performed a genome-wide meta-analysis on three samples comprising a total of 2222 AD cases. A total of ~2.5 million directly genotyped or imputed single-nucleotide polymorphisms (SNPs) were analyzed in relation to AAO of AD. As expected, the most significant associations were observed in the apolipoprotein E (APOE) region on chromosome 19 where several SNPs surpassed the conservative genome-wide significant threshold (P<5E-08). The most significant SNP outside the APOE region was located in the DCHS2 gene on chromosome 4q31.3 (rs1466662; P=4.95E-07). There were 19 additional significant SNPs in this region at P<1E-04 and the DCHS2 gene is expressed in the cerebral cortex and thus is a potential candidate for affecting AAO in AD. These findings need to be confirmed in additional well-powered samples.

Origin of Bolivian Quechua Amerindians: their relationship with other American Indians and Asians according to HLA genes.

PubMed

Martinez-Laso, Jorge; Siles, Nancy; Moscoso, Juan; Zamora, Jorge; Serrano-Vela, Juan I; R-A-Cachafeiro, Juan I; Castro, Maria J; Serrano-Rios, Manuel; Arnaiz-Villena, Antonio

2006-01-01

The Incas were Quechua-speaking people who settled down near Cuzco (Peru). They had an empire ranging from Ecuador to Chile, when Spanish conquerors seized their kingdom around 1532 AD. Nowadays, Quechua-speaking people inhabits Colombia, Ecuador, Bolivia, Peru and Argentina; however, Quechua language was imposed by both Incas and Spaniards to many non-Quechua speaking communities. We have taken a sample of Quechuan Bolivian blood donors from La Paz (Titicaca Lake region) where Inca-Quechuas themselves believed that came from. This group was compared with 6892 individuals from 68 different world populations regarding HLA/DNA allele frequencies distribution. Genetic distances, dendrograms and correspondence analyses were carried out in order to establish relationships among populations. The main conclusions are: (1) DRB1 and -DQB1 haplotypes shared with Asians are found in Quechuas and are not observed in other (Mesoamerican) Amerindians. (2) Aymara-speaking people from the same Titicaca Lake (La Paz) area shows close genetic distances with Quechuas in one dimension results (genetic distances); however, their HLA gene frequency distribution differs according to Neighbor-Joining (NJ) trees and correspondence analysis (multidimensional and more reliable analyses). Also, the common high frequency Asian and Athabascan HLA-DRB1*0901 allele is found in Quechuas in a significant frequency. Quechuas are clearly included within the Amerindian group.

Nonprofit Groups Offer Genetic Testing for Jewish Students

ERIC Educational Resources Information Center

Supiano, Beckie

2008-01-01

This article describes how nonprofit organizations like Hillel are offering free genetic testing for Jewish college students. A growing number of colleges, including Pittsburgh, Brandeis University, and Columbia University are offering students free or reduced-cost screenings for diseases common to Jewish population. Genetic diseases common to…

Developing Novel Therapeutic Approaches in Small Cell Lung Carcinoma Using Genetically Engineered Mouse Models and Human Circulating Tumor Cells

DTIC Science & Technology

2014-10-01

AD_________________ Award Number: W81XWH-13-1-0325 TITLE: Developing Novel Therapeutic Approaches in Small Cell Lung Carcinoma Using ...Genetically Engineered Mouse Models and Human Circulating Tumor Cells PRINCIPAL INVESTIGATOR: Jeffrey Engelman MD PhD CONTRACTING ORGANIZATION ...Novel Therapeutic Approaches in Small Cell Lung 5a. CONTRACT NUMBER W81XWH-13-1-0325 Carcinoma Using Genetically Engineered Mouse Models and 5b

Genetic Characterization of Zika Virus Strains: Geographic Expansion of the Asian Lineage

DTIC Science & Technology

2012-02-28

Genetic Characterization of Zika Virus Strains: Geographic Expansion of the Asian Lineage Andrew D. Haddow1*, Amy J. Schuh1, Chadwick Y. Yasuda2...Medical Research Unit, No. 2, Phnom Penh, Cambodia, 3 National Dengue Control Program, Phnom Penh, Cambodia Abstract Background: Zika virus (ZIKV) is a...underreported. Citation: Haddow AD, Schuh AJ, Yasuda CY, Kasper MR, Heang V, et al. (2012) Genetic Characterization of Zika Virus Strains: Geographic

Classification and Reporting of Potentially Proarrhythmic Common Genetic Variation in Long QT Syndrome Genetic Testing.

