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Miles MA, Luong R, To EE, Erlich JR, Liong S, Liong F, Logan JM, O’Leary J, Brooks DA, Selemidis S. TLR9 Monotherapy in Immune-Competent Mice Suppresses Orthotopic Prostate Tumor Development. Cells 2024; 13:97. [PMID: 38201300 PMCID: PMC10778079 DOI: 10.3390/cells13010097] [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: 12/12/2023] [Revised: 12/28/2023] [Accepted: 12/29/2023] [Indexed: 01/12/2024] Open
Abstract
Prostate cancer is ranked second in the world for cancer-related deaths in men, highlighting the lack of effective therapies for advanced-stage disease. Toll-like receptors (TLRs) and immunity have a direct role in prostate cancer pathogenesis, but TLR9 has been reported to contribute to both the progression and inhibition of prostate tumorigenesis. To further understand this apparent disparity, we have investigated the effect of TLR9 stimulation on prostate cancer progression in an immune-competent, syngeneic orthotopic mouse model of prostate cancer. Here, we utilized the class B synthetic agonist CPG-1668 to provoke a TLR9-mediated systemic immune response and demonstrate a significant impairment of prostate tumorigenesis. Untreated tumors contained a high abundance of immune-cell infiltrates. However, pharmacological activation of TLR9 resulted in smaller tumors containing significantly fewer M1 macrophages and T cells. TLR9 stimulation of tumor cells in vitro had no effect on cell viability or its downstream transcriptional targets, whereas stimulation in macrophages suppressed cancer cell growth via type I IFN. This suggests that the antitumorigenic effects of CPG-1668 were predominantly mediated by an antitumor immune response. This study demonstrated that systemic TLR9 stimulation negatively regulates prostate cancer tumorigenesis and highlights TLR9 agonists as a useful therapeutic for the treatment of prostate cancer.
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Affiliation(s)
- Mark A. Miles
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083, Australia
| | - Raymond Luong
- Infection and Immunity Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, VIC 3800, Australia
| | - Eunice E. To
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083, Australia
| | - Jonathan R. Erlich
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083, Australia
| | - Stella Liong
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083, Australia
| | - Felicia Liong
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083, Australia
| | - Jessica M. Logan
- Cancer Research Institute, Clinical and Health Sciences, University of South Australia, Adelaide, SA 5001, Australia
| | - John O’Leary
- Discipline of Histopathology, School of Medicine, Trinity Translational Medicine Institute (TTMI), Trinity College Dublin, D8 Dublin, Ireland
- Sir Patrick Dun’s Laboratory, Central Pathology Laboratory, St James’s Hospital, D8 Dublin, Ireland
- Molecular Pathology Laboratory, Coombe Women and Infants’ University Hospital, D8 Dublin, Ireland
| | - Doug A. Brooks
- Cancer Research Institute, Clinical and Health Sciences, University of South Australia, Adelaide, SA 5001, Australia
- Discipline of Histopathology, School of Medicine, Trinity Translational Medicine Institute (TTMI), Trinity College Dublin, D8 Dublin, Ireland
| | - Stavros Selemidis
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083, Australia
- Infection and Immunity Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, VIC 3800, Australia
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Stackowicz J, Jönsson F, Reber LL. Mouse Models and Tools for the in vivo Study of Neutrophils. Front Immunol 2020; 10:3130. [PMID: 32038641 PMCID: PMC6985372 DOI: 10.3389/fimmu.2019.03130] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 12/23/2019] [Indexed: 12/21/2022] Open
Abstract
Neutrophils are the most abundant leukocytes in human blood and critical actors of the immune system. Many neutrophil functions and facets of their activity in vivo were revealed by studying genetically modified mice or by tracking fluorescent neutrophils in animals using imaging approaches. Assessing the roles of neutrophils can be challenging, especially when exact molecular pathways are questioned or disease states are interrogated that alter normal neutrophil homeostasis. This review discusses the main in vivo models for the study of neutrophils, their advantages and limitations. The side-by-side comparison underlines the necessity to carefully choose the right model(s) to answer a given scientific question, and exhibit caveats that need to be taken into account when designing experimental procedures. Collectively, this review suggests that at least two models should be employed to legitimately conclude on neutrophil functions.
