Familial Motor Neuron Disease Research Articles

Pathogenic motor neuron disease‐linked mutations distinctly alter TDP‐43 nanoscale dynamics

AbstractBackgroundThe hallmark of motor neuron disease (MND) pathology is the abnormal accumulation of insoluble proteins that form inclusions in motor neurons within the spinal cord and primary motor cortex. How, why, and when these proteins begin to aggregate has not been fully elucidated. In up to 97% of all MND cases, TAR DNA‐binding protein‐43 (TDP‐43) is a key protein that is mislocalised from its native nuclear presence into cytoplasmic inclusions. Furthermore, genetic mutations in TDP‐43 are implicated in familial MND, further linking the function of this protein to this neurodegenerative disease. The precise mechanism that drives the aggregation of TDP‐43 in MND is unknown, however identifying the changes in the dynamics of the protein within the nucleus could shed light on how the different mutations contribute to its altered function in MND.MethodWe applied nanoscale single‐molecule imaging to identify the changes in the dynamics and localisation of TDP‐43 caused by well characterised pathogenic‐causing mutation. This was done by tagging the proteins with the photoconvertible fluorescent protien ‐ mEOS3.2. Single molecule imaging was subsequently carried out in cells and neurons expressing the proteins.ResultWe observe that the different pathogenic mutations uniquely influence the mobility of TDP‐43. Most of the MND‐linked mutations inhibit the movement of TDP‐43 similar to how oxidative stressors such as arsenite induce inclusions of TDP‐43 thereby immobilising the molecules. Furthermore, our data indicates that post‐translational modifications in TDP‐43 such as acetylation similarly restricts its dynamics within the nucleus.ConclusionTogether, our data suggests that the confinement of mobility of TDP‐43 is a key step in the formation of toxic aggregates in disease.

Dual pathogenic mutations in SQSTM1 and C9orf72 as a cause of frontotemporal dementia

AbstractBackgroundHexanucleotide repeat expansions in the C9orf72 gene have been found to be the leading genetic cause of both familial frontotemporal dementia (FTD) and motor neuron disease (MND). However there are a number of other genetic causes of both FTD and MND including, less commonly, mutations in sequestosome 1 (SQSTM1) which codes for the cargo protein p62. Occasionally, people with FTD or MND have been described with dual pathogenic mutations, although this is rare.MethodWe describe the clinical and imaging features of a woman who presented with FTD and motor neurone involvement who was found to carry both a pathogenic C9orf72 expansion and a deleterious c.1185dup, p.Glu396* heterozygous SQSTM1 mutation.ResultSymptoms started at the age of 60 with change in personality and impaired behaviour followed at the age of 63 by prosopagnosia and semantic impairment. Brain magnetic resonance imaging showed right‐sided predominant temporal more than frontal lobe atrophy, and she was initially diagnosed with behavioural variant FTD. However at the age of 66 she developed asymmetrical limb weakness and stiffness, with upper motor neurone features only on examination, suggestive of primary lateral sclerosis (PLS). She deteriorated rapidly over the next couple of years, although never developed lower motor neurone features when subsequently examined. She died at the age of 69.ConclusionThe co‐presence of both a SQSTM1 mutation and C9orf72 expansion is rare. It remains unclear which mutation accounts for which of the features seen. Focal right temporal lobe atrophy is more common with SQSTM1 mutations, but PLS is uncommon with both mutations. It may be therefore that it is the dual mutations together that explain the altered phenotype. It is paramount to better understand the roles which SQSTM1 and C9orf72 mutations have on cellular pathways and how their combination results in rare phenotypes.

