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Gong S, Chen J, Zheng X, Lu X, Chen M, Li J, Su Z, Liu Y, Chen J, Xie J, Xie Q, Li Y. Kidney targeting and modulating macrophage polarization through AMPK signaling: Therapeutic mechanism of berberine in uric acid nephropathy. Int Immunopharmacol 2024; 138:112632. [PMID: 38986300 DOI: 10.1016/j.intimp.2024.112632] [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: 06/05/2024] [Revised: 07/02/2024] [Accepted: 07/02/2024] [Indexed: 07/12/2024]
Abstract
Uric acid nephropathy (UAN), caused by a common metabolic disorder resulting from hyperuricemia (HUA), has an increasing incidence. Previous studies have shown that berberine (BBR) has clear urate-lowering and anti-inflammatory effects in UAN mice, but its mechanism needs to be further clarified. Therefore, Potassium Oxonate (PO) combined with hypoxanthine (HX) induced UAN mice model and MSU induced THP-1 cells polarization model were adopted to investigate the mechanism of BBR on UAN in terms of tissue distribution and molecular pharmacology. Study unveiled that BBR was first found to bind to red blood cells (RBCs), which were recognized and phagocytosed by monocytes, then recruited by the injured kidney. Subsequently, BBR was enriched and functional in damaged kidney. The results of in vivo experiments revealed that, BBR reduced UA, BUN, CRE levels as well as the release of TNF-α, IL-1β, IL-18 and IL-6, and alleviated renal injury in UAN mice, as consistent with previous studies. Additionally, BBR decreased MCP-1 expression, while diminishing macrophage infiltration and decreasing M1 proportion as determined by RT-qPCR. In vitro experiments, demonstrated that MSU promoted inflammatory polarization of THP-1 cells, while BBR reduced synthesis of inflammatory factors and inhibited MSU-induced inflammatory polarization. These effects of BBR were dependent on AMPK activation along with indirect inhibition of NF-κB signaling pathway mediated. However, the anti-inflammatory and macrophage polarization regulation effects of BBR were completely reversed upon administration of Compound C, an AMPK inhibitor. Therefore, BBR ameliorated kidney injury via regulating macrophage polarization through AMPK, which has therapeutic potential for UAN patients.
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Affiliation(s)
- Shiting Gong
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China; Dongguan Institute of Guangzhou University of Chinese Medicine, Dongguan 523808, China
| | - Jingzhi Chen
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Xiaohong Zheng
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Xiaowei Lu
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Manru Chen
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Jincan Li
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Ziren Su
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Yuhong Liu
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China; Dongguan Institute of Guangzhou University of Chinese Medicine, Dongguan 523808, China
| | - Jiannan Chen
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China; Dongguan Institute of Guangzhou University of Chinese Medicine, Dongguan 523808, China
| | - Jianhui Xie
- The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Qingfeng Xie
- The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
| | - Yucui Li
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China; Dongguan Institute of Guangzhou University of Chinese Medicine, Dongguan 523808, China.
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Sudi S, Thomas FM, Daud SK, Ag Daud DM, Sunggip C. The Pleiotropic Role of Extracellular ATP in Myocardial Remodelling. Molecules 2023; 28:molecules28052102. [PMID: 36903347 PMCID: PMC10004151 DOI: 10.3390/molecules28052102] [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: 01/26/2023] [Revised: 02/17/2023] [Accepted: 02/18/2023] [Indexed: 03/12/2023] Open
Abstract
Myocardial remodelling is a molecular, cellular, and interstitial adaptation of the heart in response to altered environmental demands. The heart undergoes reversible physiological remodelling in response to changes in mechanical loading or irreversible pathological remodelling induced by neurohumoral factors and chronic stress, leading to heart failure. Adenosine triphosphate (ATP) is one of the potent mediators in cardiovascular signalling that act on the ligand-gated (P2X) and G-protein-coupled (P2Y) purinoceptors via the autocrine or paracrine manners. These activations mediate numerous intracellular communications by modulating the production of other messengers, including calcium, growth factors, cytokines, and nitric oxide. ATP is known to play a pleiotropic role in cardiovascular pathophysiology, making it a reliable biomarker for cardiac protection. This review outlines the sources of ATP released under physiological and pathological stress and its cell-specific mechanism of action. We further highlight a series of cardiovascular cell-to-cell communications of extracellular ATP signalling cascades in cardiac remodelling, which can be seen in hypertension, ischemia/reperfusion injury, fibrosis, hypertrophy, and atrophy. Finally, we summarize current pharmacological intervention using the ATP network as a target for cardiac protection. A better understanding of ATP communication in myocardial remodelling could be worthwhile for future drug development and repurposing and the management of cardiovascular diseases.
