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Shinde S, Miryala SK, Anbarasu A, Ramaiah S. Systems biology approach to understand the interplay between Bacillus anthracis and human host genes that leads to CVDs. Microb Pathog 2023; 176:106019. [PMID: 36736801 DOI: 10.1016/j.micpath.2023.106019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 01/28/2023] [Accepted: 01/31/2023] [Indexed: 02/04/2023]
Abstract
Humans infected with invasive Bacillus anthracis (B. anthracis) have a very poor prognosis and are at high risk for developing cardiovascular diseases (CVDs) and shock. Several bacterial elements probably have significant pathogenic roles in this pathogenic process of anthrax. In our current work, we have analysed the molecular level interactions between B. anthracis and human genes to understand the interplay during anthrax that leads to the CVDs. Our results have shown dense interactions between the functional partners in both host and the B. anthracis Gene interaction network (GIN). The functional enrichment analysis indicated that the clusters in the host GIN had genes related to hypoxia and autophagy in response to the lethal toxin; and genes related to adherens junction and actin cytoskeleton in response to edema toxin play a significant role in multiple stages of the disease. The B. anthracis genes BA_0530, guaA, polA, rpoB, ribD, secDF, metS, dinG and human genes ACTB, EGFR, EP300, CTNNB1, ESR1 have shown more than 50 direct interactions with the functional partners and hence they can be considered as hub genes in the network and they are observed to have important roles in CVDs. The outcome of our study will help to understand the molecular pathogenesis of CVDs in anthrax. The hub genes reported in the study can be considered potential drug targets and they can be exploited for new drug discovery.
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Affiliation(s)
- Shabduli Shinde
- School of Medical Science and Technology, Indian Institute of Technology, Kharagpur, Kharagpur, 721302, West Bengal, India
| | - Sravan Kumar Miryala
- Medical and Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore, 632014, Tamil Nadu, India
| | - Anand Anbarasu
- Medical and Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore, 632014, Tamil Nadu, India
| | - Sudha Ramaiah
- Medical and Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore, 632014, Tamil Nadu, India.
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2
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Cheng B, Liu Y, Zhao Y, Li Q, Liu Y, Wang J, Chen Y, Zhang M. The role of anthrax toxin protein receptor 1 as a new mechanosensor molecule and its mechanotransduction in BMSCs under hydrostatic pressure. Sci Rep 2019; 9:12642. [PMID: 31477767 PMCID: PMC6718418 DOI: 10.1038/s41598-019-49100-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 08/16/2019] [Indexed: 02/06/2023] Open
Abstract
Anthrax toxin protein receptor (ANTXR) 1 has many similarities to integrin and is regarded in some respects as a single-stranded integrin protein. However, it is not clear whether ANTXR1 responds to mechanical signals secondary to the activation of integrins or whether it is a completely new, independent and previously undiscovered mechanosensor that responds to an undefined subset of mechanical signaling molecules. Our study demonstrates that ANTXR1 is a novel mechanosensor on the cell membrane, acting independently from the classical mechanoreceptor molecule integrinβ1. We show that bone marrow stromal cells (BMSCs) respond to the hydrostatic pressure towards chondrogenic differentiation partly through the glycogen synthase kinase (GSK) 3β/β-Catenin signaling pathway, which can be partly regulated by ANTXR1 and might be related to the direct binding between ANTXR1 and low-density lipoprotein receptor-related protein (LRP) 5/6. In addition, ANTXR1 specifically activates Smad2 and upregulates Smad4 expression to facilitate the transport of activated Smad2 to the nucleus to regulate chondrogenesis, which might be related to the direct binding between ANTXR1 and Actin/Fascin1. We also demonstrate that ANTXR1 binds to some extent with integrinβ1, but this interaction does not affect the expression and function of either protein under pressure. Thus, we conclude that ANTXR1 plays a crucial role in BMSC mechanotransduction and controls specific signaling pathways that are distinct from those of integrin to influence the chondrogenic responses of BMSCs under hydrostatic pressure.
