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Bazant J, Weiss A, Baldauf J, Schermuly RT, Hain T, Lucas R, Mraheil MA. Pneumococcal hydrogen peroxide regulates host cell kinase activity. Front Immunol 2024; 15:1414195. [PMID: 38903521 PMCID: PMC11188345 DOI: 10.3389/fimmu.2024.1414195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 05/21/2024] [Indexed: 06/22/2024] Open
Abstract
Introduction Protein kinases are indispensable reversible molecular switches that adapt and control protein functions during cellular processes requiring rapid responses to internal and external events. Bacterial infections can affect kinase-mediated phosphorylation events, with consequences for both innate and adaptive immunity, through regulation of antigen presentation, pathogen recognition, cell invasiveness and phagocytosis. Streptococcus pneumoniae (Spn), a human respiratory tract pathogen and a major cause of community-acquired pneumoniae, affects phosphorylation-based signalling of several kinases, but the pneumococcal mediator(s) involved in this process remain elusive. In this study, we investigated the influence of pneumococcal H2O2 on the protein kinase activity of the human lung epithelial H441 cell line, a generally accepted model of alveolar epithelial cells. Methods We performed kinome analysis using PamGene microarray chips and protein analysis in Western blotting in H441 lung cells infected with Spn wild type (SpnWT) or with SpnΔlctOΔspxB -a deletion mutant strongly attenuated in H2O2 production- to assess the impact of pneumococcal hydrogen peroxide (H2O2) on global protein kinase activity profiles. Results Our kinome analysis provides direct evidence that kinase activity profiles in infected H441 cells significantly vary according to the levels of pneumococcal H2O2. A large number of kinases in H441 cells infected with SpnWT are significantly downregulated, whereas this no longer occurs in cells infected with the mutant SpnΔlctOΔspxB strain, which lacks H2O2. In particular, we describe for the first time H2O2-mediated downregulation of Protein kinase B (Akt1) and activation of lymphocyte-specific tyrosine protein kinase (Lck) via H2O2-mediated phosphorylation.
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Affiliation(s)
- Jasmin Bazant
- Institute of Medical Microbiology, German Centre for Infection Giessen-Marburg-Langen Site, Justus-Liebig University Giessen, Giessen, Germany
| | - Astrid Weiss
- Department of Internal Medicine, Cardio–Pulmonary Institute (CPI), Member of German Center for Lung Research (DZL), Justus-Liebig University Giessen, Giessen, Germany
| | - Julia Baldauf
- Department of Internal Medicine, Cardio–Pulmonary Institute (CPI), Member of German Center for Lung Research (DZL), Justus-Liebig University Giessen, Giessen, Germany
| | - Ralph Theo Schermuly
- Department of Internal Medicine, Cardio–Pulmonary Institute (CPI), Member of German Center for Lung Research (DZL), Justus-Liebig University Giessen, Giessen, Germany
| | - Torsten Hain
- Institute of Medical Microbiology, German Centre for Infection Giessen-Marburg-Langen Site, Justus-Liebig University Giessen, Giessen, Germany
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Division of Pulmonary, Sleep and Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Mobarak Abu Mraheil
- Institute of Medical Microbiology, German Centre for Infection Giessen-Marburg-Langen Site, Justus-Liebig University Giessen, Giessen, Germany
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Bazant J, Ott B, Hudel M, Hain T, Lucas R, Mraheil MA. Impact of Endogenous Pneumococcal Hydrogen Peroxide on the Activity and Release of Pneumolysin. Toxins (Basel) 2023; 15:593. [PMID: 37888624 PMCID: PMC10611280 DOI: 10.3390/toxins15100593] [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: 08/10/2023] [Revised: 09/21/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2023] Open
Abstract
Streptococcus pneumoniae is the leading cause of community-acquired pneumonia. The pore-forming cholesterol-dependent cytolysin (CDC) pneumolysin (PLY) and the physiological metabolite hydrogen peroxide (H2O2) can greatly increase the virulence of pneumococci. Although most studies have focused on the contribution of both virulence factors to the course of pneumococcal infection, it is unknown whether or how H2O2 can affect PLY activity. Of note, S. pneumoniae exploits endogenous H2O2 as an intracellular signalling molecule to modulate the activity of several proteins. Here, we demonstrate that H2O2 negatively affects the haemolytic activity of PLY in a concentration-dependent manner. Prevention of cysteine-dependent sulfenylation upon substitution of the unique and highly conserved cysteine residue to serine in PLY significantly reduces the toxin's susceptibility to H2O2 treatment and completely abolishes the ability of DTT to activate PLY. We also detect a clear gradual correlation between endogenous H2O2 generation and PLY release, with decreased H2O2 production causing a decline in the release of PLY. Comparative transcriptome sequencing analysis of the wild-type S. pneumoniae strain and three mutants impaired in H2O2 production indicates enhanced expression of several genes involved in peptidoglycan (PG) synthesis and in the production of choline-binding proteins (CPBs). One explanation for the impact of H2O2 on PLY release is the observed upregulation of the PG bridge formation alanyltransferases MurM and MurN, which evidentially negatively affect the PLY release. Our findings shed light on the significance of endogenous pneumococcal H2O2 in controlling PLY activity and release.
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Affiliation(s)
- Jasmin Bazant
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Benjamin Ott
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Martina Hudel
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Torsten Hain
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Rudolf Lucas
- Vascular Biology Center, Department of Pharmacology and Toxicology and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Mobarak Abu Mraheil
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
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Romero MJ, Yue Q, Singla B, Hamacher J, Sridhar S, Moseley AS, Song C, Mraheil MA, Fischer B, Zeitlinger M, Chakraborty T, Fulton D, Gan L, Annex BH, Csanyi G, Eaton DC, Lucas R. Direct endothelial ENaC activation mitigates vasculopathy induced by SARS-CoV2 spike protein. Front Immunol 2023; 14:1241448. [PMID: 37638055 PMCID: PMC10449264 DOI: 10.3389/fimmu.2023.1241448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 07/25/2023] [Indexed: 08/29/2023] Open
Abstract
Introduction Although both COVID-19 and non-COVID-19 ARDS can be accompanied by significantly increased levels of circulating cytokines, the former significantly differs from the latter by its higher vasculopathy, characterized by increased oxidative stress and coagulopathy in lung capillaries. This points towards the existence of SARS-CoV2-specific factors and mechanisms that can sensitize the endothelium towards becoming dysfunctional. Although the virus is rarely detected within endothelial cells or in the circulation, the S1 subunit of its spike protein, which contains the receptor binding domain (RBD) for human ACE2 (hACE2), can be detected in plasma from COVID-19 patients and its levels correlate with disease severity. It remains obscure how the SARS-CoV2 RBD exerts its deleterious actions in lung endothelium and whether there are mechanisms to mitigate this. Methods In this study, we use a combination of in vitro studies in RBD-treated human lung microvascular endothelial cells (HL-MVEC), including electrophysiology, barrier function, oxidative stress and human ACE2 (hACE2) surface protein expression measurements with in vivo studies in transgenic mice globally expressing human ACE2 and injected with RBD. Results We show that SARS-CoV2 RBD impairs endothelial ENaC activity, reduces surface hACE2 expression and increases reactive oxygen species (ROS) and tissue factor (TF) generation in monolayers of HL-MVEC, as such promoting barrier dysfunction and coagulopathy. The TNF-derived TIP peptide (a.k.a. solnatide, AP301) -which directly activates ENaC upon binding to its a subunit- can override RBD-induced impairment of ENaC function and hACE2 expression, mitigates ROS and TF generation and restores barrier function in HL-MVEC monolayers. In correlation with the increased mortality observed in COVID-19 patients co-infected with S. pneumoniae, compared to subjects solely infected with SARS-CoV2, we observe that prior intraperitoneal RBD treatment in transgenic mice globally expressing hACE2 significantly increases fibrin deposition and capillary leak upon intratracheal instillation of S. pneumoniae and that this is mitigated by TIP peptide treatment.
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Affiliation(s)
- Maritza J. Romero
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Qian Yue
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA, United States
| | - Bhupesh Singla
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Jürg Hamacher
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital, Bern, Switzerland
- Lungen-und Atmungsstiftung, Bern, Switzerland
- Medical Clinic V—Pneumology, Allergology, Intensive Care Medicine, and Environmental Medicine, Faculty of Medicine, Saarland University, University Medical Centre of the Saarland, Homburg, Germany
| | - Supriya Sridhar
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Auriel S. Moseley
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA, United States
| | - Chang Song
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA, United States
| | - Mobarak A. Mraheil
- Institute for Medical Microbiology, German Centre for Infection Giessen-Marburg-Langen Site, Faculty of Medicine, Justus-Liebig University, Giessen, Germany
| | | | - Markus Zeitlinger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Trinad Chakraborty
- Institute for Medical Microbiology, German Centre for Infection Giessen-Marburg-Langen Site, Faculty of Medicine, Justus-Liebig University, Giessen, Germany
| | - David Fulton
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Lin Gan
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Brian H. Annex
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Gabor Csanyi
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Douglas C. Eaton
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA, United States
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Division of Pulmonary and Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA, United States
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Cima Cabal MD, Molina F, López-Sánchez JI, Pérez-Santín E, Del Mar García-Suárez M. Pneumolysin as a target for new therapies against pneumococcal infections: A systematic review. PLoS One 2023; 18:e0282970. [PMID: 36947540 PMCID: PMC10032530 DOI: 10.1371/journal.pone.0282970] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 02/28/2023] [Indexed: 03/23/2023] Open
Abstract
BACKGROUND This systematic review evaluates pneumolysin (PLY) as a target for new treatments against pneumococcal infections. Pneumolysin is one of the main virulence factors produced by all types of pneumococci. This toxin (53 kDa) is a highly conserved protein that binds to cholesterol in eukaryotic cells, forming pores that lead to cell destruction. METHODS The databases consulted were MEDLINE, Web of Science, and Scopus. Articles were independently screened by title, abstract, and full text by two researchers, and using consensus to resolve any disagreements that occurred. Articles in other languages different from English, patents, cases report, notes, chapter books and reviews were excluded. Searches were restricted to the years 2000 to 2021. Methodological quality was evaluated using OHAT framework. RESULTS Forty-one articles describing the effects of different molecules that inhibit PLY were reviewed. Briefly, the inhibitory molecules found were classified into three main groups: those exerting a direct effect by binding and/or blocking PLY, those acting indirectly by preventing its effects on host cells, and those whose mechanisms are unknown. Although many molecules are proposed as toxin blockers, only some of them, such as antibiotics, peptides, sterols, and statins, have the probability of being implemented as clinical treatment. In contrast, for other molecules, there are limited studies that demonstrate efficacy in animal models with sufficient reliability. DISCUSSION Most of the studies reviewed has a good level of confidence. However, one of the limitations of this systematic review is the lack of homogeneity of the studies, what prevented to carry out a statistical comparison of the results or meta-analysis. CONCLUSION A panel of molecules blocking PLY activity are associated with the improvement of the inflammatory process triggered by the pneumococcal infection. Some molecules have already been used in humans for other purposes, so they could be safe for use in patients with pneumococcal infections. These patients might benefit from a second line treatment during the initial stages of the infection preventing acute respiratory distress syndrome and invasive pneumococcal diseases. Additional research using the presented set of compounds might further improve the clinical management of these patients.
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Affiliation(s)
- María Dolores Cima Cabal
- Escuela Superior de Ingeniería y Tecnología (ESIT), Universidad Internacional de La Rioja, UNIR, Logroño, La Rioja, Spain
| | - Felipe Molina
- Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
| | - José Ignacio López-Sánchez
- Escuela Superior de Ingeniería y Tecnología (ESIT), Universidad Internacional de La Rioja, UNIR, Logroño, La Rioja, Spain
| | - Efrén Pérez-Santín
- Escuela Superior de Ingeniería y Tecnología (ESIT), Universidad Internacional de La Rioja, UNIR, Logroño, La Rioja, Spain
| | - María Del Mar García-Suárez
- Escuela Superior de Ingeniería y Tecnología (ESIT), Universidad Internacional de La Rioja, UNIR, Logroño, La Rioja, Spain
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Identifying the Molecular Mechanisms and Types of Cell Death Induced by bio- and pyr-Silica Nanoparticles in Endothelial Cells. Int J Mol Sci 2022; 23:ijms23095103. [PMID: 35563494 PMCID: PMC9100598 DOI: 10.3390/ijms23095103] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/25/2022] [Accepted: 04/27/2022] [Indexed: 12/10/2022] Open
Abstract
The term "nanosilica" refers to materials containing ultrafine particles. They have gained a rapid increase in popularity in a variety of applications and in numerous aspects of human life. Due to their unique physicochemical properties, SiO2 nanoparticles have attracted significant attention in the field of biomedicine. This study aimed to elucidate the mechanism underlying the cellular response to stress which is induced by the exposure of cells to both biogenic and pyrogenic silica nanoparticles and which may lead to their death. Both TEM and fluorescence microscopy investigations confirmed molecular changes in cells after treatment with silica nanoparticles. The cytotoxic activity of the compounds and intracellular RNS were determined in relation to HMEC-1 cells using the fluorimetric method. Apoptosis was quantified by microscopic assessment and by flow cytometry. Furthermore, the impact of nanosilica on cell migration and cell cycle arrest were determined. The obtained results compared the biological effects of mesoporous silica nanoparticles extracted from Urtica dioica L. and pyrogenic material and indicated that both types of NPs have an impact on RNS production causing apoptosis, necrosis, and autophagy. Although mesoporous silica nanoparticles did not cause cell cycle arrest, at the concentration of 50 μg/mL and higher they could disturb redox balance and stimulate cell migration.
