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Zhu B, Feng Z, Guo Y, Zhang T, Mai A, Kang Z, Weijen T, Wang D, Yin D, Zhu D, Gao J. F0F1 ATP synthase regulates extracellular calcium influx in human neutrophils by interacting with Ca v2.3 and modulates neutrophil accumulation in the lipopolysaccharide-challenged lung. Cell Commun Signal 2020; 18:19. [PMID: 32019549 PMCID: PMC7001235 DOI: 10.1186/s12964-020-0515-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 01/17/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Neutrophils form the first line of innate host defense against invading microorganisms. We previously showed that F0F1 ATP synthase (F-ATPase), which is widely known as mitochondrial respiratory chain complex V, is expressed in the plasma membrane of human neutrophils and is involved in regulating cell migration. Whether F-ATPase performs cellular functions through other pathways remains unknown. METHODS Blue native polyacrylamide gel electrophoresis followed by nano-ESI-LC MS/MS identification and bioinformatic analysis were used to identify protein complexes containing F-ATPase. Then, the identified protein complexes containing F-ATPase were verified by immunoblotting, immunofluorescence colocalization, immunoprecipitation, real-time RT-PCR and agarose gel electrophoresis. Immunoblotting, flow cytometry and a LPS-induced mouse lung injury model were used to assess the effects of the F-ATPase-containing protein complex in vitro and in vivo. RESULTS We found that the voltage-gated calcium channel (VGCC) α2δ-1 subunit is a binding partner of cell surface F-ATPase in human neutrophils. Further investigation found that the physical connection between the two proteins may exist between the F1 part (α and β subunits) of F-ATPase and the α2 part of VGCC α2δ-1. Real-time RT-PCR and PCR analyses showed that Cav2.3 (R-type) is the primary type of VGCC expressed in human neutrophils. Research on the F-ATPase/Cav2.3 functional complex indicated that it can regulate extracellular Ca2+ influx, thereby modulating ERK1/2 phosphorylation and reactive oxygen species production, which are typical features of neutrophil activation. In addition, the inhibition of F-ATPase can reduce neutrophil accumulation in the lungs of mice that were intratracheally instilled with lipopolysaccharide, suggesting that the inhibition of F-ATPase may prevent neutrophilic inflammation-induced tissue damage. CONCLUSIONS In this study, we identified a mechanism by which neutrophil activity is modulated, with simultaneous regulation of neutrophil-mediated pulmonary damage. These results show that surface F-ATPase of neutrophils is a potential innate immune therapeutic target.
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Affiliation(s)
- Baoyi Zhu
- Department of Basic Medical Research, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan, 511518 Guangdong China
| | - Zhengfu Feng
- Department of Basic Medical Research, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan, 511518 Guangdong China
| | - Yan Guo
- Clinical Laboratory of Dongcheng People’s Hospital, Dong guan, 523007 Guangdong China
| | - Tian Zhang
- Department of Basic Medical Research, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan, 511518 Guangdong China
| | - Ai Mai
- Department of Basic Medical Research, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan, 511518 Guangdong China
| | - Zhanfang Kang
- Department of Basic Medical Research, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan, 511518 Guangdong China
| | - Ting Weijen
- Department of Basic Medical Research, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan, 511518 Guangdong China
- Graduate Institute of Basic Medical Science, China Medical University, Taichung, 40402 Taiwan
| | - Dai Wang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics of Xiamen University, Xiamen, 361102 Fujian China
| | - Dazhong Yin
- Department of Basic Medical Research, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan, 511518 Guangdong China
| | - Dongxing Zhu
- Key Laboratory of Cardiovascular Diseases, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, 511436 Guangdong China
| | - Jun Gao
- Department of Basic Medical Research, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan, 511518 Guangdong China
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Nanoparticles Equipped with α2,8-Linked Sialic Acid Chains Inhibit the Release of Neutrophil Extracellular Traps. NANOMATERIALS 2019; 9:nano9040610. [PMID: 31013834 PMCID: PMC6523985 DOI: 10.3390/nano9040610] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/18/2019] [Accepted: 04/02/2019] [Indexed: 11/16/2022]
Abstract
Neutrophils can combat the invasion of pathogens by the formation of neutrophil extracellular traps (NETs). The NET mechanism is not only an effective tool for combating pathogens, but is also associated with diseases. Therefore, NETs are a potential target for combating pathologies, such as cystic fibrosis and thrombosis. We investigated the potential of nanoparticles, which were modified with α2,8-linked sialic acid chains, to modulate NET release during phorbol myristate acetate stimulation. Interestingly, when these nanoparticles were applied, the formation of reactive oxygen species was partly inhibited and the release of NET was counteracted. However, although the release of NET fibers was prevented, the nuclei still lost their characteristic segmented structure and became swollen, indicating that only the release, and not complete activation was suppressed. Intriguingly, coincubation of α2,8-sialylated particles with free sialic acid chains prevented the outlined inhibitory effects. Thus, the sialic acid chains must be attached to a linker molecule to generate an active bioconjugate that is able to inhibit the release of NET.
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Complement C5a Alters the Membrane Potential of Neutrophils during Hemorrhagic Shock. Mediators Inflamm 2018; 2018:2052356. [PMID: 30002598 PMCID: PMC5996468 DOI: 10.1155/2018/2052356] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 02/26/2018] [Accepted: 04/01/2018] [Indexed: 12/17/2022] Open
Abstract
Background Polymorphonuclear granulocytes (PMN) play a crucial role in host defense. Physiologically, exposure of PMN to the complement activation product C5a results in a protective response against pathogens, whereas in the case of systemic inflammation, excessive C5a substantially impairs neutrophil functions. To further elucidate the inability of PMN to properly respond to C5a, this study investigates the role of the cellular membrane potential of PMN in response to C5a. Methods Electrophysiological changes in cellular and mitochondrial membrane potential and intracellular pH of PMN from human healthy volunteers were determined by flow cytometry after exposure to C5a. Furthermore, PMN from male Bretoncelles-Meishan-Willebrand cross-bred pigs before and three hours after severe hemorrhagic shock were analyzed for their electrophysiological response. Results PMN showed a significant dose- and time-dependent depolarization in response to C5a with a strong response after one minute. The chemotactic peptide fMLP also evoked a significant shift in the membrane potential of PMN. Acidification of the cellular microenvironment significantly enhanced depolarization of PMN. In a clinically relevant model of porcine hemorrhagic shock, the C5a-induced changes in membrane potential of PMN were markedly diminished compared to healthy littermates. Overall, these membrane potential changes may contribute to PMN dysfunction in an inflammatory environment.
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Singh S. Glucose decorated gold nanoclusters: A membrane potential independent fluorescence probe for rapid identification of cancer cells expressing Glut receptors. Colloids Surf B Biointerfaces 2017; 155:25-34. [DOI: 10.1016/j.colsurfb.2017.03.052] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 03/14/2017] [Accepted: 03/27/2017] [Indexed: 12/12/2022]
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Gabl M, Winther M, Welin A, Karlsson A, Oprea T, Bylund J, Dahlgren C, Forsman H. P2Y2 receptor signaling in neutrophils is regulated from inside by a novel cytoskeleton-dependent mechanism. Exp Cell Res 2015; 336:242-52. [PMID: 26192818 DOI: 10.1016/j.yexcr.2015.07.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 07/07/2015] [Accepted: 07/17/2015] [Indexed: 10/23/2022]
Abstract
Functional selectivity, a process by which G-protein coupled receptors (GPCRs) can activate one signaling route while avoiding another, is regulated by ligand-mediated stabilization of specific receptor states that modulate different downstream signaling events. We propose a novel mechanism for functional selectivity, induced by the endogenous P2Y2R agonist ATP and regulated at the signaling interface by the cytoskeleton. Upon ATP stimulation of human neutrophils, a transient rise in the cytosolic concentration of free Ca(2+) was not followed by activation of the superoxide anion-generating NADPH-oxidase. This was in contrast to signals generated through the formyl peptide receptor 1 (FPR1), as its activation was accompanied by both a mobilization of Ca(2+) and activation of the NADPH-oxidase. The phospholipase C/Ca(2+) signaling route is not modulated by the cytoskeleton-disrupting drug latrunculin A, but this drug was able to launch a new signaling route downstream of P2Y2R that led to NADPH-oxidase activation. The signaling downstream of P2Y2R was rapidly terminated and the receptors were desensitized; however, in contrast to desensitized FPR1, no P2Y2 receptor reactivation could be induced by latrunculin A. Thus, P2Y2R desensitization does not appear to involve the cytoskeleton, contrary to FPR1 desensitization. In summary, we hereby describe how ATP regulates functional selectivity via the cytoskeleton, leading to intracellular Ca(2+) increase, alone or with simultaneous NADPH-oxidase activation in neutrophils.
