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Shamakhi A, Kordbacheh E. Immunoinformatic design of an epitope-based immunogen candidate against Bacillus anthracis. INFORMATICS IN MEDICINE UNLOCKED 2021. [DOI: 10.1016/j.imu.2021.100574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Xiong S, Zhou T, Zheng F, Liang X, Cao Y, Wang C, Feng Z, Tang Q, Zhu J. Different mechanisms of two anti-anthrax protective antigen antibodies and function comparison between them. BMC Infect Dis 2019; 19:940. [PMID: 31699037 PMCID: PMC6836657 DOI: 10.1186/s12879-019-4508-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 09/24/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bacillus anthracis causes a highly lethal infectious disease primarily due to toxin-mediated injury. Antibiotics are no longer effective to treat the accumulation of anthrax toxin, thereby new strategies of antibody treatment are essential. Two anti- anthrax protective antigen (PA) antibodies, hmPA6 and PA21, have been reported by our lab previously. METHODS The mechanisms of the two antibodies were elucidated by Electrophoresis, Competitive Enzyme-linked immune sorbent assay, Western blot analysis and immunoprecipitation test, and in vitro, in vivo (F344 rats) treatment test. The epitopes of the two antibodies were proved by Western blot and Enzyme-linked immune sorbent assay with different domains of PA. RESULTS In this study, we compared affinity and neutralization of these two antibodies. PA21 was better in protecting cells and rats, whereas hmPA6 had higher affinity. Furthermore, the neutralization mechanisms of the two antibodies and their recognition domains of PA were studied. The results showed that hmPA6 recognized domain IV, thus PA could not bind to cell receptors. Conversely, PA21 recognized domain II, thereby limiting heptamer oligomerization of PA63 in cells. CONCLUSIONS Our studies elucidated the mechanisms and epitopes of hmPA6 and PA21. The present investigation can advance future use of the two antibodies in anthrax treatment or prophylaxis, and potentially as a combination treatment as the antibodies target different epitopes.
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Affiliation(s)
- Siping Xiong
- Epidemiological Department, Huadong Medical Institute of Biotechniques, Nanjing, 210002, China.,Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing, 210029, China.,Department of Pathology, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, Guangdong, China
| | - Tingting Zhou
- Epidemiological Department, Huadong Medical Institute of Biotechniques, Nanjing, 210002, China
| | - Feng Zheng
- Epidemiological Department, Huadong Medical Institute of Biotechniques, Nanjing, 210002, China
| | - Xudong Liang
- National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Yongping Cao
- Epidemiological Department, Huadong Medical Institute of Biotechniques, Nanjing, 210002, China
| | - Chunhui Wang
- Epidemiological Department, Huadong Medical Institute of Biotechniques, Nanjing, 210002, China
| | - Zhengqin Feng
- Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing, 210029, China
| | - Qi Tang
- Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing, 210029, China.
| | - Jin Zhu
- Epidemiological Department, Huadong Medical Institute of Biotechniques, Nanjing, 210002, China. .,Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing, 210029, China.
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Goldberg AB, Cho E, Miller CJ, Lou HJ, Turk BE. Identification of a Substrate-selective Exosite within the Metalloproteinase Anthrax Lethal Factor. J Biol Chem 2016; 292:814-825. [PMID: 27909054 DOI: 10.1074/jbc.m116.761734] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 11/23/2016] [Indexed: 01/02/2023] Open
Abstract
The metalloproteinase anthrax lethal factor (LF) is secreted by Bacillus anthracis to promote disease virulence through disruption of host signaling pathways. LF is a highly specific protease, exclusively cleaving mitogen-activated protein kinase kinases (MKKs) and rodent NLRP1B (NACHT leucine-rich repeat and pyrin domain-containing protein 1B). How LF achieves such restricted substrate specificity is not understood. Previous studies have suggested the existence of an exosite interaction between LF and MKKs that promotes cleavage efficiency and specificity. Through a combination of in silico prediction and site-directed mutagenesis, we have mapped an exosite to a non-catalytic region of LF. Mutations within this site selectively impair proteolysis of full-length MKKs yet have no impact on cleavage of short peptide substrates. Although this region appears important for cleaving all LF protein substrates, we found that mutation of specific residues within the exosite differentially affects MKK and NLRP1B cleavage in vitro and in cultured cells. One residue in particular, Trp-271, is essential for cleavage of MKK3, MKK4, and MKK6 but dispensable for targeting of MEK1, MEK2, and NLRP1B. Analysis of chimeric substrates suggests that this residue interacts with the MKK catalytic domain. We found that LF-W271A blocked ERK phosphorylation and growth in a melanoma cell line, suggesting that it may provide a highly selective inhibitor of MEK1/2 for use as a cancer therapeutic. These findings provide insight into how a bacterial toxin functions to specifically impair host signaling pathways and suggest a general strategy for mapping protease exosite interactions.
