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Gao X, Teng T, Liu Y, Ai T, Zhao R, Fu Y, Zhang P, Han J, Zhang Y. Anthrax lethal toxin and tumor necrosis factor-α synergize on intestinal epithelia to induce mouse death. Protein Cell 2024; 15:135-148. [PMID: 37855658 PMCID: PMC10833652 DOI: 10.1093/procel/pwad050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 09/26/2023] [Indexed: 10/20/2023] Open
Abstract
Bacillus anthracis lethal toxin (LT) is a determinant of lethal anthrax. Its function in myeloid cells is required for bacterial dissemination, and LT itself can directly trigger dysfunction of the cardiovascular system. The interplay between LT and the host responses is important in the pathogenesis, but our knowledge on this interplay remains limited. Tumor necrosis factor-α (TNF-α) is a pleiotropic pro-inflammatory cytokine induced by bacterial infections. Since LT accumulates and cytokines, predominantly TNF, amass during B. anthracis infection, co-treatment of TNF + LT in mice was used to mimic in vivo conditions for LT to function in inflamed hosts. Bone marrow transplantation and genetically engineered mice showed unexpectedly that the death of intestinal epithelial cells (IECs) rather than that of hematopoietic cells led to LT + TNF-induced lethality. Inhibition of p38α mitogen-activated protein kinase (MAPK) signaling by LT in IECs promoted TNF-induced apoptosis and necroptosis of IECs, leading to intestinal damage and mouse death. Consistently, p38α inhibition by LT enhanced TNF-mediated cell death in human colon epithelial HT-29 cells. As intestinal damage is one of the leading causes of lethality in anthrax patients, the IEC damage caused by LT + TNF would most likely be a mechanism underneath this clinical manifestation and could be a target for interventions.
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Affiliation(s)
- Xinhe Gao
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - Teng Teng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - Yifei Liu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - Tingting Ai
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - Rui Zhao
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - Yilong Fu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - Peipei Zhang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - Jiahuai Han
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
- Research Unit of Cellular Stress of CAMS, Xiang’an Hospital of Xiamen University, Cancer Research Center of Xiamen University, School of Medicine, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
- Laboratory Animal Center, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - Yingying Zhang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
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Goossens PL. Bacillus anthracis, "la maladie du charbon", Toxins, and Institut Pasteur. Toxins (Basel) 2024; 16:66. [PMID: 38393144 PMCID: PMC10891547 DOI: 10.3390/toxins16020066] [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: 11/08/2023] [Revised: 12/25/2023] [Accepted: 12/30/2023] [Indexed: 02/25/2024] Open
Abstract
Institut Pasteur and Bacillus anthracis have enjoyed a relationship lasting almost 120 years, starting from its foundation and the pioneering work of Louis Pasteur in the nascent fields of microbiology and vaccination, and blooming after 1986 following the molecular biology/genetic revolution. This contribution will give a historical overview of these two research eras, taking advantage of the archives conserved at Institut Pasteur. The first era mainly focused on the production, characterisation, surveillance and improvement of veterinary anthrax vaccines; the concepts and technologies with which to reach a deep understanding of this research field were not yet available. The second period saw a new era of B. anthracis research at Institut Pasteur, with the anthrax laboratory developing a multi-disciplinary approach, ranging from structural analysis, biochemistry, genetic expression, and regulation to bacterial-host cell interactions, in vivo pathogenicity, and therapy development; this led to the comprehensive unravelling of many facets of this toxi-infection. B. anthracis may exemplify some general points on how science is performed in a given society at a given time and how a scientific research domain evolves. A striking illustration can be seen in the additive layers of regulations that were implemented from the beginning of the 21st century and their impact on B. anthracis research. B. anthracis and anthrax are complex systems that raise many valuable questions regarding basic research. One may hope that B. anthracis research will be re-initiated under favourable circumstances later at Institut Pasteur.
