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Frank BS, Niemiec S, Khailova L, Mancuso CA, Lehmann T, Mitchell MB, Morgan GJ, Twite M, DiMaria MV, Klawitter J, Davidson JA. Arginine-NO metabolites are associated with morbidity in single ventricle infants undergoing stage 2 palliation. Pediatr Res 2024; 96:347-355. [PMID: 38565916 DOI: 10.1038/s41390-024-03162-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 02/01/2024] [Accepted: 03/01/2024] [Indexed: 04/04/2024]
Abstract
BACKGROUND Infants with single ventricle heart disease (SVHD) suffer morbidity from insufficient pulmonary blood flow, which may be related to impaired arginine metabolism. No prior study has reported quantitative mapping of arginine metabolites to evaluate the relationship between circulating metabolite levels and outcomes. METHODS Prospective cohort study of 75 SVHD cases peri-Stage 2 and 50 healthy controls. We targeted pre- and post-op absolute serum quantification of 9 key members of the arginine metabolism pathway by tandem mass spectrometry. Primary outcomes were length of stay (LOS) and post-Stage 2 hypoxemia. RESULTS Pre-op cases showed alteration in 6 metabolites including decreased arginine and increased asymmetric dimethyl arginine (ADMA) levels compared to controls. Post-op cases demonstrated decreased arginine and citrulline levels persisting through 48 h. Adjusting for clinical variables, lower pre-op and 2 h post-op concentrations of multiple metabolites, including arginine and citrulline, were associated with longer post-op LOS (p < 0.01). Increased ADMA at 24 h was associated with greater post-op hypoxemia burden (p < 0.05). CONCLUSION Arginine metabolism is impaired in interstage SVHD infants and is further deranged following Stage 2 palliation. Patients with greater metabolite alterations experience greater post-op morbidity. Decreased arginine metabolism may be an important driver of pathology in SVHD. IMPACT Interstage infants with SVHD have significantly altered arginine-nitric oxide metabolism compared to healthy children with deficiency of multiple pathway intermediates persisting through 48 h post-Stage 2 palliation. After controlling for clinical covariates and classic catheterization-derived predictors of Stage 2 readiness, both lower pre-operation and lower post-operation circulating metabolite levels were associated with longer post-Stage 2 LOS while increased post-Stage 2 ADMA concentration was associated with greater post-op hypoxemia. Arginine metabolism mapping offers potential for development using personalized medicine strategies as a biomarker of Stage 2 readiness and therapeutic target to improve pulmonary vascular health in infants with SVHD.
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Affiliation(s)
- Benjamin S Frank
- University of Colorado Department of Pediatrics, Section of Cardiology, Denver, CO, USA.
| | - Sierra Niemiec
- University of Colorado Department of Biostatistics and Informatics, Denver, CO, USA
| | - Ludmila Khailova
- University of Colorado Department of Pediatrics, Section of Cardiology, Denver, CO, USA
| | | | - Tanner Lehmann
- University of Colorado Department of Pediatrics, Section of Cardiology, Denver, CO, USA
| | - Max B Mitchell
- University of Colorado Department of Surgery, Denver, CO, USA
| | - Gareth J Morgan
- University of Colorado Department of Pediatrics, Section of Cardiology, Denver, CO, USA
| | - Mark Twite
- University of Colorado Department of Anesthesiology, Denver, CO, USA
| | - Michael V DiMaria
- University of Colorado Department of Pediatrics, Section of Cardiology, Denver, CO, USA
| | - Jelena Klawitter
- University of Colorado Department of Anesthesiology, Denver, CO, USA
| | - Jesse A Davidson
- University of Colorado Department of Pediatrics, Section of Cardiology, Denver, CO, USA
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Gu C, Yin Y, Sun Y, Liu J, Li X, Zhang X. Exploring the mechanism of lung injury induced by lunar dust simulant in rats based on metabolomic analysis. ENVIRONMENTAL TOXICOLOGY 2024; 39:184-198. [PMID: 37681755 DOI: 10.1002/tox.23967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 05/30/2023] [Accepted: 08/27/2023] [Indexed: 09/09/2023]
Abstract
Inflammatory response and oxidative stress are considered to be important mechanisms of lung injury induced by lunar dust. However, the pulmonary toxicological mechanism remains unclear. In the present study, Wistar rats were exposed to CLDS-i 7 days/week, 4 h/day, for 4 weeks in the mouth and nose. Lung tissue samples were collected for histopathological analysis and ultra-performance liquid chromatography-mass spectrometry analysis. Enzyme activities and expression levels of key metabolic enzymes were detected by biochemical analysis and real-time PCR. The pathological features of lung tissue showed that CLDS-i caused congestion and inflammation in the lungs, and the lung structure was severely damaged. Metabolomics analysis showed that 141 metabolites were significantly changed in the lung tissue of the CLDS-i group compared with the control group. Combined with Kegg pathway analysis, it was found that the changes of amino acid metabolites were involved in these pathways, indicating that the simulated lunar dust exposure had the most obvious effect on amino acid metabolism in the lung tissue of rats. Real-time PCR analysis showed that the mRNA expression of six key enzymes related to amino acid metabolism was changed, and the enzyme activities of these key enzymes were also changed, which were consistent with the results of qPCR. These results suggest that changes in amino acid metabolism may be closely related to the pathogenesis of lung injury induced by lunar dust, and amino acid metabolism may be a potential biomarker of lung diseases related to lunar dust exposure.