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Affiliation(s)
- Michael Gabl
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, S-413 46 Göteborg, Sweden
| | - Malene Winther
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, S-413 46 Göteborg, Sweden
| | - Amanda Welin
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, S-413 46 Göteborg, Sweden
| | - Anna Karlsson
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, S-413 46 Göteborg, Sweden
| | - Tudor Oprea
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, S-413 46 Göteborg, Sweden; Translational Informatics Division, UNM Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Johan Bylund
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, S-413 46 Göteborg, Sweden; Department of Oral Microbiology and Immunology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Claes Dahlgren
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, S-413 46 Göteborg, Sweden.
| | - Huamei Forsman
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, S-413 46 Göteborg, Sweden
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Shin EH, Li Y, Kumar U, Sureka HV, Zhang X, Payne CK. Membrane potential mediates the cellular binding of nanoparticles. NANOSCALE 2013; 5:5879-86. [PMID: 23698734 PMCID: PMC3713847 DOI: 10.1039/c3nr01667f] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The use of nanoparticles for cellular therapeutic or sensing applications requires nanoparticles to bind, or adhere, to the cell surface. While nanoparticle parameters such as size, shape, charge, and composition are important factors in cellular binding, the cell itself must also be considered. All cells have an electrical potential across the plasma membrane driven by an ion gradient. Under standard conditions the ion gradient will result in a -10 to -100 mV potential across the membrane with a net negative charge on the cytosolic face. Using a combination of flow cytometry and fluorescence microscopy experiments and dissipative particle dynamics simulations, we have found that a decrease in membrane potential leads to decreased cellular binding of anionic nanoparticles. The decreased cellular binding of anionic nanoparticles is a general phenomenon, independent of depolarization method, nanoparticle composition, and cell type. Increased membrane potential reverses this trend resulting in increased binding of anionic nanoparticles. The cellular binding of cationic nanoparticles is minimally affected by membrane potential due to the interaction of cationic nanoparticles with cell surface proteins. The influence of membrane potential on the cellular binding of nanoparticles is especially important when considering the use of nanoparticles in the treatment or detection of diseases, such as cancer, in which the membrane potential is decreased.
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Affiliation(s)
- Edwin H. Shin
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, Georgia, 30332; Tel: 404-385-3125
| | - Ye Li
- Division of Molecular and Materials Simulation, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Umesh Kumar
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, Georgia, 30332; Tel: 404-385-3125
| | - Hursh V. Sureka
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, Georgia, 30332; Tel: 404-385-3125
| | - Xianren Zhang
- Division of Molecular and Materials Simulation, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Christine K. Payne
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, Georgia, 30332; Tel: 404-385-3125
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Decleva E, Menegazzi R, Fasolo A, Defendi F, Sebastianutto M, Dri P. Intracellular shunting of O2(-) contributes to charge compensation and preservation of neutrophil respiratory burst in the absence of voltage-gated proton channel activity. Exp Cell Res 2013; 319:1875-1888. [PMID: 23578765 PMCID: PMC3712189 DOI: 10.1016/j.yexcr.2013.03.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/28/2013] [Accepted: 03/29/2013] [Indexed: 11/19/2022]
Abstract
Proton efflux via voltage-gated proton channels (Hv1) is considered to mediate the charge compensation necessary to preserve NADPH oxidase activity during the respiratory burst. Using the Hv1 inhibitor Zn2+, we found that the PMA-induced respiratory burst of human neutrophils is inhibited when assessed as extracellular production of O2− and H2O2, in accordance with literature studies, but, surprisingly, unaffected when measured as oxygen consumption or total (extracellular plus intracellular) H2O2 production. Furthermore, we show that inhibiting Hv1 with Zn2+ results in an increased production of intracellular ROS. Similar results, i.e. decreased extracellular and increased intracellular ROS production, were obtained using a human granulocyte-like cell line with severely impaired Hv1 expression. Acidic extracellular pH, which dampens proton efflux, also augmented intracellular production of H2O2. Zinc caused an increase in the rate but not in the extent of depolarization and cytosolic acidification indicating that mechanisms other than proton efflux take part in charge compensation. Our results suggest a hitherto unpredicted mechanism of charge compensation whereby, in the absence of proton efflux, part of O2− generated within gp91phox in the plasma membrane is shunted intracellularly down electrochemical gradient to dampen excessive depolarization. This would preserve NADPH oxidase activity under conditions such as the inflammatory exudate in which the acidic pH hinders charge compensation by proton efflux. Neutrophils’ respiratory burst is not inhibited by the H+ channel inhibitor Zn2+. Intracellular production of O2− and H2O2 is increased in the presence of Zn2+. Intracellular H2O2 production is increased in H+ channels knock-down cells. Zn2+ increases the rate but not the extent of depolarization and pHi decrease. Intracellular shunting of O2− contributes to charge compensation in neutrophils.
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Affiliation(s)
- Eva Decleva
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Renzo Menegazzi
- Department of Life Sciences, University of Trieste, Trieste, Italy.
| | - Alba Fasolo
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Federica Defendi
- Université Joseph Fourier, GREPI/AGIM CNRS FRE 3405, Grenoble, France
| | | | - Pietro Dri
- Department of Life Sciences, University of Trieste, Trieste, Italy
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9
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Brasen JC, Barington T, Olsen LF. On the mechanism of oscillations in neutrophils. Biophys Chem 2010; 148:82-92. [PMID: 20227815 DOI: 10.1016/j.bpc.2010.02.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 02/19/2010] [Accepted: 02/22/2010] [Indexed: 12/19/2022]
Abstract
We have investigated the regulation of the oscillatory generation of H(2)O(2) and oscillations in shape and size in neutrophils in suspension. The oscillations are independent of cell density and hence do not represent a collective phenomena. Furthermore, the oscillations are independent of the external glucose concentration and the oscillations in H(2)O(2) production are 180 degrees out of phase with the oscillations in NAD(P)H. Cytochalasin B blocked the oscillations in shape and size whereas it increased the period of the oscillations in H(2)O(2) production. 1- and 2-butanol also blocked the oscillations in shape and size, but only 1-butanol inhibited the oscillations in H(2)O(2) production. We conjecture that the oscillations are likely to be due to feedback regulations in the signal transduction cascade involving phosphoinositide 3-kinases (PI3K). We have tested this using a simple mathematical model, which explains most of our experimental observations.
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Affiliation(s)
- Jens Christian Brasen
- CelCom, Institute of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark.
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10
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Abstract
This review is an attempt to identify and place in context some of the many questions about voltage-gated proton channels that remain unsolved. As the gene was identified only 2 years ago, the situation is very different than in fields where the gene has been known for decades. For the proton channel, most of the obvious and less obvious structure-function questions are still wide open. Remarkably, the proton channel protein strongly resembles the voltage-sensing domain of many voltage-gated ion channels, and thus offers a novel approach to study gating mechanisms. Another surprise is that the proton channel appears to function as a dimer, with two separate conduction pathways. A number of significant biological questions remain in dispute, unanswered, or in some cases, not yet asked. This latter deficit is ascribable to the intrinsic difficulty in evaluating the importance of one component in a complex system, and in addition, to the lack, until recently, of a means of performing an unambiguous lesion experiment, that is, of selectively eliminating the molecule in question. We still lack a potent, selective pharmacological inhibitor, but the identification of the gene has allowed the development of powerful new tools including proton channel antibodies, siRNA and knockout mice.
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Affiliation(s)
- Thomas E DeCoursey
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, 1750 W. Harrison, Chicago, IL 60612, USA.
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11
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Rada BK, Geiszt M, Hably C, Ligeti E. Consequences of the electrogenic function of the phagocytic NADPH oxidase. Philos Trans R Soc Lond B Biol Sci 2006; 360:2293-300. [PMID: 16321799 PMCID: PMC1569590 DOI: 10.1098/rstb.2005.1768] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
NADPH oxidase of phagocytic cells transfers a single electron from intracellular NADPH to extracellular O2, producing superoxide (O.-2), the precursor to several other reactive oxygen species. The finding that a genetic defect of the enzyme causes chronic granulomatous disease (CGD), characterized by recurrent severe bacterial infections, linked O.-2 generation to destruction of potentially pathogenic micro-organisms. In this review, we focus on the consequences of the electrogenic functioning of NADPH oxidase. We show that enzyme activity depends on the possibilities for compensating charge movements. In resting neutrophils K+ conductance dominates, but upon activation the plasma membrane rapidly depolarizes beyond the opening threshold of voltage-gated H+ channels and H+ efflux becomes the major charge compensating factor. K+ release is likely to contribute to the killing of certain bacteria but complete elimination only occurs if O.-2 production can proceed at full capacity. Finally, the reversed membrane potential of activated neutrophils inhibits Ca2+ entry, thereby preventing overloading the cells with Ca2+. Absence of this limiting mechanism in CGD cells may contribute to the pathogenesis of the disease.
