137 research outputs found

    Nitric oxide synthase 2A (NOS2A) polymorphisms are not associated with invasive pneumococcal disease

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    <p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>(pneumococcus) is responsible for over one million deaths per year, with young children, the elderly and immunocompromised individuals being most at risk. Approximately half of East African children have been reported to be asymptomatic carriers of pneumococcus with invasive infection occurring after the disruption of the respiratory membrane which is believed to be caused by the host immune response. Racial incidence of invasive pneumococcal disease (IPD) is higher in certain populations even after adjusting for environmental factors suggesting a genetic component to disease susceptibility. The nitric oxide synthase 2A (NOS2A) gene is responsible for the production of nitric oxide under pathological conditions including host defence against bacterial infection. Nitric oxide is a modulator of apoptotic and inflammatory cascades and endothelial permeability. We hypothesised that genetic variants within this gene may predispose to disease risk and survival.</p> <p>Methods</p> <p>A cohort of 299 children with IPD (221 meningitis, 41 pneumonia and 37 with bacteraemia) and 931 age matched controls from Malawi were used in this study. We investigated nine haplotype tagging single nucleotide polymorphisms within the NOS2A gene and compared the presence or absence of the minor alleles in cases and controls and survivors and non-survivors within the cases.</p> <p>Results</p> <p>We observed no significant associations between cases and controls or with survival in either all IPD cases or in the separate analysis of meningitis cases. A near significant association was obtained for the comparison of rs8078340 in cases and controls (p-value, 0.078). However, results were unadjusted for multiple testing.</p> <p>Conclusion</p> <p>Our results suggest that polymorphic variation within the NOS2A gene does not influence invasive pneumococcal disease susceptibility or survival.</p

    Regulation of Interleukin 6 by a polymorphic CpG within the frontal cortex in Alzheimer’s disease

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    The cytokine interleukin 6 (IL-6), has been linked to the pathogenesis of Alzheimer’s disease (AD). This is the first study to investigate the genetic and epigenetic interactions in the control of IL-6 in human brain and its relation to AD neuropathology in prefrontal cortex tissues from AD and controls genotyped for the SNP -174 C/G rs1800795, a polymorphic CpG in which the G allele creates a CpG site. Within CC homozygotes there were significantly higher brain levels of IL-6 protein compared to G allele carriers. The C allele that resulted in an absence of methylation at a CpG also associated with significant changes in methylation at neighbouring CpGs. Furthermore, there were differential significant differences in methylation between CC and CG/GG at CpG sites in the AD and control groups. That DNA methylation was shown to be altered in the brains by the presence of rs1800795, which further correlated with protein levels suggests the presence of a polymorphic CpG and genetic-epigenetic interactions in the regulation of IL-6 in the prefrontal cortex within AD brains

    Superior Frontal Gyrus TOMM40-APOE Locus DNA Methylation in Alzheimer’s Disease

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    Background: The APOE ɛ4 allele is the strongest known genetic risk factor for sporadic Alzheimer’s disease (AD). The neighboring TOMM40 gene has also been implicated in AD due to its close proximity to APOE. Objective: Here we tested whether methylation of the TOMM40-APOE locus may influence ApoE protein levels and AD pathology. Methods: DNA methylation levels across the TOMM40-APOE locus and ApoE levels were measured in superior frontal gyrus tissues of 62 human brains genotyped for APOE and scored for AD neuropathology. Results: Methylation levels within the TOMM40 CpG island in the promoter or APOE CpG island in Exon 4 did not differ between APOE ɛ4 carriers versus non-carriers. However, APOE ɛ4 carriers had significantly higher methylation the APOE promoter compared with non-carriers. Although DNA methylation at TOMM40, APOE promoter region, or APOE did not differ between AD pathological groups, there was a negative association between TOMM40 methylation and CERAD scores. ApoE protein concentrations did not significantly different between APOE ɛ4 carriers and non-carriers, or between AD pathological groups. Finally, there was no correlation between ApoE protein concentrations and DNA methylation levels. Conclusion: APOE gene methylation may not be affected by genotype, relate to AD pathology or ApoE protein levels in the superior frontal gyrus, though, DNA methylation at the ApoE promoter differed between genotype. DNA methylation at TOMM40 associated with amyloid-β plaques and longitudinal fluid intelligence. In sum, these results suggest a complicated regulation of the TOMM40-APOE locus in the brain in controlling ApoE protein levels and AD neuropathology.</jats:p

    Epigenetic Regulation of BMAL1 with Sleep Disturbances and Alzheimer's Disease.

