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Mulder PPG, Hooijmans CR, Vlig M, Middelkoop E, Joosten I, Koenen HJPM, Boekema BKHL. Kinetics of Inflammatory Mediators in the Immune Response to Burn Injury: Systematic Review and Meta-Analysis of Animal Studies. J Invest Dermatol 2024; 144:669-696.e10. [PMID: 37806443 DOI: 10.1016/j.jid.2023.09.269] [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: 05/25/2023] [Revised: 08/31/2023] [Accepted: 09/20/2023] [Indexed: 10/10/2023]
Abstract
Burns are often accompanied by a dysfunctional immune response, which can lead to systemic inflammation, shock, and excessive scarring. The objective of this study was to provide insight into inflammatory pathways associated with burn-related complications. Because detailed information on the various inflammatory mediators is scattered over individual studies, we systematically reviewed animal experimental data for all reported inflammatory mediators. Meta-analyses of 352 studies revealed a strong increase in cytokines, chemokines, and growth factors, particularly 19 mediators in blood and 12 in burn tissue. Temporal kinetics showed long-lasting surges of proinflammatory cytokines in blood and burn tissue. Significant time-dependent effects were seen for IL-1β, IL-6, TGF-β1, and CCL2. The response of anti-inflammatory mediators was limited. Burn technique had a profound impact on systemic response levels. Large burn size and scalds further increased systemic, but not local inflammation. Animal characteristics greatly affected inflammation, for example, IL-1β, IL-6, and TNF-α levels were highest in young, male rats. Time-dependent effects and dissimilarities in response demonstrate the importance of appropriate study design. Collectively, this review presents a general overview of the burn-induced immune response exposing inflammatory pathways that could be targeted through immunotherapy for burn patients and provides guidance for experimental set-ups to advance burn research.
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Affiliation(s)
- Patrick P G Mulder
- Preclinical Research, Association of Dutch Burn Centres (ADBC), Beverwijk, The Netherlands; Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Carlijn R Hooijmans
- Meta-Research Team, Department of Anesthesiology, Pain and Palliative Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marcel Vlig
- Preclinical Research, Association of Dutch Burn Centres (ADBC), Beverwijk, The Netherlands
| | - Esther Middelkoop
- Preclinical Research, Association of Dutch Burn Centres (ADBC), Beverwijk, The Netherlands; Department of Plastic, Reconstructive and Hand Surgery, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands; Tissue Function and Regeneration, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - Irma Joosten
- 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
| | - Bouke K H L Boekema
- Preclinical Research, Association of Dutch Burn Centres (ADBC), Beverwijk, The Netherlands; Department of Plastic, Reconstructive and Hand Surgery, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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Muro I, Qualman AC, Kovacs EJ, Idrovo JP. Burn-Induced Apoptosis in the Livers of Aged Mice Is Associated With Caspase Cleavage of Bcl-xL. J Surg Res 2023; 290:147-155. [PMID: 37267704 PMCID: PMC10330893 DOI: 10.1016/j.jss.2023.04.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 04/05/2023] [Accepted: 04/29/2023] [Indexed: 06/04/2023]
Abstract
INTRODUCTION Older adult burn victims have poorer outcomes than younger burn victims. The liver is critical for the recovery of patients with burns. Postburn hepatic apoptosis in young individuals compromises liver integrity; however, this pathway has not yet been studied in older individuals. Because aged animals with burns suffer significant liver damage, we hypothesized that apoptosis is altered in these animals and may affect liver function. Understanding postburn hepatic apoptosis and its effects on liver function in aged animals may help improve outcomes in older patients. METHODS We compared the protein and gene expression levels in young and aged mice after a 15% total-body-surface-area burn. Liver and serum samples were collected at different time points after injury. RESULTS Caspase-9 expression in liver tissue was downregulated by 47% in young animals and upregulated by 62% in aged animals 9 h postburn (P < 0.05). The livers of aged mice showed a Bcl-extra-large (Bcl-xL) transcription increase only after 6 h; however, the livers of young mice exhibited 4.3-fold, 14.4-fold, and 7.8-fold Bcl-xL transcription increases at 3, 6, and 9 h postburn, respectively (P < 0.05). The livers of young mice showed no changes in Caspase-9, Caspase-3, or Bcl-xL protein levels during the early postburn period. In contrast, the livers of aged mice contained cleaved caspase-9, reduced full-length caspase-3, and an accumulation of ΔN-Bcl-x at 6 and 9 h postburn (P < 0.05). p21 expression decreased in aged mice; however, it was significantly increased in the liver tissue of young mice postburn (P < 0.05). Serum amyloid A1 and serum amyloid A2 serum protein levels were 5.2- and 3.1-fold higher in young mice than in aged mice, respectively, at 6 and 9 h postburn (P < 0.05). CONCLUSIONS Livers of aged mice exhibited different apoptotic processes compared to those of young mice early after burn injury. Collectively, burn-induced liver apoptosis in aged mice compromises hepatic serum protein production.
