1
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Datta C, Das P, Swaroop S, Bhattacharjee A. Rac1 plays a crucial role in MCP-1-induced monocyte adhesion and migration. Cell Immunol 2024; 401-402:104843. [PMID: 38905771 DOI: 10.1016/j.cellimm.2024.104843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/12/2024] [Accepted: 06/16/2024] [Indexed: 06/23/2024]
Abstract
Monocyte migration is an important process in inflammation and atherogenesis. Identification of the key signalling pathways that regulate monocyte migration can provide prospective targets for prophylactic treatments in inflammatory diseases. Previous research showed that the focal adhesion kinase Pyk2, Src kinase and MAP kinases play an important role in MCP-1-induced monocyte migration. In this study, we demonstrate that MCP-1 induces iPLA2 activity, which is regulated by PKCβ and affects downstream activation of Rac1 and Pyk2. Rac1 interacts directly with iPLA2 and Pyk2, and plays a crucial role in MCP-1-mediated monocyte migration by modulating downstream Pyk2 and p38 MAPK activation. Furthermore, Rac1 is necessary for cell spreading and F-actin polymerization during monocyte adhesion to fibronectin. Finally, we provide evidence that Rac1 controls the secretion of inflammatory mediator vimentin from MCP-1-stimulated monocytes. Altogether, this study demonstrates that the PKCβ/iPLA2/Rac1/Pyk2/p38 MAPK signalling cascade is essential for MCP-1-induced monocyte adhesion and migration.
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Affiliation(s)
- Chandreyee Datta
- Department of Biotechnology, National Institute of Technology, Durgapur, Mahatma Gandhi Avenue, Durgapur-713209, Burdwan, West Bengal, India
| | - Pradip Das
- Department of Biotechnology, National Institute of Technology, Durgapur, Mahatma Gandhi Avenue, Durgapur-713209, Burdwan, West Bengal, India
| | - Surbhi Swaroop
- Department of Biotechnology, National Institute of Technology, Durgapur, Mahatma Gandhi Avenue, Durgapur-713209, Burdwan, West Bengal, India
| | - Ashish Bhattacharjee
- Department of Biotechnology, National Institute of Technology, Durgapur, Mahatma Gandhi Avenue, Durgapur-713209, Burdwan, West Bengal, India.
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2
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Wang C, Zhao X, Zhao L, Wang Y, Jia Y, Zhang X, Ma W. PKCζ phosphorylates VASP to mediate chemotaxis in breast cancer cells. Exp Cell Res 2023; 433:113823. [PMID: 37890607 DOI: 10.1016/j.yexcr.2023.113823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 09/17/2023] [Accepted: 10/15/2023] [Indexed: 10/29/2023]
Abstract
Breast carcinoma (BC) is one of the most common malignant cancers in females, and metastasis remains the leading cause of death in these patients. Chemotaxis plays an important role in cancer cell metastasis and the mechanism of breast cancer chemotaxis has become a central issue in contemporary research. PKCζ, a member of the atypical PKC family, has been reported to be an essential component of the EGF-stimulated chemotactic signaling pathway. However, the molecular mechanism through which PKCζ regulates chemotaxis remains unclear. Here, we used a proteomic approach to identify PKCζ-interacting proteins in breast cancer cells and identified VASP as a potential binding partner. Intriguingly, stimulation with EGF enhanced this interaction and induced the translocalization of PKCζ and VASP to the cell membrane. Further experiments showed that PKCζ catalyzes the phosphorylation of VASP at Ser157, which is critical for the biological function of VASP in regulating chemotaxis and actin polymerization in breast cancer cells. Furthermore, in PKCζ knockdown BC cells, the enrichment of VASP at the leading edge was reduced, and its interaction with profilin1 was attenuated, thereby reducing the chemotaxis and overall motility of breast cancer cells after EGF treatment. In functional assays, PKCζ promoted chemotaxis and motility of BC cells through VASP. Our findings demonstrate that PKCζ, a new kinase of VASP, plays an important role in promoting breast cancer metastasis and provides a theoretical basis for expanding new approaches to tumor biotherapy.
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Affiliation(s)
- Chunqing Wang
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Laboratory Medicine China
| | - Xiaoqing Zhao
- Department of Clinical Laboratory Medicine, The Second Hospital, Cheeloo College of Medicine, Shandong University, 250012 Jinan, Shandong China
| | - Liqing Zhao
- Department of Pediatrics, Zaozhuang Municipal Hospital, Zaozhuang, Shandong 277000, China
| | - Yunqiu Wang
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Laboratory Medicine China
| | - Yan Jia
- Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
| | - Xiaofang Zhang
- Department of Clinical Laboratory Medicine, Tianjin Medical University General Hospital, Tianjin, China.
| | - Wanshan Ma
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Laboratory Medicine China.
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3
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Abstract
The pentapeptide L-R5 has previously been shown to transiently increase the permeability of nasal epithelial cell layers in vitro, allowing paracellular transport of molecules of up to 4 kDa. Protein kinase C zeta (PKC ζ), a member of a family of serine/threonine kinases was shown to be involved in tight junction modulation induced by L-R5. We show here that the ability of L-R5 to modulate tight junctions is comparable to other permeability enhancers such as bilobalide, latrunculin A or C10. Interaction of the peptide with the target protein occurs via electrostatic interaction, with the presence of positive charges being essential for its functionality. L-R5 is myristoylated to allow quick cell entry and onset of activity. While no epithelial cytotoxicity was detected, the hydrophobic myristoyl rest was shown to cause haemolysis. Taken together, these data show that a structural optimization of L-R5 may be possible, both from a toxicological and an efficacy point of view.
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Affiliation(s)
- Joël Brunner
- Section of Pharmaceutical Sciences, Institute of Pharmaceutical Sciences of Western Switzerland (ISPSO), University of Geneva, Switzerland
| | - Gerrit Borchard
- Section of Pharmaceutical Sciences, Institute of Pharmaceutical Sciences of Western Switzerland (ISPSO), University of Geneva, Switzerland,CONTACT Gerrit Borchard Section of Pharmaceutical Sciences, Institute of Pharmaceutical Sciences of Western Switzerland (ISPSO), University of Geneva, Switzerland
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4
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Brunner J, Schvartz D, Gouiller A, Hainard A, Borchard G. Impact of peptide permeation enhancer on tight junctions opening cellular mechanisms. Biochem Biophys Rep 2022; 32:101375. [PMID: 36324528 PMCID: PMC9618981 DOI: 10.1016/j.bbrep.2022.101375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 10/03/2022] [Accepted: 10/24/2022] [Indexed: 11/09/2022] Open
Abstract
The myristoylated pentapeptide, L-R5, contains an amino acid sequence of the zeta inhibitory peptide (ZIP) portion (pseudosubstrate) of protein kinase C zeta (PKC ζ). As PKC ζ is involved in the modulation of epithelial tight junctions (TJs) through the phosphorylation of TJ proteins, L-R5 was suggested to interact with the enzyme resulting in the enhancement of paracellular permeability. This study shows that L-R5 does not bind to the enzyme but interacts directly with TJ proteins. We show here that the binding of PKC ζ to occludin and its successive phosphorylation is prevented by L-R5, which leads to TJ disruption and enhanced epithelial permeability. Although L-R5 did not show any in vitro cytotoxicity, a proteomics study revealed that L-R5 interferes with other regulatory pathways, e.g., apoptosis and immune response. We suggest that structural modification of the peptide may increase the specificity TJ protein-peptide interaction. Microscale thermophoresis (MST) showed robust results for protein bindings. The competitivity of L-R5 peptide for the binding of occludin-PKC zeta was shown. Tight junctions proteins expression was decreased due to L-R5 peptide. Multiple other mechanisms can be explored to use L-R5 for other therapies.
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Affiliation(s)
- Joël Brunner
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
| | - Domitille Schvartz
- Proteomics Core Facility, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Aurélie Gouiller
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
| | - Alexandre Hainard
- Proteomics Core Facility, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Gerrit Borchard
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland,Corresponding author.
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5
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Damascena HL, Silveira WAA, Castro MS, Fontes W. Neutrophil Activated by the Famous and Potent PMA (Phorbol Myristate Acetate). Cells 2022; 11:2889. [PMID: 36139464 PMCID: PMC9496763 DOI: 10.3390/cells11182889] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 08/28/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
This review will briefly outline the major signaling pathways in PMA-activated neutrophils. PMA is widely used to understand neutrophil pathways and formation of NETs. PMA activates PKC; however, we highlight some isoforms that contribute to specific functions. PKC α, β and δ contribute to ROS production while PKC βII and PKC ζ are involved in cytoskeleton remodeling. Actin polymerization is important for the chemotaxis of neutrophils and its remodeling is connected to ROS balance. We suggest that, although ROS and production of NETs are usually observed together in PMA-activated neutrophils, there might be a regulatory mechanism balancing both. Interestingly, we suggest that serine proteases might determine the PAD4 action. PAD4 could be responsible for the activation of the NF-κB pathway that leads to IL-1β release, triggering the cleavage of gasdermin D by serine proteases such as elastase, leading to pore formation contributing to release of NETs. On the other hand, when serine proteases are inhibited, NETs are formed by citrullination through the PAD4 pathway. This review puts together results from the last 31 years of research on the effects of PMA on the neutrophil and proposes new insights on their interpretation.
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Affiliation(s)
| | | | | | - Wagner Fontes
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Federal District, Brasilia 70910-900, Brazil
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6
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Unraveling the hidden role of a uORF-encoded peptide as a kinase inhibitor of PKCs. Proc Natl Acad Sci U S A 2021; 118:2018899118. [PMID: 34593629 PMCID: PMC8501901 DOI: 10.1073/pnas.2018899118] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2021] [Indexed: 02/01/2023] Open
Abstract
Approximately 40% of human messenger RNAs (mRNAs) contain upstream open reading frames (uORFs) in their 5' untranslated regions. Some of these uORF sequences, thought to attenuate scanning ribosomes or lead to mRNA degradation, were recently shown to be translated, although the function of the encoded peptides remains unknown. Here, we show a uORF-encoded peptide that exhibits kinase inhibitory functions. This uORF, upstream of the protein kinase C-eta (PKC-η) main ORF, encodes a peptide (uPEP2) containing the typical PKC pseudosubstrate motif present in all PKCs that autoinhibits their kinase activity. We show that uPEP2 directly binds to and selectively inhibits the catalytic activity of novel PKCs but not of classical or atypical PKCs. The endogenous deletion of uORF2 or its overexpression in MCF-7 cells revealed that the endogenously translated uPEP2 reduces the protein levels of PKC-η and other novel PKCs and restricts cell proliferation. Functionally, treatment of breast cancer cells with uPEP2 diminished cell survival and their migration and synergized with chemotherapy by interfering with the response to DNA damage. Furthermore, in a xenograft of MDA-MB-231 breast cancer tumor in mice models, uPEP2 suppressed tumor progression, invasion, and metastasis. Tumor histology showed reduced proliferation, enhanced cell death, and lower protein expression levels of novel PKCs along with diminished phosphorylation of PKC substrates. Hence, our study demonstrates that uORFs may encode biologically active peptides beyond their role as translation regulators of their downstream ORFs. Together, we point to a unique function of a uORF-encoded peptide as a kinase inhibitor, pertinent to cancer therapy.
