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Ong ZWEBB. Unravelling bacterial virulence factors in yeast: From identification to the elucidation of their mechanisms of action. Arch Microbiol 2024; 206:303. [PMID: 38878203 DOI: 10.1007/s00203-024-04023-2] [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: 04/19/2024] [Revised: 05/21/2024] [Accepted: 05/29/2024] [Indexed: 06/23/2024]
Abstract
Pathogenic bacteria employ virulence factors (VF) to establish infection and cause disease in their host. Yeasts, Saccharomyces cerevisiae and Saccharomyces pombe, are useful model organisms to study the functions of bacterial VFs and their interaction with targeted cellular processes because yeast processes and organelle structures are highly conserved and similar to higher eukaryotes. In this review, we describe the principles and applications of the yeast model for the identification and functional characterisation of bacterial VFs to investigate bacterial pathogenesis. The growth inhibition phenotype caused by the heterologous expression of bacterial VFs in yeast is commonly used to identify candidate VFs. Then, subcellular localisation patterns of bacterial VFs can provide further clues about their target molecules and functions during infection. Yeast knockout and overexpression libraries are also used to investigate VF interactions with conserved eukaryotic cell structures (e.g., cytoskeleton and plasma membrane), and cellular processes (e.g., vesicle trafficking, signalling pathways, and programmed cell death). In addition, the yeast growth inhibition phenotype is also useful for screening new drug leads that target and inhibit bacterial VFs. This review provides an updated overview of new tools, principles and applications to study bacterial VFs in yeast.
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2
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Balczon R, Lin MT, Voth S, Nelson AR, Schupp JC, Wagener BM, Pittet JF, Stevens T. Lung endothelium, tau, and amyloids in health and disease. Physiol Rev 2024; 104:533-587. [PMID: 37561137 DOI: 10.1152/physrev.00006.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 06/26/2023] [Accepted: 08/04/2023] [Indexed: 08/11/2023] Open
Abstract
Lung endothelia in the arteries, capillaries, and veins are heterogeneous in structure and function. Lung capillaries in particular represent a unique vascular niche, with a thin yet highly restrictive alveolar-capillary barrier that optimizes gas exchange. Capillary endothelium surveys the blood while simultaneously interpreting cues initiated within the alveolus and communicated via immediately adjacent type I and type II epithelial cells, fibroblasts, and pericytes. This cell-cell communication is necessary to coordinate the immune response to lower respiratory tract infection. Recent discoveries identify an important role for the microtubule-associated protein tau that is expressed in lung capillary endothelia in the host-pathogen interaction. This endothelial tau stabilizes microtubules necessary for barrier integrity, yet infection drives production of cytotoxic tau variants that are released into the airways and circulation, where they contribute to end-organ dysfunction. Similarly, beta-amyloid is produced during infection. Beta-amyloid has antimicrobial activity, but during infection it can acquire cytotoxic activity that is deleterious to the host. The production and function of these cytotoxic tau and amyloid variants are the subject of this review. Lung-derived cytotoxic tau and amyloid variants are a recently discovered mechanism of end-organ dysfunction, including neurocognitive dysfunction, during and in the aftermath of infection.
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Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Mike T Lin
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Sarah Voth
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine, Monroe, Louisiana, United States
| | - Amy R Nelson
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Jonas C Schupp
- Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yale University, New Haven, Connecticut, United States
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
- German Center for Lung Research (DZL), Hannover, Germany
| | - Brant M Wagener
- Department of Anesthesiology and Perioperative Medicine, University of Alabama-Birmingham, Birmingham, Alabama, United States
| | - Jean-Francois Pittet
- Department of Anesthesiology and Perioperative Medicine, University of Alabama-Birmingham, Birmingham, Alabama, United States
| | - Troy Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Department of Internal Medicine, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
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3
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Balczon R, Choi CS, deWeever A, Zhou C, Gwin MS, Kolb C, Francis CM, Lin MT, Stevens T. Infection promotes Ser-214 phosphorylation important for generation of cytotoxic tau variants. FASEB J 2023; 37:e23042. [PMID: 37358817 DOI: 10.1096/fj.202300620rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/02/2023] [Accepted: 06/07/2023] [Indexed: 06/27/2023]
Abstract
Patients who recover from hospital-acquired pneumonia exhibit a high incidence of end-organ dysfunction following hospital discharge, including cognitive deficits. We have previously demonstrated that pneumonia induces the production and release of cytotoxic oligomeric tau from pulmonary endothelial cells, and these tau oligomers can enter the circulation and may be a cause of long-term morbidities. Endothelial-derived oligomeric tau is hyperphosphorylated during infection. The purpose of these studies was to determine whether Ser-214 phosphorylation of tau is a necessary stimulus for generation of cytotoxic tau variants. The results of these studies demonstrate that Ser-214 phosphorylation is critical for the cytotoxic properties of infection-induced oligomeric tau. In the lung, Ser-214 phosphorylated tau contributes to disruption of the alveolar-capillary barrier, resulting in increased permeability. However, in the brain, both the Ser-214 phosphorylated tau and the mutant Ser-214-Ala tau, which cannot be phosphorylated, disrupted hippocampal long-term potentiation suggesting that inhibition of long-term potentiation was relatively insensitive to the phosphorylation status of Ser-214. Nonetheless, phosphorylation of tau is essential to its cytotoxicity since global dephosphorylation of the infection-induced cytotoxic tau variants rescued long-term potentiation. Collectively, these data demonstrate that multiple forms of oligomeric tau are generated during infectious pneumonia, with different forms of oligomeric tau being responsible for dysfunction of distinct end-organs during pneumonia.
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Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Chung-Sik Choi
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Althea deWeever
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Chun Zhou
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Meredith S Gwin
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Claire Kolb
- Department of Biochemistry and Molecular Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - C Michael Francis
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Mike T Lin
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Troy Stevens
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
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4
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Hussong SA, Banh AQ, Van Skike CE, Dorigatti AO, Hernandez SF, Hart MJ, Ferran B, Makhlouf H, Gaczynska M, Osmulski PA, McAllen SA, Dineley KT, Ungvari Z, Perez VI, Kayed R, Galvan V. Soluble pathogenic tau enters brain vascular endothelial cells and drives cellular senescence and brain microvascular dysfunction in a mouse model of tauopathy. Nat Commun 2023; 14:2367. [PMID: 37185259 PMCID: PMC10126555 DOI: 10.1038/s41467-023-37840-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 03/31/2023] [Indexed: 05/17/2023] Open
Abstract
Vascular mechanisms of Alzheimer's disease (AD) may constitute a therapeutically addressable biological pathway underlying dementia. We previously demonstrated that soluble pathogenic forms of tau (tau oligomers) accumulate in brain microvasculature of AD and other tauopathies, including prominently in microvascular endothelial cells. Here we show that soluble pathogenic tau accumulates in brain microvascular endothelial cells of P301S(PS19) mice modeling tauopathy and drives AD-like brain microvascular deficits. Microvascular impairments in P301S(PS19) mice were partially negated by selective removal of pathogenic soluble tau aggregates from brain. We found that similar to trans-neuronal transmission of pathogenic forms of tau, soluble tau aggregates are internalized by brain microvascular endothelial cells in a heparin-sensitive manner and induce microtubule destabilization, block endothelial nitric oxide synthase (eNOS) activation, and potently induce endothelial cell senescence that was recapitulated in vivo in microvasculature of P301S(PS19) mice. Our studies suggest that soluble pathogenic tau aggregates mediate AD-like brain microvascular deficits in a mouse model of tauopathy, which may arise from endothelial cell senescence and eNOS dysfunction triggered by internalization of soluble tau aggregates.
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Affiliation(s)
- Stacy A Hussong
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Oklahoma City Veterans Health Care System, 921 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Andy Q Banh
- South Texas Medical Scientist Training Program, University of Texas Health San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Candice E Van Skike
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Angela O Dorigatti
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Stephen F Hernandez
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
| | - Matthew J Hart
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Center for Therapeutic Science, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
| | - Beatriz Ferran
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
| | - Haneen Makhlouf
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
| | - Maria Gaczynska
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
| | - Pawel A Osmulski
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, 4939 Charles Katz Drive, San Antonio, TX, 78229, USA
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
| | - Salome A McAllen
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Mitchell Center for Neurodegenerative Disease, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Sealy Center for Vaccine Development, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
| | - Kelly T Dineley
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Mitchell Center for Neurodegenerative Disease, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Sealy Center for Vaccine Development, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
| | - Zoltan Ungvari
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- Department of Neurosurgery, University of Oklahoma Health Sciences Center, 800 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine, Department of Public Health, Semmelweis University, H-1085 Budapest, Üllői út 26, Budapest, Hungary
| | | | - Rakez Kayed
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Mitchell Center for Neurodegenerative Disease, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
- Sealy Center for Vaccine Development, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
| | - Veronica Galvan
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA.
- Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 940 Stanton L Young Blvd, Oklahoma City, OK, 73104, USA.
- Oklahoma City Veterans Health Care System, 921 NE 13th Street, Oklahoma City, OK, 73104, USA.
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Arbov E, Tayara A, Wu S, Rich TC, Wagener BM. COVID-19 and Long-Term Outcomes: Lessons from Other Critical Care Illnesses and Potential Mechanisms. Am J Respir Cell Mol Biol 2022; 67:275-283. [PMID: 35348443 PMCID: PMC9447134 DOI: 10.1165/rcmb.2021-0374ps] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 03/28/2022] [Indexed: 01/08/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that is currently causing a pandemic and has been termed coronavirus disease (COVID-19). The elderly or those with preexisting conditions like diabetes, hypertension, coronary heart disease, chronic obstructive pulmonary disease, cerebrovascular disease, or kidney dysfunction are more likely to develop severe cases when infected. Patients with COVID-19 admitted to the ICU have higher mortality than non-ICU patients. Critical illness has consistently posed a challenge not only in terms of mortality but also in regard to long-term outcomes of survivors. Patients who survive acute critical illness including, but not limited to, pulmonary and systemic insults associated with acute respiratory distress syndrome, pneumonia, systemic inflammation, and mechanical ventilation, will likely suffer from post-ICU syndrome, a phenomenon of cognitive, psychiatric, and/or physical disability after treatment in the ICU. Post-ICU morbidity and mortality continue to be a cause for concern when considering large-scale studies showing 12-month mortality risks of 11.8-21%. Previous studies have demonstrated that multiple mechanisms, including cytokine release, mitochondrial dysfunction, and even amyloids, may lead to end-organ dysfunction in patients. We hypothesize that COVID-19 infection will lead to post-ICU syndrome via potentially similar mechanisms as other chronic critical illnesses and cause long-term morbidity and mortality in patients. We consider a variety of mechanisms and questions that not only consider the short-term impact of the COVID-19 pandemic but its long-term effects that may not yet be imagined.