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Affiliation(s)
- Israel Muro
- Division of G.I., Trauma, and Endocrine Surgery, Department of Surgery, University of Colorado, Aurora, Colorado
| | - Andrea C Qualman
- Division of G.I., Trauma, and Endocrine Surgery, Department of Surgery, University of Colorado, Aurora, Colorado
| | - Elizabeth J Kovacs
- Division of G.I., Trauma, and Endocrine Surgery, Department of Surgery, University of Colorado, Aurora, Colorado; Division of Burn Research, Division of Alcohol Research, Department of Immunology and Microbiology, University of Colorado, Aurora, Colorado
| | - Juan-Pablo Idrovo
- Division of G.I., Trauma, and Endocrine Surgery, Department of Surgery, University of Colorado, Aurora, Colorado.
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Abstract
Severely burned patients suffer from a hypermetabolic syndrome that can last for years after the injury has resolved. The underlying cause of these metabolic alterations most likely involves the persistent elevated catecholamine levels that follow the surge induced by thermal injury. At the cellular level, endoplasmic reticulum (ER) stress in metabolic tissues is a hallmark observed in patients following burn injury and is associated with several detrimental effects. Therefore, ER stress could be the underlying cellular mechanism of persistent hypermetabolism in burned patients. Here, we show that catecholamines induce ER stress and that adreno-receptor blockers reduce stress responses in the HepG2 hepatocyte cell line. Our results also indicate that norepinephrine (NE) significantly induces ER stress in HepG2 cells and 3T3L1 mouse adipocytes. Furthermore, we demonstrate that the alpha-1 blocker, prazosin, and beta blocker, propranolol, block ER stress induced by NE. We also show that the effects of catecholamines in inducing ER stress are cell type-specific, as NE treatment failed to evoke ER stress in human fibroblasts. Thus, these findings reveal the mechanisms used by catecholamines to alter metabolism and suggest inhibition of the receptors utilized by these agents should be further explored as a potential target for the treatment of ER stress-mediated disease.
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Akhter N, Sun H, Machuki JO, Ren HQ. Protective Effect of Calcium Dobesilate on Induced AKI in Severely Burned Mice. Nephron Clin Pract 2021; 145:553-567. [PMID: 34126619 DOI: 10.1159/000515420] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 02/24/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Early acute kidney injury (AKI) predicts a high mortality rate in severely burned patients. However, the pathophysiology of early AKI induced by severe burn has not been well-defined. This study was designed to examine the protective effects of calcium dobesilate (CaD) against severe burn-induced early AKI in mice and explore the mechanism. METHODS The shaved backs of mice were immersed in 100°C water for 10 s to make severe burn (40% of the total body surface area). CD-57 male mice were randomly divided into sham, burn, burn + vehicle, and burn + CaD groups. Renal function, reactive oxygen species generation, tubular necrosis, and phosphorylation of mitogen-activated protein kinase, protein kinase B (Akt), and nuclear factor (NF)-κB were measured at 24 and 48 h after the burn. Renal histology, ELISA, qRT-PCR, and Western blotting were performed on the renal tissue of mice to examine the effects and mechanisms at 24 and 48 h after the burn. RESULTS Tubular damage, cast formation, and elevations of serum creatinine, BUN, and renal tissue kidney injury molecule 1 levels were all observed in the burned mice, and these were all alleviated in the mice with CaD treatment. In addition, the levels of oxidation-reduction potential and malondialdehyde were decreased, while the activities of the endogenous antioxidative enzymes were increased in the kidney tissues from the mice after CaD treatment. Furthermore, the activities of Akt, p38, extracellular sign-regulated kinase, Jun N-terminal kinase, and NF-κB signaling were increased in the kidney of burned mice and normalized after CaD treatment. CONCLUSION This study has established, for the first time, the protective effect of CaD against early AKI in severely burned mice. CaD may exert its protective effect through alleviating oxidative stress, apoptosis, and inflammation, as well as modulating some signaling pathways in the kidney.
