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Islam M, Jones S, Ellis I. Role of Akt/Protein Kinase B in Cancer Metastasis. Biomedicines 2023; 11:3001. [PMID: 38002001 PMCID: PMC10669635 DOI: 10.3390/biomedicines11113001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/31/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
Metastasis is a critical step in the process of carcinogenesis and a vast majority of cancer-related mortalities result from metastatic disease that is resistant to current therapies. Cell migration and invasion are the first steps of the metastasis process, which mainly occurs by two important biological mechanisms, i.e., cytoskeletal remodelling and epithelial to mesenchymal transition (EMT). Akt (also known as protein kinase B) is a central signalling molecule of the PI3K-Akt signalling pathway. Aberrant activation of this pathway has been identified in a wide range of cancers. Several studies have revealed that Akt actively engages with the migratory process in motile cells, including metastatic cancer cells. The downstream signalling mechanism of Akt in cell migration depends upon the tumour type, sites, and intracellular localisation of activated Akt. In this review, we focus on the role of Akt in the regulation of two events that control cell migration and invasion in various cancers including head and neck squamous cell carcinoma (HNSCC) and the status of PI3K-Akt pathway inhibitors in clinical trials in metastatic cancers.
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Affiliation(s)
- Mohammad Islam
- Unit of Cell and Molecular Biology, School of Dentistry, University of Dundee, Park Place, Dundee DD1 4HR, UK; (S.J.); (I.E.)
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Rodríguez-Fernández JL, Criado-García O. A meta-analysis indicates that the regulation of cell motility is a non-intrinsic function of chemoattractant receptors that is governed independently of directional sensing. Front Immunol 2022; 13:1001086. [PMID: 36341452 PMCID: PMC9630654 DOI: 10.3389/fimmu.2022.1001086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 10/03/2022] [Indexed: 11/30/2022] Open
Abstract
Chemoattraction, defined as the migration of a cell toward a source of a chemical gradient, is controlled by chemoattractant receptors. Chemoattraction involves two basic activities, namely, directional sensing, a molecular mechanism that detects the direction of a source of chemoattractant, and actin-based motility, which allows the migration of a cell towards it. Current models assume first, that chemoattractant receptors govern both directional sensing and motility (most commonly inducing an increase in the migratory speed of the cells, i.e. chemokinesis), and, second, that the signaling pathways controlling both activities are intertwined. We performed a meta-analysis to reassess these two points. From this study emerge two main findings. First, although many chemoattractant receptors govern directional sensing, there are also receptors that do not regulate cell motility, suggesting that is the ability to control directional sensing, not motility, that best defines a chemoattractant receptor. Second, multiple experimental data suggest that receptor-controlled directional sensing and motility can be controlled independently. We hypothesize that this independence may be based on the existence of separated signalling modules that selectively govern directional sensing and motility in chemotactic cells. Together, the information gathered can be useful to update current models representing the signalling from chemoattractant receptors. The new models may facilitate the development of strategies for a more effective pharmacological modulation of chemoattractant receptor-controlled chemoattraction in health and disease.
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Prichard A, Khuu L, Whitmore LC, Irimia D, Allen LAH. Helicobacter pylori-infected human neutrophils exhibit impaired chemotaxis and a uropod retraction defect. Front Immunol 2022; 13:1038349. [PMID: 36341418 PMCID: PMC9630475 DOI: 10.3389/fimmu.2022.1038349] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/05/2022] [Indexed: 11/17/2022] Open
Abstract
Helicobacter pylori is a major human pathogen that colonizes the gastric mucosa and plays a causative role in development of peptic ulcers and gastric cancer. Neutrophils are heavily infected with this organism in vivo and play a prominent role in tissue destruction and disease. Recently, we demonstrated that H. pylori exploits neutrophil plasticity as part of its virulence strategy eliciting N1-like subtype differentiation that is notable for profound nuclear hypersegmentation. We undertook this study to test the hypothesis that hypersegmentation may enhance neutrophil migratory capacity. However, EZ-TAXIScan™ video imaging revealed a previously unappreciated and progressive chemotaxis defect that was apparent prior to hypersegmentation onset. Cell speed and directionality were significantly impaired to fMLF as well as C5a and IL-8. Infected cells oriented normally in chemotactic gradients, but speed and direction were impaired because of a uropod retraction defect that led to cell elongation, nuclear lobe trapping in the contracted rear and progressive narrowing of the leading edge. In contrast, chemotactic receptor abundance, adhesion, phagocytosis and other aspects of cell function were unchanged. At the molecular level, H. pylori phenocopied the effects of Blebbistatin as indicated by aberrant accumulation of F-actin and actin spikes at the uropod together with enhanced ROCKII-mediated phosphorylation of myosin IIA regulatory light chains at S19. At the same time, RhoA and ROCKII disappeared from the cell rear and accumulated at the leading edge whereas myosin IIA was enriched at both cell poles. These data suggest that H. pylori inhibits the dynamic changes in myosin IIA contractility and front-to-back polarity that are essential for chemotaxis. Taken together, our data advance understanding of PMN plasticity and H. pylori pathogenesis.
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Affiliation(s)
- Allan Prichard
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, United States
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, MO, United States
| | - Lisa Khuu
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, MO, United States
| | - Laura C. Whitmore
- Department of Medicine, Division of Infectious Diseases, University of Iowa, Iowa City, IA, United States
| | - Daniel Irimia
- Department of Surgery, BioMEMS Resource Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Lee-Ann H. Allen
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, United States
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, MO, United States
- Department of Medicine, Division of Infectious Diseases, University of Iowa, Iowa City, IA, United States
- Iowa City VA Healthcare System, Iowa City, IA, United States
- Harry S. Truman Memorial VA Hospital, Columbia, MO, United States
- *Correspondence: Lee-Ann H. Allen,
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Subramanian BC, Majumdar R, Parent CA. The role of the LTB 4-BLT1 axis in chemotactic gradient sensing and directed leukocyte migration. Semin Immunol 2018; 33:16-29. [PMID: 29042024 DOI: 10.1016/j.smim.2017.07.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 06/07/2017] [Accepted: 07/13/2017] [Indexed: 12/11/2022]
Abstract
Directed leukocyte migration is a hallmark of inflammatory immune responses. Leukotrienes are derived from arachidonic acid and represent a class of potent lipid mediators of leukocyte migration. In this review, we summarize the essential steps leading to the production of LTB4 in leukocytes. We discuss the recent findings on the exosomal packaging and transport of LTB4 in the context of chemotactic gradients formation and regulation of leukocyte recruitment. We also discuss the dynamic roles of the LTB4 receptors, BLT1 and BLT2, in mediating chemotactic signaling in leukocytes and contrast them to other structurally related leukotrienes that bind to distinct GPCRs. Finally, we highlight the specific roles of the LTB4-BLT1 axis in mediating signal-relay between chemotaxing neutrophils and its potential contribution to a wide variety of inflammatory conditions including tumor progression and metastasis, where LTB4 is emerging as a key signaling component.
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Affiliation(s)
- Bhagawat C Subramanian
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, United States.
| | - Ritankar Majumdar
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, United States; Department of Pharmacology, University of Michigan School of Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, United States.
| | - Carole A Parent
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, United States; Department of Pharmacology, University of Michigan School of Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, United States.
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Abstract
During an innate immune response, myeloid cells undergo complex morphological adaptations in response to inflammatory cues, which allow them to exit the vasculature, enter the tissues, and destroy invading pathogens. The actin and microtubule cytoskeletons are central to many of the most essential cellular functions including cell division, cell morphology, migration, intracellular trafficking, and signaling. Cytoskeletal structure and regulation are crucial for many myeloid cell functions, which require rapid and dynamic responses to extracellular signals. In this chapter, we review the roles of the actin and microtubule cytoskeletons in myeloid cells, focusing primarily on their roles in chemotaxis and phagocytosis. The role of myeloid cell cytoskeletal defects in hematological disorders is highlighted throughout.
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Fritz-Laylin LK, Lord SJ, Mullins RD. WASP and SCAR are evolutionarily conserved in actin-filled pseudopod-based motility. J Cell Biol 2017; 216:1673-1688. [PMID: 28473602 PMCID: PMC5461030 DOI: 10.1083/jcb.201701074] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/12/2017] [Accepted: 03/31/2017] [Indexed: 01/08/2023] Open
Abstract
Eukaryotic cells use diverse cellular mechanisms to crawl through complex environments. Fritz-Laylin et al. define α-motility as a mode of migration associated with dynamic, actin-filled pseudopods and show that WASP and SCAR constitute an evolutionarily conserved genetic signature of α-motility. Diverse eukaryotic cells crawl through complex environments using distinct modes of migration. To understand the underlying mechanisms and their evolutionary relationships, we must define each mode and identify its phenotypic and molecular markers. In this study, we focus on a widely dispersed migration mode characterized by dynamic actin-filled pseudopods that we call “α-motility.” Mining genomic data reveals a clear trend: only organisms with both WASP and SCAR/WAVE—activators of branched actin assembly—make actin-filled pseudopods. Although SCAR has been shown to drive pseudopod formation, WASP’s role in this process is controversial. We hypothesize that these genes collectively represent a genetic signature of α-motility because both are used for pseudopod formation. WASP depletion from human neutrophils confirms that both proteins are involved in explosive actin polymerization, pseudopod formation, and cell migration. WASP and WAVE also colocalize to dynamic signaling structures. Moreover, retention of WASP together with SCAR correctly predicts α-motility in disease-causing chytrid fungi, which we show crawl at >30 µm/min with actin-filled pseudopods. By focusing on one migration mode in many eukaryotes, we identify a genetic marker of pseudopod formation, the morphological feature of α-motility, providing evidence for a widely distributed mode of cell crawling with a single evolutionary origin.
