1
|
Prosswimmer T, Heng A, Daggett V. Mechanistic insights into the role of amyloid-β in innate immunity. Sci Rep 2024; 14:5376. [PMID: 38438446 PMCID: PMC10912764 DOI: 10.1038/s41598-024-55423-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 02/23/2024] [Indexed: 03/06/2024] Open
Abstract
Colocalization of microbial pathogens and the β-amyloid peptide (Aβ) in the brain of Alzheimer's disease (AD) patients suggests that microbial infection may play a role in sporadic AD. Aβ exhibits antimicrobial activity against numerous pathogens, supporting a potential role for Aβ in the innate immune response. While mammalian amyloid is associated with disease, many bacteria form amyloid fibrils to fortify the biofilm that protects the cells from the surrounding environment. In the microbial AD hypothesis, Aβ aggregates in response to infection to combat the pathogen. We hypothesize that this occurs through toxic Aβ oligomers that contain α-sheet structure and form prior to fibrillization. De novo designed α-sheet peptides specifically bind to the α-sheet structure present in the oligomers of both bacterial and mammalian amyloidogenic proteins to neutralize toxicity and inhibit aggregation. Here, we measure the effect of E. coli on Aβ, including upregulation, aggregation, and toxicity. Additionally, we determined the effect of Aβ structure on E. coli amyloid fibrils, or curli comprised of the CsgA protein, and biofilm formation. We found that curli formation by E. coli increased Aβ oligomer production, and Aβ oligomers inhibited curli biogenesis and reduced biofilm cell density. Further, curli and biofilm inhibition by Aβ oligomers increased E. coli susceptibility to gentamicin. Toxic oligomers of Aβ and CsgA interact via α-sheet interactions, neutralizing their toxicity. These results suggest that exposure to toxic oligomers formed by microbial pathogens triggers Aβ oligomer upregulation and aggregation to combat infection via selective interactions between α-sheet oligomers to neutralize toxicity of both species with subsequent inhibition of fibrillization.
Collapse
Affiliation(s)
- Tatum Prosswimmer
- Molecular Engineering Program, University of Washington, Seattle, WA, 98195-5610, USA
| | - Anthony Heng
- Department of Neuroscience, University of Washington, Seattle, WA, 98195-5610, USA
- Department of Biochemistry, University of Washington, Seattle, WA, 98195-5610, USA
| | - Valerie Daggett
- Molecular Engineering Program, University of Washington, Seattle, WA, 98195-5610, USA.
- Department of Biochemistry, University of Washington, Seattle, WA, 98195-5610, USA.
- Department of Bioengineering, University of Washington, Seattle, WA, 98195-5610, USA.
| |
Collapse
|
2
|
Lathe R, Schultek NM, Balin BJ, Ehrlich GD, Auber LA, Perry G, Breitschwerdt EB, Corry DB, Doty RL, Rissman RA, Nara PL, Itzhaki R, Eimer WA, Tanzi RE. Establishment of a consensus protocol to explore the brain pathobiome in patients with mild cognitive impairment and Alzheimer's disease: Research outline and call for collaboration. Alzheimers Dement 2023; 19:5209-5231. [PMID: 37283269 PMCID: PMC10918877 DOI: 10.1002/alz.13076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 03/06/2023] [Indexed: 06/08/2023]
Abstract
Microbial infections of the brain can lead to dementia, and for many decades microbial infections have been implicated in Alzheimer's disease (AD) pathology. However, a causal role for infection in AD remains contentious, and the lack of standardized detection methodologies has led to inconsistent detection/identification of microbes in AD brains. There is a need for a consensus methodology; the Alzheimer's Pathobiome Initiative aims to perform comparative molecular analyses of microbes in post mortem brains versus cerebrospinal fluid, blood, olfactory neuroepithelium, oral/nasopharyngeal tissue, bronchoalveolar, urinary, and gut/stool samples. Diverse extraction methodologies, polymerase chain reaction and sequencing techniques, and bioinformatic tools will be evaluated, in addition to direct microbial culture and metabolomic techniques. The goal is to provide a roadmap for detecting infectious agents in patients with mild cognitive impairment or AD. Positive findings would then prompt tailoring of antimicrobial treatments that might attenuate or remit mounting clinical deficits in a subset of patients.
