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Pokharel MD, Marciano DP, Fu P, Franco MC, Unwalla H, Tieu K, Fineman JR, Wang T, Black SM. Metabolic reprogramming, oxidative stress, and pulmonary hypertension. Redox Biol 2023; 64:102797. [PMID: 37392518 PMCID: PMC10363484 DOI: 10.1016/j.redox.2023.102797] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/15/2023] [Accepted: 06/23/2023] [Indexed: 07/03/2023] Open
Abstract
Mitochondria are highly dynamic organelles essential for cell metabolism, growth, and function. It is becoming increasingly clear that endothelial cell dysfunction significantly contributes to the pathogenesis and vascular remodeling of various lung diseases, including pulmonary arterial hypertension (PAH), and that mitochondria are at the center of this dysfunction. The more we uncover the role mitochondria play in pulmonary vascular disease, the more apparent it becomes that multiple pathways are involved. To achieve effective treatments, we must understand how these pathways are dysregulated to be able to intervene therapeutically. We know that nitric oxide signaling, glucose metabolism, fatty acid oxidation, and the TCA cycle are abnormal in PAH, along with alterations in the mitochondrial membrane potential, proliferation, and apoptosis. However, these pathways are incompletely characterized in PAH, especially in endothelial cells, highlighting the urgent need for further research. This review summarizes what is currently known about how mitochondrial metabolism facilitates a metabolic shift in endothelial cells that induces vascular remodeling during PAH.
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Affiliation(s)
- Marissa D Pokharel
- Center for Translational Science, Florida International University, 11350 SW Village Parkway, Port St. Lucie, FL, 34987-2352, USA; Department of Cellular Biology & Pharmacology, Howard Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - David P Marciano
- Center for Translational Science, Florida International University, 11350 SW Village Parkway, Port St. Lucie, FL, 34987-2352, USA; Department of Cellular Biology & Pharmacology, Howard Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - Panfeng Fu
- Center for Translational Science, Florida International University, 11350 SW Village Parkway, Port St. Lucie, FL, 34987-2352, USA; Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA
| | - Maria Clara Franco
- Center for Translational Science, Florida International University, 11350 SW Village Parkway, Port St. Lucie, FL, 34987-2352, USA; Department of Cellular Biology & Pharmacology, Howard Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - Hoshang Unwalla
- Department of Immunology and Nano-Medicine, Howard Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - Kim Tieu
- Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA
| | - Jeffrey R Fineman
- Department of Pediatrics, The University of California San Francisco, San Francisco, CA, 94143, USA; Cardiovascular Research Institute, The University of California San Francisco, San Francisco, CA, 94143, USA
| | - Ting Wang
- Center for Translational Science, Florida International University, 11350 SW Village Parkway, Port St. Lucie, FL, 34987-2352, USA; Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA
| | - Stephen M Black
- Center for Translational Science, Florida International University, 11350 SW Village Parkway, Port St. Lucie, FL, 34987-2352, USA; Department of Cellular Biology & Pharmacology, Howard Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA; Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA.
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Immunohistochemistry in the Postmortem Diagnosis of Sepsis: A Systematic Review. Appl Immunohistochem Mol Morphol 2021; 28:571-578. [PMID: 31290786 DOI: 10.1097/pai.0000000000000790] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
It is not uncommon for the forensic pathologist to question whether a deceased person had experienced sepsis that could have either been the cause of or contributed to the person's death. Often, the missing typical pathologic factors or lack of clinical and circumstantial information on the death render the autopsy of a sepsis-related death a difficult task for the forensic pathologist. Several authors emphasize on how an immunohistochemical analysis could help in diagnosing death related to sepsis. The research we carried out analyzes the main scientific studies in the literature, primarily the tracing of 21 immunohistochemical antigens evaluated to help diagnose death related to sepsis. The purpose of this review was to analyze and summarize the markers studied until now and to consider the limitations of immunohistochemistry that currently exist with regard to this particular field of forensic pathology. Immunohistochemistry provided interesting and promising results, but further studies are needed in order for them to be confirmed, so that they may be applied in standard forensic practice.
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Uslu GA, Gelen V, Uslu H, Özen H. Effects of Cinnamomum cassia extract on oxidative stress, immunreactivity of iNOS and impaired thoracic aortic reactivity induced by type II diabetes in rats. BRAZ J PHARM SCI 2018. [DOI: 10.1590/s2175-97902018000317785] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Dunn JLM, Kartchner LB, Stepp WH, Glenn LI, Malfitano MM, Jones SW, Doerschuk CM, Maile R, Cairns BA. Blocking CXCL1-dependent neutrophil recruitment prevents immune damage and reduces pulmonary bacterial infection after inhalation injury. Am J Physiol Lung Cell Mol Physiol 2018; 314:L822-L834. [PMID: 29368547 DOI: 10.1152/ajplung.00272.2017] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Smoke inhalation associated with structural fires, wildfires, or explosions leads to lung injury, for which innovative and clinically relevant animal models are needed to develop effective therapeutics. We have previously reported that damage-associated molecular patterns (DAMPs) and anti-inflammatory cytokines correlate with infectious complications in patients diagnosed with inhalational injury. In this study, we describe a novel and translational murine model of acute inhalational injury characterized by an accumulation of protein and neutrophils in the bronchoalveolar space, as well as histological evidence of tissue damage. Mice were anesthetized, and a cannula was placed in the trachea and exposed to smoldering plywood smoke three times for 2-min intervals in a smoke chamber. Here we demonstrate that this model recapitulates clinically relevant phenotypes, including early release of double-stranded DNA (dsDNA), IL-10, monocyte chemoattractant protein (MCP)-1, and CXCL1 along with neutrophilia early after injury, accompanied by subsequent susceptibility to opportunistic infection with Pseudomonas aeruginosa. Further investigation of the model, and in turn a reanalysis of patient samples, revealed a late release of the DAMP hyaluronic acid (HA) from the lung. Using nitric oxide synthase-deficient mice, we found that Nos2 was required for increases in IL-10, MCP-1, and HA following injury but not release of dsDNA, CXCL1 expression, early neutrophilia, or susceptibility to opportunistic infection. Depletion of CXCL1 attenuated early neutrophil recruitment, leading to decreased histopathology scores and improved bacterial clearance in this model of smoke inhalation. Together, these data highlight the potential therapeutic benefit of attenuating neutrophil recruitment in the first 24 h after injury in patients.
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Affiliation(s)
- Julia L M Dunn
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Laurel B Kartchner
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Wesley H Stepp
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Department of Surgery, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Lindsey I Glenn
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Department of Surgery, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Madison M Malfitano
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Department of Surgery, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Samuel W Jones
- Department of Surgery, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Jaycee Burn Center, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Claire M Doerschuk
- Department of Medicine and Pathology, Center for Airway Disease, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Marsico Lung Institute, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Robert Maile
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Department of Surgery, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Jaycee Burn Center, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Bruce A Cairns
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Department of Surgery, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Jaycee Burn Center, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
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Intravenous Arginine Administration Promotes Proangiogenic Cells Mobilization and Attenuates Lung Injury in Mice with Polymicrobial Sepsis. Nutrients 2017; 9:nu9050507. [PMID: 28513569 PMCID: PMC5452237 DOI: 10.3390/nu9050507] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/13/2017] [Accepted: 05/15/2017] [Indexed: 12/12/2022] Open
Abstract
This study investigated the influence of intravenous arginine (Arg) administration on alteration of circulating proangiogenic cells and remote lung injury in a model of polymicrobial sepsis. Mice were assigned to one normal control group (NC) and two sepsis groups that were induced by cecal ligation and puncture (CLP). One of the sepsis groups was injected with saline (SS), whereas the other (SA) was administered with a single bolus of 300 mg Arg/kg body weight via the tail vein 1 h after CLP. Septic mice were sacrificed at either 24 or 48 h after CLP, with their blood and lung tissues collected for analysis. Results showed that septic groups had higher proangiogenic cells releasing factors and proangiogenic cells percentage in blood. Also, concentration of inflammatory cytokines and expression of angiopoietin (Angpt)/Tie-2 genes in lung tissues were upregulated. Arg administration promoted mobilization of circulating proangiogenic cells while it downregulated the production of inflammatory cytokines and expression of Angpt/Tie-2 genes in the lung. The results of this investigation suggested that intravenous administration of Arg shortly after the onset of sepsis enhanced the mobilization of circulating proangiogenic cells, maintained the homeostasis of the Angpt/Tie-2 axis, and attenuated remote organ injury in polymicrobial sepsis.