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Affiliation(s)
- Lillian K Fritz-Laylin
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143
| | - Samuel J Lord
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143
| | - R Dyche Mullins
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143
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Surve CR, To JY, Malik S, Kim M, Smrcka AV. Dynamic regulation of neutrophil polarity and migration by the heterotrimeric G protein subunits Gαi-GTP and Gβγ. Sci Signal 2016; 9:ra22. [PMID: 26905427 DOI: 10.1126/scisignal.aad8163] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Activation of the Gi family of heterotrimeric guanine nucleotide-binding proteins (G proteins) releases βγ subunits, which are the major transducers of chemotactic G protein-coupled receptor (GPCR)-dependent cell migration. The small molecule 12155 binds directly to Gβγ and activates Gβγ signaling without activating the Gαi subunit in the Gi heterotrimer. We used 12155 to examine the relative roles of Gαi and Gβγ activation in the migration of neutrophils on surfaces coated with the integrin ligand intercellular adhesion molecule-1 (ICAM-1). We found that 12155 suppressed basal migration by inhibiting the polarization of neutrophils and increasing their adhesion to ICAM-1-coated surfaces. GPCR-independent activation of endogenous Gαi and Gβγ with the mastoparan analog Mas7 resulted in normal migration. Furthermore, 12155-treated cells expressing a constitutively active form of Gαi1 became polarized and migrated. The extent and duration of signaling by the second messenger cyclic adenosine monophosphate (cAMP) were enhanced by 12155. Inhibiting the activity of cAMP-dependent protein kinase (PKA) restored the polarity of 12155-treated cells but did not decrease their adhesion to ICAM-1 and failed to restore migration. Together, these data provide evidence for a direct role of activated Gαi in promoting cell polarization through a cAMP-dependent mechanism and in inhibiting adhesion through a cAMP-independent mechanism.
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Affiliation(s)
- Chinmay R Surve
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, NY 14642, USA
| | - Jesi Y To
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Sundeep Malik
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Minsoo Kim
- Department of Immunology and Microbiology, University of Rochester, Rochester, NY 14642, USA
| | - Alan V Smrcka
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, NY 14642, USA. Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA.
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Al-Jarallah A, Chen X, González L, Trigatti BL. High density lipoprotein stimulated migration of macrophages depends on the scavenger receptor class B, type I, PDZK1 and Akt1 and is blocked by sphingosine 1 phosphate receptor antagonists. PLoS One 2014; 9:e106487. [PMID: 25188469 PMCID: PMC4154704 DOI: 10.1371/journal.pone.0106487] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 08/04/2014] [Indexed: 01/12/2023] Open
Abstract
HDL carries biologically active lipids such as sphingosine-1-phosphate (S1P) and stimulates a variety of cell signaling pathways in diverse cell types, which may contribute to its ability to protect against atherosclerosis. HDL and sphingosine-1-phosphate receptor agonists, FTY720 and SEW2871 triggered macrophage migration. HDL-, but not FTY720-stimulated migration was inhibited by an antibody against the HDL receptor, SR-BI, and an inhibitor of SR-BI mediated lipid transfer. HDL and FTY720-stimulated migration was also inhibited in macrophages lacking either SR-BI or PDZK1, an adaptor protein that binds to SR-BI's C-terminal cytoplasmic tail. Migration in response to HDL and S1P receptor agonists was inhibited by treatment of macrophages with sphingosine-1-phosphate receptor type 1 (S1PR1) antagonists and by pertussis toxin. S1PR1 activates signaling pathways including PI3K-Akt, PKC, p38 MAPK, ERK1/2 and Rho kinases. Using selective inhibitors or macrophages from gene targeted mice, we demonstrated the involvement of each of these pathways in HDL-dependent macrophage migration. These data suggest that HDL stimulates the migration of macrophages in a manner that requires the activities of the HDL receptor SR-BI as well as S1PR1 activity.
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Affiliation(s)
- Aishah Al-Jarallah
- Department of Biochemistry and Biomedical Sciences, and the Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Xing Chen
- Department of Biochemistry and Biomedical Sciences, and the Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Leticia González
- Department of Biochemistry and Biomedical Sciences, and the Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Bernardo L. Trigatti
- Department of Biochemistry and Biomedical Sciences, and the Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
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Moving towards a paradigm: common mechanisms of chemotactic signaling in Dictyostelium and mammalian leukocytes. Cell Mol Life Sci 2014; 71:3711-47. [PMID: 24846395 DOI: 10.1007/s00018-014-1638-8] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 04/24/2014] [Accepted: 04/29/2014] [Indexed: 12/31/2022]
Abstract
Chemotaxis, or directed migration of cells along a chemical gradient, is a highly coordinated process that involves gradient sensing, motility, and polarity. Most of our understanding of chemotaxis comes from studies of cells undergoing amoeboid-type migration, in particular the social amoeba Dictyostelium discoideum and leukocytes. In these amoeboid cells the molecular events leading to directed migration can be conceptually divided into four interacting networks: receptor/G protein, signal transduction, cytoskeleton, and polarity. The signal transduction network occupies a central position in this scheme as it receives direct input from the receptor/G protein network, as well as feedback from the cytoskeletal and polarity networks. Multiple overlapping modules within the signal transduction network transmit the signals to the actin cytoskeleton network leading to biased pseudopod protrusion in the direction of the gradient. The overall architecture of the networks, as well as the individual signaling modules, is remarkably conserved between Dictyostelium and mammalian leukocytes, and the similarities and differences between the two systems are the subject of this review.
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11
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Kim SH, Kang JH, Yang MP. Fucoidan directly regulates the chemotaxis of canine peripheral blood polymorphonuclear cells by activating F-actin polymerization. Vet Immunol Immunopathol 2013; 151:124-31. [DOI: 10.1016/j.vetimm.2012.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 10/29/2012] [Accepted: 11/02/2012] [Indexed: 12/30/2022]
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Yu C, Xu L, Chen LF, Guan YJ, Kim M, Biffl WL, Chin YE. PRBC-derived plasma induces non-muscle myosin type IIA-mediated neutrophil migration and morphologic change. Immunopharmacol Immunotoxicol 2012; 35:71-9. [PMID: 23083320 PMCID: PMC3541669 DOI: 10.3109/08923973.2012.677046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Context: Neutrophils are the primary effector cells in the pathogenesis of transfusion-related acute lung injury or multiple organ failure after blood transfusion. Objective: We aimed to investigate the effect of fresh (1 day preparation) and aged (42 day preparation) PRBC-derived plasma on neutrophil morphology, migration and phagocytosis. Materials and methods: We evaluated the production of reactive oxygen species (ROS) and the expression of non-muscle myosin heavy chain IIA (MYH9) in neutrophils treated with PRBC-derived plasma. We used western blots and antibody arrays to evaluate changes in signal transduction pathways in plasma-treated neutrophils. Results: Aged PRBC-derived plasma elicited a stronger oxidative burst in neutrophils when compared with fresh PRBC-derived plasma (p < 0.05). Antibody arrays showed increased phosphorylation of NF-ĸB proteins (p105, p50 and Ikk) in aged PRBC-derived plasma-treated neutrophils. The expression of non-muscle myosin IIA (MYH9), a cytoskeleton protein involved in immune cell migration and morphological change, was also significantly upregulated in neutrophils treated with aged PRBC-derived plasma compared to fresh plasma (p < 0.05). Pretreatment of neutrophils with blebbistatin (a specific type II myosin inhibitor), ascorbic acid (an antioxidant), or staurosporine (a protein tyrosine kinase inhibitor), effectively abrogated the morphological changes, neutrophil migration, and phagocytosis induced by aged PRBC-derived plasma. Conclusion: Upregulation of MYH9 in neutrophils treated with aged PRBC-derived plasma and abrogation of neutrophil migration in blebbistatin-treated neutrophils suggested a functional role of MYH9 in the directional migration of immune cells. Our data help elucidate the cellular and molecular mechanisms of transfusion-related injury.
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Affiliation(s)
- Chen Yu
- Department of Nephrology, Tongji Hospital, Tongji Universith School of Medicine, Shanghai, China
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Bizzarro V, Petrella A, Parente L. Annexin A1: novel roles in skeletal muscle biology. J Cell Physiol 2012; 227:3007-15. [PMID: 22213240 DOI: 10.1002/jcp.24032] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Annexin A1 (ANXA1, lipocortin-1) is the first characterized member of the annexin superfamily of proteins, so called since their main property is to bind (i.e., to annex) to cellular membranes in a Ca(2+) -dependent manner. ANXA1 has been involved in a broad range of molecular and cellular processes, including anti-inflammatory signalling, kinase activities in signal transduction, maintenance of cytoskeleton and extracellular matrix integrity, tissue growth, apoptosis, and differentiation. New insights show that endogenous ANXA1 positively modulates myoblast cell differentiation by promoting migration of satellite cells and, consequently, skeletal muscle differentiation. This suggests that ANXA1 may contribute to the regeneration of skeletal muscle tissue and may have therapeutic implications with respect to the development of ANXA1 mimetics.
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Affiliation(s)
- Valentina Bizzarro
- Department of Pharmaceutical and Biomedical Sciences, University of Salerno, Fisciano, Salerno, Italy
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Molli PR, Pradhan MB, Advani SH, Naik NR. RhoA: a therapeutic target for chronic myeloid leukemia. Mol Cancer 2012; 11:16. [PMID: 22443473 PMCID: PMC3353160 DOI: 10.1186/1476-4598-11-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 03/25/2012] [Indexed: 11/11/2022] Open
Abstract
Background Chronic Myeloid Leukemia (CML) is a malignant pluripotent stem cells disorder of myeloid cells. In CML patients, polymorphonuclear leukocytes (PMNL) the terminally differentiated cells of myeloid series exhibit defects in several actin dependent functions such as adhesion, motility, chemotaxis, agglutination, phagocytosis and microbicidal activities. A definite and global abnormality was observed in stimulation of actin polymerization in CML PMNL. Signalling molecules ras and rhoGTPases regulate spatial and temporal polymerization of actin and thus, a broad range of physiological processes. Therefore, status of these GTPases as well as actin was studied in resting and fMLP stimulated normal and CML PMNL. Methods To study expression of GTPases and actin, Western blotting and flow cytometry analysis were done, while spatial expression and colocalization of these proteins were studied by using laser confocal microscopy. To study effect of inhibitors on cell proliferation CCK-8 assay was done. Significance of differences in expression of proteins within the samples and between normal and CML was tested by using Wilcoxon signed rank test and Mann-Whitney test, respectively. Bivariate and partial correlation analyses were done to study relationship between all the parameters. Results In CML PMNL, actin expression and its architecture were altered and stimulation of actin polymerization was absent. Differences were also observed in expression, organization or stimulation of all the three GTPases in normal and CML PMNL. In normal PMNL, ras was the critical GTPase regulating expression of rhoGTPases and actin and actin polymerization. But in CML PMNL, rhoA took a central place. In accordance with these, treatment with rho/ROCK pathway inhibitors resulted in specific growth inhibition of CML cell lines. Conclusions RhoA has emerged as the key molecule responsible for functional defects in CML PMNL and therefore can be used as a therapeutic target in CML.
