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DeJesus JE, Wen JJ, Radhakrishnan R. Cytokine Pathways in Cardiac Dysfunction following Burn Injury and Changes in Genome Expression. J Pers Med 2022; 12:jpm12111876. [PMID: 36579591 PMCID: PMC9696755 DOI: 10.3390/jpm12111876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/28/2022] [Accepted: 11/05/2022] [Indexed: 11/12/2022] Open
Abstract
In 2016, an estimated 486,000 individuals sustained burn injuries requiring medical attention. Severe burn injuries lead to a persistent, hyperinflammatory response that may last up to 2 years. The persistent release of inflammatory mediators contributes to end-organ dysfunction and changes in genome expression. Burn-induced cardiac dysfunction may lead to heart failure and changes in cardiac remodeling. Cytokines promote the inflammatory cascade and promulgate mechanisms resulting in cardiac dysfunction. Here, we review the mechanisms by which TNFα, IL-1 beta, IL-6, and IL-10 cause cardiac dysfunction in post-burn injuries. We additionally review changes in the cytokine transcriptome caused by inflammation and burn injuries.
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Wen JJ, Mobli K, Radhakrishnan GL, Radhakrishnan RS. Regulation of Key Immune-Related Genes in the Heart Following Burn Injury. J Pers Med 2022; 12:jpm12061007. [PMID: 35743792 PMCID: PMC9224557 DOI: 10.3390/jpm12061007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/02/2022] [Accepted: 06/07/2022] [Indexed: 12/15/2022] Open
Abstract
Immune cascade is one of major factors leading to cardiac dysfunction after burn injury. TLRs are a class of pattern-recognition receptors (PRRs) that initiate the innate immune response by sensing conserved molecular patterns for early immune recognition of a pathogen. The Rat Toll-Like Receptor (TLR) Signaling Pathway RT² Profiler PCR Array profiles the expression of 84 genes central to TLR-mediated signal transduction and innate immunity, and is a validated tool for identifying differentially expressed genes (DEGs). We employed the PCR array to identify burn-induced cardiac TLR-signaling-related DEGs. A total of 38 up-regulated DEGs and 19 down-regulated DEGs were identified. Network analysis determined that all DEGS had 10 clusters, while up-regulated DEGs had 6 clusters and down-regulated DEGs had 5 clusters. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that DEGs were involved in TLR signaling, the RIG-I-Like receptor signaling pathway, the IL-17 signaling pathway, and the NFkB signaling pathway. Function analysis indicated that DEGs were associated with Toll-like receptor 2 binding, Lipopeptide binding, Toll-like receptor binding, and NAD(P)+ nucleosidase activity. The validation of 18 up-regulated DEGs (≥10-fold change) and 6 down-regulated DEGs (≤5-fold change) demonstrated that the PCR array is a trusted method for identifying DEGs. The analysis of validated DEG-derived protein–protein interaction networks will guide our future investigations. In summary, this study not only identified the TLR-signaling-pathway-related DEGs after burn injury, but also confirmed that the burn-induced cardiac cytokine cascade plays an important role in burn-induced heart dysfunction. The results will provide the novel therapeutic targets to protect the heart after burn injury.
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Affiliation(s)
- Jake J. Wen
- Department of Surgery University of Texas Medical Branch, Galveston, TX 77550, USA;
- Correspondence: (J.J.W.); (R.S.R.); Tel.: +1-832-722-0348
| | - Keyan Mobli
- Department of Surgery University of Texas Medical Branch, Galveston, TX 77550, USA;
| | | | - Ravi S. Radhakrishnan
- Department of Surgery University of Texas Medical Branch, Galveston, TX 77550, USA;
- Correspondence: (J.J.W.); (R.S.R.); Tel.: +1-832-722-0348
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Wang M, Scott SR, Koniaris LG, Zimmers TA. Pathological Responses of Cardiac Mitochondria to Burn Trauma. Int J Mol Sci 2020; 21:ijms21186655. [PMID: 32932869 PMCID: PMC7554938 DOI: 10.3390/ijms21186655] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/04/2020] [Accepted: 09/08/2020] [Indexed: 12/18/2022] Open
Abstract
Despite advances in treatment and care, burn trauma remains the fourth most common type of traumatic injury. Burn-induced cardiac failure is a key factor for patient mortality, especially during the initial post-burn period (the first 24 to 48 h). Mitochondria, among the most important subcellular organelles in cardiomyocytes, are a central player in determining the severity of myocardial damage. Defects in mitochondrial function and structure are involved in pathogenesis of numerous myocardial injuries and cardiovascular diseases. In this article, we comprehensively review the current findings on cardiac mitochondrial pathological changes and summarize burn-impaired mitochondrial respiration capacity and energy supply, induced mitochondrial oxidative stress, and increased cell death. The molecular mechanisms underlying these alterations are discussed, along with the possible influence of other biological variables. We hope this review will provide useful information to explore potential therapeutic approaches that target mitochondria for cardiac protection following burn injury.
