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Dehydroepiandrosterone resisted E. Coli O157:H7-induced inflammation via blocking the activation of p38 MAPK and NF-κB pathways in mice. Cytokine 2019; 127:154955. [PMID: 31864092 DOI: 10.1016/j.cyto.2019.154955] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/24/2019] [Accepted: 12/10/2019] [Indexed: 11/23/2022]
Abstract
Dehydroepiandrosterone (DHEA), a critical metabolite in cholesterol metabolism, can regulate the inflammatory responses in humans or animals. However, the precise mechanisms of these beneficial actions remains poorly understood. Present study aims to clarify the anti-inflammatory function of DHEA and its possible mechanisms in the E. coli O157:H7-stimulated mice. The results indicated that DHEA reduced the mortality of mice and bacterial concentration in the peritoneal fluid in the E. coli-stimulated mice. DHEA increased the spleen index, the activity of lactate dehydrogenase and acid phosphatase; while it decreased the nitric oxide (NO) content and inducible nitric oxide synthase (iNOS) activity in mice. The mRNA levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and interferon gamma (IFN-γ) were decreased, whereas the interleukin-4 (IL-4) and interleukin-10 (IL-10) mRNA levels were increased in the E. coli-stimulated mice treated with DHEA. Moreover, DHEA treatment reversed the increasing of IFN-γ/IL-4 ratio in mice caused by E. coli infection. Importantly, DHEA blocked the nuclear translocation of p65 through down-regulation the IκB-α protein phosphorylation level in the mice stimulated with E. coli O157:H7. No statically changes were showed on the phospho (p)-ERK1/2 and p-JNK1/2 protein level, while DHEA significantly suppressed the p-p38 protein level in mice. The above results indicated that DHEA alleviated inflammatory responses by suppressing NO secretion and promoting Th2-associated anti-inflammatory cytokines production in mice; and this action might relate to the blocking of p38 MAPK and NF-κB signaling pathways activation. All the above results provide substantial information for understanding the anti-inflammatory function of DHEA and further support it as a potential immunomodulatory in prevention inflammatory and bacterial infection diseases.
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Xia Y, Chen S, Zeng S, Zhao Y, Zhu C, Deng B, Zhu G, Yin Y, Wang W, Hardeland R, Ren W. Melatonin in macrophage biology: Current understanding and future perspectives. J Pineal Res 2019; 66:e12547. [PMID: 30597604 DOI: 10.1111/jpi.12547] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 12/26/2018] [Accepted: 12/26/2018] [Indexed: 12/13/2022]
Abstract
Melatonin is a ubiquitous hormone found in various organisms and highly affects the function of immune cells. In this review, we summarize the current understanding of the significance of melatonin in macrophage biology and the beneficial effects of melatonin in macrophage-associated diseases. Enzymes associated with synthesis of melatonin, as well as membrane receptors for melatonin, are found in macrophages. Indeed, melatonin influences the phenotype polarization of macrophages. Mechanistically, the roles of melatonin in macrophages are related to several cellular signaling pathways, such as NF-κB, STATs, and NLRP3/caspase-1. Notably, miRNAs (eg, miR-155/-34a/-23a), cellular metabolic pathways (eg, α-KG, HIF-1α, and ROS), and mitochondrial dynamics and mitophagy are also involved. Thus, melatonin modulates the development and progression of various macrophage-associated diseases, such as cancer and rheumatoid arthritis. This review provides a better understanding about the importance of melatonin in macrophage biology and macrophage-associated diseases.
