Convergent cerebrospinal fluid proteomes and metabolic ontologies in humans and animal models of Rett syndrome

MECP2 loss-of-function mutations cause Rett syndrome, a neurodevelopmental disorder resulting from a disrupted brain transcriptome. How these transcriptional defects are decoded into a disease proteome remains unknown. We studied the proteome of Rett cerebrospinal fluid (CSF) to identify consensus Rett proteome and ontologies shared across three species. Rett CSF proteomes enriched proteins annotated to HDL lipoproteins, complement, mitochondria, citrate/pyruvate metabolism, synapse compartments, and the neurosecretory protein VGF. We used shared Rett ontologies to select analytes for orthogonal quantification and functional validation. VGF and ontologically selected CSF proteins had genotypic discriminatory capacity as determined by receiver operating characteristic analysis in Mecp2(-/y) and Mecp2(−/+). Differentially expressed CSF proteins distinguished Rett from a related neurodevelopmental disorder, CDKL5 deficiency disorder. We propose that Mecp2 mutant CSF proteomes and ontologies inform putative mechanisms and biomarkers of disease. We suggest that Rett syndrome results from synapse and metabolism dysfunction

Association between alcohol and cardiovascular disease: Mendelian randomisation analysis based on individual participant data.

OBJECTIVE: To use the rs1229984 variant in the alcohol dehydrogenase 1B gene (ADH1B) as an instrument to investigate the causal role of alcohol in cardiovascular disease. DESIGN: Mendelian randomisation meta-analysis of 56 epidemiological studies. PARTICIPANTS: 261 991 individuals of European descent, including 20 259 coronary heart disease cases and 10 164 stroke events. Data were available on ADH1B rs1229984 variant, alcohol phenotypes, and cardiovascular biomarkers. MAIN OUTCOME MEASURES: Odds ratio for coronary heart disease and stroke associated with the ADH1B variant in all individuals and by categories of alcohol consumption. RESULTS: Carriers of the A-allele of ADH1B rs1229984 consumed 17.2% fewer units of alcohol per week (95% confidence interval 15.6% to 18.9%), had a lower prevalence of binge drinking (odds ratio 0.78 (95% CI 0.73 to 0.84)), and had higher abstention (odds ratio 1.27 (1.21 to 1.34)) than non-carriers. Rs1229984 A-allele carriers had lower systolic blood pressure (-0.88 (-1.19 to -0.56) mm Hg), interleukin-6 levels (-5.2% (-7.8 to -2.4%)), waist circumference (-0.3 (-0.6 to -0.1) cm), and body mass index (-0.17 (-0.24 to -0.10) kg/m(2)). Rs1229984 A-allele carriers had lower odds of coronary heart disease (odds ratio 0.90 (0.84 to 0.96)). The protective association of the ADH1B rs1229984 A-allele variant remained the same across all categories of alcohol consumption (P=0.83 for heterogeneity). Although no association of rs1229984 was identified with the combined subtypes of stroke, carriers of the A-allele had lower odds of ischaemic stroke (odds ratio 0.83 (0.72 to 0.95)). CONCLUSIONS: Individuals with a genetic variant associated with non-drinking and lower alcohol consumption had a more favourable cardiovascular profile and a reduced risk of coronary heart disease than those without the genetic variant. This suggests that reduction of alcohol consumption, even for light to moderate drinkers, is beneficial for cardiovascular health

Association of the APOE, MTHFR and ACE genes polymorphisms and stroke in Zambian patients

The aim of the present study was to investigate the association of <em>APOE</em>, <em>MTHFR</em> and <em>ACE</em> polymorphisms with stroke in the Zambian population. We analyzed 41 stroke patients and 116 control subjects all of Zambian origin for associations between the genotype of the <em>APOE</em>, <em>MTHFR</em> and <em>ACE</em> polymorphisms and stroke. The <em>APOE</em> ε2ε4 genotype showed increased risk for hemorrhagic stroke (P&lt;0.05) and also a high risk for ischemic stroke (P=0.05). There was complete absence of the <em>APOE</em> ε2ε2 and the <em>MTHFR</em> TT genotypes in the Zambian population. The difference between cases and controls was not significant for the other genetic variants when analyzed for relationship between stroke, stroke subtype and genotype. We show that genetic variation at the <em>APOE locus</em> affects susceptibility to stroke. No detectable association were observed for the <em>MTHFR</em> and <em>ACE</em> genotypes and stroke in the Zambian population

Analysis of spinal and muscle pathology in transgenic mice overexpressing wild-type and ALS-linked mutant MATR3

Abstract Mutations in MATR3 have been associated with amyotrophic lateral sclerosis (ALS) as well as a form of distal myopathy termed vocal cord pharyngeal distal myopathy (VCPDM). To begin to understand how mutations in MATR3 may cause disease, here we provide initial characterization of transgenic (Tg) mice expressing human wild-type (WT) MATR3 (MATR3WT) and ALS-mutant F115C MATR3 (MATR3F115C) proteins under the control of the mouse prion promoter (MoPrP). For each construct, we established multiple independent lines of mice that stably transmitted the transgene. Unexpectedly, for all stably-transmitting lines examined, MATR3 transgenic mRNA expression was more robust in muscle, with minimal expression in spinal cord. The levels of transgenic mRNA in muscle did not differ between mice from our lead MATR3F115C line and lead MATR3WT line, but mice from the lead MATR3F115C line had significantly higher levels of MATR3 protein in muscle over the lead MATR3WT line. Mice from the three independent, established lines of MATR3F115C mice developed weakness in both fore- and hind-limbs as early as  20 months were not overtly distinguishable from non-transgenic (NT) littermates based on basic motor phenotype. Muscle of both MATR3WT and MATR3F115C mice showed vacuoles by 2 months of age which worsened by ~ 10 months, but vacuolation was noticeably more severe in MATR3F115C mice. Overall, our results indicate that increasing the levels of MATR3 in muscle can cause pathologic changes associated with myopathy, with MATR3F115C expression causing overt muscle atrophy and a profound motor phenotype. The findings suggest that analysis of muscle pathology in individuals harboring ALS-linked MATR3 mutations should be routinely considered

