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Munley JA, Kelly LS, Park G, Pons EE, Kannan KB, Bible LE, Efron PA, Nagpal R, Mohr AM. POSTINJURY PNEUMONIA INDUCES A UNIQUE BLOOD MICROBIOME SIGNATURE. Shock 2024; 62:762-771. [PMID: 39178199 DOI: 10.1097/shk.0000000000002428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2024]
Abstract
ABSTRACT Background : Previous preclinical studies have demonstrated a pathobiome after traumatic injury; however, the impact of postinjury sepsis on gut epithelial permeability and bacterial translocation remains unknown. We hypothesized that polytrauma with postinjury pneumonia would result in impaired gut permeability leading to specific blood microbiome arrays. Methods : Male and proestrus female Sprague-Dawley rats were subjected to either polytrauma (PT), PT plus 2-hours daily chronic restraint stress (PT/CS), PT with postinjury day 1 inoculation with pseudomonas pneumonia (PT + PNA), PT/CS + PNA, or naive controls. Whole blood microbiome was measured serially using high-throughput 16S rRNA sequencing and QIIME2 bioinformatics analyses. Microbial diversity was assessed using Chao1/Shannon indices and principle coordinate analysis. Intestinal permeability was evaluated by plasma occludin and lipopolysaccharide-binding protein assays. Results : PT/CS + PNA had increased intestinal permeability compared to uninfected counterparts (PT/CS) with significantly elevated occludin ( P < 0.01). Bacteria was not detected in the blood of naïve controls, PT or PT/CS, but was present in both PT + PNA and PT/CS + PNA on days 2 and 7. The PT/CS + PNA blood biome showed dominance of Streptococcus compared to PT + PNA at day 2 ( P < 0.05). Females PT/CS + PNA had a significant abundance of Staphylococcus at day 2 and Streptococcus at day 7 in the blood biome compared to male counterparts ( P < 0.05). Conclusion : Multicompartmental trauma with postinjury pneumonia results in increased intestinal permeability and bacteremia with a unique blood biome, with sexual dimorphisms evident in the blood biome composition. These findings suggest that postinjury sepsis has clinical significance and could influence outcomes after severe trauma and critical illness.
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Affiliation(s)
- Jennifer A Munley
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Lauren S Kelly
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Gwoncheol Park
- The Gut Biome Lab, Department of Health, Nutrition, and Food Sciences, Florida State University College of Education, Health, and Human Sciences, Tallahassee, Florida
| | - Erick E Pons
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Kolenkode B Kannan
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Letita E Bible
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Philip A Efron
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Ravinder Nagpal
- The Gut Biome Lab, Department of Health, Nutrition, and Food Sciences, Florida State University College of Education, Health, and Human Sciences, Tallahassee, Florida
| | - Alicia M Mohr
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
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Kelly LS, Munley JA, Pons EE, Kannan KB, Whitley EM, Bible LE, Efron PA, Mohr AM. A rat model of multicompartmental traumatic injury and hemorrhagic shock induces bone marrow dysfunction and profound anemia. Animal Model Exp Med 2024; 7:367-376. [PMID: 38860566 PMCID: PMC11228100 DOI: 10.1002/ame2.12447] [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: 03/09/2024] [Revised: 05/06/2024] [Accepted: 05/25/2024] [Indexed: 06/12/2024] Open
Abstract
BACKGROUND Severe trauma is associated with systemic inflammation and organ dysfunction. Preclinical rodent trauma models are the mainstay of postinjury research but have been criticized for not fully replicating severe human trauma. The aim of this study was to create a rat model of multicompartmental injury which recreates profound traumatic injury. METHODS Male Sprague-Dawley rats were subjected to unilateral lung contusion and hemorrhagic shock (LCHS), multicompartmental polytrauma (PT) (unilateral lung contusion, hemorrhagic shock, cecectomy, bifemoral pseudofracture), or naïve controls. Weight, plasma toll-like receptor 4 (TLR4), hemoglobin, spleen to body weight ratio, bone marrow (BM) erythroid progenitor (CFU-GEMM, BFU-E, and CFU-E) growth, plasma granulocyte colony-stimulating factor (G-CSF) and right lung histologic injury were assessed on day 7, with significance defined as p values <0.05 (*). RESULTS Polytrauma resulted in markedly more profound inhibition of weight gain compared to LCHS (p = 0.0002) along with elevated plasma TLR4 (p < 0.0001), lower hemoglobin (p < 0.0001), and enlarged spleen to body weight ratios (p = 0.004). Both LCHS and PT demonstrated suppression of CFU-E and BFU-E growth compared to naïve (p < 0.03, p < 0.01). Plasma G-CSF was elevated in PT compared to both naïve and LCHS (p < 0.0001, p = 0.02). LCHS and PT demonstrated significant histologic right lung injury with poor alveolar wall integrity and interstitial edema. CONCLUSIONS Multicompartmental injury as described here establishes a reproducible model of multicompartmental injury with worsened anemia, splenic tissue enlargement, weight loss, and increased inflammatory activity compared to a less severe model. This may serve as a more effective model to recreate profound traumatic injury to replicate the human inflammatory response postinjury.
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Affiliation(s)
- Lauren S. Kelly
- Department of Surgery and Sepsis and Critical Illness Research CenterUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Jennifer A. Munley
- Department of Surgery and Sepsis and Critical Illness Research CenterUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Erick E. Pons
- Department of Surgery and Sepsis and Critical Illness Research CenterUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Kolenkode B. Kannan
- Department of Surgery and Sepsis and Critical Illness Research CenterUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | | | - Letitia E. Bible
- Department of Surgery and Sepsis and Critical Illness Research CenterUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Philip A. Efron
- Department of Surgery and Sepsis and Critical Illness Research CenterUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Alicia M. Mohr
- Department of Surgery and Sepsis and Critical Illness Research CenterUniversity of Florida College of MedicineGainesvilleFloridaUSA
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3
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Munley JA, Kelly LS, Gillies GS, Pons EE, Coldwell PS, Kannan KB, Whitley EM, Bible LE, Efron PA, Mohr AM. NARROWING THE GAP: PRECLINICAL TRAUMA WITH POSTINJURY SEPSIS MODEL WITH INCREASED CLINICAL RELEVANCE. Shock 2023; 60:272-279. [PMID: 37310788 PMCID: PMC10526624 DOI: 10.1097/shk.0000000000002161] [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] [Indexed: 06/15/2023]
Abstract
ABSTRACT Background : Overall outcomes for trauma patients have improved over time. However, mortality for postinjury sepsis is unchanged. The use of relevant preclinical studies remains necessary to understand mechanistic changes after injury and sepsis at the cellular and molecular level. We hypothesized that a preclinical rodent model of multicompartmental injury with postinjury pneumonia and chronic stress would replicate inflammation and organ injury similar to trauma patients in the intensive care unit. Methods : Male and proestrus female Sprague-Dawley rats ( n = 16/group) were subjected to either polytrauma (PT) (lung contusion, hemorrhagic shock, cecectomy, and bifemoral pseudofracture), PT with daily chronic restraint stress (PT/CS), PT with postinjury day one Pseudomonas pneumonia (PT + PNA), PT/CS with pneumonia (PT/CS + PNA) or naive controls. Weight, white blood cell count, plasma toll-like receptor 4 (TLR4), urine norepinephrine (NE), hemoglobin, serum creatinine, and bilateral lung histology were evaluated. Results : PT + PNA and PT/CS + PNA groups lost more weight compared with those without sepsis (PT, PT/CS) and naive rats ( P < 0.03). Similarly, both PT + PNA and PT/CS + PNA had increased leukocytosis and plasma TLR4 compared with uninfected counterparts. Urine NE was elevated in PT + PNA and PT/CS + PNA compared with naive ( P < 0.03), with PT/CS + PNA exhibiting the highest levels. PT/CS + PNA exhibited worse acute kidney injury with elevated serum creatinine compared with PT/CS ( P = 0.008). PT/CS + PNA right and left lung injury scores were worse than PT + PNA ( P < 0.01). Conclusions : Sepsis, with postinjury pneumonia, induced significant systemic inflammation, organ dysfunction following polytrauma and chronic stress. Advanced animal models that replicate the critically ill human condition will help overcome the classic limitations of previous experimental models and enhance their translational value.
