Publications by authors named "Audrey M G Ragagnin"

Hexanucleotide repeat expansions (HREs) in the chromosome 9 open reading frame 72 (C9orf72) gene are the most frequent genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Both are debilitating neurodegenerative conditions affecting either motor neurons (ALS) in the brain and spinal cord or neurons in the frontal and/or temporal cortical lobes (FTD). HREs undergo repeat-associated non-ATG (RAN) translation on both sense and anti-sense strands, generating five distinct dipeptide repeat proteins (DPRs), poly-GA, -GR, -GP, -PA and -PR.

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Amyotrophic lateral sclerosis (ALS) is a severely debilitating neurodegenerative condition that is part of the same disease spectrum as frontotemporal dementia (FTD). Mutations in the CCNF gene, encoding cyclin F, are present in both sporadic and familial ALS and FTD. However, the pathophysiological mechanisms underlying neurodegeneration remain unclear.

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Background: Pathological forms of TAR DNA-binding protein 43 (TDP-43) are present in motor neurons of almost all amyotrophic lateral sclerosis (ALS) patients, and mutations in TDP-43 are also present in ALS. Loss and gain of TDP-43 functions are implicated in pathogenesis, but the mechanisms are unclear. While the RNA functions of TDP-43 have been widely investigated, its DNA binding roles remain unclear.

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Article Synopsis
  • Pathological forms of TDP-43 are found in nearly all ALS cases, with 20% of familial ALS linked to SOD1 mutations.
  • The study shows that the redox function of protein disulfide isomerase (PDI) protects against various ALS-related issues such as protein misfolding and cell stress.
  • Mutations in PDI that lack redox activity do not provide protection against ALS symptoms, suggesting that therapies enhancing PDI's redox function could be promising for treating the disease.
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Frontotemporal dementia and amyotrophic lateral sclerosis are clinically and pathologically overlapping disorders with shared genetic causes. We previously identified a disease locus on chromosome 16p12.1-q12.

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Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are fatal neurodegenerative diseases that are related genetically and pathologically. Mutations in the UBQLN2 gene, encoding the ubiquitin-like protein ubiquilin2, are associated with familial ALS/FTD, but the pathophysiological mechanisms remain unclear. Here, we demonstrate that ALS/FTD UBQLN2 mutants P497H and P506T inhibit protein transport from the endoplasmic reticulum (ER) to the Golgi apparatus in neuronal cells.

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Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the death of both upper and lower motor neurons (MNs) in the brain, brainstem and spinal cord. The neurodegenerative mechanisms leading to MN loss in ALS are not fully understood. Importantly, the reasons why MNs are specifically targeted in this disorder are unclear, when the proteins associated genetically or pathologically with ALS are expressed ubiquitously.

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Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder and mutations in superoxide dismutase 1 (SOD1) account for 20% of familial ALS cases. The aetiology of ALS remains unclear, but protein misfolding, endoplasmic reticulum (ER) stress and neuronal apoptosis are implicated. We previously established that protein disulphide isomerase (PDIA1) is protective against ER stress and apoptosis in neuronal cells expressing mutant SOD1, and recently mutations in PDIA1 and related PDI family member endoplasmic reticulum protein 57 (ERp57/PDIA3), were associated with ALS.

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