Endoplasmic Reticulum Stress Signalling Induces Casein Kinase 1-Dependent Formation of Cytosolic TDP-43 Inclusions in Motor Neuron-Like Cells

Motor neuron disease (MND) is a progressive neurodegenerative disease with no effective treatment. One of the principal pathological hallmarks is the deposition of TAR DNA binding protein 43 (TDP-43) in cytoplasmic inclusions. TDP-43 aggregation occurs in both familial and sporadic MND; however, the mechanism of endogenous TDP-43 aggregation in disease is incompletely understood. This study focused on the induction of cytoplasmic accumulation of endogenous TDP-43 in the motor neuronal cell line NSC-34. The endoplasmic reticulum (ER) stressor tunicamycin induced casein kinase 1 (CK1)-dependent cytoplasmic accumulation of endogenous TDP-43 in differentiated NSC-34 cells, as seen by immunocytochemistry. Immunoblotting showed that induction of ER stress had no effect on abundance of TDP-43 or phosphorylated TDP-43 in the NP-40/RIPA soluble fraction. However, there were significant increases in abundance of TDP-43 and phosphorylated TDP-43 in the NP-40/RIPA-insoluble, urea-soluble fraction, including high molecular weight species. In all cases, these increases were lowered by CK1 inhibition. Thus ER stress signalling, as induced by tunicamycin, causes CK1-dependent phosphorylation of TDP-43 and its consequent cytosolic accumulation.

092 Motor neuron disease with malignancy: clinical and pathophysiological insights

IntroductionWhile some regard an association between motor neuron disease (MND) and malignancy as co-incidental, others have argued that it could represent a distinct clinical entity. The present study undertook in depth phenotyping along with assessment of cortical function to further explore disease pathophysiology in MND with malignancy (MND-M) patients.MethodsClinical features along with assessment of peripheral and cortical function was undertaken in 13 MND-M and results were compared to sporadic and familial MND cohorts.ResultsFrom a cohort 13 patients (10 males; aged 65.2±2.0 years), 30.8% were diagnosed with a haematological malignancy. The lower motor neuron phenotype predominated in the in the MND-M patients (χ2=10.8, P<0.01), with the upper motor neuron (UMN) score being significantly reduced in MND-M patients compared to sporadic and familial MND cohorts (χ2=6.84, P<0.01). The neurological deficits did not respond to treatment of the underlying malignancy in the majority of MND-M (92%) patients, and as such there were no significant differences in survival between the cohorts. Despite a paucity of UMN signs, cortical hyperexcitability was evident in MND-M patients, as indicated by reduction in short interval intracortical inhibition (P<0.01) and increase in motor evoked potential amplitude (P<0.01), that were similar to findings in sporadic and familial MND cohorts.ConclusionsThe present study suggests that MND-M falls within the spectrum of MND. A co-incidental association between MND and malignancy is underscored by cortical dysfunction and clinical findings which seems within the spectrum of abnormality evident in classical MND phenotypes.

Motor neuron disease with malignancy: Clinical and pathophysiological insights

ObjectiveWhile some regard an association between motor neuron disease (MND) and malignancy as co-incidental, others have argued that it could represent a distinct clinical entity. The present study undertook in depth phenotyping along with assessment of cortical function to further explore disease pathophysiology in MND with malignancy (MND-M) patients. MethodsClinical features along with assessment of peripheral and cortical function was undertaken in 13 MND-M and results were compared to sporadic and familial MND cohorts. ResultsFrom a cohort 13 patients (10 males; aged 65.2 ± 2.0 years), 38.5% were diagnosed with a haematological malignancy. The lower motor neuron phenotype predominated in the in the MND-M patients (χ2 = 10.8, P < 0.01), with the upper motor neuron (UMN) score being significantly reduced in MND-M patients compared to sporadic and familial MND cohorts (χ2 = 6.84, P < 0.01). The neurological deficits did not respond to treatment of the underlying malignancy in the majority of MND-M (92%) patients, and as such there were no significant differences in survival between the cohorts. Despite a paucity of UMN signs, cortical hyperexcitability was evident in MND-M patients, as indicated by reduction in short interval intracortical inhibition (P < 0.01) and increase in motor evoked potential amplitude (P < 0.01), that were similar to findings in sporadic and familial MND cohorts. ConclusionsThe present study suggests that MND-M falls within the spectrum of MND. SignificanceThe concept of a co-incidental association between MND and malignancy is supported through the present study by the presence of cortical dysfunction, combined with clinical findings that can be explained within the spectrum of abnormality evident in classical MND phenotypes.

Intrafamilial Phenotypic Variability in the C9orf72 Gene Expansion: 2 Case Studies.

