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Rohan CJ, Lohade RP, Brewer C, Travers JB. Platelet-activating factor and microvesicle particles as potential mediators for the toxicity associated with intoxicated thermal burn injury. Biofactors 2022; 48:1250-1256. [PMID: 36342751 PMCID: PMC9789186 DOI: 10.1002/biof.1917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 09/16/2022] [Indexed: 11/09/2022]
Abstract
Thermal burn injuries (TBIs) in patients who are alcohol-intoxicated result in greater morbidity and mortality. The systemic toxicity found in human patients, which includes both immediate systemic cytokine generation with multiple organ failure and a delayed systemic immunosuppression, has previously been replicated in mouse models combining ethanol and localized TBI. Though considerable insights have been provided with these models, the exact mechanisms for these pathologic effects are unclear. In this review, we highlight the roles of the lipid mediator platelet-activating factor (PAF) and subcellular microvesicle particle (MVP) release in response to intoxicated thermal burn injury (ITBI) as effectors in the pathology. Particularly, MVP is released from keratinocytes in response to PAF receptor (PAFR) activation due to excess PAF produced by ITBI. These subcellular particles carry and thus protect the metabolically labile PAF which enable binding of this potent lipid mediator to several key sites. We hypothesize that PAF carried by MVP can bind to PAFR within the gut, activating myosin light chain kinase (MLCK). The subsequent gut barrier dysfunction in response to MLCK activation then allows bacteria to invade the lymphatic system and, eventually, the bloodstream, resulting in sepsis and resultant dysregulated inflammation in multiple organs. PAF in MVP also activate the skin mast cell PAFR resulting in migration of this key effector cell to the lymph nodes to induce immunosuppression. This review thus provides a mechanism and potential therapeutic approaches for the increased toxicity and immunosuppressive outcomes of TBI in the presence of acute ethanol exposure.
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Affiliation(s)
- Carson J. Rohan
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton Ohio
| | - Rushabh P. Lohade
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton Ohio
| | - Chad Brewer
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton Ohio
| | - Jeffrey B. Travers
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine at Wright State University, Dayton Ohio
- Department of Dermatology, Boonshoft School of Medicine at Wright State University, Dayton Ohio
- Department of Medicine, Dayton Veterans Administration Hospital, Dayton Ohio
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Mulder PPG, Koenen HJPM, Vlig M, Joosten I, de Vries RBM, Boekema BKHL. Burn-Induced Local and Systemic Immune Response: Systematic Review and Meta-Analysis of Animal Studies. J Invest Dermatol 2022; 142:3093-3109.e15. [PMID: 35623415 DOI: 10.1016/j.jid.2022.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/08/2022] [Accepted: 05/02/2022] [Indexed: 10/31/2022]
Abstract
As burn injuries are often followed by a derailed immune response and excessive inflammation, a thorough understanding of the occurring reactions is key to prevent secondary complications. This systematic review, that includes 247 animal studies, shows the post-burn response of 14 different immune cell types involved in immediate and long-term effects, in both wound tissue and circulation. Peripheral blood neutrophil and monocyte numbers increased directly after burns, whereas thrombocyte numbers increased near the end of the first week. Lymphocyte numbers, however, were decreased for at least two weeks. In burn wound tissue, neutrophil and macrophage numbers accumulated during the first three weeks. Burns also altered cellular functions as we found increased migratory potential of leukocytes, impaired antibacterial activity of neutrophils and enhanced inflammatory mediator production by macrophages. Neutrophil surges were positively associated with burn size and were highest in rats. Altogether, this comprehensive overview of the temporal immune cell dynamics shows that unlike normal wound healing, burn injury induces a long-lasting inflammatory response. It provides a fundamental research basis to improve experimental set-ups, burn care and outcome.
