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Copyright © 2022 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works., Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with an estimated heritability between 40 and 50%. DNA methylation patterns can serve as proxies of (past) exposures and disease progression, as well as providing a potential mechanism that mediates genetic or environmental risk. Here, we present a blood-based epigenome-wide association study meta-analysis in 9706 samples passing stringent quality control (6763 patients, 2943 controls). We identified a total of 45 differentially methylated positions (DMPs) annotated to 42 genes, which are enriched for pathways and traits related to metabolism, cholesterol biosynthesis, and immunity. We then tested 39 DNA methylation-based proxies of putative ALS risk factors and found that high-density lipoprotein cholesterol, body mass index, white blood cell proportions, and alcohol intake were independently associated with ALS. Integration of these results with our latest genome-wide association study showed that cholesterol biosynthesis was potentially causally related to ALS. Last, DNA methylation at several DMPs and blood cell proportion estimates derived from DNA methylation data were associated with survival rate in patients, suggesting that they might represent indicators of underlying disease processes potentially amenable to therapeutic interventions., The research reported in this publication was supported by grants from The Dutch Research Council (NWO) (VENI scheme grant 09150161810018 to W.v.R.) and Prinses Beatrix Spierfond (neuromuscular fellowship grant W.F19-03 to W.v.R.), The Prinses Beatrix Spierfonds (W.OR20-08 to J.J.F.A.v.V. and J.H.V.), The Canadian Institutes of Health Research (FRN 159279 to J.P.R.), The Dutch Research Council (NWO) (VIDI grant 91719350 to K.P.K.), The European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement no. 772376-EScORIAL to J.H.V.), the Swedish Brain Foundation (grant nos. 2012-0262, 2012-0305, 2013-0279, 2016-0303, 2018-0310, and 2020-0353 to P.M.A.), the Swedish Research Council (grant nos. 2012-3167 and 2017-03100 to P.M.A.), the Knut and Alice Wallenberg Foundation (grant nos. 2012.0091, 2014.0305, and 2020.0232 to P.M.A.), the Ulla-Carin Lindquist Foundation and the Västerbotten County Council (grant no. 56103-7002829 to P.M.A.), and King Gustaf V’s and Queen Victoria’s Freemason’s Foundation. This is an EU Joint Programme–Neurodegenerative Disease Research (JPND) project. The project is supported through the following funding organizations under the aegis of JPND (www.jpnd.eu) [United Kingdom, Medical Research Council (MR/L501529/1; MR/R024804/1) and Economic and Social Research Council (ES/L008238/1)] and through the Motor Neurone Disease Association (MNDA). This study represents independent research part funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. A.A.-C. is supported by an NIHR Senior Investigator Award. Samples used in this research were entirely/in part obtained from the U.K. National DNA Bank for MND Research, funded by the MND Association and the Wellcome Trust. We would like to thank people with MND and their families for their participation in this project. We acknowledge sample management undertaken by Biobanking Solutions funded by the Medical Research Council at the Centre for Integrated Genomic Medical Research, University of Manchester. R.J.P. is funded through the Gravitation program of the Dutch Ministry of Education, Culture, and Science and the Netherlands Organization for Scientific Research (BRAINSCAPES). G.L.S. was supported by a PhD studentship from the Alzheimer’s Society. S.T.N. acknowledges support through a FightMND Mid-Career Fellowship. V.S. is supported by the Italian Ministry of Health, AriSLA, and E-Rare Joint Transnational Call. A.A.K. is funded by the MNDA and NIHR Maudsley Biomedical Research Centre. D.B., E.T., and H.R. are employees of Biogen. L.H.v.d.B. reports grants from the Netherlands ALS Foundation, grants from The Netherlands Organization for Health Research and Development (Vici scheme), grants from The European Community’s Health Seventh Framework Programme [grant agreement no. 259867 (EuroMOTOR) to L.H.v.d.B.], and grants from The Netherlands Organization for Health Research and Development (the STRENGTH project, funded through the EU Joint Programme–Neurodegenerative Disease Research, JPND), during the conduct of the study. Project MinE Belgium was supported by a grant from IWT (no. 140935), the ALS Liga België, the National Lottery of Belgium, and the KU Leuven Opening the Future Fund. P.V.D. holds a senior clinical investigatorship of FWO-Vlaanderen and is supported by the E. von Behring Chair for Neuromuscular and Neurodegenerative Disorders, the ALS Liga België, and the KU Leuven funds “Een Hart voor ALS”, “Laeversfonds voor ALS Onderzoek”, and the “Valéry Perrier Race against ALS Fund”. This work was supported by the Italian Ministry of Health (Ministero della Salute, Ricerca Sanitaria Finalizzata, grant RF-2016-02362405 to A. Chiò), the Progetti di Rilevante Interesse Nazionale program of the Ministry of Education, University and Research (grant 2017SNW5MB to A. Chiò); the European Commission’s Health Seventh Framework Programme (FP7/2007-2013 under grant agreement 259867 to A. Chiò), and the Joint Programme–Neurodegenerative Disease Research (Strength, ALS-Care and Brain-Mend projects), granted by Italian Ministry of Education, University, and Research. This study was performed under the Department of Excellence grant of the Italian Ministry of Education, University and Research to the “Rita Levi Montalcini” Department of Neuroscience, University of Torino, Italy. We acknowledge funding from the Australian National Health and Medical Research (NHMRC) Council: 1151854, 1083187, 1173790, 1078901, 1113400, 1095215, and 1176913 Enabling Grant #402703 to N.R.W. Additional funding was provided by the Motor Neurone Disease Research Institute of Australia Ice Bucket Challenge grant for the SALSA-SGC consortium. The OATS (used for controls) was facilitated through Twins Research Australia, a national resource in part supported by a Centre for Research Excellence from the Australian NHMRC Council (NHMRC 1079102 to N.R.W.). Funding for this study was awarded by the (NHMRC)/Australian Research Council Strategic Award (grant 401162 to N.R.W.) and NHMRC grants (1405325, 1024224, 1025243, 1045325, 1085606, 568969, and 1093083 to N.R.W.). The collaboration project is cofunded by the PPP Allowance made available by Health~Holland, Top Sector Life Sciences & Health, to stimulate public-private partnerships. This study was supported by the ALS Foundation Netherlands. This work was sponsored by NWO Domain Science for the use of the national computer facilities. A.N.B. is grateful to the Suna and Inan Kirac Foundation and Koc University for the excellent research environment created and for financial support. G.A.R. is supported by the Canadian Institutes of Health. Several authors of this publication are members of the Netherlands Neuromuscular Center (NL-NMD) and the European Reference Network for rare neuromuscular diseases EURO-NMD. French ALS patients of the Pitié-Salpêtrière hospital (Paris) have been collected with ARSla funding support.

