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Herrnreiter CJ, Luck ME, Cannon AR, Li X, Choudhry MA. Reduced Expression of miR-146a Potentiates Intestinal Inflammation following Alcohol and Burn Injury. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2024; 212:881-893. [PMID: 38189569 PMCID: PMC10922766 DOI: 10.4049/jimmunol.2300405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 12/13/2023] [Indexed: 01/09/2024]
Abstract
MicroRNAs (miRNAs) are small noncoding RNA molecules that negatively regulate gene expression. Within the intestinal epithelium, miRNAs play a critical role in gut homeostasis, and aberrant miRNA expression has been implicated in various disorders associated with intestinal inflammation and barrier disruption. In this study, we sought to profile changes in intestinal epithelial cell miRNA expression after alcohol and burn injury and elucidate their impact on inflammation and barrier integrity. Using a mouse model of acute ethanol intoxication and burn injury, we found that small intestinal epithelial cell expression of miR-146a is significantly decreased 1 d following injury. Using in vitro studies, we show that reduced miR-146a promotes intestinal epithelial cell inflammation by promoting p38 MAPK signaling via increased levels of its target TRAF6 (TNFR-associated factor 6). Furthermore, we demonstrate that in vivo miR-146a overexpression significantly inhibits intestinal inflammation 1 d following combined injury and potentially supports intestinal barrier homeostasis. Overall, this study highlights the important impact that miRNA expression can have on intestinal homeostasis and the valuable potential of harnessing aberrant miRNA expression as a therapeutic target to control intestinal inflammation.
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Affiliation(s)
- Caroline J. Herrnreiter
- Biochemistry, Molecular and Cancer Biology Program, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Burn & Shock Trauma Research Institute, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Alcohol Research Program, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Department of Surgery, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Stritch School of Medicine, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
| | - Marisa E. Luck
- Burn & Shock Trauma Research Institute, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Alcohol Research Program, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Department of Surgery, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Stritch School of Medicine, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
| | - Abigail R. Cannon
- Burn & Shock Trauma Research Institute, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Alcohol Research Program, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Department of Surgery, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Stritch School of Medicine, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
| | - Xiaoling Li
- Burn & Shock Trauma Research Institute, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Alcohol Research Program, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Department of Surgery, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Stritch School of Medicine, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
| | - Mashkoor A. Choudhry
- Burn & Shock Trauma Research Institute, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Alcohol Research Program, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Department of Surgery, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
- Stritch School of Medicine, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, USA
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Khair S, Walrath TM, Curtis BJ, Orlicky DJ, McMahan RH, Kovacs EJ. Ethanol exacerbates pulmonary complications after burn injury in mice, regardless of frequency of ethanol exposures. Burns 2023; 49:1935-1943. [PMID: 37574341 PMCID: PMC10811296 DOI: 10.1016/j.burns.2023.07.008] [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: 01/30/2023] [Revised: 06/25/2023] [Accepted: 07/13/2023] [Indexed: 08/15/2023]
Abstract
Burn injuries are associated with significant morbidity and mortality, and lungs are the most common organ to fail. Interestingly, patients with alcohol intoxication at the time of burn have worse clinical outcomes, including pulmonary complications. Using a clinically relevant murine model, we have previously reported that episodic ethanol exposure before burn exacerbated lung inflammation. Specifically, intoxicated burned mice had worsened pulmonary responses, including increased leukocyte infiltration and heightened levels of CXCL1 and IL-6. Herein, we examined whether a single binge ethanol exposure before scald burn injury yields similar pulmonary responses. C57BL/6 male mice were given ethanol (1.2 g/kg) 30 min before a 15 % total body surface area burn. These mice were compared to a second cohort given episodic ethanol binge for a total of 6 days (3 days ethanol, 4 days rest, 3 days ethanol) prior to burn injury. 24 h after burn, histopathological examination of lungs were performed. In addition, survival, and levels of infiltrating leukocytes, CXCL1, and IL-6 were quantified. Episodic and single ethanol exposure before burn decreased survival compared to burn only mice and sham vehicle mice, respectively (p < 0.05). However, no difference in survival was observed between burned mice with single and episodic ethanol binge. Examination of H&E-stained lung sections revealed that regardless of ethanol binge frequency, intoxication prior to burn worsened pulmonary inflammation, evidenced by elevated granulocyte accumulation and congestion, relative to burned mice without any ethanol exposure. Levels of infiltrating granulocyte in the lungs were significantly higher in burned mice with both episodic and single ethanol intoxication, compared to burn injury only (p < 0.05). In addition, there was no difference in the granulocyte count between single and ethanol binge mice with burn injury. Neutrophil chemoattractant CXCL1 levels in the lung were similarly increased following single and episodic ethanol exposure prior to burn compared to burn alone (22-fold and 26-fold respectively, p < 0.05). Lastly, we assessed pulmonary IL-6, which revealed that irrespective of frequency, ethanol exposure combined with burn injury raised pro-inflammatory cytokine IL-6 in the lungs relative to burn mice. Again, we did not find any difference in the amount of IL-6 in lungs of burned mice with single and episodic ethanol intoxication. Taken altogether, these data demonstrate that both single and episodic exposure to ethanol prior to burn injury similarly worsens pulmonary inflammation. These results suggest that ethanol-induced exacerbation of the pulmonary responses to burn injury is due to presence of ethanol at the time of injury rather than longer-term effects of ethanol exposure.
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Affiliation(s)
- Shanawaj Khair
- Department of Surgery, Division of GI, Trauma, and Endocrine Surgery, and Alcohol Research Program, Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA; Molecular Biology Graduate Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA; Medical Scientist Training Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Travis M Walrath
- Department of Surgery, Division of GI, Trauma, and Endocrine Surgery, and Alcohol Research Program, Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Brenda J Curtis
- Department of Surgery, Division of GI, Trauma, and Endocrine Surgery, and Alcohol Research Program, Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - David J Orlicky
- Department of Pathology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Rachel H McMahan
- Department of Surgery, Division of GI, Trauma, and Endocrine Surgery, and Alcohol Research Program, Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA; Veterans Health Administration, Eastern Colorado Health Care System, Rocky Mountain Regional Veterans Affairs Medical Center (RMRVAMC), Aurora, CO 80045, USA
| | - Elizabeth J Kovacs
- Department of Surgery, Division of GI, Trauma, and Endocrine Surgery, and Alcohol Research Program, Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA; Molecular Biology Graduate Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA; Medical Scientist Training Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA; Veterans Health Administration, Eastern Colorado Health Care System, Rocky Mountain Regional Veterans Affairs Medical Center (RMRVAMC), Aurora, CO 80045, USA.
