1
|
Zhou X, Ji S, Chen L, Liu X, Deng Y, You Y, Wang M, He Q, Peng B, Yang Y, Chen X, Kwan HY, Zhou L, Chen J, Zhao X. Gut microbiota dysbiosis in hyperuricaemia promotes renal injury through the activation of NLRP3 inflammasome. MICROBIOME 2024; 12:109. [PMID: 38907332 PMCID: PMC11191305 DOI: 10.1186/s40168-024-01826-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 04/29/2024] [Indexed: 06/23/2024]
Abstract
BACKGROUND The prevalence of hyperuricaemia (HUA), a metabolic disorder characterized by elevated levels of uric acid, is on the rise and is frequently associated with renal injury. Gut microbiota and gut-derived uremic toxins are critical mediators in the gut-kidney axis that can cause damage to kidney function. Gut dysbiosis has been implicated in various kidney diseases. However, the role and underlying mechanism of the gut microbiota in HUA-induced renal injury remain unknown. RESULTS A HUA rat model was first established by knocking out the uricase (UOX). HUA rats exhibited apparent renal dysfunction, renal tubular injury, fibrosis, NLRP3 inflammasome activation, and impaired intestinal barrier functions. Analysis of 16S rRNA sequencing and functional prediction data revealed an abnormal gut microbiota profile and activation of pathways associated with uremic toxin production. A metabolomic analysis showed evident accumulation of gut-derived uremic toxins in the kidneys of HUA rats. Furthermore, faecal microbiota transplantation (FMT) was performed to confirm the effects of HUA-induced gut dysbiosis on renal injury. Mice recolonized with HUA microbiota exhibited severe renal injury and impaired intestinal barrier functions following renal ischemia/reperfusion (I/R) surgery. Notably, in NLRP3-knockout (NLRP3-/-) I/R mice, the deleterious effects of the HUA microbiota on renal injury and the intestinal barrier were eliminated. CONCLUSION Our results demonstrate that HUA-induced gut dysbiosis contributes to the development of renal injury, possibly by promoting the production of gut-derived uremic toxins and subsequently activating the NLRP3 inflammasome. Our data suggest a potential therapeutic strategy for the treatment of renal diseases by targeting the gut microbiota and the NLRP3 inflammasome. Video Abstract.
Collapse
Affiliation(s)
- Xinghong Zhou
- Zhujiang Hospital of Southern Medical University, Guangzhou, 510280, China
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
- Dongguan Hospital of Guangzhou University of Chinese Medicine, Dongguan, 523000, China
| | - Shuai Ji
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Liqian Chen
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Xiaoyu Liu
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Yijian Deng
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Yanting You
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Ming Wang
- Zhujiang Hospital of Southern Medical University, Guangzhou, 510280, China
| | - Qiuxing He
- Dongguan Hospital of Guangzhou University of Chinese Medicine, Dongguan, 523000, China
| | - Baizhao Peng
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Ying Yang
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Xiaohu Chen
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Hiu Yee Kwan
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
| | - Lin Zhou
- Nanfang Hospital of Southern Medical University, Guangzhou, 510515, China.
| | - Jieyu Chen
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Xiaoshan Zhao
- Zhujiang Hospital of Southern Medical University, Guangzhou, 510280, China.
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China.
| |
Collapse
|
2
|
Ding N, Xiao H, Zhen L, Li H, Zhang Z, Ge J, Jia H. Systemic cytokines inhibition with Imp7 siRNA nanoparticle ameliorates gut injury in a mouse model of ventilator-induced lung injury. Biomed Pharmacother 2023; 165:115237. [PMID: 37516020 DOI: 10.1016/j.biopha.2023.115237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 07/22/2023] [Accepted: 07/25/2023] [Indexed: 07/31/2023] Open
Abstract
Mechanical ventilation (MV) may negatively affect the lungs and cause the release of inflammatory mediators, resulting in extra-pulmonary organ dysfunction. Studies have revealed systemically elevated levels of proinflammatory cytokines in animal models of ventilator-induced lung injury (VILI); however, whether these cytokines have an effect on gut injury and the mechanisms involved remain unknown. In this study, VILI was generated in mice with high tidal volume mechanical ventilation (20 ml/kg). Tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 concentrations in serum and gut measured by ELISA showed significant elevation in the VILI mice. Significant increases in gut injury and PANoptosis were observed in the VILI mice, which were positively correlated with the serum levels of TNF-α, IL-1β, and IL-6. The VILI mice displayed intestinal barrier defects, decreased expressions of occludin and zonula occludin-1 (ZO-1), and increased expression of claudin-2 and the activation of myosin light chain (MLC). Importantly, intratracheal administration of Imp7 siRNA nanoparticle effectively inhibited cytokines production and protected mice from VILI-induced gut injury. These data provide evidence of systemic cytokines contributing to gut injury following VILI and highlight the possibility of targeting cytokines inhibition via Imp7 siRNA nanoparticle as a potential therapeutic intervention for alleviating gut injury following VILI.
