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Different effects of granulocyte colony-stimulating factor and erythropoietin on erythropoiesis. Stem Cell Res Ther 2018; 9:119. [PMID: 29720275 PMCID: PMC5930863 DOI: 10.1186/s13287-018-0877-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/08/2018] [Accepted: 04/16/2018] [Indexed: 11/24/2022] Open
Abstract
Background Red blood cells are the most abundant cells in the blood that deliver oxygen to the whole body. Erythropoietin (EPO), a positive regulator of erythropoiesis, is currently the major treatment for chronic anemia. Granulocyte colony-stimulating factor (G-CSF) is a multifunctional cytokine and a well-known regulator of hematopoietic stem cell proliferation, differentiation, and mobilization. The use of EPO in combination with G-CSF has been reported to synergistically improve erythroid responses in a group of patients with myelodysplastic syndromes who did not respond to EPO treatment alone; however, the mechanism remains unclear. Methods C57BL/6 J mice injected with G-CSF or EPO were used to compare the erythropoiesis status and the efficiency of erythroid mobilization by flow cytometry. Results In this study, we found that G-CSF induced more orthochromatophilic erythroblast production than did EPO in the bone marrow and spleen. In addition, in contrast to EPO treatments, G-CSF treatments enhanced the efficiency of the mobilization of newly synthesized reticulocytes into peripheral blood. Our results demonstrated that the effects of G-CSF on erythropoiesis and erythrocytic mobilization were independent of EPO secretion and, in contrast to EPO, G-CSF promoted progression of erythropoiesis through transition of early stage R2 (basophilic erythroblasts) to late stage R4 (orthochromatophilic erythroblasts). Conclusions We demonstrate for the first time that G-CSF treatments induce a faster erythropoiesis-enhancing response than that of EPO. These findings suggest an alternative approach to treating acute anemia, especially when patients are experiencing a clinical emergency in remote areas without proper blood bank supplies.
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Pagire SH, Lee E, Pagire HS, Bae EJ, Ryu SJ, Lee D, Kim MH, Kim GR, Hwang KS, Ahn S, Maeng JH, Song JS, Bae MA, Lee DH, Ahn JH. Design, synthesis and biological evaluation of glutamic acid derivatives as anti-oxidant and anti-inflammatory agents. Bioorg Med Chem Lett 2018; 28:529-532. [PMID: 29295794 DOI: 10.1016/j.bmcl.2017.11.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 11/05/2017] [Accepted: 11/06/2017] [Indexed: 12/22/2022]
Abstract
A series of glutamic acid derivatives was synthesized and evaluated for their antioxidant activity and stability. We found several potent and stable glutamic acid derivatives. Among them, compound 12b exhibited good in vitro activity, chemical stability and cytotoxicity. A prototype compound 12b showed an anti-inflammatory effect in LPS-stimulated RAW 264.7 cell lines and in a zebrafish model.
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Affiliation(s)
- Suvarna H Pagire
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Eunhye Lee
- Utah-Inha Drug Delivery Systems (DDS) and Advanced Therapeutics Research Center, Incheon 21988, Republic of Korea
| | - Haushabhau S Pagire
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Eun Jung Bae
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Soo Jung Ryu
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Dahye Lee
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Min Hee Kim
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Geum Ran Kim
- Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 305-600, Republic of Korea
| | - Kyu-Seok Hwang
- Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 305-600, Republic of Korea
| | - Sukyung Ahn
- Utah-Inha Drug Delivery Systems (DDS) and Advanced Therapeutics Research Center, Incheon 21988, Republic of Korea
| | - Jin Hee Maeng
- Utah-Inha Drug Delivery Systems (DDS) and Advanced Therapeutics Research Center, Incheon 21988, Republic of Korea
| | - Jin Sook Song
- Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 305-600, Republic of Korea
| | - Myung Ae Bae
- Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 305-600, Republic of Korea
| | - Don Hang Lee
- Utah-Inha Drug Delivery Systems (DDS) and Advanced Therapeutics Research Center, Incheon 21988, Republic of Korea
| | - Jin Hee Ahn
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea.
