| 1. |
- Ahmadi, Ahmad, et al.
(författare)
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Association of a protective paraoxonase 1 (PON1) polymorphism in Parkinson's disease
- 2012
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 522:1, s. 30-35
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Tidskriftsartikel (refereegranskat)abstract
- Pesticide exposure has been suggested to increase the risk to develop Parkinson's disease (PD). The arylesterase paraoxonase 1 (PON1) is mainly expressed in the liver and hydrolyzes organophosphates such as pesticides. The polymorphism Leu54Met (rs854560) in PON1, impairing enzyme activity and leading to decreased PON1 expression levels, has been reported to be associated with Parkinson's disease (PD). PON1 is part of a cluster on chromosome 7q21.3 together with PON2 and PON3. We investigated the occurrence of four additional polymorphisms in PON1 and two in PON2 in a Swedish PD case-control material. We found a significant association (p = 0.007) with a PON1 promoter polymorphism, rs854571. The minor allele was more common among controls than PD cases which suggest a protective effect. This is strengthened by the fact that rs854571 is in strong linkage disequilibrium with another PON1 promoter polymorphism, rs854572, reported to increase PON1 gene expression. Our findings support the hypothesis that PON1 is involved in the etiology of PD and that higher PON1 levels are reducing the risk for PD. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
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| 2. |
- Anvret, Anna, et al.
(författare)
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DJ-1 Mutations are Rare in a Swedish Parkinson Cohort.
- 2011
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Ingår i: The open neurology journal. - 1874-205X. ; 5, s. 8-11
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Tidskriftsartikel (refereegranskat)abstract
- Mutations in the PARK7 gene, DJ-1, have been reported to cause early-onset and familial Parkinson's disease (PD). The function of DJ-1 and how it contributes to the development of the disease is not clear today, but several studies report that DJ-1 is responsive to oxidative stress and important for the maintenance of mitochondria. We have screened three coding regions of DJ-1 (exon 2, 5 and 7) in a Swedish Parkinson cohort. The Swedish PD material consisted of 67 patients with a self reported positive family history of PD and 77 patients with early-onset of disease (≤50 years old). We detected two patients with the previously reported synonymous mutation, Ala167Ala (c.501A>G, rs71653621), in exon 7. No Ala167Ala carriers were identified among 213 neurologically healthy Swedish controls. Mechanisms by which the synonymous Ala167Ala mutation can have consequences are unknown. It may affect the mRNA stability, secondary structure of mRNA, synthesis, turnover, protein folding and function. We could show a 1.3% decrease in DJ-1 mRNA folding energy in the A
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| 3. |
- Anvret, Anna, et al.
(författare)
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Possible involvement of a mitochondrial translation initiation factor 3 variant causing decreased mRNA levels in Parkinson's disease.
- 2010
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Ingår i: Parkinson's disease. - : Hindawi Limited. - 2042-0080. ; 2010
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Tidskriftsartikel (refereegranskat)abstract
- Genes important for mitochondrial function have been implicated in Parkinson's disease (PD). Mitochondrial translation initiation factor 3 (MTIF3) is a nuclear encoded protein required for the initiation of complex formation on mitochondrial ribosomes. Dysfunction of MTIF3 may impair mitochondrial function and dopamine neurons appear to be particularly vulnerable to oxidative stress, which may relate to their degeneration in PD. An association was recently reported between the synonymous rs7669(C>T) in MTIF3 and PD in a German case-control material. We investigated rs7669 in a Swedish Parkinson case-control material. The study revealed no significant association of the individual genotypes or alleles with PD. When comparing the combined TT/CT-genotypes versus the CC-genotype, we observed a significant association (P = .0473) with PD. We also demonstrated that the TT-genotype causes a significant decrease in MTIF3 mRNA expression compared to the CC-genotype (P = .0163). Our findings support the hypothesis that MTIF3 may be involved in the etiology of PD.
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| 4. |
- Westerlund, Marie, et al.
(författare)
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Altered enzymatic activity and allele frequency of OMI/HTRA2 in Alzheimer's disease.