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Affiliation(s)
- Eli Arbov
- Morehouse School of Medicine, Atlanta, Georgia
| | - Alia Tayara
- Department of Biomedical Sciences
- Honors College
| | - Songwei Wu
- Divisions of Molecular and Translational Biomedicine and
| | - Thomas C. Rich
- Department of Pharmacology, and
- Center for Lung Biology, University of South Alabama, Mobile, Alabama; and
| | - Brant M. Wagener
- Divisions of Molecular and Translational Biomedicine and
- Critical Care Medicine, Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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6
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Teixeira-Nunes M, Retailleau P, Comisso M, Deruelle V, Mechold U, Renault L. Bacterial Nucleotidyl Cyclases Activated by Calmodulin or Actin in Host Cells: Enzyme Specificities and Cytotoxicity Mechanisms Identified to Date. Int J Mol Sci 2022; 23:ijms23126743. [PMID: 35743184 PMCID: PMC9223806 DOI: 10.3390/ijms23126743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 02/06/2023] Open
Abstract
Many pathogens manipulate host cell cAMP signaling pathways to promote their survival and proliferation. Bacterial Exoenzyme Y (ExoY) toxins belong to a family of invasive, structurally-related bacterial nucleotidyl cyclases (NC). Inactive in bacteria, they use proteins that are uniquely and abundantly present in eukaryotic cells to become potent, unregulated NC enzymes in host cells. Other well-known members of the family include Bacillus anthracis Edema Factor (EF) and Bordetella pertussis CyaA. Once bound to their eukaryotic protein cofactor, they can catalyze supra-physiological levels of various cyclic nucleotide monophosphates in infected cells. Originally identified in Pseudomonas aeruginosa, ExoY-related NC toxins appear now to be more widely distributed among various γ- and β-proteobacteria. ExoY-like toxins represent atypical, poorly characterized members within the NC toxin family. While the NC catalytic domains of EF and CyaA toxins use both calmodulin as cofactor, their counterparts in ExoY-like members from pathogens of the genus Pseudomonas or Vibrio use actin as a potent cofactor, in either its monomeric or polymerized form. This is an original subversion of actin for cytoskeleton-targeting toxins. Here, we review recent advances on the different members of the NC toxin family to highlight their common and distinct functional characteristics at the molecular, cytotoxic and enzymatic levels, and important aspects that need further characterizations.
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Affiliation(s)
- Magda Teixeira-Nunes
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France; (M.T.-N.); (M.C.)
| | - Pascal Retailleau
- Institut de Chimie des Substances Naturelles (ICSN), CNRS-UPR2301, Université Paris-Saclay, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette, France;
| | - Martine Comisso
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France; (M.T.-N.); (M.C.)
| | - Vincent Deruelle
- Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, CNRS UMR 3528, Institut Pasteur, 75015 Paris, France; (V.D.); (U.M.)
| | - Undine Mechold
- Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, CNRS UMR 3528, Institut Pasteur, 75015 Paris, France; (V.D.); (U.M.)
| | - Louis Renault
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France; (M.T.-N.); (M.C.)
- Correspondence:
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7
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Nelson AR. Peripheral Pathways to Neurovascular Unit Dysfunction, Cognitive Impairment, and Alzheimer’s Disease. Front Aging Neurosci 2022; 14:858429. [PMID: 35517047 PMCID: PMC9062225 DOI: 10.3389/fnagi.2022.858429] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/03/2022] [Indexed: 12/11/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia. It was first described more than a century ago, and scientists are acquiring new data and learning novel information about the disease every day. Although there are nuances and details continuously being unraveled, many key players were identified in the early 1900’s by Dr. Oskar Fischer and Dr. Alois Alzheimer, including amyloid-beta (Aβ), tau, vascular abnormalities, gliosis, and a possible role of infections. More recently, there has been growing interest in and appreciation for neurovascular unit dysfunction that occurs early in mild cognitive impairment (MCI) before and independent of Aβ and tau brain accumulation. In the last decade, evidence that Aβ and tau oligomers are antimicrobial peptides generated in response to infection has expanded our knowledge and challenged preconceived notions. The concept that pathogenic germs cause infections generating an innate immune response (e.g., Aβ and tau produced by peripheral organs) that is associated with incident dementia is worthwhile considering in the context of sporadic AD with an unknown root cause. Therefore, the peripheral amyloid hypothesis to cognitive impairment and AD is proposed and remains to be vetted by future research. Meanwhile, humans remain complex variable organisms with individual risk factors that define their immune status, neurovascular function, and neuronal plasticity. In this focused review, the idea that infections and organ dysfunction contribute to Alzheimer’s disease, through the generation of peripheral amyloids and/or neurovascular unit dysfunction will be explored and discussed. Ultimately, many questions remain to be answered and critical areas of future exploration are highlighted.
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8
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Karki P, Birukova AA. Microtubules as Major Regulators of Endothelial Function: Implication for Lung Injury. Front Physiol 2021; 12:758313. [PMID: 34777018 PMCID: PMC8582326 DOI: 10.3389/fphys.2021.758313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 10/06/2021] [Indexed: 01/04/2023] Open
Abstract
Endothelial dysfunction has been attributed as one of the major complications in COVID-19 patients, a global pandemic that has already caused over 4 million deaths worldwide. The dysfunction of endothelial barrier is characterized by an increase in endothelial permeability and inflammatory responses, and has even broader implications in the pathogenesis of acute respiratory syndromes such as ARDS, sepsis and chronic illnesses represented by pulmonary arterial hypertension and interstitial lung disease. The structural integrity of endothelial barrier is maintained by cytoskeleton elements, cell-substrate focal adhesion and adhesive cell junctions. Agonist-mediated changes in endothelial permeability are directly associated with reorganization of actomyosin cytoskeleton leading to cell contraction and opening of intercellular gaps or enhancement of cortical actin cytoskeleton associated with strengthening of endothelial barrier. The role of actin cytoskeleton remodeling in endothelial barrier regulation has taken the central stage, but the impact of microtubules in this process remains less explored and under-appreciated. This review will summarize the current knowledge on the crosstalk between microtubules dynamics and actin cytoskeleton remodeling, describe the signaling mechanisms mediating this crosstalk, discuss epigenetic regulation of microtubules stability and its nexus with endothelial barrier maintenance, and overview a role of microtubules in targeted delivery of signaling molecules regulating endothelial permeability and inflammation.
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Affiliation(s)
- Pratap Karki
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Anna A Birukova
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
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9
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Balczon R, Lin MT, Lee JY, Abbasi A, Renema P, Voth SB, Zhou C, Koloteva A, Michael Francis C, Sodha NR, Pittet JF, Wagener BM, Bell J, Choi CS, Ventetuolo CE, Stevens T. Pneumonia initiates a tauopathy. FASEB J 2021; 35:e21807. [PMID: 34384141 PMCID: PMC8443149 DOI: 10.1096/fj.202100718r] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/30/2021] [Accepted: 07/06/2021] [Indexed: 12/11/2022]
Abstract
Pneumonia causes short‐ and long‐term cognitive dysfunction in a high proportion of patients, although the mechanism(s) responsible for this effect are unknown. Here, we tested the hypothesis that pneumonia‐elicited cytotoxic amyloid and tau variants: (1) are present in the circulation during infection; (2) lead to impairment of long‐term potentiation; and, (3) inhibit long‐term potentiation dependent upon tau. Cytotoxic amyloid and tau species were recovered from the blood and the hippocampus following pneumonia, and they were present in the extracorporeal membrane oxygenation oxygenators of patients with pneumonia, especially in those who died. Introduction of immunopurified blood‐borne amyloid and tau into either the airways or the blood of uninfected animals acutely and chronically impaired hippocampal information processing. In contrast, the infection did not impair long‐term potentiation in tau knockout mice and the amyloid‐ and tau‐dependent disruption in hippocampal signaling was less severe in tau knockout mice. Moreover, the infection did not elicit cytotoxic amyloid and tau variants in tau knockout mice. Therefore, pneumonia initiates a tauopathy that contributes to cognitive dysfunction.
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Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL, USA.,Center for Lung Biology, University of South Alabama, Mobile, AL, USA
| | - Mike T Lin
- Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Department of Physiology and Cell Biology, College of Medicine, Center for Lung Biology, University of South Alabama, Mobile, AL, USA
| | - Ji Young Lee
- Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Department of Physiology and Cell Biology, College of Medicine, Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Internal Medicine, University of South Alabama, Mobile, AL, USA
| | - Adeel Abbasi
- Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Alpert Medical School of Brown University, Providence, RI, USA
| | - Phoibe Renema
- Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Department of Physiology and Cell Biology, College of Medicine, Center for Lung Biology, University of South Alabama, Mobile, AL, USA
| | - Sarah B Voth
- Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Department of Physiology and Cell Biology, College of Medicine, Center for Lung Biology, University of South Alabama, Mobile, AL, USA
| | - Chun Zhou
- Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Department of Physiology and Cell Biology, College of Medicine, Center for Lung Biology, University of South Alabama, Mobile, AL, USA
| | - Anna Koloteva
- Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Department of Physiology and Cell Biology, College of Medicine, Center for Lung Biology, University of South Alabama, Mobile, AL, USA
| | - C Michael Francis
- Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Department of Physiology and Cell Biology, College of Medicine, Center for Lung Biology, University of South Alabama, Mobile, AL, USA
| | - Neel R Sodha
- Department of Surgery, Brown University, Providence, RI, USA
| | - Jean-Francois Pittet
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brant M Wagener
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jessica Bell
- Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Department of Physiology and Cell Biology, College of Medicine, Center for Lung Biology, University of South Alabama, Mobile, AL, USA
| | - Chung-Sik Choi
- Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Department of Physiology and Cell Biology, College of Medicine, Center for Lung Biology, University of South Alabama, Mobile, AL, USA
| | - Corey E Ventetuolo
- Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Alpert Medical School of Brown University, Providence, RI, USA.,Health Services, Policy and Practice, Brown University School of Public Health, Providence, RI, USA
| | - Troy Stevens
- Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Department of Physiology and Cell Biology, College of Medicine, Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Internal Medicine, University of South Alabama, Mobile, AL, USA
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10
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cAMP Compartmentalization in Cerebrovascular Endothelial Cells: New Therapeutic Opportunities in Alzheimer's Disease. Cells 2021; 10:cells10081951. [PMID: 34440720 PMCID: PMC8392343 DOI: 10.3390/cells10081951] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/19/2021] [Accepted: 07/28/2021] [Indexed: 12/20/2022] Open
Abstract
The vascular hypothesis used to explain the pathophysiology of Alzheimer’s disease (AD) suggests that a dysfunction of the cerebral microvasculature could be the beginning of alterations that ultimately leads to neuronal damage, and an abnormal increase of the blood–brain barrier (BBB) permeability plays a prominent role in this process. It is generally accepted that, in physiological conditions, cyclic AMP (cAMP) plays a key role in maintaining BBB permeability by regulating the formation of tight junctions between endothelial cells of the brain microvasculature. It is also known that intracellular cAMP signaling is highly compartmentalized into small nanodomains and localized cAMP changes are sufficient at modifying the permeability of the endothelial barrier. This spatial and temporal distribution is maintained by the enzymes involved in cAMP synthesis and degradation, by the location of its effectors, and by the existence of anchor proteins, as well as by buffers or different cytoplasm viscosities and intracellular structures limiting its diffusion. This review compiles current knowledge on the influence of cAMP compartmentalization on the endothelial barrier and, more specifically, on the BBB, laying the foundation for a new therapeutic approach in the treatment of AD.