PubMed

Giudicessi, John R; Roden, Dan M; Wilde, Arthur A M; Ackerman, Michael J

2018-02-06

The acquired and congenital forms of long QT syndrome represent 2 distinct but clinically and genetically intertwined disorders of cardiac repolarization characterized by the shared final common pathway of QT interval prolongation and risk of potentially life-threatening arrhythmias. Over the past 2 decades, our understanding of the spectrum of genetic variation that (1) perturbs the function of cardiac ion channel macromolecular complexes and intracellular calcium-handling proteins, (2) underlies acquired/congenital long QT syndrome susceptibility, and (3) serves as a determinant of QT interval duration in the general population has grown exponentially. In turn, these molecular insights led to the development and increased utilization of clinically impactful genetic testing for congenital long QT syndrome. However, the widespread adoption and potential misinterpretation of the 2015 American College of Medical Genetics and Genomics variant classification and reporting guidelines may have contributed unintentionally to the reduced reporting of common genetic variants, with compelling epidemiological and functional evidence to support a potentially proarrhythmic role in patients with congenital and acquired long QT syndrome. As a result, some genetic testing reports may fail to convey the full extent of a patient's genetic susceptibility for a potentially life-threatening arrhythmia to the ordering healthcare professional. In this white paper, we examine the current classification and reporting (or lack thereof) of potentially proarrhythmic common genetic variants and investigate potential mechanisms to facilitate the reporting of these genetic variants without increasing the risk of diagnostic miscues. © 2018 American Heart Association, Inc.

Polygenic risk score of sporadic late-onset Alzheimer's disease reveals a shared architecture with the familial and early-onset forms.

PubMed

Cruchaga, Carlos; Del-Aguila, Jorge L; Saef, Benjamin; Black, Kathleen; Fernandez, Maria Victoria; Budde, John; Ibanez, Laura; Deming, Yuetiva; Kapoor, Manav; Tosto, Giuseppe; Mayeux, Richard P; Holtzman, David M; Fagan, Anne M; Morris, John C; Bateman, Randall J; Goate, Alison M; Harari, Oscar

2018-02-01

To determine whether the extent of overlap of the genetic architecture among the sporadic late-onset Alzheimer's Disease (sLOAD), familial late-onset AD (fLOAD), sporadic early-onset AD (sEOAD), and autosomal dominant early-onset AD (eADAD). Polygenic risk scores (PRSs) were constructed using previously identified 21 genome-wide significant loci for LOAD risk. We found that there is an overlap in the genetic architecture among sEOAD, fLOAD, and sLOAD. The highest association of the PRS and risk (odds ratio [OR] = 2.27; P = 1.29 × 10 -7 ) was observed in sEOAD, followed by fLOAD (OR = 1.75; P = 1.12 × 10 -7 ) and sLOAD (OR = 1.40; P = 1.21 × 10 -3 ). The PRS was associated with cerebrospinal fluid ptau 181 -Aβ 42 on eADAD (P = 4.36 × 10 -2 ). Our analysis confirms that the genetic factors identified for LOAD modulate risk in sLOAD and fLOAD and also sEOAD cohorts. Specifically, our results suggest that the burden of these risk variants is associated with familial clustering and earlier onset of AD. Although these variants are not associated with risk in the eADAD, they may be modulating age at onset. Copyright © 2017 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Ex vivo MRI transverse relaxation in community based older persons with and without Alzheimer's dementia.

PubMed

Yu, Lei; Dawe, Robert J; Buchman, Aron S; Boyle, Patricia A; Schneider, Julie A; Arfanakis, Konstantinos; Bennett, David A

2017-03-30

Alterations of the transverse relaxation rate, R 2 , measured using MRI, are observed in older persons with Alzheimer's (AD) dementia. However, the spatial pattern of these alterations and the degree to which they reflect the accumulation of common age-related neuropathologies are unknown. In this study, we characterized the profile of R 2 alterations in post-mortem brains of persons with clinical diagnosis of AD dementia and investigated how the profile differs after accounting for neuropathologic indices of AD, cerebral infarcts, Lewy body disease, hippocampal sclerosis and transactive response DNA-binding protein 43. Data came from 567 post-mortem brains donated by participants in two cohort studies of aging and dementia. R 2 was quantified using fast spin echo imaging. Voxelwise linear regression examined R 2 alterations between subjects diagnosed with AD dementia at death and those with no cognitive impairment. Voxels showing significant R 2 alterations were clustered into regions of interest (ROIs). Three R 2 profiles were compared, which were adjusted for (1) demographics only; (2) demographics and AD pathology; (3) demographics, AD pathology and other common neuropathologies. R 2 alterations were observed throughout the hemisphere, most commonly in white matter. Of the distinct ROIs identified, the largest region encompassed large portions of white matter in all lobes. This ROI became smaller in size but remained largely intact after adjusting for AD and other neuropathologic indices. Further, R 2 alterations identify AD dementia with improved accuracy, above and beyond demographics and neuropathologic indices (p<0.0001). In conclusion, R 2 alterations in AD dementia are not solely reflective of common age-related neuropathologies, suggesting that other mechanisms are at work. Copyright © 2016 Elsevier B.V. All rights reserved.