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Affiliation(s)
- Patrick P G Mulder
- Association of Dutch Burn Centres (ADBC), Preclinical Research, Beverwijk, the Netherlands; Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands.
| | - Hans J P M Koenen
- Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Marcel Vlig
- Association of Dutch Burn Centres (ADBC), Preclinical Research, Beverwijk, the Netherlands
| | - Irma Joosten
- Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rob B M de Vries
- SYRCLE, Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Bouke K H L Boekema
- Association of Dutch Burn Centres (ADBC), Preclinical Research, Beverwijk, the Netherlands
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El Ayadi A, Wang CZ, Zhang M, Wetzel M, Prasai A, Finnerty CC, Enkhbaatar P, Herndon DN, Ansari NH. Metal chelation reduces skin epithelial inflammation and rescues epithelial cells from toxicity due to thermal injury in a rat model. BURNS & TRAUMA 2020; 8:tkaa024. [PMID: 33033727 PMCID: PMC7530369 DOI: 10.1093/burnst/tkaa024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/19/2020] [Indexed: 01/09/2023]
Abstract
BACKGROUND One of the most pervasive complications of burn injury is wound progression, characterized by continuous tissue destruction in untreated wounds, which leads to wound infection, inflammation, oxidative stress and excessive scar formation. We determined whether additional tissue destruction could be attenuated with Livionex formulation (LF) lotion, which contains a metal-chelating agent and reduces inflammation in burn wounds. METHODS We subjected male Sprague Dawley rats to a 2% total body surface area (TBSA) burn using a brass comb model and topically applied LF lotion (containing ethylenediaminetetraacetic acid and methyl sulfonyl methane) to the affected area every 8 hours over 3 days. Inflammatory cytokine levels, cell apoptosis and wound healing were compared in LF lotion-treated and untreated rats. Statistical analysis was performed using a one-way analysis of variance in conjunction with Tukey's post-hoc test. RESULTS Serum inflammatory cytokines were not detectable after 3 days, suggesting that small burn wounds induce only an immediate, localized inflammatory response. Microscopy revealed that LF lotion improved burn site pathology. Deoxynucleotidyl transferase biotin-d-UTP nick-end labeling staining showed reduced cell death in the LF-treated samples. LF lotion prevented the spread of tissue damage, as seen by increased amounts of Ki-67-positive nuclei in the adjacent epidermis and hair follicles. Tumor necrosis factor-alpha, interleukin-6 and inducible nitric oxide synthase levels in LF-treated skin sections from burned rats were comparable to the levels observed in unburned control sections, indicating that LF lotion reduces inflammation in and around the burn site. CONCLUSIONS These results establish LF lotion as a therapeutic agent for reducing inflammatory stress, cell death and tissue destruction when applied immediately after a burn injury. Further studies of LF lotion on large TBSA burns will determine its efficacy as an emergency treatment for reducing long-term morbidity and scarring.
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Affiliation(s)
- Amina El Ayadi
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Cheng Z Wang
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Min Zhang
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Michael Wetzel
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Anesh Prasai
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Celeste C Finnerty
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Perenlei Enkhbaatar
- Department of Anesthesiology, 301 University Blvd., University of Texas Medical Branch, Galveston, TX 77555, USA
| | - David N Herndon
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Naseem H Ansari
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
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Wang CZ, Ayadi AE, Goswamy J, Finnerty CC, Mifflin R, Sousse L, Enkhbaatar P, Papaconstantinou J, Herndon DN, Ansari NH. Topically applied metal chelator reduces thermal injury progression in a rat model of brass comb burn. Burns 2015; 41:1775-1787. [PMID: 26392023 DOI: 10.1016/j.burns.2015.08.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 06/26/2015] [Accepted: 08/07/2015] [Indexed: 01/03/2023]
Abstract
UNLABELLED Oxidative stress may be involved in the cellular damage and tissue destruction as burn wounds continues to progress after abatement of the initial insult. Since iron and calcium ions play key roles in oxidative stress, this study tested whether topical application of Livionex formulation (LF) lotion, that contains disodium EDTA as a metal chelator and methyl sulfonyl methane (MSM) as a permeability enhancer, would prevent or reduce burns. METHODS We used an established brass comb burn model with some modifications. Topical application of LF lotion was started 5 min post-burn, and repeated every 8 h for 3 consecutive days. Rats were euthanized and skin harvested for histochemistry and immunohistochemistry. Formation of protein adducts of 4-hydroxynonenal (HNE), malonadialdehyde (MDA) and acrolein (ACR) and expression of aldehyde dehydrogenase (ALDH) isozymes, ALDH1 and ALDH2 were assessed. RESULTS LF lotion-treated burn sites and interspaces showed mild morphological improvement compared to untreated burn sites. Furthermore, the lotion significantly decreased the immunostaining of lipid aldehyde-protein adducts including protein -HNE, -MDA and -ACR adducts, and restored the expression of aldehyde dehydrogenase isozymes in the unburned interspaces. CONCLUSION This data, for the first time, demonstrates that a topically applied EDTA-containing lotion protects burns progression with a concomitant decrease in the accumulation of reactive lipid aldehydes and protection of aldehyde dehydrogenase isozymes. Present studies are suggestive of therapeutic intervention of burns by this novel lotion.
