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Li K, Ma X, Li Z, Liu Y, Shen G, Luo Z, Wang D, Xia L, Wang Z, Tian M, Liu H, Geng F, Li B. A Natural Peptide from A Traditional Chinese Medicine Has the Potential to Treat Chronic Atrophic Gastritis by Activating Gastric Stem Cells. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2304326. [PMID: 38544338 PMCID: PMC11132046 DOI: 10.1002/advs.202304326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 02/08/2024] [Indexed: 05/29/2024]
Abstract
Chronic atrophic gastritis (AG) is initiated mainly by Helicobacter pylori infection, which may progress to stomach cancer following the Correa's cascade. The current treatment regimen is H. pylori eradication, yet evidence is lacking that this treatment is effective on later stages of AG especially gastric gland atrophy. Here, using AG mouse model, patient samples, gastric organoids, and lineage tracing, this study unraveled gastric stem cell (GSC) defect as a crucial pathogenic factor in AG in mouse and human. Moreover, a natural peptide is isolated from a traditional Chinese medicine that activated GSCs to regenerate gastric epithelia in experimental AG models and revitalized the atrophic gastric organoids derived from patients. It is further shown that the peptide exerts its functions by stabilizing the EGF-EGFR complex and specifically activating the downstream ERK and Stat1 signaling. Overall, these findings advance the understanding of AG pathogenesis and open a new avenue for AG treatment.
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Affiliation(s)
- Ke Li
- Institute of Traditional Chinese Medicine and Stem Cell ResearchCollege of Basic Medical SciencesChengdu University of Traditional Chinese MedicineChengdu611137China
- Bio‐X InstitutesShanghai Jiao Tong UniversityShanghai200240China
| | - Xiuying Ma
- Sichuan Engineering Research Center for Medicinal AnimalsSichuan Good Doctor Panxi Pharmaceutical Co., LtdChengdu610000China
| | - Zihao Li
- Bio‐X InstitutesShanghai Jiao Tong UniversityShanghai200240China
| | - Ya Liu
- Institute of Traditional Chinese Medicine and Stem Cell ResearchCollege of Basic Medical SciencesChengdu University of Traditional Chinese MedicineChengdu611137China
| | - Guiyan Shen
- Institute of Traditional Chinese Medicine and Stem Cell ResearchCollege of Basic Medical SciencesChengdu University of Traditional Chinese MedicineChengdu611137China
| | - Zecheng Luo
- Institute of Traditional Chinese Medicine and Stem Cell ResearchCollege of Basic Medical SciencesChengdu University of Traditional Chinese MedicineChengdu611137China
| | - Dong Wang
- Institute of Traditional Chinese Medicine and Stem Cell ResearchCollege of Basic Medical SciencesChengdu University of Traditional Chinese MedicineChengdu611137China
| | - Li Xia
- Department of PathophysiologyKey Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of EducationShanghai Jiao Tong University School of MedicineShanghai200025China
| | - Zhengting Wang
- Department of GastroenterologyRuijin HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai200025China
| | - Ming Tian
- Department of BurnRuijin HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai200025China
| | - Huijuan Liu
- Bio‐X InstitutesShanghai Jiao Tong UniversityShanghai200240China
| | - Funeng Geng
- Sichuan Engineering Research Center for Medicinal AnimalsSichuan Good Doctor Panxi Pharmaceutical Co., LtdChengdu610000China
| | - Baojie Li
- Institute of Traditional Chinese Medicine and Stem Cell ResearchCollege of Basic Medical SciencesChengdu University of Traditional Chinese MedicineChengdu611137China
- Bio‐X InstitutesShanghai Jiao Tong UniversityShanghai200240China
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Guo X, Zheng M, Pan R, Zang B, Gao J, Ma H, Jin M. Hydroxysafflor yellow A (HSYA) targets the platelet-activating factor (PAF) receptor and inhibits human bronchial smooth muscle activation induced by PAF. Food Funct 2019; 10:4661-4673. [PMID: 31292579 DOI: 10.1039/c9fo00896a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hydroxysafflor yellow A (HSYA) is the main active ingredient of edible plant safflower. HSYA has demonstrated anti-inflammatory effects. The inflammatory response is the key mechanism responsible for asthma, and the pro-inflammatory platelet-activating factor (PAF) is known to play a role in the pathology of bronchial asthma. In this study, we stimulated human bronchial smooth muscle cells (HBSMCs) with PAF and examined the effects of HSYA on the resulting asthma-related process. PAF stimulation induced HBSMC activation, induced proliferation, increased expression of the pro-inflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor-α, and activated asthma-related signaling pathways. All these effects were significantly inhibited by treatment with HSYA (9, 27, 81 μmol L-1). The effects of HSYA were prevented by the addition of a PAF receptor (PAFR) antagonist or by PAFR gene silencing with small interfering RNA. These results suggest that HSYA may inhibit PAF-induced activation of HBSMCs by targeting the PAFR. Overall, these findings provide evidence that HSYA can be applied as a potential therapeutic agent in the treatment of bronchial asthma.