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Oommen J, Steel HC, Theron AJ, Anderson R. Investigation into the relationship between calyculin A-mediated potentiation of NADPH oxidase activity and inhibition of store-operated uptake of calcium by human neutrophils. Biochem Pharmacol 2004; 68:1721-8. [PMID: 15450937 DOI: 10.1016/j.bcp.2004.07.004] [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: 04/30/2004] [Accepted: 07/13/2004] [Indexed: 11/18/2022]
Abstract
The primary objective of the current study was to investigate possible relationships between calyculin A (CA)-mediated potentiation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and inhibition of store-operated uptake of Ca2+ by chemoattractant-activated human neutrophils. Treatment of neutrophils with 100 nM CA, but not at lower concentrations (12.5-50 nM), prior to the addition of the N-formylated chemotactic tripeptide, N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) (1 microM), both potentiated and prolonged the activity of NADPH oxidase which was accompanied by exaggerated membrane depolarisation, delayed and attenuated membrane repolarisation, and inhibition of store-operated Ca2+ influx. Inclusion of diphenylene iodonium chloride (DPI, 10 microM), an inhibitor of NADPH oxidase, antagonised the effects of CA on NADPH oxidase activity and the membrane repolarisation responses of FMLP-activated neutrophils, but failed to restore store-operated influx of Ca2+. Similarly, CA also inhibited store-operated influx of Ca2+ into FMLP-activated neutrophils from a patient with chronic granulomatous disease, a primary immunodeficiency disorder characterised by the absence of a functional NADPH oxidase. CA also inhibited the store-operated influx of Ca2+ into control neutrophils treated with 1 microM thapsigargin, a selective inhibitor of the endomembrane Ca2+-ATPase, which does not activate NADPH oxidase. Taken together, these observations demonstrate that augmentation of NADPH oxidase activity is not primarily involved in CA-mediated inhibition of the store-operated influx of Ca2+ into activated human neutrophils.
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Affiliation(s)
- Joyce Oommen
- Medical Research Council Unit for Inflammation and Immunity, Department of Immunology, School of Medicine, Faculty of Health Sciences, University of Pretoria, South Africa
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Palmblad J, Hansson A, Heimbürger M, Ahlin A. Aberrant [correction of Abberant] cytosolic calcium ion mobilization in chronic granulomatous disease neutrophils. Inflammation 2004; 28:133-8. [PMID: 15527168 DOI: 10.1023/b:ifla.0000039559.96659.d9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Beside the inability to produce superoxide ions, neutrophils (PMN) from chronic granulomatous disease (CGD) patients show other functional defects, e.g. abnormal membrane potential reactions. We observed that PMN from a female CGD carrier, with a discrete mutation in one allele of the pg91(phox) gene and exhibiting extreme lyonization, showed a consistently and remarkably delayed PMN cytosolic calcium response to the tripeptide fMLP or leukotriene B4 (LTB4). In keeping with results from other CGD patients, membrane potential changes were abnormal, whereas chemotaxis and adherence was normal. Since phospholipase D-generated metabolites are important for calcium transients we examined the generation of phosphatidic acid, but found that to be normal. A male CGD patient with pg91(phox) deficiency exhibited a trend toward prolongation of this calcium response, whereas two other CGD patients (one with p47 and one with 67(phox) deficiencies) had normal calcium transients. Thus, our finding points to a defect of the stimulus response coupling for fMLP and LTB4, which is supposed to be characteristic for this patient or a subset of CGD patients.
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Affiliation(s)
- Jan Palmblad
- The Center for Inflammation and Hematology Research, Department of Hematology, Karolinska University Hospital, Huddinge, Sweden.
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14
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Rada BK, Geiszt M, Káldi K, Timár C, Ligeti E. Dual role of phagocytic NADPH oxidase in bacterial killing. Blood 2004; 104:2947-53. [PMID: 15251984 DOI: 10.1182/blood-2004-03-1005] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The classical model of bacterial killing by phagocytic cells has been recently challenged by questioning the toxic effect of oxygen products and attributing the fundamental role to K(+) ions in releasing antimicrobial proteins within the phagosome. In the present study we followed O(2)(*-) production, changes of membrane potential, K(+) efflux, and bacterial killing in the presence of increasing concentrations of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor diphenylene iodonium. Efficiency of bacterial killing was assessed on the basis of bacterial survival measured by a new semiautomated method. Very low rates of O(2)(*-) production were accompanied by significant membrane depolarization and K(+) release and parallel improvement of bacterial killing. When O(2)(*-) production exceeded 20% of its maximal capacity, no further change was detected in the membrane potential and only minimal further K(+) efflux occurred, yet bacterial survival decreased parallel to the increase of O(2)(*-) production. The presented results indicate that both electrophysiological changes (depolarization and consequent ion movements) and the chemical effect of reactive oxygen species play a significant role in the killing of certain pathogens. The observation that an increase of membrane depolarization can compensate for decreased O(2)(*-) production may be important for potential therapeutic applications.
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Affiliation(s)
- Balázs K Rada
- Department of Physiology, Semmelweis University, H-1444 Budapest, PO Box 259, Hungary
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15
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Tintinger GR, Anderson R. Counteracting effects of NADPH oxidase and the Na+/Ca2+ exchanger on membrane repolarisation and store-operated uptake of Ca2+ by chemoattractant-activated human neutrophils. Biochem Pharmacol 2004; 67:2263-71. [PMID: 15163557 DOI: 10.1016/j.bcp.2004.02.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2003] [Accepted: 02/18/2004] [Indexed: 10/26/2022]
Abstract
This study was designed to investigate the possible involvement of NADPH oxidase and the Na(+)/Ca(2+) exchanger in regulating membrane repolarisation and store-operated uptake of Ca(2+) by FMLP (1 microM)-activated human neutrophils. Diphenyleneiodonium chloride (DPI, 5-10 microM) and KB-R7943 (2.5-10 microM), inhibitors of NADPH oxidase and the reverse mode of the Na(+)/Ca(2+) exchanger respectively, were used as pharmacological probes. Transmembrane fluxes of Ca(2+), K(+) and Na(+) were determined radiometrically, while alterations in membrane potential and cytosolic Ca(2+) were evaluated using spectrofluorimetric procedures. DPI, added to the cells at the time of maximum FMLP-activated membrane depolarisation, accelerated the rates of both membrane repolarisation and influx of Ca(2+), while KB-R7943 effectively antagonised these processes. SKF 96365 (10 microM), an antagonist of store-operated Ca(2+) channels, abolished the influx of Ca(2+) into FMLP-activated neutrophils, but had no effects on membrane repolarisation, suggesting that the Na(+)/Ca(2+) exchanger is primarily involved in mediating membrane repolarisation, thereby facilitating uptake of Ca(2+) via store-operated channels. These observations are compatible with prominent negative and positive regulatory roles for NADPH oxidase and the Na(+)/Ca(2+) exchanger respectively in regulating the rates of membrane repolarisation and store-operated uptake of Ca(2+) by chemoattractant-activated neutrophils.
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Affiliation(s)
- Gregory R Tintinger
- Medical Research Council Unit for Inflammation and Immunity, Department of Immunology, Institute of Pathology, University of Pretoria, Pretoria, South Africa
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Abstract
The use of granulocyte transfusions to treat and prevent life-threatening infection in patients lacking neutrophil numbers or function may become increasingly important in aiding advances in the treatment of haematological malignancies. A critical factor in determining the outcome of granulocyte transfusion is the number of cells transfused, and collection of sufficiently high concentration of cells from donors remains challenging. A number of tests of granulocyte function can be performed in vitro to assess the quality of granulocyte concentrates, which may be useful in helping to optimize granulocyte collection, processing and storage methods. Studies that have examined neutrophil function in granulocyte concentrates to date have tended to focus on the assessment of viability, chemotaxis, phagocytosis and oxidative killing. How useful in vitro tests of neutrophil function are in predicting neutrophil function following granulocyte transfusion remains to be established in conjunction with well-designed clinical trials.
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Affiliation(s)
- S Bashir
- National Blood Service, Brentwood, Essex, UK.
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Zhao J, Juettner B, Scheinichen D, Jaeger K, Heine J, Piepenbrock S. Respiratory burst activity of polymorphonuclear cells is dependent on the cell preparation technique. Acta Anaesthesiol Scand 2003; 47:702-6. [PMID: 12803587 DOI: 10.1034/j.1399-6576.2003.00121.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Controversial results have been reported regarding the effect of anaesthetics on superoxide anion production during the respiratory burst (RB) of polymorphonuclear cells (PMN). The differences could be caused by the cell preparation methods and the aim of this study was to compare two techniques. METHODS RB activity was measured in cell suspensions isolated with the single-step Ficoll procedure and in unfractionated whole blood. Two concentrations of propofol (therapeutic and 10-fold of this, 6 microg ml-1 or 60 microg ml-1) were investigated after cell preparation with both methods. RB was stimulated with Escherichia coli (E. coli), phorbol 12-myristate 13-acetate (PMA) or N-formyl-methionyl-leucyl-phenylalanine (fMLP) and measured by means of fluorescence intensity in a flow cytometer. RESULTS The percentage of PMNs in whole blood which generate superoxide anions in response to fMLP was significantly lower (2.5 +/- 0.7%; mean +/- SEM) than that in Ficoll isolated cell suspensions (15.1 +/- 1.7%). Incubation with propofol led to a concentration-related decrease of RB activity in Ficoll separated PMNs after both PMA and fMLP stimulation. No significant effect of propofol was observed on the RB in PMA stimulated whole blood samples. CONCLUSION The results suggest that the influence of cell preparation methods should be considered when the in vitro effects of anaesthetics on PMN functions are studied with flow cytometric methods.
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Affiliation(s)
- J Zhao
- Department of Anaesthesiology, Peking Union Medical College Hospital, Eastern location, Beijing, China.