Key Points Question Can common genetic variants associated with essential tremor (ET) be identified? Findings In this genome-wide association study and meta-analysis including genetic data on 483 054 individuals, 5 genome-wide significant loci were associated with risk of ET and common variants were associated with approximately 18% of ET heritability. Meaning Findings of this study may help identify new genes and inform ET biology., This genome-wide association study identifies common variants associated with risk of essential tremor., Importance Essential tremor (ET) is one of the most common movement disorders, affecting 5% of the general population older than 65 years. Common variants are thought to contribute toward susceptibility to ET, but no variants have been robustly identified. Objective To identify common genetic factors associated with risk of ET. Design, Setting, and Participants Case-control genome-wide association study. Inverse-variance meta-analysis was used to combine cohorts. Multicenter samples collected from European populations were collected from January 2010 to September 2019 as part of an ongoing study. Included patients were clinically diagnosed with or reported having ET. Control individuals were not diagnosed with or reported to have ET. Of 485 250 individuals, data for 483 054 passed data quality control and were used. Main Outcomes and Measures Genotypes of common variants associated with risk of ET. Results Of the 483 054 individuals included, there were 7177 with ET (3693 [51.46%] female; mean [SD] age, 62.66 [15.12] years), and 475 877 control individuals (253 785 [53.33%] female; mean [SD] age, 56.40 [17.6] years). Five independent genome-wide significant loci and were identified and were associated with approximately 18% of ET heritability. Functional analyses found significant enrichment in the cerebellar hemisphere, cerebellum, and axonogenesis pathways. Genetic correlation (r), which measures the degree of genetic overlap, revealed significant common variant overlap with Parkinson disease (r, 0.28; P = 2.38 × 10−8) and depression (r, 0.12; P = 9.78 × 10−4). A separate fine-mapping of transcriptome-wide association hits identified genes such as BACE2, LRRN2, DHRS13, and LINC00323 in disease-relevant brain regions, such as the cerebellum. Conclusions and Relevance The results of this genome-wide association study suggest that a portion of ET heritability can be explained by common genetic variation and can help identify new common genetic risk factors for ET.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a lifetime risk of one in 350 people and an unmet need for disease-modifying therapies. We conducted a cross-ancestry genome-wide association study (GWAS) including 29,612 patients with ALS and 122,656 controls, which identified 15 risk loci. When combined with 8,953 individuals with whole-genome sequencing (6,538 patients, 2,415 controls) and a large cortex-derived expression quantitative trait locus (eQTL) dataset (MetaBrain), analyses revealed locus-specific genetic architectures in which we prioritized genes either through rare variants, short tandem repeats or regulatory effects. ALS-associated risk loci were shared with multiple traits within the neurodegenerative spectrum but with distinct enrichment patterns across brain regions and cell types. Of the environmental and lifestyle risk factors obtained from the literature, Mendelian randomization analyses indicated a causal role for high cholesterol levels. The combination of all ALS-associated signals reveals a role for perturbations in vesicle-mediated transport and autophagy and provides evidence for cell-autonomous disease initiation in glutamatergic neurons., Dutch Research Council (NWO); VENI Scheme Grant; VIDI Grant; Prinses Beatrix Spierfonds; Neuromuscular Fellowship Grant; Medical Research Council (MRC); Clinical Infrastructure Award; Epidemiology Unit; Integrative Epidemiology Unit; Canadian Institutes of Health Research; IWT; National Institute on Aging; National Health and Medical Research Council (NHMRC); Enabling Grant; NHMRC/Australian Research Council Strategic Award; NHMRC; NHMRC Centre of Research Excellence Grant; National Health and Medical Research Council of Australia (NHMRC) Research Fellowship; United Kingdom, Medical Research Council; Economic and Social Research Council; European Union (EU); Horizon 2020; European Community's Health Seventh Framework Programme; EuroMOTOR; European Research Council (ERC); Research and Innovation Programme; EScORIAL; ALS Foundation Netherlands; Alzheimer’s Society PhD Studentship; ARSla Funding; Biogen; University of Bristol; Motor Neurone Disease Association (MNDA); NIHR Maudsley Biomedical Research Centre; Dutch Ministry of Education, Culture, and Science; Netherlands Organization for Scientific Research (NWO; BRAINSCAPES); Gravitation Program; ALS Liga België; National Lottery of Belgium; KU Leuven Opening the Future Fund; KU Leuven Funds, “Een Hart voor ALS”, “Laeversfonds voor ALS Onderzoek” and the “Valéry Perrier Race against ALS Fund”; E. von Behring Chair for Neuromuscular and Neurodegenerative Disorders; ALS Liga België; “Live now” Charity Foundation; Moscow ALS palliative Care Service; Canadian Institutes of Health; Research Australia; Ice Bucket Challenge Grant; NIH Intramural Research Programs; FightMND Mid-Career Fellowship; NIHR Senior Investigator; Sheffield NIHR Biomedical Research Centre; Motor Neurone Disease Association; National Institute for Health Research (NIHR) Biomedical Research Centre; Maudsley NHS Foundation Trust; King’s College London; NIHR Senior Investigator Award; Netherlands Organization for Health Research and Development; Vici Scheme; Netherlands Organization for Health Research and Development STRENGTH Project; PPP Allowance

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a lifetime risk of one in 350 people and an unmet need for disease-modifying therapies. We conducted a cross-ancestry genome-wide association study (GWAS) including 29,612 patients with ALS and 122,656 controls, which identified 15 risk loci. When combined with 8,953 individuals with whole-genome sequencing (6,538 patients, 2,415 controls) and a large cortex-derived expression quantitative trait locus (eQTL) dataset (MetaBrain), analyses revealed locus-specific genetic architectures in which we prioritized genes either through rare variants, short tandem repeats or regulatory effects. ALS-associated risk loci were shared with multiple traits within the neurodegenerative spectrum but with distinct enrichment patterns across brain regions and cell types. Of the environmental and lifestyle risk factors obtained from the literature, Mendelian randomization analyses indicated a causal role for high cholesterol levels. The combination of all ALS-associated signals reveals a role for perturbations in vesicle-mediated transport and autophagy and provides evidence for cell-autonomous disease initiation in glutamatergic neurons.