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Affiliation(s)
- Meijing Wang
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (S.R.S.); (L.G.K.); (T.A.Z.)
- Correspondence:
| | - Susan R. Scott
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (S.R.S.); (L.G.K.); (T.A.Z.)
| | - Leonidas G. Koniaris
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (S.R.S.); (L.G.K.); (T.A.Z.)
- Simon Cancer Center, Indiana University, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indianopolis, IN 46202, USA
- Center for Cachexia Research Innovation and Therapy, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Teresa A. Zimmers
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (S.R.S.); (L.G.K.); (T.A.Z.)
- Simon Cancer Center, Indiana University, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indianopolis, IN 46202, USA
- Center for Cachexia Research Innovation and Therapy, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
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Sun Z, Wang J, Weng M, Tang J, Wang J, Xu J, Lin L, Yuan H. Role of Small Interfering RNA Silencing Protein Kinase C‐α Gene on the Occurrence of Ultrafiltration Failure in Peritoneal Dialysis Rats. J Cell Biochem 2017; 118:4607-4616. [PMID: 28485503 DOI: 10.1002/jcb.26125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 05/08/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Zhi‐Wei Sun
- Department of Hepatobiliary SurgeryThe First People's Hospital of Yunnan ProvinceKunhua Hospital Affiliated to Kunming University of Science and TechnologyKunming650031P. R. China
| | - Jian Wang
- Department of NephrologyThe First People's Hospital of Yunnan ProvinceKunhua Hospital Affiliated to Kunming University of Science and TechnologyKunming650031P. R. China
| | - Min Weng
- Department of NutritionThe First Affiliated Hospital of Kunming Medical UniversityKunming650032P. R. China
| | - Jian‐Zhong Tang
- Department of Hepatobiliary SurgeryThe First People's Hospital of Yunnan ProvinceKunhua Hospital Affiliated to Kunming University of Science and TechnologyKunming650031P. R. China
| | - Jun‐Feng Wang
- Department of Hepatobiliary SurgeryThe First People's Hospital of Yunnan ProvinceKunhua Hospital Affiliated to Kunming University of Science and TechnologyKunming650031P. R. China
| | - Jian Xu
- Department of NephrologyThe First People's Hospital of Yunnan ProvinceKunhua Hospital Affiliated to Kunming University of Science and TechnologyKunming650031P. R. China
| | - Ling Lin
- Department of Geriatric CardiologyThe First Affiliated Hospital of Kunming Medical UniversityKunming650032P. R. China
| | - Hong‐Ling Yuan
- Department of NephrologyThe First Affiliated Hospital of Kunming Medical UniversityKunming650032P. R. China
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Cardiovascular Dysfunction Following Burn Injury: What We Have Learned from Rat and Mouse Models. Int J Mol Sci 2016; 17:ijms17010053. [PMID: 26729111 PMCID: PMC4730298 DOI: 10.3390/ijms17010053] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 12/14/2015] [Accepted: 12/23/2015] [Indexed: 12/11/2022] Open
Abstract
Severe burn profoundly affects organs both proximal and distal to the actual burn site. Cardiovascular dysfunction is a well-documented phenomenon that increases morbidity and mortality following a massive thermal trauma. Beginning immediately post-burn, during the ebb phase, cardiac function is severely depressed. By 48 h post-injury, cardiac function rebounds and the post-burn myocardium becomes tachycardic and hyperinflammatory. While current clinical trials are investigating a variety of drugs targeted at reducing aspects of the post-burn hypermetabolic response such as heart rate and cardiac work, there is still a paucity of knowledge regarding the underlying mechanisms that induce cardiac dysfunction in the severely burned. There are many animal models of burn injury, from rodents, to sheep or swine, but the majority of burn related cardiovascular investigations have occurred in rat and mouse models. This literature review consolidates the data supporting the prevalent role that β-adrenergic receptors play in mediating post-burn cardiac dysfunction and the idea that pharmacological modulation of this receptor family is a viable therapeutic target for resolving burn-induced cardiac deficits.