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Wrede D, Bordak M, Abraham Y, Mehedi M. Pulmonary Pathogen-Induced Epigenetic Modifications. EPIGENOMES 2023; 7:13. [PMID: 37489401 PMCID: PMC10366755 DOI: 10.3390/epigenomes7030013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/27/2023] [Accepted: 07/03/2023] [Indexed: 07/26/2023] Open
Abstract
Epigenetics generally involves genetic control by factors other than our own DNA sequence. Recent research has focused on delineating the mechanisms of two major epigenetic phenomena: DNA methylation and histone modification. As epigenetics involves many cellular processes, it is no surprise that it can also influence disease-associated gene expression. A direct link between respiratory infections, host cell epigenetic regulations, and chronic lung diseases is still unknown. Recent studies have revealed bacterium- or virus-induced epigenetic changes in the host cells. In this review, we focused on respiratory pathogens (viruses, bacteria, and fungi) induced epigenetic modulations (DNA methylation and histone modification) that may contribute to lung disease pathophysiology by promoting host defense or allowing pathogen persistence.
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Affiliation(s)
| | | | | | - Masfique Mehedi
- School of Medicine & Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA; (D.W.); (M.B.); (Y.A.)
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Wu Y, Pernet E, Touqui L. Modulation of Airway Expression of the Host Bactericidal Enzyme, sPLA2-IIA, by Bacterial Toxins. Toxins (Basel) 2023; 15:440. [PMID: 37505708 PMCID: PMC10467128 DOI: 10.3390/toxins15070440] [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: 04/13/2023] [Revised: 06/23/2023] [Accepted: 06/29/2023] [Indexed: 07/29/2023] Open
Abstract
Host molecules with antimicrobial properties belong to a large family of mediators including type-IIA secreted phospholipase A2 (sPLA2-IIA). The latter is a potent bactericidal agent with high selectivity against Gram-positive bacteria, but it may also play a role in modulating the host inflammatory response. However, several pathogen-associated molecular patterns (PAMPs) or toxins produced by pathogenic bacteria can modulate the levels of sPLA2-IIA by either inducing or inhibiting its expression in host cells. Thus, the final sPLA2-IIA concentration during the infection process is determined by the orchestration between the levels of toxins that stimulate and those that downregulate the expression of this enzyme. The stimulation of sPLA2-IIA expression is a process that participates in the clearance of invading bacteria, while inhibition of this expression highlights a mechanism by which certain bacteria can subvert the immune response and invade the host. Here, we will review the major functions of sPLA2-IIA in the airways and the role of bacterial toxins in modulating the expression of this enzyme. We will also summarize the major mechanisms involved in this modulation and the potential consequences for the pulmonary host response to bacterial infection.
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Affiliation(s)
- Yongzheng Wu
- Unité de Biologie Cellulaire de l’Infection Microbionne, CNRS UMR3691, Institut Pasteur, Université de Paris Cité, 75015 Paris, France;
| | - Erwan Pernet
- Groupe de Recherche en Signalisation Cellulaire, Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC G8Z 4M3, Canada
| | - Lhousseine Touqui
- Sorbonne Université, Inserm U938, Centre de Recherche Saint-Antoine (CRSA), 75012 Paris, France
- Institut Pasteur, Université de Paris Cité, Mucoviscidose et Bronchopathies Chroniques, 75015 Paris, France
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Banihashemi SR, Rahbarizadeh F, Zavaran Hosseini A, Ahmadvand D, Khoshtinat Nikkhoi S. Liposome-based nanocarriers loaded with anthrax lethal factor and armed with anti-CD19 VHH for effectively inhibiting MAPK pathway in B cells. Int Immunopharmacol 2021; 100:107927. [PMID: 34500284 DOI: 10.1016/j.intimp.2021.107927] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 01/26/2023]
