Genetically-controlled Vesicle-Associated Membrane Protein 1 expression may contribute to Alzheimer’s pathophysiology and susceptibility

Background Alzheimer’s disease is a neurodegenerative disorder in which extracellular deposition of β-amyloid (Aβ) oligomers causes synaptic injury resulting in early memory loss, altered homeostasis, accumulation of hyperphosphorylated tau and cell death. Since proteins in the SNAP (Soluble N-ethylmaleimide-sensitive factor Attachment Protein) REceptors (SNARE) complex are essential for neuronal Aβ release at pre-synaptic terminals, we hypothesized that genetically controlled SNARE expression could alter neuronal Aß release at the synapse and hence play an early role in Alzheimer’s pathophysiology. Results Here we report 5 polymorphisms in Vesicle-Associated Membrane Protein 1 (VAMP1), a gene encoding a member of the SNARE complex, associated with bidirectionally altered cerebellar VAMP1 transcript levels (all p < 0.05). At the functional level, we demonstrated that control of VAMP1 expression by heterogeneous knockdown in mice resulted in up to 74% reduction in neuronal Aβ exocytosis (p < 0.001). We performed a case-control association study of the 5 VAMP1 expression regulating polymorphisms in 4,667 Alzheimer’s disease patients and 6,175 controls to determine their contribution to Alzheimer’s disease risk. We found that polymorphisms associated with increased brain VAMP1 transcript levels conferred higher risk for Alzheimer’s disease than those associated with lower VAMP1 transcript levels (p = 0.03). Moreover, we also report a modest protective association for a common VAMP1 polymorphism with Alzheimer’s disease risk (OR = 0.88, p = 0.03). This polymorphism was associated with decreased VAMP1 transcript levels (p = 0.02) and was functionally active in a dual luciferase reporter gene assay (p < 0.01). Conclusions Genetically regulated VAMP1 expression in the brain may modify both Alzheimer’s disease risk and may contribute to Alzheimer’s pathophysiology

Toward allele-specific targeting therapy and pharmacodynamic marker for spinocerebellar ataxia type 3

Spinocerebellar ataxia type 3 (SCA3), caused by a CAG repeat expansion in the ataxin-3 gene (ATXN3), is characterized by neuronal polyglutamine (polyQ) ATXN3 protein aggregates. Although there is no cure for SCA3, gene-silencing approaches to reduce toxic polyQ ATXN3 showed promise in preclinical models. However, a major limitation in translating putative treatments for this rare disease to the clinic is the lack of pharmacodynamic markers for use in clinical trials. Here, we developed an immunoassay that readily detects polyQ ATXN3 proteins in human biological fluids and discriminates patients with SCA3 from healthy controls and individuals with other ataxias. We show that polyQ ATXN3 serves as a marker of target engagement in human fibroblasts, which may bode well for its use in clinical trials. Last, we identified a single-nucleotide polymorphism that strongly associates with the expanded allele, thus providing an exciting drug target to abrogate detrimental events initiated by mutant ATXN3. Gene-silencing strategies for several repeat diseases are well under way, and our results are expected to improve clinical trial preparedness for SCA3 therapies

APOE ε4 lowers age at onset and is a high risk factor for Alzheimer's disease; A case control study from central Norway

<p>Abstract</p> <p>Background</p> <p>The objective of this study was to analyze factors influencing the risk and timing of Alzheimer's disease (AD) in central Norway. The <it>APOE </it>ε4 allele is the only consistently identified risk factor for late onset Alzheimer's disease (LOAD). We have described the allele frequencies of the apolipoprotein E gene (<it>APOE</it>) in a large population of patients with AD compared to the frequencies in a cognitively-normal control group, and estimated the effect of the <it>APOE </it>ε4 allele on the risk and the age at onset of AD in this population.</p> <p>Methods</p> <p>376 patients diagnosed with AD and 561 cognitively-normal control individuals with no known first degree relatives with dementia were genotyped for the <it>APOE </it>alleles. Allele frequencies and genotypes in patients and control individuals were compared. Odds Ratio for developing AD in different genotypes was calculated.</p> <p>Results</p> <p>Odds Ratio (OR) for developing AD was significantly increased in carriers of the <it>APOE </it>ε4 allele compared to individuals with the <it>APOE </it>ε3/ε3 genotype. Individuals carrying <it>APOE </it>ε4/ε4 had OR of 12.9 for developing AD, while carriers of <it>APOE </it>ε2/ε4 and <it>APOE </it>ε3/ε4 had OR of 3.2 and 4.2 respectively. The effect of the <it>APOE </it>ε4 allele was weaker with increasing age. Carrying the <it>APOE </it>ε2 allele showed no significant protective effect against AD and did not influence age at onset of the disease. Onset in LOAD patients was significantly reduced in a dose dependent manner from 78.4 years in patients without the <it>APOE </it>ε4 allele, to 75.3 in carriers of one <it>APOE </it>ε4 allele and 72.9 in carriers of two <it>APOE </it>ε4 alleles. Age at onset in early onset AD (EOAD) was not influenced by <it>APOE </it>ε4 alleles.</p> <p>Conclusion</p> <p><it>APOE </it>ε4 is a very strong risk factor for AD in the population of central Norway, and lowers age at onset of LOAD significantly.</p

Is inhibition of kinase activity the only therapeutic strategy for LRRK2-associated Parkinson's disease?

