A C9orf72 promoter repeat expansion in a Flanders-Belgian cohort with disorders of the frontotemporal lobar degeneration-amyotrophic lateral sclerosis spectrum: a gene identification study

Abstract Background Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease. Pathologically, it is characterized by eosinophilic hyaline intranuclear inclusions in the cells of the visceral organs as well as central, peripheral, and autonomic nervous system cells. Recently, a GGC repeat expansion in the NOTCH2NLC gene has been identified as the etiopathological agent of NIID. Interestingly, this GGC repeat expansion was also reported in some patients with a clinical diagnosis of amyotrophic lateral sclerosis (ALS). However, there are no autopsy-confirmed cases of concurrent NIID and ALS. Case presentation A 60-year-old Taiwanese woman reported a four-month history of progressive weakness beginning in the right foot that spread to all four extremities. She was diagnosed with ALS because she met the revised El Escorial diagnostic criteria for definite ALS with upper and lower motor neuron involvement in the cervical, thoracic, and lumbosacral regions. She died of respiratory failure at 22 months from ALS onset, at the age of 62 years. Brain magnetic resonance imaging (MRI) revealed lesions in the medial part of the cerebellar hemisphere, right beside the vermis (paravermal lesions). The subclinical neuropathy, indicated by a nerve conduction study (NCS), prompted a potential diagnosis of NIID. Antemortem skin biopsy and autopsy confirmed the coexistence of pathology consistent with both ALS and NIID. We observed neither eccentric distribution of p62-positive intranuclear inclusions in the areas with abundant large motor neurons nor cytopathological coexistence of ALS and NIID pathology in motor neurons. This finding suggested that ALS and NIID developed independently in this patient. Conclusions We describe a case of concurrent NIID and ALS discovered during an autopsy. Abnormal brain MRI findings, including paravermal lesions, could indicate the coexistence of NIID even in patients with ALS showing characteristic clinical phenotypes.

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Brain white matter demyelinating lesions and amyotrophic lateral sclerosis in a patient with C9orf72 hexanucleotide repeat expansion

Multiple Sclerosis and Related Disorders ◽

10.1016/j.msard.2017.06.010 ◽

2017 ◽

Vol 17 ◽

pp. 1-4 ◽

Cited By ~ 1

Author(s):

Miguel Oliveira Santos ◽

Inês Caldeira ◽

Marta Gromicho ◽

Ana Pronto-Laborinho ◽

Mamede de Carvalho

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

White Matter ◽

Repeat Expansion ◽

Hexanucleotide Repeat ◽

Brain White Matter ◽

Demyelinating Lesions ◽

Hexanucleotide Repeat Expansion ◽

Lateral Sclerosis

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O4-06-02: TDP-43 and beta-amyloid precursor protein processing products in cerebrospinal fluid of patients with amyotrophic lateral sclerosis and frontotemporal lobar degeneration

Alzheimer s & Dementia ◽

10.1016/j.jalz.2009.05.559 ◽

2009 ◽

Vol 5 (4S_Part_6) ◽

pp. P162-P162

Author(s):

Markus Otto ◽

Corinna Hendrich ◽

Anne Dorte Sperfeld ◽

Sarah Jesse ◽

Christine V. Arnim ◽

...

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Cerebrospinal Fluid ◽

Amyloid Precursor Protein ◽

Frontotemporal Lobar Degeneration ◽

Beta Amyloid ◽

Protein Processing ◽

Precursor Protein ◽

Amyloid Precursor Protein Processing ◽

Lateral Sclerosis

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The Emerging Role of DNA Damage in the Pathogenesis of the C9orf72 Repeat Expansion in Amyotrophic Lateral Sclerosis

International Journal of Molecular Sciences ◽

10.3390/ijms19103137 ◽

2018 ◽

Vol 19 (10) ◽

pp. 3137 ◽

Cited By ~ 12

Author(s):

Anna Konopka ◽

Julie Atkin

Keyword(s):

