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Derscheid RJ, Ackermann MR. Perinatal lamb model of respiratory syncytial virus (RSV) infection. Viruses 2012; 4:2359-78. [PMID: 23202468 PMCID: PMC3497056 DOI: 10.3390/v4102359] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 10/17/2012] [Accepted: 10/18/2012] [Indexed: 12/13/2022] Open
Abstract
Respiratory syncytial virus (RSV) is the most frequent cause of bronchiolitis in infants and children worldwide. Many animal models are used to study RSV, but most studies investigate disease in adult animals which does not address the unique physiology and immunology that makes infants more susceptible. The perinatal (preterm and term) lamb is a useful model of infant RSV disease as lambs have similar pulmonary structure including airway branching, Clara and type II cells, submucosal glands and Duox/lactoperoxidase (LPO) oxidative system, and prenatal alveologenesis. Lambs can be born preterm (90% gestation) and survive for experimentation although both preterm and term lambs are susceptible to ovine, bovine and human strains of RSV and develop clinical symptoms including fever, tachypnea, and malaise as well as mild to moderate gross and histologic lesions including bronchiolitis with epithelial injury, neutrophil infiltration and syncytial cell formation. RSV disease in preterm lambs is more severe than in term lambs; disease is progressively less in adults and age-dependent susceptibility is a feature similar to humans. Innate and adaptive immune responses by perinatal lambs closely parallel those of infants. The model is used to test therapeutic regimens, risk factors such as maternal ethanol consumption, and formalin inactivated RSV vaccines.
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Affiliation(s)
- Rachel J Derscheid
- Department of Veterinary Pathology, 2738 College of Veterinary Medicine, Iowa State University, Ames, Iowa 50011, USA.
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52
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Chandler JD, Day BJ. Thiocyanate: a potentially useful therapeutic agent with host defense and antioxidant properties. Biochem Pharmacol 2012; 84:1381-7. [PMID: 22968041 DOI: 10.1016/j.bcp.2012.07.029] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 07/26/2012] [Accepted: 07/26/2012] [Indexed: 12/15/2022]
Abstract
Thiocyanate (SCN) functions in host defense as part of the secreted lactoperoxidase (LPO) microbicidal pathway. SCN is the preferred substrate for LPO-driven catalytic reduction of hydrogen peroxide (H(2)O(2)) forming hypothiocyanous acid (HOSCN). HOSCN is selectively generated by many peroxidase enzymes that can utilize SCN including: eosinophil peroxidase (EPO), gastric peroxidase (GPO), myeloperoxidase (MPO), salivary peroxidase (SPO), and thyroid peroxidase (TPO). These enzymes generate HOSCN through a two-electron halogenation reaction. HOSCN is a potent microbicidal agent that kills or nullifies invading pathogens but is better tolerated by host tissue. Some controversy exists as to whether physiologic levels of HOSCN are non-toxic to host tissue, but the disagreement appears to be based on results of enzymatic generation (yielding moderate steady-state exposure) versus direct high level acute exposure in mammalian cell lines. This apparent duality is also true of other endogenous oxidants such as hydrogen peroxide and relates to the difference between physiologically relevant oxidant production versus supra-physiologic bolus dosing approaches. SCN has antioxidant properties that include the ability to protect cells against oxidizing agents such as hypochlorous acid (HOCl) and repair protein chloramines. SCN is an important endogenous molecule that has the potential to interact in complex and elegant ways with its host environment and foreign organisms. SCN's diverse properties as both host defense and antioxidant agent make it a potentially useful therapeutic.
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Affiliation(s)
- Joshua D Chandler
- Department of Medicine, National Jewish Health, Denver, CO 80206, United States
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53
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Xu C, Linderholm A, Grasberger H, Harper RW. Dual oxidase 2 bidirectional promoter polymorphisms confer differential immune responses in airway epithelia. Am J Respir Cell Mol Biol 2012; 47:484-90. [PMID: 22592922 DOI: 10.1165/rcmb.2012-0037oc] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The dual oxidase enzymes, DUOX, localized to the respiratory tract epithelium, are important components of innate host defense against bacteria and virus. However, little is known regarding the regulation of DUOX transcription. To better understand DUOX2-mediated mechanisms of antiviral host defense in the airway epithelium, we designed a bidirectional promoter luciferase reporter system to identify important cis-regulatory regions in the human DUOX2/DUOXA2 promoter. In this report, we demonstrate that the genomic region between the translation start sites of DUOX2 and DUOXA2 functions as a bidirectional promoter in human airway tissue. We also identified key regulatory regions on the DUOX2/DUOXA2 promoter that were necessary for both bidirectional and unidirectional transcriptional activity. Importantly, we discovered two functionally important single-nucleotide polymorphisms (SNPs) within the promoter that differentially regulated DUOX2/DUOXA2 transcription in response to exogenous double-stranded DNA. One of these SNPs, rs269855 (enriched in people of African descent), conferred the highest level of DUOX2 promoter activity. The clinical sequelae for individuals who carry this polymorphism remain to be determined.
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Affiliation(s)
- Changhong Xu
- Center for Comparative Respiratory Biology and Medicine, Division of Pulmonary and Critical Care Medicine, University of California at Davis, Davis, CA 95616, USA
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Alexander DB, Iigo M, Yamauchi K, Suzui M, Tsuda H. Lactoferrin: an alternative view of its role in human biological fluids. Biochem Cell Biol 2012; 90:279-306. [PMID: 22553915 DOI: 10.1139/o2012-013] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Lactoferrin is a major component of biologically important mucosal fluids and of the specific granules of neutrophils. Understanding its biological function is essential for understanding neutrophil- and mucosal-mediated immunity. In this review, we reevaluate the in vivo functions of human lactoferrin (hLF) emphasizing in vivo studies and in vitro studies performed in biologically relevant fluids. We discuss the evidence in the literature that supports (or does not support) proposed roles for hLF in mucosal immunity and in neutrophil function. We argue that the current literature supports a microbiostatic role, but not a microbicidal role, for hLF in vivo. The literature also supports a role for hLF in inhibiting colonization and infection of epithelial surfaces by microorganisms and in protecting tissues from neutrophil-mediated damage. Using this information, we briefly discuss hLF in the context of the complex biological fluids in which it is found.
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Affiliation(s)
- David B Alexander
- Laboratory of Nanotoxicology Project, Nagoya City University, 3-1 Tanabedohri, Mizuho-ku, Nagoya 467-8603, Japan.
