Solvatochromic Fluorescent Probe for Visualizing Protein Aggregation via STED Imaging DOI
Wanhao Sun, Yaqing Zhang, Hongbing Fu

et al.

Analytical Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 30, 2024

Elucidating the structure of protein aggregates is vital for overcoming human diseases arising from misfolding. It rarely reported that conventional protein-amyloid fibrillation probe ThT can be used as a STED agent to visualize aggregation structures at nanometer level, suffering small Stokes' shift and photobleaching. Herein, we report donor–acceptor (D–A)-type fluorophore, IAD2, with red emission large (196 nm). demonstrated IAD2 exhibited 7.8-fold enhancement on fluorescence intensity an obvious 94 nm blue wavelength after binding bovine insulin fibril, due alternation microenvironment. Besides, has relatively higher affinity fibrils in comparison ThT. Molecular docking assay also verified sites interaction forces between fibrils. Owing its high depletion efficiency good photostability, was utilized stain achieve imaging resolution 101.2 nm. This study will shed light design novel solvatochromic fluorescent super-resolution aggregate structure.

Language: Английский

Inhibitor-based modulation of huntingtin aggregation mechanisms mitigates fibril-induced cellular stress DOI Creative Commons
Greeshma Jain, Marina Trombetta-Lima, Irina Matlahov

et al.

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: April 15, 2025

Abstract Huntington’s disease (HD) is a neurodegenerative disorder in which mutated fragments of the huntingtin protein (Htt) undergo misfolding and aggregation. Since aggregated proteins can cause cellular stress cytotoxicity, there an interest development small molecule aggregation inhibitors as potential modulators HD pathogenesis. Here, we study how polyphenol modulates mechanism exon 1 (HttEx1) even at sub-stoichiometric ratios. Sub-stoichiometric amounts curcumin impacted primary and/or secondary nucleation events, extending pre-aggregation lag phase. Remarkably, disrupted process changed both aggregate structure its cell metabolic properties. When administered to neuronal cells, ‘break-through’ aggregates induced significantly reduced compared formed absence inhibitors. Structural analysis by electron microscopy, angle X-ray scattering (SAXS), solid-state NMR spectroscopy identified changes fibril structures, probing flanking domains fuzzy coat core. We propose that latter relate presence or polyglutamine (polyQ) β-hairpin structures. Our findings highlight multifaceted consequences modulate landscape, with implications for treatment strategies other amyloid disorders.

Language: Английский

Citations

0
Transient interdomain interactions modulate the monomeric structural ensemble and oligomerization landscape of Huntingtin Exon 1 DOI Creative Commons
Priyesh Mohanty, Tien M. Phan, Jeetain Mittal

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: May 6, 2024

Abstract Polyglutamine expansion (≥ 36 residues) within the N-terminal exon-1 of Huntingtin (Httex1) leads to Huntington’s disease, a neurogenerative condition marked by presence intranuclear Htt inclusions. Notably, polyglutamine tract in Httex1 is flanked an coiled-coil domain - N17 (17 amino acids), which undergoes self-association promote formation soluble oligomers and brings aggregation-prone polyQ tracts close spatial proximity. However, mechanisms underlying subsequent conversion into insoluble β-rich aggregates with increasing length, remain unclear. Current knowledge suggests that increases its helicity, this favors oligomerization aggregation. In addition, studies utilizing conformation-specific antibodies stable heterotetrametric system fused indicate “cross-talk” (i.e., interdomain interactions) may be necessary efficiently emergence toxic conformations (in monomers oligomers) fibrillar Here, we performed extensive atomistic molecular dynamics (MD) simulations (aggregate time ∼ 0.7 ms) N17-polyQ fragments uncover interplay between structural transformation on monomeric ensemble landscape Httex1. Our simulation ensembles validated against 13 C NMR chemical shifts indicated addition elevated α-helicity, also transient, (N17-polyQ) interactions result β-conformations. Further, decreased overall stability N17-mediated dimers counteracting stabilizing effect increased α-helicity promoted heterogenous sub-microsecond timescale. Overall, our study uncovers significance modulating conformational favor amyloid aggregates.

Language: Английский

Citations

2
Integrative determination of atomic structure of mutant huntingtin exon 1 fibrils implicated in Huntington disease DOI Creative Commons
Mahdi Bagherpoor Helabad, Irina Matlahov, Raj Kumar

et al.

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Dec. 30, 2024

Neurodegeneration in Huntington's disease (HD) is accompanied by the aggregation of fragments mutant huntingtin protein, a biomarker progression. A particular pathogenic role has been attributed to aggregation-prone exon 1 (HTTex1), generated aberrant splicing or proteolysis, and containing expanded polyglutamine (polyQ) segment. Unlike amyloid fibrils from Parkinson's Alzheimer's diseases, atomic-level structure HTTex1 remained unknown, limiting diagnostic treatment efforts. We present analyze formed polyQ peptides polyQ-expanded vitro. Atomic-resolution perspectives are enabled an integrative analysis unrestrained all-atom molecular dynamics (MD) simulations incorporating experimental data electron microscopy (EM), solid-state NMR, other techniques. Alongside use prior data, we report magic angle spinning NMR studies glutamine residues fibril core surface, distinguished via hydrogen-deuterium exchange (HDX). Our study provides understanding as well surface aggregated HTTex1, including fuzzy coat polyQ-water interface. The obtained discussed context their implications for detection such aggregates (diagnostics) known biological properties fibrils.