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Affiliation(s)
- Jennifer A. Munley
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Lauren S. Kelly
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Gwendolyn S. Gillies
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Erick E. Pons
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Preston S. Coldwell
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Kolenkode B. Kannan
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | | | - Letita E. Bible
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Philip A. Efron
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
| | - Alicia M. Mohr
- Department of Surgery and Sepsis and Critical Illness Research Center, University of Florida College of Medicine, Gainesville, Florida
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4
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Chen T, Delano MJ, Chen K, Sperry JL, Namas RA, Lamparello AJ, Deng M, Conroy J, Moldawer LL, Efron PA, Loughran P, Seymour C, Angus DC, Vodovotz Y, Chen W, Billiar TR. A road map from single-cell transcriptome to patient classification for the immune response to trauma. JCI Insight 2021; 6:145108. [PMID: 33320841 PMCID: PMC7934885 DOI: 10.1172/jci.insight.145108] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 12/09/2020] [Indexed: 01/07/2023] Open
Abstract
Immune dysfunction is an important factor driving mortality and adverse outcomes after trauma but remains poorly understood, especially at the cellular level. To deconvolute the trauma-induced immune response, we applied single-cell RNA sequencing to circulating and bone marrow mononuclear cells in injured mice and circulating mononuclear cells in trauma patients. In mice, the greatest changes in gene expression were seen in monocytes across both compartments. After systemic injury, the gene expression pattern of monocytes markedly deviated from steady state with corresponding changes in critical transcription factors, which can be traced back to myeloid progenitors. These changes were largely recapitulated in the human single-cell analysis. We generalized the major changes in human CD14+ monocytes into 6 signatures, which further defined 2 trauma patient subtypes (SG1 vs. SG2) identified in the whole-blood leukocyte transcriptome in the initial 12 hours after injury. Compared with SG2, SG1 patients exhibited delayed recovery, more severe organ dysfunction, and a higher incidence of infection and noninfectious complications. The 2 patient subtypes were also recapitulated in burn and sepsis patients, revealing a shared pattern of immune response across critical illness. Our data will be broadly useful to further explore the immune response to inflammatory diseases and critical illness.
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Affiliation(s)
- Tianmeng Chen
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Cellular and Molecular Pathology program, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Matthew J Delano
- Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA
| | - Kong Chen
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jason L Sperry
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Rami A Namas
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Ashley J Lamparello
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Meihong Deng
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Julia Conroy
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Lyle L Moldawer
- Department of Surgery, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Philip A Efron
- Department of Surgery, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Patricia Loughran
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Christopher Seymour
- The Clinical Research, Investigation and Systems Medicine of Acute Illness (CRISMA) Center, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Derek C Angus
- The Clinical Research, Investigation and Systems Medicine of Acute Illness (CRISMA) Center, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Yoram Vodovotz
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Wei Chen
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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5
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Zhong H, Li X, Zhou S, Jiang P, Liu X, Ouyang M, Nie Y, Chen X, Zhang L, Liu Y, Tao T, Tang J. Interplay between RAGE and TLR4 Regulates HMGB1-Induced Inflammation by Promoting Cell Surface Expression of RAGE and TLR4. THE JOURNAL OF IMMUNOLOGY 2020; 205:767-775. [PMID: 32580932 DOI: 10.4049/jimmunol.1900860] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 05/21/2020] [Indexed: 01/21/2023]
Abstract
Receptor for advanced glycation end-products (RAGE) and TLR4 play an important role in the inflammatory response against High-mobility group box 1 protein (HMGB1), a late proinflammatory cytokine and a damage-associated molecular pattern. As cell surface receptors, both RAGE and TLR4 are constantly trafficking between the cytoplasm and plasma membrane. However, whether TLR4 is related to the intracellular transport of RAGE in HMGB1-induced inflammation remains unknown. In this study, we demonstrated that HMGB1 not only increased RAGE expression in both the cytoplasm and plasma membrane but also upregulated the expression of TLR4 in the plasma membrane. Knocking out of RAGE led to decreased MAPK activation, TLR4 cellular membrane expression, and corresponding inflammatory cytokine generation. Meanwhile, inhibiting MAPK activation also decreased TLR4 surface expression. These results indicated that HMGB1 may bind to cell surface RAGE receptors on the cell surface, leading to MAPK activation, thus promoting TLR4 translocation on the cell surface, but does not regulate its transcription and translation. In contrast, TLR4 can increase the transcription and translation of RAGE, which translocates to the cell surface and is able to bind to more HMGB1. The cell surface receptors TLR4 and RAGE bind to HMGB1, leading to the transcription and secretion of inflammatory cytokines. Finally, we also observed these results in the mice pseudofracture model, which is closely related to HMGB1-induced inflammatory response. All these results demonstrated that the interplay between RAGE and TLR4 are critical for HMGB1-induced inflammatory response.
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Affiliation(s)
- Hanhui Zhong
- Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524000, China.,Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Xiaolian Li
- Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524000, China
| | - Shuangnan Zhou
- Liver Transplantation Center, the Fifth Medical Center of Chinese PLA General Hospital, Beijing 100039, China
| | - Ping Jiang
- Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524000, China
| | - Xiaolei Liu
- Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524000, China
| | - Mingwen Ouyang
- Department of Anesthesiology, The Fifth Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong 510900, China
| | - Ying Nie
- Department of Anesthesiology, Guangdong 999 Brain Hospital, Guangzhou, Guangdong 510510, China
| | - Xinying Chen
- School of Biomedical Engineering, Sun Yat-sen University, Guangdong 510006, China
| | - Liangqing Zhang
- Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524000, China
| | - Youtan Liu
- Department of Anesthesiology, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong 518040, China; and
| | - Tao Tao
- Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524000, China.,Department of Anesthesiology, Central People's Hospital of Zhanjiang, Zhanjiang, Guangdong 524037, China
| | - Jing Tang
- Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524000, China; .,Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, China
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6
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Dyer MR, Alexander W, Hassoune A, Chen Q, Alvikas J, Liu Y, Haldeman S, Plautz W, Loughran P, Li H, Boone B, Sadovsky Y, Sunnd P, Zuckerbraun BS, Neal MD. Platelet-derived extracellular vesicles released after trauma promote hemostasis and contribute to DVT in mice. J Thromb Haemost 2019; 17:1733-1745. [PMID: 31294514 PMCID: PMC6773503 DOI: 10.1111/jth.14563] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/24/2019] [Accepted: 06/27/2019] [Indexed: 01/30/2023]
Abstract
BACKGROUND Traumatic injury can lead to dysregulation of the normal clotting system, resulting in hemorrhagic and thrombotic complications. Platelet activation is robust following traumatic injury and one process of platelet activation is to release of extracellular vesicles (PEV) that carry heterogenous cargo loads and surface ligands. OBJECTIVES We sought to investigate and characterize the release and function of PEVs generated following traumatic injury. METHODS PEV content and quantity in circulation following trauma in humans and mice was measured using flow cytometry, size exclusion chromatography, and nanoparticle tracking analysis. PEVs were isolated from circulation and the effects on thrombin generation, bleeding time, hemorrhage control, and thrombus formation were determined. Finally, the effect of hydroxychloroquine (HCQ) on PEV release and thrombosis were examined. RESULTS Human and murine trauma results in a significant release of PEVs into circulation compared with healthy controls. These PEVs result in abundant thrombin generation, increased platelet aggregation, decreased bleeding times, and decreased hemorrhage in uncontrolled bleeding. Conversely, PEVs contributed to enhanced venous thrombus formation and were recruited to the developing thrombus site. Interestingly, HCQ treatment resulted in decreased platelet aggregation, decreased PEV release, and reduced deep vein thrombosis burden in mice. CONCLUSIONS These data demonstrate that trauma results in significant release of PEVs which are both pro-hemostatic and pro-thrombotic. The effects of PEVs can be mitigated by treatment with HCQ, suggesting the potential use as a form of deep vein thrombosis prophylaxis.