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18
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Rada BK, Geiszt M, Van Bruggen R, Nemet K, Roos D, Ligeti E. Calcium signalling is altered in myeloid cells with a deficiency in NADPH oxidase activity. Clin Exp Immunol 2003; 132:53-60. [PMID: 12653836 PMCID: PMC1808665 DOI: 10.1046/j.1365-2249.2003.02138.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The relation of O(2.-)-production and Ca2+ homeostasis was investigated in PLB-985 cell lines and neutrophilic granulocytes from peripheral blood. In differentiated wild-type PLB-985 cells, a high level of O(2.-)-production was associated with a significant decrease in the membrane potential and the inhibition of capacitative Ca2+ entry. These correlations were not observed in gp91phox -/- cells or in cells transfected with a non-functional mutant of gp91phox (Thr341Lys). Membrane depolarization and inhibition of Ca2+ entry reappeared in cells transfected with wild-type gp91phox. These experiments demonstrate that inhibition of Ca2+ entry depends on the presence of a functional NADPH oxidase. The Ca2+ signal induced by stimulation of chemotactic receptors also showed remarkable differences: [Ca2+]ic in the sustained phase was higher in gp91phox-/- than in wild-type cells. Alteration of the Ca2+ signal was reproduced by treating peripheral blood neutrophils with the NADPH oxidase inhibitor diphenylene-iodonium. It is concluded that the deficiency in O(2.-)-production is accompanied by significant alterations of Ca2+ homeostasis in myeloid cells.
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Affiliation(s)
- B K Rada
- Department of Physiology, Semmelweis University, Budapest, Hungary
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19
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Abstract
Proton channels exist in a wide variety of membrane proteins where they transport protons rapidly and efficiently. Usually the proton pathway is formed mainly by water molecules present in the protein, but its function is regulated by titratable groups on critical amino acid residues in the pathway. All proton channels conduct protons by a hydrogen-bonded chain mechanism in which the proton hops from one water or titratable group to the next. Voltage-gated proton channels represent a specific subset of proton channels that have voltage- and time-dependent gating like other ion channels. However, they differ from most ion channels in their extraordinarily high selectivity, tiny conductance, strong temperature and deuterium isotope effects on conductance and gating kinetics, and insensitivity to block by steric occlusion. Gating of H(+) channels is regulated tightly by pH and voltage, ensuring that they open only when the electrochemical gradient is outward. Thus they function to extrude acid from cells. H(+) channels are expressed in many cells. During the respiratory burst in phagocytes, H(+) current compensates for electron extrusion by NADPH oxidase. Most evidence indicates that the H(+) channel is not part of the NADPH oxidase complex, but rather is a distinct and as yet unidentified molecule.
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Affiliation(s)
- Thomas E Decoursey
- Department of Molecular Biophysics and Physiology, Rush Presbyterian St. Luke's Medical Center, Chicago, Illinois 60612, USA.
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20
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Steel HC, Anderson R. Dissociation of the PAF-receptor from NADPH oxidase and adenylate cyclase in human neutrophils results in accelerated influx and delayed clearance of cytosolic calcium. Br J Pharmacol 2002; 136:81-9. [PMID: 11976271 PMCID: PMC1762113 DOI: 10.1038/sj.bjp.0704685] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The magnitude and duration of the abruptly occurring increases in cytosolic Ca2+ in human neutrophils following activation with PAF (20 and 200 nM) and FMLP (1 microM), have been compared and related to alterations in NADPH oxidase activity, membrane potential and intracellular cyclic AMP. Cytosolic Ca2+ and membrane potential were measured by spectrofluorimetry, transmembrane fluxes of Ca2+ by radiometric procedures, and NADPH oxidase activity and cyclic AMP by chemiluminescence and radioimmunoassay respectively. Activation of neutrophils with both PAF (200 nM) and FMLP (1 microM) was accompanied by an abrupt increase in cytosolic Ca2+, which was of similar magnitude for each activator (393+/-9 and 378+/-17 nM respectively). Unlike FMLP-activated cells in which Ca2+ was rapidly removed from the cytosol, peak levels of cytosolic Ca2+ were sustained for longer (0.14+/-0.02 vs 1.16+/-0.04 min, P<or=0.0001) and declined at a slower rate in PAF-treated neutrophils. The prolonged elevation of cytosolic Ca2+ in PAF-treated cells was due to accelerated store-operated influx of extracellular cation and was attenuated by dibutyryl cyclic AMP (4 mM), the Ca2+-chelator, EGTA (5 mM), and SKF 96365 (10 microM). In contrast to FMLP, basal levels of superoxide production and cyclic AMP were unaltered in PAF-activated neutrophils, while only moderate membrane depolarization was detected. These observations demonstrate that mechanisms which restore Ca2+ homeostasis to FMLP-activated neutrophils, viz. activation of NADPH oxidase and adenylate cyclase, are not operative in PAF-treated cells, presenting the potential hazard of Ca2+ overload and hyperactivity.
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Affiliation(s)
- H C Steel
- Medical Research Council Unit for Inflammation and Immunity, Department of Immunology, Institute for Pathology, University of Pretoria, Republic of South Africa.
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21
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Geiszt M, Kapus A, Ligeti E. Chronic granulomatous disease: more than the lack of superoxide? J Leukoc Biol 2001. [DOI: 10.1189/jlb.69.2.191] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Miklós Geiszt
- Department of Physiology, Semmelweis University, H‐1444 Budapest, P.O. Box 259, Hungary
| | - András Kapus
- Department of Physiology, Semmelweis University, H‐1444 Budapest, P.O. Box 259, Hungary
| | - Erzsébet Ligeti
- Department of Physiology, Semmelweis University, H‐1444 Budapest, P.O. Box 259, Hungary
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22
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Tintinger GR, Theron AJ, Steel HC, Anderson R. Accelerated calcium influx and hyperactivation of neutrophils in chronic granulomatous disease. Clin Exp Immunol 2001; 123:254-63. [PMID: 11207656 PMCID: PMC1905991 DOI: 10.1046/j.1365-2249.2001.01447.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The relationship between activation of NADPH-oxidase, alterations in membrane potential and triggering of Ca2+ fluxes in human phagocytes has been investigated using neutrophils from four subjects with chronic granulomatous disease (CGD). Cytosolic Ca2+ and membrane potential were measured by spectrofluorimetry, and net efflux and influx of Ca2+ by radiometric procedures. Exposure of normal neutrophils to the chemotactic tripeptide, N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP; 1 microM) was accompanied by an abrupt increase in cytosolic Ca2+ coincident with membrane depolarization and efflux of the cation. These events terminated at around 30 s after the addition of FMLP and were followed by membrane repolarization and store-operated influx of Ca2+, both of which were superimposable and complete after about 5 min. Activation of CGD neutrophils was also accompanied by an increase in cytosolic Ca2+, which, in spite of an efficient efflux response, was prolonged in relation to that observed in normal cells. This prolonged increase in cytosolic Ca2+ in activated CGD neutrophils occurred in the setting of trivial membrane depolarization and accelerated influx of Ca2+, and was associated with hyperactivity of the cells according to excessive release of elastase and increased activity of phospholipase A2. Treatment of CGD neutrophils with the type 4 phosphodiesterase inhibitor, rolipram (1 microM) restored Ca2+ homeostasis and attenuated the increase in elastase release. These findings support the involvement of NADPH-oxidase in regulating membrane potential and Ca2+ influx in activated neutrophils, and may explain the disordered inflammatory responses and granuloma formation which are characteristic of CGD.
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Affiliation(s)
- G R Tintinger
- Medical Research Council Unit for Inflammationand Immunity, Department of Immunology, Institute for Pathology, University of Pretoria, Pretoria, South Africa
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23
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Segal BH, Leto TL, Gallin JI, Malech HL, Holland SM. Genetic, biochemical, and clinical features of chronic granulomatous disease. Medicine (Baltimore) 2000; 79:170-200. [PMID: 10844936 DOI: 10.1097/00005792-200005000-00004] [Citation(s) in RCA: 607] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The reduced nicotinamide dinucleotide phosphate (NADPH) oxidase complex allows phagocytes to rapidly convert O2 to superoxide anion which then generates other antimicrobial reactive oxygen intermediates, such as H2O2, hydroxyl anion, and peroxynitrite anion. Chronic granulomatous disease (CGD) results from a defect in any of the 4 subunits of the NADPH oxidase and is characterized by recurrent life-threatening bacterial and fungal infections and abnormal tissue granuloma formation. Activation of the NADPH oxidase requires translocation of the cytosolic subunits p47phox (phagocyte oxidase), p67phox, and the low molecular weight GT-Pase Rac, to the membrane-bound flavocytochrome, a heterodimer composed of the heavy chain gp91phox and the light chain p22phox. This complex transfers electrons from NADPH on the cytoplasmic side to O2 on the vacuolar or extracellular side, thereby generating superoxide anion. Activation of the NADPH oxidase requires complex rearrangements between the protein subunits, which are in part mediated by noncovalent binding between src-homology 3 domains (SH3 domains) and proline-rich motifs. Outpatient management of CGD patients relies on the use of prophylactic antibiotics and interferon-gamma. When infection is suspected, aggressive effort to obtain culture material is required. Treatment of infections involves prolonged use of systemic antibiotics, surgical debridement when feasible, and, in severe infections, use of granulocyte transfusions. Mouse knockout models of CGD have been created in which to examine aspects of pathophysiology and therapy. Gene therapy and bone marrow transplantation trials in CGD patients are ongoing and show great promise.
