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Liu H, Cui Y, Zhao X, Wei L, Wang X, Shen N, Odom T, Li X, Lawless W, Karunarathne K, Muschol M, Guida W, Cao C, Ye L, Cai J. Helical sulfonyl-γ-AApeptides modulating Aβ oligomerization and cytotoxicity by recognizing Aβ helix. Proc Natl Acad Sci U S A 2024; 121:e2311733121. [PMID: 38285951 PMCID: PMC10861862 DOI: 10.1073/pnas.2311733121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 12/10/2023] [Indexed: 01/31/2024] Open
Abstract
In contrast to prevalent strategies which make use of β-sheet mimetics to block Aβ fibrillar growth, in this study, we designed a series of sulfonyl-γ-AApeptide helices that targeted the crucial α-helix domain of Aβ13-26 and stabilized Aβ conformation to avoid forming the neurotoxic Aβ oligomeric β-sheets. Biophysical assays such as amyloid kinetics and TEM demonstrated that the Aβ oligomerization and fibrillation could be greatly prevented and even reversed in the presence of sulfonyl-γ-AApeptides in a sequence-specific and dose-dependent manner. The studies based on circular dichroism, Two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR) spectra unambiguously suggested that the sulfonyl-γ-AApeptide Ab-6 could bind to the central region of Aβ42 and induce α-helix conformation in Aβ. Additionally, Electrospray ionisation-ion mobility spectrometry-mass spectrometry (ESI-IMS-MS) was employed to rule out a colloidal mechanism of inhibitor and clearly supported the capability of Ab-6 for inhibiting the formation of Aβ aggregated forms. Furthermore, Ab-6 could rescue neuroblastoma cells by eradicating Aβ-mediated cytotoxicity even in the presence of pre-formed Aβ aggregates. The confocal microscopy demonstrated that Ab-6 could still specifically bind Aβ42 and colocalize into mitochondria in the cellular environment, suggesting the rescue of cell viability might be due to the protection of mitochondrial function otherwise impaired by Aβ42 aggregation. Taken together, our studies indicated that sulfonyl-γ-AApeptides as helical peptidomimetics could direct Aβ into the off-pathway helical secondary structure, thereby preventing the formation of Aβ oligomerization, fibrillation and rescuing Aβ induced cell cytotoxicity.
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Affiliation(s)
- Heng Liu
- Department of Chemistry, University of South Florida, Tampa, FL33620
| | - Yunpeng Cui
- Department of Chemistry, University of South Florida, Tampa, FL33620
| | - Xue Zhao
- Department of Chemistry, University of South Florida, Tampa, FL33620
| | - Lulu Wei
- Department of Chemistry, University of South Florida, Tampa, FL33620
| | - Xudong Wang
- Department of Molecular Biosciences, University of South Florida, Tampa, FL33620
| | - Ning Shen
- Department of Chemistry, University of South Florida, Tampa, FL33620
| | - Timothy Odom
- Department of Chemistry, University of South Florida, Tampa, FL33620
| | - Xuming Li
- Department of Chemistry, University of South Florida, Tampa, FL33620
| | - William Lawless
- Department of Chemistry, University of South Florida, Tampa, FL33620
| | | | - Martin Muschol
- Department of Physics, University of South Florida, Tampa, FL33620
| | - Wayne Guida
- Department of Chemistry, University of South Florida, Tampa, FL33620
| | - Chuanhai Cao
- Taneja College of Pharmacy, University of South Florida, Tampa, FL33612
| | - Libin Ye
- Department of Molecular Biosciences, University of South Florida, Tampa, FL33620
| | - Jianfeng Cai
- Department of Chemistry, University of South Florida, Tampa, FL33620
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Niyangoda C, Barton J, Bushra N, Karunarathne K, Strauss G, Fakhre F, Koria P, Muschol M. Origin, toxicity and characteristics of two amyloid oligomer polymorphs. RSC Chem Biol 2021; 2:1631-1642. [PMID: 34977578 PMCID: PMC8637835 DOI: 10.1039/d1cb00081k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 08/18/2021] [Indexed: 11/25/2022] Open
Abstract
There is compelling evidence that small oligomeric aggregates, emerging during the assembly of amyloid fibrils and plaques, are important molecular pathogens in many amyloid diseases. While significant progress has been made in revealing the mechanisms underlying fibril growth, understanding how amyloid oligomers fit into the fibril assembly process, and how they contribute to the pathogenesis of amyloid diseases, has remained elusive. Commonly, amyloid oligomers are considered to be metastable, early-stage precursors to fibril formation that are either on- or off-pathway from fibril growth. In addition, amyloid oligomers have been reported to colocalize with late-stage fibrils and plaques. Whether these early and late-stage oligomer species are identical or distinct, and whether both are relevant to pathogenesis remains unclear. Here we report on the formation of two distinct oligomer species of lysozyme, formed either during the early or late-stages of in vitro fibril growth. We further observe that the pH change from in vitro growth conditions to cell media used for toxicity studies induced distinct mesoscopic precipitates, two of which resemble either diffuse or neuritic plaques seen in Alzheimer's histology. Our biophysical characterization indicates that both oligomer species share morphological and tinctorial features considered characteristic for amyloid oligomers. At the same time, their sizes, morphologies, their immunostaining, detailed tinctorial profiles and, most prominently, their biological activity are clearly distinct from each other. Probing the conditions promoting the formation of these two distinct oligomer species suggests distinct roles of charge interactions, hydrophobicity and monomer flexibility in directing oligomer assembly.
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Affiliation(s)
| | - Jeremy Barton
- Dept. of Physics, University of South Florida Tampa FL 33620 USA
| | - Nabila Bushra
- Dept. of Physics, University of South Florida Tampa FL 33620 USA
| | | | - Graham Strauss
- Dept. of Chemical and Biomedical Engineering, University of South Florida Tampa FL 33620 USA
| | - Fadia Fakhre
- Dept. of Physics, University of South Florida Tampa FL 33620 USA
| | - Piyush Koria
- Dept. of Chemical and Biomedical Engineering, University of South Florida Tampa FL 33620 USA
| | - Martin Muschol
- Dept. of Physics, University of South Florida Tampa FL 33620 USA
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Batuwanthudawe R, Karunarathne K, Dassanayake M, de Silva S, Lalitha M, Thomas K, Steinhoff M, Abeysinghe N. Surveillance of Invasive Pneumococcal Disease in Colombo, Sri Lanka. Clin Infect Dis 2009; 48 Suppl 2:S136-40. [DOI: 10.1086/596492] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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