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Affiliation(s)
- Mitchell R. Dyer
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | | | - Adnan Hassoune
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Qiwei Chen
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Jurgis Alvikas
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Yingjie Liu
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Shannon Haldeman
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Will Plautz
- University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Patricia Loughran
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
- Center for Biological Imaging, University of Pittsburgh, Pittsburgh, PA
| | - Hui Li
- Magee-Women’s Research Institute, Department of Obstetrics, Gynecology, and Reproductive Science, Pittsburgh, PA
- Xiangya School of Medicine, Central South University, Changsha, Hunan, 410000, China
| | - Brian Boone
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Yoel Sadovsky
- Magee-Women’s Research Institute, Department of Obstetrics, Gynecology, and Reproductive Science, Pittsburgh, PA
| | - Prithu Sunnd
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | | | - Matthew D. Neal
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
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7
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Manson J, Hoffman R, Chen S, Ramadan MH, Billiar TR. Innate-Like Lymphocytes Are Immediate Participants in the Hyper-Acute Immune Response to Trauma and Hemorrhagic Shock. Front Immunol 2019; 10:1501. [PMID: 31354702 PMCID: PMC6638190 DOI: 10.3389/fimmu.2019.01501] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 06/17/2019] [Indexed: 02/03/2023] Open
Abstract
Adverse outcomes following severe traumatic injury are frequently attributed to a state of immunological dysfunction acquired during treatment and recovery. Recent genomic evidence however, suggests that the trajectory toward development of multiple organ dysfunction syndrome (MODS) is already in play at admission (<2 h following injury). Improved understanding of the molecular events during the hyper-acute immunological response to trauma, <2 h following injury, may reveal opportunities to ameliorate organ injury and expedite recovery. Lymphocytes have not previously been considered key participants in this early response; however, two observations in human trauma patients namely, raised populations of circulating NKT and NK cells during the hyper-acute phase and persistent lymphopenia beyond 48 h show association with the development of MODS during recovery. These highlight the need for greater understanding of lymphocyte function in the hyper-acute phase of inflammation. An exploratory study was therefore conducted in a well-established murine model of trauma and hemorrhagic shock (T&HS) to investigate (1) the development of lymphopenia in the murine model and (2) the phenotypic and functional changes of three innate-like lymphocyte subsets, NK1.1+ CD3–, NK1.1+ CD3+, γδTCR+ CD3+ cells, focusing on the first 6 h following injury. Rapid changes in phenotype and function were demonstrated in these cells within blood and spleen, but responses in lung tissue lagged behind. This study describes the immediacy of the innate-like lymphocyte response to trauma in different body compartments and considers new lines for further investigation to develop our understanding of MODS pathogenesis.
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Affiliation(s)
- Joanna Manson
- Department of Surgery, F1281 Presbyterian University Hospital, University of Pittsburgh, Pittsburgh, PA, United States.,Barts Centre for Trauma Sciences, Blizard Institute, Queen Mary University of London, London, United Kingdom
| | - Rosemary Hoffman
- Department of Surgery, F1281 Presbyterian University Hospital, University of Pittsburgh, Pittsburgh, PA, United States
| | - Shuhua Chen
- Department of Surgery, F1281 Presbyterian University Hospital, University of Pittsburgh, Pittsburgh, PA, United States
| | - Mostafa H Ramadan
- Department of Surgery, F1281 Presbyterian University Hospital, University of Pittsburgh, Pittsburgh, PA, United States
| | - Timothy R Billiar
- Department of Surgery, F1281 Presbyterian University Hospital, University of Pittsburgh, Pittsburgh, PA, United States
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8
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Liu L, Mao Y, Xu B, Zhang X, Fang C, Ma Y, Men K, Qi X, Yi T, Wei Y, Wei X. Induction of neutrophil extracellular traps during tissue injury: Involvement of STING and Toll-like receptor 9 pathways. Cell Prolif 2019; 52:e12579. [PMID: 30851061 PMCID: PMC6536408 DOI: 10.1111/cpr.12579] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 01/02/2019] [Accepted: 01/05/2019] [Indexed: 02/05/2023] Open
Abstract
Objectives Neutrophils are thought to release neutrophil extracellular traps (NETs) to form in response to exogenous bacteria, viruses and other pathogens. However, the mechanisms underlying NET formation during sterile inflammation are still unclear. In this study, we would like to identify neutrophil extracellular traps formation during sterile inflammation and tissue injury and associated pathways and its mechanism. Materials and methods We identified different injuries such as chemical‐induced and trauma‐induced formation of NETs and investigated mechanism of the formation of NETs in vitro and in vivo during the treatment of mtDNA. Results Here, we find the release of mitochondrial DNA (mtDNA) and oxidized mtDNA in acute peripheral tissue trauma models or other chemically induced lung injury, and moreover, endogenous mtDNA and oxidized mtDNA induce the formation of NETs and sterile inflammation. Oxidized mtDNA is a more potent inducer of NETs. Mitochondrial DNA activates neutrophils via cyclic GMP‐AMP synthase (cGAS)‐STING and the Toll‐like receptor 9 (TLR9) pathways and increases the production of neutrophil elastase and extracellular neutrophil‐derived DNA in NETs. Mitochondrial DNA also increases the production of reactive oxygen species (ROS) and expression of the NET‐associated proteins Rac 2 and peptidylarginine deiminase 4 (PAD4). Conclusions Altogether, these findings highlight that endogenous mitochondrial DNA inducted NETs formation and subsequent sterile inflammation and the mechanism associated with NET formation.
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Affiliation(s)
- Li Liu
- Lab of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, Sichuan, China
| | - Ye Mao
- Lab of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, Sichuan, China
| | - Bocheng Xu
- Lab of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, Sichuan, China
| | - Xiangxian Zhang
- Lab of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, Sichuan, China
| | - Chunju Fang
- Lab of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, Sichuan, China
| | - Yu Ma
- Department of Gynecology and Obstetrics, West China Second Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ke Men
- Lab of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, Sichuan, China
| | - Xiaorong Qi
- Department of Gynecology and Obstetrics, West China Second Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Tao Yi
- Department of Gynecology and Obstetrics, West China Second Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yuquan Wei
- Lab of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, Sichuan, China
| | - Xiawei Wei
- Lab of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, Sichuan, China
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9
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Mira JC, Nacionales DC, Loftus TJ, Ungaro R, Mathias B, Mohr AM, Moldawer LL, Efron PA. Mouse Injury Model of Polytrauma and Shock. Methods Mol Biol 2018; 1717:1-15. [PMID: 29468579 PMCID: PMC6296232 DOI: 10.1007/978-1-4939-7526-6_1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Severe injury and shock remain major sources of morbidity and mortality worldwide. Immunologic dysregulation following trauma contributes to these poor outcomes. Few, if any, therapeutic interventions have benefited these patients, and this is due to our limited understanding of the host response to injury and shock. The Food and Drug Administration requires preclinical animal studies prior to any interventional trials in humans; thus, animal models of injury and shock will remain the mainstay for trauma research. However, adequate animal models that reflect the severe response to trauma in both the acute and subacute phases have been limited. Here we describe a novel murine model of polytrauma and shock that combines hemorrhagic shock, cecectomy, long bone fracture, and soft-tissue damage. This model produces an equivalent Injury Severity Score associated with adverse outcomes in humans, and may better recapitulate the human leukocyte, cytokine, transcriptomic, and overall inflammatory response following injury and hemorrhagic shock.
