| 1. |
- Cerrato, Carmine P. P., et al.
(författare)
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Monitoring Disassembly and Cargo Release of Phase-Separated Peptide Coacervates with Native Mass Spectrometry
- 2023
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 95:29, s. 10869-10872
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Tidskriftsartikel (refereegranskat)abstract
- Engineering liquid-liquid phase separation (LLPS)of proteinsand peptides holds great promise for the development of therapeuticcarriers with intracellular delivery capability but requires accuratedetermination of their assembly properties in vitro, usually with fluorescently labeled cargo. Here, we use mass spectrometry(MS) to investigate redox-sensitive coacervate microdroplets (thedense phase formed during LLPS) assembled from a short His- and Tyr-richpeptide. We can monitor the enrichment of a reduced peptide in dilutephase as the microdroplets dissolve triggered by their redox-sensitiveside chain, thus providing a quantitative readout for disassembly.Furthermore, MS can detect the release of a short peptide from coacervatesunder reducing conditions. In summary, with MS, we can monitor thedisassembly and cargo release of engineered coacervates used as therapeuticcarriers without the need for additional labels.
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| 2. |
- Delcoigne, Bénédicte, et al.
(författare)
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Blood neurofilament light levels segregate treatment effects in multiple sclerosis
- 2020
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Ingår i: Neurology. - 1526-632X. ; 94
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Tidskriftsartikel (refereegranskat)abstract
- Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology. OBJECTIVE: To determine factors (including the role of specific disease modulatory treatments [DMTs]) associated with (1) baseline, (2) on-treatment, and (3) change (from treatment start to on-treatment assessment) in plasma neurofilament light chain (pNfL) concentrations in relapsing-remitting multiple sclerosis (RRMS). METHODS: Data including blood samples analyses and long-term clinical follow-up information for 1,261 Swedish patients with RRMS starting novel DMTs were analyzed using linear regressions to model pNfL and changes in pNfL concentrations as a function of clinical variables and DMTs (alemtuzumab, dimethyl fumarate, fingolimod, natalizumab, rituximab, and teriflunomide). RESULTS: The baseline pNfL concentration was positively associated with relapse rate, Expanded Disability Status Scale score, Age-Related MS Severity Score, and MS Impact Score (MSIS-29), and negatively associated with Symbol Digit Modalities Test performance and the number of previously used DMTs. All analyses, which used inverse propensity score weighting to correct for differences in baseline factors at DMT start, highlighted that both the reduction in pNfL concentration from baseline to on-treatment measurement and the on-treatment pNfL level differed across DMTs. Patients starting alemtuzumab displayed the highest reduction in pNfL concentration and lowest on-treatment pNfL concentrations, while those starting teriflunomide had the smallest decrease and highest on-treatment levels, but also starting from lower values. Both on-treatment pNfL and decrease in pNfL concentrations were highly dependent on baseline concentrations. CONCLUSION: Choice of DMT in RRMS is significantly associated with degree of reduction in pNfL, which supports a role for pNfL as a drug response marker.
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| 3. |
- Khalil, Michael, et al.
(författare)
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Neurofilaments as biomarkers in neurological disorders - towards clinical application.
- 2024
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Ingår i: Nature Reviews Neurology. - 1759-4758 .- 1759-4766. ; 20:5, s. 269-287
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Tidskriftsartikel (refereegranskat)abstract
- Neurofilament proteins have been validated as specific body fluid biomarkers of neuro-axonal injury. The advent of highly sensitive analytical platforms that enable reliable quantification of neurofilaments in blood samples and simplify longitudinal follow-up has paved the way for the development of neurofilaments as a biomarker in clinical practice. Potential applications include assessment of disease activity, monitoring of treatment responses, and determining prognosis in many acute and chronic neurological disorders as well as their use as an outcome measure in trials of novel therapies. Progress has now moved the measurement of neurofilaments to the doorstep of routine clinical practice for the evaluation of individuals. In this Review, we first outline current knowledge on the structure and function of neurofilaments. We then discuss analytical and statistical approaches and challenges in determining neurofilament levels in different clinical contexts and assess the implications of neurofilament light chain (NfL) levels in normal ageing and the confounding factors that need to be considered when interpreting NfL measures. In addition, we summarize the current value and potential clinical applications of neurofilaments as a biomarker of neuro-axonal damage in a range of neurological disorders, including multiple sclerosis, Alzheimer disease, frontotemporal dementia, amyotrophic lateral sclerosis, stroke and cerebrovascular disease, traumatic brain injury, and Parkinson disease. We also consider the steps needed to complete the translation of neurofilaments from the laboratory to the management of neurological diseases in clinical practice.