Abstract
OBJECTIVE One of the vital signaling pathways in cancer development and metastasis is mitogen-activated protein kinases (MAPKs). Bacillus anthracis Lethal Toxin (LT) is a potent MAPK signaling inhibitor. This toxin is comprised of two distinct domains, Lethal Factor (LF), MAPK inhibitor, and Protective Antigen (PA). To enter various cell lines, LF must be associated with the protective antigen (PA), which facilitates LF delivery. In the current study, to block MAPK signaling, LF was loaded into anti-CD19 immunoliposomes nanoparticle to deliver the cargo to Raji B cells. METHODS The liposome nanoparticle was prepared using classical lipid film formation, then conjugated to anti-CD19 VHH. The binding efficiency was measured through flow cytometry. The targeted cytotoxicity of LF immunoliposome was confirmed by BrdU lymphoproliferation assay. This was followed by Real-Time PCR to assess the effect of formulation on pro-apoptotic genes. The inhibitory effect of LF on MAPK signaling was confirmed by western blot. RESULTS Liposome nano-formulation was optimized to reach the maximum LF encapsulation and targeted delivery. Next, phosphorylation of MAPK pathway mediators like MEK1/2, P38 and JNK were inhibited following the treatment of Raji cells with LF-immunoliposome. The treatment also upregulated caspase genes, clearly illustrating cell death induced by LF through pyroptosis and caspase-dependent apoptosis. CONCLUSIONS In conclusion, anti-CD19 VHH immunoliposome was loaded with LF, a potent MAPK inhibitor targeting B cells, which curbs proliferation and ushers B cells toward apoptosis. Thus, immunoliposome presents as a versatile nanoparticle for delivery of LF to block aberrant MAPK activation. To use LF as a therapy, it would be necessary to materialize LF without PA. In the current study, PA was substituted with anti-CD19 immunoliposome to make it targeted to CD19+ while keeping the normal cells intact.
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Affiliation(s)
- S Reza Banihashemi
- Department of Medical Immunology, Faculty of Medical Sciences, Tarbiat Modarres University, Tehran, Iran; Department of Immunology, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization, Karaj, Iran
| | - Fatemeh Rahbarizadeh
- Department of Medical Biotechnology, Faculty of Medical Sciences, Tarbiat Modarres University, Tehran, Iran.
| | - Ahmad Zavaran Hosseini
- Department of Medical Immunology, Faculty of Medical Sciences, Tarbiat Modarres University, Tehran, Iran
| | - Davoud Ahmadvand
- School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
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Das UN. "Cell Membrane Theory of Senescence" and the Role of Bioactive Lipids in Aging, and Aging Associated Diseases and Their Therapeutic Implications. Biomolecules 2021; 11:biom11020241. [PMID: 33567774 PMCID: PMC7914625 DOI: 10.3390/biom11020241] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/28/2021] [Accepted: 02/01/2021] [Indexed: 12/12/2022] Open
Abstract
Lipids are an essential constituent of the cell membrane of which polyunsaturated fatty acids (PUFAs) are the most important component. Activation of phospholipase A2 (PLA2) induces the release of PUFAs from the cell membrane that form precursors to both pro- and ant-inflammatory bioactive lipids that participate in several cellular processes. PUFAs GLA (gamma-linolenic acid), DGLA (dihomo-GLA), AA (arachidonic acid), EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are derived from dietary linoleic acid (LA) and alpha-linolenic acid (ALA) by the action of desaturases whose activity declines with age. Consequently, aged cells are deficient in GLA, DGLA, AA, AA, EPA and DHA and their metabolites. LA, ALA, AA, EPA and DHA can also be obtained direct from diet and their deficiency (fatty acids) may indicate malnutrition and deficiency of several minerals, trace elements and vitamins some of which are also much needed co-factors for the normal activity of desaturases. In many instances (patients) the plasma and tissue levels of GLA, DGLA, AA, EPA and DHA