Modification to the Capsid of the Adenovirus Vector That Enhances Dendritic Cell Infection and Transgene-Specific Cellular Immune Responses

PubMed Central

Worgall, Stefan; Busch, Annette; Rivara, Michael; Bonnyay, David; Leopold, Philip L.; Merritt, Robert; Hackett, Neil R.; Rovelink, Peter W.; Bruder, Joseph T.; Wickham, Thomas J.; Kovesdi, Imi; Crystal, Ronald G.

2004-01-01

Adenovirus (Ad) gene transfer vectors can be used to transfer and express antigens and function as strong adjuvants and thus are useful platforms for the development of genetic vaccines. Based on the hypothesis that Ad vectors with enhanced infectibility of dendritic cells (DC) may be able to evoke enhanced immune responses against antigens encoded by the vector in vivo, the present study analyzes the vaccine potential of an Ad vector expressing β-galactosidase as a model antigen and genetically modified with RGD on the fiber knob [AdZ.F(RGD)] to more selectively infect DC and consequently enhance immunity against the β-galactosidase antigen. Infection of murine DC in vitro with AdZ.F(RGD) showed an eightfold-increased transgene expression following infection compared to AdZ (also expressing β-galactosidase, but with a wild-type capsid). Binding, cellular uptake, and trafficking in DC were also increased with AdZ.F(RGD) compared to AdZ. To determine whether AdZ.F(RGD) could evoke enhanced immune responses to β-galactosidase in vivo, C57BL/6 mice were immunized with AdZ.F(RGD) or AdZ subcutaneously via the footpad. Humoral responses with both vectors were comparable, with similar anti-β-galactosidase antibody levels following vector administration. However, cellular responses to β-galactosidase were significantly enhanced, with the frequency of CD4+ as well as the CD8+ β-galactosidase-specific gamma interferon response in cells isolated from the draining lymph nodes increased following immunization with AdZ.F(RGD) compared to Ad.Z (P < 0.01). Importantly, this enhanced cellular immune response of the AdZ.F(RGD) vector was sufficient to evoke enhanced inhibition of the growth of preexisting tumors expressing β-galactosidase: BALB/c mice implanted with the CT26 syngeneic β-galactosidase-expressing colon carcinoma cell line and subsequently immunized with AdZ.F(RGD) showed decreased tumor growth and improved survival compared to mice immunized with AdZ. These data demonstrate that addition of an RGD motif to the Ad fiber knob increases the infectibility of DC and leads to enhanced cellular immune responses to the Ad-transferred transgene, suggesting that the RGD capsid modification may be useful in developing Ad-based vaccines. PMID:14963160

A genomewide screen for late-onset Alzheimer disease in a genetically isolated Dutch population.

PubMed

Liu, Fan; Arias-Vásquez, Alejandro; Sleegers, Kristel; Aulchenko, Yurii S; Kayser, Manfred; Sanchez-Juan, Pascual; Feng, Bing-Jian; Bertoli-Avella, Aida M; van Swieten, John; Axenovich, Tatiana I; Heutink, Peter; van Broeckhoven, Christine; Oostra, Ben A; van Duijn, Cornelia M