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Affiliation(s)
- Poonam R Molli
- Cancer Research Institute, ACTREC, Tata Memorial Centre, Kharghar, Navi Mumbai 410210, India
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Palani K, Rahman M, Hasan Z, Zhang S, Qi Z, Jeppsson B, Thorlacius H. Rho-kinase regulates adhesive and mechanical mechanisms of pulmonary recruitment of neutrophils in abdominal sepsis. Eur J Pharmacol 2012; 682:181-7. [PMID: 22374257 DOI: 10.1016/j.ejphar.2012.02.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 02/03/2012] [Accepted: 02/08/2012] [Indexed: 12/22/2022]
Abstract
We hypothesized that Rho-kinase signaling plays a role in mechanical and adhesive mechanisms of neutrophil accumulation in lung. Male C57BL/6 mice were treated with the Rho-kinase inhibitor Y-27632 prior to cecal ligation and puncture (CLP). Lung levels of myeloperoxidase (MPO) and histological tissue damage were determined 6h and 24h after CLP. Expression of Mac-1 and F-actin formation in neutrophils were quantified by using flow cytometry 6h after CLP. Mac-1 expression and F-actin formation were also determined in isolated neutrophils up to 3h after stimulation with CXCL2. Labeled and activated neutrophils co-incubated with Y-27632, an anti-Mac-1 antibody and cytochalasin B were adoptively transferred to CLP mice. Y-27632 reduced the CLP-induced pulmonary injury and MPO activity as well as Mac-1 on neutrophils. Neutrophil F-actin formation peaked at 6h and returned to baseline levels 24h after CLP induction. Rho-kinase inhibition decreased CLP-provoked F-actin formation in neutrophils. CXCL2 rapidly increased Mac-1 expression and F-actin formation in neutrophils. Co-incubation with Y-27632 abolished CXCL2-induced Mac-1 up-regulation and formation of F-actin in neutrophils. Notably, co-incubation with cytochalasin B inhibited formation of F-actin but did not reduce Mac-1 expression on activated neutrophils. Adoptive transfer experiments revealed that co-incubation of neutrophils with the anti-Mac-1 antibody or cytochalasin B significantly decreased pulmonary accumulation of neutrophils in septic mice. Our data show that targeting Rho-kinase effectively reduces neutrophil recruitment and tissue damage in abdominal sepsis. Moreover, these findings demonstrate that Rho-kinase-dependent neutrophil accumulation in septic lung injury is regulated by both adhesive and mechanical mechanisms.
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Affiliation(s)
- Karzan Palani
- Department of Clinical Sciences, Section of Surgery, Malmö, Lund University, 20502 Malmö, Sweden
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Hattori H, Subramanian KK, Sakai J, Luo HR. Reactive oxygen species as signaling molecules in neutrophil chemotaxis. Commun Integr Biol 2011; 3:278-81. [PMID: 20714413 DOI: 10.4161/cib.3.3.11559] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Accepted: 02/16/2010] [Indexed: 11/19/2022] Open
Abstract
Neutrophil chemotaxis is a critical component in innate immunity. Recently, using a small-molecule functional screening, we identified NADPHoxidase- dependent Reactive Oxygen Species (ROS) as key regulators of neutrophil chemotactic migration. Neutrophils depleted of ROS form more frequent multiple pseudopodia and lost their directionality as they migrate up a chemoattractant concentration gradient. Here, we further studied the role of ROS in neutrophil chemotaxis and found that multiple pseudopodia formation induced by NADPH inhibitor diphenyleneiodonium chloride (DPI) was more prominent in relatively shallow chemoattractant gradient. It was reported that, in shallow chemoattractant gradients, new pseudopods are usually generated when existing ones bifurcate. Directional sensing is mediated by maintaining the most accurate existing pseudopod, and destroying pseudopods facing the wrong direction by actin depolymerization. We propose that NADPH-mediated ROS production may be critical for disruption of misoriented pseudopods in chemotaxing neutrophils. Thus, inhibition of ROS production will lead to formation of multiple pseudopodia.
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Affiliation(s)
- Hidenori Hattori
- Department of Pathology; Harvard Medical School; Dana-Farber/Harvard Cancer Center; Department of Lab Medicine; Children's Hospital Boston; USA
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Nakajima T, Owen CA. Polymorphonuclear neutrophils move into the fast lane in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2011; 183:1118-20. [PMID: 21531949 DOI: 10.1164/rccm.201102-0208ed] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Ogasawara H, Kawato M. The protein kinase Mζ network as a bistable switch to store neuronal memory. BMC SYSTEMS BIOLOGY 2010; 4:181. [PMID: 21194445 PMCID: PMC3022653 DOI: 10.1186/1752-0509-4-181] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2010] [Accepted: 12/31/2010] [Indexed: 11/10/2022]
Abstract
Background Protein kinase Mζ (PKMζ), the brain-specific, atypical protein kinase C isoform, plays a key role in long-term maintenance of memory. This molecule is essential for long-term potentiation of the neuron and various modalities of learning such as spatial memory and fear conditioning. It is unknown, however, how PKMζ stores information for long periods of time despite molecular turnover. Results We hypothesized that PKMζ forms a bistable switch because it appears to constitute a positive feedback loop (PKMζ induces its local synthesis) part of which is ultrasensitive (PKMζ stimulates its synthesis through dual pathways). To examine this hypothesis, we modeled the biochemical network of PKMζ with realistic kinetic parameters. Bifurcation analyses of the model showed that the system maintains either the up state or the down state according to previous inputs. Furthermore, the model was able to reproduce a variety of previous experimental results regarding synaptic plasticity and learning, which suggested that it captures the essential mechanism for neuronal memory. We proposed in vitro and in vivo experiments that would critically examine the validity of the model and illuminate the pivotal role of PKMζ in synaptic plasticity and learning. Conclusions This study revealed bistability of the PKMζ network and supported its pivotal role in long-term storage of memory.
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Affiliation(s)
- Hideaki Ogasawara
- National Institute of Information and Communications Technology, 2-2-2, Hikaridai, Seika, Kyoto 619-0288, Japan.
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Trans-10, cis-12 conjugated linoleic acid directly enhances the chemotactic activity of porcine peripheral blood polymorphonuclear neutrophillic leukocytes by activating F-actin polymerization in vitro. Res Vet Sci 2010; 89:191-5. [DOI: 10.1016/j.rvsc.2010.02.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Revised: 01/18/2010] [Accepted: 02/17/2010] [Indexed: 01/03/2023]
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Bizzarro V, Fontanella B, Franceschelli S, Pirozzi M, Christian H, Parente L, Petrella A. Role of Annexin A1 in mouse myoblast cell differentiation. J Cell Physiol 2010; 224:757-65. [PMID: 20578244 DOI: 10.1002/jcp.22178] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Annexin A1 (ANXA1) is a calcium- and phospholipid-binding protein involved in a broad range of cellular events. This study used molecular and microscopy approaches to explore the role of ANXA1 in mouse myoblast C2C12 cell differentiation. We report that ANXA1 expression increases during differentiation and that the down-regulation of ANXA1 significantly inhibits the differentiation process. ANXA1 is expressed in vivo in both quiescent and activated satellite cells and is highly localized in the cells that migrate in the lumen of regenerating fibers after an acute injury. Endogenous ANXA1 co-localizes with actin fibers at the protruding ends of undifferentiated but not differentiated cells suggesting a role of the protein in cell migration. Furthermore, ANXA1 neutralizing antibody reduces MyHC expression, decreases myotube formation and significantly inhibits cell migration. The data reported here suggest for the first time that ANXA1 plays a role in myogenic differentiation.
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Affiliation(s)
- Valentina Bizzarro
- Department of Pharmaceutical Sciences, University of Salerno, Salerno, Italy
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Passos GF, Figueiredo CP, Prediger RDS, Silva KABS, Siqueira JM, Duarte FS, Leal PC, Medeiros R, Calixto JB. Involvement of phosphoinositide 3-kinase gamma in the neuro-inflammatory response and cognitive impairments induced by beta-amyloid 1-40 peptide in mice. Brain Behav Immun 2010; 24:493-501. [PMID: 20025958 DOI: 10.1016/j.bbi.2009.12.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 12/05/2009] [Accepted: 12/13/2009] [Indexed: 12/24/2022] Open
Abstract
Alzheimer disease (AD) is the most common form of dementia in the elderly, and the neuro-pathological hallmarks of AD include neurofibrillary tangles (NFT), and deposition of beta-amyloid (Abeta) in extracellular plaques. In addition, chronic inflammation due to recruitment of activated glial cells to amyloid plaques are an invariant component in AD, and several studies have reported that the use of non-steroidal anti-inflammatory drugs (NSAIDs) may provide a measure of protection against AD. In this report we have investigated whether phosphoinositide 3-kinase gamma (PI3Kgamma), which is important in inflammatory cell migration, plays a critical role in the neuro-inflammation, synaptic dysfunction, and cognitive deficits induced by intracerebroventricular injection of Abeta(1-40) in mice. We found that the selective inhibitor of PI3Kgamma, AS605240, was able to attenuate the Abeta(1-40)-induced accumulation of activated astrocytes and microglia in the hippocampus, and decrease immuno-staining for p-Akt and cyclooxygenase-2 (COX-2). Interestingly, Abeta(1-40) activated macrophages treated with AS605240 or another PI3Kgamma inhibitor, AS252424, displayed impaired chemotaxis in vitro, but their expression of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) was unaffected. Finally, AS605240 prevented Abeta(1-40)-induced cognitive deficits and synaptic dysfunction, but failed to modify scopolamine-induced amnesia. Our data suggests that inhibition of PI3Kgamma may represent a novel therapeutic target for treating AD patients.