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    BACKGROUND:An early symptom of Alzheimer's disease (AD) is a disturbance of the circadian rhythm that is associated with disrupted sleep/wake cycles. OBJECTIVE:To investigate if BMAL1, a key gene that drives the circadian cycle, is epigenetically regulated in brains in relation to longitudinal changes in cognition, sleep quality, and AD neuropathology. METHODS:Frontal cortex tissues were acquired from the Manchester Brain Bank (N = 96). DNA methylation at six CpG sites at the promoter of BMAL1, determined using bisulfite pyrosequencing, was tested for associations with Braak stage, CERAD score, and Thal phase, longitudinal changes in cognition, sleep measurements, and cross-section measures of depressive symptoms (BDI score). RESULTS:Methylation across all the CpGs strongly correlated with each other. We found increased CpG2 methylation with higher Braak (t(92) = 2.47, p = 0.015) and CERAD (t(94) = 2.04, p = 0.044) stages. No significance was found between longitudinal fluid intelligence, processing speed, and memory tests, but methylation at CpG1 (r = 0.20, p = 0.05) and CpG4 (r = 0.20, p = 0.05) positively correlated with vocabulary. CpG2 positively correlated with cross-sectional fluid intelligence (r = 0.20 p = 0.05) and vocabulary (r = 0.22 p = 0.03). Though longitudinal analysis revealed no significance between sleep duration, midsleep, and efficiency for any of the CpG sites, CpG3 (B = 0.03, 95% CI = 0.00/0.06, p = 0.03) and CpG5 (B = 0.04, 95% CI = 0.01,0.07, p = 0.01) significantly correlated with night wake. CpG4 correlated with depressive symptoms (B = -0.27, 95% CI=0.49/-0.05, p = 0.02). CONCLUSION:Methylation of BMAL1 associated with tau pathology, changes in cognitive measures, a measure of sleep and depressive symptoms, suggesting an involvement of the circadian cycle

    Early changes in visuospatial episodic memory can help distinguish primary age‐related tauopathy from Alzheimer’s disease

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    From Wiley via Jisc Publications RouterHistory: received 2021-02-08, rev-recd 2021-03-19, accepted 2021-05-01, pub-electronic 2021-05-29Article version: VoRPublication status: PublishedFunder: Alzheimer's Research Trust; Id: http://dx.doi.org/10.13039/501100000319Funder: Medical Research Council; Id: http://dx.doi.org/10.13039/501100000265Funder: Unilever; Id: http://dx.doi.org/10.13039/100007190Funder: Economic and Social Research Council; Id: http://dx.doi.org/10.13039/501100000269Funder: Alzheimer's Society; Id: http://dx.doi.org/10.13039/501100000320Funder: Wellcome Trust; Grant(s): 00388

    The non-synonymous SNP, R1150W, in SCN9A is not associated with chronic widespread pain susceptibility

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    Acknowledgements The authors wish to thank all of the primary care practices and participants in the EPIFUND study, the EPIFUND study team and Arthritis Research UK lab staff for carrying out the genotyping. The authors thank the men who participated in the seven countries and the research/nursing staff in the seven centres of the EMAS study used in the current analysis: C Pott (Manchester), E Wouters (Leuven), M del Mar Fernandez (Santiago de Compostela), M Jedrzejowska (Lodz), H-M Tabo (Tartu) and A Heredi (Szeged) for their data collection, and C Moseley (Manchester) for data entry and project coordination. DV and SB are senior clinical investigators of the Fund for Scientific Research-Flanders, Belgium (F W O-Vlaanderen). SB is holder of the Leuven University Chair in Gerontology and Geriatrics. The researchers thank the Framingham study participants and personnel. This work was supported by Arthritis Research UK, Chesterfield, UK. The European Male Ageing Study (EMAS) is funded by the Commission of the European Communities Fifth Framework Programme ‘Quality of life and management of living resources’ grant QLK6-CT-2001-00258. Genotyping of the Dyne Steel DNA Bank for Ageing and Cognition cohort was supported by the BBSRC and the study was supported by AgeUK. The Framingham study was supported by grants from the National Heart, Lung, and Blood Institute (NHLBI contract N01-HC-25195) and NIH AR47785 and AG18393.Peer reviewedPublisher PD