Collapse
Affiliation(s)
- Ning Ding
- Key Laboratory of Intensive Care Rehabilitation of Shandong, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250031, China; Department of Anesthesiology, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250031, China.
| | - Hui Xiao
- Key Laboratory of Intensive Care Rehabilitation of Shandong, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250031, China
| | - Lixiao Zhen
- Key Laboratory of Intensive Care Rehabilitation of Shandong, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250031, China
| | - Huiqing Li
- Key Laboratory of Intensive Care Rehabilitation of Shandong, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250031, China; Department of Anesthesiology, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250031, China
| | - Zengzhen Zhang
- Key Laboratory of Intensive Care Rehabilitation of Shandong, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250031, China; Department of Anesthesiology, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250031, China
| | - Junke Ge
- Key Laboratory of Intensive Care Rehabilitation of Shandong, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250031, China; Department of Intensive Care Medicine, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Haiyan Jia
- Key Laboratory of Intensive Care Rehabilitation of Shandong, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250031, China; Department of Intensive Care Medicine, Shandong Provincial Third Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| |
Collapse
|
3
|
van Leeuwen ALI, Borgdorff MP, Dekker NAM, van den Brom CE. Therapeutically Targeting Microvascular Leakage in Experimental Hemorrhagic SHOCK: A Systematic Review and Meta-Analysis. Shock 2021; 56:890-900. [PMID: 33927137 DOI: 10.1097/shk.0000000000001796] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND Microvascular leakage is proposed as main contributor to disturbed microcirculatory perfusion following hemorrhagic shock and fluid resuscitation, leading to organ dysfunction and unfavorable outcome. Currently, no drugs are available to reduce or prevent microvascular leakage in clinical practice. We therefore aimed to provide an overview of therapeutic agents targeting microvascular leakage following experimental hemorrhagic shock and fluid resuscitation. METHODS PubMed, EMBASE.com, and Cochrane Library were searched in January 2021 for preclinical studies of hemorrhagic shock using any therapeutic agent on top of standard fluid resuscitation. Primary outcome was vascular leakage, defined as edema, macromolecule extravasation, or glycocalyx degradation. Drugs were classified by targeting pathways and subgroup analyses were performed per organ. RESULTS Forty-five studies, published between 1973 and 2020, fulfilled eligibility criteria. The included studies tested 54 different therapeutics mainly in pulmonary and intestinal vascular beds. Most studies induced trauma besides hemorrhagic shock. Forty-four therapeutics (81%) were found effective to reduce microvascular leakage, edema formation, or glycocalyx degradation in at least one organ. Targeting oxidative stress and apoptosis was the predominantly effective strategy (SMD: -2.18, CI [-3.21, -1.16], P < 0.0001). Vasoactive agents were found noneffective in reducing microvascular leakage (SMD: -0.86, CI [-3.07, 1.36], P = 0.45). CONCLUSION Pharmacological modulation of pathways involved in cell metabolism, inflammation, endothelial barrier regulation, sex hormones and especially oxidative stress and apoptosis were effective in reducing microvascular leakage in experimental hemorrhagic shock with fluid resuscitation. Future studies should investigate whether targeting these pathways can restore microcirculatory perfusion and reduce organ injury following hemorrhagic shock. SYSTEMATIC REVIEW REGISTRATION NUMBER CRD42018095432.