- 2011
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Ingår i: The FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - : Wiley. - 1530-6860. ; 25:4, s. 1345-52
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Tidskriftsartikel (refereegranskat)abstract
- The serine-protease OMI/HTRA2, required for several cellular processes, including mitochondrial function, autophagy, chaperone activity, and apoptosis, has been implicated in the pathogenesis of both Alzheimer's disease (AD) and Parkinson's disease (PD). Western blot quantification of OMI/HTRA2 in frontal cortex of patients with AD (n=10) and control subjects (n=10) in two separate materials indicated reduced processed (active, 35 kDa) OMI/HTRA2 levels, whereas unprocessed (50 kDa) enzyme levels were not significantly different between the groups. Interestingly, the specific protease activity of OMI/HTRA2 was found to be significantly increased in patients with AD (n=10) compared to matched control subjects (n=10) in frontal cortex in two separate materials. Comparison of OMI/HTRA2 mRNA levels in frontal cortex and hippocampus, two brain areas particularly affected by AD, indicated similar levels in patients with AD (n=10) and matched control subjects (n=10). In addition, we analyzed the occurrence of the OMI/HTRA2 variants A141S and G399S in Swedish case-control materials for AD and PD and found a weak association of A141S with AD, but not with PD. In conclusion, our genetic, histological, and biochemical findings give further support to an involvement of OMI/HTRA2 in the pathology of AD; however, further studies are needed to clarify the role of this gene in neurodegeneration.
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| 5. |
- Westerlund, Marie, et al.
(författare)
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Association of a polymorphism in the ABCB1 gene with Parkinson's disease.
- 2009
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Ingår i: Parkinsonism & related disorders. - : Elsevier BV. - 1353-8020 .- 1873-5126. ; 15:6, s. 422-424
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Tidskriftsartikel (refereegranskat)abstract
- The ATP-binding cassette, sub-family B, member 1 (ABCB1) gene encoding the protein P-glycoprotein (P-gp) has been implicated in the pathophysiology of Parkinson's disease (PD) due to its role in regulating transport of endogenous molecules and exogenous toxins. In the present study, we analyzed the ABCB1 single nucleotide polymorphisms (SNPs) 1236C/T (exon 12), 2677G/T/A (exon 21) and 3435C/T (exon 26) in 288 Swedish PD patients and 313 control subjects and found a significant association of SNP 1236C/T with disease (p=0.0159; chi(2)=8.28), whereas the distributions of wild-type and mutated alleles were similar for 2677G/T/A and 3435C/T in patients and controls. Haplotype analysis revealed significant association of the 1236C-2677G haplotype with PD (p=0.026; chi(2)=4.955) and a trend towards association with disease of the 1236C-2677G-3435C haplotype (p=0.072; chi(2)=3.229). Altered ABCB1 and/or P-pg expression was recently shown in PD patients, and impaired drug efflux across barriers such as the gastrointestinal and nasal mucosal linings or the blood-brain barrier, might result in accumulation of drugs and/or endogenous molecules in toxic amounts, possibly contributing to disease. ABCB1 polymorphisms thus constitute an example of how genetic predisposition and environmental influences may combine to increase risk of PD.
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| 6. |
- Westerlund, Marie, et al.
(författare)
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Cerebellar alpha-synuclein levels are decreased in Parkinson's disease and do not correlate with SNCA polymorphisms associated with disease in a Swedish material.