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| 4. |
- Leppert, Axel, et al.
(författare)
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Liquid-Liquid Phase Separation Primes Spider Silk Proteins for Fiber Formation via a Conditional Sticker Domain
- 2023
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 23:12, s. 5836-5841
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Many protein condensates can convert to fibrillar aggregates, but the underlying mechanisms are unclear. Liquid-liquid phase separation (LLPS) of spider silk proteins, spidroins, suggests a regulatory switch between both states. Here, we combine microscopy and native mass spectrometry to investigate the influence of protein sequence, ions, and regulatory domains on spidroin LLPS. We find that salting out-effects drive LLPS via low-affinity stickers in the repeat domains. Interestingly, conditions that enable LLPS simultaneously cause dissociation of the dimeric C-terminal domain (CTD), priming it for aggregation. Since the CTD enhances LLPS of spidroins but is also required for their conversion into amyloid-like fibers, we expand the stickers and spacers-model of phase separation with the concept of folded domains as conditional stickers that represent regulatory units.
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| 5. |
- Rydell, Andreas, et al.
(författare)
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Plasma proteomics and lung function in four community-based cohorts
- 2021
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Ingår i: Respiratory Medicine. - : Elsevier. - 0954-6111 .- 1532-3064. ; 176
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Underlying mechanism leading to impaired lung function are incompletely understood.OBJECTIVES: To investigate whether protein profiling can provide novel insights into mechanisms leading to impaired lung function.METHODS: We used four community-based studies (n = 2552) to investigate associations between 79 cardiovascular/inflammatory proteins and forced expiratory volume in 1 s percent predicted (FEV1%) assessed by spirometry. We divided the cohorts into discovery and replication samples and used risk factor-adjusted linear regression corrected for multiple comparison (false discovery rate of 5%). We performed Mendelian randomization analyses using genetic and spirometry data from the UK Biobank (n = 421,986) to assess causality.MEASUREMENTS AND MAIN RESULTS: In cross-sectional analysis, 22 proteins were associated with lower FEV1% in both the discovery and replication sample, regardless of stratification by smoking status. The combined proteomic data cumulatively explained 5% of the variation in FEV1%. In longitudinal analyses (n = 681), higher plasma levels of growth differentiation factor 15 (GDF-15) and interleukin 6 (IL-6) predicted a more rapid 5-year decline in lung function (change in FEV1% per standard deviation of protein level -1.4, (95% CI, -2.5 to -0.3) for GDF-15, and -0.8, (95% CI, -1.5 to -0.2) for IL-6. Mendelian randomization analysis in UK-biobank provided support for a causal effect of increased GDF-15 levels and reduced FEV1%.CONCLUSIONS: Our combined approach identified GDF-15 as a potential causal factor in the development of impaired lung function in the general population. These findings encourage additional studies evaluating the role of GDF-15 as a causal factor for impaired lung function.
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| 6. |
- Saluri, Mihkel, et al.
(författare)
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A “grappling hook” interaction connects self-assembly and chaperone activity of Nucleophosmin 1
- 2023
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Ingår i: pnas nexus. - : Oxford University Press (OUP). - 2752-6542. ; 2:2
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Tidskriftsartikel (refereegranskat)abstract
- How the self-assembly of partially disordered proteins generates functional compartments in the cytoplasm and particularly in the nucleus is poorly understood. Nucleophosmin 1 (NPM1) is an abundant nucleolar protein that forms large oligomers and undergoes liquid-liquid phase separation by binding RNA or ribosomal proteins. It provides the scaffold for ribosome assembly but also prevents protein aggregation as part of the cellular stress response. Here, we use aggregation assays and native mass spectrometry (MS) to examine the relationship between the self-assembly and chaperone activity of NPM1. We find that oligomerization of full-length NPM1 modulates its ability to retard amyloid formation in vitro. Machine learning-based structure prediction and cryo-electron microscopy reveal fuzzy interactions between the acidic disordered region and the C-terminal nucleotide-binding domain, which cross-link NPM1 pentamers into partially disordered oligomers. The addition of basic peptides results in a tighter association within the oligomers, reducing their capacity to prevent amyloid formation. Together, our findings show that NPM1 uses a grappling hook mechanism to form a network-like structure that traps aggregation-prone proteins. Nucleolar proteins and RNAs simultaneously modulate the association strength and chaperone activity, suggesting a mechanism by which nucleolar composition regulates the chaperone activity of NPM1.
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