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Sun DS, Chang YW, Kau JH, Huang HH, Ho PH, Tzeng YJ, Chang HH. Soluble P-selectin rescues mice from anthrax lethal toxin-induced mortality through PSGL-1 pathway-mediated correction of hemostasis. Virulence 2017; 8:1216-1228. [PMID: 28102766 DOI: 10.1080/21505594.2017.1282027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
As one of the virulence factors of Bacillus anthracis, lethal toxin (LT) induces various pathogenic responses including the suppression of the coagulation system. In this study, we observed that LT markedly increased the circulating soluble P-selectin (sP-sel) levels and microparticle (MP) count in wild-type but not P-selectin (P-sel, Selp-/-) or P-sel ligand-1 (PSGL-1, Selplg-/-) knockout mice. Because sP-sel induces a hypercoagulable state through PSGL-1 pathway to generate tissue factor-positive MPs, we hypothesized that the increase in plasma sP-sel levels can be a self-rescue response in hosts against the LT-mediated suppression of the coagulation system. In agreement with our hypothesis, our results indicated that compared with wild-type mice, Selp-/- and Selplg-/- mice were more sensitive to LT. In addition, the recombinant sP-sel treatment markedly ameliorated LT-mediated pathogenesis and reduced mortality. As a result, elicitation of circulating sP-sel is potentially a self-rescue response, which is beneficial to host recovery from an LT-induced hypocoagulation state. These results suggest that the administration of sP-sel is likely to be useful in the development of a new strategy to treat anthrax.
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Affiliation(s)
- Der-Shan Sun
- a Department of Molecular Biology and Human Genetics , Tzu-Chi University , Hualien , Taiwan.,b Center for Vascular Medicine , Tzu-Chi University , Hualien , Taiwan
| | - Yao-Wen Chang
- a Department of Molecular Biology and Human Genetics , Tzu-Chi University , Hualien , Taiwan
| | - Jyh-Hwa Kau
- c Institute of Microbiology and Immunology, National Defense Medical Center , Taipei , Taiwan.,d Institute of Preventive Medicine, National Defense Medical Center , Taipei , Taiwan
| | - Hsin-Hsien Huang
- d Institute of Preventive Medicine, National Defense Medical Center , Taipei , Taiwan
| | - Pei-Hsun Ho
- a Department of Molecular Biology and Human Genetics , Tzu-Chi University , Hualien , Taiwan
| | - Yin-Jeh Tzeng
- a Department of Molecular Biology and Human Genetics , Tzu-Chi University , Hualien , Taiwan
| | - Hsin-Hou Chang
- a Department of Molecular Biology and Human Genetics , Tzu-Chi University , Hualien , Taiwan.,b Center for Vascular Medicine , Tzu-Chi University , Hualien , Taiwan
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Antibacterial Properties of Visible-Light-Responsive Carbon-Containing Titanium Dioxide Photocatalytic Nanoparticles against Anthrax. NANOMATERIALS 2016; 6:nano6120237. [PMID: 28335365 PMCID: PMC5302719 DOI: 10.3390/nano6120237] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/28/2016] [Accepted: 12/06/2016] [Indexed: 01/12/2023]
Abstract
The bactericidal activity of conventional titanium dioxide (TiO2) photocatalyst is effective only on irradiation by ultraviolet light, which restricts the applications of TiO2 for use in living environments. Recently, carbon-containing TiO2 nanoparticles [TiO2(C) NP] were found to be a visible-light-responsive photocatalyst (VLRP), which displayed significantly enhanced antibacterial properties under visible light illumination. However, whether TiO2(C) NPs exert antibacterial properties against Bacillus anthracis remains elusive. Here, we evaluated these VLRP NPs in the reduction of anthrax-induced pathogenesis. Bacteria-killing experiments indicated that a significantly higher proportion (40%–60%) of all tested Bacillus species, including B. subtilis, B. cereus, B. thuringiensis, and B. anthracis, were considerably eliminated by TiO2(C) NPs. Toxin inactivation analysis further suggested that the TiO2(C) NPs efficiently detoxify approximately 90% of tested anthrax lethal toxin, a major virulence factor of anthrax. Notably, macrophage clearance experiments further suggested that, even under suboptimal conditions without considerable bacterial killing, the TiO2(C) NP-mediated photocatalysis still exhibited antibacterial properties through the reduction of bacterial resistance against macrophage killing. Our results collectively suggested that TiO2(C) NP is a conceptually feasible anti-anthrax material, and the relevant technologies described herein may be useful in the development of new strategies against anthrax.