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Dunn JLM, Hunter RA, Gast K, Maile R, Cairns BA, Schoenfisch MH. Direct detection of blood nitric oxide reveals a burn-dependent decrease of nitric oxide in response to Pseudomonas aeruginosa infection. Burns 2016; 42:1522-1527. [PMID: 27268107 DOI: 10.1016/j.burns.2016.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 04/08/2016] [Accepted: 05/06/2016] [Indexed: 01/20/2023]
Abstract
PURPOSE Burn is associated with severe immune dysfunction, including an anti-inflammatory state that occurs late after burn. While increased nitric oxide (NO) production is associated with severe infection and sepsis, the effect of burn trauma on these levels during a non-lethal infection remains unknown. We hypothesized that in a mouse model, (1) NO levels would be increased after infection without trauma and (2) burn would lead to decreased NO production even during infection. METHODS Mice were infected via intra-tracheal inoculation with Pseudomonas aeruginosa 14 d following a 20% total body surface area contact burn. At 48h following infection, blood was drawn to quantify NO concentrations using a microfluidic electrochemical sensor. SIGNIFICANT FINDINGS In uninjured mice, infection caused a significant increase in blood NO levels. Increases in NO occurred in a dose-dependent response to the bacterial inoculum. Following burn, an identical infection did not elicit increases in NO. CONCLUSIONS While increases in NO are expected over the course of an infection without prior trauma, burn and subsequent immune suppression decreases NO levels even in the presence of infection.
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Affiliation(s)
- Julia L M Dunn
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, United States.
| | - Rebecca A Hunter
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, United States.
| | - Karli Gast
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, United States.
| | - Robert Maile
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, United States; North Carolina Jaycee Burn Center, Department of Surgery, University of North Carolina, Chapel Hill, NC 27599, United States.
| | - Bruce A Cairns
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, United States; North Carolina Jaycee Burn Center, Department of Surgery, University of North Carolina, Chapel Hill, NC 27599, United States.
| | - Mark H Schoenfisch
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, United States.
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Supplemental Carvacrol Can Reduce the Severity of Inflammation by Influencing the Production of Mediators of Inflammation. Inflammation 2014; 38:1020-7. [DOI: 10.1007/s10753-014-0066-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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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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Altunal C, Agalar F, Agalar C, Daphan C, Saygun O, Aydinuraz K, Sahiner T, Atasoy P, Caglayan O, Dom S. The Effect of Simvastatin on Pulmonary Damage in Experimental Peritonitis in Rats. Indian J Surg 2013; 77:370-5. [PMID: 26730028 DOI: 10.1007/s12262-013-0845-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 01/16/2013] [Indexed: 01/11/2023] Open
Abstract
Statins are widely used in the treatment of hyperlipidemia, as they inhibit cholesterol synthesis. They also have anti-inflammatory, antioxidant, immunomodulatory, and positive endothelial-functional effects. It is hypothesized that simvastatin ameliorates pulmonary damage secondary to peritonitis in rats. Forty Wistar albino rats were divided into four groups. In sham group, laparotomy was the standard procedure. In simvastatin group, simvastatin was given perorally before laparotomy. In sepsis group, peritoneal sepsis was constituted by cecal ligation and puncture technique. In sepsis + simvastatin group, the procedures of simvastatin and sepsis groups were applied together. After sacrification at the 72nd hour, tissue samples from lungs were harvested for histopathological examination, wet and dry weight measurements, and tissue culture, tissue malondialdehyde, and nitric oxide tests. Blood samples were taken for C-reactive protein and whole blood count. While the malondialdehyde levels were found to be significantly higher in sepsis group, nitric oxide levels were found to be significantly lower in simvastatin + sepsis group. Alveolar hemorrhage was highest in simvastatin + sepsis group. There was no difference for C-reactive protein, leukocyte levels, and histopathological examination between any groups. The ratios of wet and dry lung weights were higher in simvastatin-given groups. Simvastatin has no positive effect in terms of lung dysfunction on experimental sepsis model. For a better understanding of the effects of simvastatin on lung injury in peritoneal sepsis, experimental models of longer duration that enable to search the effects of simvastatin beyond 3 days will be more useful.
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Affiliation(s)
- Cetin Altunal
- Department of General Surgery, Muş State Hospital, Muş, Turkey
| | - Fatih Agalar
- Department of General Surgery, Anadolu Medical Center, Kocaeli, Turkey
| | - Canan Agalar
- Departments of Infectious Diseases, Kırıkkale University School of Medicine, Kırıkkale, Turkey
| | - Cagatay Daphan
- Departments of General Surgery, Kırıkkale University School of Medicine, Kırıkkale, Turkey ; Tip Fakultesi Genel Cerrahi A.D, Kırıkkale Universitesi, Sağlık Cad, 71100 Kırıkkale, Turkey
| | - Oral Saygun
- Departments of General Surgery, Kırıkkale University School of Medicine, Kırıkkale, Turkey
| | - Kuzey Aydinuraz
- Departments of General Surgery, Kırıkkale University School of Medicine, Kırıkkale, Turkey
| | - Tayfun Sahiner
- Department of General Surgery, Kırşehir State Hospital, Kırşehir, Turkey
| | - Pinar Atasoy
- Departments of Pathology, Kırıkkale University School of Medicine, Kırıkkale, Turkey
| | - Osman Caglayan
- Departments of Biochemistry, Kırıkkale University School of Medicine, Kırıkkale, Turkey
| | - Sedat Dom
- Departments of General Surgery, Kırıkkale University School of Medicine, Kırıkkale, Turkey
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Ware LB, Magarik JA, Wickersham N, Cunningham G, Rice TW, Christman BW, Wheeler AP, Bernard GR, Summar ML. Low plasma citrulline levels are associated with acute respiratory distress syndrome in patients with severe sepsis. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2013; 17:R10. [PMID: 23327349 PMCID: PMC4056746 DOI: 10.1186/cc11934] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 01/09/2013] [Indexed: 01/11/2023]
Abstract
INTRODUCTION The role of nitric oxide synthase (NOS) in the pathophysiology of acute respiratory distress syndrome (ARDS) is not well understood. Inducible NOS is upregulated during physiologic stress; however, if NOS substrate is insufficient then NOS can uncouple and switch from NO generation to production of damaging peroxynitrites. We hypothesized that NOS substrate levels are low in patients with severe sepsis and that low levels of the NOS substrate citrulline would be associated with end organ damage including ARDS in severe sepsis. METHODS Plasma citrulline, arginine and ornithine levels and nitrate/nitrite were measured at baseline in 135 patients with severe sepsis. ARDS was diagnosed by consensus definitions. RESULTS Plasma citrulline levels were below normal in all patients (median 9.2 uM, IQR 5.2 - 14.4) and were significantly lower in ARDS compared to the no ARDS group (6.0 (3.3 - 10.4) vs. 10.1 (6.2 - 16.6), P = 0.002). The rate of ARDS was 50% in the lowest citrulline quartile compared to 15% in the highest citrulline quartile (P = 0.002). In multivariable analyses, citrulline levels were associated with ARDS even after adjustment for covariates including severity of illness. CONCLUSIONS In severe sepsis, levels of the NOS substrate citrulline are low and are associated with ARDS. Low NOS substrate levels have been shown in other disease states to lead to NOS uncoupling and oxidative injury suggesting a potential mechanism for the association between low citrulline and ARDS. Further studies are needed to determine whether citrulline supplementation could prevent the development of ARDS in patients with severe sepsis and to determine its role in NOS coupling and function.
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Circulating microparticles from septic shock patients exert differential tissue expression of enzymes related to inflammation and oxidative stress. Crit Care Med 2011; 39:1739-48. [PMID: 21494101 DOI: 10.1097/ccm.0b013e3182190b4b] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Septic shock is characterized by hypotension and multiple organ failure after infection of microorganisms. Septic shock patients display high levels of circulating microparticles. These are small vesicles released from the plasma membrane of activated or apoptotic cells. Here, we have investigated the effects of in vivo injection of microparticles from nonseptic or septic subjects on protein expression in mouse tissues. DESIGN Prospective, controlled experiments. SETTING Animal basic science laboratory. SUBJECTS Male Swiss mice were randomly assigned to one of two groups: 11 animals injected with microparticles isolated from healthy subjects and 15 animals injected with microparticles isolated from septic patients. INTERVENTIONS Microparticles were extracted from whole blood of septic and nonseptic subjects and were intravenously injected in mice. After 24 hrs, mice were killed and heart, lungs, liver, and kidneys were isolated for Western blot assays. Organs were also used for direct measurements of nitric oxide and superoxide anion production by electron paramagnetic resonance. MEASUREMENTS AND MAIN RESULTS In heart and lungs, microparticles from septic shock patients increased the expression of endothelial and inducible nitric oxide synthases, cyclooxygenase-2, and nuclear factor-κB. However, extracellular superoxide dismutase was only increased in the heart. These effects were associated either with a greater oxidative or nitrative stress in heart and lungs, without affecting nitric oxide production. The liver exhibited an increase in oxidative stress linked to decreased endothelial nitric oxide synthase and manganese superoxide dismutase expression. However, cyclooxygenase-2 expression and IκBα phosphorylation were decreased. Septic microparticles did not change superoxide anion and nitric oxide productions in kidneys. CONCLUSIONS Results suggest that microparticles from septic shock patients exert pleiotropic and differential effects depending on target tissues with regard to the expression of proinflammatory proteins related with nitrative and oxidative stresses. Thus, microparticles might participate in organ dysfunction observed in septic shock patients.
