1
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Carreno-Florez GP, Kocak BR, Hendricks MR, Melvin JA, Mar KB, Kosanovich J, Cumberland RL, Delgoffe GM, Shiva S, Empey KM, Schoggins JW, Bomberger JM. Interferon signaling drives epithelial metabolic reprogramming to promote secondary bacterial infection. PLoS Pathog 2023; 19:e1011719. [PMID: 37939149 PMCID: PMC10631704 DOI: 10.1371/journal.ppat.1011719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/28/2023] [Indexed: 11/10/2023] Open
Abstract
Clinical studies report that viral infections promote acute or chronic bacterial infections at multiple host sites. These viral-bacterial co-infections are widely linked to more severe clinical outcomes. In experimental models in vitro and in vivo, virus-induced interferon responses can augment host susceptibility to secondary bacterial infection. Here, we used a cell-based screen to assess 389 interferon-stimulated genes (ISGs) for their ability to induce chronic Pseudomonas aeruginosa infection. We identified and validated five ISGs that were sufficient to promote bacterial infection. Furthermore, we dissected the mechanism of action of hexokinase 2 (HK2), a gene involved in the induction of aerobic glycolysis, commonly known as the Warburg effect. We report that HK2 upregulation mediates the induction of Warburg effect and secretion of L-lactate, which enhances chronic P. aeruginosa infection. These findings elucidate how the antiviral immune response renders the host susceptible to secondary bacterial infection, revealing potential strategies for viral-bacterial co-infection treatment.
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Affiliation(s)
- Grace P. Carreno-Florez
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Brian R. Kocak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Matthew R. Hendricks
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Jeffrey A. Melvin
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Katrina B. Mar
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Jessica Kosanovich
- Department of Pharmacy and Therapeutics and Center for Clinical Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania, United States of America
| | - Rachel L. Cumberland
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Greg M. Delgoffe
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Sruti Shiva
- Department of Pharmacology and Chemical Biology and Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Kerry M. Empey
- Department of Pharmacy and Therapeutics and Center for Clinical Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania, United States of America
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - John W. Schoggins
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Jennifer M. Bomberger
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
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2
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Haas AL, Zemke AC, Melvin JA, Armbruster CR, Hendricks MR, Moore J, Nouraie SM, Thibodeau PH, Lee SE, Bomberger JM. Iron bioavailability regulates Pseudomonas aeruginosa interspecies interactions through type VI secretion expression. Cell Rep 2023; 42:112270. [PMID: 36930643 PMCID: PMC10586262 DOI: 10.1016/j.celrep.2023.112270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 12/16/2022] [Accepted: 03/01/2023] [Indexed: 03/18/2023] Open
Abstract
The cystic fibrosis (CF) respiratory tract harbors pathogenic bacteria that cause life-threatening chronic infections. Of these, Pseudomonas aeruginosa becomes increasingly dominant with age and is associated with worsening lung function and declining microbial diversity. We aimed to understand why P. aeruginosa dominates over other pathogens to cause worsening disease. Here, we show that P. aeruginosa responds to dynamic changes in iron concentration, often associated with viral infection and pulmonary exacerbations, to become more competitive via expression of the TseT toxic effector. However, this behavior can be therapeutically targeted using the iron chelator deferiprone to block TseT expression and competition. Overall, we find that iron concentration and TseT expression significantly correlate with microbial diversity in the respiratory tract of people with CF. These findings improve our understanding of how P. aeruginosa becomes increasingly dominant with age in people with CF and provide a therapeutically targetable pathway to help prevent this shift.
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Affiliation(s)
- Allison L Haas
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Anna C Zemke
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Jeffrey A Melvin
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Catherine R Armbruster
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Matthew R Hendricks
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - John Moore
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Seyed Mehdi Nouraie
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Patrick H Thibodeau
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Stella E Lee
- Division of Otolaryngology, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Jennifer M Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA.