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Affiliation(s)
- Nazma Akhter
- Department of Physiology, Xuzhou Medical University, Xuzhou, China.,Department of Pharmacy, Southeast University, Dhaka, Bangladesh
| | - Hong Sun
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | | | - Hong-Qi Ren
- Department of Nephrology, The Affiliated Huaihai Hospital of Xuzhou Medical University, Xuzhou, China
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Idrovo JP, Boe DM, Kaahui S, Yang WL, Kovacs EJ. Hepatic inflammation after burn injury is associated with necroptotic cell death signaling. J Trauma Acute Care Surg 2020; 89:768-774. [PMID: 33017135 PMCID: PMC8386183 DOI: 10.1097/ta.0000000000002865] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Burn injury still has a high attributable mortality. The elevated mortality rate of severe burns is still concerning. Hepatic inflammation and injury are common after burns and are associated with poor outcomes. Necroptosis is a programmed cell death linked with inflammation. Thus, assessing necroptotic pathways in the liver can lead to new therapeutic modalities to improve mortality after severe burns. METHODS Mice underwent 15% total body surface area burn or sham injury. Three hours after burn, the mice were euthanized to collect blood and livers. Histology, injury markers, genes expression, and tissue protein levels were compared between groups. RESULTS Compared with sham, burned mice had heightened liver inflammatory cell infiltration and edema. Serum aspartate aminotransferase and alanine aminotransferase were increased by 4.9- and 3.4-fold, respectively, in burned mice relative to sham (p < 0.05). Expression of tumor necrosis factor α, interleukin-6, interleukin-1β, and CXCL1 (KC) genes were elevated in livers of burned mice by 10-, 86-, 10-, and 828-fold, respectively, compared with sham (p < 0.05). Expression of necroptotic genes, namely, receptor-interacting protein kinases 1 and 3, and mixed lineage kinase domain-like in livers of burned mice were increased by 10-, 13-, and 4.5-fold, respectively, relative to sham (p < 0.05). Receptor-interacting protein kinase 1 and phosphorylated mixed lineage kinase domain-like protein levels measured by Western-blot in livers after burn injury were elevated by 22- and 17-fold, respectively, compared with sham (p < 0.05). CONCLUSION Liver damage occurs early after burns in mice and is associated with elevation of proinflammatory cytokines, chemokine, and proteins involved in the necroptotic pathway. This study suggests that necroptosis plays a role in the pathogenesis of liver failure secondary to burn injury.