Cognitive impairment is a core feature of schizophrenia which precedes the onset of full psychotic symptoms, even in the ultra-high-risk stage (UHR). Polygenic risk scores (PRS) can be computed for many psychiatric disorders and phenotyping traits, including scores for resilience. We explored the correlations between several PRS and neurocognition in UHR individuals. We included 107 UHR individuals; 29.9% of them converted to psychosis (UHR-C) while 57.0% did not (UHR-NC) during the 1-year follow-up. Cognitive performances were assessed with the Wechsler Adult Intelligence Scale estimating the Intelligence Quotient (IQ), the Trail Making Test, the verbal fluency, the Stroop test, and the Wisconsin card sorting test. Linear regression models were used to test their association with the PRS for schizophrenia, bipolar disorder, major depression, ADHD, cross-disorders, cognitive performance, intelligence, education attainment, and resilience to schizophrenia. UHR-C had a lower IQ than UHR-NC. The PRS for schizophrenia negatively correlated with IQ, while the PRS for cognitive performance and for resilience positively correlated with IQ. PRS for schizophrenia showed a significant correlation with working memory and processing speed indices. PRS for schizophrenia showed a higher effect on IQ in UHR-NC, and UHR-NC with high PRS for schizophrenia had a similar IQ as UHR-C. Conversely, UHR-C with a high PRS for resilience performed as well as UHR-NC. Our findings suggest that cognitive deficits may predate the onset of psychosis. The genetic architecture of schizophrenia seems to impacts the cognition in UHR-NC. Cognition is also mediated by PRS for resilience.

In the version of this article initially published, the affiliation for Nazli Başak appeared incorrectly. Nazli Başak is at Koç University, School of Medicine, KUTTAM-NDAL, Istanbul, Turkey, and not Bogazici University. The error has been corrected in the HTML and PDF versions of the article.

Introduction Essential tremor (ET) is one of the most common movement disorders. Despite its high prevalence and heritability, its genetic etiology remains elusive with only a few susceptibility genes identified and poorly replicated. Our aim was to find novel candidate genes involved in ET predisposition through whole exome sequencing. Methods We studied eight multigenerational families (N = 40 individuals) with an autosomal-dominant inheritance using a comprehensive strategy combining whole exome sequencing followed by case-control association testing of prioritized variants in a separate cohort comprising 521 ET cases and 596 controls. We further performed gene-based burden analyses in an additional dataset comprising 789 ET patients and 770 healthy individuals to investigate whether there was an enrichment of rare deleterious variants within our candidate genes. Results Fifteen variants co-segregated with disease status in at least one of the families, among which rs749875462 in CCDC183, rs535864157 in MMP10 and rs114285050 in GPR151 showed a nominal association with ET. However, we found no significant enrichment of rare variants within these genes in cases compared with controls. Interestingly, MMP10 protein is involved in the inflammatory response to neuronal damage and has been previously associated with other neurological disorders. Conclusions We prioritized a set of promising genes, especially MMP10, for further genetic and functional studies in ET. Our study suggests that rare deleterious coding variants that markedly increase susceptibility to ET are likely to be found in many genes. Future studies are needed to replicate and further infer biological mechanisms and potential disease causality for our identified genes.

Importance: Essential tremor (ET) is one of the most common movement disorders, affecting 5% of the general population older than 65 years. Common variants are thought to contribute toward susceptibility to ET, but no variants have been robustly identified. Objective: To identify common genetic factors associated with risk of ET. Design, Setting, and Participants: Case-control genome-wide association study. Inverse-variance meta-analysis was used to combine cohorts. Multicenter samples collected from European populations were collected from January 2010 to September 2019 as part of an ongoing study. Included patients were clinically diagnosed with or reported having ET. Control individuals were not diagnosed with or reported to have ET. Of 485250 individuals, data for 483054 passed data quality control and were used. Main Outcomes and Measures: Genotypes of common variants associated with risk of ET. Results: Of the 483054 individuals included, there were 7177 with ET (3693 [51.46%] female; mean [SD] age, 62.66 [15.12] years), and 475877 control individuals (253785 [53.33%] female; mean [SD] age, 56.40 [17.6] years). Five independent genome-wide significant loci and were identified and were associated with approximately 18% of ET heritability. Functional analyses found significant enrichment in the cerebellar hemisphere, cerebellum, and axonogenesis pathways. Genetic correlation (r), which measures the degree of genetic overlap, revealed significant common variant overlap with Parkinson disease (r, 0.28; P = 2.38 × 10-8) and depression (r, 0.12; P = 9.78 × 10-4). A separate fine-mapping of transcriptome-wide association hits identified genes such as BACE2, LRRN2, DHRS13, and LINC00323 in disease-relevant brain regions, such as the cerebellum. Conclusions and Relevance: The results of this genome-wide association study suggest that a portion of ET heritability can be explained by common genetic variation and can help identify new common genetic risk factors for ET.

Additional file 1: Table S1. Raw proportions of the six different cell types both in the methylation dataset and in the RNA sequencing dataset. Table S2. Pearson’s correlation between the proportion of each cell type estimated from the methylomic dataset and the transcriptomic dataset.