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11
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Morin CD, Déziel E, Gauthier J, Levesque RC, Lau GW. An Organ System-Based Synopsis of Pseudomonas aeruginosa Virulence. Virulence 2021; 12:1469-1507. [PMID: 34180343 PMCID: PMC8237970 DOI: 10.1080/21505594.2021.1926408] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Driven in part by its metabolic versatility, high intrinsic antibiotic resistance, and a large repertoire of virulence factors, Pseudomonas aeruginosa is expertly adapted to thrive in a wide variety of environments, and in the process, making it a notorious opportunistic pathogen. Apart from the extensively studied chronic infection in the lungs of people with cystic fibrosis (CF), P. aeruginosa also causes multiple serious infections encompassing essentially all organs of the human body, among others, lung infection in patients with chronic obstructive pulmonary disease, primary ciliary dyskinesia and ventilator-associated pneumonia; bacteremia and sepsis; soft tissue infection in burns, open wounds and postsurgery patients; urinary tract infection; diabetic foot ulcers; chronic suppurative otitis media and otitis externa; and keratitis associated with extended contact lens use. Although well characterized in the context of CF, pathogenic processes mediated by various P. aeruginosa virulence factors in other organ systems remain poorly understood. In this review, we use an organ system-based approach to provide a synopsis of disease mechanisms exerted by P. aeruginosa virulence determinants that contribute to its success as a versatile pathogen.
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Affiliation(s)
- Charles D Morin
- Centre Armand-Frappier Santé Biotechnologie, Institut National De La Recherche Scientifique (INRS), Laval, Quebec, Canada
| | - Eric Déziel
- Centre Armand-Frappier Santé Biotechnologie, Institut National De La Recherche Scientifique (INRS), Laval, Quebec, Canada
| | - Jeff Gauthier
- Département De Microbiologie-infectiologie Et Immunologie, Institut De Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Québec City, Quebec, Canada
| | - Roger C Levesque
- Département De Microbiologie-infectiologie Et Immunologie, Institut De Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Québec City, Quebec, Canada
| | - Gee W Lau
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, US
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12
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Pittet JF, Hu PJ, Honavar J, Brandon AP, Evans CA, Muthalaly R, Ding Q, Wagener BM. Estrogen Alleviates Sex-Dependent Differences in Lung Bacterial Clearance and Mortality Secondary to Bacterial Pneumonia after Traumatic Brain Injury. J Neurotrauma 2020; 38:989-999. [PMID: 33203297 DOI: 10.1089/neu.2020.7327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Traumatic brain injury (TBI) is the leading cause of injury-related death and disability in patients under the age of 46 years. Survivors of the initial injury often endure systemic complications such as pulmonary infection, and Pseudomonas aeruginosa is one of the most common causes of nosocomial pneumonia in intensive care units. Female patients are less likely to develop secondary pneumonia after TBI, and pre-clinical studies have revealed a salutary role for estrogen after trauma. Therefore, we hypothesized that female mice would experience less mortality after post-TBI pneumonia with P. aeruginosa. We employed a mouse model of TBI followed by P. aeruginosa pneumonia. Male mice had greater mortality and impaired lung bacterial clearance after post-TBI pneumonia compared with female mice. This was confirmed as a difference in sex hormones, as oophorectomized wild-type mice had mortality and lung bacterial clearance similar to male mice. There were differences in tumor necrosis factor-α secretion in male and female alveolar macrophages after P. aeruginosa infection. Finally, injection of male or oophorectomized wild-type female mice with estrogen restored lung bacterial clearance and prevented mortality. Our model of TBI followed by P. aeruginosa pneumonia is among the first to reveal sex dimorphism in secondary, long-term TBI complications.
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Affiliation(s)
- Jean-Francois Pittet
- Divisions of Critical Care Medicine and University of Alabama at Birmingham, Birmingham, Alabama, USA.,Molecular and Translational Biomedicine, Department of Anesthesiology and Perioperative Medicine and University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Parker J Hu
- Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jaideep Honavar
- Molecular and Translational Biomedicine, Department of Anesthesiology and Perioperative Medicine and University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Angela P Brandon
- Molecular and Translational Biomedicine, Department of Anesthesiology and Perioperative Medicine and University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Cilina A Evans
- Molecular and Translational Biomedicine, Department of Anesthesiology and Perioperative Medicine and University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Rebekah Muthalaly
- Molecular and Translational Biomedicine, Department of Anesthesiology and Perioperative Medicine and University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Qiang Ding
- Molecular and Translational Biomedicine, Department of Anesthesiology and Perioperative Medicine and University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Brant M Wagener
- Divisions of Critical Care Medicine and University of Alabama at Birmingham, Birmingham, Alabama, USA.,Molecular and Translational Biomedicine, Department of Anesthesiology and Perioperative Medicine and University of Alabama at Birmingham, Birmingham, Alabama, USA
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13
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Balczon R, Morrow KA, Leavesley S, Francis CM, Stevens TC, Agwaramgbo E, Williams C, Stevens RP, Langham G, Voth S, Cioffi EA, Weintraub SE, Stevens T. Cystatin C regulates the cytotoxicity of infection-induced endothelial-derived β-amyloid. FEBS Open Bio 2020; 10:2464-2477. [PMID: 33030263 PMCID: PMC7609779 DOI: 10.1002/2211-5463.12997] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 08/25/2020] [Accepted: 10/05/2020] [Indexed: 02/06/2023] Open
Abstract
Infection of rat pulmonary microvascular endothelial cells with the bacterium Pseudomonas aeruginosa induces the production and release of cytotoxic oligomeric tau and beta amyloid (Aβ). Here, we characterized these cytotoxic amyloids. Cytotoxic behavior and oligomeric tau were partially resistant to digestion with proteinase K, but cytotoxicity was abolished by various denaturants including phenol, diethylpyrocarbonate (DEPC), and 1,1,1,3,3,3-hexafluoro-2-isopropanol (HFIP). Ultracentrifugation for 8 h at 150 000 g was required to remove cytotoxic activity from the supernatant. Ultracentrifugation, DEPC treatment, and immunodepletion using antibodies against Aβ also demonstrated that cytoprotective protein(s) are released from endothelial cells during P. aeruginosa infection. Mass spectrometry of endothelial cell culture media following P. aeruginosa infection allowed identification of multiple potential secreted modulators of Aβ, including cystatin C, gelsolin, and ApoJ/clusterin. Immunodepletion, co-immunoprecipitation, and ultracentrifugation determined that the cytoprotective factor released during infection of endothelial cells by P. aeruginosa is cystatin C, which appears to be in a complex with Aβ. Cytoprotective cystatin C may provide a novel therapeutic avenue for protection against the long-term consequences of infection with P. aeruginosa.
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Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular BiologyUniversity of South AlabamaMobileALUSA
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
| | - Kyle A. Morrow
- Department of Cell Biology and PhysiologyEdward Via College of Osteopathic MedicineMonroeLAUSA
| | - Silas Leavesley
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Chemical and Biomedical EngineeringUniversity of South AlabamaMobileALUSA
| | - Christopher M. Francis
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | - Trevor C. Stevens
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | - Ezinne Agwaramgbo
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | | | - Reece P. Stevens
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | - Geri Langham
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | - Sarah Voth
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | - Eugene A. Cioffi
- Department of PharmacologyUniversity of South AlabamaMobileALUSA
| | - Susan E. Weintraub
- Department of Biochemistry and Structural Biology and Mass Spectrometry LaboratoryUniversity of Texas at San Antonio Health Sciences CenterTXUSA
| | - Troy Stevens
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
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14
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Renema P, Kozhukhar N, Pastukh V, Spadafora D, Paudel SS, Tambe DT, Alexeyev M, Frank DW, Stevens T. Exoenzyme Y induces extracellular active caspase-7 accumulation independent from apoptosis: modulation of transmissible cytotoxicity. Am J Physiol Lung Cell Mol Physiol 2020; 319:L380-L390. [PMID: 32579398 DOI: 10.1152/ajplung.00508.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Caspase-3 and -7 are executioner caspases whose enzymatic activity is necessary to complete apoptotic cell death. Here, we questioned whether endothelial cell infection leads to caspase-3/7-mediated cell death. Pulmonary microvascular endothelial cells (PMVECs) were infected with Pseudomonas aeruginosa (PA103). PA103 caused cell swelling with a granular appearance, paralleled by intracellular caspase-3/7 activation and cell death. In contrast, PMVEC infection with ExoY+ (PA103 ΔexoUexoT::Tc pUCPexoY) caused cell rounding, but it did not activate intracellular caspase-3/7 and it did not cause cell death. However, ExoY+ led to a time-dependent accumulation of active caspase-7, but not caspase-3, in the supernatant, independent of apoptosis. To study the function of extracellular caspase-7, caspase-7- and caspase-3-deficient PMVECs were generated using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology. Caspase-7 activity was significantly reduced in supernatants from infected caspase-7-deficient cells but was unchanged in supernatants from infected caspase-3 deficient cells, indicating an uncoupling in the mechanism of activation of these two enzymes. Because ExoY+ leads to the release of heat stable amyloid cytotoxins that are responsible for transmissible cytotoxicity, we next questioned whether caspase-7 contributes to the severity of this process. Supernatants obtained from infected caspase-7-deficient cells displayed significantly reduced transmissible cytotoxicity when compared with supernatants from infected wild-type controls, illustrating an essential role for caspase-7 in promoting the potency of transmissible cytotoxicity. Thus, we report a mechanism whereby ExoY+ infection induces active caspase-7 accumulation in the extracellular space, independent of both caspase-3 and cell death, where it modulates ExoY+-induced transmissible cytotoxicity.
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Affiliation(s)
- Phoibe Renema
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama.,Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Natalya Kozhukhar
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama.,Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Viktoriya Pastukh
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama.,Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | | | - Sunita Subedi Paudel
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama.,Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Dhananjay T Tambe
- Department of Pharmacology, University of South Alabama, Mobile, Alabama.,Department of Mechanical Engineering, University of South Alabama, Mobile, Alabama.,Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Mikhail Alexeyev
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama.,Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Dara W Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Troy Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama.,Department of Internal Medicine, University of South Alabama, Mobile, Alabama.,Center for Lung Biology, University of South Alabama, Mobile, Alabama
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15
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Pneumonia-induced endothelial amyloids reduce dendritic spine density in brain neurons. Sci Rep 2020; 10:9327. [PMID: 32518286 PMCID: PMC7283224 DOI: 10.1038/s41598-020-66321-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/14/2020] [Indexed: 12/26/2022] Open
Abstract
Pseudomonas aeruginosa pneumonia elicits endothelial cell release of cytotoxic amyloids that can be recovered from the bronchoalveolar lavage and cerebrospinal fluids of critically ill patients. Introduction of these cytotoxic amyloids into the lateral ventricle impairs learning and memory in mice. However, it is unclear whether the amyloids of lung origin (1) are neurotropic, and (2) cause structural remodeling of hippocampal dendrites. Thus, we used electrophysiological studies in brain slices and structural analysis of post-mortem tissues obtained from animals exposed to endothelium-derived amyloids to assess these issues. The amyloids were administered via three different routes, by intracerebroventricular, intratracheal, and intraperitoneal injections. Synaptic long-term potentiation was abolished following intracerebroventricular amyloid injection. Fluorescence dialysis or Golgi-impregnation labeling showed reduced dendritic spine density and destabilized spines of hippocampal pyramidal neurons 4 weeks after intracerebroventricular amyloid injection. In comparison, endothelial amyloids introduced to the airway caused the most prominent dendritic spine density reduction, yet intraperitoneal injection of these amyloids did not affect spine density. Our findings indicate that infection-elicited lung endothelial amyloids are neurotropic and reduce neuronal dendritic spine density in vivo. Amyloids applied into the trachea may either be disseminated through the circulation and cross the blood-brain barrier to access the brain, initiate feed-forward amyloid transmissibility among cells of the blood-brain barrier or access the brain in other ways. Nevertheless, lung-derived amyloids suppress hippocampal signaling and cause injury to neuronal structure.
