Publications by authors named "Halliday G"

The α-synuclein seed amplification assay (αSyn-SAA) sensitively detects Lewy pathology, the amyloid state of α-synuclein, in the cerebrospinal fluid (CSF) of patients with Parkinson's disease (PD). The αSyn-SAA harnesses the physics of seeding, whereby a superconcentrated solution of recombinant α-synuclein lowers the thermodynamic threshold (nucleation barrier) for aggregated α-synuclein to act as a nucleation catalyst ("seed") to trigger the precipitation (nucleation) of monomeric α-synuclein into pathology. This laboratory setup increases the signal for identifying a catalyst if one is present in the tissue examined.

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Background: Parkinson's disease (PD) and multiple system atrophy (MSA) are classified as α-synucleinopathies and are primarily differentiated by their clinical phenotypes. Delineating these diseases based on their specific α-synuclein (α-Syn) proteoform pathologies is crucial for accurate antemortem biomarker diagnosis. Newly identified α-Syn pathologies in PD raise questions about whether MSA exhibits a similar diversity.

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Background: Parkinson's disease (PD) is characterised by degeneration of ventral midbrain dopaminergic (DA) neurons and abnormal deposition of α-synuclein (α-syn) in neurons. Activation of the innate immune pathogen recognition receptor toll-like receptor 2 (TLR2) is associated with exacerbation of α-syn pathology. TLR2 is increased on neurons in the PD brain, and its activation results in the accumulation and propagation of α-syn through autophagy inhibition in neurons.

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Article Synopsis
  • The MJF-14 PLA is a new technique for detecting α-synuclein aggregates, demonstrating high specificity and sensitivity for non-Lewy body pathology.
  • This assay shows a strong correlation between α-synuclein aggregation and specific conditions in both cell cultures and human neuronal samples linked to neurodegenerative diseases.
  • The findings indicate that a significant amount of α-synuclein pathology occurs before the formation of Lewy bodies in diseases such as Parkinson's, suggesting the need for further research using brain samples.
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SMOC1 has emerged as one of the most significant and consistent new biomarkers of early Alzheimer's disease (AD). Recent studies show that SMOC1 is one of the earliest changing proteins in AD, with levels in the cerebrospinal fluid increasing many years before symptom onset. Despite this clear association with disease, little is known about the role of SMOC1 in AD or its function in the brain.

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SMOC1 has emerged as one of the most significant and consistent new biomarkers of early Alzheimer's disease (AD). Recent studies show that SMOC1 is one of the earliest changing proteins in AD, with levels in the cerebrospinal fluid increasing many years before symptom onset. Despite this clear association with disease, little is known about the role of SMOC1 in AD or its function in the brain.

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Article Synopsis
  • - Multiple system atrophy (MSA) is a serious neurodegenerative disease that leads to autonomic system failure and motor control issues, with a key feature being the buildup of α-synuclein in oligodendroglial cells.
  • - Current research suggests that MSA might not only stem from oligodendroglial problems but could also involve neuron or immune system dysfunction, highlighting differences in the structure of α-synuclein when compared to other diseases like Parkinson's.
  • - Advances in areas like genetics and molecular pathology are expected to provide deeper insights into MSA, paving the way for personalized treatment approaches using advanced techniques such as pluripotent stem cells.
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The Western Pacific Region (WPR) is characterized by a group of socioeconomically, culturally, and geopolitically heterogenous countries and represents a microcosm of the global endemic of neurodegeneration. This review will chart the known risk factors for dementia across the WPR. We explore the intersection between the established risk factors for dementia including the (cardiovascular and metabolic disease, sleep, hearing loss, depression, alcohol, smoking, traumatic brain injury, genetics) and (social disadvantage, limited education, systemic racism) as well as incorporate neuroimaging data, where available, to predict disease progression in the WPR.

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  • Tau is a protein that interacts with special helpers called hnRNPs, which help manage RNA in our cells.
  • Researchers studied how these hnRNP proteins behave in different brain diseases like Alzheimer's, but found they didn't stick together with the bad tau proteins as expected.
  • They discovered that the hnRNP proteins did get mixed up and moved to the wrong places in the cells during these diseases, which might affect how RNA works in the brain.
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Mutations in the mitochondrial cristae protein CHCHD2 lead to a late-onset autosomal dominant form of Parkinson's disease (PD) which closely resembles idiopathic PD, providing the opportunity to gain new insights into the mechanisms of mitochondrial dysfunction contributing to PD. To begin to address this, we used CRISPR genome-editing to generate CHCHD2 T61I point mutant mice. CHCHD2 T61I mice had normal viability, and had only subtle motor deficits with no signs of premature dopaminergic (DA) neuron degeneration.

