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Nature Medicine Jun 2024Minimally invasive biomarkers are urgently needed to detect molecular pathology in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Here, we show...
Minimally invasive biomarkers are urgently needed to detect molecular pathology in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Here, we show that plasma extracellular vesicles (EVs) contain quantifiable amounts of TDP-43 and full-length tau, which allow the quantification of 3-repeat (3R) and 4-repeat (4R) tau isoforms. Plasma EV TDP-43 levels and EV 3R/4R tau ratios were determined in a cohort of 704 patients, including 37 genetically and 31 neuropathologically proven cases. Diagnostic groups comprised patients with TDP-43 proteinopathy ALS, 4R tauopathy progressive supranuclear palsy, behavior variant FTD (bvFTD) as a group with either tau or TDP-43 pathology, and healthy controls. EV tau ratios were low in progressive supranuclear palsy and high in bvFTD with tau pathology. EV TDP-43 levels were high in ALS and in bvFTD with TDP-43 pathology. Both markers discriminated between the diagnostic groups with area under the curve values >0.9, and between TDP-43 and tau pathology in bvFTD. Both markers strongly correlated with neurodegeneration, and clinical and neuropsychological markers of disease severity. Findings were replicated in an independent validation cohort of 292 patients including 34 genetically confirmed cases. Taken together, the combination of EV TDP-43 levels and EV 3R/4R tau ratios may aid the molecular diagnosis of FTD, FTD spectrum disorders and ALS, providing a potential biomarker to monitor disease progression and target engagement in clinical trials.
Topics: Humans; Amyotrophic Lateral Sclerosis; tau Proteins; Extracellular Vesicles; Frontotemporal Dementia; Biomarkers; DNA-Binding Proteins; Female; Male; Aged; Middle Aged; Supranuclear Palsy, Progressive; Protein Isoforms
PubMed: 38890531
DOI: 10.1038/s41591-024-02937-4 -
Japanese Journal of Radiology Jun 2024The findings of brain perfusion single-photon emission computed tomography (SPECT), which detects abnormalities often before changes manifest in morphological imaging,... (Review)
Review
The findings of brain perfusion single-photon emission computed tomography (SPECT), which detects abnormalities often before changes manifest in morphological imaging, mainly reflect neurodegeneration and contribute to dementia evaluation. A major shift is about to occur in dementia practice to the approach of diagnosing based on biomarkers and treating with disease-modifying drugs. Accordingly, brain perfusion SPECT will be required to serve as a biomarker of neurodegeneration. Hypoperfusion in Alzheimer's disease (AD) is typically seen in the posterior cingulate cortex and precuneus early in the disease, followed by the temporoparietal cortices. On the other hand, atypical presentations of AD such as the posterior variant, logopenic variant, frontal variant, and corticobasal syndrome exhibit hypoperfusion in areas related to symptoms. Additionally, hypoperfusion especially in the precuneus and parietal association cortex can serve as a predictor of progression from mild cognitive impairment to AD. In dementia with Lewy bodies (DLB), the differentiating feature is the presence of hypoperfusion in the occipital lobes in addition to that observed in AD. Hypoperfusion of the occipital lobe is not a remarkable finding, as it is assumed to reflect functional loss due to impairment of the cholinergic and dopaminergic systems rather than degeneration per se. Moreover, the cingulate island sign reflects the degree of AD pathology comorbid in DLB. Frontotemporal dementia is characterized by regional hypoperfusion according to the three clinical types, and the background pathology is diverse. Idiopathic normal pressure hydrocephalus shows apparent hypoperfusion around the Sylvian fissure and corpus callosum and apparent hyperperfusion in high-convexity areas. The cortex or striatum with diffusion restriction on magnetic resonance imaging in prion diseases reflects spongiform degeneration and brain perfusion SPECT reveals hypoperfusion in the same areas. Brain perfusion SPECT findings in dementia should be carefully interpreted considering background pathology.
PubMed: 38888851
DOI: 10.1007/s11604-024-01612-5 -
Frontiers in Genome Editing 2023Influenza A virus (IAV) infection is initiated by hemagglutinin (HA), a glycoprotein exposed on the virion's lipid envelope that undergoes cleavage by host cell...