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16
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Lucas R, Hadizamani Y, Gonzales J, Gorshkov B, Bodmer T, Berthiaume Y, Moehrlen U, Lode H, Huwer H, Hudel M, Mraheil MA, Toque HAF, Chakraborty T, Hamacher J. Impact of Bacterial Toxins in the Lungs. Toxins (Basel) 2020; 12:toxins12040223. [PMID: 32252376 PMCID: PMC7232160 DOI: 10.3390/toxins12040223] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial toxins play a key role in the pathogenesis of lung disease. Based on their structural and functional properties, they employ various strategies to modulate lung barrier function and to impair host defense in order to promote infection. Although in general, these toxins target common cellular signaling pathways and host compartments, toxin- and cell-specific effects have also been reported. Toxins can affect resident pulmonary cells involved in alveolar fluid clearance (AFC) and barrier function through impairing vectorial Na+ transport and through cytoskeletal collapse, as such, destroying cell-cell adhesions. The resulting loss of alveolar-capillary barrier integrity and fluid clearance capacity will induce capillary leak and foster edema formation, which will in turn impair gas exchange and endanger the survival of the host. Toxins modulate or neutralize protective host cell mechanisms of both the innate and adaptive immunity response during chronic infection. In particular, toxins can either recruit or kill central players of the lung's innate immune responses to pathogenic attacks, i.e., alveolar macrophages (AMs) and neutrophils. Pulmonary disorders resulting from these toxin actions include, e.g., acute lung injury (ALI), the acute respiratory syndrome (ARDS), and severe pneumonia. When acute infection converts to persistence, i.e., colonization and chronic infection, lung diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) can arise. The aim of this review is to discuss the impact of bacterial toxins in the lungs and the resulting outcomes for pathogenesis, their roles in promoting bacterial dissemination, and bacterial survival in disease progression.
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Affiliation(s)
- Rudolf Lucas
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
| | - Yalda Hadizamani
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
| | - Joyce Gonzales
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Thomas Bodmer
- Labormedizinisches Zentrum Dr. Risch, Waldeggstr. 37 CH-3097 Liebefeld, Switzerland;
| | - Yves Berthiaume
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada;
| | - Ueli Moehrlen
- Pediatric Surgery, University Children’s Hospital, Zürich, Steinwiesstrasse 75, CH-8032 Zürch, Switzerland;
| | - Hartmut Lode
- Insitut für klinische Pharmakologie, Charité, Universitätsklinikum Berlin, Reichsstrasse 2, D-14052 Berlin, Germany;
| | - Hanno Huwer
- Department of Cardiothoracic Surgery, Voelklingen Heart Center, 66333 Voelklingen/Saar, Germany;
| | - Martina Hudel
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Mobarak Abu Mraheil
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Haroldo Alfredo Flores Toque
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Trinad Chakraborty
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Jürg Hamacher
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
- Medical Clinic V-Pneumology, Allergology, Intensive Care Medicine and Environmental Medicine, Faculty of Medicine, Saarland University, University Medical Centre of the Saarland, D-66421 Homburg, Germany
- Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, D-66421 Homburg, Germany
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
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17
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Che P, Wagener BM, Zhao X, Brandon AP, Evans CA, Cai GQ, Zhao R, Xu ZX, Han X, Pittet JF, Ding Q. Neuronal Wiskott-Aldrich syndrome protein regulates Pseudomonas aeruginosa-induced lung vascular permeability through the modulation of actin cytoskeletal dynamics. FASEB J 2020; 34:3305-3317. [PMID: 31916311 DOI: 10.1096/fj.201902915r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 02/06/2023]
Abstract
Pulmonary edema associated with increased vascular permeability is a severe complication of Pseudomonas (P.) aeruginosa-induced acute lung injury. The mechanisms underlying P aeruginosa-induced vascular permeability are not well understood. In the present study, we investigated the role of neuronal Wiskott Aldrich syndrome protein (N-WASP) in modulating P aeruginosa-induced vascular permeability. Using lung microvascular endothelial and alveolar epithelial cells, we demonstrated that N-WASP downregulation attenuated P aeruginosa-induced actin stress fiber formation and prevented paracellular permeability. P aeruginosa-induced dissociation between VE-cadherin and β-catenin, but increased association between N-WASP and VE-cadherin, suggesting a role for N-WASP in promoting P aeruginosa-induced adherens junction rupture. P aeruginosa increased N-WASP-Y256 phosphorylation, which required the activation of Rho GTPase and focal adhesion kinase. Increased N-WASP-Y256 phosphorylation promotes N-WASP and integrin αVβ6 association as well as TGF-β-mediated permeability across alveolar epithelial cells. Inhibition of N-WASP-Y256 phosphorylation by N-WASP-Y256F overexpression blocked N-WASP effects in P aeruginosa-induced actin stress fiber formation and increased paracellular permeability. In vivo, N-WASP knockdown attenuated the development of pulmonary edema and improved survival in a mouse model of P aeruginosa pneumonia. Together, our data demonstrate that N-WASP plays an essential role in P aeruginosa-induced vascular permeability and pulmonary edema through the modulation of actin cytoskeleton dynamics.
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Affiliation(s)
- Pulin Che
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.,Molecular and Translational Biomedicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brant M Wagener
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.,Molecular and Translational Biomedicine, University of Alabama at Birmingham, Birmingham, AL, USA.,Divisions of Critical Care, University of Alabama at Birmingham, Birmingham, AL, USA.,Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Xueke Zhao
- Department of Infectious Diseases, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Angela P Brandon
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Cilina A Evans
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Guo-Qiang Cai
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rui Zhao
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Zhi-Xiang Xu
- Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Xiaosi Han
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jean-Francois Pittet
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.,Divisions of Critical Care, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Qiang Ding
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.,Molecular and Translational Biomedicine, University of Alabama at Birmingham, Birmingham, AL, USA
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18
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Chen X, Jiang H. Tau as a potential therapeutic target for ischemic stroke. Aging (Albany NY) 2019; 11:12827-12843. [PMID: 31841442 PMCID: PMC6949092 DOI: 10.18632/aging.102547] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 11/19/2019] [Indexed: 12/12/2022]
Abstract
Tau is a protein mainly expressed in adult human brain. It plays important roles both in neurodegenerative diseases and stroke. Stroke is an important cause of adult death and disability, ischemic stroke almost account for 80% in all cases. Abundant studies have proven that the increase of dysfunctional tau may act as a vital factor in pathological changes after ischemic stroke. However, the relationship between tau and ischemic stroke remains ununified. Based on present studies, we firstly introduced the structure and biological function of tau protein. Secondly, we summarized the potential regulatory mechanisms of tau protein in the process of ischemic stroke. Thirdly, we discussed about the findings in therapeutic researches of ischemic stroke. This review may be helpful in implementing new therapies for ischemic stroke and may be beneficial for the clinical and experimental studies.
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Affiliation(s)
- Xin Chen
- Department of Geriatrics, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Hua Jiang
- Department of Geriatrics, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
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19
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A Potent Anti-SpuE Antibody Allosterically Inhibits Type III Secretion System and Attenuates Virulence of Pseudomonas Aeruginosa. J Mol Biol 2019; 431:4882-4896. [DOI: 10.1016/j.jmb.2019.10.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 10/12/2019] [Accepted: 10/20/2019] [Indexed: 01/12/2023]
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20
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Balczon R, Pittet JF, Wagener BM, Moser SA, Voth S, Vorhees CV, Williams MT, Bridges JP, Alvarez DF, Koloteva A, Xu Y, Zha XM, Audia JP, Stevens T, Lin MT. Infection-induced endothelial amyloids impair memory. FASEB J 2019; 33:10300-10314. [PMID: 31211919 PMCID: PMC6704457 DOI: 10.1096/fj.201900322r] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/21/2019] [Indexed: 01/14/2023]
Abstract
Patients with nosocomial pneumonia exhibit elevated levels of neurotoxic amyloid and tau proteins in the cerebrospinal fluid (CSF). In vitro studies indicate that pulmonary endothelium infected with clinical isolates of either Pseudomonas aeruginosa, Klebsiella pneumoniae, or Staphylococcus aureus produces and releases cytotoxic amyloid and tau proteins. However, the effects of the pulmonary endothelium-derived amyloid and tau proteins on brain function have not been elucidated. Here, we show that P. aeruginosa infection elicits accumulation of detergent insoluble tau protein in the mouse brain and inhibits synaptic plasticity. Mice receiving endothelium-derived amyloid and tau proteins via intracerebroventricular injection exhibit a learning and memory deficit in object recognition, fear conditioning, and Morris water maze studies. We compared endothelial supernatants obtained after the endothelia were infected with P. aeruginosa possessing an intact [P. aeruginosa isolated from patient 103 (PA103) supernatant] or defective [mutant strain of P. aeruginosa lacking a functional type 3 secretion system needle tip complex (ΔPcrV) supernatant] type 3 secretion system. Whereas the PA103 supernatant impaired working memory, the ΔPcrV supernatant had no effect. Immunodepleting amyloid or tau proteins from the PA103 supernatant with the A11 or T22 antibodies, respectively, overtly rescued working memory. Recordings from hippocampal slices treated with endothelial supernatants or CSF from patients with or without nosocomial pneumonia indicated that endothelium-derived neurotoxins disrupted the postsynaptic synaptic response. Taken together, these results establish a plausible mechanism for the neurologic sequelae consequent to nosocomial bacterial pneumonia.-Balczon, R., Pittet, J.-F., Wagener, B. M., Moser, S. A., Voth, S., Vorhees, C. V., Williams, M. T., Bridges, J. P., Alvarez, D. F., Koloteva, A., Xu, Y., Zha, X.-M., Audia, J. P., Stevens, T., Lin, M. T. Infection-induced endothelial amyloids impair memory.