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Affiliation(s)
- Juan-Pablo Idrovo
- From the Division of GI, Trauma, and Endocrine Surgery, Department of Surgery (J.-P.I., S.K.), Division of GI, Trauma, and Endocrine Surgery, Department of Surgery, Burn Research Program (D.M.B., E.J.K.), and Department of Immunology and Microbiology (D.M.B., E.J.K.), University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado; Department of Radiation Oncology (W.-L.Y.), Albert Einstein College of Medicine, Bronx, New York; Division of GI, Trauma, and Endocrine Surgery, Department of Surgery, Alcohol Research Program (E.J.K.), University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
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Diao L, Yousuf Y, Amini‐Nik S, Jeschke MG. Increased proliferation of hepatic periportal ductal progenitor cells contributes to persistent hypermetabolism after trauma. J Cell Mol Med 2020; 24:1578-1587. [PMID: 31793707 PMCID: PMC6991656 DOI: 10.1111/jcmm.14845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 10/16/2019] [Accepted: 10/28/2019] [Indexed: 12/13/2022] Open
Abstract
Prolonged and persistent hypermetabolism and excessive inflammatory response after severe trauma is detrimental and associated with poor outcome. The predisposing pathology or signals mediating this complex response are essentially unknown. As the liver is the central organ mediating the systemic metabolic responses and considering that adult hepatic stem cells are on top of the hierarchy of cell differentiation and may pass epigenetic information to their progeny, we asked whether liver progenitor cells are activated, signal hypermetabolism upon post-traumatic cellular stress responses, and pass this to differentiated progeny. We generated Sox9CreERT2 : ROSA26 EYFP mice to lineage-trace the periportal ductal progenitor cells (PDPCs) and verify the fate of these cells post-burn. We observed increased proliferation of PDPCs and their progeny peaking around two weeks post-burn, concomitant with the hepatomegaly and the cellular stress responses. We then sorted out PDPCs, PDPC-derived hepatocytes and mature hepatocytes, compared their transcriptome and showed that PDPCs and their progeny present a significant up-regulation in signalling pathways associated with inflammation and metabolic activation, contributing to persistent hypermetabolic and hyper-inflammatory state. Furthermore, concomitant down-regulation of LXR signalling in PDPCs and their progeny implicates the therapeutic potential of early and short-term administration of LXR agonists in ameliorating such persistent hypermetabolism.
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Affiliation(s)
- Li Diao
- Sunnybrook Research InstituteTorontoONCanada
| | | | - Saeid Amini‐Nik
- Sunnybrook Research InstituteTorontoONCanada
- Division of Plastic SurgeryDepartment of SurgeryUniversity of TorontoTorontoONCanada
- Department of Laboratory Medicine and Pathobiology (LMP)University of TorontoTorontoONCanada
| | - Marc G. Jeschke
- Sunnybrook Research InstituteTorontoONCanada
- Division of Plastic SurgeryDepartment of SurgeryUniversity of TorontoTorontoONCanada
- Department of ImmunologyUniversity of TorontoTorontoONCanada
- Ross Tilley Burn CentreSunnybrook Health Sciences CentreTorontoONCanada
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Guo SX, Fang Q, You CG, Jin YY, Wang XG, Hu XL, Han CM. Effects of hydrogen-rich saline on early acute kidney injury in severely burned rats by suppressing oxidative stress induced apoptosis and inflammation. J Transl Med 2015; 13:183. [PMID: 26047940 PMCID: PMC4467622 DOI: 10.1186/s12967-015-0548-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 05/26/2015] [Indexed: 01/21/2023] Open
Abstract
Background Early acute kidney injury (AKI) in severely burned patients predicts a high mortality that is multi-factorial. Hydrogen has been reported to alleviate organ injury via selective quenching of reactive oxygen species. This study investigated the potential protective effects of hydrogen against severe burn-induced early AKI in rats. Methods Severe burn were induced via immersing the shaved back of rats into a 100°C bath for 15 s. Fifty-six Sprague–Dawley rats were randomly divided into Sham, Burn + saline, and Burn + hydrogen-rich saline (HS) groups, and renal function and the apoptotic index were measured. Kidney histopathology and immunofluorescence staining, quantitative real-time PCR, ELISA and western blotting were performed on the sera or renal tissues of burned rats to explore the underlying effects and mechanisms at varying time points post burn. Results Renal function and tubular apoptosis were improved by HS treatment. In addition, the oxidation–reduction potential and malondialdehyde levels were markedly reduced with HS treatment, whereas endogenous antioxidant enzyme activities were significantly increased. HS also decreased the myeloperoxidase levels and influenced the release of inflammatory mediators in the sera and renal tissues of the burned rats. The regulatory effects of HS included the inhibition of p38, JNK, ERK and NF-κB activation, and an increase in Akt phosphorylation. Conclusion Hydrogen can attenuate severe burn-induced early AKI; the mechanisms of protection include the inhibition of oxidative stress induced apoptosis and inflammation, which may be mediated by regulation of the MAPKs, Akt and NF-κB signalling pathways.
