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Journal of Neuropathology and... Jun 2024Proteins exhibiting prion-like properties are implicated in tauopathies. The prion-like traits of tau influence disease progression and correlate with severity....
Proteins exhibiting prion-like properties are implicated in tauopathies. The prion-like traits of tau influence disease progression and correlate with severity. Techniques to measure tau bioactivity such as RT-QuIC and biosensor cells lack spatial specificity. Therefore, we developed a histological probe aimed at detecting and localizing bioactive tau in situ. We first induced the recruitment of a tagged probe by bioactive Tau in human brain tissue slices using biosensor cell lysates containing a fluorescent probe. We then enhanced sensitivity and flexibility by designing a recombinant probe with a myc tag. The probe design aimed to replicate the recruitment process seen in prion-like mechanisms based on the cryo-EM structure of tau aggregates in Alzheimer disease (AD). Using this novel probe, we observed selective staining of misfolded tau in pre- and post-synaptic structures within neurofibrillary tangles and neurites, whether or not associated with neuritic plaques. The probe specifically targeted AD-associated bioactive tau and did not recognize bioactive tau from other neurodegenerative diseases. Electron microscopy and immunolabeling further confirmed the identification of fibrillar and non-fibrillar tau. Finally, we established a correlation between quantifying bioactive tau using this technique and gold standard biosensor cells. This technique presents a robust approach for detecting bioactive tau in AD tissues and has potential applications for deciphering mechanisms of tau propagation and degradation pathways.
PubMed: 38917443
DOI: 10.1093/jnen/nlae059 -
BioRxiv : the Preprint Server For... Jun 2024facsimiles of biomolecular condensates are formed by different types of intrinsically disordered proteins including prion-like low complexity domains (PLCDs). PLCD...
facsimiles of biomolecular condensates are formed by different types of intrinsically disordered proteins including prion-like low complexity domains (PLCDs). PLCD condensates are viscoelastic materials defined by time-dependent, sequence-specific complex shear moduli. Here, we show that viscoelastic moduli can be computed directly using a generalization of the Rouse model and information regarding intra- and inter-chain contacts that is extracted from equilibrium configurations of lattice-based Metropolis Monte Carlo (MMC) simulations. The key ingredient of the generalized Rouse model is the Zimm matrix that we compute from equilibrium MMC simulations. We compute two flavors of Zimm matrices, one referred to as the single-chain model that accounts only for intra-chain contacts, and the other referred to as a collective model, that accounts for inter-chain interactions. The single-chain model systematically overestimates the storage and loss moduli, whereas the collective model reproduces the measured moduli with greater fidelity. However, in the long time, low-frequency domain, a mixture of the two models proves to be most accurate. In line with the theory of Rouse, we find that a continuous distribution of relaxation times exists in condensates. The single crossover frequency between dominantly elastic versus dominantly viscous behaviors is influenced by the totality of the relaxation modes. Hence, our analysis suggests that viscoelastic fluid-like condensates are best described as generalized Maxwell fluids. Finally, we show that the complex shear moduli can be used to solve an inverse problem to obtain distributions of relaxation times that underlie the dynamics within condensates.
PubMed: 38915484
DOI: 10.1101/2024.06.11.598543 -
Preparative Biochemistry & Biotechnology Jun 2024Proteases, enzymes that hydrolyze peptide bonds, have various applications in medicine, clinical applications, and pharmaceutical development. They are used in cancer... (Review)
Review
Proteases, enzymes that hydrolyze peptide bonds, have various applications in medicine, clinical applications, and pharmaceutical development. They are used in cancer treatment, wound debridement, contact lens cleaning, prion degradation, biofilm removal, and fibrinolytic agents. Proteases are also crucial in cardiovascular disease treatment, emphasizing the need for safe, affordable, and effective fibrinolytic drugs. Proteolytic enzymes and protease biosensors are increasingly used in diagnostic and therapeutic applications. Advanced technologies, such as nanomaterials-based sensors, are being developed to enhance the sensitivity, specificity, and versatility of protease biosensors. These biosensors are becoming effective tools for disease detection due to their precision and rapidity. They can detect extracellular and intracellular proteases, as well as fluorescence-based methods for real-time and label-free detection of virus-related proteases. The active utilization of proteolytic enzymatic biosensors is expected to expand significantly in biomedical research, model systems, and drug development. We focused on journal articles and books published in English between 1982 and 2024 for this study.
PubMed: 38909284
DOI: 10.1080/10826068.2024.2364234 -
Journal of Neuro-oncology Jun 2024This study investigates the outcomes of microsurgical resection of multiple brain metastasis (BMs).
PURPOSE
This study investigates the outcomes of microsurgical resection of multiple brain metastasis (BMs).
METHODS
This retrospective, monocentric analysis included clinical data from all consecutive BM patients, who underwent simultaneous resection of ≥ 2 BMs between January 2018 and May 2023. Postoperative neurological and functional outcomes, along with perioperative complications, as well as survival data were evaluated.