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Walrath T, McMahan RH, Idrovo JP, Quillinan N, Kovacs EJ. Cutaneous burn injury induces neuroinflammation and reactive astrocyte activation in the hippocampus of aged mice. Exp Gerontol 2022; 169:111975. [PMID: 36208823 DOI: 10.1016/j.exger.2022.111975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND By 2050, one in six people globally will be 65 or older. Confusion and delirium are significant complications after burn injury, especially in the elderly population. The etiology is still unknown, however complications may be driven by pro-inflammatory activation of astrocytes within the hippocampus (HPC) after burn injury. Reduced levels of phosphorylated cyclic-AMP response binding element (pCREB), caused by elevated systemic pro-inflammatory cytokines, could lead to cognitive decline and memory impairment. METHODS To examine the effects of remote injury on neuroinflammation in advanced age, young and aged mice were subjected to a 15 % total body surface area scald burn or sham injury, and euthanized after 24 h. Expression of ccl2 and tnfa were measured by qPCR in the whole brain and HPC. Astrocyte activation was measured by immunofluorescence within the HPC. pCREB was measured by immunohistochemistry in the dentate gyrus. RESULTS We saw an 80-fold increase in ccl2 and a 30-fold elevation in tnfa after injury in the whole brain of aged mice compared to young groups and aged sham mice (p < 0.05 and p < 0.05, respectively). Additionally, there was a 30-fold increase in ccl2 within isolated HPC of aged injured mice when compared to sham injured animals (p < 0.05). When investigating specific HPC regions, immunofluorescence staining showed a >20 % rise in glial fibrillary acidic protein (GFAP) positive astrocytes within the cornu ammonis 3 (CA3) of aged injured mice when compared to all other groups (p < 0.05). Lastly, we observed a >20 % decrease in pCREB staining by immunohistochemistry in the dentate gyrus of aged mice compared to young regardless of injury (p < 0.05). CONCLUSIONS These novel data suggest that remote injury in aged, but not young, mice is associated with neuroinflammation and astrocyte activation within the HPC. These factors, paired with an age related reduction in pCREB, could help explain the increased cognitive decline seen in burn patients of advanced age. To our knowledge, we are the first group to examine the impact of advanced age combined with burn injury on inflammation and astrocyte activation within the brain.
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Affiliation(s)
- Travis Walrath
- Department of Surgery, Division of GI, Trauma, and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Rachel H McMahan
- Department of Surgery, Division of GI, Trauma, and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Juan-Pablo Idrovo
- Department of Surgery, Division of GI, Trauma, and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Nidia Quillinan
- Department of Anesthesiology, Neuronal Injury Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Elizabeth J Kovacs
- Department of Surgery, Division of GI, Trauma, and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America.
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Awoyemi AA, Borchers C, Liu L, Chen Y, Rapp CM, Brewer CA, Elased R, Travers JB. Acute ethanol exposure stimulates microvesicle particle generation in keratinocytes. Toxicol Lett 2022; 355:100-105. [PMID: 34801640 PMCID: PMC8702459 DOI: 10.1016/j.toxlet.2021.11.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/25/2021] [Accepted: 11/16/2021] [Indexed: 02/03/2023]
Abstract
Ethanol has been demonstrated to exert profound effects upon cells and tissues via multiple mechanisms. One recently appreciated means by which cells can communicate with other cells is via the production and release of extracellular vesicles. Though smaller exosomes have been demonstrated to be released in response to ethanol exposure, the ability of ethanol to modulate the generation and release of larger microvesicle particles (MVP) is lesser studied. The present studies examined the ability of exogenous ethanol to generate MVP with a focus on skin cells. Acute ethanol exposure resulted in augmented MVP release in keratinocytes and in the skin and blood of mice. Unlike other stimuli such as ultraviolet B radiation or thermal burn injury, ethanol-mediated MVP release was independent of the Platelet-activating Factor receptor (PAFR). However, ethanol pretreatment was found to augment thermal burn injury-induced MVP in a PAFR-dependent manner. These studies provide a novel mechanism for ethanol-mediated effects, that could be relevant in the significant toxicity associated with thermal burn injury in the setting of alcohol intoxication.
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Affiliation(s)
- Azeezat A. Awoyemi
- Departments of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton, OH 45435
| | - Christina Borchers
- Departments of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton, OH 45435
| | - Langni Liu
- Departments of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton, OH 45435
| | - Yanfang Chen
- Departments of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton, OH 45435
| | - Christine M. Rapp
- Departments of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton, OH 45435
| | - Chad A. Brewer
- Departments of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton, OH 45435
| | - Ramzi Elased
- Departments of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton, OH 45435
| | - Jeffrey B. Travers
- Departments of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton, OH 45435,Department of Dermatology, Boonshoft School of Medicine at Wright State University, Dayton, OH 45435,The Dayton V.A. Medical Center, Dayton, OH 45428.,Corresponding author: Jeffrey B. Travers, M.D., Ph.D., Department of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, 3640 Col Glenn Hwy, Dayton, OH 46435,
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Najarro KM, Boe DM, Walrath TM, Mullen JE, Paul MT, Frankel JH, Hulsebus HJ, Idrovo JP, McMahan RH, Kovacs EJ. Advanced age exacerbates intestinal epithelial permeability after burn injury in mice. Exp Gerontol 2022; 158:111654. [PMID: 34915110 PMCID: PMC9188353 DOI: 10.1016/j.exger.2021.111654] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 12/05/2021] [Accepted: 12/06/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND Advanced age is an independent risk factor for morbidity and mortality after burn injury. Following burn, the intestines can become permeable leading to the leakage of bacteria and their products from the lumen of the ileum to the portal and systemic circulation. Here, we sought to determine the effects of advanced age on intestinal permeability post burn injury and assess intestinal inflammatory biomarkers. METHODS Young (4-5 months) and aged (18-22 months) female BALB/cBy mice were subjected to a 12-15% total body surface area (TBSA) sham or burn injury. 24 h after injury, mice were euthanized, and organs collected. Colony-forming units (CFU) were counted from plated mesenteric lymph nodes (MLN). Gene expression of ileal tight junctional proteins, occludin and zonula occludens 1 (ZO-1), in addition to ileal damage associated molecular pattern (DAMP) proteins, S100A8 and S100A9, as well as ileal inflammatory markers IL-6 and TNF-α were measured by qPCR. Intestinal cell death was measured by ELISA. Intestinal permeability was determined by FITC fluorescence in serum; 4kD FITC-dextran was given by oral gavage 3 h before euthanasia. RESULTS Aged mice subjected to burn injury had increased intestinal permeability as evidenced by a 5.8-fold higher level of FITC-dextran in their serum when compared to all other groups (p < 0.05). In addition, aged burn-injured mice exhibited heightened bacterial accumulation in the MLN with a 15.5-fold increase over all other groups (p < 0.05). Histology of ileum failed to show differences in villus length among all groups. Analysis of ileal tight junctional proteins and inflammatory marker gene expression revealed no difference in Ocln, Tjp1, Il6, or Tnf expression among all groups, but 2.3 and 2.9-fold upregulation of S100a8 and S100a9, respectively, in aged burn-injured mice relative to both young groups and aged sham-injured mice (p < 0.05). Lastly, cell death in the ileum was elevated more than two-fold in aged burn-injured mice relative to young animals regardless of injury (p < 0.05). CONCLUSIONS These data demonstrate that advanced age exacerbates intestinal epithelial permeability after burn injury. Heightened apoptosis may be responsible for the elevated intestinal leakiness and accumulation of bacteria in mesenteric lymph nodes. In addition, S100a8/9 may serve as a biomarker of elevated inflammation within the intestine.