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Affiliation(s)
- Cheng Z Wang
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-0647, United States
| | - Amina El Ayadi
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555-0647, United States; Shriners Hospital for Children, Galveston, TX, United States
| | - Juhi Goswamy
- University of Miami Miller School of Medicine, Miami, FL 33124, United States
| | - Celeste C Finnerty
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555-0647, United States; Institute for Translational Sciences, Galveston, TX, United States; Shriners Hospital for Children, Galveston, TX, United States
| | - Randy Mifflin
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555-0647, United States; Shriners Hospital for Children, Galveston, TX, United States
| | - Linda Sousse
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555-0647, United States; Shriners Hospital for Children, Galveston, TX, United States
| | - Perenlei Enkhbaatar
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555-0647, United States
| | - John Papaconstantinou
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-0647, United States
| | - David N Herndon
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555-0647, United States; Shriners Hospital for Children, Galveston, TX, United States
| | - Naseem H Ansari
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-0647, United States.
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Fazal N, Shelip A, Siddiqui E, Ali A, Azim AC, Al-Ghoul WM. Differential effector responses by circulating/blood and tissue/peritoneal neutrophils following burn combined with Enterococcus faecalis infection. ACTA ACUST UNITED AC 2012; 64:191-204. [PMID: 22066701 DOI: 10.1111/j.1574-695x.2011.00881.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recently we found that superimposition of Enterococcus faecalis infection on burn injury caused an eruption of host mortality not seen with either individual challenge. We hypothesized that the Enterococcus bacteria, and/or factors related to these organisms, aggravate burn-induced modulations in host defense by neutrophils. Our study focuses on alterations in neutrophils' oxidative, proteolytic, and adhesive functions and transendothelial migration of neutrophils in burn rats inoculated with E. faecalis. Rats were subjected to burn (30% total body surface area) and then intra-abdominally inoculated with E. faecalis (10(4)CFU kg(-1) b.w). Polymorphonuclear neutrophils (PMNs) were harvested from circulating/blood and tissue/peritoneal cavity at day-2 post injury. Extracellular release of O(-)(2) anion production was determined by luminometry, and intracellular production of reactive oxygen species was measured by digital imaging technique. Fluoroscan analysis and confocal microscopy determined intracellular elastase production. The expression of adhesion molecule CD11b/CD18 was performed by flow cytometry. Calcein AM-labeled PMNs were co-cultured with TNF-α-stimulated rat lung microvascular endothelial cells, and their ability to adhere was assessed by fluorometry and digital imaging and finally, chemotaxis was measured by neutrophil transmigration assays. The results showed differential effector responses by circulatory and/or tissue PMNs. Tissue/peritoneal PMNs produced more O(-)(2), less intracellular elastase, and increased expression of CD11b/CD18 accompanied with increased adhesivity of MIP-2-stimulated PMNs to endothelial cells as compared to circulatory/blood PMNs. This differential effect was more pronounced following burn plus E. faecalis infection, indicating that the combined injury changed neutrophil functions.
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Affiliation(s)
- Nadeem Fazal
- Department of Pharmaceutical Sciences, College of Pharmacy, Chicago State University, Chicago, IL 60628, USA.