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Affiliation(s)
- Baixiang Cheng
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, No.145 West Changle Road, Xi'an, 710032, China
| | - Yanzheng Liu
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, No.145 West Changle Road, Xi'an, 710032, China
| | - Ying Zhao
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, No.145 West Changle Road, Xi'an, 710032, China
| | - Qiang Li
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, No.145 West Changle Road, Xi'an, 710032, China
| | - Yanli Liu
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, No.145 West Changle Road, Xi'an, 710032, China
| | - Junjun Wang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, No.145 West Changle Road, Xi'an, 710032, China
| | - Yongjin Chen
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, No.145 West Changle Road, Xi'an, 710032, China.
| | - Min Zhang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, No.145 West Changle Road, Xi'an, 710032, China.
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3
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Cui X, Xu W, Neupane P, Weiser-Schlesinger A, Weng R, Pockros B, Li Y, Moayeri M, Leppla SH, Fitz Y, Eichacker PQ. Bacillus anthracis lethal toxin, but not edema toxin, increases pulmonary artery pressure and permeability in isolated perfused rat lungs. Am J Physiol Heart Circ Physiol 2019; 316:H1076-H1090. [PMID: 30767685 DOI: 10.1152/ajpheart.00685.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Although lethal toxin (LT) and edema toxin (ET) contribute to lethality during Bacillus anthracis infection, whether they increase vascular permeability and the extravascular fluid accumulation characterizing this infection is unclear. We employed an isolated perfused Sprague-Dawley rat lung model to investigate LT and ET effects on pulmonary vascular permeability. Lungs (n ≥ 6 per experimental group) were isolated, ventilated, suspended from a force transducer, and perfused. Lung weight and pulmonary artery (Ppa) and left atrial pressures were measured over 4 h, after which pulmonary capillary filtration coefficients (Kf.c) and lung wet-to-dry weight ratios (W/D) were determined. When compared with controls, LT increased Ppa over 4 h and Kf.c and W/D at 4 h (P < 0.0001). ET decreased Ppa in a significant trend (P = 0.09) but did not significantly alter Kf.c or W/D (P ≥ 0.29). Edema toxin actually blocked LT increases in Ppa but not LT increases in Kf.c and W/D. When Ppa was maintained at control levels, LT still increased Kf.c and W/D (P ≤ 0.004). Increasing the dose of each toxin five times significantly increased and a toxin-directed monoclonal antibody decreased the effects of each toxin (P ≤ 0.05). Two rho-kinase inhibitors (GSK269962 and Y27632) decreased LT increases in Ppa (P ≤ 0.02) but actually increased Kf.c and W/D in LT and control lungs (P ≤ 0.05). A vascular endothelial growth factor receptor inhibitor (ZM323881) had no significant effect (P ≥ 0.63) with LT. Thus, LT but not ET can increase pulmonary vascular permeability independent of increased Ppa and could contribute to pulmonary fluid accumulation during anthrax infection. However, pulmonary vascular dilation with ET could disrupt protective hypoxic vasoconstriction. NEW & NOTEWORTHY The most important findings from the present study are that Bacillus anthracis lethal toxin increases pulmonary artery pressure and pulmonary permeability independently in the isolated rat lung, whereas edema toxin decreases the former and does not increase permeability. Each effect could be a basis for organ dysfunction in patients with this lethal infection. These findings further support the need for adjunctive therapies that limit the effects of both toxins during infection.
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Affiliation(s)
- Xizhong Cui
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Wanying Xu
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Pranita Neupane
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Andie Weiser-Schlesinger
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Ray Weng
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Benjamin Pockros
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Yan Li
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Mahtab Moayeri
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda, Maryland
| | - Stephen H Leppla
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda, Maryland
| | - Yvonne Fitz
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Peter Q Eichacker
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
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4
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Rolando M, Stefani C, Doye A, Acosta MI, Visvikis O, Yevick HG, Buchrieser C, Mettouchi A, Bassereau P, Lemichez E. Contractile actin cables induced by Bacillus anthracis lethal toxin depend on the histone acetylation machinery. Cytoskeleton (Hoboken) 2015; 72:542-56. [PMID: 26403219 DOI: 10.1002/cm.21256] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 09/18/2015] [Accepted: 09/22/2015] [Indexed: 12/25/2022]
Abstract
It remains a challenge to decode the molecular basis of the long-term actin cytoskeleton rearrangements that are governed by the reprogramming of gene expression. Bacillus anthracis lethal toxin (LT) inhibits mitogen-activated protein kinase (MAPK) signaling, thereby modulating gene expression, with major consequences for actin cytoskeleton organization and the loss of endothelial barrier function. Using a laser ablation approach, we characterized the contractile and tensile mechanical properties of LT-induced stress fibers. These actin cables resist pulling forces that are transmitted at cell-matrix interfaces and at cell-cell discontinuous adherens junctions. We report that treating the cells with trichostatin A (TSA), a broad range inhibitor of histone deacetylases (HDACs), or with MS-275, which targets HDAC1, 2 and 3, induces stress fibers. LT decreased the cellular levels of HDAC1, 2 and 3 and reduced the global HDAC activity in the nucleus. Both the LT and TSA treatments induced Rnd3 expression, which is required for the LT-mediated induction of actin stress fibers. Furthermore, we reveal that treating the LT-intoxicated cells with garcinol, an inhibitor of histone acetyl-transferases (HATs), disrupts the stress fibers and limits the monolayer barrier dysfunctions. These data demonstrate the importance of modulating the flux of protein acetylation in order to control actin cytoskeleton organization and the endothelial cell monolayer barrier.