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Affiliation(s)
- Kevin M. Najarro
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Devin M. Boe
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America,Immunology Graduate Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America,Medical Scientist Training Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, United States of America
| | - Travis M. Walrath
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Juliet E. Mullen
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Madison T. Paul
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - John H. Frankel
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Holly J. Hulsebus
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America,Immunology Graduate Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Juan-Pablo Idrovo
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Rachel H. McMahan
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America,GI and Liver Innate Immune Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Elizabeth J. Kovacs
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America,Immunology Graduate Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America,Medical Scientist Training Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, United States of America,GI and Liver Innate Immune Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, United States of America,Corresponding author at: Department of Surgery, GITES, University of Colorado Denver/Anschutz Medical Campus, 12700 East 19th Ave, RC2, Mail Stop #8620, Aurora, CO 80045, United States of America. (E.J. Kovacs)
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Dyamenahalli K, Choy K, Frank DN, Najarro K, Boe D, Colborn KL, Idrovo JP, Wagner AL, Wiktor AJ, Afshar M, Burnham EL, McMahan RH, Kovacs EJ. Age and Injury Size Influence the Magnitude of Fecal Dysbiosis in Adult Burn Patients. J Burn Care Res 2022; 43:1145-1153. [PMID: 35020913 PMCID: PMC9435505 DOI: 10.1093/jbcr/irac001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Clinical studies have demonstrated that age 50 years or older is an independent risk factor associated with poor prognosis after burn injury, the second leading cause of traumatic injuries in the aged population. While mechanisms driving age-dependent postburn mortality are perplexing, changes in the intestinal microbiome, may contribute to the heightened, dysregulated systemic response seen in aging burn patients. The fecal microbiome from 22 patients admitted to a verified burn center from July 2018 to February 2019 was stratified based on the age of 50 years and total burn surface area (TBSA) size of ≥10%. Significant differences (P = .014) in overall microbiota community composition (ie, beta diversity) were measured across the four patient groups: young <10% TBSA, young ≥10% TBSA, older <10% TBSA, and older ≥10% TBSA. Differences in beta diversity were driven by %TBSA (P = .013) and trended with age (P = .087). Alpha diversity components, richness, evenness, and Shannon diversity were measured. We observed significant differences in bacterial species evenness (P = .0023) and Shannon diversity (P = .0033) between the groups. There were significant correlations between individual bacterial species and levels of short-chain fatty acids. Specifically, levels of fecal butyrate correlated with the presence of Enterobacteriaceae, an opportunistic gut pathogen, when elevated in burn patients lead to worsen outcomes. Overall, our findings reveal that age-specific changes in the fecal microbiome following burn injuries may contribute to immune system dysregulation in patients with varying TBSA burns and potentially lead to worsened clinical outcomes with heightened morbidity and mortality.
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Affiliation(s)
| | | | - Daniel N Frank
- Department of Medicine, Division of Infectious Diseases, University of Colorado Anschutz Medical Campus, Aurora, USA,Gastrointestinal and Liver and Innate Immunity Program, University of Colorado Anschutz Medical Campus, Aurora, USA
| | - Kevin Najarro
- Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, USA,Rocky Mountain Regional VA Medical Center, VA Eastern Colorado Health Care System Research Service, Aurora, USA
| | - Devin Boe
- Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, USA
| | - Kathryn L Colborn
- Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, USA
| | - Juan-Pablo Idrovo
- Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, USA
| | - Anne L Wagner
- Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, USA
| | - Arek J Wiktor
- Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, USA
| | - Majid Afshar
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Ellen L Burnham
- Department of Medicine, Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, USA
| | - Rachel H McMahan
- Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, USA,Rocky Mountain Regional VA Medical Center, VA Eastern Colorado Health Care System Research Service, Aurora, USA
| | - Elizabeth J Kovacs
- Address correspondence to Elizabeth J. Kovacs, PhD, Department of Surgery, GITES, University of Colorado Anschutz Medical Campus, 12700 East 19th Ave, RC2, Mail Stop #8620, Aurora, CO 80045, USA.
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Zhou D, Wang Q, Liu H. Coronavirus disease-19 and the gut-lung axis. Int J Infect Dis 2021; 113:300-307. [PMID: 34517046 PMCID: PMC8431834 DOI: 10.1016/j.ijid.2021.09.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 08/19/2021] [Accepted: 09/06/2021] [Indexed: 01/08/2023] Open
Abstract
Gastrointestinal and respiratory tract diseases often occur together. There are many overlapping pathologies, leading to the concept of the ‘gut–lung axis’ in which stimulation on one side triggers a response on the other side. This axis appears to be implicated in infections involving severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which has triggered the global coronavirus disease 2019 (COVID-19) pandemic, in which respiratory symptoms of fever, cough and dyspnoea often occur together with gastrointestinal symptoms such as nausea, vomiting, abdominal pain and diarrhoea. Besides the gut–lung axis, it should be noted that the gut participates in numerous axes which may affect lung function, and consequently the severity of COVID-19, through several pathways. This article focuses on the latest evidence and the mechanisms that drive the operation of the gut–lung axis, and discusses the interaction between the gut–lung axis and its possible involvement in COVID-19 from the perspective of microbiota, microbiota metabolites, microbial dysbiosis, common mucosal immunity and angiotensin-converting enzyme II, raising hypotheses and providing methods to guide future research on this new disease and its treatments.
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Affiliation(s)
- Dan Zhou
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China; Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education
| | - Qiu Wang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education; Department of Rehabilitation Medicine, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Hanmin Liu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China; Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education.
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8
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Zhang J, Garrett S, Sun J. Gastrointestinal symptoms, pathophysiology, and treatment in COVID-19. Genes Dis 2021; 8:385-400. [PMID: 33521210 PMCID: PMC7836435 DOI: 10.1016/j.gendis.2020.08.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/18/2020] [Accepted: 08/28/2020] [Indexed: 01/08/2023] Open
Abstract
The novel coronavirus Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has emerged and is responsible for the Coronavirus Disease 2019 global pandemic. Coronaviruses, including SARS-CoV-2, are strongly associated with respiratory symptoms during infection, but gastrointestinal symptoms, such as diarrhea, vomiting, nausea, and abdominal pain, have been identified in subsets of COVID-19 patients. This article focuses on gastrointestinal symptoms and pathophysiology in COVID-19 disease. Evidence suggests that the gastrointestinal tract could be a viral target for SARS-CoV-2 infection. Not only is the SARS-CoV-2 receptor ACE2 highly expressed in the GI tract and is associated with digestive symptoms, but bleeding and inflammation are observed in the intestine of COVID-19 patients. We further systemically summarize the correlation between COVID-19 disease, gastrointestinal symptoms and intestinal microbiota. The potential oral-fecal transmission of COVID-19 was supported by viral RNA and live virus detection in the feces of COVID-19 patients. Additionally, the viral balance in the GI tract could be disordered during SARS-CoV-2 infection which could further impact the homeostasis of the gut microbial flora. Finally, we discuss the clinical and ongoing trials of treatments/therapies, including antiviral drugs, plasma transfusion and immunoglobulins, and diet supplementations for COVID-19. By reviewing the pathogenesis of SARS-CoV-2 virus, and understanding the correlation among COVID-19, inflammation, intestinal microbiota, and lung microbiota, we provide perspective in prevention and control, as well as diagnosis and treatment of the COVID-19 disease.