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Affiliation(s)
- Julien Stackowicz
- Institut Pasteur, Department of Immunology, Unit of Antibodies in Therapy and Pathology, UMR INSERM 1222, Paris, France.,Sorbonne Université, Collège Doctoral, Paris, France
| | - Friederike Jönsson
- Institut Pasteur, Department of Immunology, Unit of Antibodies in Therapy and Pathology, UMR INSERM 1222, Paris, France
| | - Laurent L Reber
- Institut Pasteur, Department of Immunology, Unit of Antibodies in Therapy and Pathology, UMR INSERM 1222, Paris, France.,Center for Pathophysiology Toulouse-Purpan (CPTP), UMR 1043, University of Toulouse, INSERM, CNRS, Toulouse, France
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3
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Maelfait J, Liverpool L, Rehwinkel J. Nucleic Acid Sensors and Programmed Cell Death. J Mol Biol 2020; 432:552-568. [PMID: 31786265 PMCID: PMC7322524 DOI: 10.1016/j.jmb.2019.11.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/15/2019] [Accepted: 11/15/2019] [Indexed: 02/07/2023]
Abstract
Nucleic acids derived from microorganisms are powerful triggers for innate immune responses. Proteins called RNA and DNA sensors detect foreign nucleic acids and, in mammalian cells, include RIG-I, cGAS, and AIM2. On binding to nucleic acids, these proteins initiate signaling cascades that activate host defense responses. An important aspect of this defense program is the production of cytokines such as type I interferons and IL-1β. Studies conducted over recent years have revealed that nucleic acid sensors also activate programmed cell death pathways as an innate immune response to infection. Indeed, RNA and DNA sensors induce apoptosis, pyroptosis, and necroptosis. Cell death via these pathways prevents replication of pathogens by eliminating the infected cell and additionally contributes to the release of cytokines and inflammatory mediators. Interestingly, recent evidence suggests that programmed cell death triggered by nucleic acid sensors plays an important role in a number of noninfectious pathologies. In addition to nonself DNA and RNA from microorganisms, nucleic acid sensors also recognize endogenous nucleic acids, for example when cells are damaged by genotoxic agents and in certain autoinflammatory diseases. This review article summarizes current knowledge on the links between nucleic acid sensing and cell death and explores important open questions for future studies in this area.
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Affiliation(s)
- Jonathan Maelfait
- VIB Center for Inflammation Research, 9052 Ghent, Belgium; Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium.
| | - Layal Liverpool
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Jan Rehwinkel
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, UK.
