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Chen WA, Dou Y, Fletcher HM, Boskovic DS. Local and Systemic Effects of Porphyromonas gingivalis Infection. Microorganisms 2023; 11:470. [PMID: 36838435 PMCID: PMC9963840 DOI: 10.3390/microorganisms11020470] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/16/2023] Open
Abstract
Porphyromonas gingivalis, a gram-negative anaerobe, is a leading etiological agent in periodontitis. This infectious pathogen can induce a dysbiotic, proinflammatory state within the oral cavity by disrupting commensal interactions between the host and oral microbiota. It is advantageous for P. gingivalis to avoid complete host immunosuppression, as inflammation-induced tissue damage provides essential nutrients necessary for robust bacterial proliferation. In this context, P. gingivalis can gain access to the systemic circulation, where it can promote a prothrombotic state. P. gingivalis expresses a number of virulence factors, which aid this pathogen toward infection of a variety of host cells, evasion of detection by the host immune system, subversion of the host immune responses, and activation of several humoral and cellular hemostatic factors.
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Affiliation(s)
- William A Chen
- Division of Biochemistry, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Yuetan Dou
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Hansel M Fletcher
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Danilo S Boskovic
- Division of Biochemistry, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
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2
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Liu W, Cronin CG, Cao Z, Wang C, Ruan J, Pulikkot S, Hall A, Sun H, Groisman A, Chen Y, Vella AT, Hu L, Liang BT, Fan Z. Nexinhib20 Inhibits Neutrophil Adhesion and β 2 Integrin Activation by Antagonizing Rac-1-Guanosine 5'-Triphosphate Interaction. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 209:1574-1585. [PMID: 36165184 PMCID: PMC9529951 DOI: 10.4049/jimmunol.2101112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 08/03/2022] [Indexed: 11/07/2022]
Abstract
Neutrophils are critical for mediating inflammatory responses. Inhibiting neutrophil recruitment is an attractive approach for preventing inflammatory injuries, including myocardial ischemia-reperfusion (I/R) injury, which exacerbates cardiomyocyte death after primary percutaneous coronary intervention in acute myocardial infarction. In this study, we found out that a neutrophil exocytosis inhibitor Nexinhib20 inhibits not only exocytosis but also neutrophil adhesion by limiting β2 integrin activation. Using a microfluidic chamber, we found that Nexinhib20 inhibited IL-8-induced β2 integrin-dependent human neutrophil adhesion under flow. Using a dynamic flow cytometry assay, we discovered that Nexinhib20 suppresses intracellular calcium flux and β2 integrin activation after IL-8 stimulation. Western blots of Ras-related C3 botulinum toxin substrate 1 (Rac-1)-GTP pull-down assays confirmed that Nexinhib20 inhibited Rac-1 activation in leukocytes. An in vitro competition assay showed that Nexinhib20 antagonized the binding of Rac-1 and GTP. Using a mouse model of myocardial I/R injury, Nexinhib20 administration after ischemia and before reperfusion significantly decreased neutrophil recruitment and infarct size. Our results highlight the translational potential of Nexinhib20 as a dual-functional neutrophil inhibitory drug to prevent myocardial I/R injury.
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Affiliation(s)
- Wei Liu
- Department of Immunology, School of Medicine, UConn Health, Farmington, CT
| | - Chunxia G Cronin
- Pat and Jim Calhoun Cardiology Center, School of Medicine, UConn Health, Farmington, CT
| | - Ziming Cao
- Department of Immunology, School of Medicine, UConn Health, Farmington, CT
| | - Chengliang Wang
- Department of Immunology, School of Medicine, UConn Health, Farmington, CT
| | - Jianbin Ruan
- Department of Immunology, School of Medicine, UConn Health, Farmington, CT
| | - Sunitha Pulikkot
- Department of Immunology, School of Medicine, UConn Health, Farmington, CT
| | - Alexxus Hall
- Department of Immunology, School of Medicine, UConn Health, Farmington, CT
| | - Hao Sun
- Department of Medicine, University of California San Diego, La Jolla, CA
| | - Alex Groisman
- Department of Physics, University of California San Diego, La Jolla, CA
| | - Yunfeng Chen
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX
- Department of Pathology, University of Texas Medical Branch, Galveston, TX
| | - Anthony T Vella
- Department of Immunology, School of Medicine, UConn Health, Farmington, CT
| | - Liang Hu
- Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China; and
| | - Bruce T Liang
- Pat and Jim Calhoun Cardiology Center, School of Medicine, UConn Health, Farmington, CT;
| | - Zhichao Fan
- Department of Immunology, School of Medicine, UConn Health, Farmington, CT;
- Division of Inflammation Biology, La Jolla Institute for Immunology, La Jolla, CA
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3
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Sex-dependent effect of aging on calcium signaling and expression of TRPM2 and CRAC channels in human neutrophils. Hum Immunol 2022; 83:645-655. [PMID: 35660323 DOI: 10.1016/j.humimm.2022.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 04/26/2022] [Accepted: 05/15/2022] [Indexed: 11/22/2022]
Abstract
The vulnerability of older adults to bacterial infections has been associated with age-related changes in neutrophils. We analyzed the consequences of aging on calcium (Ca2+) mobilization and TRPM2 and CRAC channels expression in human neutrophils. The percentages of granulocytes, mature neutrophils, and neutrophil precursors were equivalent between young and older adults. However, neutrophil chemotaxis towards IL-8, C5a, or fMLP was lower in older adults of both sexes. Interestingly, a stronger Ca2+ transient followed by an identical Ca2+ influx to IL-8 was observed in older adult females. In addition, the Ca2+ response to LPS was delayed and prolonged in neutrophils of older adult males. There was no significant difference in Ca2+ response to fMLP, C5a, or store-operated Ca2+ entry in the older adults. There were also no differences in the expression of CXCR2, CD88, FPLR1, and TLR4. Interestingly, TRPM2- and ORAI1-mRNA expression was lower in neutrophils of older adults, mainly in females. Both channels were detected intracellularly in the neutrophils. TRPM2 was in late endosomes in young adults and in lysosomes in older adult neutrophils. In summary, defective neutrophil chemotaxis in aging seemed not to stem from alterations in Ca2+ signals; nevertheless, the low TRPM2 and ORAI1 expression may affect other functions.
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4
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Bekeschus S, Clemen R, Haralambiev L, Niessner F, Grabarczyk P, Weltmann KD, Menz J, Stope M, von Woedtke T, Gandhirajan R, Schmidt A. The Plasma-Induced Leukemia Cell Death is Dictated by the ROS Chemistry and the HO-1/CXCL8 Axis. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2021. [DOI: 10.1109/trpms.2020.3020686] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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5
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Abstract
Neutrophils are critical to innate immunity, including host defense against bacterial and fungal infections. They achieve their host defense role by phagocytosing pathogens, secreting their granules full of cytotoxic enzymes, or expelling neutrophil extracellular traps (NETs) during the process of NETosis. NETs are weblike DNA structures decorated with histones and antimicrobial proteins released by activated neutrophils. Initially described as a means for neutrophils to neutralize pathogens, NET release also occurs in sterile inflammation, promotes thrombosis, and can mediate tissue damage. To effectively manipulate this double-edged sword to fight a particular disease, researchers must work toward understanding the mechanisms driving NETosis. Such understanding would allow the generation of new drugs to promote or prevent NETosis as needed. While knowledge regarding the (patho)physiological roles of NETosis is accumulating, little is known about the cellular and biophysical bases of this process. In this review, we describe and discuss our current knowledge of the molecular, cellular, and biophysical mechanisms mediating NET release as well as open questions in the field.
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Affiliation(s)
- Hawa Racine Thiam
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health, Bethesda, Maryland 20892, USA; ,
| | - Siu Ling Wong
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232
| | - Denisa D Wagner
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Division of Hematology/Oncology, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Clare M Waterman
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health, Bethesda, Maryland 20892, USA; ,
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6
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Harvey KL, Jarocki VM, Charles IG, Djordjevic SP. The Diverse Functional Roles of Elongation Factor Tu (EF-Tu) in Microbial Pathogenesis. Front Microbiol 2019; 10:2351. [PMID: 31708880 PMCID: PMC6822514 DOI: 10.3389/fmicb.2019.02351] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 09/27/2019] [Indexed: 12/25/2022] Open
Abstract
Elongation factor thermal unstable Tu (EF-Tu) is a G protein that catalyzes the binding of aminoacyl-tRNA to the A-site of the ribosome inside living cells. Structural and biochemical studies have described the complex interactions needed to effect canonical function. However, EF-Tu has evolved the capacity to execute diverse functions on the extracellular surface of both eukaryote and prokaryote cells. EF-Tu can traffic to, and is retained on, cell surfaces where can interact with membrane receptors and with extracellular matrix on the surface of plant and animal cells. Our structural studies indicate that short linear motifs (SLiMs) in surface exposed, non-conserved regions of the molecule may play a key role in the moonlighting functions ascribed to this ancient, highly abundant protein. Here we explore the diverse moonlighting functions relating to pathogenesis of EF-Tu in bacteria and examine putative SLiMs on surface-exposed regions of the molecule.
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Affiliation(s)
- Kate L Harvey
- The ithree Institute, University of Technology Sydney, Ultimo, NSW, Australia
| | - Veronica M Jarocki
- The ithree Institute, University of Technology Sydney, Ultimo, NSW, Australia
| | - Ian G Charles
- Quadram Institute, Norwich, United Kingdom.,Norwich Medical School, Norwich, United Kingdom
| | - Steven P Djordjevic
- The ithree Institute, University of Technology Sydney, Ultimo, NSW, Australia
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7
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Tabei Y, Fukui H, Nishioka A, Hagiwara Y, Sato K, Yoneda T, Koyama T, Horie M. Effect of iron overload from multi walled carbon nanotubes on neutrophil-like differentiated HL-60 cells. Sci Rep 2019; 9:2224. [PMID: 30778158 PMCID: PMC6379482 DOI: 10.1038/s41598-019-38598-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 12/28/2018] [Indexed: 01/17/2023] Open
Abstract
Multi walled carbon nanotubes (MWCNTs) are one of the most intensively explored nanomaterials because of their unique physical and chemical properties. Due to the widespread use of MWCNTs, it is important to investigate their effects on human health. The precise mechanism of MWCNT toxicity has not been fully elucidated. The present study was designed to examine the mechanisms of MWCNT toxicity toward human promyelocytic leukemia HL-60 cells. First, we found that MWCNTs decreased the viability of neutrophil-like differentiated HL-60 cells but not undifferentiated HL-60 cells. Because neutrophil-like differentiated HL-60 cells exhibit enhanced phagocytic activity, the cytotoxicity of MWCNTs is dependent on the intracellularly localized MWCNTs. Next, we revealed that the cytotoxicity of MWCNTs is correlated with the intracellular accumulation of iron that is released from the engulfed MWCNTs in an acidic lysosomal environment. The intracellular accumulation of iron was repressed by treatment with cytochalasin D, a phagocytosis inhibitor. In addition, our results indicated that iron overload enhanced the release of interleukin-8 (IL-8), a chemokine that activates neutrophils, and subsequently elevated intracellular calcium concentration ([Ca2+]i). Finally, we found that the sustained [Ca2+]i elevation resulted in the loss of mitochondrial membrane potential and the increase of caspase-3 activity, thereby inducing apoptotic cell death. These findings suggest that the iron overload caused by engulfed MWCNTs results in the increase of IL-8 production and the elevation of [Ca2+]i, thereby activating the mitochondria-mediated apoptotic pathway.