Collapse
Affiliation(s)
- Anoek L I van Leeuwen
- Department of Anesthesiology, Amsterdam UMC, VU University, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
- Department of Physiology, Amsterdam UMC, VU University, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Marieke P Borgdorff
- Department of Anesthesiology, Amsterdam UMC, VU University, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Nicole A M Dekker
- Department of Anesthesiology, Amsterdam UMC, VU University, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
- Department of Physiology, Amsterdam UMC, VU University, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Charissa E van den Brom
- Department of Anesthesiology, Amsterdam UMC, VU University, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
- Department of Physiology, Amsterdam UMC, VU University, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
- Department of Intensive Care, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
4
|
Skelton JK, Purcell R. Preclinical models for studying immune responses to traumatic injury. Immunology 2021; 162:377-388. [PMID: 32986856 PMCID: PMC7968398 DOI: 10.1111/imm.13272] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/13/2022] Open
Abstract
Traumatic injury initiates a large and complex immune response in the minutes after the initial insult, comprising of simultaneous pro- and anti-inflammatory responses. In patients that survive the initial injury, these immune responses are believed to contribute towards complications such as the development of sepsis and multiple organ dysfunction syndrome. These post-traumatic complications affect a significant proportion of patients and are a major contributing factor for poor outcomes and an increased burden on healthcare systems. Therefore, understanding the immune responses to trauma is crucial for improving patient outcomes through the development of novel therapeutics and refining resuscitation strategies. In order to do this, preclinical animal models must mimic human immune responses as much as possible, and as such, we need to understand the constraints of each species in the context of trauma. A number of species have been used in this field; however, these models are limited by their genetic background and their capacity for recapitulating human immune function. This review provides a brief overview of the immune response in critically injured human patients and discusses the most commonly used species for modelling trauma, focusing on how their immune response to serious injury and haemorrhage compares to that of humans.
Collapse
Affiliation(s)
| | - Robert Purcell
- CBR Division, Defence Science and Technology Laboratory, Salisbury, UK
| |
Collapse
|
5
|
Evaluation of gut-blood barrier dysfunction in various models of trauma, hemorrhagic shock, and burn injury. J Trauma Acute Care Surg 2017; 83:944-953. [DOI: 10.1097/ta.0000000000001654] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
6
|
C-peptide attenuates acute lung inflammation in a murine model of hemorrhagic shock and resuscitation by reducing gut injury. J Trauma Acute Care Surg 2017; 83:256-262. [PMID: 28452895 DOI: 10.1097/ta.0000000000001539] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The study aims to evaluate whether C-peptide can reduce gut injury during hemorrhagic shock (HS) and resuscitation (R) therefore attenuate shock-induced inflammation and subsequent acute lung injury. METHODS Twelve-week-old male mice (C57/BL6) were hemorrhaged (mean arterial blood pressure maintained at 35 mm Hg for 60 minutes) and then resuscitated with Ringer's lactate, followed by red blood cell transfusion with (HS/R) or without C-peptide (HS/R + C-peptide). Mouse gut permeability, bacterial translocation into the circulatory system and intestinal pathology, circulating HMGB1, and acute lung injury were assessed at different times after R. The mice in the control group underwent sham procedures without HS. RESULTS Compared to the sham group, the mice in the HS/R group showed increased gut permeability (6.07 ± 3.41 μg of FD4/mL) and bacterial translocation into the circulatory system (10.05 ± 4.92, lipopolysaccharide [LPS] of pg/mL), and increased gut damage; conversely, mice in the HS/R + C-peptide group showed significantly reduced gut permeability (1.59 ± 1.39 μg of FD4/mL; p < 0.05) and bacterial translocation (4.53 ± 1.08 pg of LPS/mL; p < 0.05) with reduced intestine damage. In addition, mice in the HS/R group had increased circulating HMGB1 (21.64 ± 14.17 ng/mL), lung myeloperoxidase) activity (34.4 ± 8.91 mU/g of tissue), and pulmonary protein leakage (2.33 ± 1.16 μg Evans blue/g tissue per minute). Mice in the HS/R + C-peptide group showed decreased HMGB1 (7.27 ± 1.93 ng/mL; p < 0.05), lung myeloperoxidase (23.73 ± 8.39 mU/g of tissue; p < 0.05), and pulmonary protein leakage (1.17 ± 0.42 Evans Blue/g tissue per minute; p < 0.05). CONCLUSION Our results indicate that C-peptide exerts beneficial effects to attenuate gut injury and dysfunction, therefore diminishing lung inflammation and subsequent injury in mice with HS and R.