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Affiliation(s)
- Chen Gu
- College of Basic Medical Sciences, Shenyang Medical College, Shenyang, China
| | - Yuhang Yin
- College of Basic Medical Sciences, Shenyang Medical College, Shenyang, China
| | - Yan Sun
- College of Pharmacy, Shenyang Medical College, Shenyang, China
| | - Jinguo Liu
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China
| | - Xiongyao Li
- Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China
| | - Xiaoping Zhang
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Taipa, China
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Furlong MA, Liu T, Snider JM, Tfaily MM, Itson C, Beitel S, Parsawar K, Keck K, Galligan J, Walker DI, Gulotta JJ, Burgess JL. Evaluating changes in firefighter urinary metabolomes after structural fires: an untargeted, high resolution approach. Sci Rep 2023; 13:20872. [PMID: 38012297 PMCID: PMC10682406 DOI: 10.1038/s41598-023-47799-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 11/18/2023] [Indexed: 11/29/2023] Open
Abstract
Firefighters have elevated rates of urinary tract cancers and other adverse health outcomes, which may be attributable to environmental occupational exposures. Untargeted metabolomics was applied to characterize this suite of environmental exposures and biological changes in response to occupational firefighting. 200 urine samples from 100 firefighters collected at baseline and two to four hours post-fire were analyzed using untargeted liquid-chromatography and high-resolution mass spectrometry. Changes in metabolite abundance after a fire were estimated with fixed effects linear regression, with false discovery rate (FDR) adjustment. Partial least squares discriminant analysis (PLS-DA) was also used, and variable important projection (VIP) scores were extracted. Systemic changes were evaluated using pathway enrichment for highly discriminating metabolites. Metabolome-wide-association-study (MWAS) identified 268 metabolites associated with firefighting activity at FDR q < 0.05. Of these, 20 were annotated with high confidence, including the amino acids taurine, proline, and betaine; the indoles kynurenic acid and indole-3-acetic acid; the known uremic toxins trimethylamine n-oxide and hippuric acid; and the hormone 7a-hydroxytestosterone. Partial least squares discriminant analysis (PLS-DA) additionally implicated choline, cortisol, and other hormones. Significant pathways included metabolism of urea cycle/amino group, alanine and aspartate, aspartate and asparagine, vitamin b3 (nicotinate and nicotinamide), and arginine and proline. Firefighters show a broad metabolic response to fires, including altered excretion of indole compounds and uremic toxins. Implicated pathways and features, particularly uremic toxins, may be important regulators of firefighter's increased risk for urinary tract cancers.
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Affiliation(s)
- Melissa A Furlong
- Environmental Health Sciences, Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N Martin Ave, Tucson, AZ, 85724, USA.
| | - Tuo Liu
- Environmental Health Sciences, Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N Martin Ave, Tucson, AZ, 85724, USA
| | - Justin M Snider
- School of Nutritional Sciences and Wellness, University of Arizona, Tucson, USA
- University of Arizona Cancer Center, Tucson, USA
| | - Malak M Tfaily
- Department of Environmental Science, University of Arizona, Tucson, USA
| | - Christian Itson
- Department of Environmental Science, University of Arizona, Tucson, USA
| | - Shawn Beitel
- Environmental Health Sciences, Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N Martin Ave, Tucson, AZ, 85724, USA
| | - Krishna Parsawar
- Analytical and Biological Mass Spectrometry Core, University of Arizona, Tucson, USA
| | - Kristen Keck
- Analytical and Biological Mass Spectrometry Core, University of Arizona, Tucson, USA
| | | | - Douglas I Walker
- Gangarosa Department of Environmental Health, Emory University Rollins School of Public Health, Atlanta, GA, USA
| | | | - Jefferey L Burgess
- Environmental Health Sciences, Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N Martin Ave, Tucson, AZ, 85724, USA
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Mahung C, Stepp WH, Long C, Malfitano M, Saklayici I, Wallet SM, Zhou LY, Zhou H, Cairns BA, Maile R. Early expression of IL-10, IL-12, ARG1, and NOS2 genes in peripheral blood mononuclear cells synergistically correlate with patient outcome after burn injury. J Trauma Acute Care Surg 2022; 93:702-711. [PMID: 35363228 PMCID: PMC9522922 DOI: 10.1097/ta.0000000000003602] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 02/21/2022] [Accepted: 02/27/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND No methods exist to rapidly and accurately quantify the immune insult created by burn injuries. The development of a rapid, noninvasive clinical biomarker assay that evaluates a burn patient's underlying immune dysfunction and predicts clinical outcomes could transform burn care. We aimed to determine a set of peripheral biomarkers that correlates with clinical outcomes of burn patients. METHODS This prospective observational study enrolled two patient cohorts within a single burn center into an institutionally approved institutional review board study. Blood draws were performed <48 hours after injury. Initial unbiased immune gene expression analysis compared 23 burn patients and 6 healthy controls using multiplex immune gene expression analysis of RNA from peripheral blood mononuclear cells. We then performed confirmatory outcomes analysis in 109 burn patients and 19 healthy controls using a targeted rapid quantitative polymerase chain reaction. Findings were validated and modeled associations with clinical outcomes using a regression model. RESULTS A total of 149 genes with a significant difference in expression from burn patients compared with controls were identified. Pathway analysis identified pathways related to interleukin (IL)-10 and inducible nitric oxide synthase signaling to have significant z scores. quantitative polymerase chain reaction analysis of IL-10, IL-12, arginase 1 (ARG1), and inducible nitric oxide synthase demonstrated that burn injury was associated with increased expression of ARG1 and IL-10, and decreased expression of nitric oxide synthase 2 (NOS2) and IL-12. Burn severity, acute lung injury, development of infection, failure of skin autograft, and mortality significantly correlated with expression of one or more of these genes. Ratios of IL-10/IL-12, ARG1/NOS2, and (ARG1-IL-10)/(NOS2-IL-12) transcript levels further improved the correlation with outcomes. Using a multivariate regression model, adjusting for patient confounders demonstrated that (ARG1-IL-10)/(NOS2-IL-12) significantly correlated with burn severity and development of acute lung injury. CONCLUSION We present a means to predict patient outcomes early after burn injury using peripheral blood, allowing early identification of underlying immune dysfunction. LEVEL OF EVIDENCE Prognostic/Epidemiological; Level II.
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Lu Q, Zemskov EA, Sun X, Wang H, Yegambaram M, Wu X, Garcia-Flores A, Song S, Tang H, Kangath A, Cabanillas GZ, Yuan JXJ, Wang T, Fineman JR, Black SM. Activation of the mechanosensitive Ca 2+ channel TRPV4 induces endothelial barrier permeability via the disruption of mitochondrial bioenergetics. Redox Biol 2021; 38:101785. [PMID: 33221570 PMCID: PMC7691184 DOI: 10.1016/j.redox.2020.101785] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/29/2020] [Accepted: 11/01/2020] [Indexed: 12/20/2022] Open
Abstract
Mechanical ventilation is a life-saving intervention in critically ill patients with respiratory failure due to acute respiratory distress syndrome (ARDS), a refractory lung disease with an unacceptable high mortality rate. Paradoxically, mechanical ventilation also creates excessive mechanical stress that directly augments lung injury, a syndrome known as ventilator-induced lung injury (VILI). The specific mechanisms involved in VILI-induced pulmonary capillary leakage, a key pathologic feature of VILI are still far from resolved. The mechanoreceptor, transient receptor potential cation channel subfamily V member 4, TRPV4 plays a key role in the development of VILI through unresolved mechanism. Endothelial nitric oxide synthase (eNOS) uncoupling plays an important role in sepsis-mediated ARDS so in this study we investigated whether there is a role for eNOS uncoupling in the barrier disruption associated with TRPV4 activation during VILI. Our data indicate that the TRPV4 agonist, 4α-Phorbol 12,13-didecanoate (4αPDD) induces pulmonary arterial endothelial cell (EC) barrier disruption through the disruption of mitochondrial bioenergetics. Mechanistically, this occurs via the mitochondrial redistribution of uncoupled eNOS secondary to a PKC-dependent phosphorylation of eNOS at Threonine 495 (T495). A specific decoy peptide to prevent T495 phosphorylation reduced eNOS uncoupling and mitochondrial redistribution and preserved PAEC barrier function under 4αPDD challenge. Further, our eNOS decoy peptide was able to preserve lung vascular integrity in a mouse model of VILI. Thus, we have revealed a functional link between TRPV4 activation, PKC-dependent eNOS phosphorylation at T495, and EC barrier permeability. Reducing pT495-eNOS could be a new therapeutic approach for the prevention of VILI.