are low (as seen in patients with hypertension, type 2 diabetes mellitus) but they do not have deficiency of other nutrients. Hence, it is reasonable to consider that the deficiency of GLA, DGLA, AA, EPA and DHA noted in these conditions are due to the decreased activity of desaturases and elongases. PUFAs stimulate SIRT1 through protein kinase A-dependent activation of SIRT1-PGC1α complex and thus, increase rates of fatty acid oxidation and prevent lipid dysregulation associated with aging. SIRT1 activation prevents aging. Of all the SIRTs, SIRT6 is critical for intermediary metabolism and genomic stability. SIRT6-deficient mice show shortened lifespan, defects in DNA repair and have a high incidence of cancer due to oncogene activation. SIRT6 overexpression lowers LDL and triglyceride level, improves glucose tolerance, and increases lifespan of mice in addition to its anti-inflammatory effects at the transcriptional level. PUFAs and their anti-inflammatory metabolites influence the activity of SIRT6 and other SIRTs and thus, bring about their actions on metabolism, inflammation, and genome maintenance. GLA, DGLA, AA, EPA and DHA and prostaglandin E2 (PGE2), lipoxin A4 (LXA4) (pro- and anti-inflammatory metabolites of AA respectively) activate/suppress various SIRTs (SIRt1 SIRT2, SIRT3, SIRT4, SIRT5, SIRT6), PPAR-γ, PARP, p53, SREBP1, intracellular cAMP content, PKA activity and peroxisome proliferator-activated receptor γ coactivator 1-α (PGC1-α). This implies that changes in the metabolism of bioactive lipids as a result of altered activities of desaturases, COX-2 and 5-, 12-, 15-LOX (cyclo-oxygenase and lipoxygenases respectively) may have a critical role in determining cell age and development of several aging associated diseases and genomic stability and gene and oncogene activation. Thus, methods designed to maintain homeostasis of bioactive lipids (GLA, DGLA, AA, EPA, DHA, PGE2, LXA4) may arrest aging process and associated metabolic abnormalities.
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Affiliation(s)
- Undurti N. Das
- UND Life Sciences, 2221 NW 5th St, Battle Ground, WA 98604, USA; ; Tel.: +508-904-5376
- BioScience Research Centre and Department of Medicine, GVP Medical College and Hospital, Visakhapatnam 530048, India
- International Research Centre, Biotechnologies of the third Millennium, ITMO University, 191002 Saint-Petersburg, Russia
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van Hensbergen VP, Wu Y, van Sorge NM, Touqui L. Type IIA Secreted Phospholipase A2 in Host Defense against Bacterial Infections. Trends Immunol 2020; 41:313-326. [PMID: 32151494 DOI: 10.1016/j.it.2020.02.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 02/07/2020] [Accepted: 02/08/2020] [Indexed: 12/13/2022]
Abstract
The enzyme type IIA secreted phospholipase A2 (sPLA2-IIA) is crucial for mammalian innate host defense against bacterial pathogens. Most studies have investigated the role of sPLA2-IIA in systemic bacterial infections, identifying molecular pathways of bacterial resistance against sPLA2-IIA-mediated killing, and providing insight into sPLA2-IIA mechanisms of action. Sensitization of (antibiotic-resistant) bacteria to sPLA2-IIA action by blocking bacterial resistance or by applying sPLA2-IIA to treat bacterial infections might represent a therapeutic option in the future. Because sPLA2-IIA is highly expressed at mucosal barriers, we also discuss how sPLA2-IIA is likely to be an important driver of microbiome composition; we anticipate that future research in this area may bring new insights into the role of sPLA2-IIA in health and disease.
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Affiliation(s)
- Vincent P van Hensbergen
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Yongzheng Wu
- Unité de Biologie Cellulaire de l'infection Microbienne, CNRS UMR3691, Institut Pasteur, Paris, France
| | - Nina M van Sorge
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
| | - Lhousseine Touqui
- Mucoviscidose et Bronchopathies Chroniques, département Santé Globale; Pasteur Institute, Paris, France.