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Mussbacher M, Salzmann M, Brostjan C, Hoesel B, Schoergenhofer C, Datler H, Hohensinner P, Basílio J, Petzelbauer P, Assinger A, Schmid JA. Cell Type-Specific Roles of NF-κB Linking Inflammation and Thrombosis. Front Immunol 2019; 10:85. [PMID: 30778349 PMCID: PMC6369217 DOI: 10.3389/fimmu.2019.00085] [Citation(s) in RCA: 372] [Impact Index Per Article: 74.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 01/11/2019] [Indexed: 12/22/2022] Open
Abstract
The transcription factor NF-κB is a central mediator of inflammation with multiple links to thrombotic processes. In this review, we focus on the role of NF-κB signaling in cell types within the vasculature and the circulation that are involved in thrombo-inflammatory processes. All these cells express NF-κB, which mediates important functions in cellular interactions, cell survival and differentiation, as well as expression of cytokines, chemokines, and coagulation factors. Even platelets, as anucleated cells, contain NF-κB family members and their corresponding signaling molecules, which are involved in platelet activation, as well as secondary feedback circuits. The response of endothelial cells to inflammation and NF-κB activation is characterized by the induction of adhesion molecules promoting binding and transmigration of leukocytes, while simultaneously increasing their thrombogenic potential. Paracrine signaling from endothelial cells activates NF-κB in vascular smooth muscle cells and causes a phenotypic switch to a “synthetic” state associated with a decrease in contractile proteins. Monocytes react to inflammatory situations with enforced expression of tissue factor and after differentiation to macrophages with altered polarization. Neutrophils respond with an extension of their life span—and upon full activation they can expel their DNA thereby forming so-called neutrophil extracellular traps (NETs), which exert antibacterial functions, but also induce a strong coagulatory response. This may cause formation of microthrombi that are important for the immobilization of pathogens, a process designated as immunothrombosis. However, deregulation of the complex cellular links between inflammation and thrombosis by unrestrained NET formation or the loss of the endothelial layer due to mechanical rupture or erosion can result in rapid activation and aggregation of platelets and the manifestation of thrombo-inflammatory diseases. Sepsis is an important example of such a disorder caused by a dysregulated host response to infection finally leading to severe coagulopathies. NF-κB is critically involved in these pathophysiological processes as it induces both inflammatory and thrombotic responses.
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Affiliation(s)
- Marion Mussbacher
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Manuel Salzmann
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Christine Brostjan
- Department of Surgery, General Hospital, Medical University of Vienna, Vienna, Austria
| | - Bastian Hoesel
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | | | - Hannes Datler
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Philipp Hohensinner
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria
| | - José Basílio
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Peter Petzelbauer
- Skin and Endothelial Research Division, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Alice Assinger
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Johannes A Schmid
- Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
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Puyo CA, Earhart A, Staten N, Prince OA, Haug C, Kollef M, Awad M. Endotracheal intubation results in acute tracheal damage induced by mtDNA/TLR9/NF-κB activity. J Leukoc Biol 2018; 105:577-587. [PMID: 30548974 PMCID: PMC7379990 DOI: 10.1002/jlb.5a0718-254rr] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 10/19/2018] [Accepted: 11/25/2018] [Indexed: 12/11/2022] Open
Abstract
Tracheitis secondary to placement of an endotracheal tube (ETT) is characterized by neutrophil accumulation in the tracheal lumen, which is generally associated with epithelial damage. Mitochondrial DNA (mtDNA), has been implicated in systemic inflammation and organ dysfunction following trauma; however, less is known about the effects of a foreign body on local trauma and tissue damage. We hypothesized that tracheal damage secondary to the ETT will result in local release of mtDNA at sufficient levels to induce TLR9 and NF‐κB activation. In a swine model we compared the differences between uncoated, and chloroquine (CQ) and N‐acetylcysteine (NAC) coated ETTs as measured by tracheal lavage fluids (TLF) over a period of 6 h. The swine model allowed us to recreate human conditions. ETT presence was characterized by neutrophil activation, necrosis, and release of proinflammatory cytokines mediated by TLR9/NF‐κB induction. Amelioration of the tracheal damage was observed in the CQ and NAC coated ETT group as shown in tracheal tissue specimens and TLF. The role of TLR9/NF‐κB dependent activity was confirmed by HEK‐Blue hTLR9 reporter cell line analysis after coincubation with TLF specimens with predetermined concentrations of NAC or CQ alone or TLR9 inhibitory oligodeoxynucleotide (iODN). These findings indicate that therapeutic interventions aimed at preventing mtDNA/TLR9/NF‐κB activity may have benefits in prevention of acute tracheal damage.