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Affiliation(s)
- Yosuke Tabei
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa, 761-0395, Japan.
| | - Hiroko Fukui
- Safety Evaluation Center, Showa Denko K.K., 1-1-1 Ohnodai, Midori-ku, Chiba-shi, Chiba, 267-0056, Japan
| | - Ayako Nishioka
- Safety Evaluation Center, Showa Denko K.K., 1-1-1 Ohnodai, Midori-ku, Chiba-shi, Chiba, 267-0056, Japan
| | - Yuji Hagiwara
- Safety Evaluation Center, Showa Denko K.K., 1-1-1 Ohnodai, Midori-ku, Chiba-shi, Chiba, 267-0056, Japan
| | - Kei Sato
- Safety Evaluation Center, Showa Denko K.K., 1-1-1 Ohnodai, Midori-ku, Chiba-shi, Chiba, 267-0056, Japan
| | - Tadashi Yoneda
- Safety Evaluation Center, Showa Denko K.K., 1-1-1 Ohnodai, Midori-ku, Chiba-shi, Chiba, 267-0056, Japan
| | - Tamami Koyama
- Institute for Advanced and Core Technology, Showa Denko K.K., 1-1-1 Ohnodai, Midori-ku, Chiba-shi, Chiba, 267-0056, Japan
| | - Masanori Horie
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa, 761-0395, Japan
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8
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Store-operated calcium entry in thrombosis and thrombo-inflammation. Cell Calcium 2018; 77:39-48. [PMID: 30530092 DOI: 10.1016/j.ceca.2018.11.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/31/2018] [Accepted: 11/14/2018] [Indexed: 01/03/2023]
Abstract
Cytosolic free calcium (Ca2+) is a second messenger regulating a wide variety of functions in blood cells, including adhesion, activation, proliferation and migration. Store-operated Ca2+ entry (SOCE), triggered by depletion of Ca2+ from the endoplasmic reticulum, provides a main mechanism of regulated Ca2+ influx in blood cells. SOCE is mediated and regulated by isoforms of the ion channel proteins ORAI and TRP, and the transmembrane Ca2+ sensors stromal interaction molecules (STIMs), respectively. This report provides an overview of the (patho)physiological importance of SOCE in blood cells implicated in thrombosis and thrombo-inflammation, i.e. platelets and immune cells. We also discuss the physiological consequences of dysregulated SOCE in platelets and immune cells and the potential of SOCE inhibition as a therapeutic option to prevent or treat arterial thrombosis as well as thrombo-inflammatory disease states such as ischemic stroke.
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9
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Immler R, Simon SI, Sperandio M. Calcium signalling and related ion channels in neutrophil recruitment and function. Eur J Clin Invest 2018; 48 Suppl 2:e12964. [PMID: 29873837 PMCID: PMC6221920 DOI: 10.1111/eci.12964] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 06/04/2018] [Indexed: 12/15/2022]
Abstract
The recruitment of neutrophils to sites of inflammation, their battle against invading microorganisms through phagocytosis and the release of antimicrobial agents is a highly coordinated and tightly regulated process that involves the interplay of many different receptors, ion channels and signalling pathways. Changes in intracellular calcium levels, caused by cytosolic Ca2+ store depletion and the influx of extracellular Ca2+ via ion channels, play a critical role in synchronizing neutrophil activation and function. In this review, we provide an overview of how Ca2+ signalling is initiated in neutrophils and how changes in intracellular Ca2+ levels modulate neutrophil function.
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Affiliation(s)
- Roland Immler
- Walter Brendel Centre of Experimental Medicine, Biomedical Center, Klinikum der Universität, Ludwig-Maximilians-Universität München, Germany
| | - Scott I. Simon
- Department of Biomedical Engineering, Graduate Group in Immunology, University of California, Davis, CA, USA
| | - Markus Sperandio
- Walter Brendel Centre of Experimental Medicine, Biomedical Center, Klinikum der Universität, Ludwig-Maximilians-Universität München, Germany
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10
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Francis EA, Heinrich V. Extension of chemotactic pseudopods by nonadherent human neutrophils does not require or cause calcium bursts. Sci Signal 2018. [PMID: 29535263 DOI: 10.1126/scisignal.aal4289] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Global bursts in free intracellular calcium (Ca2+) are among the most conspicuous signaling events in immune cells. To test the common view that Ca2+ bursts mediate rearrangement of the actin cytoskeleton in response to the activation of G protein-coupled receptors, we combined single-cell manipulation with fluorescence imaging and monitored the Ca2+ concentration in individual human neutrophils during complement-mediated chemotaxis. By decoupling purely chemotactic pseudopod formation from cell-substrate adhesion, we showed that physiological concentrations of anaphylatoxins, such as C5a, induced nonadherent human neutrophils to form chemotactic pseudopods but did not elicit Ca2+ bursts. By contrast, pathological or supraphysiological concentrations of C5a often triggered Ca2+ bursts, but pseudopod protrusion stalled or reversed in such cases, effectively halting chemotaxis, similar to sepsis-associated neutrophil paralysis. The maximum increase in cell surface area during pseudopod extension in pure chemotaxis was much smaller-by a factor of 8-than the known capacity of adherent human neutrophils to expand their surface. Because the measured rise in cortical tension was not sufficient to account for this difference, we attribute the limited deformability to a reduced ability of the cytoskeleton to generate protrusive force in the absence of cell adhesion. Thus, we hypothesize that Ca2+ bursts in neutrophils control a mechanistic switch between two distinct modes of cytoskeletal organization and dynamics. A key element of this switch appears to be the expedient coordination of adhesion-dependent lock or release events of cytoskeletal membrane anchors.
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Affiliation(s)
- Emmet A Francis
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
| | - Volkmar Heinrich
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA.
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11
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Huang B, Ling Y, Lin J, Fang Y, Wu J. Mechanical regulation of calcium signaling of HL-60 on P-selectin under flow. Biomed Eng Online 2016; 15:153. [PMID: 28155729 PMCID: PMC5260098 DOI: 10.1186/s12938-016-0271-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background Binding of P-selectin to P-selectin glycoprotein ligand-1 (PSGL-1) makes neutrophils roll on and adhere to inflammatory site. Intracellular calcium bursting of adhered neutrophils is a key event for subsequent arresting firmly at and migrating into the injured tissue. But, it remains unclear how the cytoplasmic calcium signaling of the cells were modulated by the fluid shear stress. Here, we focus on mechanical regulation of P-selectin-induced calcium signaling of neutrophil-like HL-60 cells under flow. Methods HL-60 cells were loaded with Fluo-4 AM for fluorescent detection of intracellular calcium ion, and then perfused over P-selectin-coated bottom of parallel-plate flow chamber. The intracellular calcium concentration of firmly adhered cell under flow was observed in real time by fluorescence microscopy. Results Force triggered, enhanced and quickened cytoplasmic calcium bursting of HL-60 on P-selectin. This force-dependent calcium signaling was induced by the immobilized P-selectin coated on substrates in absence of chemokine. Increasing of both shear stress and P-selectin concentration made the calcium signaling intensive, through quickening the cytosolic calcium release and upregulating both probability and peak level of calcium signaling. Conclusions Immobilized P-selectin-induced calcium signaling of HL-60 cells is P-selectin concentration- and mechanical force-dependent. The higher both the P-selectin concentration and the external force on cell, the more intensive the calcium signaling. It might provide a novel insight into the mechano-chemical regulation mechanism for intracellular signaling pathways induced by adhesion molecules.
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Affiliation(s)
- Bing Huang
- School of Bioscience & Bioengineering, South China University of Technology, Guangzhou, 510006, China
| | - Yingchen Ling
- School of Bioscience & Bioengineering, South China University of Technology, Guangzhou, 510006, China
| | - Jiangguo Lin
- School of Bioscience & Bioengineering, South China University of Technology, Guangzhou, 510006, China
| | - Ying Fang
- School of Bioscience & Bioengineering, South China University of Technology, Guangzhou, 510006, China.
| | - Jianhua Wu
- School of Bioscience & Bioengineering, South China University of Technology, Guangzhou, 510006, China.
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12
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Maeda DY, Peck AM, Schuler A, Quinn MT, Kirpotina LN, Wicomb WN, Fan GH, Zebala JA. Discovery of 2-[5-(4-Fluorophenylcarbamoyl)pyridin-2-ylsulfanylmethyl]phenylboronic Acid (SX-517): Noncompetitive Boronic Acid Antagonist of CXCR1 and CXCR2. J Med Chem 2014; 57:8378-97. [PMID: 25254640 PMCID: PMC4207547 DOI: 10.1021/jm500827t] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Indexed: 12/15/2022]
Abstract
The G protein-coupled chemokine receptors CXCR1 and CXCR2 play key roles in inflammatory diseases and carcinogenesis. In inflammation, they activate and recruit polymorphonuclear cells (PMNs) through binding of the chemokines CXCL1 (CXCR1) and CXCL8 (CXCR1 and CXCR2). Structure-activity studies that examined the effect of a novel series of S-substituted 6-mercapto-N-phenyl-nicotinamides on CXCL1-stimulated Ca(2+) flux in whole human PMNs led to the discovery of 2-[5-(4-fluorophenylcarbamoyl)pyridin-2-ylsulfanylmethyl]phenylboronic acid (SX-517), a potent noncompetitive boronic acid CXCR1/2 antagonist. SX-517 inhibited CXCL1-induced Ca(2+) flux (IC50 = 38 nM) in human PMNs but had no effect on the Ca(2+) flux induced by C5a, fMLF, or PAF. In recombinant HEK293 cells that stably expressed CXCR2, SX-517 antagonized CXCL8-induced [(35)S]GTPγS binding (IC50 = 60 nM) and ERK1/2 phosphorylation. Inhibition was noncompetitive, with SX-517 unable to compete the binding of [(125)I]-CXCL8 to CXCR2 membranes. SX-517 (0.2 mg/kg iv) significantly inhibited inflammation in an in vivo murine model. SX-517 is the first reported boronic acid chemokine antagonist and represents a novel pharmacophore for CXCR1/2 antagonism.