- 2008
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Ingår i: The FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - : Wiley. - 1530-6860. ; 22:10, s. 3509-14
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Tidskriftsartikel (refereegranskat)abstract
- Alterations of brain and plasma alpha-synuclein levels and SNCA gene variability have been implicated in the pathogenesis of Parkinson's disease (PD). We therefore measured alpha-synuclein protein levels in postmortem PD and control cerebellum tissue using Western blot and investigated whether the levels correlated to SNCA genotype. We found markedly decreased alpha-synuclein levels in PD patients (n=16) compared to gender- and age-matched controls (n=14; P=0.004) normalized to alpha-tubulin. We also performed an association study of the noncoding polymorphisms rs2737029 (A/G) and rs356204 (A/G) (intron 4), and of rs356219 (T/C) (3'-region) of SNCA in a Swedish PD case-control material. Using a two-sided chi(2) test, we found significant association of rs2737029 (P=0.003; chi(2)=9.07) and rs356204 (P=0.048; chi(2)=3.91) with disease, strengthening the involvement of SNCA polymorphisms in sporadic PD. Stratification of the human postmortem brain material by genotype of the three investigated polymorphisms, did not indicate any influence of genotype on alpha-synuclein protein levels when comparing PD with controls. Taken together, our findings demonstrate that the investigated Parkinson patients have markedly reduced levels of alpha-synuclein in cerebellum, and that this reduction is general, rather then correlated to the investigated polymorphisms, although two of the polymorphisms also associated with disease in a Swedish material.
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| 7. |
- Anvret, Anna
(författare)
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Genes involved in Parkinson's disease : focus on mitochondrial and detoxifying enzymes
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Parkinson's disease is a common progressive neurodegenerative disorder which mostly affects the elderly population, with a prevalence of more than 1.5% in the population over the age of 65 years. Clinical motor symptoms are mainly caused by degeneration of dopamine neurons in substantia nigra pars compacta. In order to identify genes with potential roles in the pathology of Parkinson’s disease, the candidate gene approach has been applied. Investigated genes assumed to play a role in mitochondrial maintenance were DJ-1, PTEN-induced putative kinase 1 (PINK1), the serine-protease OMI/HTRA2, mitochondrial translation initiation factor 3 (MTIF3), DNA polymerase gamma 1 (POLG1), mitochondrial Ras homolog gene family, member T1 and T2 (MIRO1, MIRO2). Genes involved in detoxification including paraoxonases (PON1, PON2, PON3) and alcohol dehydrogenases (ADH1C, ADH4) were also studied. Association studies were performed in a Swedish case-control material consisting of 619 Parkinson patients and 1564 neurologically healthy controls. The screening resulted in identification of several potential risk or protective factors such as DJ-1 Ala167Ala (c.501A>G), MTIF3 rs7669 (C>T), POLG1 CAG repeat variability and PON1 rs854571 (G>A). MIRO1 and MIRO2 need further investigations before they can be excluded as contributing factors. The investigation of OMI/HTRA2 A141S (G>T) in Parkinson and Alzheimer patients resulted in an association with Alzheimer’s disease. In situ hybridization of human postmortem brain tissue was used to detect any alteration of PINK1 mRNA expression in Parkinson patients and of OMI/HTRA2 mRNA in patients with either Parkinson’s or Alzhemier’s disease. No differences compared to control levels were observed for the two genes. Protein quantification of OMI/HTRA2 in frontal cortex indicated reduced levels of the active enzyme form and increased protease activity in patients with Alzheimer’s disease. Using quantitative real-time PCR we detected a reduction of mRNA expression from the MTIF3 rs7669 minor allele. Based on previous report on association of genetic variants in ADH1C and ADH4 with Parkinson’s disease, we studied spontaneous and drug induced locomotor behavior in Adh1 and Adh4 knockout mice, and in Adh1/4 double knockout mice with respect to dopamine-system-related activity and olfactory function. Neurotransmitter levels were analyzed with high-performance liquid chromatography in different brain regions. All three knockout strains displayed increased drug induced behavior, as well as alteration of levels of monoamines and their metabolites compared to wild-type littermates. Adh4-/- mice had a reduced sense of smell as well as reduction of dopamine in the olfactory bulb, and results from Adh1/4-/- pointed in the same direction. In conclusion, the findings presented in this thesis suggest genetic variability has an important role in the pathogenesis of Parkinson’s disease. The disease is a multifactorial and genetically complex disorder for which the etiology is unknown in most of the cases. It needs to be resolved how different molecular pathways involving different genes individually or together, contribute to disease by causing degeneration of dopamine neurons and other neuron types.
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