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Lucas R, Hadizamani Y, Enkhbaatar P, Csanyi G, Caldwell RW, Hundsberger H, Sridhar S, Lever AA, Hudel M, Ash D, Ushio-Fukai M, Fukai T, Chakraborty T, Verin A, Eaton DC, Romero M, Hamacher J. Dichotomous Role of Tumor Necrosis Factor in Pulmonary Barrier Function and Alveolar Fluid Clearance. Front Physiol 2022; 12:793251. [PMID: 35264975 PMCID: PMC8899333 DOI: 10.3389/fphys.2021.793251] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 11/30/2021] [Indexed: 02/04/2023] Open
Abstract
Alveolar-capillary leak is a hallmark of the acute respiratory distress syndrome (ARDS), a potentially lethal complication of severe sepsis, trauma and pneumonia, including COVID-19. Apart from barrier dysfunction, ARDS is characterized by hyper-inflammation and impaired alveolar fluid clearance (AFC), which foster the development of pulmonary permeability edema and hamper gas exchange. Tumor Necrosis Factor (TNF) is an evolutionarily conserved pleiotropic cytokine, involved in host immune defense against pathogens and cancer. TNF exists in both membrane-bound and soluble form and its mainly -but not exclusively- pro-inflammatory and cytolytic actions are mediated by partially overlapping TNFR1 and TNFR2 binding sites situated at the interface between neighboring subunits in the homo-trimer. Whereas TNFR1 signaling can mediate hyper-inflammation and impaired barrier function and AFC in the lungs, ligand stimulation of TNFR2 can protect from ventilation-induced lung injury. Spatially distinct from the TNFR binding sites, TNF harbors within its structure a lectin-like domain that rather protects lung function in ARDS. The lectin-like domain of TNF -mimicked by the 17 residue TIP peptide- represents a physiological mediator of alveolar-capillary barrier protection. and increases AFC in both hydrostatic and permeability pulmonary edema animal models. The TIP peptide directly activates the epithelial sodium channel (ENaC) -a key mediator of fluid and blood pressure control- upon binding to its α subunit, which is also a part of the non-selective cation channel (NSC). Activity of the lectin-like domain of TNF is preserved in complexes between TNF and its soluble TNFRs and can be physiologically relevant in pneumonia. Antibody- and soluble TNFR-based therapeutic strategies show considerable success in diseases such as rheumatoid arthritis, psoriasis and inflammatory bowel disease, but their chronic use can increase susceptibility to infection. Since the lectin-like domain of TNF does not interfere with TNF's anti-bacterial actions, while exerting protective actions in the alveolar-capillary compartments, it is currently evaluated in clinical trials in ARDS and COVID-19. A more comprehensive knowledge of the precise role of the TNFR binding sites versus the lectin-like domain of TNF in lung injury, tissue hypoxia, repair and remodeling may foster the development of novel therapeutics for ARDS.
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Affiliation(s)
- Rudolf Lucas
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States,*Correspondence: Rudolf Lucas,
| | - Yalda Hadizamani
- Lungen-und Atmungsstiftung Bern, Bern, Switzerland,Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, Bern, Switzerland
| | - Perenlei Enkhbaatar
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, United States
| | - Gabor Csanyi
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States
| | - Robert W. Caldwell
- Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States
| | - Harald Hundsberger
- Department of Medical Biotechnology, University of Applied Sciences, Krems, Austria,Department of Dermatology, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Supriya Sridhar
- Vascular Biology Center, Augusta University, Augusta, GA, United States
| | - Alice Ann Lever
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Martina Hudel
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Dipankar Ash
- Vascular Biology Center, Augusta University, Augusta, GA, United States
| | - Masuko Ushio-Fukai
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Tohru Fukai
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States,Charlie Norwood Veterans Affairs Medical Center, Augusta, GA, United States
| | - Trinad Chakraborty
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Alexander Verin
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Douglas C. Eaton
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA, United States
| | - Maritza Romero
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States,Department of Anesthesiology and Perioperative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Jürg Hamacher
- Lungen-und Atmungsstiftung Bern, Bern, Switzerland,Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, Bern, Switzerland,Medical Clinic V-Pneumology, Allergology, Intensive Care Medicine, and Environmental Medicine, Faculty of Medicine, University Medical Centre of the Saarland, Saarland University, Homburg, Germany,Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, Homburg, Germany,Jürg Hamacher,
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7
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Xiang P, Jing W, Lin Y, Liu Q, Shen J, Hu X, Chen J, Cai R, Hare JM, Zhu W, Schally AV, Yu H. Improvement of cardiac and systemic function in old mice by agonist of growth hormone-releasing hormone. J Cell Physiol 2021; 236:8197-8207. [PMID: 34224586 DOI: 10.1002/jcp.30490] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 06/01/2021] [Accepted: 06/14/2021] [Indexed: 12/15/2022]
Abstract
Age-related diseases such as cardiovascular diseases portend disability, increase health expenditures, and cause late-life mortality. Synthetic agonists of growth hormone-releasing hormone (GHRH) exhibit several favorable effects on heart function and remodeling. Here we assessed whether GHRH agonist MR409 can modulate heart function and systemic parameters in old mice. Starting at the age of 15 months, mice were injected subcutaneously with MR409 (10 µg/day, n = 8) or vehicle (n = 7) daily for 6 months. Mice treated with MR409 showed improvements in exercise activity, cardiac function, survival rate, immune function, and hair growth in comparison with the controls. More stem cell colonies were grown out of the bone marrow recovered from the MR409-treated mice. Mitochondrial functions of cardiomyocytes (CMs) from the MR409-treated mice were also significantly improved with more mitochondrial fusion. Fewer β-gal positive cells were observed in endothelial cells after 10 passages with MR409. In Doxorubicin-treated H9C2 cardiomyocytes, cell senescence marker p21 and reactive oxygen species were significantly reduced after cultured with MR409. MR409 also improved cellular ATP production and oxygen consumption rate in Doxorubicin-treated H9C2 cells. Mitochondrial protein OPA1 long isoform was significantly increased after treatment with MR409. The effects of MR409 were mediated by GHRH receptor and protein kinase A (PKA). In short, GHRH agonist MR409 reversed the aging-associated changes with respect of heart function, mobility, hair growth, cellular energy production, and senescence biomarkers. The improvement of heart function may be related to a better mitochondrial functions through GHRH receptor/cAMP/PKA/OPA1 signaling pathway and relieved cardiac inflammation.
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Affiliation(s)
- Pingping Xiang
- Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Wangwei Jing
- Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yinuo Lin
- Department of Cardiology, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qi Liu
- Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jian Shen
- Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xinyang Hu
- Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jinghai Chen
- Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Renzhi Cai
- Departments of Medicine and Pathology, Miller School of Medicine, University of Miami, Miami, Florida, USA.,Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, Florida, USA
| | - Joshua M Hare
- Departments of Medicine and Pathology, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Wei Zhu
- Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Andrew V Schally
- Departments of Medicine and Pathology, Miller School of Medicine, University of Miami, Miami, Florida, USA.,Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, Florida, USA
| | - Hong Yu
- Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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8
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Letsiou E, Teixeira Alves LG, Fatykhova D, Felten M, Mitchell TJ, Müller-Redetzky HC, Hocke AC, Witzenrath M. Microvesicles released from pneumolysin-stimulated lung epithelial cells carry mitochondrial cargo and suppress neutrophil oxidative burst. Sci Rep 2021; 11:9529. [PMID: 33953279 PMCID: PMC8100145 DOI: 10.1038/s41598-021-88897-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 04/13/2021] [Indexed: 01/16/2023] Open
Abstract
Microvesicles (MVs) are cell-derived extracellular vesicles that have emerged as markers and mediators of acute lung injury (ALI). One of the most common pathogens in pneumonia-induced ALI is Streptococcus pneumoniae (Spn), but the role of MVs during Spn lung infection is largely unknown. In the first line of defense against Spn and its major virulence factor, pneumolysin (PLY), are the alveolar epithelial cells (AEC). In this study, we aim to characterize MVs shed from PLY-stimulated AEC and explore their contribution in mediating crosstalk with neutrophils. Using in vitro cell and ex vivo (human lung tissue) models, we demonstrated that Spn in a PLY-dependent manner stimulates AEC to release increased numbers of MVs. Spn infected mice also had higher levels of epithelial-derived MVs in their alveolar compartment compared to control. Furthermore, MVs released from PLY-stimulated AEC contain mitochondrial content and can be taken up by neutrophils. These MVs then suppress the ability of neutrophils to produce reactive oxygen species, a critical host-defense mechanism. Taken together, our results demonstrate that AEC in response to pneumococcal PLY release MVs that carry mitochondrial cargo and suggest that these MVs regulate innate immune responses during lung injury.
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Affiliation(s)
- E Letsiou
- Division of Pulmonary Inflammation, and Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117, Berlin, Germany. .,Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA.
| | - L G Teixeira Alves
- Division of Pulmonary Inflammation, and Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117, Berlin, Germany
| | - D Fatykhova
- Division of Pulmonary Inflammation, and Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117, Berlin, Germany
| | - M Felten
- Division of Pulmonary Inflammation, and Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117, Berlin, Germany
| | - T J Mitchell
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - H C Müller-Redetzky
- Division of Pulmonary Inflammation, and Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117, Berlin, Germany
| | - A C Hocke
- Division of Pulmonary Inflammation, and Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117, Berlin, Germany.,German Center for Lung Research, (DZL), Berlin, Germany
| | - M Witzenrath
- Division of Pulmonary Inflammation, and Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117, Berlin, Germany.,German Center for Lung Research, (DZL), Berlin, Germany
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9
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Mraheil MA, Toque HA, La Pietra L, Hamacher J, Phanthok T, Verin A, Gonzales J, Su Y, Fulton D, Eaton DC, Chakraborty T, Lucas R. Dual Role of Hydrogen Peroxide as an Oxidant in Pneumococcal Pneumonia. Antioxid Redox Signal 2021; 34:962-978. [PMID: 32283950 PMCID: PMC8035917 DOI: 10.1089/ars.2019.7964] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Significance:Streptococcus pneumoniae (Spn), a facultative anaerobic Gram-positive human pathogen with increasing rates of penicillin and macrolide resistance, is a major cause of lower respiratory tract infections worldwide. Pneumococci are a primary agent of severe pneumonia in children younger than 5 years and of community-acquired pneumonia in adults. A major defense mechanism toward Spn is the generation of reactive oxygen species, including hydrogen peroxide (H2O2), during the oxidative burst of neutrophils and macrophages. Paradoxically, Spn produces high endogenous levels of H2O2 as a strategy to promote colonization. Recent Advances: Pneumococci, which express neither catalase nor common regulators of peroxide stress resistance, have developed unique mechanisms to protect themselves from H2O2. Spn generates high levels of H2O2 as a strategy to promote colonization. Production of H2O2 moreover constitutes an important virulence phenotype and its cellular activities overlap and complement those of other virulence factors, such as pneumolysin, in modulating host immune responses and promoting organ injury. Critical Issues: This review examines the dual role of H2O2 in pneumococcal pneumonia, from the viewpoint of both the pathogen (defense mechanisms, lytic activity toward competing pathogens, and virulence) and the resulting host-response (inflammasome activation, endoplasmic reticulum stress, and damage to the alveolar-capillary barrier in the lungs). Future Directions: An understanding of the complexity of H2O2-mediated host-pathogen interactions is necessary to develop novel strategies that target these processes to enhance lung function during severe pneumonia.
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Affiliation(s)
- Mobarak Abu Mraheil
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Haroldo A Toque
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Luigi La Pietra
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Juerg Hamacher
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland.,Internal Medicine V-Pneumology, Allergology, Respiratory and Environmental Medicine, Faculty of Medicine, Saarland University, Saarbrücken, Germany
| | - Tenzing Phanthok
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Alexander Verin
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Joyce Gonzales
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Yunchao Su
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - David Fulton
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Douglas C Eaton
- Department of Medicine, Emory School of Medicine, Atlanta, Georgia, USA
| | - Trinad Chakraborty
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Rudolf Lucas
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
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10
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Streptococcus pneumoniae and Its Virulence Factors H 2O 2 and Pneumolysin Are Potent Mediators of the Acute Chest Syndrome in Sickle Cell Disease. Toxins (Basel) 2021; 13:toxins13020157. [PMID: 33671422 PMCID: PMC7922783 DOI: 10.3390/toxins13020157] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/08/2021] [Accepted: 02/11/2021] [Indexed: 01/27/2023] Open
Abstract
Sickle cell disease (SCD) is one of the most common autosomal recessive disorders in the world. Due to functional asplenia, a dysfunctional antibody response, antibiotic drug resistance and poor response to immunization, SCD patients have impaired immunity. A leading cause of hospitalization and death in SCD patients is the acute chest syndrome (ACS). This complication is especially manifested upon infection of SCD patients with Streptococcus pneumoniae (Spn)—a facultative anaerobic Gram-positive bacterium that causes lower respiratory tract infections. Spn has developed increased rates of antibiotics resistance and is particularly virulent in SCD patients. The primary defense against Spn is the generation of reactive oxygen species (ROS) during the oxidative burst of neutrophils and macrophages. Paradoxically, Spn itself produces high levels of the ROS hydrogen peroxide (H2O2) as a virulence strategy. Apart from H2O2, Spn also secretes another virulence factor, i.e., the pore-forming exotoxin pneumolysin (PLY), a potent mediator of lung injury in patients with pneumonia in general and particularly in those with SCD. PLY is released early on in infection either by autolysis or bacterial lysis following the treatment with antibiotics and has a broad range of biological activities. This review will discuss recent findings on the role of pneumococci in ACS pathogenesis and on strategies to counteract the devastating effects of its virulence factors on the lungs in SCD patients.
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11
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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: 19] [Impact Index Per Article: 4.8] [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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12
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Adams W, Bhowmick R, Bou Ghanem EN, Wade K, Shchepetov M, Weiser JN, McCormick BA, Tweten RK, Leong JM. Pneumolysin Induces 12-Lipoxygenase-Dependent Neutrophil Migration during Streptococcus pneumoniae Infection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2020; 204:101-111. [PMID: 31776202 PMCID: PMC7195902 DOI: 10.4049/jimmunol.1800748] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 10/16/2019] [Indexed: 12/23/2022]
Abstract
Streptococcus pneumoniae is a major cause of pneumonia, wherein infection of respiratory mucosa drives a robust influx of neutrophils. We have previously shown that S. pneumoniae infection of the respiratory epithelium induces the production of the 12-lipoxygenase (12-LOX)-dependent lipid inflammatory mediator hepoxilin A3, which promotes recruitment of neutrophils into the airways, tissue damage, and lethal septicemia. Pneumolysin (PLY), a member of the cholesterol-dependent cytolysin (CDC) family, is a major S. pneumoniae virulence factor that generates ∼25-nm diameter pores in eukaryotic membranes and promotes acute inflammation, tissue damage, and bacteremia. We show that a PLY-deficient S. pneumoniae mutant was impaired in triggering human neutrophil transepithelial migration in vitro. Ectopic production of PLY endowed the nonpathogenic Bacillus subtilis with the ability to trigger neutrophil recruitment across human-cultured monolayers. Purified PLY, several other CDC family members, and the α-toxin of Clostridium septicum, which generates pores with cross-sectional areas nearly 300 times smaller than CDCs, reproduced this robust neutrophil transmigration. PLY non-pore-forming point mutants that are trapped at various stages of pore assembly did not recruit neutrophils. PLY triggered neutrophil recruitment in a 12-LOX-dependent manner in vitro. Instillation of wild-type PLY but not inactive derivatives into the lungs of mice induced robust 12-LOX-dependent neutrophil migration into the airways, although residual inflammation induced by PLY in 12-LOX-deficient mice indicates that 12-LOX-independent pathways also contribute to PLY-triggered pulmonary inflammation. These data indicate that PLY is an important factor in promoting hepoxilin A3-dependent neutrophil recruitment across pulmonary epithelium in a pore-dependent fashion.