Machado-Joseph disease (MJD/SCA3) is the most common form of dominantly inherited ataxia worldwide. The disorder is caused by an expanded CAG repeat in the ATXN3 gene. Past studies have revealed that the length of the expansion partly explains the disease age at onset (AO) variability of MJD, which is confirmed in this study (Pearson’s correlation coefficient R2 = 0.62). Using a total of 786 MJD patients from five different geographical origins, a genome-wide association study (GWAS) was conducted to identify additional AO modifying factors that could explain some of the residual AO variability. We identified nine suggestively associated loci (P < 1 × 10−5). These loci were enriched for genes involved in vesicle transport, olfactory signaling, and synaptic pathways. Furthermore, associations between AO and the TRIM29 and RAG genes suggests that DNA repair mechanisms might be implicated in MJD pathogenesis. Our study demonstrates the existence of several additional genetic factors, along with CAG expansion, that may lead to a better understanding of the genotype-phenotype correlation in MJD.

Figure S1. a Schematic of the endogenous zebrafish atp13a2 ortholog. The exons are shown are rectangles and the introns as horizontal lines. The splice junctions targeted with antisense morpholino oligonucleotides (atp13a2_3x4_SB and atp13a2_3x6_SB) are shown with red asterisks. b Gel images showing the efficiency of the atp13a2_3x4_SB and atp13a2_3x6_SB morpholinos. The first lane in each gel photograph shows amplicons from the respective loci flanking the targeted sequences, with no aberrations observed. In the embryos injected with morpholino oligonucleotides, aberrant bands were evident, showing that the morpholinos were efficient in knocking down the expression of endogenous atp13a2. Figure S2 a Bar graph showing the percentage of embryos displaying motor neuron defects upon overexpression of either wild-type or mutant human ATP13A2 mRNA. We observed no statistically significant difference in the number of control versus injected embryos for any of the mRNAs tested, suggesting that both the wild-type and mutant transcripts (ATP13A2 WT, ATP13A2 p.Gly504Arg, ATP13A2 p.Glu613Ter) do not induce dominant negative effects. (PDF 13488 kb)

The present study aimed to examine whether the APOE ε4 allele, associated with dementia with Lewy bodies (DLB), and possibly with dementia in Parkinson's disease (PD), is also associated with idiopathic rapid eye movement sleep behavior disorder (RBD). Two single nucleotide polymorphisms, rs429358 and rs7412, were genotyped in RBD patients (n = 480) and in controls (n = 823). APOE ε4 allele frequency was 0.14 among RBD patients and 0.13 among controls (OR = 1.11, 95% CI: 0.88–1.40, p = 0.41). APOE ε4 allele frequencies were similar in those who converted to DLB (0.14) and those who converted to Parkinson's disease (0.12) or multiple system atrophy (0.14, p = 1.0). The APOE ε4 allele is neither a risk factor for RBD nor it is associated with conversion from RBD to DLB or other synucleinopathies.

Introduction The most common forms of amyotrophic lateral sclerosis and frontotemporal dementia are caused by a large GGGGCC repeat expansion in the first intron of the C9orf72 gene. The repeat-containing intron should be degraded after being spliced out, however GGGGCC repeat-containing RNA species either accumulate in nuclear foci or are exported to the cytoplasm where they are translated into potentially toxic dipeptide repeat proteins by repeat-associated non-AUG-initiated (RAN) translation. Results In order to determine the mechanisms of repeat-containing intron misprocessing, we have analyzed C9orf72 transcripts in lymphoblasts from C9orf72 expansion carriers (n = 15) and control individuals (n = 15). We have identified polyadenylated C9orf72 RNA species retaining the repeat-containing intron and in which downstream exons are spliced correctly resulting in a C9orf72 mRNA with an enlarged 5’-UTR containing the GGGGCC repeats. Intron-retaining transcripts are produced from both wild-type and mutant alleles. Intron-retaining C9orf72 transcripts were also detected in brain with a 2.7 fold increase measured in the frontal cortex from heterozygous expansion carriers (n = 11) compared to controls (n = 10). The level of intron-retaining transcripts was increased 5.9 fold in a case homozygous for the expansion. We also show that a large proportion of intron 1-retaining C9orf72 transcripts accumulate in the nucleus. Conclusions Retention of the repeat-containing intron in mature C9orf72 mRNA can potentially explain nuclear foci formation as well as nuclear export of GGGGCC repeat RNA and suggests that the misprocessing of C9orf72 transcripts initiates the pathogenic process caused by C9orf72 hexanucleotide repeat expansions as well as provides the basis for novel therapeutic strategies. Electronic supplementary material The online version of this article (doi:10.1186/s40478-016-0289-4) contains supplementary material, which is available to authorized users.

Dans le cadre du plan Algues vertes mis en place en 2010 par le gouvernement, un comité scientifique a été constitué pour en valider les principales orientations. Ce comité scientifique Algues vertes (CSAV) a analysé dans un premier temps le cahier des charges de l’appel à propositions, puis examiné chacun des huit plans d’actions territoriaux qui ont été proposés par les périmètres concernés et définis au Schéma directeur d’aménagement et de gestion des eaux du bassin Loire-Bretagne (SDAGE 2010-2015).La présence d’un comité scientifique en appui à une décision politique proposant une démarche de concertation territorialisée, ainsi que les échanges entre le comité et les porteurs de projet sont des expériences relativement inédites. Il nous paraît donc intéressant d’analyser l’interaction entre les scientifiques et le processus d’élaboration des projets et de synthétiser les avis rendus sur ces projets. Certains des membres du comité ont souhaité réaliser cette analyse qui se décompose en quatre parties. Dans un premier temps, on analysera comment la logique rationnelle et scientifique « objectifs-actions » se heurte à des logiques socioculturelles des acteurs de terrain, puis comment ces logiques et jeux d’acteurs condamnent les projets à n’avoir qu’une portée limitée. On montreraensuite comment le CSAV a tenté de ne pas se poser en scientifique censeur et à garder la plus grande objectivité possible et comment il a apporté des expertises qui ont permis certaines évolutions. Enfin on rappellera comment le travail a permis d’identifier des dynamiques positives et de tracer des voies d’actions plus efficaces.