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Affiliation(s)
- Juan C Mira
- Department of Surgery, University of Florida College of Medicine, Gainesville, FL, USA
| | - Dina C Nacionales
- Department of Surgery, University of Florida College of Medicine, Gainesville, FL, USA
| | - Tyler J Loftus
- Department of Surgery, University of Florida College of Medicine, Gainesville, FL, USA
| | - Ricardo Ungaro
- Department of Surgery, University of Florida College of Medicine, Gainesville, FL, USA
| | - Brittany Mathias
- Department of Surgery, University of Florida College of Medicine, Gainesville, FL, USA
| | - Alicia M Mohr
- Department of Surgery, University of Florida College of Medicine, Gainesville, FL, USA
| | - Lyle L Moldawer
- Department of Surgery, University of Florida College of Medicine, Gainesville, FL, USA
| | - Philip A Efron
- Department of Surgery, Shands Hospital, University of Florida College of Medicine, Gainesville, FL, USA.
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10
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von Ungern-Sternberg SNI, Vogel S, Walker-Allgaier B, Geue S, Maurer A, Wild AM, Münzer P, Chatterjee M, Heinzmann D, Kremmer E, Borst O, Loughran P, Zernecke A, Neal MD, Billiar TR, Gawaz M, Seizer P. Extracellular Cyclophilin A Augments Platelet-Dependent Thrombosis and Thromboinflammation. Thromb Haemost 2017; 117:2063-2078. [PMID: 28981554 DOI: 10.1160/th17-01-0067] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cyclophilin A (CyPA) is involved in the pathophysiology of several inflammatory and cardiovascular diseases. To our knowledge, there is no specific inhibitor targeting extracellular CyPA without affecting other extracellular cyclophilins or intracellular CyPA functions. In this study, we developed an antibody-based inhibitor of extracellular CyPA and analysed its effects in vitro and in vivo. To generate a specific antibody, mice and rats were immunized with a peptide containing the extracellular matrix metalloproteinase inducer binding site and various antibody clones were selected and purified. At first, antibodies were tested for their binding capacity to recombinant CyPA and their functional activity. The clone 8H7-mAb was chosen for further experiments. 8H7-mAb reduced the CyPA-induced migration of inflammatory cells in vitro and in vivo. Furthermore, 8H7-mAb revealed strong antithrombotic effects by inhibiting CyPA-dependent activation of platelets and thrombus formation in vitro and in vivo. Surprisingly, 8H7-mAb did not influence in vivo tail bleeding time or in vitro whole blood coagulation parameters. Our study provides first evidence that antibody-based inhibition of extracellular CyPA inhibits thrombosis and thromboinflammation without affecting blood homeostasis. Thus, 8H7-mAb may be a promising compound for thrombi modulation in inflammatory diseases to prevent organ dysfunction.
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Affiliation(s)
| | - Sebastian Vogel
- Medizinische Klinik III, Kardiologie und Kreislauferkrankungen, Eberhard Karls-Universität Tübingen, Tübingen, Germany
| | - Britta Walker-Allgaier
- Medizinische Klinik III, Kardiologie und Kreislauferkrankungen, Eberhard Karls-Universität Tübingen, Tübingen, Germany
| | - Sascha Geue
- Medizinische Klinik III, Kardiologie und Kreislauferkrankungen, Eberhard Karls-Universität Tübingen, Tübingen, Germany
| | - Andreas Maurer
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls-Universität Tübingen, Tübingen, Germany
| | - Anna-Maria Wild
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls-Universität Tübingen, Tübingen, Germany
| | - Patrick Münzer
- Medizinische Klinik III, Kardiologie und Kreislauferkrankungen, Eberhard Karls-Universität Tübingen, Tübingen, Germany
| | - Madhumita Chatterjee
- Medizinische Klinik III, Kardiologie und Kreislauferkrankungen, Eberhard Karls-Universität Tübingen, Tübingen, Germany
| | - David Heinzmann
- Medizinische Klinik III, Kardiologie und Kreislauferkrankungen, Eberhard Karls-Universität Tübingen, Tübingen, Germany
| | - Elisabeth Kremmer
- Helmholtz Zentrum München, Institut für Molekulare Immunologie, München, Germany
| | - Oliver Borst
- Medizinische Klinik III, Kardiologie und Kreislauferkrankungen, Eberhard Karls-Universität Tübingen, Tübingen, Germany
| | - Patricia Loughran
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States.,Center for Biological Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Alma Zernecke
- Institut für Experimentelle Biomedizin, Universitätsklinikum Würzburg, Germany
| | - Matthew D Neal
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Meinrad Gawaz
- Medizinische Klinik III, Kardiologie und Kreislauferkrankungen, Eberhard Karls-Universität Tübingen, Tübingen, Germany
| | - Peter Seizer
- Medizinische Klinik III, Kardiologie und Kreislauferkrankungen, Eberhard Karls-Universität Tübingen, Tübingen, Germany
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11
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Stortz JA, Raymond SL, Mira JC, Moldawer LL, Mohr AM, Efron PA. Murine Models of Sepsis and Trauma: Can We Bridge the Gap? ILAR J 2017; 58:90-105. [PMID: 28444204 PMCID: PMC5886315 DOI: 10.1093/ilar/ilx007] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 02/20/2017] [Accepted: 02/23/2017] [Indexed: 02/06/2023] Open
Abstract
Sepsis and trauma are both leading causes of death in the United States and represent major public health challenges. Murine models have largely been used in sepsis and trauma research to better understand the pathophysiological changes that occur after an insult and to develop potential life-saving therapeutic agents. Mice are favorable subjects for this type of research given the variety of readily available strains including inbred, outbred, and transgenic strains. In addition, they are relatively easy to maintain and have a high fecundity. However, pharmacological therapies demonstrating promise in preclinical mouse models of sepsis and trauma often fail to demonstrate similar efficacy in human clinical trials, prompting considerable criticism surrounding the capacity of murine models to recapitulate complex human diseases like sepsis and traumatic injury. Fundamental differences between the two species include, but are not limited to, the divergence of the transcriptomic response, the mismatch of temporal response patterns, differences in both innate and adaptive immunity, and heterogeneity within the human population in comparison to the homogeneity of highly inbred mouse strains. Given the ongoing controversy, this narrative review aims to not only highlight the historical importance of the mouse as an animal research model but also highlight the current benefits and limitations of the model as it pertains to sepsis and trauma. Lastly, this review will propose future directions that may promote further use of the model.
