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Brittany N Flores, Mark E Dulchavsky, Amy Krans, Michael R Sawaya, Henry L Paulson, Peter K Todd, Sami J Barmada, Magdalena I Ivanova
Hexanucleotide repeat expansions in C9orf72 are the most common inherited cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The expansions elicit toxicity in part through repeat-associated non-AUG (RAN) translation of the intronic (GGGGCC)n sequence into dipeptide repeat-containing proteins (DPRs). Little is known, however, about the structural characteristics and aggregation propensities of the dipeptide units comprising DPRs. To address this question, we synthesized dipeptide units corresponding to the three sense-strand RAN translation products, analyzed their structures by circular dichroism, electron microscopy and dye binding assays, and assessed their relative toxicity when applied to primary cortical neurons...
2016: PloS One
Bor L Tang
Hexanucleotide repeat expansion in an intron of Chromosome 9 open reading frame 72 (C9orf72) is the most common genetic cause of Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD). While functional haploinsufficiency of C9orf72 resulting from the mutation may play a role in ALS/FTD, the actual cellular role of the protein has been unclear. Recent findings have now shown that C9orf72 physically and functionally interacts with multiple members of the Rab small GTPases family, consequently exerting important influences on cellular membrane traffic and the process of autophagy...
2016: Frontiers in Cellular Neuroscience
Yaara Cohen-Hadad, Gheona Altarescu, Talia Eldar-Geva, Ephrat Levi-Lahad, Ming Zhang, Ekaterina Rogaeva, Marc Gotkine, Osnat Bartok, Reut Ashwal-Fluss, Sebastian Kadener, Silvina Epsztejn-Litman, Rachel Eiges
We established two human embryonic stem cell (hESC) lines with a GGGGCC expansion in the C9orf72 gene (C9), and compared them with haploidentical and unrelated C9 induced pluripotent stem cells (iPSCs). We found a marked difference in C9 methylation between the cells. hESCs and parental fibroblasts are entirely unmethylated while the iPSCs are hypermethylated. In addition, we show that the expansion alters promoter usage and interferes with the proper splicing of intron 1, eventually leading to the accumulation of repeat-containing mRNA following neural differentiation...
October 17, 2016: Stem Cell Reports
J Lagarde, M Sarazin
Frontotemporal degeneration (FTD) in its behavioral variant (bvFTD) is probably one of the conditions that best illustrates the links between psychiatry and neurology. It is indeed admitted that between a third and half of patients with this condition, especially in early-onset forms, receive an initial diagnosis of psychiatric disorder (depression, schizophrenia, bipolar disorder) and are then referred to a psychiatric ward. BvFTD can thus be considered a neurological disorder with a psychiatric presentation...
October 20, 2016: L'Encéphale
Yi Lin, Eiichiro Mori, Masato Kato, Siheng Xiang, Leeju Wu, Ilmin Kwon, Steven L McKnight
Two complementary approaches were used in search of the intracellular targets of the toxic PR poly-dipeptide encoded by the repeat sequences expanded in the C9orf72 form of amyotrophic lateral sclerosis. The top categories of PRn-bound proteins include constituents of non-membrane invested cellular organelles and intermediate filaments. PRn targets are enriched for the inclusion of low complexity (LC) sequences. Evidence is presented indicating that LC sequences represent the direct target of PRn binding and that interaction between the PRn poly-dipeptide and LC domains is polymer-dependent...
October 20, 2016: Cell
Kyung-Ha Lee, Peipei Zhang, Hong Joo Kim, Diana M Mitrea, Mohona Sarkar, Brian D Freibaum, Jaclyn Cika, Maura Coughlin, James Messing, Amandine Molliex, Brian A Maxwell, Nam Chul Kim, Jamshid Temirov, Jennifer Moore, Regina-Maria Kolaitis, Timothy I Shaw, Bing Bai, Junmin Peng, Richard W Kriwacki, J Paul Taylor
Expansion of a hexanucleotide repeat GGGGCC (G4C2) in C9ORF72 is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Transcripts carrying (G4C2) expansions undergo unconventional, non-ATG-dependent translation, generating toxic dipeptide repeat (DPR) proteins thought to contribute to disease. Here, we identify the interactome of all DPRs and find that arginine-containing DPRs, polyGly-Arg (GR) and polyPro-Arg (PR), interact with RNA-binding proteins and proteins with low complexity sequence domains (LCDs) that often mediate the assembly of membrane-less organelles...