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Fazal N, Al-Ghoul WM. Thermal injury-plus-sepsis contributes to a substantial deletion of intestinal mesenteric lymph node CD4 T cell via apoptosis. Int J Biol Sci 2007; 3:393-401. [PMID: 17895960 PMCID: PMC1989035 DOI: 10.7150/ijbs.3.393] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Accepted: 08/30/2007] [Indexed: 12/16/2022] Open
Abstract
Thermal injury (TI) with septic complications continues to be a serious clinical problem. One of the main concerns in such patients is immunosuppression related to functional derangements in intestinal CD4+ T lymphocytes. Extensive previous studies in thermal injury/septic patients and animal models of thermal injury/sepsis have shown decreased responsiveness of intestinal CD4+ T cells to antigen/mitogen. This hyporesponsiveness could significantly contribute to increase injured host susceptibility to pathogens including those translocating from host's gut lumen. Our previous studies indicated that while thermal injury or sepsis alone lead to suppressed proliferation and IL-2 production of intestinal CD4+ T cells, this study showed a substantial deletion via apoptosis of the Mesenteric Lymph Nodes (MLN) CD4+ T cells. Hence, thermal injury-plus-sepsis contributes not only to suppressed CD4+ T proliferation/IL-2 production but also to a substantial modulation of CD4+ T cell survivability. These findings allow us to conclude that while thermal injury alone can produce attenuated cell mediated responses without an overt change in CD4+ T cell survival, thermal injury with septic complications causes CD4+ T cell death and an irreversible loss of cell-mediated responses. The latter happening could be responsible for high morbidity and mortality in the injured host afflicted with thermal injury plus a critical infection.
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Affiliation(s)
- Nadeem Fazal
- Department of Biological Sciences, Chicago State University, Chicago, IL 60628, USA.
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8
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Wolf P, Nghiem DX, Walterscheid JP, Byrne S, Matsumura Y, Matsumura Y, Bucana C, Ananthaswamy HN, Ullrich SE. Platelet-activating factor is crucial in psoralen and ultraviolet A-induced immune suppression, inflammation, and apoptosis. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 169:795-805. [PMID: 16936256 PMCID: PMC1579250 DOI: 10.2353/ajpath.2006.060079] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Psoralen plus UVA (PUVA) is used as a very effective treatment modality for various diseases, including psoriasis and cutaneous T-cell lymphoma. PUVA-induced immune suppression and/or apoptosis are thought to be responsible for the therapeutic action. However, the molecular mechanisms by which PUVA acts are not well understood. We have previously identified platelet-activating factor (PAF), a potent phospholipid mediator, as a crucial substance triggering ultraviolet B radiation-induced immune suppression. In this study, we used PAF receptor knockout mice, a selective PAF receptor antagonist, a COX-2 inhibitor (presumably blocking downstream effects of PAF), and PAF-like molecules to test the role of PAF receptor binding in PUVA treatment. We found that activation of the PAF pathway is crucial for PUVA-induced immune suppression (as measured by suppression of delayed type hypersensitivity to Candida albicans) and that it plays a role in skin inflammation and apoptosis. Downstream of PAF, interleukin-10 was involved in PUVA-induced immune suppression but not inflammation. Better understanding of PUVA's mechanisms may offer the opportunity to dissect the therapeutic from the detrimental (ie, carcinogenic) effects and/or to develop new drugs (eg, using the PAF pathway) that act like PUVA but have fewer side effects.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Apoptosis/radiation effects
- Candida albicans/immunology
- Candidiasis/drug therapy
- Candidiasis/immunology
- Candidiasis/pathology
- Combined Modality Therapy/methods
- Female
- Ficusin/pharmacology
- Humans
- Hypersensitivity, Delayed/drug therapy
- Hypersensitivity, Delayed/immunology
- Hypersensitivity, Delayed/pathology
- Immune Tolerance/drug effects
- Immune Tolerance/immunology
- Immune Tolerance/radiation effects
- Immunosuppression Therapy/methods
- Inflammation/drug therapy
- Inflammation/immunology
- Inflammation/pathology
- Interleukin-10/immunology
- Lymphoma, T-Cell, Cutaneous/drug therapy
- Lymphoma, T-Cell, Cutaneous/immunology
- Lymphoma, T-Cell, Cutaneous/pathology
- Male
- Mice
- Mice, Knockout
- PUVA Therapy/adverse effects
- PUVA Therapy/methods
- Platelet Activating Factor/immunology
- Platelet Membrane Glycoproteins/deficiency
- Platelet Membrane Glycoproteins/immunology
- Psoriasis/drug therapy
- Psoriasis/immunology
- Psoriasis/pathology
- Receptors, G-Protein-Coupled/deficiency
- Receptors, G-Protein-Coupled/immunology
- Signal Transduction/drug effects
- Signal Transduction/immunology
- Signal Transduction/radiation effects
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Affiliation(s)
- Peter Wolf
- Research Unit for Photodermatology, Department of Dermatology, Medical University Graz, Auenbrugger Platz 8, A-8036 Graz, Austria.