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Affiliation(s)
- Yaoyao Xia
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Subtropical Institute of Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
- University of Chinese Academy of Sciences, Beijing, China
- Laboratory of Animal Nutrition and Health and Key Laboratory of Agro-Ecology, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
| | - Siyuan Chen
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Subtropical Institute of Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Sijing Zeng
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Subtropical Institute of Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Yuanyuan Zhao
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Subtropical Institute of Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Congrui Zhu
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoo Noses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | - Baichuan Deng
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Subtropical Institute of Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Guoqiang Zhu
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoo Noses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Yulong Yin
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Subtropical Institute of Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
- Laboratory of Animal Nutrition and Health and Key Laboratory of Agro-Ecology, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
| | - Wence Wang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Subtropical Institute of Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Rüdiger Hardeland
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Göttingen, Germany
| | - Wenkai Ren
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Subtropical Institute of Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoo Noses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
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3
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Hu W, Deng C, Ma Z, Wang D, Fan C, Li T, Di S, Gong B, Reiter RJ, Yang Y. Utilizing melatonin to combat bacterial infections and septic injury. Br J Pharmacol 2017; 174:754-768. [PMID: 28213968 PMCID: PMC5387000 DOI: 10.1111/bph.13751] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 02/07/2017] [Accepted: 02/13/2017] [Indexed: 12/11/2022] Open
Abstract
Melatonin, also known as N-acetyl-5-methoxytryptamine, is a ubiquitously acting molecule that is produced by the pineal gland and other organs of animals, including humans. As melatonin and its metabolites are potent antioxidants and free radical scavengers, they are protective against a variety of disorders. Moreover, multiple molecular targets of melatonin have been identified, and its actions are both receptor-mediated and receptor-independent. Recent studies have shown that melatonin may be useful in fighting against sepsis and septic injury due to its antioxidative and anti-inflammatory actions; the results generally indicate a promising therapeutic application for melatonin in the treatment of sepsis. To provide a comprehensive understanding regarding the protective effects of melatonin against septic injury, in the present review we have evaluated the published literature in which melatonin has been used to treat experimental and clinical sepsis. Firstly, we present the evidence from studies that have used melatonin to resist bacterial pathogens. Secondly, we illustrate the protective effect of melatonin against septic injury and discuss the possible mechanisms. Finally, the potential directions for future melatonin research against sepsis are summarized.
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Affiliation(s)
- Wei Hu
- Department of Thoracic and Cardiovascular SurgeryNanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical SchoolNanjingChina
- Department of Biomedical EngineeringThe Fourth Military Medical UniversityXi'anChina
| | - Chao Deng
- Department of Cardiovascular Surgery, Xijing HospitalThe Fourth Military Medical UniversityXi'anChina
- Department of Thoracic Surgery, Tangdu HospitalThe Fourth Military Medical UniversityXi'anChina
| | - Zhiqiang Ma
- Department of Aerospace MedicineThe Fourth Military Medical UniversityXi'anChina
| | - Dongjin Wang
- Department of Thoracic and Cardiovascular SurgeryNanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical SchoolNanjingChina
| | - Chongxi Fan
- Department of Aerospace MedicineThe Fourth Military Medical UniversityXi'anChina
| | - Tian Li
- Department of Biomedical EngineeringThe Fourth Military Medical UniversityXi'anChina
| | - Shouyin Di
- Department of Aerospace MedicineThe Fourth Military Medical UniversityXi'anChina
| | - Bing Gong
- Department of Thoracic and Cardiovascular SurgeryNanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical SchoolNanjingChina
| | - Russel J Reiter
- Department of Cellular and Structural BiologyUT Health Science Center at San AntonioSan AntonioTXUSA
| | - Yang Yang
- Department of Thoracic and Cardiovascular SurgeryNanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical SchoolNanjingChina
- Department of Biomedical EngineeringThe Fourth Military Medical UniversityXi'anChina
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Calvo JR, González-Yanes C, Maldonado MD. The role of melatonin in the cells of the innate immunity: a review. J Pineal Res 2013; 55:103-20. [PMID: 23889107 DOI: 10.1111/jpi.12075] [Citation(s) in RCA: 297] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 07/03/2013] [Indexed: 02/06/2023]
Abstract
Melatonin is the major secretory product synthesized and secreted by the pineal gland and shows both a wide distribution within phylogenetically distant organisms from bacteria to humans and a great functional versatility. In recent years, a considerable amount of experimental evidence has accumulated showing a relationship between the nervous, endocrine, and immune systems. The molecular basis of the communication between these systems is the use of a common chemical language. In this framework, currently melatonin is considered one of the members of the neuroendocrine-immunological network. A number of in vivo and in vitro studies have documented that melatonin plays a fundamental role in neuroimmunomodulation. Based on the information published, it is clear that the majority of the present data in the literature relate to lymphocytes; thus, they have been rather thoroughly investigated, and several reviews have been published related to the mechanisms of action and the effects of melatonin on lymphocytes. However, few studies concerning the effects of melatonin on cells belonging to the innate immunity have been reported. Innate immunity provides the early line of defense against microbes and consists of both cellular and biochemical mechanisms. In this review, we have focused on the role of melatonin in the innate immunity. More specifically, we summarize the effects and action mechanisms of melatonin in the different cells that belong to or participate in the innate immunity, such as monocytes-macrophages, dendritic cells, neutrophils, eosinophils, basophils, mast cells, and natural killer cells.