The C9orf72 genetic mutation is the most common cause of familial frontotemporal dementia (FTD) and motor neuron disease (MND). Previous family studies suggest that while some common clinical features may distinguish gene carriers from sporadic patients, the clinical features, age of onset and disease progression vary considerably in affected patients. Whilst disease presentations may vary across families, age at disease onset appears to be relatively uniform within each family. Here, we report two individuals with a C9orf72 repeat expansion from two generations of the same family with markedly different age at disease onset, clinical presentation and disease progression: one who developed motor neuron and behavioural symptoms in their mid 40s and died 3 years later with confirmed TDP-43 pathology and MND; and a second who developed cognitive and mild behavioural symptoms in their mid 70s and 8 years later remains alive with only slow deterioration. This report highlights the phenotypic variability, including age of onset, within a family with the C9orf72 repeat expansion.

New Phenotypic and Genotype SOD1 Mutation in Dominant Familial Motor Neuron Disease: A Case Report of a Family

New Phenotypic and Genotype SOD1 Mutation in Dominant Familial Motor Neuron Disease: A Case Report of a Family

Novel UBQLN2 mutations linked to amyotrophic lateral sclerosis and atypical hereditary spastic paraplegia phenotype through defective HSP70-mediated proteolysis

Mutations in UBQLN2 have been associated with rare cases of X-linked juvenile and adult forms of amyotrophic lateral sclerosis (ALS) and ALS linked to frontotemporal dementia (FTD). Here, we report 1 known (c.1489C>T, p.Pro497Ser, P497S) and 3 novel (c.1481C>T, p.Pro494Leu, P494L; c.1498C>T, p.Pro500Ser, P500S; and c.1516C>G, p.Pro506Ala, P506A) missense mutations in the PXX domain of UBQLN2 in familial motor neuron diseases including ALS and spastic paraplegia (SP). A novel missense mutation (c.1462G>A, p.Ala488Thr, A488T) adjacent to this hotspot UBQLN2 domain was identified in a sporadic case of ALS. These mutations are conserved in mammals, are absent from ExAC and gnomAD browsers, and are predicted to be deleterious by SIFT in silico analysis. Patient lymphoblasts carrying a UBQLN2 mutation showed absence of ubiquilin-2 accumulation, disrupted binding with HSP70, and impaired autophagic pathway. Our results confirm the role of PXX repeat in ALS pathogenesis, show that UBQLN2-linked disease can manifest like a SP phenotype, evidence a highly reduced disease penetrance in females carrying UBQLN2 mutations, which is important information for genetic counseling, and underline the pivotal role of ubiquilin-2 in proteolysis regulation pathways.

Loss of Ranbp2 in motoneurons causes disruption of nucleocytoplasmic and chemokine signaling, proteostasis of hnRNPH3 and Mmp28, and development of amyotrophic lateral sclerosis-like syndromes.

ABSTRACTThe pathogenic drivers of sporadic and familial motor neuron disease (MND), such amyotrophic lateral sclerosis (ALS), are unknown. MND impairs the Ran GTPase cycle, which controls nucleocytoplasmic transport, ribostasis and proteostasis; however, cause-effect mechanisms of Ran GTPase modulators in motoneuron pathobiology have remained elusive. The cytosolic and peripheral nucleoporin Ranbp2 is a crucial regulator of the Ran GTPase cycle and of the proteostasis of neurological disease-prone substrates, but the roles of Ranbp2 in motoneuron biology and disease remain unknown. This study shows that conditional ablation of Ranbp2 in mouse Thy1 motoneurons causes ALS syndromes with hypoactivity followed by hindlimb paralysis, respiratory distress and, ultimately, death. These phenotypes are accompanied by: a decline in the nerve conduction velocity, free fatty acids and phophatidylcholine of the sciatic nerve; a reduction in the g-ratios of sciatic and phrenic nerves; and hypertrophy of motoneurons. Furthermore, Ranbp2 loss disrupts the nucleocytoplasmic partitioning of the import and export nuclear receptors importin β and exportin 1, respectively, Ran GTPase and histone deacetylase 4. Whole-transcriptome, proteomic and cellular analyses uncovered that the chemokine receptor Cxcr4, its antagonizing ligands Cxcl12 and Cxcl14, and effector, latent and activated Stat3 all undergo early autocrine and proteostatic deregulation, and intracellular sequestration and aggregation as a result of Ranbp2 loss in motoneurons. These effects were accompanied by paracrine and autocrine neuroglial deregulation of hnRNPH3 proteostasis in sciatic nerve and motoneurons, respectively, and post-transcriptional downregulation of metalloproteinase 28 in the sciatic nerve. Mechanistically, our results demonstrate that Ranbp2 controls nucleocytoplasmic, chemokine and metalloproteinase 28 signaling, and proteostasis of substrates that are crucial to motoneuronal homeostasis and whose impairments by loss of Ranbp2 drive ALS-like syndromes.