International audience; The recently identified C9orf72 gene accounts for a large proportion of amyotrophic lateral sclerosis and frontotemporal lobar degenerations. As several forms of these disorders are associated with parkinsonism, we hypothesized that some patients with Parkinson's disease or other forms of parkinsonism might carry pathogenic C9orf72 expansions. Therefore, we looked for C9orf72 repeat expansions in 1446 unrelated parkinsonian patients consisting of 1225 patients clinically diagnosed with Parkinson's disease, 123 with progressive supranuclear palsy, 21 with corticobasal degeneration syndrome, 43 with Lewy body dementia and 25 with multiple system atrophy-parkinsonism. Of the 1446 parkinsonian patients, five carried C9orf72 expansions: three patients with typical Parkinson's disease, one with corticobasal degeneration syndrome and another with progressive supranuclear palsy. This study shows that (i) although rare, C9orf72 repeat expansions may be associated with clinically typical Parkinson's disease and also with other parkinsonism; (ii) in several patients, parkinsonism was levodopa-responsive and remained pure, without associated dementia, for >10 years and (iii) interestingly, all C9orf72 repeat expansion carriers had positive family histories of parkinsonism, degenerative dementias or amyotrophic lateral sclerosis. This study also provides the tools for identifying parkinsonian patients with C9orf72 expansions, with important consequences for genetic counselling.

International audience; The recently identified C9orf72 gene accounts for a large proportion of amyotrophic lateral sclerosis and frontotemporal lobar degenerations. As several forms of these disorders are associated with parkinsonism, we hypothesized that some patients with Parkinson's disease or other forms of parkinsonism might carry pathogenic C9orf72 expansions. Therefore, we looked for C9orf72 repeat expansions in 1446 unrelated parkinsonian patients consisting of 1225 patients clinically diagnosed with Parkinson's disease, 123 with progressive supranuclear palsy, 21 with corticobasal degeneration syndrome, 43 with Lewy body dementia and 25 with multiple system atrophy-parkinsonism. Of the 1446 parkinsonian patients, five carried C9orf72 expansions: three patients with typical Parkinson's disease, one with corticobasal degeneration syndrome and another with progressive supranuclear palsy. This study shows that (i) although rare, C9orf72 repeat expansions may be associated with clinically typical Parkinson's disease and also with other parkinsonism; (ii) in several patients, parkinsonism was levodopa-responsive and remained pure, without associated dementia, for >10 years and (iii) interestingly, all C9orf72 repeat expansion carriers had positive family histories of parkinsonism, degenerative dementias or amyotrophic lateral sclerosis. This study also provides the tools for identifying parkinsonian patients with C9orf72 expansions, with important consequences for genetic counselling.

International audience; La préfecture de la région Bretagne a demandé une expertise des documents relatifs aux algues vertes diffusés par la fédération départementale des syndicats d’exploitants agricoles (FDSEA) et le centre départemental des jeunes agriculteurs (CDJA) du Finistère. Pour l’organisation de la réponse, coordonnée par l’Institut français de recherche pour l’exploitation de la mer (IFREMER) et élaborée par des scientifiques de l’IFREMER, du Centre d’étude et de valorisation des algues (CEVA), d’Agrocampus Ouest et de l’Institut national de la recherche agronomique (INRA), ont été identifiées des questions et des assertions posées par ces syndicats et par l’association nommée « Institut de l’environnement ». À chacune de ces questions, ou assertions, une réponse est donnée par un ou plusieurs organismes rédacteurs dont nous indiquons, à la fin de chaque réponse, le principal.

International audience; The chemical composition and structures of several ulvan extracts isolated from various Ulva species were studied. They were all composed mainly of rhamnose, glucuronic acid, xylose, glucose and sulphate with smaller amounts of iduronic acid and traces of galactose. Proteins were also present, most likely as contaminants. Precise quantification of the uronic acid content by chemical-enzymatic hydrolysis coupled to HPAEC-PAD analysis and by colorimetry was not achieved, most likely due to the incomplete hydrolysis of glucuronan segments, inadequate HPAEC-pulsed-amperometric response factor for iduronic acid and to a possible differential colorimetric response of the two uronic acids. 13C NMR spectroscopic investigation of different ulvans demonstrated that they were all based on ulvanobiuronic acid 3-sulphate A and B repeating units [β-D-Glc pA-(1->4)-α-L-Rhap3S and α-L-IdopA-(1->4)-α-L-Rha p3S, respectively] as well as contiguous β 1->4 linked D-glucuronic acids possibly occurring either in ulvan or as a separate glucuronan. Marked variations in the content of the repeating structures were seen among the different samples. However, due to the limited number of samples studied, no conclusion was reached concerning the effects of species and ecophysiological conditions on the chemistry of ulvan.

L'Ulve des marées vertes appartient à la catégorie des végétaux qui peuvent répondre à des perturbations de leurs conditions trophiques par une production de masse. L'étude des relations entre conditions trophiques et production de masse nécessite l'analyse écophysiologique de cette production, laquelle doit permettre plus particulièrement : (1) l'identification des facteurs de croissance responsables (2) la mesure de leur effet limitant sur la production. Cette analyse peut se faire selon deux approches complémentaires : (l) le suivi in situ du statut physiologique de la biomasse au cours de son cycle de croissance (2) la simulation en conditions contrôlées de l'action des facteurs externes sur la production. Dans le cadre de son programme général d'étude sur les proliférations algales, l'IFREMER s'est proposé d'élaborer un modèle numérique du fonctionnement de la marée verte en baie de St Brieuc. Ce modèle intègre un modèle physique (concernant les caractéristiques courantologiques de la baie) et un modèle biologique considéré essentiellement sous ses aspects écophysiologiques. L'objectif du présent travail est de compléter l'information à destination de ce modèle biologique par : (1) un suivi de la composition des Ulves concernant le phosphore total, l'azote total, leurs fractions minérales respectives et enfin le rapport C\N (2) une simulation en laboratoire de l'activité photosynthétique de l'Ulve en fonction de la lumière.