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Affiliation(s)
- Julie A. Stortz
- Julie A. Stortz, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Steven L. Raymond, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Juan C. Mira, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Lyle L. Moldawer, PhD, is the Robert H. and Kathleen M. Axline Basic Science Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Alicia M. Mohr, MD, is an Associate Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Philip A. Efron, MD, is an Associate Professor of Surgery and Anesthesiology at the University of Florida College of Medicine and Medical Director for the surgical intensive care unit at the University of Florida Health Shands Hospital, Department of Surgery, University of Florida College of Medicine, Gainesville, FL.
| | - Steven L. Raymond
- Julie A. Stortz, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Steven L. Raymond, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Juan C. Mira, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Lyle L. Moldawer, PhD, is the Robert H. and Kathleen M. Axline Basic Science Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Alicia M. Mohr, MD, is an Associate Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Philip A. Efron, MD, is an Associate Professor of Surgery and Anesthesiology at the University of Florida College of Medicine and Medical Director for the surgical intensive care unit at the University of Florida Health Shands Hospital, Department of Surgery, University of Florida College of Medicine, Gainesville, FL.
| | - Juan C. Mira
- Julie A. Stortz, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Steven L. Raymond, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Juan C. Mira, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Lyle L. Moldawer, PhD, is the Robert H. and Kathleen M. Axline Basic Science Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Alicia M. Mohr, MD, is an Associate Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Philip A. Efron, MD, is an Associate Professor of Surgery and Anesthesiology at the University of Florida College of Medicine and Medical Director for the surgical intensive care unit at the University of Florida Health Shands Hospital, Department of Surgery, University of Florida College of Medicine, Gainesville, FL.
| | - Lyle L. Moldawer
- Julie A. Stortz, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Steven L. Raymond, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Juan C. Mira, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Lyle L. Moldawer, PhD, is the Robert H. and Kathleen M. Axline Basic Science Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Alicia M. Mohr, MD, is an Associate Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Philip A. Efron, MD, is an Associate Professor of Surgery and Anesthesiology at the University of Florida College of Medicine and Medical Director for the surgical intensive care unit at the University of Florida Health Shands Hospital, Department of Surgery, University of Florida College of Medicine, Gainesville, FL.
| | - Alicia M. Mohr
- Julie A. Stortz, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Steven L. Raymond, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Juan C. Mira, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Lyle L. Moldawer, PhD, is the Robert H. and Kathleen M. Axline Basic Science Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Alicia M. Mohr, MD, is an Associate Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Philip A. Efron, MD, is an Associate Professor of Surgery and Anesthesiology at the University of Florida College of Medicine and Medical Director for the surgical intensive care unit at the University of Florida Health Shands Hospital, Department of Surgery, University of Florida College of Medicine, Gainesville, FL.
| | - Philip A. Efron
- Julie A. Stortz, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Steven L. Raymond, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Juan C. Mira, MD, is a research fellow at the University of Florida Health Shands Hospital in Gainesville, Florida. Lyle L. Moldawer, PhD, is the Robert H. and Kathleen M. Axline Basic Science Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Alicia M. Mohr, MD, is an Associate Professor of Surgery at the University of Florida College of Medicine in Gainesville, FL. Philip A. Efron, MD, is an Associate Professor of Surgery and Anesthesiology at the University of Florida College of Medicine and Medical Director for the surgical intensive care unit at the University of Florida Health Shands Hospital, Department of Surgery, University of Florida College of Medicine, Gainesville, FL.
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12
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Xu J, Guardado J, Hoffman R, Xu H, Namas R, Vodovotz Y, Xu L, Ramadan M, Brown J, Turnquist HR, Billiar TR. IL33-mediated ILC2 activation and neutrophil IL5 production in the lung response after severe trauma: A reverse translation study from a human cohort to a mouse trauma model. PLoS Med 2017; 14:e1002365. [PMID: 28742815 PMCID: PMC5526517 DOI: 10.1371/journal.pmed.1002365] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 06/20/2017] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The immunosuppression and immune dysregulation that follows severe injury includes type 2 immune responses manifested by elevations in interleukin (IL) 4, IL5, and IL13 early after injury. We hypothesized that IL33, an alarmin released early after tissue injury and a known regulator of type 2 immunity, contributes to the early type 2 immune responses after systemic injury. METHODS AND FINDINGS Blunt trauma patients admitted to the trauma intensive care unit of a level I trauma center were enrolled in an observational study that included frequent blood sampling. Dynamic changes in IL33 and soluble suppression of tumorigenicity 2 (sST2) levels were measured in the plasma and correlated with levels of the type 2 cytokines and nosocomial infection. Based on the observations in humans, mechanistic experiments were designed in a mouse model of resuscitated hemorrhagic shock and tissue trauma (HS/T). These experiments utilized wild-type C57BL/6 mice, IL33-/- mice, B6.C3(Cg)-Rorasg/sg mice deficient in group 2 innate lymphoid cells (ILC2), and C57BL/6 wild-type mice treated with anti-IL5 antibody. Severely injured human blunt trauma patients (n = 472, average injury severity score [ISS] = 20.2) exhibited elevations in plasma IL33 levels upon admission and over time that correlated positively with increases in IL4, IL5, and IL13 (P < 0.0001). sST2 levels also increased after injury but in a delayed manner compared with IL33. The increases in IL33 and sST2 were significantly greater in patients that developed nosocomial infection and organ dysfunction than similarly injured patients that did not (P < 0.05). Mechanistic studies were carried out in a mouse model of HS/T that recapitulated the early increase in IL33 and delayed increase in sST2 in the plasma (P < 0.005). These studies identified a pathway where IL33 induces ILC2 activation in the lung within hours of HS/T. ILC2 IL5 up-regulation induces further IL5 expression by CXCR2+ lung neutrophils, culminating in early lung injury. The major limitations of this study are the descriptive nature of the human study component and the impact of the potential differences between human and mouse immune responses to polytrauma. Also, the studies performed did not permit us to make conclusions about the impact of IL33 on pulmonary function. CONCLUSIONS These results suggest that IL33 may initiate early detrimental type 2 immune responses after trauma through ILC2 regulation of neutrophil IL5 production. This IL33-ILC2-IL5-neutrophil axis defines a novel regulatory role for ILC2 in acute lung injury that could be targeted in trauma patients prone to early lung dysfunction.
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Affiliation(s)
- Jing Xu
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- State Key Laboratory of Trauma, Burns and Combined Injury, Second Department of Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, P. R. China
| | - Jesse Guardado
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Rosemary Hoffman
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Hui Xu
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- State Key Laboratory of Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Rami Namas
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Yoram Vodovotz
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Li Xu
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Emergency Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, P. R. China
| | - Mostafa Ramadan
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Joshua Brown
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Heth R. Turnquist
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail: (TRB); (HRT)
| | - Timothy R. Billiar
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail: (TRB); (HRT)
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13
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Dyer M, Haldeman S, Gutierrez A, Kohut L, Sen Gupta A, Neal MD. Uncontrolled Hemorrhagic Shock Modeled via Liver Laceration in Mice with Real Time Hemodynamic Monitoring. J Vis Exp 2017. [PMID: 28570538 DOI: 10.3791/55554] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Uncontrolled hemorrhage is an important cause of preventable deaths among trauma patients. We have developed a murine model of uncontrolled hemorrhage via a liver laceration that results in consistent blood loss, hemodynamic alterations, and survival. Mice undergo a standardized resection of the left-middle lobe of the liver. They are allowed to bleed without mechanical intervention. Hemostatic agents can be administered as pre-treatment or rescue therapy depending on the interest of the investigator. During the time of hemorrhage, real-time hemodynamic monitoring via a left femoral arterial line is performed. Mice are then sacrificed, blood loss is quantified, blood is collected for further analysis, and organs are harvested for analysis of injury. Experimental design is described to allow for simultaneous testing of multiple animals. Liver hemorrhage as a model of uncontrolled hemorrhage exists in the literature, primarily in rat and porcine models. Some of these models utilize hemodynamic monitoring or quantify blood loss but lack consistency. The present model incorporates quantification of blood loss, real-time hemodynamic monitoring in a murine model that offers the advantage of using transgenic lines and a high-throughput mechanism to further investigate the pathophysiologic mechanisms in uncontrolled hemorrhage.