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Affiliation(s)
- Giselle F Passos
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil
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Small-molecule screen identifies reactive oxygen species as key regulators of neutrophil chemotaxis. Proc Natl Acad Sci U S A 2010; 107:3546-51. [PMID: 20142487 DOI: 10.1073/pnas.0914351107] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neutrophil chemotaxis plays an essential role in innate immunity, but the underlying cellular mechanism is still not fully characterized. Here, using a small-molecule functional screening, we identified NADPH oxidase-dependent reactive oxygen species as key regulators of neutrophil chemotactic migration. Neutrophils with pharmacologically inhibited oxidase, or isolated from chronic granulomatous disease (CGD) patients and mice, formed more frequent multiple pseudopodia and lost their directionality as they migrated up a chemoattractant concentration gradient. Knocking down NADPH oxidase in differentiated neutrophil-like HL60 cells also led to defective chemotaxis. Consistent with the in vitro results, adoptively transferred CGD murine neutrophils showed impaired in vivo recruitment to sites of inflammation. Together, these results present a physiological role for reactive oxygen species in regulating neutrophil functions and shed light on the pathogenesis of CGD.
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McArthur S, Yazid S, Christian H, Sirha R, Flower R, Buckingham J, Solito E. Annexin A1 regulates hormone exocytosis through a mechanism involving actin reorganization. FASEB J 2009; 23:4000-10. [DOI: 10.1096/fj.09-131391] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Simon McArthur
- Department of Cellular and Molecular Neuroscience Imperial College London Hammersmith Campus London UK
| | | | - Helen Christian
- Department of Physiology Anatomy and Genetics University of Oxford Oxford UK
| | - Ravneet Sirha
- Department of Cellular and Molecular Neuroscience Imperial College London Hammersmith Campus London UK
| | | | - Julia Buckingham
- Department of Cellular and Molecular Neuroscience Imperial College London Hammersmith Campus London UK
| | - Egle Solito
- Department of Cellular and Molecular Neuroscience Imperial College London Hammersmith Campus London UK
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6-Amino-4-oxo-1,3-diphenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonyl derivatives as a new class of potent inhibitors of Interleukin-8-induced neutrophil chemotaxis. Bioorg Med Chem 2009; 17:3580-7. [DOI: 10.1016/j.bmc.2009.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Revised: 04/02/2009] [Accepted: 04/06/2009] [Indexed: 12/16/2022]
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Cooperation of Mtmr8 with PI3K regulates actin filament modeling and muscle development in zebrafish. PLoS One 2009; 4:e4979. [PMID: 19325702 PMCID: PMC2656612 DOI: 10.1371/journal.pone.0004979] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Accepted: 02/28/2009] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND It has been shown that mutations in at least four myotubularin family genes (MTM1, MTMR1, 2 and 13) are causative for human neuromuscular disorders. However, the pathway and regulative mechanism remain unknown. METHODOLOGY/PRINCIPAL FINDINGS Here, we reported a new role for Mtmr8 in neuromuscular development of zebrafish. Firstly, we cloned and characterized zebrafish Mtmr8, and revealed the expression pattern predominantly in the eye field and somites during early somitogenesis. Using morpholino knockdown, then, we observed that loss-of-function of Mtmr8 led to defects in somitogenesis. Subsequently, the possible underlying mechanism and signal pathway were examined. We first checked the Akt phosphorylation, and observed an increase of Akt phosphorylation in the morphant embryos. Furthermore, we studied the PH/G domain function within Mtmr8. Although the PH/G domain deletion by itself did not result in embryonic defect, addition of PI3K inhibitor LY294002 did give a defective phenotype in the PH/G deletion morphants, indicating that the PH/G domain was essential for Mtmr8's function. Moreover, we investigated the cooperation of Mtmr8 with PI3K in actin filament modeling and muscle development, and found that both Mtmr8-MO1 and Mtmr8-MO2+LY294002 led to the disorganization of the actin cytoskeleton. In addition, we revealed a possible participation of Mtmr8 in the Hedgehog pathway, and cell transplantation experiments showed that Mtmr8 worked in a non-cell autonomous manner in actin modeling. CONCLUSION/SIGNIFICANCE The above data indicate that a conserved functional cooperation of Mtmr8 with PI3K regulates actin filament modeling and muscle development in zebrafish, and reveal a possible participation of Mtmr8 in the Hedgehog pathway. Therefore, this work provides a new clue to study the physiological function of MTM family members.
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Orelio C, Kuijpers TW. Shwachman-Diamond syndrome neutrophils have altered chemoattractant-induced F-actin polymerization and polarization characteristics. Haematologica 2009; 94:409-13. [PMID: 19211642 PMCID: PMC2649349 DOI: 10.3324/haematol.13733] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 10/04/2008] [Accepted: 10/16/2008] [Indexed: 12/31/2022] Open
Abstract
Shwachman-Diamond syndrome is a hereditary disorder characterized by pancreatic insufficiency and bone marrow failure. Most Shwachman-Diamond syndrome patients have mutations in the SBDS gene located at chromosome 7 and suffer from recurrent infections, due to neutropenia in combination with impaired neutrophil chemotaxis. Currently, the role of the actin cytoskeleton in Shwachman-Diamond syndrome neutrophils has not been investigated. Therefore, we performed immunofluorescence for SBDS and F-actin on human neutrophilic cells. Additionally, we examined in control neutrophils and cells from genetically defined Shwachman-Diamond syndrome patients F-actin polymerization and cytoskeletal polarization characteristics upon chemoattractant stimulation. These studies showed that SBDS and F-actin co-localize in neutrophilic cells and that F-actin polymerization and depolymerization characteristics are altered in Shwachman-Diamond syndrome neutrophils as compared to control neutrophils in response to both fMLP and C5a. Moreover, F-actin cytoskeletal polarization is delayed in Shwachman-Diamond syndrome neutrophils. Thus, Shwachman-Diamond syndrome neutrophils have aberrant chemoattractant-induced F-actin properties which might contribute to the impaired neutrophil chemotaxis.
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Affiliation(s)
- Claudia Orelio
- Sanquin Research and Landsteiner Laboratory Dept. Blood Cell Research Phagocyte Laboratory, Amsterdam
| | - Taco W. Kuijpers
- Emma Children’s Hospital, University of Amsterdam Academic Medical Centre, Amsterdam, The Netherlands
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Gaines P, Tien CW, Olins AL, Olins DE, Shultz LD, Carney L, Berliner N. Mouse neutrophils lacking lamin B-receptor expression exhibit aberrant development and lack critical functional responses. Exp Hematol 2008; 36:965-76. [PMID: 18550262 PMCID: PMC2543941 DOI: 10.1016/j.exphem.2008.04.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 03/20/2008] [Accepted: 04/11/2008] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The capacity of neutrophils to eradicate bacterial infections is dependent on normal development and activation of functional responses, which include chemotaxis and generation of oxygen radicals during the respiratory burst. A unique feature of the neutrophil is its highly lobulated nucleus, which is thought to facilitate chemotaxis, but may also play a role in other critical neutrophil functions. Nuclear lobulation is dependent on expression of the inner nuclear envelope protein, the lamin B receptor (LBR), mutations of which cause hypolobulated neutrophil nuclei in human Pelger-Huët anomaly and the "ichthyosis" (ic) phenotype in mice. In this study, we have investigated roles for LBR in mediating neutrophil development and activation of multiple neutrophil functions, including chemotaxis and the respiratory burst. MATERIALS AND METHODS A progenitor EML cell line was generated from an ic/ic mouse, and derived cells that lacked LBR expression were induced to mature neutrophils and then examined for abnormal morphology and functional responses. RESULTS Neutrophils derived from EML-ic/ic cells exhibited nuclear hypolobulation identical to that observed in ichthyosis mice. The ic/ic neutrophils also displayed abnormal chemotaxis, supporting the notion that nuclear segmentation augments neutrophil extravasation. Furthermore, promyelocytic forms of ic/ic cells displayed decreased proliferative responses and produced a deficient respiratory burst upon terminal maturation. CONCLUSIONS Our studies of promyelocytes that lack LBR expression have identified roles for LBR in regulating not only the morphologic maturation of the neutrophil nucleus, but also proliferative and functional responses that are critical to innate immunity.
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Affiliation(s)
- Peter Gaines
- University of Massachusetts Lowell, Department of Biological Sciences, Lowell, MA
| | - Chiung W. Tien
- University of Massachusetts Lowell, Department of Biological Sciences, Lowell, MA
| | - Ada L. Olins
- Bowdoin College, Biology Department, Brunswick, ME
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Heit B, Liu L, Colarusso P, Puri KD, Kubes P. PI3K accelerates, but is not required for, neutrophil chemotaxis to fMLP. J Cell Sci 2008; 121:205-14. [PMID: 18187452 DOI: 10.1242/jcs.020412] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
PI3K activity, resulting in the accumulation of PIP(3) along the leading edge of a chemotaxing cell, has been proposed to be an indispensable signaling event that is required for cells to undergo chemotaxis to endogenous and exogenous chemoattractants. Some studies have suggested that this might be the case for chemoattractants such as IL8, whereas chemotaxis to other stimuli, such as the bacterial peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP), might occur normally in the absence of PI3K activity. Herein, we systematically analyze the role of PI3K in mediating chemotaxis to fMLP, both in vitro and in vivo. Using short- and long-term in vitro assays, as well as an in vivo chemotaxis assay, we investigated the importance of PI3K in response to the prototypic chemoattractant fMLP. Exposure of neutrophils to fMLP induced an immediate polarization, which resulted in directional migration towards fMLP within 2-3 minutes. PI3K-inhibited cells also polarized and migrated in a directional fashion towards fMLP; however, this process was delayed by approximately 15 minutes, demonstrating that PI3K accelerates the initial response to fMLP, but an alternative pathway replaces PI3K over time. By contrast, p38-MAPK-inhibited cells, or cells lacking MK2, were unable to polarize in response to fMLP. Long-term chemotaxis assays using a pan-PI3K inhibitor, a PI3Kdelta-specific inhibitor or PI3Kgamma-knockout neutrophils, demonstrated no role for PI3K in mediating chemotaxis to fMLP, regardless of the steepness of the fMLP gradient. Similar results were observed in vivo, with PI3Kgamma(-/-) cells displaying a delayed, but otherwise normal, chemotactic response to gradients of fMLP. Together, these data demonstrate that, although PI3K can enhance early responses to the bacterial chemoattractant fMLP, it is not required for migration towards this chemoattractant.