DCTN1 p.K56R in progressive supranuclear palsy

IntroductionMutations in dynactin DCTN1 (p150glued) have previously been linked to familial motor neuron disease or Perry syndrome (PS) consisting of depression, parkinsonism and hypoventilation. MethodsWe sequenced DCTN1 in 636 Caucasian patients with parkinsonism (Parkinson's disease and Parkinson-plus syndromes) and 508 healthy controls. Variants (MAF < 0.01) were subsequently genotyped in Caucasian (1360 cases and 1009 controls) and Asian cohorts (1046 cases and 830 controls), and the functional implications of pathogenic variants were assessed. ResultsWe identified 17 rare variants leading to non-synonymous amino-acid substitutions. Four of the variants were only observed in control subjects, four in both cases and controls and the remaining nine in cases only. One of the variants, DCTN1 p.K56R, was present in two patients with progressive supranuclear palsy (PSP) with a shared minimal 2.2 Mb haplotype. Both subjects have parkinsonism as the most prominent symptom with abnormal ocular movements, moderate cognitive impairment and little to no l-dopa response. Neither subject presents with depression, central hypoventilation or weight loss. For one of the subjects MRI shows symmetrical atrophy of temporal and frontoparietal lobes. In HEK293 cells mutant p150glued (p.K56R) shows less affinity for microtubules than wild-type, with a more diffuse cytoplasmic distribution. ConclusionsWe have identified DCTN1 p.K56R in patients with PSP. This variant is immediately adjacent to the N-terminal p150glued ‘CAP-Gly’ domain, affects a highly conserved amino acid and alters the protein's affinity to microtubules and its cytoplasmic distribution.

The perplexing conundrum of frontotemporal dementia

This is the type of book that seems unimaginable to contemplate writing these days: a comprehensive monograph covering all aspects of a complex disorder. It is the work of a master researcher at the peak of his career and reflects 25 years of dedication to understanding frontotemporal dementia (FTD). Over the past 15 years, the group of outstanding researchers led by Bruce Miller at UCSF has contributed more to our understanding of this disorder than any other group in the world. The book is a fitting summary of these contributions but gives appropriate acknowledgement to the others around the world who have also contributed to the field. It is certainly timely, given the discovery in 2011 of the C9orf72 gene expansion which accounts for a sizeable proportion of familial FTD and motor neuron disease. The discovery links, at a genetic level, the growing overlap between these two apparently disparate disorders. After an excellent historical introduction, the book is divided into chapters dealing with each of the main clinical presentations of FTD, followed by overviews of the related disorders, namely FTD with amyotrophic lateral sclerosis (motor neuron disease, MND), corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP). There follows a primer on FTD pathology and a section on genetics. One of the most interesting chapters deals with reflections on psychology and philosophy, and finally there is an overview of management and treatment options. It is beautifully illustrated and written with the type of clarity and integration that can only come from a single author book. Bruce’s ability to synthesize genetics, cell biology, neuropathology, neuroimaging and psychology is inspiring. I can think of no better place to start for someone embarking on a research career in FTD or indeed clinicians encountering these patients who want …

Brain distribution of dipeptide repeat proteins in frontotemporal lobar degeneration and motor neurone disease associated with expansions in C9ORF72.