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Affiliation(s)
- Allison B Goldberg
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Eunice Cho
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Chad J Miller
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Hua Jane Lou
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Benjamin E Turk
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
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Kim MK, Choi HS, Cho SG, Shin YC, Ko SG. Rubus coreanus Miquel extract causes apoptosis of doxorubicin-resistant NCI/ADR-RES ovarian cancer cells via JNK phosphorylation. Mol Med Rep 2016; 13:4065-72. [PMID: 26986492 DOI: 10.3892/mmr.2016.4996] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 01/25/2016] [Indexed: 11/06/2022] Open
Abstract
Cancer cells can acquire an anticancer, drug-resistant phenotype following chemotherapy, which is tightly linked to cancer malignancy and patient survival rates. Therefore, the identification of options to treat chemotherapy‑resistant cancer cells is an urgent requirement. Rubus coreanus Miquel (RCM) has long been used as a source of food. In addition, it has been reported that RCM has effective functions against particular diseases, including cancer and inflammation. In the present study, it was demonstrated that RCM extract caused the apoptotic cell death of doxorubicin‑resistant NCI/ADR‑RES ovarian cancer cells by phosphorylating c‑Jun N‑terminal kinase (JNK). The RCM‑mediated reduction of cell viability showed no synergism with doxorubicin. In addition, ellagic acid and quercetin, which are phytochemicals found in RCM, also caused apoptosis of the NCI/ADR‑RES cells. In subsequent investigations of the RCM‑altered signaling pathway, RCM extract, ellagic acid and quercetin were found to commonly induce the phosphorylation of JNK and AKT. Additionally, the inhibition of JNK with SP600125 repressed the apoptotic cell death induced by RCM extract, ellagic acid and quercetin, and the inhibition of JNK appeared to switch apoptosis to necrosis. JNK inhibition also reduced the phosphorylation of AKT, which was induced by RCM extract, ellagic acid and quercetin, suggesting that the phosphorylation of JNK is required for AKT phosphorylation in RCM‑, ellagic acid‑ or quercetin‑induced apoptotic cell death. Therefore, the data obtained in the present study led to the conclusion that RCM caused apoptosis of doxorubicin‑resistant NCI/ADR-RES ovarian cancer cells via JNK phosphorylation, and suggested that RCM may be effective in the treatment of chemotherapy‑resistant cancer cells.