Influenza A virus (IAV) infection is initiated by hemagglutinin (HA), a glycoprotein exposed on the virion's lipid envelope that undergoes cleavage by host cell proteases to ensure membrane fusion, entry into the host cells, and completion of the viral cycle. Transmembrane protease serine S1 member 2 (TMPRSS2) is a host transmembrane protease expressed throughout the porcine airway epithelium and is purported to play a major role in the HA cleavage process, thereby influencing viral pathogenicity and tissue tropism. Pigs are natural hosts of IAV and IAV disease causes substantial economic impact on the pork industry worldwide. Previous studies in mice demonstrated that knocking out expression of gene was safe and inhibited the spread of IAV after experimental challenge. Therefore, we hypothesized that knockout of will prevent IAV infectivity in the swine model. We investigated this hypothesis by comparing pathogenesis of an H1N1pdm09 virus challenge in wildtype (WT) control and in knockout ( ) pigs. We demonstrated that was expressed in the respiratory tract in WT pigs with and without IAV infection. No differences in nasal viral shedding and lung lavage viral titers were observed between WT and pigs. However, the pig group had significantly less lung lesions and significant reductions in antiviral and proinflammatory cytokines in the lung. The virus titer results in our direct challenge model contradict prior studies in the murine animal model, but the reduced lung lesions and cytokine profile suggest a possible role for TMPRSS2 in the proinflammatory antiviral response. Further research is warranted to investigate the role of TMPRSS2 in swine IAV infection and disease.
PubMed: 38883409
DOI: 10.3389/fgeed.2023.1320180 -
Angewandte Chemie (International Ed. in... Jun 2024While protein aggregation is a hallmark of many neurodegenerative diseases, acquiring structural information on protein aggregates inside live cells remains challenging....
While protein aggregation is a hallmark of many neurodegenerative diseases, acquiring structural information on protein aggregates inside live cells remains challenging. Traditional microscopy does not provide structural information on protein systems. Routinely used fluorescent protein tags, such as Green Fluorescent Protein (GFP), might perturb native structures. Here, we report a counter-propagating mid-infrared photothermal imaging approach enabling mapping of secondary structure of protein aggregates in live cells modeling Huntington's disease. By comparing mid-infrared photothermal spectra of label-free and GFP-tagged huntingtin inclusions, we demonstrate that GFP fusions indeed perturb the secondary structure of aggregates. By implementing spectra with small spatial step for dissecting spectral features within sub-micrometer distances, we reveal that huntingtin inclusions partition into a β-sheet-rich core and a ɑ-helix-rich shell. We further demonstrate that this structural partition exists only in cells with the [RNQ+] prion state, while [rnq-] cells only carry smaller β-rich non-toxic aggregates. Collectively, our methodology has the potential to unveil detailed structural information on protein assemblies in live cells, enabling high-throughput structural screenings of macromolecular assemblies.
PubMed: 38880765
DOI: 10.1002/anie.202408163 -
NPJ Parkinson's Disease Jun 2024Most neurodegenerative diseases lack definitive diagnostic tests, and the identification of easily accessible and reliable biomarkers remains a critical unmet need....
Most neurodegenerative diseases lack definitive diagnostic tests, and the identification of easily accessible and reliable biomarkers remains a critical unmet need. Since tau protein is highly expressed in skin of tauopathies patients, we aimed to exploit the ultrasensitive seeding activity assay (SAA) to assess tau seeding activity in skin of patients with tauopathies. In this multicentric, case-control study, patients with tauopathies and synucleinopathies were consecutively recruited and sex-matched to healthy controls (HC). Subjects underwent a double 3 mm skin biopsy in cervical area and ankle. Skin tau-SAA, using TauK18 and TauK19 as reaction substrates for 4R and 3R isoforms, seeding score, clinical scales, biochemical and morphological characterization of SAA end-products were evaluated. We analyzed 58 subjects: 24 tauopathies (18 progressive supranuclear palsy, PSP, and 6 corticobasal degeneration, CBD), 20 synucleinopathies (14 Parkinson's disease, PD, and 6 multiple system atrophy, MSA), and 14 HC. PSP and CBD showed higher tau seeding activity at both anatomical sites. A greater sensitivity of 4R-SAA than 3R-SAA was observed. 4R tau-SAA identified tauopathies with 71% sensitivity and 93% specificity. Accuracy was higher for PSP than CBD: PSP vs HC / PD (AUC 0.825), while CBD vs HC / PD (AUC 0.797), and PSP vs MSA (AU 0.778). SAA end-products showed differences in biochemical and morphological characterization according to the anatomical site. Skin tau-SAA identifies tauopathies with good accuracy and can be used to implement the in-vivo clinical diagnosis of patients with neurodegenerative diseases. Further characterization of peripheral tau seed in skin may elucidate the structure of tau deposits in brain.