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Affiliation(s)
- Qing Lu
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA
| | - Evgeny A Zemskov
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA
| | - Xutong Sun
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA
| | - Hui Wang
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA; College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Manivannan Yegambaram
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA
| | - Xiaomin Wu
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA
| | - Alejandro Garcia-Flores
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA
| | - Shanshan Song
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA
| | - Haiyang Tang
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA; College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Archana Kangath
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA
| | - Gabriela Zubiate Cabanillas
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA; Department of Chemist-Biological Sciences, Universidad de Sonora, Hermosillo, SON, Mexico
| | - Jason X-J Yuan
- Department of Medicine, University of California, San Diego, CA, USA
| | - Ting Wang
- Department of Internal Medicine, The University of Arizona Health Sciences, Phoenix, AZ, USA
| | - Jeffrey R Fineman
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA; Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | - Stephen M Black
- Department of Medicine, Division of Translational & Regenerative Medicine, University of Arizona, Tucson, AZ, USA.
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6
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Epithelial Dysfunction in Lung Diseases: Effects of Amino Acids and Potential Mechanisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1265:57-70. [PMID: 32761570 DOI: 10.1007/978-3-030-45328-2_4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lung diseases affect millions of individuals all over the world. Various environmental factors, such as toxins, chemical pollutants, detergents, viruses, bacteria, microbial dysbiosis, and allergens, contribute to the development of respiratory disorders. Exposure to these factors activates stress responses in host cells and disrupt lung homeostasis, therefore leading to dysfunctional epithelial barriers. Despite significant advances in therapeutic treatments for lung diseases in the last two decades, novel interventional targets are imperative, considering the side effects and limited efficacy in patients treated with currently available drugs. Nutrients, such as amino acids (e.g., arginine, glutamine, glycine, proline, taurine, and tryptophan), peptides, and bioactive molecules, have attracted more and more attention due to their abilities to reduce oxidative stress, inhibit apoptosis, and regulate immune responses, thereby improving epithelial barriers. In this review, we summarize recent advances in amino acid metabolism in the lungs, as well as multifaceted functions of amino acids in attenuating inflammatory lung diseases based on data from studies with both human patients and animal models. The underlying mechanisms for the effects of physiological amino acids are likely complex and involve cell signaling, gene expression, and anti-oxidative reactions. The beneficial effects of amino acids are expected to improve the respiratory health and well-being of humans and other animals. Because viruses (e.g., coronavirus) and environmental pollutants (e.g., PM2.5 particles) induce severe damage to the lungs, it is important to determine whether dietary supplementation or intravenous administration of individual functional amino acids (e.g., arginine-HCl, citrulline, N-acetylcysteine, glutamine, glycine, proline and tryptophan) or their combinations to affected subjects may alleviate injury and dysfunction in this vital organ.
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Intravenous Arginine Administration Downregulates NLRP3 Inflammasome Activity and Attenuates Acute Kidney Injury in Mice with Polymicrobial Sepsis. Mediators Inflamm 2020; 2020:3201635. [PMID: 32454788 PMCID: PMC7238342 DOI: 10.1155/2020/3201635] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/29/2020] [Accepted: 04/20/2020] [Indexed: 12/18/2022] Open
Abstract
Acute kidney injury (AKI) is a major complication of sepsis. Nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasomes are multiprotein complexes that mediate septic AKI. L-arginine (Arg) is a conditionally essential amino acid in catabolic conditions and a substrate for nitric oxide (NO) production; however, its use in sepsis is controversial. This study investigated the effect of intravenous Arg supplementation on modulating NLRP3 inflammasome activity in relation to septic AKI. Mice were divided into normal control (NC), sham, sepsis saline (SS), and sepsis Arg (SA) groups. In order to investigate the role of NO, L-N6-(1-iminoethyl)-lysine hydrochloride (L-NIL), an inducible NO synthase inhibitor, was administered to the sepsis groups. Sepsis was induced using cecal ligation and puncture (CLP). The SS and SA groups received saline or Arg via tail vein 1 h after CLP. Mice were sacrificed at 6, 12, and 24 h after sepsis. The results showed that compared to the NC group, septic mice had higher plasma kidney function parameters and lower Arg levels. Also, renal NLRP3 inflammasome protein expression and tubular injury score increased. After Arg treatment, plasma Arg and NO levels increased, kidney function improved, and expressions of renal NLRP3 inflammasome-related proteins were downregulated. Changes in plasma NO and renal NLRP3 inflammasome-related protein expression were abrogated when L-NIL was given to the Arg sepsis groups. Arg plus L-NIL administration also attenuated kidney injury after CLP. The findings suggest that intravenous Arg supplementation immediately after sepsis restores plasma Arg levels and is beneficial for attenuating septic AKI, partly via NO-mediated NLRP3 inflammasome inhibition.
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Abstract
This article summarizes research conducted over the last decade in the field of inhalation injury in thermally injured patients. This includes brief summaries of the findings of the 2006 State of the Science meeting with regard to inhalation injury, and of the subsequent 2007 Inhalation Injury Consensus Conference. The reviewed studies are categorized in to five general areas: diagnosis and grading; mechanical ventilation; systemic and inhalation therapy; mechanistic alterations; and outcomes.