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7
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Polymorphonuclear Cell Chemotaxis and Suicidal NETosis: Simultaneous Observation Using fMLP, PMA, H7, and Live Cell Imaging. J Immunol Res 2020; 2020:1415947. [PMID: 32879894 PMCID: PMC7448108 DOI: 10.1155/2020/1415947] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/19/2020] [Accepted: 07/25/2020] [Indexed: 12/19/2022] Open
Abstract
Chemotaxis and the formation of suicidal neutrophil extracellular traps (suicidal NETosis) are key functions of polymorphonuclear cells (PMNs). Neutrophil extracellular traps in particular are known to be significantly involved in the severity of inflammatory and immunological disorders such as rheumatoid arthritis and Crohn's disease. Therefore, detailed knowledge of PMNs is essential for analyzing the mechanisms involved in, and developing new therapies for, such diseases. To date, no standard method to analyze these cell activities has been established. This study used in vitro live cell imaging to simultaneously observe and analyze PMN functions. To demonstrate this, the effects of phorbol-12-myristat-13-acetat (PMA, 0.1-10 nM), N-formylmethionine-leucyl-phenylalanine (fMLP, 10 nM), and protein kinase C inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H7) on PMN chemotaxis and suicidal NETosis were studied. PMA (1 nM-10 nM) resulted in significant concentration-dependent behavior in chemotaxis and an earlier onset of maximum oxidative burst and NET formation of up to 44%. When adding H7, PMA-triggered PMN functions were reduced, demonstrating that all three functions rely mostly on protein kinase C (PKC) activity, while PKC is not essential for fMLP-induced PMN activity. Thus, the method here described can be used to objectively quantify PMN functions and, especially through the regulation of the PKC pathway, could be useful in further clinical studies of immunological disorders.
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8
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Zeta Inhibitory Peptide attenuates learning and memory by inducing NO-mediated downregulation of AMPA receptors. Nat Commun 2020; 11:3688. [PMID: 32703948 PMCID: PMC7378180 DOI: 10.1038/s41467-020-17484-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/02/2020] [Indexed: 02/07/2023] Open
Abstract
Zeta inhibitory peptide (ZIP), a PKMζ inhibitor, is widely used to interfere with the maintenance of acquired memories. ZIP is able to erase memory even in the absence of PKMζ, via an unknown mechanism. We found that ZIP induces redistribution of the AMPARGluA1 in HEK293 cells and primary cortical neurons, and decreases AMPAR-mediated currents in the nucleus accumbens (NAc). These effects were mimicked by free arginine or by a modified ZIP in which all but the arginine residues were replaced by alanine. Redistribution was blocked by a peptidase-resistant version of ZIP and by treatment with the nitric oxide (NO)-synthase inhibitor L-NAME. ZIP increased GluA1-S831 phosphorylation and ZIP-induced redistribution was blocked by nitrosyl-mutant GluA1-C875S or serine-mutant GluA1-S831A. Introducing the cleavable arginine-alanine peptide into the NAc attenuated expression of cocaine-conditioned reward. Together, these results suggest that ZIP may act as an arginine donor, facilitating NO-dependent downregulation of AMPARs, thereby attenuating learning and memory. Zeta inhibitory peptide (ZIP) impairs the maintenance of acquired memories. ZIP is known as an inhibitor of PKMζ. Here, the authors unveil how ZIP impairs memory maintenance acting as an arginine donor, facilitating NO-dependent down-regulation of AMPARs, independently of its action on PKMζ.
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9
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Wu J, Rowart P, Jouret F, Gassaway BM, Rajendran V, Rinehart J, Caplan MJ. Mechanisms involved in AMPK-mediated deposition of tight junction components to the plasma membrane. Am J Physiol Cell Physiol 2020; 318:C486-C501. [PMID: 31913699 DOI: 10.1152/ajpcell.00422.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
AMP-activated protein kinase (AMPK) activation promotes early stages of epithelial junction assembly. AMPK activation in MDCK renal epithelial cells facilitates localization of the junction-associated proteins aPKCζ and Par3 to the plasma membrane and promotes conversion of Cdc42, a key regulator of epithelial polarization and junction assembly, to its active GTP bound state. Furthermore, Par3 is an important regulator of AMPK-mediated aPKCζ localization. Both aPKCζ and Par3 serve as intermediates in AMPK-mediated junction assembly, with inhibition of aPKCζ activity or Par3 knockdown disrupting AMPK's ability to facilitate zonula occludens (ZO-1) localization. AMPK phosphorylates the adherens junction protein afadin and regulates its interaction with the tight-junction protein zonula occludens-1. Afadin is phosphorylated at two critical sites, S228 (residing within an aPKCζ consensus site) and S1102 (residing within an AMPK consensus site), that are differentially regulated during junction assembly and that exert different effects on the process. Expression of phospho-defective mutants (S228A and S1102A) perturbed ZO-1 localization to the plasma membrane during AMPK-induced junction assembly. Expression of S228A increased the ZO-1/afadin interaction, while S1102A reduced this interaction during extracellular calcium-induced junction assembly. Inhibition of aPKCζ activity also increased the ZO-1/afadin interaction. Taken together, these data suggest that aPKCζ phosphorylation of afadin terminates the ZO-1/afadin interaction and thus permits the later stages of junction assembly.
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Affiliation(s)
- Jingshing Wu
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut
| | - Pascal Rowart
- Groupe Interdisciplinaire de Génoprotéomique Appliquée, Cardiovascular Sciences, University of Liège, Liège, Belgium
| | - Francois Jouret
- Groupe Interdisciplinaire de Génoprotéomique Appliquée, Cardiovascular Sciences, University of Liège, Liège, Belgium
| | - Brandon M Gassaway
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut.,Systems Biology Institute, Yale University, West Haven, Connecticut
| | - Vanathy Rajendran
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut
| | - Jesse Rinehart
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut.,Systems Biology Institute, Yale University, West Haven, Connecticut
| | - Michael J Caplan
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut
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10
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TLR4 counteracts BVRA signaling in human leukocytes via differential regulation of AMPK, mTORC1 and mTORC2. Sci Rep 2019; 9:7020. [PMID: 31065010 PMCID: PMC6504875 DOI: 10.1038/s41598-019-43347-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 04/16/2019] [Indexed: 12/30/2022] Open
Abstract
TLR4 is implicated in diseases associated with chronic low-grade inflammation, yet homeostatic signaling mechanisms that prevent and/or are affected by chronic TLR4 activation are largely uncharacterized. We recently reported that LPS/TLR4 activates in human leukocytes signaling intermediates (SI), abbreviated TLR4-SI, which include mTORC1-specific effectors and targets, and that leukocytes of patients with T2D or after cardiopulmonary bypass (CPB) expressed similar SI. Extending these previous findings, here we show that TLR4-SI expression post-CPB was associated with low serum bilirubin and reduced preoperative expression of biliverdin reductase A (BVRA), the enzyme that converts biliverdin to bilirubin, in patient’s leukocytes. Biliverdin inhibited TLR4 signaling in leukocytes and triggered phosphorylation of mTORC2-specific targets, including Akt, PKCζ, AMPKα-LKB1-TSC1/2, and their association with BVRA. Torin, PP242, and a PKCζ inhibitory peptide, but not rapamycin, prevented these biliverdin-induced responses and TLR4 inhibition. In contrast, LPS/TLR4 triggered decreases in BVRA, AMPKα and PKCζ expression, and an increase in haptoglobin, a heme binding protein, in leukocytes in vivo and in vitro, indicating that activated TLR4 may suppress biliverdin/BVRA signaling. Significantly, compared to non-diabetics, BVRA and PKCζ expression was low and haptoglobin was high in T2D patients leukocytes. Sustained TLR4 activation may deregulate homeostatic anti-inflammatory BVRA/mTORC2 signaling and thereby contribute to chronic inflammatory diseases.
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11
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Hou C, Li Y, Liu H, Dang M, Qin G, Zhang N, Chen R. Profiling the interactome of protein kinase C ζ by proteomics and bioinformatics. Proteome Sci 2018; 16:5. [PMID: 29491746 PMCID: PMC5828088 DOI: 10.1186/s12953-018-0134-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 02/11/2018] [Indexed: 11/10/2022] Open
Abstract
Background Protein kinase C ζ (PKCζ), an isoform of the atypical protein kinase C, is a pivotal regulator in cancer. However, the molecular and cellular mechanisms whereby PKCζ regulates tumorigenesis and metastasis are still not fully understood. In this study, proteomics and bioinformatics analyses were performed to establish a protein-protein interaction (PPI) network associated with PKCζ, laying a stepping stone to further understand the diverse biological roles of PKCζ. Methods Protein complexes associated with PKCζ were purified by co-immunoprecipitation from breast cancer cell MDA-MB-231 and identified by LC-MS/MS. Two biological replicates and two technical replicates were analyzed. The observed proteins were filtered using the CRAPome database to eliminate the potential false positives. The proteomics identification results were combined with PPI database search to construct the interactome network. Gene ontology (GO) and pathway analysis were performed by PANTHER database and DAVID. Next, the interaction between PKCζ and protein phosphatase 2 catalytic subunit alpha (PPP2CA) was validated by co-immunoprecipitation, Western blotting and immunofluorescence. Furthermore, the TCGA database and the COSMIC database were used to analyze the expressions of these two proteins in clinical samples. Results The PKCζ centered PPI network containing 178 nodes and 1225 connections was built. Network analysis showed that the identified proteins were significantly associated with several key signaling pathways regulating cancer related cellular processes. Conclusions Through combining the proteomics and bioinformatics analyses, a PKCζ centered PPI network was constructed, providing a more complete picture regarding the biological roles of PKCζ in both cancer regulation and other aspects of cellular biology. Electronic supplementary material The online version of this article (10.1186/s12953-018-0134-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chunyu Hou
- 1Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin, 300070 China.,2Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, 300070 China
| | - Yuan Li
- 1Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin, 300070 China.,2Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, 300070 China
| | - Huiqin Liu
- 1Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin, 300070 China.,2Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, 300070 China
| | - Mengjiao Dang
- 3School of Microelectronics, Tianjin University, Tianjin, 300072 China
| | - Guoxuan Qin
- 3School of Microelectronics, Tianjin University, Tianjin, 300072 China
| | - Ning Zhang
- 1Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin, 300070 China.,2Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, 300070 China
| | - Ruibing Chen
- 1Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin, 300070 China.,2Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, 300070 China
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12
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Ko YE, Yoon SY, Ly SY, Kim JH, Sohn KY, Kim JW. 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) reduces hepatic injury in concanavalin A-treated mice. J Cell Biochem 2017; 119:1392-1405. [PMID: 28749086 DOI: 10.1002/jcb.26299] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 07/18/2017] [Indexed: 11/10/2022]
Abstract
1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG), a chemically synthesized monoacetyldiaglyceride, is one of the constituents in Sika deer antlers and has been known traditionally as having immunomodulatory effects. However, the mechanism by which PLAG controls neutrophil migration, which evokes liver injury in the hepatitis animal model, remains largely unknown. This study was designed to evaluate the immunomodulatory effects of PLAG on cytokine secretion and neutrophil migration in vivo and in vitro. Concanavalin A (Con A) induced leukocyte infiltration in the liver and increased plasma cytokine levels. Pretreatment with PLAG reduced the levels of interleukin (IL)-4, IL-6, IL-10, and CXCL2, but maintained interferon (IFN)-γ levels and modulated neutrophil recruitment toward the liver. Furthermore, the mRNA and protein levels of IL-4 and CXCL2 in liver tissue were also decreased in the Con A-treated mice. Liver histology analyses showed that PLAG reduced Con A-induced hepatic necrosis, which was accompanied by leukocyte infiltration. The in vitro studies revealed that PLAG reduced IL-4 secretion in Con A stimulated T cell and blocked signal transducer and activator of transcription 6 (STAT6) Con A induced hepatocyte. PLAG attenuated IL-4 induced activation of atypical protein kinase C (PKC)/STAT6 in hepatocytes and inhibited neutrophil migration toward the liver tissue through suppression of IL-8/vascular cell adhesion molecule (VCAM) expression. These results suggest that PLAG could mitigate excess neutrophil migration into liver tissue and potentially have a therapeutic effect on immune-mediated liver injury.