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Affiliation(s)
- B H Segal
- Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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24
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Kim JA, Kang YS, Jung MW, Lee SH, Lee YS. Involvement of Ca2+ influx in the mechanism of tamoxifen-induced apoptosis in HepG2 human hepatoblastoma cells. Cancer Lett 1999; 147:115-23. [PMID: 10660097 DOI: 10.1016/s0304-3835(99)00284-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The signaling mechanism of tamoxifen (TAM)-induced apoptosis was investigated in HepG2 human hepatoblastoma cells which do not express the estrogen receptor (ER). TAM induced cytotoxicity and DNA fragmentation, a hallmark of apoptosis, in a dose-dependent manner. TAM increased the intracellular concentration of Ca2+. This effect was completely inhibited by the extracellular Ca2+ chelation with EGTA. TAM also induced a Mn2+ influx, indicating that TAM activated Ca2+ influx pathways. This action of TAM was significantly inhibited by flufenamic acid (FA), a known non-selective cation channel blocker. Quantitative analysis of apoptosis by flow cytometry revealed that treatment with either FA or BAPTA, an intracellular Ca2+ chelator, significantly inhibited TAM-induced apoptosis. These results suggest that intracellular Ca2+ signals may play a central role in the mechanism of the TAM-induced apoptotic cell death in ER-negative HepG2 cells.
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Affiliation(s)
- J A Kim
- Physiology Section, College of Pharmacy, Yeungnam University, Kyongsan, South Korea
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25
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Jankowski A, Grinstein S. A noninvasive fluorimetric procedure for measurement of membrane potential. Quantification of the NADPH oxidase-induced depolarization in activated neutrophils. J Biol Chem 1999; 274:26098-104. [PMID: 10473559 DOI: 10.1074/jbc.274.37.26098] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The electrogenic activity of the NADPH oxidase is associated with depolarization of the plasma membrane in activated neutrophils. The magnitude and consequences of this depolarization, however, remain unknown. Neutrophils are not amenable to electrophysiological determinations of membrane potential by current clamp. Instead, the occurrence of depolarization has been inferred from the use of potential-sensitive fluorescent dyes. However, such dyes partition into intracellular organelles and may yield erroneous results, particularly because the NADPH oxidase resides largely in secretory granules, where it has been claimed to become activated. We confirmed the intracellular generation of oxidase products using dihydrorhodamine, which is converted to the fluorescent rhodamine 123 when oxidized. Rhodamine 123 accumulated inside endomembrane organelles in both neutrophils and in differentiated HL60 cells, where it co-localized with the primary granule marker CD63. To estimate the surface membrane potential without interference from organelles, we devised a method based on the voltage-driven uptake of Mn(2+) across the plasmalemma. The uptake of Mn(2+) through calcium release-activated channels was measured as the rate of Indo-1 fluorescence quenching in thapsigargin-treated cells. The rate of Mn(2+) influx was found to vary when the membrane potential was manipulated using conductive ionophores and also when the NADPH oxidase was activated. A calibration curve in the positive potential range was constructed using the Na(+) ionophore SQI-Pr. Using this calibration, the membrane potential of phorbol ester-activated neutrophils was found to reach +58 +/- 6 mV, a sustained depolarization of over 100 mV compared with the resting potential. The depolarization was greatly diminished when the NADPH oxidase was inhibited with diphenylene iodonium. Together, these results indicate that the NADPH oxidase can generate a large depolarization of the plasmalemma, which should suffice to activate a variety of voltage-gated channels, including the outwardly rectifying H(+) conductance.
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Affiliation(s)
- A Jankowski
- Cell Biology Programme, Research Institute, The Hospital for Sick Children, Toronto, Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1X8, Canada
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26
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Kim JA, Kang YS, Lee SH, Lee EH, Yoo BH, Lee YS. Glibenclamide induces apoptosis through inhibition of cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channels and intracellular Ca(2+) release in HepG2 human hepatoblastoma cells. Biochem Biophys Res Commun 1999; 261:682-8. [PMID: 10441486 DOI: 10.1006/bbrc.1999.1108] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glibenclamide, an inhibitor of cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channels, induced apoptosis in a dose- and time-dependent manner in HepG2 human hepatoblastoma cells. Glibenclamide increased intracellular Ca(2+) concentration, which was significantly inhibited by Ca(2+) release blockers dantrolene and TMB-8. BAPTA/AM, an intracellular Ca(2+) chelator, and the Ca(2+) release blockers significantly inhibited glibenclamide-induced apoptosis. Glibanclamide also increased intracellular Cl(-) concentration, which was significantly blocked by CFTR Cl(-) channel activators levamisole and bromotetramisole. These activators also significantly inhibited both intracellular Ca(2+) release and apoptosis induced by glibenclamide. The expression of CFTR protein in the cells was confirmed by Western blot analysis. These results suggest that glibenclamide induced apoptosis through inhibition of CFTR Cl(-) channels and intracellular Ca(2+) release and that this protein may be a good target for treatment of human hepatomas.
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Affiliation(s)
- J A Kim
- College of Pharmacy, Yeungnam University, Kyongsan, 712-749, Korea
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27
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Nunoi H, Yamazaki T, Tsuchiya H, Kato S, Malech HL, Matsuda I, Kanegasaki S. A heterozygous mutation of beta-actin associated with neutrophil dysfunction and recurrent infection. Proc Natl Acad Sci U S A 1999; 96:8693-8. [PMID: 10411937 PMCID: PMC17578 DOI: 10.1073/pnas.96.15.8693] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
A human disorder caused by mutation in nonmuscle actin has not been reported. We report here a variant of nonmuscle actin in a female patient with recurrent infections, photosensitivity, and mental retardation. She also had abnormalities in neutrophil chemotaxis, superoxide production, and membrane potential response. Two-dimensional PAGE analysis of proteins from neutrophils and other cell types from this patient demonstrated a unique protein spot migrating at 42 kDa with pI shifted slightly to neutral relative to normal beta- and gamma-actin. Digestion peptide mapping and Western blotting showed this spot to be an abnormal actin. A full-length cDNA library was constructed by using mRNA from patient's cells and cDNA encoding the mutant beta-actin molecule was identified by an in vitro translation method. Sequencing of the clones demonstrated a G-1174 to A substitution, predicting a glutamic acid-364 to lysine substitution in beta-actin and eliminating a HinfI DNase restriction site found in normal beta-actin sequence. By HinfI digestion and by sequencing, the mutation in one allele of patient's genomic DNA was confirmed. Though no defect in cell-free polymerization of actin was detected, this defect lies in a domain important for binding to profilin and other actin-regulatory molecules. In fact, the mutant actin bound to profilin less efficiently than normal actin did. Heterozygous expression of mutant beta-actin in neutrophils and other cells of this patient may act in a dominant-negative fashion to adversely affect cellular activities dependent on the function of nonmuscle actin.
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Affiliation(s)
- H Nunoi
- Institute of Medical Science, University of Tokyo, Minatoku, Tokyo 108-8639, Japan.
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28
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Pieri C, Recchioni R, Moroni F, Marcheselli F, Marra M, Marinoni S, Di Primio R. Melatonin regulates the respiratory burst of human neutrophils and their depolarization. J Pineal Res 1998; 24:43-9. [PMID: 9468117 DOI: 10.1111/j.1600-079x.1998.tb00364.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The effect of different doses of melatonin on the respiratory burst as well as on the membrane potential changes of human neutrophils stimulated with phorbol 12-myristate 13-acetate (PMA) was investigated. The intracellular production of reactive oxygen species (ROS) in stimulated neutrophils was quantified in individual cells by flow cytometry, measuring the oxidation of nonfluorescent dihydrorhodamine 123 to the green fluorescent rhodamine 123. The transmembrane potential change was measured using the fluorescent probe oxonol. Preincubating the cells with micromolar concentrations of the indole resulted in an increase of the response to PMA. In two of six subjects investigated, the respiratory burst was also increased by a 10 nM concentration of the indole, but when the melatonin concentration was increased to 2 mM the respiratory burst was inhibited. The change in the transmembrane potential of neutrophils paralleled the respiratory burst. Indeed, the treatment of the cells with doses of melatonin up to 0.5 mM increased the depolarization occurring subsequent to PMA stimulation, whereas 2 mM melatonin concentration decreased the extent of depolarization. To investigate whether melatonin could directly affect the transmembrane potential changes of neutrophils, the extent of depolarization, induced by increasing the extracellular potassium concentration, was measured in cells preincubated with 2 mM melatonin. This treatment resulted in a decrease of the extent of depolarization, which suggests that melatonin can directly alter membrane ion conductance in human neutrophils.
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Affiliation(s)
- C Pieri
- Center of Cytology, Gerontol. Res. Dept. of I.N.R.C.A. N. Masera, Chieti, Italy.