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Affiliation(s)
- Carlos A Puyo
- Departments of Anesthesiology and Critical Care, Washington University School of Medicine in Saint Louis, St. Louis, Missouri, USA
| | - Alexander Earhart
- Departments of Anesthesiology and Critical Care, Washington University School of Medicine in Saint Louis, St. Louis, Missouri, USA
| | - Nicholas Staten
- Departments of Anesthesiology and Critical Care, Washington University School of Medicine in Saint Louis, St. Louis, Missouri, USA
| | - Oliver A Prince
- Departments of Anesthesiology and Critical Care, Washington University School of Medicine in Saint Louis, St. Louis, Missouri, USA
| | - Colleen Haug
- Departments of Anesthesiology and Critical Care, Washington University School of Medicine in Saint Louis, St. Louis, Missouri, USA
| | - Marin Kollef
- Internal Medicine, Washington University School of Medicine in Saint Louis, St. Louis, Missouri, USA
| | - Michael Awad
- Surgery, Washington University School of Medicine in Saint Louis, St. Louis, Missouri, USA
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6
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Infection with flaviviruses requires BCLXL for cell survival. PLoS Pathog 2018; 14:e1007299. [PMID: 30261081 PMCID: PMC6177207 DOI: 10.1371/journal.ppat.1007299] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/09/2018] [Accepted: 08/27/2018] [Indexed: 12/12/2022] Open
Abstract
BCL2 family proteins including pro-survival proteins, BH3-only proteins and BAX/BAK proteins control mitochondria-mediated apoptosis to maintain cell homeostasis via the removal of damaged cells and pathogen-infected cells. In this study, we examined the roles of BCL2 proteins in the induction of apoptosis in cells upon infection with flaviviruses, such as Japanese encephalitis virus, Dengue virus and Zika virus. We showed that survival of the infected cells depends on BCLXL, a pro-survival BCL2 protein due to suppression of the expression of another pro-survival protein, MCL1. Treatment with BCLXL inhibitors, as well as deficient BCLXL gene expression, induced BAX/BAK-dependent apoptosis upon infection with flaviviruses. Flavivirus infection attenuates cellular protein synthesis, which confers reduction of short-half-life proteins like MCL1. Inhibition of BCLXL increased phagocytosis of virus-infected cells by macrophages, thereby suppressing viral dissemination and chemokine production. Furthermore, we examined the roles of BCLXL in the death of JEV-infected cells during in vivo infection. Haploinsufficiency of the BCLXL gene, as well as administration of BH3 mimetic compounds, increased survival rate after challenge of JEV infection and suppressed inflammation. These results suggest that BCLXL plays a crucial role in the survival of cells infected with flaviviruses, and that BCLXL may provide a novel antiviral target to suppress propagation of the family of Flaviviridae viruses. The genus Flavivirus including Japanese encephalitis virus, Dengue virus, and Zika virus all of which are mosquito-borne human pathogen and cause serious diseases in humans. Therefore, the development of effective vaccines and antivirals against several flaviviruses is still needed. BCL2 family proteins control mitochondria-mediated apoptosis to maintain cell homeostasis via the removal of damaged cells and pathogen-infected cells, deregulation of which leads to severe diseases including cancer and autoimmune diseases. Here, we showed that BCLXL is a critical cell survival factor during infection with flaviviruses, and that inhibition of BCLXL by treatment with BH3 mimetics restricts the production of infectious particles and the expression of chemokines in vitro and in vivo. Inhibition of BCLXL induces apoptosis in cells infected with flaviviruses and these cells are quickly removed by engulfment of phagocytes, which leads to inhibition of virus dissemination without any inflammatory reaction. Based on these data, BCLXL would appear to be a suitable target for the development of novel antivirals against a broad range of flavivirus infections.