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Affiliation(s)
- Suhaini Sudi
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
| | - Fiona Macniesia Thomas
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
| | - Siti Kadzirah Daud
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
| | - Dayang Maryama Ag Daud
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
- Health through Exercise and Active Living (HEAL) Research Unit, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
| | - Caroline Sunggip
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
- Correspondence:
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Praetorius H. The bacteria and the host: a story of purinergic signaling in urinary tract infections. Am J Physiol Cell Physiol 2021; 321:C134-C146. [PMID: 33979212 DOI: 10.1152/ajpcell.00054.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The local environment forces a selection of bacteria that might invade the urinary tract, allowing only the most virulent to access the kidney. Quite similar to the diet in setting the stage for the gut microbiome, renal function determines the conditions for bacteria-host interaction in the urinary tract. In the kidney, the term local environment or microenvironment is completely justified because the environment literally changes within a few micrometers. The precise composition of the urine is a function of the epithelium lining the microdomain, and the microenvironment in the kidney shows more variation in the content of nutrients, ion composition, osmolality, and pH than any other site of bacteria-host interaction. This review will cover some of the aspects of bacterial-host interaction in this unique setting and how uropathogenic bacteria can alter the condition for bacteria-host interaction. There will be a particular focus on the recent findings regarding how bacteria specifically trigger host paracrine signaling, via release of extracellular ATP and activation of P2 purinergic receptors. These finding will be discussed from the perspective of severe urinary tract infections, including pyelonephritis and urosepsis.
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Prevention of P2 Receptor-Dependent Thrombocyte Activation by Pore-Forming Bacterial Toxins Improves Outcome in A Murine Model of Urosepsis. Int J Mol Sci 2020; 21:ijms21165652. [PMID: 32781764 PMCID: PMC7460651 DOI: 10.3390/ijms21165652] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 12/31/2022] Open
Abstract
Urosepsis is a potentially life-threatening, systemic reaction to uropathogenic bacteria entering the bloodstream of the host. One of the hallmarks of sepsis is early thrombocyte activation with a following fall in circulating thrombocytes as a result of intravascular aggregation and sequestering of thrombocytes in the major organs. Development of a thrombocytopenic state is associated with a poorer outcome of sepsis. Uropathogenic Escherichia coli frequently produce the pore-forming, virulence factor α-haemolysin (HlyA), of which the biological effects are mediated by ATP release and subsequent activation of P2 receptors. Thus, we speculated that inhibition of thrombocyte P2Y1 and P2Y12 receptors might ameliorate the septic response to HlyA-producing E. coli. The study combined in vitro measurements of toxin-induced thrombocyte activation assessed as increased membrane abundance of P-selectin, fibronectin and CD63 and data from in vivo murine model of sepsis-induced by HlyA-producing E. coli under infusion of P2Y1 and P2Y12 antagonists. Our data show that the P2Y1 receptor antagonist almost abolishes thrombocyte activation by pore-forming bacterial toxins. Inhibition of P2Y1, by constant infusion of MRS2500, markedly increased the survival in mice with induced sepsis. Moreover, MRS2500 partially prevented the sepsis-induced depletion of circulating thrombocytes and dampened the sepsis-associated increase in proinflammatory cytokines. In contrast, P2Y12 receptor inhibition had only a marginal effect in vivo and in vitro. Taken together, inhibition of the P2Y1 receptor gives a subtle dampening of the thrombocyte activation and the cytokine response to bacteraemia, which may explain the improved survival observed by P2Y1 receptor antagonists.