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are a common cause of familial Parkinson's disease (PD). Variation around the LRRK2 locus also contributes to the risk of sporadic PD. The LRRK2 protein contains a central catalytic region, and pathogenic mutations cluster in the Ras of complex protein C terminus of Ras of complex protein (mutations N1437H, R1441G/C and Y1699C) and kinase (G2019S and I2020T) domains. Much attention has been focused on the kinase domain, because kinase-dead versions of mutant LRRK2 are less toxic than kinase-active versions of the same proteins. Furthermore, kinase inhibitors may be able to mimic this effect in mouse models, although the currently tested inhibitors are not completely specific. In this review, we discuss the recent progress in the development of specific LRRK2 kinase inhibitors. We also discuss non-kinase-based therapeutic strategies for LRRK2-associated PD as it is possible that different approaches may be needed for different mutations

GeoERA Raw Materials Monograph : the past and the future

ABSTRACT: GeoERA Minerals projects have produced data aimed at supporting Europe’s minerals sector and to assist the European Commission to realise its goals for raw materials. Data has been compiled on mineral occurrences and mineral provinces across Europe, in particular, areas with potential to host Critical Raw Materials. Anecdotal evidence from the minerals sector provides an indication of the likelihood of exploration leading to mine development. For every 1,000 mineral showings examined, only 100 may receive further exploration work and of those 100, only 10 may warrant more detailed sampling either through trenching, drilling or other means and of those 10 only 1 may proceed to an evaluation through a full feasibility study which itself has only 50% chance of being positive. Following this, any project for which a mine proposal is made must undergo a full evaluation and permitting by authorities including full public consultation. The proposal may or may not pass this scrutiny. In terms of a schedule, the generally accepted minimum time frame from discovery to production is 10 years and usually much more, up to 20 years.info:eu-repo/semantics/publishedVersio

Genome-wide association and Meta-analysis of age at onset in Parkinson Disease

Background and Objectives Considerable heterogeneity exists in the literature concerning genetic determinants of the age at onset (AAO) of Parkinson disease (PD), which could be attributed to a lack of well-powered replication cohorts. The previous largest genome-wide association studies (GWAS) identified SNCA and TMEM175 loci on chromosome (Chr) 4 with a significant influence on the AAO of PD; these have not been independently replicated. This study aims to conduct a meta-analysis of GWAS of PD AAO and validate previously observed findings in worldwide populations. Methods A meta-analysis was performed on PD AAO GWAS of 30 populations of predominantly European ancestry from the Comprehensive Unbiased Risk Factor Assessment for Genetics and Environment in Parkinson's Disease (COURAGE-PD) Consortium. This was followed by combining our study with the largest publicly available European ancestry dataset compiled by the International Parkinson Disease Genomics Consortium (IPDGC). Results The COURAGE-PD Consortium included a cohort of 8,535 patients with PD (91.9%: Europeans and 9.1%: East Asians). The average AAO in the COURAGE-PD dataset was 58.9 years (SD = 11.6), with an underrepresentation of females (40.2%). The heritability estimate for AAO in COURAGE-PD was 0.083 (SE = 0.057). None of the loci reached genome-wide significance (p < 5 × 10−8). Nevertheless, the COURAGE-PD dataset confirmed the role of the previously published TMEM175 variant as a genetic determinant of the AAO of PD with Bonferroni-corrected nominal levels of significance (p < 0.025): (rs34311866: β(SE)COURAGE = 0.477(0.203), pCOURAGE = 0.0185). The subsequent meta-analysis of COURAGE-PD and IPDGC datasets (Ntotal = 25,950) led to the identification of 2 genome-wide significant association signals on Chr 4, including the previously reported SNCA locus (rs983361: β(SE)COURAGE+IPDGC = 0.720(0.122), pCOURAGE+IPDGC = 3.13 × 10−9) and a novel BST1 locus (rs4698412: β(SE)COURAGE+IPDGC = −0.526(0.096), pCOURAGE+IPDGC = 4.41 × 10−8). Discussion Our study further refines the genetic architecture of Chr 4 underlying the AAO of the PD phenotype through the identification of BST1 as a novel AAO PD locus. These findings open a new direction for the development of treatments to delay the onset of PD