Collapse
|
7
|
Kao RL, Xu X, Xenocostas A, Parry N, Mele T, Martin CM, Rui T. Induction of acute lung inflammation in mice with hemorrhagic shock and resuscitation: role of HMGB1. JOURNAL OF INFLAMMATION-LONDON 2014; 11:30. [PMID: 25309129 PMCID: PMC4193406 DOI: 10.1186/s12950-014-0030-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 09/29/2014] [Indexed: 01/08/2023]
Abstract
Background Hemorrhagic shock and resuscitation (HS/R) can induce multiple organ failure which is associated with high mortality. The lung is an organ commonly affected by the HS/R. Acute lung injury is a major cause of dysfunction in other organ systems. The objective of this study is to test the hypothesis that HS/R causes increased gut permeability which results in induction of high mobility group box1 protein (HMGB1) and further leads to the development of acute lung inflammation. Materials and methods A mouse model of HS/R was employed in this study. Gut permeability and bacterial translocation were assessed with circulating FD4 and lipopolysaccharide (LPS). Circulating HMGB1 was determined with ELISA. Acute lung inflammation (ALI) was determined with lung myeloperoxidase (MPO) activity and pulmonary protein leakage. Results HS/R induced intestinal barrier dysfunction as evidenced by increased circulating FD4 and LPS at 30 min and 2 hrs after resuscitation, respectively. In addition, circulating HMGB1 levels were increased in mice with HS/R as compared with sham animals (p < 0.05). HS/R resulted in ALI (increased lung MPO activity and pulmonary protein leakage in mice with HS/R compared with sham mice, p < 0.05). Inhibition of HMGB1 (A-box and TLR4−/−) attenuated the ALI in mice with HS/R. However, inhibition of HMGB1 did not show protective effect on gut injury in early phase of HS/R in mice. Conclusions Our results suggest that induction of HMGB1 is important in hemorrhagic shock and resuscitation-induced acute lung inflammation.
Collapse
Affiliation(s)
- Raymond Lc Kao
- Department of National Defense, Canadian Forces Health Services, Ottawa, ON Canada ; Critical Care Western, Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON Canada ; Center for Critical Illness Research, Lawson Health Research Institute, 800 Commissioner's Rd E, N6A 5 W9 London, ON Canada
| | - Xuemei Xu
- Center for Critical Illness Research, Lawson Health Research Institute, 800 Commissioner's Rd E, N6A 5 W9 London, ON Canada
| | - Anargyros Xenocostas
- Division of Hematology, Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON Canada
| | - Neil Parry
- Critical Care Western, Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON Canada
| | - Tina Mele
- Critical Care Western, Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON Canada
| | - Claudio M Martin
- Critical Care Western, Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON Canada ; Center for Critical Illness Research, Lawson Health Research Institute, 800 Commissioner's Rd E, N6A 5 W9 London, ON Canada
| | - Tao Rui
- Critical Care Western, Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON Canada ; Center for Critical Illness Research, Lawson Health Research Institute, 800 Commissioner's Rd E, N6A 5 W9 London, ON Canada
| |
Collapse
|
8
|
Geng Y, Li J, Wang F, Li Q, Wang X, Sun L, Li W. Epidermal growth factor promotes proliferation and improves restoration after intestinal ischemia-reperfusion injury in rats. Inflammation 2014; 36:670-9. [PMID: 23397076 DOI: 10.1007/s10753-012-9591-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Epidermal growth factor (EGF) is an attractive and promising therapeutic application for intestinal disorders. The current study examined its influence on proliferation and restoration after ischemia-reperfusion (I/R) injury in rat small intestine. Six groups were performed: sham operation (Con); ischemia for 30 min with subsequent reperfusion for 30 min (I/R); I/R injured with 500 μg/kg EGF injected 5 min before ischemia (Pre-l); I/R injured with 50 μg/kg EGF injected 5 min before ischemia (Pre-s); I/R injured with 500 μg/kg EGF injected 5 min after reperfusion (Post-l); and I/R injured with 50 μg/kg EGF injected 5 min after reperfusion (Post-s). Intestinal histological damage, crypt cell proliferation degree, mucosal permeability, tight junction proteins expression, and levels of inflammation factors were studied for each group. Compared with the I/R group, administration of EGF in the Pre-l, Pre-s, and Post-l groups all presented a significant proliferation effect. The levels of FD4, IL-6, and TNF-α were dramatically decreased in all EGF-treated groups. Histological destruction was improved and TJs recovery was notably accelerated in all EGF-treated groups except the Post-s group. D-lactate concentration was only diminished in the Pre-l group. These results suggest that mucosally applied EGF can promote intestinal proliferation and improve restoration after I/R injury. EGF intraluminal administration is an effective treatment against intestinal I/R injury.