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29
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Geiszt M, Kapus A, Német K, Farkas L, Ligeti E. Regulation of capacitative Ca2+ influx in human neutrophil granulocytes. Alterations in chronic granulomatous disease. J Biol Chem 1997; 272:26471-8. [PMID: 9334224 DOI: 10.1074/jbc.272.42.26471] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Ca2+ entry through the capacitative (store-regulated) pathway was shown to be inhibited in neutrophil granulocytes by the protein kinase C activator phorbol 12-myristate 13-acetate and the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (fMLP) by a hitherto unknown mechanism. Measuring both Ca2+ and Mn2+ entry into store-depleted cells we show in the present study that inhibition of the capacitative pathway is absent in various forms of chronic granulomatous disease. To establish the possible relationship between inhibition of the capacitative pathway and ability of O-2 production and consequent membrane depolarization, gradual changes of the membrane potential were evoked in neutrophils of healthy individuals. This was accomplished by pharmacological manipulation of the membrane potential and by variations of the concentration and type of the stimulant. Close relationship was observed between membrane depolarization and inhibition of Mn2+ entry through the capacitative transport route. Our results provide an explanation for the inhibitory action of fMLP and phorbol 12-myristate 13-acetate on capacitative cation influx and reveal that upon physiological stimulation, Ca2+ entry into neutrophils is restricted by the depolarization accompanying O-2 production.
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Affiliation(s)
- M Geiszt
- Department of Physiology and Laboratory of Cellular and Molecular Physiology, Semmelweis Medical University, H-1444 Budapest, Hungary
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30
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Affiliation(s)
- L M Henderson
- Department of Biochemistry, School of Medical Sciences, University of Bristol, UK
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31
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Fukuda T, Kitagawa S, Azuma E, Yuo A, Kawamata N, Miki T, Hirosawa S, Aoki N. Treatment with granulocyte colony-stimulating factor for pneumonia in a patient with a variant form of X-linked chronic granulomatous disease. Eur J Haematol 1995; 55:63-4. [PMID: 7542203 DOI: 10.1111/j.1600-0609.1995.tb00238.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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32
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Holevinsky KO, Nelson DJ. Simultaneous detection of free radical release and membrane current during phagocytosis. J Biol Chem 1995; 270:8328-36. [PMID: 7713941 DOI: 10.1074/jbc.270.14.8328] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Stimulation of macrophages induces the "respiratory burst" response which is associated with the generation of superoxide (O2-), a drop in cytoplasmic pH, and a pronounced depolarization of the membrane potential. The purpose of the present studies was to determine whether an increase in O2- was temporally related to changes in membrane potential and transmembrane current. Release of O2- at the single cell level was photometrically monitored during phagocytosis of immune complexes while simultaneously measuring whole-cell current. Membrane depolarization and the generation of a non-selective current followed an increase in O2- production with a variable lag time which was correlated with the state of cellular maturation in culture. In the absence of phagocytosis, the exposure of macrophages to O2- generated by a xanthine-xanthine oxidase reaction activated a non-selective current similar to that seen after phagocytosis. These results provide the first demonstration of the relationship between free radical release and the ensuing electrophysiological signaling events which are linked to particle engulfment in phagocytic cells.
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Affiliation(s)
- K O Holevinsky
- Department of Neurology, University of Chicago, Illinois 60637, USA
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Emmendörffer A, Nakamura M, Rothe G, Spiekermann K, Lohmann-Matthes ML, Roesler J. Evaluation of flow cytometric methods for diagnosis of chronic granulomatous disease variants under routine laboratory conditions. CYTOMETRY 1994; 18:147-55. [PMID: 7813334 DOI: 10.1002/cyto.990180306] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Neutrophils from 50 pediatric patients with normal phagocyte functions, from 150 healthy adults, from 10 chronic granulomatous disease (CGD)-patients (4 CGD+), and from 18 X-linked carriers for CGD have been tested for their production of H2O2 using staining with dihydrorhodamine 123 and subsequent flow cytometry. Additionally, neutrophils from three patients with myeloperoxidase deficiency were assessed. Cells were activated to produce H2O2 by the phorbol ester phorbol-myristate-acetate (PMA) and by phagocytosis of Escherichia coli bacteria. To evaluate the sensitivity of the method, H2O2-production by neutrophils which was inhibited by different concentrations of diphenyljodonium (DPI) was measured. The results were compared to those from other methods (NBT-testing, cytochrome c-reduction, and especially chemiluminescence). Normal values and ranges of scatter profile were evaluated in terms of peak channel fluorescence: 97% > 700, x = 840 +/- 59 (S.D.), 97% < 890, for pediatric patients. Normal quantitative values also resulted from small blood samples of infants (< 1 year, n = 6, x = 830 +/- 52). For CGD+ (n = 4) the results were clearly far below the normal range. In indicating decreased production of reactive oxygen intermediates the method was at least as sensitive as lucigenin enhanced chemiluminescence. Cytochrome b558-expression of neutrophils from patients and healthy controls was established by flow cytometry following staining with the monoclonal antibody 7D5. The normal range was 97% > 485, 97% < 680, peak channel fluorescence. We conclude that flow cytometric routine diagnostics of CGD can easily enhance the reliability of recognition and the yield of information about this disease compared to conventional methods.
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Affiliation(s)
- A Emmendörffer
- Department of Immunobiology, Fraunhofer Institute, Hannover, Germany
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Venaille TJ, Misso NL, Phillips MJ, Robinson BW, Thompson PJ. Effects of different density gradient separation techniques on neutrophil function. Scand J Clin Lab Invest 1994; 54:385-91. [PMID: 7527931 DOI: 10.3109/00365519409088438] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Investigation of the pathogenesis of inflammatory diseases has involved assessment of polymorphonuclear leukocyte (PMN) activity and a variety of techniques for separating PMNs from whole blood have been described. In this study the effects of Percoll gradient, Ficoll-Hypaque/Dextran sedimentation (FH/DS) and Mono-Poly Resolving Medium (M-PRM) on activation and function of PMNs were compared. All three separation techniques gave similar cell yield and purity. The mean (+/- SEM) percentage of cells demonstrating pseudopodia formation for Percoll, FH/DS and M-PRM were 39 +/- 9, 57 +/- 6 and 63 +/- 5, respectively, while superoxide release from resting cells was 1.9 +/- 0.9, 7.2 +/- 3.5 and 11 +/- 4.8 pmols per 10(6) cells min-1, respectively, indicating that activation of cells during separation may be less with Percoll compared to the other methods. The functional capacity of the cells to respond to a stimulus was similar for all methods as indicated by similar EC50 values for chemotaxis to zymosan-activated serum and similar superoxide production induced by tetradecanoyl phorbol acetate. All three separation techniques produce functionally active PMNs of high purity but the use of Percoll gradients may be preferable when a quick method of separation which causes minimum pre-activation of PMNs is required.
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Affiliation(s)
- T J Venaille
- Department of Medicine, University of Western Australia, Nedlands
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Ballarin-Denti A, Slayman CL, Kuroda H. Small lipid-soluble cations are not membrane voltage probes for Neurospora or Saccharomyces. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1190:43-56. [PMID: 8110820 DOI: 10.1016/0005-2736(94)90033-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Small lipid-soluble cations, such as tetraphenylphosphonium (TPP+) and tetraphenylarsonium (TPA+) are frequently used as probes of membrane voltage (delta psi, or Vm) for small animal cells, organelles, and vesicles. Because much controversy has accompanied corresponding measurements on 'walled' eukaryotic cells (plants, fungi), we studied their transport and relation to Vm in the large-celled fungus Neurospora crassa-where Vm can readily be determined with microelectrodes-as well as in the most commonly used model eukaryotic cell, the yeast Saccharomyces cerevisiae. We found no reasonable conditions under which the distribution of TPP+ or TPA+, between the cytoplasm (i) and extracellular solution (o), can serve to estimate Vm, even roughly, in either of these organisms. When applied at probe concentrations (i.e., < or = 100 microM, which did not depolarize the cells nor deplete ATP), TPP+ stabilized at ratios (i/o) below 30 in both organisms. That would imply apparent Vm values positive to -90 mV, in the face of directly measured Vm values (in Neurospora) negative to -180 mV. When applied at moderate or high concentrations (1-30 mM), TPP+ and TPA+ induced several phases of depolarization and changes of membrane resistance (Rm), as well as depletion of cytoplasmic energy stores. Only the first phase depolarization, occurring within the perfusion-turnover time and accompanied by a nearly proportionate decline of Rm, could have resulted from TPP+ or TPA+ currents per se. And the implied currents were small. Repeated testing, furthermore, greatly reduced the depolarizing effects of these lipid-soluble ions, implicating an active cellular response to decrease membrane permeability.