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van Hensbergen VP, Movert E, de Maat V, Lüchtenborg C, Le Breton Y, Lambeau G, Payré C, Henningham A, Nizet V, van Strijp JAG, Brügger B, Carlsson F, McIver KS, van Sorge NM. Streptococcal Lancefield polysaccharides are critical cell wall determinants for human Group IIA secreted phospholipase A2 to exert its bactericidal effects. PLoS Pathog 2018; 14:e1007348. [PMID: 30321240 PMCID: PMC6201954 DOI: 10.1371/journal.ppat.1007348] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 10/25/2018] [Accepted: 09/20/2018] [Indexed: 12/21/2022] Open
Abstract
Human Group IIA secreted phospholipase A2 (hGIIA) is an acute phase protein with bactericidal activity against Gram-positive bacteria. Infection models in hGIIA transgenic mice have suggested the importance of hGIIA as an innate defense mechanism against the human pathogens Group A Streptococcus (GAS) and Group B Streptococcus (GBS). Compared to other Gram-positive bacteria, GAS is remarkably resistant to hGIIA activity. To identify GAS resistance mechanisms, we exposed a highly saturated GAS M1 transposon library to recombinant hGIIA and compared relative mutant abundance with library input through transposon-sequencing (Tn-seq). Based on transposon prevalence in the output library, we identified nine genes, including dltA and lytR, conferring increased hGIIA susceptibility. In addition, seven genes conferred increased hGIIA resistance, which included two genes, gacH and gacI that are located within the Group A Carbohydrate (GAC) gene cluster. Using GAS 5448 wild-type and the isogenic gacI mutant and gacI-complemented strains, we demonstrate that loss of the GAC N-acetylglucosamine (GlcNAc) side chain in the ΔgacI mutant increases hGIIA resistance approximately 10-fold, a phenotype that is conserved across different GAS serotypes. Increased resistance is associated with delayed penetration of hGIIA through the cell wall. Correspondingly, loss of the Lancefield Group B Carbohydrate (GBC) rendered GBS significantly more resistant to hGIIA-mediated killing. This suggests that the streptococcal Lancefield antigens, which are critical determinants for streptococcal physiology and virulence, are required for the bactericidal enzyme hGIIA to exert its bactericidal function.
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Affiliation(s)
- Vincent P. van Hensbergen
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Elin Movert
- Department of Experimental Medical Science, Section for Immunology, Lund University, Lund, Sweden
| | - Vincent de Maat
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | - Yoann Le Breton
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, United States of America
| | - Gérard Lambeau
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Department of Biochemistry, Valbonne, France
| | - Christine Payré
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Department of Biochemistry, Valbonne, France
| | - Anna Henningham
- Department of Pediatrics and Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States of America
| | - Victor Nizet
- Department of Pediatrics and Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States of America
- Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States of America
| | - Jos A. G. van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Britta Brügger
- Heidelberg University, Biochemistry Center (BZH), Heidelberg, Germany
| | - Fredric Carlsson
- Department of Experimental Medical Science, Section for Immunology, Lund University, Lund, Sweden
- Department of Biology, Section for Molecular Cell Biology, Lund University, Lund, Sweden
| | - Kevin S. McIver
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, United States of America
| | - Nina M. van Sorge
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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Dore E, Boilard E. Roles of secreted phospholipase A 2 group IIA in inflammation and host defense. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:789-802. [PMID: 30905346 DOI: 10.1016/j.bbalip.2018.08.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 01/08/2023]
Abstract
Among all members of the secreted phospholipase A2 (sPLA2) family, group IIA sPLA2 (sPLA2-IIA) is possibly the most studied enzyme. Since its discovery, many names have been associated with sPLA2-IIA, such as "non-pancreatic", "synovial", "platelet-type", "inflammatory", and "bactericidal" sPLA2. Whereas the different designations indicate comprehensive functions or sources proposed for this enzyme, the identification of the precise roles of sPLA2-IIA has remained a challenge. This can be attributed to: the expression of the enzyme by various cells of different lineages, its limited activity towards the membranes of immune cells despite its expression following common inflammatory stimuli, its ability to interact with certain proteins independently of its catalytic activity, and its absence from multiple commonly used mouse models. Nevertheless, elevated levels of the enzyme during inflammatory processes and associated consistent release of arachidonic acid from the membrane of extracellular vesicles suggest that sPLA2-IIA may contribute to inflammation by using endogenous substrates in the extracellular milieu. Moreover, the remarkable potency of sPLA2-IIA towards bacterial membranes and its induced expression during the course of infections point to a role for this enzyme in the defense of the host against invading pathogens. In this review, we present current knowledge related to mammalian sPLA2-IIA and its roles in sterile inflammation and host defense.