October 20, 2016: Cell
Christopher P Webster, Emma F Smith, Andrew J Grierson, Kurt J De Vos
A GGGGCC hexanucleotide repeat expansion in the first intron of the C9orf72 gene is the most common genetic defect associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) (C9ALS/FTD). Haploinsufficiency and a resulting loss of C9orf72 protein function has been suggested as a possible pathogenic mechanism in C9ALS/FTD. C9ALS/FTD patients exhibit specific ubiquitin and p62/sequestosome-1 positive but TDP-43 negative inclusions in the cerebellum and hippocampus, indicating possible autophagy deficits in these patients...
October 21, 2016: Small GTPases
Giorgio Biasiotto, Silvana Archetti, Diego Di Lorenzo, Francesca Merola, Giulia Paiardi, Barbara Borroni, Antonella Alberici, Alessandro Padovani, Massimiliano Filosto, Cristian Bonvicini, Luigi Caimi, Isabella Zanella
Although large expansions of the non-coding GGGGCC repeat in C9orf72 gene are clearly defined as pathogenic for Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Lobar Degeneration (FTLD), intermediate-length expansions have also been associated with those and other neurodegenerative diseases. Intermediate-length allele sizing is complicated by intrinsic properties of current PCR-based methodologies, in that somatic mosaicism could be suspected. We designed a protocol that allows the exact sizing of intermediate-length alleles, as well as the identification of large expansions...
October 17, 2016: Molecular and Cellular Probes
Henk-Jan Westeneng, Renée Walhout, Milou Straathof, Ruben Schmidt, Jeroen Hendrikse, Jan H Veldink, Martijn P van den Heuvel, Leonard H van den Berg
BACKGROUND: In patients with a C9orf72 repeat expansion (C9+), a neuroimaging phenotype with widespread structural cerebral changes has been found. We aimed to investigate the specificity of this neuroimaging phenotype in patients with amyotrophic lateral sclerosis (ALS). METHODS: 156 C9- and 14 C9+ patients with ALS underwent high-resolution T1-weighted MRI; a subset (n=126) underwent diffusion-weighted imaging. Cortical thickness, subcortical volumes and white matter integrity were compared between C9+ and C9- patients...
October 18, 2016: Journal of Neurology, Neurosurgery, and Psychiatry
Hemi Malkki
No abstract text is available yet for this article.
October 14, 2016: Nature Reviews. Neurology
Thomas Westergard, Brigid K Jensen, Xinmei Wen, Jingli Cai, Elizabeth Kropf, Lorraine Iacovitti, Piera Pasinelli, Davide Trotti
Aberrant hexanucleotide repeat expansions in C9orf72 are the most common genetic change underlying amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). RNA transcripts containing these expansions undergo repeat-associated non-ATG translation (RAN-T) to form five dipeptide repeat proteins (DPRs). DPRs are found as aggregates throughout the CNS of C9orf72-ALS/FTD patients, and some cause degeneration when expressed in vitro in neuronal cultures and in vivo in animal models. The spread of characteristic disease-related proteins drives the progression of pathology in many neurodegenerative diseases...
October 11, 2016: Cell Reports
Rajeeve Sivadasan, Daniel Hornburg, Carsten Drepper, Nicolas Frank, Sibylle Jablonka, Anna Hansel, Xenia Lojewski, Jared Sterneckert, Andreas Hermann, Pamela J Shaw, Paul G Ince, Matthias Mann, Felix Meissner, Michael Sendtner
Intronic hexanucleotide expansions in C9ORF72 are common in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia, but it is unknown whether loss of function, toxicity by the expanded RNA or dipeptides from non-ATG-initiated translation are responsible for the pathophysiology. We determined the interactome of C9ORF72 in motor neurons and found that C9ORF72 was present in a complex with cofilin and other actin binding proteins. Phosphorylation of cofilin was enhanced in C9ORF72-depleted motor neurons, in patient-derived lymphoblastoid cells, induced pluripotent stem cell-derived motor neurons and post-mortem brain samples from ALS patients...