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Lee YM. A Study on the Mechanism of Immunomodulating Effects of Moxifloxacin in Oleic Acid-Induced Acute Lung Injury. Tuberc Respir Dis (Seoul) 2011. [DOI: 10.4046/trd.2011.71.2.97] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Young Man Lee
- Department of Physiology, The Catholic University of Daegu School of Medicine, Daegu, Korea
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Species differences in expression pattern of arginase isoenzymes and differential effects of arginase inhibition on collagen synthesis in human and rat pulmonary fibroblasts. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2010; 381:297-304. [PMID: 20107769 DOI: 10.1007/s00210-009-0489-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Accepted: 12/29/2009] [Indexed: 10/19/2022]
Abstract
Arginase was shown to be up-regulated in different animal models of inflammatory and fibrotic airway diseases. Since arginase provides L-ornithine, one precursor for L-proline, an essential substrate for collagen synthesis, it has been suggested that arginase might be a key enzyme in airway remodelling. The present study aimed to characterize expression of arginase isoenzymes in rat and human pulmonary fibroblasts, and to test whether arginase inhibition affects collagen synthesis. In primary rat tracheal and lung fibroblasts, mRNA for arginase I and II could be detected, with arginase I as predominant isoenzyme. In contrast, in human lung fibroblasts (primary cells and different cells lines) mRNA levels for arginase I were at or below detection limit whereas arginase II mRNA was markedly higher than in rat pulmonary fibroblasts. Arginase activity in rat tracheal and lung fibroblasts was between 20 and 30 mU/mg protein, but was below detection limit (2.5 mU/mg) in human lung fibroblasts. In rat tracheal and lung fibroblasts cultured in proline-free medium, arginase inhibition by N(omega)-hydroxy-nor-L-arginine caused a reduction by about one-third of basal collagen I accumulation (determined by western blot analysis) and largely attenuated transforming growth factor beta 1 (TGF-beta(1))-induced increase in collagen accumulation, whereas basal and TGF-beta(1)-induced collagen accumulation by human lung fibroblasts was not affected by arginase inhibition. In conclusion, arginase isoenzymes reveal a species specific expression pattern. Arginase contributes significantly to L-proline supply for collagen synthesis in rat fibroblasts, in which arginase I is the predominant isoenzyme, but not in human fibroblasts, in which arginase II is the only isoenzyme expressed.
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Abstract
The enzyme arginase metabolizes L-arginine to L-ornithine and urea. Besides its fundamental role in the hepatic urea cycle, arginase is also expressed the immune system of mice and man. While significant interspecies differences exist regarding expression, subcellular localization and regulation of immune cell arginase, associated pathways of immunopathology are comparable between species. Arginase is induced in murine myeloid cells mainly by Th2 cytokines and inflammatory agents and participates in a variety of inflammatory diseases by down-regulation of nitric oxide synthesis, induction of fibrosis and tissue regeneration. In humans, arginase I is constitutively expressed in polymorphonuclear neutrophils and is liberated during inflammation. Myeloid cell arginase-mediated L-arginine depletion profoundly suppresses T cell immune responses and this has emerged as a fundamental mechanism of inflammation-associated immunosuppression. Pharmacological interference with L-arginine metabolism is a novel promising strategy in the treatment of cancer, autoimmunity or unwanted immune deviation.
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Affiliation(s)
- Markus Munder
- Department of Hematology, Oncology and Rheumatology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany.
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15
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Rodríguez PC, Ochoa AC, Rodríguez PC. Arginine regulation by myeloid derived suppressor cells and tolerance in cancer: mechanisms and therapeutic perspectives. Immunol Rev 2009; 222:180-91. [PMID: 18364002 DOI: 10.1111/j.1600-065x.2008.00608.x] [Citation(s) in RCA: 522] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Patients with cancer have an impaired T-cell response that can decrease the potential therapeutic benefit of cancer vaccines and other forms of immunotherapy. L-arginine (L-Arg) is a conditionally essential amino acid that is fundamental for the function of T lymphocytes. Recent findings in tumor-bearing mice and cancer patients indicate that increased metabolism of L-Arg by myeloid derived suppressor cells (MDSCs) producing arginase I inhibits T-lymphocyte responses. Here we discuss some of the most recent concepts how MDSC expressing arginase I may regulate T-cell function in cancer and other chronic inflammatory diseases and suggest possible therapeutic interventions to overcome this inhibitory effect.
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Affiliation(s)
- Paulo C Rodríguez
- Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, LA, USA
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Morris CR, Gladwin MT, Kato GJ. Nitric oxide and arginine dysregulation: a novel pathway to pulmonary hypertension in hemolytic disorders. Curr Mol Med 2009; 8:620-32. [PMID: 18991648 DOI: 10.2174/156652408786241447] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Secondary pulmonary hypertension (PH) is emerging as one of the leading causes of mortality and morbidity in patients with hemolytic anemias such as sickle cell disease (SCD) and thalassemia. Impaired nitric oxide (NO) bioavailability represents the central feature of endothelial dysfunction, and is a major factor in the pathophysiology of PH. Inactivation of NO correlates with hemolytic rate and is associated with the erythrocyte release of cell-free hemoglobin, which consumes NO directly, and the simultaneous release of the arginine-metabolizing enzyme arginase, which limits bioavailability of the NO synthase substrate arginine during the process of intravascular hemolysis. Rapid consumption of NO is accelerated by oxygen radicals that exists in both SCD and thalassemia. A dysregulation of arginine metabolism contributes to endothelial dysfunction and PH in SCD, and is strongly associated with prospective patient mortality. The central mechanism responsible for this metabolic disorder is enhanced arginine turnover, occurring secondary to enhanced plasma arginase activity. This is consistent with a growing appreciation of the role of excessive arginase activity in human diseases, including asthma and pulmonary arterial hypertension. New treatments aimed at improving arginine and NO bioavailability through arginase inhibition, suppression of hemolytic rate, oral arginine supplementation, or use of NO donors represent potential therapeutic strategies for this common pulmonary complication of hemolytic disorders.
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Affiliation(s)
- Claudia R Morris
- Department of Emergency Medicine, Children's Hospital & Research Center Oakland, Oakland, CA 94609, USA.
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Moon Y, Kim J, Lee YM. Presumptive Role of Neutrophilic Oxidative Stress in Oxygen-induced Acute Lung Injury in Rats. Tuberc Respir Dis (Seoul) 2008. [DOI: 10.4046/trd.2008.65.6.464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Yongsuck Moon
- Department of Anatomy, Catholic University of Daegu, School of Medicine, Daegu, Korea
| | - Jihye Kim
- Department of Physiology, Catholic University of Daegu, School of Medicine, Daegu, Korea
| | - Young Man Lee
- Department of Physiology, Catholic University of Daegu, School of Medicine, Daegu, Korea
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Inhibition of NADPH oxidase by apocynin inhibits lipopolysaccharide (LPS) induced up-regulation of arginase in rat alveolar macrophages. Eur J Pharmacol 2007; 579:403-10. [PMID: 18001708 DOI: 10.1016/j.ejphar.2007.10.043] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Revised: 10/16/2007] [Accepted: 10/18/2007] [Indexed: 11/22/2022]
Abstract
Reactive oxygen species participate in the pathogenesis of inflammatory airway diseases, in which increased arginase may play a role by interfering with nitric oxide (NO) synthesis and providing substrate for collagen synthesis. Therefore a modulatory role of reactive oxygen species for arginase was explored in alveolar macrophages using the NADPH oxidase inhibitor apocynin. The effects of lipopolysacharides (LPS) and apocynin on nitrite accumulation, arginase activity and mRNA for inducible NO synthase (iNOS), arginase I and II were determined. Superoxide anion (O(2)(-)) release was analysed by the iodonitrotetrazolium (INT) formazan assay. LPS (1 microg/ml) caused a 55%, transient increase in INT formation, i.e. O(2)(-) release which was inhibited by apocynin (500 microM). LPS caused a 2 fold increase in arginase activity and a marked increase in mRNA encoding arginase I, the predominant isoenzyme. Both effects were largely attenuated by apocynin. Apocynin did not affect the stability of arginase I mRNA, but accelerated the decline of arginase activity when protein synthesis was inhibited by cycloheximide. Apocynin also reduced LPS-induced nitrite accumulation (by 30%) and iNOS mRNA expression, but the magnitude of these effects was smaller than that on arginase I. Arginase I mRNA was also increased following exposure to hydrogen peroxide (H(2)O(2), 200 muM). In conclusion, inhibition of NADPH oxidase in alveolar macrophages causes down-regulation of arginase, indicating that reactive oxygen species exert stimulatory effects on arginase. Enhanced transcription of arginase mRNA and prolongation of the life time of the active enzyme appear to contribute to the enhanced arginase activity.