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Affiliation(s)
- Monica Rolando
- Microbial Toxins in Host-Pathogen Interactions, Equipe Labellisée La Ligue Contre Le Cancer, INSERM, U1065, Centre Méditerranéen De Médecine Moléculaire (C3M), 151 Route St Antoine de Ginestière, BP 2 3194, 06204 Nice Cedex, France.,UFR Médecine, IFR50, Faculté De Médecine, Université De Nice-Sophia Antipolis, Nice, France.,Biologie Des Bactéries Intracellulaires, Institut Pasteur, Paris, France.,UMR 3525, CNRS, Paris, France
| | - Caroline Stefani
- Microbial Toxins in Host-Pathogen Interactions, Equipe Labellisée La Ligue Contre Le Cancer, INSERM, U1065, Centre Méditerranéen De Médecine Moléculaire (C3M), 151 Route St Antoine de Ginestière, BP 2 3194, 06204 Nice Cedex, France.,UFR Médecine, IFR50, Faculté De Médecine, Université De Nice-Sophia Antipolis, Nice, France.,Immunology Program, Benaroya Research Institute at Virginia Mason, Seattle, WA 98101, USA
| | - Anne Doye
- Microbial Toxins in Host-Pathogen Interactions, Equipe Labellisée La Ligue Contre Le Cancer, INSERM, U1065, Centre Méditerranéen De Médecine Moléculaire (C3M), 151 Route St Antoine de Ginestière, BP 2 3194, 06204 Nice Cedex, France.,UFR Médecine, IFR50, Faculté De Médecine, Université De Nice-Sophia Antipolis, Nice, France
| | - Maria I Acosta
- Microbial Toxins in Host-Pathogen Interactions, Equipe Labellisée La Ligue Contre Le Cancer, INSERM, U1065, Centre Méditerranéen De Médecine Moléculaire (C3M), 151 Route St Antoine de Ginestière, BP 2 3194, 06204 Nice Cedex, France.,UFR Médecine, IFR50, Faculté De Médecine, Université De Nice-Sophia Antipolis, Nice, France
| | - Orane Visvikis
- Microbial Toxins in Host-Pathogen Interactions, Equipe Labellisée La Ligue Contre Le Cancer, INSERM, U1065, Centre Méditerranéen De Médecine Moléculaire (C3M), 151 Route St Antoine de Ginestière, BP 2 3194, 06204 Nice Cedex, France.,UFR Médecine, IFR50, Faculté De Médecine, Université De Nice-Sophia Antipolis, Nice, France
| | - Hannah G Yevick
- Institut Curie-Centre de Recherche, Membrane and Cell Functions Group; CNRS UMR 168, Physico-Chimie Curie, Université Pierre et Marie Curie, 26 Rue d'ulm, Paris Cedex 05, 75248, France
| | - Carmen Buchrieser
- Biologie Des Bactéries Intracellulaires, Institut Pasteur, Paris, France.,UMR 3525, CNRS, Paris, France
| | - Amel Mettouchi
- Microbial Toxins in Host-Pathogen Interactions, Equipe Labellisée La Ligue Contre Le Cancer, INSERM, U1065, Centre Méditerranéen De Médecine Moléculaire (C3M), 151 Route St Antoine de Ginestière, BP 2 3194, 06204 Nice Cedex, France.,UFR Médecine, IFR50, Faculté De Médecine, Université De Nice-Sophia Antipolis, Nice, France
| | - Patricia Bassereau
- Institut Curie-Centre de Recherche, Membrane and Cell Functions Group; CNRS UMR 168, Physico-Chimie Curie, Université Pierre et Marie Curie, 26 Rue d'ulm, Paris Cedex 05, 75248, France
| | - Emmanuel Lemichez