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Affiliation(s)
- Dean Y. Maeda
- Syntrix
Biosystems, 215 Clay
Street, Auburn, Washington 98001, United States
| | - Angela M. Peck
- Syntrix
Biosystems, 215 Clay
Street, Auburn, Washington 98001, United States
| | - Aaron
D. Schuler
- Syntrix
Biosystems, 215 Clay
Street, Auburn, Washington 98001, United States
| | - Mark T. Quinn
- Department
of Microbiology and Immunology, Montana
State University, 960
Technology Boulevard, Bozeman, Montana 59717, United States
| | - Liliya N. Kirpotina
- Department
of Microbiology and Immunology, Montana
State University, 960
Technology Boulevard, Bozeman, Montana 59717, United States
| | - Winston N. Wicomb
- Infectious
Disease Research Institute, 1616 Eastlake Avenue East, Seattle, Washington 98102, United States
| | - Guo-Huang Fan
- Department
of Pharmacology, Meharry Medical College, 1005 Dr. DB Todd Boulevard, Nashville, Tennessee 37208, United States
| | - John A. Zebala
- Syntrix
Biosystems, 215 Clay
Street, Auburn, Washington 98001, United States
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13
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Gupta AK, Giaglis S, Hasler P, Hahn S. Efficient neutrophil extracellular trap induction requires mobilization of both intracellular and extracellular calcium pools and is modulated by cyclosporine A. PLoS One 2014; 9:e97088. [PMID: 24819773 PMCID: PMC4018253 DOI: 10.1371/journal.pone.0097088] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 04/14/2014] [Indexed: 12/21/2022] Open
Abstract
Excessive or aberrant generation of neutrophil extracellular traps (NETs) has recently become implicated in the underlying aetiology of a number of human pathologies including preeclampsia, systemic lupus erythromatosus, rheumatoid arthritis, auto-antibody induced small vessel vasculitis, coagulopathies such as deep vein thrombosis or pulmonary complications. These results imply that effective pharmacological therapeutic strategies will need to be developed to counter overt NETosis in these and other inflammatory disorders. As calcium flux is implicated in the generation of reactive oxygen species and histone citrullination, two key events in NETosis, we analysed the roles of both extra- and intracellular calcium pools and their modulation by pharmacological agents in the NETotic process in detail. Interleukin-8 (IL-8) was used as a physiological stimulus of NETosis. Our data demonstrate that efficient induction of NETosis requires mobilisation of both extracellular and intracellular calcium pools. Since modulation of the calcineurin pathway by cyclosporine A has been described in neutrophils, we investigated its influence on NETosis. Our data indicate that IL-8 induced NETosis is reduced by ascomycin and cyclosporine A, antagonists of the calcineurin pathway, but not following treatment with rapamycin, which utilizes the mTOR pathway. The action of the G protein coupled receptor phospholipase C pathway appears to be essential for the induction of NETs by IL-8, as NETosis was diminished by treatment with either pertussis toxin, a G-protein inhibitor, the phospholipase C inhibitor, U73122, or staurosporine, an inhibitor of protein kinase C. The data regarding the calcineurin antagonists, ascomycin and cyclosporine A, open the possibility to therapeutically supress or modulate NETosis. They also provide new insight into the mechanism whereby such immune suppressive drugs render transplant patients susceptible to opportunistic fungal infections.
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Affiliation(s)
- Anurag Kumar Gupta
- Laboratory for Prenatal Medicine, Department of Biomedicine, University Hospital Basel, Basel, Switzerland
| | - Stavros Giaglis
- Laboratory for Prenatal Medicine, Department of Biomedicine, University Hospital Basel, Basel, Switzerland
- Department of Rheumatology, Cantonal Hospital Aarau, Aarau, Switzerland
| | - Paul Hasler
- Department of Rheumatology, Cantonal Hospital Aarau, Aarau, Switzerland
| | - Sinuhe Hahn
- Laboratory for Prenatal Medicine, Department of Biomedicine, University Hospital Basel, Basel, Switzerland
- * E-mail:
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14
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Intracellular secretory leukoprotease inhibitor modulates inositol 1,4,5-triphosphate generation and exerts an anti-inflammatory effect on neutrophils of individuals with cystic fibrosis and chronic obstructive pulmonary disease. BIOMED RESEARCH INTERNATIONAL 2013; 2013:560141. [PMID: 24073410 PMCID: PMC3773400 DOI: 10.1155/2013/560141] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 07/01/2013] [Accepted: 07/15/2013] [Indexed: 02/01/2023]
Abstract
Secretory leukoprotease inhibitor (SLPI) is an anti-inflammatory protein present in respiratory secretions. Whilst epithelial cell SLPI is extensively studied, neutrophil associated SLPI is poorly characterised. Neutrophil function including chemotaxis and degranulation of proteolytic enzymes involves changes in cytosolic calcium (Ca2+) levels which is mediated by production of inositol 1,4,5-triphosphate (IP3) in response to G-protein-coupled receptor (GPCR) stimuli. The aim of this study was to investigate the intracellular function of SLPI and the mechanism-based modulation of neutrophil function by this antiprotease. Neutrophils were isolated from healthy controls (n = 10), individuals with cystic fibrosis (CF) (n = 5) or chronic obstructive pulmonary disease (COPD) (n = 5). Recombinant human SLPI significantly inhibited fMet-Leu-Phe (fMLP) and interleukin(IL)-8 induced neutrophil chemotaxis (P < 0.05) and decreased degranulation of matrix metalloprotease-9 (MMP-9), hCAP-18, and myeloperoxidase (MPO) (P < 0.05). The mechanism of inhibition involved modulation of cytosolic IP3 production and downstream Ca2+ flux. The described attenuation of Ca2+ flux was overcome by inclusion of exogenous IP3 in electropermeabilized cells. Inhibition of IP3 generation and Ca2+ flux by SLPI may represent a novel anti-inflammatory mechanism, thus strengthening the attractiveness of SLPI as a potential therapeutic molecule in inflammatory airway disease associated with excessive neutrophil influx including CF, non-CF bronchiectasis, and COPD.
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15
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Serafini N, Dahdah A, Barbet G, Demion M, Attout T, Gautier G, Arcos-Fajardo M, Souchet H, Jouvin MH, Vrtovsnik F, Kinet JP, Benhamou M, Monteiro RC, Launay P. The TRPM4 channel controls monocyte and macrophage, but not neutrophil, function for survival in sepsis. THE JOURNAL OF IMMUNOLOGY 2012; 189:3689-99. [PMID: 22933633 DOI: 10.4049/jimmunol.1102969] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A favorable outcome following acute bacterial infection depends on the ability of phagocytic cells to be recruited and properly activated within injured tissues. Calcium (Ca(2+)) is a ubiquitous second messenger implicated in the functions of many cells, but the mechanisms involved in the regulation of Ca(2+) mobilization in hematopoietic cells are largely unknown. The monovalent cation channel transient receptor potential melastatin (TRPM) 4 is involved in the control of Ca(2+) signaling in some hematopoietic cell types, but the role of this channel in phagocytes and its relevance in the control of inflammation remain unexplored. In this study, we report that the ablation of the Trpm4 gene dramatically increased mouse mortality in a model of sepsis induced by cecal ligation and puncture. The lack of the TRPM4 channel affected macrophage population within bacteria-infected peritoneal cavities and increased the systemic level of Ly6C(+) monocytes and proinflammatory cytokine production. Impaired Ca(2+) mobilization in Trpm4(-/-) macrophages downregulated the AKT signaling pathway and the subsequent phagocytic activity, resulting in bacterial overgrowth and translocation to the bloodstream. In contrast, no alteration in the distribution, function, or Ca(2+) mobilization of Trpm4(-/-) neutrophils was observed, indicating that the mechanism controlling Ca(2+) signaling differs among phagocytes. Our results thus show that the tight control of Ca(2+) influx by the TRPM4 channel is critical for the proper functioning of monocytes/macrophages and the efficiency of the subsequent response to infection.
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16
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Abstract
Mutations in genes encoding the calcium-release activated calcium (CRAC) channel abolish calcium influx in cells of the immune system and cause severe congenital immunodeficiency. Patients with autosomal recessive mutations in the CRAC channel gene ORAI1, its activator stromal interaction molecule 1 (STIM1), and mice with targeted deletion of Orai1, Stim1, and Stim2 genes reveal important roles for CRAC channels in adaptive and innate immune responses to infection and in autoimmunity. Because CRAC channels have important functions outside the immune system, deficiency of either ORAI1 or STIM1 is associated with a unique clinical phenotype. This review will give an overview of CRAC channel function in the immune system, examine the consequences of CRAC channel deficiency for immunity in human patients and mice, and discuss genetic defects in immunoreceptor-associated signaling molecules that compromise calcium influx and cause immunodeficiency.
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Affiliation(s)
- Stefan Feske
- Department of Pathology, New York University Langone Medical Center, New York, USA.
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17
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Shaw PJ, Feske S. Physiological and pathophysiological functions of SOCE in the immune system. Front Biosci (Elite Ed) 2012. [PMID: 22202035 DOI: 10.2741/540] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Calcium signals play a critical role in many cell-type specific effector functions during innate and adaptive immune responses. The predominant mechanism to raise intracellular (Ca²⁺) used by most immune cells is store-operated Ca²⁺ entry (SOCE), whereby the depletion of endoplasmic reticulum (ER) Ca²⁺ stores triggers the influx of extracellular Ca²⁺. SOCE in immune cells is mediated by the highly Ca²⁺ selective Ca²⁺-release-activated Ca²⁺ (CRAC) channel, encoded by ORAI1, ORAI2 and ORAI3 genes. ORAI proteins are activated by stromal interaction molecules (STIM) 1 and 2, which act as sensors of ER Ca²⁺ store depletion. The importance of SOCE mediated by STIM and ORAI proteins for immune function is evident from the immunodeficiency and autoimmunity in patients with mutations in STIM1 and ORAI1 genes. These patients and studies in gene-targeted mice have revealed an essential role for ORAI/STIM proteins in the function of several immune cells. This review focuses on recent advances made towards understanding the role of SOCE in immune cells with an emphasis on the immune dysregulation that results from defects in SOCE in human patients and transgenic mice.
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Affiliation(s)
- Patrick J Shaw
- Department of Pathology, New York University Langone Medical Center, New York, NY 10016, USA
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18
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Burgos RA, Conejeros I, Hidalgo MA, Werling D, Hermosilla C. Calcium influx, a new potential therapeutic target in the control of neutrophil-dependent inflammatory diseases in bovines. Vet Immunol Immunopathol 2011; 143:1-10. [PMID: 21764141 DOI: 10.1016/j.vetimm.2011.05.037] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 05/06/2011] [Accepted: 05/08/2011] [Indexed: 01/07/2023]
Abstract
Neutrophils are the first line of defense against pathogens in bovines; however, they are also one of the most aggressive cells during the inflammatory process, causing injury in surrounding tissues. At present, anti-inflammatory drugs are limited in acute diseases, such as pneumonia, mastitis and endometritis, because neutrophils are mostly insensitive. One of the earliest events during neutrophil activation is the increase in intracellular calcium concentration. The calcium movement is attributed to the release from intracellular stores and influx through the calcium channels in the plasma membrane, a process called store operated calcium entry (SOCE). Recently, several calcium influx blockers have been shown to have strong effects on bovine neutrophils, and this suggests that the manipulation of this pathway can be useful in the control of neutrophil functions during acute inflammatory processes. In this paper, we will review the role of calcium influx as a potential anti-inflammatory target and summarize the most recent evidences for this in bovine neutrophils.
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Affiliation(s)
- R A Burgos
- Laboratory of Molecular Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Universidad Austral de Chile, Valdivia, Chile.