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Affiliation(s)
- Xinjing Guo
- Department of Pharmacology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Diseases, Chaoyang District, Beijing, China.
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Hamel-Côté G, Lapointe F, Gendron D, Rola-Pleszczynski M, Stankova J. Regulation of platelet-activating factor-induced interleukin-8 expression by protein tyrosine phosphatase 1B. Cell Commun Signal 2019; 17:21. [PMID: 30832675 PMCID: PMC6399872 DOI: 10.1186/s12964-019-0334-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 02/22/2019] [Indexed: 12/21/2022] Open
Abstract
Background Platelet-activating factor (PAF) is a potent lipid mediator whose involvement in the onset and progression of atherosclerosis is mediated by, among others, the modulation of cytokine expression patterns. The presence of multiple potential protein-tyrosine phosphatase (PTP) 1B substrates in PAF receptor signaling pathways brought us to investigate its involvement in PAF-induced cytokine expression in monocyte-derived dendritic cells (Mo-DCs) and to study the pathways involved in this modulation. Methods We used in-vitro-matured human dendritic cells and the HEK-293 cell line in our studies. PTP1B inhibition was though siRNAs and a selective inhibitor. Cytokine expression was studied with RT-PCR, luciferase assays and ELISA. Phosphorylation status of kinases and transcription factors was studied with western blotting. Results Here, we report that PTP1B was involved in the modulation of cytokine expression in PAF-stimulated Mo-DCs. A study of the down-regulation of PAF-induced IL-8 expression, by PTP1B, showed modulation of PAF-induced transactivation of the IL-8 promoter which was dependent on the presence of the C/EBPß -binding site. Results also suggested that PTP1B decreased PAF-induced IL-8 production by a glycogen synthase kinase (GSK)-3-dependent pathway via activation of the Src family kinases (SFK). These kinases activated an unidentified pathway at early stimulation times and the PI3K/Akt signaling pathway in a later phase. This change in GSK-3 activity decreased the C/EBPß phosphorylation levels of the threonine 235, a residue whose phosphorylation is known to increase C/EBPß transactivation potential, and consequently modified IL-8 expression. Conclusion The negative regulation of GSK-3 activity by PTP1B and the consequent decrease in phosphorylation of the C/EBPß transactivation domain could be an important negative feedback loop by which cells control their cytokine production after PAF stimulation. Electronic supplementary material The online version of this article (10.1186/s12964-019-0334-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Geneviève Hamel-Côté
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, J1H 4N5, Canada
| | - Fanny Lapointe
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, J1H 4N5, Canada
| | - Daniel Gendron
- Agriculture and Agri-Food Canada, Dairy and Swine Research and Development Center, 2000 College Street, Sherbrooke, QC, Canada
| | - Marek Rola-Pleszczynski
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, J1H 4N5, Canada
| | - Jana Stankova
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, J1H 4N5, Canada.
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Hamel-Côté G, Gendron D, Rola-Pleszczynski M, Stankova J. Regulation of platelet-activating factor-mediated protein tyrosine phosphatase 1B activation by a Janus kinase 2/calpain pathway. PLoS One 2017; 12:e0180336. [PMID: 28686728 PMCID: PMC5501562 DOI: 10.1371/journal.pone.0180336] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 06/14/2017] [Indexed: 11/18/2022] Open
Abstract
Atherosclerosis is a pro-inflammatory condition underlying many cardiovascular diseases. Platelet-activating factor (PAF) and interleukin 6 (IL-6) are actively involved in the onset and progression of atherosclerotic plaques. The involvement of monocyte-derived macrophages is well characterized in the installation of inflammatory conditions in the plaque, but less is known about the contribution of monocyte-derived dendritic cells (Mo-DCs). In the same way, the involvement of calcium, phospholipase C and A2 in PAF-induced IL-6 production, in different cells types, has been shown; however, the importance of the Jak/STAT pathway and its regulation by protein-tyrosine phosphatases in this response have not been addressed. In this study, we report that PAF stimulates PTP1B activity via Jak2, thereby modulating PAF-induced IL-6 production. Using HEK 293 cells stably transfected with the PAF receptor in order to discriminate the pathway components, our results suggest that Jak2 modulates PAF-induced IL-6 production via both positive and negative pathways. Jak2 kinase activity was necessary for maximal transactivation of the IL-6 promoter, as seen by luciferase assays, whereas the same kinase also downregulated this promoter transactivation through the activation of a calcium/calpain/PTP1B pathway. The same pathways were operational in monocyte-derived dendritic cells, since PAF-induced PTP1B activation negatively regulated PAF-induced IL-6 mRNA production and, in addition, Jak2 activated calpain, one of the components involved in PAF-induced PTP1B activation. Results obtained in this study indicate that Jak2 activation is important for maximal IL-6 promoter transactivation by PAF and that PTP1B is involved in the negative regulation of this transactivation. However, PTP1B does not directly regulate Jak2 activation, but rather Jak2 regulates PAF-induced PTP1B activation.