PubMed: 38879633
DOI: 10.1038/s41531-024-00728-9 -
Scientific Reports Jun 2024Prion diseases are fatal, infectious, neurodegenerative disorders resulting from accumulation of misfolded cellular prion protein in the brain. Early pathological...
Prion diseases are fatal, infectious, neurodegenerative disorders resulting from accumulation of misfolded cellular prion protein in the brain. Early pathological changes during CNS prion disease also include reactive astrocyte activation with increased CD44 expression, microgliosis, as well as loss of dendritic spines and synapses. CD44 is a multifunctional cell surface adhesion and signalling molecule which is considered to play roles in astrocyte morphology and the maintenance of dendritic spine integrity and synaptic plasticity. However, the role of CD44 in prion disease was unknown. Here we used mice deficient in CD44 to determine the role of CD44 during prion disease. We show that CD44-deficient mice displayed no difference in their response to CNS prion infection when compared to wild type mice. Furthermore, the reactive astrocyte activation and microgliosis that accompanies CNS prion infection was unimpaired in the absence of CD44. Together, our data show that although CD44 expression is upregulated in reactive astrocytes during CNS prion disease, it is dispensable for astrocyte and microglial activation and the development of prion neuropathogenesis.
Topics: Animals; Astrocytes; Hyaluronan Receptors; Prion Diseases; Mice; Mice, Knockout; Microglia; Brain; Mice, Inbred C57BL
PubMed: 38877012
DOI: 10.1038/s41598-024-63464-3 -
Spatial and Spatio-temporal Epidemiology Jun 2024Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy that was first detected in captive cervids in Colorado, United States (US) in 1967, but has...
Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy that was first detected in captive cervids in Colorado, United States (US) in 1967, but has since spread into free-ranging white-tailed deer (Odocoileus virginianus) across the US and Canada as well as to Scandinavia and South Korea. In some areas, the disease is considered endemic in wild deer populations, and governmental wildlife agencies have employed epidemiological models to understand long-term environmental risk. However, continued rapid spread of CWD into new regions of the continent has underscored the need for extension of these models into broader tools applicable for wide use by wildlife agencies. Additionally, efforts to semi-automate models will facilitate access of technical scientific methods to broader users. We introduce software (Habitat Risk) designed to link a previously published epidemiological model with spatially referenced environmental and disease testing data to enable agency personnel to make up-to-date, localized, data-driven predictions regarding the odds of CWD detection in surrounding areas after an outbreak is discovered. Habitat Risk requires pre-processing publicly available environmental datasets and standardization of disease testing (surveillance) data, after which an autonomous computational workflow terminates in a user interface that displays an interactive map of disease risk. We demonstrated the use of the Habitat Risk software with surveillance data of white-tailed deer from Tennessee, USA.
Topics: Wasting Disease, Chronic; Animals; Deer; Software; Ecosystem; Animals, Wild; Risk Assessment
PubMed: 38876563
DOI: 10.1016/j.sste.2024.100650 -
Plasmid Jun 2024Gene overexpression by transient transfection of in vitro cultured model cell lines with plasmid DNA is a commonly used method for studying molecular aspects of human...