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19
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Jakob M, Hemeda H, Janeschik S, Bootz F, Rotter N, Lang S, Brandau S. Human nasal mucosa contains tissue-resident immunologically responsive mesenchymal stromal cells. Stem Cells Dev 2010; 19:635-44. [PMID: 19761404 DOI: 10.1089/scd.2009.0245] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Multipotent mesenchymal stromal cells (MSC) are present in bone marrow and other tissues such as adipose tissue, muscle, pancreas, liver, and so on. Recent evidence suggests that MSC migrate to sites of infection, inflammation, and cancer, and interact with different immune cell subsets. Here, we report for the first time on the isolation and characterization of multipotent nasal mucosa-derived mesenchymal stromal cells (nm-MSC). nm-MSC showed a plastic adherent and fibroblast-like morphology and were able to form colonies. They expressed the typical bone marrow MSC marker antigens CD29, CD44, CD73, CD90, and CD105 and were able to differentiate along the adipogenic, chondrogenic, and osteogenic pathways. nm-MSC produced a set of inflammatory cytokines, expressed chemokine receptors, and were responsive to stimulation with cytokines, chemokines, and TLR4 ligand LPS. Thus, these cells may serve as an alternative adult stromal cell resource for regenerative tissue repair and may represent important regulators of local mucosal immunity.
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Affiliation(s)
- Mark Jakob
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Essen, Germany
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20
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Abstract
The dynamic response of neutrophils to interleukin-8 (IL-8) is of central interest in inflammation. Chemokine -induced β(2) integrin dependent adhesion can take several minutes after initial contact with IL-8 as evidenced by increased cell adhesion to intracellular adhesion molecule 1 (ICAM-1). The goal of this study is to identify signaling events that are critical for this response. We demonstrate that neither the PI3K inhibitor wortmannin, nor the PKC inhibitor bisindolymaleimide had any effect on IL-8 induced adhesion to ICAM-1. However, inhibition of PLC with U73122 or stopping the release of intracellular calcium by its downstream effector IP3 with caffeine or 2-aminoethoxydiphenyl borate completely blocked the adhesive response. Chelation of intracellular calcium with BAPTA or extracellular calcium with EGTA completely abrogated neutrophil adhesion to ICAM-1. This adhesion is mediated by LFA-1 (α(L)β(2)) within first 300 seconds after chemokine stimulation, followed by Mac-1 (α(M)β(2)) mediated adhesion, beginning 350 seconds after stimulus. Inhibition of p38MAP kinase results in a time course similar to Mac-1 inhibition, consistent with published evidence that Mac-1 mediated adhesion is p38MAP kinase dependent. These findings confirm a PLC dependent, PKC independent pathway from chemokine stimulus to integrin activation previously identified in other cell types, and demonstrate distinct dynamics and different requirements for LFA-1 vs. Mac-1 activation in primary human neutrophils.
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21
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Orai1 regulates intracellular calcium, arrest, and shape polarization during neutrophil recruitment in shear flow. Blood 2009; 115:657-66. [PMID: 19965684 DOI: 10.1182/blood-2009-05-224659] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Orai1 was reported to function as a calcium channel subunit that facilitates store operated calcium entry (SOCE) in T cells and is necessary for formation of the immune synapse. We reasoned that SOCE via Orai1 might regulate PMNs activation during recruitment to inflamed endothelium. Orai1 function was assessed by real-time imaging of calcium transients as PMNs were stimulated to roll, arrest, and migrate on E-selectin and ICAM-1 in shear flow. Calcium entry was significantly reduced when Orai1 function was impaired by heterozygous knockout in a mouse model or by siRNA knockdown in HL-60 cells. Reduced Orai-1 expression correlated with the delayed onset of arrest and reduced ability to transition to a polarized migratory phenotype. Inhibition of SOCE by treatment with 2-APB, or blocking phospholipase C (PLC) mediated calcium store release with U73122, abrogated formyl peptide induced calcium elevation, and delayed subsequent cell arrest and polarization. These results suggest that calcium entry via Orai1 is the predominant SOCE that cooperates with cytoplasmic calcium store release in coordinating integrin-dependent PMN arrest and migration in the acute response to inflammation.
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22
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Feske S. ORAI1 and STIM1 deficiency in human and mice: roles of store-operated Ca2+ entry in the immune system and beyond. Immunol Rev 2009; 231:189-209. [PMID: 19754898 DOI: 10.1111/j.1600-065x.2009.00818.x] [Citation(s) in RCA: 252] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Store-operated Ca2+ entry (SOCE) is a mechanism used by many cells types including lymphocytes and other immune cells to increase intracellular Ca2+ concentrations to initiate signal transduction. Activation of immunoreceptors such as the T-cell receptor, B-cell receptor, or Fc receptors results in the release of Ca2+ ions from endoplasmic reticulum (ER) Ca2+ stores and subsequent activation of plasma membrane Ca2+ channels such as the well-characterized Ca2+ release-activated Ca2+ (CRAC) channel. Two genes have been identified that are essential for SOCE: ORAI1 as the pore-forming subunit of the CRAC channel in the plasma membrane and stromal interaction molecule-1 (STIM1) sensing the ER Ca2+ concentration and activating ORAI1-CRAC channels. Intense efforts in the past several years have focused on understanding the molecular mechanism of SOCE and the role it plays for cell functions in vitro and in vivo. A number of transgenic mouse models have been generated to investigate the role of ORAI1 and STIM1 in immunity. In addition, mutations in ORAI1 and STIM1 identified in immunodeficient patients provide valuable insight into the role of both genes and SOCE. This review focuses on the role of ORAI1 and STIM1 in vivo, discussing the phenotypes of ORAI1- and STIM1-deficient human patients and mice.
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Affiliation(s)
- Stefan Feske
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
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23
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Baron S, Struyf S, Wuytack F, Van Damme J, Missiaen L, Raeymaekers L, Vanoevelen J. Contribution of intracellular Ca2+ stores to Ca2+ signaling during chemokinesis of human neutrophil granulocytes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:1041-9. [PMID: 19095014 DOI: 10.1016/j.bbamcr.2008.11.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 11/06/2008] [Accepted: 11/16/2008] [Indexed: 10/21/2022]
Abstract
Extracellular agonists increase the cytosolic free Ca2+ concentration ([Ca2+]c) by Ca2+ influx and by stimulating Ca2+ release from intracellular stores, mainly the endoplasmic reticulum and to a lesser extent also later compartments of the secretory pathway, particularly the Golgi. The Golgi takes up Ca2+ via Sarco/Endoplasmic Reticulum Ca2+ATPases (SERCAs) and the Secretory-Pathway Ca2+ATPases (SPCAs). The endogenous expression of SERCAs and SPCAs neutrophils was demonstrated by Western blotting and immunocytochemistry. Up till now, all cytosolic Ca2+ transients due to intracellular Ca2+ release have been found to originate from SERCA-dependent stores. We found that human neutrophils also present Ca2+ release from a SERCA-independent store. Changes in [Ca2+]c of neutrophils were investigated during chemokinesis induced by chemotactic factors in Ca2+-free solution with and without the SERCA-specific inhibitor thapsigargin. Using N-formyl-methionyl-leucyl-phenylalanine or interleukin-8 as agonists, Ca2+ release from intracellular stores was observed in respectively about 40% and 20% of the neutrophils pre-treated with Ca2+-free solution and thapsigargin. In the latter condition, 20-30% of the cells preserved migratory behaviour. These results indicate that both SERCA-dependent and SERCA-independent (presumably SPCA-dependent) intracellular Ca2+ stores contribute to Ca2+ signaling during chemokinesis of human neutrophil granulocytes.
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Affiliation(s)
- Szilvia Baron
- Laboratory of Ca2+-transport ATPases, Department of Molecular Cell Biology, KULeuven Campus Gasthuisberg, Leuven, Belgium
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24
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Signal transduction in cells of the immune system in microgravity. Cell Commun Signal 2008; 6:9. [PMID: 18957108 PMCID: PMC2583999 DOI: 10.1186/1478-811x-6-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Accepted: 10/28/2008] [Indexed: 01/03/2023] Open
Abstract
Life on Earth developed in the presence and under the constant influence of gravity. Gravity has been present during the entire evolution, from the first organic molecule to mammals and humans. Modern research revealed clearly that gravity is important, probably indispensable for the function of living systems, from unicellular organisms to men. Thus, gravity research is no more or less a fundamental question about the conditions of life on Earth. Since the first space missions and supported thereafter by a multitude of space and ground-based experiments, it is well known that immune cell function is severely suppressed in microgravity, which renders the cells of the immune system an ideal model organism to investigate the influence of gravity on the cellular and molecular level. Here we review the current knowledge about the question, if and how cellular signal transduction depends on the existence of gravity, with special focus on cells of the immune system. Since immune cell function is fundamental to keep the organism under imnological surveillance during the defence against pathogens, to investigate the effects and possible molecular mechanisms of altered gravity is indispensable for long-term space flights to Earth Moon or Mars. Thus, understanding the impact of gravity on cellular functions on Earth will provide not only important informations about the development of life on Earth, but also for therapeutic and preventive strategies to cope successfully with medical problems during space exploration.
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25
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26
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The other side of the medal: How chemokines promote analgesia. Neurosci Lett 2008; 437:203-8. [DOI: 10.1016/j.neulet.2008.02.071] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Accepted: 02/21/2008] [Indexed: 11/15/2022]
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27
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Huynh N, Mallik B, Zhang L, Martins-Green M, Morikis D. Computational studies of CXCR1, the receptor of IL-8/CXCL8, using molecular dynamics and electrostatics. Biopolymers 2008; 89:52-61. [PMID: 17876799 DOI: 10.1002/bip.20851] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The three-dimensional structure of IL-8/CXCL8 has been previously determined using NMR spectroscopy and X-ray crystallography, but the structure of the receptors for this chemokine has not been determined experimentally. We present here the development of a model for the structure of the IL-8/CXCL8 receptor CXCR1, using a combination of homology modeling and a molecular dynamics simulation. Based on this model, we discuss the analysis of structural, dynamic, and physicochemical properties of CXCR1. We focused on the role of pairwise ionic interactions in local structural stability of CXCR1 and the role of electrostatic potentials in recognition of CXCR1 with IL-8/CXCL8. We have performed theoretical mutations of six charged amino acids in CXCR1, which abolish binding as suggested by earlier experimental data, to shed light on the effect of charge on association ability. We propose that the observed loss of binding in the six CXCR1 mutants is owed to loss of local structural stability, rather than hindrance of the recognition process because of changes in the overall electrostatic properties of the receptor. Based on further structural analysis, we propose some mutations of charged residues involving ion pairs in different elements of transmembrane helices and extracellular loops, which are expected to alter the local structure and possibly affect binding.