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Gupta K, Mehrotra M, Kumar P, Gogia AR, Prasad A, Fisher JA. Smoke Inhalation Injury: Etiopathogenesis, Diagnosis, and Management. Indian J Crit Care Med 2018; 22:180-188. [PMID: 29657376 PMCID: PMC5879861 DOI: 10.4103/ijccm.ijccm_460_17] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Smoke inhalation injury is a major determinant of morbidity and mortality in fire victims. It is a complex multifaceted injury affecting initially the airway; however, in short time, it can become a complex life-threatening systemic disease affecting every organ in the body. In this review, we provide a summary of the underlying pathophysiology of organ dysfunction and provide an up-to-date survey of the various critical care modalities that have been found beneficial in caring for these patients. Major pathophysiological change is development of edema in the respiratory tract. The tracheobronchial tree is injured by steam and toxic chemicals, leading to bronchoconstriction. Lung parenchyma is damaged by the release of proteolytic elastases, leading to release of inflammatory mediators, increase in transvascular flux of fluids, and development of pulmonary edema and atelectasis. Decreased levels of surfactant and immunomodulators such as interleukins and tumor-necrosis-factor-α accentuate the injury. A primary survey is conducted at the site of fire, to ensure adequate airway, breathing, and circulation. A good intravenous access is obtained for the administration of resuscitation fluids. Early intubation, preferably with fiberoptic bronchoscope, is prudent before development of airway edema. Bronchial hygiene is maintained, which involves therapeutic coughing, chest physiotherapy, deep breathing exercises, and early ambulation. Pharmacological agents such as beta-2 agonists, racemic epinephrine, N-acetyl cysteine, and aerosolized heparin are used for improving oxygenation of lungs. Newer agents being tested are perfluorohexane, porcine pulmonary surfactant, and ClearMate. Early diagnosis and treatment of smoke inhalation injury are the keys for better outcome.
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Affiliation(s)
- Kapil Gupta
- Department of Anaesthesia, Vardhaman Mahavir Medical College & Safdarjung Hospital, New Delhi, India
| | - Mayank Mehrotra
- Department of Anesthesia, Integral Institute of Medical Sciences, Lucknow, India
| | - Parul Kumar
- Department of Emergency Medicine, Sinai Health Systems, Chicago, USA
| | - Anoop Raj Gogia
- Department of Anaesthesia, Vardhaman Mahavir Medical College & Safdarjung Hospital, New Delhi, India
| | - Arun Prasad
- Department of Anaesthesia, University Health Network, and University of Toronto, Toronto, Canada
| | - Joseph Arnold Fisher
- Department of Anaesthesia, University Health Network, and University of Toronto, Toronto, Canada
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10
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Arginine Is a Critical Substrate for the Pathogenesis of Pseudomonas aeruginosa in Burn Wound Infections. mBio 2017; 8:mBio.02160-16. [PMID: 28292986 PMCID: PMC5350470 DOI: 10.1128/mbio.02160-16] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Environmental conditions affect bacterial behavior and can greatly influence the course of an infection. However, the environmental cues that elicit bacterial responses in specific infection sites are relatively unknown. Pseudomonas aeruginosa is ubiquitous in nature and typically innocuous. However, it is also one of the most prevalent causes of fatal sepsis in burn wound patients. The aim of this study was to determine the impact of environmental factors, specifically the availability of arginine, on the pathogenesis of P. aeruginosa in burn wound infections. Comparison of burned versus noninjured tissue revealed that l-arginine (l-Arg) was significantly depleted in burn wounds as a consequence of elevated arginase produced by myeloid-derived suppressor cells. We also observed that l-Arg was a potent chemoattractant for P. aeruginosa, and while low concentrations of l-Arg increased P. aeruginosa’s swimming motility, high concentrations resulted in diminished swimming. Based on these observations, we tested whether the administration of exogenous l-Arg into the burn wound could attenuate the virulence of P. aeruginosa in thermally injured mice. Administration of l-Arg resulted in decreased P. aeruginosa spread and sepsis and increased animal survival. Taken together, these data demonstrate that the availability of environmental arginine greatly influences the virulence of P. aeruginosa in vivo and may represent a promising phenotype-modulating tool for future therapeutic avenues. Despite our growing understanding of the pathophysiology of burn wounds and the evolution of techniques and practices to manage infections, sepsis remains a significant medical concern for burn patients. P. aeruginosa continues to be a leader among all causes of bacteremic infections due to its tendency to cause complications in immunocompromised patients and its ubiquitous presence in the hospital setting. With the unforgiving emergence of multidrug-resistant strains, it is critical that alternative strategies to control or prevent septic infections in burn patients be developed in parallel with novel antimicrobial agents. In this study, we observed that administration of l-Arg significantly reduced bacterial spread and sepsis in burned mice infected with P. aeruginosa. Given the safety of l-Arg in high doses and its potential wound-healing benefits, this conditionally essential amino acid may represent a useful tool to modulate bacterial behavior in vivo and prevent sepsis in burn patients.
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Kellner M, Noonepalle S, Lu Q, Srivastava A, Zemskov E, Black SM. ROS Signaling in the Pathogenesis of Acute Lung Injury (ALI) and Acute Respiratory Distress Syndrome (ARDS). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 967:105-137. [PMID: 29047084 PMCID: PMC7120947 DOI: 10.1007/978-3-319-63245-2_8] [Citation(s) in RCA: 237] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The generation of reactive oxygen species (ROS) plays an important role for the maintenance of cellular processes and functions in the body. However, the excessive generation of oxygen radicals under pathological conditions such as acute lung injury (ALI) and its most severe form acute respiratory distress syndrome (ARDS) leads to increased endothelial permeability. Within this hallmark of ALI and ARDS, vascular microvessels lose their junctional integrity and show increased myosin contractions that promote the migration of polymorphonuclear leukocytes (PMNs) and the transition of solutes and fluids in the alveolar lumen. These processes all have a redox component, and this chapter focuses on the role played by ROS during the development of ALI/ARDS. We discuss the origins of ROS within the cell, cellular defense mechanisms against oxidative damage, the role of ROS in the development of endothelial permeability, and potential therapies targeted at oxidative stress.
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Affiliation(s)
- Manuela Kellner
- Department of Medicine, Center for Lung Vascular Pathobiology, University of Arizona, 1501 N Campbell Ave., Tucson, AZ, 85719, USA
| | - Satish Noonepalle
- Department of Medicine, Center for Lung Vascular Pathobiology, University of Arizona, 1501 N Campbell Ave., Tucson, AZ, 85719, USA
| | - Qing Lu
- Department of Medicine, Center for Lung Vascular Pathobiology, University of Arizona, 1501 N Campbell Ave., Tucson, AZ, 85719, USA
| | - Anup Srivastava
- Department of Medicine, Center for Lung Vascular Pathobiology, University of Arizona, 1501 N Campbell Ave., Tucson, AZ, 85719, USA
| | - Evgeny Zemskov
- Department of Medicine, Center for Lung Vascular Pathobiology, University of Arizona, 1501 N Campbell Ave., Tucson, AZ, 85719, USA
| | - Stephen M Black
- Department of Medicine, Center for Lung Vascular Pathobiology, University of Arizona, 1501 N Campbell Ave., Tucson, AZ, 85719, USA.