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Affiliation(s)
| | | | | | | | - Anirban Sen Gupta
- Department of Biomedical Engineering, Case Western Reserve University
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14
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Chen S, Hoffman RA, Scott M, Manson J, Loughran P, Ramadan M, Demetris AJ, Billiar TR. NK1.1 + cells promote sustained tissue injury and inflammation after trauma with hemorrhagic shock. J Leukoc Biol 2017; 102:127-134. [PMID: 28515228 DOI: 10.1189/jlb.3a0716-333r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 02/23/2017] [Accepted: 03/28/2017] [Indexed: 01/02/2023] Open
Abstract
Various cell populations expressing NK1.1 contribute to innate host defense and systemic inflammatory responses, but their role in hemorrhagic shock and trauma remains uncertain. NK1.1+ cells were depleted by i.p. administration of anti-NK1.1 (or isotype control) on two consecutive days, followed by hemorrhagic shock with resuscitation and peripheral tissue trauma (HS/T). The plasma levels of IL-6, MCP-1, alanine transaminase (ALT), and aspartate aminotransferase (AST) were measured at 6 and 24 h. Histology in liver and gut were examined at 6 and 24 h. The number of NK cells, NKT cells, neutrophils, and macrophages in liver, as well as intracellular staining for TNF-α, IFN-γ, and MCP-1 in liver cell populations were determined by flow cytometry. Control mice subjected to HS/T exhibited end organ damage manifested by marked increases in circulating ALT, AST, and MCP-1 levels, as well as histologic evidence of hepatic necrosis and gut injury. Although NK1.1+ cell-depleted mice exhibited a similar degree of organ damage as nondepleted animals at 6 h, NK1.1+ cell depletion resulted in marked suppression of both liver and gut injury by 24 h after HS/T. These findings indicate that NK1.1+ cells contribute to the persistence of inflammation leading to end organ damage in the liver and gut.
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Affiliation(s)
- Shuhua Chen
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Department of Biochemistry, School of Life Sciences, Central South University, Changsha, Hunan, P.R. China; and
| | - Rosemary A Hoffman
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Melanie Scott
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Joanna Manson
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Patricia Loughran
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Mostafa Ramadan
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anthony J Demetris
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; and
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; .,Clinical Translational Medical Center of Vascular Disease of the Third Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China
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15
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Li Z, Fan EK, Liu J, Scott MJ, Li Y, Li S, Xie W, Billiar TR, Wilson MA, Jiang Y, Wang P, Fan J. Cold-inducible RNA-binding protein through TLR4 signaling induces mitochondrial DNA fragmentation and regulates macrophage cell death after trauma. Cell Death Dis 2017; 8:e2775. [PMID: 28492546 PMCID: PMC5584526 DOI: 10.1038/cddis.2017.187] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/24/2017] [Accepted: 03/27/2017] [Indexed: 02/06/2023]
Abstract
Trauma is a major cause of systemic inflammatory response syndrome and multiple organ dysfunction syndrome. Macrophages (Mϕ) direct trauma-induced inflammation, and Mϕ death critically influences the progression of the inflammatory response. In the current study, we explored an important role of trauma in inducing mitochondrial DNA (mtDNA) damage in Mϕ and the subsequent regulation of Mϕ death. Using an animal pseudo-fracture trauma model, we demonstrated that tissue damage induced NADPH oxidase activation and increased the release of reactive oxygen species via cold-inducible RNA-binding protein (CIRP)–TLR4–MyD88 signaling. This in turn, activates endonuclease G, which serves as an executor for the fragmentation of mtDNA in Mϕ. We further showed that fragmented mtDNA triggered both p62-related autophagy and necroptosis in Mϕ. However, autophagy activation also suppressed Mϕ necroptosis and pro-inflammatory responses. This study demonstrates a previously unidentified intracellular regulation of Mϕ homeostasis in response to trauma.
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Affiliation(s)
- Zhigang Li
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.,Research and Development, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA 15240, USA
| | - Erica K Fan
- University of Pittsburgh School of Arts and Science, Pittsburgh, PA 15213, USA
| | - Jinghua Liu
- Guangdong Provincial Key Laboratory of Proteomics, State Key Laboratory of Organ Failure Research, Southern Medical University, Guangzhou 510515, China
| | - Melanie J Scott
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Yuehua Li
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.,Research and Development, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA 15240, USA
| | - Song Li
- Department of Pharmaceutical Sciences, Center for Pharmacogenetics, University of Pittsburgh School of Pharmacy, Pittsburgh, PA 15261, USA
| | - Wen Xie
- Department of Pharmaceutical Sciences, Center for Pharmacogenetics, University of Pittsburgh School of Pharmacy, Pittsburgh, PA 15261, USA
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.,McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Mark A Wilson
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.,Research and Development, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA 15240, USA
| | - Yong Jiang
- Guangdong Provincial Key Laboratory of Proteomics, State Key Laboratory of Organ Failure Research, Southern Medical University, Guangzhou 510515, China
| | - Ping Wang
- The Feinstein Institute for Medical Research, Manhasset, NY 11030, USA
| | - Jie Fan
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.,Research and Development, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA 15240, USA.,McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219, USA
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16
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Zettel KR, Dyer M, Raval JS, Wu X, Klune JR, Gutierrez A, Triulzi DJ, Billiar TR, Neal MD. Aged Human Stored Red Blood Cell Supernatant Inhibits Macrophage Phagocytosis in an HMGB1 Dependent Manner After Trauma in a Murine Model. Shock 2017; 47:217-224. [PMID: 27488090 PMCID: PMC5235959 DOI: 10.1097/shk.0000000000000716] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Red blood cell transfusions in the setting of trauma are a double-edged sword, as it is a necessary component for life-sustaining treatment in massive hemorrhagic shock, but also associated with increased risk for nosocomial infections and immune suppression. The mechanisms surrounding this immune suppression are unclear. Using supernatant from human packed red blood cell (RBC), we demonstrate that clearance of Escherichia coli by macrophages is inhibited both in vitro and in vivo using a murine model of trauma and hemorrhagic shock. We further explore the mechanism of this inhibition by demonstrating that human-stored RBCs contain soluble high-mobility group box 1 protein (HMGB1) that increases throughout storage. HMGB1 derived from the supernatant of human-stored RBCs was shown to inhibit bacterial clearance, as neutralizing antibodies to HMGB1 restored the ability of macrophages to clear bacteria. These findings demonstrate that extracellular HMGB1 within stored RBCs could be one factor leading to immune suppression following transfusion in the trauma setting.