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Affiliation(s)
- Young E Ko
- Cell Factory Research Center, Division of Systems Biology and Bioengineering, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea.,Department of Food and Nutrition, Chungnam National University, Daejeon, Republic of Korea
| | - Sun Y Yoon
- Division of Global New Drug Development, ENZYCHEM Lifesciences, Daejeon, Korea
| | - Sun Y Ly
- Department of Food and Nutrition, Chungnam National University, Daejeon, Republic of Korea
| | - Joo H Kim
- Department of Pathology, EulJi University School of Medicine, Daejeon, Republic of Korea
| | - Ki Y Sohn
- Division of Global New Drug Development, ENZYCHEM Lifesciences, Daejeon, Korea
| | - Jae W Kim
- Cell Factory Research Center, Division of Systems Biology and Bioengineering, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
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13
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FAK phosphorylation plays a central role in thrombin-induced RPE cell migration. Cell Signal 2017; 36:56-66. [DOI: 10.1016/j.cellsig.2017.04.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 04/21/2017] [Accepted: 04/22/2017] [Indexed: 02/06/2023]
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14
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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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15
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Buonfiglio LGV, Bagegni M, Borcherding JA, Sieren JC, Caraballo JC, Reger A, Zabner J, Li X, Comellas AP. Protein Kinase Cζ Inhibitor Promotes Resolution of Bleomycin-Induced Acute Lung Injury. Am J Respir Cell Mol Biol 2017; 55:869-877. [PMID: 27486964 DOI: 10.1165/rcmb.2015-0006oc] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Protein kinase Cζ (PKCζ) is highly expressed in the lung, where it plays several regulating roles in the pathogenesis of acute lung injury (ALI). Proliferation and differentiation of integrin β4+ distal lung epithelial progenitor cells seem to play a key role in proper lung regeneration. We investigated the effects of a myristoylated PKCζ inhibitor (PKCζi) in a murine model of bleomycin-induced ALI. After intratracheal injury, we treated mice three times a week with PKCζi or its vehicle, DMSO. We found that mice injured with bleomycin and then treated with PKCζi for one week showed decreased activation of PKCζ, improved lung compliance, and decreased lung protein permeability compared to injured mice treated with DMSO. Mice treated continuously with PKCζi for 6 weeks showed reduced evidence of lung fibrosis by computed tomographic images, decreased lung collagen deposition, and decreased active transforming growth factor-β in the bronchoalveolar lavage fluid. In addition, we found an increased number of lung β4+ cells compared to DMSO at Week 6. Therefore, we grew isolated integrin β4+ lung progenitor cells in the presence of PKCζi or DMSO and found that β4+ cells treated with PKCζi proliferated more in vitro compared to DMSO. We conclude that the use of a PKCζi promotes resolution of lung fibrosis in a bleomycin ALI model and increases the number of β4+ progenitor cells with regenerative potential in the lung.
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Affiliation(s)
- Luis G Vargas Buonfiglio
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Mosaab Bagegni
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Jennifer A Borcherding
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | | | - Juan C Caraballo
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Andrew Reger
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Joseph Zabner
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Xiaopeng Li
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Alejandro P Comellas
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
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In Vitro Neutrophil Migration Requires Protein Kinase C-Delta (δ-PKC)-Mediated Myristoylated Alanine-Rich C-Kinase Substrate (MARCKS) Phosphorylation. Inflammation 2016; 38:1126-41. [PMID: 25515270 DOI: 10.1007/s10753-014-0078-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Dysregulated release of neutrophil reactive oxygen species and proteolytic enzymes contributes to both acute and chronic inflammatory diseases. Therefore, molecular regulators of these processes are potential targets for new anti-inflammatory therapies. We have shown previously that myristoylated alanine-rich C-kinase substrate (MARCKS), a well-known actin binding protein and protein kinase C (PKC) substrate, is a key regulator of neutrophil functions. In the current study, we investigate the role of PKC-mediated MARCKS phosphorylation in neutrophil migration and adhesion in vitro. We report that treatment of human neutrophils with the δ-PKC inhibitor rottlerin significantly attenuates f-Met-Leu-Phe (fMLF)-induced MARCKS phosphorylation (IC50=5.709 μM), adhesion (IC50=8.4 μM), and migration (IC50=6.7 μM), while α-, β-, and ζ-PKC inhibitors had no significant effect. We conclude that δ-PKC-mediated MARCKS phosphorylation is essential for human neutrophil migration and adhesion in vitro. These results implicate δ-PKC-mediated MARCKS phosphorylation as a key step in the inflammatory response of neutrophils.
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17
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Wu J, Liu S, Fan Z, Zhang L, Tian Y, Yang R. A novel and selective inhibitor of PKC ζ potently inhibits human breast cancer metastasis in vitro and in mice. Tumour Biol 2016; 37:8391-401. [DOI: 10.1007/s13277-015-4744-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 12/27/2015] [Indexed: 12/16/2022] Open
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Zeta Inhibitory Peptide, a Candidate Inhibitor of Protein Kinase Mζ, Is Excitotoxic to Cultured Hippocampal Neurons. J Neurosci 2015; 35:12404-11. [PMID: 26354909 DOI: 10.1523/jneurosci.0976-15.2015] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The ζ-inhibitory peptide (ZIP) is considered a candidate inhibitor of the atypical protein kinase Mζ (PKMζ). ZIP has been shown to reverse established LTP and disrupt several forms of long-term memory. However, recent studies have challenged the specificity of ZIP, as it was reported to exert its effect also in PKMζ knock-out mice. These results raise the question of what are the targets of ZIP that may underlie its effect on LTP and memory. Here we report that ZIP as well as its inactive analog, scrambled ZIP, induced a dose-dependent increase in spontaneous activity of neurons in dissociated cultures of rat hippocampus. This was followed by a sustained elevation of intracellular calcium concentration ([Ca(2+)]i) which could not be blocked by conventional channel blockers. Furthermore, ZIP caused an increase in frequency of mEPSCs followed by an increase in membrane noise in patch-clamped neurons both in culture and in acute brain slices. Finally, at 5-10 μM, ZIP-induced excitotoxic death of the cultured neurons. Together, our results suggest that the potential contribution of cellular toxicity should be taken into account in interpretation of ZIP's effects on neuronal and behavioral plasticity. Significance statement: The ζ-inhibitory peptide (ZIP) is considered a candidate inhibitor of the atypical protein kinase Mζ (PKMζ). ZIP has been shown to reverse established LTP and disrupt several forms of long-term memory. Here we report that ZIP as well as its inactive analog, scrambled ZIP, induced a dose-dependent increase in spontaneous activity of neurons in dissociated cultures and brain slices of rat hippocampus. Furthermore, ZIP caused a dose- and time-dependent neuronal death in the dissociated cultures. These findings impact on the assumption that ZIP erases memory due to specific inhibition of PKMz.
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19
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Tamoxifen augments the innate immune function of neutrophils through modulation of intracellular ceramide. Nat Commun 2015; 6:8369. [PMID: 26458291 PMCID: PMC4610010 DOI: 10.1038/ncomms9369] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Accepted: 08/13/2015] [Indexed: 02/06/2023] Open
Abstract
Tamoxifen is a selective estrogen receptor modulator widely used for the treatment of breast cancer. In addition to its activity as an estrogen receptor agonist/antagonist, tamoxifen also modulates sphingolipid biosynthesis, which has been shown to play an important role in the regulation of neutrophil activity. Here, we find that tamoxifen stimulation enhances several pro-inflammatory pathways in human neutrophils, including chemotaxis, phagocytosis and neutrophil extracellular trap (NET) formation. The enhancement of NET production occurs via a ceramide/PKCζ-mediated pathway, and treatment with synthetic ceramide is sufficient to promote NET formation. Pretreatment of human neutrophils with tamoxifen boosts neutrophil bactericidal capacity against a variety of pathogens in vitro and enhances clearance of the leading human pathogen methicillin-resistant Staphylococcus aureus in vivo. Our results suggest that tamoxifen, and the lipid signaling pathways it modulates, merit further exploration as targets for boosting host innate immune function.
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20
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Chow LH, Tao PL, Chen YH, Lin YH, Huang EYK. Angiotensin IV possibly acts through PKMzeta in the hippocampus to regulate cognitive memory in rats. Neuropeptides 2015; 53:1-10. [PMID: 26412453 DOI: 10.1016/j.npep.2015.09.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 08/10/2015] [Accepted: 09/10/2015] [Indexed: 10/23/2022]
Abstract
Ang IV is an endogenous peptide generated from the degradation of angiotensin II. Ang IV was found to enhance learning and memory in CNS. PKMzeta was identified to be a fragment of PKCzeta (protein kinase Czeta). Its continuous activation was demonstrated to be correlated with the formation of memory in the hippocampus. Therefore, we investigated whether PKMzeta participates in the effects of Ang IV on memory. We first examined the effect of Ang IV on non-spatial memory/cognition in modified object recognition test in rats. Our data showed that Ang IV could increase the exploration time on novel object. The co-administration of ZIP (PKMzeta inhibitor) with Ang IV significantly blocked the effect by Ang IV. The effects of Ang IV on hippocampal LTP at the CA1 region were also evaluated. Ang IV significantly increased the amplitude and slope of the EPSPs, which was consistent with other reports. Surprisingly, instead of potentiating LTP, Ang IV caused a failed maintenance of LTP. Moreover, there was no quantitative change in PKMzeta induced by Ang IV and/or ZIP after behavioral experiments. Taken together, our data re-confirmed the finding of the positive effect of Ang IV to enhance memory/cognition. The increased strength of EPSPs with Ang IV could also have certain functional relevance. Since the behavioral results suggested the involvement of PKMzeta, we hypothesized that the enhancement of memory/cognition by Ang IV may rely on an increase in PKMzeta activity. Overall, the present study provided important advances in our understanding of the action of Ang IV in the hippocampus.
