A novel electrochemical immunosensor fabricated from gold compact disc electrodes was designed for rapid evaluation of aggregation processes that lead to the formation of oligomeric and fibrillar states of amyloid-beta(1-42) (Aβ(1-42)) during Alzheimer's disease. Conformation-specific antibodies were immobilized on the surface of the gold electrode using a 3,3'-dithiobis (sulfosuccinimidyl) propionate (DTSSP) linker. Surface binding events were analyzed by electrochemical impedance spectroscopy (EIS) in which the formation of an antigen-antibody complex was quantified as a function of charge transfer resistance using a [Fe(CN)6](3-/4-) redox probe. The effectiveness of novel sym-triazine-derived aggregation modulators (TAE-1, TAE-2) to reduce the population of toxic oligomers was evaluated. Aβ fibril formation was validated by thioflavin T (ThT) fluorescence, whereas oligomer formation was investigated by MALDI. Antigen detection by EIS was further supported by immuno dot blot assays for oligomeric and fibrillar components. Docking simulations of the aggregation modulators TAE-1 and TAE-2 with Aβ(1-42) fibrils performed using Autodock Vina suggest a mechanism for the improved aggregation inhibition observed for TAE-2. The results demonstrate the utility and convenience of impedance immunosensing as an analytical tool for rapid and comprehensive evaluation of effective Aβ aggregation modulating agents.
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Mol Neurodegener
December 2024
German Center for Neurodegenerative Diseases (LMU), Klinikum, Germany.
Background: The prion-like spreading of Tau pathology is the leading cause of disease progression in various tauopathies. A critical step in propagating pathologic Tau in the brain is the transport from the extracellular environment and accumulation inside naïve neurons. Current research indicates that human neurons internalize both the physiological extracellular Tau (eTau) monomers and the pathological eTau aggregates.
View Article and Find Full Text PDFiScience
December 2024
Department of Biomedical and Clinical Sciences, Department of Clinical Pathology, Linköping University, Linköping, Sweden.
Accumulating evidence demonstrates that alpha-synuclein (α-syn) pathology associated with Parkinson's disease (PD) is not limited to the brain, as it also appears in a select number of peripheral tissues including the liver. In this study, we identified a number of PD-associated α-syn post-translational modifications in the livers of (Thy-1)-h[A30P] mice, a mouse model of familial PD expressing human α-syn harboring the A30P mutation driven by a neuron-specific promoter. , we also demonstrate that human hepatocytes induce post-translational modifications following α-syn fibrillar (PFF) treatment.
View Article and Find Full Text PDFNPJ Parkinsons Dis
October 2024
Latvian Biomedical Research and Study Centre, Ratsupites 1, k-1, LV-1067, Riga, Latvia.
Alpha-synuclein (α-syn) inclusions in the brain are hallmarks of so-called Lewy body diseases. Lewy bodies contain mainly aggregated α-syn together with some other proteins. Monomeric α-syn lacks a well-defined three-dimensional structure, but it can aggregate into oligomeric and fibrillar amyloid species, which can be detected using specific antibodies.
View Article and Find Full Text PDFSci Adv
October 2024
Department of Physics, Bernal Institute, University of Limerick, Limerick V94T9PX, Ireland.
Protein fibril surfaces tend to generate toxic oligomers catalytically. To date, efforts to study the accelerated aggregation steps involved with Alzheimer's disease-linked amyloid-β (Aβ)-42 proteins on fibril surfaces have mainly relied on fluorophore-based analytics. Here, we visualize rare secondary nucleation events on the surface of Aβ-42 fibrils from embryonic to endpoint stages using liquid-based atomic force microscopy.
View Article and Find Full Text PDFJ Clin Endocrinol Metab
October 2024
Hacettepe University, Faculty of Science, Department of Biology, Molecular Biology Section, Ankara, Turkey.
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