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Affiliation(s)
- Etienne Dore
- Centre de Recherche du CHU de Québec, Université Laval, Department of Infectious Diseases and Immunity, Québec City, QC, Canada
| | - Eric Boilard
- Centre de Recherche du CHU de Québec, Université Laval, Department of Infectious Diseases and Immunity, Québec City, QC, Canada; Canadian National Transplantation Research Program, Edmonton, AB, Canada.
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10
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Das UN. Arachidonic acid and other unsaturated fatty acids and some of their metabolites function as endogenous antimicrobial molecules: A review. J Adv Res 2018; 11:57-66. [PMID: 30034876 PMCID: PMC6052656 DOI: 10.1016/j.jare.2018.01.001] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 01/01/2018] [Accepted: 01/01/2018] [Indexed: 12/13/2022] Open
Abstract
Our body is endowed with several endogenous anti-microbial compounds such as interferon, cytokines, free radicals, etc. However, little attention has been paid to the possibility that lipids could function as antimicrobial compounds. In this short review, the antimicrobial actions of various polyunsaturated fatty acids (PUFAs, mainly free acids) and their putative mechanisms of action are described. In general, PUFAs kill microbes by their direct action on microbial cell membranes, enhancing generation of free radicals, augmenting the formation of lipid peroxides that are cytotoxic, and by increasing the formation of their bioactive metabolites, such as prostaglandins, lipoxins, resolvins, protectins and maresins that enhance the phagocytic action of leukocytes and macrophages. Higher intakes of α-linolenic and cis-linoleic acids (ALA and LA respectively) and fish (a rich source of eicosapentaenoic acid and docosahexaenoic acid) might reduce the risk pneumonia. Previously, it was suggested that polyunsaturated fatty acids (PUFAs): linoleic, α-linolenic, γ-linolenic (GLA), dihomo-GLA (DGLA), arachidonic (AA), eicosapentaenoic (EPA), and docosahexaenoic acids (DHA) function as endogenous anti-bacterial, anti-fungal, anti-viral, anti-parasitic, and immunomodulating agents. A variety of bacteria are sensitive to the growth inhibitory actions of LA and ALA in vitro. Hydrolyzed linseed oil can kill methicillin-resistant Staphylococcus aureus. Both LA and AA have the ability to inactivate herpes, influenza, Sendai, and Sindbis virus within minutes of contact. AA, EPA, and DHA induce death of Plasmodium falciparum both in vitro and in vivo. Prostaglandin E1 (PGE1) and prostaglandin A (PGA), derived from DGLA, AA, and EPA inhibit viral replication and show anti-viral activity. Oral mucosa, epidermal cells, lymphocytes and macrophages contain and release significant amounts of PUFAs on stimulation. PUFAs stimulate NADPH-dependent superoxide production by macrophages, neutrophils and lymphocytes to kill the invading microorganisms. Cytokines induce the release of PUFAs from cell membrane lipid pool, a potential mechanism for their antimicrobial action. AA, EPA, and DHA give rise to lipoxins (LXs), resolvins, protectins, and maresins that limit and resolve inflammation and have antimicrobial actions. Thus, PUFAs and their metabolites have broad antimicrobial actions.