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Affiliation(s)
- Juan R Calvo
- Department Medical Biochemistry, Molecular Biology and Immunology, University of Seville Medical School, Seville, Spain.
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Bushell WC, Theise ND. Toward a Unified Field of Study: Longevity, Regeneration, and Protection of Health through Meditation and Related Practices. Ann N Y Acad Sci 2009; 1172:5-19. [DOI: 10.1111/j.1749-6632.2009.04959.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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McConnell MJ, Hanna PC, Imperiale MJ. Cytokine response and survival of mice immunized with an adenovirus expressing Bacillus anthracis protective antigen domain 4. Infect Immun 2006; 74:1009-15. [PMID: 16428747 PMCID: PMC1360362 DOI: 10.1128/iai.74.2.1009-1015.2006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Revised: 10/29/2005] [Accepted: 11/05/2005] [Indexed: 01/21/2023] Open
Abstract
Adenovirus vectors are promising for use in vaccinating against potential agents of bioterrorism and emerging infections because of their proven safety in humans and their ability to elicit rapid immune responses. Here, we describe the construction and evaluation of an adenovirus vaccine expressing domain 4 of Bacillus anthracis protective antigen, Ad.D4. Ad.D4 elicited antibodies to protective antigen 14 days after a single intramuscular injection, which were further increased upon boosting. Furthermore, two doses of Ad.D4 4 weeks apart were sufficient to protect 67% of mice from toxin challenge. Additionally, we have characterized the release of inflammatory cytokines from vaccinated mice after lethal-toxin challenge. We demonstrate that interleukin 1beta (IL-1beta) levels in mice that survive lethal toxin challenge are similar to levels in nonsurvivors and that IL-6 levels are higher in survivors than in nonsurvivors. These findings suggest that lethal-toxin-mediated death may not be a direct result of inflammatory-cytokine release.
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Affiliation(s)
- Michael J McConnell
- Department of Microbiology and Immunololgy, University of Michigan Medical School, 6304 Cancer Center, 1500 E. Medical Center Dr., Ann Arbor, MI 48109-0942, USA
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Webster JI, Sternberg EM. Anthrax lethal toxin represses glucocorticoid receptor (GR) transactivation by inhibiting GR-DNA binding in vivo. Mol Cell Endocrinol 2005; 241:21-31. [PMID: 15964137 DOI: 10.1016/j.mce.2005.03.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2004] [Revised: 02/23/2005] [Accepted: 03/07/2005] [Indexed: 11/16/2022]
Abstract
Anthrax lethal factor (LF) is a non-competitive repressor of glucocorticoid (GR) and progesterone receptor (PR) transactivation. This repression was shown to be specific and selective and was dependent on promoter context and receptor subtype. Anthrax lethal toxin (LeTx) selectively repressed GR-mediated transactivation but not transrepression. The DNA binding region of GR was required for repression by LeTx and LeTx prevented GR-DNA binding in vivo, which had downstream consequences on polymerase II binding and histone acetylation. In addition, LeTx also prevented the accessory protein C/EBP from binding to a GR-responsive promoter. We hypothesize that LeTx may remove/inactivate one of the many co-factors or accessory proteins that are required to stabilize the GR-DNA complex. These findings enhance the current knowledge of the molecular mechanism by which the anthrax lethal factor represses nuclear hormone receptors and could provide an approach to overcome some of LeTx's effects.
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Affiliation(s)
- Jeanette I Webster
- Section on Neuroendocrine Immunology and Behavior, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892-9401, USA.