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Sayeed MM. INFLAMMATORY/CARDIOVASCULAR-METABOLIC RESPONSES IN A RAT MODEL OF BURN INJURY WITH SUPERIMPOSED INFECTION. Shock 2005; 24 Suppl 1:40-4. [PMID: 16374371 DOI: 10.1097/01.shk.0000191412.56343.1e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Infection remains the major cause of morbidity and mortality in burn patients. Furthermore, the use of antibiotics in such patients has led to the prevalence of antibiotic-resistant microbial infections; one such infection in intensive care unit turns out to be caused by the enterococcal organisms. Our laboratory studies have used a rat model of bum injury and Enterococcus faecalis infection. Sprague-Dawley male rats ( approximately 250 g) were initially given an intragastric gavage of the antibiotic ciprofloxacin for 3 days. This procedure allowed for decontamination of intestine of gram-negative and some gram-positive organisms. The remainders of the gram-positive organisms were, to a large extent, Enterococci. After the decontamination procedure, rats were intra-abdominally inoculated with E. faecalis; inoculation involved preparation of sterilized rat fecal pellets impregnated with E. faecalis (10 colony-forming units) and their implants through a midline abdominal wall incision. Some of the rats that were implanted with the fecal pellets were subject to full-thickness skin bums ( approximately 30% total body surface area; 95 degrees C water for 7 s). Sham abdominal infection rats received a sterile pellet only; sham bum procedure consisted of exposing the skin to room temperature water. All sham and bum and/or E. faecalis infection procedures were carried out on rats under pentobarbital anesthesia. Inflammation and innate host defense-related responses were assessed via measurements of neutrophil effector responses, i.e., oxygen anion free radical (O2)/eIastase production, CD11b/CD18 expression, apoptosis, and tissue infiltration. Determining epithelial lactulose permeability, microvascular albumin leakage, and epithelial tight junction integrity assessed the status of intestinal function/structural derangements. The animals' metabolic and cardiovascular integrity was evaluated determining blood pH, p02, pC02, heart rate, respiratory rate, blood pressure, and cardiac output. Whereas the aforementioned measurements were carried out at 24 to 48 h postbum injury with and without the Enterococcal infection, animal mortality was determined for up to 5 days after the experimental injuries. The results of the studies indicated that whereas bum or E. faecalis infection alone did not produce significant mortality, the dual insult with bum and E. faecalis infection resulted in significant animal death accompanied by relatively more profound metabolic and cardiovascular derangements. Inappropriately heightened neutrophil effector responses were present with bum alone as well as with the dual bum and infection complications. These studies suggest that animal models of bum injury with Enterococcal infection complications simulate the adverse outcomes bum patients infected with Enterococcal organisms.