2007-07-01

Alzheimer disease (AD) is the most common cause of dementia. We conducted a genome screen of 103 patients with late-onset AD who were ascertained as part of the Genetic Research in Isolated Populations (GRIP) program that is conducted in a recently isolated population from the southwestern area of The Netherlands. All patients and their 170 closely related relatives were genotyped using 402 microsatellite markers. Extensive genealogy information was collected, which resulted in an extremely large and complex pedigree of 4,645 members. The pedigree was split into 35 subpedigrees, to reduce the computational burden of linkage analysis. Simulations aiming to evaluate the effect of pedigree splitting on false-positive probabilities showed that a LOD score of 3.64 corresponds to 5% genomewide type I error. Multipoint analysis revealed four significant and one suggestive linkage peaks. The strongest evidence of linkage was found for chromosome 1q21 (heterogeneity LOD [HLOD]=5.20 at marker D1S498). Approximately 30 cM upstream of this locus, we found another peak at 1q25 (HLOD=4.0 at marker D1S218). These two loci are in a previously established linkage region. We also confirmed the AD locus at 10q22-24 (HLOD=4.15 at marker D10S185). There was significant evidence of linkage of AD to chromosome 3q22-24 (HLOD=4.44 at marker D3S1569). For chromosome 11q24-25, there was suggestive evidence of linkage (HLOD=3.29 at marker D11S1320). We next tested for association between cognitive function and 4,173 single-nucleotide polymorphisms in the linked regions in an independent sample consisting of 197 individuals from the GRIP region. After adjusting for multiple testing, we were able to detect significant associations for cognitive function in four of five AD-linked regions, including the new region on chromosome 3q22-24 and regions 1q25, 10q22-24, and 11q25. With use of cognitive function as an endophenotype of AD, our study indicates the that the RGSL2, RALGPS2, and C1orf49 genes are the potential disease-causing genes at 1q25. Our analysis of chromosome 10q22-24 points to the HTR7, MPHOSPH1, and CYP2C cluster. This is the first genomewide screen that showed significant linkage to chromosome 3q23 markers. For this region, our analysis identified the NMNAT3 and CLSTN2 genes. Our findings confirm linkage to chromosome 11q25. We were unable to confirm SORL1; instead, our analysis points to the OPCML and HNT genes.

Genetic and Environmental Influences on Female Sexual Orientation, Childhood Gender Typicality and Adult Gender Identity

PubMed Central

Burri, Andrea; Cherkas, Lynn; Spector, Timothy; Rahman, Qazi

2011-01-01

Background Human sexual orientation is influenced by genetic and non-shared environmental factors as are two important psychological correlates – childhood gender typicality (CGT) and adult gender identity (AGI). However, researchers have been unable to resolve the genetic and non-genetic components that contribute to the covariation between these traits, particularly in women. Methodology/Principal Findings Here we performed a multivariate genetic analysis in a large sample of British female twins (N = 4,426) who completed a questionnaire assessing sexual attraction, CGT and AGI. Univariate genetic models indicated modest genetic influences on sexual attraction (25%), AGI (11%) and CGT (31%). For the multivariate analyses, a common pathway model best fitted the data. Conclusions/Significance This indicated that a single latent variable influenced by a genetic component and common non-shared environmental component explained the association between the three traits but there was substantial measurement error. These findings highlight common developmental factors affecting differences in sexual orientation. PMID:21760939

Premature hippocampus-dependent memory decline in middle-aged females of a genetic rat model of depression.

PubMed

Lim, Patrick H; Wert, Stephanie L; Tunc-Ozcan, Elif; Marr, Robert; Ferreira, Adriana; Redei, Eva E

2018-02-25

Aging and major depressive disorder are risk factors for dementia, including Alzheimer's Disease (AD), but the mechanism(s) linking depression and dementia are not known. Both AD and depression show greater prevalence in women. We began to investigate this connection using females of the genetic model of depression, the inbred Wistar Kyoto More Immobile (WMI) rat. These rats consistently display depression-like behavior compared to the genetically close control, the Wistar Kyoto Less Immobile (WLI) strain. Hippocampus-dependent contextual fear memory did not differ between young WLI and WMI females, but, by middle-age, female WMIs showed memory deficits compared to same age WLIs. This deficit, measured as duration of freezing in the fear provoking-context was not related to activity differences between the strains prior to fear conditioning. Hippocampal expression of AD-related genes, such as amyloid precursor protein, amyloid beta 42, beta secretase, synucleins, total and dephosphorylated tau, and synaptophysin, did not differ between WLIs and WMIs in either age group. However, hippocampal transcript levels of catalase (Cat) and hippocampal and frontal cortex expression of insulin-like growth factor 2 (Igf2) and Igf2 receptor (Igf2r) paralleled fear memory differences between middle-aged WLIs and WMIs. This data suggests that chronic depression-like behavior that is present in this genetic model is a risk factor for early spatial memory decline in females. The molecular mechanisms of this early memory decline likely involve the interaction of aging processes with the genetic components responsible for the depression-like behavior in this model. Copyright © 2018 Elsevier B.V. All rights reserved.