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Affiliation(s)
- Kent R. Zettel
- Department of Surgery, University of Pittsburgh College of Medicine
| | - Mitchell Dyer
- Department of Surgery, University of Pittsburgh College of Medicine
| | - Jay S. Raval
- Department of Pathology and Laboratory Medicine, University of North Carolina School of Medicine
| | - Xubo Wu
- Department of Surgery, University of Pittsburgh College of Medicine
- Department of Surgery, Minhang Hospital, Fudan University, Shanghai China 201199
| | - John R. Klune
- Department of Surgery, University of Pittsburgh College of Medicine
| | - Andres Gutierrez
- Department of Surgery, University of Pittsburgh College of Medicine
| | | | | | - Matthew D. Neal
- Department of Surgery, University of Pittsburgh College of Medicine
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17
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Tissue damage negatively regulates LPS-induced macrophage necroptosis. Cell Death Differ 2016; 23:1428-47. [PMID: 26943325 DOI: 10.1038/cdd.2016.21] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 01/24/2016] [Accepted: 02/02/2016] [Indexed: 01/10/2023] Open
Abstract
Infection is a common clinical complication following tissue damage resulting from surgery and severe trauma. Studies have suggested that cell pre-activation by antecedent trauma/tissue damage profoundly impacts the response of innate immune cells to a secondary infectious stimulus. Cell necroptosis, a form of regulated inflammatory cell death, is one of the mechanisms that control cell release of inflammatory mediators from important innate immune executive cells such as macrophages (Mφ), which critically regulate the progress of inflammation. In this study, we investigated the mechanism and role of trauma/tissue damage in the regulation of LPS-induced Mφ necroptosis using a mouse model simulating long-bone fracture. We demonstrate that LPS acting through Toll-like receptor (TLR) 4 promotes Mφ necroptosis. However, necroptosis is ameliorated by high-mobility group box 1 (HMGB1) release from damaged tissue. We show that HMGB1 acting through cell surface receptor for advanced glycation end products (RAGE) upregulates caveolin-1 expression, which in turn induces caveolae-mediated TLR4 internalization and desensitization to decrease Mφ necroptosis. We further show that RAGE-MyD88 activation of Cdc42 and subsequent activation of transcription factor Sp1 serves as a mechanism underlying caveolin-1 transcriptional upregulation. These results reveal a previous unidentified protective role of damage-associated molecular pattern (DAMP) molecules in restricting inflammation in response to exogenous pathogen-associated molecular pattern molecules.
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18
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Vogel S, Bodenstein R, Chen Q, Feil S, Feil R, Rheinlaender J, Schäffer TE, Bohn E, Frick JS, Borst O, Münzer P, Walker B, Markel J, Csanyi G, Pagano PJ, Loughran P, Jessup ME, Watkins SC, Bullock GC, Sperry JL, Zuckerbraun BS, Billiar TR, Lotze MT, Gawaz M, Neal MD. Platelet-derived HMGB1 is a critical mediator of thrombosis. J Clin Invest 2015; 125:4638-54. [PMID: 26551681 DOI: 10.1172/jci81660] [Citation(s) in RCA: 249] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 10/01/2015] [Indexed: 12/16/2022] Open
Abstract
Thrombosis and inflammation are intricately linked in several major clinical disorders, including disseminated intravascular coagulation and acute ischemic events. The damage-associated molecular pattern molecule high-mobility group box 1 (HMGB1) is upregulated by activated platelets in multiple inflammatory diseases; however, the contribution of platelet-derived HMGB1 in thrombosis remains unexplored. Here, we generated transgenic mice with platelet-specific ablation of HMGB1 and determined that platelet-derived HMGB1 is a critical mediator of thrombosis. Mice lacking HMGB1 in platelets exhibited increased bleeding times as well as reduced thrombus formation, platelet aggregation, inflammation, and organ damage during experimental trauma/hemorrhagic shock. Platelets were the major source of HMGB1 within thrombi. In trauma patients, HMGB1 expression on the surface of circulating platelets was markedly upregulated. Moreover, evaluation of isolated platelets revealed that HMGB1 is critical for regulating platelet activation, granule secretion, adhesion, and spreading. These effects were mediated via TLR4- and MyD88-dependent recruitment of platelet guanylyl cyclase (GC) toward the plasma membrane, followed by MyD88/GC complex formation and activation of the cGMP-dependent protein kinase I (cGKI). Thus, we establish platelet-derived HMGB1 as an important mediator of thrombosis and identify a HMGB1-driven link between MyD88 and GC/cGKI in platelets. Additionally, these findings suggest a potential therapeutic target for patients sustaining trauma and other inflammatory disorders associated with abnormal coagulation.
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Bone Components Downregulate Expression of Toll-Like Receptor 4 on the Surface of Human Monocytic U937 Cells: A Cell Model for Postfracture Immune Dysfunction. Mediators Inflamm 2015; 2015:896576. [PMID: 26273144 PMCID: PMC4529969 DOI: 10.1155/2015/896576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 03/17/2015] [Accepted: 04/02/2015] [Indexed: 11/24/2022] Open
Abstract
To mimic the immune status of monocyte in the localized fracture region, toll-like receptor 4 (TLR4) surface expression in human monocytic U937 cells was used as the main target to assess immune dysfunction following bone component exposure. We first identified the effects of bone components (including the marrow content) on TLR4 surface expression and then examined the mechanisms underlying the changes. The level of microRNA-146a expression, an indicator of endotoxin tolerance, was also assayed. Bone component exposure downregulated TLR4 surface expression at 24 h by flow cytometry analysis, compatible with the result obtained from the membranous portion of TLR4 by western blot analysis. The cytoplasmic portion of TLR4 paradoxically increased after bone component exposure. Impaired TLR4 trafficking from the cytoplasm to the membrane was related to gp96 downregulation, as observed by western blot analysis, and this was further evidenced by gp96-TLR4 colocalization under confocal microscopy. TaqMan analysis revealed that the expression of microRNA-146a was also upregulated. This cell model demonstrated that bone component exposure downregulated TLR4 surface expression in a gp96-related manner in human monocytic U937 cells, an indicator of immunosuppression at 24 h. Immune dysfunction was further evidenced by upregulation of microRNA-146a expression at the same time point.
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Mitochondrial damage-associated molecular patterns from fractures suppress pulmonary immune responses via formyl peptide receptors 1 and 2. J Trauma Acute Care Surg 2015; 78:272-9; discussion 279-81. [PMID: 25757111 DOI: 10.1097/ta.0000000000000509] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND No known biologic mechanisms link tissue injury with pneumonia (PNA). Neutrophils (PMNs) are innate immune cells that clear bacteria from the lung by migration toward chemoattractants and killing bacteria in neutrophil extracellular traps (NETs). We predicted that tissue injury would suppress PMN antimicrobial function in the lung. We have also shown that mitochondria-derived damage-associated molecular pattern molecules from the bone can alter PMN phenotype and so hypothesized that formyl peptides (FPs) from fractures predispose to PNA by suppressing PMN activity in the lung. METHODS Animal studies involved the following. (1) Rats were divided into three groups (10 per condition) as follows: (a) saline injection in the thigh (b) Staphylococcus aureus (SA, 3 × 10) injected intratracheally, or (c) pseudofracture (PsFx; bone supernatant injected in the thigh) plus intratracheally injected SA. (2) Rats were divided into four groups as follows: (a) control, (b) pulmonary contusion (PC), (c) PsFx, and (d) PC + PsFx. Bronchoalveolar lavage was performed 16 hours later. Clinical studies involved the following. (3) Human bone supernatant was assayed for its FP-receptor (FPR) stimulation. (4) Trauma patients' PMN (n = 32; mean ± SE Injury Severity Score [ISS], 27 ± 10) were assayed for chemotaxis (CTX) or treated with Phorbol 12-myristate 13-acetate (PMA, Phorbol ester) and analyzed for NET formation. RESULTS In the animal studies, (1) SA was rapidly cleared by the uninjured mice and PsFx markedly suppressed lung bacterial clearance (p < 0.01). (2a) PC induces PMN traffic to the lung, but PsFx decreases PC-induced PMN traffic (p < 0.01). (2b) SA increased bronchoalveolar lavage PMN, and PsFx decreased that influx (p < 0.01). In the clinical studies, (3) bone supernatant activates PMN both via FPR-1 and FPR-2. (4) Trauma decreases PMN CTX to multiple chemokines. Circulating PMNs show NETs spontaneously after trauma, but maximal NET formation is markedly attenuated. CONCLUSION Fractures may decrease lung bacterial clearance because FP suppresses PMN CTX to other chemoattractants via FPR-1/2. Trauma activates NETosis but suppresses maximal NETosis. Fractures decrease lung bacterial clearance by multiple mechanisms. PNA after fractures may reflect damage-associated molecular pattern-mediated suppression of PMN antimicrobial function in the lung.