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Johnsen N, Hamilton ADM, Greve AS, Christensen MG, Therkildsen JR, Wehmöller J, Skals M, Praetorius HA. α-Haemolysin production, as a single factor, causes fulminant sepsis in a model of Escherichia coli-induced bacteraemia. Cell Microbiol 2019; 21:e13017. [PMID: 30761726 DOI: 10.1111/cmi.13017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 02/08/2019] [Accepted: 02/10/2019] [Indexed: 12/14/2022]
Abstract
α-Haemolysin (HlyA) from uropathogenic Escherichia coli has been demonstrated to be a significant virulence factor for ascending urinary tract infections. Once the E. coli reach the well-vascularised kidneys, there is a high risk of bacteraemia and a subsequent septic host response. Despite this, HlyA has the potential to accelerate the host response both directly and via its ability to facilitate adenosine triphosphate release from cells. It has not been settled whether HlyA aggravates bacteraemia into a septic state. To address this, we used an E. coli strain in a model of acute urosepsis that was either transfected with a plasmid containing the full HlyA operon or one with deletion in the HlyA gene. Here, we show that HlyA accelerates the host response to E. coli in the circulation. Mice exposed to HlyA-producing E. coli showed massively increased proinflammatory cytokines, a substantial fall in circulating thrombocytes, extensive haematuria, and intravascular haemolysis. This was not seen in mice exposed to either E. coli that do not secrete HlyA or vehicle controls. Consistent with the massive host response to the bacteria, the mice exposed to HlyA-producing E. coli died exceedingly early, whereas mice exposed to E. coli without HlyA production and vehicle controls survived the entire observation period. These data allow us to conclude that HlyA is a virulence factor that accelerates a state of bacteraemia into fulminant sepsis in a mouse model.
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Affiliation(s)
- Nanna Johnsen
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | | | | | | | | | - Julia Wehmöller
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Marianne Skals
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
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6
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Fagerberg SK, Patel P, Andersen LW, Lui X, Donnino MW, Praetorius HA. Erythrocyte P2X 1 receptor expression is correlated with change in haematocrit in patients admitted to the ICU with blood pathogen-positive sepsis. Crit Care 2018; 22:181. [PMID: 30071869 PMCID: PMC6091015 DOI: 10.1186/s13054-018-2100-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 06/19/2018] [Indexed: 12/03/2022] Open
Abstract
Background Pore-forming proteins released from bacteria or formed as result of complement activation are known to produce severe cell damage. Inhibition of purinergic P2X receptors markedly reduces damage inflicted by cytolytic bacterial toxin and after complement activation in both erythrocytes and monocytes. P2X expression generally shows variation throughout the population. Here, we investigate correlation between P2X receptor abundance in blood cell plasma membranes and haematocrit during sepsis, in patients admitted to the emergency department (ED) or intensive care unit (ICU). Method Patients admitted to the ED and successively transferred to ICU with the diagnosis sepsis (< 2 systemic inflammatory response syndrome (SIRS) criteria and suspected infection), were grouped as either blood pathogen-positive (14 patients) or blood pathogen-negative (20 patients). Blood samples drawn at ICU admission were analysed for P2X1 and P2X7 receptor abundance using indirect flow cytometry. Results Here, we find inverse correlation between P2X1 receptor expression and change in haematocrit (rs − 0.80) and haemoglobin (rs − 0.78) levels from admission to ED to arrival at ICU in patients with pathogen-positive sepsis. This correlation was not found in patients without confirmed bacteraemia. Patients with high P2X1 expression had a significantly greater change in both haematocrit (− 0.59 ± 0.36) and haemoglobin levels (− 0.182 ± 0.038 mg/dl) per hour, during the first hours after hospital admission compared to patients with low P2X1 expression (0.007 ± 0.182 and − 0.020 ± 0.058 mg/dl, respectively). Conclusion High levels of P2X1 are correlated with more pronounced reduction in haematocrit and haemoglobin in patients with confirmed bacteraemia. This supports previous in vitro findings of P2X activation as a significant component in cell damage caused by pore-forming bacterial toxins and complement-dependent major attack complex. These data suggest a new potential target for future therapeutics in initial stages of sepsis. Electronic supplementary material The online version of this article (10.1186/s13054-018-2100-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Steen K Fagerberg
- Department of Biomedicine, Physiology, Aarhus University, Ole Worms Alle 3, build 1170, 8000, Aarhus C, Denmark.,Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Parth Patel
- Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Lars W Andersen
- Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.,Research Center for Emergency Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Xiaowen Lui
- Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Michael W Donnino
- Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Helle A Praetorius
- Department of Biomedicine, Physiology, Aarhus University, Ole Worms Alle 3, build 1170, 8000, Aarhus C, Denmark.