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Affiliation(s)
- Bryan Heit
- Immunology Research Group, Department of Physiology and Biophysics, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
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Bruno O, Brullo C, Bondavalli F, Schenone S, Ranise A, Arduino N, Bertolotto MB, Montecucco F, Ottonello L, Dallegri F, Tognolini M, Ballabeni V, Bertoni S, Barocelli E. Synthesis and Biological Evaluation of N-Pyrazolyl-N‘-alkyl/benzyl/phenylureas: a New Class of Potent Inhibitors of Interleukin 8-Induced Neutrophil Chemotaxis. J Med Chem 2007; 50:3618-26. [PMID: 17608466 DOI: 10.1021/jm0704402] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Neutrophils chemotaxis is a complex multistep process that, if upregulated, causes acute inflammation and a number of autoimmune diseases. We report here the synthesis of a new N-(4-substituted)pyrazolyl-N'-alkyl/benzyl/phenylureas that are potent inhibitors of interleukin-8 (IL8)-induced neutrophil chemotaxis. The first series of compounds, obtained by functionalization with a urea moiety of the 5-amino-1-(2-hydroxy-2-phenylethyl)-1H-pyrazole-4-carboxylic acid ethyl ester 3, blocked the IL8-induced neutrophil chemotaxis, while they did not block N-formylmethionylleucylphenylalanine-mediated chemotaxis. The most active compounds, 3-benzyl- (4d), 3-(4-benzylpiperazinyl)- (4i), 3-phenyl- (4k) and 3-isopropylureido (4a) derivatives, showed an IC50 of 10, 14, 45, and 55 nM, respectively. Several different molecules were then synthesized to obtain more information for SAR study. Compounds 4a, 4d, and 4k were inactive in the binding assays on CXCR1 and CXCR2 (IL8 receptors), whereas they inhibited the phosphorylation of PTKs (protein tyrosine kinases) in the 50-70 kDa region. Moreover, in the presence of the same derivatives, we observed a complete block of F-actin rise and pseudopod formation.
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Affiliation(s)
- Olga Bruno
- Dipartimento di Scienze Farmaceutiche, University of Genoa, v.le Benedetto XV, 3-Genoa, Italy.
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Fox R, Nhan TQ, Law GL, Morris DR, Liles WC, Schwartz SM. PSGL-1 and mTOR regulate translation of ROCK-1 and physiological functions of macrophages. EMBO J 2007; 26:505-15. [PMID: 17245434 PMCID: PMC1783463 DOI: 10.1038/sj.emboj.7601522] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Accepted: 11/30/2006] [Indexed: 10/23/2022] Open
Abstract
Rho-associated kinases (ROCKs) are critical molecules involved in the physiological functions of macrophages, such as chemotaxis and phagocytosis. We demonstrate that macrophage adherence promotes rapid changes in physiological functions that depend on translational upregulation of preformed ROCK-1 mRNA, but not ROCK-2 mRNA. Before adherence, both ROCK mRNAs were present in the cytoplasm of macrophages, whereas ROCK proteins were undetectable. Macrophage adherence promoted signaling through P-selectin glycoprotein ligand-1 (PSGL-1)/Akt/mTOR that resulted in synthesis of ROCK-1, but not ROCK-2. Following synthesis, ROCK-1 was catalytically active. In addition, there was a rapamycin/sirolimus-sensitive enhanced loading of ribosomes on preformed ROCK-1 mRNAs. Inhibition of mTOR by rapamycin abolished ROCK-1 synthesis in macrophages resulting in an inhibition of chemotaxis and phagocytosis. Macrophages from PSGL-1-deficient mice recapitulated pharmacological inhibitor studies. These results indicate that receptor-mediated regulation at the level of translation is a component of a rapid set of mechanisms required to direct the macrophage phenotype upon adherence and suggest a mechanism for the immunosuppressive and anti-inflammatory effects of rapamycin/sirolimus.
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Affiliation(s)
- Richard Fox
- Department of Pathology, University of Washington, Seattle, WA, USA
- Department of Pathology, University of Washington, 815 Mercer Street, Seattle, WA 98109, USA. Tel.: +1 206 390 2997; Fax: +1 206 897 1540; E-mail:
| | - Thomas Q Nhan
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - G Lynn Law
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - David R Morris
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - W Conrad Liles
- Department of Pathology, University of Washington, Seattle, WA, USA
- Department of Medicine, University of Toronto/University Health Network, Toronto General Hospital, Toronto, Ontario, Canada
| | - Stephen M Schwartz
- Department of Pathology, University of Washington, Seattle, WA, USA
- Department of Pathology, University of Washington, 815 Mercer Street, Room 421, Seattle, WA 98109-4714, USA. Tel.: +1 206 543 0258; Fax: +1 206 897 1540; E-mail:
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Zelck UE, Gege BE, Schmid S. Specific inhibitors of mitogen-activated protein kinase and PI3-K pathways impair immune responses by hemocytes of trematode intermediate host snails. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2007; 31:321-31. [PMID: 16926049 DOI: 10.1016/j.dci.2006.06.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Revised: 06/20/2006] [Accepted: 06/21/2006] [Indexed: 05/11/2023]
Abstract
To characterize molecular mechanisms regulating snail cellular immune responses, the contributions of mitogen-activated protein kinases (MAPKs) and phosphatidylinositol 3-kinase (PI3-K) were examined in hemocytes of the trematode intermediate host snails Biomphalaria glabrata and Lymnaea stagnalis. Simultaneous measurement of phagocytosis/encapsulation and H2O2 production by hemocytes in the presence or absence of specific signal transduction inhibitors was used to assess the role of extracellular-signal regulated kinases 1 and 2 (ERK1/2), p38, JNK and PI3-K. Hemocyte spreading was significantly reduced in a dose-dependent manner by the ERK inhibitor, PD098059, and by wortmannin, a potent PI3-K inhibitor. The JNK inhibitor, SP600125, and the p38 kinase inhibitor, SB203580, had no effect on hemocyte spreading. Sheep red blood cell phagocytosis was significantly impaired by PD098059, SP600125, and SB203580. Hydrogen peroxide production during phagocytosis was severely inhibited by PD098059. Additionally, PD098059, but not the other inhibitors, significantly impaired the cellular encapsulation of trematode larvae and H2O2 production during encapsulation. These results suggest that MAPK and PI3-K signal transduction pathways play a pivotal role in the immune responses of snail hemocytes. PI3-K and ERK appear to strongly regulate cell motility. ERK, JNK and p38 contribute to phagocytosis-mediated signal transduction. ERK also play a major role in oxidative burst activation and the encapsulation of trematode larvae by snail hemocytes.
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Affiliation(s)
- Ulrike E Zelck
- Molecular Parasitology Unit, Institute for Tropical Medicine, Wilhelmstr. 27, D-72074 Tuebingen, Germany.
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Rückle T, Schwarz MK, Rommel C. PI3Kgamma inhibition: towards an 'aspirin of the 21st century'? Nat Rev Drug Discov 2006; 5:903-18. [PMID: 17080027 DOI: 10.1038/nrd2145] [Citation(s) in RCA: 204] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Class IB phosphatidylinositol 3-kinase p110gamma (PI3Kgamma) has gained increasing attention as a promising drug target for the treatment of inflammatory disease. Extensive target-validation data are available, which are derived from studies using both pharmacological and genetic tools. More recent findings have uncovered further therapeutic applications for PI3Kgamma inhibitors, opening up potentially huge opportunities for these drugs. Several companies have been pursuing small-molecule PI3Kgamma inhibitor projects, but none of them has progressed to the clinic yet. Here, we discuss the insights gained so far and the main challenges that are emerging on the path to developing PI3Kgamma inhibitors for the treatment of human disease.
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Affiliation(s)
- Thomas Rückle
- Serono Pharmaceutical Research Institute, Serono International S.A., 14 Chemin des Aulx, 1228 Plan-les-Ouates, Geneva, Switzerland
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Abstract
BACKGROUND AND PURPOSE The small G protein rhoA and its downstream effector rho-kinase are both expressed in vascular cells and are involved in several cellular processes. One of these processes is the regulation of the phosphorylation state of myosin light chain in vascular muscle and thus, the development of force. Recently, considerable evidence for increased activity of this pathway in cerebral and noncerebral vessels has been reported in several cardiovascular diseases associated with increased vascular tone. SUMMARY OF REVIEW The main aim of this brief review is to summarize current evidence for the involvement of rhoA/rho-kinase signaling in dysfunction of the cerebral circulation in disease states, such as cerebral vasospasm, hypertension, diabetes, and ischemic brain injury. We will also briefly consider the novel hypothesis that augmented activity of endothelial rho-kinase decreases nitric oxide production and contributes to increased vascular tone in disease and the possibility of this action being a key therapeutic target of statins (inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase) in cerebral and noncerebral arteries. CONCLUSIONS Considerable evidence indicates that rhoA/rho-kinase activity is commonly increased in cerebral vascular disease, not only in vascular muscle, but also in the endothelium and possibly in inflammatory cells and neurons.
