| 1. |
- Abramsson, Alexandra, 1973, et al.
(author)
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No Association of LOXL1 Gene Polymorphisms with Alzheimer's Disease
- 2011
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In: NeuroMolecular Medicine. - : Springer Science and Business Media LLC. - 1535-1084 .- 1559-1174. ; 13:2, s. 160-166
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Journal article (peer-reviewed)abstract
- Aggregation of amyloid-beta is one of the major characteristics in brains of patients with Alzheimer's disease (AD). Although several mechanisms behind the formation of such aggregates have been suggested the regulatory factors are still unknown. The present study aimed at investigating the association of lysyl oxidase-like 1 (LOXL1) polymorphisms with AD diagnosis and cerebrospinal fluid biomarkers (CSF) for the disease. Proteins of the lysyl oxidase (LOX) family are involved in cross-linking extracellular matrix proteins to insoluble fibers and have been associated with neurodegenerative diseases including AD. Genetic polymorphisms in LOXL1 (rs1048661, rs3825942, and rs2165241) have been linked to exfoliation syndrome and exfoliation glaucoma, conditions that have shown association with AD. The polymorphisms were genotyped by Taqman allelic discrimination in a study sample including AD patients (n = 318) and controls (n = 575). In a subgroup of the population, the polymorphisms were analyzed in relation to APOE epsilon 4 genotype and to CSF (T-tau, P-tau, and A beta(1-42)). No evidence for associations of these polymorphisms with risk for AD or any of the studied CSF biomarkers measured was found. These results do not support LOXL1 as being a major risk gene for AD.
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| 2. |
- Landgren, Sara, 1980, et al.
(author)
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Expression of the gene encoding the ghrelin receptor in rats selected for differential alcohol preference.
- 2011
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In: Behavioural brain research. - : Elsevier BV. - 1872-7549 .- 0166-4328. ; 221:1, s. 182-8
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Journal article (peer-reviewed)abstract
- The mechanisms involved in alcohol use disorder, a chronic relapsing brain disorder, are complex and involve various signalling systems in the brain. Recently, the orexigenic peptide ghrelin was shown to be required for alcohol-induced reward, an effect mediated via ghrelin receptors, GHS-R1A, at the level of the cholinergic-dopaminergic reward link. Moreover, ghrelin increases and GHR-R1A antagonists reduce moderate alcohol consumption in mice, and a single nucleotide polymorphism in the GHS-R1A gene has been associated with high alcohol consumption in humans. Therefore, GHS-R1A gene expression and alcohol intake were investigated in high, AA (Alko, Alcohol), versus low, ANA (Alko, Non-Alcohol), alcohol consuming rats as well as in Wistar rats. In the AA and ANA rats plasma ghrelin levels were also measured. GHS-R1A gene expression was increased in AA compared to ANA rats in nucleus accumbens, ventral tegmental area, amygdala, prefrontal cortex and hippocampus. A similar trend was observed in the ventral tegmental area of Wistar rats consuming high amounts of alcohol. Furthermore, the AA rats had significantly smaller reduction of plasma ghrelin levels over time, after several weeks of alcohol exposure, than had the ANA rats. The present study provides further evidence for that the ghrelin signalling system, in particular at the level of the mesocortocolimbic dopamine system, is involved in alcohol consumption, and thus possibly contributes to alcohol use disorder. Therefore the GHS-R1A may constitute a novel candidate for development of new treatment strategies for alcohol dependence.
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| 3. |
- Landgren, Sara, 1980, et al.
(author)
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Genetic variation of the ghrelin signaling system in females with severe alcohol dependence
- 2010
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In: Alcoholism: Clinical and Experimental Research. - : Wiley. - 0145-6008 .- 1530-0277. ; 34:9, s. 1519-1524
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Journal article (peer-reviewed)abstract
- INTRODUCTION: Central ghrelin signaling is required for the rewarding effects of alcohol in mice. Because ghrelin is implied in other addictive behaviors such as eating disorders and smoking, and because there is co-morbidity between these disorders and alcohol dependence, the ghrelin signaling system could be involved in mediating reward in general. Furthermore, in humans, single nucleotide polymorphisms (SNPs) and haplotypes of the pro-ghrelin gene (GHRL) and the ghrelin receptor gene (GHSR) have previously been associated with increased alcohol consumption and increased body weight. Known gender differences in plasma ghrelin levels prompted us to investigate genetic variation of the ghrelin signaling system in females with severe alcohol dependence (n = 113) and in a selected control sample of female low-consumers of alcohol from a large cohort study in southwest Sweden (n = 212). METHODS: Six tag SNPs in the GHRL (rs696217, rs3491141, rs4684677, rs35680, rs42451, and rs26802) and four tag SNPs in the GHSR (rs495225, rs2232165, rs572169, and rs2948694) were genotyped in all individuals. RESULTS: We found that one GHRL haplotype was associated with reports of paternal alcohol dependence as well as with reports of withdrawal symptoms in the female alcohol-dependent group. Associations with 2 GHSR haplotypes and smoking were also shown. One of these haplotypes was also negatively associated with BMI in controls, while another haplotype was associated with having the early-onset, more heredity-driven, type 2 form of alcohol dependence in the patient group. CONCLUSION: Taken together, the genes encoding the ghrelin signaling system cannot be regarded as major susceptibility genes for female alcohol dependence, but is, however, involved in paternal heritability and may affect other reward- and energy-related factors such as smoking and BMI.