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3
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Armbruster CR, Li K, Kiedrowski MR, Zemke AC, Melvin JA, Moore J, Atteih S, Fitch AC, DuPont M, Manko CD, Weaver ML, Gaston JR, Alcorn JF, Morris A, Methé BA, Lee SE, Bomberger JM. Low Diversity and Instability of the Sinus Microbiota over Time in Adults with Cystic Fibrosis. Microbiol Spectr 2022; 10:e0125122. [PMID: 36094193 PMCID: PMC9603634 DOI: 10.1128/spectrum.01251-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 08/10/2022] [Indexed: 12/30/2022] Open
Abstract
Chronic rhinosinusitis (CRS) is a common, yet underreported and understudied manifestation of upper respiratory disease in people with cystic fibrosis (CF). Recently developed standard of care guidelines for the management of CF CRS suggest treatment of upper airway disease may ameliorate lower airway disease. We sought to determine whether changes to sinus microbial community diversity and specific taxa known to cause CF lung disease are associated with increased respiratory disease and inflammation. We performed 16S rRNA gene sequencing, supplemented with cytokine analyses, microscopy, and bacterial culturing, on samples from the sinuses of 27 adults with CF CRS. At each study visit, participants underwent endoscopic paranasal sinus sampling and clinical evaluation. We identified key drivers of microbial community composition and evaluated relationships between diversity and taxa with disease outcomes and inflammation. Sinus community diversity was low, and the composition was unstable, with many participants exhibiting alternating dominance between Pseudomonas aeruginosa and staphylococci over time. Despite a tendency for dominance by these two taxa, communities were highly individualized and shifted composition during exacerbation of sinus disease symptoms. Exacerbations were also associated with communities dominated by Staphylococcus spp. Reduced microbial community diversity was linked to worse sinus disease and the inflammatory status of the sinuses (including increased interleukin-1β [IL-1β]). Increased IL-1β was also linked to worse sinus endoscopic appearance, and other cytokines were linked to microbial community dynamics. Our work revealed previously unknown instability of sinus microbial communities and a link between inflammation, lack of microbial community diversity, and worse sinus disease. IMPORTANCE Together with prior sinus microbiota studies of adults with CF chronic rhinosinusitis, our study underscores similarities between sinus and lower respiratory tract microbial community structures in CF. We show how community structure tracks with inflammation and several disease measures. This work strongly suggests that clinical management of CRS could be leveraged to improve overall respiratory health in CF. Our work implicates elevated IL-1β in reduced microbiota diversity and worse sinus disease in CF CRS, suggesting applications for existing therapies targeting IL-1β. Finally, the widespread use of highly effective cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy has led to less frequent availability of spontaneous expectorated sputum for microbiological surveillance of lung infections. A better understanding of CF sinus microbiology could provide a much-needed alternative site for monitoring respiratory infection status by important CF pathogens.
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Affiliation(s)
- Catherine R. Armbruster
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Kelvin Li
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Megan R. Kiedrowski
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Anna C. Zemke
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jeffrey A. Melvin
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - John Moore
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Samar Atteih
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Adam C. Fitch
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Matthew DuPont
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Christopher D. Manko
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Madison L. Weaver
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jordon R. Gaston
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - John F. Alcorn
- Department of Pediatrics, Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alison Morris
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Barbara A. Methé
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Stella E. Lee
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Jennifer M. Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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4
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Armbruster CR, Marshall CW, Garber AI, Melvin JA, Zemke AC, Moore J, Zamora PF, Li K, Fritz IL, Manko CD, Weaver ML, Gaston JR, Morris A, Methé B, DePas WH, Lee SE, Cooper VS, Bomberger JM. Adaptation and genomic erosion in fragmented Pseudomonas aeruginosa populations in the sinuses of people with cystic fibrosis. Cell Rep 2021; 37:109829. [PMID: 34686349 PMCID: PMC8667756 DOI: 10.1016/j.celrep.2021.109829] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/09/2021] [Accepted: 09/22/2021] [Indexed: 10/20/2022] Open
Abstract
Pseudomonas aeruginosa notoriously adapts to the airways of people with cystic fibrosis (CF), yet how infection-site biogeography and associated evolutionary processes vary as lifelong infections progress remains unclear. Here we test the hypothesis that early adaptations promoting aggregation influence evolutionary-genetic trajectories by examining longitudinal P. aeruginosa from the sinuses of six adults with CF. Highly host-adapted lineages harbored mutator genotypes displaying signatures of early genome degradation associated with recent host restriction. Using an advanced imaging technique (MiPACT-HCR [microbial identification after passive clarity technique]), we find population structure tracks with genome degradation, with the most host-adapted, genome-degraded P. aeruginosa (the mutators) residing in small, sparse aggregates. We propose that following initial adaptive evolution in larger populations under strong selection for aggregation, P. aeruginosa persists in small, fragmented populations that experience stronger effects of genetic drift. These conditions enrich for mutators and promote degenerative genome evolution. Our findings underscore the importance of infection-site biogeography to pathogen evolution.
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Affiliation(s)
- Catherine R Armbruster
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | | | - Arkadiy I Garber
- Biodesign Center for Mechanisms of Evolution and School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
| | - Jeffrey A Melvin
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Anna C Zemke
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - John Moore
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Paula F Zamora
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Kelvin Li
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Ian L Fritz
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Christopher D Manko
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Madison L Weaver
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Jordan R Gaston
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Alison Morris
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Barbara Methé
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - William H DePas
- Department of Pediatrics, Children's Hospital of Pittsburgh and University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Stella E Lee
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA.