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7
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Mitochondrial DNA induces Foley catheter related bladder inflammation via Toll-like receptor 9 activation. Sci Rep 2018; 8:6377. [PMID: 29686303 PMCID: PMC5913242 DOI: 10.1038/s41598-018-24818-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 04/03/2018] [Indexed: 02/08/2023] Open
Abstract
Bladder instrumentation engages the innate immune system via neutrophil activation, promoting inflammation and pain. Elevated levels of mitochondrial DNA (mtDNA) have been associated with tissue damage and organ dysfunction. We hypothesized that local bladder trauma induced by a Foley catheter (FC) will result in mtDNA release, migration of neutrophils into the bladder lumen, and activation of the Toll-like receptor 9 (TLR9) and nuclear factor kappa B (NF-κB) pathway leading to bladder tissue damage. We randomized 10 swine into two groups receiving uncoated, or chloroquine/N-Acetylcysteine (CQ/NAC)-coated FCs. Urine samples were analyzed for mtDNA activation of TLR9/NF-κB as demonstrated by indicators of neutrophil adhesion, migration, and activation. We found that uncoated FCs resulted in a unique active neutrophil phenotype that correlated with bladder epithelial injury, neutrophilia, necrosis, mtDNA release, TLR9/NF-κB activation, transcription and secretion of pro-inflammatory cytokines, and enhanced respiratory burst. In our study we observed that the high levels of mtDNA and elevated TLR9/NF-κB activity were ameliorated in the CQ/NAC-coated FC group. These findings suggest that post-migrated bladder luminal neutrophils are involved in local tissue damage and amelioration of the mtDNA/TLR9/NF-κB inflammatory axis may represent a therapeutic target to prevent inflammation, and bladder tissue injury.
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Phoomvuthisarn P, Cross A, Glennon-Alty L, Wright HL, Edwards SW. The CDK inhibitor purvalanol A induces neutrophil apoptosis and increases the turnover rate of Mcl-1: potential role of p38-MAPK in regulation of Mcl-1 turnover. Clin Exp Immunol 2018; 192:171-180. [PMID: 29377076 DOI: 10.1111/cei.13107] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2018] [Indexed: 12/31/2022] Open
Abstract
Human neutrophils are terminally differentiated cells that do not replicate and yet express a number of enzymes, notably cell cycle-dependent kinases (CDKs), that are associated normally with control of DNA synthesis and cell cycle progression. In neutrophils, CDKs appear to function mainly to regulate apoptosis, although the mechanisms by which they regulate this process are largely unknown. Here we show that the CDK2 inhibitor, purvalanol A, induces a rapid decrease in myeloid cell leukaemia factor-1 (Mcl-1) levels in human neutrophils and peripheral blood mononuclear cells (PBMCs), but only induces apoptosis in neutrophils which are dependent upon expression on this protein for survival. This rapid decrease in cellular Mcl-1 protein levels was due to a purvalanol A-induced decrease in stability, with the half-life of the protein decreasing from approximately 2 h in control cells to just over 1 h after addition of the CDK2 inhibitor: it also blocked the granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent stabilization of Mcl-1. Purvanalol A blocked GM-CSF-stimulated activation of extracellular-regulated kinase (Erk) and signal transducer and activator of transcription (STAT)-3, and stimulated an additive activation of protein kinase B (Akt) with GM-CSF. Purvalanol A alone stimulated a rapid and sustained activation of p38-mitogen-activated protein kinase (MAPK) and the pan p38-MAPK inhibitor, BIRB796, partly blocked the purvalanol A-induced apoptosis and Mcl-1 loss. These novel effects of purvalanol A may result, at least in part, from blocking GM-CSF-mediated Erk activation. In addition, we propose that purvalanol A-induced activation of p38-MAPK is, at least in part, responsible for its rapid effects on Mcl-1 turnover and acceleration of neutrophil apoptosis.