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Yu X, Jia B, Wang F, Lv X, Peng X, Wang Y, Li H, Wang Y, Lu D, Wang H. α₁ adrenoceptor activation by norepinephrine inhibits LPS-induced cardiomyocyte TNF-α production via modulating ERK1/2 and NF-κB pathway. J Cell Mol Med 2014; 18:263-73. [PMID: 24304472 PMCID: PMC3930413 DOI: 10.1111/jcmm.12184] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 10/08/2013] [Indexed: 02/05/2023] Open
Abstract
Cardiomyocyte tumour necrosis factor α (TNF-α) production contributes to myocardial depression during sepsis. This study was designed to observe the effect of norepinephrine (NE) on lipopolysaccharide (LPS)-induced cardiomyocyte TNF-α expression and to further investigate the underlying mechanisms in neonatal rat cardiomyocytes and endotoxaemic mice. In cultured neonatal rat cardiomyocytes, NE inhibited LPS-induced TNF-α production in a dose-dependent manner. α₁- adrenoceptor (AR) antagonist (prazosin), but neither β₁- nor β₂-AR antagonist, abrogated the inhibitory effect of NE on LPS-stimulated TNF-α production. Furthermore, phenylephrine (PE), an α₁-AR agonist, also suppressed LPS-induced TNF-α production. NE inhibited p38 phosphorylation and NF-κB activation, but enhanced extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and c-Fos expression in LPS-treated cardiomyocytes, all of which were reversed by prazosin pre-treatment. To determine whether ERK1/2 regulates c-Fos expression, p38 phosphorylation, NF-κB activation and TNF-α production, cardiomyocytes were also treated with U0126, a selective ERK1/2 inhibitor. Treatment with U0126 reversed the effects of NE on c-Fos expression, p38 mitogen-activated protein kinase (MAPK) phosphorylation and TNF-α production, but not NF-κB activation in LPS-challenged cardiomyocytes. In addition, pre-treatment with SB202190, a p38 MAPK inhibitor, partly inhibited LPS-induced TNF-α production in cardiomyocytes. In endotoxaemic mice, PE promoted myocardial ERK1/2 phosphorylation and c-Fos expression, inhibited p38 phosphorylation and IκBα degradation, reduced myocardial TNF-α production and prevented LPS-provoked cardiac dysfunction. Altogether, these findings indicate that activation of α₁-AR by NE suppresses LPS-induced cardiomyocyte TNF-α expression and improves cardiac dysfunction during endotoxaemia via promoting myocardial ERK phosphorylation and suppressing NF-κB activation.
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Affiliation(s)
- Xiaohui Yu
- Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan UniversityGuangzhou, Guangdong, China
| | - Baoyin Jia
- Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan UniversityGuangzhou, Guangdong, China
| | - Faqiang Wang
- Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan UniversityGuangzhou, Guangdong, China
| | - Xiuxiu Lv
- Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan UniversityGuangzhou, Guangdong, China
| | - Xuemei Peng
- Department of Anesthesiology, The First Affiliated Hospital, Jinan UniversityGuangzhou, Guangdong, China
| | - Yiyang Wang
- Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan UniversityGuangzhou, Guangdong, China
| | - Hongmei Li
- Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan UniversityGuangzhou, Guangdong, China
| | - Yanping Wang
- Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan UniversityGuangzhou, Guangdong, China
| | - Daxiang Lu
- Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan UniversityGuangzhou, Guangdong, China
| | - Huadong Wang
- Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan UniversityGuangzhou, Guangdong, China
- *Correspondence to: Prof. Huadong WANG, M.D., Ph.D., Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, China., Tel.: 86-20-85220241, Fax: 86-20-85221343, E-mail:
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Joo DJ, Fang YH, Huh KH, Kim MS, Suh H, Kim YS. Changes in Serum Cytokine Profile after AEB071 (Sotrastaurin) or Tacrolimus versus Their Combinations in Rat Heterotopic Cardiac Allografts. KOREAN JOURNAL OF TRANSPLANTATION 2012. [DOI: 10.4285/jkstn.2012.26.4.248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Dong Jin Joo
- The Research Institute for Transplantation,Yonsei University College of Medicine, Seoul, Korea
- Department of Transplantation Surgery, Yonsei University Health System, Seoul, Korea