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Affiliation(s)
- Min Kyoung Kim
- Department of Preventive Medicine, College of Korean Medicine, Kyung Hee University, Seoul 130‑701, Republic of Korea
| | - Hyeong Sim Choi
- Department of Preventive Medicine, College of Korean Medicine, Kyung Hee University, Seoul 130‑701, Republic of Korea
| | - Sung-Gook Cho
- Department of Biotechnology, Korea National University of Transportation, Jeungpyeong‑gun, Chungbuk 368‑701, Republic of Korea
| | - Yong Cheol Shin
- Department of Preventive Medicine, College of Korean Medicine, Kyung Hee University, Seoul 130‑701, Republic of Korea
| | - Seong-Gyu Ko
- Department of Preventive Medicine, College of Korean Medicine, Kyung Hee University, Seoul 130‑701, Republic of Korea
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Does Bacillus anthracis Lethal Toxin Directly Depress Myocardial Function? A Review of Clinical Cases and Preclinical Studies. Toxins (Basel) 2015; 7:5417-34. [PMID: 26703730 PMCID: PMC4690141 DOI: 10.3390/toxins7124891] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 11/24/2015] [Accepted: 12/07/2015] [Indexed: 12/17/2022] Open
Abstract
The US outbreak of B.anthracis infection in 2001 and subsequent cases in the US and Europe demonstrate that anthrax is a continuing risk for the developed world. While several bacterial components contribute to the pathogenesis of B. anthracis, production of lethal toxin (LT) is strongly associated with the development of hypotension and lethality. However, the mechanisms underlying the cardiovascular instability LT produces are unclear. Some evidence suggests that LT causes shock by impairing the peripheral vasculature, effects consistent with the substantial extravasation of fluid in patients dying with B. anthracis. Other data suggests that LT directly depresses myocardial function. However a clinical correlate for this latter possibility is less evident since functional studies and post-mortem examination in patients demonstrate absent or minimal cardiac changes. The purposes of this review were to first present clinical studies of cardiac functional and histologic pathology with B. anthracis infection and to then examine in vivo, in vitro, and ex vivo preclinical studies of LT’s myocardial effects. Together, these data suggest that it is unclear whether that LT directly depresses cardiac function. This question is important for the clinical management and development of new therapies for anthrax and efforts should continue to be made to answer it.
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Kirchhefer U, Brekle C, Eskandar J, Isensee G, Kučerová D, Müller FU, Pinet F, Schulte JS, Seidl MD, Boknik P. Cardiac function is regulated by B56α-mediated targeting of protein phosphatase 2A (PP2A) to contractile relevant substrates. J Biol Chem 2014; 289:33862-73. [PMID: 25320082 DOI: 10.1074/jbc.m114.598938] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dephosphorylation of important myocardial proteins is regulated by protein phosphatase 2A (PP2A), representing a heterotrimer that is comprised of catalytic, scaffolding, and regulatory (B) subunits. There is a multitude of B subunit family members directing the PP2A holoenzyme to different myocellular compartments. To gain a better understanding of how these B subunits contribute to the regulation of cardiac performance, we generated transgenic (TG) mice with cardiomyocyte-directed overexpression of B56α, a phosphoprotein of the PP2A-B56 family. The 2-fold overexpression of B56α was associated with an enhanced PP2A activity that was localized mainly in the cytoplasm and myofilament fraction. Contractility was enhanced both at the whole heart level and in isolated cardiomyocytes of TG compared with WT mice. However, peak amplitude of [Ca]i did not differ between TG and WT cardiomyocytes. The basal phosphorylation of cardiac troponin inhibitor (cTnI) and the myosin-binding protein C was reduced by 26 and 35%, respectively, in TG compared with WT hearts. The stimulation of β-adrenergic receptors by isoproterenol (ISO) resulted in an impaired contractile response of TG hearts. At a depolarizing potential of -5 mV, the ICa,L current density was decreased by 28% after administration of ISO in TG cardiomyocytes. In addition, the ISO-stimulated phosphorylation of phospholamban at Ser(16) was reduced by 27% in TG hearts. Thus, the increased PP2A-B56α activity in TG hearts is localized to specific subcellular sites leading to the dephosphorylation of important contractile proteins. This may result in higher myofilament Ca(2+) sensitivity and increased basal contractility in TG hearts. These effects were reversed by β-adrenergic stimulation.