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Schwiering M, Husmann M, Hellmann N. P2X-Receptor Antagonists Inhibit the Interaction of S. aureus Hemolysin A with Membranes. Toxins (Basel) 2017; 9:toxins9100332. [PMID: 29048353 PMCID: PMC5666378 DOI: 10.3390/toxins9100332] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/08/2017] [Accepted: 10/15/2017] [Indexed: 11/21/2022] Open
Abstract
The pore forming hemolysin A, Hla, is a major virulence factor of Staphylococcus aureus. Apparently, 1–2 pore(s) per cell suffice(s) to cause cell death. Accumulated experimental evidence points towards a major role of ATP-gated purinergic receptors (P2XR) for hemolysis caused by Hla, complement and other pore forming proteins, presumably by increasing membrane permeability. Indeed, in experiments employing rabbit erythrocytes, inhibitory concentrations of frequently employed P2XR-antagonists were in a similar range as previously reported for erythrocytes of other species and other toxins. However, Hla-dependent hemolysis was not enhanced by extracellular ATP, and oxidized adenosinetriphosphate (oxATP) had only a minor inhibitory effect. Unexpectedly, P2XR-inhibitors also prevented Hla-induced lysis of pure lipid membranes, demonstrating that the inhibition did not even depend on the presence of P2XR. Fluorescence microscopy and gel-electrophoresis clearly revealed that P2XR-inhibitors interfere with binding and subsequent oligomerisation of Hla with membranes. Similar results were obtained employing HaCaT-cells. Furthermore, calorimetric data and hemolysis experiments with Hla pre-treated with pyridoxal phosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS) showed that this compound directly binds to Hla. Our results call for a critical re-assessment of the appealing concept, which suggests that P2XR are general amplifiers of damage by pore-forming proteins.
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Affiliation(s)
- Markus Schwiering
- Institute for Molecular Biophysics, Jakob-Welder-Weg 26, University of Mainz, 55128 Mainz, Germany.
| | - Matthias Husmann
- Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg-University Mainz, Hochhaus am Augustusplatz, 55131 Mainz, Germany.
| | - Nadja Hellmann
- Institute for Molecular Biophysics, Jakob-Welder-Weg 26, University of Mainz, 55128 Mainz, Germany.
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Söderström CM, Fagerberg SK, Brogaard MB, Leipziger J, Skals M, Praetorius HA. Loop Diuretics Diminish Hemolysis Induced by α-Hemolysin from Escherichia coli. J Membr Biol 2017; 250:301-313. [DOI: 10.1007/s00232-017-9963-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 04/18/2017] [Indexed: 10/19/2022]
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Greve AS, Skals M, Fagerberg SK, Tonnus W, Ellermann-Eriksen S, Evans RJ, Linkermann A, Praetorius HA. P2X 1, P2X 4, and P2X 7 Receptor Knock Out Mice Expose Differential Outcome of Sepsis Induced by α-Haemolysin Producing Escherichia coli. Front Cell Infect Microbiol 2017; 7:113. [PMID: 28428949 PMCID: PMC5382212 DOI: 10.3389/fcimb.2017.00113] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/21/2017] [Indexed: 11/13/2022] Open
Abstract
α-haemolysin (HlyA)-producing Escherichia coli commonly inflict severe urinary tract infections, including pyelonephritis, which comprises substantial risk for sepsis. In vitro, the cytolytic effect of HlyA is mainly mediated by ATP release through the HlyA pore and subsequent P2X1/P2X7 receptor activation. This amplification of the lytic process is not unique to HlyA but is observed by many other pore-forming proteins including complement-induced haemolysis. Since free hemoglobin in the blood is known to be associated with a worse outcome in sepsis one could speculate that inhibition of P2X receptors would ameliorate the course of sepsis. Surprisingly, this study demonstrates that [Formula: see text] and [Formula: see text] mice are exceedingly sensitive to sepsis with uropathogenic E. coli. These mice have markedly lower survival, higher cytokine levels and activated intravascular coagulation. Quite the reverse is seen in [Formula: see text] mice, which had markedly lower cytokine levels and less coagulation activation compared to controls after exposure to uropathogenic E. coli. The high cytokine levels in the [Formula: see text] mouse are unexpected, since P2X7 is implicated in caspase-1-dependent IL-1β production. Here, we demonstrate that IL-1β production during sepsis with uropathogenic E. coli is mediated by caspase-8, since caspase-8 and RIPK3 double knock out mice show substantially lower cytokine during sepsis and increased survival after injection of TNFα. These data support that P2X7 and P2X4 receptor activation has a protective effect during severe E. coli infection.