Language: Английский

Citations

2
Integrative determination of the atomic structure of mutant huntingtin exon 1 fibrils from Huntington’s disease DOI Creative Commons
Mahdi Bagherpoor Helabad, Irina Matlahov,

Raj Kumar

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: July 21, 2023

Abstract Neurodegeneration in Huntington’s disease (HD) is accompanied by the aggregation of fragments mutant huntingtin protein, a biomarker progression. A particular pathogenic role has been attributed to aggregation-prone exon 1 (HTTex1), generated aberrant splicing or proteolysis, and containing expanded polyglutamine (polyQ) segment. Unlike amyloid fibrils from Parkinson’s Alzheimer’s diseases, atomic-level structure HTTex1 remained unknown, limiting diagnostic treatment efforts. We present analyze formed polyQ peptides polyQ-expanded vitro. Atomic-resolution perspectives are enabled an integrative analysis unrestrained all-atom molecular dynamics (MD) simulations incorporating experimental data electron microscopy (EM), solid-state NMR, other techniques. Alongside use prior data, we report new magic angle spinning NMR studies glutamine residues fibril core surface, distinguished via hydrogen-deuterium exchange (HDX). Our study provides understanding as well surface aggregated HTTex1, including fuzzy coat polyQ–water interface. The obtained discussed context their implications for detection such aggregates (diagnostics) known biological properties fibrils.

Language: Английский

Citations

4
Inhibitor-based modulation of huntingtin aggregation mechanisms reduces fibril toxicity DOI Creative Commons
Greeshma Jain, Marina Trombetta-Lima, Irina Matlahov

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: April 25, 2023

Abstract Huntington’s disease (HD) is a neurodegenerative disorder in which mutated fragments of the huntingtin protein (Htt) undergo misfolding and aggregation. Since misfolded aggregated proteins can cause cellular stress cytotoxicity, there an interest development small molecule aggregation inhibitors as potential modulators HD pathogenesis. Here, we study how polyphenol modulates mechanism exon 1 (HttEx1) even at sub-stoichiometric ratios. Sub-stoichiometric amounts curcumin impacted primary and/or secondary nucleation events, extending pre-aggregation lag phase. Remarkably, disrupted process changed both aggregate structure its cell metabolic properties. When administered to neuronal cells, ‘break-through’ aggregates induced significantly reduced compared formed absence inhibitors. Structural analysis by electron microscopy, angle X-ray scattering (SAXS), solid-state NMR spectroscopy identified changes fibril structures, probing flanking domains that form fuzzy coat, well core. The biggest affected latter, propose relate presence or polyglutamine (polyQ) β-hairpin structures. Our findings highlight multifaceted consequences modulate landscape, with implications for treatment strategies other amyloid disorders.

Language: Английский

Citations

3
The Underestimated Role of Iron in Frontotemporal Dementia: A Narrative Review DOI Open Access

Sara Ferretti,

Isabella Zanella

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(23), P. 12987 - 12987

Published: Dec. 3, 2024

The term frontotemporal dementia (FTD) comprises a group of neurodegenerative disorders characterized by the progressive degeneration frontal and temporal lobes brain with language impairment changes in cognitive, behavioral executive functions, some cases motor manifestations. A high proportion FTD are due to genetic mutations inherited an autosomal-dominant manner variable penetrance depending on implicated gene. Iron is crucial microelement that involved several cellular essential functions whole body plays additional specialized roles central nervous system (CNS) mainly through its redox-cycling properties. Such feature may be harmful under aerobic conditions, since it lead generation highly reactive hydroxyl radicals. Dysfunctions iron homeostasis CNS indeed disorders, although still challenging determine whether dyshomeostasis this but metal direct cause neurodegeneration, contributor factor or simply consequence other mechanisms. Unlike many evidence dysfunction scarce; nonetheless, recent literature intriguingly suggests possible involvement. present review aims summarize what currently known about contribution based clinical, imaging, histological, biochemical molecular studies, further suggesting new perspectives offering insights for future investigations underexplored field research.

Language: Английский

Citations

0
Solvatochromic Fluorescent Probe for Visualizing Protein Aggregation via STED Imaging DOI
Wanhao Sun, Yaqing Zhang, Hongbing Fu

et al.

Analytical Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 30, 2024

Elucidating the structure of protein aggregates is vital for overcoming human diseases arising from misfolding. It rarely reported that conventional protein-amyloid fibrillation probe ThT can be used as a STED agent to visualize aggregation structures at nanometer level, suffering small Stokes' shift and photobleaching. Herein, we report donor–acceptor (D–A)-type fluorophore, IAD2, with red emission large (196 nm). demonstrated IAD2 exhibited 7.8-fold enhancement on fluorescence intensity an obvious 94 nm blue wavelength after binding bovine insulin fibril, due alternation microenvironment. Besides, has relatively higher affinity fibrils in comparison ThT. Molecular docking assay also verified sites interaction forces between fibrils. Owing its high depletion efficiency good photostability, was utilized stain achieve imaging resolution 101.2 nm. This study will shed light design novel solvatochromic fluorescent super-resolution aggregate structure.

Language: Английский

Citations

0