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55
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Pattison DI, Davies MJ, Hawkins CL. Reactions and reactivity of myeloperoxidase-derived oxidants: Differential biological effects of hypochlorous and hypothiocyanous acids. Free Radic Res 2012; 46:975-95. [DOI: 10.3109/10715762.2012.667566] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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56
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Reszka KJ, Xiong Y, Sallans L, Pasula R, Olakanmi O, Hassett DJ, Britigan BE. Inactivation of the potent Pseudomonas aeruginosa cytotoxin pyocyanin by airway peroxidases and nitrite. Am J Physiol Lung Cell Mol Physiol 2012; 302:L1044-56. [PMID: 22345574 DOI: 10.1152/ajplung.00172.2011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pyocyanin (1-hydroxy-N-methylphenazine, PCN) is a cytotoxic pigment and virulence factor secreted by the human bacterial pathogen, Pseudomonas aeruginosa. Here, we report that exposure of PCN to airway peroxidases, hydrogen peroxide (H(2)O(2)), and NaNO(2) generates unique mononitrated PCN metabolites (N-PCN) as revealed by HPLC/mass spectrometry analyses. N-PCN, in contrast to PCN, was devoid of antibiotic activity and failed to kill Escherichia coli and Staphylococcus aureus. Furthermore, in contrast to PCN, intratracheal instillation of N-PCN into murine lungs failed to induce a significant inflammatory response. Surprisingly, at a pH of ∼7, N-PCN was more reactive than PCN with respect to NADH oxidation but resulted in a similar magnitude of superoxide production as detected by electron paramagnetic resonance and spin trapping experiments. When incubated with Escherichia coli or lung A549 cells, PCN and N-PCN both led to superoxide formation, but lesser amounts were detected with N-PCN. Our results demonstrate that PCN that has been nitrated by peroxidase/H(2)O(2)/NO(2)(-) systems possesses less cytotoxic/proinflammatory activity than native PCN. Yield of N-PCN was decreased by the presence of the competing physiological peroxidase substrates (thiocyonate) SCN(-) (myeloperoxidase, MPO, and lactoperoxidase, LPO) and Cl(-) (MPO), which with Cl(-) yielded chlorinated PCNs. These reaction products also showed decreased proinflammatory ability when instilled into the lungs of mice. These observations add important insights into the complexity of the pathogenesis of lung injury associated with Pseudomonas aeruginosa infections and provide additional rationale for exploring the efficacy of NO(2)(-) in the therapy of chronic Pseudomonas aeruginosa airway infection in cystic fibrosis.
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Ganesan S, Sajjan US. Host evasion by Burkholderia cenocepacia. Front Cell Infect Microbiol 2012; 1:25. [PMID: 22919590 PMCID: PMC3417383 DOI: 10.3389/fcimb.2011.00025] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 12/22/2011] [Indexed: 11/13/2022] Open
Abstract
Burkholderia cenocepacia is an opportunistic respiratory pathogen of individuals with cystic fibrosis (CF). Some strains of B. cenocepacia are highly transmissible and resistant to almost all antibiotics. Approximately one-third of B. cenocepacia infected CF patients go on to develop fatal "cepacia syndrome." During the last two decades, substantial progress has been made with regards to evasion of host innate defense mechanisms by B. cenocepacia. Almost all strains of B. cenocepacia have the capacity to survive and replicate intracellularly in both airway epithelial cells and macrophages, which are primary sentinels of the lung and play a pivotal role in clearance of infecting bacteria. Those strains of B. cenocepacia, which express both cable pili and the associated 22 kDa adhesin are also capable of transmigrating across airway epithelium and persist in mouse models of infection. In this review, we will discuss how this type of interaction between B. cenocepacia and host may lead to persistence of bacteria as well as lung inflammation in CF patients.
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Affiliation(s)
- Shyamala Ganesan
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, USA
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59
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Souza CEA, Maitra D, Saed GM, Diamond MP, Moura AA, Pennathur S, Abu-Soud HM. Hypochlorous acid-induced heme degradation from lactoperoxidase as a novel mechanism of free iron release and tissue injury in inflammatory diseases. PLoS One 2011; 6:e27641. [PMID: 22132121 PMCID: PMC3222650 DOI: 10.1371/journal.pone.0027641] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 10/21/2011] [Indexed: 12/02/2022] Open
Abstract
Lactoperoxidase (LPO) is the major consumer of hydrogen peroxide (H2O2) in the airways through its ability to oxidize thiocyanate (SCN−) to produce hypothiocyanous acid, an antimicrobial agent. In nasal inflammatory diseases, such as cystic fibrosis, both LPO and myeloperoxidase (MPO), another mammalian peroxidase secreted by neutrophils, are known to co-localize. The aim of this study was to assess the interaction of LPO and hypochlorous acid (HOCl), the final product of MPO. Our rapid kinetic measurements revealed that HOCl binds rapidly and reversibly to LPO-Fe(III) to form the LPO-Fe(III)-OCl complex, which in turn decayed irreversibly to LPO Compound II through the formation of Compound I. The decay rate constant of Compound II decreased with increasing HOCl concentration with an inflection point at 100 µM HOCl, after which the decay rate increased. This point of inflection is the critical concentration of HOCl beyond which HOCl switches its role, from mediating destabilization of LPO Compound II to LPO heme destruction. Lactoperoxidase heme destruction was associated with protein aggregation, free iron release, and formation of a number of fluorescent heme degradation products. Similar results were obtained when LPO-Fe(II)-O2, Compound III, was exposed to HOCl. Heme destruction can be partially or completely prevented in the presence of SCN−. On the basis of the present results we concluded that a complex bi-directional relationship exists between LPO activity and HOCl levels at sites of inflammation; LPO serve as a catalytic sink for HOCl, while HOCl serves to modulate LPO catalytic activity, bioavailability, and function.
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Affiliation(s)
- Carlos Eduardo A. Souza
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Dhiman Maitra
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Ghassan M. Saed
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Michael P. Diamond
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | | | - Subramaniam Pennathur
- Division of Nephrology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Husam M. Abu-Soud
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- * E-mail:
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Abstract
Hypothiocyanous acid (HOSCN) is produced in biological systems by the peroxidase-catalyzed reaction of thiocyanate (SCN(-)) with H(2)O(2). This oxidant plays an important role in the human immune system, owing to its potent bacteriostatic properties. Significant amounts of HOSCN are also formed by immune cells under inflammatory conditions, yet the reactivity of this oxidant with host tissue is poorly characterized. Traditionally, HOSCN has been viewed as a mild oxidant, which is innocuous to mammalian cells. Indeed, recent studies show that the presence of SCN(-) in airways has a protective function, by preventing the formation of other, more damaging, inflammatory oxidants. However, there is an increasing body of evidence that challenges this dogma, showing that the selectivity of HOSCN for specific thiol-containing cellular targets results in the initiation of significant cellular damage. This propensity to induce cellular dysfunction is gaining considerable interest, particularly in the cardiovascular field, as smokers have elevated plasma SCN(-), the precursor for HOSCN. This review will outline the beneficial and detrimental aspects of HOSCN formation in biological systems.
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Affiliation(s)
- Tessa J Barrett
- Inflammation Group, The Heart Research Institute , 7 Eliza Street, Newtown, Sydney, NSW 2042, Australia
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61
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Ghouleh IA, Khoo NK, Knaus UG, Griendling KK, Touyz RM, Thannickal VJ, Barchowsky A, Nauseef WM, Kelley EE, Bauer PM, Darley-Usmar V, Shiva S, Cifuentes-Pagano E, Freeman BA, Gladwin MT, Pagano PJ. Oxidases and peroxidases in cardiovascular and lung disease: new concepts in reactive oxygen species signaling. Free Radic Biol Med 2011; 51:1271-88. [PMID: 21722728 PMCID: PMC3205968 DOI: 10.1016/j.freeradbiomed.2011.06.011] [Citation(s) in RCA: 187] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 06/06/2011] [Accepted: 06/07/2011] [Indexed: 12/17/2022]
Abstract
Reactive oxygen species (ROS) are involved in numerous physiological and pathophysiological responses. Increasing evidence implicates ROS as signaling molecules involved in the propagation of cellular pathways. The NADPH oxidase (Nox) family of enzymes is a major source of ROS in the cell and has been related to the progression of many diseases and even environmental toxicity. The complexity of this family's effects on cellular processes stems from the fact that there are seven members, each with unique tissue distribution, cellular localization, and expression. Nox proteins also differ in activation mechanisms and the major ROS detected as their product. To add to this complexity, mounting evidence suggests that other cellular oxidases or their products may be involved in Nox regulation. The overall redox and metabolic status of the cell, specifically the mitochondria, also has implications on ROS signaling. Signaling of such molecules as electrophilic fatty acids has an impact on many redox-sensitive pathologies and thus, as anti-inflammatory molecules, contributes to the complexity of ROS regulation. This review is based on the proceedings of a recent international Oxidase Signaling Symposium at the University of Pittsburgh's Vascular Medicine Institute and Department of Pharmacology and Chemical Biology and encompasses further interaction and discussion among the presenters.