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Affiliation(s)
| | - Marianne Skals
- Department of Biomedicine, Aarhus UniversityAarhus, Denmark.,Department of Clinical Microbiology, Aarhus University HospitalAarhus, Denmark
| | | | - Wulf Tonnus
- Division of Nephrology, Medical Clinic III, University Hospital Carl Gustav Carus DresdenDresden, Germany
| | | | - Richard J Evans
- Department of Molecular and Cell Biology, University of LeicesterLeicester, UK
| | - Andreas Linkermann
- Division of Nephrology, Medical Clinic III, University Hospital Carl Gustav Carus DresdenDresden, Germany
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Inhibition of P2X Receptors Protects Human Monocytes against Damage by Leukotoxin from Aggregatibacter actinomycetemcomitans and α-Hemolysin from Escherichia coli. Infect Immun 2016; 84:3114-3130. [PMID: 27528275 DOI: 10.1128/iai.00674-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 01/14/2023] Open
Abstract
α-Hemolysin (HlyA) from Escherichia coli and leukotoxin A (LtxA) from Aggregatibacter actinomycetemcomitans are important virulence factors in ascending urinary tract infections and aggressive periodontitis, respectively. The extracellular signaling molecule ATP is released immediately after insertion of the toxins into plasma membranes and, via P2X receptors, is essential for the erythrocyte damage inflicted by these toxins. Moreover, ATP signaling is required for the ensuing recognition and phagocytosis of damaged erythrocytes by the monocytic cell line THP-1. Here, we investigate how these toxins affect THP-1 monocyte function. We demonstrate that both toxins trigger early ATP release and a following increase in the intracellular Ca2+ concentration ([Ca2+]i) in THP-1 monocytes. The HlyA- and LtxA-induced [Ca2+]i response is diminished by the P2 receptor antagonist in a pattern that fits the functional P2 receptor expression in these cells. Both toxins are capable of lysing THP-1 cells, with LtxA being more aggressive. Either desensitization or blockage of P2X1, P2X4, or P2X7 receptors markedly reduces toxin-induced cytolysis. This pattern is paralleled in freshly isolated human monocytes from healthy volunteers. Interestingly, only a minor fraction of the toxin-damaged THP-1 monocytes eventually lyse. P2X7 receptor inhibition generally prevents cell damage, except from a distinct cell shrinkage that prevails in response to the toxins. Moreover, we find that preexposure to HlyA preserves the capacity of THP-1 monocytes to phagocytose damaged erythrocytes and may induce readiness to discriminate between damaged and healthy erythrocytes. These findings suggest a new pharmacological target for protecting monocytes during exposure to pore-forming cytolysins during infection or injury.
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Burnstock G. Blood cells: an historical account of the roles of purinergic signalling. Purinergic Signal 2015; 11:411-34. [PMID: 26260710 PMCID: PMC4648797 DOI: 10.1007/s11302-015-9462-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 07/23/2015] [Indexed: 12/17/2022] Open
Abstract
The involvement of purinergic signalling in the physiology of erythrocytes, platelets and leukocytes was recognised early. The release of ATP and the expression of purinoceptors and ectonucleotidases on erythrocytes in health and disease are reviewed. The release of ATP and ADP from platelets and the expression and roles of P1, P2Y(1), P2Y(12) and P2X1 receptors on platelets are described. P2Y(1) and P2X(1) receptors mediate changes in platelet shape, while P2Y(12) receptors mediate platelet aggregation. The changes in the role of purinergic signalling in a variety of disease conditions are considered. The successful use of P2Y(12) receptor antagonists, such as clopidogrel and ticagrelor, for the treatment of thrombosis, myocardial infarction and stroke is discussed.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK.
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Australia.