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Affiliation(s)
- Song-Xue Guo
- Department of Burn, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China.
| | - Quan Fang
- Department of Plastic Surgery, Binjiang Branch, Second Affiliated Hospital, School of Medicine, Zhejiang University, 1511 Jianghong Road, Hangzhou, 310000, Zhejiang, China.
| | - Chuan-Gang You
- Department of Burn, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China.
| | - Yun-Yun Jin
- Department of Burn, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China.
| | - Xin-Gang Wang
- Department of Burn, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China.
| | - Xin-Lei Hu
- Department of Orthopedic, Binjiang Branch, Second Affiliated Hospital, School of Medicine, Zhejiang University, 1511 Jianghong Road, Hangzhou, 31000, Zhejiang, China.
| | - Chun-Mao Han
- Department of Burn, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China.
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Burn plus lipopolysaccharide augments endoplasmic reticulum stress and NLRP3 inflammasome activation and reduces PGC-1α in liver. Shock 2014; 41:138-44. [PMID: 24434416 DOI: 10.1097/shk.0000000000000075] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Extensively burned patients often suffer from sepsis (especially caused by Pseudomonas aeruginosa), which may prolong metabolic derangement, contribute to multiple organ failure, and increase mortality. The molecular and cellular mechanisms of such infection-related metabolic derangement and organ dysfunction are unclear. We have previously shown that severely burned patients have significant and persisting hepatic endoplasmic reticulum (ER) stress. We hypothesized that ER stress and the unfolded protein response correlate with NOD-like receptor, pyrin domain containing 3 (NLRP3) inflammasome activation in burn. These may trigger profound metabolic changes in the liver, which form the pathological basis of liver damage and liver dysfunction after burn injury. A two-hit rat model was established by a 60% total body surface area scald burn and intraperitoneal injection of P. aeruginosa-derived lipopolysaccharide (LPS) 3 days after burn. One day later, animals were killed, and liver tissue samples were collected for gene expression and protein analysis of NLRP3 inflammasome activation, ER stress, and glucose and lipid metabolism. Liver damage was assessed by plasma markers (alanine aminotransferase and aspartate aminotransferase) and liver immunohistochemical analysis. Our results showed that burn injury and LPS injection induced inflammasome activation in liver and augmented hepatic ER stress and liver damage. Although there was an increased metabolic demand after burn, hepatic NLRP3 inflammasome activation corresponded to inhibition of PGC-1α (peroxisome proliferator-activated receptor γ-coactivator 1α) and its upstream regulators protein kinase A catalyst unit, AMP-activated protein kinase α, and sirtuin-1 may provide a mechanism for the enhanced metabolic derangement after major burn injury plus sepsis. In conclusion, burn + LPS augments inflammasome activation and ER stress in liver, which in turn contribute to postburn metabolic derangement.
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Animal models in burn research. Cell Mol Life Sci 2014; 71:3241-55. [PMID: 24714880 DOI: 10.1007/s00018-014-1612-5] [Citation(s) in RCA: 252] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 03/14/2014] [Accepted: 03/17/2014] [Indexed: 01/08/2023]
Abstract
Burn injury is a severe form of trauma affecting more than 2 million people in North America each year. Burn trauma is not a single pathophysiological event but a devastating injury that causes structural and functional deficits in numerous organ systems. Due to its complexity and the involvement of multiple organs, in vitro experiments cannot capture this complexity nor address the pathophysiology. In the past two decades, a number of burn animal models have been developed to replicate the various aspects of burn injury, to elucidate the pathophysiology, and to explore potential treatment interventions. Understanding the advantages and limitations of these animal models is essential for the design and development of treatments that are clinically relevant to humans. This review aims to highlight the common animal models of burn injury in order to provide investigators with a better understanding of the benefits and limitations of these models for translational applications. While many animal models of burn exist, we limit our discussion to the skin healing of mouse, rat, and pig. Additionally, we briefly explain hypermetabolic characteristics of burn injury and the animal model utilized to study this phenomena. Finally, we discuss the economic costs associated with each of these models in order to guide decisions of choosing the appropriate animal model for burn research.