    SKA2 regulated hyperactive secretory autophagy drives neuroinflammation-induced neurodegeneration

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    High levels of proinflammatory cytokines induce neurotoxicity and catalyze inflammation-driven neurodegeneration, but the specific release mechanisms from microglia remain elusive. Here we show that secretory autophagy (SA), a non-lytic modality of autophagy for secretion of vesicular cargo, regulates neuroinflammation-mediated neurodegeneration via SKA2 and FKBP5 signaling. SKA2 inhibits SA-dependent IL-1β release by counteracting FKBP5 function. Hippocampal Ska2 knockdown in male mice hyperactivates SA resulting in neuroinflammation, subsequent neurodegeneration and complete hippocampal atrophy within six weeks. The hyperactivation of SA increases IL-1β release, contributing to an inflammatory feed-forward vicious cycle including NLRP3-inflammasome activation and Gasdermin D-mediated neurotoxicity, which ultimately drives neurodegeneration. Results from protein expression and co-immunoprecipitation analyses of male and female postmortem human brains demonstrate that SA is hyperactivated in Alzheimer's disease. Overall, our findings suggest that SKA2-regulated, hyperactive SA facilitates neuroinflammation and is linked to Alzheimer's disease, providing mechanistic insight into the biology of neuroinflammation

    Pleiotropic meta-analysis of cognition, education, and schizophrenia differentiates roles of early neurodevelopmental and adult synaptic pathways

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    Susceptibility to schizophrenia is inversely correlated with general cognitive ability at both the phenotypic and the genetic level. Paradoxically, a modest but consistent positive genetic correlation has been reported between schizophrenia and educational attainment, despite the strong positive genetic correlation between cognitive ability and educational attainment. Here we leverage published genome-wide association studies (GWASs) in cognitive ability, education, and schizophrenia to parse biological mechanisms underlying these results. Association analysis based on subsets (ASSET), a pleiotropic meta-analytic technique, allowed jointly associated loci to be identified and characterized. Specifically, we identified subsets of variants associated in the expected (“concordant”) direction across all three phenotypes (i.e., greater risk for schizophrenia, lower cognitive ability, and lower educational attainment); these were contrasted with variants that demonstrated the counterintuitive (“discordant”) relationship between education and schizophrenia (i.e., greater risk for schizophrenia and higher educational attainment). ASSET analysis revealed 235 independent loci associated with cognitive ability, education, and/or schizophrenia at p < 5 × 10−8. Pleiotropic analysis successfully identified more than 100 loci that were not significant in the input GWASs. Many of these have been validated by larger, more recent single-phenotype GWASs. Leveraging the joint genetic correlations of cognitive ability, education, and schizophrenia, we were able to dissociate two distinct biological mechanisms—early neurodevelopmental pathways that characterize concordant allelic variation and adulthood synaptic pruning pathways—that were linked to the paradoxical positive genetic association between education and schizophrenia. Furthermore, genetic correlation analyses revealed that these mechanisms contribute not only to the etiopathogenesis of schizophrenia but also to the broader biological dimensions implicated in both general health outcomes and psychiatric illness

    Identifying nootropic drug targets via large-scale cognitive GWAS and transcriptomics

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    Broad-based cognitive deficits are an enduring and disabling symptom for many patients with severe mental illness, and these impairments are inadequately addressed by current medications. While novel drug targets for schizophrenia and depression have emerged from recent large-scale genome-wide association studies (GWAS) of these psychiatric disorders, GWAS of general cognitive ability can suggest potential targets for nootropic drug repurposing. Here, we (1) meta-analyze results from two recent cognitive GWAS to further enhance power for locus discovery; (2) employ several complementary transcriptomic methods to identify genes in these loci that are credibly associated with cognition; and (3) further annotate the resulting genes using multiple chemoinformatic databases to identify "druggable" targets. Using our meta-analytic data set (N = 373,617), we identified 241 independent cognition-associated loci (29 novel), and 76 genes were identified by 2 or more methods of gene identification. Actin and chromatin binding gene sets were identified as novel pathways that could be targeted via drug repurposing. Leveraging our transcriptomic and chemoinformatic databases, we identified 16 putative genes targeted by existing drugs potentially available for cognitive repurposing.Peer reviewe
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