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Affiliation(s)
- Geneviève Hamel-Côté
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Daniel Gendron
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Marek Rola-Pleszczynski
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Jana Stankova
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
- * E-mail:
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Bögershausen N, Tsai IC, Pohl E, Kiper PÖS, Beleggia F, Percin EF, Keupp K, Matchan A, Milz E, Alanay Y, Kayserili H, Liu Y, Banka S, Kranz A, Zenker M, Wieczorek D, Elcioglu N, Prontera P, Lyonnet S, Meitinger T, Stewart AF, Donnai D, Strom TM, Boduroglu K, Yigit G, Li Y, Katsanis N, Wollnik B. RAP1-mediated MEK/ERK pathway defects in Kabuki syndrome. J Clin Invest 2015; 125:3585-99. [PMID: 26280580 PMCID: PMC4588287 DOI: 10.1172/jci80102] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 07/09/2015] [Indexed: 02/06/2023] Open
Abstract
The genetic disorder Kabuki syndrome (KS) is characterized by developmental delay and congenital anomalies. Dominant mutations in the chromatin regulators lysine (K)-specific methyltransferase 2D (KMT2D) (also known as MLL2) and lysine (K)-specific demethylase 6A (KDM6A) underlie the majority of cases. Although the functions of these chromatin-modifying proteins have been studied extensively, the physiological systems regulated by them are largely unknown. Using whole-exome sequencing, we identified a mutation in RAP1A that was converted to homozygosity as the result of uniparental isodisomy (UPD) in a patient with KS and a de novo, dominant mutation in RAP1B in a second individual with a KS-like phenotype. We elucidated a genetic and functional interaction between the respective KS-associated genes and their products in zebrafish models and patient cell lines. Specifically, we determined that dysfunction of known KS genes and the genes identified in this study results in aberrant MEK/ERK signaling as well as disruption of F-actin polymerization and cell intercalation. Moreover, these phenotypes could be rescued in zebrafish models by rebalancing MEK/ERK signaling via administration of small molecule inhibitors of MEK. Taken together, our studies suggest that the KS pathophysiology overlaps with the RASopathies and provide a potential direction for treatment design.
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Affiliation(s)
- Nina Bögershausen
- Institute of Human Genetics
- Center for Molecular Medicine Cologne (CMMC), and
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - I-Chun Tsai
- Center for Human Disease Modeling and Department of Cell Biology, Duke University, Durham, North Carolina, USA
| | - Esther Pohl
- Institute of Human Genetics
- Center for Molecular Medicine Cologne (CMMC), and
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Pelin Özlem Simsek Kiper
- Pediatric Genetics Unit, Department of Pediatrics, Hacettepe University Medical Faculty, Ankara, Turkey
| | - Filippo Beleggia
- Institute of Human Genetics
- Center for Molecular Medicine Cologne (CMMC), and
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - E. Ferda Percin
- Department of Medical Genetics, Gazi University Faculty of Medicine, Ankara, Turkey
| | - Katharina Keupp
- Institute of Human Genetics
- Center for Molecular Medicine Cologne (CMMC), and
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Angela Matchan
- Oxford Gene Technology (OGT), Begbroke Science Park, Begbroke, Oxfordshire, United Kingdom
| | - Esther Milz
- Institute of Human Genetics
- Center for Molecular Medicine Cologne (CMMC), and
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Yasemin Alanay
- Pediatric Genetics Unit, Department of Pediatrics, Hacettepe University Medical Faculty, Ankara, Turkey
- Pediatric Genetics, Department of Pediatrics, Acibadem University, School of Medicine, Istanbul, Turkey
| | - Hülya Kayserili
- Medical Genetics Department, Koç University, School of Medicine, Istanbul, Turkey
| | - Yicheng Liu
- Institute of Human Genetics
- Center for Molecular Medicine Cologne (CMMC), and
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Siddharth Banka