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Wang T, Gross C, Desai AA, Zemskov E, Wu X, Garcia AN, Jacobson JR, Yuan JXJ, Garcia JGN, Black SM. Endothelial cell signaling and ventilator-induced lung injury: molecular mechanisms, genomic analyses, and therapeutic targets. Am J Physiol Lung Cell Mol Physiol 2016; 312:L452-L476. [PMID: 27979857 DOI: 10.1152/ajplung.00231.2016] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 12/08/2016] [Accepted: 12/11/2016] [Indexed: 12/13/2022] Open
Abstract
Mechanical ventilation is a life-saving intervention in critically ill patients with respiratory failure due to acute respiratory distress syndrome (ARDS). Paradoxically, mechanical ventilation also creates excessive mechanical stress that directly augments lung injury, a syndrome known as ventilator-induced lung injury (VILI). The pathobiology of VILI and ARDS shares many inflammatory features including increases in lung vascular permeability due to loss of endothelial cell barrier integrity resulting in alveolar flooding. While there have been advances in the understanding of certain elements of VILI and ARDS pathobiology, such as defining the importance of lung inflammatory leukocyte infiltration and highly induced cytokine expression, a deep understanding of the initiating and regulatory pathways involved in these inflammatory responses remains poorly understood. Prevailing evidence indicates that loss of endothelial barrier function plays a primary role in the development of VILI and ARDS. Thus this review will focus on the latest knowledge related to 1) the key role of the endothelium in the pathogenesis of VILI; 2) the transcription factors that relay the effects of excessive mechanical stress in the endothelium; 3) the mechanical stress-induced posttranslational modifications that influence key signaling pathways involved in VILI responses in the endothelium; 4) the genetic and epigenetic regulation of key target genes in the endothelium that are involved in VILI responses; and 5) the need for novel therapeutic strategies for VILI that can preserve endothelial barrier function.
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Affiliation(s)
- Ting Wang
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Christine Gross
- Vascular Biology Center, Augusta University, Augusta, Georgia
| | - Ankit A Desai
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Evgeny Zemskov
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Xiaomin Wu
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Alexander N Garcia
- Department of Pharmacology University of Illinois at Chicago, Chicago, Illinois; and
| | - Jeffrey R Jacobson
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Jason X-J Yuan
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Joe G N Garcia
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Stephen M Black
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona;
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Inflammatory Mediators and Oxidative Stress in Animals Subjected to Smoke Inhalation: A Systematic Review. Lung 2016; 194:487-99. [DOI: 10.1007/s00408-016-9879-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 04/11/2016] [Indexed: 01/31/2023]
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14
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Stringer KA, McKay RT, Karnovsky A, Quémerais B, Lacy P. Metabolomics and Its Application to Acute Lung Diseases. Front Immunol 2016; 7:44. [PMID: 26973643 PMCID: PMC4770032 DOI: 10.3389/fimmu.2016.00044] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 01/29/2016] [Indexed: 12/27/2022] Open
Abstract
Metabolomics is a rapidly expanding field of systems biology that is gaining significant attention in many areas of biomedical research. Also known as metabonomics, it comprises the analysis of all small molecules or metabolites that are present within an organism or a specific compartment of the body. Metabolite detection and quantification provide a valuable addition to genomics and proteomics and give unique insights into metabolic changes that occur in tangent to alterations in gene and protein activity that are associated with disease. As a novel approach to understanding disease, metabolomics provides a "snapshot" in time of all metabolites present in a biological sample such as whole blood, plasma, serum, urine, and many other specimens that may be obtained from either patients or experimental models. In this article, we review the burgeoning field of metabolomics in its application to acute lung diseases, specifically pneumonia and acute respiratory disease syndrome (ARDS). We also discuss the potential applications of metabolomics for monitoring exposure to aerosolized environmental toxins. Recent reports have suggested that metabolomics analysis using nuclear magnetic resonance (NMR) and mass spectrometry (MS) approaches may provide clinicians with the opportunity to identify new biomarkers that may predict progression to more severe disease, such as sepsis, which kills many patients each year. In addition, metabolomics may provide more detailed phenotyping of patient heterogeneity, which is needed to achieve the goal of precision medicine. However, although several experimental and clinical metabolomics studies have been conducted assessing the application of the science to acute lung diseases, only incremental progress has been made. Specifically, little is known about the metabolic phenotypes of these illnesses. These data are needed to substantiate metabolomics biomarker credentials so that clinicians can employ them for clinical decision-making and investigators can use them to design clinical trials.
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Affiliation(s)
- Kathleen A. Stringer
- Department of Clinical Pharmacy, College of Pharmacy, University of Michigan, Ann Arbor, MI, USA
| | - Ryan T. McKay
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Alla Karnovsky
- Department of Computational Medicine and Bioinformatics, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | | | - Paige Lacy
- Department of Medicine, University of Alberta, Edmonton, AB, Canada
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Steinhoff MS, von Mentzer B, Geppetti P, Pothoulakis C, Bunnett NW. Tachykinins and their receptors: contributions to physiological control and the mechanisms of disease. Physiol Rev 2014; 94:265-301. [PMID: 24382888 DOI: 10.1152/physrev.00031.2013] [Citation(s) in RCA: 413] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The tachykinins, exemplified by substance P, are one of the most intensively studied neuropeptide families. They comprise a series of structurally related peptides that derive from alternate processing of three Tac genes and are expressed throughout the nervous and immune systems. Tachykinins interact with three neurokinin G protein-coupled receptors. The signaling, trafficking, and regulation of neurokinin receptors have also been topics of intense study. Tachykinins participate in important physiological processes in the nervous, immune, gastrointestinal, respiratory, urogenital, and dermal systems, including inflammation, nociception, smooth muscle contractility, epithelial secretion, and proliferation. They contribute to multiple diseases processes, including acute and chronic inflammation and pain, fibrosis, affective and addictive disorders, functional disorders of the intestine and urinary bladder, infection, and cancer. Neurokinin receptor antagonists are selective, potent, and show efficacy in models of disease. In clinical trials there is a singular success: neurokinin 1 receptor antagonists to treat nausea and vomiting. New information about the involvement of tachykinins in infection, fibrosis, and pruritus justifies further trials. A deeper understanding of disease mechanisms is required for the development of more predictive experimental models, and for the design and interpretation of clinical trials. Knowledge of neurokinin receptor structure, and the development of targeting strategies to disrupt disease-relevant subcellular signaling of neurokinin receptors, may refine the next generation of neurokinin receptor antagonists.