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA; Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA; Pittsburgh Center for Evolutionary Biology & Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
| | - Jennifer M Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
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5
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Hendricks MR, Lane S, Melvin JA, Ouyang Y, Stolz DB, Williams JV, Sadovsky Y, Bomberger JM. Extracellular vesicles promote transkingdom nutrient transfer during viral-bacterial co-infection. Cell Rep 2021; 34:108672. [PMID: 33503419 PMCID: PMC7918795 DOI: 10.1016/j.celrep.2020.108672] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 03/10/2020] [Accepted: 12/30/2020] [Indexed: 01/28/2023] Open
Abstract
Extracellular vesicles (EVs) are increasingly appreciated as a mechanism of communication among cells that contribute to many physiological processes. Although EVs can promote either antiviral or proviral effects during viral infections, the role of EVs in virus-associated polymicrobial infections remains poorly defined. We report that EVs secreted from airway epithelial cells during respiratory viral infection promote secondary bacterial growth, including biofilm biogenesis, by Pseudomonas aeruginosa. Respiratory syncytial virus (RSV) increases the release of the host iron-binding protein transferrin on the extravesicular face of EVs, which interact with P. aeruginosa biofilms to transfer the nutrient iron and promote bacterial biofilm growth. Vesicular delivery of iron by transferrin more efficiently promotes P. aeruginosa biofilm growth than soluble holo-transferrin delivered alone. Our findings indicate that EVs are a nutrient source for secondary bacterial infections in the airways during viral infection and offer evidence of transkingdom communication in the setting of polymicrobial infections.
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Affiliation(s)
- Matthew R Hendricks
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Sidney Lane
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA; Program in Microbiology and Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Jeffrey A Melvin
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Yingshi Ouyang
- Magee-Womens Research Institute, Department of OBGYN and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Donna B Stolz
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - John V Williams
- Department of Pediatrics, University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA 15224, USA
| | - Yoel Sadovsky
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA; Magee-Womens Research Institute, Department of OBGYN and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jennifer M Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
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6
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Cornforth DM, Diggle FL, Melvin JA, Bomberger JM, Whiteley M. Quantitative Framework for Model Evaluation in Microbiology Research Using Pseudomonas aeruginosa and Cystic Fibrosis Infection as a Test Case. mBio 2020; 11:e03042-19. [PMID: 31937646 PMCID: PMC6960289 DOI: 10.1128/mbio.03042-19] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 11/27/2019] [Indexed: 01/14/2023] Open
Abstract
Laboratory models are a cornerstone of modern microbiology, but the accuracy of these models has not been systematically evaluated. As a result, researchers often choose models based on intuition or incomplete data. We propose a general quantitative framework to assess model accuracy from RNA sequencing data and use this framework to evaluate models of Pseudomonas aeruginosa cystic fibrosis (CF) lung infection. We found that an in vitro synthetic CF sputum medium model and a CF airway epithelial cell model had the highest genome-wide accuracy but underperformed on distinct functional categories, including porins and polyamine biosynthesis for the synthetic sputum medium and protein synthesis for the epithelial cell model. We identified 211 "elusive" genes that were not mimicked in a reference strain grown in any laboratory model but found that many were captured by using a clinical isolate. These methods provide researchers with an evidence-based foundation to select and improve laboratory models.IMPORTANCE Laboratory models have become a cornerstone of modern microbiology. However, the accuracy of even the most commonly used models has never been evaluated. Here, we propose a quantitative framework based on gene expression data to evaluate model performance and apply it to models of Pseudomonas aeruginosa cystic fibrosis lung infection. We discovered that these models captured different aspects of P. aeruginosa infection physiology, and we identify which functional categories are and are not captured by each model. These methods will provide researchers with a solid basis to choose among laboratory models depending on the scientific question of interest and will help improve existing experimental models.