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12
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Graham A. Mitochondrial regulation of macrophage cholesterol homeostasis. Free Radic Biol Med 2015; 89:982-92. [PMID: 26416507 DOI: 10.1016/j.freeradbiomed.2015.08.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 07/28/2015] [Accepted: 08/11/2015] [Indexed: 12/19/2022]
Abstract
This review explores the relationship between mitochondrial structure and function in the regulation of macrophage cholesterol metabolism and proposes that mitochondrial dysfunction contributes to loss of the elegant homeostatic mechanisms which normally maintain cellular sterol levels within defined limits. Mitochondrial sterol 27-hydroxylase (CYP27A1) can generate oxysterol activators of liver X receptors which heterodimerise with retinoid X receptors, enhancing the transcription of ATP binding cassette transporters (ABCA1, ABCG1, and ABCG4), that can remove excess cholesterol via efflux to apolipoproteins A-1, E, and high density lipoprotein, and inhibit inflammation. The activity of CYP27A1 is regulated by the rate of supply of cholesterol substrate to the inner mitochondrial membrane, mediated by a complex of proteins. The precise identity of this dynamic complex remains controversial, even in steroidogenic tissues, but may include steroidogenic acute regulatory protein and the 18 kDa translocator protein, together with voltage-dependent anion channels, ATPase AAA domain containing protein 3A, and optic atrophy type 1 proteins. Certainly, overexpression of StAR and TSPO proteins can enhance macrophage cholesterol efflux to apoA-I and/or HDL, while perturbations in mitochondrial function, or changes in the expression of mitochondrial fusion proteins, alter the efficiency of cholesterol efflux. Molecules which can sustain or improve mitochondrial function or increase the activity of the protein complex involved in cholesterol transfer may have utility in resolving the problem of dysregulated macrophage cholesterol homeostasis, a condition which may contribute to inflammation, atherosclerosis, nonalcoholic steatohepatitis, osteoblastic bone resorption, and some disorders of the central nervous system.
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Affiliation(s)
- Annette Graham
- Department of Life Sciences, School of Health and Life Sciences, and Institute for Applied Health Research, Glasgow Caledonian University, 70 Cowcaddens Road, Glasgow G4 0BA, United Kingdom.
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13
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Sluyter R. P2X and P2Y receptor signaling in red blood cells. Front Mol Biosci 2015; 2:60. [PMID: 26579528 PMCID: PMC4623207 DOI: 10.3389/fmolb.2015.00060] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 10/10/2015] [Indexed: 12/29/2022] Open
Abstract
Purinergic signaling involves the activation of cell surface P1 and P2 receptors by extracellular nucleosides and nucleotides such as adenosine and adenosine triphosphate (ATP), respectively. P2 receptors comprise P2X and P2Y receptors, and have well-established roles in leukocyte and platelet biology. Emerging evidence indicates important roles for these receptors in red blood cells. P2 receptor activation stimulates a number of signaling pathways in progenitor red blood cells resulting in microparticle release, reactive oxygen species formation, and apoptosis. Likewise, activation of P2 receptors in mature red blood cells stimulates signaling pathways mediating volume regulation, eicosanoid release, phosphatidylserine exposure, hemolysis, impaired ATP release, and susceptibility or resistance to infection. This review summarizes the distribution of P2 receptors in red blood cells, and outlines the functions of P2 receptor signaling in these cells and its implications in red blood cell biology.
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Affiliation(s)
- Ronald Sluyter
- School of Biological Sciences, University of WollongongWollongong, NSW, Australia
- Centre for Medical and Molecular Bioscience, University of WollongongWollongong, NSW, Australia
- Illawarra Health and Medical Research InstituteWollongong, NSW, Australia
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14
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Nagahama M, Seike S, Shirai H, Takagishi T, Kobayashi K, Takehara M, Sakurai J. Role of P2X7 receptor in Clostridium perfringens beta-toxin-mediated cellular injury. Biochim Biophys Acta Gen Subj 2015; 1850:2159-67. [PMID: 26299247 DOI: 10.1016/j.bbagen.2015.08.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/29/2015] [Accepted: 08/12/2015] [Indexed: 01/02/2023]
Abstract
BACKGROUND Clostridium perfringens beta-toxin is a pore-forming toxin (PFT) and an important agent of necrotic enteritis and enterotoxemia. We recently reported that beta-toxin strongly induced cell death in THP-1 cells via the formation of oligomers. We here describe that the P2X(7) receptor, which is an ATP receptor, interacts with beta-toxin. METHODS We tested the role of P2X(7) receptor in beta-toxin-induced toxicity using specific inhibitors, knockdown of receptor, expression of the receptor and interaction by dot-blot assay. The potency of P2X(7) receptor was further determined using an in vivo mouse model. RESULTS Selective P2X(7) receptor antagonists (oxidized ATP (o-ATP), oxidized ADP, and Brilliant Blue G (BBG)) inhibited beta-toxin-induced cytotoxicity in THP-1 cells. o-ATP also blocked the binding of beta-toxin to cells. The P2X(7) receptor and beta-toxin oligomer were localized in the lipid rafts of THP-1 cells. siRNA for the P2X(7) receptor inhibited toxin-induced cytotoxicity and binding of the toxin. In contrast, the siRNA knockdown of P2Y(2) or P2Y(6) had no effect on beta-toxin-induced cytotoxicity. The addition of beta-toxin to P2X(7)-transfected HEK-293 cells resulted in binding of beta-toxin oligomer. Moreover, beta-toxin specifically bound to immobilized P2X(7) receptors in vitro and colocalized with the P2X(7) receptor on the THP-1 cell surface. Furthermore, beta-toxin-induced lethality in mice was blocked by the preadministration of BBG. CONCLUSIONS The results of this study indicate that the P2X(7) receptor plays a role in beta-toxin-mediated cellular injury. GENERAL SIGNIFICANCE P2X(7) receptor is a potential target for the treatment of C. perfringens type C infection.