RESULTS
A total of 47 patients, with a median age of 61 years (IQR 48-69), underwent 73 craniotomies (median 2; range 1-3) for resection of 104 BMs. Among patients, 80.8% presented with symptomatic BMs, causing focal neurological deficits in 53% of cases. Gross total resection was achieved in 87.2% of BMs. Karnofsky Performance Scale (KPS) scores improved in 42.6% of patients, remained unchanged in 46.8%, and worsened in 10.6% after surgery. Perioperative complications were observed in 29.8% of cases, with transient complications occurring in 19.2% and permanent deficits in 10.6%. The 30-days mortality rate was 2.1%. Logistic regression identified eloquent localization (p = 0.036) and infratentorial craniotomy (p = 0.018) as significant predictors of postoperative complications. Concerning overall prognosis, patients with permanent neurological deficits post-surgery (HR 11.34, p = 0.007) or progressive extracranial disease (HR: 4.649; p = 0.006) exhibited inferior survival.
CONCLUSION
Microsurgical resection of multiple BMs leads to clinical stabilization or functional improvement in most patients. Although transient complications do not affect overall survival, the presence of persistent neurological deficits (> 3 months post-surgery) and progressive extracranial disease negatively impact overall survival. This highlights the importance of careful patient selection for resection of multiple BMs.
PubMed: 38904924
DOI: 10.1007/s11060-024-04744-w -
PLoS Pathogens Jun 2024
Review
Topics: Prion Diseases; Astrocytes; Humans; Animals; Prions
PubMed: 38900746
DOI: 10.1371/journal.ppat.1012286 -
Neurology Jul 2024
Topics: Humans; Biomarkers; Prion Diseases; Predictive Value of Tests; Prions
PubMed: 38896818
DOI: 10.1212/WNL.0000000000209580 -
Neurology Jul 2024To longitudinally characterize disease-relevant CSF and plasma biomarkers in individuals at risk for genetic prion disease up to disease conversion.
OBJECTIVES
To longitudinally characterize disease-relevant CSF and plasma biomarkers in individuals at risk for genetic prion disease up to disease conversion.
METHODS
This single-center longitudinal cohort study has followed known carriers of pathogenic variants at risk for prion disease, individuals with a close relative who died of genetic prion disease but who have not undergone predictive genetic testing, and controls. All participants were asymptomatic at first visit and returned roughly annually. We determined genotypes, measured NfL and GFAP in plasma, and RT-QuIC, total PrP, NfL, T-tau, and beta-synuclein in CSF.
RESULTS
Among 41 carriers and 21 controls enrolled, 28 (68%) and 15 (71%) were female, and mean ages were 47.5 and 46.1. At baseline, all individuals were asymptomatic. We observed RT-QuIC seeding activity in the CSF of 3 asymptomatic E200K carriers who subsequently converted to symptomatic and died of prion disease. 1 P102L carrier remained RT-QuIC negative through symptom conversion. No other individuals developed symptoms. The prodromal window from detection of RT-QuIC positivity to disease onset was 1 year long in an E200K individual homozygous (V/V) at PRNP codon 129 and 2.5 and 3.1 years in 2 codon 129 heterozygotes (M/V). Changes in neurodegenerative and neuroinflammatory markers were variably observed prior to onset, with increases observed for plasma NfL in 4/4 converters, and plasma GFAP, CSF NfL, CSF T-tau, and CSF beta-synuclein each in 2/4 converters, although values relative to age and fold changes relative to individual baseline were not remarkable for any of these markers. CSF PrP was longitudinally stable with mean coefficient of variation 9.0% across all individuals over up to 6 years, including data from converting individuals at RT-QuIC-positive timepoints.
DISCUSSION
CSF prion seeding activity may represent the earliest detectable prodromal sign in E200K carriers. Neuronal damage and neuroinflammation markers show limited sensitivity in the prodromal phase. CSF PrP levels remain stable even in the presence of RT-QuIC seeding activity.
CLINICAL TRIALS REGISTRATION
ClinicalTrials.gov NCT05124392 posted 2017-12-01, updated 2023-01-27.
Topics: Humans; Female; Male; Middle Aged; Biomarkers; Prion Proteins; Prion Diseases; Longitudinal Studies; Adult; tau Proteins; Neurofilament Proteins; Heterozygote; Glial Fibrillary Acidic Protein; Disease Progression; alpha-Synuclein
PubMed: 38896810
DOI: 10.1212/WNL.0000000000209506 -
Archives of Microbiology Jun 2024Prion-like proteins (PrLPs) have emerged as beneficial molecules with implications in adaptive responses. These proteins possess a conserved prion-like domain (PrLD)...