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Affiliation(s)
- P Phoomvuthisarn
- Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - A Cross
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - L Glennon-Alty
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - H L Wright
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - S W Edwards
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
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Pinegin B, Vorobjeva N, Pashenkov M, Chernyak B. The role of mitochondrial ROS in antibacterial immunity. J Cell Physiol 2017; 233:3745-3754. [PMID: 28771715 DOI: 10.1002/jcp.26117] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 08/01/2017] [Indexed: 12/26/2022]
Abstract
Reactive oxygen species (ROS) are essential participants of various innate immune cell responses against microorganisms and are also involved in many cellular regulatory pathways. It was believed that the main pool of ROS in the innate immune cells is generated by the NADPH oxidase enzymatic complex. However, it was discovered recently that mitochondrial ROS (mtROS) are equally important for the functioning of the immune system. mtROS play an important role in the development of the antimicrobial innate immune responses. The present mini-review summarizes the most recent data on the role of mtROS in the antibacterial immunity. The principles of mtROS formation and possible mechanisms of their generation under the activation of innate immunity are highlighted in this review. We also speculate on the possibilities of using activators of mtROS production in clinical practice.
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Affiliation(s)
- Boris Pinegin
- Laboratory of Clinical Immunology, National Research Center "Institute of Immunology" of the Federal Medical-Biological Agency, Moscow, Russia
| | - Nina Vorobjeva
- Department of Immunology, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Mikhail Pashenkov
- Laboratory of Clinical Immunology, National Research Center "Institute of Immunology" of the Federal Medical-Biological Agency, Moscow, Russia
| | - Boris Chernyak
- Department of Bioenergetics, A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
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10
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MicroRNA-451 sensitizes lung cancer cells to cisplatin through regulation of Mcl-1. Mol Cell Biochem 2016; 423:85-91. [PMID: 27686452 DOI: 10.1007/s11010-016-2827-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 09/22/2016] [Indexed: 12/16/2022]
Abstract
As one of the most widely used chemotherapy drugs for lung cancer, chemoresistance of cisplatin (DPP) is one of the major hindrances in treatment of this malignancy. The microRNAs (miRNAs) have been identified to mediate chemotherapy drug resistance. MiR-451 as a tumor suppressor has been evaluated its potential effect on the sensitivity of cancer cells to DDP. However, the role of miR-451 in regulatory mechanism of chemosensitivity in lung cancer cells is still largely unknown. In this study, we first constructed a cisplatin-resistant A549 cell line (A549/DPP) accompanied with a decreased expression of miR-451 and an increased expression of Mcl-1in the drug resistant cells compared with the parental cells. Exogenous expression of miR-451 level in A549/DPP was found to sensitize their reaction to the treatment of cisplatin, which coincides with reduced expression of Mcl-1. Interestingly, Mcl-1 knockdown in A549/DPP cells increased the chemosensitivity to DPP, suggesting the dependence of Mcl-1 regulation in miR-451 activity. Moreover, miR-451 can restore cisplatin treatment response in cisplatin-resistant xenografts in vivo, while Mcl-1 protein levels were decreased. Thus, these findings provided that in lung cancer cells, tumor suppressor miR-451 enhanced DPP sensitivity via regulation of Mcl-1 expression, which could be served as a novel therapeutic target for the treatment of chemotherapy resistant in lung cancer.