A hexanucleotide (GGGGCC) expansion in C9ORF72 gene is the most common genetic change seen in familial Frontotemporal Lobar Degeneration (FTLD) and familial Motor Neurone Disease (MND). Pathologically, expansion bearers show characteristic p62 positive, TDP-43 negative inclusion bodies within cerebellar and hippocampal neurons which also contain dipeptide repeat proteins (DPR) formed from sense and antisense RAN (repeat associated non ATG-initiated) translation of the expanded repeat region itself. ‘Inappropriate’ formation, and aggregation, of DPR might therefore confer neurotoxicity and influence clinical phenotype. Consequently, we compared the topographic brain distribution of DPR in 8 patients with Frontotemporal dementia (FTD), 6 with FTD + MND and 7 with MND alone (all 21 patients bearing expansions in C9ORF72) using a polyclonal antibody to poly-GA, and related this to the extent of TDP-43 pathology in key regions of cerebral cortex and hippocampus. There were no significant differences in either the pattern or severity of brain distribution of DPR between FTD, FTD + MND and MND groups, nor was there any relationship between the distribution of DPR and TDP-43 pathologies in expansion bearers. Likewise, there were no significant differences in the extent of TDP-43 pathology between FTLD patients bearing an expansion in C9ORF72 and non-bearers of the expansion. There were no association between the extent of DPR pathology and TMEM106B or APOE genotypes. However, there was a negative correlation between the extent of DPR pathology and age at onset. Present findings therefore suggest that although the presence and topographic distribution of DPR may be of diagnostic relevance in patients bearing expansion in C9ORF72 this has no bearing on the determination of clinical phenotype. Because TDP-43 pathologies are similar in bearers and non-bearers of the expansion, the expansion may act as a major genetic risk factor for FTLD and MND by rendering the brain highly vulnerable to those very same factors which generate FTLD and MND in sporadic disease.Electronic supplementary materialThe online version of this article (doi:10.1186/2051-5960-2-70) contains supplementary material, which is available to authorized users.

C9ORF72 familial motor neuron disease − frontotemporal dementia associated with lung adenocarcinoma and anti‐Ma2/Ta antibodies: a chance association?

European Journal of NeurologyVolume 21, Issue 4 p. e31-e33 Letter to the Editor C9ORF72 familial motor neuron disease − frontotemporal dementia associated with lung adenocarcinoma and anti-Ma2/Ta antibodies: a chance association? N. Geevasinga, N. Geevasinga Western Clinical School, University of Sydney, Westmead, Sydney, NSW, Australia Department of Neurology and Neurophysiology, Royal North Shore Hospital and University of Sydney, Sydney, NSW, AustraliaSearch for more papers by this authorJ. R. Burrell, J. R. Burrell Neuroscience Research Australia and University of New South Wales, Randwick, NSW, AustraliaSearch for more papers by this authorM. Hibbert, M. Hibbert Department of Respiratory Medicine, Royal North Shore Hospital and University of Sydney, Sydney, NSW, AustraliaSearch for more papers by this authorS. Vucic, S. Vucic Western Clinical School, University of Sydney, Westmead, Sydney, NSW, AustraliaSearch for more papers by this authorK. Ng, Corresponding Author K. Ng Department of Neurology and Neurophysiology, Royal North Shore Hospital and University of Sydney, Sydney, NSW, AustraliaCorrespondence: Dr Karl Ng, Department of Neurology, Royal North Shore Hospital, St Leonards, NSW 2065, Australia (tel.: +61 2 94631833; fax: +61 2 94631058; e-mail: Karl.Ng@health.nsw.gov.au).Search for more papers by this author N. Geevasinga, N. Geevasinga Western Clinical School, University of Sydney, Westmead, Sydney, NSW, Australia Department of Neurology and Neurophysiology, Royal North Shore Hospital and University of Sydney, Sydney, NSW, AustraliaSearch for more papers by this authorJ. R. Burrell, J. R. Burrell Neuroscience Research Australia and University of New South Wales, Randwick, NSW, AustraliaSearch for more papers by this authorM. Hibbert, M. Hibbert Department of Respiratory Medicine, Royal North Shore Hospital and University of Sydney, Sydney, NSW, AustraliaSearch for more papers by this authorS. Vucic, S. Vucic Western Clinical School, University of Sydney, Westmead, Sydney, NSW, AustraliaSearch for more papers by this authorK. Ng, Corresponding Author K. Ng Department of Neurology and Neurophysiology, Royal North Shore Hospital and University of Sydney, Sydney, NSW, AustraliaCorrespondence: Dr Karl Ng, Department of Neurology, Royal North Shore Hospital, St Leonards, NSW 2065, Australia (tel.: +61 2 94631833; fax: +61 2 94631058; e-mail: Karl.Ng@health.nsw.gov.au).Search for more papers by this author First published: 13 March 2014 https://doi.org/10.1111/ene.12347Citations: 5Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume21, Issue4April 2014Pages e31-e33 RelatedInformation