Retraction Note: Transgenic mice overexpressing the ALS-linked protein Matrin 3 develop a profound muscle phenotype

Abstract The authors are retracting this article. The article describes mice expressing wild-type human MATR3. However, since publication the authors have become aware that all of the lines of mice described express human MATR3 containing the F115C mutation. Transgenic mice expressing wild-type and mutant Matrin were created simultaneously in their laboratory and, at a crucial stage of generating the DNA for embryo injection, as confirmed by an investigation by the University of Florida, the DNA preparations were accidentally mislabelled. All of the founders created were mosaic, requiring extensive breeding to isolate stable lines. Mice mislabelled as expressing wild-type MATR3 were the first to produce lines that stably transmitted the transgene and thus were the first to be characterized. However, as lines of mice that were mislabelled as expressing the mutant (F115C) MATR3 were ultimately established, the data began to suggest that an error had been made. Sequence analysis of amplified tail DNA from mice descended from the lines reported in the article have revealed that they express the F115C variant. The data described are therefore an accurate description of the pathology of mice that express the F115C variant of MATR3, but not of mice expressing wild-type MATR3. The authors are preparing a new manuscript reporting data from both mice expressing the F115C variant of MATR3 and mice expressing wild-type MATR3

GWAS risk factors in Parkinson's disease : lRRK2 coding variation and genetic interaction with PARK16

Parkinson's disease (PD) is a multifactorial movement disorder characterized by progressive neurodegeneration. Genome-wide association studies (GWAS) have nominated over fifteen distinct loci associated with risk of PD, however the biological mechanisms by which these loci influence disease risk are mostly unknown. GWAS are only the first step in the identification of disease genes: the specific causal variants responsible for the risk within the associated loci and the interactions between them must be identified to fully comprehend their impact on the development of PD. In the present study, we first attempted to replicate the association signals of 17 PD GWAS loci in our series of 1381 patients with PD and 1328 controls. BST1, SNCA, HLA-DRA, CCDC62/HIP1R and MAPT all showed a significant association with PD under different models of inheritance and LRRK2 showed a suggestive association. We then examined the role of coding LRRK2 variants in the GWAS association signal for that gene. The previously identified LRRK2 risk mutant p.M1646T and protective haplotype p.N551K-R1398H-K1423K did not explain the association signal of LRRK2 in our series. Finally, we investigated the gene-gene interaction between PARK16 and LRRK2 that has previously been proposed. We observed no interaction between PARK16 and LRRK2 GWAS variants, but did observe a non-significant trend toward interaction between PARK16 and LRRK2 variants within the protective haplotype. Identification of causal variants and the interactions between them is the crucial next step in making biological sense of the massive amount of data generated by GWAS studies. Future studies combining larger sample sizes will undoubtedly shed light on the complex molecular interplay leading to the development of PD

NOTCH3 variants and risk of ischemic stroke

Background: Mutations within the NOTCH3 gene cause cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). CADASIL mutations appear to be restricted to the first twenty-four exons, resulting in the gain or loss of a cysteine amino acid. The role of other exonic NOTCH3 variation not involving cysteine residues and mutations in exons 25-33 in ischemic stroke remains unresolved. Methods: All 33 exons of NOTCH3 were sequenced in 269 Caucasian probands from the Siblings With Ischemic Stroke Study (SWISS), a 70-center North American affected sibling pair study and 95 healthy Caucasian control subjects. Variants identified by sequencing in the SWISS probands were then tested for association with ischemic stroke using US Caucasian controls collected at the Mayo Clinic (n=654), and further assessed in a Caucasian (n=802) and African American (n=298) patient-control series collected through the Ischemic Stroke Genetics Study (ISGS). Results: Sequencing of the 269 SWISS probands identified one (0.4%) with small vessel type stroke carrying a known CADASIL mutation (p.R558C; Exon 11). Of the 19 common NOTCH3 variants identified, the only variant significantly associated with ischemic stroke after multiple testing adjustment was p.R1560P (rs78501403; Exon 25) in the combined SWISS and ISGS Caucasian series (Odds Ratio [OR] 0.50, P=0.0022) where presence of the minor allele was protective against ischemic stroke. Although only significant prior to adjustment for multiple testing, p.T101T (rs3815188; Exon 3) was associated with an increased risk of small-vessel stroke (OR: 1.56, P=0.008) and p.P380P (rs61749020; Exon 7) was associated with decreased risk of large-vessel stroke (OR: 0.35, P=0.047) in Caucasians. No significant associations were observed in the small African American series. Conclusion: Cysteine-affecting NOTCH3 mutations are rare in patients with typical ischemic stroke, however our observation that common NOTCH3 variants may be associated with risk of ischemic stroke warrants further study