Collapse
Affiliation(s)
- Yanxia Geng
- Department of Intensive Care Unit, Jiangsu Province Chinese Medicine Hospital, 155 Han Zhong Road, Nanjing 210029, China
| | | | | | | | | | | | | |
Collapse
|
9
|
Myosin light chain kinase mediates intestinal barrier disruption following burn injury. PLoS One 2012; 7:e34946. [PMID: 22529961 PMCID: PMC3329538 DOI: 10.1371/journal.pone.0034946] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 03/07/2012] [Indexed: 12/14/2022] Open
Abstract
Background Severe burn injury results in the loss of intestinal barrier function, however, the underlying mechanism remains unclear. Myosin light chain (MLC) phosphorylation mediated by MLC kinase (MLCK) is critical to the pathophysiological regulation of intestinal barrier function. We hypothesized that the MLCK-dependent MLC phosphorylation mediates the regulation of intestinal barrier function following burn injury, and that MLCK inhibition attenuates the burn-induced intestinal barrier disfunction. Methodology/Principal Findings Male balb/c mice were assigned randomly to either sham burn (control) or 30% total body surface area (TBSA) full thickness burn without or with intraperitoneal injection of ML-9 (2 mg/kg), an MLCK inhibitor. In vivo intestinal permeability to fluorescein isothiocyanate (FITC)-dextran was measured. Intestinal mucosa injury was assessed histologically. Tight junction proteins ZO-1, occludin and claudin-1 was analyzed by immunofluorescent assay. Expression of MLCK and phosphorylated MLC in ileal mucosa was assessed by Western blot. Intestinal permeability was increased significantly after burn injury, which was accompanied by mucosa injury, tight junction protein alterations, and increase of both MLCK and MLC phosphorylation. Treatment with ML-9 attenuated the burn-caused increase of intestinal permeability, mucosa injury, tight junction protein alterations, and decreased MLC phosphorylation, but not MLCK expression. Conclusions/Significance The MLCK-dependent MLC phosphorylation mediates intestinal epithelial barrier dysfunction after severe burn injury. It is suggested that MLCK-dependent MLC phosphorylation may be a critical target for the therapeutic treatment of intestinal epithelial barrier disruption after severe burn injury.
Collapse
|
10
|
McGhan LJ, Jaroszewski DE. The role of toll-like receptor-4 in the development of multi-organ failure following traumatic haemorrhagic shock and resuscitation. Injury 2012; 43:129-36. [PMID: 21689818 DOI: 10.1016/j.injury.2011.05.032] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Accepted: 05/25/2011] [Indexed: 02/02/2023]
Abstract
Haemorrhagic shock and resuscitation (HS/R) following major trauma results in a global ischaemia and reperfusion injury that may lead to multiple organ dysfunction syndrome (MODS). Systemic activation of the immune system is fundamental to the development of MODS in this context, and shares many features in common with the systemic inflammatory response syndrome (SIRS) that complicates sepsis. An important advancement in the understanding of the innate response to infection involved the identification of mammalian toll-like receptors (TLRs) expressed on cells of the immune system. Ten TLR homologues have been identified in humans and toll-like receptor-4 (TLR4) has been studied most intensively. Initially found to recognise bacterial lipopolysaccharide (LPS), it has also recently been discovered that TLR4 is capable of activation by endogenous 'danger signal' molecules released following cellular injury; this has since implicated TLR4 in several non-infectious pathophysiologic processes, including HS/R. The exact events leading to multi-organ dysfunction following HS/R have not yet been clearly defined, although TLR4 is believed to play a central role as has been shown to be expressed at sites including the liver, lungs and myocardium following HS/R. Multi-organ dysfunction syndrome remains an important cause of morbidity and mortality in trauma patients, and current therapy is based on supportive care. Understanding the pathophysiology of HS/R will allow for the development of targeted therapeutic strategies aimed at minimising organ dysfunction and improving patient outcomes following traumatic haemorrhage. A review of the pathogenesis of haemorrhagic shock is presented, and the complex, yet critical role of TLR4 as both a key mediator and therapeutic target is discussed.