L'Ulve des marées vertes appartient à la catégorie des végétaux qui peuvent répondre à des perturbations de leurs conditions trophiques par une production de masse. L'étude des relations entre conditions trophiques et production de masse nécessite l'analyse écophysiologique de cette production, laquelle doit permettre plus particulièrement : (1) l'identification des facteurs de croissance responsables (2) la mesure de leur effet limitant sur la production. Cette analyse peut se faire selon deux approches complémentaires : (1} le suivi in situ du statut physiologique de la biomasse au cours de son cycle de croissance (2) la simulation en conditions contrôlées de l'action des facteurs externes sur la production. Dans le cadre de son programme général d'étude sur les proliférations algales, l'IFREMER s'est proposé d'élaborer un modèle numérique du fonctionnement de la marée verte en baie de St Brieuc. Ce modèle intègre un modèle physique (concernant les caractéristiques courantologiques de biologique de la baie) et un modèle biologique considéré essentiellement sous aspect écophysiologiques.

INTRODUCTION - Originaire du Japon, l'algue phéophycée S. muticum est apparue vers 1975 en Normandie, après avoir été introduite accidentellement quelques années plus tôt en Grande-Bretagne. Cette espèce n'a cessé, depuis, de proliférer le long des côtes françaises. Son implantation actuelle en Bretagne est localement favorisée par l'existence de retenues d'eau et de chenaux qui parsèment les grands espaces découvrant de la zone de balancement des marées. Pour ce qui des données biologiques existantes concernant cette algue, des étapes de sa progression géographique, des nuisances occasionnées et des moyens de lutte inventoriés, on se reportera aux documents de synthèse émanant du groupe "Sargasse" animé par IFREMER (cf. BELSHER 1983, BELSHER 1986). Les nuisances occasionnées sont globalement de deux ordres : gêne de la conchyliculture et gêne de la petite navigation côtière au niveau des entrées de port. Actuellement, aucun des moyens de lutte imaginés contre la prolifération de cette espèce apparue économiquement ou écologiquement envisageable.

Supplementary material. (PDF 456Â kb)

Supplementary material. (PDF 456Â kb)

Scans of exposures resulting from the Western blots immunodetection presented on Figures 1a, 1b, 2a and 2b.

Background: Mild traumatic brain injury (mTBI) often results in post-concussion symptoms, chronic pain, and sleepiness. Genetic factors are thought to play an important role in poor prognosis. Aims: The aims of this study are to (1) document the prevalence of pain and post-concussion symptoms in mTBI patients in acute and chronic phases (2) determine whether candidate genes predispose to post-concussive symptoms and pain. Methods: Posttraumatic symptoms, evaluated using the Rivermead Post-Concussion Symptoms Questionnaire, and pain were assessed in 94 mTBI patients in the acute phase as well as in 22 healthy controls. Assessment was repeated in 36 patients after one year who agreed to participate in the follow-up visit. Gene polymorphisms and expression were assessed in mTBI patients and healthy controls. Results: In the acute phase, mTBI patients with pain (69%) presented more psychological symptoms and sleepiness and were less able to return to work than those without pain. At one year, 19% of mTBI patients had persistent pain and psychological distress. Two haplotypes (H2 and H3) in the brain-derived neurotrophic factor (BDNF) gene were shown to be respectively deleterious and protective against post-concussion symptoms and pain in both acute and chronic phases. Protective haplotype H3 was associated with a decreased expression of the anti-sense of BDNF (BDNF-AS). Deleterious haplotype H2 predicted the development of chronic pain at one year, whereas H3 was protective. Conclusions: This pilot study suggests a protective mechanism of a multilocus effect in BDNF, through BDNF-AS, against post-concussion symptoms and pain in the acute phase and possibly chronic pain at one year post-mTBI. The role of antisense RNA should be validated in larger cohorts.

Scans of exposures resulting from the Western blots immunodetection presented on Figures 1a, 1b, 2a and 2b.

Background: Mild traumatic brain injury (mTBI) often results in post-concussion symptoms, chronic pain, and sleepiness. Genetic factors are thought to play an important role in poor prognosis. Aims: The aims of this study are to (1) document the prevalence of pain and post-concussion symptoms in mTBI patients in acute and chronic phases (2) determine whether candidate genes predispose to post-concussive symptoms and pain. Methods: Posttraumatic symptoms, evaluated using the Rivermead Post-Concussion Symptoms Questionnaire, and pain were assessed in 94 mTBI patients in the acute phase as well as in 22 healthy controls. Assessment was repeated in 36 patients after one year who agreed to participate in the follow-up visit. Gene polymorphisms and expression were assessed in mTBI patients and healthy controls. Results: In the acute phase, mTBI patients with pain (69%) presented more psychological symptoms and sleepiness and were less able to return to work than those without pain. At one year, 19% of mTBI patients had persistent pain and psychological distress. Two haplotypes (H2 and H3) in the brain-derived neurotrophic factor (BDNF) gene were shown to be respectively deleterious and protective against post-concussion symptoms and pain in both acute and chronic phases. Protective haplotype H3 was associated with a decreased expression of the anti-sense of BDNF (BDNF-AS). Deleterious haplotype H2 predicted the development of chronic pain at one year, whereas H3 was protective. Conclusions: This pilot study suggests a protective mechanism of a multilocus effect in BDNF, through BDNF-AS, against post-concussion symptoms and pain in the acute phase and possibly chronic pain at one year post-mTBI. The role of antisense RNA should be validated in larger cohorts.

International audience; The present study aimed to examine whether the APOE ε4 allele, associated with dementia with Lewy bodies (DLB), and possibly with dementia in Parkinson's disease (PD), is also associated with idiopathic rapid eye movement sleep behavior disorder (RBD). Two single nucleotide polymorphisms, rs429358 and rs7412, were genotyped in RBD patients (n = 480) and in controls (n = 823). APOE ε4 allele frequency was 0.14 among RBD patients and 0.13 among controls (OR = 1.11, 95% CI: 0.88-1.40, p = 0.41). APOE ε4 allele frequencies were similar in those who converted to DLB (0.14) and those who converted to Parkinson's disease (0.12) or multiple system atrophy (0.14, p = 1.0). The APOE ε4 allele is neither a risk factor for RBD nor it is associated with conversion from RBD to DLB or other synucleinopathies.