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Affiliation(s)
- Lok-Hi Chow
- Department of Pharmacology, National Defense Medical Center, Nei-Hu, 114 Taipei, Taiwan, ROC; Department of Anesthesiology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Department of Anesthesiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan, ROC
| | - Pao-Luh Tao
- Center for Neuropsychiatric Research, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County 350, Taiwan, ROC
| | - Yuan-Hao Chen
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Nei-Hu, 114 Taipei, Taiwan, ROC
| | - Yu-Hui Lin
- Department of Pharmacology, National Defense Medical Center, Nei-Hu, 114 Taipei, Taiwan, ROC
| | - Eagle Yi-Kung Huang
- Department of Pharmacology, National Defense Medical Center, Nei-Hu, 114 Taipei, Taiwan, ROC.
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21
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C6-ceramide nanoliposome suppresses tumor metastasis by eliciting PI3K and PKCζ tumor-suppressive activities and regulating integrin affinity modulation. Sci Rep 2015; 5:9275. [PMID: 25792190 PMCID: PMC4366857 DOI: 10.1038/srep09275] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 02/02/2015] [Indexed: 01/07/2023] Open
Abstract
Nanoliposomal formulation of C6-ceramide, a proapoptotic sphingolipid metabolite, presents an effective way to treat malignant tumor. Here, we provide evidence that acute treatment (30 min) of melanoma and breast cancer cells with nanoliposomal C6-ceramide (NaL-C6) may suppress cell migration without inducing cell death. By employing a novel flow migration assay, we demonstrated that NaL-C6 decreased tumor extravasation under shear conditions. Compared with ghost nanoliposome, NaL-C6 triggered phosphorylation of PI3K and PKCζ and dephosphorylation of PKCα. Concomitantly, activated PKCζ translocated into cell membrane. siRNA knockdown or pharmacological inhibition of PKCζ or PI3K rescued NaL-C6-mediated suppression of tumor migration. By inducing dephosphorylation of paxillin, PKCζ was responsible for NaL-C6-mediated stress fiber depolymerization and focal adhesion disassembly in the metastatic tumor cells. PKCζ and PI3K regulated cell shear-resistant adhesion in a way that required integrin αvβ3 affinity modulation. In conclusion, we identified a novel role of acute nanoliposomal ceramide treatment in reducing integrin affinity and inhibiting melanoma metastasis by conferring PI3K and PKCζ tumor-suppressive activities.
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22
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Lu R, Dalgalan D, Mandell EK, Parker SS, Ghosh S, Wilson JM. PKCι interacts with Rab14 and modulates epithelial barrier function through regulation of claudin-2 levels. Mol Biol Cell 2015; 26:1523-31. [PMID: 25694446 PMCID: PMC4395131 DOI: 10.1091/mbc.e14-12-1613] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 02/10/2015] [Indexed: 01/03/2023] Open
Abstract
PKCι is essential for the establishment of epithelial polarity and the normal assembly of tight junctions. We find that PKCι knockdown does not compromise the steady-state distribution of most tight junction proteins but results in increased transepithelial resistance (TER) and decreased paracellular permeability. Analysis of the levels of tight junction components demonstrates that claudin-2 protein levels are decreased. However, other tight junction proteins, such as claudin-1, ZO-1, and occludin, are unchanged. Incubation with an aPKC pseudosubstrate recapitulates the phenotype of PKCι knockdown, including increased TER and decreased levels of claudin-2. In addition, overexpression of PKCι results in increased claudin-2 levels. ELISA and coimmunoprecipitation show that the TGN/endosomal small GTPase Rab14 and PKCι interact directly. Immunolabeling shows that PKCι and Rab14 colocalize in both intracellular puncta and at the plasma membrane and that Rab14 expression is required for normal PKCι distribution in cysts in 3D culture. We showed previously that knockdown of Rab14 results in increased TER and decreased claudin-2. Our results suggest that Rab14 and aPKC interact to regulate trafficking of claudin-2 out of the lysosome-directed pathway.
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Affiliation(s)
- Ruifeng Lu
- Department of Cellular and Molecular Medicine, University of Arizona College of Medicine, Tucson, AZ 85724
| | - Dogukan Dalgalan
- Department of Cellular and Molecular Medicine, University of Arizona College of Medicine, Tucson, AZ 85724
| | - Edward K Mandell
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06511
| | - Sara S Parker
- Department of Cellular and Molecular Medicine, University of Arizona College of Medicine, Tucson, AZ 85724
| | - Sourav Ghosh
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06511
| | - Jean M Wilson
- Department of Cellular and Molecular Medicine, University of Arizona College of Medicine, Tucson, AZ 85724
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23
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Deng Z, Lubinski AJ, Page TL. Zeta inhibitory peptide (ZIP) erases long-term memories in a cockroach. Neurobiol Learn Mem 2014; 118:89-95. [PMID: 25434819 DOI: 10.1016/j.nlm.2014.11.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/11/2014] [Accepted: 11/21/2014] [Indexed: 12/20/2022]
Abstract
Recent efforts to identify the molecules that are involved in the maintenance of long-term memories in mammals have focused attention on atypical isoforms of protein kinase C (PKC). Inhibition of these kinases by either the general PKC inhibitor, chelerythrine, or the more specific inhibitor, zeta inhibitory peptide (ZIP), can abolish both long-term potentiation in the hippocampus and as well as spatial, fear, appetitive, and sensorimotor memories. These inhibitors can also abolish long-term facilitation and long-term sensitization in the mollusk Aplysia californica. We have extended these results to an insect, the cockroach Leucophaea maderae. We show that systemic injections of either chelerythrine or ZIP erase long-term olfactory memories in the cockroach, but have no effect on memory acquisition during conditioning. We also show that inhibition of either protein kinase A (PKA) or protein synthesis can block memory acquisition but neither has an effect on the memory once it is formed. The results suggest that sustaining memories in insects requires the persistent activity of one or more isoforms of PKC and point to a strong evolutionary conservation of the molecular mechanisms that underlie the persistence of long-term memories in the central nervous system.
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Affiliation(s)
- Zhouheng Deng
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, United States
| | - Alexander J Lubinski
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, United States
| | - Terry L Page
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, United States.
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24
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Lin CY, Zu CH, Yang CC, Tsai PJ, Shyu JF, Chen CP, Weng ZC, Chen TH, Wang HS. IL-1β-Induced Mesenchymal Stem Cell Migration Involves MLCK Activation via PKC Signaling. Cell Transplant 2014; 24:2011-28. [PMID: 25333338 DOI: 10.3727/096368914x685258] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Mesenchymal stem cells (MSCs) migrate via the bloodstream to sites of injury, possibly attracted by inflammatory cytokines. Although many cytokines can induce stem cell migration, the underlying mechanism is not fully understood. We found that tail vein-injected MSCs migrate to the pancreas in nonobese diabetic (NOD) mice. An ELISA assay revealed that hyperglycemic NOD mice have higher pancreatic levels of interleukin-1β (IL-1β) than normal NOD mice and that IL-1β stimulates MSC migration in a Transwell assay and electric cell-substrate impedance sensing system. Microarray analysis showed that myosin light chain kinase (MLCK) is involved in IL-1β-induced MSC migration, while Western blots showed that IL-1β stimulates MLCK expression and activation and that MLCK-siRNA transfection reduces MSC migration. Kinase inhibitors, chromatin immunoprecipitation, and a knockdown study revealed that IL-1β-induced MLCK expression is regulated by the PKCδ/NF-κB signaling pathway, and a kinase inhibitor study revealed that IL-1β-induced MLCK activation occurs via the PKCα/MEK/ERK signaling pathway. These results show that IL-1β released from the pancreas of hyperglycemic NOD mice induces MSC migration and that this is dependent on MLCK expression via the PKCδ/NF-κB pathway and on MLCK activation via the PKCα/MEK/ERK signaling cascade. This study increases our understanding of the mechanisms by which MSCs home to injury sites.
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Affiliation(s)
- Cheng-Yu Lin
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang Ming University, Taipei, Taiwan
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25
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An K, Zhen C, Liu ZH, Zhao Q, Liu HP, Zhong XL, Huang WQ. Spinal protein kinase Mζ contributes to the maintenance of peripheral inflammation-primed persistent nociceptive sensitization after plantar incision. Eur J Pain 2014; 19:39-47. [PMID: 24782097 DOI: 10.1002/ejp.517] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2014] [Indexed: 11/12/2022]
Abstract
BACKGROUND Previous studies suggest that persistent post-surgical pain (PPSP) is correlated with preoperative pain status and amplification of central sensitization. Protein kinase Mζ (PKMζ) is an essential substrate of the late long-term potentiation underlying central sensitization, which is one mechanism of pain memory formation. However, the potential contributions of spinal PKMζ to PPSP, a condition in which preoperative pain is prevalent, are not known. METHODS Here, a modified 'hyperalgesia priming' model was established to simulate the clinical situation. This model used intraplantar injections of carrageenan (Car) as priming stimuli to elicit persistent nociceptive sensitization after plantar incision in rats. Upon treatment with PKMζ inhibitor ZIP, Scr-ZIP or protein kinase Cs (PKCs) inhibitor NPC-15437, altered behaviour and spinal PKMζ/PKCs expression were observed. RESULTS A long-lasting hypersensitivity induced by Car-priming was identified and precipitated by subsequent plantar incision in this 'two-hit' paradigm. Post-treatment with ZIP, but not Scr-ZIP and NPC-15437, after the resolution of Car-priming selectively relieved hypersensitivity. In contrast, pre-priming NPC-15437 treatment only prevented Car-induced initial transient hyperalgesia. Immunoassays showed a significant decrease in spinal PKMζ expression after plantar incision with post-priming ZIP treatment as compared with Scr-ZIP and NPC-15437, but no notable differences in PKCs expression were observed. CONCLUSIONS Spinal PKCs solely contribute to the initial induction of persistent pain, whereas PKMζ plays an essential role in spinal plasticity storage. PKMζ is responsible for the maintenance of peripheral inflammation-primed PPSP. Therefore, spinal PKMζ may be a therapeutic target to prevent surgery-induced chronic pain in patients with preoperative pain.