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Affiliation(s)
- Walter Adams
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111
- Department of Biological Sciences, San Jose State University, San Jose, CA 95192
| | - Rudra Bhowmick
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111
| | - Elsa N Bou Ghanem
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111
| | - Kristin Wade
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Mikhail Shchepetov
- Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104
| | - Jeffrey N Weiser
- Department of Microbiology, New York University School of Medicine, New York, NY 10016; and
| | - Beth A McCormick
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
| | - Rodney K Tweten
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - John M Leong
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111;
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13
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Zemskov EA, Lu Q, Ornatowski W, Klinger CN, Desai AA, Maltepe E, Yuan JXJ, Wang T, Fineman JR, Black SM. Biomechanical Forces and Oxidative Stress: Implications for Pulmonary Vascular Disease. Antioxid Redox Signal 2019; 31:819-842. [PMID: 30623676 PMCID: PMC6751394 DOI: 10.1089/ars.2018.7720] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Significance: Oxidative stress in the cell is characterized by excessive generation of reactive oxygen species (ROS). Superoxide (O2-) and hydrogen peroxide (H2O2) are the main ROS involved in the regulation of cellular metabolism. As our fundamental understanding of the underlying causes of lung disease has increased it has become evident that oxidative stress plays a critical role. Recent Advances: A number of cells in the lung both produce, and respond to, ROS. These include vascular endothelial and smooth muscle cells, fibroblasts, and epithelial cells as well as the cells involved in the inflammatory response, including macrophages, neutrophils, eosinophils. The redox system is involved in multiple aspects of cell metabolism and cell homeostasis. Critical Issues: Dysregulation of the cellular redox system has consequential effects on cell signaling pathways that are intimately involved in disease progression. The lung is exposed to biomechanical forces (fluid shear stress, cyclic stretch, and pressure) due to the passage of blood through the pulmonary vessels and the distension of the lungs during the breathing cycle. Cells within the lung respond to these forces by activating signal transduction pathways that alter their redox state with both physiologic and pathologic consequences. Future Directions: Here, we will discuss the intimate relationship between biomechanical forces and redox signaling and its role in the development of pulmonary disease. An understanding of the molecular mechanisms induced by biomechanical forces in the pulmonary vasculature is necessary for the development of new therapeutic strategies.
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Affiliation(s)
- Evgeny A Zemskov
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Qing Lu
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Wojciech Ornatowski
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Christina N Klinger
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Ankit A Desai
- Department of Medicine, Indiana University, Indianapolis, Indiana
| | - Emin Maltepe
- Department of Pediatrics, University of California, San Francisco, San Francisco, California
| | - Jason X-J Yuan
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Ting Wang
- Department of Internal Medicine, The University of Arizona Health Sciences, Phoenix, Arizona
| | - Jeffrey R Fineman
- Department of Pediatrics, University of California, San Francisco, San Francisco, California
| | - Stephen M Black
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
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14
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Gutbier B, Neuhauß AK, Reppe K, Ehrler C, Santel A, Kaufmann J, Scholz M, Weissmann N, Morawietz L, Mitchell TJ, Aliberti S, Hippenstiel S, Suttorp N, Witzenrath M. Prognostic and Pathogenic Role of Angiopoietin-1 and -2 in Pneumonia. Am J Respir Crit Care Med 2019; 198:220-231. [PMID: 29447449 DOI: 10.1164/rccm.201708-1733oc] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
RATIONALE During pneumonia, pathogen-host interaction evokes inflammation and lung barrier dysfunction. Tie2 activation by angiopoietin-1 reduces, whereas Tie2 blockade by angiopoietin-2 increases, inflammation and permeability during sepsis. The role of angiopoietin-1/-2 in pneumonia remains unidentified. OBJECTIVES To investigate the prognostic and pathogenic impact of angiopoietins in regulating pulmonary vascular barrier function and inflammation in bacterial pneumonia. METHODS Serum angiopoietin levels were quantified in pneumonia patients of two independent cohorts (n = 148, n = 395). Human postmortem lung tissue, pneumolysin- or angiopoietin-2-stimulated endothelial cells, isolated perfused and ventilated mouse lungs, and mice with pneumococcal pneumonia were investigated. MEASUREMENTS AND MAIN RESULTS In patients with pneumonia, decreased serum angiopoietin-1 and increased angiopoietin-2 levels were observed as compared with healthy subjects. Higher angiopoietin-2 serum levels were found in patients with community-acquired pneumonia who died within 28 days of diagnosis compared with survivors. Receiver operating characteristic analysis revealed improved prognostic accuracy of CURB-65 for 28-day survival, intensive care treatment, and length of hospital stay if combined with angiopoietin-2 serum levels. In vitro, pneumolysin enhanced endothelial angiopoietin-2 release, angiopoietin-2 increased endothelial permeability, and angiopoietin-1 reduced pneumolysin-evoked endothelial permeability. Ventilated and perfused lungs of mice with angiopoietin-2 knockdown showed reduced permeability on pneumolysin stimulation. Increased pulmonary angiopoietin-2 and reduced angiopoietin-1 mRNA expression were observed in Streptococcus pneumoniae-infected mice. Finally, angiopoietin-1 therapy reduced inflammation and permeability in murine pneumonia. CONCLUSIONS These data suggest a central role of angiopoietin-1/-2 in pneumonia-evoked inflammation and permeability. Increased angiopoietin-2 serum levels predicted mortality and length of hospital stay, and angiopoietin-1 may provide a therapeutic target for severe pneumonia.
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Affiliation(s)
- Birgitt Gutbier
- 1 Division of Pulmonary Inflammation and.,2 Department of Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Anne-Kathrin Neuhauß
- 2 Department of Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Katrin Reppe
- 1 Division of Pulmonary Inflammation and.,2 Department of Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Carolin Ehrler
- 2 Department of Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | | | | | - Markus Scholz
- 4 Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, Leipzig, Germany
| | - Norbert Weissmann
- 5 Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center, member of the German Center for Lung Research, Justus-Liebig-University, Giessen, Germany
| | - Lars Morawietz
- 6 Pathology, Healthcare Center Fuerstenberg-Karree, Berlin, Germany
| | - Timothy J Mitchell
- 7 Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Stefano Aliberti
- 8 Department of Pathophysiology and Transplantation, University of Milan, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Cà Granda Ospedale Maggiore Policlinico, Milan, Italy; and
| | - Stefan Hippenstiel
- 2 Department of Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Norbert Suttorp
- 2 Department of Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,9 CAPNETZ STIFTUNG, Hannover, Germany
| | - Martin Witzenrath
- 1 Division of Pulmonary Inflammation and.,2 Department of Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,9 CAPNETZ STIFTUNG, Hannover, Germany
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15
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Schally AV, Zhang X, Cai R, Hare JM, Granata R, Bartoli M. Actions and Potential Therapeutic Applications of Growth Hormone-Releasing Hormone Agonists. Endocrinology 2019; 160:1600-1612. [PMID: 31070727 DOI: 10.1210/en.2019-00111] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 04/03/2019] [Indexed: 11/19/2022]
Abstract
In this article, we briefly review the identification of GHRH, provide an abridged overview of GHRH antagonists, and focus on studies with GHRH agonists. Potent GHRH agonists of JI and MR class were synthesized and evaluated biologically. Besides the induction of the release of pituitary GH, GHRH analogs promote cell proliferation and exert stimulatory effects on various tissues, which express GHRH receptors (GHRH-Rs). A large body of work shows that GHRH agonists, such as MR-409, improve pancreatic β-cell proliferation and metabolic functions and facilitate engraftment of islets after transplantation in rodents. Accordingly, GHRH agonists offer a new therapeutic approach to treating diabetes. Various studies demonstrate that GHRH agonists promote repair of cardiac tissue, producing improvement of ejection fraction and reduction of infarct size in rats, reduction of infarct scar in swine, and attenuation of cardiac hypertrophy in mice, suggesting clinical applications. The presence of GHRH-Rs in ocular tissues and neuroprotective effects of GHRH analogs in experimental diabetic retinopathy indicates their possible therapeutic applications for eye diseases. Other effects of GHRH agonists, include acceleration of wound healing, activation of immune cells, and action on the central nervous system. As GHRH might function as a growth factor, we examined effects of GHRH agonists on tumors. In vitro, GHRH agonists stimulate growth of human cancer cells and upregulate GHRH-Rs. However, in vivo, GHRH agonists inhibit growth of human cancers xenografted into nude mice and downregulate pituitary and tumoral GHRH-Rs. Therapeutic applications of GHRH analogs are discussed. The development of GHRH analogs should lead to their clinical use.
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Affiliation(s)
- Andrew V Schally
- Veterans Affairs Medical Center, Miami, Florida
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida
- Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida
| | - Xianyang Zhang
- Interdisciplinary Stem Cell Institute, Miller School of Medicine, University of Miami, Miami, Florida
| | - Renzhi Cai
- Veterans Affairs Medical Center, Miami, Florida
| | - Joshua M Hare
- Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
- Interdisciplinary Stem Cell Institute, Miller School of Medicine, University of Miami, Miami, Florida
| | - Riccarda Granata
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Manuela Bartoli
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, Georgia
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16
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Chen J, Li N, Wang B, Liu X, Liu J, Chang Q. Upregulation of CBP by PLY can cause permeability of blood‐brain barrier to increase meningitis. J Biochem Mol Toxicol 2019; 33:e22333. [PMID: 30980515 DOI: 10.1002/jbt.22333] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 03/03/2019] [Accepted: 03/15/2019] [Indexed: 01/16/2023]
Affiliation(s)
- Jia‐Quan Chen
- Department of EncephalopathyYantai Traditional Chinese Medicine HospitalYantai People's Republic of China
| | - Nan‐Nan Li
- Department of EncephalopathyOriental Hospital of Beijing University of Chinese MedicineBeijing People's Republic of China
| | - Bo‐Wen Wang
- Department of EncephalopathyYantai Traditional Chinese Medicine HospitalYantai People's Republic of China
| | - Xiu‐Fang Liu
- Department of OncologyChinese PLA 251 HospitalZhangjiakou People's Republic of China
| | - Jia‐Lin Liu
- Department of EncephalopathyOriental Hospital of Beijing University of Chinese MedicineBeijing People's Republic of China
| | - Qing Chang
- Department of EncephalopathyOriental Hospital of Beijing University of Chinese MedicineBeijing People's Republic of China
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17
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Basic and clinical research progress in acute lung injury/acute respiratory distress syndrome. INFECTION INTERNATIONAL 2018. [DOI: 10.2478/ii-2018-0017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Abstract
Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is an acute progressive respiratory failure caused by severe infection, trauma, shock, poisoning, inhaled harmful gas, acute pancreatitis, and pathological obstetrics. ALI and ARDS demonstrate similar pathophysiological changes. The severe stage of ALI is defined as ARDS. At present, a significant progress has been achieved in the study of the pathogenesis and pathophysiology of ALI/ARDS. Whether or not ALI/ARDS patients can recover depends on the degree of lung injury, extra-pulmonary organ damage, original primary disease of a patient, and adequacy in supportive care. Conservative infusion strategies and protective lung ventilation reduce ARDS disability and mortality. In this study, the pathogenesis of ALI/ARDS, lung injury, molecular mechanisms of lung repair, and conservative infusion strategies and pulmonary protective ventilation are reviewed comprehensively.
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Hamacher J, Hadizamani Y, Borgmann M, Mohaupt M, Männel DN, Moehrlen U, Lucas R, Stammberger U. Cytokine-Ion Channel Interactions in Pulmonary Inflammation. Front Immunol 2018; 8:1644. [PMID: 29354115 PMCID: PMC5758508 DOI: 10.3389/fimmu.2017.01644] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/10/2017] [Indexed: 12/12/2022] Open
Abstract
The lungs conceptually represent a sponge that is interposed in series in the bodies’ systemic circulation to take up oxygen and eliminate carbon dioxide. As such, it matches the huge surface areas of the alveolar epithelium to the pulmonary blood capillaries. The lung’s constant exposure to the exterior necessitates a competent immune system, as evidenced by the association of clinical immunodeficiencies with pulmonary infections. From the in utero to the postnatal and adult situation, there is an inherent vital need to manage alveolar fluid reabsorption, be it postnatally, or in case of hydrostatic or permeability edema. Whereas a wealth of literature exists on the physiological basis of fluid and solute reabsorption by ion channels and water pores, only sparse knowledge is available so far on pathological situations, such as in microbial infection, acute lung injury or acute respiratory distress syndrome, and in the pulmonary reimplantation response in transplanted lungs. The aim of this review is to discuss alveolar liquid clearance in a selection of lung injury models, thereby especially focusing on cytokines and mediators that modulate ion channels. Inflammation is characterized by complex and probably time-dependent co-signaling, interactions between the involved cell types, as well as by cell demise and barrier dysfunction, which may not uniquely determine a clinical picture. This review, therefore, aims to give integrative thoughts and wants to foster the unraveling of unmet needs in future research.
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Affiliation(s)
- Jürg Hamacher
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Internal Medicine V - Pneumology, Allergology, Respiratory and Environmental Medicine, Faculty of Medicine, Saarland University, Saarbrücken, Germany.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Yalda Hadizamani
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Michèle Borgmann
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Markus Mohaupt
- Internal Medicine, Sonnenhofspital Bern, Bern, Switzerland
| | | | - Ueli Moehrlen
- Paediatric Visceral Surgery, Universitäts-Kinderspital Zürich, Zürich, Switzerland
| | - Rudolf Lucas
- Department of Pharmacology and Toxicology, Vascular Biology Center, Medical College of Georgia, Augusta, GA, United States
| | - Uz Stammberger
- Lungen- und Atmungsstiftung Bern, Bern, Switzerland.,Novartis Institutes for Biomedical Research, Translational Clinical Oncology, Novartis Pharma AG, Basel, Switzerland
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Protective effects of agonists of growth hormone-releasing hormone (GHRH) in early experimental diabetic retinopathy. Proc Natl Acad Sci U S A 2017; 114:13248-13253. [PMID: 29180438 PMCID: PMC5740669 DOI: 10.1073/pnas.1718592114] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The studies described here are relevant to the cure of diabetic retinopathy, a leading cause of blindness with currently limited therapeutic options. Here we provided evidence showing that agonists of growth hormone-releasing hormone (GHRH) can significantly diminish retinal neurovascular injury characterizing the early stages of diabetic retinopathy through antioxidant and anti-inflammatory effects. The results of the presented studies provide information on the potential therapeutic effects of GHRH agonists and shed light on the role of hypothalamic hormones in retinal physiology and their effect on visual disorders. In addition, our findings suggest protective effects of GHRH analogs in other disease conditions affecting retinal neuronal cells and, possibly, other nonretinal neurons. The potential therapeutic effects of agonistic analogs of growth hormone-releasing hormone (GHRH) and their mechanism of action were investigated in diabetic retinopathy (DR). Streptozotocin-induced diabetic rats (STZ-rats) were treated with 15 μg/kg GHRH agonist, MR-409, or GHRH antagonist, MIA-602. At the end of treatment, morphological and biochemical analyses assessed the effects of these compounds on retinal neurovascular injury induced by hyperglycemia. The expression levels of GHRH and its receptor (GHRH-R) measured by qPCR and Western blotting were significantly down-regulated in retinas of STZ-rats and in human diabetic retinas (postmortem) compared with their respective controls. Treatment of STZ-rats with the GHRH agonist, MR-409, prevented retinal morphological alteration induced by hyperglycemia, particularly preserving survival of retinal ganglion cells. The reverse, using the GHRH antagonist, MIA-602, resulted in worsening of retinal morphology and a significant alteration of the outer retinal layer. Explaining these results, we have found that MR-409 exerted antioxidant and anti-inflammatory effects in retinas of the treated rats, as shown by up-regulation of NRF-2-dependent gene expression and down-regulation of proinflammatory cytokines and adhesion molecules. MR-409 also significantly down-regulated the expression of vascular endothelial growth factor while increasing that of pigment epithelium-derived factor in diabetic retinas. These effects correlated with decreased vascular permeability. In summary, our findings suggest a neurovascular protective effect of GHRH analogs during the early stage of diabetic retinopathy through their antioxidant and anti-inflammatory properties.