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Affiliation(s)
- Nicholas Huynh
- Department of Biochemistry, University of California, Riverside, CA 92521, USA
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28
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El Zein N, Badran B, Sariban E. The neuropeptide pituitary adenylate cyclase activating polypeptide modulates Ca2+ and pro-inflammatory functions in human monocytes through the G protein-coupled receptors VPAC-1 and formyl peptide receptor-like 1. Cell Calcium 2008; 43:270-84. [PMID: 17651798 DOI: 10.1016/j.ceca.2007.05.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Revised: 05/18/2007] [Accepted: 05/30/2007] [Indexed: 12/01/2022]
Abstract
In human neutrophils, the neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) acting via the G protein-coupled receptors vasoactive intestinal peptide/PACAP receptor 1 (VPAC-1) and formyl peptide receptor-like 1 (FPRL1) modulates Ca2+ and pro-inflammatory activities. We evaluated in human monocytes the importance of the Ca2+ signal and the participation of FPRL1 in PACAP-associated signaling pathways and pro-inflammatory activities. PACAP-evoked Ca2+ transient involved both Ca2+ influx and intracytoplasmic Ca2+ mobilisation. This was pertussis toxin, protein kinase A and adenylate cyclase dependent indicating the participation of Galphai and Galphas with mobilisation of both InsP3 sensitive and insensitive stores. Intra- or extracellular Ca2+ depletion resulted in the inhibition of PACAP-induced, Akt, ERK, p38 and NF-kappaB activations as well as a decrease in PACAP-associated reactive oxygen species (ROS) production and integrin CD11b membrane upregulation. The FPRL1 antagonist, Trp-Arg-Trp-Trp-Trp (WRW4), decreased PACAP-evoked Ca2+ signal, Akt, ERK phosphorylation, ROS and CD11b upregulation without affecting p38 phosphorylation. NF-kappaB inhibitors prevented PACAP-induced Ca2+ mobilisation. Monocytes pre-treatment with fMLP but not with LPS desensitised cells to the pro-inflammatory effects of PACAP. Thus, both intra- and extracellular Ca2+ play a role in controlling pro-inflammatory functions stimulated by PACAP which acts through a VPAC-1, FPRL1/Galphai/PI3K/ERK pathway and a VPAC-1/Galphas/PKA/p38 pathway to fully activate monocytes.
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Affiliation(s)
- Nabil El Zein
- Hemato-Oncology Unit and Laboratory of Pediatric Oncology, Hôpital Universitaire des Enfants, 1020 Brussels, Belgium
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29
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Schaff UY, Yamayoshi I, Tse T, Griffin D, Kibathi L, Simon SI. Calcium flux in neutrophils synchronizes beta2 integrin adhesive and signaling events that guide inflammatory recruitment. Ann Biomed Eng 2008; 36:632-46. [PMID: 18278555 PMCID: PMC2668576 DOI: 10.1007/s10439-008-9453-8] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 01/28/2008] [Indexed: 12/11/2022]
Abstract
Intracellular calcium flux is an early step in the signaling cascade that bridges ligation of selectin and chemokine receptors to activation of adhesive and motile functions during recruitment on inflamed endothelium. Calcium flux was imaged in real time and provided a means of correlating signaling events in neutrophils rolling on E-selectin and stimulated by chemokine in a microfluidic chamber. Integrin dependent neutrophil arrest was triggered by E-selectin tethering and ligation of IL-8 seconds before a rapid rise in intracellular calcium, which was followed by the onset of pseudopod formation. Calcium flux on rolling neutrophils increased in a shear dependent manner, and served to link integrin adhesion and signaling of cytoskeletally driven cell polarization. Abolishing calcium influx through membrane expressed store operated calcium channels inhibited activation of high affinity beta(2) integrin and subsequent cell arrest. We conclude that calcium influx at the plasma membrane integrates chemotactic and adhesive signals, and functions to synchronize signaling of neutrophil arrest and migration in a shear stress dependent manner.
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Affiliation(s)
- Ulrich Y Schaff
- Department of Biomedical Engineering, Genome and Biomedical Sciences Facility, University of California, Davis, 451 E. Health Sciences Dr., Davis, CA 95616-5294, USA
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30
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Rittner HL, Labuz D, Schaefer M, Mousa SA, Schulz S, Schäfer M, Stein C, Brack A. Pain control by CXCR2 ligands through Ca2+-regulated release of opioid peptides from polymorphonuclear cells. FASEB J 2006; 20:2627-9. [PMID: 17060402 DOI: 10.1096/fj.06-6077fje] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Leukocytes counteract inflammatory pain by releasing opioid peptides, which bind to opioid receptors on peripheral sensory neurons. In the early phase of inflammation, polymorphonuclear cells (PMN) are the major source of opioids. Their recruitment is governed by ligands at the chemokine receptor CXCR2. Here, we examined whether chemokines can also induce opioid peptide secretion from PMN and thus inhibit inflammatory pain. In rats with hindpaw inflammation, intraplantar injection of CXCL2/3, but not of the CXCR4 ligand CXCL12, elicited naloxone-reversible (i.e., opioid receptor mediated) mechanical and thermal analgesia, which was abolished by systemic PMN depletion. Both CXCR1/2- and CXCR4-ligands induced PMN chemotaxis, but only CXCR1/2 ligands triggered opioid release from human and rat PMN in vitro. This release was unaltered by extracellular Ca2+ chelation, was mimicked by thapsigargin and was blocked by inhibitors of the inositol 1,4,5-triphosphate receptor (IP3) and by intracellular Ca2+ chelation, indicating that it required Ca2+ from intracellular but not extracellular sources. Furthermore, release was partially reduced by phosphoinositol-3-kinase (PI3K) inhibitors. Adoptive transfer of allogenic PMN into PMN-depleted rats reconstituted CXCL2/3-induced analgesia, which was inhibited by prior ex vivo chelation of intracellular Ca2+. These findings demonstrate that, beyond cell recruitment, CXCR2 ligands induce Ca2+-regulated opioid release from PMN and thereby inhibit inflammatory pain in vivo.
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Affiliation(s)
- Heike L Rittner
- Klinik für Anaesthesiologie und Operative Intensivmedizin, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany.
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31
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Shideman CR, Hu S, Peterson PK, Thayer SA. CCL5 evokes calcium signals in microglia through a kinase-, phosphoinositide-, and nucleotide-dependent mechanism. J Neurosci Res 2006; 83:1471-84. [PMID: 16547971 DOI: 10.1002/jnr.20839] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Microglia, the resident macrophages of the CNS, are responsible for the innate immune response in the brain and participate in the pathogenesis of certain neurodegenerative disorders. Chemokines initiate activation and migration of microglia. The beta-chemokine CCL5 induces an elevation in intracellular calcium concentration ([Ca(2+)](i)) in human microglia. Here, we examined the signal transduction pathway linking activation of chemokine receptor CCR5 to an elevation in [Ca(2+)](i) in cultured microglia by using pharmacological approaches in combination with Fura-2-based digital imaging. The CCL5-induced response required Janus kinase (Jak) activity and the stimulation of an inhibitory G protein. Multiple downstream signaling pathways were involved, including phosphatidylinositol 3-kinase (PI3K), Bruton's tyrosine kinase (Btk), and phospholipase C (PLC)-mediated release of Ca(2+) from inositol 1,4,5-trisphosphate (IP(3))-sensitive stores. Activation of both the kinase and the lipase pathways was required for eliciting the Ca(2+) response. However, the majority of the [Ca(2+)](i) increase was derived from sources activated by NAD metabolites. Cyclic ADP-ribose (cADPR) evoked Ca(2+) release from intracellular stores, and ADPR evoked Ca(2+) influx via a nimodipine-sensitive channel. Thus, a multistep cascade couples CCR5 activation to Ca(2+) increases in human microglia. Because changes in [Ca(2+)](i) affect chemotaxis, secretion, and gene expression, pharmacologic modulation of this pathway may alter inflammatory and degenerative processes in the CNS.
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MESH Headings
- Agammaglobulinaemia Tyrosine Kinase
- Calcium/metabolism
- Calcium Channels/drug effects
- Calcium Channels/metabolism
- Calcium Signaling/drug effects
- Calcium Signaling/immunology
- Cells, Cultured
- Chemokine CCL5
- Chemokines, CC/immunology
- Chemokines, CC/metabolism
- Chemokines, CC/pharmacology
- Cyclic ADP-Ribose/metabolism
- Encephalitis/immunology
- Encephalitis/metabolism
- Encephalitis/physiopathology
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- Humans
- Immunity, Innate/immunology
- Immunologic Surveillance/immunology
- Inositol 1,4,5-Trisphosphate/metabolism
- Janus Kinase 1
- Microglia/drug effects
- Microglia/immunology
- Microglia/metabolism
- NAD/metabolism
- Nerve Degeneration/immunology
- Nerve Degeneration/metabolism
- Nerve Degeneration/physiopathology
- Phosphatidylinositol 3-Kinases/metabolism
- Protein-Tyrosine Kinases/metabolism
- Receptors, CCR5/agonists
- Receptors, CCR5/immunology
- Receptors, CCR5/metabolism
- Signal Transduction/drug effects
- Signal Transduction/immunology
- Signal Transduction/physiology
- Type C Phospholipases/metabolism
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Affiliation(s)
- C R Shideman
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota, USA
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McNeill E, Conway SJ, Roderick HL, Bootman MD, Hogg N. Defective chemoattractant-induced calcium signalling in S100A9 null neutrophils. Cell Calcium 2006; 41:107-21. [PMID: 16814379 DOI: 10.1016/j.ceca.2006.05.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Revised: 05/14/2006] [Accepted: 05/18/2006] [Indexed: 10/24/2022]
Abstract
The S100 family member S100A9 and its heterodimeric partner, S100A8, are cytosolic Ca2+ binding proteins abundantly expressed in neutrophils. To understand the role of this EF-hand-containing complex in Ca2+ signalling, neutrophils from S100A9 null mice were investigated. There was no role for the complex in buffering acute cytosolic Ca2+ elevations. However, Ca2+ responses to inflammatory agents such as chemokines MIP-2 and KC and other agonists are altered. For S100A9 null neutrophils, signalling at the level of G proteins is normal, as is release of Ca2+ from the IP(3) receptor-gated intracellular stores. However MIP-2 and FMLP signalling in S100A9 null neutrophils was less susceptible than wildtype to PLCbeta inhibition, revealing dis-regulation of the signalling pathway at this level. Downstream of PLCbeta, there was reduced intracellular Ca2+ release induced by sub-maximal levels of chemokines. Conversely the response to FMLP was uncompromised, demonstrating different regulation compared to MIP-2 stimulation. Study of the activity of PLC product DAG revealed that chemokine-induced signalling was susceptible to inhibition by elevated DAG with S100A9 null cells showing enhanced inhibition by DAG. This study defines a lesion in S100A9 null neutrophils associated with inflammatory agonist-induced IP3-mediated Ca2+ release that is manifested at the level of PLCbeta.