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Zhao G, Yu YM, Shoup TM, Elmaleh DR, Bonab AA, Tompkins RG, Fischman AJ. Membrane potential-dependent uptake of 18F-triphenylphosphonium--a new voltage sensor as an imaging agent for detecting burn-induced apoptosis. J Surg Res 2014; 188:473-9. [PMID: 24582214 DOI: 10.1016/j.jss.2014.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 12/12/2013] [Accepted: 01/07/2014] [Indexed: 12/30/2022]
Abstract
BACKGROUND Mitochondrial dysfunction has been closely related to many pathologic processes, such as cellular apoptosis. Alterations in organelle membrane potential are associated with mitochondrial dysfunction. A fluorine-18 labeled phosphonium compound: (18)F-triphenylphosphonium ((18)F-TPP) was prepared to determine its potential use as a mitochondria-targeting radiopharmaceutical to evaluate cellular apoptosis. METHODS Studies were conducted in both ex vivo cell lines and in vivo using a burned animal model. Uptake of (18)F-TPP was assessed in PC-3 cells by gamma counting under the following conditions: graded levels of extracellular potassium concentrations, incubation with carbonyl cyanide m-chlorophenylhydrazone and staurosporine. Apoptosis was studied in a burn animal model using terminal deoxynucleotidyl transferase dUTP nick end labeling staining and simultaneous assessment of (18)F-TPP uptake by biodistribution. RESULTS We found that stepwise membrane depolarization by potassium (K) resulted in a linear decrease in (18)F-TPP uptake, with a slope of 0.62 ± 0.08 and a correlation coefficient of 0.936 ± 0.11. Gradually increased concentrations of m-chlorophenylhydrazone lead to decreased uptake of (18)F-TPP. Staurosporine significantly decreased the uptake of (18)F-TPP in PC-3 cells from 14.2 ± 3.8% to 5.6 ± 1.3% (P < 0.001). Burn-induced significant apoptosis (sham: 4.4 ± 1.8% versus burn: 24.6 ± 6.7 %; P < 0.005) and a reduced uptake of tracer in the spleens of burn-injured animals as compared with sham burn controls (burn: 1.13 ± 0.24% versus sham: 3.28 ± 0.67%; P < 0.005). Biodistribution studies demonstrated that burn-induced significant reduction in (18)F-TPP uptake in spleen, heart, lung, and liver, which were associated with significantly increased apoptosis. CONCLUSIONS (18)F-TPP is a promising new voltage sensor for detecting mitochondrial dysfunction and apoptosis in various tissues.
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Affiliation(s)
- Gaofeng Zhao
- Department of Surgery, Massachusetts General Hospital, Shriners Hospitals for Children, and Harvard Medical School, Boston, Massachusetts
| | - Yong-Ming Yu
- Department of Surgery, Massachusetts General Hospital, Shriners Hospitals for Children, and Harvard Medical School, Boston, Massachusetts
| | - Timothy M Shoup
- Department of Surgery, Massachusetts General Hospital, Shriners Hospitals for Children, and Harvard Medical School, Boston, Massachusetts
| | - David R Elmaleh
- Department of Surgery, Massachusetts General Hospital, Shriners Hospitals for Children, and Harvard Medical School, Boston, Massachusetts
| | - Ali A Bonab
- Department of Surgery, Massachusetts General Hospital, Shriners Hospitals for Children, and Harvard Medical School, Boston, Massachusetts
| | - Ronald G Tompkins
- Department of Surgery, Massachusetts General Hospital, Shriners Hospitals for Children, and Harvard Medical School, Boston, Massachusetts
| | - Alan J Fischman
- Department of Surgery, Massachusetts General Hospital, Shriners Hospitals for Children, and Harvard Medical School, Boston, Massachusetts.
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