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Babbin BA, Lee WY, Parkos CA, Winfree LM, Akyildiz A, Perretti M, Nusrat A. Annexin I regulates SKCO-15 cell invasion by signaling through formyl peptide receptors. J Biol Chem 2006; 281:19588-99. [PMID: 16675446 DOI: 10.1074/jbc.m513025200] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Annexin 1 (AnxA1) is a multifunctional phospholipid-binding protein associated with the development of metastasis in some invasive epithelial malignancies. However, the role of AnxA1 in the migration/invasion of epithelial cells is not known. In this study, experiments were performed to investigate the role of AnxA1 in the invasion of a model epithelial cell line, SKCO-15, derived from colorectal adenocarcinoma. Small interfering RNA-mediated knockdown of AnxA1 expression resulted in a significant reduction in invasion through Matrigel-coated filters. Localization studies revealed a translocation of AnxA1 to the cell surface upon the induction of cell migration, and functional inhibition of cell surface AnxA1 using antiserum (LCO1) significantly reduced cell invasion. Conversely, SKCO-15 cell invasion was increased by approximately 2-fold in the presence of recombinant full-length AnxA1 and the AnxA1 N-terminal-derived peptide mimetic, Ac2-26. Because extracellular AnxA1 has been shown to regulate leukocyte migratory events through interactions with n-formyl peptide receptors (nFPRs), we examined the expression of FPR-1, FPRL-1, and FPRL-2 in SKCO-15 cells by reverse transcriptase-PCR and identified expression of all three receptors in this cell line. Treatment of SKCO-15 cells with AnxA1, Ac2-26, and the classical nFPR agonist, formylmethionylleucylphenylalanine, induced intracellular calcium release consistent with nFPR activation. Furthermore, the nFPR antagonist, Boc2, abrogated the AnxA1 and Ac2-26-induced intracellular calcium release and increase in SKCO-15 cell invasion. Together, these results support an autocrine/paracrine role for membrane AnxA1 in stimulating SKCO-15 cell migration through nFPR activation. The findings in this study suggest that activation of nFPRs stimulates epithelial cell motility important in the development of metastasis as well as wound healing.
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Affiliation(s)
- Brian A Babbin
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia 30322, USA.
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Street M, Marsh SJ, Stabach PR, Morrow JS, Brown DA, Buckley NJ. Stimulation of Gαq-coupled M1 muscarinic receptor causes reversible spectrin redistribution mediated by PLC, PKC and ROCK. J Cell Sci 2006; 119:1528-36. [PMID: 16551696 DOI: 10.1242/jcs.02872] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spectrin is a cytoskeletal protein that plays a role in formation of the specialized plasma membrane domains. However, little is known of the molecular mechanism that regulates responses of spectrin to extracellular stimuli, such as activation of G-protein-coupled receptor (GPCR). We have found that αII spectrin is a component of the Gαq/11-associated protein complex in CHO cells stably expressing the M1 muscarinic receptor, and investigated the effect of activation of GPCR on the cellular localization of yellow-fluorescent-protein-tagged αII spectrin. Stimulation of Gαq/11-coupled M1 muscarinic receptor triggered reversible redistribution of αII spectrin following a rise in intracellular Ca2+ concentration. This redistribution, accompanied by non-apoptotic membrane blebbing, required an intact actin cytoskeleton and was dependent on activation of phospholipase C, protein kinase C, and Rho-associated kinase ROCK. Muscarinic-agonist-induced spectrin remodeling appeared particularly active at localized domains, which is clear contrast to that caused by constitutive activation of ROCK and to global rearrangement of the spectrin lattice caused by changes in osmotic pressure. These results suggest a role for spectrin in providing a dynamic and reversible signaling platform to the specific domains of the plasma membrane in response to stimulation of GPCR.
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Affiliation(s)
- Miyoko Street
- University of Leeds, Institute of Membrane and Systems Biology, Garstang Building, Mount Preston Street, Leeds LS2 9JT, UK.
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37
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Even-Faitelson L, Ravid S. PAK1 and aPKCzeta regulate myosin II-B phosphorylation: a novel signaling pathway regulating filament assembly. Mol Biol Cell 2006; 17:2869-81. [PMID: 16611744 PMCID: PMC1483025 DOI: 10.1091/mbc.e05-11-1001] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Many signaling pathways regulate the function of the cellular cytoskeleton. Yet we know very little about the proteins involved in the cross-talk between the signaling and the cytoskeletal systems. Here we show that myosin II-B, an important cytoskeletal protein, resides in a complex with p21-activated kinase 1 (PAK1) and atypical protein kinase C (PKC) zeta (aPKCzeta) and that the interaction between these proteins is EGF-dependent. We further show that PAK1 is involved in aPKCzeta phosphorylation and that aPKCzeta phosphorylates myosin II-B directly on a specific serine residue in an EGF-dependent manner. This latter phosphorylation is specific to isoform B of myosin II, and it leads to slower filament assembly of myosin II-B. Furthermore, a decrease in aPKCzeta expression in the cells alters myosin II-B cellular organization. Our finding of a new signaling pathway involving PAK1, aPKCzeta, and myosin II-B, which is implicated in myosin II-B filament assembly and cellular organization, provides an important link between the signaling system and cytoskeletal dynamics.
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Affiliation(s)
- Liron Even-Faitelson
- Department of Biochemistry, Institute of Medical Sciences, Faculty of Medicine, The Hebrew University, Jerusalem 91120, Israel
| | - Shoshana Ravid
- Department of Biochemistry, Institute of Medical Sciences, Faculty of Medicine, The Hebrew University, Jerusalem 91120, Israel
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Kim C, Dinauer MC. Impaired NADPH oxidase activity in Rac2-deficient murine neutrophils does not result from defective translocation of p47phox and p67phox and can be rescued by exogenous arachidonic acid. J Leukoc Biol 2006; 79:223-34. [PMID: 16275890 DOI: 10.1189/jlb.0705371] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Rac2 is a hematopoietic-specific Rho-GTPase that plays a stimulus-specific role in regulating reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and other functional responses in neutrophils. In this study, rac2-/- neutrophils were shown to have significantly decreased NADPH oxidase activity and actin remodeling in response to exogenous arachidonic acid (AA), as previously observed for phorbol 12-myristate 13-acetate (PMA) or formyl-Met-Leu-Phe (fMLP) as agonists. PMA-, fMLP-, or AA-induced translocation of p47phox and p67phox to the plasma membrane was not impaired in rac2-/- neutrophils. Combined stimulation of rac2-/- neutrophils with exogenous AA and PMA had a synergistic effect on NADPH oxidase activity, and superoxide production increased to a level that was at least as high as wild-type cells and had no effect on fMLP-elicited enzyme activity. Membrane translocation of p47phox and p67phox as well as Rac1 activation was not increased further by combined PMA and AA stimulation. Inhibitor studies were consistent with important roles for phorbol ester-activated protein kinase C (PKC) isoforms and an atypical isoform, PKCzeta, in superoxide production by wild-type and rac2-/- neutrophils stimulated with AA and PMA. In addition, PMA-stimulated release of AA and cytoplasmic phospholipase A2 expression in rac2-/- neutrophils were similar to wild-type, suggesting that deficient AA production by PMA-stimulated rac2-/- neutrophils does not explain the effect of exogenous AA on oxidase activity. Although not required for translocation of p47phox and p67phox, Rac2 is necessary for optimal activity of the assembled oxidase complex, an effect that can be replaced by exogenous AA, which may act directly or via an exogenous AA-induced mediator.
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Affiliation(s)
- Chaekyun Kim
- Herman B. Wells Center for Pediatric Research, Department of Pediatrics (Hematology/Oncology), James Whitcomb Riley Hospital for Children, Indiana University Medical Center, Indianapolis, IN, USA
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Kouroumalis A, Nibbs RJ, Aptel H, Wright KL, Kolios G, Ward SG. The chemokines CXCL9, CXCL10, and CXCL11 differentially stimulate G alpha i-independent signaling and actin responses in human intestinal myofibroblasts. THE JOURNAL OF IMMUNOLOGY 2005; 175:5403-11. [PMID: 16210647 DOI: 10.4049/jimmunol.175.8.5403] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Intestinal myofibroblasts have been implicated in the pathogenesis of chronic inflammatory conditions such as Crohn's disease via interactions with an elaborate network of cytokines, growth factors, and other inflammatory mediators. CXCR3 is a Galpha(i) protein-coupled receptor that binds the proinflammatory chemokines CXCL9, CXCL10, and CXCL11, which are released from the intestinal epithelium. The three CXCR3 ligands shared the ability to activate biochemical (e.g., PI3K and MAPK activation) and functional events (actin reorganization) in intestinal myofibroblasts. However, CXCL11 is unique in its ability to elevate intracellular calcium. Surprisingly, although CXCR3 mRNA is detectable in these myofibroblasts, there is no detectable surface expression of CXCR3. Furthermore, the biochemical responses and actin reorganization stimulated by the CXCR3 ligands in intestinal myofibroblasts are insensitive to the Galpha(i) inhibitor, pertussis toxin. This suggests either the existence of differential receptor coupling mechanisms in myofibroblasts for CXCR3 that are distinct from those observed in PBLs and/or that these cells express a modified or variant CXCR3 compared with the CXCR3 expressed on PBLs.
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40
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Seres I, Fóris G, Páll D, Kosztáczky B, Paragh G, Varga Z, Paragh G. Angiotensin II-induced oxidative burst is fluvastatin sensitive in neutrophils of patients with hypercholesterolemia. Metabolism 2005; 54:1147-54. [PMID: 16125525 DOI: 10.1016/j.metabol.2005.03.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2004] [Revised: 03/18/2005] [Accepted: 03/29/2005] [Indexed: 11/18/2022]
Abstract
The aim of this study was to investigate the effect of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor fluvastatin (Flu) on angiotensin II (AII)-stimulated neutrophils of patients with hypercholesterolemia. Results suggest that a 6-week-long Flu administration completely counteracted the AII-induced increase in superoxide anion and leukotriene C4 production of the neutrophils of patients with hypercholesterolemia. However, the failure of signal processing through pertussis toxin-sensitive G protein, the increase in [Ca2+]i in membrane-bound protein kinase C activity, and the increase in neutrophil-bound cholesterol content were only partially restored by Flu. In addition, Flu had no effect on the increased membrane rigidity of the neutrophils of patients with hypercholesterolemia. To sum it up, Flu administration had a beneficial effect on AII-triggered reactive oxygen species generation; it resulted in partial restoration of signaling processes and of membrane composition, but membrane fluidity remained unchanged.