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Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA
| | - Jean-Francois Pittet
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Brant M. Wagener
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Stephen A. Moser
- Department of Pathology, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Sarah Voth
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA
| | - Charles V. Vorhees
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
- Department of Environmental Health, University of Cincinnati, Cincinnati, Ohio, USA
| | | | - James P. Bridges
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
| | - Diego F. Alvarez
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA
| | - Anna Koloteva
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA
| | - Yuanyuan Xu
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA
| | - Xiang-Ming Zha
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA
| | - Jonathon P. Audia
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA
- Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama, USA
| | - Troy Stevens
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA
- Department of Internal Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Mike T. Lin
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA
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21
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Nieto V, Kroken AR, Grosser MR, Smith BE, Metruccio MME, Hagan P, Hallsten ME, Evans DJ, Fleiszig SMJ. Type IV Pili Can Mediate Bacterial Motility within Epithelial Cells. mBio 2019; 10:e02880-18. [PMID: 31431558 PMCID: PMC6703432 DOI: 10.1128/mbio.02880-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 07/31/2019] [Indexed: 02/07/2023] Open
Abstract
Pseudomonas aeruginosa is among bacterial pathogens capable of twitching motility, a form of surface-associated movement dependent on type IV pili (T4P). Previously, we showed that T4P and twitching were required for P. aeruginosa to cause disease in a murine model of corneal infection, to traverse human corneal epithelial multilayers, and to efficiently exit invaded epithelial cells. Here, we used live wide-field fluorescent imaging combined with quantitative image analysis to explore how twitching contributes to epithelial cell egress. Results using time-lapse imaging of cells infected with wild-type PAO1 showed that cytoplasmic bacteria slowly disseminated throughout the cytosol at a median speed of >0.05 μm s-1 while dividing intracellularly. Similar results were obtained with flagellin (fliC) and flagellum assembly (flhA) mutants, thereby excluding swimming, swarming, and sliding as mechanisms. In contrast, pilA mutants (lacking T4P) and pilT mutants (twitching motility defective) appeared stationary and accumulated in expanding aggregates during intracellular division. Transmission electron microscopy confirmed that these mutants were not trapped within membrane-bound cytosolic compartments. For the wild type, dissemination in the cytosol was not prevented by the depolymerization of actin filaments using latrunculin A and/or the disruption of microtubules using nocodazole. Together, these findings illustrate a novel form of intracellular bacterial motility differing from previously described mechanisms in being directly driven by bacterial motility appendages (T4P) and not depending on polymerized host actin or microtubules.IMPORTANCE Host cell invasion can contribute to disease pathogenesis by the opportunistic pathogen Pseudomonas aeruginosa Previously, we showed that the type III secretion system (T3SS) of invasive P. aeruginosa strains modulates cell entry and subsequent escape from vacuolar trafficking to host lysosomes. However, we also showed that mutants lacking either type IV pili (T4P) or T4P-dependent twitching motility (i) were defective in traversing cell multilayers, (ii) caused less pathology in vivo, and (iii) had a reduced capacity to exit invaded cells. Here, we report that after vacuolar escape, intracellular P. aeruginosa can use T4P-dependent twitching motility to disseminate throughout the host cell cytoplasm. We further show that this strategy for intracellular dissemination does not depend on flagellin and resists both host actin and host microtubule disruption. This differs from mechanisms used by previously studied pathogens that utilize either host actin or microtubules for intracellular dissemination independently of microbe motility appendages.
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Affiliation(s)
- Vincent Nieto
- School of Optometry, University of California, Berkeley, California, USA
| | - Abby R Kroken
- School of Optometry, University of California, Berkeley, California, USA
| | - Melinda R Grosser
- School of Optometry, University of California, Berkeley, California, USA
| | - Benjamin E Smith
- Vision Science Program, University of California, Berkeley, California, USA
| | | | - Patrick Hagan
- Undergraduate Research Apprentice Program, University of California, Berkeley, California, USA
| | - Mary E Hallsten
- Undergraduate Research Apprentice Program, University of California, Berkeley, California, USA
| | - David J Evans
- School of Optometry, University of California, Berkeley, California, USA
- College of Pharmacy, Touro University California, Vallejo, California, USA
| | - Suzanne M J Fleiszig
- School of Optometry, University of California, Berkeley, California, USA
- Vision Science Program, University of California, Berkeley, California, USA
- Graduate Group in Microbiology, University of California, Berkeley, California, USA
- Graduate Group in Infectious Diseases and Immunity, University of California, Berkeley, California, USA
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22
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Munder A, Rothschuh J, Schirmer B, Klockgether J, Kaever V, Tümmler B, Seifert R, Kloth C. The Pseudomonas aeruginosa ExoY phenotype of high-copy-number recombinants is not detectable in natural isolates. Open Biol 2019; 8:rsob.170250. [PMID: 29386405 PMCID: PMC5795057 DOI: 10.1098/rsob.170250] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 01/03/2018] [Indexed: 12/31/2022] Open
Abstract
The nucleotidyl cyclase ExoY is an effector protein of the type III secretion system of Pseudomonas aeruginosa. We compared the cyclic nucleotide production and lung disease phenotypes caused by the ExoY-overexpressing strain PA103ΔexoUexoT::Tc pUCPexoY, its vector control strain PA103ΔexoUexoT::Tc pUCP18, its loss-of-function control PA103ΔexoUexoT::Tc pUCPexoY K81M and natural ExoY-positive and ExoY-negative isolates in a murine acute airway infection model. Only the P. aeruginosa carrier of the exoY-plasmid produced high levels of cUMP and caused the most severe course of infection. The pathology ascribed to ExoY from studies using the high-copy-number plasmid on mammalian cells in vitro and in vivo was not observed with natural P. aeruginosa isolates. This indicates that the role of ExoY during infection with real-life P. aeruginosa still needs to be resolved.
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Affiliation(s)
- Antje Munder
- Clinic for Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany .,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research, Hannover, Germany
| | - Justin Rothschuh
- Institute of Pharmacology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Bastian Schirmer
- Institute of Pharmacology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Jens Klockgether
- Clinic for Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Volkhard Kaever
- Research Core Unit Metabolomics, Hannover Medical School, 30625 Hannover, Germany
| | - Burkhard Tümmler
- Clinic for Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research, Hannover, Germany
| | - Roland Seifert
- Institute of Pharmacology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Christina Kloth
- Institute of Pharmacology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany.,Institute of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
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23
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Chua MD, Liou CH, Bogdan AC, Law HT, Yeh KM, Lin JC, Siu LK, Guttman JA. Klebsiella pneumoniae disassembles host microtubules in lung epithelial cells. Cell Microbiol 2018; 21:e12977. [PMID: 30415487 DOI: 10.1111/cmi.12977] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 10/29/2018] [Accepted: 10/31/2018] [Indexed: 01/21/2023]
Abstract
Klebsiella pneumoniae raises significant concerns to the health care industry as these microbes are the source of widespread contamination of medical equipment, cause pneumonia as well as other multiorgan metastatic infections and have gained multidrug resistance. Despite soaring mortality rates, the host cell alterations occurring during these infections remain poorly understood. Here, we show that during in vitro and in vivo K. pneumoniae infections of lung epithelia, microtubules are severed and then eliminated. This destruction does not require direct association of K. pneumoniae with the host cells, as microtubules are disassembled in cells that are distant from the infecting bacteria. This microtubule dismantling is dependent on the K. pneumoniae (Kp) gene ytfL as non-pathogenic Escherichia coli expressing Kp ytfL disassemble microtubules in the absence of K. pneumoniae itself. Our data points to the host katanin catalytic subunit A like 1 protein (KATNAL1) and the katanin regulatory subunit B1 protein (KATNB1) as the gatekeepers to the microtubule severing event as both proteins localise specifically to microtubule cut sites. Infected cells that had either of these proteins knocked out maintained intact microtubules. Taken together, we have identified a novel mechanism that a bacterial pathogen has exploited to cause microtubule destruction within the host epithelia.
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Affiliation(s)
- Michael Dominic Chua
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Ci-Hong Liou
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | | | - Hong T Law
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Kuo-Ming Yeh
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Jung-Chung Lin
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - L Kristopher Siu
- Division of Infection Diseases, National Health Research Institutes, Miaoli, Taiwan
| | - Julian Andrew Guttman
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
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24
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Belyy A, Santecchia I, Renault L, Bourigault B, Ladant D, Mechold U. The extreme C terminus of the Pseudomonas aeruginosa effector ExoY is crucial for binding to its eukaryotic activator, F-actin. J Biol Chem 2018; 293:19785-19796. [PMID: 30377256 DOI: 10.1074/jbc.ra118.003784] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 10/22/2018] [Indexed: 12/25/2022] Open
Abstract
Bacterial nucleotidyl cyclase toxins are potent virulence factors that upon entry into eukaryotic cells are stimulated by endogenous cofactors to catalyze the production of large amounts of 3'5'-cyclic nucleoside monophosphates. The activity of the effector ExoY from Pseudomonas aeruginosa is stimulated by the filamentous form of actin (F-actin). Utilizing yeast phenotype analysis, site-directed mutagenesis, functional biochemical assays, and confocal microscopy, we demonstrate that the last nine amino acids of the C terminus of ExoY are crucial for the interaction with F-actin and, consequently, for ExoY's enzymatic activity in vitro and toxicity in a yeast model. We observed that isolated C-terminal sequences of P. aeruginosa ExoY that had been fused to a carrier protein bind to F-actin and that synthetic peptides corresponding to the extreme ExoY C terminus inhibit ExoY enzymatic activity in vitro and compete with the full-length enzyme for F-actin binding. Interestingly, we noted that various P. aeruginosa isolates of the PA14 family, including highly virulent strains, harbor ExoY variants with a mutation altering the C terminus of this effector. We found that these naturally occurring ExoY variants display drastically reduced enzymatic activity and toxicity. Our findings shed light on the molecular basis of the ExoY-F-actin interaction, revealing that the extreme C terminus of ExoY is critical for binding to F-actin in target cells and that some P. aeruginosa isolates carry C-terminally mutated, low-activity ExoY variants.
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Affiliation(s)
- Alexander Belyy
- From the Institut Pasteur, CNRS UMR 3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie and
| | - Ignacio Santecchia
- Unité Biologie et Génétique de la Paroi Bactérienne, Département de Microbiologie, 75724 Paris cedex 15, France and
| | - Louis Renault
- the Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Blandine Bourigault
- the Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Daniel Ladant
- From the Institut Pasteur, CNRS UMR 3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie and
| | - Undine Mechold
- From the Institut Pasteur, CNRS UMR 3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie and
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25
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Balczon R, Francis M, Leavesley S, Stevens T. Methods for Detecting Cytotoxic Amyloids Following Infection of Pulmonary Endothelial Cells by Pseudomonas aeruginosa. J Vis Exp 2018. [PMID: 30059033 DOI: 10.3791/57447] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Patients who survive pneumonia have elevated death rates in the months following hospital discharge. It has been hypothesized that infection of pulmonary tissue during pneumonia results in the production of long-lived cytotoxins that can lead to subsequent end organ failure. We have developed in vitro assays to test the hypothesis that cytotoxins are produced during pulmonary infection. Isolated rat pulmonary endothelial cells and the bacterium Pseudomonas aeruginosa are used as model systems, and the production of cytoxins following infection of the endothelial cells by the bacteria is demonstrated using cell culture followed by direct quantitation using lactate dehydrogenase assays and a novel microscopic method utilizing ImageJ technology. The amyloid nature of these cytotoxins was demonstrated by thioflavin T binding assays and by immunoblotting and immunodepletion using A11 anti-amyloid antibody. Further analyses using immunoblotting demonstrated that oligomeric tau and Aβ were produced and released by endothelial cells following infection by P. aeruginosa. These methods should be readily adaptable to analyses of human clinical samples.
