Polyphosphate (polyP), a several billion-year-old biopolymer, is produced in every cell, tissue, and organism studied. Structurally extremely simple, polyP consists of long chains of covalently linked inorganic phosphate groups. We report here the surprising discovery that polyP shows a remarkable efficacy in accelerating amyloid fibril formation. We found that polyP serves as an effective nucleation source for various different amyloid proteins, ranging from bacterial CsgA to human α-synuclein, Aβ1-40/42, and Tau. polyP-associated α-synuclein fibrils show distinct differences in seeding behavior, morphology, and fibril stability compared with fibrils formed in the absence of polyP. In vivo, the amyloid-stimulating and fibril-stabilizing effects of polyP have wide-reaching consequences, increasing the rate of biofilm formation in pathogenic bacteria and mitigating amyloid toxicity in differentiated neuroblastoma cells and C. elegans strains that serve as models for human folding diseases. These results suggest that we have discovered a conserved cytoprotective modifier of amyloidogenic processes.
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http://dx.doi.org/10.1016/j.molcel.2016.07.016 | DOI Listing |
Neurosci Biobehav Rev
December 2024
Department of Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy.
A hallmark event in neurodegenerative diseases is represented by the misfolding, aggregation and accumulation of proteins, leading to cellular and network dysfunction preceding the development of clinical symptoms by years. Early diagnosis represents a crucial issue in the field of neuroscience as it offers the potential to utilize this therapeutic window in the future to manage disease-modifying therapy. Seed amplification assays, including Real-Time Quaking-Induced Conversion (RT-QuIC) and Protein Misfolding Cyclic Amplification (PMCA), have emerged in recent years as innovative techniques developed to detect minute amounts of amyloidogenic proteins.
View Article and Find Full Text PDFMembranes (Basel)
November 2024
Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MSD 2080 Msida, Malta.
The transition of peptides or proteins along a misfolding continuum from soluble functional states to pathological aggregates, to ultimately deposit as amyloid fibrils, is a process that underlies an expanding group of human diseases-collectively known as protein-misfolding disorders (PMDs). These include common and debilitating conditions, such as Alzheimer's disease, Parkinson's disease, and type-2 diabetes. Compelling evidence has emerged that the complex interplay between the misfolded proteins and biological membranes is a key determinant of the pathogenic mechanisms by which harmful amyloid entities are formed and exert their cytotoxicity.
View Article and Find Full Text PDFbioRxiv
October 2024
Department of Neurology, Northwestern University Feinberg School of Medicine; Chicago, IL USA.
In Alzheimer's disease (AD), amyloid-beta (Aβ) peptides are produced by proteolytic cleavage of the amyloid precursor protein (APP), which can occur during synaptic vesicle (SV) cycling at presynapses. Precisely how amyloidogenic APP processing may impair presynaptic proteostasis and how to therapeutically target this process remains poorly understood. Using knock-in mouse models of early Aβ pathology, we found proteins with hampered degradation accumulate at presynaptic sites.
View Article and Find Full Text PDFDrug Dev Res
November 2024
Department of Pharmacology, Institute of Pharmacy, Nirma University, Ahmedabad, Gujarat, India.
Ambroxol (ABX) is used to manage excessive production of mucus in the respiratory system. The present study sought to assess the neuroprotective potential of ambroxol by influencing the amyloidogenic, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and nuclear factor erythroid 2-related factor 2 (Nrf2) pathways in a rat model of Alzheimer's disease (AD) induced by scopolamine. The AD pathology was induced by chronic administration of scopolamine.
View Article and Find Full Text PDFProtein J
November 2024
Trinity Biomedical Sciences Institute (TBSI), School of Biochemistry & Immunology, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.
Due to the large size and rapid growth of the global therapeutic antibody market, there is major interest in understanding the aggregation of protein products as it can compromise efficacy, concentration, and safety. Various production and storage conditions have been identified as capable of inducing aggregation of polyclonal and monoclonal antibody (mAb) therapies such as low pH, freezing, light exposure, lyophilisation and increased ionic strength. The addition of stabilising excipients to these therapeutics helps to combat the formation of aggregates with future aggregation inhibition mechanisms involving the introduction of point mutations and glycoengineering within aggregation prone regions (APRs).
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