Common genetic architecture underlying young children's food fussiness and liking for vegetables and fruit.

PubMed

Fildes, Alison; van Jaarsveld, Cornelia H M; Cooke, Lucy; Wardle, Jane; Llewellyn, Clare H

2016-04-01

Food fussiness (FF) is common in early childhood and is often associated with the rejection of nutrient-dense foods such as vegetables and fruit. FF and liking for vegetables and fruit are likely all heritable phenotypes; the genetic influence underlying FF may explain the observed genetic influence on liking for vegetables and fruit. Twin analyses make it possible to get a broad-based estimate of the extent of the shared genetic influence that underlies these traits. We quantified the extent of the shared genetic influence that underlies FF and liking for vegetables and fruit in early childhood with the use of a twin design. Data were from the Gemini cohort, which is a population-based sample of twins born in England and Wales in 2007. Parents of 3-y-old twins (n= 1330 pairs) completed questionnaire measures of their children's food preferences (liking for vegetables and fruit) and the FF scale from the Children's Eating Behavior Questionnaire. Multivariate quantitative genetic modeling was used to estimate common genetic influences that underlie FF and liking for vegetables and fruit. Genetic correlations were significant and moderate to large in size between FF and liking for both vegetables (-0.65) and fruit (-0.43), which indicated that a substantial proportion of the genes that influence FF also influence liking. Common genes that underlie FF and liking for vegetables and fruit largely explained the observed phenotypic correlations between them (68-70%). FF and liking for fruit and vegetables in young children share a large proportion of common genetic factors. The genetic influence on FF may determine why fussy children typically reject fruit and vegetables.

USE OF THE MIXED FLASK CULTURE (MFC) MICROCOSM PROTOCOL TO ESTIMATE THE SURVIVAL AND EFFECTS OF MICROORGANISMS ADDED TO FRESHWATER ECOSYSTEMS

EPA Science Inventory

The ability to manipulate an organism's genetic substance offers benefits to many aspects of human health and well-being. oupled with this positive aspect of genetic engineering, however, is a concern about potential adverse effects on human welfare and environmental quality. ive...

A comparison of protein and phenolic compounds in seed from GMO and non-GMO soybean

USDA-ARS?s Scientific Manuscript database

Soybean protein is a valuable and important component in human and animal diets. Approximately 94% of the soybean planted in the US is genetically modified (GM) to enhance quality and productivity. Since value-added traits are continuously being developed by genetic modification, it is important t...

Climate change and atopic dermatitis: is there a link?

PubMed

Nguyen, Giang Huong; Andersen, Louise Kronborg; Davis, Mark Denis P

2018-06-05

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease with a growing health concern, because of its high prevalence and associated low quality of life. The etiology of AD is multifactorial with interaction between various factors such as genetic predisposition, immune, and importantly, environmental factors. Since climate change is associated with a profound shift in environmental factors, we suggest that AD is being influenced by climate change. This review highlights the effects of ultraviolet light, temperature, humidity, pollens, air pollutants, and their interaction between them contributing to the epidemiology and pathophysiology of AD. © 2018 The International Society of Dermatology.

Optimization of laminated stacking sequence for buckling load maximization by genetic algorithm

NASA Technical Reports Server (NTRS)

Le Riche, Rodolphe; Haftka, Raphael T.

1992-01-01

The use of a genetic algorithm to optimize the stacking sequence of a composite laminate for buckling load maximization is studied. Various genetic parameters including the population size, the probability of mutation, and the probability of crossover are optimized by numerical experiments. A new genetic operator - permutation - is proposed and shown to be effective in reducing the cost of the genetic search. Results are obtained for a graphite-epoxy plate, first when only the buckling load is considered, and then when constraints on ply contiguity and strain failure are added. The influence on the genetic search of the penalty parameter enforcing the contiguity constraint is studied. The advantage of the genetic algorithm in producing several near-optimal designs is discussed.

Genetic enhancement in sport: just another form of doping?

PubMed

Mehlman, Maxwell J

2012-12-01

Patented genetic technologies such as the ACTN3 genetic test are adding a new dimension to the types of performance enhancement available to elite athletes. Organized sports organizations and governments are seeking to prevent athletes' use of biomedical enhancements. This paper discusses how these interdiction efforts will affect the use and availability of genetic technologies that can enhance athletic performance. The paper provides a working definition of enhancement, and in light of that definition and the concerns of the sports community, reviews genetic enhancement as a result of varied technologies, including, genetic testing to identify innate athletic ability, performance-enhancing drugs developed with genetic science and technology, pharmacogenetics, enhancement through reproductive technologies, somatic gene transfer, and germ line gene transfer.