Gene overexpression by transient transfection of in vitro cultured model cell lines with plasmid DNA is a commonly used method for studying molecular aspects of human biology and pathobiology. However, there is accumulating evidence suggesting that human cells may actively secrete fragments of DNA and the implications of this phenomenon for in vitro cultured cells transiently transfected with foreign nucleic acids has been overlooked. Therefore, in the current study we investigated whether a cell-to-cell transmission of acquired plasmid DNA takes place in a commonly used human cell line model. We transiently transfected HEK293 cells with EGFP encoding plasmids to serve as donor cells and either co-cultured these with stably mCherry expressing recipient cells in different set-ups or transferred their culture medium to the recipient cells. We found that recipient cells produced EGFP after being co-cultured with donor cells but not when they were exposed to their culture medium. The employment of different co-culture set-ups excluded that the observed effect stemmed from technical artefacts and provided evidence that an intercellular plasmid transfer takes place requiring physical proximity between living cells. This phenomenon could represent a significant biological artefact for certain studies such as those addressing protein transmissions in prion diseases.
PubMed: 38876373
DOI: 10.1016/j.plasmid.2024.102729 -
Nature Communications Jun 2024Influenza A viruses in swine have considerable genetic diversity and continue to pose a pandemic threat to humans due to a potential lack of population level immunity....
Influenza A viruses in swine have considerable genetic diversity and continue to pose a pandemic threat to humans due to a potential lack of population level immunity. Here we describe a pipeline to characterize and triage influenza viruses for their pandemic risk and examine the pandemic potential of two widespread swine origin viruses. Our analysis reveals that a panel of human sera collected from healthy adults in 2020 has no cross-reactive neutralizing antibodies against a α-H1 clade strain (α-swH1N2) but do against a γ-H1 clade strain. The α-swH1N2 virus replicates efficiently in human airway cultures and exhibits phenotypic signatures similar to the human H1N1 pandemic strain from 2009 (H1N1pdm09). Furthermore, α-swH1N2 is capable of efficient airborne transmission to both naïve ferrets and ferrets with prior seasonal influenza immunity. Ferrets with H1N1pdm09 pre-existing immunity show reduced α-swH1N2 viral shedding and less severe disease signs. Despite this, H1N1pdm09-immune ferrets that became infected via the air can still onward transmit α-swH1N2 with an efficiency of 50%. These results indicate that this α-swH1N2 strain has a higher pandemic potential, but a moderate level of impact since there is reduced replication fitness and pathology in animals with prior immunity.
Topics: Animals; Ferrets; Humans; Swine; Influenza, Human; Orthomyxoviridae Infections; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H1N2 Subtype; Pandemics; Antibodies, Viral; Antibodies, Neutralizing; Swine Diseases; Female; Virus Shedding; Male; Adult; Virus Replication
PubMed: 38871701
DOI: 10.1038/s41467-024-49117-z -
Journal of Wildlife Diseases Jun 2024After detecting chronic wasting disease (CWD) in white-tailed deer (Odocoileus virginianus) in Hampshire County, West Virginia, USA, in 2005, we investigated the change...
After detecting chronic wasting disease (CWD) in white-tailed deer (Odocoileus virginianus) in Hampshire County, West Virginia, USA, in 2005, we investigated the change of CWD apparent prevalence and potential factors influencing infection risk during the invasion front. Over eight sampling years (2006-2012 and 2017) during a 12-yr period within a 101-km2-area monitoring zone, we sampled and tested a total of 853 deer for CWD by ELISA and immunohistochemistry. Bayesian logistic regression of risk factors included collection year, age class, sex, and adjusted body weight (weight after accounting for sex, age, kidney fat index, and number of fetuses). In the whole-herd model (n=634), collection year, age, and adjusted body weight were associated with increased odds of CWD, whereas an age-weight interaction had a negative relationship. We found that males drove the positive associations with age and adjusted body weight, whereas females were responsible for the negative interaction effect. These findings suggest potential behavioral and physiological mechanisms related to sex that may influence CWD exposure. Older males exhibited higher CWD prevalence, aligning with previous studies. Notably, the novel finding of adjusted body weight as a risk factor in males warrants further investigation, and this study highlights the need for future research on social behavior and its role in CWD transmission within white-tailed deer populations.
PubMed: 38871352
DOI: 10.7589/JWD-D-22-00160