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11
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Lin J, Cheng Y, Wang T, Tang L, Sun Y, Lu X, Yu H. Soyasaponin Ab inhibits lipopolysaccharide-induced acute lung injury in mice. Int Immunopharmacol 2016; 30:121-128. [PMID: 26672918 DOI: 10.1016/j.intimp.2015.12.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 11/04/2015] [Accepted: 12/01/2015] [Indexed: 11/23/2022]
Abstract
Soyasaponin Ab (SA) has been reported to have anti-inflammatory effect. However, the effects of SA on lipopolysaccharide (LPS)-induced acute lung injury (ALI) have not been reported. The aim of this study was to investigate the anti-inflammatory effects of SA on LPS-induced ALI and clarify the possible mechanism. The mice were stimulated with LPS to induce ALI. SA was given 1h after LPS treatment. 12h later, lung tissues were collected to assess pathological changes and edema. Bronchoalveolar lavage fluid (BALF) was collected to assess inflammatory cytokines and nitric oxide (NO) production. In vitro, mice alveolar macrophages were used to investigate the anti-inflammatory mechanism of SA. Our results showed that SA attenuated LPS-induced lung pathological changes, edema, the expression of cycloxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in lung tissues, as well as TNF-α, IL-6, IL-1β, and NO production in mice. Meanwhile, SA up-regulated the activities of superoxide dismutase (SOD) and catalase decreased by LPS in mice. SA also inhibited LPS-induced TNF-α, IL-6 and IL-1β production as well as NF-κB activation in alveolar macrophages. Furthermore, SA could activate Liver X Receptor Alpha (LXRα) and knockdown of LXRα by RNAi abrogated the anti-inflammatory effects of SA. In conclusion, the current study demonstrated that SA exhibited protective effects against LPS-induced acute lung injury and the possible mechanism was involved in activating LXRα, thereby inhibiting LPS-induced inflammatory response.
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Affiliation(s)
- Jing Lin
- Chinese Medicine Department of The 2nd Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, China
| | - Yanwen Cheng
- Pharmaceutical Department of The 2nd Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, China
| | - Tao Wang
- Basic Medical College of Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, China
| | - Lihua Tang
- Medical Record Quality Department of The 2nd Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, China
| | - Yan Sun
- Chinese Medicine Department of The 2nd Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, China
| | - Xiuyun Lu
- Chinese Medicine Department of The 2nd Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, China
| | - Huimin Yu
- Chinese Medicine Department of The 2nd Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, China.
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12
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Goossens PL, Tournier JN. Crossing of the epithelial barriers by Bacillus anthracis: the Known and the Unknown. Front Microbiol 2015; 6:1122. [PMID: 26500645 PMCID: PMC4598578 DOI: 10.3389/fmicb.2015.01122] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 09/28/2015] [Indexed: 12/15/2022] Open
Abstract
Anthrax, caused by Bacillus anthracis, a Gram-positive spore-forming bacterium, is initiated by the entry of spores into the host body. There are three types of human infection: cutaneous, inhalational, and gastrointestinal. For each form, B. anthracis spores need to cross the cutaneous, respiratory or digestive epithelial barriers, respectively, as a first obligate step to establish infection. Anthrax is a toxi-infection: an association of toxemia and rapidly spreading infection progressing to septicemia. The pathogenicity of Bacillus anthracis mainly depends on two toxins and a capsule. The capsule protects bacilli from the immune system, thus promoting systemic dissemination. The toxins alter host cell signaling, thereby paralyzing the immune response of the host and perturbing the endocrine and endothelial systems. In this review, we will mainly focus on the events and mechanisms leading to crossing of the respiratory epithelial barrier, as the majority of studies have addressed inhalational infection. We will discuss the critical gaps of knowledge that need to be addressed to gain a comprehensive view of the initial steps of inhalational anthrax. We will then discuss the few data available on B. anthracis crossing the cutaneous and digestive epithelia.