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Affiliation(s)
- Jilei Zhang
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Shari Garrett
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Jun Sun
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
- UIC Cancer Center, University of Illinois at Chicago, Chicago, IL 60612, USA
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9
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Idrovo JP, Boe DM, Kaahui S, Walrath T, McMahan RH, Kovacs EJ. Advanced age heightens hepatic damage in a murine model of scald burn injury. J Trauma Acute Care Surg 2021; 90:731-737. [PMID: 33306599 PMCID: PMC7979479 DOI: 10.1097/ta.0000000000003048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Elderly burn patients exhibit a lower survival rate compared with younger counterparts. The liver is susceptible to damage after burn injury, which predisposes to poor outcomes. Lipid homeostasis and the antioxidant glutathione system play fundamental roles in preserving liver integrity. Herein, we explored changes in these major pathways associated with liver damage in the aging animals after burn injury. METHODS We compared liver enzymes, histology, lipid-peroxidation, and glutathione-metabolism profiles from young and aged female mice after a 15% total body surface area burn. Mice were euthanized at 24 hours after injury, and livers and serum were collected. RESULTS Aged burn animals exhibited elevated (p < 0.05) aspartate aminotransferase and alanine aminotransferase levels and increased inflammatory cell infiltration, edema, and necrosis compared with their younger counterparts. The percentage of adipophilin-stained area in livers from young sham, young burn, aged sham, and aged burn groups was 10%, 44%, 16%, and 78% (p < 0.05), respectively. Liver malondialdehyde levels were 1.4 ± 0.5 nmol/mg, 2.06 ± 0.2 nmol/mg, 1.81 ± 0.12 nmol/mg, and 3.45 ± 0.2 nmol/mg (p < 0.05) in young sham, young burn, aged sham, and aged burn mice, respectively. Oxidized glutathione (GSSG) content increased 50% in the young burn, and 88% in aged burn animals compared with the young sham group (p < 0.05). The reduced glutathione GSH/GSSG ratio was significantly reduced by 54% in aged burn mice compared with young sham animals (p < 0.05). Furthermore, glutathione peroxidase gene expression showed a 96% decrease in the aged burn group compared with young sham mice (p < 0.05). CONCLUSION Aged burn animals exhibit severe liver damage from heightened lipid peroxidation and inadequate antioxidative response. The increased peroxidation is associated with abundant lipid deposits in hepatic tissue postburn and a weak antioxidative response due to hepatic glutathione peroxidase downregulation. Further studies will focus on the functional significance of these findings concerning hepatic homeostasis.
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Affiliation(s)
- Juan-Pablo Idrovo
- From the Division of G.I., Trauma, and Endocrine Surgery, (J.-P.I., D.M.B. S.K., T.W., R.H.M., E.J.K.), Division of Burn Research, Department of Surgery (D.M.B., T.W., R.H.M., E.J.K.), Department of Immunology and Microbiology (D.M.B., T.W., E.J.K.), Division of Alcohol Research, Department of Surgery (R.H.M., E.J.K.), University of Colorado, Aurora, Colorado
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10
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Walrath T, Dyamenahalli KU, Hulsebus HJ, McCullough RL, Idrovo JP, Boe DM, McMahan RH, Kovacs EJ. Age-related changes in intestinal immunity and the microbiome. J Leukoc Biol 2020; 109:1045-1061. [PMID: 33020981 DOI: 10.1002/jlb.3ri0620-405rr] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 09/11/2020] [Accepted: 09/13/2020] [Indexed: 12/19/2022] Open
Abstract
The gastrointestinal (GI) tract is a vitally important site for the adsorption of nutrients as well as the education of immune cells. Homeostasis of the gut is maintained by the interplay of the intestinal epithelium, immune cells, luminal Ags, and the intestinal microbiota. The well-being of the gut is intrinsically linked to the overall health of the host, and perturbations to this homeostasis can have severe impacts on local and systemic health. One factor that causes disruptions in gut homeostasis is age, and recent research has elucidated how critical systems within the gut are altered during the aging process. Intestinal stem cell proliferation, epithelial barrier function, the gut microbiota, and the composition of innate and adaptive immune responses are all altered in advanced age. The aging population continues to expand worldwide, a phenomenon referred to as the "Silver Tsunami," and every effort must be made to understand how best to prevent and treat age-related maladies. Here, recent research about changes observed in the intestinal epithelium, the intestinal immune system, the microbiota, and how the aging gut interacts with and influences other organs such as the liver, lung, and brain are reviewed. Better understanding of these age-related changes and their impact on multi-organ interactions will aid the development of therapies to increase the quality of life for all aged individuals.
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Affiliation(s)
- Travis Walrath
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Aurora, Colorado, USA
| | - Kiran U Dyamenahalli
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Aurora, Colorado, USA
| | - Holly J Hulsebus
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Aurora, Colorado, USA.,Immunology Graduate Program, University of Colorado Denver, Aurora, Colorado, USA
| | - Rebecca L McCullough
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, Colorado, USA.,GI and Liver Innate Immune Program, University of Colorado Denver, Aurora, Colorado, USA
| | - Juan-Pablo Idrovo
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Aurora, Colorado, USA
| | - Devin M Boe
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Aurora, Colorado, USA.,Immunology Graduate Program, University of Colorado Denver, Aurora, Colorado, USA.,Medical Scientist Training Program, University of Colorado Denver, Aurora, Colorado, USA
| | - Rachel H McMahan
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Aurora, Colorado, USA
| | - Elizabeth J Kovacs
- Department of Surgery, Division of GI, Trauma and Endocrine Surgery, and Burn Research Program, University of Colorado Denver, Aurora, Colorado, USA.,Immunology Graduate Program, University of Colorado Denver, Aurora, Colorado, USA.,Medical Scientist Training Program, University of Colorado Denver, Aurora, Colorado, USA.,GI and Liver Innate Immune Program, University of Colorado Denver, Aurora, Colorado, USA
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11
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Idrovo JP, Boe DM, Kaahui S, Yang WL, Kovacs EJ. Hepatic inflammation after burn injury is associated with necroptotic cell death signaling. J Trauma Acute Care Surg 2020; 89:768-774. [PMID: 33017135 PMCID: PMC8386183 DOI: 10.1097/ta.0000000000002865] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Burn injury still has a high attributable mortality. The elevated mortality rate of severe burns is still concerning. Hepatic inflammation and injury are common after burns and are associated with poor outcomes. Necroptosis is a programmed cell death linked with inflammation. Thus, assessing necroptotic pathways in the liver can lead to new therapeutic modalities to improve mortality after severe burns. METHODS Mice underwent 15% total body surface area burn or sham injury. Three hours after burn, the mice were euthanized to collect blood and livers. Histology, injury markers, genes expression, and tissue protein levels were compared between groups. RESULTS Compared with sham, burned mice had heightened liver inflammatory cell infiltration and edema. Serum aspartate aminotransferase and alanine aminotransferase were increased by 4.9- and 3.4-fold, respectively, in burned mice relative to sham (p < 0.05). Expression of tumor necrosis factor α, interleukin-6, interleukin-1β, and CXCL1 (KC) genes were elevated in livers of burned mice by 10-, 86-, 10-, and 828-fold, respectively, compared with sham (p < 0.05). Expression of necroptotic genes, namely, receptor-interacting protein kinases 1 and 3, and mixed lineage kinase domain-like in livers of burned mice were increased by 10-, 13-, and 4.5-fold, respectively, relative to sham (p < 0.05). Receptor-interacting protein kinase 1 and phosphorylated mixed lineage kinase domain-like protein levels measured by Western-blot in livers after burn injury were elevated by 22- and 17-fold, respectively, compared with sham (p < 0.05). CONCLUSION Liver damage occurs early after burns in mice and is associated with elevation of proinflammatory cytokines, chemokine, and proteins involved in the necroptotic pathway. This study suggests that necroptosis plays a role in the pathogenesis of liver failure secondary to burn injury.