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Affiliation(s)
- Ildiko Seres
- First Department of Medicine, Medical and Health Science Center, University of Debrecen, H-4012 Debrecen, Hungary
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41
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Rane MJ, Gozal D, Butt W, Gozal E, Pierce WM, Guo SZ, Wu R, Goldbart AD, Thongboonkerd V, McLeish KR, Klein JB. Gamma-amino butyric acid type B receptors stimulate neutrophil chemotaxis during ischemia-reperfusion. THE JOURNAL OF IMMUNOLOGY 2005; 174:7242-9. [PMID: 15905570 DOI: 10.4049/jimmunol.174.11.7242] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Serine/threonine kinase Akt, or protein kinase B, has been shown to regulate a number of neutrophil functions. We sought to identify Akt binding proteins in neutrophils to provide further insights into understanding the mechanism by which Akt regulates various neutrophil functions. Proteomic and immunoprecipitation studies identified gamma-amino butyric acid (GABA) type B receptor 2 (GABA(B)R2) as an Akt binding protein in human neutrophils. Neutrophil lysates subjected to Akt immunoprecipitation followed by immunoblotting with anti-GABA(B)R2 demonstrated Akt association with the intact GABA(B)R. Similar results were obtained when reciprocal immunoprecipitations were performed with anti-GABA(B)R2 Ab. Additionally, GABA(B)R2 and Akt colocalization was demonstrated by confocal microscopy. A GABA(B)R agonist, baclofen, activated Akt and stimulated neutrophil-directed migration in a PI3K-dependent manner, whereas CGP52432, a GABA(B)R antagonist blocked such effects. Baclofen, stimulated neutrophil chemotaxis and tubulin reorganization in a PI3K-dependent manner. Additionally, a GABA(B)R agonist failed to stimulate neutrophil superoxide burst. We are unaware of the association of GABA(B)R with Akt in any cell type. The present study shows for the first time that a brain-specific receptor, GABA(B)R2 is present in human neutrophils and that it is functionally associated with Akt. Intraventricular baclofen pretreatment in rats subjected to a stroke model showed increased migration of neutrophils to the ischemic lesion. Thus, the GABA(B)R is functionally expressed in neutrophils, and acts as a chemoattractant receptor via an Akt-dependent pathway. The GABA(B)R potentially plays a significant role in the inflammatory response and neutrophil-dependent ischemia-reperfusion injury such as stroke.
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Affiliation(s)
- Madhavi J Rane
- Department of Medicine, University of Louisville, Louisville, KY 40202, USA.
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42
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Singh N, Webb R, Adams R, Evans SA, Al-Mosawi A, Evans M, Roberts AW, Thomas AW. The PPAR-γ activator, Rosiglitazone, inhibits actin polymerisation in monocytes: Involvement of Akt and intracellular calcium. Biochem Biophys Res Commun 2005; 333:455-62. [PMID: 15950942 DOI: 10.1016/j.bbrc.2005.05.127] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Accepted: 05/18/2005] [Indexed: 11/15/2022]
Abstract
Monocyte hyperactivation as seen in diabetes results in increased cytoskeletal rigidity and reduced cell deformability leading to microchannel occlusions and microvascular complications. The thiazolidinediones (TZDs) are PPAR-gamma agonists that have been reported to exert beneficial non-metabolic effects on the vasculature. This study demonstrates that the TZD, Rosiglitazone, significantly reduces f-MLP-induced actin polymerisation in human monocytic cells (p < 0.05). Two of the key signalling processes known to be involved in the regulation of cytoskeletal remodelling were investigated: PI(3)K-dependent Akt phosphorylation and intracellular calcium concentration [Ca(2+)](i). The PI(3)K inhibitor, Wortmannin, ameliorated f-MLP-induced actin polymerisation (p < 0.05), while the Ca(2+) sequestration inhibitor, thapsigargin, induced actin depolymerisation (p < 0.05), confirming the involvement of both processes in cytoskeletal remodelling. Rosiglitazone significantly reduced f-MLP activation of Akt (p < 0.05), and significantly increased [Ca(2+)](i) in both resting and f-MLP-stimulated cells (p < 0.05). Therefore, Rosiglitazone interacts with signalling events downstream of occupancy of the f-MLP receptor, to modulate cytoskeletal remodelling in a PPAR-gamma-independent manner. To our knowledge, these results are the first to present evidence that a PPAR-gamma agonist can modulate actin remodelling in monocytes, and may therefore be protective against microvascular damage in diabetes.
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Affiliation(s)
- Neenu Singh
- School of Applied Science, University of Wales Institute Cardiff, Western Avenue, Cardiff CF5 2YB, UK
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43
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Thomas MJ, Smith A, Head DH, Milne L, Nicholls A, Pearce W, Vanhaesebroeck B, Wymann MP, Hirsch E, Trifilieff A, Walker C, Finan P, Westwick J. Airway inflammation: chemokine-induced neutrophilia and the class I phosphoinositide 3-kinases. Eur J Immunol 2005; 35:1283-91. [PMID: 15739165 DOI: 10.1002/eji.200425634] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Class I phosphoinositide 3-kinases (PI3K) are known to play a significant role in neutrophil chemotaxis. However, the relative contributions of different PI3K isoforms, and how these impact on lung inflammation, have not been addressed. In vitro studies using wild-type and PI3Kgamma knockout neutrophils demonstrated the major role of the gamma isoform in chemotactic but not chemokinetic events. This was confirmed by a model of direct chemokine instillation into the airways in vivo. Within all studies, a low yet significant degree of neutrophil movement in the absence of PI3Kgamma could be observed. No role for the delta isoform was demonstrated both in vitro and in vivo using PI3Kdelta kinase-dead knock-in mice. Moreover, further studies using the broad-spectrum PI3K inhibitors wortmannin or LY294002 showed no other class I PI3K isoforms to be involved in these chemotactic processes. Here, we identify a contributory PI3K-independent mechanism of neutrophil movement, yet demonstrate PI3Kgamma as the pivotal mediator through which the majority of neutrophils migrate into the lung in response to chemokines. These data resolve the complexities of chemokine-induced neutrophilia and PI3K signaling and define the gamma isoform as a promising target for new therapeutics to treat airway inflammatory diseases.
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44
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Riol-Blanco L, Sánchez-Sánchez N, Torres A, Tejedor A, Narumiya S, Corbí AL, Sánchez-Mateos P, Rodríguez-Fernández JL. The Chemokine Receptor CCR7 Activates in Dendritic Cells Two Signaling Modules That Independently Regulate Chemotaxis and Migratory Speed. THE JOURNAL OF IMMUNOLOGY 2005; 174:4070-80. [PMID: 15778365 DOI: 10.4049/jimmunol.174.7.4070] [Citation(s) in RCA: 178] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
CCR7 is necessary to direct dendritic cells (DCs) to secondary lymphoid nodes and to elicit an adaptative immune response. Despite its importance, little is known about the molecular mechanisms used by CCR7 to direct DCs to lymph nodes. In addition to chemotaxis, CCR7 regulates the migratory speed of DCs. We investigated the intracellular pathways that regulate CCR7-dependent chemotaxis and migratory speed. We found that CCR7 induced a G(i)-dependent activation of MAPK members ERK1/2, JNK, and p38, with ERK1/2 and p38 controlling JNK. MAPK members regulated chemotaxis, but not the migratory speed, of DCs. CCR7 induced activation of PI3K/Akt; however, these enzymes did not regulate either chemotaxis or the speed of DCs. CCR7 also induced activation of the GTPase Rho, the tyrosine kinase Pyk2, and inactivation of cofilin. Pyk2 activation was independent of G(i) and Src and was dependent on Rho. Interference with Rho or Pyk2 inhibited cofilin inactivation and the migratory speed of DCs, but did not affect chemotaxis. Interference with Rho/Pyk2/cofilin inhibited DC migratory speed even in the absence of chemokines, suggesting that this module controls the speed of DCs and that CCR7, by activating its components, induces an increase in migratory speed. Therefore, CCR7 activates two independent signaling modules, one involving G(i) and a hierarchy of MAPK family members and another involving Rho/Pyk2/cofilin, which control, respectively, chemotaxis and the migratory speed of DCs. The use of independent signaling modules to control chemotaxis and speed can contribute to regulate the chemotactic effects of CCR7.
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Affiliation(s)
- Lorena Riol-Blanco
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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45
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Ottonello L, Montecucco F, Bertolotto M, Arduino N, Mancini M, Corcione A, Pistoia V, Dallegri F. CCL3 (MIP-1α) induces in vitro migration of GM-CSF-primed human neutrophils via CCR5-dependent activation of ERK 1/2. Cell Signal 2005; 17:355-63. [PMID: 15567066 DOI: 10.1016/j.cellsig.2004.08.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2004] [Revised: 07/30/2004] [Accepted: 08/10/2004] [Indexed: 10/26/2022]
Abstract
CCL3 (MIP-1alpha), a prototype of CC chemokines, is a potent chemoattractant toward human neutrophils pre-treated with GM-CSF for 15 min. GM-CSF-treated neutrophils migrate also to the selective CCR5 agonist CCL4 (MIP-1beta). CCL3- and CCL4-triggered migration of GM-CSF-primed neutrophils was inhibited by the CCR5 antagonist TAK-779. Accordingly, freshly isolated neutrophils express CCR5. Extracellular signal-regulated kinases (ERK)-1/2 and p38 mitogen-activated protein kinase (MAPK) inhibitors blocked CCL3-induced migration of GM-CSF-primed neutrophils. When the activation of ERK-1/2 and p38 MAPK by CCL3 and the classical neutrophilic chemokine CXCL8 (IL-8) were compared, both the chemokines were capable of activating p38 MAPK. On the contrary, whereas both ERK-1 and ERK-2 were activated by CXCL8, no ERK-1 band was detectable after CCL3 triggering. Finally, neutrophil pre-treatment with GM-CSF activated both ERK-1 and ERK-2. This suggests that by activating ERK-1, GM-CSF renders neutrophils rapidly responsive to CCL3 stimulation throughout CCR5 which is constitutively expressed on the cell surface.