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Affiliation(s)
- E McNeill
- Leukocyte Adhesion Laboratory, Cancer Research UK London Research Institute (CRUK LRI), 44 Lincoln's Inn Fields, London WC2A 3PX, UK
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Deitch EA, Ananthakrishnan P, Cohen DB, Xu DZ, Feketeova E, Hauser CJ. Neutrophil activation is modulated by sex hormones after trauma-hemorrhagic shock and burn injuries. Am J Physiol Heart Circ Physiol 2006; 291:H1456-65. [PMID: 16617133 DOI: 10.1152/ajpheart.00694.2005] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent literature indicates that females are more resistant to shock-, trauma-, and sepsis-induced immune dysfunction and organ injury than are males. Consequently, using trauma-hemorrhagic shock (T/HS) and burn models, we tested whether the neutrophil response to trauma occurred in a sexually dimorphic fashion and, if so, the role of sex hormones. Neutrophil activation, as reflected by CD11b expression and respiratory burst activity, was increased to a greater extent in male rats than in female rats after T/HS or burn injury. Testosterone appeared to potentiate neutrophil activation, because castration reduced neutrophil activation, whereas ovariectomy had little effect. Mechanistically, this sexually dimorphic neutrophil response appeared to be due to both cellular and humoral factors. Evidence for a cellular difference between male and female neutrophils is based on the observation that naive female neutrophils were more resistant to activation by burn or T/HS plasma and lymph than naive male neutrophils and that this resistance varied over the estrus cycle. Additionally, the humoral environment was more neutrophil activating in male rats, because burn and T/HS plasma and lymph from male rats activated naive male neutrophils to a greater extent than comparable samples from females. Last, on the basis of in vitro experiments examining the effects of estrogen on calcium signaling, it appears that estrogen limits trauma-induced neutrophil activation, at least in part, by limiting the entry of calcium into the cell via store-operated calcium entry mechanisms. In conclusion, there is a striking sexual dimorphism in neutrophil responses after trauma, and these changes reflect both cellular resistance to activation as well as a less activating humoral environment.
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Affiliation(s)
- Edwin A Deitch
- Department of Surgery, MSB G506, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, 185 South Orange Ave., Newark, NJ 07103, USA.
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Harfi I, Corazza F, D'Hondt S, Sariban E. Differential calcium regulation of proinflammatory activities in human neutrophils exposed to the neuropeptide pituitary adenylate cyclase-activating protein. THE JOURNAL OF IMMUNOLOGY 2005; 175:4091-102. [PMID: 16148159 DOI: 10.4049/jimmunol.175.6.4091] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The neuropeptide pituitary adenylate cyclase-activating protein (PACAP) acts via the G protein-coupled receptor vasoactive intestinal peptide/PACAP receptor-1 to induce phospholipase C/calcium and MAPK-dependent proinflammatory activities in human polymorphonuclear neutrophils (PMNs). In this study, we evaluate other mechanisms that regulate PACAP-evoked calcium transients, the nature of the calcium sources, and the role of calcium in proinflammatory activities. Reduction in the activity of PMNs to respond to PACAP was observed after cell exposure to inhibitors of the cAMP/protein kinase A, protein kinase C, and PI3K pathways, to pertussis toxin, genistein, and after chelation of intracellular calcium or after extracellular calcium depletion. Mobilization of intracellular calcium stores was based on the fact that PACAP-associated calcium transient was decreased after exposure to 1) thapsigargin, 2) Xestospongin C, and 3) the protonophore carbonyl cyanide 4-(trifluoromethoxy) phenyl hydrazone; inhibition of calcium increase by calcium channel blockers, by nifedipine and verapamil, indicated that PACAP was also acting on calcium influx. Such mobilization was not dependent on a functional actin cytoskeleton. Homologous desensitization with nanomoles of PACAP concentration and heterologous receptors desensibilization by G protein-coupled receptor agonists were observed. Intracellular calcium depletion modulated PACAP-associated ERK but not p38 phosphorylation; in contrast, extracellular calcium depletion modulated PACAP-associated p38 but not ERK phosphorylation. In PACAP-treated PMNs, reactive oxygen species production and CD11b membrane up-regulation in contrast to lactoferrin release were dependent on both intra- and extracellular calcium, whereas matrix metalloproteinase-9 release was unaffected by extracellular calcium depletion. These data indicate that both extracellular and intracellular calcium play key roles in PACAP proinflammatory activities.
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Affiliation(s)
- Issam Harfi
- Hemato-Oncology Unit and Laboratory of Pediatric Oncology, Hôpital Universitaire des Enfants, Brussels, Belgium
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35
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Wang JP, Chang LC, Kuan YH, Tsao LT, Huang LJ, Kuo SC. 2-Benzyloxybenzaldehyde inhibits formyl peptide-stimulated increase in intracellular Ca2+ in neutrophils mainly by blocking Ca2+ entry. Naunyn Schmiedebergs Arch Pharmacol 2004; 370:353-60. [PMID: 15526104 DOI: 10.1007/s00210-004-0993-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Accepted: 09/24/2004] [Indexed: 10/26/2022]
Abstract
2-Benzyloxybenzaldehyde (CCY1a) inhibited the formyl-Met-Leu-Phe (fMLP)-induced elevation of cytosolic [Ca(2+)]() ([Ca(2+)](i)) in rat neutrophils. The late plateau phase, but not the initial Ca(2+) spike, of the fMLP-induced [Ca(2+)](i) change was inhibited by CCY1a. In the absence of external Ca(2+), CCY1a had no appreciable effect on either the fMLP- or cyclopiazonic acid (CPA)-induced [Ca(2+)](i) elevation. CCY1a failed to inhibit [Ca(2+)](i) changes induced by N-ethylmaleimide, GEA3162, ionomycin or sphingosine, but slightly inhibited the Ca(2+) signals elicited by ATP or interleukin-8 (IL-8). In a classical Ca(2+) readdition protocol, addition of CCY1a after cell activation strongly inhibited the [Ca(2+)](i) response to fMLP, whilst that to CPA was only slightly reduced. CCY1a nearly abrogated the fMLP-stimulated Mn(2+) influx but was less effective on the CPA-induced response. CCY1a attenuated the levels of tyrosine-phosphorylated bands in the 70-85 kDa molecular mass range. CCY1a had no effect on the basal [Ca(2+)](i) level, the pharmacologically isolated plasma membrane Ca(2+)-ATPase activity or on the mitochondrial membrane potential. Thus, CCY1a blocks fMLP-induced Ca(2+) entry into neutrophils probably by blocking the relevant Ca(2+) channel directly or, alternatively, indirectly through the attenuation of tyrosine phosphorylation of some cellular proteins.
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Affiliation(s)
- Jih-Pyang Wang
- Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan; Graduate Institute of Pharmaceutical Chemistry, China Medical University, Taichung, Taiwan, ROC.
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36
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Tarlowe MH, Kannan KB, Itagaki K, Adams JM, Livingston DH, Hauser CJ. Inflammatory chemoreceptor cross-talk suppresses leukotriene B4 receptor 1-mediated neutrophil calcium mobilization and chemotaxis after trauma. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:2066-73. [PMID: 12902512 DOI: 10.4049/jimmunol.171.4.2066] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
G protein-coupled chemoattractants recruit neutrophils (PMN) to sites of injury and infection. The leukotrienes (LT) and CXC chemokines (CXC) and their receptors (BLT1/BLT2 and CXCR1/CXCR2) are all known to play roles in these responses. Each system has been studied separately in vitro, but in vivo they act concurrently, and the clinical interactions between the two systems are unstudied. We prospectively studied calcium mobilization and chemotactic responses to LTB(4) in PMN from major trauma patients. The responses of the high affinity BLT1 receptor were suppressed at the 3-day postinjury time point, but recovered by 1 wk. Trauma patients had transient elevations of plasma LT and CXC levels. Functional deficits identical with those in trauma PMN were reproduced in vitro by exposing healthy PMN to CXCs at the elevated plasma concentrations found. Functional responses to LTB(4) were suppressed by cross-talk with CXC and BLT2 receptors that desensitize BLT1. Since the suppression of intracellular calcium mobilization was prominent, we also studied the role of suppressed cell calcium mobilization in the defective chemotactic responses to LTB(4). We noted that PMN chemotaxis to LTB(4) showed far more dependence on store-operated calcium entry than on the release of cellular calcium stores, and that store-operated calcium responses to BLT1 activation were markedly inhibited during the same time period as was chemotaxis. The intermittent release of inflammatory mediators after injury can blunt PMN responses to LTs by suppressing BLT1 as well as downstream calcium entry. Diminished LT receptor activity due to cross-talk with CXC receptors can inhibit PMN recruitment to infective sites. This may predispose injured patients to septic complications.
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MESH Headings
- Adolescent
- Adult
- Aged
- Calcium/antagonists & inhibitors
- Calcium/metabolism
- Calcium/physiology
- Calcium Signaling/physiology
- Chemotaxis, Leukocyte/physiology
- Female
- Humans
- Inflammation Mediators/metabolism
- Inflammation Mediators/physiology
- Interleukin-8/blood
- Interleukin-8/pharmacology
- Leukotriene B4/blood
- Leukotriene B4/pharmacology
- Male
- Middle Aged
- Neutrophils/cytology
- Neutrophils/metabolism
- Neutrophils/physiology
- Prospective Studies
- Receptor Cross-Talk/physiology
- Receptors, Chemokine/metabolism
- Receptors, Chemokine/physiology
- Receptors, Interleukin-8A/metabolism
- Receptors, Interleukin-8A/physiology
- Receptors, Interleukin-8B/metabolism
- Receptors, Interleukin-8B/physiology
- Receptors, Leukotriene B4/antagonists & inhibitors
- Receptors, Leukotriene B4/metabolism
- Receptors, Leukotriene B4/physiology
- Wounds and Injuries/immunology
- Wounds and Injuries/metabolism
- Wounds and Injuries/pathology
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Affiliation(s)
- Michael H Tarlowe
- Department of Surgery, Division of Trauma, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, NJ 07103, USA
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Timoshenko AV, Gorudko IV, Maslakova OV, André S, Kuwabara I, Liu FT, Kaltner H, Gabius HJ. Analysis of selected blood and immune cell responses to carbohydrate-dependent surface binding of proto- and chimera-type galectins. Mol Cell Biochem 2003; 250:139-49. [PMID: 12962152 DOI: 10.1023/a:1024952727159] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Cell surface glycans present docking sites to endogenous lectins. With growing insight into the diversity of lectin families it becomes important to answer the question on the activity profiles of individual family members. Focusing on galectins (beta-galactoside-binding proteins without Ca(2+)-requirement sharing the jelly-roll-like folding pattern), this study was performed to assess the potency of proto-type galectins (galectins-1 and -7 and CG-16) and the chimera-type galectin-3 to elicit selected cell responses by carbohydrate-dependent surface binding and compare the results. The galectins, except for galectin-1, were found to enhance detergent (SDS)-induced hemolysis of human erythrocytes to different degrees. Their ability to confer increased membrane osmofragility thus differs. Aggregation of neutrophils, thymocytes and platelets was induced by the proto-type galectin-1 but not -7, by CG-16 and also galectin-3. Cell-type-specific quantitative differences and the importance of the fine-specificity of the galectin were clearly apparent. In order to detect cellular responses based on galectin binding and bridging of cells the formation of haptenic-sugar-resistant (HSR) intercellular contacts (an indicator of post-binding signaling) was monitored. It was elicited by CG-16 and galectin-1 but not galectin-3, revealing another level at which activities of individual galectins can differ. Acting as potent elicitor of neutrophil aggregation, CG-16-dependent post-binding effects were further analyzed. Carbohydrate-dependent binding to the neutrophils' surface led to a sustained increase of cytoplasmic Ca2+ concentration in a dose-dependent manner. The ability of CG-16 to activate H2O2 generation by human peripheral blood neutrophils was primed by the Ca(2+)-ionophor ionomycin and by cytochalasin B. In a general context, these results emphasize that--besides plant lectins as laboratory tools--animal lectins can trigger cell reaction cascades, implying potential in vivo relevance for the measured activities. Within the family of galectins, the activity profiles depend on the target cell type and the individual galectin. Notably, proto-type galectins do not necessarily share a uniform capacity as elicitor.