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Pawlak J, Singh J, Lea RW, Skwarlo-Sonta K. Effect of melatonin on phagocytic activity and intracellular free calcium concentration in testicular macrophages from normal and streptozotocin-induced diabetic rats. Mol Cell Biochem 2005; 275:207-13. [PMID: 16335800 DOI: 10.1007/s11010-005-1995-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This study examined the effect of melatonin (MLT) on in vitro phagocytosis of testicular macrophages taken from control and streptozotocin (STZ)-induced diabetic rats and the possible mechanism of its action. The phagocytic activity was measured as a number of latex beads ingested by 100 macrophages (PI, phagocytic index) in consecutive time points of the incubation. Changes in intracellular free calcium level [Ca2+]i in isolated macrophages in vitro were measured with the use of ratio-image fluorescence microscopy (fluorescent dye: Fura2/AM). Phagocytic index in macrophages isolated from healthy rats was 20% higher than in those from diabetic animals. Melatonin in physiological concentration (10(-7) M) significantly (p < 0.05) increased the PI in testicular macrophages from control animals (PI = 68 +/- 5 with MLT compared to PI = 46 +/- 7 without MLT) while no such effect was observed in the cells from diabetic rats (PI = 36 +/- 23 with MLT compared to PI = 31 +/- 11 without MLT). Basal [Ca2+]i was significantly (p < 0.01) higher in macrophages from diabetic rats compared to control. Stimulation of both control and diabetic testicular macrophages with 10(-7) M MLT resulted in a significant (p < 0.05) increase in [Ca2+]i in cells incubated in 2.5 mM calcium solution while no such response was observed in calcium-free Tyrode solution. However, MLT evoked [Ca2+]i response in macrophages isolated from diabetic animals was much lower than in macrophages isolated from age-matched controls and the time needed for maximal response was much longer. Lack of response in calcium-free solution suggests that extracellular calcium may be necessary to trigger MLT response and in its progression.
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Affiliation(s)
- Joanna Pawlak
- Department of Vertebrate Physiology, Faculty of Biology, Warsaw University, ul. Miecznikowa 1, 02-096 Warsaw, Poland.
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Wang H, Wei W, Zhang SY, Shen YX, Wang NP, Yue L, Xu SY. Melatonin-selenium nanoparticles protects liver against immunological injury induced by bacillus Calmette-Guerin and lipopolysaccharide. Acta Pharmacol Sin 2005; 26:745-52. [PMID: 15916742 DOI: 10.1111/j.1745-7254.2005.00745.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIM Melatonin-selenium nanoparticle (MT-Se), a novel complex, was synthesized by preparing selenium nanoparticles in a melatonin medium. The present investigation was designed to determine the protective effects of MT-Se against immunological liver injury in mice induced by bacillus Calmette-Guerin (BCG)/lipopolysaccharide (LPS). METHODS The model of immunological liver injury in mice was prepared. The levels of alanine aminotransferase, aspartate amino-transferase, nitric oxide (NO) in serum, malondialdehyde content, superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) activities in a liver homogenate were assayed by spectrophotometry. The content of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) were determined by ELISA. The splenocyte proliferation was assayed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) dye reduction. Meanwhile, a hepatic pathological examination was observed. RESULTS In the BCG/LPS-induced hepatic injury model, MT-Se administered at doses of 5, 10, or 20 mg/kg to the BCG/LPS-treated mice for 10 d significantly reduced the increase in serum aminotransferase, reduced the severe extent of hepatic cell damage and the immigration of inflammatory cells. It also attenuated the increase in the content of thiobarbituric acid-reactive substances and enhanced the decrease in activities of SOD and GSH-px. In contrast, the treatment with MT-Se suppressed the increase in NO level in both the serum and liver tissue. Furthermore, MT-Se significantly lowered an increase in TNF-alpha and IL-1beta levels in the liver and inhibited the production of TNF- alpha and IL-1beta by peritoneal macrophages. A downregulation effect of MT-Se on splenocyte proliferation was also observed. CONCLUSION MT-Se showed a hepatic protective action on immunological liver injury in mice.