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Kitowska K, Zakrzewicz D, Königshoff M, Chrobak I, Grimminger F, Seeger W, Bulau P, Eickelberg O. Functional role and species-specific contribution of arginases in pulmonary fibrosis. Am J Physiol Lung Cell Mol Physiol 2007; 294:L34-45. [PMID: 17934065 DOI: 10.1152/ajplung.00007.2007] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Lung fibrosis is characterized by increased deposition of ECM, especially collagens, and enhanced proliferation of fibroblasts. l-arginine is a key precursor of nitric oxide, asymmetric dimethylarginine, and proline, an amino acid enriched in collagen. We hypothesized that l-arginine metabolism is altered in pulmonary fibrosis, ultimately affecting collagen synthesis. Expression analysis of key enzymes in the arginine pathway, protein arginine methyltransferases (Prmt), arginine transporters, and arginases by quantitative (q) RT-PCR and Western blot revealed significant upregulation of arginase-1 and -2, but not Prmt or arginine transporters, during bleomycin-induced pulmonary fibrosis in mice. HPLC revealed a concomitant, time-dependent decrease in pulmonary l-arginine levels. Arginase-1 and -2 mRNA and protein expression was increased in primary fibroblasts isolated from bleomycin-treated mice, compared with controls, and assessed by qRT-PCR and Western blot analysis. TGF-beta1, a key profibrotic mediator, induced arginase-1 and -2 mRNA expression in primary and NIH/3T3 fibroblasts. Treatment of fibroblasts with the arginase inhibitor, NG-hydroxy-l-arginine, attenuated TGF-beta1-stimulated collagen deposition, but not collagen mRNA expression or Smad signaling, in fibroblasts. In human lungs derived from patients with idiopathic pulmonary fibrosis, arginase activity was unchanged, but arginase-1 expression significantly decreased when compared with donor lungs. Our results thus demonstrate that arginase-1 is expressed and functionally important for collagen deposition in lung fibroblasts. TGF-beta1-induced upregulation of arginase-1 suggests an interplay between profibrotic agents and l-arginine metabolism during the course of lung fibrosis in the mouse, whereas species-specific regulatory mechanisms may account for the differences observed in mouse and human.
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Affiliation(s)
- Kamila Kitowska
- Department of Medicine II, Univ. of Giessen School of Medicine, Aulweg 123, D-35392 Giessen, Germany
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Abstract
Given the multiple biological, metabolic, and pharmacologic effects of supplemental arginine, much effort has been devoted to defining its role in numerous clinical conditions. Herein, we review the multiple pathways of arginine metabolism with its various enzyme systems; the effect of arginine on nutrition, healing, and immune system; and its clinical use. Sepsis has been postulated to be an arginine-deficient state and/or a syndrome with elevated levels of nitric oxide. So-called immunonutritional formulations containing various nutritional components have been used most often, yet the effects often are attributed to arginine alone. Such conclusions led to guidelines recommending against the use of arginine-supplemented diets in critically ill patients. While caution in the face of a lack of evidence for benefit in sepsis is commended, well-defined studies examining arginine monotherapy in the context of full nutritional support should be carried out so as to define the possible clinical uses of arginine in critically ill and septic patients.
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Affiliation(s)
- Adrian Barbul
- Department of Surgery, Sinai Hospital and Johns Hopkins Medical Institutions, Baltimore, MD, USA.
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Vasilijevic A, Buzadzic B, Korac A, Petrovic V, Jankovic A, Korac B. Beneficial effects of L-arginine nitric oxide-producing pathway in rats treated with alloxan. J Physiol 2007; 584:921-33. [PMID: 17717015 PMCID: PMC2276988 DOI: 10.1113/jphysiol.2007.140277] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In an attempt to elucidate molecular mechanisms and factors involved in beta cell regeneration, we evaluated a possible role of the L-arginine-nitric oxide (NO)-producing pathway in alloxan-induced diabetes mellitus. Diabetes was induced in male Mill Hill rats with a single alloxan dose (120 mg kg(-1)). Both non-diabetic and diabetic groups were additionally separated into three subgroups: (i) receiving L-arginine . HCl (2.25%), (ii) receiving L-NAME . HCl (0.01%) for 12 days as drinking liquids, and (iii) control. Treatment of diabetic animals started after diabetes induction (glucose level > or = 12 mmol l(-1)). We found that disturbed glucose homeostasis, i.e. blood insulin and glucose levels in diabetic rats was restored after L-arginine treatment. Immunohistochemical findings revealed that L-arginine had a favourable effect on beta cell neogenesis, i.e. it increased the area of insulin-immunopositive cells. Moreover, confocal microscopy showed colocalization of insulin and pancreas duodenum homeobox-1 (PDX-1) in both endocrine and exocrine pancreas. This increase in insulin-expressing cells was accompanied by increased cell proliferation (observed by proliferating cell nuclear antigen-PCNA immunopositivity) which occurred in a regulated manner since it was associated with increased apoptosis (detected by the TUNEL method). Furthermore, L-arginine enhanced both nuclear factor-kB (NF-kB) and neuronal nitric oxide synthase (nNOS) immunopositivities. The effect of L-arginine on antioxidative defence was observed especially in restoring to control level the diabetes-induced increase in glutathione peroxidase activity. In contrast to L-arginine, diabetic pancreas was not affected by L-NAME supplementation. In conclusion, the results suggest beneficial L-arginine effects on alloxan-induced diabetes resulting from the stimulation of beta cell neogenesis, including complex mechanisms of transcriptional and redox regulation.
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Affiliation(s)
- Ana Vasilijevic
- Department of Physiology, Institute for Biological Research, Sinia Stankovi, University of Belgrade, Bulevar Despota Stefana 142, 11060, Belgrade, Serbia
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Crimi E, Sica V, Slutsky AS, Zhang H, Williams-Ignarro S, Ignarro LJ, Napoli C. Role of oxidative stress in experimental sepsis and multisystem organ dysfunction. Free Radic Res 2006; 40:665-72. [PMID: 16983993 DOI: 10.1080/10715760600669612] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Massive increase in radical species can lead to oxidative stress, promoting cell injury and death. This review focuses on experimental evidence of oxidative stress in critical illnesses, sepsis and multisystem organ dysfunction. Oxidative stress could negatively affect organ injury and thus overall survival of experimental models. Based on this experimental evidence, we could improve the rationale of supplementation of antioxidants alone or in combination with standard therapies aimed to reduce oxidative stress as novel adjunct treatment in critical care.
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Affiliation(s)
- Ettore Crimi
- Department of Anesthesiology and Critical Care Medicine, University of Eastern Piedmont, Novara, Italy.
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23
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Zhang H, Zhi L, Moore PK, Bhatia M. Role of hydrogen sulfide in cecal ligation and puncture-induced sepsis in the mouse. Am J Physiol Lung Cell Mol Physiol 2006; 290:L1193-201. [PMID: 16428267 DOI: 10.1152/ajplung.00489.2005] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Endogenous hydrogen sulfide (H2S) is naturally synthesized in various types of mammalian cells from l-cysteine in a reaction catalyzed by two enzymes, cystathionine-γ-lyase (CSE) and/or cystathionine-β-synthase. The latest studies have implied that H2S functions as a vasodilator and neurotransmitter. However, so far there is little information about the role played by H2S in systemic inflammation such as sepsis. Thus the aim of this study was to investigate the potential role of endogenous H2S in cecal ligation and puncture (CLP)-induced sepsis. Male Swiss mice were subjected to CLP-induced sepsis and treated with saline (ip), dl-propargylglycine (PAG, 50 mg/kg ip), a CSE inhibitor, or sodium hydrosulfide (NaHS; 10 mg/kg ip). PAG was administered either 1 h before or 1 h after the induction of sepsis, whereas NaHS was given at the same time of CLP. CLP-induced sepsis significantly increased the plasma H2S level and the liver H2S synthesis 8 h after CLP compared with sham operation. Induction of sepsis also resulted in a significant upregulation of CSE mRNA in liver. On the other hand, prophylactic as well as therapeutic administration of PAG significantly reduced sepsis-associated systemic inflammation, as evidenced by myeloperoxidase activity and histological changes in lung and liver, and attenuated the mortality of CLP-induced sepsis. Injection of NaHS significantly aggravated sepsis-associated systemic inflammation. Therefore, the effect of inhibition of H2S formation and administration of NaHS suggests that H2S plays a proinflammatory role in regulating the severity of sepsis and associated organ injury.