Collapse
Affiliation(s)
- Richard Lathe
- Division of Infection Medicine, Chancellor's Building, University of Edinburgh Medical School, Edinburgh, UK
| | | | - Brian J. Balin
- Department of Bio-Medical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA 19131, USA
| | - Garth D. Ehrlich
- Center for Genomic Sciences, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | | | - George Perry
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Edward B. Breitschwerdt
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
| | - David B. Corry
- Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Richard L. Doty
- Smell and Taste Center, Department of Otorhinolaryngology: Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert A. Rissman
- Department of Neurosciences, University of California, San Diego and VA San Diego Healthcare System, La Jolla, CA
| | | | - Ruth Itzhaki
- Institute of Population Ageing, University of Oxford, Oxford, UK
| | - William A. Eimer
- Genetics and Aging Research Unit, Mass General Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
- McCance Cancer Center for Brain Health, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Rudolph E. Tanzi
- Genetics and Aging Research Unit, Mass General Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
- McCance Cancer Center for Brain Health, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Intracell Research Group Consortium Collaborators
- David L. Hahn (Intracell Research Group, USA), Benedict C. Albensi (Nova Southeastern, USA), James St John (Griffith University, Australia), Jenny Ekberg (Griffith University, Australia), Mark L. Nelson (Intracell Research Group, USA), Gerald McLaughlin (National Institutes of Health, USA), Christine Hammond (Philadelphia College of Osteopathic Medicine, USA), Judith Whittum-Hudson (Wayne State University, USA), Alan P. Hudson (Wayne State University, USA), Guillaume Sacco (Université Cote d’Azur, Centre Hospitalier Universitaire de Nice, CoBTek, France), Alexandra Konig (Université Cote d’Azur and CoBTek, France), Bruno Pietro Imbimbo (Chiesi Farmaceutici, Parma, Italy), Nicklas Linz (Ki Elements Ltd, Saarbrücken, Germany), Nicole Danielle Bell (Author, 'What Lurks in the Woods'), Shima T. Moein (Smell and Taste Center, Department of Otorhinolaryngology, Perelman School of Medicine, University of Philadelphia, USA), Jürgen G. Haas (Infection Medicine, University of Edinburgh Medical School, UK)
| |
Collapse
|
3
|
Lindblom N, Lindquist L, Westman J, Åström M, Bullock R, Hendrix S, Wahlund LO. Potential Virus Involvement in Alzheimer's Disease: Results from a Phase IIa Trial Evaluating Apovir, an Antiviral Drug Combination. J Alzheimers Dis Rep 2021; 5:413-431. [PMID: 34189413 PMCID: PMC8203284 DOI: 10.3233/adr-210301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Background: Accumulating data suggest infectious agents are involved in Alzheimer’s disease (AD). The two primary aims of this trial were to assess safety and efficacy of an antiviral drug combination on AD progression. Objective: The trial evaluated whether Apovir, a combination of two antiviral agents, pleconaril (active on enteroviruses) and ribavirin (active on several viruses), could slow AD progression. Methods: Sixty-nine patients 60–85 years were treated with Apovir or placebo for 9 months and followed until 12 months after end of treatment. Cognitive tests, safety, biomarkers, drug plasma, and cerebrospinal fluid concentrations were assessed. Results: The tolerability of Apovir was compromised as demonstrated by the large drop-out rate and increased frequency and severity of adverse events. The primary endpoint, demonstrating a difference in change from baseline to 9 months between groups in ADAS-cog total score, was not met (p = 0.1809). However, there were observations indicating potential effects on both ADAS-cog and CDR-SB but these effects need to be verified. Also, there was a decrease in cerebrospinal fluid amyloid-β in Apovir at 9 months (p = 0.0330) but no change in placebo. Conclusion: This was the first randomized, placebo controlled clinical trial exploring antiviral treatment on AD progression. The trial is considered inconclusive due to the large drop-out rate. New trials are needed to verify if the indications of effect observed can be confirmed and which component(s) in Apovir contributed to such effects. Pleconaril alone may be studied to improve the tolerability and to verify if enterovirus is involved in the disease process.