Background: MAPT haplotypes are associated with PD, but their association with rapid eye movement sleep behavior disorder is unclear. Objective: To study the role of MAPT variants in rapid eye movement sleep behavior disorder. Methods: Two cohorts were included: (A) PD (n = 600), rapid eye movement sleep behavior disorder (n = 613) patients, and controls (n = 981); (B) dementia with Lewy bodies patients with rapid eye movement sleep behavior disorder (n = 271) and controls (n = 950). MAPT‐associated variants and the entire coding sequence of MAPT were analyzed. Age‐, sex‐, and ethnicity‐adjusted analyses were performed to examine the association between MAPT, PD, and rapid eye movement sleep behavior disorder. Results: MAPT‐H2 variants were associated with PD (odds ratios: 0.62‐0.65; P = 0.010‐0.019), but not with rapid eye movement sleep behavior disorder. In PD, the H1 haplotype odds ratio was 1.60 (95% confidence interval: 1.12‐2.28; P = 0.009), and the H2 odds ratio was 0.68 (95% confidence interval: 0.48‐0.96; P = 0.03). The H2/H1 haplotypes were not associated with rapid eye movement sleep behavior disorder. Conclusions: Our results confirm the protective effect of the MAPT‐H2 haplotype in PD, and define its components. Furthermore, our results suggest that MAPT does not play a major role in rapid eye movement sleep behavior disorder, emphasizing different genetic background than in PD in this locus.

La Sclérose Latérale Amyotrophique (SLA) est une maladie neurodégénérative qui affecte les neurones moteurs. 10% des cas sont des cas familiaux et l’étude de ces familles a mené à la découverte de plusieurs gènes pouvant causer la SLA, incluant SOD1, TARDBP et FUS. L’expansion de la répétition GGGGCC dans le gène C9orf72 est, à ce jour, la cause la plus connue de SLA. L’impact de cette expansion est encore méconnu et il reste à déterminer si la toxicité est causée par un gain de fonction, une perte de fonction ou les deux. Plusieurs gènes impliqués dans la SLA sont conservés entre le nématode Caenorhabditis elegans et l’humain. C. elegans est un vers transparent fréquemment utilisé pour des études anatomiques, comportementales et génétiques. Il possède une lignée cellulaire invariable qui inclue 302 neurones. Aussi, les mécanismes de réponse au stress ainsi que les mécanismes de vieillissement sont très bien conservés entre ce nématode et l’humain. Donc, notre groupe, et plusieurs autres, ont utilisé C. elegans pour étudier plusieurs aspects de la SLA. Pour mieux comprendre la toxicité causée par l’expansion GGGGCC de C9orf72, nous avons développé deux modèles de vers pour étudier l’impact d’une perte de fonction ainsi que d’un gain de toxicité de l’ARN. Pour voir les conséquences d’une perte de fonction, nous avons étudié l’orthologue de C9orf72 dans C. elegans, alfa-1 (ALS/FTD associated gene homolog). Les vers mutants alfa-1(ok3062) développent des problèmes moteurs causant une paralysie et une dégénérescence spécifique des neurones moteurs GABAergiques. De plus, les mutants sont sensibles au stress osmotique qui provoque une dégénérescence. D’autre part, l’expression de la séquence d’ARN contenant une répétition pathogénique GGGGCC cause aussi des problèmes moteurs et de la dégénérescence affectant les neurones moteurs. Nos résultats suggèrent donc qu’un gain de toxicité de l’ARN ainsi qu’une perte de fonction de C9orf72 sont donc toxiques pour les neurones. Puisque le mouvement du vers peut être rapidement évalué en cultivant les vers dans un milieu liquide, nous avons développé un criblage de molécules pouvant affecter le mouvement des vers mutants alfa-1 en culture liquide. Plus de 4 000 composés ont été évalués et 80 ameliore la mobilité des vers alfa-1. Onze molécules ont aussi été testées dans les vers exprimant l’expansion GGGGCC et huit diminuent aussi le phénotype moteur de ces vers. Finalement, des huit molécules qui diminent la toxicité causée par la perte de fonction de C9orf72 et la toxicité de l’ARN, deux restaurent aussi l’expression anormale de plusieurs transcrits d’ARN observée dans des cellules dérivées de patient C9orf72. Avec ce projet, nous voulons identifier des molécules pouvant affecter tous les modes de toxicité de C9orf72 et possiblement ouvrir de nouvelles avenues thérapeutiques, Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting the motor neurons. 10% of the cases are familial and using those families, many genes were shown to be involved in ALS pathogenesis, including SOD1, TARDBP and FUS. The GGGGCC repeat found in the first intron of C9orf72 is, to this day, the most common genetic cause of ALS. Many hypotheses have been speculated to explain the toxicity of the pathogenic GGGGCC repeat, including loss and gain of function mechanisms. Many proteins involved in amyotrophic lateral sclerosis (ALS) are evolutionarily conserved in the worm Caenorhabditis elegans. C. elegans is a transparent nematode widely used for anatomical, behavioural and genetic studies. It possesses an invariant cell lineage that includes 302 neurons in the adult nematode. Also, cellular stress responses and survival mechanisms are genetically regulated and conserved from the nematode and human. Therefore, our group, and others, have used C. elegans to model different aspects of neurodegenerative diseases including ALS. To better understand the toxicity caused by the GGGGCC repeat expansion in C9orf72, we have developed two C. elegans models to understand either the impact of the loss of function of C9orf72 or the gain of toxicity of the RNA containing the GGGGCC repeat. To understand the loss of function, we have characterized the orthologue of C9orf72 in C. elegans, alfa-1 (ALS/FTD associated gene homolog). Mutant alfa-1 worms exhibit motor impairments leading to paralysis and neurodegenereation of the GABAergic neurons. Mutant worms are also sensitive to osmotic stress which can lead to increased neurodegeneration. On the other part, exposure of C. elegans neurons to the RNA containing the GGGGCC repeat causes also motor problem and degeneration affecting the motor neurons. Therefore, our data suggest that both loss of function of C9orf72 and toxic gain of function are detrimental to neurons. Since motor dysfunctions in worms can be easily accessed in liquid culture, we have screened more than 4,000 FDA approved compounds in the alfa-1(ok3062) worms. 80 molecules were shown to improve alfa-1 impaired function and eleven of those were also tested for their effect to reduce the neurotoxicity caused by the GGGGCC repeat RNA. Eight molecules were shown to affect both types of neurotoxicity. Finally, from these eight molecules that can improveboth types of toxicity, two were shown to restore the abnormal RNA expression observed in C9orf72 patient-derive cells. With this project, we aimed to identify molecules that can affect the loss of C9orf72 toxicity and the toxic gain of RNA function containing the GGGGCC repeat to hopefully open new therapeutic avenues for ALS patients.