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16
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Tan HB, Danilla S, Murray A, Serra R, El Dib R, Henderson TOW, Wasiak J. Immunonutrition as an adjuvant therapy for burns. Cochrane Database Syst Rev 2014; 2014:CD007174. [PMID: 25536183 PMCID: PMC9719413 DOI: 10.1002/14651858.cd007174.pub2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND With burn injuries involving a large total body surface area (TBSA), the body can enter a state of breakdown, resulting in a condition similar to that seen with severe lack of proper nutrition. In addition, destruction of the effective skin barrier leads to loss of normal body temperature regulation and increased risk of infection and fluid loss. Nutritional support is common in the management of severe burn injury, and the approach of altering immune system activity with specific nutrients is termed immunonutrition. Three potential targets have been identified for immunonutrition: mucosal barrier function, cellular defence and local or systemic inflammation. The nutrients most often used for immunonutrition are glutamine, arginine, branched-chain amino acids (BCAAs), omega-3 (n-3) fatty acids and nucleotides. OBJECTIVES To assess the effects of a diet with added immunonutrients (glutamine, arginine, BCAAs, n-3 fatty acids (fish oil), combined immunonutrients or precursors to known immunonutrients) versus an isonitrogenous diet (a diet wherein the overall protein content is held constant, but individual constituents may be changed) on clinical outcomes in patients with severe burn injury. SEARCH METHODS The search was run on 12 August 2012. We searched the Cochrane Injuries Group's Specialised Register, The Cochrane Library, MEDLINE (OvidSP), Embase (OvidSP), ISI WOS SCI-EXPANDED & CPCI-S and four other databases. We handsearched relevant journals and conference proceedings, screened reference lists and contacted pharmaceutical companies. We updated this search in October 2014, but the results of this updated search have not yet been incorporated. SELECTION CRITERIA Randomised controlled trials comparing the addition of immunonutrients to a standard nutritional regimen versus an isonitrogenated diet or another immunonutrient agent. DATA COLLECTION AND ANALYSIS Two review authors were responsible for handsearching, reviewing electronic search results and identifying potentially eligible studies. Three review authors retrieved and reviewed independently full reports of these studies for inclusion. They resolved differences by discussion. Two review authors independently extracted and entered data from the included studies. A third review author checked these data. Two review authors independently assessed the risk of bias of each included study and resolved disagreements through discussion or consultation with the third and fourth review authors. Outcome measures of interest were mortality, hospital length of stay, rate of burn wound infection and rate of non-wound infection (bacteraemia, pneumonia and urinary tract infection). MAIN RESULTS We identified 16 trials involving 678 people that met the inclusion criteria. A total of 16 trials contributed data to the analysis. Of note, most studies failed to report on randomisation methods and intention-to-treat principles; therefore study results should be interpreted with caution. Glutamine was the most common immunonutrient and was given in seven of the 16 included studies. Use of glutamine compared with an isonitrogenous control led to a reduction in length of hospital stay (mean stay -5.65 days, 95% confidence interval (CI) -8.09 to -3.22) and reduced mortality (pooled risk ratio (RR) 0.25, 95% CI 0.08 to 0.78). However, because of the small sample size, it is likely that these results reflect a false-positive effect. No study findings suggest that glutamine has an effect on burn wound infection or on non-wound infection. All other agents investigated showed no evidence of an effect on mortality, length of stay or burn wound infection or non-wound infection rates. AUTHORS' CONCLUSIONS Although we found evidence of an effect of glutamine on mortality reduction, this finding should be taken with care. The number of study participants analysed in this systematic review was not sufficient to permit conclusions that recommend or refute the use of glutamine. Glutamine may be effective in reducing mortality, but larger studies are needed to determine the overall effects of glutamine and other immunonutrition agents.
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Affiliation(s)
- Hannah B Tan
- The Alfred HospitalVictorian Adult Burns ServiceCommercial RoadPrahranVictoriaAustralia
- Monash UniversityMelbourneAustralia
| | - Stefan Danilla
- Hospital Clínico Universidad de ChileDepartamento de CirugiaSantos Dumont 999IndependenciaSantiagoChile
| | - Alexandra Murray
- The Alfred HospitalVictorian Adult Burns ServiceCommercial RoadMelbourneAustralia
| | - Ramón Serra
- Hospital de Las Fuerzas Armadas Punta ArenasHealth Research and DevelopmentSan Carlos de Apoquindo 2200Las CondesSantiagoRegión MetropolitanaChile
| | - Regina El Dib
- Botucatu Medical School, UNESP–Universidade Estadual PaulistaDepartment of AnaesthesiologyDistrito de Rubião Júnior, s/nBotucatu, São PauloBrazil18603‐970
| | - Tom OW Henderson
- The Alfred HospitalVictorian Adult Burns ServiceCommercial RoadMelbourneAustralia
- Oxford UniversityUniversity of Oxford Clinical SchoolJohn Radcliffe HospitalHeadingtonOxfordUKOX3 9DU
| | - Jason Wasiak
- The Epworth HospitalDepartment of Radiation Oncology89 Bridge RdRichmondAustralia3121
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γ-tocopherol nebulization decreases oxidative stress, arginase activity, and collagen deposition after burn and smoke inhalation in the ovine model. Shock 2013; 38:671-6. [PMID: 23160521 DOI: 10.1097/shk.0b013e3182758759] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
More than 20,000 burn injury victims suffer from smoke inhalation injury in the United States annually. In an ovine model of acute lung injury, γ-tocopherol had a beneficial effect when nebulized into the airway. We hypothesize that γ-tocopherol scavenges reactive oxygen species (ROS) and reactive nitrogen species resulting from burn and smoke inhalation injury and that these ROS/reactive nitrogen species activate the arginase pathway, leading to increased collagen deposition and decreased pulmonary function. To test this hypothesis, ewes were operatively prepared for chronic study, then they were randomly divided into groups (n = 8): uninjured, injured, or injured with nebulization (γ-tocopherol [950 mg/g] and α-tocopherol [40 mg/g] from hours 3 to 48 after the injury). The injury, under deep anesthesia, consisted of a 20% total body surface burn and 36 breaths of cotton smoke; all animals were killed after 3 weeks. Treatment increased lung γ-tocopherol at 3 weeks after γ-tocopherol nebulization compared with injured sheep (1.75 ± 0.62 nmol/g vs. 0.45 ± 0.06, P < 0.05). The expression of dimethylarginine dimethylaminohydrolase-2, which degrades asymmetrical dimethylarginine, a nitric oxide synthase inhibitor, significantly increases with γ-tocopherol treatment compared with injured sheep (P < 0.05). Arginase activity (0.15 ± 0.02 μM urea/μg protein vs. 0.24 ± 0.009, P < 0.05), ornithine aminotransferase (11,720 ± 888 vs. 13,170 ± 1,775), and collagen deposition (0.62 ± 0.12 μM hydroxyproline/μg protein vs. 1.02 ± 0.13, P < 0.05) significantly decrease with γ-tocopherol compared with injured animals without γ-tocopherol. The decreases in arginase and collagen with γ-tocopherol are associated with significantly increased diffusion capacity (P < 0.05) and decreased lung wet-to-dry ratio (P < 0.05). Smoke-induced chronic pulmonary dysfunction is mediated through the ROS/asymmetrical dimethylarginine/arginase pathway, and ROS scavengers such as γ-tocopherol may be a potential therapeutic management of burn patients with inhalation injury.