Generalizing genetical genomics: getting added value from environmental perturbation.

PubMed

Li, Yang; Breitling, Rainer; Jansen, Ritsert C

2008-10-01

Genetical genomics is a useful approach for studying the effect of genetic perturbations on biological systems at the molecular level. However, molecular networks depend on the environmental conditions and, thus, a comprehensive understanding of biological systems requires studying them across multiple environments. We propose a generalization of genetical genomics, which combines genetic and sensibly chosen environmental perturbations, to study the plasticity of molecular networks. This strategy forms a crucial step toward understanding why individuals respond differently to drugs, toxins, pathogens, nutrients and other environmental influences. Here we outline a strategy for selecting and allocating individuals to particular treatments, and we discuss the promises and pitfalls of the generalized genetical genomics approach.

Hereditary spastic paraplegia: LOD-score considerations for confirmation of linkage in a heterogeneous trait.

PubMed

Dubé, M P; Mlodzienski, M A; Kibar, Z; Farlow, M R; Ebers, G; Harper, P; Kolodny, E H; Rouleau, G A; Figlewicz, D A

1997-03-01

Hereditary spastic paraplegia (HSP) is a degenerative disorder of the motor system, defined by progressive weakness and spasticity of the lower limbs. HSP may be inherited as an autosomal dominant (AD), autosomal recessive, or an X-linked trait. AD HSP is genetically heterogeneous, and three loci have been identified so far: SPG3 maps to chromosome 14q, SPG4 to 2p, and SPG4a to 15q. We have undertaken linkage analysis with 21 uncomplicated AD families to the three AD HSP loci. We report significant linkage for three of our families to the SPG4 locus and exclude several families by multipoint linkage. We used linkage information from several different research teams to evaluate the statistical probability of linkage to the SPG4 locus for uncomplicated AD HSP families and established the critical LOD-score value necessary for confirmation of linkage to the SPG4 locus from Bayesian statistics. In addition, we calculated the empirical P-values for the LOD scores obtained with all families with computer simulation methods. Power to detect significant linkage, as well as type I error probabilities, were evaluated. This combined analytical approach permitted conclusive linkage analyses on small to medium-size families, under the restrictions of genetic heterogeneity.

Comprehensive Search for Alzheimer Disease Susceptibility Loci in the APOE Region

PubMed Central

Jun, Gyungah; Vardarajan, Badri N.; Buros, Jacqueline; Yu, Chang-En; Hawk, Michele V.; Dombroski, Beth A.; Crane, Paul K.; Larson, Eric B.; Mayeux, Richard; Haines, Jonathan L.; Lunetta, Kathryn L.; Pericak-Vance, Margaret A.; Schellenberg, Gerard D.; Farrer, Lindsay A.

2013-01-01

Objective To evaluate the association of risk and age at onset (AAO) of Alzheimer disease (AD) with single-nucleotide polymorphisms (SNPs) in the chromosome 19 region including apolipoprotein E (APOE) and a repeat-length polymorphism in TOMM40 (poly-T, rs10524523). Design Conditional logistic regression models and survival analysis. Setting Fifteen genome-wide association study data sets assembled by the Alzheimer's Disease Genetics Consortium. Participants Eleven thousand eight hundred forty AD cases and 10 931 cognitively normal elderly controls. Main Outcome Measures Association of AD risk and AAO with genotyped and imputed SNPs located in an 800-Mb region including APOE in the entire Alzheimer's Disease Genetics Consortium data set and with the TOMM40 poly-T marker genotyped in a subset of 1256 cases and 1605 controls. Results In models adjusting for APOE ε4, no SNPs in the entire region were significantly associated with AAO at P<.001. Rs10524523 was not significantly associated with AD or AAO in models adjusting for APOE genotype or within the subset of ε3/ε3 subjects. Conclusions APOE alleles ε2, ε3, and ε4 account for essentially all the inherited risk of AD associated with this region. Other variants including a poly-T track in TOMM40 are not independent risk or AAO loci. PMID:22869155

Mutations in Splicing Factor Genes Are a Major Cause of Autosomal Dominant Retinitis Pigmentosa in Belgian Families