A Novel DCTN1 mutation with late‐onset parkinsonism and frontotemporal atrophy

Depression, parkinsonism, and hypoventilation (Perry syndrome) or familial motor neuron disease have been linked to mutations in dynactin P150(Glued) (DCTN1). We employed genealogic, clinical, neurologic, and MRI investigations, as well as analysis of genes implicated in parkinsonism. Cellular transfection, immunocytochemistry, and immunoprecipitation analysis of wild-type (WT) and mutant DCTN1 were also performed. A novel heterozygous mutation, DCTN1 c.156T>G, encoding p.Phe52Leu, segregates with parkinsonism in a Japanese family. The substitution was not observed in affected probands with familial parkinsonism or control subjects and is evolutionarily conserved. In contrast to Perry syndrome, affected carriers have late-onset disease and slower progression, with frontotemporal atrophy revealed by MRI. In vitro studies suggest the mutant protein has impaired microtubule binding, compared to WT dynactin p150(Glued) . DCTN1 mutations may contribute to disparate neurodegenerative diagnoses, including familial motor neuron disease, parkinsonism, and frontotemporal atrophy, and further studies of dynactin-mediated cargo transport may prove insightful.

Accumulation of the sigma‐1 receptor is common to neuronal nuclear inclusions in various neurodegenerative diseases

The sigma-1 receptor (SIGMAR1) is now known to be one of the endoplasmic reticulum (ER) chaperones, which participate in the degradation of misfolded proteins in cells via the ER-related degradation machinery linked to the ubiquitin-proteasome pathway. Mutations of the SIGMAR1 gene are implicated in the pathogenesis of familial frontotemporal lobar degeneration and motor neuron disease. Involvement of ER dysfunction in the formation of inclusion bodies in various neurodegenerative diseases has also become evident. We performed immunohistochemical staining to clarify the localization of SIGMAR1 in the brains of patients with neurodegenerative disorders, including trans-activation response DNA protein 43 (TDP-43) proteinopathy, tauopathy, α-synucleinopathy, polyglutamine disease and intranuclear inclusion body disease (INIBD). Double-immunocytofluorescence and Western blot analyses of cultured cells were also performed to investigate the role of SIGMAR1 using a specific exportin 1 inhibitor, leptomycin B and an ER stress inducer, thapsigargin. SIGMAR1 was consistently shown to be co-localized with neuronal nuclear inclusions in TDP-43 proteinopathy, five polyglutamine diseases and INIBD, as well as in intranuclear Marinesco bodies in aged normal controls. Cytoplasmic inclusions in neurons and glial cells were unreactive for SIGMAR1. In cultured cells, immunocytofluorescent study showed that leptomycin B and thapsigargin were shown to sequester SIGMAR1 within the nucleus, acting together with p62. This finding was also supported by immunoblot analysis. These results indicate that SIGMAR1 might shuttle between the nucleus and the cytoplasm. Neurodegenerative diseases characterized by neuronal nuclear inclusions might utilize the ER-related degradation machinery as a common pathway for the degradation of aberrant proteins.