| | - Yu Hui Fang
- The Research Institute for Transplantation,Yonsei University College of Medicine, Seoul, Korea
- Graduate Program of Nanoscience and Technology, Yonsei University Health System, Seoul, Korea
| | - Kyu Ha Huh
- The Research Institute for Transplantation,Yonsei University College of Medicine, Seoul, Korea
- Department of Transplantation Surgery, Yonsei University Health System, Seoul, Korea
| | - Myoung Soo Kim
- The Research Institute for Transplantation,Yonsei University College of Medicine, Seoul, Korea
- Department of Transplantation Surgery, Yonsei University Health System, Seoul, Korea
| | - Hwal Suh
- Graduate Program of Nanoscience and Technology, Yonsei University Health System, Seoul, Korea
| | - Yu Seun Kim
- The Research Institute for Transplantation,Yonsei University College of Medicine, Seoul, Korea
- Department of Transplantation Surgery, Yonsei University Health System, Seoul, Korea
- Graduate Program of Nanoscience and Technology, Yonsei University Health System, Seoul, Korea
- Yonsei University, BK for Medical Science, Yonsei University Health System, Seoul, Korea
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Zhang DX, Yan H, Hu JY, Zhang JP, Teng M, Tong DL, Xiang F, Zhang Q, Fang YD, Liang GP, Huang YS. Identification of mitochondria translation elongation factor Tu as a contributor to oxidative damage of postburn myocardium. J Proteomics 2012; 77:469-79. [DOI: 10.1016/j.jprot.2012.09.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 09/19/2012] [Accepted: 09/22/2012] [Indexed: 12/30/2022]
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Insulin-Mediated Inhibition of p38 Mitogen-Activated Protein Kinase Protects Cardiomyocytes in Severe Burns. J Burn Care Res 2011; 32:591-9. [DOI: 10.1097/bcr.0b013e31822dc3f2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Burn-induced apoptosis of cardiomyocytes is survivin dependent and regulated by PI3K/Akt, p38 MAPK and ERK pathways. Basic Res Cardiol 2011; 106:1207-20. [DOI: 10.1007/s00395-011-0199-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 06/07/2011] [Accepted: 06/17/2011] [Indexed: 01/17/2023]
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Zang QS, Maass DL, Wigginton JG, Barber RC, Martinez B, Idris AH, Horton JW, Nwariaku FE. Burn serum causes a CD14-dependent mitochondrial damage in primary cardiomyocytes. Am J Physiol Heart Circ Physiol 2010; 298:H1951-8. [PMID: 20348223 DOI: 10.1152/ajpheart.00927.2009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Studies from animal models suggest that myocardial mitochondrial damage contributes to cardiac dysfunction after burn injury. In this report, we used an ex vivo model of primary cardiomyocyte culture to investigate the mechanisms of burn-induced mitochondrial impairment. Briefly, blood serum was collected from Sprague-Dawley (SD) rats subjected to 40% total body surface area burn and added (10% vol/vol) to primary cardiomyocytes prepared from SD rats. The effect of the burn serum on mitochondrial function and membrane integrity in the myocytes was analyzed. Exposure of myocytes to burn serum doubled the mitochondrial membrane damage measured by two independent assays. This treatment also significantly elevated mitochondrial oxidative stress, indicated by a more than 30% increase in lipid oxidation. Downregulation of mitochondrial antioxidant defense was also evident since the activities of the antioxidant enzymes superoxide dismutase and glutathione peroxidase were reduced by about 30% and 50%, respectively. Burn serum also induced deficiency of mitochondrial metabolism, indicated by a 30% decrease in the activity of cytochrome c oxidase. These mitochondrial dysfunctions appear to be generated by oxidative stress because burn serum induced a significant increase of mitochondrial oxygen species (mtROS) in cardiomyocytes, and pretreatment of cardiomyocytes with the antioxidant N-acetyl-cysteine prevented the mitochondrial damages induced by burn serum. Remarkably, the increase in mtROS was abolished by an antibody-mediated blockade of CD14. Furthermore, burn injury-induced mitochondrial damage in cardiomyocytes was prevented in CD14 knockout mice. Taken together, these data suggested that burn injury produces CD14-dependent mitochondrial damage via oxidative stress in myocardium.