October 10, 2016: Nature Neuroscience
Rodrigo Lopez-Gonzalez, Yubing Lu, Tania F Gendron, Anna Karydas, Helene Tran, Dejun Yang, Leonard Petrucelli, Bruce L Miller, Sandra Almeida, Fen-Biao Gao
GGGGCC repeat expansions in C9ORF72 are the most common genetic cause of both ALS and FTD. To uncover underlying pathogenic mechanisms, we found that DNA damage was greater, in an age-dependent manner, in motor neurons differentiated from iPSCs of multiple C9ORF72 patients than control neurons. Ectopic expression of the dipeptide repeat (DPR) protein (GR)80 in iPSC-derived control neurons increased DNA damage, suggesting poly(GR) contributes to DNA damage in aged C9ORF72 neurons. Oxidative stress was also increased in C9ORF72 neurons in an age-dependent manner...
September 20, 2016: Neuron
Julian Little, Caroline Barakat-Haddad, Rosemary Martino, Tamara Pringsheim, Helen Tremlett, Kyla A McKay, Pascal van Lieshout, Stephanie J Walsh, James Gomes, Daniel Krewski
This paper presents an overview of genetic variation associated with the onset and progression of 14 neurological disorders, focusing primarily on association studies. The 14 disorders are heterogeneous in terms of their frequency, age of onset, etiology and progression. There is substantially less evidence on progression than onset. With regard to onset, the conditions are diverse in terms of their epidemiology and patterns of familial aggregation. While the muscular dystrophies and Huntington's disease are monogenic diseases, for the other 12 conditions only a small proportion of cases is associated with specific genetic syndromes or mutations...
October 3, 2016: Neurotoxicology
Erika N Guerrero, Haibo Wang, Joy Mitra, Pavana M Hegde, Sara E Stowell, Nicole F Liachko, Brian C Kraemer, Ralph M Garruto, K S Rao, Muralidhar L Hegde
Amyotrophic lateral sclerosis (ALS), a common motor neuron disease affecting two per 100,000 people worldwide, encompasses at least five distinct pathological subtypes, including, ALS-SOD1, ALS-C9orf72, ALS-TDP-43, ALS-FUS and Guam-ALS. The etiology of a major subset of ALS involves toxicity of the TAR DNA-binding protein-43 (TDP-43). A second RNA/DNA binding protein, fused in sarcoma/translocated in liposarcoma (FUS/TLS) has been subsequently associated with about 1% of ALS patients. While mutations in TDP-43 and FUS have been linked to ALS, the key contributing molecular mechanism(s) leading to cell death are still unclear...
September 28, 2016: Progress in Neurobiology
Laura Ferraiuolo, Kathrin Meyer, Thomas W Sherwood, Jonathan Vick, Shibi Likhite, Ashley Frakes, Carlos J Miranda, Lyndsey Braun, Paul R Heath, Ricardo Pineda, Christine E Beattie, Pamela J Shaw, Candice C Askwith, Dana McTigue, Brian K Kaspar
Oligodendrocytes have recently been implicated in the pathophysiology of amyotrophic lateral sclerosis (ALS). Here we show that, in vitro, mutant superoxide dismutase 1 (SOD1) mouse oligodendrocytes induce WT motor neuron (MN) hyperexcitability and death. Moreover, we efficiently derived human oligodendrocytes from a large number of controls and patients with sporadic and familial ALS, using two different reprogramming methods. All ALS oligodendrocyte lines induced MN death through conditioned medium (CM) and in coculture...
September 29, 2016: Proceedings of the National Academy of Sciences of the United States of America
Rosanne Govaarts, Emma Beeldman, Mike J Kampelmacher, Marie-Jose van Tol, Leonard H van den Berg, Anneke J van der Kooi, Peter J Wijkstra, Marianne Zijnen-Suyker, Nicolle A M Cobben, Ben A Schmand, Rob J de Haan, Marianne de Visser, Joost Raaphorst
Thirty percent of ALS patients have a frontotemporal syndrome (FS), defined as behavioral changes or cognitive impairment. Despite previous studies, there are no firm conclusions on the effect of the FS on survival and the use of non-invasive ventilation (NIV) in ALS. We examined the effect of the FS on survival and the start and duration of NIV in ALS. Behavioral changes were defined as >22 points on the ALS-Frontotemporal-Dementia-Questionnaire or ≥3 points on ≥2 items of the Neuropsychiatric Inventory...