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Affiliation(s)
- Juan-Pablo Idrovo
- From the Division of GI, Trauma, and Endocrine Surgery, Department of Surgery (J.-P.I., S.K.), Division of GI, Trauma, and Endocrine Surgery, Department of Surgery, Burn Research Program (D.M.B., E.J.K.), and Department of Immunology and Microbiology (D.M.B., E.J.K.), University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado; Department of Radiation Oncology (W.-L.Y.), Albert Einstein College of Medicine, Bronx, New York; Division of GI, Trauma, and Endocrine Surgery, Department of Surgery, Alcohol Research Program (E.J.K.), University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
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12
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Curtis BJ, Shults JA, Boe DM, Ramirez L, Kovacs EJ. Mesenchymal stem cell treatment attenuates liver and lung inflammation after ethanol intoxication and burn injury. Alcohol 2019; 80:139-148. [PMID: 30217504 DOI: 10.1016/j.alcohol.2018.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 08/31/2018] [Accepted: 09/06/2018] [Indexed: 12/25/2022]
Abstract
Cutaneous burn injury is one of the most devastating injuries one can obtain, with tissue damage extending beyond the skin wound to distal organs, including the gastrointestinal tract, liver, and lungs. Multiple organ failure is a leading cause of death after burn injury, resulting in excessive systemic and localized inflammation directly contributing to end organ damage. We postulated that the gut-liver-lung inflammatory axis underscores multiple organ failure in the context of burn injury and is hyper-activated when ethanol intoxication precedes burn. Mesenchymal stem cells (MSCs) are regenerative and anti-inflammatory, and MSC treatment has been shown to be beneficial in several immune disorders and injury models. Our objective was to determine whether intravenous infusion of exogenous bone marrow-derived MSCs could reduce post-burn and intoxication pulmonary, hepatic, and systemic inflammation. Vehicle- or ethanol- (1.6 g/kg) treated mice were subjected to sham or 15% total body surface area scald burn. One hour post-injury, mice were given 5 × 105 CFSE-labeled MSCs or phosphate-buffered saline intravenously (i.v.) and were euthanized 24 h later. We assessed circulating biomarkers of inflammation and liver damage, measured cytokine and chemokine production, and quantified apoptosis in lung and liver tissue. Compared to intoxicated and burned mice, those treated with MSCs had less cellularity, limited apoptosis, and a slight reduction in the pro-inflammatory cytokine interleukin-6 (IL-6) and the neutrophil chemokine, KC (CXCL1) in lung tissue. Mice with MSCs treatment had more dramatic anti-inflammatory effects on systemic and hepatic inflammation, as serum IL-6 levels were diminished by 43%, and il6 and kc expression in liver tissue were markedly reduced, as were biomarkers of liver damage, aspartate transaminase (AST) and alanine transaminase (AST), compared with intoxicated and burned mice. Taken together, our results suggest intravenous MSCs treatment can diminish systemic inflammation, lessen hepatic damage, and decrease liver and lung apoptosis and inflammation, indicating MSCs as a novel therapy for restoring homeostasis of multiple organ systems in intoxicated burn patients.
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Affiliation(s)
- Brenda J Curtis
- Burn Research and Alcohol Research Programs, Department of Surgery, Division of GI, Trauma and Endocrine Surgery, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, United States
| | - Jill A Shults
- Alcohol Research Program, Burn and Shock Trauma Research Institute, Department of Surgery, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, IL, United States
| | - Devin M Boe
- Burn Research and Alcohol Research Programs, Department of Surgery, Division of GI, Trauma and Endocrine Surgery, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, United States
| | - Luis Ramirez
- Alcohol Research Program, Burn and Shock Trauma Research Institute, Department of Surgery, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, IL, United States
| | - Elizabeth J Kovacs
- Burn Research and Alcohol Research Programs, Department of Surgery, Division of GI, Trauma and Endocrine Surgery, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, United States.
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13
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Samuelson DR, Siggins RW, Ruan S, Amedee AM, Sun J, Zhu QK, Marasco WA, Taylor CM, Luo M, Welsh DA, Shellito JE. Alcohol consumption increases susceptibility to pneumococcal pneumonia in a humanized murine HIV model mediated by intestinal dysbiosis. Alcohol 2019; 80:33-43. [PMID: 30213614 PMCID: PMC6449221 DOI: 10.1016/j.alcohol.2018.08.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/23/2018] [Accepted: 08/24/2018] [Indexed: 02/07/2023]
Abstract
Alcohol use in persons living with HIV (PLWH) worsens the severity of bacterial pneumonia. However, the exact mechanism(s) by which this occurs remain ill-defined. We hypothesized that alcohol in the setting of HIV infection decreases Streptococcus pneumoniae clearance from the lung through mechanisms mediated by the gut microbiota. Humanized BLT (bone marrow, liver, thymus) mice were infected with 1 × 104 TCID50 of HIV (BAL and JRCSF strains) via intraperitoneal (i.p.) injection. One week post-HIV infection, animals were switched to a Lieber-DeCarli 5% ethanol diet or an isocaloric control diet for 10 days. Alcohol-fed animals were also given two binges of 2 g/kg ethanol on days 5 and 10. Feces were also collected, banked, and the community structures were analyzed. Mice were then infected with 1 × 105 CFU (colony-forming units) of S. pneumoniae and were sacrificed 48 h later. HIV-infected mice had viral loads of ∼2 × 104 copies/mL of blood 1 week post-infection, and exhibited an ∼57% decrease in the number of circulating CD4+ T cells at the time of sacrifice. Fecal microbial community structure was significantly different in each of the feeding groups, as well as with HIV infection. Alcohol-fed mice had a significantly higher burden of S. pneumoniae 48 h post-infection, regardless of HIV status. In follow-up experiments, female C57BL/6 mice were treated with a cocktail of antibiotics daily for 2 weeks and recolonized by gavage with intestinal microbiota from HIV+ ethanol-fed, HIV+ pair-fed, HIV- ethanol-fed, or HIV- pair-fed mice. Recolonized mice were then infected with S. pneumoniae and were sacrificed 48 h later. The intestinal microbiota from alcohol-fed mice (regardless of HIV status) significantly impaired clearance of S. pneumoniae. Collectively, these data indicate that alcohol feeding, as well as alcohol-associated intestinal dysbiosis, compromise pulmonary host defenses against pneumococcal pneumonia. Determining whether HIV infection acts synergistically with alcohol use in impairing pulmonary host defenses will require additional study.
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Affiliation(s)
- Derrick R Samuelson
- Department of Internal Medicine, Section of Pulmonary/Critical Care & Allergy/Immunology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Robert W Siggins
- Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Sanbao Ruan
- Department of Internal Medicine, Section of Pulmonary/Critical Care & Allergy/Immunology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Angela M Amedee
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Jiusong Sun
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Harvard Medical School Boston, MA, United States
| | - Quan Karen Zhu
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Harvard Medical School Boston, MA, United States
| | - Wayne A Marasco
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Harvard Medical School Boston, MA, United States
| | - Christopher M Taylor
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Meng Luo
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - David A Welsh
- Department of Internal Medicine, Section of Pulmonary/Critical Care & Allergy/Immunology, Louisiana State University Health Sciences Center, New Orleans, LA, United States; Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Judd E Shellito
- Department of Internal Medicine, Section of Pulmonary/Critical Care & Allergy/Immunology, Louisiana State University Health Sciences Center, New Orleans, LA, United States; Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States.