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Chang HH, Chiang YW, Lin TK, Lin GL, Lin YY, Kau JH, Huang HH, Hsu HL, Wang JH, Sun DS. Erythrocytic mobilization enhanced by the granulocyte colony-stimulating factor is associated with reduced anthrax-lethal-toxin-induced mortality in mice. PLoS One 2014; 9:e111149. [PMID: 25384016 PMCID: PMC4226491 DOI: 10.1371/journal.pone.0111149] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 09/26/2014] [Indexed: 12/27/2022] Open
Abstract
Anthrax lethal toxin (LT), one of the primary virulence factors of Bacillus anthracis, causes anthrax-like symptoms and death in animals. Experiments have indicated that levels of erythrocytopenia and hypoxic stress are associated with disease severity after administering LT. In this study, the granulocyte colony-stimulating factor (G-CSF) was used as a therapeutic agent to ameliorate anthrax-LT- and spore-induced mortality in C57BL/6J mice. We demonstrated that G-CSF promoted the mobilization of mature erythrocytes to peripheral blood, resulting in a significantly faster recovery from erythrocytopenia. In addition, combined treatment using G-CSF and erythropoietin tended to ameliorate B. anthracis-spore-elicited mortality in mice. Although specific treatments against LT-mediated pathogenesis remain elusive, these results may be useful in developing feasible strategies to treat anthrax.
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Affiliation(s)
- Hsin-Hou Chang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Ya-Wen Chiang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Ting-Kai Lin
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Guan-Ling Lin
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - You-Yen Lin
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Jyh-Hwa Kau
- Department of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan
| | - Hsin-Hsien Huang
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Hui-Ling Hsu
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Jen-Hung Wang
- Department of Medical Research, Tzu Chi General Hospital, Hualien, Taiwan
| | - Der-Shan Sun
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
- * E-mail:
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Chang HH, Wang TP, Chen PK, Lin YY, Liao CH, Lin TK, Chiang YW, Lin WB, Chiang CY, Kau JH, Huang HH, Hsu HL, Liao CY, Sun DS. Erythropoiesis suppression is associated with anthrax lethal toxin-mediated pathogenic progression. PLoS One 2013; 8:e71718. [PMID: 23977125 PMCID: PMC3747219 DOI: 10.1371/journal.pone.0071718] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 07/01/2013] [Indexed: 01/01/2023] Open
Abstract
Anthrax is a disease caused by the bacterium Bacillus anthracis, which results in high mortality in animals and humans. Although some of the mechanisms are already known such as asphyxia, extensive knowledge of molecular pathogenesis of this disease is deficient and remains to be further investigated. Lethal toxin (LT) is a major virulence factor of B. anthracis and a specific inhibitor/protease of mitogen-activated protein kinase kinases (MAPKKs). Anthrax LT causes lethality and induces certain anthrax-like symptoms, such as anemia and hypoxia, in experimental mice. Mitogen-activated protein kinases (MAPKs) are the downstream pathways of MAPKKs, and are important for erythropoiesis. This prompted us to hypothesize that anemia and hypoxia may in part be exacerbated by erythropoietic dysfunction. As revealed by colony-forming cell assays in this study, LT challenges significantly reduced mouse erythroid progenitor cells. In addition, in a proteolytic activity-dependent manner, LT suppressed cell survival and differentiation of cord blood CD34+-derived erythroblasts in vitro. Suppression of cell numbers and the percentage of erythroblasts in the bone marrow were detected in LT-challenged C57BL/6J mice. In contrast, erythropoiesis was provoked through treatments of erythropoietin, significantly ameliorating the anemia and reducing the mortality of LT-treated mice. These data suggested that suppressed erythropoiesis is part of the pathophysiology of LT-mediated intoxication. Because specific treatments to overcome LT-mediated pathogenesis are still lacking, these efforts may help the development of effective treatments against anthrax.