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Affiliation(s)
- Uwe Kirchhefer
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Christiane Brekle
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - John Eskandar
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Gunnar Isensee
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Dana Kučerová
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Frank U Müller
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Florence Pinet
- INSERM, U744, Institut Pasteur de Lille, 59019 Lille, France
| | - Jan S Schulte
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Matthias D Seidl
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Peter Boknik
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
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Andrographolide inhibits nuclear factor-κB activation through JNK-Akt-p65 signaling cascade in tumor necrosis factor-α-stimulated vascular smooth muscle cells. ScientificWorldJournal 2014; 2014:130381. [PMID: 25114952 PMCID: PMC4121194 DOI: 10.1155/2014/130381] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 06/30/2014] [Indexed: 11/24/2022] Open
Abstract
Critical vascular inflammation leads to vascular dysfunction and cardiovascular diseases, including abdominal aortic aneurysms, hypertension, and atherosclerosis. Andrographolide is the most active and critical constituent isolated from the leaves of Andrographis paniculata, a herbal medicine widely used for treating anti-inflammation in Asia. In this study, we investigated the mechanisms of the inhibitory effects of andrographolide in vascular smooth muscle cells (VSMCs) exposed to a proinflammatory stimulus, tumor necrosis factor-α (TNF-α). Treating TNF-α-stimulated VSMCs with andrographolide suppressed the expression of inducible nitric oxide synthase in a concentration-dependent manner. A reduction in TNF-α-induced c-Jun N-terminal kinase (JNK), Akt, and p65 phosphorylation was observed in andrographolide-treated VSMCs. However, andrographolide affected neither IκBα degradation nor p38 mitogen-activated protein kinase or extracellular signal-regulated kinase 1/2 phosphorylation under these conditions. Both treatment with LY294002, a phosphatidylinositol 3-kinase/Akt inhibitor, and treatment with SP600125, a JNK inhibitor, markedly reversed the andrographolide-mediated inhibition of p65 phosphorylation. In addition, LY294002 and SP600125 both diminished Akt phosphorylation, whereas LY294002 had no effects on JNK phosphorylation. These results collectively suggest that therapeutic interventions using andrographolide can benefit the treatment of vascular inflammatory diseases, and andrographolide-mediated inhibition of NF-κB activity in TNF-α-stimulated VSMCs occurs through the JNK-Akt-p65 signaling cascade, an IκBα-independent mechanism.
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Dostal DE, Feng H, Nizamutdinov D, Golden HB, Afroze SH, Dostal JD, Jacob JC, Foster DM, Tong C, Glaser S, Gerilechaogetu F. Mechanosensing and Regulation of Cardiac Function. ACTA ACUST UNITED AC 2014; 5:314. [PMID: 25485172 PMCID: PMC4255974 DOI: 10.4172/2155-9880.1000314] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The role of mechanical force as an important regulator of structure and function of mammalian cells, tissues, and organs has recently been recognized. However, mechanical overload is a pathogenesis or comorbidity existing in a variety of heart diseases, such as hypertension, aortic regurgitation and myocardial infarction. Physical stimuli sensed by cells are transmitted through intracellular signal transduction pathways resulting in altered physiological responses or pathological conditions. Emerging evidence from experimental studies indicate that β1-integrin and the angiotensin II type I (AT1) receptor play critical roles as mechanosensors in the regulation of heart contraction, growth and leading to heart failure. Integrin link the extracellular matrix and the intracellular cytoskeleton to initiate the mechanical signalling, whereas, the AT1 receptor could be activated by mechanical stress through an angiotensin-II-independent mechanism. Recent studies show that both Integrin and AT1 receptor and their downstream signalling factors including MAPKs, AKT, FAK, ILK and GTPase regulate heart function in cardiac myocytes. In this review we describe the role of mechanical sensors residing within the plasma membrane, mechanical sensor induced downstream signalling factors and its potential roles in cardiac contraction and growth.
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Affiliation(s)
- David E Dostal
- Central Texas Veterans Health Care System, Temple, Texas, USA ; Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Hao Feng
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Damir Nizamutdinov
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Honey B Golden
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Syeda H Afroze
- Scott & White Healthcare - Digestive Disease Research Centre, Temple, Texas, USA
| | - Joseph D Dostal
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - John C Jacob
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Donald M Foster
- Central Texas Veterans Health Care System, Temple, Texas, USA
| | - Carl Tong
- Systems Biology and Translational Medicine, the Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Shannon Glaser
- Central Texas Veterans Health Care System, Temple, Texas, USA ; Scott & White Healthcare - Digestive Disease Research Centre, Temple, Texas, USA
| | - Fnu Gerilechaogetu
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
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