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Affiliation(s)
- A Ballarin-Denti
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06510
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Demaurex N, Schrenzel J, Jaconi ME, Lew DP, Krause KH. Proton channels, plasma membrane potential, and respiratory burst in human neutrophils. Eur J Haematol 1993; 51:309-12. [PMID: 8282093 DOI: 10.1111/j.1600-0609.1993.tb01613.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
When confronted with invading microorganisms, neutrophils undergo a number of nearly synchronous reactions including the generation of microbicidal reactive oxygen intermediates by the NADPH oxidase. These reactions are accompanied by a slow depolarization, from resting values of-60 mV to levels probably exceeding 0 mV. The depolarization is transient, indicating that a compensatory charge transport mechanism is activated. Activation of the oxidase system causes a massive burst of metabolic acid generation that would, if uncompensated, lower the intracellular pH of neutrophils by over 5 units, to lethal levels (pH = 2). Neutrophils must therefore possess particularly effective regulatory systems to avoid excessive cytosolic acidification. The recently described H+ conductance of neutrophils may counteract both the acidification and the depolarization. Activation of the H+ conductance occurs at depolarizing voltages and is promoted by cytosolic acidification, a combination that takes place during the respiratory burst. The NADPH oxidase of neutrophils is thus associated to an unusual, particularly efficient mechanism of H+ export and charge compensation. The sequential activation of these two systems causes neutrophils to depolarize through the activation of an electron transport chain, and to repolarize through the activation of a H+ conductance.
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Affiliation(s)
- N Demaurex
- Division of Infectious Diseases, University Hospital, Geneva, Switzerland
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37
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Membrane potentials of hypertensive, diabetic and arthritic polymorphonuclear leukocytes. Indian J Clin Biochem 1993. [DOI: 10.1007/bf02867719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Rudkowski R, Ziegler JB, Graham GG, Joulianos G. Gold complexes and activation of human polymorphonuclear leukocytes. Dissociation of changes in membrane potential and oxidative burst. Biochem Pharmacol 1992; 44:1091-8. [PMID: 1417933 DOI: 10.1016/0006-2952(92)90372-p] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effects of the gold compounds on the alteration of membrane potential of polymorphonuclear leukocytes (PMN) in response to various stimulants have been compared with their effects on the oxidative burst. The present studies have shown that gold complexes [auranofin (AF), aurothiomalate (Autm), aurocyanide (Au(CN)2-)] have contrasting effects on the membrane potential of 3,3'-dipentyloxacarbocyanine [di-O-C5(3)] loaded PMN. Au(CN)2- at concentrations which inhibit the oxidative burst of PMN did not affect the membrane depolarization after activation of PMN by phorbol myristate acetate (PMA) and N-formyl-methionyl-leucyl phenylalanine (FMLP); Autm slightly stimulated the oxidative burst but had no effect on the depolarization of PMN. In contrast, AF inhibited the depolarization of stimulated PMN to an extent depending upon the concentration of AF, the time of preincubation and the stimulus. The membrane depolarization of PMN caused by PMA, FMLP and concanavalin A (ConA) was inhibited by AF (5 microM) but the depolarization induced by calcium ionophore (A23187) was not affected. AF at the same conditions inhibits the oxidative burst of PMN induced by all these single stimuli including the calcium ionophore. Dissociation of membrane depolarization and superoxide generation caused by AF was also seen in PMN activated by two stimuli. AF (5 microM) had little initial inhibitory effect on the oxidative burst of PMN stimulated by combinations of PMA and ConA or PMA and FMLP whereas it almost totally blocked the depolarization caused by these combinations. Preincubation of cells with 5 microM AF for less than 5 min prior to the addition of PMA allowed membrane depolarization which was followed rapidly by repolarization. None of the gold complexes studied had any effect on the resting membrane potential of PMN.
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Affiliation(s)
- R Rudkowski
- Prince of Wales Children's Hospital, Randwick, NSW, Australia
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Shephard EG, Anderson R, Rosen O, Fridkin M. C-reactive protein (CRP) peptides inactivate enolase in human neutrophils leading to depletion of intracellular ATP and inhibition of superoxide generation. Immunology 1992; 76:79-85. [PMID: 1321093 PMCID: PMC1421737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The nature and the biochemical mechanism of inhibition of neutrophil membrane-associated oxidative metabolism by two synthetic peptides p77-82 and p201-206 (amino acid sequences Val-Gly-Gly-Ser-Glu-Ile and Lys-Pro-Gln-Leu-Trp-Pro respectively, from the primary amino acid sequence of C-reactive protein) have been ascertained. Preincubating neutrophils for 15 min with 50 microM of p77-82 or p201-206 resulted in superoxide generation by opsonized zymosan stimulated neutrophils being inhibited by 34 +/- 2% (P less than 0.005) and 29 +/- 2% (P less than 0.005) respectively. With a 60-min preincubation period 6.25 microM of p77-82 or p201-206 was effective in inhibiting this superoxide generation by 12 +/- 2% (P less than 0.01) and 10 +/- 1% (P less than 0.01) respectively. Neither peptide inhibited neutrophil arachidonic acid release, transmembrane potential or transductional events preceding superoxide generation. Inhibition of neutrophil functions was found to be due to the ability of each peptide (50 microM) following a 15-min preincubation period to inhibit both neutrophil glycolysis and ATP generation by approximately 30%. The inhibition of ATP generation and glycolysis in neutrophils is attributable to the ability of these peptides to inhibit uncompetitively the glycolytic enzyme enolase. Using purified enolase the relative Ki values for p77-82 and p201-206 were 27 and 19 microM respectively. Inhibition of neutrophil function by the peptides is concluded to be due to effective interference of neutrophil energy metabolism.
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Affiliation(s)
- E G Shephard
- Department of Medicine, University of Cape Town, Observatory, Republic of South Africa
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40
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Kapus A, Szászi K, Ligeti E. Phorbol 12-myristate 13-acetate activates an electrogenic H(+)-conducting pathway in the membrane of neutrophils. Biochem J 1992; 281 ( Pt 3):697-701. [PMID: 1371386 PMCID: PMC1130747 DOI: 10.1042/bj2810697] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The mode of activation of an H(+)-conducting pathway present in the membrane of neutrophils was investigated. (1) Resting neutrophils released protons through an electrogenic Cd(2+)-inhibitable (K0.5 approximately 20 microM) route when a pH gradient and appropriate charge compensation was provided. (2) The rate of H+ efflux was stimulated over 2.5-fold by 4 beta-phorbol 12-myristate 13-acetate (PMA; K0.5 approximately 0.7 nM) or by 4 beta-phorbol 12,13-dibutyrate (K0.5 approximately 20 nM) even when the NADPH oxidase was blocked by p-chloromercuribenzoate. (3) Staurosporine inhibited the effect of PMA. (4) The H+ egress was not enhanced by 4 alpha-phorbol 12,13-didecanoate. (5) Low concentrations of Cd2+ (less than 40 microM) inhibited the H+ flux without influencing the oxidase. The results raise the possibility that protein kinase C could be involved in the activation of an electrogenic H(+)-conducting pathway in the membrane of neutrophils. The activation of this route by phorbol esters seems to be independent of the stimulation of NADPH oxidase.
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Affiliation(s)
- A Kapus
- Department of Physiology, Semmelweis University Medical School, Budapest, Hungary
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41
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Nanda A, Grinstein S. Protein kinase C activates an H+ (equivalent) conductance in the plasma membrane of human neutrophils. Proc Natl Acad Sci U S A 1991; 88:10816-20. [PMID: 1720552 PMCID: PMC53022 DOI: 10.1073/pnas.88.23.10816] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The rate of metabolic acid generation by neutrophils increases greatly when they are activated. Intracellular acidification is prevented in part by Na+/H+ exchange, but a sizable component of H+ extrusion persists in the nominal absence of Na+ and HCO3-. In this report we determined the contribution to H+ extrusion of a putative H+ conductive pathway and its mode of activation. In unstimulated cells, H+ conductance was found to be low and unaffected by depolarization. An experimental system was designed to minimize the metabolic acid generation and membrane potential changes associated with neutrophil activation. By using this system, beta-phorbol esters were shown to increase the H+ (equivalent) permeability of the plasma membrane. The direction of the phorbol ester-induced fluxes was dictated by the electrochemical H+ gradient. Moreover, the parallel migration of a counterion through a rheogenic pathway was necessary for the displacement of measurable amounts of H+ equivalents across the membrane. These findings suggest that the H+ flux is conductive. The effect of beta-phorbol esters was mimicked by diacylglycerol and mezerein and was blocked by staurosporine, whereas alpha-phorbol esters were ineffective. Together, these findings indicate that stimulation of protein kinase C induces the activation of an H+ conductance in the plasma membrane of human neutrophils. Preliminary evidence for activation of a separate, bafilomycin A1-sensitive H+ extrusion mechanism, likely a vacuolar type H(+)-ATPase, is also presented.