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Affiliation(s)
- Hua Wang
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei 230032, China
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Wang H, Wei W, Shen YX, Dong C, Zhang LL, Wang NP, Yue L, Xu SY. Protective effect of melatonin against liver injury in mice induced by Bacillus Calmette-Guerin plus lipopolysaccharide. World J Gastroenterol 2004; 10:2690-6. [PMID: 15309720 PMCID: PMC4572194 DOI: 10.3748/wjg.v10.i18.2690] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: To investigate the effects and mechanisms of melatonin on immunological liver injury in mice.
METHODS: A model of liver injury was induced by tail vein injection of Bacillus Calmette Guerin (BCG) and lipopolysaccharide (LPS) in mice. Kupffer cells and hepatocytes were isolated and cultured according to a modified two-step collagenase perfusion technique. Levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and nitric oxide (NO), content of malondiadehyde (MDA), activity of superoxide dismutase (SOD), were measured by biochemical methods. Tumor necrosis factor-α (TNF-α) activity was determined by RIA. Interleukin (IL)-1 activity was measured by thymocyte proliferation bioassay. Hepatic tissue sections were stained with hematoxylin and eosin and examined under a light microscope.
RESULTS: Immunological liver injury induced by BCG+LPS was successfully duplicated. Serum transaminase (ALT, AST) activities were significantly decreased by melatonin (0.25, 1.0, 4.0 mg/kg bm). Meanwhile, MDA content was decreased and SOD in liver homogenates was upregulated. Furthermore, pro-inflammatory mediators (TNF-α, IL-1, NO) in serum and liver homogenates were significantly reduced by melatonin. Histological examination demonstrated that melatonin could attenuate the area and extent of necrosis, reduce the immigration of inflammatory cells. In in vitro experiment, TNF-α was inhibited at the concentrations of 10-8-10-6 mol/L of melatonin, while IL-1 production of Kupffer cells induced by LPS (5 μg/mL) was decreased only at the concentration of 10-6 mol/L of melatonin, but no effect on NO production was observed. Immunological liver injury model in vitro was established by incubating hepatocytes with BCG- and LPS-induced Kupffer cells. Activities of ALT, TNF-α, IL-1, and MDA in supernatant were significantly increased. Melatonin had little effect on the level of ALT, but reduced the content of TNF-α and MDA at concentrations of 10-7-10-5 mol/L and decreased the content of IL-1 at concentrations of 10-6-10-5 mol/L.
CONCLUSION: Melatonin could significantly protect liver injury in mice, which was related to free radical scavenging, increased SOD activity and pro-inflammatory mediators.
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Affiliation(s)
- Hua Wang
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei 230032, Anhui Province, China
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Webster JI, Moayeri M, Sternberg EM. Novel repression of the glucocorticoid receptor by anthrax lethal toxin. Ann N Y Acad Sci 2004; 1024:9-23. [PMID: 15265771 DOI: 10.1196/annals.1321.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Death from anthrax has been reported to occur from systemic shock. The lethal toxin (LeTx) is the major effector of anthrax mortality. Although the mechanism of entry of this toxin into cells is well understood, its actions once inside the cell are not as well understood. LeTx is known to cleave and inactivate MAPKKs. We have recently shown that LeTx represses the glucocorticoid receptor (GR) both in vitro and in vivo. This repression is partial and specific, repressing the glucocorticoid, progesterone, and estrogen receptor alpha, but not the mineralocorticoid or estrogen receptor beta. This toxin does not affect GR ligand or DNA binding, and we have suggested that it may function by removing/inactivating one or more of the many cofactors involved in nuclear hormone receptor signaling. Although the precise involvement of this nuclear hormone receptor repression in LeTx toxicity is unknown, examples of blunted HPA axis and glucocorticoid signaling in numerous autoimmune/inflammatory diseases suggest that such repression of critically important receptors could have deleterious effects on health.