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Role of HIF-1α in Alcohol-Mediated Multiple Organ Dysfunction. Biomolecules 2018; 8:biom8040170. [PMID: 30544759 PMCID: PMC6316086 DOI: 10.3390/biom8040170] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 11/30/2018] [Accepted: 12/06/2018] [Indexed: 12/12/2022] Open
Abstract
Excess alcohol consumption is a global crisis contributing to over 3 million alcohol-related deaths per year worldwide and economic costs exceeding $200 billion dollars, which include productivity losses, healthcare, and other effects (e.g., property damages). Both clinical and experimental models have shown that excessive alcohol consumption results in multiple organ injury. Although alcohol metabolism occurs primarily in the liver, alcohol exposure can lead to pathophysiological conditions in multiple organs and tissues, including the brain, lungs, adipose, liver, and intestines. Understanding the mechanisms by which alcohol-mediated organ dysfunction occurs could help to identify new therapeutic approaches to mitigate the detrimental effects of alcohol misuse. Hypoxia-inducible factor (HIF)-1 is a transcription factor comprised of HIF-1α and HIF-1β subunits that play a critical role in alcohol-mediated organ dysfunction. This review provides a comprehensive analysis of recent studies examining the relationship between HIF-1α and alcohol consumption as it relates to multiple organ injury and potential therapies to mitigate alcohol’s effects.
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15
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Abstract
The widespread and rapidly increasing trend of binge drinking is accompanied by a concomitant rise in the prevalence of trauma patients under the influence of alcohol at the time of their injury. Epidemiological evidence suggests up to half of all adult burn patients are intoxicated at the time of admission, and the presence of alcohol is an independent risk factor for death in the early stages post burn. As the major site of alcohol metabolism and toxicity, the liver is a critical determinant of postburn outcome, and experimental evidence implies an injury threshold exists beyond which burn-induced hepatic derangement is observed. Alcohol may lower this threshold for postburn hepatic damage through a variety of mechanisms including modulation of extrahepatic events, alteration of the gut-liver axis, and changes in signaling pathways. The direct and indirect effects of alcohol may prime the liver for the second-hit of many overlapping physiologic responses to burn injury. In an effort to gain a deeper understanding of how alcohol potentiates postburn hepatic damage, the authors summarize possible mechanisms by which alcohol modulates the postburn hepatic response.
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Samuelson DR, Shellito JE, Maffei VJ, Tague ED, Campagna SR, Blanchard EE, Luo M, Taylor CM, Ronis MJJ, Molina PE, Welsh DA. Alcohol-associated intestinal dysbiosis impairs pulmonary host defense against Klebsiella pneumoniae. PLoS Pathog 2017; 13:e1006426. [PMID: 28604843 PMCID: PMC5481032 DOI: 10.1371/journal.ppat.1006426] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 06/22/2017] [Accepted: 05/22/2017] [Indexed: 02/07/2023] Open
Abstract
Chronic alcohol consumption perturbs the normal intestinal microbial communities (dysbiosis). To investigate the relationship between alcohol-mediated dysbiosis and pulmonary host defense we developed a fecal adoptive transfer model, which allows us to investigate the impact of alcohol-induced gut dysbiosis on host immune response to an infectious challenge at a distal organ, independent of prevailing alcohol use. Male C57BL/6 mice were treated with a cocktail of antibiotics (ampicillin, gentamicin, neomycin, vancomycin, and metronidazole) via daily gavage for two weeks. A separate group of animals was fed a chronic alcohol (or isocaloric dextrose pair-fed controls) liquid diet for 10 days. Microbiota-depleted mice were recolonized with intestinal microbiota from alcohol-fed or pair-fed (control) animals. Following recolonization groups of mice were sacrificed prior to and 48 hrs. post respiratory infection with Klebsiella pneumoniae. Klebsiella lung burden, lung immunology and inflammation, as well as intestinal immunology, inflammation, and barrier damage were examined. Results showed that alcohol-associated susceptibility to K. pneumoniae is, in part, mediated by gut dysbiosis, as alcohol-naïve animals recolonized with a microbiota isolated from alcohol-fed mice had an increased respiratory burden of K. pneumoniae compared to mice recolonized with a control microbiota. The increased susceptibility in alcohol-dysbiosis recolonized animals was associated with an increase in pulmonary inflammatory cytokines, and a decrease in the number of CD4+ and CD8+ T-cells in the lung following Klebsiella infection but an increase in T-cell counts in the intestinal tract following Klebsiella infection, suggesting intestinal T-cell sequestration as a factor in impaired lung host defense. Mice recolonized with an alcohol-dysbiotic microbiota also had increased intestinal damage as measured by increased levels of serum intestinal fatty acid binding protein. Collectively, these results suggest that alterations in the intestinal immune response as a consequence of alcohol-induced dysbiosis contribute to increased host susceptibility to Klebsiella pneumonia.
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Affiliation(s)
- Derrick R. Samuelson
- Department of Medicine, Section of Pulmonary/Critical Care & Allergy/Immunology, Louisiana State University Health Sciences Center, New Orleans, LA, United States of America
- * E-mail:
| | - Judd E. Shellito
- Department of Medicine, Section of Pulmonary/Critical Care & Allergy/Immunology, Louisiana State University Health Sciences Center, New Orleans, LA, United States of America
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States of America
| | - Vincent J. Maffei
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States of America
| | - Eric D. Tague
- The Department of Chemistry, The University of Tennessee Knoxville, Knoxville, TN, United States of America
| | - Shawn R. Campagna
- The Department of Chemistry, The University of Tennessee Knoxville, Knoxville, TN, United States of America
| | - Eugene E. Blanchard
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States of America
| | - Meng Luo
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States of America
| | - Christopher M. Taylor
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States of America
| | - Martin J. J. Ronis
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA, United States of America
| | - Patricia E. Molina
- Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, LA, United States of America
| | - David A. Welsh
- Department of Medicine, Section of Pulmonary/Critical Care & Allergy/Immunology, Louisiana State University Health Sciences Center, New Orleans, LA, United States of America
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States of America
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Kupffer Cell p38 Mitogen-Activated Protein Kinase Signaling Drives Postburn Hepatic Damage and Pulmonary Inflammation When Alcohol Intoxication Precedes Burn Injury. Crit Care Med 2017; 44:e973-9. [PMID: 27322363 DOI: 10.1097/ccm.0000000000001817] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Clinical and animal studies demonstrate that alcohol intoxication at the time of injury worsens postburn outcome. The purpose of this study was to determine the role and mechanism of Kupffer cell derangement in exacerbating postburn end organ damage in alcohol-exposed mice. DESIGN Interventional study. SETTING Research Institute. SUBJECTS Male C57BL/6 mice. INTERVENTIONS Alcohol administered 30 minutes before a 15% scald burn injury. Antecedent Kupffer cell depletion with clodronate liposomes (0.5 mg/kg). p38 mitogen-activated protein kinase inhibition via SB203580 (10 mg/kg). MEASUREMENTS AND MAIN RESULTS Kupffer cells were isolated 24 hours after injury and analyzed for p38 activity and interleukin-6 production. Intoxicated burned mice demonstrated a two-fold (p < 0.05) elevation of Kupffer cell p38 activation relative to either insult alone, and this corresponded to a 43% (p < 0.05) increase in interleukin-6 production. Depletion of Kupffer cells attenuated hepatic damage as seen by decreases of 53% (p < 0.05) in serum alanine aminotransferase and 74% (p < 0.05) in hepatic triglycerides, as well as a 77% reduction (p < 0.05) in serum interleukin-6 levels compared to matched controls. This mitigation of hepatic damage was associated with a 54% decrease (p < 0.05) in pulmonary neutrophil infiltration and reduced alveolar wall thickening by 45% (p < 0.05). In vivo p38 inhibition conferred nearly identical hepatic and pulmonary protection after the combined injury as mice depleted of Kupffer cells. CONCLUSIONS Intoxication exacerbates postburn hepatic damage through p38-dependent interleukin-6 production in Kupffer cells.