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Affiliation(s)
- A Nanda
- Division of Cell Biology, Hospital for Sick Children, Toronto, Canada
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42
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Morel F, Doussiere J, Vignais PV. The superoxide-generating oxidase of phagocytic cells. Physiological, molecular and pathological aspects. EUROPEAN JOURNAL OF BIOCHEMISTRY 1991; 201:523-46. [PMID: 1657601 DOI: 10.1111/j.1432-1033.1991.tb16312.x] [Citation(s) in RCA: 389] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Professional phagocytes (neutrophils, eosinophils, monocytes and macrophages) possess an enzymatic complex, the NADPH oxidase, which is able to catalyze the one-electron reduction of molecular oxygen to superoxide, O2-. The NADPH oxidase is dormant in non-activated phagocytes. It is suddenly activated upon exposure of phagocytes to the appropriate stimuli and thereby contributes to the microbicidal activity of these cells. Oxidase activation in phagocytes involves the assembly, in the plasma membrane, of membrane-bound and cytosolic components of the oxidase complex, which were diassembled in the resting state. One of the membrane-bound components in resting phagocytes has been identified as a low-potential b-type cytochrome, a heterodimer composed of two subunits of 22-kDa and 91-kDa. The link between NADPH and cytochrome b is probably a flavoprotein whose subcellular localization in resting phagocytes remains to be determined. Genetic defects in the cytochrome b subunits and in the cytosolic factors have been shown to be the molecular basis of chronic granulomatous disease, a group of inherited disorders in the host defense, characterized by severe, recurrent bacterial and fungal infections in which phagocytic cells fail to generate O2- upon stimulation. The present review is focused on recent data concerning the signaling pathway which leads to oxidase activation, including specific receptors, the production of second messengers, the organization of the oxidase complex and the molecular defects responsible for granulomatous disease.
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Affiliation(s)
- F Morel
- Département de Biologie Moléculaire et Structurale, Centre d'Etudes Nucléaires, Grenoble, France
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43
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Novak MJ, Cohen HJ. Depolarization of polymorphonuclear leukocytes by Porphyromonas (Bacteroides) gingivalis 381 in the absence of respiratory burst activation. Infect Immun 1991; 59:3134-42. [PMID: 1652560 PMCID: PMC258144 DOI: 10.1128/iai.59.9.3134-3142.1991] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Bacteroides spp. may contribute to the chronicity of mixed infections by affecting the normal functions of polymorphonuclear leukocytes (PMN). This study evaluated the physiologic and biochemical responses of human peripheral blood PMN to a variety of strains of the oral periodontal pathogen Porphyromonas (Bacteroides) gingivalis. Strain 381 and ATCC type strain 33277 caused rapid and lasting depolarization of the electrochemical potential that exists across the PMN membrane by a mechanism that was independent of activation of the pertussis toxin-sensitive G protein or protein kinase C. Membrane depolarization did not initiate increases in intracellular calcium or respiratory burst activation, and activity was not inhibited by surface proteolysis or sugars. However, membrane depolarization was associated with inhibition of PMN responses to the chemotactic peptide N-formylmethionyl leucyl phenylalanine. Membrane-depolarizing activity was isolated with the outer membrane of strain 381 by surface extraction of the bacteria by using Zwittergent 3,14, followed by Sephacryl S-200 gel filtration chromatography. The partially purified outer membrane components were heat stable, were not inhibited by tosyl-lysine chloromethyl ketone, and inhibited N-formylmethionyl leucyl phenylalanine-stimulated superoxide production. The results suggest that outer membrane components of P. gingivalis 381 and 33277 have porinlike activity that can depolarize PMN membranes and immobilize PMN responses to chemotactic peptides. This may prove to be an important virulence characteristic of these strains.
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Affiliation(s)
- M J Novak
- Department of Dental Research and Microbiology, University of Rochester Medical Center, New York 14642
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44
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Bergethon PR. Altered electrophysiologic and pharmacologic response of smooth muscle cells on exposure to electrical fields generated by blood flow. Biophys J 1991; 60:588-95. [PMID: 1932549 PMCID: PMC1260102 DOI: 10.1016/s0006-3495(91)82088-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The flow of the blood past the vascular wall gives rise to an electrical potential. This field is calculated to have a periodic waveform with a transluminal peak-to-peak amplitude of approximately 1.35 V/m-1. Digital imaging fluorescent microscopy was used to measure changes in the membrane potentials of smooth muscle cells by following changes in the fluorescence of the potential sensitive dye, 3,3'-dipropyloxacarbocyanine iodide (di-O-C5[3]). The effect of the low level electrical field on the membrane potentials of cultured smooth muscle vascular cells was shown to cause a steady-state depolarization of approximately 10 mV. The degree of steady-state depolarization was shown to directly vary with the frequency of the applied field and the effect was not dependent on the presence of extracellular Ca+2 or Mg+2. These effects are though to be most consistent with an electroconformational coupling mechanism. The presence of this electrokinetic field was also shown to alter the electrophysiological response of smooth muscle cells treated with 5-hydroxytryptamine. Cells exposed concurrently to both 5-HT and the electrical field showed an increased membrane depolarization thus implying that the electrokinetic field may be important in both normal and pathologic cellular responses.
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MESH Headings
- Animals
- Animals, Newborn
- Aorta/cytology
- Aorta/drug effects
- Aorta/physiology
- Blood Circulation
- Cells, Cultured
- Electric Stimulation
- Membrane Potentials/drug effects
- Microscopy, Fluorescence
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Potassium/pharmacology
- Rats
- Rats, Inbred Strains
- Serotonin/pharmacology
- Valinomycin/pharmacology
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Affiliation(s)
- P R Bergethon
- Department of Biochemistry, Boston University School of Medicine, Massachusetts 02118
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Haines KA, Reibman J, Tang XY, Blake M, Weissmann G. Effects of protein I of Neisseria gonorrhoeae on neutrophil activation: generation of diacylglycerol from phosphatidylcholine via a specific phospholipase C is associated with exocytosis. J Biophys Biochem Cytol 1991; 114:433-42. [PMID: 1907286 PMCID: PMC2289089 DOI: 10.1083/jcb.114.3.433] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Upon engagement of chemoattractant receptors, neutrophils generate inositol trisphosphate and diacylglycerol (DG) by means of a phosphatidylinositol-specific phospholipase C (PI-PLC) which is regulated by a GTP-binding protein(s). We have previously reported (Reibman, J., H. M. Korchak, L. B. Vosshall, K. A. Haines, A. M. Rich, and G. Weissmann. 1988. J. Biol. Chem. 263:6322-6328) a biphasic rise in DG after exposure of neutrophils to the chemoattractant FMLP: a rapid (less than or equal to 15 s) phase ("triggering") and a slow (greater than or equal to 30 s) phase ("activation"). These derive from distinct intracellular lipid pools. To study the source of rapid and slow DG, we have used a unique probe, protein I, a porin that is the major outer membrane protein of Neisseria gonorrhoeae. Treatment of neutrophils with protein I inhibits exocytosis and homotypic cell adhesion provoked by FMLP without inhibiting assembly of the NADPH oxidase responsible for O2-. generation. DG turnover in PMN labeled with [3H]arachidonate and [14C]glycerol was profoundly altered by protein I. Whereas the rapid peak of DG was only modestly diminished (FMLP vs. FMLP plus protein I = DG labeled with [3H]arachidonic acid (3H-a.a.-DG): 142 +/- 14% SEM vs. 125 +/- 22%; DG labeled with the glycerol backbone with [14C]glycerol (D-14C-G): 125 +/- 10% SEM vs. 107 +/- 8.5% SEM), the slow rise in both 3H-a.a.-DG and D-14C-G was essentially abolished. Moreover, treatment of neutrophils with 4-4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), which, like protein I, inhibits exocytosis without affecting O2-. generation also inhibited slow DG. However, protein phosphorylation and dephosphorylation (47phox, 66phox) were unaffected in the absence of slow DG. To determine the source of the slow DG, we have analyzed radiolabeled phospholipid (PL) turnover after FMLP +/- protein I (P.I.). Treatment of PMN with FMLP (0.1 microM) resulted in breakdown of phosphatidylcholine (PC), beginning at 30 s, and reaching a nadir at 60 s (3H-PC = 59 +/- 10.2% SEM of resting, 14C-PC = 57 +/- 6.4%). Protein I (0.25 microM) significantly inhibited PC turnover after FMLP ([3H]PC = 95 +/- 5.6% and [14C]PC = 86 +/- 8.4% of resting at 60 s), but failed to alter the metabolism of 3H- or 14C-phosphatidylinositol after FMLP (91 +/- 19.6 and 88 +/- 16.5% vs. 92 +/- 9.2 and 91 +/- 16% at 60 s).(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- K A Haines
- Department of Medicine, New York University Medical Center, New York 10016
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Jullien S, Capuozzo E, Salerno C, Crifò C. Effects of polyene antibiotics on the activation of human polymorphonuclear leukocytes. Biochem Pharmacol 1991; 41:2037-40. [PMID: 2039552 DOI: 10.1016/0006-2952(91)90147-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- S Jullien
- Department of Biochemical Sciences, University of Rome La Sapienza, Italy
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Cross AR, Jones OT. Enzymic mechanisms of superoxide production. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1057:281-98. [PMID: 1851438 DOI: 10.1016/s0005-2728(05)80140-9] [Citation(s) in RCA: 361] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- A R Cross
- Department of Biochemistry, School of Medical Sciences, University of Bristol, U.K
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Forehand JR, Bomalski JS, Johnston RB. Mechanisms of lipopolysaccharide priming for enhanced respiratory burst activity in human neutrophils. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1991; 297:65-73. [PMID: 1767756 DOI: 10.1007/978-1-4899-3629-5_6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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49
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Pittet D, Di Virgilio F, Pozzan T, Monod A, Lew D. Correlation between plasma membrane potential and second messenger generation in the promyelocytic cell line HL-60. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(18)77294-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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50
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