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Affiliation(s)
- Huili Zhang
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 18 Medical Drive, Singapore 117597
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25
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Yu Z, Xia X, Kone BC. Expression profile of a human inducible nitric oxide synthase promoter reporter in transgenic mice during endotoxemia. Am J Physiol Renal Physiol 2005; 288:F214-20. [PMID: 15507544 DOI: 10.1152/ajprenal.00258.2004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Inducible nitric oxide synthase (iNOS) is involved in many physiological and pathophysiological processes, including septic shock and acute kidney failure. Little is known about transcriptional regulation of the human iNOS gene in vivo under basal conditions or in sepsis. Accordingly, we developed transgenic mice carrying an insertional human iNOS promoter-reporter gene construct. In these mice, the proximal 8.3 kb of the human iNOS 5′-flanking region controls expression of the reporter gene of enhanced green fluorescent protein (EGFP). Patterns of human iNOS promoter/EGFP transgene expression in tissues were examined by fluorescence microscopy and immunoblotting. Endogenous murine iNOS was basally undetectable in kidney, intestine, spleen, heart, lung, liver, stomach, or brain. In contrast, EGFP from the transgene was basally expressed in kidney, brain, and spleen, but not the other tissues of the transgenic mice. Bacterial lipopolysaccharide induced endogenous iNOS expression in kidney, intestine, spleen, lung, liver, stomach, and heart, but not brain. In contrast, human iNOS promoter/EGFP transgene expression was induced above basal levels only in intestine, spleen, brain, stomach, and lung. Within kidney, human iNOS promoter/EGFP fluorescence was detected most prominently in proximal tubules of the outer cortex and collecting ducts and colocalized with endogenous mouse iNOS. Within the collecting duct, both endogenous iNOS and the human iNOS promoter/EGFP transgene were expressed in cells lacking aquaporin-2 immunoreactivity, consistent with expression in intercalated cells. Although it remains possible that essential regulatory elements reside in remote locations of the gene, our data concerning this 8.3-kb region provide the first in vivo evidence suggesting differential transcriptional control of the human iNOS gene in these organs and marked differences in transcriptional regulatory regions between the murine and human genes.
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Affiliation(s)
- Zhiyuan Yu
- Department of Internal Medicine, The University of Texas Medical School at Houston, 6431 Fannin, MSB 1.150, Houston, TX 77030, USA
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26
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Dzik JM, Gołos B, Jagielska E, Zielinski Z, Wałajtys-Rode E. A non-classical type of alveolar macrophage response to Trichinella spiralis infection. Parasite Immunol 2004; 26:197-205. [PMID: 15367297 DOI: 10.1111/j.0141-9838.2004.00700.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Studies of arginase expression and activity in guinea pig alveolar macrophages during Trichinella spiralis infection, prompted by earlier observation of innate lung response to the parasite, showed the macrophages to express both activity and protein of arginase type I. In cultured macrophages part of the enzyme was found to be always released to the extracellular medium. Whereas BCG in vivo treatment, alone or preceded by T. spiralis infection, stimulated arginase activity, T. spiralis infection alone affected the enzyme distribution between intracellular and extracellular fractions, and properties (K(m) and V(max)), rather than total (intracellular + extracellular) activity, with TGF-beta apparently responsible for a part of the effect. Anti-TGF-beta antibody treatment of the animals influenced both arginase activation by Mn(2+) and dependence of the enzyme-catalysed reaction on pH. Whereas T. spiralis infection activated guinea pig alveolar macrophages by the type II macrophage activation, as indicated by constant arginase expression, associated with previously demonstrated lack of stimulation of nitric oxide production, BCG treatment invoked an alternative type of activation mechanism, reflected by stimulation of macrophage arginase, but not iNOS, activity.
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Affiliation(s)
- J M Dzik
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland.
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27
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Fischer LG, Hilpert JH, Freise H, Wendholt D, Van Aken H, Sielenkämper AW. Bradykinin-Induced Pulmonary Vasoconstriction Is Time and Inducible Nitric Oxide Synthase Dependent in a Peritonitis Sepsis Model. Anesth Analg 2004; 99:864-871. [PMID: 15333423 DOI: 10.1213/01.ane.0000133000.65613.f5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In an isolated perfused lung model, bradykinin induced pulmonary vasoconstriction in rats made septic by the injection of lipopolysaccharide (LPS). To mimic the pathophysiology of sepsis in humans more closely, we investigated pulmonary endothelial injury in a peritonitis model (cecal ligation and perforation; CLP). Male Sprague-Dawley rats were randomly divided into nine groups (n = 6-8). LPS and CLP rats were compared after 6 h with and without treatment with a selective inhibitor of inducible nitric oxide synthase (iNOS), L-N(6)-(1-iminoethyl)-lysine. Time dependency was investigated in CLP-treated rats at 24 h. The pulmonary circulation was isolated and perfused with a constant flow after the rats' tracheas were intubated and ventilated. Bradykinin (1, 3, and 6 microg) was injected, and changes in perfusion pressure were measured. Lungs were harvested for Western blot analysis to determine the role of iNOS in pulmonary endothelial dysfunction. In contrast to CLP 24 h rats, dose-dependent bradykinin-induced pulmonary vasoconstriction was observed in LPS and CLP 6 h rats. Concomitant administration of L-N(6)-(1-iminoethyl)-lysine significantly attenuated this vasoconstriction in both groups. The iNOS protein was expressed in lung homogenates from LPS 6 h and CLP 6 h but not from CLP 24 h rats. Both sepsis models caused bradykinin-induced pulmonary vasoconstriction, with the CLP groups demonstrating a time dependency of this effect. In conjunction with the time-dependent decrease in iNOS protein, the attenuated bradykinin-induced vasoconstriction due to selective iNOS inhibition suggests an important role for iNOS in pulmonary endothelial injury for both sepsis models.
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Affiliation(s)
- Lars G Fischer
- Department of Anesthesiology and Intensive Care, University of Münster, Münster, Germany
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Barksdale AR, Bernard AC, Maley ME, Gellin GL, Kearney PA, Boulanger BR, Tsuei BJ, Ochoa JB. Regulation of arginase expression by T-helper II cytokines and isoproterenol. Surgery 2004; 135:527-35. [PMID: 15118590 DOI: 10.1016/j.surg.2003.10.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Trauma causes a release of catecholamines, transforming growth factor-beta (TGF-beta), and T-helper II cytokines (TH2). Individually, these substances also induce arginase in macrophages. The purpose of this study was to determine the synergistic interactions between isoproterenol, TGF-beta, and TH2 cytokines on arginase expression in macrophages. METHODS Confluent RAW 264.7 macrophages were incubated with various combinations of interleukins 4, 10, and 13 (IL-4, IL-10, IL-13), and TGF-beta with isoproterenol over 48 hours. Arginase activity, as well as arginase I expression by Western blot and reverse transcriptase-polymerase chain reaction, were measured. RESULTS Although isoproterenol, IL-4, IL-10, and IL-13 individually induced arginase, significant synergy between the combination of isoproterenol with either TGF-beta or the TH2 cytokines was observed. All cytokines except IL-10 also induced arginase I protein and mRNA. Arginase II protein was detected in cells exposed to IL-10. CONCLUSIONS We conclude that isoproterenol synergizes with IL-4, IL-13, and TGF-beta to increase arginase I mRNA and protein, as well as arginase activity in RAW 264.7 macrophages. Further, IL-10 synergizes with isoproterenol to increase arginase activity and arginase II protein. These synergistic mechanisms may compete with nitric oxide synthase for l-arginine substrate, thus shunting away available arginine from nitric oxide production and contributing to cellular immunosuppression observed after trauma.