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Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular Biology, University of South Alabama; Center for Lung Biology, University of South Alabama;
| | - Michael Francis
- Department of Physiology and Cell Biology, University of South Alabama; Center for Lung Biology, University of South Alabama
| | - Silas Leavesley
- Department of Chemical and Biomolecular Engineering, University of South Alabama; Center for Lung Biology, University of South Alabama
| | - Troy Stevens
- Department of Physiology and Cell Biology, University of South Alabama; Center for Lung Biology, University of South Alabama
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26
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Khanppnavar B, Datta S. Crystal structure and substrate specificity of ExoY, a unique T3SS mediated secreted nucleotidyl cyclase toxin from Pseudomonas aeruginosa. Biochim Biophys Acta Gen Subj 2018; 1862:2090-2103. [PMID: 29859257 DOI: 10.1016/j.bbagen.2018.05.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/15/2018] [Accepted: 05/25/2018] [Indexed: 01/03/2023]
Abstract
BACKGROUND The nucleotidyl cyclase toxin ExoY is an important virulence determinant of Pseudomonas aeruginosa that causes severe acute and chronic infections in immune-compromised individuals. Additionally, this unique T3SS effector shows a striking preference for cUMP, a newly identified non-canonical secondary messenger. Thereby, ExoY is also considered as a potential tool to study unexplored cUMP signaling pathways. METHODS The crystal structure of ExoY was determined at 2.2 Å resolutions by in-situ proteolysis assisted crystallization and Rosetta-molecular replacement method. Additionally, isothermal calorimetric (ITC) and molecular dynamic (MD) simulation studies were also carried out to gain molecular insights into its substrate specificity and catalysis. RESULTS AND CONCLUSION ExoY is a partially unfolded protein with higher propensity to form soluble higher-order oligomers. However, with meticulous attempts of removing of disordered regions by proteases, the recalcitrant ExoY could be successfully crystallized. The crystal structure of ExoY revealed similar overall structural fold present in other anthrax toxA family of nucleotidyl cyclases, with two-to-three distinctly conserved regions conferring specificity to eukaryotic binding partner. The in-vitro catalytic preference of ExoY is in the following order: cGMP > cUMP > cAMP > cCMP. The substrate specificity of ExoY mainly depends on its ability to bind NTP in proper geometrical orientations. ExoY also seems to prefer one-metal-ion dependent catalysis than two-metal-ion dependent catalysis. GENERAL SIGNIFICANCE Our results provide much needed structural insight on ExoY, an important virulence determinant of Pseudomonas aeruginosa and an exciting tool to study non-canonical cNMP signaling pathways. ACCESSION NUMBERS The structure factors and coordinate files have been deposited in the Protein Data Bank with accession number 5XNW.
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Affiliation(s)
- Basavraj Khanppnavar
- Department of Structural Biology and Bioinformatics, CSIR-Indian Institute of Chemical Biology (CSIR-IICB), Kolkata, India; Academy of Scientific and Innovative Research (AcSIR), India
| | - Saumen Datta
- Department of Structural Biology and Bioinformatics, CSIR-Indian Institute of Chemical Biology (CSIR-IICB), Kolkata, India; Academy of Scientific and Innovative Research (AcSIR), India.
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27
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The Role of Pseudomonas aeruginosa ExoY in an Acute Mouse Lung Infection Model. Toxins (Basel) 2018; 10:toxins10050185. [PMID: 29734720 PMCID: PMC5983241 DOI: 10.3390/toxins10050185] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/20/2018] [Accepted: 05/02/2018] [Indexed: 12/31/2022] Open
Abstract
The effector protein Exotoxin Y (ExoY) produced by Pseudomonas aeruginosa is injected via the type III secretion system (T3SS) into host cells. ExoY acts as nucleotidyl cyclase promoting the intracellular accumulation of cyclic nucleotides. To what extent nucleotidyl cyclase activity contributes to the pathogenicity of ExoY and which mechanisms participate in the manifestation of lung infection is still unclear. Here, we used an acute airway infection model in mice to address the role of ExoY in lung infection. In infected lungs, a dose-dependent phenotype of infection with bacteria-expressing ExoY was mirrored by haemorrhage, formation of interstitial oedema in alveolar septa, and infiltration of the perivascular space with erythrocytes and neutrophilic granulocytes. Analyses of the infection process on the cellular and organismal level comparing infections with Pseudomonas aeruginosa mutants expressing either nucleotidyl cyclase-active or -inactive ExoY revealed differential cytokine secretion, increased prevalence of apoptosis, and a break of lung barrier integrity in mice infected with cyclase-active ExoY. Notably, of all measured cyclic nucleotides, only the increase of cyclic UMP in infected mouse lungs coincides temporally with the observed early pathologic changes. In summary, our results suggest that the nucleotidyl cyclase activity of ExoY can contribute to P. aeruginosa acute pathogenicity.
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28
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Jeon J, Kim YJ, Shin H, Ha UH. T3SS effector ExoY reduces inflammasome-related responses by suppressing bacterial motility and delaying activation of NF-κB and caspase-1. FEBS J 2017; 284:3392-3403. [PMID: 28815941 DOI: 10.1111/febs.14199] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 07/05/2017] [Accepted: 08/11/2017] [Indexed: 11/28/2022]
Abstract
Type III-secreted effectors are essential for modulating host immune responses during the pathogenesis of Pseudomonas aeruginosa infections. Little is known about the impact of one of the effectors, ExoY, on inflammasome activation, which results in IL-1β production and pyroptotic cell death. In this study, we found that transcriptional expression of Il-1β was induced to a lesser extent in response to an exoY-harboring strain than to a deleted mutant. This suppressive effect of ExoY was verified by complementation assay as well as by direct translocation of exoY into host cells. In addition to the production of IL-1β, pyroptotic cell death was also diminished in response to an exoY-harboring strain. These inflammasome responses were mediated by the adenylate cyclase activity of ExoY, which plays a role in delaying the activation of NF-κB and caspase-1, a key component of inflammasome-mediated responses. Moreover, the negative effects of ExoY on these responses were in part conferred by the suppression of bacterial motility, which could reduce the degree of bacterial contact with cells. Together, these results demonstrate that the adenylate cyclase activity of P. aeruginosa ExoY can reduce inflammasome-related responses by influencing both the host and the bacterium itself by delaying the activation of inflammatory pathways and suppressing bacterial motility.
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Affiliation(s)
- Jisu Jeon
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Korea
| | - Yong-Jae Kim
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Korea
| | - Heesung Shin
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Korea
| | - Un-Hwan Ha
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Korea
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29
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Zhu B, Lindsey A, Li N, Lee K, Ramirez-Alcantara V, Canzoneri JC, Fajardo A, Madeira da Silva L, Thomas M, Piazza JT, Yet L, Eberhardt BT, Gurpinar E, Otali D, Grizzle W, Valiyaveettil J, Chen X, Keeton AB, Piazza GA. Phosphodiesterase 10A is overexpressed in lung tumor cells and inhibitors selectively suppress growth by blocking β-catenin and MAPK signaling. Oncotarget 2017; 8:69264-69280. [PMID: 29050202 PMCID: PMC5642477 DOI: 10.18632/oncotarget.20566] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/04/2017] [Indexed: 12/14/2022] Open
Abstract
Phosphodiesterase 10A (PDE10) is a cyclic nucleotide (e.g. cGMP) degrading enzyme highly expressed in the brain striatum where it plays an important role in dopaminergic neurotransmission, but has limited expression and no known physiological function outside the central nervous system. Here we report that PDE10 mRNA and protein levels are strongly elevated in human non-small cell lung cancer cells and lung tumors compared with normal human airway epithelial cells and lung tissue, respectively. Genetic silencing of PDE10 or inhibition by small molecules such as PQ10 was found to selectively inhibit the growth and colony formation of lung tumor cells. PQ10 treatment of lung tumor cells rapidly increased intracellular cGMP levels and activated cGMP-dependent protein kinase (PKG) at concentrations that inhibit lung tumor cell growth. PQ10 also increased the phosphorylation of β-catenin and reduced its levels, which paralleled the suppression of cyclin D1 and survivin but preceded the activation of PARP and caspase cleavage. PQ10 also suppressed RAS-activated RAF/MAPK signaling within the same concentration range and treatment period as required for cGMP elevation and PKG activation. These results show that PDE10 is overexpressed during lung cancer development and essential for lung tumor cell growth in which inhibitors can selectively induce apoptosis by increasing intracellular cGMP levels and activating PKG to suppress oncogenic β-catenin and MAPK signaling.
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Affiliation(s)
- Bing Zhu
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Ashley Lindsey
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Nan Li
- Department of Biochemistry and Molecular Biology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Kevin Lee
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Veronica Ramirez-Alcantara
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Joshua C Canzoneri
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Alexandra Fajardo
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Luciana Madeira da Silva
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Meagan Thomas
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - John T Piazza
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Larry Yet
- Department of Chemistry, University of South Alabama, Mobile, Alabama, USA
| | - Brian T Eberhardt
- Department of Chemistry, University of South Alabama, Mobile, Alabama, USA
| | - Evrim Gurpinar
- Department of Pharmacology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Dennis Otali
- Department of Pathology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - William Grizzle
- Department of Pathology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jacob Valiyaveettil
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Xi Chen
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Adam B Keeton
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Gary A Piazza
- Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
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30
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Bacterial Nucleotidyl Cyclase Inhibits the Host Innate Immune Response by Suppressing TAK1 Activation. Infect Immun 2017; 85:IAI.00239-17. [PMID: 28652310 DOI: 10.1128/iai.00239-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 06/13/2017] [Indexed: 12/22/2022] Open
Abstract
Exoenzyme Y (ExoY) is a type III secretion system effector found in 90% of the Pseudomonas aeruginosa isolates. Although it is known that ExoY is a soluble nucleotidyl cyclase that increases the cytoplasmic levels of nucleoside 3',5'-cyclic monophosphates (cNMPs) to mediate endothelial Tau phosphorylation and permeability, its functional role in the innate immune response is still poorly understood. Transforming growth factor β-activated kinase 1 (TAK1) is critical for mediating Toll-like receptor (TLR) signaling and subsequent activation of NF-κB and AP-1, which are transcriptional activators of innate immunity. Here, we report that ExoY inhibits proinflammatory cytokine production through suppressing the activation of TAK1 as well as downstream NF-κB and mitogen-activated protein (MAP) kinases. Mice infected with ExoY-deficient P. aeruginosa had higher levels of tumor necrosis factor (TNF) and interleukin-6 (IL-6), more neutrophil recruitment, and a lower bacterial load in lung tissue than mice infected with wild-type P. aeruginosa Taken together, our findings identify a previously unknown mechanism by which P. aeruginosa ExoY inhibits the host innate immune response.
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31
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Balczon R, Morrow KA, Zhou C, Edmonds B, Alexeyev M, Pittet JF, Wagener BM, Moser SA, Leavesley S, Zha X, Frank DW, Stevens T. Pseudomonas aeruginosa infection liberates transmissible, cytotoxic prion amyloids. FASEB J 2017; 31:2785-2796. [PMID: 28314768 DOI: 10.1096/fj.201601042rr] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 02/26/2017] [Indexed: 12/28/2022]
Abstract
Patients who recover from pneumonia subsequently have elevated rates of death after hospital discharge as a result of secondary organ damage, the causes of which are unknown. We used the bacterium Pseudomonas aeruginosa, a common cause of hospital-acquired pneumonia, as a model for investigating this phenomenon. We show that infection of pulmonary endothelial cells by P. aeruginosa induces production and release of a cytotoxic amyloid molecule with prion characteristics, including resistance to various nucleases and proteases. This cytotoxin was self-propagating, was neutralized by anti-amyloid Abs, and induced death of endothelial cells and neurons. Moreover, the cytotoxin induced edema in isolated lungs. Endothelial cells and isolated lungs were protected from cytotoxin-induced death by stimulation of signal transduction pathways that are linked to prion protein. Analysis of bronchoalveolar lavage fluid collected from human patients with P. aeruginosa pneumonia demonstrated cytotoxic activity, and lavage fluid contained amyloid molecules, including oligomeric τ and Aβ. Demonstration of long-lived cytotoxic agents after Pseudomonas infection may establish a molecular link to the high rates of death as a result of end-organ damage in the months after recovery from pneumonia, and modulation of signal transduction pathways that have been linked to prion protein may provide a mechanism for intervention.-Balczon, R., Morrow, K. A., Zhou, C., Edmonds, B., Alexeyev, M., Pittet, J.-F., Wagener, B. M., Moser, S. A., Leavesley, S., Zha, X., Frank, D. W., Stevens, T. Pseudomonas aeruginosa infection liberates transmissible, cytotoxic prion amyloids.