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38
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Wehage E, Eisfeld J, Heiner I, Jüngling E, Zitt C, Lückhoff A. Activation of the cation channel long transient receptor potential channel 2 (LTRPC2) by hydrogen peroxide. A splice variant reveals a mode of activation independent of ADP-ribose. J Biol Chem 2002; 277:23150-6. [PMID: 11960981 DOI: 10.1074/jbc.m112096200] [Citation(s) in RCA: 278] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
LTRPC2 is a cation channel recently reported to be activated by adenosine diphosphate-ribose (ADP-ribose) and NAD. Since ADP-ribose can be formed from NAD and NAD is elevated during oxidative stress, we studied whole cell currents and increases in the intercellular free calcium concentration ([Ca(2+)](i)) in long transient receptor potential channel 2 (LTRPC2)-transfected HEK 293 cells after stimulation with hydrogen peroxide (H(2)O(2)). Cation currents carried by monovalent cations and Ca(2+) were induced by H(2)O(2) (5 mm in the bath solution) as well as by intracellular ADP-ribose (0.3 mm in the pipette solution) but not by NAD (1 mm). H(2)O(2)-induced currents developed slowly after a characteristic delay of 3-6 min and receded after wash-out of H(2)O(2). [Ca(2+)](i) was rapidly increased by H(2)O(2) in LTRPC2-transfected cells as well as in control cells; however, in LTRPC2-transfected cells, H(2)O(2) evoked a second delayed rise in [Ca(2+)](i). A splice variant of LTRPC2 with a deletion in the C terminus (amino acids 1292-1325) was identified in neutrophil granulocytes. This variant was stimulated by H(2)O(2) as the wild type. However, it did not respond to ADP-ribose. We conclude that activation of LTRPC2 by H(2)O(2) is independent of ADP-ribose and that LTRPC2 may mediate the influx of Na(+) and Ca(2+) during oxidative stress, such as the respiratory burst in granulocytes.
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Affiliation(s)
- Edith Wehage
- Institute of Physiology, Medical Faculty, Rheinisch-Westfälische Technische Hochschule Aachen, Pauwelsstrasse 30, D-52057 Aachen, Germany
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39
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Werry TD, Christie MI, Dainty IA, Wilkinson GF, Willars GB. Ca(2+) signalling by recombinant human CXCR2 chemokine receptors is potentiated by P2Y nucleotide receptors in HEK cells. Br J Pharmacol 2002; 135:1199-208. [PMID: 11877327 PMCID: PMC1573230 DOI: 10.1038/sj.bjp.0704566] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. Human embryonic kidney (HEK)-293 cells expressing recombinant G alpha(i)-coupled, human CXC chemokine receptor 2 (CXCR2) were used to study the elevation of the intracellular [Ca(2+)] ([Ca(2+)](i)) in response to interleukin-8 (IL-8) following pre-stimulation of endogenously expressed P2Y1 or P2Y2 nucleotide receptors. 2. Pre-stimulation of cells with adenosine 5'-triphosphate (ATP) revealed a substantial Ca(2+) signalling component mediated by IL-8 (E(max)=83 +/- 8% of maximal ATP response, pEC(50) of IL-8 response=9.7 +/- 0.1). 3. 1 microM 2-methylthioadenosine 5'-diphosphate (2MeSADP; P2Y1 selective) and 100 microM uridine 5'-triphosphate (UTP; P2Y2 selective) stimulated equivalent maximal increases in [Ca(2+)](i) elevation. However, UTP caused a sustained elevation, whilst following 2MeSADP [Ca(2+)](i) rapidly returned to basal levels. 4. Both UTP and 2MeSADP increased the potency and magnitude of IL-8-mediated [Ca(2+)](i) elevation but the effects of UTP (E(max) of IL-8 response increased to 50 +/- 1% of the maximal response to ATP, pEC(50) increased to 9.8 +/- 0.1) were greater than those of 2MeSADP (E(max) increased to 36 +/- 2%, pEC(50) increased to 8.7 +/- 0.2). 5. 5. The potentiation of IL-8-mediated Ca(2+) signalling by UTP was not dependent upon the time of IL-8 addition following UTP but was dependent on the continued presence of UTP. Potentiated IL-8 Ca(2+) signalling was apparent in the absence of extracellular Ca(2+), demonstrating the release of Ca(2+) from intracellular stores. 6. Activation of P2Y1 and P2Y2 receptors also revealed Ca(2+) signalling by an endogenously expressed, G alpha(s)-coupled beta-adrenoceptor. 7. In conclusion, pre-stimulation of P2Y nucleotide receptors, particularly P2Y2, facilitates Ca(2+) signalling by either recombinant CXCR2 or endogenous beta-adrenoceptors.
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Affiliation(s)
- Tim D Werry
- Department of Cell Physiology and Pharmacology, Maurice Shock Medical Sciences Building, University Road, Leicester, LE1 9HN, UK.
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40
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Partida-Sánchez S, Cockayne DA, Monard S, Jacobson EL, Oppenheimer N, Garvy B, Kusser K, Goodrich S, Howard M, Harmsen A, Randall TD, Lund FE. Cyclic ADP-ribose production by CD38 regulates intracellular calcium release, extracellular calcium influx and chemotaxis in neutrophils and is required for bacterial clearance in vivo. Nat Med 2001; 7:1209-16. [PMID: 11689885 DOI: 10.1038/nm1101-1209] [Citation(s) in RCA: 349] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cyclic ADP-ribose is believed to be an important calcium-mobilizing second messenger in invertebrate, mammalian and plant cells. CD38, the best-characterized mammalian ADP-ribosyl cyclase, is postulated to be an important source of cyclic ADP-ribose in vivo. Using CD38-deficient mice, we demonstrate that the loss of CD38 renders mice susceptible to bacterial infections due to an inability of CD38-deficient neutrophils to directionally migrate to the site of infection. Furthermore, we show that cyclic ADP-ribose can directly induce intracellular Ca++ release in neutrophils and is required for sustained extracellular Ca++ influx in neutrophils that have been stimulated by the bacterial chemoattractant, formyl-methionyl-leucyl-phenylalanine (fMLP). Finally, we demonstrate that neutrophil chemotaxis to fMLP is dependent on Ca++ mobilization mediated by cyclic ADP-ribose. Thus, CD38 controls neutrophil chemotaxis to bacterial chemoattractants through its production of cyclic ADP-ribose, and acts as a critical regulator of inflammation and innate immune responses.
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41
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Puma C, Danik M, Quirion R, Ramon F, Williams S. The chemokine interleukin-8 acutely reduces Ca(2+) currents in identified cholinergic septal neurons expressing CXCR1 and CXCR2 receptor mRNAs. J Neurochem 2001; 78:960-71. [PMID: 11553670 DOI: 10.1046/j.1471-4159.2001.00469.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The chemokine IL-8 is known to be synthesized by glial cells in the brain. It has traditionally been shown to have an important role in neuroinflammation but recent evidence indicates that it may also be involved in rapid signaling in neurons. We investigated how IL-8 participates in rapid neuronal signaling by using a combination of whole-cell recording and single-cell RT-PCR on dissociated rat septal neurons. We show that IL-8 can acutely reduce Ca(2+) currents in septal neurons, an effect that was concentration-dependent, involved the closure of L- and N-type Ca(2+) channels, and the activation of G(ialpha1) and/or G(ialpha2) subtype(s) of G-proteins. Analysis of the mRNAs from the recorded neurons revealed that the latter were all cholinergic in nature. Moreover, we found that all cholinergic neurons that responded to IL-8, expressed mRNAs for either one or both IL-8 receptors CXCR1 and CXCR2. This is the first report of a chemokine that modulates ion channels in neurons via G-proteins, and the first demonstration that mRNAs for CXCR1 are expressed in the brain. Our results suggest that IL-8 release by glial cells in vivo may activate CXCR1 and CXCR2 receptors on cholinergic septal neurons and acutely modulate their excitability by closing calcium channels.
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Affiliation(s)
- C Puma
- McGill University, Department of Psychiatry, Douglas Hospital Research Center, Verdun, Quebec, Canada
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42
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Chen LW, Jan CR. Mechanisms and modulation of formyl-methionyl-leucyl-phenylalanine (fMLP)-induced Ca2+ mobilization in human neutrophils. Int Immunopharmacol 2001; 1:1341-9. [PMID: 11460314 DOI: 10.1016/s1567-5769(01)00066-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The effect of fMLP (N-formyl-methionyl-leucyl-phenylalanine), a neutrophil-stimulating bacterial peptide, on Ca2+ mobilization in human neutrophils was examined using fura-2 as a Ca2+ indicator. fMLP (10 nM-10 microM) increased [Ca2+]i concentration-dependently. The [Ca2+]i signal comprised an initial rise followed by a gradual decay and a sustained phase. External Ca2+ removal partly decreased the signal. La3+ (50 microM) pretreatment mimicked the effect of Ca2+ removal. In Ca(2+)-free medium, pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) prevented 10 microM fMLP from increasing [Ca2+]i; whereas 1 microM thapsigargin still significantly increased [Ca2+]i after pretreatment with 10 microM fMLP. Addition of 3 mM Ca2+ induced a concentration-dependent [Ca2+]i increase after pretreatment with fMLP in Ca(2+)-free medium. This Ca2+ entry was partly inhibited by econazole (25 microM), SKF96365 (50 microM), and a phospholipase A2 inhibitor (aristolochic acid; 20 microM). The fMLP (10 microM)-induced Ca2+ release was abolished by inhibiting phospholipase C with 2 microM U73122. The fMLP-induced [Ca2+]i increase was inhibited by 25% by pretreatment with 10 nM phorbol ester to activate protein kinase C but was augmented by 27% by pretreatment with 2 microM GF 109203X to inactivate protein kinase C. We found that fMLP increase reactive oxygen intermediate (ROI) production in neutrophils, which can be suppressed by U73122 pretreatment. Collectively, this study shows that in human neutrophils, fMLP increased [Ca2+]i concentration-dependently by releasing Ca2+ from phospholipase C-coupled, thapsigargin-sensitive stores, accompanied by Ca2+ entry. The fMLP-induced [Ca2+]i rise was modulated by protein kinase C, and the fMLP-induced Ca2+ entry was abolished by La3+, and was reduced by econazole, SKF96365 and inhibition of phospholipase A2.
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Affiliation(s)
- L W Chen
- Department of Surgery, Kaohsiung Veterans General Hospital, 386 Ta Chung 1st Rd., Kaohsiung 813, Taiwan
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43
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Abstract
Bordetella pertussis exploits extracellular and intracellular niches in the respiratory tract and a variety of immune evasion strategies to prolong its survival in the host. This article reviews evidence of complementary roles for cellular and humoral immunity in protection. It discusses the effector mechanisms of bacterial elimination, the strategies employed by the bacteria to subvert protective immune responses and the immunological basis for systemic and neurological responses to infection and vaccination.
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Affiliation(s)
- K H Mills
- Infection and Immunity Group, Institute of Immunology, Department of Biology, National University of Ireland, Maynooth, Co., Kildare, Ireland.