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Affiliation(s)
- Jeanette I Webster
- Section on Neuroendocrine Immunology and Behavior, National Institute of Mental Health, NIH, Bethesda, MD 20892-4020, USA
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12
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Cui X, Moayeri M, Li Y, Li X, Haley M, Fitz Y, Correa-Araujo R, Banks SM, Leppla SH, Eichacker PQ. Lethality during continuous anthrax lethal toxin infusion is associated with circulatory shock but not inflammatory cytokine or nitric oxide release in rats. Am J Physiol Regul Integr Comp Physiol 2004; 286:R699-709. [PMID: 14715494 DOI: 10.1152/ajpregu.00593.2003] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although circulatory shock related to lethal toxin (LeTx) may play a primary role in lethality due to Bacillus anthracis infection, its mechanisms are unclear. We investigated whether LeTx-induced shock is associated with inflammatory cytokine and nitric oxide (NO) release. Sprague-Dawley rats with central venous and arterial catheters received 24-h infusions of LeTx (lethal factor 100 microg/kg; protective antigen 200 microg/kg) that produced death beginning at 9 h and a 7-day mortality rate of 53%. By 9 h, mean arterial blood pressure, heart rate, pH, and base excess were decreased and lactate and hemoglobin levels were increased in LeTx nonsurvivors compared with LeTx survivors and controls (diluent only) (P < or = 0.05 for each comparing the 3 groups). Despite these changes, arterial oxygen and circulating leukocytes and platelets were not decreased and TNF-alpha, IL-beta, IL-6, and IL-10 levels were not increased comparing either LeTx nonsurvivors or survivors to controls. Nitrate/nitrite levels and tissue histology also did not differ comparing LeTx animals and controls. In additional experiments, although 24-h infusions of LeTx and Escherichia coli LPS produced similar mortality rates (54 and 56%, respectively) and times to death (13.2 +/- 0.8 vs. 11.0 +/- 1.7 h, respectively) compared with controls, only LPS reduced circulating leukocytes, platelets, and IL-2 levels and increased TNF-alpha, IL-1 alpha and -1 beta, IL-6, IL-10, interferon-gamma, granulocyte macrophage-colony stimulating factor, RANTES, migratory inhibitory protein-1 alpha, -2, and -3, and monocyte chemotactic protein-1, as well as nitrate/nitrite levels (all P < or = 0.05 for the effects of LPS). Thus, in contrast to LPS, excessive inflammatory cytokine and NO release does not appear to contribute to the circulatory shock and lethality occurring with LeTx in this at model. Although therapies to modulate these host mediators may be applicable fo shock caused by LPS or other bacterial toxins, they may not with LeTx.
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Affiliation(s)
- Xizhong Cui
- Critical Care Medicine Department, National Institutes of Health, Bldg. 10, Rm. 7D43, Bethesda, MD 20892, USA.
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Prendergast BJ, Hotchkiss AK, Bilbo SD, Kinsey SG, Nelson RJ. Photoperiodic adjustments in immune function protect Siberian hamsters from lethal endotoxemia. J Biol Rhythms 2003; 18:51-62. [PMID: 12568244 DOI: 10.1177/0748730402239676] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Seasonal changes in day length enhance or suppress components of immune function in individuals of several mammalian species. Siberian hamsters (Phodopus sungorus) exhibit multiple changes in neuroendocrine, reproductive, and immune function after exposure to short days. The manner in which these changes are integrated into the host response to pathogens is not well understood. The present experiments tested the hypothesis that short-day changes in immune function alter the pathogenesis of septic shock and survival after challenge with endotoxin. Male and female Siberian hamsters raised in long-day photoperiods were transferred as adults to short days or remained in their natal photoperiod. Six to 8 weeks later, hamsters were injected i.p. with 0, 1, 2.5, 10, 25, or 50 mg/kg bacterial lipopolysaccharide (LPS) (the biologically active constituent of endotoxin), and survival was monitored for 96 h. Short days significantly improved survival of male hamsters treated with 10 or 25 mg/kg LPS and improved survival in females treated with 50 mg/kg LPS. Transfer from long to short days shifted the LD50 in males by approximately 90%, from 5.3 to 9.9 mg/kg, and in females from 11.1 to 15.0 mg/kg (+35%). Long-day females were more resistant than were males to lethal endotoxemia. In vitro production of the proinflammatory cytokine TNFalpha in response to LPS stimulation was significantly lower in macrophages extracted from short-day relative to long-day hamsters, as were circulating concentrations of TNFalpha in vivo after i.p. administration of LPS, suggesting that diminished cytokine responses to LPS in short days may mitigate the lethality of endotoxemia. Adaptation to short days induces changes in immune parameters that affect survival in the face of immune challenges.