Collapse
Affiliation(s)
- Lee J McGhan
- Resident in General Surgery, Mayo Clinic, 5777 East Mayo Boulevard, Phoenix, AZ 85054, United States.
| | | |
Collapse
|
11
|
Recombinant human erythropoietin improves gut barrier function in a hemorrhagic shock and resuscitation rat model. ACTA ACUST UNITED AC 2012; 71:S456-61. [PMID: 22072003 DOI: 10.1097/ta.0b013e318232e782] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND Gut injury and bacterial translocation develop and persist after limited periods of hemorrhagic shock. Erythropoietin (EPO) can exert hemodynamic, anti-inflammatory, and tissue protective effects. We tested the hypothesis that EPO given at the time of resuscitation with saline will reduce functional ileal injury 24 hours after shock. METHODS Sprague-Dawley rats (n = 6 per group) were randomized to sham surgery or hemorrhagic shock maintained at mean arterial pressure 40 mm Hg for 60 minutes and then treated with either saline resuscitation (three times the volume of shed blood) or saline + recombinant human EPO (rHuEPO) resuscitation. Intravenous rHuEPO (1,000 U/kg) was given at the start of saline resuscitation, and at 24 hours ileal function was evaluated using quantitative cultures of mesenteric lymph nodes to assess for bacterial translocation (colony-forming units per gram of tissue [CFU/g]), determination of portal vein plasma endotoxin levels and histopathological evaluation using semi-thin plastic sections of the distal ileum. In a second series of animals, fluorescein isothiocyanate-dextran 4000 (FD-4) was used to assess mucosal permeability of the distal ileum to macromolecules. RESULTS At 24 hours, the saline group had morphologic evidence of intestinal injury when compared with the sham group, and the degree of mucosal injury was less in the saline + rHuEPO when compared with the saline group, which demonstrated significantly reduced bacterial translocation to the mesenteric lymph nodes (383 CFU/g ± 111 CFU/g vs. 1130 CFU/g ± 297 CFU/g; p < 0.05) and decreased terminal ileum permeability to FD-4 (3.08 μg/mL ± 0.31 μg/mL vs. 5.14 μg/mL ± 0.88 μg/mL; p < 0.05). No significant difference was found in the portal vein endotoxin levels between the two groups. Histopathological evaluation demonstrated a trend for decreased enterocyte disarray or disruption and vacuolization in the saline + rHuEPO versus saline group. CONCLUSION Using rHuEPO at time of saline resuscitation resulted in decreased bacterial translocation and permeability to macromolecules 24 hours after shock. These observations suggest that rHuEPO can mediate a protective effect on intestinal mucosal barrier function during ischemic injury.
Collapse
|
12
|
Deitch EA. Gut lymph and lymphatics: a source of factors leading to organ injury and dysfunction. Ann N Y Acad Sci 2010; 1207 Suppl 1:E103-11. [PMID: 20961300 DOI: 10.1111/j.1749-6632.2010.05713.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Major trauma, shock, sepsis, and other conditions can lead to the acute respiratory distress syndrome (ARDS), which may progress to the highly lethal multiple organ dysfunction syndrome (MODS). Although a number of therapeutic strategies have been initiated, their success has been limited largely due to an incomplete understanding of the biology of MODS. However, recent studies indicate that the intestinal lymphatics serve as the primary route for nonbacterial, tissue injurious gut-derived factors, which can induce acute ARDS and MODS. The gut lymph hypothesis of ARDS and MODS thus helps clarify several important issues. First, because the lung is the first organ exposed to mesenteric lymph and not the liver (i.e., mesenteric lymph enters the subclavian vein via the thoracic duct, which, in turn, empties directly into the heart and lungs), it would explain the clinical observation that the lung is generally the first organ to fail. Second, this hypothesis provides new pathophysiologic information, thereby providing a basis for novel therapies. Finally, by studying the composition of lymph, MODS-inducing factors can be isolated and identified.