Dna Damage ◽

Amyotrophic Lateral Sclerosis ◽

Motor Neurons ◽

Repeat Expansion ◽

Chromosome 9 ◽

Gene Encoding ◽

C9orf72 Repeat Expansion ◽

Reading Frame ◽

Early Onset Dementia ◽

Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal, rapidly progressing neurodegenerative disease affecting motor neurons, and frontotemporal dementia (FTD) is a behavioural disorder resulting in early-onset dementia. Hexanucleotide (G4C2) repeat expansions in the gene encoding chromosome 9 open reading frame 72 (C9orf72) are the major cause of familial forms of both ALS (~40%) and FTD (~20%) worldwide. The C9orf72 repeat expansion is known to form abnormal nuclei acid structures, such as hairpins, G-quadruplexes, and R-loops, which are increasingly associated with human diseases involving microsatellite repeats. These configurations form during normal cellular processes, but if they persist they also damage DNA, and hence are a serious threat to genome integrity. It is unclear how the repeat expansion in C9orf72 causes ALS, but recent evidence implicates DNA damage in neurodegeneration. This may arise from abnormal nucleic acid structures, the greatly expanded C9orf72 RNA, or by repeat-associated non-ATG (RAN) translation, which generates toxic dipeptide repeat proteins. In this review, we detail recent advances implicating DNA damage in C9orf72-ALS. Furthermore, we also discuss increasing evidence that targeting these aberrant C9orf72 confirmations may have therapeutic value for ALS, thus revealing new avenues for drug discovery for this disorder.

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Possible concurrence of TDP-43, tau and other proteins in amyotrophic lateral sclerosis/frontotemporal lobar degeneration

Neuropathology ◽

10.1111/neup.12428 ◽

2017 ◽

Vol 38 (1) ◽

pp. 72-81 ◽

Cited By ~ 13

Author(s):

Takahiro Takeda

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Frontotemporal Lobar Degeneration ◽

Lateral Sclerosis

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The nuclear ubiquitin ligase adaptor SPOP is a conserved regulator of C9orf72 dipeptide toxicity

10.1101/2021.03.09.434618 ◽

2021 ◽

Author(s):

Carley Snoznik ◽

Valentina Medvedeva ◽

Jelena Mojsilovic-Petrovic ◽

Paige Rudich ◽

James Oosten ◽

...

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Nuclear Localization ◽

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

Repeat Expansion ◽

Dipeptide Repeat Proteins ◽

C Elegans ◽

Repeat Proteins ◽

Lateral Sclerosis ◽

Dipeptide Repeat

AbstractA hexanucleotide repeat expansion in the C9orf72 gene is the most common cause of inherited amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Unconventional translation of the C9orf72 repeat produces dipeptide repeat proteins (DPRs). Previously, we showed that the DPRs (PR)50 and (GR)50 are highly toxic when expressed in C. elegans and this toxicity depends on nuclear localization of the DPR. In an unbiased genome-wide RNAi screen for suppressors of (PR)50 toxicity, we identified 12 genes that consistently suppressed either the developmental arrest and/or paralysis phenotype evoked by (PR)50 expression. All of these genes have vertebrate homologs and 7/12 contain predicted nuclear localization signals. One of these genes was spop-1, the C. elegans homolog of SPOP, a nuclear localized E3 ubiquitin ligase adaptor only found in metazoans. SPOP is also required for (GR)50 toxicity and functions in a genetic pathway that includes cul-3, which is the canonical E3 ligase partner for SPOP. Genetic or pharmacological inhibition of SPOP in mammalian primary spinal cord motor neurons suppressed DPR toxicity without affecting DPR expression levels. Finally, we find that genetic inhibition of bet-1, the C. elegans homolog of the known SPOP ubiquitination targets BRD2/3/4, suppresses the protective effect of SPOP mutations. Together, these data suggest a model in which SPOP promotes the DPR-dependent ubiquitination and degradation of BRD proteins. We speculate the pharmacological manipulation of this pathway, which is currently underway for multiple cancer subtypes, could also represent a novel entry point for therapeutic intervention to treat C9 FTD/ALS.Significance statementThe G4C2 repeat expansion in the C9orf72 gene is a major cause of Fronto-Temporal Dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS). Unusual translation of the repeat sequence produces two highly toxic dipeptide repeat proteins, PRX and GRX, which accumulate in the brain tissue of individuals with these diseases. Here, we show that PR and GR toxicity in both C. elegans and mammalian neurons depends on the E3 ubiquitin ligase adaptor SPOP. SPOP acts through the bromodomain protein BET-1 to mediate dipeptide toxicity. SPOP inhibitors, which are currently being developed to treat SPOP-dependent renal cancer, also protect neurons against DPR toxicity. Our findings identify a highly conserved and ‘druggable’ pathway that may represent a new strategy for treating these currently incurable diseases.

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