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| 4. |
- Landgren, Sara, 1980, et al.
(author)
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No Association of VEGF Polymorphims with Alzheimer's Disease
- 2010
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In: NeuroMolecular Medicine. - : Springer Science and Business Media LLC. - 1535-1084 .- 1559-1174. ; 12:3, s. 224-228
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Journal article (peer-reviewed)abstract
- The vascular hypothesis of Alzheimer's disease (AD) has brought the vascular endothelial growth factor (VEGF) into focus. The genomic region including the VEGF gene has been linked to AD and single nucleotide polymorphisms (SNPs) of the VEGF have in previous studies been associated with AD risk. To further evaluate these findings, we genotyped two SNPs in the VEGF gene (rs699947 [-2578]) and rs1570360 [-1154]) by TaqMan Allelic Discrimination in a study sample including AD patients (n = 801) and controls (n = 286). In a subgroup of the population these SNPs were analyzed in relation to APOE epsilon 4 genotype, to cerebrospinal fluid biomarkers (T-tau, P-tau, and beta(42)-Amyloid) as well as to neuropathological markers for AD (neurofibrillary tangles and senile plaques). No significant associations with risk for AD or any of the studied biomarkers could be found in this study, thus not supporting VEGF as being a major risk gene for AD.
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| 5. |
- Landgren, Sara, 1980, et al.
(author)
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Reward-related genes and personality traits in alcohol-dependent individuals: a pilot case control study.
- 2011
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In: Neuropsychobiology. - : S. Karger AG. - 1423-0224 .- 0302-282X. ; 64:1, s. 38-46
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Journal article (peer-reviewed)abstract
- Components of the brain reward system, i.e. the mesolimbic dopamine, laterodorsal cholinergic and ghrelin signaling systems, have been implicated in alcohol reward in preclinical studies. Genetic variants of these systems have previously been linked to alcohol dependence. Here, we genotyped 31 single nucleotide polymorphisms (SNPs): 1 SNP in the dopamine D(2) receptor (DRD2) gene, 20 SNPs in 5 different nicotinic acetylcholine receptor subunit (CHRN*) genes, and 10 SNPs in the genes encoding pro-ghrelin (GHRL) and its receptor (GHSR), in a pilot study of type 1 alcoholics (n = 84) and healthy controls (n = 32). These individuals were characterized using the Temperament and Character Inventory. None of the SNPs were associated with risk of alcohol dependence in this population. The GG genotype of SNP rs13261190 in the CHRNB3 was associated with increased novelty seeking, while SNPs of the ghrelin signaling system were associated with decreased self-directedness (AA of rs495225, GHSR) and alterations in self-transcendence (AA of both rs42451 and rs35680, GHRL). In conclusion, this pilot study suggests that reward-related genes are associated with altered personality scores in type 1 alcohol dependence, which warrants future studies of these associations in larger study samples.
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| 6. |
- von Otter, Malin, 1978, et al.
(author)
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Association of Nrf2-encoding NFE2L2 haplotypes with Parkinson's disease.
- 2010
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In: BMC medical genetics. - : Springer Science and Business Media LLC. - 1471-2350. ; 11
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Journal article (peer-reviewed)abstract
- BACKGROUND: Oxidative stress is heavily implicated in the pathogenic process of Parkinson's disease. Varying capacity to detoxify radical oxygen species through induction of phase II antioxidant enzymes in substantia nigra may influence disease risk. Here, we hypothesize that variation in NFE2L2 and KEAP1, the genes encoding the two major regulators of the phase II response, may affect the risk of Parkinson's disease. METHODS: The study included a Swedish discovery case-control material (165 cases and 190 controls) and a Polish replication case-control material (192 cases and 192 controls). Eight tag single nucleotide polymorphisms representing the variation in NFE2L2 and three representing the variation in KEAP1 were chosen using HapMap data and were genotyped using TaqMan Allelic Discrimination. RESULTS: We identified a protective NFE2L2 haplotype in both of our European case-control materials. Each haplotype allele was associated with five years later age at onset of the disease (p = 0.001) in the Swedish material, and decreased risk of PD (p = 2 x 10(-6)), with an odds ratio of 0.4 (95% CI 0.3-0.6) for heterozygous and 0.2 (95% CI 0.1-0.4) for homozygous carriers, in the Polish material. The identified haplotype includes a functional promoter haplotype previously associated with high transcriptional activity. Genetic variation in KEAP1 did not show any associations. CONCLUSION: These data suggest that variation in NFE2L2 modifies the Parkinson's disease process and provide another link between oxidative stress and neurodegeneration.