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Affiliation(s)
- Imad Al Ghouleh
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
| | - Nicholas K.H. Khoo
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA
| | - Ulla G. Knaus
- Conway Institute, University College Dublin, Dublin, Ireland
| | - Kathy K. Griendling
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, GA
| | - Rhian M. Touyz
- Ottawa Hospital Research Institute, Univ of Ottawa, Ottawa, Ontario, Canada
| | - Victor J. Thannickal
- Pulmonary, Allergy & Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Aaron Barchowsky
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA
| | - William M. Nauseef
- Inflammation Program, Department of Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa
- Department of Microbiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa
- Veterans Administration Medical Center, Iowa City, IA
| | - Eric E. Kelley
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
- Department of Anesthesiology, University of Pittsburgh, Pittsburgh, PA
| | - Phillip M. Bauer
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Victor Darley-Usmar
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Sruti Shiva
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
| | - Eugenia Cifuentes-Pagano
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
| | - Bruce A. Freeman
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA
| | - Mark T. Gladwin
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
- Department of Pulmonary, Allergy & Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Patrick J. Pagano
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
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Venerando A, Pagano MA, Tosoni K, Meggio F, Cassidy D, Stobbart M, Pinna LA, Mehta A. Understanding protein kinase CK2 mis-regulation upon F508del CFTR expression. Naunyn Schmiedebergs Arch Pharmacol 2011; 384:473-88. [PMID: 21607646 PMCID: PMC3208816 DOI: 10.1007/s00210-011-0650-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 04/28/2011] [Indexed: 12/17/2022]
Abstract
We review areas of overlap between nucleoside diphosphate kinase (NDPK; nm23) and two proteins manifesting an equivalent diversity of action, each with many thousands of publications. The first is a constitutively active protein kinase, CK2 (formerly casein kinase 2), that includes NDPK amongst its hundreds of targets. The second is an enigmatic member of the ATP-binding cassette (ABC) family of membrane pumps that normally hydrolyse ATP to transport substrates. Yet our unusual family member (ABCC7) is not a pump but, uniquely, acts as a regulated anion channel. ABCC7 is the cystic fibrosis transmembrane conductance regulator (CFTR), and we discuss the highly prevalent CFTR mutation (F508del CFTR) in terms of the uncertainties surrounding the molecular basis of cystic fibrosis that cloud approaches to corrective therapy. Using lysates from cells stably expressing either wild-type or F508del CFTR, incubated with the CK2 substrate GTP, we show that the phosphoproteome of F508del CFTR-expressing cells both differs from wild-type CFTR-expressing cells and is significantly enhanced in intensity by ∼1.5-fold (p < 0.05, paired t test with Bonferroni correction, n = 4). Phosphorylation is about 50% attenuated with a specific CK2 inhibitor. We propose that a new function may exist for the CFTR region that is commonly mutated, noting that its sequence (PGTIKENIIF508GVSYDEYRYR) is not only highly conserved within the C sub-family of ABC proteins but also a related sequence is found in NDPK. We conclude that a latent path may exist between mutation of this conserved sequence, CK2 hyperactivity and disease pathogenesis that might also explain the heterozygote advantage for the common F508del CFTR mutant .
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Affiliation(s)
- Andrea Venerando
- Department of Biological Chemistry and CNR Institute of Neurosciences, University of Padova, viale G. Colombo 3, 35131, Padua, Italy
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63
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Petrov M, Cwiklik L, Jungwirth P. Interactions of molecular ions with model phospholipid membranes. ACTA ACUST UNITED AC 2011. [DOI: 10.1135/cccc2011026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The affinities of a series of biologically relevant ions for a hydrated phospholipid membrane were investigated using molecular dynamics simulation. Interactions of molecular ions, such as guanidinium, tetramethylammonium, and thiocyanate with the bilayer were computationally characterized for the first time. Simulations reveal strong ion specificity. On one hand, ions like guanidinium and thiocyanate adsorb relatively strongly to the headgroup region of the membrane. On the other hand, potassium or chloride interact very weakly with the phospholipids and merely act as neutralizing counterions. Calculations also show that these ions affect differently biophysical properties of the membrane, such as lipid diffusion, headgroup hydration and tilt angle.
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64
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Lorentzen D, Durairaj L, Pezzulo AA, Nakano Y, Launspach J, Stoltz DA, Zamba G, McCray PB, Zabner J, Welsh MJ, Nauseef WM, Bánfi B. Concentration of the antibacterial precursor thiocyanate in cystic fibrosis airway secretions. Free Radic Biol Med 2011; 50:1144-50. [PMID: 21334431 PMCID: PMC3070840 DOI: 10.1016/j.freeradbiomed.2011.02.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 01/31/2011] [Accepted: 02/11/2011] [Indexed: 10/18/2022]
Abstract
A recently discovered enzyme system produces antibacterial hypothiocyanite (OSCN(-)) in the airway lumen by oxidizing the secreted precursor thiocyanate (SCN(-)). Airway epithelial cultures have been shown to secrete SCN(-) in a CFTR-dependent manner. Thus, reduced SCN(-) availability in the airway might contribute to the pathogenesis of cystic fibrosis (CF), a disease caused by mutations in the CFTR gene and characterized by an airway host defense defect. We tested this hypothesis by analyzing the SCN(-) concentration in the nasal airway surface liquid (ASL) of CF patients and non-CF subjects and in the tracheobronchial ASL of CFTR-ΔF508 homozygous pigs and control littermates. In the nasal ASL, the SCN(-) concentration was ~30-fold higher than in serum independent of the CFTR mutation status of the human subject. In the tracheobronchial ASL of CF pigs, the SCN(-) concentration was somewhat reduced. Among human subjects, SCN(-) concentrations in the ASL varied from person to person independent of CFTR expression, and CF patients with high SCN(-) levels had better lung function than those with low SCN(-) levels. Thus, although CFTR can contribute to SCN(-) transport, it is not indispensable for the high SCN(-) concentration in ASL. The correlation between lung function and SCN(-) concentration in CF patients may reflect a beneficial role for SCN(-).