- Department of Genetic Medicine, St. Mary’s Hospital, Manchester Academic Health Sciences Centre (MAHSC), University of Manchester, Manchester, United Kingdom
| | - Andrea Kranz
- Genomics, Bio-Innovationszentrum, Dresden University of Technology, Dresden, Germany
| | - Martin Zenker
- Institute of Human Genetics, University Hospital Magdeburg, Magdeburg, Germany
| | - Dagmar Wieczorek
- Institut für Humangenetik, Universitätsklinikum Essen, Essen, Germany
| | - Nursel Elcioglu
- Department of Pediatric Genetics, Marmara University Medical Faculty, Istanbul, Turkey
| | - Paolo Prontera
- Medical Genetics Unit, Hospital and University of Perugia, Perugia, Italy
| | - Stanislas Lyonnet
- Université Paris Descartes-Sorbonne Paris Cité, Institut Imagine, INSERM U781, Hôpital Necker-Enfants Malades, Paris, France
| | - Thomas Meitinger
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - A. Francis Stewart
- Genomics, Bio-Innovationszentrum, Dresden University of Technology, Dresden, Germany
| | - Dian Donnai
- Department of Genetic Medicine, St. Mary’s Hospital, Manchester Academic Health Sciences Centre (MAHSC), University of Manchester, Manchester, United Kingdom
| | - Tim M. Strom
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Human Genetics, Technische Universität München, Munich, Germany
| | - Koray Boduroglu
- Pediatric Genetics Unit, Department of Pediatrics, Hacettepe University Medical Faculty, Ankara, Turkey
| | - Gökhan Yigit
- Institute of Human Genetics
- Center for Molecular Medicine Cologne (CMMC), and
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Yun Li
- Institute of Human Genetics
- Center for Molecular Medicine Cologne (CMMC), and
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Nicholas Katsanis
- Center for Human Disease Modeling and Department of Cell Biology, Duke University, Durham, North Carolina, USA
| | - Bernd Wollnik
- Institute of Human Genetics
- Center for Molecular Medicine Cologne (CMMC), and
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
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Correa-Costa M, Andrade-Oliveira V, Braga TT, Castoldi A, Aguiar CF, Origassa CST, Rodas ACD, Hiyane MI, Malheiros DMAC, Rios FJO, Jancar S, Câmara NOS. Activation of platelet-activating factor receptor exacerbates renal inflammation and promotes fibrosis. J Transl Med 2014; 94:455-66. [PMID: 24492283 DOI: 10.1038/labinvest.2013.155] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 11/20/2013] [Accepted: 12/19/2013] [Indexed: 12/13/2022] Open
Abstract
Platelet-activating factor (PAF) is a lipid mediator with important pro-inflammatory effects, being synthesized by several cell types including kidney cells. Although there is evidence of its involvement in acute renal dysfunction, its role in progressive kidney injury is not completely known. In the present study, we investigated the role of PAF receptor (PAFR) in an experimental model of chronic renal disease. Wild-type (WT) and PAFR knockout (KO) mice underwent unilateral ureter obstruction (UUO), and at kill time, urine and kidney tissue was collected. PAFR KO animals compared with WT mice present: (a) less renal dysfunction, evaluated by urine protein/creatinine ratio; (b) less fibrosis evaluated by collagen deposition, type I collagen, Lysyl Oxidase-1 (LOX-1) and transforming growth factor β (TGF-β) gene expression, and higher expression of bone morphogenetic protein 7 (BMP-7) (3.3-fold lower TGF-β/BMP-7 ratio); (c) downregulation of extracellular matrix (ECM) and adhesion molecule-related machinery genes; and (d) lower levels of pro-inflammatory cytokines. These indicate that PAFR engagement by PAF or PAF-like molecules generated during UUO potentiates renal dysfunction and fibrosis and might promote epithelial-to-mesenchymal transition (EMT). Also, early blockade of PAFR after UUO leads to a protective effect, with less fibrosis deposition. In conclusion, PAFR signaling contributes to a pro-inflammatory environment in the model of obstructive nephropathy, favoring the fibrotic process, which lately will generate renal dysfunction and progressive organ failure.