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Affiliation(s)
- Daniel M Cornforth
- School of Biological Sciences, Georgia Institute of Technology, Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
- Emory-Children's Cystic Fibrosis Center, Atlanta, Georgia, USA
| | - Frances L Diggle
- School of Biological Sciences, Georgia Institute of Technology, Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
- Emory-Children's Cystic Fibrosis Center, Atlanta, Georgia, USA
| | - Jeffrey A Melvin
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jennifer M Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Marvin Whiteley
- School of Biological Sciences, Georgia Institute of Technology, Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
- Emory-Children's Cystic Fibrosis Center, Atlanta, Georgia, USA
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7
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Purcaro G, Rees CA, Melvin JA, Bomberger JM, Hill JE. Volatile fingerprinting of Pseudomonas aeruginosa and respiratory syncytial virus infection in an in vitro cystic fibrosis co-infection model. J Breath Res 2018; 12:046001. [PMID: 29735804 DOI: 10.1088/1752-7163/aac2f1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Volatile molecules in exhaled breath represent potential biomarkers in the setting of infectious diseases, particularly those affecting the respiratory tract. In particular, Pseudomonas aeruginosa is a critically important respiratory pathogen in specific subsets of the population, such as those with cystic fibrosis (CF). Infections caused by P. aeruginosa can be particularly problematic when co-infection with respiratory syncytial virus (RSV) occurs, as this is correlated with the establishment of chronic P. aeruginosa infection. In the present study, we evaluate the volatile metabolites produced by P. aeruginosa (PAO1)-infected, RSV-infected, co-infected, or uninfected CF bronchial epithelial (CFBE) cells, in vitro. We identified a volatile metabolic signature that could discriminate between P. aeruginosa-infected and non-P. aeruginosa-infected CFBE with an area under the receiver operating characteristic curve (AUROC) of 0.850, using the machine learning algorithm random forest (RF). Although we could not discriminate between RSV-infected and non-RSV-infected CFBE (AUROC = 0.431), we note that sample classification probabilities for RSV-infected cell, generated using RF, were between those of uninfected CFBE and P. aeruginosa-infected CFBE, suggesting that RSV infection may result in a volatile metabolic profile that shares attributes with both of these groups. To more precisely elucidate the biological origins of the volatile metabolites that were discriminatory between P. aeruginosa-infected and non-P. aeruginosa-infected CFBE, we measured the volatile metabolites produced by P. aeruginosa grown in the absence of CFBE. Our findings suggest that the discriminatory metabolites produced likely result from the interaction of P. aeruginosa with the CFBE cells, rather than the metabolism of media components by the bacterium. Taken together, our findings support the notion that P. aeruginosa interacting with CFBE yields a particular volatile metabolic signature. Such a signature may have clinical utility in the monitoring of individuals with CF.
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Affiliation(s)
- Giorgia Purcaro
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, United States of America
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8
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Melvin JA, Montelaro RC, Bomberger JM. Clinical potential of engineered cationic antimicrobial peptides against drug resistant biofilms. Expert Rev Anti Infect Ther 2016; 14:989-991. [PMID: 27626708 DOI: 10.1080/14787210.2016.1236687] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Jeffrey A Melvin
- a Department of Microbiology and Molecular Genetics , University of Pittsburgh , Pittsburgh , PA , USA
| | - Ronald C Montelaro
- a Department of Microbiology and Molecular Genetics , University of Pittsburgh , Pittsburgh , PA , USA
| | - Jennifer M Bomberger
- a Department of Microbiology and Molecular Genetics , University of Pittsburgh , Pittsburgh , PA , USA
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9
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Affiliation(s)
- Jeffrey A. Melvin
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jennifer M. Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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10
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Deschamps JD, Ogunsola AF, Jameson JB, Yasgar A, Flitter BA, Freedman CJ, Melvin JA, Nguyen JVMH, Maloney DJ, Jadhav A, Simeonov A, Bomberger JM, Holman TR. Biochemical and Cellular Characterization and Inhibitor Discovery of Pseudomonas aeruginosa 15-Lipoxygenase. Biochemistry 2016; 55:3329-40. [PMID: 27226387 DOI: 10.1021/acs.biochem.6b00338] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that can cause nosocomial and chronic infections in immunocompromised patients. P. aeruginosa secretes a lipoxygenase, LoxA, but the biological role of this enzyme is currently unknown. LoxA is poorly similar in sequence to both soybean LOX-1 (s15-LOX-1) and human 15-LOX-1 (37 and 39%, respectively) yet has kinetics comparably fast versus those of s15-LOX-1 (at pH 6.5, Kcat = 181 ± 6 s(-1) and Kcat/KM = 16 ± 2 μM(-1) s(-1)). LoxA is capable of efficiently catalyzing the peroxidation of a broad range of free fatty acid (FA) substrates (e.g., AA and LA) with high positional specificity, indicating a 15-LOX. Its mechanism includes hydrogen atom abstraction [a kinetic isotope effect (KIE) of >30], yet LoxA is a poor catalyst against phosphoester FAs, suggesting that LoxA is not involved in membrane decomposition. LoxA also does not react with 5- or 15-HETEs, indicating poor involvement in lipoxin production. A LOX high-throughput screen of the LOPAC library yielded a variety of low-micromolar inhibitors; however, none selectively targeted LoxA over the human LOX isozymes. With respect to cellular activity, the level of LoxA expression is increased when P. aeruginosa undergoes the transition to a biofilm mode of growth, but LoxA is not required for biofilm growth on abiotic surfaces. However, LoxA does appear to be required for biofilm growth in association with the host airway epithelium, suggesting a role for LoxA in mediating bacterium-host interactions during colonization.