PubMed Central

Coppieters, Frauke; Roels, Dimitri; De Jaegere, Sarah; Flipts, Helena; De Zaeytijd, Julie; Walraedt, Sophie; Claes, Charlotte; Fransen, Erik; Van Camp, Guy; Depasse, Fanny; Casteels, Ingele; de Ravel, Thomy

2017-01-01

Purpose Autosomal dominant retinitis pigmentosa (adRP) is characterized by an extensive genetic heterogeneity, implicating 27 genes, which account for 50 to 70% of cases. Here 86 Belgian probands with possible adRP underwent genetic testing to unravel the molecular basis and to assess the contribution of the genes underlying their condition. Methods Mutation detection methods evolved over the past ten years, including mutation specific methods (APEX chip analysis), linkage analysis, gene panel analysis (Sanger sequencing, targeted next-generation sequencing or whole exome sequencing), high-resolution copy number screening (customized microarray-based comparative genomic hybridization). Identified variants were classified following American College of Medical Genetics and Genomics (ACMG) recommendations. Results Molecular genetic screening revealed mutations in 48/86 cases (56%). In total, 17 novel pathogenic mutations were identified: four missense mutations in RHO, five frameshift mutations in RP1, six mutations in genes encoding spliceosome components (SNRNP200, PRPF8, and PRPF31), one frameshift mutation in PRPH2, and one frameshift mutation in TOPORS. The proportion of RHO mutations in our cohort (14%) is higher than reported in a French adRP population (10.3%), but lower than reported elsewhere (16.5–30%). The prevalence of RP1 mutations (10.5%) is comparable to other populations (3.5%-10%). The mutation frequency in genes encoding splicing factors is unexpectedly high (altogether 19.8%), with PRPF31 the second most prevalent mutated gene (10.5%). PRPH2 mutations were found in 4.7% of the Belgian cohort. Two families (2.3%) have the recurrent NR2E3 mutation p.(Gly56Arg). The prevalence of the recurrent PROM1 mutation p.(Arg373Cys) was higher than anticipated (3.5%). Conclusions Overall, we identified mutations in 48 of 86 Belgian adRP cases (56%), with the highest prevalence in RHO (14%), RP1 (10.5%) and PRPF31 (10.5%). Finally, we expanded the molecular spectrum of PRPH2, PRPF8, RHO, RP1, SNRNP200, and TOPORS-associated adRP by the identification of 17 novel mutations. PMID:28076437

An Underlying Common Factor, Influenced by Genetics and Unique Environment, Explains the Covariation Between Major Depressive Disorder, Generalized Anxiety Disorder, and Burnout: A Swedish Twin Study.

PubMed

Mather, Lisa; Blom, Victoria; Bergström, Gunnar; Svedberg, Pia

2016-12-01

Depression and anxiety are highly comorbid due to shared genetic risk factors, but less is known about whether burnout shares these risk factors. We aimed to examine whether the covariation between major depressive disorder (MDD), generalized anxiety disorder (GAD), and burnout is explained by common genetic and/or environmental factors. This cross-sectional study included 25,378 Swedish twins responding to a survey in 2005-2006. Structural equation models were used to analyze whether the trait variances and covariances were due to additive genetics, non-additive genetics, shared environment, and unique environment. Univariate analyses tested sex limitation models and multivariate analysis tested Cholesky, independent pathway, and common pathway models. The phenotypic correlations were 0.71 (0.69-0.74) between MDD and GAD, 0.58 (0.56-0.60) between MDD and burnout, and 0.53 (0.50-0.56) between GAD and burnout. Heritabilities were 45% for MDD, 49% for GAD, and 38% for burnout; no statistically significant sex differences were found. A common pathway model was chosen as the final model. The common factor was influenced by genetics (58%) and unique environment (42%), and explained 77% of the variation in MDD, 69% in GAD, and 44% in burnout. GAD and burnout had additive genetic factors unique to the phenotypes (11% each), while MDD did not. Unique environment explained 23% of the variability in MDD, 20% in GAD, and 45% in burnout. In conclusion, the covariation was explained by an underlying common factor, largely influenced by genetics. Burnout was to a large degree influenced by unique environmental factors not shared with MDD and GAD.

Dietary fructose in nonalcoholic fatty liver disease.