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Affiliation(s)
- K An
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
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26
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Monturiol-Gross L, Flores-Díaz M, Pineda-Padilla MJ, Castro-Castro AC, Alape-Giron A. Clostridium perfringens phospholipase C induced ROS production and cytotoxicity require PKC, MEK1 and NFκB activation. PLoS One 2014; 9:e86475. [PMID: 24466113 PMCID: PMC3900566 DOI: 10.1371/journal.pone.0086475] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 12/11/2013] [Indexed: 02/07/2023] Open
Abstract
Clostridium perfringens phospholipase C (CpPLC), also called α-toxin, is the most toxic extracellular enzyme produced by this bacteria and is essential for virulence in gas gangrene. At lytic concentrations, CpPLC causes membrane disruption, whereas at sublytic concentrations this toxin causes oxidative stress and activates the MEK/ERK pathway, which contributes to its cytotoxic and myotoxic effects. In the present work, the role of PKC, ERK 1/2 and NFκB signalling pathways in ROS generation induced by CpPLC and their contribution to CpPLC-induced cytotoxicity was evaluated. The results demonstrate that CpPLC induces ROS production through PKC, MEK/ERK and NFκB pathways, the latter being activated by the MEK/ERK signalling cascade. Inhibition of either of these signalling pathways prevents CpPLC's cytotoxic effect. In addition, it was demonstrated that NFκB inhibition leads to a significant reduction in the myotoxicity induced by intramuscular injection of CpPLC in mice. Understanding the role of these signalling pathways could lead towards developing rational therapeutic strategies aimed to reduce cell death during a clostridialmyonecrosis.
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Affiliation(s)
- Laura Monturiol-Gross
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Marietta Flores-Díaz
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Maria Jose Pineda-Padilla
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | | | - Alberto Alape-Giron
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
- Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San José, Costa Rica
- Centro de investigación en estructuras microscópicas, Universidad de Costa Rica, San José, Costa Rica
- * E-mail:
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Abstract
The acute respiratory distress syndrome (ARDS) is a major public health problem and a leading source of morbidity in intensive care units. Lung tissue in patients with ARDS is characterized by inflammation, with exuberant neutrophil infiltration, activation, and degranulation that is thought to initiate tissue injury through the release of proteases and oxygen radicals. Treatment of ARDS is supportive primarily because the underlying pathophysiology is poorly understood. This gap in knowledge must be addressed to identify urgently needed therapies. Recent research efforts in anti-inflammatory drug development have focused on identifying common control points in multiple signaling pathways. The protein kinase C (PKC) serine-threonine kinases are master regulators of proinflammatory signaling hubs, making them attractive therapeutic targets. Pharmacological inhibition of broad-spectrum PKC activity and, more importantly, of specific PKC isoforms (as well as deletion of PKCs in mice) exerts protective effects in various experimental models of lung injury. Furthermore, PKC isoforms have been implicated in inflammatory processes that may be involved in the pathophysiologic changes that result in ARDS, including activation of innate immune and endothelial cells, neutrophil trafficking to the lung, regulation of alveolar epithelial barrier functions, and control of neutrophil proinflammatory and prosurvival signaling. This review focuses on the mechanistic involvement of PKC isoforms in the pathogenesis of ARDS and highlights the potential of developing new therapeutic paradigms based on the selective inhibition (or activation) of specific PKC isoforms.
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28
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Broytman O, Baertsch NA, Baker-Herman TL. Spinal TNF is necessary for inactivity-induced phrenic motor facilitation. J Physiol 2013; 591:5585-98. [PMID: 23878370 DOI: 10.1113/jphysiol.2013.256644] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A prolonged reduction in central neural respiratory activity elicits a form of plasticity known as inactivity-induced phrenic motor facilitation (iPMF), a 'rebound' increase in phrenic burst amplitude apparent once respiratory neural activity is restored. iPMF requires atypical protein kinase C (aPKC) activity within spinal segments containing the phrenic motor nucleus to stabilize an early transient increase in phrenic burst amplitude and to form long-lasting iPMF following reduced respiratory neural activity. Upstream signal(s) leading to spinal aPKC activation are unknown. We tested the hypothesis that spinal tumour necrosis factor-α (TNFα) is necessary for iPMF via an aPKC-dependent mechanism. Anaesthetized, ventilated rats were exposed to a 30 min neural apnoea; upon resumption of respiratory neural activity, a prolonged increase in phrenic burst amplitude (42 ± 9% baseline; P < 0.05) was apparent, indicating long-lasting iPMF. Pretreatment with recombinant human soluble TNF receptor 1 (sTNFR1) in the intrathecal space at the level of the phrenic motor nucleus prior to neural apnoea blocked long-lasting iPMF (2 ± 8% baseline; P > 0.05). Intrathecal TNFα without neural apnoea was sufficient to elicit long-lasting phrenic motor facilitation (pMF; 62 ± 7% baseline; P < 0.05). Similar to iPMF, TNFα-induced pMF required spinal aPKC activity, as intrathecal delivery of a ζ-pseudosubstrate inhibitory peptide (PKCζ-PS) 35 min following intrathecal TNFα arrested TNFα-induced pMF (28 ± 8% baseline; P < 0.05). These data demonstrate that: (1) spinal TNFα is necessary for iPMF; and (2) spinal TNFα is sufficient to elicit pMF via a similar aPKC-dependent mechanism. These data are consistent with the hypothesis that reduced respiratory neural activity elicits iPMF via a TNFα-dependent increase in spinal aPKC activity.
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Affiliation(s)
- Oleg Broytman
- T. Baker-Herman: Department of Comparative Biosciences, University of Wisconsin, 2015 Linden Drive, Madison, WI, USA.
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29
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Jin R, Yu S, Song Z, Zhu X, Wang C, Yan J, Wu F, Nanda A, Granger DN, Li G. Soluble CD40 ligand stimulates CD40-dependent activation of the β2 integrin Mac-1 and protein kinase C zeda (PKCζ) in neutrophils: implications for neutrophil-platelet interactions and neutrophil oxidative burst. PLoS One 2013; 8:e64631. [PMID: 23785403 PMCID: PMC3675111 DOI: 10.1371/journal.pone.0064631] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 04/11/2013] [Indexed: 11/18/2022] Open
Abstract
Recent work has revealed an essential involvement of soluble CD40L (sCD40L) in inflammation and vascular disease. Activated platelets are the major source of sCD40L, which has been implicated in platelet and leukocyte activation, although its exact functional impact on leukocyte-platelet interactions and the underlying mechanisms remain undefined. We aimed to determine the impact and the mechanisms of sCD40L on neutrophils. We studied neutrophil interactions with activated, surface-adherent platelets as a model for leukocyte recruitment to the sites of injury. Our data show that CD40L contributes to neutrophil firm adhesion to and transmigration across activated surface-adherent platelets, possibly through two potential mechanisms. One involves the direct interaction of ligand-receptor (CD40L-CD40), i.e., platelet surface CD40L interaction with neutrophil CD40; another involves an indirect mechanism, i.e. soluble CD40L stimulates activation of the leukocyte-specific β2 integrin Mac-1 in neutrophils and thereby further promotes neutrophil adhesion and migration. Activation of the integrin Mac-1 is known to be critical for mediating neutrophil adhesion and migration. sCD40L activated Mac-1 in neutrophils and enhanced neutrophil-platelet interactions in wild-type neutrophils, but failed to elicit such responses in CD40-deficient neutrophils. Furthermore, our data show that the protein kinase C zeta (PKCζ) is critically required for sCD40L-induced Mac-1 activation and neutrophil adhesive function. sCD40L strongly stimulated the focal clustering of Mac-1 (CD11b) and the colocalization of Mac-1 with PKCζ in wild-type neutrophils, but had minimal effect in CD40-deficient neutrophils. Blocking PKCζ completely inhibited sCD40L-induced neutrophil firm adhesion. Moreover, sCD40L strongly stimulates neutrophil oxidative burst via CD40-dependent activation of PI3K/NF-KB, but independent of Mac-1 and PKCζ. These findings may contribute to a better understanding of the underlying mechanisms by which sCD40L/CD40 pathway contributes to inflammation and vascular diseases.
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Affiliation(s)
- Rong Jin
- Vascular Biology and Stroke Research Laboratory, Department of Neurosurgery, Louisiana State University Health Science Center in Shreveport, Shreveport, Louisiana, United States of America
| | - Shiyong Yu
- Vascular Biology and Stroke Research Laboratory, Department of Neurosurgery, Louisiana State University Health Science Center in Shreveport, Shreveport, Louisiana, United States of America
- Institute of Cardiovascular Diseases, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Zifang Song
- Vascular Biology and Stroke Research Laboratory, Department of Neurosurgery, Louisiana State University Health Science Center in Shreveport, Shreveport, Louisiana, United States of America
| | - Xiaolei Zhu
- Vascular Biology and Stroke Research Laboratory, Department of Neurosurgery, Louisiana State University Health Science Center in Shreveport, Shreveport, Louisiana, United States of America
| | - Cuiping Wang
- Vascular Biology and Stroke Research Laboratory, Department of Neurosurgery, Louisiana State University Health Science Center in Shreveport, Shreveport, Louisiana, United States of America
- Department of Cardiology, The Affiliated Hospital of Jiangsu University, Jiangsu, Zhenjiang, China
| | - Jinchuan Yan
- Department of Cardiology, The Affiliated Hospital of Jiangsu University, Jiangsu, Zhenjiang, China
| | - Fusheng Wu
- Department of Surgical Oncology, The First Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Anil Nanda
- Vascular Biology and Stroke Research Laboratory, Department of Neurosurgery, Louisiana State University Health Science Center in Shreveport, Shreveport, Louisiana, United States of America
| | - D. Neil Granger
- Department of Physiology, Louisiana State University Health Science Center in Shreveport, Shreveport, Louisiana, United States of America
| | - Guohong Li
- Vascular Biology and Stroke Research Laboratory, Department of Neurosurgery, Louisiana State University Health Science Center in Shreveport, Shreveport, Louisiana, United States of America
- Department of Physiology, Louisiana State University Health Science Center in Shreveport, Shreveport, Louisiana, United States of America
- * E-mail:
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Chen R, Wang Y, Liu Y, Zhang Q, Zhang X, Zhang F, Shieh CHP, Yang D, Zhang N. Quantitative Study of the Interactome of PKCζ Involved in the EGF-induced Tumor Cell Chemotaxis. J Proteome Res 2013; 12:1478-86. [PMID: 23402259 DOI: 10.1021/pr3011292] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Ruibing Chen
- Research Center of
Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Yanping Wang
- Research Center of
Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Yan Liu
- Research Center of
Basic Medical Sciences, Tianjin Medical University, Tianjin, China
- Laboratory
of Cancer Cell Biology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Qing Zhang
- EncodeGenomics Bio-Technology Co., Ltd, Suzhou, China
| | - Xiaofang Zhang
- Research Center of
Basic Medical Sciences, Tianjin Medical University, Tianjin, China
- Laboratory
of Cancer Cell Biology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Fei Zhang
- Research Center of
Basic Medical Sciences, Tianjin Medical University, Tianjin, China
- Laboratory
of Cancer Cell Biology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | | | - De Yang
- Research Center of
Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Ning Zhang
- Research Center of
Basic Medical Sciences, Tianjin Medical University, Tianjin, China
- Laboratory
of Cancer Cell Biology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
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31
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Neeli I, Radic M. Opposition between PKC isoforms regulates histone deimination and neutrophil extracellular chromatin release. Front Immunol 2013; 4:38. [PMID: 23430963 PMCID: PMC3576869 DOI: 10.3389/fimmu.2013.00038] [Citation(s) in RCA: 169] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 01/31/2013] [Indexed: 11/29/2022] Open
Abstract
In response to inflammation, neutrophils deiminate histones and externalize chromatin. Neutrophil extracellular traps (NETs) are an innate immune defense mechanism, yet NETs also may aggravate chronic inflammatory and autoimmune disorders. Activation of peptidylarginine deiminase 4 (PAD4) is associated with NET release (NETosis) but the precise mechanisms of PAD4 regulation are unknown. We observed that, in human neutrophils, calcium ionophore induced histone deimination, whereas phorbol myristate acetate (PMA), an activator of protein kinase C (PKC), suppressed ionophore-induced deimination. Conversely, low doses of chelerythrine and sanguinarine, two inhibitors of PKC, reversed PMA inhibition and enhanced ionophore-stimulated deimination. In addition, a peptide inhibitor of PKCα superinduced ionophore activation of PAD4, thus identifying PKCα as the PMA-induced inhibitor of PAD4. At higher doses, chelerythrine, sanguinarine, and structurally unrelated PKC inhibitors blocked histone deimination, suggesting that a different PKC isoform activates histone deimination. We identify PKCζ as activator of PAD4 because a specific peptide inhibitor of this PKC isoform suppressed histone deimination. Confocal microscopy confirmed that, in the presence of PMA, NETosis proceeds without detectable histone deimination, and that ionophore cooperates with PMA to induce more extensive NET release. Broad inhibition of PKC by chelerythrine or specific inhibition of PKCζ suppressed NETosis. Our observations thus reveal an intricate antagonism between PKC isoforms in the regulation of histone deimination, identify a dominant role for PKCα in the repression of histone deimination, and assign essential functions to PKCζ in the activation of PAD4 and the execution of NETosis. The precise balance between opposing PKC isoforms in the regulation of NETosis affirms the idea that NET release underlies specific and vitally important evolutionary selection pressures.