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Affiliation(s)
- Hsin-Hou Chang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Tsung-Pao Wang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Po-Kong Chen
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Yo-Yin Lin
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Chih-Hsien Liao
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Ting-Kai Lin
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Ya-Wen Chiang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Wen-Bin Lin
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Chih-Yu Chiang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Jyh-Hwa Kau
- Department of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan
| | - Hsin-Hsien Huang
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Hui-Ling Hsu
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Chi-Yuan Liao
- Department of Obstetrics and Gynecology, Mennonite Christian HospitalHualien, Taiwan
| | - Der-Shan Sun
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
- * E-mail:
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Kau JH, Shih YL, Lien TS, Lee CC, Huang HH, Lin HC, Sun DS, Chang HH. Activated protein C ameliorates Bacillus anthracis lethal toxin-induced lethal pathogenesis in rats. J Biomed Sci 2012; 19:98. [PMID: 23170801 PMCID: PMC3536616 DOI: 10.1186/1423-0127-19-98] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 10/18/2012] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Lethal toxin (LT) is a major virulence factor of Bacillus anthracis. Sprague Dawley rats manifest pronounced lung edema and shock after LT treatments, resulting in high mortality. The heart failure that is induced by LT has been suggested to be a principal mechanism of lung edema and mortality in rodents. Since LT-induced death occurs more rapidly in rats than in mice, suggesting that other mechanisms in addition to the heart dysfunction may be contributed to the fast progression of LT-induced pathogenesis in rats. Coagulopathy may contribute to circulatory failure and lung injury. However, the effect of LT on coagulation-induced lung dysfunction is unclear. METHODS To investigate the involvement of coagulopathy in LT-mediated pathogenesis, the mortality, lung histology and coagulant levels of LT-treated rats were examined. The effects of activated protein C (aPC) on LT-mediated pathogenesis were also evaluated. RESULTS Fibrin depositions were detected in the lungs of LT-treated rats, indicating that coagulation was activated. Increased levels of plasma D-dimer and thrombomodulin, and the ameliorative effect of aPC further suggested that the activation of coagulation-fibrinolysis pathways plays a role in LT-mediated pathogenesis in rats. Reduced mortality was associated with decreased plasma levels of D-dimer and thrombomodulin following aPC treatments in rats with LT-mediated pathogenesis. CONCLUSIONS These findings suggest that the activation of coagulation in lung tissue contributes to mortality in LT-mediated pathogenesis in rats. In addition, anticoagulant aPC may help to develop a feasible therapeutic strategy.