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11
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Saxena M, Busca A, Holcik M, Kumar A. Bacterial DNA Protects Monocytic Cells against HIV-Vpr-Induced Mitochondrial Membrane Depolarization. THE JOURNAL OF IMMUNOLOGY 2016; 196:3754-67. [PMID: 26969755 DOI: 10.4049/jimmunol.1402379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 02/19/2016] [Indexed: 12/26/2022]
Abstract
Monocytes and macrophages are important HIV reservoirs, as they exhibit marked resistance to apoptosis upon infection. However, the mechanism underlying resistance to apoptosis in these cells is poorly understood. Using HIV-viral protein R-52-96 aa peptide (Vpr), we show that primary monocytes and THP-1 cells treated with Vpr are highly susceptible to mitochondrial depolarization, but develop resistance following stimulation with bacterial DNA or CpG oligodeoxynucleotide. We have shown that Vpr-induced mitochondrial depolarization is mediated by TNFR-associated factor-1 (TRAF-1) and TRAF-2 degradation and subsequent activation of caspase-8, Bid, and Bax. To provide the mechanism governing such resistance to mitochondrial depolarization, our results show that prior stimulation with CpG oligodeoxynucleotide or Escherichia coli DNA prevented: 1) TRAF-1/2 downregulation; 2) activation of caspase-8, Bid, and Bax; and 3) subsequent mitochondrial depolarization and release of apoptosis-inducing factor and cytochrome c Furthermore, this protection was mediated by upregulation of antiapoptotic protein (c-IAP-2) through calmodulin-dependent kinase-II activation. Thus, c-IAP-2 may prevent Vpr-mediated mitochondrial depolarization through stabilizing TRAF-1/2 expression and sequential inhibition of caspase-8, Bid, and Bax.
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Affiliation(s)
- Mansi Saxena
- Department of Biochemistry, Microbiology and Immunology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
| | - Aurelia Busca
- Department of Biochemistry, Microbiology and Immunology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
| | - Martin Holcik
- Research Institute, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada; and
| | - Ashok Kumar
- Department of Biochemistry, Microbiology and Immunology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada; Research Institute, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada; and Department of Pathology and Laboratory Medicine, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
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12
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Abstract
Upon entry to the systemic circulation, neutrophils exhibit a short mean time to cell death. The viability of most cell types in a steady state is preserved by the interplay of the Bcl-2 family of proteins, wherein the anti-apoptotic members inhibit the action of their pro-apoptotic counterparts. Neutrophils, however, display absent or severely reduced expression of several anti-apoptotic Bcl-2 family proteins. Hence, they rely on the expression of Mcl-1, an anti-apoptotic member of the Bcl-2 family, for survival. This protein is uniquely short-lived relative to related proteins and its loss likely precipitates the induction of apoptosis in neutrophils. This review describes the role of Mcl-1 in the neutrophil in the context of apoptosis and highlights the proteins' importance to the cell. We also address neutrophil apoptosis in the broader context of the cells' response to pathogens, focussing particularly on the strategies used by pathogens to manipulate the apoptotic pathway to their own ends.
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Affiliation(s)
- Mark P Murphy
- Centre for Microbial-Host Interactions, Institute of Technology Tallaght, Old Blessington Road, Tallaght, Dublin 24, Ireland,
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13
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Yang ZW, Meng XX, Xu P. Central role of neutrophil in the pathogenesis of severe acute pancreatitis. J Cell Mol Med 2015; 19:2513-20. [PMID: 26249268 PMCID: PMC4627557 DOI: 10.1111/jcmm.12639] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 05/20/2015] [Indexed: 02/06/2023] Open
Abstract
Severe acute pancreatitis (SAP) is an acute abdominal disease with the strong systemic inflammatory response, and rapidly progresses from a local pancreatic damage into multiple organ dysfunction. For many decades, the contributions of neutrophils to the pathology of SAP were traditionally thought to be the chemokine and cytokine cascades that accompany inflammation. In this review, we focus mainly on those recently recognized aspects of neutrophils in SAP processes. First, emerging evidence suggests that therapeutic interventions targeting neutrophils significantly lower tissue damage and protect against the occurrence of pancreatitis. Second, trypsin activation promotes the initial neutrophils recruitment into local pancreas, and subsequently neutrophils infiltration in turn triggers trypsin production. Finally, neutrophils have the unique ability to release neutrophil extracellular traps even in the absence of pathogens.
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Affiliation(s)
- Zhi-Wen Yang
- Pharmacy Department, Songjiang Hospital Affiliated the First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Xiao-Xiao Meng
- Digestive Department, Songjiang Hospital Affiliated the First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Ping Xu
- Digestive Department, Songjiang Hospital Affiliated the First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
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