La sclérose latérale amyotrophique (SLA) est la maladie des neurones moteurs la plus fréquente, affectant 4-6 individus par 100,000 habitants à l’échelle mondiale. La maladie se caractérise par une faiblesse et une atrophie musculaire suite à la dégénérescence des neurones du cortex moteur, tronc cérébral et moelle épinière. Les personnes atteintes développent les premiers symptômes à l’âge adulte et la maladie progresse sur une période de trois à cinq ans. Il a été répertorié qu’environ 10% des patients ont une histoire familiale de SLA; 90% des gens affectés le sont donc de façon sporadique. La découverte il y a 19 ans de mutations dans le gène zinc/copper superoxide dismutase (SOD1), présentes dans 15-20% des cas familiaux de SLA et environ 2% du total des individus affectés, a été l’événement déclencheur pour la découverte de variations génétiques responsables de la maladie. La recherche sur la génétique de la SLA a connu une progression rapide ces quatre dernières années avec l’identification de mutations dans de nouveaux gènes. Toutefois, même si certains de ces gènes ont été démontrés comme réellement liés à la maladie, la contribution d’autres gènes demeure incertaine puisque les résultats publiés de ceux-ci n’ont pas, à ce jour, été répliqués. Une portion substantielle de cas reste cependant à être génétiquement expliquée, et aucun traitement à ce jour n’a été démontré comme étant efficace pour remédier, atténuer ou prévenir la maladie. Le but du projet de recherche de doctorat était d’identifier de nouveaux gènes mutés dans la SLA, tout en évaluant la contribution de gènes nouvellement identifiés chez une importante cohorte multiethnique de cas familiaux et sporadiques. Les résultats présentés sont organisés en trois sections différentes. Dans un premier temps, la contribution de mutations présentes dans le gène FUS est évaluée chez les patients familiaux, sporadiques et juvéniles de SLA. Précisément, de nouvelles mutations sont rapportées et la proportion de mutations retrouvées chez les cas familiaux et sporadiques de SLA est évaluée. De plus, une nouvelle mutation est rapportée dans un cas juvénile de SLA; cette étude de cas est discutée. Dans un deuxième temps, de nouvelles avenues génétiques sont explorées concernant le gène SOD1. En effet, une nouvelle mutation complexe est rapportée chez une famille française de SLA. De plus, la possibilité qu’une mutation présente dans un autre gène impliqué dans la SLA ait un impact sur l’épissage du gène SOD1 est évaluée. Finalement, la dernière section explique la contribution de nouveaux gènes candidats chez les patients atteints de SLA. Spécifiquement, le rôle des gènes OPTN, SIGMAR1 et SORT1 dans le phénotype de SLA est évalué. Il est souhaité que nos résultats combinés avec les récents développements en génétique et biologie moléculaire permettent une meilleure compréhension du mécanisme pathologique responsable de cette terrible maladie tout en guidant le déploiement de thérapies suite à l’identification des cibles appropriées., Amyotrophic lateral sclerosis (ALS) is the most common of motor neuron diseases, affecting 4-6 individuals per 100,000 individuals worldwide. ALS is characterized by muscle weakness and atrophy caused by the degeneration of neurons located in the motor cortex, brain stem and spinal cord. This fatal disease generally has an adult onset and progresses over a three to five year period. While 10% of patients affected have a family history of the disease, 90% of cases do not and are considered sporadic. The finding of mutations in the zinc/copper superoxide dismutase gene (SOD1) gene 19 years ago in about 15-20% of familial ALS (FALS) patients and approximately 2% of overall cases developed the interest of identifying rare genetics variants causing the disease. The ALS research field experienced a rapid progression during the last four years as mutations in new genes have been identified. While mutations in some of those new genes have been clearly linked to ALS, the role of others is still questionable and so far has not been positively replicated in other populations. Importantly, a significant portion of cases still need to be genetically explained and, unfortunately, there is still no effective treatment to cure, attenuate or prevent the disease. The aim of this Ph.D research project was to identify new ALS mutated genes while analysing the causative role of other newly identified genes in a large familial and sporadic ALS cohort of different origins. The results presented here are categorized into three different sections. First, the contribution of FUS mutations to familial, sporadic and juvenile ALS is analysed. Specifically, new FUS mutations are reported in ALS cases and the proportions of variants present in the tested familial and sporadic ALS cohorts are assessed. In addition, a new mutation is reported in a juvenile ALS patient, and this interesting case is discussed. Second, new genetic avenues are explored for the SOD1 gene. Precisely, a new and complex SOD1 mutation is reported in a French ALS family. Moreover, the possibility that other ALS mutated genes influence SOD1 splicing events is evaluated. Third, the contribution of new candidate genes is evaluated. Precisely, the contribution of OPTN, SIGMAR1 and SORT1 genes to the ALS phenotype is assessed. Hopefully, our different findings combined with recent developments in genetics and molecular biology will permit a better understanding of the pathological mechanisms involved in the disease and will lead to the identification of the right targets in order to develop appropriate therapeutics for ALS patients.