- Microbial Toxins in Host-Pathogen Interactions, Equipe Labellisée La Ligue Contre Le Cancer, INSERM, U1065, Centre Méditerranéen De Médecine Moléculaire (C3M), 151 Route St Antoine de Ginestière, BP 2 3194, 06204 Nice Cedex, France.,UFR Médecine, IFR50, Faculté De Médecine, Université De Nice-Sophia Antipolis, Nice, France
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5
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Pontier-Bres R, Rampal P, Peyron JF, Munro P, Lemichez E, Czerucka D. The Saccharomyces boulardii CNCM I-745 strain shows protective effects against the B. anthracis LT toxin. Toxins (Basel) 2015; 7:4455-67. [PMID: 26529015 PMCID: PMC4663514 DOI: 10.3390/toxins7114455] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 10/15/2015] [Accepted: 10/26/2015] [Indexed: 12/11/2022] Open
Abstract
The probiotic yeast Saccharomyces boulardii (S. boulardii) has been prescribed for the prophylaxis and treatment of several infectious diarrheal diseases. Gastrointestinal anthrax causes fatal systemic disease. In the present study, we investigated the protective effects conferred by Saccharomyces boulardii CNCM I-745 strain on polarized T84 columnar epithelial cells intoxicated by the lethal toxin (LT) of Bacillus anthracis. Exposure of polarized T84 cells to LT affected cell monolayer integrity, modified the morphology of tight junctions and induced the formation of actin stress fibers. Overnight treatment of cells with S. boulardii before incubation with LT maintained the integrity of the monolayers, prevented morphological modification of tight junctions, restricted the effects of LT on actin remodeling and delayed LT-induced MEK-2 cleavage. Mechanistically, we demonstrated that in the presence of S. boulardii, the medium is depleted of both LF and PA sub-units of LT and the appearance of a cleaved form of PA. Our study highlights the potential of the S. boulardii CNCM I-745 strain as a prophylactic agent against the gastrointestinal form of anthrax.
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Affiliation(s)
| | - Patrick Rampal
- Centre Scientifique de Monaco, Monaco 98000, Monaco; E-Mails: (R.P.-B.); (P.R.)
| | - Jean-François Peyron
- Team Inflammation, Cancer, Cancer Stem Cells, Centre Méditerranéen de Médecine Moléculaire (C3M), INSERM, U1065, Nice 06204, France; E-Mail:
- Faculté de Médecine, UFR Médecine, IFR50, Université de Nice-Sophia Antipolis, UNSA, Nice 06204, France; E-Mails: (P.M.); (E.L.)
| | - Patrick Munro
- Faculté de Médecine, UFR Médecine, IFR50, Université de Nice-Sophia Antipolis, UNSA, Nice 06204, France; E-Mails: (P.M.); (E.L.)
- Team Microbial Toxins in Host Pathogen Interactions, Centre Méditerranéen de Médecine Moléculaire (C3M), INSERM, U1065, Nice 06204, France
| | - Emmanuel Lemichez
- Faculté de Médecine, UFR Médecine, IFR50, Université de Nice-Sophia Antipolis, UNSA, Nice 06204, France; E-Mails: (P.M.); (E.L.)