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Affiliation(s)
- Andrew R Barksdale
- Department of Surgery, University of Kentucky College of Medicine, Lexington, KY 40536, USA
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Rodriguez PC, Zea AH, Culotta KS, Zabaleta J, Ochoa JB, Ochoa AC. Regulation of T cell receptor CD3zeta chain expression by L-arginine. J Biol Chem 2002; 277:21123-9. [PMID: 11950832 DOI: 10.1074/jbc.m110675200] [Citation(s) in RCA: 350] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
L-Arg plays a central role in the normal function of several organ systems including the immune system. L-Arg can be depleted by arginase I produced by macrophages and hepatocytes in several disease states such as trauma and sepsis and following liver transplantation. The decrease in L-Arg levels induces a profound decrease in T cell function through mechanisms that have remained unclear. The data presented here demonstrate that Jurkat T cells cultured in medium without L-Arg (L-Arg-free RPMI) have a rapid decrease in the expression of the T cell antigen receptor zeta chain (CD3zeta), the principal signal transduction element in this receptor, and a decrease in T cell proliferation. This phenomenon is completely reversed by the replenishment of L-Arg but not other amino acids. These changes are not caused by cell apoptosis; instead, the diminished expression of CD3zeta protein is paralleled by a decrease in CD3zeta mRNA. This change in CD3zeta mRNA expression is not caused by a decrease in the transcription rate but rather by a significantly shorter CD3zeta mRNA half-life. This mechanism is sensitive to cycloheximide. Therefore, the regulation of L-Arg concentration in the microenvironment could represent an important mechanism to modulate the expression of CD3zeta and the T cell receptor and consequently of T cell function.
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Affiliation(s)
- Paulo C Rodriguez
- Tumor Immunology Program, Stanley S. Scott Cancer Center and Department of Pediatrics, Louisiana State University, Health Sciences Center, New Orleans, Louisiana 70112, USA
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Janech MG, Chen R, Klein J, Nowak MW, McFee W, Paul RV, Fitzgibbon WR, Ploth DW. Molecular and functional characterization of a urea transporter from the kidney of a short-finned pilot whale. Am J Physiol Regul Integr Comp Physiol 2002; 282:R1490-500. [PMID: 11959693 DOI: 10.1152/ajpregu.00323.2001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cetaceans (whales and dolphins) always excrete urine with an osmolality markedly higher than that of plasma. Although the mechanisms by which cetaceans concentrate urine have not been elucidated, data support a role for medullary urea accumulation in this process, as is the case for terrestrial mammals. Therefore, we hypothesized that facilitated urea transporters are present in the kidney of cetaceans. Using 5'/3'-rapid amplification of cDNA ends, we cloned a 2.7-kb cDNA from the kidney of the short-finned pilot whale Globicephala macrorhynchus. The putative open-reading frame encoded a 397-amino acid protein [pilot whale urea transporter A2 (whUT-A2)] that has 94% amino acid sequence identity to the A2 isoform of the human urea transporter (hUT-A2). Heterologous expression of whUT-A2 cRNA in Xenopus oocytes induced phloretin-inhibitable urea transport. Although Northern analysis and RT-PCR indicated that whUT-A2 was exclusively expressed in kidney, Western blotting using a polyclonal antibody to rat UT-A1/UT-A2 detected various immunoreactive proteins in kidney and other tissues. Furthermore, RT-PCR analysis suggested the presence of alternatively spliced UT-A transcripts in the kidney as well as extrarenal tissues. We conclude that renal urea transporters are highly conserved among mammals inhabiting terrestrial and pelagic environments. A urea-based concentrating mechanism, presumably evolved to meet the demands of an arid terrestrial environment, may have contributed a fortuitous preadaptation that enabled the ancestors of cetaceans to reinvade the sea.
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Affiliation(s)
- Michael G Janech
- Department of Marine Biomedicine and Environmental Sciences, Medical University of South Carolina, Charleston 29412, USA
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Abstract
l-Arginine is converted to nitric oxide and citrulline by the enzyme nitric oxide synthase (NOS). Its in vivo inhibition has led to the revelation of a multitude of diverse, often conflicting functions in the inflammatory melee. l-Arginine is also converted to ornithine and urea by the enzyme arginase as a part of the hepatic urea cycle. However, a more holistic interpretation of the two pathways and the associated metabolism (summarized in Fig. 1) has led to its reassessment as a pathologically significant enzyme. This is reflected by the continued increase over the past five years of the number of publications discussing both nitric oxide and arginase. The strong association between inflammation and high arginase and NOS activity is epitomized by immune complex-induced glomerulonephritis and other glomerulonephritides. Arginase is encoded by two recently discovered genes (Arginase I and Arginase II). There is now substantial evidence for an interaction between both arginase isoforms and all three NOS isoforms in pathological situations. This review considers the relationship between Arginases I and II and the inflammation-associated isoform of NOS called NOS II. In particular, it consolidates the current understanding of arginase and associated metabolic pathways, and highlights some of the issues that are often overlooked in such studies.
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Affiliation(s)
- Simon N Waddington
- Gene Therapy Group, Section of Cell and Molecular Biology, Faculty of Medicine, Imperial College School of Science Technology and Medicine, Sir Alexander Fleming Building, Imperial College Road, London, England SW7 2AZ, UK.
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Abstract
Both arginase isoforms (AI and AII) regulate high-level NO production by the inducible NOS, but whether the arginase isoforms also regulate low-level NO production by neuronal NOS (nNOS) is not known. In this study, 293 cells that stably overexpress nNOS gene (293nNOS cells) were transfected with rat AI (pEGFP-AI) or AII (pcDNA-AII) plasmids, and nitrite production was measured with or without supplemental L-arginine. Transfection with pEGFP-AI increased AI expression and activity 10-fold and decreased intracellular l-arginine by 50%. Nitrite production was inhibited by >80% when no l-arginine was supplemented but not when 1 mM L-arginine was present. The inhibition was reversed by an arginase inhibitor, N(omega)-hydroxy-L-arginine. Transfection with pcDNA-AII increased AII expression and activity but had little effect on nitrite production even if no l-arginine was added. These results suggest that, in 293nNOS cells, AI was more effective in regulating NO production by nNOS, most likely by competing for L-arginine.
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Affiliation(s)
- Loretta G. Que
- Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Samuel E. George
- Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Tomomi Gotoh
- Department of Molecular Genetics, Kumamoto University, School of Medicine, Kumamoto, Japan
| | - Masataka Mori
- Department of Molecular Genetics, Kumamoto University, School of Medicine, Kumamoto, Japan
| | - Yuh-Chin T. Huang
- Department of Medicine, Duke University Medical Center, Durham, North Carolina
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Feihl F, Waeber B, Liaudet L. Is nitric oxide overproduction the target of choice for the management of septic shock? Pharmacol Ther 2001; 91:179-213. [PMID: 11744067 DOI: 10.1016/s0163-7258(01)00155-3] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Sepsis is a heterogeneous class of syndromes caused by a systemic inflammatory response to infection. Septic shock, a severe form of sepsis, is associated with the development of progressive damage in multiple organs, and is a leading cause of patient mortality in intensive care units. Despite important advances in understanding its pathophysiology, therapy remains largely symptomatic and supportive. A decade ago, the overproduction of nitric oxide (NO) had been discovered as a potentially important event in this condition. As a result, great hopes arose that the pharmacological inhibition of NO synthesis could be developed into an efficient, mechanism-based therapeutic approach. Since then, an extraordinary effort by the scientific community has brought a deeper insight regarding the feasibility of this goal. Here we present in summary form the present state of knowledge of the biological chemistry and physiology of NO. We then proceed to a systematic review of experimental and clinical data, indicating an up-regulation of NO production in septic shock; information on the role of NO in septic shock, as provided by experiments in transgenic mice that lack the ability to up-regulate NO production; effects of pharmacological inhibitors of NO production in various experimental models of septic shock; and relevant clinical experience. The accrued evidence suggests that the contribution of NO to the pathophysiology of septic shock is highly heterogeneous and, therefore, difficult to target therapeutically without appropriate monitoring tools, which do not exist at present.
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Affiliation(s)
- F Feihl
- Division of Pathophysiology and Medical Teaching, Department of Internal Medicine, University Hospital, PPA, BH19-317, CHUV, CH 1011 Lausanne, Switzerland.
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Satriano J, Schwartz D, Ishizuka S, Lortie MJ, Thomson SC, Gabbai F, Kelly CJ, Blantz RC. Suppression of inducible nitric oxide generation by agmatine aldehyde: beneficial effects in sepsis. J Cell Physiol 2001; 188:313-20. [PMID: 11473357 DOI: 10.1002/jcp.1119] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The induction of inducible nitric oxide synthase (iNOS) serves an important immuno-protective function in inflammatory states, but ungoverned nitric oxide (NO) generation can contribute to a number of pathologic consequences. Delineation of the mechanisms that can downregulate iNOS-generated NO in inflammation could have therapeutic relevance. Here we show that agmatine, a metabolite of arginine, inhibits iNOS mediated nitric oxide generation in cytokine stimulated cell culture preparations. This effect was not cell type specific. Increased diamine oxidase (DAO) and decreased aldehyde dehydrogenase (AldDH) activities are also representative of inflammatory settings. Increasing the conversion of agmatine to an aldehyde form by addition of purified DAO or suppression of aldehyde breakdown by inhibition of AldDH activity increases the inhibitory effects of agmatine in an additive fashion. Inhibitors of DAO, but not monoamine oxidase (MAO), decreased the inhibitory effects of agmatine, as did the addition of AldDH or reacting aldehydes with phenylhydrazine. We examined rats given lipopolysaccharide (LPS) to evaluate the potential effects of agmatine in vivo. Endotoxic rats administered agmatine prevented the decreases in blood pressure and renal function normally associated with sepsis. Agmatine treatment also increased the survival of LPS treated mice. Our data demonstrate the capacity of agmatine aldehyde to suppress iNOS mediated NO generation, and indicate a protective function of agmatine in a model of endotoxic shock. How agmatine may aid in coordinating the early NO phase and the later repair phase responses in models of inflammation is discussed.