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Affiliation(s)
- Joshua D Deschamps
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
| | - Abiola F Ogunsola
- Department of Microbiology and Molecular Genetics, University of Pittsburgh , Pittsburgh, Pennsylvania 15219, United States
| | - J Brian Jameson
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
| | - Adam Yasgar
- National Center for Advancing Translational Sciences, National Institutes of Health , 9800 Medical Center Drive, MSC 3370, Bethesda, Maryland 20892, United States
| | - Becca A Flitter
- Department of Microbiology and Molecular Genetics, University of Pittsburgh , Pittsburgh, Pennsylvania 15219, United States
| | - Cody J Freedman
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
| | - Jeffrey A Melvin
- Department of Microbiology and Molecular Genetics, University of Pittsburgh , Pittsburgh, Pennsylvania 15219, United States
| | - Jason V M H Nguyen
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
| | - David J Maloney
- National Center for Advancing Translational Sciences, National Institutes of Health , 9800 Medical Center Drive, MSC 3370, Bethesda, Maryland 20892, United States
| | - Ajit Jadhav
- National Center for Advancing Translational Sciences, National Institutes of Health , 9800 Medical Center Drive, MSC 3370, Bethesda, Maryland 20892, United States
| | - Anton Simeonov
- National Center for Advancing Translational Sciences, National Institutes of Health , 9800 Medical Center Drive, MSC 3370, Bethesda, Maryland 20892, United States
| | - Jennifer M Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh , Pittsburgh, Pennsylvania 15219, United States
| | - Theodore R Holman
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
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11
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Lashua LP, Melvin JA, Deslouches B, Pilewski JM, Montelaro RC, Bomberger JM. Engineered cationic antimicrobial peptide (eCAP) prevents Pseudomonas aeruginosa biofilm growth on airway epithelial cells. J Antimicrob Chemother 2016; 71:2200-7. [PMID: 27231279 DOI: 10.1093/jac/dkw143] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 03/24/2016] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVES Chronic infections with the opportunistic pathogen Pseudomonas aeruginosa are responsible for the majority of the morbidity and mortality in patients with cystic fibrosis (CF). While P. aeruginosa infections may initially be treated successfully with standard antibiotics, chronic infections typically arise as bacteria transition to a biofilm mode of growth and acquire remarkable antimicrobial resistance. To address the critical need for novel antimicrobial therapeutics that can effectively suppress chronic bacterial infections in challenging physiological environments, such as the CF lung, we have rationally designed a de novo engineered cationic antimicrobial peptide, the 24-residue WLBU2, with broad-spectrum antibacterial activity for pan-drug-resistant P. aeruginosa in liquid culture. In the current study, we tested the hypothesis that WLBU2 also prevents P. aeruginosa biofilm growth. METHODS Using abiotic and biotic biofilm assays, co-culturing P. aeruginosa with polarized human airway epithelial cells, we examined the ability of WLBU2 to prevent biofilm biogenesis alone and in combination with currently used antibiotics. RESULTS We observed a dose-dependent reduction in biofilm growth on an abiotic surface and in association with CF airway epithelial cells. WLBU2 prevented P. aeruginosa biofilm formation when co-cultured with mucus-producing primary human CF airway epithelial cells and using CF clinical isolates of P. aeruginosa, even at low pH and high salt conditions that mimic the CF airway. When used in combination, WLBU2 significantly increases killing by the commonly used antibiotics tobramycin, ciprofloxacin, ceftazidime and meropenem. CONCLUSIONS While other studies have demonstrated the ability of natural and synthetic antimicrobial peptides to prevent abiotic bacterial biofilm formation, the current studies for the first time demonstrate the effective peptide treatment of a biotic bacterial biofilm in a setting similar to the CF airway, and without negative effects on human airway epithelial cells, thus highlighting the unique potential of this engineered cationic antimicrobial peptide for treatment of human respiratory infections.
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Affiliation(s)
- Lauren P Lashua
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jeffrey A Melvin
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Berthony Deslouches
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, USA
| | - Joseph M Pilewski
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ronald C Montelaro
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jennifer M Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA
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Noël CR, Mazar J, Melvin JA, Sexton JA, Cotter PA. The prodomain of the Bordetella two-partner secretion pathway protein FhaB remains intracellular yet affects the conformation of the mature C-terminal domain. Mol Microbiol 2012; 86:988-1006. [PMID: 23035892 DOI: 10.1111/mmi.12036] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2012] [Indexed: 12/26/2022]
Abstract
Two-partner secretion (TPS) systems use β-barrel proteins of the Omp85-TpsB superfamily to transport large exoproteins across the outer membranes of Gram-negative bacteria. The Bordetella FHA/FhaC proteins are prototypical of TPS systems in which the exoprotein contains a large C-terminal prodomain that is removed during translocation. Although it is known that the FhaB prodomain is required for FHA function in vivo, its role in FHA maturation has remained mysterious. We show here that the FhaB prodomain is required for the extracellularly located mature C-terminal domain (MCD) of FHA to achieve its proper conformation. We show that the C-terminus of the prodomain is retained intracellularly and that sequences within the N-terminus of the prodomain are required for this intracellular localization. We also identify sequences at the C-terminus of the MCD that are required for release of mature FHA from the cell surface. Our data support a model in which the intracellularly located prodomain affects the final conformation of the extracellularly located MCD. We hypothesize that maturation triggers cleavage and degradation of the prodomain.