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Krenn K, Lucas R, Croizé A, Boehme S, Klein KU, Hermann R, Markstaller K, Ullrich R. Inhaled AP301 for treatment of pulmonary edema in mechanically ventilated patients with acute respiratory distress syndrome: a phase IIa randomized placebo-controlled trial. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2017; 21:194. [PMID: 28750677 PMCID: PMC5531100 DOI: 10.1186/s13054-017-1795-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/12/2017] [Indexed: 02/08/2023]
Abstract
Background High-permeability pulmonary edema is a hallmark of acute respiratory distress syndrome (ARDS) and is frequently accompanied by impaired alveolar fluid clearance (AFC). AP301 enhances AFC by activating epithelial sodium channels (ENaCs) on alveolar epithelial cells, and we investigated its effect on extravascular lung water index (EVLWI) in mechanically ventilated patients with ARDS. Methods Forty adult mechanically ventilated patients with ARDS were included in a randomized, double-blind, placebo-controlled trial for proof of concept. Patients were treated with inhaled AP301 (n = 20) or placebo (0.9% NaCl; n = 20) twice daily for 7 days. EVLWI was measured by thermodilution (PiCCO®), and treatment groups were compared using the nonparametric Mann–Whitney U test. Results AP301 inhalation was well tolerated. No differences in mean baseline-adjusted change in EVLWI from screening to day 7 were found between the AP301 and placebo group (p = 0.196). There was no difference in the PaO2/FiO2 ratio, ventilation pressures, Murray lung injury score, or 28-day mortality between the treatment groups. An exploratory subgroup analysis according to severity of illness showed reductions in EVLWI (p = 0.04) and ventilation pressures (p < 0.05) over 7 days in patients with initial sequential organ failure assessment (SOFA) scores ≥11 inhaling AP301 versus placebo, but not in patients with SOFA scores ≤10. Conclusions There was no difference in mean baseline-adjusted EVLWI between the AP301 and placebo group. An exploratory post-hoc subgroup analysis indicated reduced EVLWI in patients with SOFA scores ≥11 receiving AP301. These results suggest further confirmation in future clinical trials of inhaled AP301 for treatment of pulmonary edema in patients with ARDS. Trial registration The study was prospectively registered at clinicaltrials.gov, NCT01627613. Registered 20 June 2012. Electronic supplementary material The online version of this article (doi:10.1186/s13054-017-1795-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katharina Krenn
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria
| | - Rudolf Lucas
- Vascular Biology Center, Department of Pharmacology and Toxicology and Division of Pulmonary and Critical Care Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Adrien Croizé
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria
| | - Stefan Boehme
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria
| | - Klaus Ulrich Klein
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria
| | | | - Klaus Markstaller
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria
| | - Roman Ullrich
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria.
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Czikora I, Alli AA, Sridhar S, Matthay MA, Pillich H, Hudel M, Berisha B, Gorshkov B, Romero MJ, Gonzales J, Wu G, Huo Y, Su Y, Verin AD, Fulton D, Chakraborty T, Eaton DC, Lucas R. Epithelial Sodium Channel-α Mediates the Protective Effect of the TNF-Derived TIP Peptide in Pneumolysin-Induced Endothelial Barrier Dysfunction. Front Immunol 2017; 8:842. [PMID: 28785264 PMCID: PMC5519615 DOI: 10.3389/fimmu.2017.00842] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/04/2017] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Streptococcus pneumoniae is a major etiologic agent of bacterial pneumonia. Autolysis and antibiotic-mediated lysis of pneumococci induce release of the pore-forming toxin, pneumolysin (PLY), their major virulence factor, which is a prominent cause of acute lung injury. PLY inhibits alveolar liquid clearance and severely compromises alveolar-capillary barrier function, leading to permeability edema associated with pneumonia. As a consequence, alveolar flooding occurs, which can precipitate lethal hypoxemia by impairing gas exchange. The α subunit of the epithelial sodium channel (ENaC) is crucial for promoting Na+ reabsorption across Na+-transporting epithelia. However, it is not known if human lung microvascular endothelial cells (HL-MVEC) also express ENaC-α and whether this subunit is involved in the regulation of their barrier function. METHODS The presence of α, β, and γ subunits of ENaC and protein phosphorylation status in HL-MVEC were assessed in western blotting. The role of ENaC-α in monolayer resistance of HL-MVEC was examined by depletion of this subunit by specific siRNA and by employing the TNF-derived TIP peptide, a specific activator that directly binds to ENaC-α. RESULTS HL-MVEC express all three subunits of ENaC, as well as acid-sensing ion channel 1a (ASIC1a), which has the capacity to form hybrid non-selective cation channels with ENaC-α. Both TIP peptide, which specifically binds to ENaC-α, and the specific ASIC1a activator MitTx significantly strengthened barrier function in PLY-treated HL-MVEC. ENaC-α depletion significantly increased sensitivity to PLY-induced hyperpermeability and in addition, blunted the protective effect of both the TIP peptide and MitTx, indicating an important role for ENaC-α and for hybrid NSC channels in barrier function of HL-MVEC. TIP peptide blunted PLY-induced phosphorylation of both calmodulin-dependent kinase II (CaMKII) and of its substrate, the actin-binding protein filamin A (FLN-A), requiring the expression of both ENaC-α and ASIC1a. Since non-phosphorylated FLN-A promotes ENaC channel open probability and blunts stress fiber formation, modulation of this activity represents an attractive target for the protective actions of ENaC-α in both barrier function and liquid clearance. CONCLUSION Our results in cultured endothelial cells demonstrate a previously unrecognized role for ENaC-α in strengthening capillary barrier function that may apply to the human lung. Strategies aiming to activate endothelial NSC channels that contain ENaC-α should be further investigated as a novel approach to improve barrier function in the capillary endothelium during pneumonia.
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Affiliation(s)
- Istvan Czikora
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States.,Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida College of Medicine, Gainesville, FL, United States
| | - Supriya Sridhar
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Michael A Matthay
- Cardiovascular Research Institute, UCSF, San Francisco, CA, United States
| | - Helena Pillich
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Martina Hudel
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Besim Berisha
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Maritza J Romero
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Joyce Gonzales
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Yuqing Huo
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Yunchao Su
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Alexander D Verin
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - David Fulton
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Trinad Chakraborty
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Douglas C Eaton
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
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22
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Lucas R, Yue Q, Alli A, Duke BJ, Al-Khalili O, Thai TL, Hamacher J, Sridhar S, Lebedyeva I, Su H, Tzotzos S, Fischer B, Gameiro AF, Loose M, Chakraborty T, Shabbir W, Aufy M, Lemmens-Gruber R, Eaton DC, Czikora I. The Lectin-like Domain of TNF Increases ENaC Open Probability through a Novel Site at the Interface between the Second Transmembrane and C-terminal Domains of the α-Subunit. J Biol Chem 2016; 291:23440-23451. [PMID: 27645999 DOI: 10.1074/jbc.m116.718163] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Indexed: 12/29/2022] Open
Abstract
Regulation of the epithelial sodium channel (ENaC), which regulates fluid homeostasis and blood pressure, is complex and remains incompletely understood. The TIP peptide, a mimic of the lectin-like domain of TNF, activates ENaC by binding to glycosylated residues in the extracellular loop of ENaC-α, as well as to a hitherto uncharacterized internal site. Molecular docking studies suggested three residues, Val567, Glu568, and Glu571, located at the interface between the second transmembrane and C-terminal domains of ENaC-α, as a critical site for binding of the TIP peptide. We generated Ala replacement mutants in this region of ENaC-α and examined its interaction with TIP peptide (3M, V567A/E568A/E571A; 2M, V567A/E568A; and 1M, E571A). 3M and 2M ENaC-α, but not 1M ENaC-α, displayed significantly reduced binding capacity to TIP peptide and to TNF. When overexpressed in H441 cells, 3M mutant ENaC-α formed functional channels with similar gating and density characteristics as the WT subunit and efficiently associated with the β and γ subunits in the plasma membrane. We subsequently assayed for increased open probability time and membrane expression, both of which define ENaC activity, following addition of TIP peptide. TIP peptide increased open probability time in H441 cells overexpressing wild type and 1M ENaC-α channels, but not 3M or 2M ENaC-α channels. On the other hand, TIP peptide-mediated reduction in ENaC ubiquitination was similar in cells overexpressing either WT or 3M ENaC-α subunits. In summary, this study has identified a novel site in ENaC-α that is crucial for activation of the open probability of the channel, but not membrane expression, by the lectin-like domain of TNF.
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Affiliation(s)
- Rudolf Lucas
- From the Vascular Biology Center, .,the Department of Pharmacology and Toxicology, and.,the Division of Pulmonary and Critical Care Medicine, Medical College of Georgia, Augusta, Georgia 30912
| | - Qiang Yue
- the Department of Physiology, Emory University, Atlanta, Georgia 30322
| | - Abdel Alli
- the Department of Physiology, Emory University, Atlanta, Georgia 30322.,the Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida 32610
| | | | - Otor Al-Khalili
- the Department of Physiology, Emory University, Atlanta, Georgia 30322
| | - Tiffany L Thai
- the Department of Physiology, Emory University, Atlanta, Georgia 30322
| | - Jürg Hamacher
- the Department of Pulmonology, Saarland University, D-66421 Homburg, Germany
| | | | - Iryna Lebedyeva
- the Department of Chemistry, Augusta University, Augusta, Georgia 30912
| | - Huabo Su
- From the Vascular Biology Center
| | - Susan Tzotzos
- Apeptico Research and Development, 1150 Vienna, Austria
| | | | | | - Maria Loose
- the Institute for Medical Microbiology, Justus-Liebig University, 35390 Giessen, Germany, and
| | - Trinad Chakraborty
- the Institute for Medical Microbiology, Justus-Liebig University, 35390 Giessen, Germany, and
| | - Waheed Shabbir
- the Department of Pharmacology and Toxicology, University Vienna, 1010 Vienna, Austria
| | - Mohammed Aufy
- the Department of Pharmacology and Toxicology, University Vienna, 1010 Vienna, Austria
| | - Rosa Lemmens-Gruber
- the Department of Pharmacology and Toxicology, University Vienna, 1010 Vienna, Austria
| | - Douglas C Eaton
- the Department of Physiology, Emory University, Atlanta, Georgia 30322,
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Granata R. Peripheral activities of growth hormone-releasing hormone. J Endocrinol Invest 2016; 39:721-7. [PMID: 26891937 DOI: 10.1007/s40618-016-0440-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 02/03/2016] [Indexed: 12/21/2022]
Abstract
Growth hormone (GH)-releasing hormone (GHRH) is produced by the hypothalamus and stimulates GH synthesis and release in the anterior pituitary gland. In addition to its endocrine role, GHRH exerts a wide range of extrapituitary effects which include stimulation of cell proliferation, survival and differentiation, and inhibition of apoptosis. Accordingly, expression of GHRH, as well as the receptor GHRH-R and its splice variants, has been demonstrated in different peripheral tissues and cell types. Among the direct peripheral activities, GHRH regulates pancreatic islet and β-cell survival and function and endometrial cell proliferation, promotes cardioprotection and wound healing, influences the immune and reproductive systems, reduces inflammation, indirectly increases lifespan and adiposity and acts on skeletal muscle cells to inhibit cell death and atrophy. Therefore, it is becoming increasingly clear that GHRH exerts important extrapituitary functions, suggesting potential therapeutic use of the peptide and its analogs in a wide range of medical settings.
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Affiliation(s)
- R Granata
- Lab of Molecular and Cellular Endocrinology, Division of Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, University of Torino, Corso Dogliotti, 14, 10126, Turin, Italy.
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Kanashiro-Takeuchi RM, Szalontay L, Schally AV, Takeuchi LM, Popovics P, Jaszberenyi M, Vidaurre I, Zarandi M, Cai RZ, Block NL, Hare JM, Rick FG. New therapeutic approach to heart failure due to myocardial infarction based on targeting growth hormone-releasing hormone receptor. Oncotarget 2016; 6:9728-39. [PMID: 25797248 PMCID: PMC4496393 DOI: 10.18632/oncotarget.3303] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 02/08/2015] [Indexed: 12/21/2022] Open
Abstract
Background We previously showed that growth hormone-releasing hormone (GHRH) agonists are cardioprotective following myocardial infarction (MI). Here, our aim was to evaluate the in vitro and in vivo activities of highly potent new GHRH agonists, and elucidate their mechanisms of action in promoting cardiac repair. Methods and Results H9c2 cells were cultured in serum-free medium, mimicking nutritional deprivation. GHRH agonists decreased calcium influx and significantly improved cell survival. Rats with cardiac infarction were treated with GHRH agonists or placebo for four weeks. MI size was reduced by selected GHRH agonists (JI-38, MR-356, MR-409); this accompanied an increased number of cardiac c-kit+ cells, cellular mitotic divisions, and vascular density. One week post-MI, MR-409 significantly reduced plasma levels of IL-2, IL-6, IL-10 and TNF-α compared to placebo. Gene expression studies revealed favorable outcomes of MR-409 treatment partially result from inhibitory activity on pro-apoptotic molecules and pro-fibrotic systems, and by elevation of bone morphogenetic proteins. Conclusions Treatment with GHRH agonists appears to reduce the inflammatory responses post-MI and may consequently improve mechanisms of healing and cardiac remod eling by regulating pathways involved in fibrosis, apoptosis and cardiac repair. Patients with cardiac dysfunction could benefit from treatment with novel GHRH agonists.