Collapse
Affiliation(s)
- Edwin A Deitch
- Department of Surgery, University of Medicine and Dentistry New Jersey, Newark, New Jersey, USA.
| |
Collapse
|
13
|
Shah SK, Uray KS, Stewart RH, Laine GA, Cox CS. Resuscitation-induced intestinal edema and related dysfunction: state of the science. J Surg Res 2009; 166:120-30. [PMID: 19959186 DOI: 10.1016/j.jss.2009.09.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 07/24/2009] [Accepted: 09/04/2009] [Indexed: 11/26/2022]
Abstract
High volume resuscitation and damage control surgical methods, while responsible for significantly decreasing morbidity and mortality from traumatic injuries, are associated with pathophysiologic derangements that lead to subsequent end organ edema and dysfunction. Alterations in hydrostatic and oncotic pressures frequently result in intestinal edema and subsequent dysfunction. The purpose of this review is to examine the principles involved in the development of intestinal edema, current and historical models for the study of edema, effects of edema on intestinal function (particularly ileus), molecular mediators governing edema-induced dysfunction, potential role of mechanotransduction , and therapeutic effects of hypertonic saline. We review the current state of the science as it relates to resuscitation induced intestinal edema and resultant dysfunction.
Collapse
Affiliation(s)
- Shinil K Shah
- Department of Pediatric Surgery, University of Texas Medical School at Houston, Houston, Texas 77030, USA
| | | | | | | | | |
Collapse
|
14
|
Abstract
Even if trauma patients initially avoid death after trauma (due to massive blood volume loss, primary severe brain injury), they are still at risk for multiple organ failure. Thus, it is crucial to elucidate the underlying pathophysiological mechanisms of trauma/hemorrhagic shock and the immune response involved. As of now, many hemorrhagic shock/trauma studies have used various types of animal models. Despite a large number of results from these efforts, some authors have argued that animal model results are difficult to translate directly into the clinical scenario. This review summarizes the advantages and the disadvantages of using animal models in trauma/hemorrhagic shock studies and discusses the relevance of various animal studies to the clinical scenario.
Collapse
|
15
|
Clark JA, Coopersmith CM. Intestinal crosstalk: a new paradigm for understanding the gut as the "motor" of critical illness. Shock 2008; 28:384-93. [PMID: 17577136 PMCID: PMC2084394 DOI: 10.1097/shk.0b013e31805569df] [Citation(s) in RCA: 328] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
For more than 20 years, the gut has been hypothesized to be the "motor" of multiple organ dysfunction syndrome. As critical care research has evolved, there have been multiple mechanisms by which the gastrointestinal tract has been proposed to drive systemic inflammation. Many of these disparate mechanisms have proved to be important in the origin and propagation of critical illness. However, this has led to an unusual situation where investigators describing the gut as a "motor" revving the systemic inflammatory response syndrome are frequently describing wholly different processes to support their claim (i.e., increased apoptosis, altered tight junctions, translocation, cytokine production, crosstalk with commensal bacteria, etc). The purpose of this review is to present a unifying theory as to how the gut drives critical illness. Although the gastrointestinal tract is frequently described simply as "the gut," it is actually made up of (1) an epithelium; (2) a diverse and robust immune arm, which contains most of the immune cells in the body; and (3) the commensal bacteria, which contain more cells than are present in the entire host organism. We propose that the intestinal epithelium, the intestinal immune system, and the intestine's endogenous bacteria all play vital roles driving multiple organ dysfunction syndrome, and the complex crosstalk between these three interrelated portions of the gastrointestinal tract is what cumulatively makes the gut a "motor" of critical illness.