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44
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Dianzani C, Lombardi G, Collino M, Ferrara C, Cassone MC, Fantozzi R. Priming effects of substance P on calcium changes evoked by interleukin‐8 in human neutrophils. J Leukoc Biol 2001. [DOI: 10.1189/jlb.69.6.1013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Chiara Dianzani
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin, Turin, Italy, and
| | - Grazia Lombardi
- Department of Alimentary, Chemical, Pharmaceutical and Pharmacological Sciences, University of Piemonte Orientale, Novara, Italy
| | - Massimo Collino
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin, Turin, Italy, and
| | - Cinzia Ferrara
- Department of Alimentary, Chemical, Pharmaceutical and Pharmacological Sciences, University of Piemonte Orientale, Novara, Italy
| | - Maria Chiara Cassone
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin, Turin, Italy, and
| | - Roberto Fantozzi
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin, Turin, Italy, and
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45
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Chen LW, Jan CR. Effect of the antianginal drug bepridil on intracellular Ca2+ release and extracellular Ca2+ influx in human neutrophils. Int Immunopharmacol 2001; 1:945-53. [PMID: 11379049 DOI: 10.1016/s1567-5769(01)00031-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
To understand more fully the effects of bepridil, an antiarrhythmic and antianginal drug, on myocardial ischemia-reperfusion injury and systemic immune responses, its effect on intracellular Ca2+ levels ([Ca2+]i) in human neutrophils was investigated by using fura-2 as a fluorescent probe. Bepridil (10-200 microM) increased [Ca2+]i in a concentration-dependent fashion. This signal was partly inhibited by removal of extracellular Ca2+. In a Ca(2+)-free medium, pretreatment with bepridil (100 microM) abolished the Ca2+ release induced by thapsigargin (1 microM), an endoplasmic reticulum Ca2+ pump inhibitor, and by carbonylcyanide m-chlorophenylhydrazone (2 microM), a mitochondrial uncoupler. Pretreatment with carbonylcyanide m-chlorophenylhydrazone and thapsigargin, respectively, partly inhibited bepridil-induced Ca2+ release. Addition of Ca2+ (3 mM) increased [Ca2+]i after pretreatment with bepridil (100 microM) in a Ca(2+)-free medium. Bepridil (100 microM)-induced Ca2+ release was not altered when phospholipase C was inhibited by U73122 (2 microM). Both Ca2+ release and Ca2+ entry induced by bepridil (100 microM) were augmented by activating protein kinase C with phorbol 12-myristate 13-acetate (10 nM), and were suppressed by inhibiting protein kinase C with GF 109203X (2 microM). Treatment with bepridil (10-20 microM) for 30 min increased the production of reactive oxygen intermediates (ROI) by more than 50%. Collectively, it was found that bepridil increased [Ca2+]i concentration-dependently in human neutrophils by releasing Ca2+ from the endoplasmic reticulum, mitochondria and, possibly, other compartments in a phospholipase C-independent manner. Bepridil also activated Ca2+ influx. The activity of protein kinase C may regulate bepridil-induced Ca2+ release and Ca2+ entry.
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Affiliation(s)
- L W Chen
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
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McGill JM, Yen MS, Cummings OW, Alpini G, LeSage G, Pollok KE, Miller B, Engle SK, Stansfield AP. Interleukin-5 inhibition of biliary cell chloride currents and bile flow. Am J Physiol Gastrointest Liver Physiol 2001; 280:G738-45. [PMID: 11254501 DOI: 10.1152/ajpgi.2001.280.4.g738] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Recent studies have detected significant elevations of interleukin (IL)-5 mRNA in the liver parenchyma of patients with both primary biliary cirrhosis and acute rejection after liver transplantation. In both of these disorders, intrahepatic biliary epithelial cells (BECs) are the targets of injury. We hypothesized that BECs may themselves express IL-5 receptors that may modulate key biliary functions. RNAs coding for IL-5alpha and -beta receptors were amplified by RT/PCR from a biliary cell line derived from a human cholangiocarcinoma (Mz-ChA-1) and verified by DNA sequencing. IL-5 receptor distribution was detected immunocytochemically on Mz-ChA-1 cells, immortalized murine BEC, bile duct-ligated rat liver, and isolated cholangiocytes. Patch-clamp studies on Mz-ChA-1 cells showed that IL-5 inhibits 5'-N-ethylcarboxamidoadenosine-stimulated chloride currents. Additional functional studies showed that IL-5 inhibits secretin-induced bile flow. We conclude that BECs express IL-5 receptors and that IL-5 modulates BEC chloride currents and fluid secretion. Since IL-5 has previously been associated with cholestatic liver disease, we speculate that IL-5 may contribute to liver injury through its effects on biliary secretion.
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Affiliation(s)
- J M McGill
- Roudebush Veterans Affairs Medical Center, Herman B. Wells Center for Pediatric Research, Riley Hospital for Children, Indiana, USA.
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Crane IJ, Wallace CA, McKillop-Smith S, Forrester JV. CXCR4 receptor expression on human retinal pigment epithelial cells from the blood-retina barrier leads to chemokine secretion and migration in response to stromal cell-derived factor 1 alpha. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:4372-8. [PMID: 11035074 DOI: 10.4049/jimmunol.165.8.4372] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Retinal pigment epithelial (RPE) cells form part of the blood-retina barrier and have recently been shown to produce various chemokines in response to proinflammatory cytokines. As the scope of chemokine action has been shown to extend beyond the regulation of leukocyte migration, we have investigated the expression of chemokine receptors on RPE cells to determine whether they could be a target for chemokine signaling. RT-PCR analysis indicated that the predominant receptor expressed on RPE cells was CXCR4. The level of CXCR4 mRNA expression, but not cell surface expression, increased on stimulation with IL-1beta or TNF-alpha. CXCR4 protein could be detected on the surface of 16% of the RPE cells using flow cytometry. Calcium mobilization in response to the CXCR4 ligand stromal cell-derived factor 1alpha (SDF-1alpha) indicated that the CXCR4 receptors were functional. Incubation with SDF-1alpha resulted in secretion of monocyte chemoattractant protein-1, IL-8, and growth-related oncogene alpha. RPE cells also migrated in response to SDF-1alpha. As SDF-1alpha expression by RPE cells was detected constitutively, we postulate that SDF-1-CXCR4 interactions may modulate the affects of chronic inflammation and subretinal neovascularization at the RPE site of the blood-retina barrier.
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Affiliation(s)
- I J Crane
- Department of Ophthalmology, University of Aberdeen Medical School, Aberdeen, United Kingdom
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Involvement of the proinflammatory cytokines tumor necrosis factor-alpha, IL-1 beta, and IL-6 but not IL-8 in the development of heat hyperalgesia: effects on heat-evoked calcitonin gene-related peptide release from rat skin. J Neurosci 2000. [PMID: 10934280 DOI: 10.1523/jneurosci.20-16-06289.2000] [Citation(s) in RCA: 251] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Proinflammatory cytokines contribute to the development of inflammatory and neuropathic pain and hyperalgesia in many in vivo models. The rat skin model was used to investigate the effects of proinflammatory cytokines on the basal and heat-evoked release of calcitonin gene-related peptide from nociceptors in vitro. In contrast to the excitatory effects of cytokines observed in vivo, none of the cytokines tested evoked any calcitonin gene-related peptide (CGRP) release at normal skin temperature of 32 degrees C. However, the cytokines IL-1beta, tumor necrosis factor (TNF)-alpha, and IL-6 but not IL-8 induced a pronounced and transient sensitization of the heat-evoked CGRP release from nociceptors in vitro. This heat sensitization was dose dependent, with EC(50) for IL-1 beta of 2.7 ng/ml and for TNF-alpha of 3.1 ng/ml. The maximum IL-1 beta effect reached almost 600% of the heat-evoked release, and the maximum TNF-alpha effect induced a rise in CGRP release of 350%. In contrast to IL-1 beta and TNF-alpha, IL-6 did not induce heat sensitization when applied alone but was only effective in the presence of soluble IL-6 receptor. This suggests a constitutive expression of signaling receptors for TNF and IL-1 beta and the signal transduction molecule gp130 but not IL-6 receptor or IL-8 receptor. Furthermore, the acute cytokine signaling observed in the present study was independent of transcriptional pathways because sensitization occurred on short latency in vitro and under conditions that excluded chemotactic accumulation of immune cells from blood vessels. Our results demonstrate that interleukins may play an important role in the initiation of heat hyperalgesia in inflammation and neuropathy.
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Wennemuth G, Aumüller G, Bacher M, Meinhardt A. Macrophage migration inhibitory factor-induced Ca(2+) response in rat testicular peritubular cells. Biol Reprod 2000; 62:1632-9. [PMID: 10819765 DOI: 10.1095/biolreprod62.6.1632] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Macrophage migration inhibitory factor (MIF), originally described as a T-cell product, has recently been identified in several endocrine organs. In the rat testis, MIF is secreted by the Leydig cells into testicular interstitial fluid that directly contacts Sertoli and peritubular cells. To investigate whether MIF is involved in calcium-dependent signal transduction, we have isolated rat Sertoli and peritubular cells. Despite progress in understanding functional properties of MIF, the molecular mechanism of MIF action in target cells is almost completely unknown. Here we find that recombinant MIF evokes a transient increase in calcium levels in peritubular cells but not in Sertoli cells from dissociated rat testis. Concentrations in the range between 12.5 ng/ml and 120 ng/ml of recombinant MIF were found to be effective, with 50 ng/ml yielding the largest increase in intracellular calcium. Preincubation of MIF with a neutralizing monoclonal antibody specifically blocked the response. Incubation of the peritubular cells in calcium-free buffer clearly decreased the evoked response in intracellular calcium concentration. However, the calcium response was greatly decreased by thapsigargin, an inhibitor of the Ca(2+) ATPase of the endoplasmic reticulum. The results strongly indicate that calcium is mobilized from reticulum stores during MIF-mediated signal transduction in the testis. In conclusion, our results provide the first characterization of MIF signal transduction in the testis and suggest that signaling from Leydig cells to peritubular cells through MIF is mediated by receptors coupled to release of intracellular calcium.
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Affiliation(s)
- G Wennemuth
- Department of Anatomy and Cell Biology and Institute of Immunology, Philipps-University, D-35037 Marburg, Germany.
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Abstract
Interleukin-8 was originally discovered as one of the first chemokines activating neutrophil granulocytes (neutrophils) after secretion by lipopolysaccharide-stimulated monocytes. A wealth of information has been gathered concerning the intracellular events mediated by interleukin-8 and the role of interleukin-8 in numerous physiologic and pathophysiologic processes. We discuss recent advances in the understanding of the initial intracellular signals elicited by interleukin-8. Detailed investigation of these events has led to the identification of subtle but significant differences in the signal transduction processes evoked by interleukin-8 receptors. In particular, much has been learned concerning differences in the cellular mechanisms leading to desensitization, internalization, and recycling of interleukin-8 receptors, and functional consequences of interleukin-8 receptor diversity are now being unraveled.
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Affiliation(s)
- H U Zeilhofer
- Department of Experimental and Clinical Pharmacology and Toxicology, University of Erlangen-Nürnberg, Erlangen, Germany.
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