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Affiliation(s)
- Daniel Lorentzen
- Inflammation Program, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Immunology Program, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
| | - Lakshmi Durairaj
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
| | - Alejandro A. Pezzulo
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
| | - Yoko Nakano
- Inflammation Program, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
| | - Janice Launspach
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
| | - David A. Stoltz
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
| | - Gideon Zamba
- Department of Biostatistics, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
| | - Paul B. McCray
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
| | - Joseph Zabner
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
| | - Michael J. Welsh
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Howard Hughes Medical Institute, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
| | - William M. Nauseef
- Inflammation Program, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Immunology Program, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Dept. of Veterans Affairs, Iowa City VA Medical Center, Iowa City, Iowa 52242, USA
| | - Botond Bánfi
- Inflammation Program, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Department of Otolaryngology – Head and Neck Surgery, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Correspondence to: Botond Bánfi, M.D. Ph.D., Inflammation Program, University of Iowa Carver College of Medicine, 2501 Crosspark Road, Coralville, IA 52241, USA, , tel.: 1-319-335-4228, fax.: 1-319-335-4194
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65
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Fischer AJ, Lennemann NJ, Krishnamurthy S, Pócza P, Durairaj L, Launspach JL, Rhein BA, Wohlford-Lenane C, Lorentzen D, Bánfi B, McCray PB. Enhancement of respiratory mucosal antiviral defenses by the oxidation of iodide. Am J Respir Cell Mol Biol 2011; 45:874-81. [PMID: 21441383 DOI: 10.1165/rcmb.2010-0329oc] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Recent reports postulate that the dual oxidase (DUOX) proteins function as part of a multicomponent oxidative pathway used by the respiratory mucosa to kill bacteria. The other components include epithelial ion transporters, which mediate the secretion of the oxidizable anion thiocyanate (SCN(-)) into airway surface liquid, and lactoperoxidase (LPO), which catalyzes the H(2)O(2)-dependent oxidation of the pseudohalide SCN(-) to yield the antimicrobial molecule hypothiocyanite (OSCN(-)). We hypothesized that this oxidative host defense system is also active against respiratory viruses. We evaluated the activity of oxidized LPO substrates against encapsidated and enveloped viruses. When tested for antiviral properties, the LPO-dependent production of OSCN(-) did not inactivate adenovirus or respiratory syncytial virus (RSV). However, substituting SCN(-) with the alternative LPO substrate iodide (I(-)) resulted in a marked reduction of both adenovirus transduction and RSV titer. Importantly, well-differentiated primary airway epithelia generated sufficient H(2)O(2) to inactivate adenovirus or RSV when LPO and I(-) were supplied. The administration of a single dose of 130 mg of oral potassium iodide to human subjects increased serum I(-) concentrations, and resulted in the accumulation of I(-) in upper airway secretions. These results suggest that the LPO/I(-)/H(2)O(2) system can contribute to airway antiviral defenses. Furthermore, the delivery of I(-) to the airway mucosa may augment innate antiviral immunity.
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Affiliation(s)
- Anthony J Fischer
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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66
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van der Vliet A. Nox enzymes in allergic airway inflammation. Biochim Biophys Acta Gen Subj 2011; 1810:1035-44. [PMID: 21397663 DOI: 10.1016/j.bbagen.2011.03.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 02/28/2011] [Accepted: 03/03/2011] [Indexed: 12/30/2022]
Abstract
Chronic airway diseases such as asthma are linked to oxidative environmental factors and are associated with increased production of reactive oxygen species (ROS). Therefore, it is commonly assumed that oxidative stress is an important contributing factor to asthma disease pathogenesis and that antioxidant strategies may be useful in the treatment of asthma. A primary source of ROS production in biological systems is NADPH oxidase (NOX), originally associated primarily with inflammatory cells but currently widely appreciated as an important enzyme system in many cell types, with a wide array of functional properties ranging from antimicrobial host defense to immune regulation and cell proliferation, differentiation and apoptosis. Given the complex nature of asthma disease pathology, involving many lung cell types that all express NOX homologs, it is not surprising that the contributions of NOX-derived ROS to various aspects of asthma development and progression are highly diverse and multifactorial. It is the purpose of the present review to summarize the current knowledge with respect to the functional aspects of NOX enzymes in various pulmonary cell types, and to discuss their potential importance in asthma pathogenesis. This article is part of a Special Issue entitled: Biochemistry of Asthma.
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Affiliation(s)
- Albert van der Vliet
- Department of Pathology, Vermont Lung Cancer, College of Medicine, Universitu of Vermont, Burlington, VT 05405, USA.
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67
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Wine JJ, Joo NS, Choi JY, Cho HJ, Krouse ME, Wu JV, Khansaheb M, Irokawa T, Ianowski J, Hanrahan JW, Cuthbert AW, Tran KV. Measurement of fluid secretion from intact airway submucosal glands. Methods Mol Biol 2011; 742:93-112. [PMID: 21547728 DOI: 10.1007/978-1-61779-120-8_6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Human airways are kept sterile by a mucosal innate defense system that includes mucus secretion. Mucus is secreted in healthy upper airways primarily by submucosal glands and consists of defense molecules mixed with mucins, electrolytes, and water and is also a major component of sputum. Mucus traps pathogens and mechanically removes them via mucociliary clearance while inhibiting their growth via molecular (e.g., lysozyme) and cellular (e.g., neutrophils, macrophages) defenses. Fluid secretion rates of single glands in response to various mediators can be measured by trapping the primary gland mucus secretions in an oil layer, where they form spherical bubbles that can be optically measured at any desired interval to provide detailed temporal analysis of secretion rates. The composition and properties of the mucus (e.g., solids, viscosity, pH) can also be determined. These methods have now been applied to mice, ferrets, cats, pigs, sheep, and humans, with a main goal of comparing gland secretion in control and CFTR-deficient humans and animals.
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Affiliation(s)
- Jeffrey J Wine
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, CA 94305-2130, USA.
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68
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Donkó A, Ruisanchez E, Orient A, Enyedi B, Kapui R, Péterfi Z, de Deken X, Benyó Z, Geiszt M. Urothelial cells produce hydrogen peroxide through the activation of Duox1. Free Radic Biol Med 2010; 49:2040-8. [PMID: 21146788 DOI: 10.1016/j.freeradbiomed.2010.09.027] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 09/08/2010] [Accepted: 09/27/2010] [Indexed: 02/07/2023]
Abstract
Hydrogen peroxide (H(2)O(2)) has important messenger and effector functions in the plant and animal kingdom. Phagocytes produce H(2)O(2) to kill pathogens, and epithelial cells of large airways have also been reported to produce H(2)O(2) for signaling and host defense purposes. In this report, we show for the first time that urothelial cells produce H(2)O(2) in response to a calcium signal. Using a gene-deficient mouse model we also demonstrate that H(2)O(2) is produced by the NADPH oxidase Duox1, which is expressed in the mouse urothelium. In contrast, we found no evidence for the expression of lactoperoxidase, an enzyme that has been shown to cooperate with Duox enzymes. We also found that specific activation of TRPV4 calcium channels elicits a calcium signal and stimulates H(2)O(2) production in urothelial cells. Furthermore, we detected altered pressure responses in the urinary bladders of Duox1 knockout animals. Our results raise the possibility that mechanosensing in epithelial cells involves calcium-dependent H(2)O(2) production similar to that observed in plants.
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Affiliation(s)
- Agnes Donkó
- Department of Physiology, Semmelweis University, Budapest, Hungary
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69
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Gould NS, Gauthier S, Kariya CT, Min E, Huang J, Brian DJ. Hypertonic saline increases lung epithelial lining fluid glutathione and thiocyanate: two protective CFTR-dependent thiols against oxidative injury. Respir Res 2010; 11:119. [PMID: 20799947 PMCID: PMC2936384 DOI: 10.1186/1465-9921-11-119] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 08/27/2010] [Indexed: 11/10/2022] Open
Abstract
Background Cystic fibrosis is a debilitating lung disease due to mutations in the cystic fibrosis transmembrane conductance regulator protein (CFTR) and is associated with chronic infections resulting in elevated myeloperoxidase activity and generation of hypochlorous acid (HOCl). CFTR mutations lead to decreased levels of glutathione (GSH) and thiocyanate (SCN) in the epithelial lining fluid (ELF). Hypertonic saline is used to improve lung function however the mechanism is uncertain. Methods In the present study, the effect of GSH and SCN on HOCl-mediated cell injury and their changes in the ELF after hypertonic saline nebulization in wild type (WT) and CFTR KO mice was examined. CFTR sufficient and deficient lung cells were assessed for GSH, SCN and corresponding sensitivity towards HOCl-mediated injury, in vitro. Results CFTR (-) cells had lower extracellular levels of both GSH and SCN and were more sensitive to HOCl-mediated injury. In vivo, hypertonic saline increased ELF GSH in the WT and to a lesser extent in the CFTR KO mice but only SCN in the WT ELF. Finally, potential protective effects of GSH and SCN at concentrations found in the ELF against HOCl toxicity were examined in vitro. Conclusions While the concentrations of GSH and SCN associated with the WT ELF protect against HOCl toxicity, those found in the CFTR KO mice were less sufficient to inhibit cell injury. These data suggests that CFTR has important roles in exporting GSH and SCN which are protective against oxidants and that hypertonic saline treatment may have beneficial effects by increasing their levels in the lung.