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Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA; .,Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - K Adam Morrow
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Chun Zhou
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Bradley Edmonds
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Mikhail Alexeyev
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Jean-Francois Pittet
- Department of Anesthesia and Perioperative Medicine, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Brant M Wagener
- Department of Anesthesia and Perioperative Medicine, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Stephen A Moser
- Department of Pathology, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Silas Leavesley
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Chemical and Biomedical Engineering, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Xiangming Zha
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Dara W Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Troy Stevens
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
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32
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Belyy A, Raoux-Barbot D, Saveanu C, Namane A, Ogryzko V, Worpenberg L, David V, Henriot V, Fellous S, Merrifield C, Assayag E, Ladant D, Renault L, Mechold U. Actin activates Pseudomonas aeruginosa ExoY nucleotidyl cyclase toxin and ExoY-like effector domains from MARTX toxins. Nat Commun 2016; 7:13582. [PMID: 27917880 PMCID: PMC5150216 DOI: 10.1038/ncomms13582] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/13/2016] [Indexed: 12/15/2022] Open
Abstract
The nucleotidyl cyclase toxin ExoY is one of the virulence factors injected by the Pseudomonas aeruginosa type III secretion system into host cells. Inside cells, it is activated by an unknown eukaryotic cofactor to synthesize various cyclic nucleotide monophosphates. ExoY-like adenylate cyclases are also found in Multifunctional-Autoprocessing Repeats-in-ToXin (MARTX) toxins produced by various Gram-negative pathogens. Here we demonstrate that filamentous actin (F-actin) is the hitherto unknown cofactor of ExoY. Association with F-actin stimulates ExoY activity more than 10,000 fold in vitro and results in stabilization of actin filaments. ExoY is recruited to actin filaments in transfected cells and alters F-actin turnover. Actin also activates an ExoY-like adenylate cyclase MARTX effector domain from Vibrio nigripulchritudo. Finally, using a yeast genetic screen, we identify actin mutants that no longer activate ExoY. Our results thus reveal a new sub-group within the class II adenylyl cyclase family, namely actin-activated nucleotidyl cyclase (AA-NC) toxins.
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Affiliation(s)
- Alexander Belyy
- Institut Pasteur, CNRS UMR3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, 25-28 rue du Docteur Roux, 75724 Paris cedex 15, France
- Department of Bacterial Infections, Gamaleya Research Center, Moscow 123098, Russia
| | - Dorothée Raoux-Barbot
- Institut Pasteur, CNRS UMR3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, 25-28 rue du Docteur Roux, 75724 Paris cedex 15, France
| | - Cosmin Saveanu
- Institut Pasteur, CNRS UMR3525, Génétique des Interactions Macromoléculaires, Département de Génomes et Génétique, 25-28 rue du Docteur Roux, 75724 Paris cedex 15, France
| | - Abdelkader Namane
- Institut Pasteur, CNRS UMR3525, Génétique des Interactions Macromoléculaires, Département de Génomes et Génétique, 25-28 rue du Docteur Roux, 75724 Paris cedex 15, France
| | - Vasily Ogryzko
- Institut Gustave Roussy, CNRS UMR 8126, Unité de Signaling, Nuclei and Innovations in Oncology, 94805 Villejuif, France
| | - Lina Worpenberg
- Institut Pasteur, CNRS UMR3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, 25-28 rue du Docteur Roux, 75724 Paris cedex 15, France
| | - Violaine David
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Veronique Henriot
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Souad Fellous
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Christien Merrifield
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Elodie Assayag
- Institut Pasteur, CNRS UMR3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, 25-28 rue du Docteur Roux, 75724 Paris cedex 15, France
| | - Daniel Ladant
- Institut Pasteur, CNRS UMR3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, 25-28 rue du Docteur Roux, 75724 Paris cedex 15, France
| | - Louis Renault
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Undine Mechold
- Institut Pasteur, CNRS UMR3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, 25-28 rue du Docteur Roux, 75724 Paris cedex 15, France
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Morrow KA, Frank DW, Balczon R, Stevens T. The Pseudomonas aeruginosa Exoenzyme Y: A Promiscuous Nucleotidyl Cyclase Edema Factor and Virulence Determinant. Handb Exp Pharmacol 2016; 238:67-85. [PMID: 28181005 DOI: 10.1007/164_2016_5003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Exoenzyme Y (ExoY) was identified as a component of the Pseudomonas aeruginosa type 3 secretion system secretome in 1998. It is a common contributor to the arsenal of type 3 secretion system effectors, as it is present in approximately 90% of Pseudomonas isolates. ExoY has adenylyl cyclase activity that is dependent upon its association with a host cell cofactor. However, recent evidence indicates that ExoY is not just an adenylyl cyclase; rather, it is a promiscuous cyclase capable of generating purine and pyrimidine cyclic nucleotide monophosphates. ExoY's enzymatic activity causes a characteristic rounding of mammalian cells, due to microtubule breakdown. In endothelium, this cell rounding disrupts cell-to-cell junctions, leading to loss of barrier integrity and an increase in tissue edema. Microtubule breakdown seems to depend upon tau phosphorylation, where the elevation of cyclic nucleotide monophosphates activates protein kinases A and G and causes phosphorylation of endothelial microtubule associated protein tau. Phosphorylation is a stimulus for tau release from microtubules, leading to microtubule instability. Phosphorylated tau accumulates inside endothelium as a high molecular weight, oligomeric form, and is then released from the cell. Extracellular high molecular weight tau causes a transmissible cytotoxicity that significantly hinders cellular repair following infection. Thus, ExoY may contribute to bacterial virulence in at least two ways; first, by microtubule breakdown leading to loss of endothelial cell barrier integrity, and second, by promoting release of a high molecular weight tau cytotoxin that impairs cellular recovery following infection.
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Affiliation(s)
- K Adam Morrow
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, AL, 36688, USA
- The Center for Lung Biology, University of South Alabama, Mobile, AL, 36688, USA
| | - Dara W Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
- Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Ron Balczon
- The Center for Lung Biology, University of South Alabama, Mobile, AL, 36688, USA
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL, 36688, USA
| | - Troy Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, AL, 36688, USA.
- The Center for Lung Biology, University of South Alabama, Mobile, AL, 36688, USA.
- Department of Medicine, University of South Alabama, Mobile, AL, 36688, USA.
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Morrow KA, Ochoa CD, Balczon R, Zhou C, Cauthen L, Alexeyev M, Schmalzer KM, Frank DW, Stevens T. Pseudomonas aeruginosa exoenzymes U and Y induce a transmissible endothelial proteinopathy. Am J Physiol Lung Cell Mol Physiol 2015; 310:L337-53. [PMID: 26637633 DOI: 10.1152/ajplung.00103.2015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 12/02/2015] [Indexed: 11/22/2022] Open
Abstract
We tested the hypothesis that Pseudomonas aeruginosa type 3 secretion system effectors exoenzymes Y and U (ExoY and ExoU) induce release of a high-molecular-weight endothelial tau, causing transmissible cell injury characteristic of an infectious proteinopathy. Both the bacterial delivery of ExoY and ExoU and the conditional expression of an activity-attenuated ExoU induced time-dependent pulmonary microvascular endothelial cell gap formation that was paralleled by the loss of intracellular tau and the concomitant appearance of high-molecular-weight extracellular tau. Transfer of the high-molecular-weight tau in filtered supernatant to naïve endothelial cells resulted in intracellular accumulation of tau clusters, which was accompanied by cell injury, interendothelial gap formation, decreased endothelial network stability in Matrigel, and increased lung permeability. Tau oligomer monoclonal antibodies captured monomeric tau from filtered supernatant but did not retrieve higher-molecular-weight endothelial tau and did not rescue the injurious effects of tau. Enrichment and transfer of high-molecular-weight tau to naïve cells was sufficient to cause injury. Thus we provide the first evidence for a pathophysiological stimulus that induces release and transmissibility of high-molecular-weight endothelial tau characteristic of an endothelial proteinopathy.
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Affiliation(s)
- K Adam Morrow
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Cristhiaan D Ochoa
- Physician-Scientist Training Program, Department of Medicine, University of Texas-Southwestern Medical Center, Dallas, Texas; Division of Pulmonary and Critical Care, University of Texas-Southwestern Medical Center, Dallas, Texas
| | - Ron Balczon
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Chun Zhou
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Laura Cauthen
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Mikhail Alexeyev
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Katherine M Schmalzer
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin; Division of Hematology/Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Dara W Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin; and Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Troy Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Department of Medicine, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama;
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35
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Morrow KA, Seifert R, Kaever V, Britain AL, Sayner SL, Ochoa CD, Cioffi EA, Frank DW, Rich TC, Stevens T. Heterogeneity of pulmonary endothelial cyclic nucleotide response to Pseudomonas aeruginosa ExoY infection. Am J Physiol Lung Cell Mol Physiol 2015; 309:L1199-207. [PMID: 26386118 PMCID: PMC4652153 DOI: 10.1152/ajplung.00165.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 09/11/2015] [Indexed: 01/16/2023] Open
Abstract
Here, we tested the hypothesis that a promiscuous bacterial cyclase synthesizes purine and pyrimidine cyclic nucleotides in the pulmonary endothelium. To test this hypothesis, pulmonary endothelial cells were infected with a strain of the Gram-negative bacterium Pseudomonas aeruginosa that introduces only exoenzyme Y (PA103 ΔexoUexoT::Tc pUCPexoY; ExoY(+)) via a type III secretion system. Purine and pyrimidine cyclic nucleotides were simultaneously detected using mass spectrometry. Pulmonary artery (PAECs) and pulmonary microvascular (PMVECs) endothelial cells both possess basal levels of four different cyclic nucleotides in the following rank order: cAMP > cUMP ≈ cGMP ≈ cCMP. Endothelial gap formation was induced in a time-dependent manner following ExoY(+) intoxication. In PAECs, intercellular gaps formed within 2 h and progressively increased in size up to 6 h, when the experiment was terminated. cGMP concentrations increased within 1 h postinfection, whereas cAMP and cUMP concentrations increased within 3 h, and cCMP concentrations increased within 4 h postinfection. In PMVECs, intercellular gaps did not form until 4 h postinfection. Only cGMP and cUMP concentrations increased at 3 and 6 h postinfection, respectively. PAECs generated higher cyclic nucleotide levels than PMVECs, and the cyclic nucleotide levels increased earlier in response to ExoY(+) intoxication. Heterogeneity of the cyclic nucleotide signature in response to P. aeruginosa infection exists between PAECs and PMVECs, suggesting the intracellular milieu in PAECs is more conducive to cNMP generation.