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18
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Method development and validation for rat serum fingerprinting with CE-MS: application to ventilator-induced-lung-injury study. Anal Bioanal Chem 2013; 405:4849-58. [PMID: 23535741 DOI: 10.1007/s00216-013-6882-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Revised: 02/13/2013] [Accepted: 02/27/2013] [Indexed: 02/06/2023]
Abstract
In the search for a noninvasive and reliable rapid screening method to detect biomarkers, a metabolomics fingerprinting approach was developed and applied to rat serum samples using capillary electrophoresis coupled to an electrospray ionization-time of flight-mass spectrometer (CE-TOF-MS). An ultrafiltration method was used for sample pretreatment. To evaluate performance the method was validated with carnitine, choline, ornithine, alanine, acetylcarnitine, betaine, and citrulline, covering the entire electropherogram of pool of rat serum. The linearity for all metabolites was >0.99, with good recovery and precision. Approximately 34 compounds were also confirmed in the pool of rat serum. The method was successfully applied to real serum samples from rats with ventilator-induced lung injury, an experimental rat model for acute lung injury (ALI), giving a total of 1163 molecular features. By use of univariate and multivariate statistics 18 significant compounds were found, of which five were confirmed. The involvement of arginase and nitric oxide synthase has been proved for other lung diseases, meaning the increase of asymmetric dimethyl arginine (ADMA) and ornithine and the decrease of arginine found were in accordance with published literature. Ultimately this fingerprinting approach offers the possibility of identifying biomarkers that could be regularly screened for as part of routine disease control. In this way it might be possible to prevent the development of ALI in patients in critical care units.
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Abstract
More than 50% of severely injured patients have chest trauma. Second insults frequently result in acute lung injury (ALI), with sepsis being the main underlying condition. We aimed to develop a standardized, reproducible, and clinically relevant double-hit mouse model of ALI induced by chest trauma and polymicrobial sepsis and to investigate the pathophysiologic role of activated neutrophils. Lung contusion was applied to C57Bl/6 mice via a focused blast wave. Twenty-four hours later, sepsis was induced by cecal ligation and puncture. For polymorphonuclear leukocyte (PMN) depletion, animals received intravenous injections of PMN-depleting antibody. In response to blunt chest trauma followed by sepsis as well as after sepsis alone, a significant local and systemic inflammatory response with increased cytokine/chemokine levels in lung and plasma was observed. In contrast, lung apoptosis was markedly elevated only after a double hit. Intra-alveolar neutrophils and total bronchoalveolar lavage protein concentrations were markedly increased following isolated chest trauma or the combined insult, but not after sepsis alone. Lung myeloperoxidase activity was enhanced only in response to the double hit accompanied by histological disruption of the alveolar architecture, lung congestion, and marked cellular infiltrates. Neutrophil depletion significantly diminished lung interleukin 1β and interleukin 6 concentrations and reduced the degree of septic ALI. Here we have established a novel and highly reproducible mouse model of chest trauma-induced septic ALI characterizing a clinical relevant double-hit scenario. In particular, the depletion of neutrophils substantially mitigated the extent of lung injury, indicating a pathomechanistic role for neutrophils in chest trauma-induced septic ALI.
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Pseudomonas aeruginosa is associated with increased lung cytokines and asymmetric dimethylarginine compared with methicillin-resistant Staphylococcus aureus. Shock 2012; 36:466-70. [PMID: 21921834 DOI: 10.1097/shk.0b013e3182336b45] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The objective of the study was to investigate pulmonary responses to Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) using ovine and mice models of sepsis with emphasis on lung cytokine expression, asymmetric dimethylarginine (ADMA) concentration, and the arginase pathway. Sheep were instilled with either MRSA, P. aeruginosa, or saline under deep anesthesia; mechanically ventilated; resuscitated with fluid; and killed after 24 h. Mice were instilled with either MRSA, P. aeruginosa, or saline under deep anesthesia and killed after 8 h. Lungs were assessed for ADMA concentration, arginase activity, oxidative stress, and cytokine expression, and plasma was assessed for nitrate/nitrite concentrations. The severity of lung injury was more pronounced in P. aeruginosa sepsis compared with MRSA. The significant changes in sheep lung function after P. aeruginosa sepsis were associated with significantly increased ADMA concentrations and arginase activity compared with MRSA. However, the plasma concentration of nitrites and nitrates were significantly increased in MRSA sepsis compared with P. aeruginosa sepsis. In the mice model, P. aeruginosa significantly increased lung cytokine expression (IL-1 and IL-13), protein oxidation, and arginase activity compared with MRSA. Our data suggest that the greater expression of cytokines and ADMA concentrations may be responsible for severity of acute lung injury in P. aeruginosa sepsis. The lack of arginase activity may explain the greater nitric oxide production in MRSA sepsis.
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Acute lung injury-induced collagen deposition is associated with elevated asymmetric dimethylarginine and arginase activity. Shock 2011; 35:282-8. [PMID: 20938379 DOI: 10.1097/shk.0b013e3181fddd82] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Evidence suggests that lung structure and function are partly maintained by a balance between the competing arginine-metabolizing enzymes arginase and nitric oxide (NO) synthase. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthase. It is metabolized by dimethylarginine dimethylaminohydrolase 2 (DDAH-2), which is oxidant-sensitive. The mechanism that induces excess lung collagen deposition in burned patients has not yet been explored. Our objective was to investigate the role of ADMA and the arginase pathway in acute lung injury. An ovine model for burn and smoke inhalation injury was used to assess excess lung collagen deposition. Sheep were deeply anesthetized during the injury, mechanically ventilated, resuscitated with fluid, and killed after either 2 or 3 weeks. Lungs were assessed histologically and biochemically for collagen content, arginase activity, lipid peroxidation product and antioxidant concentration, and protein concentrations. Plasma was assessed for amino acid and nitrate/nitrite concentrations. Burn and inhalation injury resulted in significantly reduced pulmonary function and increased lung collagen deposition. These physiological changes were associated with significantly increased lung arginase activity, collagen synthesis precursor ornithine aminotransferase, and ornithine decarboxylase, which is associated with cell proliferation. Significant decreases in plasma nitrate/nitrite after injury were associated with increased lung ADMA concentrations and decreased DDAH-2 expression. The decreased DDAH-2 expression was associated with significantly increased lipid peroxidation product and decreased antioxidant content in the lung. These data support that excess lung collagen deposition and reduced pulmonary function in acute lung injury after burn and inhalation injury are mediated through the arginase pathway.