An unusual autopsy case of progressive muscular atrophy with widespread fus positive inclusions

Progressive muscular atrophy (PMA) is the lower motor neuron-predominant form of motor neuron disease (MND). MND is a relatively common, progressive fatal neurodegenerative disease, the pathogenetic basis of which is not fully understood. Recent genetic studies have identified mutations in the Fused in sarcoma/ translated in liposarcoma (FUS/TLS) gene at chromosome 16 in approximately 3% of familial MND and less than 1% of sporadic patients. The mutation usually leads to an earlier onset and more aggressive phenotype of MND. In this case study we describe the autopsy neuropathology of a late-onset and seemingly sporadic case of PMA. The pathology was dominated by loss of lower motor neurons and widespread FUS positive cytoplasmic inclusions. These inclusions were negative for TDP-43, distinguishing them from typical sporadic MND cases. FUS positive cytoplasmic inclusions were also found in other regions, in both neurons and glia. They were present in brainstem nuclei, cerebellum and deep grey structures but were absent from hippocampus and neocortical areas. This unique case broadens the phenotypic and neuropatho-logical spectrum of FUS-related neurodegenerative conditions and may provide additional insights into the role of FUS in both sporadic and familial MND.

Frontotemporal dementia with the C9ORF72 hexanucleotide repeat expansion: clinical, neuroanatomical and neuropathological features.

An expanded hexanucleotide repeat in the C9ORF72 gene has recently been identified as a major cause of familial frontotemporal lobar degeneration and motor neuron disease, including cases previously identified as linked to chromosome 9. Here we present a detailed retrospective clinical, neuroimaging and histopathological analysis of a C9ORF72 mutation case series in relation to other forms of genetically determined frontotemporal lobar degeneration ascertained at a specialist centre. Eighteen probands (19 cases in total) were identified, representing 35% of frontotemporal lobar degeneration cases with identified mutations, 36% of cases with clinical evidence of motor neuron disease and 7% of the entire cohort. Thirty-three per cent of these C9ORF72 cases had no identified relevant family history. Families showed wide variation in clinical onset (43–68 years) and duration (1.7–22 years). The most common presenting syndrome (comprising a half of cases) was behavioural variant frontotemporal dementia, however, there was substantial clinical heterogeneity across the C9ORF72 mutation cohort. Sixty per cent of cases developed clinical features consistent with motor neuron disease during the period of follow-up. Anxiety and agitation and memory impairment were prominent features (between a half to two-thirds of cases), and dominant parietal dysfunction was also frequent. Affected individuals showed variable magnetic resonance imaging findings; however, relative to healthy controls, the group as a whole showed extensive thinning of frontal, temporal and parietal cortices, subcortical grey matter atrophy including thalamus and cerebellum and involvement of long intrahemispheric, commissural and corticospinal tracts. The neuroimaging profile of the C9ORF72 expansion was significantly more symmetrical than progranulin mutations with significantly less temporal lobe involvement than microtubule-associated protein tau mutations. Neuropathological examination in six cases with C9ORF72 mutation from the frontotemporal lobar degeneration series identified histomorphological features consistent with either type A or B TAR DNA-binding protein-43 deposition; however, p62-positive (in excess of TAR DNA-binding protein-43 positive) neuronal cytoplasmic inclusions in hippocampus and cerebellum were a consistent feature of these cases, in contrast to the similar frequency of p62 and TAR DNA-binding protein-43 deposition in 53 control cases with frontotemporal lobar degeneration–TAR DNA-binding protein. These findings corroborate the clinical importance of the C9ORF72 mutation in frontotemporal lobar degeneration, delineate phenotypic and neuropathological features that could help to guide genetic testing, and suggest hypotheses for elucidating the neurobiology of a culprit subcortical network.

A Trypanosoma brucei Protein Required for Maintenance of the Flagellum Attachment Zone and Flagellar Pocket ER Domains

Trypanosomes and Leishmanias are important human parasites whose cellular architecture is centred on the single flagellum. In trypanosomes, this flagellum is attached to the cell along a complex flagellum attachment zone (FAZ), comprising flagellar and cytoplasmic components, the integrity of which is required for correct cell morphogenesis and division. The cytoplasmic FAZ cytoskeleton is conspicuously associated with a sheet of endoplasmic reticulum termed the ‘FAZ ER’. In the present work, 3D electron tomography of bloodstream form trypanosomes was used to clarify the nature of the FAZ ER. We also identified TbVAP, a T. brucei protein whose knockdown by RNAi in procyclic form cells leads to a dramatic reduction in the FAZ ER, and in the ER associated with the flagellar pocket. TbVAP is an orthologue of VAMP-associated proteins (VAPs), integral ER membrane proteins whose mutation in humans has been linked to familial motor neuron disease. The localisation of tagged TbVAP and the phenotype of TbVAP RNAi in procyclic form trypanosomes are consistent with a function for TbVAP in the maintenance of sub-populations of the ER associated with the FAZ and the flagellar pocket. Nevertheless, depletion of TbVAP did not affect cell viability or cell cycle progression.