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Affiliation(s)
- Masahiro Nagahama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
| | - Soshi Seike
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Hidenori Shirai
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Teruhisa Takagishi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Keiko Kobayashi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Masaya Takehara
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Jun Sakurai
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
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15
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Skals M, Praetorius HA. Mechanisms of cytolysin-induced cell damage -- a role for auto- and paracrine signalling. Acta Physiol (Oxf) 2013; 209:95-113. [PMID: 23927595 DOI: 10.1111/apha.12156] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/21/2013] [Accepted: 07/30/2013] [Indexed: 12/22/2022]
Abstract
Cytolysins inflict cell damage by forming pores in the plasma membrane. The Na(+) conductivity of these pores results in an ion influx that exceeds the capacity of the Na(+) /K(+) -pump to extrude Na(+) . This net load of intracellular osmolytes results in swelling and eventual lysis of the attacked cell. Many nucleated cells have the capacity to reduce the potential damage of pore-forming proteins, whereas erythrocytes have been regarded as essentially defenceless against cytolysin-induced cell damage. This review addresses how autocrine/paracrine signalling and the cells intrinsic volume regulation markedly influence the fate of the cell after membrane insertion of cytolysins. Moreover, it regards the various steps that may explain the relative large degree of diversity between cell types and species as well as highlights some of the current gaps in the mechanistic understanding of cytolysin-induced cell injury.
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Affiliation(s)
- M. Skals
- Department of Biomedicine; Aarhus University; Aarhus C; Denmark
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Differences in purinergic amplification of osmotic cell lysis by the pore-forming RTX toxins Bordetella pertussis CyaA and Actinobacillus pleuropneumoniae ApxIA: the role of pore size. Infect Immun 2013; 81:4571-82. [PMID: 24082076 DOI: 10.1128/iai.00711-13] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A large subgroup of the repeat in toxin (RTX) family of leukotoxins of Gram-negative pathogens consists of pore-forming hemolysins. These can permeabilize mammalian erythrocytes (RBCs) and provoke their colloid osmotic lysis (hemolytic activity). Recently, ATP leakage through pannexin channels and P2X receptor-mediated opening of cellular calcium and potassium channels were implicated in cell permeabilization by pore-forming toxins. In the study described here, we examined the role played by purinergic signaling in the cytolytic action of two RTX toxins that form pores of different sizes. The cytolytic potency of ApxIA hemolysin of Actinobacillus pleuropneumoniae, which forms pores about 2.4 nm wide, was clearly reduced in the presence of P2X7 receptor antagonists or an ATP scavenger, such as pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS), Brilliant Blue G, ATP oxidized sodium salt, or hexokinase. In contrast, antagonists of purinergic signaling had no impact on the hemolytic potency of the adenylate cyclase toxin-hemolysin (CyaA) of Bordetella pertussis, which forms pores of 0.6 to 0.8 nm in diameter. Moreover, the conductance of pores formed by ApxIA increased with the toxin concentration, while the conductance of the CyaA single pore units was constant at various toxin concentrations. However, the P2X7 receptor antagonist PPADS inhibited in a concentration-dependent manner the exacerbated hemolytic activity of a CyaA-ΔN489 construct (lacking 489 N-terminal residues of CyaA), which exhibited a strongly enhanced pore-forming propensity (>20-fold) and also formed severalfold larger conductance units in planar lipid bilayers than intact CyaA. These results point to a pore size threshold of purinergic amplification involvement in cell permeabilization by pore-forming RTX toxins.
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