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Affiliation(s)
- Brian J Prendergast
- Department of Psychology and Neuroscience, The Ohio State University, Columbus, OH 43210, USA.
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Popov SG, Villasmil R, Bernardi J, Grene E, Cardwell J, Wu A, Alibek D, Bailey C, Alibek K. Lethal toxin of Bacillus anthracis causes apoptosis of macrophages. Biochem Biophys Res Commun 2002; 293:349-55. [PMID: 12054607 DOI: 10.1016/s0006-291x(02)00227-9] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Lethal toxin is a major anthrax virulence factor, causing the rapid death of experimental animals. Lethal toxin can enter most cell types, but only certain macrophages and cell lines are susceptible to toxin-mediated cytolysis. We have shown that in murine RAW 264.7 cells, sublytic amounts of lethal toxin trigger intracellular signaling events typical for apoptosis, including changes in membrane permeability, loss of mitochondrial membrane potential, and DNA fragmentation. The cells were protected from the toxin by specific inhibitors of caspase-1, -2, -3, -4, -6, and -8. Phagocytic activity of macrophages was inhibited by sublytic concentrations of lethal toxin. Infection of cells with anthrax (Sterne) spores impaired their bactericidal capacity, which could be reversed by a lethal toxin inhibitor, bestatin. We suggest that apoptosis rather than direct lysis is biologically relevant to lethal toxin intracellular activity.
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Affiliation(s)
- Serguei G Popov
- Hadron Advanced Biosystems, Inc., 10900 University Boulevard, MSN 1A8, Manassas, VA 20110, USA.
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Tomas-Camardiel M, Sanchez-Hidalgo MC, Sanchez del Pino MJ, Navarro A, Machado A, Cano J. Comparative study of the neuroprotective effect of dehydroepiandrosterone and 17beta-estradiol against 1-methyl-4-phenylpyridium toxicity on rat striatum. Neuroscience 2002; 109:569-84. [PMID: 11823067 DOI: 10.1016/s0306-4522(01)00502-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effects of dehydroepiandrosterone, estradiol and testosterone on 1-methyl-4-phenylpyridium (MPP+)-induced neurotoxicity of the nigrostriatal dopaminergic system were examined in rat. They were subjected to a unilateral intrastriatal infusion of the following treatment conditions: MPP+ alone or co-injection of MPP+ plus each hormone. Four days after injection, concentrations of dopamine and their metabolites were determined from the corpus striatum. To corroborate the neurochemical data an immunohistochemical analysis of tyrosine hydroxylase-immunoreactive fibers and acetylcholinesterase histochemistry in the striatum was performed. Moreover, we performed a dose-response study of the three hormones on the high-affinity dopamine transport system in rat striatal synaptosomes. Rats co-injected within the striatum with MPP+ and either dehydroepiandrosterone or estradiol had significantly greater concentrations of dopamine and less tyrosine hydroxylase-immunoreactive fibers and acetylcholinesterase fiber density loss compared with their respective controls. In addition, 4 days after injection, the brain was fixed and cut into coronal sections, and was immunostained with major histocompatibility complex class II antigens for activated microglia, and glial fibrillary acidic protein for activated astrocytes. Dehydroepiandrosterone also attenuated microglial cell activation. In contrast, testosterone showed reductions in dopamine concentrations similar to those obtained by MPP+. The protective effect of dehydroepiandrosterone against the MPP+ neurotoxic dopaminergic system may be produced by its partial prevention of MPP+ inhibition of NADH oxidase activity, whereas the estradiol may function as a neuroprotectant by reducing the uptake of MPP+ into dopaminergic neurons. Our findings we suggest indicate that dehydroepiandrosterone and estradiol by a non-genomic effect may have an important modulatory action, capable of attenuating degeneration within the striatum, and in this way serve as neuroprotectants of the nigrostriatal dopaminergic system.
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Affiliation(s)
- M Tomas-Camardiel
- Departmento de Bromatologia y Toxicologia, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
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