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  • The study investigates protein-rich inclusions in neurodegeneration, noting that current iPSC models lack reproducibility and speed in developing these inclusions.
  • Researchers created new iPSC models that allow for rapid production of CNS cells with proteins prone to aggregation, enabling the tracking of inclusions at a single level.
  • They identified various inclusion types with differing effects on neuron survival and isolated proteins that could influence toxicity, paving the way for improved drug development for neurodegenerative diseases.
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Parkinson's disease (PD) has two main pathological hallmarks, the loss of nigral dopamine neurons and the proteinaceous aggregations of ⍺-synuclein (⍺Syn) in neuronal Lewy pathology. These two co-existing features suggest a causative association between ⍺Syn aggregation and the underpinning mechanism of neuronal degeneration in PD. Both increased levels and post-translational modifications of ⍺Syn can contribute to the formation of pathological aggregations of ⍺Syn in neurons.

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Frontotemporal lobar degeneration with neuronal inclusions of the TAR DNA-binding protein 43 (FTLD-TDP) is a fatal neurodegenerative disorder with only a limited number of risk loci identified. We report our comprehensive genome-wide association study as part of the International FTLD-TDP Whole-Genome Sequencing Consortium, including 985 cases and 3,153 controls, and meta-analysis with the Dementia-seq cohort, compiled from 26 institutions/brain banks in the United States, Europe and Australia. We confirm as the strongest overall FTLD-TDP risk factor and identify as a novel FTLD-TDP risk factor.

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Various forms of Parkinson's disease, including its common sporadic form, are characterized by prominent α-synuclein (αSyn) aggregation in affected brain regions. However, the role of αSyn in the pathogenesis and evolution of the disease remains unclear, despite vast research efforts of more than a quarter century. A better understanding of the role of αSyn, either primary or secondary, is critical for developing disease-modifying therapies.

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Identifying biological factors which contribute to the clinical progression of heterogeneous motor and non-motor phenotypes in Parkinson's disease may help to better understand the disease process. Several lipid-related genetic risk factors for Parkinson's disease have been identified, and the serum lipid signature of Parkinson's disease patients is significantly distinguishable from controls. However, the extent to which lipid profiles are associated with clinical outcomes remains unclear.

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Article Synopsis
  • * A study analyzed 4,685 sporadic FTD cases and found significant genetic variants at the MAPT and APOE loci that increase the risk for the disease, indicating potential genetic overlap with other neurodegenerative diseases.
  • * The genetic risk factors appear to vary by population, with MAPT and APOE associations predominantly found in Central/Nordic and Mediterranean Europeans, suggesting a need for further research into these population-specific features for better understanding of sporadic FTD.
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The rate and prevalence of hallucinations in behavioural variant frontotemporal dementia is well established. The mechanisms for underlying vulnerability however are the least well described in FTD compared with other neuropsychiatric conditions, despite the presence of these features significantly complicating the diagnostic process. As such, this present study aimed to provide a detailed characterization of the neural, cognitive and behavioural profile associated with a predisposition to hallucinatory experiences in behavioural variant frontotemporal dementia.

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Objective: Sertoli-Leydig cell tumors (SLCTs) are rare sex cord-stromal tumors, representing <0.5% of all ovarian tumors. We sought to describe prognostic factors, treatment and outcomes for individuals with ovarian SLCT.

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  • Parkinson's disease involves the death of dopamine neurons in the substantia nigra, but the mechanisms behind this degeneration are still unclear.
  • Researchers developed a chemogenetic mouse model to increase dopamine neuron activity, discovering that this led to changes in locomotor activity and early degeneration of specific neuron projections.
  • This study suggests that excessive neural activity contributes to the vulnerability and eventual death of dopamine neurons, providing new insights into the pathophysiology of Parkinson's disease.
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  • Pick's disease is a rare form of frontotemporal dementia characterized by Pick bodies in the brain, which are linked to the MAPT gene and its haplotypes, H1 and H2.
  • The study aimed to investigate how the MAPT H2 haplotype influences the risk, age of onset, and duration of Pick's disease.
  • Data was collected from 338 individuals with confirmed Pick's disease across multiple sites, and associations of MAPT variants with the disease were analyzed using statistical models.
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The International Parkinson and Movement Disorder Society (MDS) created a task force (TF) to provide a critical overview of the Parkinson's disease (PD) subtyping field and develop a guidance on future research in PD subtypes. Based on a literature review, we previously concluded that PD subtyping requires an ultimate alignment with principles of precision medicine, and consequently novel approaches were needed to describe heterogeneity at the individual patient level. In this manuscript, we present a novel purpose-driven framework for subtype research as a guidance to clinicians and researchers when proposing to develop, evaluate, or use PD subtypes.

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Parkinson's disease (PD) is a chronic neurodegenerative disorder that affects the motor system. Increasing evidence indicates that lysosomal dysfunction is pivotal in the pathogenesis of PD, typically characterized by dysregulation of sphingolipids in lysosomes. ATP-binding cassette subfamily A member 5 (ABCA5) is a lysosomal transporter that mediates the removal of excess sphingomyelin from lysosomes.

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