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Affiliation(s)
- Rosemeire M Kanashiro-Takeuchi
- Interdisciplinary Stem Cell Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America.,Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Florida, United States of America
| | - Luca Szalontay
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, Florida, United States of America
| | - Andrew V Schally
- Interdisciplinary Stem Cell Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America.,Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, Florida, United States of America.,Department of Pathology, University of Miami, Miller School of Medicine, Miami, Florida, United States of America.,Department of Medicine, Divisions of Hematology/Oncology and Endocrinology, University of Miami, Miller School of Medicine, Miami, Florida, United States of America.,Sylvester Comprehensive Cancer Center, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Lauro M Takeuchi
- Interdisciplinary Stem Cell Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Petra Popovics
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, Florida, United States of America.,Department of Medicine III, Medical Faculty Carl Gustav Carus, TU Dresden, Germany.,Department of Medicine, Division of Cardiology, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Miklos Jaszberenyi
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, Florida, United States of America.,Department of Pathology, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Irving Vidaurre
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, Florida, United States of America
| | - Marta Zarandi
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, Florida, United States of America
| | - Ren-Zhi Cai
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, Florida, United States of America.,Department of Pathology, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Norman L Block
- Interdisciplinary Stem Cell Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America.,Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, Florida, United States of America.,Department of Pathology, University of Miami, Miller School of Medicine, Miami, Florida, United States of America.,Department of Medicine, Divisions of Hematology/Oncology and Endocrinology, University of Miami, Miller School of Medicine, Miami, Florida, United States of America.,Sylvester Comprehensive Cancer Center, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Joshua M Hare
- Interdisciplinary Stem Cell Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America.,Department of Medicine, Division of Cardiology, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Ferenc G Rick
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education, Miami, Florida, United States of America.,Department of Urology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, United States of America
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Role of growth hormone-releasing hormone in dyslipidemia associated with experimental type 1 diabetes. Proc Natl Acad Sci U S A 2016; 113:1895-900. [PMID: 26831066 DOI: 10.1073/pnas.1525520113] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Dyslipidemia associated with triglyceride-rich lipoproteins (TRLs) represents an important residual risk factor for cardiovascular and chronic kidney disease in patients with type 1 diabetes (T1D). Levels of growth hormone (GH) are elevated in T1D, which aggravates both hyperglycemia and dyslipidemia. The hypothalamic growth hormone-releasing hormone (GHRH) regulates the release of GH by the pituitary but also exerts separate actions on peripheral GHRH receptors, the functional role of which remains elusive in T1D. In a rat model of streptozotocin (STZ)-induced T1D, GHRH receptor expression was found to be up-regulated in the distal small intestine, a tissue involved in chylomicron synthesis. Treatment of T1D rats with a GHRH antagonist, MIA-602, at a dose that did not affect plasma GH levels, significantly reduced TRL, as well as markers of renal injury, and improved endothelial-dependent vasorelaxation. Glucagon-like peptide 1 (GLP-1) reduces hyperglucagonemia and postprandial TRL, the latter in part through a decreased synthesis of apolipoprotein B-48 (ApoB-48) by intestinal cells. Although plasma GLP-1 levels were elevated in diabetic animals, this was accompanied by increased rather than reduced glucagon levels, suggesting impaired GLP-1 signaling. Treatment with MIA-602 normalized GLP-1 and glucagon to control levels in T1D rats. MIA-602 also decreased secretion of ApoB-48 from rat intestinal epithelial cells in response to oleic acid stimulation in vitro, in part through a GLP-1-dependent mechanism. Our findings support the hypothesis that antagonizing the signaling of GHRH in T1D may improve GLP-1 function in the small intestine, which, in turn, diminishes TRL and reduces renal and vascular complications.
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Fridlyand LE, Tamarina NA, Schally AV, Philipson LH. Growth Hormone-Releasing Hormone in Diabetes. Front Endocrinol (Lausanne) 2016; 7:129. [PMID: 27777568 PMCID: PMC5056186 DOI: 10.3389/fendo.2016.00129] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 09/06/2016] [Indexed: 12/13/2022] Open
Abstract
Growth hormone-releasing hormone (GHRH) is produced by the hypothalamus and stimulates growth hormone synthesis and release in the anterior pituitary gland. In addition, GHRH is an important regulator of cellular functions in many cells and organs. Expression of GHRH G-Protein Coupled Receptor (GHRHR) has been demonstrated in different peripheral tissues and cell types, including pancreatic islets. Among the peripheral activities, recent studies demonstrate a novel ability of GHRH analogs to increase and preserve insulin secretion by beta-cells in isolated pancreatic islets, which makes them potentially useful for diabetes treatment. This review considers the role of GHRHR in the beta-cell and addresses the unique engineered GHRH agonists and antagonists for treatment of type 2 diabetes mellitus. We discuss the similarity of signaling pathways activated by GHRHR in pituitary somatotrophs and in pancreatic beta-cells and possible ways as to how the GHRHR pathway can interact with glucose and other secretagogues to stimulate insulin secretion. We also consider the hypothesis that novel GHRHR agonists can improve glucose metabolism in Type 2 diabetes by preserving the function and survival of pancreatic beta-cells. Wound healing and cardioprotective action with new GHRH agonists suggest that they may prove useful in ameliorating certain diabetic complications. These findings highlight the future potential therapeutic effectiveness of modulators of GHRHR activity for the development of new therapeutic approaches in diabetes and its complications.
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Affiliation(s)
- Leonid E. Fridlyand
- Department of Medicine, Kovler Diabetes Center, The University of Chicago, Chicago, IL, USA
- *Correspondence: Leonid E. Fridlyand,
| | - Natalia A. Tamarina
- Department of Medicine, Kovler Diabetes Center, The University of Chicago, Chicago, IL, USA
| | - Andrew V. Schally
- VA Medical Center, Miami, FL, USA
- Department of Pathology and Medicine, Division of Endocrinology and Hematology-Oncology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Louis H. Philipson
- Department of Medicine, Kovler Diabetes Center, The University of Chicago, Chicago, IL, USA
- Department of Pediatrics, The University of Chicago, Chicago, IL, USA
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Loose M, Pillich H, Chakraborty T. Fisetin Protects Against Listeria monocytogenes Infection by Reducing the Production of Listeriolysin O. J Infect Dis 2015; 213:684-5. [PMID: 26347572 DOI: 10.1093/infdis/jiv437] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 08/25/2015] [Indexed: 11/14/2022] Open
Affiliation(s)
- Maria Loose
- Institute for Medical Microbiology, German Centre for Infection Giessen-Marburg-Langen Site, Justus-Liebig University, Giessen, Germany
| | - Helena Pillich
- Institute for Medical Microbiology, German Centre for Infection Giessen-Marburg-Langen Site, Justus-Liebig University, Giessen, Germany
| | - Trinad Chakraborty
- Institute for Medical Microbiology, German Centre for Infection Giessen-Marburg-Langen Site, Justus-Liebig University, Giessen, Germany
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Ndjom CGN, Jones HP. CRH promotes S. pneumoniae growth in vitro and increases lung carriage in mice. Front Microbiol 2015; 6:279. [PMID: 25904910 PMCID: PMC4389549 DOI: 10.3389/fmicb.2015.00279] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/19/2015] [Indexed: 11/13/2022] Open
Abstract
Streptococcus pneumoniae (S. pneumoniae), a commensal across the nasal passages, is responsible for the majority of infectious pneumonia cases worldwide. Previous studies have shown that hormonal factors may be influential in regulating S. pneumoniae’s transition from a non-pathogen to a pathogenic state. The current study investigated the effects of corticotropin-releasing hormone (CRH), a peptide hormone involved in stress, on the pathogenicity of S. pneumoniae. Mice were infected with CRH-treated S. pneumoniae via intranasal route, showing an increase in pulmonary bacterial burden. We also quantified S. pneumoniae’s response to CRH through limited serial dilutions and growth curve analysis. We demonstrated that CRH promotes S. pneumoniae titer-dependent proliferation, as well as accelerates log-phase growth. Results also showed an increase in pneumococcal-associated virulence protein A virulence gene expression in response to CRH. These results demonstrate a role for CRH in S. pneumoniae pathogenicity, thus implicating CRH in mediating the transition of S. pneumoniae into a pathogenic state.
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Affiliation(s)
- Colette G Ngo Ndjom
- Department of Molecular and Medical Genetics, University of North Texas Health Science Center, Fort Worth, TX USA ; Center for Biotechnology Education, Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, MD USA
| | - Harlan P Jones
- Department of Molecular and Medical Genetics, University of North Texas Health Science Center, Fort Worth, TX USA
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Liu MW, Su MX, Zhang W, Wang YH, Qin LF, Liu X, Tian ML, Qian CY. Effect of Melilotus suaveolens extract on pulmonary microvascular permeability by downregulating vascular endothelial growth factor expression in rats with sepsis. Mol Med Rep 2015; 11:3308-16. [PMID: 25571852 PMCID: PMC4368078 DOI: 10.3892/mmr.2015.3146] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Accepted: 05/23/2014] [Indexed: 11/23/2022] Open
Abstract
A typical indicator of sepsis is the development of progressive subcutaneous and body-cavity edema, which is caused by the breakdown of endothelial barrier function, leading to a marked increase in vascular permeability. Microvascular leakage predisposes to microvascular thrombosis, breakdown of microcirculatory flow and organ failure, which are common events preceding mortality in patients with severe sepsis. Melilotus suaveolens (M. suaveolens) is a Traditional Tibetan Medicine. Previous pharmacological studies have demonstrated that an ethanolic extract of M. suaveolens has powerful anti-inflammatory activity and leads to an improvement in capillary permeability. However, the mechanisms underlying its pharmacological activity remain elusive. The present study aimed to assess the impact of M. suaveolens extract tablets on pulmonary vascular permeability, and their effect on regulating lung inflammation and the expression of vascular endothelial growth factor (VEGF) in the lung tissue of rats with sepsis. A cecal ligation and puncture (CLP) sepsis model was established for both the control and treatment groups. ~2 h prior to surgery, 25 mg/kg of M. suaveolens extract tablet was administered to the treatment group. Polymerase chain reaction and western blot analyses were used to assess the expression of nuclear factor (NF)-κB and VEGF in the lung tissue, and ELISA was applied to detect changes in serum tumor necrosis factor-α as well as interleukins (IL) -1, -4, -6, and -10. The lung permeability, wet/dry weight ratio and lung pathology were determined. The results demonstrated that in the lung tissue of CLP-rats with sepsis, M. suaveolens extract inhibited the expression of NF-κB, reduced the inflammatory response and blocked the expression of VEGF, and thus significantly decreased lung microvascular permeability. The effects of M. Suaveolens extract may be of potential use in the treatment of CLP-mediated lung microvascular permeability.
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Affiliation(s)
- Ming-Wei Liu
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Mei-Xian Su
- Surgical Intensive Care Unit, The Second Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650106, P.R. China
| | - Wei Zhang
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Yun Hui Wang
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Lan-Fang Qin
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Xu Liu
- Department of Infectious Diseases, Yan'an Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650051, P.R. China
| | - Mao-Li Tian
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Chuan-Yun Qian
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650032, P.R. China
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Czikora I, Alli A, Bao HF, Kaftan D, Sridhar S, Apell HJ, Gorshkov B, White R, Zimmermann A, Wendel A, Pauly-Evers M, Hamacher J, Garcia-Gabay I, Fischer B, Verin A, Bagi Z, Pittet JF, Shabbir W, Lemmens-Gruber R, Chakraborty T, Lazrak A, Matthay MA, Eaton DC, Lucas R. A novel tumor necrosis factor-mediated mechanism of direct epithelial sodium channel activation. Am J Respir Crit Care Med 2014; 190:522-32. [PMID: 25029038 DOI: 10.1164/rccm.201405-0833oc] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
RATIONALE Alveolar liquid clearance is regulated by Na(+) uptake through the apically expressed epithelial sodium channel (ENaC) and basolaterally localized Na(+)-K(+)-ATPase in type II alveolar epithelial cells. Dysfunction of these Na(+) transporters during pulmonary inflammation can contribute to pulmonary edema. OBJECTIVES In this study, we sought to determine the precise mechanism by which the TIP peptide, mimicking the lectin-like domain of tumor necrosis factor (TNF), stimulates Na(+) uptake in a homologous cell system in the presence or absence of the bacterial toxin pneumolysin (PLY). METHODS We used a combined biochemical, electrophysiological, and molecular biological in vitro approach and assessed the physiological relevance of the lectin-like domain of TNF in alveolar liquid clearance in vivo by generating triple-mutant TNF knock-in mice that express a mutant TNF with deficient Na(+) uptake stimulatory activity. MEASUREMENTS AND MAIN RESULTS TIP peptide directly activates ENaC, but not the Na(+)-K(+)-ATPase, upon binding to the carboxy-terminal domain of the α subunit of the channel. In the presence of PLY, a mediator of pneumococcal-induced pulmonary edema, this binding stabilizes the ENaC-PIP2-MARCKS complex, which is necessary for the open probability conformation of the channel and preserves ENaC-α protein expression, by means of blunting the protein kinase C-α pathway. Triple-mutant TNF knock-in mice are more prone than wild-type mice to develop edema with low-dose intratracheal PLY, correlating with reduced pulmonary ENaC-α subunit expression. CONCLUSIONS These results demonstrate a novel TNF-mediated mechanism of direct ENaC activation and indicate a physiological role for the lectin-like domain of TNF in the resolution of alveolar edema during inflammation.
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Antagonistic analogs of growth hormone-releasing hormone increase the efficacy of treatment of triple negative breast cancer in nude mice with doxorubicin; A preclinical study. Oncoscience 2014; 1:665-73. [PMID: 25593995 PMCID: PMC4278278 DOI: 10.18632/oncoscience.92] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 10/23/2014] [Indexed: 12/11/2022] Open
Abstract
Introduction This study evaluated the effects of an antagonistic analog of growth hormone-releasing hormone, MIA-602, on tumor growth, response to doxorubicin, expression of drug resistance genes, and efflux pump function in human triple negative breast cancers. Methods HCC1806 (doxorubicin-sensitive) and MX-1 (doxorubicin-resistant), cell lines were xenografted into nude mice and treated with MIA-602, doxorubicin, or their combination. Tumors were evaluated for changes in volume and the expression of the drug resistance genes MDR1 and NANOG. In-vitro cell culture assays were used to analyze the effect of MIA-602 on efflux pump function. Results Therapy with MIA-602 significantly reduced tumor growth and enhanced the efficacy of doxorubicin in both cell lines. Control HCC1806 tumors grew by 435%, while the volume of tumors treated with MIA-602 enlarged by 172.2% and with doxorubicin by 201.6%. Treatment with the combination of MIA-602 and doxorubicin resulted in an increase in volume of only 76.2%. Control MX-1 tumors grew by 907%, while tumors treated with MIA-602 enlarged by 434.8% and with doxorubicin by 815%. The combination of MIA-602 and doxorubicin reduced the increase in tumor volume to 256%. Treatment with MIA-602 lowered the level of growth hormone-releasing hormone and growth hormone-releasing hormone receptors and significantly reduced the expression of multidrug resistance (MDR1) gene and the drug resistance regulator NANOG. MIA-602 also suppressed efflux pump function in both cell lines. Conclusions We conclude that treatment of triple negative breast cancers with growth hormone-releasing hormone antagonists reduces tumor growth and potentiates the effects of cytotoxic therapy by nullifying drug resistance.