September 26, 2016: Journal of Neurology
Celia Kun-Rodrigues, Owen A Ross, Tatiana Orme, Claire Shepherd, Laura Parkkinen, Lee Darwent, Dena Hernandez, Olaf Ansorge, Lorraine N Clark, Lawrence S Honig, Karen Marder, Afina Lemstra, Philippe Scheltens, Wiesje van der Flier, Eva Louwersheimer, Henne Holstege, Ekaterina Rogaeva, Peter St George-Hyslop, Elisabet Londos, Henrik Zetterberg, Imelda Barber, Anne Braae, Kristelle Brown, Kevin Morgan, Walter Maetzler, Daniela Berg, Claire Troakes, Safa Al-Sarraj, Tammaryn Lashley, Janice Holton, Yaroslau Compta, Vivianna Van Deerlin, John Q Trojanowski, Geidy E Serrano, Thomas G Beach, Jordi Clarimon, Alberto Lleó, Estrella Morenas-Rodríguez, Suzanne Lesage, Douglas Galasko, Eliezer Masliah, Isabel Santana, Monica Diez, Pau Pastor, Pentti J Tienari, Liisa Myllykangas, Minna Oinas, Tamas Revesz, Andrew Lees, Brad F Boeve, Ronald C Petersen, Tanis J Ferman, Valentina Escott-Price, Neill Graff-Radford, Nigel J Cairns, John C Morris, David J Stone, Stuart Pickering-Brown, David Mann, Dennis W Dickson, Glenda M Halliday, Andrew Singleton, Rita Guerreiro, Jose Bras
C9orf72 repeat expansions are a common cause of amyotrophic lateral sclerosis and frontotemporal dementia. To date, no large-scale study of dementia with Lewy bodies (DLB) has been undertaken to assess the role of C9orf72 repeat expansions in the disease. Here, we investigated the prevalence of C9orf72 repeat expansions in a large cohort of DLB cases and identified no pathogenic repeat expansions in neuropathologically or clinically defined cases, showing that C9orf72 repeat expansions are not causally associated with DLB...
September 2, 2016: Neurobiology of Aging
James Rooney, Isabella Fogh, Henk-Jan Westeneng, Alice Vajda, Russell McLaughlin, Mark Heverin, Ashley Jones, Ruben van Eijk, Andrea Calvo, Letizia Mazzini, Christopher Shaw, Karen Morrison, Pamela J Shaw, Wim Robberecht, Phillip Van Damme, Ammar Al-Chalabi, Leonard van den Berg, Adriano Chiò, Jan Veldink, Orla Hardiman
INTRODUCTION: The C9orf72 repeat expansion has been reported as a negative prognostic factor in amyotrophic lateral sclerosis (ALS). We have examined the prognostic impact of the C9orf72 repeat expansion in European subgroups based on gender and site of onset. METHODS: C9orf72 status and demographic/clinical data from 4925 patients with ALS drawn from 3 prospective ALS registers (Ireland, Italy and the Netherlands), and clinical data sets in the UK and Belgium. Flexible parametric survival models were built including known prognostic factors (age, diagnostic delay and site of onset), gender and the presence of an expanded repeat in C9orf72...
September 23, 2016: Journal of Neurology, Neurosurgery, and Psychiatry
Annemiek Dols, Welmoed Krudop, Christiane Möller, Kenneth Shulman, Martha Sajatovic, Yolande Al Pijnenburg
OBJECTIVES: Although bipolar disorder has been understood classically as a cyclic disease with full recovery between mood episodes, in the last decade, evidence has accumulated supporting progressive features. The clinical picture of advanced or end-stage bipolar disorder is heterogeneous with possible deficits in cognition and behavior, as illustrated by our case series. CASES: From our neuropsychiatric outpatient clinic, we describe four cases with bipolar disorder gradually developing a clinical syndrome, including apathy, disinhibition, loss of empathy, stereotypical behavior, and compulsiveness, fulfilling the criteria for possible behavioral variant frontotemporal dementia...
2016: Neuropsychiatric Disease and Treatment
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