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Affiliation(s)
- Mohammed M Sayeed
- Department of Surgery and Physiology, Loyola University Stritch School of Medicine, Maywood, IL, USA
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10
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Al-Ghoul WM, Khan M, Fazal N, Sayeed MM. Mechanisms of postburn intestinal barrier dysfunction in the rat: Roles of epithelial cell renewal, E-cadherin, and neutrophil extravasation*. Crit Care Med 2004; 32:1730-9. [PMID: 15286551 DOI: 10.1097/01.ccm.0000132896.62368.01] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Our group has previously shown that the intestinal epithelium exhibits increased postburn barrier permeability and bacterial translocation associated with deranged neutrophil activity. The purpose of this investigation is to explore possible underlying intestinal structural mechanisms, leading to those functional changes with emphasis on (1) neutrophil influx and extravasation in the intestinal lamina propria 1-3 days after burn and (2) enterocyte proliferation, migration, apoptosis, and E-cadherin junctional epithelium levels 3 days after burn. DESIGN Freshly isolated ileum specimens were quick frozen, then cut by a cryostat into 30-micron-thick sections. Sections from day 1 postburn rats were immunostained with (1) anti-granulocyte or anti-elastase antibodies to assess neutrophil influx or (2) combined anti-granulocyte and anti-von Willebrand factor double immunolabeling to compare levels of neutrophil extravasation. Sections from day 3 postburn rats were immunostained with (1) bromodeoxyuridine immunohistochemistry 1, 3, 6, or 18 hrs after bromodeoxyuridine injection to assess enterocyte proliferation and migration, (2) cytokeratin-18 M30-immunohistochemistry to compare levels of enterocyte apoptosis, and (3) E-cadherin immunohistochemistry to compare junctional E-cadherin integrity. Ileal myeloperoxidase activity and bacterial translocation of Enterococcus faecalis were assessed biochemically and by E. faecalis-specific bacterial cultures, respectively, in day 3 postburn rats. SETTING : Research laboratories in a medical center and an academic institution. SUBJECTS Male Sprague-Dawley rats given sham treatment or treatment as a burn model with full-thickness skin scald over 30% total body surface area. CONCLUSIONS We report (1) increased levels of neutrophil influx and extravasation in villi lamina propriae, including elastase-positive cells (postburn day 1), (2) heightened levels of intestinal myeloperoxidase activity (postburn day 3), (3) decreased levels of epithelial cell proliferation, migration, and E-cadherin (postburn day 3), and (4) increased enterocyte apoptosis and E. faecalis bacterial translocation (postburn day 3). Based on these structural and functional abnormalities, we propose a mechanism for burn injury-related intestinal barrier dysfunction that includes increased trans- and para-cellular leakage caused by impaired enterocyte renewal and decreased junctional E-cadherin levels subsequent to increased neutrophil influx and extravasation within the villus lamina propria microenvironment.
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Affiliation(s)
- Walid M Al-Ghoul
- Trauma/Critical Care Labs, Department of Surgery, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.
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Affiliation(s)
- Jeffrey R Saffle
- Department of Surgery, Intermountain Burn Center, University of Utah Health Center, Salt Lake City, UT 84132, USA
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12
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Fazal N, Al-Ghoul WM, Schmidt MJ, Choudhry MA, Sayeed MM. Lyn- and ERK-mediated vs. Ca2+ -mediated neutrophil O responses with thermal injury. Am J Physiol Cell Physiol 2002; 283:C1469-79. [PMID: 12372808 DOI: 10.1152/ajpcell.00114.2002] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We evaluated the dependency of neutrophil O production on PTK-Lyn and MAPK-ERK1/2 in rats after thermal injury. Activation of PTK-Lyn was assessed by immunoprecipitation. Phosphorylation of ERK1/2 was assessed by Western blot analysis. O production was measured by isoluminol-enhanced luminometry. Imaging technique was employed to measure neutrophil [Ca2+](i) in individual cells. Thermal injury caused marked upregulation of Lyn and ERK1/2 accompanying enhanced neutrophil O production. Treatment of rats with PTK blocker (AG556) or MAPK blocker (AG1478) before burn injury caused complete inhibition of the respective kinase activation. Both AG556 and AG1478 produced an ~66% inhibition in O production. Treatment with diltiazem (DZ) produced an ~37% inhibition of O production without affecting Lyn or ERK1/2 activation with burn injury. Ca2+ mobilization was upregulated with burn injury but not affected by treatment of burn rats with AG556. Unlike the partial inhibition of burn-induced O production by AG556, AG1478, or DZ, platelet-activating factor antagonist (PAFa) treatment of burn rats produced near complete inhibition of O production. PAFa treatment also blocked activation of Lyn. The findings suggest that the near complete inhibition of O production by PAFa was a result of blockade of PTK as well as Ca2+ signaling. Overall, our studies show that enhanced neutrophil O production after thermal injury is a result of potentiation of Ca2+ -linked and -independent signaling triggered by inflammatory agents such as PAF.
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Affiliation(s)
- Nadeem Fazal
- Burn & Shock Trauma Institute, Department of Surgery, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois 60153, USA
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