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Affiliation(s)
- Jyh-Hwa Kau
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan, ROC
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8
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Ren L, Perera C, Hemar Y. Antitumor activity of mushroom polysaccharides: a review. Food Funct 2012; 3:1118-30. [DOI: 10.1039/c2fo10279j] [Citation(s) in RCA: 300] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Yoon I, Park HS, Cui BC, Li JZ, Kim JH, Lkhagvadulam B, Shim YK. Photodynamic and Antioxidant Activities of Divalent Transition Metal Complexes of Methyl Pheophorbide-a. B KOREAN CHEM SOC 2011. [DOI: 10.5012/bkcs.2011.32.8.2981] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Kau JH, Sun DS, Huang HS, Lien TS, Huang HH, Lin HC, Chang HH. Sublethal doses of anthrax lethal toxin on the suppression of macrophage phagocytosis. PLoS One 2010; 5:e14289. [PMID: 21170330 PMCID: PMC3000823 DOI: 10.1371/journal.pone.0014289] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 11/18/2010] [Indexed: 11/19/2022] Open
Abstract
Background Lethal toxin (LT), the major virulence factor produced by Bacillus anthracis, has been shown to suppress the immune system, which is beneficial to the establishment of B. anthracis infections. It has been suggested that the suppression of MEK/MAPK signaling pathways of leukocytes contributes to LT-mediated immunosuppressive effects. However, the involvement of MAPK independent pathways has not been clearly elucidated; nor has the crucial role played by LT in the early stages of infection. Determining whether LT exerts any pathological effects before being enriched to an MEK inhibitory level is an important next step in the furtherance of this field. Methodology/Principal Findings Using a cell culture model, we determined that low doses of LT inhibited phagocytosis of macrophages, without influencing MAPK pathways. Consistent low doses of LT significantly suppressed bacterial clearance and enhanced the mortality of mice with bacteremia, without suppressing the MEK1 of splenic and peripheral blood mononuclear cells. Conclusion/Significance These results suggest that LT suppresses the phagocytes in a dose range lower than that required to suppress MEK1 in the early stages of infection.
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Affiliation(s)
- Jyh-Hwa Kau
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Der-Shan Sun
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan, Republic of China
| | - Hsuan-Shun Huang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan, Republic of China
| | - Te-Sheng Lien
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan, Republic of China
| | - Hsin-Hsien Huang
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Hung-Chi Lin
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Hsin-Hou Chang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan, Republic of China
- * E-mail:
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Moayeri M, Leppla SH. Cellular and systemic effects of anthrax lethal toxin and edema toxin. Mol Aspects Med 2009; 30:439-55. [PMID: 19638283 DOI: 10.1016/j.mam.2009.07.003] [Citation(s) in RCA: 175] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 07/21/2009] [Indexed: 12/21/2022]
Abstract
Anthrax lethal toxin (LT) and edema toxin (ET) are the major virulence factors of anthrax and can replicate the lethality and symptoms associated with the disease. This review provides an overview of our current understanding of anthrax toxin effects in animal models and the cytotoxicity (necrosis and apoptosis) induced by LT in different cells. A brief reexamination of early historic findings on toxin in vivo effects in the context of our current knowledge is also presented.
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Affiliation(s)
- Mahtab Moayeri
- Bacterial Toxins and Therapeutics Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Building 33, Room 1W20B, Bethesda, MD 20892, USA.
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12
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Kau JH, Sun DS, Huang HH, Wong MS, Lin HC, Chang HH. Role of visible light-activated photocatalyst on the reduction of anthrax spore-induced mortality in mice. PLoS One 2009; 4:e4167. [PMID: 19132100 PMCID: PMC2613519 DOI: 10.1371/journal.pone.0004167] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Accepted: 12/07/2008] [Indexed: 11/28/2022] Open
Abstract
Background Photocatalysis of titanium dioxide (TiO2) substrates is primarily induced by ultraviolet light irradiation. Anion-doped TiO2 substrates were shown to exhibit photocatalytic activities under visible-light illumination, relative environmentally-friendly materials. Their anti-spore activity against Bacillus anthracis, however, remains to be investigated. We evaluated these visible-light activated photocatalysts on the reduction of anthrax spore-induced pathogenesis. Methodology/Principal Findings Standard plating method was used to determine the inactivation of anthrax spore by visible light-induced photocatalysis. Mouse models were further employed to investigate the suppressive effects of the photocatalysis on anthrax toxin- and spore-mediated mortality. We found that anti-spore activities of visible light illuminated nitrogen- or carbon-doped titania thin films significantly reduced viability of anthrax spores. Even though the spore-killing efficiency is only approximately 25%, our data indicate that spores from photocatalyzed groups but not untreated groups have a less survival rate after macrophage clearance. In addition, the photocatalysis could directly inactivate lethal toxin, the major virulence factor of B. anthracis. In agreement with these results, we found that the photocatalyzed spores have tenfold less potency to induce mortality in mice. These data suggest that the photocatalysis might injury the spores through inactivating spore components. Conclusion/Significance Photocatalysis induced injuries of the spores might be more important than direct killing of spores to reduce pathogenicity in the host.