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Affiliation(s)
- J Satriano
- Division of Nephrology-Hypertension, Department of Medicine, University of California, San Diego 92161, USA.
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Mistry SK, Zheng M, Rouse BT, Morris SM. Induction of arginases I and II in cornea during herpes simplex virus infection. Virus Res 2001; 73:177-82. [PMID: 11172921 DOI: 10.1016/s0168-1702(00)00243-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Induction of inducible nitric oxide synthase (iNOS) following corneal infection with herpes simplex virus type-1 (HSV-1) generates nitric oxide (NO), an important player in the defense against viral infection. Changes in arginine metabolism during infection are not limited to effects of iNOS but can also involve arginases, which can modulate NO synthesis and produce ornithine for the generation of polyamines and proline. The latter are important molecules involved in tissue damage and repair during inflammation. In this study we determined the responses of arginase I and II in a murine model of HSV-1-induced stromal keratitis (HSK). In the cornea iNOS and arginase II mRNA were co-induced as the initial inflammation developed at 2 days postinfection (p.i.). As stromal keratitis progressed (days 8-15 p.i.) arginase I mRNA was induced tenfold, in contrast to a moderate decrease in arginase II and a loss of iNOS expression. These results suggest that elevated expression of arginase I and II in the cornea at late stages of ocular HSV-1 infection may play a role in lesion expression in HSK.
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Affiliation(s)
- S K Mistry
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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Mastrangelo D, Frossard JL, Hadengue A, Pastor CM. Sepsis decreases the spontaneous and agonist-induced contractile activities in the rat portal vein. J Hepatol 2000; 33:933-40. [PMID: 11131455 DOI: 10.1016/s0168-8278(00)80125-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS The portal vein has spontaneous and agonist-induced contractile activities and whether sepsis alters these two types of contractile activities is unknown. METHODS To study the effect of sepsis on the spontaneous contractile activity and the contractile responses to norepinephrine (NE), angiotensin II (AT(II)), and neurokinin B (NKB) in the rat portal vein (RPV), we performed a cecal ligature and puncture (CLP) 24 h before RPV isolation. RESULTS CLP decreased the spontaneous activity and induced hyporesponsiveness to AT(II) and NKB. The vascular failure was correlated to the severity of sepsis. In contrast, the reactivity to NE was not altered. Although inducible NO synthase was detected in RPV isolated from CLP rats, NO synthase inhibitors did not restore either the responsiveness to AT(II) and NKB or the spontaneous activity. Additionally, hyporesponsiveness to AT(II) and NKB was not modified by indomethacin. CONCLUSIONS CLP decreases the spontaneous activity of the RPV as well as the contractile responses to AT(II) and NKB. The vascular failure is correlated to the severity of sepsis. The reactivity to NE is not altered in this model. Neither NO nor prostaglandins are responsible for the vascular abnormalities observed during CLP.
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Affiliation(s)
- D Mastrangelo
- Clinique d'Urologie and Division d'Hépatologie et de Gastro-entérologie, H pital Cantonal Universitaire de Genève, Switzerland
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Kielbasa W, Fung HL. Nitrite inhalation in rats elevates tissue NOS III expression and alters tyrosine nitration and phosphorylation. Biochem Biophys Res Commun 2000; 275:335-42. [PMID: 10964667 DOI: 10.1006/bbrc.2000.3324] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Organic nitrites are nitric oxide (NO) donors that are used predominantly as inhalant drugs of abuse and have been shown to have immunomodulating effects. NO donors can modulate NOS activity and expression, thus altering the level of endogenous NO production. NO can react with superoxide (O(*)(2)(-)) to form peroxynitrite (ONOO(-)), which can nitrate tyrosine residues in proteins and alter tyrosine phosphorylation. We investigated the effects of inhaled isobutyl nitrite (ISBN) on NOS expression, tyrosine nitration, and tyrosine phosphorylation in selected organs of rats. Following exposures of 109 and 1517 ppm ISBN for 4 h, the lung, spleen, liver, and kidney were removed and assayed by SDS-PAGE for NOS III (eNOS), NOS II (iNOS), nitrotyrosine (NT)- and phosphotyrosine (PT)-immunoreactive proteins using specific antibodies. ISBN at 1517 ppm, but not 109 ppm, caused an increase in NOS III expression in the liver and kidney, but not in the lung and spleen. No apparent effect on NOS II expression was observed in these organs. The expressions of NT and PT protein bands (30-200 kDa) were increased in the liver and kidney, but not in the lung and spleen. This increase in NT persisted for 24 h post-exposure. Increased NOS III expression in the liver and kidney may promote peroxynitrite formation and contribute to the increase in NT and PT immunoreactivity. ISBN inhalation may thus cause changes in cellular signaling involving tyrosine phosphorylation. These findings may suggest a mechanistic basis for the apparent immunotoxicity associated with nitrite abuse.
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Affiliation(s)
- W Kielbasa
- Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, DC 0710, Indianapolis, Indiana 46285, USA
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Abstract
The immediate metabolic response to a septic challenge is probably adaptive, meaning that nutritional interference, mainly via the parenteral route, during this early phase of instability can do more harm than good. During the later phases, a gradual increase in enteral nutrition, at the expense of parenteral nutrition, combined with the administration of nutraceuticals such as glutamine and omega-3 fatty acids, can counteract wasting and modulate the complex inflammatory response and immunosuppression associated with sepsis. In these times of scarce resources, there is an urgent need to clearly document the efficacy of immuno/pharmaconutrients, individually and in combination, enterally or parenterally, before proposing them for routine management of septic patients in the intensive care unit.
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Affiliation(s)
- Gérard Nitenberg
- Department of Anesthesia, Analgesia, Intensive Care and Infectious Diseases, Institut Gustave Roussy, Villejuif, France
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Lortie MJ, Ishizuka S, Schwartz D, Blantz RC. Bioactive products of arginine in sepsis: tissue and plasma composition after LPS and iNOS blockade. Am J Physiol Cell Physiol 2000; 278:C1191-9. [PMID: 10837347 DOI: 10.1152/ajpcell.2000.278.6.c1191] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Blockade or gene deletion of inducible nitric oxide synthase (iNOS) fails to fully abrogate all the sequelae leading to the high morbidity of septicemia. An increase in substrate uptake may be necessary for the increased production of nitric oxide (NO), but arginine is also a precursor for other bioactive products. Herein, we demonstrate an increase in alternate arginine products via arginine and ornithine decarboxylase in rats given lipopolysaccharide (LPS). The expression of iNOS mRNA in renal tissue was evident 60 but not 30 min post-LPS, yet a rapid decrease in blood pressure was obtained within 30 min that was completely inhibited by selective iNOS blockade. Plasma levels of arginine and ornithine decreased by at least 30% within 60 min of LPS administration, an effect not inhibited by the iNOS blocker L-N(6)(1-iminoethyl)lysine (L-NIL). Significant increases in plasma nitrates and citrulline occurred only 3-4 h post-LPS, an effect blocked by L-NIL pretreatment. The intracellular composition of organs harvested 6 h post-LPS reflected tissue-specific profiles of arginine and related metabolites. Tissue arginine concentration, normally an order of magnitude higher than in plasma, did not decrease after LPS. Pretreatment with L-NIL had a significant impact on the disposition of tissue arginine that was organ specific. These data demonstrate changes in arginine metabolism before and after de novo iNOS activity. Selective blockade of iNOS did not prevent uptake and can deregulate the production of other bioactive arginine metabolites.
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Affiliation(s)
- M J Lortie
- Division of Nephrology/Hypertension, University of California San Diego School of Medicine and Veterans Affairs Health Care System, San Diego 92161, USA.