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Anti-HMGB1 monoclonal antibody ameliorates immunosuppression after peripheral tissue trauma: attenuated T-lymphocyte response and increased splenic CD11b (+) Gr-1 (+) myeloid-derived suppressor cells require HMGB1. Mediators Inflamm 2015; 2015:458626. [PMID: 25709155 PMCID: PMC4325468 DOI: 10.1155/2015/458626] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 09/10/2014] [Indexed: 01/13/2023] Open
Abstract
Although tissue-derived high mobility group box 1 (HMGB1) is involved in many aspects of inflammation and tissue injury after trauma, its role in trauma-induced immune suppression remains elusive. Using an established mouse model of peripheral tissue trauma, which includes soft tissue and fracture components, we report here that treatment with anti-HMGB1 monoclonal antibody ameliorated the trauma-induced attenuated T-cell responses and accumulation of CD11b+Gr-1+ myeloid-derived suppressor cells in the spleens seen two days after injury. Our data suggest that HMGB1 released after tissue trauma contributes to signaling pathways that lead to attenuation of T-lymphocyte responses and enhancement of myeloid-derived suppressor cell expansion.
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Selective roles for toll-like receptors 2, 4, and 9 in systemic inflammation and immune dysfunction following peripheral tissue injury. J Trauma Acute Care Surg 2013; 74:1454-61. [PMID: 23694872 DOI: 10.1097/ta.0b013e3182905ed2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Toll-like receptors (TLRs) detect endogenous ligands released after trauma and contribute to the proinflammatory response to injury. Posttraumatic mortality correlates with the extent of the immunoinflammatory response to injury that is composed of a complex regulation of innate and adaptive immune responses. Although TLRs are known to modulate innate immune responses, their role in the suppression of lymphocyte responses following traumatic tissue injury is unclear. METHODS This study used a murine model of severe peripheral tissue injury, involving muscle crush injury and injection of fracture components, to evaluate the roles of TLR2, TLR4, and TLR9 in the early and delayed immunoinflammatory phenotype. Posttraumatic immune dysfunction was measured in our trauma model using the following parameters: ex vivo splenocyte proliferation, TH1 cytokine release, and iNOS (inducible nitric oxide synthase) induction within splenic myeloid-derived suppressor cells. Systemic inflammation and liver damage were determined by circulating interleukin 6 levels and hepatocellular injury. RESULTS Suppression of splenocyte responses after injury was dependent on TLR4 and TLR9 signaling as was posttraumatic iNOS upregulation in splenic myeloid-derived suppressor cells. TLR2 was found to have only a partial role through contribution to inhibition of splenocyte proliferation. This study also reveals the involvement of TLR2 and TLR4 in the initial systemic inflammatory response to traumatic tissue injury; however, this response was found to be TLR9 independent. CONCLUSION These findings demonstrate the previously unidentified role of TLR2, TLR4, and TLR9 in the T cell-associated immune dysfunction following traumatic tissue injury. Importantly, this study also illustrates that TLRs play differing and selective roles in both the initial proinflammatory response and adaptive immune response after trauma. Furthermore, results in TLR9-deficient mice establish that the upregulation of early proinflammatory markers do not always correlate with the extent of sustained immune dysfunction. This suggests potential for targeted therapies that could limit immune dysfunction through selective inhibition of receptor function following injury.
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Abstract
Trauma results in a persistent depression in adaptive immunity, which contributes to patient morbidity and mortality. This state of immune paralysis following trauma is characterized by a change in cell-mediated immunity, specifically a depression in T-cell function and a shift toward TH2 T-cell phenotype. Upregulation of inducible nitric oxide synthase (iNOS) is well recognized after injury and contributes to the inflammatory response and organ damage early after trauma. However, it is unknown whether iNOS plays a role in adaptive immune dysfunction after trauma. This study utilized a murine model of severe peripheral tissue injury to show that iNOS is rapidly upregulated in macrophages and a (Gr-1-CD11b) myeloid-derived suppressor cell subpopulation in the spleen. Through the use of iNOS knockout mice, a specific iNOS inhibitor, and a nitric oxide (NO) scavenger, this study demonstrates that iNOS-derived NO is required for the depression in T-lymphocyte proliferation, interferon γ, and interleukin 2 production within the spleen at 48 h after trauma. These findings support the hypothesis that iNOS regulates immune suppression following trauma and suggest that targeting the sustained production of NO by iNOS may attenuate posttraumatic immune depression.
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Kohut LK, Darwiche SS, Brumfield JM, Frank AM, Billiar TR. Fixed volume or fixed pressure: a murine model of hemorrhagic shock. J Vis Exp 2011:2068. [PMID: 21673646 PMCID: PMC3197026 DOI: 10.3791/2068] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
It is common knowledge that severe blood loss and traumatic injury can lead to a cascade of detrimental signaling events often resulting in mortality. 1, 2, 3, 4, 5 These signaling events can also lead to sepsis and/or multiple organ dysfunction (MOD). 6, 7, 8, 9 It is critical then to investigate the causes of suppressed immune function and detrimental signaling cascades in order to develop more effective ways to help patients who suffer from traumatic injuries. 10 This fixed pressure Hemorrhagic Shock (HS) procedure, although technically challenging, is an excellent resource for investigation of these pathophysiologic conditions. 11, 12, 13 Advances in the assessment of biological systems, i.e. Systems Biology have enabled the scientific community to further understand complex physiologic networks and cellular communication patterns. 14 Hemorrhagic Shock has proven to be a vital tool for unveiling these cellular communication patterns as they relate to immune function. 15, 16, 17, 18 This procedure can be mastered! This procedure can also be used as either a fixed volume or fixed pressure approach. We adapted this technique in the murine model to enhance research in innate and adaptive immune function. 19, 20, 21 Due to their small size HS in mice presents unique challenges. However due to the many available mouse strains, this species represents an unparalleled resource for the study of the biologic responses. The HS model is an important model for studying cellular communication patterns and the responses of systems such as hormonal and inflammatory mediator systems, and danger signals, i.e. DAMP and PAMP upregulation as it elicits distinct responses that differ from other forms of shock. 22, 23, 24, 25 The development of transgenic murine strains and the induction of biologic agents to inhibit specific signaling have presented valuable opportunities to further elucidate our understanding of the up and down regulation of signal transduction after severe blood loss, i.e. HS and trauma 26, 27, 28, 29, 30. There are numerous resuscitation methods (R) in association with HS and trauma. 31, 32, 33, 34 A fixed volume resuscitation method of solely lactated ringer solution (LR), equal to three times the shed blood volume, is used in this model to study endogenous mechanisms such as remote organ injury and systemic inflammation. 35, 36, 38 This method of resuscitation is proven to be effective in evaluating the effects of HS and trauma 38, 39.
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