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Affiliation(s)
- Christopher R Noël
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599-7290, USA
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13
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Melvin JA, Murphy CF, Dubois LG, Thompson JW, Moseley MA, McCafferty DG. Staphylococcus aureus sortase A contributes to the Trojan horse mechanism of immune defense evasion with its intrinsic resistance to Cys184 oxidation. Biochemistry 2011; 50:7591-9. [PMID: 21812416 DOI: 10.1021/bi200844h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Staphylococcus aureus is a Gram-positive bacterial pathogen that causes serious infections which have become increasingly difficult to treat due to antimicrobial resistance and natural virulence strategies. Bacterial sortase enzymes are important virulence factors and good targets for future antibiotic development. It has recently been shown that sortase enzymes are integral to bacterial survival of phagocytosis, an underappreciated, but vital, step in S. aureus pathogenesis. Of note, the reaction mechanism of sortases relies on a solvent-accessible cysteine for transpeptidation. Because of the common strategy of oxidative damage employed by professional phagocytes to kill pathogens, it is possible that this cysteine may be oxidized inside the phagosome, thereby inhibiting the enzyme. This study addresses this apparent paradox by assessing the ability of physiological reactive oxygen species, hydrogen peroxide and hypochlorite, to inhibit sortase A (SrtA) from S. aureus. Surprisingly, we found that SrtA is highly resistant to oxidative inhibition, both in vitro and in vivo. The mechanism of resistance to oxidative damage is likely mediated by maintaining a high reduction potential of the catalytic cysteine residue, Cys184. This is due to the unusual active site utilized by S. aureus SrtA, which employs a reverse protonation mechanism for transpeptidation, resulting in a high pK(a) as well as reduction potential for Cys184. The results of this study suggest that S. aureus SrtA is able to withstand the extreme conditions encountered in the phagosome and maintain function, contributing to survival of phagocytotic killing.
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Affiliation(s)
- Jeffrey A Melvin
- Department of Biochemistry, Duke University, Durham, North Carolina 27708, United States
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Hu X, Hu H, Melvin JA, Clancy KW, McCafferty DG, Yang W. Autocatalytic intramolecular isopeptide bond formation in gram-positive bacterial pili: a QM/MM simulation. J Am Chem Soc 2011; 133:478-85. [PMID: 21142157 PMCID: PMC3081525 DOI: 10.1021/ja107513t] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many gram-positive pathogens possess external pili or fimbriae with which they adhere to host cells during the infection process. Unusual dual intramolecular isopeptide bonds between Asn and Lys side chains within the N-terminal and C-terminal domains of the pilus subunits have been observed initially in the Streptococcus pyogenes pilin subunit Spy0128 and subsequently in GBS52 from Streptococcus agalactiae, in the BcpA major pilin of Bacillus cereus and in the RrgB pilin of Streptococcus pneumoniae, among others. Within each pilin subunit, intramolecular isopeptide bonds serve to stabilize the protein. These bonds provide a means to withstand large external mechanical forces, as well as possibly assisting in supporting a conformation favored for pilin subunit polymerization via sortase transpeptidases. Genome-wide analyses of pili-containing gram-positive bacteria are known or suspected to contain isopeptide bonds in pilin subunits. For the autocatalytic formation of isopeptide cross-links, a conservation of three amino acids including Asn, Lys, and a catalytically important acidic Glu (or Asp) residue are responsible. However, the chemical mechanism of how isopeptide bonds form within pilin remains poorly understood. Although it is possible that several mechanistic paths could lead to isopeptide bond formation in pili, the requirement of a conserved glutamate and highly organized positioning of residues within the hydrophobic environment of the active site were found in numerous pilin crystal structures such as Spy0128 and RrgB. This suggests a mechanism involving direct coupling of lysine side chain amine to the asparagine carboxamide mediated by critical acid/base or hydrogen bonding interactions with the catalytic glutamate residue. From this mechanistic perspective, we used the QM/MM minimum free-energy path method to examine the reaction details of forming the isopeptide bonds with Spy0128 as a model pilin, specifically focusing on the role of the glutamate in catalysis. It was determined that the reaction mechanism likely consists of two major steps: the nucleophilic attack on Cγ by nitrogen in the unprotonated Lys ε-amino group and, then two concerted proton transfers occur during the formation of the intramolecular isopeptide bond to subsequently release ammonia. More importantly, within the dual active sites of Spy0128, Glu(117), and Glu(258) residues function as crucial catalysts for each isopeptide bond formation, respectively, by relaying two proton transfers. This work also suggests that domain-domain interactions within Spy0128 may modulate the reactivity of residues within each active site. Our results may hopefully shed light on the molecular mechanisms of pilin biogenesis in gram-positive bacteria.