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Affiliation(s)
- Indira Neeli
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center Memphis, TN, USA
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Oxytocin promotes long-term potentiation by enhancing epidermal growth factor receptor-mediated local translation of protein kinase Mζ. J Neurosci 2013; 32:15476-88. [PMID: 23115185 DOI: 10.1523/jneurosci.2429-12.2012] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In addition to triggering the birthing process and milk release, the hypothalamic neuropeptide oxytocin (OXT) plays an important role in the regulation of complex social cognition and behavior. Previous work has shown that OXT can regulate hippocampal synaptic plasticity and improve hippocampus-dependent cognitive functions in the female mice, but the underlying mechanisms remain largely unclear. Here, we demonstrate that OXT promotes the maintenance of long-term potentiation (LTP) induced by one train of tetanic stimulation (TS) in the CA1 region of hippocampal slices from both nulliparous female and male rats through a previously unknown mechanism involving OXT receptor (OXTR)-dependent and epidermal growth factor receptor (EGFR)-mediated local translation of an atypical protein kinase C isoform, protein kinase Mζ (PKMζ), in dendrites. Using pharmacological and biochemical approaches, we show that both the conventional OXTR-associated signaling pathway (G(q/11)-coupled phospholipase C) and the transactivated EGFR downstream signaling pathways (phosphatidylinositol 3 kinase and extracellular signal-regulated kinase 1/2) are involved in the regulation of OXT. In addition, OXT stimulates local dendritic PKMζ mRNA translation via activation of a mammalian target of rapamycin-regulated mechanism. Furthermore, blockade of OXTR results in a modest decrease in the ability to maintain late-phase LTP induced by three trains of TS. These results reveal a novel OXTR-to-EGFR communication to regulate the new synthesis of PKMζ, which functions to promote the maintenance of LTP at hippocampal CA1 synapses.
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Abstract
Metastasis is the major cause of morbidity and mortality from breast cancer. Cell motility and chemotaxis play important roles in the metastatic cascade of cancer cells. Protein kinase C ζ (PKCζ) mediates cancer cell chemotaxis by regulating cytoskeleton rearrangement and cell adhesion. In the current study, we investigated the inhibitory effect of a compound called J-4 targeting PKCζ. J-4 was tested with inhibitory concentration (IC(50)) of 10 µmol/l using a Z'-LYTE™ Kinase Assay-Ser/Thr 7 Peptide Kit. Our results show that J-4 inhibited spontaneous migration and epidermal growth factor (EGF)-induced chemotaxis of human breast cancer cell MDA-MB-231. Through an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, the drug designated as J-4 had no obvious cytotoxicity in vitro. Meanwhile, in the presence of J-4, the cells showed defects in EGF-induced actin polymerization and adhesion. Furthermore, J-4 dampened EGF-induced phosphorylation and recycling of cofilin. Taken together, our data demonstrate that J-4 is a new and typical inhibitor that blocks the PKCζ pathway. Moreover, a better understanding of the mechanism of action of J-4 may provide a novel medical therapeutic strategy for cancer treatment that would block metastasis, thereby reducing the proliferation and dissemination of cancer cells and increasing patient survival.
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Selective kinase inhibitors as tools for neuroscience research. Neuropharmacology 2012; 63:1227-37. [DOI: 10.1016/j.neuropharm.2012.07.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 07/06/2012] [Accepted: 07/11/2012] [Indexed: 01/02/2023]
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35
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Identification of key regulatory pathways of myeloid differentiation using an mESC-based karyotypically normal cell model. Blood 2012; 120:4712-9. [PMID: 23086752 DOI: 10.1182/blood-2012-03-414979] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Understanding the process of myeloid differentiation offers important insights into both normal and abnormal developmental processes but is limited by the dearth of experimental models. Here we show that myeloid progenitors can be derived from embryonic stem cells, immortalized, and applied to the study of the mechanisms underlying myeloid differentiation. The embryonic stem cell-derived myeloid progenitors, when immortalized with estrogen-regulated Hoxb8 protein, demonstrate normal karyotyping, are genetically tractable, and can be differentiated into functional neutrophils. Using this model, we identified mammalian target of rapamycin complex 1 as a critical regulator of myeloid differentiation. Together, our studies led to a convenient, karyotypically normal, and genetically manipulatable cellular system, which can be used to shed new light on the mechanisms for myeloid differentiation.
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Sacktor TC. Memory maintenance by PKMζ--an evolutionary perspective. Mol Brain 2012; 5:31. [PMID: 22986281 PMCID: PMC3517905 DOI: 10.1186/1756-6606-5-31] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 08/29/2012] [Indexed: 11/20/2022] Open
Abstract
Long-term memory is believed to be maintained by persistent modifications of synaptic transmission within the neural circuits that mediate behavior. Thus, long-term potentiation (LTP) is widely studied as a potential physiological basis for the persistent enhancement of synaptic strength that might sustain memory. Whereas the molecular mechanisms that initially induce LTP have been extensively characterized, the mechanisms that persistently maintain the potentiation have not. Recently, however, a candidate molecular mechanism linking the maintenance of LTP and the storage of long-term memory has been identified. The persistent activity of the autonomously active, atypical protein kinase C (aPKC) isoform, PKMζ, is both necessary and sufficient for maintaining LTP. Furthermore, blocking PKMζ activity by pharmacological or dominant negative inhibitors disrupts previously stored long-term memories in a variety of neural circuits, including spatial and trace memories in the hippocampus, aversive memories in the basolateral amygdala, appetitive memories in the nucleus accumbens, habit memory in the dorsal lateral striatum, and elementary associations, extinction, and skilled sensorimotor memories in the neocortex. During LTP and memory formation, PKMζ is synthesized de novo as a constitutively active kinase. This molecular mechanism for memory storage is evolutionarily conserved. PKMζ formation through new protein synthesis likely originated in early vertebrates ~500 million years ago during the Cambrian period. Other mechanisms for forming persistently active PKM from aPKC are found in invertebrates, and inhibiting this atypical PKM disrupts long-term memory in the invertebrate model systems Drosophila melanogaster and Aplysia californica. Conversely, overexpressing PKMζ enhances memory in flies and rodents. PKMζ persistently enhances synaptic strength by maintaining increased numbers of AMPA receptors at postsynaptic sites, a mechanism that might have evolved from the general function of aPKC in trafficking membrane proteins to the apical compartment of polarized cells. This mechanism of memory may have had adaptive advantages because it is both stable and reversible, as demonstrated by the downregulation of experience-dependent, long-term increases in PKMζ after extinction and reconsolidation blockade that attenuate learned behavior. Thus, PKMζ, the “working end” of LTP, is a component of an evolutionarily conserved molecular mechanism for the persistent, yet flexible storage of long-term memory.
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Affiliation(s)
- Todd Charlton Sacktor
- The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology, State University of New York Downstate Medical Center, 450 Clarkson Ave, Brooklyn, NY 10705, USA.