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Affiliation(s)
- Neal S Gould
- Department of Medicine, University of Colorado Denver, Aurora, CO 80045 USA
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70
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Joo NS, Cho HJ, Khansaheb M, Wine JJ. Hyposecretion of fluid from tracheal submucosal glands of CFTR-deficient pigs. J Clin Invest 2010; 120:3161-6. [PMID: 20739758 DOI: 10.1172/jci43466] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Accepted: 06/01/2010] [Indexed: 11/17/2022] Open
Abstract
Cystic fibrosis (CF) results from mutations that disrupt CF transmembrane conductance regulator (CFTR), an anion channel found mainly in apical membranes of epithelial cells. CF leads to chronic infection of the airways with normally innocuous bacteria and fungi. Hypotheses to explain the pathophysiology of CF airways have been difficult to test because mouse models of CF do not develop human-like airway disease. The recent production of pigs lacking CFTR and pigs expressing the most common CF-causing CFTR mutant, DeltaF508, provide another model that might help clarify the pathophysiology of CF airway disease. Here, we studied individual submucosal glands from 1-day-old piglets in situ in explanted tracheas, using optical methods to monitor mucus secretion rates from multiple glands in parallel. Secretion rates from control piglets (WT and CFTR+/-) and piglets with CF-like disease (CFTR-/- and CFTR-/DeltaF508) were measured under 5 conditions: unstimulated (to determine basal secretion), stimulated with forskolin, stimulated with carbachol, stimulated with substance P, and, as a test for synergy, stimulated with forskolin and a low concentration of carbachol. Glands from piglets with CF-like disease responded qualitatively to all agonists like glands from human patients with CF, producing virtually no fluid in response to stimulation with forskolin and substantially less in response to all other agonists except carbachol. These data are a step toward determining whether gland secretory defects contribute to CF airway disease.
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Affiliation(s)
- Nam Soo Joo
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California 94305-2130, USA
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71
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Bae YS, Choi MK, Lee WJ. Dual oxidase in mucosal immunity and host-microbe homeostasis. Trends Immunol 2010; 31:278-87. [PMID: 20579935 DOI: 10.1016/j.it.2010.05.003] [Citation(s) in RCA: 159] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 04/29/2010] [Accepted: 05/03/2010] [Indexed: 01/25/2023]
Abstract
Mucosal epithelia are in direct contact with microbes, which range from beneficial symbionts to pathogens. Accordingly, hosts must have a conflicting strategy to combat pathogens efficiently while tolerating symbionts. Recent progress has revealed that dual oxidase (DUOX) plays a key role in mucosal immunity in organisms that range from flies to humans. Information from the genetic model of Drosophila has advanced our understanding of the regulatory mechanism of DUOX and its role in mucosal immunity. Further investigations of DUOX regulation in response to symbiotic or non-symbiotic bacteria and the in vivo consequences in host physiology will give a novel insight into the microbe-controlling system of the mucosa.
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Affiliation(s)
- Yun Soo Bae
- Division of Life and Pharmaceutical Science, Department of Life Science, Department of Bioinspired Science, Ewha Woman's University, Seoul 120-750, South Korea
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72
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Linderholm AL, Onitsuka J, Xu C, Chiu M, Lee WM, Harper RW. All-trans retinoic acid mediates DUOX2 expression and function in respiratory tract epithelium. Am J Physiol Lung Cell Mol Physiol 2010; 299:L215-21. [PMID: 20511343 DOI: 10.1152/ajplung.00015.2010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
DUOX1 and DUOX2 are members of the NADPH oxidase family that are specifically regulated to produce hydrogen peroxide in epithelia of the thyroid, gastrointestinal tract, and respiratory tract. The determinants of DUOX1 or DUOX2 expression in various tissues have not been established. Using respiratory tract epithelial cells as a model, we investigated changes in DUOX mRNA and protein expression during the first 10 days of differentiation. By comparing a respiratory tract cell line, HBE1, with primary tracheobronchial epithelial (TBE) cells, we determined that DUOX2 was significantly expressed only in cell conditions that included all-trans retinoic acid (ATRA). In HBE1 cells, DUOX2 mRNA increased 6-fold after ATRA treatment. Similarly, ATRA induced a 19-fold increase in DUOX2 mRNA expression in primary TBE cells with parallel increases in DUOX protein and DUOX-mediated H(2)O(2) production as well. In addition, DUOX2 induction by rhinovirus required the presence of ATRA. ATRA had no effect on DUOX1 expression for all the conditions studied. Our data indicate that for respiratory epithelial cells, ATRA is important in the regulation of DUOX2 expression, function, and rhinovirus-mediated DUOX2 inducibility.
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73
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Evans SE, Xu Y, Tuvim MJ, Dickey BF. Inducible innate resistance of lung epithelium to infection. Annu Rev Physiol 2010; 72:413-35. [PMID: 20148683 DOI: 10.1146/annurev-physiol-021909-135909] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Most studies of innate immunity have focused on leukocytes such as neutrophils, macrophages, and natural killer cells. However, epithelial cells play key roles in innate defenses that include providing a mechanical barrier to microbial entry, signaling to leukocytes, and directly killing pathogens. Importantly, all these defenses are highly inducible in response to the sensing of microbial and host products. In healthy lungs, the level of innate immune epithelial function is low at baseline. This is indicated by low levels of spontaneous microbial killing and cytokine release, reflecting low constitutive stimulation in the nearly sterile lower respiratory tract when mucociliary clearance mechanisms are functioning effectively. This contrasts with the colon, where bacteria are continuously present and epithelial cells are constitutively activated. Although the surface area of the lungs presents a large target for microbial invasion, activated lung epithelial cells that are closely apposed to deposited pathogens are ideally positioned for microbial killing.
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Affiliation(s)
- Scott E Evans
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
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74
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Abstract
Hypohalous acids (HOX), produced by peroxidase-catalysed reactions of halide and pseudohalide ions with H(2)O(2), play an important role in the human immune system. However, there is compelling evidence that these oxidants also mediate host tissue damage and contribute to the progression of a number of inflammatory diseases. Although it is well established that significant amounts of hypothiocyanous acid (HOSCN) are formed under physiological conditions, the reactions of this oxidant with host biological systems are relatively poorly characterized. It is generally accepted that HOSCN is a mild oxidant that reacts selectively with thiols. However, it is becoming increasingly recognized that this selectivity can result in the induction of significant cellular damage, which may contribute to disease. This review will outline the formation and reactivity of HOSCN and the role of this oxidant in biological systems.
