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Alahari S, Farrell A, Ermini L, Park C, Sallais J, Roberts S, Gillmore T, Litvack M, Post M, Caniggia I. JMJD6 Dysfunction Due to Iron Deficiency in Preeclampsia Disrupts Fibronectin Homeostasis Resulting in Diminished Trophoblast Migration. Front Cell Dev Biol 2021; 9:652607. [PMID: 34055782 PMCID: PMC8149756 DOI: 10.3389/fcell.2021.652607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/31/2021] [Indexed: 12/12/2022] Open
Abstract
The mechanisms contributing to excessive fibronectin in preeclampsia, a pregnancy-related disorder, remain unknown. Herein, we investigated the role of JMJD6, an O2- and Fe2+-dependent enzyme, in mediating placental fibronectin processing and function. MALDI-TOF identified fibronectin as a novel target of JMJD6-mediated lysyl hydroxylation, preceding fibronectin glycosylation, deposition, and degradation. In preeclamptic placentae, fibronectin accumulated primarily in lysosomes of the mesenchyme. Using primary placental mesenchymal cells (pMSCs), we found that fibronectin fibril formation and turnover were markedly impeded in preeclamptic pMSCs, partly due to impaired lysosomal degradation. JMJD6 knockdown in control pMSCs recapitulated the preeclamptic FN phenotype. Importantly, preeclamptic pMSCs had less total and labile Fe2+ and Hinokitiol treatment rescued fibronectin assembly and promoted lysosomal degradation. Time-lapse imaging demonstrated that defective ECM deposition by preeclamptic pMSCs impeded HTR-8/SVneo cell migration, which was rescued upon Hinokitiol exposure. Our findings reveal new Fe2+-dependent mechanisms controlling fibronectin homeostasis/function in the placenta that go awry in preeclampsia.
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Affiliation(s)
- Sruthi Alahari
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Abby Farrell
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Leonardo Ermini
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, Canada
| | - Chanho Park
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, Canada
| | - Julien Sallais
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Sarah Roberts
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, Canada
| | - Taylor Gillmore
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Michael Litvack
- Program in Translational Medicine, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, ON, Canada
| | - Martin Post
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Program in Translational Medicine, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, ON, Canada
| | - Isabella Caniggia
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Department of Obstetrics and Gynecology, University of Toronto, Toronto, ON, Canada
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2
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Slac2-b Coordinates Extracellular Vesicle Secretion to Regulate Keratinocyte Adhesion and Migration. J Invest Dermatol 2020; 141:523-532.e2. [PMID: 32890627 DOI: 10.1016/j.jid.2020.08.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 11/21/2022]
Abstract
Slac2-b, also known as exophilin-5, is a Rab27b effector protein with a role in exosome transport and is encoded by the EXPH5 gene. We previously described biallelic loss-of-function mutations in EXPH5 in an autosomal recessive form of epidermolysis bullosa simplex. However, how the loss of Slac2-b expression leads to skin fragility and erosions is unknown. In this study, we demonstrate that keratinocytes (KCs) isolated from two different individuals with mutations in EXPH5 have significant defects in cell‒matrix adhesion. EXPH5-mutant KCs also showed increased perinuclear accumulation and significantly reduced trafficking of CD63+ vesicles. These phenotypes were also seen in Slac2-b‒deficient KCs. This was coincident with a reduction in Rab27a protein expression in Slac2-b‒mutant KCs as well as reduced secretion of extracellular vesicles containing extracellular matrix proteins. Live imaging analysis revealed a strong correlation between CD63+ vesicle trafficking to the plasma membrane and focal adhesion dynamics. These findings support a role for Slac2-b in regulating local focal adhesion dynamics to support effective KC adhesion and provide insight into the underlying pathophysiology of inherited skin blistering.
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3
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Iring A, Jin YJ, Albarrán-Juárez J, Siragusa M, Wang S, Dancs PT, Nakayama A, Tonack S, Chen M, Künne C, Sokol AM, Günther S, Martínez A, Fleming I, Wettschureck N, Graumann J, Weinstein LS, Offermanns S. Shear stress-induced endothelial adrenomedullin signaling regulates vascular tone and blood pressure. J Clin Invest 2019; 129:2775-2791. [PMID: 31205027 DOI: 10.1172/jci123825] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 05/01/2019] [Indexed: 12/22/2022] Open
Abstract
Hypertension is a primary risk factor for cardiovascular diseases including myocardial infarction and stroke. Major determinants of blood pressure are vasodilatory factors such as nitric oxide (NO) released from the endothelium under the influence of fluid shear stress exerted by the flowing blood. Several endothelial signaling processes mediating fluid shear stress-induced formation and release of vasodilatory factors have been described. It is, however, still poorly understood how fluid shear stress induces these endothelial responses. Here we show that the endothelial mechanosensitive cation channel PIEZO1 mediated fluid shear stress-induced release of adrenomedullin, which in turn activated its Gs-coupled receptor. The subsequent increase in cAMP levels promoted the phosphorylation of endothelial NO synthase (eNOS) at serine 633 through protein kinase A (PKA), leading to the activation of the enzyme. This Gs/PKA-mediated pathway synergized with the AKT-mediated pathways leading to eNOS phosphorylation at serine 1177. Mice with endothelium-specific deficiency of adrenomedullin, the adrenomedullin receptor, or Gαs showed reduced flow-induced eNOS activation and vasodilation and developed hypertension. Our data identify fluid shear stress-induced PIEZO1 activation as a central regulator of endothelial adrenomedullin release and establish the adrenomedullin receptor and subsequent Gs-mediated formation of cAMP as a critical endothelial mechanosignaling pathway regulating basal endothelial NO formation, vascular tone, and blood pressure.