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The significance of reduced airway hyperemia and enhanced oxygenation after epinephrine nebulization in a preclinical evaluation*. Crit Care Med 2011; 39:891-3. [DOI: 10.1097/ccm.0b013e318211f8e0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Veress LA, O'Neill HC, Hendry-Hofer TB, Loader JE, Rancourt RC, White CW. Airway obstruction due to bronchial vascular injury after sulfur mustard analog inhalation. Am J Respir Crit Care Med 2010; 182:1352-61. [PMID: 20639443 DOI: 10.1164/rccm.200910-1618oc] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Sulfur mustard (SM) is a frequently used chemical warfare agent, even in modern history. SM inhalation causes significant respiratory tract injury, with early complications due to airway obstructive bronchial casts, akin to those seen after smoke inhalation and in single-ventricle physiology. This process with SM is poorly understood because animal models are unavailable. OBJECTIVES To develop a rat inhalation model for airway obstruction with the SM analog 2-chloroethyl ethyl sulfide (CEES), and to investigate the pathogenesis of bronchial cast formation. METHODS Adult rats were exposed to 0, 5, or 7.5% CEES in ethanol via nose-only aerosol inhalation (15 min). Airway microdissection and confocal microscopy were used to assess cast formation (4 and 18 h after exposure). Bronchoalveolar lavage fluid (BALF) retrieval and intravascular dye injection were done to evaluate vascular permeability. MEASUREMENTS AND MAIN RESULTS Bronchial casts, composed of abundant fibrin and lacking mucus, occluded dependent lobar bronchi within 18 hours of CEES exposure. BALF contained elevated concentrations of IgM, protein, and fibrin. Accumulation of fibrin-rich fluid in peribronchovascular regions (4 h) preceded cast formation. Monastral blue dye leakage identified bronchial vessels as the site of leakage. CONCLUSIONS After CEES inhalation, increased permeability from damaged bronchial vessels underlying damaged airway epithelium leads to the appearance of plasma proteins in both peribronchovascular regions and BALF. The subsequent formation of fibrin-rich casts within the airways then leads to airways obstruction, causing significant morbidity and mortality acutely after exposure.
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Affiliation(s)
- Livia A Veress
- Department of Pediatrics, University of Colorado Health Sciences Center, Denver, USA
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Saunders FD, Westphal M, Enkhbaatar P, Wang J, Pazdrak K, Nakano Y, Hamahata A, Jonkam CC, Lange M, Connelly RL, Kulp GA, Cox RA, Hawkins HK, Schmalstieg FC, Horvath E, Szabo C, Traber LD, Whorton E, Herndon DN, Traber DL. Molecular biological effects of selective neuronal nitric oxide synthase inhibition in ovine lung injury. Am J Physiol Lung Cell Mol Physiol 2009; 298:L427-36. [PMID: 19965980 DOI: 10.1152/ajplung.00147.2009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neuronal nitric oxide synthase is critically involved in the pathogenesis of acute lung injury resulting from combined burn and smoke inhalation injury. We hypothesized that 7-nitroindazole, a selective neuronal nitric oxide synthase inhibitor, blocks central molecular mechanisms involved in the pathophysiology of this double-hit insult. Twenty-five adult ewes were surgically prepared and randomly allocated to 1) an uninjured, untreated sham group (n = 7), 2) an injured control group with no treatment (n = 7), 3) an injury group treated with 7-nitroindazole from 1-h postinjury to the remainder of the 24-h study period (n = 7), or 4) a sham-operated group subjected only to 7-nitroindazole to judge the effects in health. The combination injury was associated with twofold increased activity of neuronal nitric oxide synthase and oxidative/nitrosative stress, as indicated by significant increases in plasma nitrate/nitrite concentrations, 3-nitrotyrosine (an indicator of peroxynitrite formation), and malondialdehyde lung tissue content. The presence of systemic inflammation was evidenced by twofold, sixfold, and threefold increases in poly(ADP-ribose) polymerase, IL-8, and myeloperoxidase lung tissue concentrations, respectively (each P < 0.05 vs. sham). These molecular changes were linked to tissue damage, airway obstruction, and pulmonary shunting with deteriorated gas exchange. 7-Nitroindazole blocked, or at least attenuated, all these pathological changes. Our findings suggest 1) that nitric oxide formation derived from increased neuronal nitric oxide synthase activity represents a pivotal reactive agent in the patho-physiology of combined burn and smoke inhalation injury and 2) that selective neuronal nitric oxide synthase inhibition represents a goal-directed approach to attenuate the degree of injury.
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Affiliation(s)
- Fiona D Saunders
- Investigational Intensive Care Unit, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, USA.
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Abstract
Sex is increasingly recognized as a major factor in the outcome of patients who have trauma and sepsis. Moreover, sex steroids influence chemokine/adhesion molecule expression and neutrophil accumulation. Heat shock proteins, heat shock factor 1, and peroxisome proliferator-activated receptor [gamma] coactivator 1 are regulated by the estrogen receptors and consequently contribute to organ protection after trauma-hemorrhage. Additionally, sex steroids regulate inflammatory cytokines, leading to increased morbidity and mortality. This article deals with trauma-hemorrhage and examines the following: 1) the evidence for sex differences; 2) the mechanisms by which sex hormones affect organ protection; 3) the tissue-specific effect of sex hormone receptors; and 4) the effect of genomic and nongenomic (i.e. membrane-initiated steroid signaling) pathways of sex hormones after trauma. The available information indicates that sex steroids modulate cardiovascular responses after trauma. Thus, alteration or modulation of the prevailing hormone milieu at the time of injury seems to be a novel therapeutic option for improving outcome after injury
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WHAT'S NEW IN SHOCK, October 2007? Shock 2007. [DOI: 10.1097/shk.0b013e31814a54f8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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