TDP-43 proteinopathy in familial motor neurone disease with TARDBP A315T mutation: a case report

Neuropathology and Applied NeurobiologyVolume 36, Issue 7 p. 673-679 TDP-43 proteinopathy in familial motor neurone disease with TARDBP A315T mutation: a case report N. J. Cairns, N. J. Cairns Charles F and Joanne Knight Alzheimer's Disease Research Center Department of Neurology Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorR. J. Perrin, R. J. Perrin Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorR. E. Schmidt, R. E. Schmidt Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorA. Gru, A. Gru Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorK. G. Green, K. G. Green Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorD. Carter, D. Carter Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorL. Taylor-Reinwald, L. Taylor-Reinwald Charles F and Joanne Knight Alzheimer's Disease Research Center Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorJ. C. Morris, J. C. Morris Charles F and Joanne Knight Alzheimer's Disease Research Center Department of Neurology Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorM. A. Gitcho, M. A. Gitcho Charles F and Joanne Knight Alzheimer's Disease Research Center Department of NeurologySearch for more papers by this authorR. H. Baloh, R. H. Baloh Department of NeurologySearch for more papers by this author N. J. Cairns, N. J. Cairns Charles F and Joanne Knight Alzheimer's Disease Research Center Department of Neurology Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorR. J. Perrin, R. J. Perrin Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorR. E. Schmidt, R. E. Schmidt Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorA. Gru, A. Gru Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorK. G. Green, K. G. Green Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorD. Carter, D. Carter Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorL. Taylor-Reinwald, L. Taylor-Reinwald Charles F and Joanne Knight Alzheimer's Disease Research Center Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorJ. C. Morris, J. C. Morris Charles F and Joanne Knight Alzheimer's Disease Research Center Department of Neurology Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USASearch for more papers by this authorM. A. Gitcho, M. A. Gitcho Charles F and Joanne Knight Alzheimer's Disease Research Center Department of NeurologySearch for more papers by this authorR. H. Baloh, R. H. Baloh Department of NeurologySearch for more papers by this author First published: 31 August 2010 https://doi.org/10.1111/j.1365-2990.2010.01121.xCitations: 14 Disclosure: The authors report no conflicts of interest. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume36, Issue7December 2010Pages 673-679 RelatedInformation

Integrative gene–tissue microarray-based approach for identification of human disease biomarkers: application to amyotrophic lateral sclerosis

Advances in genomics and proteomics permit rapid identification of disease-relevant genes and proteins. Challenges include biological differences between animal models and human diseases, high discordance between DNA and protein expression data and a lack of experimental models to study human complex diseases. To overcome some of these limitations, we developed an integrative approach using animal models, postmortem human material and a combination of high-throughput microarray methods to identify novel molecular markers of amyotrophic lateral sclerosis (ALS). We used laser capture microdissection coupled with microarrays to identify early transcriptome changes occurring in spinal cord motor neurons or surrounding glial cells. Two models of familial motor neuron disease, SOD1(G93A) and TAU(P301L), transgenic mice were used at the presymptomatic stage. Identified gene expression changes were predominantly model-specific. However, several genes were regulated in both models. The relevance of identified genes as clinical biomarkers was tested in the peripheral blood transcriptome of presymptomatic SOD1(G93A) animals using custom-designed ALS microarray. To confirm the relevance of identified genes in human sporadic ALS (SALS), selected corresponding protein products were examined by high-throughput immunoassays using tissue microarrays constructed from human postmortem spinal cord tissues. Genes that were identified by these experiments and located within a linkage region associated with familial ALS/frontotemporal dementia were sequenced in several families. This large-scale gene and protein expression study pointing to distinct molecular mechanisms of TAU- and SOD1-induced motor neuron degeneration identified several new SALS-relevant proteins (CNGA3, CRB1, OTUB2, MMP14, SLK, DDX58, RSPO2) and putative blood biomarkers, including Nefh, Prph and Mgll.