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Yao Y, Shao C, Jothianandan D, Tcherepanov A, Shouval H, Sacktor TC. Matching biochemical and functional efficacies confirm ZIP as a potent competitive inhibitor of PKMζ in neurons. Neuropharmacology 2012; 64:37-44. [PMID: 22846225 DOI: 10.1016/j.neuropharm.2012.07.018] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 07/06/2012] [Accepted: 07/08/2012] [Indexed: 01/08/2023]
Abstract
PKMζ is an autonomously active, atypical protein kinase C (aPKC) isoform that is both necessary and sufficient for maintaining long-term potentiation (LTP) and long-term memory. The myristoylated ζ-pseudosubstrate peptide, ZIP, potently inhibits PKMζ biochemically in vitro, within cultured cells, and within neurons in hippocampal slices, and reverses LTP maintenance and erases long-term memory storage. A recent study (Wu-Zhang et al., 2012), however, suggested ZIP was not effective on a PKMζ fusion protein overexpressed in cultured cells. Chelerythrine, a redox-sensitive PKC inhibitor that inhibits PKMζ and disrupts LTP maintenance and memory storage, was also reported by Wu-Zhang et al. (2012) not to inhibit the expressed PKMζ fusion protein. However, the efficacy of inhibitors on endogenous enzymes in cells may not be adequately assessed in expression systems in which levels of expression of exogenous enzymes greatly exceed those of endogenous enzymes. Thus, we show, biochemically, that when PKMζ reaches a level beyond that necessary for substrate phosphorylation such that much of the enzyme is excess or 'spare' kinase, ZIP and chelerythrine do not effectively block substrate phosphorylation. We also show that the cellular overexpression techniques used by Wu-Zhang et al. (2012) increase kinase levels ~30-40 fold above normal levels in transfected cells. Using a mathematical model we show that at such level of overexpression, standard concentrations of inhibitor should have no noticeable effect. Furthermore, we demonstrate the standard concentrations of ZIP, but not scrambled ZIP, inhibit the ability of PKMζ to potentiate AMPAR responses at postsynaptic sites, the physiological function of the kinase. Wu-Zhang et al. (2012) had also claimed that staurosporine, a general kinase inhibitor that does not effectively inhibit PKMζ biochemically in vitro, nonetheless indirectly blocked the PKMζ fusion protein overexpressed in cultured cells by inhibiting phosphoinositide-dependent protein kinase-1 (PDK1). However, here we show that staurosporine does not affect PDK1 phosphorylation of the endogenous PKMζ in hippocampal slices. Thus, the biochemical in vitro effects of PKMζ inhibitors correspond with their intracellular effects, and ZIP and chelerythrine, together with scrambled ZIP and staurosporine as controls, are effective tools to examine the function of PKMζ in neurons. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
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Affiliation(s)
- Yudong Yao
- Department of Physiology and Pharmacology, State University of New York Downstate Medical Center, 450 Clarkson Ave, Brooklyn, NY 11203, USA
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Rimessi A, Zecchini E, Siviero R, Giorgi C, Leo S, Rizzuto R, Pinton P. The selective inhibition of nuclear PKCζ restores the effectiveness of chemotherapeutic agents in chemoresistant cells. Cell Cycle 2012; 11:1040-8. [PMID: 22333579 DOI: 10.4161/cc.11.5.19520] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The atypical protein kinase C (PKC) isoform zeta (PKCζ) has been implicated in the intracellular transduction of mitogenic and apoptotic signals by acting on different signaling pathways. The key role of these processes in tumorigenesis suggests a possible involvement of PKCζ in this event. PKCζ is activated by cytotoxic treatments, inhibits apoptotic cell death and reduces the sensitivity of cancer cells to chemotherapeutic agents. Here, using pharmacological and DNA recombinant approaches, we show that oxidative stress triggers nuclear translocation of PKCζ and induces resistance to apoptotic agents. Accordingly, chemoresistant cells show accumulation of PKCζ within the nucleus, and a nuclear-targeted PKCζ transfected in tumor cells decreases sensitivity to apoptosis. We thus developed a novel recombinant protein capable of selectively inhibiting the nuclear fraction of PKCζ that restored the susceptibility to apoptosis in cells in which PKCζ was enriched in the nuclear fraction, including chemoresistant cells. These findings establish the importance of PKCζ as a possible target to increase the effectiveness of anticancer therapies and highlight potential sites of intervention.
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Affiliation(s)
- Alessandro Rimessi
- Department of Experimental and Diagnostic Medicine, Section of General Pathology, Interdisciplinary Center for the Study of Inflammation (ICSI), Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
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Ruiz-Loredo AY, López E, López-Colomé AM. Thrombin stimulates stress fiber assembly in RPE cells by PKC/CPI-17-mediated MLCP inactivation. Exp Eye Res 2012; 96:13-23. [DOI: 10.1016/j.exer.2012.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 01/11/2012] [Accepted: 01/17/2012] [Indexed: 12/29/2022]
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40
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Beste MT, Lee D, King MR, Koretzky GA, Hammer DA. An integrated stochastic model of "inside-out" integrin activation and selective T-lymphocyte recruitment. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:2225-2237. [PMID: 22149624 PMCID: PMC3269544 DOI: 10.1021/la203803e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The pattern of T-lymphocyte homing is hypothesized to be controlled by combinations of chemokine receptors and complementary chemokines. Here, we use numerical simulation to explore the relationship among chemokine potency and concentration, signal transduction, and adhesion. We have developed a form of adhesive dynamics-a mechanically accurate stochastic simulation of adhesion-that incorporates stochastic signal transduction using the next subvolume method. We show that using measurable parameter estimates derived from a variety of sources, including signaling measurements that allow us to test parameter values, we can readily simulate approximate time scales for T-lymphocyte arrest. We find that adhesion correlates with total chemokine receptor occupancy, not the frequency of occupation, when multiple chemokine receptors feed through a single G-protein. A general strategy for selective T-lymphocyte recruitment appears to require low affinity chemokine receptors. For a single chemokine receptor, increases in multiple cross-reactive chemokines can lead to an overwhelming increase in adhesion. Overall, the methods presented here provide a predictive framework for understanding chemokine control of T-lymphocyte recruitment.
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Affiliation(s)
- Michael T. Beste
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Dooyoung Lee
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Michael R. King
- Department of Biomedical Engineering, Cornell University, Ithaca, New York
| | - Gary A. Koretzky
- Department of Immunology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Daniel A. Hammer
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
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Abstract
During abstinence, memories of drug-associated cues persist for many months, and exposure to these cues often provokes relapse to drug use. The mechanisms underlying the maintenance of these memories are unknown. A constitutively active atypical protein kinase C (PKC) isozyme, protein kinase M ζ (PKMζ), is required for maintenance of spatial memory, conditioned taste aversion, and other memory forms. We used conditioned place preference (CPP) and conditioned place aversion (CPA) procedures to study the role of nucleus accumbens PKMζ in the maintenance of drug reward and aversion memories in rats. Morphine CPP training (10 mg/kg, 4 pairings) increased PKMζ levels in accumbens core but not shell. Injections of the PKMζ inhibitor ζ inhibitory peptide (ZIP) into accumbens core but not shell after CPP training blocked morphine CPP expression for up to 14 d after injections. This effect was mimicked by the PKC inhibitor chelerythrine, which inhibits PKMζ, but not by the conventional and novel PKC inhibitor staurosporine, which does not effectively inhibit PKMζ. ZIP injections into accumbens core after training also blocked the expression of cocaine (10 mg/kg) and high-fat food CPP but had no effect on CPA induced by naloxone-precipitated morphine withdrawal. Accumbens core injections of Tat-GluR2(3Y), which inhibits GluR2-dependent AMPA receptor endocytosis, prevented the impairment in morphine CPP induced by local ZIP injections, indicating that the persistent effect of PKMζ is on GluR2-containing AMPA receptors. Results indicate that PKMζ activity in accumbens core is a critical cellular substrate for the maintenance of memories of relapse-provoking reward cues during prolonged abstinence periods.
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Chemokine triggered integrin activation and actin remodeling events guiding lymphocyte migration across vascular barriers. Exp Cell Res 2011; 317:632-41. [PMID: 21376176 DOI: 10.1016/j.yexcr.2010.12.007] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Revised: 12/07/2010] [Accepted: 12/07/2010] [Indexed: 01/13/2023]
Abstract
Chemokine signals activate leukocyte integrins and actin remodeling machineries critical for leukocyte adhesion and motility across vascular barriers. The arrest of leukocytes at target blood vessel sites depends on rapid conformational activation of their α4 and β2 integrins by the binding of endothelial-displayed chemokines to leukocyte Gi-protein coupled receptors (GPCRs). A universal regulator of this event is the integrin-actin adaptor, talin1. Chemokine-stimulated GPCRs can transmit within fractions of seconds signals via multiple Rho GTPases, which locally raise plasma membrane levels of the talin activating phosphatidyl inositol, PtdIns(4,5)P2 (PIP2). Additional pools of GPCR stimulated Rac-1 and Rap-1 GTPases together with GPCR stimulated PLC and PI3K family members regulate the turnover of focal contacts of leukocyte integrins, induce the collapse of leukocyte microvilli, and promote polarized leukocyte crawling in search of exit cues. Concomitantly, other leukocyte GTPases trigger invasive protrusions into and between endothelial cells in search of basolateral chemokine exit cues. We will review here major findings and open questions related to these sequential guiding activities of endothelial presented chemokines, focusing mainly on lymphocyte-endothelial interactions as a paradigm for other leukocytes.
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Liu G, Vogel SM, Gao X, Javaid K, Hu G, Danilov SM, Malik AB, Minshall RD. Src phosphorylation of endothelial cell surface intercellular adhesion molecule-1 mediates neutrophil adhesion and contributes to the mechanism of lung inflammation. Arterioscler Thromb Vasc Biol 2011; 31:1342-50. [PMID: 21474822 DOI: 10.1161/atvbaha.110.222208] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE The goal of this study was to determine whether tumor necrosis factor α (TNFα)-induced Src activation and intercellular adhesion molecule-1 (ICAM-1) phosphorylation rapidly increase endothelial cell adhesivity and polymorphonuclear leukocyte (PMN) sequestration independently of de novo ICAM-1 synthesis. METHODS AND RESULTS TNFα exposure of mouse lungs for 5 minutes produced a 3-fold increase in (125)I-anti-ICAM-1 monoclonal antibody (mAb) binding and (111)In oxine-labeled PMN sequestration, as well as Src activation, ICAM-1 Tyr518 phosphorylation, and phospho- Tyr518-ICAM-1 coimmunoprecipitation with actin. The response was absent in Nox2(-/-) lungs or following Src inhibition. In COS-7 cells transfected with wild-type (WT), phospho-defective (Tyr518Phe), or phospho-mimicking (Tyr518Asp) mouse ICAM-1 cDNA constructs, TNFα increased the B(max) of YN1/1.7.4 anti-ICAM-1 mAb binding to WT-ICAM-1 but not to Tyr518Phe-ICAM-1, indicating increased binding avidity secondary to ICAM-1 phosphorylation. This effect was mimicked by expression of the Tyr518Asp-ICAM-1 mutant. TNFα also increased the staining intensity and cell surface clustering of YN1/1.7.4 mAb-labeled WT-ICAM-1 that colocalized with F-actin, which was not observed with Tyr518Phe-ICAM-1 but was recapitulated with Tyr518Asp-ICAM-1. Finally, overexpression of ICAM-1 in mouse lungs significantly increased lipopolysaccharide-induced transvascular albumin leakage and bronchoalveolar lavage PMN counts at 2 and 24 hours after lipopolysaccharide inhalation compared with lungs expressing the Tyr518Phe ICAM-1 mutant. CONCLUSION Src-dependent phosphorylation of endothelial cell ICAM-1 Tyr518 induces PMN adhesion by promoting ICAM-1 clustering, which we propose mediates rapid-phase lung vascular accumulation of PMNs during inflammation.
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Affiliation(s)
- Guoquan Liu
- Department of Pharmacology, University of Illinois, Chicago, IL, USA
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44
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Song C, Rahim RT, Davey PC, Bednar F, Bardi G, Zhang L, Zhang N, Oppenheim JJ, Rogers TJ. Protein kinase Czeta mediates micro-opioid receptor-induced cross-desensitization of chemokine receptor CCR5. J Biol Chem 2011; 286:20354-65. [PMID: 21454526 DOI: 10.1074/jbc.m110.177303] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have previously shown that the μ-opioid receptor (MOR) is capable of mediating cross-desensitization of several chemokine receptors including CCR5, but the biochemical mechanism of this process has not been fully elucidated. We have carried out a series of functional and biochemical studies and found that the mechanism of MOR-induced cross-desensitization of CCR5 involves the activation of PKCζ. Inhibition of PKCζ by its pseudosubstrate inhibitor, or its siRNA, or dominant negative mutants suppresses the cross-desensitization of CCR5. Our results further indicate that the activation of PKCζ is mediated through a pathway involving phosphoinositol-dependent kinase-1 (PDK1). In addition, activation of MOR elevates the phosphorylation level and kinase activity of PKCζ. The phosphorylation of PKCζ can be suppressed by a dominant negative mutant of PDK1. We observed that following MOR activation, the interaction between PKCζ and PDK1 is immediately increased based on the analysis of fluorescent resonance energy transfer in cells with the expression of PKCζ-YFP and PDK1-CFP. In addition, cells expressing PKCζ kinase motif mutants (Lys-281, Thr-410, Thr-560) fail to exhibit full MOR-induced desensitization of CCR5 activity. Taken together, we propose that upon DAMGO treatment, MOR activates PKCζ through a PDK1-dependent signaling pathway to induce CCR5 phosphorylation and desensitization. Because CCR5 is a highly proinflammatory receptor, and a critical coreceptor for HIV-1, these results may provide a novel approach for the development of specific therapeutic agents to treat patients with certain inflammatory diseases or AIDS.