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Affiliation(s)
- Xiangqian Hu
- Department of Chemistry, Duke University, Durham, NC 27708
| | - Hao Hu
- Department of Chemistry, The University of Hong Kong
| | - Jeffrey A. Melvin
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27708
| | | | | | - Weitao Yang
- Department of Chemistry, Duke University, Durham, NC 27708
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15
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Clancy KW, Melvin JA, McCafferty DG. Erratum: Invited Review: Sortase transpeptidases: Insights into mechanism, substrate specificity, and inhibition. Biopolymers 2010. [DOI: 10.1002/bip.21529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Abstract
Gram-positive bacteria pose a serious healthcare threat. The growing antibiotic resistance epidemic creates a dire need for new antibiotic targets. The sortase family of enzymes is a promising target for antimicrobial therapy. This review covers the current knowledge of the mechanism, substrate specificity, and inhibitory studies of the Gram-positive bacterial [corrected] enzyme sortase.
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Affiliation(s)
| | | | - Dewey G. McCafferty
- Department of Chemistry, Duke University, Durham, NC
- Department of Biochemistry, Duke University, Durham, NC
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Gubler WD, Feliciano AJ, Bordas AC, Civerolo EC, Melvin JA, Welch NC. First Report of Blossom Blight of Strawberry Caused by Xanthomonas fragariae and Cladosporium cladosporioides in California. Plant Dis 1999; 83:400. [PMID: 30845607 DOI: 10.1094/pdis.1999.83.4.400a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In the spring of 1996, severe blossom blight occurred in some strawberry fruit production fields in the Watsonville area. The symptoms, in addition to blighting of entire flowers, were as follows: on the lower surface of the calyx, watersoaked lesions that appeared dark green under reflected light and translucent under transmitted light; necrotic calyces of seemingly healthy green and ripe fruits; watersoaking of the base of the calyx that extended into the pedicel; green-gray sporulation on dead anthers; and presence of flower clusters with small and irregularly shaped fruits. Yellow bacterial colonies were consistently isolated from water-soaked and necrotic lesions on calyces and pedicels. These colonies were entire, circular, raised, glistening, mucoid, and slow growing, characteristics typical of Xanthomonas fragariae on nutrient agar-glucose-yeast extract medium. The bacterial isolate was also identified by rep-polymerase chain reaction as X. fragariae. In addition to the yellow bacteria, a fungus was also frequently isolated from infected anthers, sepals, petals, and pistils, and was identified as Cladosporium cladosporioides. On potato dextrose agar, the fungus had velvetlike colonies colored olivaceous-green to olivaceous-brown, apically and laterally branched conidiophores, and lemon-shaped conidia that were usually smooth but sometimes textured. Blossoms of greenhouse-grown strawberry plants cv. Selva were inoculated with either or both organisms. Blossoms inoculated with X. fragariae developed symptoms distinct from those inoculated with C. cladosporioides. The most prominent visible symptoms caused by X. fragariae were watersoaked lesions on calyces that later became necrotic, watersoaking of the calyx that extended into the pedicel, and blighting of flowers and developing fruits as a result of girdling of the pedicel. Infection by C. cladosporioides was characterized by necrosis of flower parts or the entire flower, presence of green-gray sporulation on dead anthers, and production of small and malformed or misshapen fruits. Inoculation with both organisms produced all the symptoms described above in different flowers of a plant. Infection with both organisms aggravated disease severity, but each organism was capable of inducing blossom blight independently. Both organisms were reisolated from artificially inoculated strawberry flowers, fulfilling Koch's postulate for proof of pathogenicity. This is the first report of the two organisms causing blossom blight of strawberry in California. This is also the first report that C. cladosporioides is a pathogen of strawberry.
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Affiliation(s)
- W D Gubler
- Department of Plant Pathology, University of California, Davis 95616
| | - A J Feliciano
- Department of Plant Pathology, University of California, Davis 95616
| | - A C Bordas
- Department of Plant Pathology, University of California, Davis 95616
| | - E C Civerolo
- USDA/ARS, Department of Plant Pathology, University of California, Davis 95616
| | - J A Melvin
- USDA/ARS, Department of Plant Pathology, University of California, Davis 95616
| | - N C Welch
- University of California Cooperative Extension, Santa Cruz County, Santa Cruz 95076-2796
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18
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George MS, Melvin JA, Kellner CH. Obsessive-compulsive symptoms in neurologic disease: a review. Behav Neurol 1992; 5:3-10. [PMID: 24487654 DOI: 10.3233/ben-1992-5101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Abstract
Obsessive-compulsive disorder (OCD) is an increasingly recognized disorder with a prevalence of 2-3% (Robins et al., 1984). Once thought to be psychodynamic in origin, OCD is now generally recognized as having a neurobiological cause. Although the exact pathophysiology of OCD in its pure form remains unknown, there are numerous reports of obsessive-compulsive symptoms arising in the setting of known neurological disease. In this paper, we review the reported cases of obsessive-compulsive symptoms associated with neurologic diseases and outline the known facts about the underlying neurobiology of OCD. Finally, we synthesize these findings into a proposed theory of the pathophysiology of OCD, in both its pure form and when it accompanies other neurological illness.