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Affiliation(s)
- Qun S Zang
- Dept. of Surgery, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9160, USA.
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Gatson JW, Maass DL, Simpkins JW, Idris AH, Minei JP, Wigginton JG. Estrogen treatment following severe burn injury reduces brain inflammation and apoptotic signaling. J Neuroinflammation 2009; 6:30. [PMID: 19849845 PMCID: PMC2774304 DOI: 10.1186/1742-2094-6-30] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Accepted: 10/22/2009] [Indexed: 11/22/2022] Open
Abstract
Background Patients with severe burn injury experience a rapid elevation in multiple circulating pro-inflammatory cytokines, with the levels correlating with both injury severity and outcome. Accumulations of these cytokines in animal models have been observed in remote organs, however data are lacking regarding early brain cytokine levels following burn injury, and the effects of estradiol on these levels. Using an experimental animal model, we studied the acute effects of a full-thickness third degree burn on brain levels of TNF-α, IL-1β, and IL-6 and the protective effects of acute estrogen treatment on these levels. Additionally, the acute administration of estrogen on regulation of inflammatory and apoptotic events in the brain following severe burn injury were studied through measuring the levels of phospho-ERK, phospho-Akt, active caspase-3, and PARP cleavage in the placebo and estrogen treated groups. Methods In this study, 149 adult Sprague-Dawley male rats received 3rd degree 40% total body surface area (TBSA) burns. Fifteen minutes following burn injury, the animals received a subcutaneous injection of either placebo (n = 72) or 17 beta-estradiol (n = 72). Brains were harvested at 0.5, 1, 2, 4, 6, 8, 12, 18, and 24 hours after injury from the control (n = 5), placebo (n = 8/time point), and estrogen treated animals (n = 8/time point). The brain cytokine levels were measured using the ELISA method. In addition, we assessed the levels of phosphorylated-ERK, phosphorylated-Akt, active caspase-3, and the levels of cleaved PARP at the 24 hour time-point using Western blot analysis. Results In burned rats, 17 beta-estradiol significantly decreased the levels of brain tissue TNF-α (~25%), IL-1β (~60%), and IL-6 (~90%) when compared to the placebo group. In addition, we determined that in the estrogen-treated rats there was an increase in the levels of phospho-ERK (p < 0.01) and Akt (p < 0.05) at the 24 hour time-point, and that 17 beta-estradiol blocked the activation of caspase-3 (p < 0.01) and subsequent cleavage of PARP (p < 0.05). Conclusion Following severe burn injury, estrogens decrease both brain inflammation and the activation of apoptosis, represented by an increase in the levels of phospho-Akt and inhibition of caspase-3 activation and PARP cleavage. Results from these studies will help further our understanding of how estrogens protect the brain following burn injury, and may provide a novel, safe, and effective clinical treatment to combat remote secondary burn injury in the brain and to preserve cognition.
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Affiliation(s)
- Joshua W Gatson
- Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Alterations in the cardiac inflammatory response to burn trauma in mice lacking a functional Toll-like receptor 4 gene. Shock 2009; 30:740-6. [PMID: 18496236 DOI: 10.1097/shk.0b013e318173f329] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Our group and others have previously shown that Toll-like receptor 4 (TLR-4) inactivation prevents burn-induced myocardial contractile dysfunction; however, the molecular mechanisms that are involved in this cardioprotection are not well defined. This present study examines the involvement of TLR-4 in the cardiac inflammatory response to thermal insult. C3H/HeJ (TLR-4 mutant mice) and C3H/HeN wild-type (WT) mice were subjected to either a sham burn or 40% full-thickness burn injury and were fluid resuscitated with lactated Ringer using the Parkland formula. Mice (n = 7-9 per group) were killed at 2, 4, or 24 h postsham or burn, and heart tissue was harvested. Immunoblotting was performed to evaluate phosphorylated p38 mitogen-activated protein kinase (MAPK), nuclear p50, and cytoplasmic p50. Nuclear factor-kappaB was also characterized via electrophoretic mobility shift assay. Systemic and cardiac myocyte secretion of TNF-alpha, IL-1 beta, IL-6, and IL-10 were measured by enzyme-linked immunosorbent assay. Burn injury in WT mice promoted myocardial inflammatory signaling that included increased expression of phosphorylated p38 MAPK, nuclear p50, and increased cardiac myocyte secretion of cytokines. Systemic cytokines were also increased in WT animals, although not to the extent of the myocardial cytokine expression. Toll-like receptor 4 inactivation resulted in an attenuation of several burn-induced responses, including phosphorylation of p38 MAPK, nuclear translocation of nuclear factor-kappaB, and cytokine secretion. These data suggest that burn injury initiates an inflammatory response via Toll/IL-1 signaling in the heart, which contributes to cardiac injury and contractile dysfunction.