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Affiliation(s)
- K A Morrow
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - R Seifert
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany
| | - V Kaever
- Research Core Unit Metabolomics, Hannover Medical School, Hannover, Germany
| | - A L Britain
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - S L Sayner
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - C D Ochoa
- Physician-Scientist Training Program, Department of Medicine, University of Texas-Southwestern Medical Center, Dallas, Texas; Physician-Scientist Training Program, Division of Pulmonary and Critical Care, University of Texas-Southwestern Medical Center, Dallas, Texas
| | - E A Cioffi
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - D W Frank
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin; and Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - T C Rich
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - T Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Department of Medicine, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama;
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36
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Nickols J, Obiako B, Ramila KC, Putinta K, Schilling S, Sayner SL. Lipopolysaccharide-induced pulmonary endothelial barrier disruption and lung edema: critical role for bicarbonate stimulation of AC10. Am J Physiol Lung Cell Mol Physiol 2015; 309:L1430-7. [PMID: 26475732 DOI: 10.1152/ajplung.00067.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 10/14/2015] [Indexed: 12/11/2022] Open
Abstract
Bacteria-induced sepsis is a common cause of pulmonary endothelial barrier dysfunction and can progress toward acute respiratory distress syndrome. Elevations in intracellular cAMP tightly regulate pulmonary endothelial barrier integrity; however, cAMP signals are highly compartmentalized: whether cAMP is barrier-protective or -disruptive depends on the compartment (plasma membrane or cytosol, respectively) in which the signal is generated. The mammalian soluble adenylyl cyclase isoform 10 (AC10) is uniquely stimulated by bicarbonate and is expressed in pulmonary microvascular endothelial cells (PMVECs). Elevated extracellular bicarbonate increases cAMP in PMVECs to disrupt the endothelial barrier and increase the filtration coefficient (Kf) in the isolated lung. We tested the hypothesis that sepsis-induced endothelial barrier disruption and increased permeability are dependent on extracellular bicarbonate and activation of AC10. Our findings reveal that LPS-induced endothelial barrier disruption is dependent on extracellular bicarbonate: LPS-induced barrier failure and increased permeability are exacerbated in elevated bicarbonate compared with low extracellular bicarbonate. The AC10 inhibitor KH7 attenuated the bicarbonate-dependent LPS-induced barrier disruption. In the isolated lung, LPS failed to increase Kf in the presence of minimal perfusate bicarbonate. An increase in perfusate bicarbonate to the physiological range (24 mM) revealed the LPS-induced increase in Kf, which was attenuated by KH7. Furthermore, in PMVECs treated with LPS for 6 h, there was a dose-dependent increase in AC10 expression. Thus these findings reveal that LPS-induced pulmonary endothelial barrier failure requires bicarbonate activation of AC10.
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Affiliation(s)
- Jordan Nickols
- Department of Physiology and Cell Biology, University South Alabama, Mobile, Alabama
| | - Boniface Obiako
- Department of Pharmacology, University South Alabama, Mobile, Alabama; Center for Lung Biology, University South Alabama, Mobile, Alabama; and
| | - K C Ramila
- Department of Physiology and Cell Biology, University South Alabama, Mobile, Alabama
| | - Kevin Putinta
- Department of Physiology and Cell Biology, University South Alabama, Mobile, Alabama
| | - Sarah Schilling
- University of Applied Sciences Bingen, Bingen am Rhein, Germany
| | - Sarah L Sayner
- Department of Physiology and Cell Biology, University South Alabama, Mobile, Alabama; Center for Lung Biology, University South Alabama, Mobile, Alabama; and
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Slevin M, Matou S, Zeinolabediny Y, Corpas R, Weston R, Liu D, Boras E, Di Napoli M, Petcu E, Sarroca S, Popa-Wagner A, Love S, Font MA, Potempa LA, Al-Baradie R, Sanfeliu C, Revilla S, Badimon L, Krupinski J. Monomeric C-reactive protein--a key molecule driving development of Alzheimer's disease associated with brain ischaemia? Sci Rep 2015; 5:13281. [PMID: 26335098 PMCID: PMC4558604 DOI: 10.1038/srep13281] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 06/04/2015] [Indexed: 01/02/2023] Open
Abstract
Alzheimer’s disease (AD) increases dramatically in patients with ischaemic stroke. Monomeric C-reactive protein (mCRP) appears in the ECM of ischaemic tissue after stroke, associating with microvasculature, neurons and AD-plaques, Aβ, also, being able to dissociate native-CRP into inflammatory, mCRP in vivo. Here, mCRP injected into the hippocampal region of mice was retained within the retrosplenial tract of the dorsal 3rd ventrical and surrounding major vessels. Mice developed behavioural/cognitive deficits within 1 month, concomitant with mCRP staining within abnormal looking neurons expressing p-tau and in beta-amyloid 1-42-plaque positive regions. mCRP co-localised with CD105 in microvessels suggesting angiogenesis. Phospho-arrays/Western blotting identified signalling activation in endothelial cells and neurons through p-IRS-1, p-Tau and p-ERK1/2-which was blocked following pre-incubation with mCRP-antibody. mCRP increased vascular monolayer permeability and gap junctions, increased NCAM expression and produced haemorrhagic angiogenesis in mouse matrigel implants. mCRP induced tau244–372 aggregation and assembly in vitro. IHC study of human AD/stroke patients revealed co-localization of mCRP with Aβ plaques, tau-like fibrils and IRS-1/P-Tau positive neurons and high mCRP-levels spreading from infarcted core regions matched reduced expression of Aβ/Tau. mCRP may be responsible for promoting dementia after ischaemia and mCRP clearance could inform therapeutic avenues to reduce the risk of future dementia.
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Affiliation(s)
- M Slevin
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK.,University of Medicine and Pharmacy, Targu Mures, Romania.,Department of Pathology/Medicine, Griffith University, Brisbane, Australia
| | - S Matou
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - Y Zeinolabediny
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - R Corpas
- Instituto De Investigaciones Biomedicas De Barcelona, CSIC, Barcelona, Spain
| | - R Weston
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - D Liu
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - E Boras
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - M Di Napoli
- Neurological Service, San Camillo de' Lellis General Hospital, Rieti, Italy
| | - E Petcu
- Department of Pathology/Medicine, Griffith University, Brisbane, Australia
| | - S Sarroca
- Instituto De Investigaciones Biomedicas De Barcelona, CSIC, Barcelona, Spain
| | - A Popa-Wagner
- Clinic of Neurology, Medical University Greifswald, Germany
| | - S Love
- Department of Neuropathology, Institute of Clinical Neurosciences, School of Clinical Sciences, University of Bristol, Bristol, BS16 1LE, UK
| | - M A Font
- CSIC-ICCC, Hospital de la Santa Creu I Sant Pau, Barcelona, Spain
| | | | - R Al-Baradie
- College of Applied Medical Science, Al Majmaah University, Majmaah City, Kingdom of Saudi Arabia P.O Box 66
| | - C Sanfeliu
- Instituto De Investigaciones Biomedicas De Barcelona, CSIC, Barcelona, Spain
| | - S Revilla
- Instituto De Investigaciones Biomedicas De Barcelona, CSIC, Barcelona, Spain
| | - L Badimon
- CSIC-ICCC, Hospital de la Santa Creu I Sant Pau, Barcelona, Spain
| | - J Krupinski
- Hospital Universitari Mútua de Terrassa, Department of Neurology, Terrassa (Barcelona), Spain
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38
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Stevens TC, Ochoa CD, Morrow KA, Robson MJ, Prasain N, Zhou C, Alvarez DF, Frank DW, Balczon R, Stevens T. The Pseudomonas aeruginosa exoenzyme Y impairs endothelial cell proliferation and vascular repair following lung injury. Am J Physiol Lung Cell Mol Physiol 2014; 306:L915-24. [PMID: 24705722 DOI: 10.1152/ajplung.00135.2013] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Exoenzyme Y (ExoY) is a Pseudomonas aeruginosa toxin that is introduced into host cells through the type 3 secretion system (T3SS). Once inside the host cell cytoplasm, ExoY generates cyclic nucleotides that cause tau phosphorylation and microtubule breakdown. Microtubule breakdown causes interendothelial cell gap formation and tissue edema. Although ExoY transiently induces interendothelial cell gap formation, it remains unclear whether ExoY prevents repair of the endothelial cell barrier. Here, we test the hypothesis that ExoY intoxication impairs recovery of the endothelial cell barrier following gap formation, decreasing migration, proliferation, and lung repair. Pulmonary microvascular endothelial cells (PMVECs) were infected with P. aeruginosa strains for 6 h, including one possessing an active ExoY (PA103 exoUexoT::Tc pUCPexoY; ExoY(+)), one with an inactive ExoY (PA103ΔexoUexoT::Tc pUCPexoY(K81M); ExoY(K81M)), and one that lacks PcrV required for a functional T3SS (ΔPcrV). ExoY(+) induced interendothelial cell gaps, whereas ExoY(K81M) and ΔPcrV did not promote gap formation. Following gap formation, bacteria were removed and endothelial cell repair was examined. PMVECs were unable to repair gaps even 3-5 days after infection. Serum-stimulated growth was greatly diminished following ExoY intoxication. Intratracheal inoculation of ExoY(+) and ExoY(K81M) caused severe pneumonia and acute lung injury. However, whereas the pulmonary endothelial cell barrier was functionally improved 1 wk following ExoY(K81M) infection, pulmonary endothelium was unable to restrict the hyperpermeability response to elevated hydrostatic pressure following ExoY(+) infection. In conclusion, ExoY is an edema factor that chronically impairs endothelial cell barrier integrity following lung injury.
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Affiliation(s)
- Trevor C Stevens
- Center for Lung Biology, University of South Alabama, Mobile, Alabama;
| | - Cristhiaan D Ochoa
- Physician-Scientist Training Program, Department of Medicine, University of Texas-Southwestern Medical Center, Dallas, Texas; Division of Pulmonary and Critical Care, University of Texas-Southwestern Medical Center, Dallas, Texas
| | - K Adam Morrow
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Matthew J Robson
- Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Nutan Prasain
- Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University, Indianapolis, Indiana
| | - Chun Zhou
- Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Diego F Alvarez
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Department of Medicine, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Dara W Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin; and Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ron Balczon
- Department of Cell Biology and Neuroscience, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Troy Stevens
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Department of Medicine, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
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Tümmler B, Wiehlmann L, Klockgether J, Cramer N. Advances in understanding Pseudomonas. F1000PRIME REPORTS 2014; 6:9. [PMID: 24592321 PMCID: PMC3913036 DOI: 10.12703/p6-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Pseudomonas aeruginosa, the type species of pseudomonads, is an opportunistic pathogen that colonizes a wide range of niches. Current genome sequencing projects are producing previously inconceivable detail about the population biology and evolution of P. aeruginosa. Its pan-genome has a larger genetic repertoire than the human genome, which explains the broad metabolic capabilities of P. aeruginosa and its ubiquitous distribution in aquatic habitats. P. aeruginosa may persist in the airways of individuals with cystic fibrosis for decades. The ongoing whole-genome analyses of serial isolates from cystic fibrosis patients provide the so far singular opportunity to monitor the microevolution of a bacterial pathogen during chronic infection over thousands of generations. Although the evolution in cystic fibrosis lungs is neutral overall, some pathoadaptive mutations are selected during the within-host evolutionary process. Even a single mutation may be sufficient to generate novel complex traits provided that predisposing mutational events have previously occurred in the clonal lineage.
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