Collapse
Affiliation(s)
- Jessica A Clark
- Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, USA
| | | |
Collapse
|
16
|
Postresuscitation tissue neutrophil infiltration is time-dependent and organ-specific. J Surg Res 2007; 143:119-25. [PMID: 17950080 DOI: 10.1016/j.jss.2007.04.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Revised: 04/03/2007] [Accepted: 04/04/2007] [Indexed: 01/18/2023]
Abstract
BACKGROUND Hemorrhagic shock with conventional resuscitation (CR) primes circulating neutrophils and activates vascular endothelium for increased systemic inflammation, superoxide release, and end-organ damage. Adjunctive direct peritoneal resuscitation (DPR) with intraperitoneal instillation of a clinical peritoneal dialysis solution decreases systemic inflammation and edema formation by enhancing tissue perfusion. The aim of this study is to determine the effect of adjunctive DPR on neutrophil and fluid sequestration. METHODS Anesthetized rats were hemorrhaged to 40% mean arterial pressure for 60 min. Animals were randomized for CR with the return of the shed blood plus two volumes of saline, or CR plus adjunctive DPR with 30 mL of intraperitoneal injection of a clinical peritoneal dialysis solution. Tissue myeloperoxidase (MPO) level, a marker of neutrophil sequestration, and total water content were assessed in the gut, lung, and liver in sham animals and at time-points 1, 2, 4, and 24 h postresuscitation. RESULTS Resuscitation from hemorrhagic shock increases MPO level in all tissues in a near-linear fashion during the first 4 h following resuscitation. This occurs irrespective of the resuscitation regimen used. Tissue MPO level returned to baseline at 24 h following resuscitation except in the liver where CR and not adjunctive DPR caused a significant rebound increase. Adjunctive DPR prevented the CR-mediated obligatory fluid sequestration in the gut and lung and maintained a relative normal tissue water in these organs compared with CR alone (n = 7, F = 10.1, P < 0.01). CONCLUSION Hemorrhagic shock and resuscitation produces time-dependent organ-specific trends of neutrophil sequestration as measured with tissue levels of myeloperoxidase, a marker of neutrophil infiltration. Modulation of the splanchnic blood flow by direct peritoneal resuscitation did not alter the time-dependent neutrophil infiltration in end-organs, suggesting a subordinate role of blood rheology in the hemorrhage-induced neutrophil sequestration. Vulnerable window for neutrophil-mediated tissue damage exists during the first 4 h following resuscitation from hemorrhagic shock in rats. Direct peritoneal resuscitation prevents the early obligatory fluid sequestration and promotes early fluid mobilization.
Collapse
|
17
|
Zakaria ER, Li N, Matheson PJ, Garrison RN. Cellular edema regulates tissue capillary perfusion after hemorrhage resuscitation. Surgery 2007; 142:487-96; discussion 496.e1-2. [PMID: 17950340 PMCID: PMC2131728 DOI: 10.1016/j.surg.2007.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Revised: 08/08/2007] [Accepted: 08/10/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND Hemorrhage-induced activation of endothelial cell Na+/H+ -exchanger results in cellular swelling, which physically impedes capillary filling and compromises gut perfusion. We hypothesized that correction of the vascular volume deficit by conventional resuscitation does not improve capillary filling unless cellular swelling is prevented. Also, we hypothesized that adjunctive direct peritoneal resuscitation (DPR) with topical peritoneal dialysis solution (Delflex; Fresenius USA, Inc., Ogden, Ut) enhances capillary filling and gut perfusion by mechanisms that are independent of the Na+/H+ function. METHODS In vivo intravital videomicroscopy and Doppler velocimeter were used by us to measure microvascular diameter and flow, capillary filling (index of functional capillary density, FCD), and endothelial cell function in the terminal ileum of anesthetized rats. Rats were bled to 50% mean arterial pressure for 60 min and resuscitated with the shed blood plus 2 volumes of saline (conventional resuscitation). Prevention of endothelial cell swelling was achieved with topical amiloride (specific Na+/H+ inhibitor) in the tissue bath before hemorrhage or simultaneously with conventional resuscitation. DPR was simulated by instillation of Delflex in the tissue bath as adjunctive to conventional resuscitation. Sham no hemorrhage group and a simulated DPR group that received topical amiloride treatment served as controls. RESULTS Conventional resuscitation from hemorrhagic shock restored and maintained central hemodynamics but caused progressive and persistent intestinal vasoconstriction and hypoperfusion associated with low FCD and endothelial cell dysfunction. Prevention of endothelial cell swelling when combined with conventional resuscitation, preserved endothelial cell function, and restored local intestinal microvascular variables to near-prehemorrhage levels. Simulated adjunctive DPR produced rapid, sustained, and generalized vasodilation associated with restoration of endothelial cell function, and maximum recruitment of FCD independent of the Na+/H+ -exchanger function. CONCLUSIONS Paradoxical endothelial cell swelling occurs early during hemorrhagic shock because of activation of the Na+/H+ exchanger. This cellular edema, which is not resolved by correction of the vascular volume deficit, explains the persistent postresuscitation endothelial cell dysfunction and gut hypoperfusion. Simulated adjunctive DPR in this study reversed endothelial cell swelling and enhanced gut perfusion by mechanisms that are independent of the Na+/H+ exchanger activity.
Collapse
Affiliation(s)
- El Rasheid Zakaria
- Department of Physiology and Biophysics, University of Louisville, Louisville, KY 40292, USA.
| | | | | | | |
Collapse
|