Collapse
Affiliation(s)
| | - Lars Lindquist
- Clinic for Infectious Diseases and Institution of Medicine, Karolinska University Hospital and Karolinska Institutet, Huddinge, Sweden
| | | | | | | | | | - Lars-Olof Wahlund
- NVS Department, Section of Clinical Geriatrics, Karolinska Institutet and Karolinska University Hospital, Huddinge, Sweden
| |
Collapse
|
4
|
Jones TPW, Buckland M, Breuer J, Lowe DM. Viral infection in primary antibody deficiency syndromes. Rev Med Virol 2019; 29:e2049. [PMID: 31016825 DOI: 10.1002/rmv.2049] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 03/24/2019] [Accepted: 03/25/2019] [Indexed: 12/22/2022]
Abstract
Patients with primary antibody deficiency syndromes such as X-linked agammaglobulinemia (XLA) and common variable immunodeficiency (CVID) are at increased risk of severe and invasive infection. Viral infection in these populations has been of increasing interest as evidence mounts that viruses contribute significant morbidity and mortality: this is mediated both directly and via aberrant immune responses. We explain the importance of the humoral immune system in defence against viral pathogens before highlighting several significant viral syndromes in patients with antibody deficiency. We explore historical cases of hepatitis C via contaminated immunoglobulin products, the predisposition to invasive enteroviral infections, prolonged excretion of vaccine-derived poliovirus, the morbidity of chronic norovirus infection, and recent literature revealing the importance of respiratory viral infections. We discuss evidence that herpesviruses may play a role in driving the inflammatory disease seen in a subset of patients. We explore the phenomenon of within-host evolution during chronic viral infection and the potential emergence of new pathogenic strains. We highlight novel and emerging viruses identified via deep sequencing techniques. We describe the treatment strategies that have been attempted in all these scenarios and the urgent outstanding questions for research.
Collapse
Affiliation(s)
- Timothy P W Jones
- Department of Infectious Disease and Microbiology, Royal Free Hospital, London, UK
| | - Matthew Buckland
- Institute of Immunity and Transplantation, Royal Free Campus, University College, London, UK
| | - Judith Breuer
- Division of Infection and Immunity, University College London, London, UK
| | - David M Lowe
- Institute of Immunity and Transplantation, Royal Free Campus, University College, London, UK
| |
Collapse
|
5
|
Schulz R, Atef A, Becker D, Gottschalk F, Tauber C, Wagner S, Arkona C, Abdel-Hafez AA, Farag HH, Rademann J, Wolber G. Phenylthiomethyl Ketone-Based Fragments Show Selective and Irreversible Inhibition of Enteroviral 3C Proteases. J Med Chem 2018; 61:1218-1230. [PMID: 29328649 DOI: 10.1021/acs.jmedchem.7b01440] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Lead structure discovery mainly focuses on the identification of noncovalently binding ligands. Covalent linkage, however, is an essential binding mechanism for a multitude of successfully marketed drugs, although discovered by serendipity in most cases. We present a concept for the design of fragments covalently binding to proteases. Covalent linkage enables fragment binding unrelated to affinity to shallow protein binding sites and at the same time allows differentiated targeted hit verification and binding location verification through mass spectrometry. We describe a systematic and rational computational approach for the identification of covalently binding fragments from compound collections inhibiting enteroviral 3C protease, a target with high therapeutic potential. By implementing reactive groups potentially forming covalent bonds as a chemical feature in our 3D pharmacophore methodology, covalent binders were discovered by high-throughput virtual screening. We present careful experimental validation of the virtual hits using enzymatic assays and mass spectrometry unraveling a novel, previously unknown irreversible inhibition of the 3C protease by phenylthiomethyl ketone-based fragments. Subsequent synthetic optimization through fragment growing and reactivity analysis against catalytic and noncatalytic cysteines revealed specific irreversible 3C protease inhibition.
Collapse
Affiliation(s)
- Robert Schulz
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin , Königin-Luise Straße 2+4, Berlin 14195, Germany
| | - Amira Atef
- Medicinal Chemistry Department, Faculty of Pharmacy, Assiut University , Assiut 71526, Egypt
| | - Daniel Becker
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin , Königin-Luise Straße 2+4, Berlin 14195, Germany
| | - Franziska Gottschalk
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin , Königin-Luise Straße 2+4, Berlin 14195, Germany
| | - Carolin Tauber
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin , Königin-Luise Straße 2+4, Berlin 14195, Germany
| | - Stefan Wagner
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin , Königin-Luise Straße 2+4, Berlin 14195, Germany
| | - Christoph Arkona
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin , Königin-Luise Straße 2+4, Berlin 14195, Germany
| | - Atef A Abdel-Hafez
- Medicinal Chemistry Department, Faculty of Pharmacy, Assiut University , Assiut 71526, Egypt
| | - Hassan H Farag
- Medicinal Chemistry Department, Faculty of Pharmacy, Assiut University , Assiut 71526, Egypt
| | - Jörg Rademann
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin , Königin-Luise Straße 2+4, Berlin 14195, Germany
| | - Gerhard Wolber
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin , Königin-Luise Straße 2+4, Berlin 14195, Germany
| |
Collapse
|