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Affiliation(s)
- Jyh-Hwa Kau
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Der-Shan Sun
- Institute of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Science, Tzu-Chi University, Hualien, Taiwan
| | - Hsin-Hsien Huang
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Ming-Show Wong
- Department of Materials Science and Engineering, National Dong-Hwa University, Hualien, Taiwan, Republic of China
| | - Hung-Chi Lin
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Hsin-Hou Chang
- Institute of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Science, Tzu-Chi University, Hualien, Taiwan
- * E-mail:
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13
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Inactivation of rho GTPases by statins attenuates anthrax lethal toxin activity. Infect Immun 2008; 77:348-59. [PMID: 18936176 DOI: 10.1128/iai.01005-08] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Anthrax lethal factor (LF), secreted by Bacillus anthracis, interacts with protective antigen to form a bipartite toxin (lethal toxin [LT]) that exerts pleiotropic biological effects resulting in subversion of the innate immune response. Although the mitogen-activated protein kinase kinases (MKKs) are the major intracellular protein targets of LF, the pathology induced by LT is not well understood. The statin family of HMG-coenzyme A reductase inhibitors have potent anti-inflammatory effects independent of their cholesterol-lowering properties, which have been attributed to modulation of Rho family GTPase activity. The Rho GTPases regulate vesicular trafficking, cytoskeletal dynamics, and cell survival and proliferation. We hypothesized that disruption of Rho GTPase function by statins might alter LT action. We show here that statins delay LT-induced death and MKK cleavage in RAW macrophages and that statin-mediated effects on LT action are attributable to disruption of Rho GTPases. The Rho GTPase-inactivating toxin, toxin B, did not significantly affect LT binding or internalization, suggesting that the Rho GTPases regulate trafficking and/or localization of LT once internalized. The use of drugs capable of inhibiting Rho GTPase activity, such as statins, may provide a means to attenuate intoxication during B. anthracis infection.
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14
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Ngamwongsatit P, Banada PP, Panbangred W, Bhunia AK. WST-1-based cell cytotoxicity assay as a substitute for MTT-based assay for rapid detection of toxigenic Bacillus species using CHO cell line. J Microbiol Methods 2008; 73:211-5. [DOI: 10.1016/j.mimet.2008.03.002] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 03/04/2008] [Accepted: 03/05/2008] [Indexed: 11/25/2022]
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Abstract
Infectious microbes face an unwelcoming environment in their mammalian hosts, which have evolved elaborate multicelluar systems for recognition and elimination of invading pathogens. A common strategy used by pathogenic bacteria to establish infection is to secrete protein factors that block intracellular signalling pathways essential for host defence. Some of these proteins also act as toxins, directly causing pathology associated with disease. Bacillus anthracis, the bacterium that causes anthrax, secretes two plasmid-encoded enzymes, LF (lethal factor) and EF (oedema factor), that are delivered into host cells by a third bacterial protein, PA (protective antigen). The two toxins act on a variety of cell types, disabling the immune system and inevitably killing the host. LF is an extraordinarily selective metalloproteinase that site-specifically cleaves MKKs (mitogen-activated protein kinase kinases). Cleavage of MKKs by LF prevents them from activating their downstream MAPK (mitogen-activated protein kinase) substrates by disrupting a critical docking interaction. Blockade of MAPK signalling functionally impairs cells of both the innate and adaptive immune systems and induces cell death in macrophages. EF is an adenylate cyclase that is activated by calmodulin through a non-canonical mechanism. EF causes sustained and potent activation of host cAMP-dependent signalling pathways, which disables phagocytes. Here I review recent progress in elucidating the mechanisms by which LF and EF influence host signalling and thereby contribute to disease.