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Affiliation(s)
- Matheus Correa-Costa
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Vinicius Andrade-Oliveira
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Tarcio T Braga
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Angela Castoldi
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Cristhiane F Aguiar
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | | | - Andrea C D Rodas
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Meire I Hiyane
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | | | - Francisco J O Rios
- 1] Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil [2] British Heart Foundation, Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - Sonia Jancar
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Niels O S Câmara
- 1] Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil [2] Nephrology Division, Federal University of São Paulo, São Paulo, Brazil
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Xu C, Reichert EC, Nakano T, Lohse M, Gardner AA, Revelo MP, Topham MK, Stafforini DM. Deficiency of phospholipase A2 group 7 decreases intestinal polyposis and colon tumorigenesis in Apc(Min/+) mice. Cancer Res 2013; 73:2806-16. [PMID: 23361301 DOI: 10.1158/0008-5472.can-12-2374] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Platelet-activating factor (PAF) is a naturally occurring phospholipid that mediates diverse effects such as physiological and pathological inflammation, immunosuppression, and cancer. Several lines of evidence support both positive and negative roles for PAF in carcinogenesis. PAF stimulates cell growth, oncogenic transformation, and metastasis, but can also limit proliferation and induce apoptosis. The biological context and microenvironment seem to define whether PAF has pro- or anticarcinogenic effects. To investigate the role of exacerbated PAF signaling in colon cancer, we conducted cell-based and in vivo studies using genetically engineered mice lacking expression of phospholipase A2 group 7 (PLA2G7), an enzyme that specifically metabolizes PAF and structurally related glycerophospholipids. Absence of Pla2g7 robustly decreased intestinal polyposis and colon tumor formation in Apc(Min)(/+) mice, suggesting an antitumorigenic role for PAF in settings characterized by aberrant function of the tumor suppressor Adenomatous polyposis coli (Apc). In colonic epithelial cells, exposure to a PAF analog led to dephosphorylation of Akt at serine-473 and induction of apoptosis. The mechanism of this response involved formation of a complex between β-arrestin 1 and the Akt phosphatase PHLPP2, and activation of the intrinsic pathway of apoptosis. Our results suggest that strategies based on inhibiting PLA2G7 activity or increasing PAF-mediated signaling hold promise for the treatment of intestinal malignancies that harbor mutations in APC.
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Affiliation(s)
- Changxin Xu
- Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, USA
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Dupré DJ, Rola-Pleszczynski M, Stankova J. Rescue of internalization-defective platelet-activating factor receptor function by EBP50/NHERF1. J Cell Commun Signal 2012; 6:205-16. [PMID: 22878922 DOI: 10.1007/s12079-012-0175-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 08/01/2012] [Indexed: 12/20/2022] Open
Abstract
Platelet-activating factor (PAF) is a potent phospholipid mediator involved in specific disease states such as allergic asthma, atherosclerosis and psoriasis. The human PAF receptor (PAFR) is a member of the G protein-coupled receptor (GPCR) family. Following PAF stimulation, cells become rapidly desensitized; this refractory state can be maintained for hours and is dependent on PAFR phosphorylation, internalization and trafficking. EBP50/NHERF1 has been found to interact with a variety of proteins and these interactions are involved in a growing range of functions including the assembly of signalling complexes, receptor recycling and transport of proteins to the cell surface. Crucial roles of EBP50 in GPCR physiology include its involvement in internalization, recycling, and downregulation. We were interested in identifying the role of EBP50 in PAFR trafficking. Our results showed that EBP50 binds the PAFR in its basal state, while stimulation decreased the ratio of interaction between the two proteins. We also demonstrated that EBP50 could bind PAFR via its PDZ 2 domain. In addition, we studied the role of EBP50 in various functions of the PAFR such as PAF-induced inositol phosphate accumulation and receptor internalization: EBP50 decreased the WT PAFR response and rescued the function of internalization-deficient mutant receptors, as previously described for the arrestins and the GRKs. These results suggest new roles for EBP50, some of which could help understanding the complex formation after receptor activation.
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Affiliation(s)
- Denis J Dupré
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, 5850 College St., PO BOX 15000, Halifax, NS, B3H 4R2, Canada,
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Nogués L, Salcedo A, Mayor F, Penela P. Multiple scaffolding functions of {beta}-arrestins in the degradation of G protein-coupled receptor kinase 2. J Biol Chem 2010; 286:1165-73. [PMID: 21081496 DOI: 10.1074/jbc.m110.203406] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
G protein-coupled receptor kinase 2 (GRK2) plays a fundamental role in the regulation of G protein-coupled receptors (GPCRs), and changes in GRK2 expression levels can have an important impact on cell functions. GRK2 is known to be degraded by the proteasome pathway. We have shown previously that β-arrestins participate in enhanced kinase turnover upon GPCR stimulation by facilitating GRK2 phosphorylation by c-Src or by MAPK or by recruiting the Mdm2 E3 ubiquitin ligase to the receptor complex. In this report, we have investigated how such diverse β-arrestin scaffold functions are integrated to modulate GRK2 degradation. Interestingly, we found that in the absence of GPCR activation, β-arrestins do not perform an adaptor role for GRK2/Mdm2 association, but rather compete with GRK2 for direct Mdm2 binding to regulate basal kinase turnover. Upon agonist stimulation, β-arrestins-mediated phosphorylation of GRK2 at serine 670 by MAPK facilitates Mdm2-mediated GRK2 degradation, whereas c-Src-dependent phosphorylation would support the action of an undetermined β-arrestin-recruited ligase in the absence of GPCR activation. The ability of β-arrestins to play different scaffold functions would allow coordination of both Mdm2-dependent and -independent processes aimed at the specific modulation of GRK2 turnover in different signaling contexts.