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Affiliation(s)
- Luciano Ottonello
- Laboratory of Phagocyte Physiopathology and Inflammation, Department of Internal Medicine, University of Genoa, G. Gaslini Institute, Genoa, Italy.
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46
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Zhelev DV, Alteraifi AM, Chodniewicz D. Controlled pseudopod extension of human neutrophils stimulated with different chemoattractants. Biophys J 2005; 87:688-95. [PMID: 15240502 PMCID: PMC1304392 DOI: 10.1529/biophysj.103.036699] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The formation of pseudopods and lamellae after ligation of chemoattractant sensitive G-protein coupled receptors (GPCRs) is essential for chemotaxis. Here, pseudopod extension was stimulated with chemoattractant delivered from a micropipet. The chemoattractant diffusion and convection mass transport were considered, and it is shown that when the delivery of chemoattractant was limited by diffusion there was a strong chemoattractant gradient along the cell surface. The diffusion-limited delivery of chemoattractant from a micropipet allowed for maintaining an almost constant chemoattractant concentration at the leading edge of single pseudopods during their growth. In these conditions, the rate of pseudopod extension was dependent on the concentration of chemoattractant in the pipet delivering chemoattractant. The pseudopod extension induced using micropipets was oscillatory even in the presence of a constant delivery of chemoattractant. This oscillatory pseudopod extension was controlled by activated RhoA and its downstream effector kinase ROCK and was abolished after the inhibition of RhoA activation with Clostridium botulinium C3 exoenzyme (C3) or the blocking of ROCK activation with Y-27632. The ability of the micropipet assay to establish a well-defined chemoattractant distribution around the activated cell over a wide range of molecular weights of the used chemoattractants allowed for comparison of the effect of chemoattractant stimulation on the dynamics of pseudopod growth. Pseudopod growth was stimulated using N-formylated peptide (N-formyl-methionyl-leucyl-phenylalanine (fMLP)), platelet activating factor (PAF), leukotriene B4 (LTB(4)), C5a anaphylotoxin (C5a), and interleukin-8 (IL-8), which represent the typical ligands for G-protein coupled chemotactic receptors. The dependence of the rate of pseudopod extension on the concentration of these chemoattractants and their equimolar mixture was measured and shown to be similar for all chemoattractants. The inhibition of the activity of phosphoinositide-3 kinase (PI3K) with wortmannin showed that 72%-80% of the rate of pseudopod extension induced with N-formyl-methionyl-leucyl-phenylalanine, platelet activating factor, and leukotriene B4 was phosphoinositide-3 kinase-dependent, in contrast to 55% of the rate of pseudopod extension induced with interleukin-8. The dependence of the rate of pseudopod extension on the concentration of individual chemoattractants and their equimolar mixture suggests that there is a common rate-limiting mechanism for the polymerization of cytoskeletal F-actin in the pseudopod region induced by G-protein coupled chemoattractant receptors.
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Affiliation(s)
- Doncho V Zhelev
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708-0300, USA.
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47
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Chodniewicz D, Klemke RL. Regulation of integrin-mediated cellular responses through assembly of a CAS/Crk scaffold. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2004; 1692:63-76. [PMID: 15246680 DOI: 10.1016/j.bbamcr.2004.03.006] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Accepted: 03/16/2004] [Indexed: 01/09/2023]
Abstract
The molecular coupling of CAS and Crk in response to integrin activation is an evolutionary conserved signaling module that controls cell proliferation, survival and migration. However, when deregulated, CAS/Crk signaling also contributes to cancer progression and developmental defects in humans. Here we highlight recent advances in our understanding of how CAS/Crk complexes assemble in cells to modulate the actin cytoskeleton, and the molecular mechanisms that regulate this process. We discuss in detail the spatiotemporal dynamics of CAS/Crk assembly and how this scaffold recruits specific effector proteins that couple integrin signaling networks to the migration machinery of cells. We also highlight the importance of CAS/Crk signaling in the dual regulation of cell migration and survival mechanisms that operate in invasive cells during development and pathological conditions associated with cancer metastasis.
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Affiliation(s)
- David Chodniewicz
- Department of Immunology, The Scripps Research Institute, 10550 North Torrey Pines Road, SP231, La Jolla, CA 92037, USA
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48
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Yamaguchi T, Wallace DP, Magenheimer BS, Hempson SJ, Grantham JJ, Calvet JP. Calcium restriction allows cAMP activation of the B-Raf/ERK pathway, switching cells to a cAMP-dependent growth-stimulated phenotype. J Biol Chem 2004; 279:40419-30. [PMID: 15263001 DOI: 10.1074/jbc.m405079200] [Citation(s) in RCA: 249] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
cAMP can be either mitogenic or anti-mitogenic, depending on the cell type. We demonstrated previously that cAMP inhibited the proliferation of normal renal epithelial cells and stimulated the proliferation of cells derived from the cysts of polycystic kidney disease (PKD) patients. The protein products of the genes causing PKD, polycystin-1 and polycystin-2, are thought to regulate intracellular calcium levels, suggesting that abnormal polycystin function may affect calcium signaling and thus cause a switch to the cAMP growth-stimulated phenotype. To test this hypothesis, we disrupted intracellular calcium mobilization by treating immortalized mouse M-1 collecting duct cells and primary cultures of human kidney epithelial cells with calcium channel blockers and by lowering extracellular calcium with EGTA. Calcium restriction for 3-5 h converted both cell types from a normal cAMP growth-inhibited phenotype to an abnormal cAMP growth-stimulated phenotype, characteristic of PKD. In M-1 cells, we showed that calcium restriction was associated with an elevation in B-Raf protein levels and cAMP-stimulated, Ras-dependent activation of B-Raf and ERK. Moreover, the activity of Akt, a negative regulator of B-Raf, was decreased by calcium restriction. Inhibition of Akt or phosphatidylinositol 3-kinase also allowed cAMP-dependent activation of B-Raf and ERK in normal calcium. These results suggest that calcium restriction causes an inhibition of the phosphatidylinositol 3-kinase/Akt pathway, which relieves the inhibition of B-Raf to allow the cAMP growth-stimulated phenotypic switch. Finally, M-1 cells stably overexpressing an inducible polycystin-1 C-terminal cytosolic tail construct were shown to exhibit a cAMP growth-stimulated phenotype involving B-Raf and ERK activation, which was reversed by the calcium ionophore A23187. We conclude that disruption of calcium mobilization in cells that are normally growth-inhibited by cAMP can derepress the B-Raf/ERK pathway, thus converting these cells to a phenotype that is growth-stimulated by cAMP.
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Affiliation(s)
- Tamio Yamaguchi
- Department of Biochemistry, the Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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49
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Cronshaw DG, Owen C, Brown Z, Ward SG. Activation of Phosphoinositide 3-Kinases by the CCR4 Ligand Macrophage-Derived Chemokine Is a Dispensable Signal for T Lymphocyte Chemotaxis. THE JOURNAL OF IMMUNOLOGY 2004; 172:7761-70. [PMID: 15187160 DOI: 10.4049/jimmunol.172.12.7761] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Macrophage-derived chemokine (MDC/CC chemokine ligand 22 (CCL22)) mediates its cellular effects principally by binding to its receptor CCR4, and together they constitute a multifunctional chemokine/receptor system with homeostatic and inflammatory roles in the body. We report the CCL22-induced accumulation of phosphatidylinositol-(3,4,5)-trisphosphate (PI(3,4,5)P(3)) in the leukemic T cell line CEM. CCL22 also had the ability to chemoattract human Th2 cells and CEM cells in a pertussis toxin-sensitive manner. Although the PI(3,4,5)P(3) accumulation along with the pertussis toxin-susceptible phosphorylation of protein kinase B were sensitive to the two phosphoinositide 3-kinase inhibitors, LY294002 and wortmannin, cell migration was unaffected. However, cell migration was abrogated with the Rho-dependent kinase inhibitor, Y-27632. These data demonstrate that although there is PI(3,4,5)P(3) accumulation downstream of CCR4, phosphoinositide 3-kinase activity is a dispensable signal for CCR4-stimulated chemotaxis of Th2 cells and the CEM T cell line.
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Affiliation(s)
- Darran G Cronshaw
- Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
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50
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Chodniewicz D, Alteraifi AM, Zhelev DV. Experimental Evidence for the Limiting Role of Enzymatic Reactions in Chemoattractant-induced Pseudopod Extension in Human Neutrophils. J Biol Chem 2004; 279:24460-6. [PMID: 15051729 DOI: 10.1074/jbc.m312764200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chemoattractant-stimulated pseudopod growth in human neutrophils was used as a model system to study the rate-limiting mechanism of cytoskeleton rearrangement induced by activated G-protein-coupled receptors. Cells were activated with N-formyl-Met-Leu-Phe, and the temperature dependence of the rate of pseudopod extension was measured in the presence of pharmacological inhibitors with known mechanisms of action. Three groups of inhibitors were used: (i) inhibitors sequestering substrates involved in F-actin polymerization (latrunculin A for G-actin and cytochalasin D for actin filament-free barbed ends) or sequestering secondary messengers (PIP-binding peptide for phosphoinositide lipids); (ii) competitively binding inhibitors (Akt-inhibitor for Akt/protein kinase B); and (iii) inhibitors that reduce enzyme activity (wortmannin for phosphoinositide 3-kinase and chelerythrine for protein kinase C). The experimental data are consistent with a model in which the relative involvement of a given pathway of F-actin polymerization to the measured rate of pseudopod extension is limited by a slowest (bottleneck) reaction in the cascade of reactions involved in the overall signaling pathway. The approach we developed was used to demonstrate that chemoattractant-induced pseudopod growth and mechanically stimulated cytoskeleton rearrangement are controlled by distinct pathways of F-actin polymerization.
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Affiliation(s)
- David Chodniewicz
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708-0300, USA
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