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Rehou S, Mason S, MacDonald J, Pinto R, Jeschke MG. The influence of substance misuse on clinical outcomes following burn. Burns 2017; 43:1493-1498. [PMID: 28506508 DOI: 10.1016/j.burns.2017.03.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 03/30/2017] [Accepted: 03/30/2017] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Ongoing increases in the prevalence of substance misuse among burn-injured patients necessitate a contemporary analysis of the association between substance misuse and clinical outcomes in burn-injured adults. METHODS We conducted a retrospective cohort study of 1199 patients admitted to a regional burn center. History of substance misuse was derived from a prospective clinical registry and categorized as alcohol, illicit drug, or both. The primary outcome was hospital length of stay; association of substance misuse and inpatient complications were secondary outcomes. Multivariable logistic regression was used to model the association between categories of substance misuse and each outcome, adjusting for patient and injury characteristics. RESULTS The incidence of substance misuse was 34% overall. After adjustment for patient and injury characteristics, drug misuse was associated with a significantly longer length of stay (RR 1.12; 95% CI 1.00-1.25), as was alcohol misuse (RR 1.32; 95% CI 1.14-1.52), and drug/alcohol misuse (RR 1.34; 95% CI 1.16-1.56). Drug/alcohol misuse was associated with significantly higher rates of bacteremia (OR 3.84; 95% CI 1.83-8.04) and sepsis (OR 2.50; CI 1.13-5.53). CONCLUSIONS A history of substance misuse is associated with an increased risk of inpatient complications and longer hospital stay. Providers should be cognizant of increased complications in this cohort with a view to improving outcomes.
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Affiliation(s)
- Sarah Rehou
- Ross Tilley Burn Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
| | - Stephanie Mason
- Ross Tilley Burn Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Division of General Surgery, Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
| | - Jessie MacDonald
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
| | - Ruxandra Pinto
- Department of Critical Care Medicine, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
| | - Marc G Jeschke
- Ross Tilley Burn Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Division of Plastic and Reconstructive Surgery, Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
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He Y, Wen Q, Yao F, Xu D, Huang Y, Wang J. Gut-lung axis: The microbial contributions and clinical implications. Crit Rev Microbiol 2016; 43:81-95. [PMID: 27781554 DOI: 10.1080/1040841x.2016.1176988] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Gut microbiota interacts with host immune system in ways that influence the development of disease. Advances in respiratory immune system also broaden our knowledge of the interaction between host and microbiome in the lung. Increasing evidence indicated the intimate relationship between the gastrointestinal tract and respiratory tract. Exacerbations of chronic gut and lung disease have been shown to share key conceptual features with the disorder and dysregulation of the microbial ecosystem. In this review, we discuss the impact of gut and lung microbiota on disease exacerbation and progression, and the recent understanding of the immunological link between the gut and the lung, the gut-lung axis.
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Affiliation(s)
- Yang He
- a Department of Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Qu Wen
- a Department of Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Fangfang Yao
- a Department of Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Dong Xu
- b Department of Infectious Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Yuancheng Huang
- b Department of Infectious Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Junshuai Wang
- c Department of Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
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Yeligar SM, Chen MM, Kovacs EJ, Sisson JH, Burnham EL, Brown LAS. Alcohol and lung injury and immunity. Alcohol 2016; 55:51-59. [PMID: 27788778 DOI: 10.1016/j.alcohol.2016.08.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 07/07/2016] [Accepted: 08/24/2016] [Indexed: 02/06/2023]
Abstract
Annually, excessive alcohol use accounts for more than $220 billion in economic costs and 80,000 deaths, making excessive alcohol use the third leading lifestyle-related cause of death in the US. Patients with an alcohol-use disorder (AUD) also have an increased susceptibility to respiratory pathogens and lung injury, including a 2-4-fold increased risk of acute respiratory distress syndrome (ARDS). This review investigates some of the potential mechanisms by which alcohol causes lung injury and impairs lung immunity. In intoxicated individuals with burn injuries, activation of the gut-liver axis drives pulmonary inflammation, thereby negatively impacting morbidity and mortality. In the lung, the upper airway is the first checkpoint to fail in microbe clearance during alcohol-induced lung immune dysfunction. Brief and prolonged alcohol exposure drive different post-translational modifications of novel proteins that control cilia function. Proteomic approaches are needed to identify novel alcohol targets and post-translational modifications in airway cilia that are involved in alcohol-dependent signal transduction pathways. When the upper airway fails to clear inhaled pathogens, they enter the alveolar space where they are primarily cleared by alveolar macrophages (AM). With chronic alcohol ingestion, oxidative stress pathways in the AMs are stimulated, thereby impairing AM immune capacity and pathogen clearance. The epidemiology of pneumococcal pneumonia and AUDs is well established, as both increased predisposition and illness severity have been reported. AUD subjects have increased susceptibility to pneumococcal pneumonia infections, which may be due to the pro-inflammatory response of AMs, leading to increased oxidative stress.
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Affiliation(s)
- Samantha M Yeligar
- Department of Medicine, Emory University and Atlanta Veterans Affairs Medical Center, Decatur, GA 30033, USA
| | - Michael M Chen
- Burn and Shock Trauma Research Institute, Alcohol Research Program, Integrative Cell Biology Program, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - Elizabeth J Kovacs
- Department of Surgery, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Joseph H Sisson
- Pulmonary, Critical Care, Sleep and Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Ellen L Burnham
- Department of Medicine, Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Lou Ann S Brown
- Department of Pediatrics, Emory University, Atlanta, GA 30322, USA.