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Affiliation(s)
- Clare L Hawkins
- Inflammation Group, The Heart Research Institute, 7 Eliza Street, Newtown, Sydney, NSW 2042, Australia.
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75
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Xu Y, Szép S, Lu Z. The antioxidant role of thiocyanate in the pathogenesis of cystic fibrosis and other inflammation-related diseases. Proc Natl Acad Sci U S A 2009; 106:20515-9. [PMID: 19918082 PMCID: PMC2777967 DOI: 10.1073/pnas.0911412106] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Indexed: 01/06/2023] Open
Abstract
Cystic fibrosis (CF) is a pleiotropic disease, originating from mutations in the CF transmembrane conductance regulator (CFTR). Lung injuries inflicted by recurring infection and excessive inflammation cause approximately 90% of the morbidity and mortality of CF patients. It remains unclear how CFTR mutations lead to lung illness. Although commonly known as a Cl(-) channel, CFTR also conducts thiocyanate (SCN(-)) ions, important because, in several ways, they can limit potentially harmful accumulations of hydrogen peroxide (H(2)O(2)) and hypochlorite (OCl(-)). First, lactoperoxidase (LPO) in the airways catalyzes oxidation of SCN(-) to tissue-innocuous hypothiocyanite (OSCN(-)), while consuming H(2)O(2). Second, SCN(-) even at low concentrations competes effectively with Cl(-) for myeloperoxidase (MPO) (which is released by white blood cells), thus limiting OCl(-) production by the enzyme. Third, SCN(-) can rapidly reduce OCl(-) without catalysis. Here, we show that SCN(-) and LPO protect a lung cell line from injuries caused by H(2)O(2); and that SCN(-) protects from OCl(-) made by MPO. Of relevance to inflammation in other diseases, we find that in three other tested cell types (arterial endothelial cells, a neuronal cell line, and a pancreatic beta cell line) SCN(-) at concentrations of > or =100 microM greatly attenuates the cytotoxicity of MPO. Humans naturally derive SCN(-) from edible plants, and plasma SCN(-) levels of the general population vary from 10 to 140 microM. Our findings raise the possibility that insufficient levels of antioxidant SCN(-) provide inadequate protection from OCl(-), thus worsening inflammatory diseases, and predisposing humans to diseases linked to MPO activity, including atherosclerosis, neurodegeneration, and certain cancers.
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Affiliation(s)
- Yanping Xu
- Department of Physiology, Howard Hughes Medical Institute, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104
| | - Szilvia Szép
- Department of Physiology, Howard Hughes Medical Institute, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104
| | - Zhe Lu
- Department of Physiology, Howard Hughes Medical Institute, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104
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76
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Gattas MV, Forteza R, Fragoso MA, Fregien N, Salas P, Salathe M, Conner GE. Oxidative epithelial host defense is regulated by infectious and inflammatory stimuli. Free Radic Biol Med 2009; 47:1450-8. [PMID: 19703552 PMCID: PMC2767478 DOI: 10.1016/j.freeradbiomed.2009.08.017] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 08/05/2009] [Accepted: 08/19/2009] [Indexed: 12/15/2022]
Abstract
Epithelia express oxidative antimicrobial protection that uses lactoperoxidase (LPO), hydrogen peroxide (H(2)O(2)), and thiocyanate to generate the reactive hypothiocyanite. Duox1 and Duox2, found in epithelia, are hypothesized to provide H(2)O(2) for use by LPO. To investigate the regulation of oxidative LPO-mediated host defense by bacterial and inflammatory stimuli, LPO and Duox mRNA were followed in differentiated primary human airway epithelial cells challenged with Pseudomonas aeruginosa flagellin or IFN-gamma. Flagellin upregulated Duox2 mRNA 20-fold, but upregulated LPO mRNA only 2.5-fold. IFN-gamma increased Duox2 mRNA 127-fold and upregulated LPO mRNA 10-fold. DuoxA2, needed for Duox2 activity, was also upregulated by flagellin and IFN-gamma. Both stimuli increased H(2)O(2) synthesis and LPO-dependent killing of P. aeruginosa. Reduction of Duox1 by siRNA showed little effect on basal H(2)O(2) production, whereas Duox2 siRNA markedly reduced basal H(2)O(2) production and resulted in an 8-fold increase in Nox4 mRNA. In conclusion, large increases in Duox2-mediated H(2)O(2) production seem to be coordinated with increases in LPO mRNA and, without increased LPO, H(2)O(2) levels in airway secretion are expected to increase substantially. The data suggest that Duox2 is the major contributor to basal H(2)O(2) synthesis despite the presence of greater amounts of Duox1.
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Affiliation(s)
| | - Radia Forteza
- Department of Cell Biology and Anatomy, University of Miami, Miami, FL 33136 USA
| | - Miryam A. Fragoso
- Department of Cell Biology and Anatomy, University of Miami, Miami, FL 33136 USA
| | - Nevis Fregien
- Department of Cell Biology and Anatomy, University of Miami, Miami, FL 33136 USA
| | - Pedro Salas
- Department of Cell Biology and Anatomy, University of Miami, Miami, FL 33136 USA
| | - Matthias Salathe
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136 USA
| | - Gregory E. Conner
- Department of Cell Biology and Anatomy, University of Miami, Miami, FL 33136 USA
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Miller School of Medicine, University of Miami, Miami, FL 33136 USA
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77
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Abstract
The human lung produces considerable amounts of H(2)O(2). In the normal uninflamed epithelium of both the airways and the alveoli, mucosal release of H(2)O(2) is readily detected both in cell cultures in vitro and in the exhaled breath of humans. The dual oxidases DUOX1 and DUOX2 are the H(2)O(2)-producing isoforms of the NADPH oxidase family found in epithelial cells. The DUOXs are prominently expressed at the apical cell pole of ciliated cells in the airways and in type II cells of the alveoli. Recent studies focused on the functional consequences of H(2)O(2) release by DUOX into the lung lining fluid. In the airways, a major function of DUOX is to support lactoperoxidase (LPO) to generate bactericidal OSCN(-), and there are indications that the DUOX/LPO defense system is critically dependent on the function of the CFTR Cl(-) channel, which provides both SCN(-) (for LPO function) and HCO(3)(-) (for pH adjustment) to the airway surface liquid. Although DUOX is also functional in the alveolar epithelium, no comparable heme peroxidase is present in the alveolus, and thus DUOX-mediated H(2)O(2) release by alveolar cells may have other functions, such as cellular signaling.
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Affiliation(s)
- Horst Fischer
- Children's Hospital Oakland Research Institute, Oakland, California 94609, USA.