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Affiliation(s)
- M S George
- Departments of Neurology, and Psychiatry and Behavioral Sciences, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425-0742, USA
| | - J A Melvin
- Departments of Neurology, and Psychiatry and Behavioral Sciences, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425-0742, USA
| | - C H Kellner
- Departments of Neurology, and Psychiatry and Behavioral Sciences, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425-0742, USA
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20
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Austin LS, Arana GW, Melvin JA. Toxicity resulting from lithium augmentation of antidepressant treatment in elderly patients. J Clin Psychiatry 1990; 51:344-5. [PMID: 2380160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Lithium augmentation of antidepressant treatment is a commonly used strategy for treatment-resistant cases of depression. Two cases are described in which significant neurotoxicity developed in elderly patients despite therapeutic doses of antidepressant and lithium.
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Affiliation(s)
- L S Austin
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston 29464
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21
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Melvin JA, Santos A. Pseudotetanus from illicit drug use. Am J Emerg Med 1989; 7:455-6. [PMID: 2735998 DOI: 10.1016/0735-6757(89)90070-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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22
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Kellner CH, Melvin JA. Neuroleptic malignant syndrome associated with basal ganglia hemorrhage. J Neuropsychiatry Clin Neurosci 1989; 1:339. [PMID: 2521078 DOI: 10.1176/jnp.1.3.339b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Hernandez DE, Stanley DA, Melvin JA, Prange AJ. Involvement of brain dopamine systems on neurotensin-induced protection against stress gastric lesions. Brain Res 1986; 381:159-63. [PMID: 3756495 DOI: 10.1016/0006-8993(86)90705-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We have previously demonstrated that intracisternal (i.c.) administration of neurotensin (NT), a brain and gastrointestinal tridecapeptide, potently inhibits gastric ulcer formation induced by cold-restraint stress (CRS) in rats. This study evaluated the effect of i.c. NT (17.9 nmol) or vehicle (10 microliter of 0.9% NaCl) on the development of CRS-induced gastric ulcers and on dopamine (DA) concentrations and DA turnover (DOPAC/DA) in selected brain regions after 0, 1, 2 and 3 h of CRS. As anticipated, and in confirmation of previous findings, NT significantly reduced the incidence and severity of CRS gastric ulcers in a time-dependent manner. Neurotensin significantly decreased DA concentration and DA turnover in the striatum. In the nucleus accumbens, however, NT produced a decrease in DA concentration and a concomitant increase in DA turnover after 2 and 3 h of CRS. No significant effects of brain NT on DA concentration and DA turnover were observed in the hypothalamus or olfactory tubercles. These findings suggest that the anti-ulcer effect of brain NT may be mediated, at least in part, by a differential activation of the mesolimbic and nigrostriatal DA systems.
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Abstract
We have reported previously that intracisternal (IC) administration of neurotensin (NT) prevents stress-induced gastric ulcers in rats. This effect of NT appears to be mediated by the central nervous system because peripheral (IV) NT is totally ineffective. The present study sought to clarify the central mechanism of the cytoprotective effect of NT by utilizing pharmacological treatments which alter the function of brain neurotransmitter systems. Pretreatment with intracerebroventricular (ICV) administration of agonists and antagonists of acetylcholine (ACh), gamma-aminobutyric acid (GABA), and serotonin (5-HT) receptors or with an anti-opiate (naloxone) agent did not significantly alter NT-induced cytoprotection. However, pretreatment with ICV haloperidol, a dopamine (DA) receptor antagonist, totally blocked NT's cytoprotective effect. In addition, pretreatment with methylphenidate, a DA receptor agonist, produced cytoprotection similar to IC NT. These data indicate that NT-induced cytoprotection is not mediated by 5-HT, GABA, ACh (muscarinic) receptors, or endogenous opiate systems, but suggest interactions between brain DA systems and NT.
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MESH Headings
- Animals
- Brain Chemistry/drug effects
- Cisterna Magna
- Cold Temperature
- Haloperidol/pharmacology
- Humans
- Injections
- Injections, Intraperitoneal
- Injections, Intraventricular
- Male
- Neurotensin/administration & dosage
- Neurotensin/pharmacology
- Neurotransmitter Agents/physiology
- Rats
- Rats, Inbred Strains
- Receptors, Dopamine/physiology
- Receptors, GABA-A/physiology
- Receptors, Muscarinic/physiology
- Receptors, Opioid/physiology
- Receptors, Serotonin/physiology
- Restraint, Physical
- Stomach Ulcer/prevention & control
- Stress, Psychological/physiopathology
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