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Affiliation(s)
- Laura Nogués
- Departamento de Biología Molecular and Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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Poisson C, Rollin S, Véronneau S, Bousquet SM, Larrivée JF, Le Gouill C, Boulay G, Stankova J, Rola-Pleszczynski M. Caveolae Facilitate but Are Not Essential for Platelet-Activating Factor-Mediated Calcium Mobilization and Extracellular Signal-Regulated Kinase Activation. THE JOURNAL OF IMMUNOLOGY 2009; 183:2747-57. [DOI: 10.4049/jimmunol.0802651] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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11
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Zhang X, Pan XL, Liu XT, Wang S, Wang LJ. Down-regulation of platelet-activating factor receptor gene expression during focal reversible cerebral ischemia in rats. Neurochem Res 2007; 32:451-6. [PMID: 17268849 DOI: 10.1007/s11064-006-9248-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Accepted: 12/01/2006] [Indexed: 11/28/2022]
Abstract
Platelet-activating factor (PAF) is an endogenous potent phospholipid mediator in stroke and related to the post-ischemic brain damage. The aim of this study was to investigate the regulation and mechanisms of PAF receptor gene expression in the perifocal regions of cerebral infarction after middle cerebral artery occlusion/reperfusion. Sixty mature Wistar rats were randomly divided into 12 groups: sham-operated control group, simple ischemia 90 min group, 6, 12, 18 h, 1 day (1 d), 2, 3, 4, 5, 6, 7 d reperfusion groups. After the right middle cerebral artery occluded, the rats were suffered from ischemia for 90 min, and then reperfusion was allowed for different time courses. Reverse transcription-polymerase chain reaction (RT-PCR) and radioimmunoassay were applied to evaluate the PAF receptor messenger RNA (mRNA) expression and PAF levels in the perifocal regions of cerebral infarction respectively. RT-PCR analysis revealed that PAF receptor mRNA was 0.95 +/- 0.15 in control group. However, following ischemia-reperfusion, the levels of PAF receptor mRNA progressively decreased until 2 d of reperfusion (0.54 +/- 0.10), then returned to control group's levels gradually. Compared with the control group's (582 +/- 72 pg/g wet weight), the PAF concentrations of simple ischemic and 6, 12, 18 h, 1, 2 d reperfusion group were significantly higher than that of any other groups. These results indicate that PAF receptor gene expression may be subject to down-regulation in the perifocal regions of cerebral infarction after cerebral ischemia-reperfusion and relative to the increase of endogenous PAF concentrations.
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Affiliation(s)
- Xiong Zhang
- Department of Neurology, Guangdong Provincial People's Hospital, Nanfang Medical University, 106, Zhongshan Er Road, Guangzhou, Guangdong Province 510080, PR China
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12
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Zhou W, Ibe BO, Raj JU. Platelet-activating factor induces ovine fetal pulmonary venous smooth muscle cell proliferation: role of epidermal growth factor receptor transactivation. Am J Physiol Heart Circ Physiol 2007; 292:H2773-81. [PMID: 17322418 DOI: 10.1152/ajpheart.01018.2006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have previously reported that platelet-activating factor (PAF) is present in very high levels in the ovine fetal lung and circulation and that PAF serves as an important physiological vasoconstrictor of the pulmonary circulation in utero. However, it is not known whether PAF stimulates pulmonary vascular smooth muscle cell (SMC) proliferation. In this study, we used ovine fetal pulmonary venous SMCs as our model system to study the effects and mechanisms of action of PAF on SMC proliferation. We found that PAF induced SMC proliferation in a dose-dependent manner. PAF also stimulated activation of both ERK and p38 but not c-Jun NH(2) terminal kinase (JNK) mitogen-activated protein (MAP) kinase pathways. PAF (10 nM) induced phosphorylation of epidermal growth factor receptor (EGFR). Specific inhibition of EGFR by AG-1478 and by the expression of a dominant-negative EGFR mutant in SMCs attenuated PAF-stimulated cell proliferation. Inhibition of heparin-binding EGF-like growth factor (HB-EGF) release by CRM-197 and inhibition of matrix metalloproteinases (MMP) by GM-6001 abolished PAF-induced MAP kinase activation and cell proliferation. Increased alkaline phosphatase (AP) activity after PAF treatment in AP-HB-EGF fusion construct-transfected SMCs indicated that PAF induced the release of HB-EGF within 1 min. Gelatin zymography data showed that PAF stimulated MMP-2 activity and MMP-9 activity within 1 min. These results suggest that PAF promotes pulmonary vascular SMC proliferation via transactivation of EGFR through MMP activation and HB-EGF, resulting in p38 and ERK activation and that EGFR transactivation is essential for the mitogenic effect of PAF in pulmonary venous SMC.