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Liu MW, Wang YH, Qian CY, Li H. Xuebijing exerts protective effects on lung permeability leakage and lung injury by upregulating Toll-interacting protein expression in rats with sepsis. Int J Mol Med 2014; 34:1492-504. [PMID: 25269519 PMCID: PMC4214342 DOI: 10.3892/ijmm.2014.1943] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Accepted: 09/16/2014] [Indexed: 01/07/2023] Open
Abstract
Xuebijing (XBJ) is a type of traditional Tibetan medicine, and previous pharmacological studies have shown that the ethanol extract is derived from Chuanxiong, Chishao, Danshen and Honghua. Chuanxiong, Chishao, Danshen and Honghua possesses potent anti-inflammatory activity, and has been used in the treatment of inflammatory infectious diseases. In the present study, we investigated the effects of XBJ on pulmonary permeability and lung injury in cecal ligation and puncture (CLP)-induced sepsis in rats. A CLP sepsis model was established for the control and treatment groups, respectively. Approximately 2 h prior to surgery, an amount of 100 mg/kg XBJ injection was administered to the treatment group. Reverse transcription polymerase chain reaction (PT-PCR) and western blot analysis were used to examine the expression of Toll-interacting protein (Tollip), interleukin-1 receptor-associated kinase 1 (IRAK1), Toll-like receptor 4 (TLR4), nuclear factor-κB65 (NF-κB65) and TNF receptor-associated factor 6 (TRAF6) in lung tissue. ELISA was applied to detect changes of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1 (IL-1), interleukin-4 (IL-4) and interleukin-10 (IL-10) levels in bronchoalveolar lavage (BAL) fluid, and intercellular adhesion molecule 1 (ICAM-1) and von Willebrand factor (vWF) in serum. The number of neutrophils, albumin and total cells in the BAL fluid were measured. For histological analysis, hematoxylin and eosin (H&E) stains were evaluated. Lung permeability, the wet/dry weight ratio (W/D) and the lung pathology score were determined following the induction of ALI by CLP for 24 h. The results demonstrated that XBJ upregulated Tollip expression and blocked the activity of IRAK1, TLR4, NF-κβ65 and TRAF6. Additionally, the number of neutrophils and total cells were significantly decreased in the XBJ group compared to that in the control group. Lung permeability, the wet/dry weight ratio (W/D) and the lung pathology score were significantly decreased in the XBJ group. The histological results also demonstrated the attenuation effect of XBJ on CLP-induced lung inflammation. The results of the present study indicated that XBJ has a significantly reduced CLP-induced lung permeability by upregulating Tollip expression. The protective effects of XBJ suggest its therapeutic potential in CLP-induced acute lung injury treatment.
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Affiliation(s)
- Ming-Wei Liu
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650000, P.R. China
| | - Yun-Hui Wang
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650000, P.R. China
| | - Chuan-Yun Qian
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650000, P.R. China
| | - Hui Li
- Surgical Intensive Care Unit, The Second Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650000, P.R. China
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Loose M, Hudel M, Zimmer KP, Garcia E, Hammerschmidt S, Lucas R, Chakraborty T, Pillich H. Pneumococcal hydrogen peroxide-induced stress signaling regulates inflammatory genes. J Infect Dis 2014; 211:306-16. [PMID: 25183769 DOI: 10.1093/infdis/jiu428] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Microbial infections can induce aberrant responses in cellular stress pathways, leading to translational attenuation, metabolic restriction, and activation of oxidative stress, with detrimental effects on cell survival. Here we show that infection of human airway epithelial cells with Streptococcus pneumoniae leads to induction of endoplasmic reticulum (ER) and oxidative stress, activation of mitogen-associated protein kinase (MAPK) signaling pathways, and regulation of their respective target genes. We identify pneumococcal H2O2 as the causative agent for these responses, as both catalase-treated and pyruvate oxidase-deficient bacteria lacked these activities. Pneumococcal H2O2 induced nuclear NF-κB translocation and transcription of proinflammatory cytokines. Inhibition of translational arrest and ER stress by salubrinal or of MAPK signaling pathways attenuate cytokine transcription. These results provide strong evidence for the notion that inhibition of translation is an important host pathway in monitoring harmful pathogen-associated activities, thereby enabling differentiation between pathogenic and nonpathogenic bacteria.
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Affiliation(s)
- Maria Loose
- Institute for Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site
| | - Martina Hudel
- Institute for Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site
| | | | - Ernesto Garcia
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, and Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Madrid, Spain
| | - Sven Hammerschmidt
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, Ernst Moritz Arndt University of Greifswald, Germany
| | - Rudolf Lucas
- Vascular Biology Center, Department of Pharmacology and Toxicology, Georgia Health Sciences University, Augusta
| | - Trinad Chakraborty
- Institute for Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site
| | - Helena Pillich
- Institute for Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site
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Czikora I, Sridhar S, Gorshkov B, Alieva IB, Kasa A, Gonzales J, Potapenko O, Umapathy NS, Pillich H, Rick FG, Block NL, Verin AD, Chakraborty T, Matthay MA, Schally AV, Lucas R. Protective effect of Growth Hormone-Releasing Hormone agonist in bacterial toxin-induced pulmonary barrier dysfunction. Front Physiol 2014; 5:259. [PMID: 25076911 PMCID: PMC4097355 DOI: 10.3389/fphys.2014.00259] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 06/19/2014] [Indexed: 01/17/2023] Open
Abstract
RATIONALE Antibiotic treatment of patients infected with G(-) or G(+) bacteria promotes release of the toxins lipopolysaccharide (LPS) and pneumolysin (PLY) in their lungs. Growth Hormone-releasing Hormone (GHRH) agonist JI-34 protects human lung microvascular endothelial cells (HL-MVEC), expressing splice variant 1 (SV-1) of the receptor, from PLY-induced barrier dysfunction. We investigated whether JI-34 also blunts LPS-induced hyperpermeability. Since GHRH receptor (GHRH-R) signaling can potentially stimulate both cAMP-dependent barrier-protective pathways as well as barrier-disruptive protein kinase C pathways, we studied their interaction in GHRH agonist-treated HL-MVEC, in the presence of PLY, by means of siRNA-mediated protein kinase A (PKA) depletion. METHODS Barrier function measurements were done in HL-MVEC monolayers using Electrical Cell substrate Impedance Sensing (ECIS) and VE-cadherin expression by Western blotting. Capillary leak was assessed by Evans Blue dye (EBD) incorporation. Cytokine generation in broncho-alveolar lavage fluid (BALF) was measured by multiplex analysis. PKA and PKC-α activity were assessed by Western blotting. RESULTS GHRH agonist JI-34 significantly blunts LPS-induced barrier dysfunction, at least in part by preserving VE-cadherin expression, while not affecting inflammation. In addition to activating PKA, GHRH agonist also increases PKC-α activity in PLY-treated HL-MVEC. Treatment with PLY significantly decreases resistance in control siRNA-treated HL-MVEC, but does so even more in PKA-depleted monolayers. Pretreatment with GHRH agonist blunts PLY-induced permeability in control siRNA-treated HL-MVEC, but fails to improve barrier function in PKA-depleted PLY-treated monolayers. CONCLUSIONS GHRH signaling in HL-MVEC protects from both LPS and PLY-mediated endothelial barrier dysfunction and concurrently induces a barrier-protective PKA-mediated and a barrier-disruptive PKC-α-induced pathway in the presence of PLY, the former of which dominates the latter.
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Affiliation(s)
- Istvan Czikora
- Department of Pharmacology and Toxicology, Vascular Biology Center, Georgia Regents University Augusta, GA, USA
| | - Supriya Sridhar
- Department of Pharmacology and Toxicology, Vascular Biology Center, Georgia Regents University Augusta, GA, USA
| | - Boris Gorshkov
- Department of Pharmacology and Toxicology, Vascular Biology Center, Georgia Regents University Augusta, GA, USA
| | - Irina B Alieva
- Department of Pharmacology and Toxicology, Vascular Biology Center, Georgia Regents University Augusta, GA, USA ; Department of Electron Microscopy, A.N. Belozorksy Institute, Moscow State University Moscow, Russia
| | - Anita Kasa
- Department of Pharmacology and Toxicology, Vascular Biology Center, Georgia Regents University Augusta, GA, USA
| | - Joyce Gonzales
- Department of Medicine, Division of Pulmonary Medicine, Medical College of Georgia, Georgia Regents University Augusta, GA, USA
| | - Olena Potapenko
- Department of Pharmacology and Toxicology, Vascular Biology Center, Georgia Regents University Augusta, GA, USA
| | - Nagavedi S Umapathy
- Department of Pharmacology and Toxicology, Vascular Biology Center, Georgia Regents University Augusta, GA, USA
| | - Helena Pillich
- Department of Medicine, Institute of Medical Microbiology, Justus-Liebig University Giessen Giessen, Germany
| | - Ferenc G Rick
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center Miami, FL, USA ; Department of Urology, Herbert Wertheim College of Medicine, Florida International University Miami, FL, USA
| | - Norman L Block
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center Miami, FL, USA ; Department of Pathology, Miller School of Medicine, University of Miami Miami, FL, USA ; Department of Medicine, Miller School of Medicine, University of Miami Miami, FL, USA ; Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami Miami, FL, USA
| | - Alexander D Verin
- Department of Pharmacology and Toxicology, Vascular Biology Center, Georgia Regents University Augusta, GA, USA
| | - Trinad Chakraborty
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center Miami, FL, USA
| | - Michael A Matthay
- Department of Medicine and Anesthesia, Cardiovascular Research Institute, University of California San Francisco San Francisco, CA, USA
| | - Andrew V Schally
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center Miami, FL, USA ; Department of Pathology, Miller School of Medicine, University of Miami Miami, FL, USA ; Department of Medicine, Miller School of Medicine, University of Miami Miami, FL, USA ; Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami Miami, FL, USA
| | - Rudolf Lucas
- Department of Pharmacology and Toxicology, Vascular Biology Center, Georgia Regents University Augusta, GA, USA ; Department of Medicine, Division of Pulmonary Medicine, Medical College of Georgia, Georgia Regents University Augusta, GA, USA ; Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University Augusta, GA, USA
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Cai R, Schally AV, Cui T, Szalontay L, Halmos G, Sha W, Kovacs M, Jaszberenyi M, He J, Rick FG, Popovics P, Kanashiro-Takeuchi R, Hare JM, Block NL, Zarandi M. Synthesis of new potent agonistic analogs of growth hormone-releasing hormone (GHRH) and evaluation of their endocrine and cardiac activities. Peptides 2014; 52:104-12. [PMID: 24373935 PMCID: PMC4745889 DOI: 10.1016/j.peptides.2013.12.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 12/17/2013] [Accepted: 12/18/2013] [Indexed: 11/30/2022]
Abstract
In view of the recent findings of stimulatory effects of GHRH analogs, JI-34, JI-36 and JI-38, on cardiomyocytes, pancreatic islets and wound healing, three series of new analogs of GHRH(1-29) have been synthesized and evaluated biologically in an endeavor to produce more potent compounds. "Agmatine analogs", MR-356 (N-Me-Tyr(1)-JI-38), MR-361(N-Me-Tyr(1), D-Ala(2)-JI-38) and MR-367(N-Me-Tyr(1), D-Ala(2), Asn(8)-JI-38), in which Dat in JI-38 is replaced by N-Me-Tyr(1), showed improved relative potencies on GH release upon subcutaneous administration in vivo and binding in vitro. Modification with N-Me-Tyr(1) and Arg(29)-NHCH3 as in MR-403 (N-Me-Tyr(1), D-Ala(2), Arg(29)-NHCH3-JI-38), MR-406 (N-Me-Tyr(1), Arg(29)-NHCH3-JI-38) and MR-409 (N-Me-Tyr(1), D-Ala(2), Asn(8), Arg(29)-NHCH3-JI-38), and MR-410 (N-Me-Tyr(1), D-Ala(2), Thr(8), Arg(29)-NHCH3-JI-38) resulted in dramatically increased endocrine activities. These appear to be the most potent GHRH agonistic analogs so far developed. Analogs with Apa(30)-NH2 such as MR-326 (N-Me-Tyr(1), D-Ala(2), Arg(29), Apa(30)-NH2-JI-38), and with Gab(30)-NH2, as MR-502 (D-Ala(2), 5F-Phe(6), Ser(28), Arg(29),Gab(30)-NH2-JI-38) also exhibited much higher potency than JI-38 upon i.v. administration. The relationship between the GH-releasing potency and the analog structure is discussed. Fourteen GHRH agonists with the highest endocrine potencies were subjected to cardiologic tests. MR-409 and MR-356 exhibited higher potency than JI-38 in activating myocardial repair in rats with induced myocardial infarction. As the previous class of analogs, exemplified by JI-38, had shown promising results in multiple fields including cardiology, diabetes and wound healing, our new, more potent, GHRH agonists should manifest additional efficacy for possible medical applications.