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| 7. |
- von Otter, Malin, 1978, et al.
(author)
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Kinesin Light Chain 1 Gene Haplotypes in Three Conformational Diseases
- 2010
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In: NeuroMolecular Medicine. - : Springer Science and Business Media LLC. - 1535-1084 .- 1559-1174. ; 12:3, s. 229-236
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Journal article (peer-reviewed)abstract
- A functional intracellular transport system is essential to maintain cell shape and function especially in elongated cells, e.g. neurons and lens fibre cells. Impaired intracellular transport has been suggested as a common pathological mechanism for age-related diseases characterised by protein aggregation. Here, we hypothesise that common genetic variation in the transport protein kinesin may influence the risk of Parkinson's disease (PD), Alzheimer's disease (AD) and age-related cataract. This case-control study involves a PD material (165 cases and 190 controls), an AD material (653 cases and 845 controls) and a cataract material (495 cases and 183 controls). Genetic variation in the kinesin light chain 1-encoding gene (KLC1) was tagged by six tag single nucleotide polymorphisms (SNPs). Single SNPs and haplotypes were analysed for associations with disease risk, age parameters, mini-mental state examination scores and cerebrospinal fluid biomarkers for AD using logistic or linear regression. Genetic variation in KLC1 did not influence risk of PD. Weak associations with risk of AD were seen for rs8007903 and rs3212079 (P (c) = 0.04 and P (c) = 0.02, respectively). Two SNPs (rs8007903 and rs8702) influenced risk of cataract (P (c) = 0.0007 and P (c) = 0.04, respectively). However, the allele of rs8007903 that caused increased risk of AD caused reduced risk of cataract, speaking against a common functional effect of this particular SNP in the two diseases. Haplotype analyses did not add significantly to the associations found in the single SNP analyses. Altogether, these results do not convincingly support KLC1 as a major susceptibility gene in any of the studied diseases, although there is a small effect of KLC1 in relation to cataract.
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| 8. |
- von Otter, Malin, 1978, et al.
(author)
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Nrf2-encoding NFE2L2 haplotypes influence disease progression but not risk in Alzheimer's disease and age-related cataract
- 2010
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In: Mechanisms of Ageing and Development. - : Elsevier BV. - 0047-6374 .- 1872-6216. ; 131:2, s. 105-110
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Journal article (peer-reviewed)abstract
- Alzheimer's disease (AD) and age-related cataract, disorders characterized by protein aggregation causing late-onset disease, both involve oxidative stress. We hypothesize that common variants of NFE2L2 and KEAP1, the genes encoding the main regulators of the Nrf2 system, an important defence system against oxidative stress, may influence risk of AD and/or age-related cataract. This case-control study combines an AD material (725 cases and 845 controls), and a cataract material (489 cases and 182 controls). Genetic variation in NFE2L2 and KEAP1 was tagged by eight and three tag single nucleotide polymorphisms (SNPs), respectively. Single SNPs and haplotypes were analyzed for associations with disease risk, age parameters, MMSE and AD cerebrospinal fluid biomarkers. NFE2L2 and KEAP1 were not associated with risk of AD or cataract. However, one haplotype allele of NFE2L2 was associated with 2 years earlier age at AD onset (pc 0.013) and 4 years earlier age at surgery for posterior subcapsular cataract (p(c) = 0.019). Another haplotype of NFE2L2 was associated with 4 years later age at surgery for cortical cataract (p(c) = 0.009). Our findings do not support NFE2L2 or KEAP1 as susceptibility genes for AD or cataract. However, common variants of the NFE2L2 gene may affect disease progression, potentially altering clinically recognized disease onset. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
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| 9. |
- Zetterberg, Madeleine, 1969, et al.
(author)
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Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) S18Y polymorphism in Alzheimer's disease.
- 2010
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In: Molecular neurodegeneration. - : Springer Science and Business Media LLC. - 1750-1326. ; 5
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Journal article (peer-reviewed)abstract
- ABSTRACT: Alzheimer's disease (AD) is characterized by protein aggregates, i.e. senile plaques and neurofibrillary tangles. The ubiquitin-proteasome system has been proposed a role in proteolytic removal of these protein aggregates. Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) is a de-ubiquitinating enzyme with important functions in recycling of ubiquitin. The S18Y polymorphism of the UCHL1 gene confers protection against Parkinson's disease. In this study, the genotype and allele frequencies of the UCHL1 S18Y polymorphism were investigated in 452 AD patients and 234 control subjects, recruited from four memory clinics in Sweden. Using a binary logistic regression model including UCHL1 allele A and APOE epsilon4 allele positivity, age and sex as covariates with AD diagnosis as dependent variable, an adjusted OR of 0.82 ([95% CI 0.55-1.24], P = 0.35) was obtained for a positive UCHL1 allele A carrier status. The present study thus do not support a protective effect of the UCHL1 S18Y polymorphism against AD.
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