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MESH Headings
- Animals
- Bacterial Proteins/pharmacology
- Cell Proliferation/drug effects
- Cells, Cultured
- Dipeptides/pharmacology
- Dose-Response Relationship, Drug
- Enzyme Activation
- Enzyme Inhibitors/pharmacology
- Epidermal Growth Factor/genetics
- Epidermal Growth Factor/metabolism
- ErbB Receptors/drug effects
- ErbB Receptors/genetics
- ErbB Receptors/metabolism
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Heparin-binding EGF-like Growth Factor
- Intercellular Signaling Peptides and Proteins
- Matrix Metalloproteinase 2/metabolism
- Matrix Metalloproteinase 9/metabolism
- Matrix Metalloproteinase Inhibitors
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/embryology
- Muscle, Smooth, Vascular/metabolism
- Mutation
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Phosphorylation
- Platelet Activating Factor/metabolism
- Platelet Activating Factor/pharmacology
- Pulmonary Veins/cytology
- Pulmonary Veins/embryology
- Pulmonary Veins/metabolism
- Quinazolines
- Sheep
- Signal Transduction/drug effects
- Time Factors
- Transfection
- Tyrphostins/pharmacology
- p38 Mitogen-Activated Protein Kinases/metabolism
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Affiliation(s)
- Weilin Zhou
- Division of Neonatology, Harbor-University of California, Los Angeles (UCLA) Medical Center, Los Angeles Biomedical Institute, 1124 West Carson St., Torrance, CA 90502, USA.
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13
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Navarro V, Martin S, Mazella J. Internalization-dependent regulation of HT29 cell proliferation by neurotensin. Peptides 2006; 27:2502-7. [PMID: 16870305 DOI: 10.1016/j.peptides.2006.04.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2005] [Accepted: 04/13/2006] [Indexed: 11/24/2022]
Abstract
In this study, we have investigated the involvement of the internalization process induced by neurotensin (NT) on MAP kinases Erk1/2 activation, inositol phosphates (IP) accumulation and cell growth in the human colonic cancer cell line HT29. Reversible blocking of NT/neurotensin receptor (NTR) complex endocytosis by hyperosmolar sucrose totally abolished both the phosphorylation of the MAP kinases Erk1/2 and the [3H]-thymidine incorporation induced by the peptide. By contrast, NT-evoked IP formation was not affected by sucrose treatment. These results therefore indicate that NT/NTR complex endocytosis triggers MAP kinase activation and subsequently the growth of HT29 cells. This property could be useful for the development of novel anticancer treatments.
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Affiliation(s)
- Valérie Navarro
- Institut de Pharmacologie Moléculaire et Cellulaire, Unité Mixte de Recherche 6097 du Centre National de la Recherche Scientifique, 660 route des Lucioles, Sophia Antipolis, 06560 Valbonne, France
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14
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McLaughlin NJD, Banerjee A, Kelher MR, Gamboni-Robertson F, Hamiel C, Sheppard FR, Moore EE, Silliman CC. Platelet-activating factor-induced clathrin-mediated endocytosis requires beta-arrestin-1 recruitment and activation of the p38 MAPK signalosome at the plasma membrane for actin bundle formation. THE JOURNAL OF IMMUNOLOGY 2006; 176:7039-50. [PMID: 16709866 DOI: 10.4049/jimmunol.176.11.7039] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Clathrin-mediated endocytosis (CME) is a common pathway used by G protein-linked receptors to transduce extracellular signals. We hypothesize that platelet-activating factor (PAF) receptor (PAFR) ligation requires CME and causes engagement of beta-arrestin-1 and recruitment of a p38 MAPK signalosome that elicits distinct actin rearrangement at the receptor before endosomal scission. Polymorphonuclear neutrophils were stimulated with buffer or 2 microM PAF (1 min), and whole cell lysates or subcellular fractions were immunoprecipitated or slides prepared for colocalization and fluorescent resonance energy transfer analysis. In select experiments, beta-arrestin-1 or dynamin-2 were neutralized by intracellular introduction of specific Abs. PAFR ligation caused 1) coprecipitation of the PAFR and clathrin with beta-arrestin-1, 2) fluorescent resonance energy transfer-positive interactions among the PAFR, beta-arrestin-1, and clathrin, 3) recruitment and activation of the apoptosis signal-regulating kinase-1/MAPK kinase-3/p38 MAPK (ASK1/MKK3/p38 MAPK) signalosome, 4) cell polarization, and 5) distinct actin bundle formation at the PAFR. Neutralization of beta-arrestin-1 inhibited all of these cellular events, including PAFR internalization; conversely, dynamin-2 inhibition only affected receptor internalization. Selective p38 MAPK inhibition globally abrogated actin rearrangement; however, inhibition of MAPK-activated protein kinase-2 and its downstream kinase leukocyte-specific protein-1 inhibited only actin bundle formation and PAFR internalization. In addition, ASK1/MKK3/p38 MAPK signalosome assembly appears to occur in a novel manner such that the ASK1/p38 MAPK heterodimer is recruited to a beta-arrestin-1 bound MKK3. In polymorphonuclear neutrophils, leukocyte-specific protein-1 may play a role similar to fascin for actin bundle formation. We conclude that PAF signaling requires CME, beta-arrestin-1 recruitment of a p38 MAPK signalosome, and specific actin bundle formation at the PAFR for transduction before endosomal scission.