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Abstract
Burn injury has been associated with systemic/compartmental inflammatory responses and myocardial dysfunction. We hypothesized that burn size correlates with the extent of cardiac inflammatory response/contractile dysfunction. Adult male Sprague-Dawley rats were divided to receive anesthesia, a 3-degree burn covering 20%, 30%, 40%, or 60% total body surface area (TBSA) plus fluid resuscitation (lactated Ringer, 4 mL/kg per percent burn); sham burn animals were included as controls. There were seven rats in each group. Rats were euthanized Twenty-four h postburn, and TNF-alpha, IL-1beta, and IL-6 were measured in the plasma and in supernatant from isolated cardiac myocytes by enzyme-linked immunosorbent assay. In addition, left ventricular function (Langendorff) was studied in vitro, and troponin levels were measured by enzyme-linked immunosorbent assay. There were progressive, statistically significant increases in plasma and myocyte inflammatory cytokine levels, as well as plasma troponin with increasing burn size. Similarly, left ventricular pressure (in millimeters of mercury) and +/-dP/dtmax (in millimeters of mercury per second) progressively fell with increasing burn size. However, myocardial contractile depression induced by 60% TBSA burn was similar to that produced by 40% TBSA burn. These data suggest that the degree of inflammatory response, cardiac tissue injury, and myocardial contractile depression were correlated directly with the percent TBSA burn. However, unlike inflammation and cardiac tissue damage, myocardial contractile depression reached a plateau, with maximal myocardial contraction and relaxation defects observed at 40% TBSA burn, which were not further aggravated by a larger (60%) burn.
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Horton JW, Tan J, White DJ, Maass DL. Burn injury decreases myocardial Na-K-ATPase activity: role of PKC inhibition. Am J Physiol Regul Integr Comp Physiol 2007; 293:R1684-92. [PMID: 17634196 DOI: 10.1152/ajpregu.00219.2007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiomyocyte sodium accumulation after burn injury precedes the development of myocardial contractile dysfunction. The present study examined the effects of burn injury on Na-K-ATPase activity in adult rat hearts after major burn injury and explored the hypothesis that burn-related changes in myocardial Na-K-ATPase activity are PKC dependent. A third-degree burn injury (or sham burn) was given over 40% total body surface area, and rats received lactated Ringer solution (4 ml·kg−1·% burn−1). Subgroups of rats were killed 2, 4, or 24 h after burn ( n = 6 rats/time period), hearts were homogenized, and Na-K-ATPase activity was determined from ouabain-sensitive phosphate generation from ATP by cardiac sarcolemmal vesicles. Additional groups of rats were studied at several times after burn to determine the time course of myocyte sodium loading and the time course of myocardial dysfunction. Additional groups of sham burn-injured and burn-injured rats were given calphostin, an inhibitor of PKC, and Na-K-ATPase activity, cell Na+, and myocardial function were measured. Burn injury caused a progressive rise in cardiomyocyte Na+, and myocardial Na-K-ATPase activity progressively decreased after burn, while PKC activity progressively rose. Administration of calphostin to inhibit PKC activity prevented both the burn-related decrease in myocardial Na-K-ATPase and the rise in intracellular Na+and improved postburn myocardial contractile performance. We conclude that burn-related inhibition of Na-K-ATPase likely contributes to the cardiomyocyte accumulation of intracellular Na+. Since intracellular Na+is one determinant of electrical-mechanical recovery after insults such as burn injury, burn-related inhibition of Na-K-ATPase may be critical in postburn recovery of myocardial contractile function.
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Affiliation(s)
- Jureta W Horton
- Dept. of Surgery, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9160, USA.
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