PubMed

Vos, Miriam B; Lavine, Joel E

2013-06-01

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in adults and children. A number of genetic and environmental factors are known to predispose individuals to NAFLD. Certain dietary sugars, particularly fructose, are suspected to contribute to the development of NAFLD and its progression. The increasing quantity of fructose in the diet comes from sugar additives (most commonly sucrose and high fructose corn syrup) in beverages and processed foods. Substantial links have been demonstrated between increased fructose consumption and obesity, dyslipidemia, and insulin resistance. Growing evidence suggests that fructose contributes to the development and severity of NAFLD. In human studies, fructose is associated with increasing hepatic fat, inflammation, and possibly fibrosis. Whether fructose alone can cause NAFLD or if it serves only as a contributor when consumed excessively in the setting of insulin resistance, positive energy balance, and sedentary lifestyle is unknown. Sufficient evidence exists to support clinical recommendations that fructose intake be limited through decreasing foods and drinks high in added (fructose-containing) sugars. Copyright © 2013 American Association for the Study of Liver Diseases.

Combinatorial therapy with adenoviral-mediated PTEN and a PI3K inhibitor suppresses malignant glioma cell growth in vitro and in vivo by regulating the PI3K/AKT signaling pathway.

PubMed

Nan, Yang; Guo, Liyun; Song, Yunpeng; Wang, Le; Yu, Kai; Huang, Qiang; Zhong, Yue

2017-08-01

Glioblastoma is a highly invasive and challenging tumor of the central nervous system. The mutation/deletion of the tumor suppressor phosphatase and tensin homolog (PTEN) gene is the main genetic change identified in glioblastomas. PTEN plays a critical role in tumorigenesis and has been shown to be an important therapeutic target. The phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 is commonly used to inhibit glioma cell growth via regulation of the PI3K/AKT signaling pathway. In this study, we examined the growth inhibitory effects of a combinatorial therapy of adenoviral-mediated PTEN (Ad-PTEN) and LY294002 on LN229 and U251 glioma cells in vitro and on tumor xenografts in vivo. In vitro, LN229 and U251 glioma cells were treated by combinatorial therapy with Ad-PTEN and LY294002. The growth ability was determined by MTT assay. The cell cycle distribution was analyzed by flow cytometry. Cell invasive ability was analyzed by transwell invasion assay and cell apoptosis analysis via FITC-Annexin V analysis. In vivo, U251 subcutaneous glioblastoma xenograft was used to assay anti-tumor effect of combinatorial therapy with Ad-PTEN and LY294002 by mean volume of tumors, immunohistochemistry and TUNEL method. The combinatorial treatment clearly suppressed cell proliferation, arrested the cell cycle, reduced cell invasion and promoted cell apoptosis compared with the Ad-PTEN or LY294002 treatment alone. The treatment worked by inhibiting the PI3K/AKT pathway. In addition, the growth of U251 glioma xenografts treated with the combination of Ad-PTEN and LY294002 was significantly inhibited compared with those treated with Ad-PTEN or LY294002 alone. Our data indicated that the combination of Ad-PTEN and LY294002 effectively suppressed the malignant growth of human glioma cells in vitro and in tumor xenografts, suggesting a promising new approach for glioma gene therapy that warrants further investigation.

A Kernel Machine Method for Detecting Effects of Interaction Between Multidimensional Variable Sets: An Imaging Genetics Application

PubMed Central

Ge, Tian; Nichols, Thomas E.; Ghosh, Debashis; Mormino, Elizabeth C.

2015-01-01

Measurements derived from neuroimaging data can serve as markers of disease and/or healthy development, are largely heritable, and have been increasingly utilized as (intermediate) phenotypes in genetic association studies. To date, imaging genetic studies have mostly focused on discovering isolated genetic effects, typically ignoring potential interactions with non-genetic variables such as disease risk factors, environmental exposures, and epigenetic markers. However, identifying significant interaction effects is critical for revealing the true relationship between genetic and phenotypic variables, and shedding light on disease mechanisms. In this paper, we present a general kernel machine based method for detecting effects of interaction between multidimensional variable sets. This method can model the joint and epistatic effect of a collection of single nucleotide polymorphisms (SNPs), accommodate multiple factors that potentially moderate genetic influences, and test for nonlinear interactions between sets of variables in a flexible framework. As a demonstration of application, we applied the method to data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) to detect the effects of the interactions between candidate Alzheimer's disease (AD) risk genes and a collection of cardiovascular disease (CVD) risk factors, on hippocampal volume measurements derived from structural brain magnetic resonance imaging (MRI) scans. Our method identified that two genes, CR1 and EPHA1, demonstrate significant interactions with CVD risk factors on hippocampal volume, suggesting that CR1 and EPHA1 may play a role in influencing AD-related neurodegeneration in the presence of CVD risks. PMID:25600633