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Affiliation(s)
- Nathan J D McLaughlin
- Department of Pediatrics, University of Colorado School of Medicine, Denver, CO 80262, USA
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15
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Gaudreault E, Thompson C, Stankova J, Rola-Pleszczynski M. Involvement of BLT1 Endocytosis and Yes Kinase Activation in Leukotriene B4-Induced Neutrophil Degranulation. THE JOURNAL OF IMMUNOLOGY 2005; 174:3617-25. [PMID: 15749899 DOI: 10.4049/jimmunol.174.6.3617] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
One of the important biological activities of human neutrophils is degranulation, which can be induced by leukotriene B4 (LTB4). Here we investigated the intracellular signaling events involved in neutrophil degranulation mediated by the high affinity LTB4 receptor, BLT1. Peripheral blood neutrophils as well as the promyeloid PLB-985 cell line, stably transfected with BLT1 cDNA and differentiated into a neutrophil-like cell phenotype, were used throughout this study. LTB4-induced enzyme release was inhibited by 50-80% when cells were pretreated with the pharmacological inhibitors of endocytosis sucrose, Con A and NH4Cl. In addition, transient transfection with a dominant negative form of dynamin (K44A) resulted in approximately 70% inhibition of ligand-induced degranulation. Pretreating neutrophils or BLT1-expressing PLB-985 cells with the Src family kinase inhibitor PP1 resulted in a 30-60% inhibition in BLT1-mediated degranulation. Yes kinase, but not c-Src, Fgr, Hck, or Lyn, was found to exhibit up-regulated kinase activity after LTB4 stimulation. Moreover, BLT1 endocytosis was found to be necessary for Yes kinase activation in neutrophils. LTB4-induced degranulation was also sensitive to inhibition of PI3K. In contrast, it was not affected by inhibition of the mitogen-activated protein kinase MEK kinase, the Janus kinases, or the receptor tyrosine kinase epidermal growth factor receptor or platelet-derived growth factor receptor. Taken together, our results suggest an essential role for BLT1 endocytosis and Yes kinase activation in LTB4-mediated degranulation of human neutrophils.
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Affiliation(s)
- Eric Gaudreault
- Immunology Division, Department of Pediatrics, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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Grey A, Banovic T, Zhu Q, Watson M, Callon K, Palmano K, Ross J, Naot D, Reid IR, Cornish J. The Low-Density Lipoprotein Receptor-Related Protein 1 Is a Mitogenic Receptor for Lactoferrin in Osteoblastic Cells. Mol Endocrinol 2004; 18:2268-78. [PMID: 15178744 DOI: 10.1210/me.2003-0456] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Lactoferrin induces osteoblast proliferation and survival in vitro and is anabolic to bone in vivo. The molecular mechanisms by which lactoferrin exerts these biological actions are not known, but lactoferrin is known to bind to two members of the low-density lipoprotein receptor family, low- density lipoprotein receptor-related proteins 1 (LRP1) and 2 (LRP2). We have examined the role(s) of these receptors in the actions of lactoferrin on osteoblasts. We show that lactoferrin binds to cultured osteoblastic cells, and that LRP1 and LRP2 are expressed in several osteoblastic cell types. In primary rat osteoblastic cells, the LRP1/2 inhibitor receptor associated protein blocks endocytosis of lactoferrin and abrogates lactoferrin-induced p42/44 MAPK signaling and mitogenesis. Lactoferrin-induced mitogenesis is also inhibited by an antibody to LRP1. Lactoferrin also induces receptor associated protein-sensitive activation of p42/44 MAPK signaling and proliferation in osteoblastic human SaOS-2 cells, which express LRP1 but not LRP2. The mitogenic response of LRP1-null fibroblastic cells to lactoferrin is substantially reduced compared with that of cells expressing wild-type LRP1. The endocytic and signaling functions of LRP1 are independent of each other, because lactoferrin can activate mitogenic signaling in conditions in which endocytosis is inhibited. Taken together, these results 1) suggest that mitogenic signaling through LRP1 to p42/44 MAPKs contributes to the anabolic skeletal actions of lactoferrin; 2) demonstrate growth-promoting actions of a third LRP family member in osteoblasts; and 3) provide further evidence that LRP1 functions as a signaling receptor in addition to its recognized role in ligand endocytosis.
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Affiliation(s)
- Andrew Grey
- Department of Medicine, University of Auckland, Private Bag 92019, Auckland, New Zealand.
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