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Affiliation(s)
- Benjamin E Turk
- Department of Pharmacology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
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Panchal RG, Ruthel G, Brittingham KC, Lane D, Kenny TA, Gussio R, Lazo JS, Bavari S. Chemical Genetic Screening Identifies Critical Pathways in Anthrax Lethal Toxin-Induced Pathogenesis. ACTA ACUST UNITED AC 2007; 14:245-55. [PMID: 17379140 DOI: 10.1016/j.chembiol.2007.01.007] [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] [Received: 10/24/2006] [Revised: 12/28/2006] [Accepted: 01/09/2007] [Indexed: 11/23/2022]
Abstract
Anthrax lethal toxin (LT)-induced cell death via mitogen-activated protein kinase kinase (MAPKK) cleavage remains questionable. Here, a chemical genetics approach was used to investigate what pathways mediate LT-induced cell death. Several small molecules were found to protect macrophages from anthrax LT cytotoxicity and MAPKK from cleavage by lethal factor (LF), without inhibiting LF enzymatic activity or cellular proteasome activity. Interestingly, the compounds activated MAPK-signaling molecules, induced proinflammatory cytokine production, and inhibited LT-induced macrophage apoptosis in a concentration-dependent manner. We propose that induction of antiapoptotic responses by MAPK-dependent or -independent pathways and activation of host innate responses may protect macrophages from anthrax LT-induced cell death. Altering host responses through a chemical genetics approach can help identify critical cellular pathways involved in the pathogenesis of anthrax and can be exploited to further explore host-pathogen interactions.
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Affiliation(s)
- Rekha G Panchal
- Target Structure-Based Drug Discovery Group, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA.
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Ulett GC, Adderson EE. Regulation of Apoptosis by Gram-Positive Bacteria: Mechanistic Diversity and Consequences for Immunity. ACTA ACUST UNITED AC 2006; 2:119-141. [PMID: 19081777 DOI: 10.2174/157339506776843033] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Apoptosis, or programmed cell death (PCD), is an important physiological mechanism, through which the human immune system regulates homeostasis and responds to diverse forms of cellular damage. PCD may also be involved in immune counteraction to microbial infection. Over the past decade, the amount of research on bacteria-induced PCD has grown tremendously, and the implications of this mechanism on immunity are being elucidated. Some pathogenic bacteria actively trigger the suicide response in critical lineages of leukocytes that orchestrate both the innate and adaptive immune responses; other bacteria proactively prevent PCD to benefit their own survival and persistence. Currently, the microbial virulence factors, which represent the keys to unlocking the suicide response in host cells, are a primary focus of this field. In this review, we discuss these bacterial "apoptosis regulatory molecules" and the apoptotic events they either trigger or prevent, the host target cells of this regulatory activity, and the possible ramifications for immunity to infection. Gram-positive pathogens including Staphylococcus, Streptococcus, Bacillus, Listeria, and Clostridia species are discussed as important agents of human infection that modulate PCD pathways in eukaryotic cells.
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Affiliation(s)
- Glen C Ulett
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105-2794, USA
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Abstract
Bacillus anthracis, the etiological agent of anthrax, secretes three polypeptides that assemble into toxic complexes on the cell surfaces of the host it infects. One of these polypeptides, protective antigen (PA), binds to the integrin-like domains of ubiquitously expressed membrane proteins of mammalian cells. PA is then cleaved by membrane endoproteases of the furin family. Cleaved PA molecules assemble into heptamers, which can then associate with the two other secreted polypeptides: edema factor (EF) and/or lethal factor (LF). The heptamers of PA are relocalized to lipid rafts where they are quickly endocytosed and routed to an acidic compartment. The low pH triggers a conformational change in the heptamers, resulting in the formation of cation-specific channels and the translocation of EF/LF. EF is a calcium- and calmodulin-dependent adenylate cyclase that dramatically raises the intracellular concentration of cyclic adenosine monophosphate (cAMP). LF is a zinc-dependent endoprotease that cleaves the amino terminus of mitogen-activated protein kinase kinases (Meks). Cleaved Meks cannot bind to their substrates and have reduced kinase activity, resulting in alterations of the signaling pathways they govern. The structures of PA, PA heptamer, EF, and LF have been solved and much is now known about the molecular details of the intoxication mechanism. The in vivo action of the toxins, on the other hand, is still poorly understood and hotly debated. A better understanding of the toxins will help in the design of much-needed anti-toxin drugs and the development of new toxin-based medical applications.