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Affiliation(s)
- Renzhi Cai
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Andrew V Schally
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States; Division of Hematology/Oncology, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States; Division of Endocrinology, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States.
| | - Tengjiao Cui
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Luca Szalontay
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States
| | - Gabor Halmos
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Wei Sha
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Interdisciplinary Stem Cell Institute, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Magdolna Kovacs
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Miklos Jaszberenyi
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States
| | - Jinlin He
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States
| | - Ferenc G Rick
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Urology, Florida International University, Herbert Wertheim College of Medicine, Miami, FL, United States
| | - Petra Popovics
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; Division of Cardiology, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Rosemeire Kanashiro-Takeuchi
- Interdisciplinary Stem Cell Institute, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Joshua M Hare
- Division of Cardiology, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States; Interdisciplinary Stem Cell Institute, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Norman L Block
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States; Division of Hematology/Oncology, Department of Medicine, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Marta Zarandi
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, University of Miami, Miller School of Medicine, Miami, FL, United States
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Rafikov R, Dimitropoulou C, Aggarwal S, Kangath A, Gross C, Pardo D, Sharma S, Jezierska-Drutel A, Patel V, Snead C, Lucas R, Verin A, Fulton D, Catravas JD, Black SM. Lipopolysaccharide-induced lung injury involves the nitration-mediated activation of RhoA. J Biol Chem 2014; 289:4710-22. [PMID: 24398689 DOI: 10.1074/jbc.m114.547596] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Acute lung injury (ALI) is characterized by increased endothelial hyperpermeability. Protein nitration is involved in the endothelial barrier dysfunction in LPS-exposed mice. However, the nitrated proteins involved in this process have not been identified. The activation of the small GTPase RhoA is a critical event in the barrier disruption associated with LPS. Thus, in this study we evaluated the possible role of RhoA nitration in this process. Mass spectroscopy identified a single nitration site, located at Tyr(34) in RhoA. Tyr(34) is located within the switch I region adjacent to the nucleotide-binding site. Utilizing this structure, we developed a peptide designated NipR1 (nitration inhibitory peptide for RhoA 1) to shield Tyr(34) against nitration. TAT-fused NipR1 attenuated RhoA nitration and barrier disruption in LPS-challenged human lung microvascular endothelial cells. Further, treatment of mice with NipR1 attenuated vessel leakage and inflammatory cell infiltration and preserved lung function in a mouse model of ALI. Molecular dynamics simulations suggested that the mechanism by which Tyr(34) nitration stimulates RhoA activity was through a decrease in GDP binding to the protein caused by a conformational change within a region of Switch I, mimicking the conformational shift observed when RhoA is bound to a guanine nucleotide exchange factor. Stopped flow kinetic analysis was used to confirm this prediction. Thus, we have identified a new mechanism of nitration-mediated RhoA activation involved in LPS-mediated endothelial barrier dysfunction and show the potential utility of "shielding" peptides to prevent RhoA nitration in the management of ALI.
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Affiliation(s)
- Ruslan Rafikov
- From the Program in Pulmonary Vascular Disease, Vascular Biology Center and
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Szalontay L, Schally AV, Popovics P, Vidaurre I, Krishan A, Zarandi M, Cai RZ, Klukovits A, Block NL, Rick FG. Novel GHRH antagonists suppress the growth of human malignant melanoma by restoring nuclear p27 function. Cell Cycle 2014; 13:2790-7. [PMID: 25486366 PMCID: PMC4615138 DOI: 10.4161/15384101.2015.945879] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 06/13/2014] [Accepted: 06/16/2014] [Indexed: 01/21/2023] Open
Abstract
Malignant melanoma is the deadliest form of skin cancer; the treatment of advanced and recurrent forms remains a challenge. It has recently been reported that growth hormone-releasing hormone (GHRH) receptor is involved in the pathogenesis of melanoma. Therefore, we investigated the effects of our new GHRH antagonists on a human melanoma cancer cell line. Antiproliferative effects of GHRH antagonists, MIA-602, MIA-606 and MIA-690, on the human melanoma cell line, A-375, were studied in vitro using the MTS assay. The effect of MIA-690 (5 μg/day 28 d) was further evaluated in vivo in nude mice bearing xenografts of A-375. Subcellular localization of p27 was detected with Western blot and immunofluorescent staining. MIA-690 inhibited the proliferation of A-375 cells in a dose-dependent manner (33% at 10 μM, and 19.2% at 5 μM, P < 0 .05 vs. control), and suppressed the growth of xenografted tumors by 70.45% (P < 0.05). Flow cytometric analysis of cell cycle effects following the administration of MIA-690 revealed a decrease in the number of cells in G2/M phase (from 19.7% to 12.9%, P < 0.001). Additionally, Western blot and immunofluorescent studies showed that exposure of A-375 cells to MIA-690 triggered the nuclear accumulation of p27. MIA-690 inhibited tumor growth in vitro and in vivo, and increased the translocation of p27 into the nucleus thus inhibiting progression of the cell cycle. Our findings indicate that patients with malignant melanoma could benefit from treatment regimens, which combine existing chemotherapy agents and novel GHRH-antagonists.
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Key Words
- ANOVA, one-way analysis of variance
- Abu, a-aminobutyric acid
- Ac, acetyl
- Ada, 12-aminododecanoyl
- Agm, agmatine
- Amc, 8-aminocaprylyl
- Cpa, parachlorophenylalanine
- FBS, fetal bovine serum
- Fpa5, pentafluoro-phenylalanine
- GH, growth hormone
- GHRH, growth hormone-releasing hormone
- GHRH-R, growth hormone-releasing hormone receptor
- Har, homoarginine
- IGF-I, insulin-like growth factor I
- MTS, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfonphenyl)-2H-tetrazolium
- Nle, norleucine
- Orn, ornithine
- Ph, phenyl
- PhAc, phenylacetyl
- SVs, splice variants
- TBS, tris-buffered saline
- Tyr(Me), O-methyltyrosine
- growth hormone-releasing hormone antagonist
- hGHRH, human growth hormone-releasing hormone
- mTOR, mammalian target of rapamycin
- melanoma
- p27
- pGHRH-R, pituitary type GHRH-receptor
- targeted therapy
- xenografted mouse model
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Affiliation(s)
- Luca Szalontay
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
| | - Andrew V Schally
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
- Divisions of Hematology/Oncology; University of Miami; Miller School of Medicine; Miami, FL USA
- Department of Endocrinology; University of Miami; Miller School of Medicine; Miami, FL USA
- Sylvester Comprehensive Cancer Center; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Petra Popovics
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Cardiovascular Diseases; Department of Medicine; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Irving Vidaurre
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
| | - Awtar Krishan
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Marta Zarandi
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Ren-Zhi Cai
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Anna Klukovits
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Norman L Block
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Pathology; University of Miami; Miller School of Medicine; Miami, FL USA
- Divisions of Hematology/Oncology; University of Miami; Miller School of Medicine; Miami, FL USA
| | - Ferenc G Rick
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education; Miami, FL USA
- Department of Urology; Herbert Wertheim College of Medicine; Florida International University; Miami, FL, USA
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Romero MJ, Yao L, Sridhar S, Bhatta A, Dou H, Ramesh G, Brands MW, Pollock DM, Caldwell RB, Cederbaum SD, Head CA, Bagi Z, Lucas R, Caldwell RW. l-Citrulline Protects from Kidney Damage in Type 1 Diabetic Mice. Front Immunol 2013; 4:480. [PMID: 24400007 PMCID: PMC3871963 DOI: 10.3389/fimmu.2013.00480] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 12/09/2013] [Indexed: 01/01/2023] Open
Abstract
RATIONALE Diabetic nephropathy (DN) is a major cause of end-stage renal disease, associated with endothelial dysfunction. Chronic supplementation of l-arginine (l-arg), the substrate for endothelial nitric oxide synthase (eNOS), failed to improve vascular function. l-Citrulline (l-cit) supplementation not only increases l-arg synthesis, but also inhibits cytosolic arginase I, a competitor of eNOS for the use of l-arg, in the vasculature. AIMS To investigate whether l-cit treatment reduces DN in streptozotocin (STZ)-induced type 1 diabetes (T1D) in mice and rats and to study its effects on arginase II (ArgII) function, the main renal isoform. METHODS STZ-C57BL6 mice received l-cit or vehicle supplemented in the drinking water. For comparative analysis, diabetic ArgII knock out mice and l-cit-treated STZ-rats were evaluated. RESULTS l-Citrulline exerted protective effects in kidneys of STZ-rats, and markedly reduced urinary albumin excretion, tubulo-interstitial fibrosis, and kidney hypertrophy, observed in untreated diabetic mice. Intriguingly, l-cit treatment was accompanied by a sustained elevation of tubular ArgII at 16 weeks and significantly enhanced plasma levels of the anti-inflammatory cytokine IL-10. Diabetic ArgII knock out mice showed greater blood urea nitrogen levels, hypertrophy, and dilated tubules than diabetic wild type (WT) mice. Despite a marked reduction in collagen deposition in ArgII knock out mice, their albuminuria was not significantly different from diabetic WT animals. l-Cit also restored nitric oxide/reactive oxygen species balance and barrier function in high glucose-treated monolayers of human glomerular endothelial cells. Moreover, l-cit also has the ability to establish an anti-inflammatory profile, characterized by increased IL-10 and reduced IL-1β and IL-12(p70) generation in the human proximal tubular cells. CONCLUSION l-Citrulline supplementation established an anti-inflammatory profile and significantly preserved the nephron function during T1D.
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Affiliation(s)
- Maritza J Romero
- Department of Pharmacology and Toxicology, Georgia Regents University , Augusta, GA , USA ; Department of Anesthesiology and Perioperative Medicine, Georgia Regents University , Augusta, GA , USA ; Vascular Biology Center, Georgia Regents University , Augusta, GA , USA
| | - Lin Yao
- Department of Pharmacology and Toxicology, Georgia Regents University , Augusta, GA , USA
| | - Supriya Sridhar
- Vascular Biology Center, Georgia Regents University , Augusta, GA , USA
| | - Anil Bhatta
- Department of Pharmacology and Toxicology, Georgia Regents University , Augusta, GA , USA
| | - Huijuan Dou
- Vascular Biology Center, Georgia Regents University , Augusta, GA , USA
| | - Ganesan Ramesh
- Vascular Biology Center, Georgia Regents University , Augusta, GA , USA ; Department of Medicine, Georgia Regents University , Augusta, GA , USA
| | - Michael W Brands
- Department of Physiology, Georgia Regents University , Augusta, GA , USA
| | - David M Pollock
- Department of Pharmacology and Toxicology, Georgia Regents University , Augusta, GA , USA ; Department of Medicine, Georgia Regents University , Augusta, GA , USA
| | - Ruth B Caldwell
- Vascular Biology Center, Georgia Regents University , Augusta, GA , USA ; Department of Cell Biology and Anatomy, Georgia Regents University , Augusta, GA , USA ; Department of Ophthalmology, Georgia Regents University , Augusta, GA , USA ; VA Medical Center, Georgia Regents University , Augusta, GA , USA
| | - Stephen D Cederbaum
- Intellectual and Developmental Disabilities Research Center/Neuropsychiatric Institute (IDDRC/NPI), University of California Los Angeles School of Medicine , Los Angeles, CA , USA
| | - C Alvin Head
- Department of Anesthesiology and Perioperative Medicine, Georgia Regents University , Augusta, GA , USA
| | - Zsolt Bagi
- Vascular Biology Center, Georgia Regents University , Augusta, GA , USA
| | - Rudolf Lucas
- Department of Pharmacology and Toxicology, Georgia Regents University , Augusta, GA , USA ; Vascular Biology Center, Georgia Regents University , Augusta, GA , USA ; Division of Pulmonary Medicine, Georgia Regents University , Augusta, GA , USA
| | - Robert W Caldwell
- Department of Pharmacology and Toxicology, Georgia Regents University , Augusta, GA , USA ; Department of Physiology, Georgia Regents University , Augusta, GA , USA
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Lucas R, Parikh SJ, Sridhar S, Guo DH, Bhagatwala J, Dong Y, Caldwell R, Mellor A, Caldwell W, Zhu H, Dong Y. Cytokine profiling of young overweight and obese female African American adults with prediabetes. Cytokine 2013; 64:310-5. [PMID: 23769592 PMCID: PMC4058336 DOI: 10.1016/j.cyto.2013.05.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 05/03/2013] [Accepted: 05/24/2013] [Indexed: 02/08/2023]
Abstract
Approximately 5-10% of subjects with prediabetes become diabetic every year. Inflammation is involved in the development of obesity-related type 2 diabetes (T2D). However, to date, the relationship between inflammation and prediabetes, defined by hemoglobin A1c (HbA1c) ≥5.7 and <6.5%, remains largely unexplored, especially in African Americans. Therefore, in this study we examined a comprehensive panel of 13 cytokines involved in the inflammatory response in overweight/obese subjects with prediabetes. A total of 21 otherwise healthy, overweight/obese, young adult African American females with prediabetes, together with 20 matched overweight/obese controls, were selected for this study. Plasma cytokines were assessed by multiplex cytokine profiling. Plasma concentrations of interleukin (IL)-5, IL-6, IL-7, tumor necrosis factor-α (TNF-α), and granulocyte-monocyte colony-stimulating factor (GM-CSF) were significantly higher in the prediabetic group, as compared to the control group (all p<0.05). Plasma concentrations of all the other cytokines, interferon-γ (IFN-γ), IL-1β, IL-2, IL-4, IL-8, IL-10, IL-12p70 and IL-13, seemed to be elevated in the prediabetic group, but failed to reach statistical significances. Upon merging both groups, HbA1c was found to be positively correlated with IFN-γ, IL-1β, IL-2, IL-5, IL-7, IL-8, TNF-α and GM-CSF. This study demonstrates elevated levels of various pro-inflammatory cytokines in overweight/obese young subjects with prediabetes, which place them at higher risk of developing T2D and cardiovascular diseases. Our data also call for further investigations in animal models and population cohorts to establish the roles of a variety of pro-inflammatory cytokines in the early development of obesity-related T2D.
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Affiliation(s)
- Rudolf Lucas
- Vascular Biology Center, Georgia Regents University, Augusta, Georgia
- Department of Pharmacology and Toxicology, Georgia Regents University, Augusta, Georgia
- Division of Pulmonary Medicine, Georgia Regents University, Augusta, Georgia
| | - Samip J. Parikh
- Internal Medicine, Department of Medicine, Georgia Regents University, Augusta, Georgia
- Georgia Prevention Center, Institute for Public and Preventive Health, Department of Pediatrics, Georgia Regents University Augusta, Georgia
| | - Supriya Sridhar
- Vascular Biology Center, Georgia Regents University, Augusta, Georgia
| | - De-Huang Guo
- Georgia Prevention Center, Institute for Public and Preventive Health, Department of Pediatrics, Georgia Regents University Augusta, Georgia
| | - Jigar Bhagatwala
- Internal Medicine, Department of Medicine, Georgia Regents University, Augusta, Georgia
- Georgia Prevention Center, Institute for Public and Preventive Health, Department of Pediatrics, Georgia Regents University Augusta, Georgia
| | - Yutong Dong
- Georgia Prevention Center, Institute for Public and Preventive Health, Department of Pediatrics, Georgia Regents University Augusta, Georgia
| | - Ruth Caldwell
- Vascular Biology Center, Georgia Regents University, Augusta, Georgia
| | - Andrew Mellor
- Immunotherapy Center, Georgia Regents University, Augusta, Georgia
| | - William Caldwell
- Department of Pharmacology and Toxicology, Georgia Regents University, Augusta, Georgia
| | - Haidong Zhu
- Georgia Prevention Center, Institute for Public and Preventive Health, Department of Pediatrics, Georgia Regents University Augusta, Georgia
| | - Yanbin Dong
- Georgia Prevention Center, Institute for Public and Preventive Health, Department of Pediatrics, Georgia Regents University Augusta, Georgia
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40
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Lucas R, Czikora I, Sridhar S, Zemskov EA, Oseghale A, Circo S, Cederbaum SD, Chakraborty T, Fulton DJ, Caldwell RW, Romero MJ. Arginase 1: an unexpected mediator of pulmonary capillary barrier dysfunction in models of acute lung injury. Front Immunol 2013; 4:228. [PMID: 23966993 PMCID: PMC3736115 DOI: 10.3389/fimmu.2013.00228] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 07/19/2013] [Indexed: 12/31/2022] Open
Abstract
The integrity of epithelial and endothelial barriers in the lower airspaces of the lungs has to be tightly regulated, in order to prevent leakage and to assure efficient gas exchange between the alveoli and capillaries. Both G− and G+ bacterial toxins, such as lipopolysaccharide and pneumolysin, respectively, can be released in high concentrations within the pulmonary compartments upon antibiotic treatment of patients suffering from acute respiratory distress syndrome (ARDS) or severe pneumonia. These toxins are able to impair endothelial barrier function, either directly, or indirectly, by induction of pro-inflammatory mediators and neutrophil sequestration. Toxin-induced endothelial hyperpermeability can involve myosin light chain phosphorylation and/or microtubule rearrangement. Endothelial nitric oxide synthase (eNOS) was proposed to be a guardian of basal barrier function, since eNOS knock-out mice display an impaired expression of inter-endothelial junction proteins and as such an increased vascular permeability, as compared to wild type mice. The enzyme arginase, the activity of which can be regulated by the redox status of the cell, exists in two isoforms – arginase 1 (cytosolic) and arginase 2 (mitochondrial) – both of which can be expressed in lung microvascular endothelial cells. Upon activation, arginase competes with eNOS for the substrate l-arginine, as such impairing eNOS-dependent NO generation and promoting reactive oxygen species generation by the enzyme. This mini-review will discuss recent findings regarding the interaction between bacterial toxins and arginase during acute lung injury and will as such address the role of arginase in bacterial toxin-induced pulmonary endothelial barrier dysfunction.