- Team Microbial Toxins in Host Pathogen Interactions, Centre Méditerranéen de Médecine Moléculaire (C3M), INSERM, U1065, Nice 06204, France
| | - Dorota Czerucka
- Centre Scientifique de Monaco, Monaco 98000, Monaco; E-Mails: (R.P.-B.); (P.R.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +377-97-77-44-35
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6
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Micropatterned macrophage analysis reveals global cytoskeleton constraints induced by Bacillus anthracis edema toxin. Infect Immun 2015; 83:3114-25. [PMID: 26015478 DOI: 10.1128/iai.00479-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 05/16/2015] [Indexed: 12/20/2022] Open
Abstract
Bacillus anthracis secretes the edema toxin (ET) that disrupts the cellular physiology of endothelial and immune cells, ultimately affecting the adherens junction integrity of blood vessels that in turn leads to edema. The effects of ET on the cytoskeleton, which is critical in cell physiology, have not been described thus far on macrophages. In this study, we have developed different adhesive micropatterned surfaces (L and crossbow) to control the shape of bone marrow-derived macrophages (BMDMs) and primary peritoneal macrophages. We found that macrophage F-actin cytoskeleton adopts a specific polar organization slightly different from classical human HeLa cells on the micropatterns. Moreover, ET induced a major quantitative reorganization of F-actin within 16 h with a collapse at the nonadhesive side of BMDMs along the nucleus. There was an increase in size and deformation into a kidney-like shape, followed by a decrease in size that correlates with a global cellular collapse. The collapse of F-actin was correlated with a release of focal adhesion on the patterns and decreased cell size. Finally, the cell nucleus was affected by actin reorganization. By using this technology, we could describe many previously unknown macrophage cellular dysfunctions induced by ET. This novel tool could be used to analyze more broadly the effects of toxins and other virulence factors that target the cytoskeleton.
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Regulatory mechanisms of anthrax toxin receptor 1-dependent vascular and connective tissue homeostasis. Matrix Biol 2015; 42:56-73. [PMID: 25572963 PMCID: PMC4409530 DOI: 10.1016/j.matbio.2014.12.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 12/24/2014] [Indexed: 01/06/2023]
Abstract
It is well known that angiogenesis is linked to fibrotic processes in fibroproliferative diseases, but insights into pathophysiological processes are limited, due to lack of understanding of molecular mechanisms controlling endothelial and fibroblastic homeostasis. We demonstrate here that the matrix receptor anthrax toxin receptor 1 (ANTXR1), also known as tumor endothelial marker 8 (TEM8), is an essential component of these mechanisms. Loss of TEM8 function in mice causes reduced synthesis of endothelial basement membrane components and hyperproliferative and leaky blood vessels in skin. In addition, endothelial cell alterations in mutants are almost identical to those of endothelial cells in infantile hemangioma lesions, including activated VEGF receptor signaling in endothelial cells, increased expression of the downstream targets VEGF and CXCL12, and increased numbers of macrophages and mast cells. In contrast, loss of TEM8 in fibroblasts leads to increased rates of synthesis of fiber-forming collagens, resulting in progressive fibrosis in skin and other organs. Compromised interactions between TEM8-deficient endothelial and fibroblastic cells cause dramatic reduction in the activity of the matrix-degrading enzyme MMP2. In addition to insights into mechanisms of connective tissue homeostasis, our data provide molecular explanations for vascular and connective tissue abnormalities in GAPO syndrome, caused by loss-of-function mutations in ANTXR1. Furthermore, the loss of MMP2 activity suggests that fibrotic skin abnormalities in GAPO syndrome are, in part, the consequence of pathophysiological mechanisms underlying syndromes (NAO, Torg and Winchester) with multicentric skin nodulosis and osteolysis caused by homozygous loss-of-function mutations in MMP2.
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8
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Qiu P, Li Y, Shiloach J, Cui X, Sun J, Trinh L, Kubler-Kielb J, Vinogradov E, Mani H, Al-Hamad M, Fitz Y, Eichacker PQ. Bacillus anthracis cell wall peptidoglycan but not lethal or edema toxins produces changes consistent with disseminated intravascular coagulation in a rat model. J Infect Dis 2013; 208:978-89. [PMID: 23737601 DOI: 10.1093/infdis/jit247] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Disseminated intravascular coagulation (DIC) appears to be important in the pathogenesis of Bacillus anthracis infection, but its causes are unclear. Although lethal toxin (LT) and edema toxin (ET) could contribute, B. anthracis cell wall peptidoglycan (PGN), not the toxins, stimulates inflammatory responses associated with DIC. METHODS AND RESULTS To better understand the pathogenesis of DIC during anthrax, we compared the effects of 24-hour infusions of PGN, LT, ET, or diluent (control) on coagulation measures 6, 24, or 48 hours after infusion initiation in 135 rats. No control recipient died. Lethality rates (approximately 30%) did not differ among PGN, LT, and ET recipients (P = .78). Thirty-three of 35 deaths (94%) occurred between 6 and 24 hours after the start of challenge. Among challenge components, PGN most consistently altered coagulation measures. Compared with control at 6 hours, PGN decreased platelet and fibrinogen levels and increased prothrombin and activated partial thromboplastin times and tissue factor, tissue factor pathway inhibitor, protein C, plasminogen activator inhibitor (PAI), and thrombin-antithrombin complex levels, whereas LT and ET only decreased the fibrinogen level or increased the PAI level (P ≤ .05). Nearly all effects associated with PGN infusion significantly differed from changes associated with toxin infusion (P ≤ .05 for all comparisons except for PAI level). CONCLUSION DIC during B. anthracis infection may be related more to components such as PGN than to LT or ET.