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Affiliation(s)
- M Mourez
- Faculté de Médecine Vétérinaire, Département de Pathologie et Microbiologie, Université de Montréal, J2S 7C6, Saint Hyacinthe, QC, Canada.
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Affiliation(s)
- Ana M Sánchez
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Charles E. Young Drive East, Los Angeles, CA 80094, USA
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Webster JI, Tonelli LH, Moayeri M, Simons SS, Leppla SH, Sternberg EM. Anthrax lethal factor represses glucocorticoid and progesterone receptor activity. Proc Natl Acad Sci U S A 2003; 100:5706-11. [PMID: 12724519 PMCID: PMC156265 DOI: 10.1073/pnas.1036973100] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We report here that a bacterial toxin, anthrax lethal toxin (LeTx), at very low concentrations represses glucocorticoid receptor (GR) transactivation in a transient transfection system and the activity of an endogenous GR-regulated gene in both a cellular system and an animal model. This repression is noncompetitive and does not affect ligand binding or DNA binding, suggesting that anthrax lethal toxin (LeTx) probably exerts its effects through a cofactor(s) involved in the interaction between GR and the basal transcription machinery. LeTx-nuclear receptor repression is selective, repressing GR, progesterone receptor B (PR-B), and estrogen receptor alpha (ERalpha), but not the mineralocorticoid receptor (MR) or ERbeta. GR repression was also caused by selected p38 mitogen-activated protein (MAP) kinase inhibitors, suggesting that the LeTx action may result in part from its known inactivation of MAP kinases. Simultaneous loss of GR and other nuclear receptor activities could render an animal more susceptible to lethal or toxic effects of anthrax infection by removing the normally protective antiinflammatory effects of these hormones, similar to the increased mortality seen in animals exposed to both GR antagonists and infectious agents or bacterial products. These finding have implications for development of new treatments and prevention of the toxic effects of anthrax.
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Affiliation(s)
- Jeanette I Webster
- Section on Neuroendocrine Immunology and Behavior, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
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Kim SO, Jing Q, Hoebe K, Beutler B, Duesbery NS, Han J. Sensitizing anthrax lethal toxin-resistant macrophages to lethal toxin-induced killing by tumor necrosis factor-alpha. J Biol Chem 2003; 278:7413-21. [PMID: 12488448 DOI: 10.1074/jbc.m209279200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Macrophages from different inbred mouse strains exhibit striking differences in their sensitivity to anthrax lethal toxin (LeTx)-induced cytolysis. Although LeTx-induced cytolysis of macrophages plays an important role in the outcome of anthrax infection, the sensitivity of macrophages in vitro does not correlate with in vivo susceptibility to infection of Bacillus anthracis. This divergence suggests that additional factors other than LeTx are involved in the cytolysis of LeTx-resistant macrophages in vivo. We found that LeTx-resistant macrophages became sensitive to LeTx-induced cytolysis when these cells were activated by bacterial components. Tumor necrosis factor-alpha induced by bacterial components was a key factor that cooperated with LeTx in inducing LeTx-resistant macrophage death. Tumor necrosis factor-alpha/LeTx-induced death of LeTx-resistant macrophages was dependent on mTor (mammalian target of rapamycin), but independent of caspases. Our data indicate that host responses to anthrax infection contribute to cytolysis of LeTx- resistant macrophages.
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Affiliation(s)
- Sung O Kim
- Department of Immunology, Scripps Research Institute, La Jolla, California 92037, USA
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