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21
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Shults JA, Curtis BJ, Boe DM, Ramirez L, Kovacs EJ. Ethanol intoxication prolongs post-burn pulmonary inflammation: role of alveolar macrophages. J Leukoc Biol 2016; 100:1037-1045. [PMID: 27531926 DOI: 10.1189/jlb.3ma0316-111r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/26/2016] [Indexed: 02/06/2023] Open
Abstract
In this study, the role and fate of AMs were examined in pulmonary inflammation after intoxication and injury. Clinical evidence has revealed that half of all burn patients brought to the emergency department are intoxicated at the time of injury. This combined insult results in amplified neutrophil accumulation and pulmonary edema, with an increased risk of lung failure and mortality, relative to either insult alone. We believe that this excessive pulmonary inflammation, which also parallels decreased lung function, is mediated in part by AMs. Restoration of lung tissue homeostasis is dependent on the eradication of neutrophils and removal of apoptotic cells, both major functions of AMs. Thirty minutes after binge ethanol intoxication, mice were anesthetized and given a 15% total body surface area dorsal scald injury. At 24 h, we found a 50% decrease in the total number of AMs (P < 0.05) and observed a proinflammatory phenotype on the remaining lung AMs. Loss of AMs paralleled a 6-fold increase in the number of TUNEL+ lung apoptotic cells (P < 0.05) and a 3.5-fold increase in the percentage of annexin V+ apoptotic cells in BAL (P < 0.05), after intoxication and injury, relative to controls. In contrast to the reduction in the number of cells, AMs from intoxicated and injured mice had a 4-fold increase in efferocytosis (P < 0.05). In summary, these data suggest that loss of AMs may delay resolution of inflammation, resulting in the pulmonary complications and elevated mortality rates observed in intoxicated and burn-injured patients.
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Affiliation(s)
- Jill A Shults
- Alcohol Research Program, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Burn and Shock Trauma Research Institute, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Department of Surgery, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Integrative Cell Biology Program, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA
| | - Brenda J Curtis
- Alcohol Research Program, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Burn and Shock Trauma Research Institute, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Department of Surgery, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA
| | - Devin M Boe
- Alcohol Research Program, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Burn and Shock Trauma Research Institute, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Department of Surgery, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Integrative Cell Biology Program, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA
| | - Luis Ramirez
- Alcohol Research Program, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Burn and Shock Trauma Research Institute, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Department of Surgery, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA
| | - Elizabeth J Kovacs
- Alcohol Research Program, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA; .,Burn and Shock Trauma Research Institute, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Department of Surgery, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA.,Integrative Cell Biology Program, Loyola University Chicago, Health Sciences Campus, Stritch School of Medicine, Maywood, Illinois, USA
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22
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Abstract
Traumatic injury remains one of the most prevalent reasons for patients to be hospitalized. Burn injury accounts for 40,000 hospitalizations in the United States annually, resulting in a large burden on both the health and economic system and costing millions of dollars every year. The complications associated with postburn care can quickly cause life-threatening conditions including sepsis and multiple organ dysfunction and failure. In addition, alcohol intoxication at the time of burn injury has been shown to exacerbate these problems. One of the biggest reasons for the onset of these complications is the global suppression of the host immune system and increased susceptibility to infection. It has been hypothesized that infections after burn and other traumatic injury may stem from pathogenic bacteria from within the host's gastrointestinal tract. The intestine is the major reservoir of bacteria within the host, and many studies have demonstrated perturbations of the intestinal barrier after burn injury. This article reviews the findings of these studies as they pertain to changes in the intestinal immune system after alcohol and burn injury.
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Shults JA, Curtis BJ, Chen MM, O'Halloran EB, Ramirez L, Kovacs EJ. Impaired respiratory function and heightened pulmonary inflammation in episodic binge ethanol intoxication and burn injury. Alcohol 2015; 49:713-20. [PMID: 26364264 DOI: 10.1016/j.alcohol.2015.06.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 06/18/2015] [Accepted: 06/19/2015] [Indexed: 01/25/2023]
Abstract
Clinical data indicate that cutaneous burn injuries covering greater than 10% of the total body surface area are associated with significant morbidity and mortality, in which pulmonary complications, including acute respiratory distress syndrome (ARDS), contribute to nearly half of all patient deaths. Approximately 50% of burn patients are intoxicated at the time of hospital admission, which increases days on ventilators by 3-fold, and doubles the length of hospitalization, compared to non-intoxicated burn patients. The most common drinking pattern in the United States is binge drinking, where an individual rapidly consumes alcoholic beverages (4 for women, 5 for men) in 2 h. An estimated 38 million Americans binge drink, often several times per month. Experimental data demonstrate that a single binge-ethanol exposure, prior to scald injury, impairs innate and adaptive immune responses, thereby enhancing infection susceptibility and amplifying pulmonary inflammation, neutrophil infiltration, and edema, and is associated with increased mortality. Since these characteristics are similar to those observed in ARDS burn patients, our study objective was to determine whether ethanol intoxication and burn injury and the subsequent pulmonary congestion affect physiological parameters of lung function, using non-invasive and unrestrained plethysmography in a murine model system. Furthermore, to mirror young adult binge-drinking patterns, and to determine the effect of multiple ethanol exposures on pulmonary inflammation, we utilized an episodic binge-ethanol exposure regimen, where mice were exposed to ethanol for a total of 6 days (3 days ethanol, 4 days rest, 3 days ethanol) prior to burn injury. Our analyses demonstrate mice exposed to episodic binge ethanol and burn injury have higher mortality, increased pulmonary congestion and neutrophil infiltration, elevated neutrophil chemoattractants, and respiratory dysfunction, compared to burn or ethanol intoxication alone. Overall, our study identifies plethysmography as a useful tool for characterizing respiratory function in a murine burn model and for future identification of therapeutic compounds capable of restoring pulmonary functionality.
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Alcohol potentiates postburn remote organ damage through shifts in fluid compartments mediated by bradykinin. Shock 2015; 43:80-4. [PMID: 25243425 DOI: 10.1097/shk.0000000000000265] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Of the 450,000 burn patients each year, 50% have a positive blood alcohol content, and this predisposes them to worsened clinical outcomes. Despite high prevalence and established consequences, the mechanisms responsible for alcohol-mediated complications of postburn remote organ damage are currently unknown. To this end, mice received a single dose of alcohol (1.12 g/kg) or water by oral gavage and were subjected to a 15% total body surface area burn. Animals with a burn alone lost ∼5% of their body weight in 24 h, whereas intoxicated and burned mice lost only 1% body weight (P < 0.05) despite a 17% increase in hematocrit (P < 0.05) and a 57% increase in serum creatinine (P < 0.05) over burn injury alone. This retention of water weight despite increased dehydration suggests that intoxication at the time of a burn causes a shift in fluid compartments that may exacerbate end-organ ischemia and damage as evidenced by a 3-fold increase in intestinal bacterial translocation (P < 0.05), a 30% increase (P < 0.05) in liver weight-to-body weight ratio, and an increase in alveolar wall thickness over a burn alone. Furthermore, administration of the bradykinin antagonist HOE140 30 min after intoxication and burn restored fluid balance and alleviated end-organ damage. These findings suggest that alcohol potentiates postburn remote organ damage through shifts in fluid compartments mediated by bradykinin.
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Gauthier TW. Prenatal Alcohol Exposure and the Developing Immune System. Alcohol Res 2015; 37:279-85. [PMID: 26695750 PMCID: PMC4590623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Evidence from research in humans and animals suggest that ingesting alcohol during pregnancy can disrupt the fetal immune system and result in an increased risk of infections and disease in newborns that may persist throughout life. Alcohol may have indirect effects on the immune system by increasing the risk of premature birth, which itself is a risk factor for immune-related problems. Animal studies suggest that alcohol exposure directly disrupts the developing immune system. A comprehensive knowledge of the mechanisms underlying alcohol's effects on the developing immune system only will become clear once researchers establish improved methods for identifying newborns exposed to alcohol in utero.
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