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Affiliation(s)
- Ping Qiu
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
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9
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D'Agnillo F, Williams MC, Moayeri M, Warfel JM. Anthrax lethal toxin downregulates claudin-5 expression in human endothelial tight junctions. PLoS One 2013; 8:e62576. [PMID: 23626836 PMCID: PMC3633853 DOI: 10.1371/journal.pone.0062576] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 03/22/2013] [Indexed: 01/22/2023] Open
Abstract
Vascular leakage pathologies such as pleural effusion and hemorrhage are hallmarks of anthrax pathogenesis. We previously reported that anthrax lethal toxin (LT), the major virulence factor of anthrax, reduces barrier function in cultured primary human microvascular endothelial cells. Here, we show that LT-induced barrier dysfunction is accompanied by the reduced expression of the endothelial tight junction (TJ) protein claudin-5 but no change in the expression of other TJ components occludin, ZO-1, ZO-2, or the adherens junction (AJ) protein VE-cadherin. The downregulation of claudin-5 correlated temporally and dose-dependently with the reduction of transendothelial electrical resistance. LT-induced loss of claudin-5 was independent of cell death and preceded the appearance of actin stress fibers and altered AJ morphology. Pharmacological inhibition of MEK-1/2, two kinases that are proteolytically inactivated by LT, showed a similar reduction in claudin-5 expression. We found that LT reduced claudin-5 mRNA levels but did not accelerate the rate of claudin-5 degradation. Mice challenged with LT also showed significant reduction in claudin-5 expression. Together, these findings support a possible role for LT disruption of endothelial TJs in the vascular leakage pathologies of anthrax.
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Affiliation(s)
- Felice D'Agnillo
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America.
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10
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Studies in mice reveal a role for anthrax toxin receptors in matrix metalloproteinase function and extracellular matrix homeostasis. Toxins (Basel) 2013; 5:315-26. [PMID: 23389402 PMCID: PMC3640537 DOI: 10.3390/toxins5020315] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 01/31/2013] [Indexed: 02/07/2023] Open
Abstract
The genes encoding Anthrax Toxin Receptors (ANTXRs) were originally identified based on expression in endothelial cells suggesting a role in angiogenesis. The focus of this review is to discuss what has been learned about the physiological roles of these receptors through evaluation of the Antxr knockout mouse phenotypes. Mice mutant in Antxr genes have defects in extracellular matrix homeostasis. We discuss how knowledge of physiological ANTXR function relates to what is already known about anthrax intoxication.
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11
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Lemichez E, Gonzalez-Rodriguez D, Bassereau P, Brochard-Wyart F. Transcellular tunnel dynamics: Control of cellular dewetting by actomyosin contractility and I-BAR proteins. Biol Cell 2013. [PMID: 23189935 DOI: 10.1111/boc.201200063] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Dewetting is the spontaneous withdrawal of a liquid film from a non-wettable surface by nucleation and growth of dry patches. Two recent reports now propose that the principles of dewetting explain the physical phenomena underpinning the opening of transendothelial cell macroaperture (TEM) tunnels, referred to as cellular dewetting. This was discovered by studying a group of bacterial toxins endowed with the property of corrupting actomyosin cytoskeleton contractility. For both liquid and cellular dewetting, the growth of holes is governed by a competition between surface forces and line tension. We also discuss how the dynamics of TEM opening and closure represent remarkable systems to investigate actin cytoskeleton regulation by sensors of plasma membrane curvature and investigate the impact on membrane tension and the role of TEM in vascular dysfunctions.
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Affiliation(s)
- Emmanuel Lemichez
- INSERM, U1065, Université de Nice-Sophia-Antipolis, Centre Méditerranéen de Médecine Moléculaire, C3M, Nice 06204, France.
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