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78
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Lemma K, Ashby MT. Reactive Sulfur Species: Kinetics and Mechanism of the Reaction of Hypothiocyanous Acid with Cyanide To Give Dicyanosulfide in Aqueous Solution. Chem Res Toxicol 2009; 22:1622-8. [DOI: 10.1021/tx900212r] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kelemu Lemma
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019
| | - Michael T. Ashby
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019
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79
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Hypothiocyanous acid reactivity with low-molecular-mass and protein thiols: absolute rate constants and assessment of biological relevance. Biochem J 2009; 422:111-7. [DOI: 10.1042/bj20090276] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
MPO (myeloperoxidase) catalyses the oxidation of chloride, bromide and thiocyanate by H2O2 to HOCl (hypochlorous acid), HOBr (hypobromous acid) and HOSCN (hypothiocyanous acid, also know as cyanosulfenic acid) respectively. Specificity constants indicate that thiocyanate, SCN−, is a major substrate for MPO. HOSCN is also a major oxidant generated by other peroxidases including salivary, gastric and eosinophil peroxidases. Whereas HOCl and HOBr are powerful oxidizing agents, HOSCN appears to be a less reactive, but more thiol-specific oxidant. Although it is established that HOSCN selectively targets thiols, absolute kinetic data for the reactions of thiols with HOSCN are absent from the literature. This study shows for the first time that the reactions of HOSCN with low-molecular-mass thiol residues occur with rate constants in the range from 7.3×103 M−1·s−1 (for N-acetyl-cysteine at pH 7.4) to 7.7×106 M−1·s−1 (for 5-thio-2-nitrobenzoic acid at pH 6.0). An inverse relationship between the rate of reaction and the pKa of the thiol group was observed. The rates of reaction of HOSCN with thiol-containing proteins were also investigated for four proteins (creatine kinase, BSA, β-lactoglobulin and β-L-crystallins). The values obtained for cysteine residues on these proteins are in the range 1×104– 7×104 M−1·s−1. These second-order rate constants indicate that HOSCN is a major mediator of thiol oxidation in biological systems exposed to peroxidase/H2O2 systems at (patho)physiological concentrations of halide and SCN− ions, and that HOSCN may play an important role in inflammation-induced oxidative damage.
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80
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Donkó A, Orient A, Szabó PT, Németh G, Vántus T, Kéri G, Orfi L, Hunyady L, Buday L, Geiszt M. Detection of hydrogen peroxide by lactoperoxidase-mediated dityrosine formation. Free Radic Res 2009; 43:440-5. [PMID: 19340621 DOI: 10.1080/10715760902859069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The aim of this work was to study the dityrosine-forming activity of lactoperoxidase (LPO) and its potential application for measuring hydrogen peroxide (H2O2). It was observed that LPO was able to form dityrosine at low H2O2 concentrations. Since dityrosine concentration could be measured in a simple fluorimetric reaction, this activity of the enzyme was utilized for the measurement of H2O2 production in different systems. These experiments successfully measured the activity of NADPH oxidase 4 (Nox4) by this method. It was concluded that LPO-mediated dityrosine formation offers a simple way for H2O2 measurement.
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Affiliation(s)
- Agnes Donkó
- Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, Hungary
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81
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Redox warfare between airway epithelial cells and Pseudomonas: dual oxidase versus pyocyanin. Immunol Res 2009; 43:198-209. [PMID: 18979077 DOI: 10.1007/s12026-008-8071-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The importance of reactive oxygen species-dependent microbial killing by the phagocytic cell NADPH oxidase has been appreciated for some time, although only recently has an appreciation developed for the partnership of lactoperoxidase with related dual oxidases (Duox) within secretions of the airway surface layer. This system produces mild oxidants designed for extracellular killing that are effective against several airway pathogens, including Staphylococcus aureus, Burkholderia cepacia, and Pseudomonas aeruginosa. Establishment of chronic pseudomonas infections involves adaptations to resist oxidant-dependent killing by expression of a redox-active virulence factor, pyocyanin, that competitively inhibits epithelial Duox activity by consuming intracellular NADPH and producing superoxide, thereby inflicting oxidative stress on the host.
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82
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Sow FB, Gallup JM, Meyerholz DK, Ackermann MR. Gene profiling studies in the neonatal ovine lung show enhancing effects of VEGF on the immune response. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2009; 33:761-771. [PMID: 19189846 PMCID: PMC2791060 DOI: 10.1016/j.dci.2009.01.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Revised: 01/07/2009] [Accepted: 01/10/2009] [Indexed: 05/27/2023]
Abstract
Preterm and young neonates have an increased predisposition to respiratory distress syndrome (RDS) associated with an immature development of lung surfactant. Glucocorticoids (GCs) are the major immunomodulatory agents used to increase lung development and reduce the mortality and morbidity of preterm infants with RDS. However, their safety remains uncertain, and the precise mechanisms by which they improve lung function are unclear. In previous studies, we found that vascular endothelial growth factor (VEGF) enhances the innate immune response by respiratory epithelial cells, causes a monocytic infiltration into the lung, and reduces the severity of infection by respiratory syncytial virus (RSV), a respiratory pathogen known to affect preterm infants at a high prevalence. The purpose of this study is to measure the effects of VEGF administration on local immune responses in neonatal lambs, as the ovine lung is well suited for comparison to the human lung, due to similarities in alveolar development, immune responses, and RSV susceptibility. We hypothesized that VEGF induces the expression of genes necessary for host immune responses. We analyzed global gene expression profiles in the lungs of neonate lambs treated with VEGF by real-time qPCR. We report that VEGF induced the expression of chemokines (IL-8, RANTES, MCP-1), cytokines (IFN-gamma, IL-6, TNF-alpha, GMCSF), Toll-like receptor (TLR)-4, complement family members (C3, CFB, CFH) and collectins (SP-A, SP-D). These results suggest that VEGF can regulate local immune gene expression in vivo and should be further explored as a potential exogenous therapy for various lung diseases.
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Affiliation(s)
- Fatoumata B Sow
- Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
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Rada B, Lekstrom K, Damian S, Dupuy C, Leto TL. The Pseudomonas toxin pyocyanin inhibits the dual oxidase-based antimicrobial system as it imposes oxidative stress on airway epithelial cells. THE JOURNAL OF IMMUNOLOGY 2008; 181:4883-93. [PMID: 18802092 DOI: 10.4049/jimmunol.181.7.4883] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The dual oxidase-thiocyanate-lactoperoxidase (Duox/SCN(-)/LPO) system generates the microbicidal oxidant hypothiocyanite in the airway surface liquid by using LPO, thiocyanate, and Duox-derived hydrogen peroxide released from the apical surface of the airway epithelium. This system is effective against several microorganisms that infect airways of cystic fibrosis and other immunocompromised patients. We show herein that exposure of airway epithelial cells to Pseudomonas aeruginosa obtained from long-term cultures inhibits Duox1-dependent hydrogen peroxide release, suggesting that some microbial factor suppresses Duox activity. These inhibitory effects are not seen with the pyocyanin-deficient P. aeruginosa strain PA14 Phz1/2. We show that purified pyocyanin, a redox-active virulence factor produced by P. aeruginosa, inhibits human airway cell Duox activity by depleting intracellular stores of NADPH, as it generates intracellular superoxide. Long-term exposure of human airway (primary normal human bronchial and NCI-H292) cells to pyocyanin also blocks induction of Duox1 by Th2 cytokines (IL-4, IL-13), which was prevented by the antioxidants glutathione and N-acetylcysteine. Furthermore, we showed that low concentrations of pyocyanin blocked killing of wild-type P. aeruginosa by the Duox/SCN(-)/LPO system on primary normal human bronchial epithelial cells. Thus, pyocyanin can subvert Pseudomonas killing by the Duox-based system as it imposes oxidative stress on the host. We also show that lactoperoxidase can oxidize pyocyanin, thereby diminishing its cytotoxicity. These data establish a novel role for pyocyanin in the survival of P. aeruginosa in human airways through competitive redox-based reactions between the pathogen and host.