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Affiliation(s)
- Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia, Georgia Regents University , Augusta, GA , USA ; Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University , Augusta, GA , USA ; Division of Pulmonary Medicine, Medical College of Georgia, Georgia Regents University , Augusta, GA , USA
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Mini-review: novel therapeutic strategies to blunt actions of pneumolysin in the lungs. Toxins (Basel) 2013; 5:1244-60. [PMID: 23860351 PMCID: PMC3737495 DOI: 10.3390/toxins5071244] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 06/25/2013] [Accepted: 06/27/2013] [Indexed: 01/11/2023] Open
Abstract
Severe pneumonia is the main single cause of death worldwide in children under five years of age. The main etiological agent of pneumonia is the G+ bacterium Streptococcus pneumoniae, which accounts for up to 45% of all cases. Intriguingly, patients can still die days after commencing antibiotic treatment due to the development of permeability edema, although the pathogen was successfully cleared from their lungs. This condition is characterized by a dramatically impaired alveolar epithelial-capillary barrier function and a dysfunction of the sodium transporters required for edema reabsorption, including the apically expressed epithelial sodium channel (ENaC) and the basolaterally expressed sodium potassium pump (Na+-K+-ATPase). The main agent inducing this edema formation is the virulence factor pneumolysin, a cholesterol-binding pore-forming toxin, released in the alveolar compartment of the lungs when pneumococci are being lysed by antibiotic treatment or upon autolysis. Sub-lytic concentrations of pneumolysin can cause endothelial barrier dysfunction and can impair ENaC-mediated sodium uptake in type II alveolar epithelial cells. These events significantly contribute to the formation of permeability edema, for which currently no standard therapy is available. This review focuses on discussing some recent developments in the search for the novel therapeutic agents able to improve lung function despite the presence of pore-forming toxins. Such treatments could reduce the potentially lethal complications occurring after antibiotic treatment of patients with severe pneumonia.
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Los FCO, Randis TM, Aroian RV, Ratner AJ. Role of pore-forming toxins in bacterial infectious diseases. Microbiol Mol Biol Rev 2013; 77:173-207. [PMID: 23699254 PMCID: PMC3668673 DOI: 10.1128/mmbr.00052-12] [Citation(s) in RCA: 298] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Pore-forming toxins (PFTs) are the most common bacterial cytotoxic proteins and are required for virulence in a large number of important pathogens, including Streptococcus pneumoniae, group A and B streptococci, Staphylococcus aureus, Escherichia coli, and Mycobacterium tuberculosis. PFTs generally disrupt host cell membranes, but they can have additional effects independent of pore formation. Substantial effort has been devoted to understanding the molecular mechanisms underlying the functions of certain model PFTs. Likewise, specific host pathways mediating survival and immune responses in the face of toxin-mediated cellular damage have been delineated. However, less is known about the overall functions of PFTs during infection in vivo. This review focuses on common themes in the area of PFT biology, with an emphasis on studies addressing the roles of PFTs in in vivo and ex vivo models of colonization or infection. Common functions of PFTs include disruption of epithelial barrier function and evasion of host immune responses, which contribute to bacterial growth and spreading. The widespread nature of PFTs make this group of toxins an attractive target for the development of new virulence-targeted therapies that may have broad activity against human pathogens.
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Affiliation(s)
| | - Tara M. Randis
- Department of Pediatrics, Columbia University, New York, New York, USA
| | - Raffi V. Aroian
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, USA
| | - Adam J. Ratner
- Department of Pediatrics, Columbia University, New York, New York, USA
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Different mechanisms for metal-induced adaptation to cadmium in the human lung cell lines A549 and H441. Cell Biol Toxicol 2013; 29:159-73. [DOI: 10.1007/s10565-013-9243-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 03/25/2013] [Indexed: 12/28/2022]
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Dulebo A, Ettrich R, Lucas R, Kaftan D. A computational study of the oligosaccharide binding sites in the lectin-like domain of Tumor Necrosis Factor and the TNF-derived TIP peptide. Curr Pharm Des 2013; 18:4236-43. [PMID: 22697478 DOI: 10.2174/138161212802430549] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 06/11/2012] [Indexed: 01/18/2023]
Abstract
The lectin-like domain of Tumor Necrosis Factor (TNF), mimicked by the TIP peptide, activates amiloride-sensitive sodium uptake in type II alveolar epithelial cells and as such increases alveolar liquid clearance in dysfunctional lungs. This protective effect is blunted upon mutation of residues T105, E107 and E110 in human TNF into alanine or upon pre-incubation of the cytokine with the disaccharide N,N'-diacetylchitobiose. In this study, we used molecular docking and molecular dynamics simulation to predict the binding sites for N,N'-diacetylchitobiose and trimannose-O-ethyl in the lectin-like domain of TNF and in the TIP peptide. Specific sites (K98, S99, P100, Q102 and E116) in the three loops of the lectin-like domain provide specific binding for both oligosaccharides, but none of the residues crucial for anti-edema activity are involved in hydrogen bonding with oligosaccharides or are subjected to steric hindrance by them. These results thus suggest that neither chitobiose nor trimannose affect crucial amino acids, while they occupy the cavity in the lectin-like domain. Consequently, both crucial amino acids and the emptiness of the cavity in the lectin-like domain may be critical for TNF's lectin-like activity. Analogously, the R4, E5, P7, Y16 amino acids of the TIP peptide are involved in forming hydrogen bonds with both oligosaccharides, whereas residues T6, E8 and E11 (corresponding to T105, E107 and E110 in hTNF) play an important role in stabilizing the peptide-oligosaccharide complex, supporting the hypothesis that amino acids in the polar region (TPEGAE) of the TIP peptide represent only a partial binding motif for sugars.
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Affiliation(s)
- Alexander Dulebo
- University of South Bohemia in Ceské Budejovice, Faculty of Science, Czech Republic
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45
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Pflüger M, Kapuscik A, Lucas R, Koppensteiner A, Katzlinger M, Jokela J, Eger A, Jacobi N, Wiesner C, Hofmann E, Önder K, Kopecky J, Schütt W, Hundsberger H. A Combined Impedance and AlphaLISA-Based Approach to Identify Anti-inflammatory and Barrier-Protective Compounds in Human Endothelium. ACTA ACUST UNITED AC 2012; 18:67-74. [DOI: 10.1177/1087057112458316] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Chronic inflammation is at least partially mediated by the chemokine-mediated attraction and by the adhesion molecule–directed binding of leukocytes to the activated endothelium. Therefore, it is therapeutically important to identify anti-inflammatory compounds able to control the interaction between leukocytes and the endothelial compartments of the micro- and macrocirculation. When testing novel drug candidates, it is, however, of the utmost importance to detect side effects, such as potential cytotoxic and barrier-disruptive activities. Indeed, minor changes in the endothelial monolayer integrity may increase the permeability of small blood vessels and capillaries, which, in extreme cases, can lead to edema development. Here, we describe the development of a high-throughput screening (HTS) platform, based on AlphaLISA technology, able to identify anti-inflammatory nontoxic natural or synthetic compounds capable of reducing tumor necrosis factor (TNF)–induced chemokine (interleukin [IL]–8) and adhesion molecule (ICAM-1) expression in human lung microvascular endothelial cells. Quantification of cell membrane–expressed ICAM-1 and of cell culture supernatant–associated levels of IL-8 was analyzed in HTS. In parallel, we monitored monolayer integrity and endothelial cell viability using the electrical cell substrate impedance sensing method. This platform allowed us to identify natural secondary metabolites from cyanobacteria, capable of reducing ICAM-1 and IL-8 levels in TNF-activated human microvascular endothelial cells in the absence of endothelial monolayer barrier disruption.
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Affiliation(s)
- Maren Pflüger
- Department of Medical and Pharmaceutical Biotechnology, University of Applied Sciences, Krems, Austria
| | - Aleksandra Kapuscik
- Institute of Microbiology, Department of Phototrophic microorganisms–ALGATECH, Academy of Sciences of the Czech Republic, Opatovický Mlýn, Czech Republic
| | - Rudolf Lucas
- Vascular Biology Center, Department of Pharmacology and Toxicology, Division of Pulmonary Medicine, Georgia Health Sciences University, GA, USA
| | - Anita Koppensteiner
- Department of Medical and Pharmaceutical Biotechnology, University of Applied Sciences, Krems, Austria
| | | | - Jouni Jokela
- Department for Food and Environmental Sciences Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Finland
| | - Andreas Eger
- Department of Medical and Pharmaceutical Biotechnology, University of Applied Sciences, Krems, Austria
| | - Nico Jacobi
- Department of Medical and Pharmaceutical Biotechnology, University of Applied Sciences, Krems, Austria
| | | | - Elisabeth Hofmann
- Department of Medical and Pharmaceutical Biotechnology, University of Applied Sciences, Krems, Austria
| | - Kamil Önder
- Division of Molecular Dermatology, Department of Dermatology, Paracelsus Private, Medical University Salzburg, Austria
| | - Jiri Kopecky
- Institute of Microbiology, Department of Phototrophic microorganisms–ALGATECH, Academy of Sciences of the Czech Republic, Opatovický Mlýn, Czech Republic
| | - Wolfgang Schütt
- Department of Medical and Pharmaceutical Biotechnology, University of Applied Sciences, Krems, Austria
| | - Harald Hundsberger
- Department of Medical and Pharmaceutical Biotechnology, University of Applied Sciences, Krems, Austria
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46
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Matthay MA, Ware LB, Zimmerman GA. The acute respiratory distress syndrome. J Clin Invest 2012; 122:2731-40. [PMID: 22850883 DOI: 10.1172/jci60331] [Citation(s) in RCA: 1306] [Impact Index Per Article: 108.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The acute respiratory distress syndrome (ARDS) is an important cause of acute respiratory failure that is often associated with multiple organ failure. Several clinical disorders can precipitate ARDS, including pneumonia, sepsis, aspiration of gastric contents, and major trauma. Physiologically, ARDS is characterized by increased permeability pulmonary edema, severe arterial hypoxemia, and impaired carbon dioxide excretion. Based on both experimental and clinical studies, progress has been made in understanding the mechanisms responsible for the pathogenesis and the resolution of lung injury, including the contribution of environmental and genetic factors. Improved survival has been achieved with the use of lung-protective ventilation. Future progress will depend on developing novel therapeutics that can facilitate and enhance lung repair.
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Affiliation(s)
- Michael A Matthay
- Cardiovascular Research Institute and Departments of Medicine and Anesthesia, UCSF, San Francisco, CA, USA.
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47
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Lucas R, Yang G, Gorshkov BA, Zemskov EA, Sridhar S, Umapathy NS, Jezierska-Drutel A, Alieva IB, Leustik M, Hossain H, Fischer B, Catravas JD, Verin AD, Pittet JF, Caldwell RB, Mitchell TJ, Cederbaum SD, Fulton DJ, Matthay MA, Caldwell RW, Romero MJ, Chakraborty T. Protein kinase C-α and arginase I mediate pneumolysin-induced pulmonary endothelial hyperpermeability. Am J Respir Cell Mol Biol 2012; 47:445-53. [PMID: 22582175 DOI: 10.1165/rcmb.2011-0332oc] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Antibiotics-induced release of the pore-forming virulence factor pneumolysin (PLY) in patients with pneumococcal pneumonia results in its presence days after lungs are sterile and is a major factor responsible for the induction of permeability edema. Here we sought to identify major mechanisms mediating PLY-induced endothelial dysfunction. We evaluated PLY-induced endothelial hyperpermeability in human lung microvascular endothelial cells (HL-MVECs) and human lung pulmonary artery endothelial cells in vitro and in mice instilled intratracheally with PLY. PLY increases permeability in endothelial monolayers by reducing stable and dynamic microtubule content and modulating VE-cadherin expression. These events, dependent upon an increased calcium influx, are preceded by protein kinase C (PKC)-α activation, perturbation of the RhoA/Rac1 balance, and an increase in myosin light chain phosphorylation. At later time points, PLY treatment increases the expression and activity of arginase in HL-MVECs. Arginase inhibition abrogates and suppresses PLY-induced endothelial barrier dysfunction by restoring NO generation. Consequently, a specific PKC-α inhibitor and the TNF-derived tonoplast intrinsic protein peptide, which blunts PLY-induced PKC-α activation, are able to prevent activation of arginase in HL-MVECs and to reduce PLY-induced endothelial hyperpermeability in mice. Arginase I (AI)(+/-)/arginase II (AII)(-/-) C57BL/6 mice, displaying a significantly reduced arginase I expression in the lungs, are significantly less sensitive to PLY-induced capillary leak than their wild-type or AI(+/+)/AII(-/-) counterparts, indicating an important role for arginase I in PLY-induced endothelial hyperpermeability. These results identify PKC-α and arginase I as potential upstream and downstream therapeutic targets in PLY-induced pulmonary endothelial dysfunction.
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Affiliation(s)
- Rudolf Lucas
- Vascular Biology Center and Dept. of Pharmacology and Toxicology, Georgia Health Sciences University, 1459 Laney-Walker Blvd., Augusta, GA 30912-2500, USA.
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