Prion-like proteins (PrLPs) have emerged as beneficial molecules with implications in adaptive responses. These proteins possess a conserved prion-like domain (PrLD) which is an intrinsically disordered region capable of adopting different conformations upon perceiving external stimuli. Owing to changes in protein conformation, functional characteristics of proteins harboring PrLDs get altered thereby, providing a unique mode of protein-based regulation. Since PrLPs are ubiquitous in nature and involved in diverse functions, through this study, we aim to explore the role of such domains in yet another important physiological process viz. plant-microbe interactions to get insights into the mechanisms dictating cross-kingdom interactions. We have evaluated the presence and functions of PrLPs in 18 different plant-associated fungi of agricultural importance to unravel their role in plant-microbe interactions. Of the 241,997 proteins scanned, 3,820 (~ 1.6%) were identified as putative PrLPs with pathogenic fungi showing significantly higher PrLP density than their beneficial counterparts. Further, through GO enrichment analysis, we could predict several PrLPs from pathogenic fungi to be involved in virulence and formation of stress granules. Notably, PrLPs involved in (retro)transposition were observed exclusively in pathogenic fungi. We even analyzed publicly available data for the expression alterations of fungal PrLPs upon their interaction with their respective hosts which revealed perturbation in the levels of some PrLP-encoding genes during interactions with plants. Overall, our work sheds light into the probable role of prion-like candidates in plant-fungi interaction, particularly in context of pathogenesis, paving way for more focused studies for validating their role.
Topics: Fungal Proteins; Plants; Fungi; Computer Simulation; Plant Diseases; Prion Proteins; Prions; Virulence; Host-Pathogen Interactions
PubMed: 38896139
DOI: 10.1007/s00203-024-04040-1 -
BioRxiv : the Preprint Server For... Jun 2024RNA binding proteins have emerged as central players in the mechanisms of many neurodegenerative diseases. In particular, a proteinopathy of fu sed in s arcoma (FUS) is...
RNA binding proteins have emerged as central players in the mechanisms of many neurodegenerative diseases. In particular, a proteinopathy of fu sed in s arcoma (FUS) is present in some instances of familial Amyotrophic lateral sclerosis (ALS) and about 10% of sporadic FTLD. Here we establish that focal injection of sonicated human FUS fibrils into brains of mice in which ALS-linked mutant or wild-type human FUS replaces endogenous mouse FUS is sufficient to induce focal cytoplasmic mislocalization and aggregation of mutant and wild-type FUS which with time spreads to distal regions of the brain. Human FUS fibril-induced FUS aggregation in the mouse brain of humanized FUS mice is accelerated by an ALS-causing FUS mutant relative to wild-type human FUS. Injection of sonicated human FUS fibrils does not induce FUS aggregation and subsequent spreading after injection into naïve mouse brains containing only mouse FUS, indicating a species barrier to human FUS aggregation and its prion-like spread. Fibril-induced human FUS aggregates recapitulate pathological features of FTLD including increased detergent insolubility of FUS and TAF15 and amyloid-like, cytoplasmic deposits of FUS that accumulate ubiquitin and p62, but not TDP-43. Finally, injection of sonicated FUS fibrils is shown to exacerbate age-dependent cognitive and behavioral deficits from mutant human FUS expression. Thus, focal seeded aggregation of FUS and further propagation through prion-like spread elicits FUS-proteinopathy and FTLD-like disease progression.
PubMed: 38895337
DOI: 10.1101/2024.06.03.593639 -
Animals : An Open Access Journal From... May 2024Prion diseases are fatal neurodegenerative disorders characterized by an accumulation of misfolded prion protein (PrP) in brain tissues. The shadow of prion protein...
Prion diseases are fatal neurodegenerative disorders characterized by an accumulation of misfolded prion protein (PrP) in brain tissues. The shadow of prion protein (Sho) encoded by the shadow of prion protein gene () is involved in prion disease progress. The interaction between Sho and PrP accelerates the PrP conversion rate while the gene polymorphisms have been associated with prion disease susceptibility in several species. Until now, the gene has not been investigated in ducks. We identified the duck gene sequence and investigated the genetic polymorphisms of 184 Pekin ducks. We compared the duck nucleotide sequence and the duck Sho protein amino acid sequence with those of several other species. Finally, we predicted the duck Sho protein structure and the effects of non-synonymous single nucleotide polymorphisms (SNPs) using computational programs. We were the first to report the Pekin duck gene sequence. The duck Sho protein sequence showed 100% identity compared with the chicken Sho protein sequence. We found 27 novel SNPs in the duck gene. Four amino acid substitutions were predicted to affect the hydrogen bond distribution in the duck Sho protein structure. Although MutPred2 and SNPs&GO predicted that all non-synonymous polymorphisms were neutral or benign, SIFT predicted that four variants, A22T, G49D, A68T, and M105I, were deleterious. To the best of our knowledge, this is the first report about the genetic and structural characteristics of the duck gene.
PubMed: 38891635
DOI: 10.3390/ani14111588