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Affiliation(s)
- Changcheng Song
- Fels Institute for Cancer Research and Molecular Biology, Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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45
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Bertram A, Ley K. Protein kinase C isoforms in neutrophil adhesion and activation. Arch Immunol Ther Exp (Warsz) 2011; 59:79-87. [PMID: 21298489 DOI: 10.1007/s00005-011-0112-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 10/08/2010] [Indexed: 01/13/2023]
Abstract
Neutrophils are the first line of defense against bacterial and mycotic pathogens. In order to reach the pathogens, neutrophils need to transmigrate through the vascular endothelium and migrate to the site of infection. Defense strategies against pathogens include phagocytosis, production and release of oxygen radicals through the oxidative burst, and degranulation of antimicrobial and inflammatory molecules. Protein kinase C (PKC)-δ is required for full assembly of NADPH oxidase and activation of the respiratory burst. Neutrophils also express PKC-α and -β, which may be involved in adhesion, degranulation and phagocytosis, but the evidence is not conclusive yet. This review focuses on the potential impact of protein kinase C isoforms on neutrophil adhesion and activation.
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Affiliation(s)
- Anna Bertram
- Department of Nephrology, Hannover Medical School, Carl-Neuberg-Strasse 1, Hannover, Germany
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46
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Ruiz-Loredo AY, López E, López-Colomé AM. Thrombin promotes actin stress fiber formation in RPE through Rho/ROCK-mediated MLC phosphorylation. J Cell Physiol 2011; 226:414-23. [PMID: 20672289 DOI: 10.1002/jcp.22347] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The retinal pigment epithelium (RPE) forms the outer blood-retina barrier (BRB). Most retinal diseases involve BRB breakdown, whereupon thrombin contained in serum directly contacts the RPE. Thrombin is known to promote actin stress fiber formation, an important determinant in eye diseases involving the epithelial-mesenchymal transition (EMT) and migration of RPE cells, such as proliferative vitreoretinopathy. We analyzed thrombin effect on signaling pathways leading to myosin light chain (MLC) phosphorylation and actin stress fiber formation in primary cultures of rat RPE cells, in order to support a role for thrombin in RPE transdifferentiation. MLC phosphorylation was measured by Western blot; actin cytoskeleton was visualized using immunofluorescent phalloidin, and Rho GTPase activation was assessed by ELISA. We showed that thrombin/PAR-1 induces the time- and dose-dependent phosphorylation of MLC through the activation of Rho/ROCK and myosin light chain kinase (MLCK). ROCK increased phospho-MLC by phosphorylating MLC and by inhibiting MLC phosphatase. Thrombin effect was abolished by the ROCK inhibitor Y-27632, whereas MLCK inhibitor ML-7 and PLC-β inhibitor U73122 attenuated MLC phosphorylation by ≈50%, suggesting the activation of MLCK by PLC-β-mediated calcium increase. Additionally, thrombin-induced MLC phosphorylation was blocked by the inhibitory PKCζ pseudosubstrate, wortmannin, and LY294002, indicating IP(3)/PKCζ involvement in the control of MLC phosphorylation. Moreover, we demonstrated that thrombin effect on MLC induces actin stress fiber formation, since this effect was prevented by inhibiting the pathways leading to MLC phosphorylation. We conclude that thrombin stimulation of MLC phosphorylation and actin stress fiber formation may be involved in thrombin-induced RPE cell transformation subsequent to BRB dysfunction.
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Affiliation(s)
- Ariadna Yolanda Ruiz-Loredo
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México, D.F., Mexico
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Ding RQ, Tsao J, Chai H, Mochly-Rosen D, Zhou W. Therapeutic potential for protein kinase C inhibitor in vascular restenosis. J Cardiovasc Pharmacol Ther 2010; 16:160-7. [PMID: 21183728 DOI: 10.1177/1074248410382106] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Vascular restenosis, an overreaction of biological response to injury, is initialized by thrombosis and inflammation. This response is characterized by increased smooth muscle cell migration and proliferation. Available pharmacological treatments include anticoagulants, antiplatelet agents, immunosuppressants, and antiproliferation agents. Protein kinase C (PKC), a large family of serine/threonine kinases, has been shown to participate in various pathological stages of restenosis. Consequently, PKC inhibitors are expected to exert a wide range of pharmacological activities therapeutically beneficial for restenosis. In this review, the roles of PKC isozymes in platelets, leukocytes, endothelial cells, and smooth muscle cells are discussed, with emphasis given to smooth muscle cells. We will describe cellular and animal studies assessing prevention of restenosis with PKC inhibitors, particularly targeting -α, -β, -δ, and -ζ isozymes. The delivery strategy, efficacy, and safety of such PKC regulators will also be discussed.
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Affiliation(s)
- Richard Qinxue Ding
- Division of Vascular and Endovascular Surgery, Department of Surgery, Stanford University, Stanford, CA 94350, USA
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Sewald X, Jiménez-Soto L, Haas R. PKC-dependent endocytosis of the Helicobacter pylori vacuolating cytotoxin in primary T lymphocytes. Cell Microbiol 2010; 13:482-96. [DOI: 10.1111/j.1462-5822.2010.01551.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Eckert RE, Neuder LE, Park J, Adler KB, Jones SL. Myristoylated alanine-rich C-kinase substrate (MARCKS) protein regulation of human neutrophil migration. Am J Respir Cell Mol Biol 2010; 42:586-94. [PMID: 19574534 PMCID: PMC2874444 DOI: 10.1165/rcmb.2008-0394oc] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Accepted: 05/29/2009] [Indexed: 01/01/2023] Open
Abstract
Neutrophil migration into infected tissues is essential for host defense, but products of activated neutrophils can be quite damaging to host cells. Neutrophil influx into the lung and airways and resultant inflammation characterizes diseases such as chronic obstructive pulmonary disease, bronchiectasis, and cystic fibrosis. To migrate, neutrophils must reorganize the actin cytoskeleton to establish a leading edge pseudopod and a trailing edge uropod. The actin-binding protein myristoylated alanine-rich C-kinase substrate (MARCKS) has been shown to bind and cross-link actin in a variety of cell types and to co-localize with F-actin in the leading edge lamellipodium of migrating fibroblasts. The hypothesis that MARCKS has a role in the regulation of neutrophil migration was tested using a cell-permeant peptide derived from the MARCKS myristoylated aminoterminus (MANS peptide). Treatment of isolated human neutrophils with MANS significantly inhibited both their migration and beta2 integrin-dependent adhesion in response to N-formyl-methionyl-leucyl-phenylalanine (fMLF), IL-8, or leukotriene (LT)B(4). The IC(50) for fMLF-induced migration and adhesion was 17.1 microM and 12.5 microM, respectively. MANS significantly reduced the F-actin content in neutrophils 30 seconds after fMLF stimulation, although the peptide did not alter the ability of cells to polarize or spread. MANS did not alter fMLF-induced increases in surface beta2 integrin expression. These results suggest that MARCKS, via its myristoylated aminoterminus, is a key regulator of neutrophil migration and adhesion.
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Affiliation(s)
- Rachael E. Eckert
- Department of Clinical Sciences, Department of Molecular Biomedical Sciences, and Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Caroline State University, Raleigh, North Carolina
| | - Laura E. Neuder
- Department of Clinical Sciences, Department of Molecular Biomedical Sciences, and Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Caroline State University, Raleigh, North Carolina
| | - Joungjoa Park
- Department of Clinical Sciences, Department of Molecular Biomedical Sciences, and Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Caroline State University, Raleigh, North Carolina
| | - Kenneth B. Adler
- Department of Clinical Sciences, Department of Molecular Biomedical Sciences, and Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Caroline State University, Raleigh, North Carolina
| | - Samuel L. Jones
- Department of Clinical Sciences, Department of Molecular Biomedical Sciences, and Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Caroline State University, Raleigh, North Carolina
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Bordeleau F, Galarneau L, Gilbert S, Loranger A, Marceau N. Keratin 8/18 modulation of protein kinase C-mediated integrin-dependent adhesion and migration of liver epithelial cells. Mol Biol Cell 2010; 21:1698-713. [PMID: 20357007 PMCID: PMC2869376 DOI: 10.1091/mbc.e09-05-0373] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hepatocyte and hepatoma cell IFs are made solely of keratins 8/18 (K8/K18). Cell adhesion and migration involve integrin interactions with focal adhesion kinase (FAK) and protein kinase C (PKC). Here we report a new regulatory function for K8/K18 IFs in the PKC-mediated integrin/FAK-dependent adhesion and migration of simple epithelial cells. Keratins are intermediate filament (IF) proteins of epithelial cells, expressed as pairs in a lineage/differentiation manner. Hepatocyte and hepatoma cell IFs are made solely of keratins 8/18 (K8/K18), the hallmark of all simple epithelia. Cell attachment/spreading (adhesion) and migration involve the formation of focal adhesions at sites of integrin interactions with extracellular matrix, actin adaptors such as talin and vinculin, and signaling molecules such as focal adhesion kinase (FAK) and member(s) of the protein kinase C (PKC) family. Here, we identify the novel PKCδ as mediator of the K8/K18 modulation of hepatoma cell adhesion and migration. We also demonstrate a K8/K18-dependent relationship between PKCδ and FAK activation through an integrin/FAK-positive feedback loop, in correlation with a reduced FAK time residency at focal adhesions. Notably, a K8/K18 loss results to a time course modulation of the receptor of activated C-kinase-1, β1-integrin, plectin, PKC, and c-Src complex formation. Although the K8/K18 modulation of hepatocyte adhesion also occurs through a PKC mediation, these differentiated epithelial cells exhibit minimal migrating ability, in link with marked differences in protein partner content and distribution. Together, these results uncover a key regulatory function for K8/K18 IFs in the PKC-mediated integrin/FAK-dependent adhesion and migration of simple epithelial cells.
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Affiliation(s)
- François Bordeleau
- Centre de Recherche en Cancérologie and Département de Médecine de l'Université Laval, and Centre de Recherche du Centre Hospitalier Universitaire de Québec (CRCHUQ), Quebec City, QC, Canada
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