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Affiliation(s)
- Balázs Rada
- National Institutes of Health, National Institute of Allergy and Infectious Diseases, Laboratory of Host Defenses, Rockville, MD 20852, USA
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84
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Fischer AJ, Goss KL, Scheetz TE, Wohlford-Lenane CL, Snyder JM, McCray PB. Differential gene expression in human conducting airway surface epithelia and submucosal glands. Am J Respir Cell Mol Biol 2008; 40:189-99. [PMID: 18703793 DOI: 10.1165/rcmb.2008-0240oc] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Human conducting airways contain two anatomically distinct epithelial cell compartments: surface epithelium and submucosal glands (SMG). Surface epithelial cells interface directly with the environment and function in pathogen detection, fluid and electrolyte transport, and mucus elevation. SMG secrete antimicrobial molecules and most of the airway surface fluid. Despite the unique functional roles of surface epithelia and SMG, little is known about the differences in gene expression and cellular metabolism that orchestrate the specialized functions of these epithelial compartments. To approach this problem, we performed large-scale transcript profiling using epithelial cell samples obtained by laser capture microdissection (LCM) of human bronchus specimens. We found that SMG expressed high levels of many transcripts encoding known or putative innate immune factors, including lactoferrin, zinc alpha-2 glycoprotein, and proline-rich protein 4. By contrast, surface epithelial cells expressed high levels of genes involved in basic nutrient catabolism, xenobiotic clearance, and ciliated structure assembly. Selected confirmation of differentially expressed genes in surface and SMG epithelia demonstrated the predictive power of this approach in identifying genes with localized tissue expression. To characterize metabolic differences between surface epithelial cells and SMG, immunostaining for a mitochondrial marker (isocitrate dehydrogenase) was performed. Because greater staining was observed in the surface compartment, we predict that these cells use significantly more energy than SMG cells. This study illustrates the power of LCM in defining the roles of specific anatomic features in airway biology and may be useful in examining how disease states alter transcriptional programs in the conducting airways.
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Affiliation(s)
- Anthony J Fischer
- Department of Pediatrics, University of Iowa, Iowa City, IA 52242, USA
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85
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How to prevent immunological reactions in leprosy patients and interrupt transmission of Mycobacterium leprae to healthy subjects: two hypotheses. Med Hypotheses 2008; 71:551-63. [PMID: 18614293 DOI: 10.1016/j.mehy.2008.05.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 04/04/2008] [Accepted: 05/13/2008] [Indexed: 11/21/2022]
Abstract
The basis of World Health Organization strategy for leprosy elimination is that the only source and reservoir for infection are patients with the disease. It was assumed that multi drug therapy (MDT) would reduce transmission of Mycobacterium leprae, but there is no convincing evidence for this. Furthermore, even if MDT has been proved to be extremely effective against the infectious disease, a noticeable proportion of leprosy patients can suffer from immunologic hypersensitivity reactions which are now the most significant issue in the managements of the disease. In endemic areas it was found that: M. leprae survives outside human body; healthy individuals harbor M. leprae bacilli in nasal cavity and shed micro-organisms in environment; there is widespread subclinical transmission of M. leprae with transient infection of the nose resulting in the development of a mucosal immune response. This disparate clinical, epidemiologic, and microbiologic evidence leads to the first hypothesis: that antigenic load in local tissues, sufficient to trigger the immune response, comes from external supply of M. leprae organisms. The hypothiocyanite anion (OSCN-) is generated in vivo by the reaction of thiocyanate with hydrogen peroxide catalyzed by lactoperoxidase. OSCN- is an antimicrobial oxidizing agent that prevents growth of bacteria, fungi, and viruses. OSNC- exists in lower airway secretions and lung has never been reported to be affected by leprosy. There is a sufficient concentration of OSCN- in the saliva, and accordingly mouth is rarely affected by leprosy. By contrast, the concentration of this compound is low or nil in nasal and lacrimal secretions and leprosy very often affects nose and eyes. The second hypothesis is that OSCN- may also protect from leprosy. Recently a method of OSCN- production, not involving enzymatic steps or use of toxic heavy-metal salts, has been patented. Studies on the susceptibility of M. leprae to hypothiocyanite could be carried out and, in case of positive results, the substance might be used in order to sterilize the nasal cavity of healthy carriers and prevent transmission of M. leprae to healthy subjects and to leprosy patients in whom it may trigger an immune response.
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86
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Davies MJ, Hawkins CL, Pattison DI, Rees MD. Mammalian heme peroxidases: from molecular mechanisms to health implications. Antioxid Redox Signal 2008; 10:1199-234. [PMID: 18331199 DOI: 10.1089/ars.2007.1927] [Citation(s) in RCA: 423] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A marked increase in interest has occurred over the last few years in the role that mammalian heme peroxidase enzymes, primarily myeloperoxidase, eosinophil peroxidase, and lactoperoxidase, may play in both disease prevention and human pathologies. This increased interest has been sparked by developments in our understanding of polymorphisms that control the levels of these enzymes, a greater understanding of the basic chemistry and biochemistry of the oxidants formed by these species, the development of specific biomarkers that can be used in vivo to detect damage induced by these oxidants, the detection of active forms of these peroxidases at most, if not all, sites of inflammation, and a correlation between the levels of these enzymes and a number of major human pathologies. This article reviews recent developments in our understanding of the enzymology, chemistry, biochemistry and biologic roles of mammalian peroxidases and the oxidants that they generate, the potential role of these oxidants in human disease, and the use of the levels of these enzymes in disease prognosis.
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Affiliation(s)
- Michael J Davies
- The Heart Research Institute, Camperdown, University of Sydney, Sydney, Australia., Faculty of Medicine, University of Sydney, Sydney, Australia.
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87
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Rogers CS, Abraham WM, Brogden KA, Engelhardt JF, Fisher JT, McCray PB, McLennan G, Meyerholz DK, Namati E, Ostedgaard LS, Prather RS, Sabater JR, Stoltz DA, Zabner J, Welsh MJ. The porcine lung as a potential model for cystic fibrosis. Am J Physiol Lung Cell Mol Physiol 2008; 295:L240-63. [PMID: 18487356 DOI: 10.1152/ajplung.90203.2008] [Citation(s) in RCA: 187] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Airway disease currently causes most of the morbidity and mortality in patients with cystic fibrosis (CF). However, understanding the pathogenesis of CF lung disease and developing novel therapeutic strategies have been hampered by the limitations of current models. Although the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) has been targeted in mice, CF mice fail to develop lung or pancreatic disease like that in humans. In many respects, the anatomy, biochemistry, physiology, size, and genetics of pigs resemble those of humans. Thus pigs with a targeted CFTR gene might provide a good model for CF. Here, we review aspects of porcine airways and lung that are relevant to CF.
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Affiliation(s)
- Christopher S Rogers
- Department of Internal Medicine, Roy J. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA
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Abstract
Increasingly, reactive oxygen species such as superoxide and hydrogen peroxide are recognized to be intentionally generated intracellularly to serve important cellular functions. A key protein family responsible for the regulated generation of reactive oxygen species in multiple cell types is the NOX/DUOX enzyme family. Two family members, DUOX1 and DUOX2, appear to be highly expressed in tissues of endodermal origin including the thyroid, respiratory tract, and gastrointestinal tract. In this chapter, we will focus our review on DUOX proteins in the respiratory tract. We will discuss a brief history of the discovery of the DUOX isoforms, the estimated hydrogen peroxide-generating capacity of DUOX in respiratory tract epithelium, putative functions of the DUOX enzymes, and some regulatory factors responsible for DUOX gene expression and oxidase activity.
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Affiliation(s)
- Giuseppe Valacchi
- grid.9024.f0000000417574641Department of Physiology, University of Siena, Via Moro 7, 53100 Siena Italy
| | - Paul A. Davis
- grid.27860.3b0000000419369684Department of Nutrition, University of California Davis, 95616 Davis, CA USA
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