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Affiliation(s)
- Pierre L Goossens
- Pathogénie des Toxi-Infections Bactériennes, Institut Pasteur , Paris, France
| | - Jean-Nicolas Tournier
- Pathogénie des Toxi-Infections Bactériennes, Institut Pasteur , Paris, France ; Unité Interactions Hôte-Agents Pathogènes, Institut de Recherche Biomédicale des Armées , Brétigny-sur-Orge, France ; Ecole du Val-de-Grâce , Paris, France
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13
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Pernet E, Brunet J, Guillemot L, Chignard M, Touqui L, Wu Y. Staphylococcus aureusAdenosine Inhibits sPLA2-IIA–Mediated Host Killing in the Airways. THE JOURNAL OF IMMUNOLOGY 2015; 194:5312-9. [DOI: 10.4049/jimmunol.1402665] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 03/17/2015] [Indexed: 12/19/2022]
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14
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Remy KE, Qiu P, Li Y, Cui X, Eichacker PQ. B. anthracis associated cardiovascular dysfunction and shock: the potential contribution of both non-toxin and toxin components. BMC Med 2013; 11:217. [PMID: 24107194 PMCID: PMC3851549 DOI: 10.1186/1741-7015-11-217] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 09/13/2013] [Indexed: 01/31/2023] Open
Abstract
The development of cardiovascular dysfunction and shock in patients with invasive Bacillus anthracis infection has a particularly poor prognosis. Growing evidence indicates that several bacterial components likely play important pathogenic roles in this injury. As with other pathogenic Gram-positive bacteria, the B. anthracis cell wall and its peptidoglycan constituent produce a robust inflammatory response with its attendant tissue injury, disseminated intravascular coagulation and shock. However, B. anthracis also produces lethal and edema toxins that both contribute to shock. Growing evidence suggests that lethal toxin, a metalloprotease, can interfere with endothelial barrier function as well as produce myocardial dysfunction. Edema toxin has potent adenyl cyclase activity and may alter endothelial function, as well as produce direct arterial and venous relaxation. Furthermore, both toxins can weaken host defense and promote infection. Finally, B. anthracis produces non-toxin metalloproteases which new studies show can contribute to tissue injury, coagulopathy and shock. In the future, an understanding of the individual pathogenic effects of these different components and their interactions will be important for improving the management of B. anthracis infection and shock.
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Affiliation(s)
- Kenneth E Remy
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA.
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15
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Emerging roles of secreted phospholipase A2 enzymes: An update. Biochimie 2013; 95:43-50. [DOI: 10.1016/j.biochi.2012.09.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 09/11/2012] [Indexed: 01/18/2023]
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16
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Bacillus anthracis factors for phagosomal escape. Toxins (Basel) 2012; 4:536-53. [PMID: 22852067 PMCID: PMC3407891 DOI: 10.3390/toxins4070536] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 06/21/2012] [Accepted: 07/02/2012] [Indexed: 12/27/2022] Open
Abstract
The mechanism of phagosome escape by intracellular pathogens is an important step in the infectious cycle. During the establishment of anthrax, Bacillus anthracis undergoes a transient intracellular phase in which spores are engulfed by local phagocytes. Spores germinate inside phagosomes and grow to vegetative bacilli, which emerge from their resident intracellular compartments, replicate and eventually exit from the plasma membrane. During germination, B. anthracis secretes multiple factors that can help its resistance to the phagocytes. Here the possible role of B. anthracis toxins, phospholipases, antioxidant enzymes and capsules in the phagosomal escape and survival, is analyzed and compared with that of factors of other microbial pathogens involved in the same type of process.
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