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Pulido EJ, Shames BD, Fullerton DA, Sheridan BC, Selzman CH, Gamboni-Robertson F, Bensard DD, McIntyre RC. Differential inducible nitric oxide synthase expression in systemic and pulmonary vessels after endotoxin. Am J Physiol Regul Integr Comp Physiol 2000; 278:R1232-9. [PMID: 10801292 DOI: 10.1152/ajpregu.2000.278.5.r1232] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Inducible nitric oxide synthase (iNOS) is associated with vascular hypocontractility in systemic vessels after endotoxin lipopolysaccharide (LPS) administration. Although lung iNOS is increased after LPS, its role in the pulmonary circulation is unclear. We hypothesized that whereas iNOS upregulation is responsible for LPS-induced vascular dysfunction in systemic vessels, iNOS does not play a significant role in the pulmonary artery (PA). Using isolated aorta (AO) and PA rings, we examined the effect of nonselective NOS inhibition [N(G)-monomethyl-L-arginine (L-NMMA); 100 micromol/l] and selective iNOS inhibition (aminoguanidine, AG; 100 micromol/l) on alpha(1)-adrenergic-mediated vasoconstriction (phenylephrine; 10(-9) to 10(-3) M) after LPS (Salmonella typhimurium, 20 mg/kg ip). We also determined the presence of iNOS using Western blot and immunohistochemistry. LPS markedly impaired AO contractility (maximal control tension 1,076 +/- 33 mg vs. LPS 412 +/- 39 mg, P < 0.05), but PA contractility was unchanged (control 466 +/- 29 mg vs. LPS 455 +/- 27 mg, P > 0.05). Selective iNOS inhibition restored the AO's response to vasoconstriction (LPS + AG 1,135 +/- 54 mg, P > 0.05 vs. control and P < 0.05 vs. LPS), but had no effect on the PA (LPS + AG 422 +/- 38 mg, P > 0.05 vs. control and LPS). Western blot and immunohistochemistry revealed increased iNOS expression in the AO after LPS, but iNOS was not detected in the PA. Our results suggest that differential iNOS expression after LPS in systemic and pulmonary vessels contributes to the phenomenon of sepsis/endotoxemia-induced systemic hypotension and pulmonary hypertension.
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Affiliation(s)
- E J Pulido
- Department of Surgery, University of Colorado Health Sciences Center Denver 80262, Colorado, USA
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Vyas JR, Currie AE, Shuker DE, Field DJ, Kotecha S. Concentration of nitric oxide products in bronchoalveolar fluid obtained from infants who develop chronic lung disease of prematurity. Arch Dis Child Fetal Neonatal Ed 1999; 81:F217-20. [PMID: 10525028 PMCID: PMC1721017 DOI: 10.1136/fn.81.3.f217] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To determine if nitric oxide (NO) products (nitrate and nitrite) are increased in bronchoalveolar lavage (BAL) fluid obtained from infants who develop chronic lung disease of prematurity (CLD). METHODS One hundred and thirty six serial bronchoalveolar lavages were performed on 37 ventilated infants (12 with CLD, 18 with respiratory distress syndrome (RDS), and seven control infants) who did not receive inhaled NO. RESULTS During the first week of life nitrate concentration was between 25-31 micromol/l in all three groups. Thereafter, the concentration of BAL fluid nitrate decreased to 14 micromol/l and 5.5 micromol/l, respectively in the RDS and control groups by 14 days of age. In contrast, nitrate in the CLD infants remained constant until 28 days of age (31.3 micromol/l at day 14; p<0.05). In all BAL fluid samples the mean concentration of nitrite was <1.2 micromol/l throughout the first 28 days with no significant differences noted among the three groups. CONCLUSION The similar concentration of BAL fluid nitrate in all groups during the first week of life suggest that NO may be important in the adaptation of the pulmonary circulation after birth. However, persistence of nitrate in the BAL fluid of infants with CLD during the second week may reflect pulmonary maladaptation, or, more likely, persisting pulmonary inflammation.
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Affiliation(s)
- J R Vyas
- Department of Child Health, Centre for Mechanisms of Human Toxicity, University of Leicester, Leicester LE2 7LX
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Munder M, Eichmann K, Morán JM, Centeno F, Soler G, Modolell M. Th1/Th2-Regulated Expression of Arginase Isoforms in Murine Macrophages and Dendritic Cells. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.7.3771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Activated murine macrophages metabolize arginine by two alternative pathways involving the enzymes inducible NO synthase (iNOS) or arginase. The balance between the two enzymes is competitively regulated by Th1 and Th2 T helper cells via their secreted cytokines: Th1 cells induce iNOS, whereas Th2 cells induce arginase. Whereas the role of macrophages expressing iNOS as inflammatory cells is well established, the functional competence of macrophages expressing arginase remains a matter of speculation. Two isoforms of mammalian arginases exist, hepatic arginase I and extrahepatic arginase II. We investigated the regulation of arginase isoforms in murine bone marrow-derived macrophages (BMMΦ) in the context of Th1 and Th2 stimulation. Surprisingly, in the presence of either Th2 cytokines or Th2 cells, we observe a specific induction of the hepatic isoform arginase I in BMMΦ. Induction of arginase I was shown on the mRNA and protein levels and obeyed the recently demonstrated synergism among the Th2 cytokines IL-4 and IL-10. Arginase II was detectable in unstimulated BMMΦ and was not significantly modulated by Th1 or Th2 stimulation. Similar to murine BMMΦ, murine bone marrow-derived dendritic cells, as well as a dendritic cell line, up-regulated arginase I expression and arginase activity upon Th2 stimulation, whereas arginase II was never detected. In addition to revealing the unexpected expression of arginase I in the macrophage/monocyte lineage, these results uncover a further intriguing parallelism between iNOS and arginase: both have a constitutive and an inducible isoform, the latter regulated by the Th1/Th2 balance.
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Affiliation(s)
- Markus Munder
- *Max-Planck-Institut für Immunbiologie, Freiburg, Germany; and
| | - Klaus Eichmann
- *Max-Planck-Institut für Immunbiologie, Freiburg, Germany; and
| | - José M. Morán
- †Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Universidad de Extremadura, Cáceres, Spain
| | - Francisco Centeno
- †Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Universidad de Extremadura, Cáceres, Spain
| | - Germán Soler
- †Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Universidad de Extremadura, Cáceres, Spain
| | - Manuel Modolell
- *Max-Planck-Institut für Immunbiologie, Freiburg, Germany; and
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Park KW, Tofukuji M, Metais C, Comunale ME, Dai HB, Simons M, Stahl GL, Agah A, Sellke FW. Attenuation of Endothelium-Dependent Dilation of Pig Pulmonary Arterioles After Cardiopulmonary Bypass Is Prevented by Monoclonal Antibody to Complement C5a. Anesth Analg 1999. [DOI: 10.1213/00000539-199907000-00008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Park KW, Tofukuji M, Metais C, Comunale ME, Dai HB, Simons M, Stahl GL, Agah A, Sellke FW. Attenuation of endothelium-dependent dilation of pig pulmonary arterioles after cardiopulmonary bypass is prevented by monoclonal antibody to complement C5a. Anesth Analg 1999; 89:42-8. [PMID: 10389776 DOI: 10.1097/00000539-199907000-00008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
UNLABELLED We examined whether pulmonary endothelial dysfunction associated with cardiopulmonary bypass (CPB) may be mediated by complement C5a in pigs. Pigs were placed on normothermic CPB for 1 h with or without a previous administration of 1.6 mg/kg anti-C5a monoclonal antibody (MAb), then reperfused for 2 h. Pulmonary tissue myeloperoxidase activity was measured. Expression of nitric oxide synthase (NOS) was measured by reverse transcriptase polymerase chain reaction and Western blotting. Pulmonary arterioles approximately 100 microm in diameter were preconstricted with the thromboxane analog U46619 1 microM, and relaxation responses to adenosine diphosphate 10(-9)-10(-4) M, substance P 10(-12)-10(-6) M, and sodium nitroprusside 10(-9)-10(-4) M were examined in vitro by videomicroscopy. Relaxation to the endothelium-dependent dilators adenosine diphosphate and substance P was attenuated after CPB; this attenuation was prevented by the previous administration of MAb. Relaxation to sodium nitroprusside was not affected by CPB. Neutrophil sequestration, as measured by MPO activity, increased after CPB, either with or without MAb. Transcription of NOS was unchanged by CPB, but translation of constitutive NOS was decreased after CPB, and this decrease was prevented by a previous administration of MAb. We conclude that pig pulmonary endothelial dysfunction associated with CPB may be mediated by C5a. The mechanism may involve changes in NOS translation. IMPLICATIONS In pigs, pulmonary endothelial dysfunction may occur after cardiopulmonary bypass due to product(s) of complement activation.
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Affiliation(s)
- K W Park
- Department of Anesthesia and Critical Care, Beth Israel Deaconess Medical Center and Center for Experimental Therapeutics and Reperfusion Injury, Harvard Medical School, Boston, Massachusetts 02215, USA.
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