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Affiliation(s)
- Andras Iring
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Young-June Jin
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Julián Albarrán-Juárez
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Mauro Siragusa
- Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt am Main, Germany.,German Centre for Cardiovascular Research (DZHK), Rhine-Main site, Frankfurt and Bad Nauheim, Germany
| | - ShengPeng Wang
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany.,Cardiovascular Research Center, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Yanta District, Xi'an, China
| | - Péter T Dancs
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary
| | - Akiko Nakayama
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Sarah Tonack
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Min Chen
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland, USA
| | | | - Anna M Sokol
- Scientific Service Group Biomolecular Mass Spectrometry, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | | | - Alfredo Martínez
- Oncology Area, Center for Biomedical Research of La Rioja (CIBIR), Logroño, Spain
| | - Ingrid Fleming
- Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt am Main, Germany.,German Centre for Cardiovascular Research (DZHK), Rhine-Main site, Frankfurt and Bad Nauheim, Germany
| | - Nina Wettschureck
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany.,German Centre for Cardiovascular Research (DZHK), Rhine-Main site, Frankfurt and Bad Nauheim, Germany.,Centre for Molecular Medicine, Medical Faculty, Goethe University, Frankfurt am Main, Germany
| | - Johannes Graumann
- German Centre for Cardiovascular Research (DZHK), Rhine-Main site, Frankfurt and Bad Nauheim, Germany.,Scientific Service Group Biomolecular Mass Spectrometry, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Lee S Weinstein
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland, USA
| | - Stefan Offermanns
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany.,German Centre for Cardiovascular Research (DZHK), Rhine-Main site, Frankfurt and Bad Nauheim, Germany.,Centre for Molecular Medicine, Medical Faculty, Goethe University, Frankfurt am Main, Germany
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4
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Li L, Kołodziej T, Jafari N, Chen J, Zhu H, Rajfur Z, Huang C. Cdk5-mediated phosphorylation regulates phosphatidylinositol 4-phosphate 5-kinase type I γ 90 activity and cell invasion. FASEB J 2018; 33:631-642. [PMID: 30040488 DOI: 10.1096/fj.201800296r] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Phosphatidylinositol 4-phosphate 5-kinase type I γ (PIPKIγ90) regulates cell migration, invasion, and metastasis. However, it is unknown how cellular signals regulate those processes. Here, we show that cyclin-dependent kinase 5 (Cdk5), a protein kinase that regulates cell migration and invasion, phosphorylates PIPKIγ90 at S453, and that Cdk5-mediated PIPKIγ90 phosphorylation is essential for cell invasion. Moreover, Cdk5-mediated phosphorylation down-regulates the activity of PIPKIγ90 and the secretion of fibronectin, an extracellular matrix protein that regulates cell migration and invasion. Furthermore, inhibition of PIPKIγ activity with the chemical inhibitor UNC3230 suppresses fibronectin secretion in a dose-dependent manner, whereas depletion of Cdk5 enhances fibronectin secretion. With total internal reflection fluorescence microscopy, we found that secreted fibronectin appears as round dots, which colocalize with Tks5 and CD9 but not with Zyxin. These data suggest that Cdk5-mediated PIPKIγ90 phosphorylation regulates cell invasion by controlling PIPKIγ90 activity and fibronectin secretion.-Li, L., Kołodziej, T., Jafari, N., Chen, J., Zhu, H., Rajfur, Z., Huang, C. Cdk5-mediated phosphorylation regulates phosphatidylinositol 4-phosphate 5-kinase type I γ 90 activity and cell invasion.
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Affiliation(s)
- Liqing Li
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
| | - Tomasz Kołodziej
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA.,Faculty of Physics, Astronomy, and Applied Computer Science, Institute of Physics, Jagiellonian University, Krakow, Poland
| | - Naser Jafari
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
| | - Jing Chen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, USA; and
| | - Haining Zhu
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, USA; and
| | - Zenon Rajfur
- Faculty of Physics, Astronomy, and Applied Computer Science, Institute of Physics, Jagiellonian University, Krakow, Poland
| | - Cai Huang
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA.,Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
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5
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Sampayo RG, Toscani AM, Rubashkin MG, Thi K, Masullo LA, Violi IL, Lakins JN, Cáceres A, Hines WC, Coluccio Leskow F, Stefani FD, Chialvo DR, Bissell MJ, Weaver VM, Simian M. Fibronectin rescues estrogen receptor α from lysosomal degradation in breast cancer cells. J Cell Biol 2018; 217:2777-2798. [PMID: 29980625 PMCID: PMC6080927 DOI: 10.1083/jcb.201703037] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 12/20/2017] [Accepted: 05/03/2018] [Indexed: 02/07/2023] Open
Abstract
Estrogen receptor α (ERα) is expressed in tissues as diverse as brains and mammary glands. In breast cancer, ERα is a key regulator of tumor progression. Therefore, understanding what activates ERα is critical for cancer treatment in particular and cell biology in general. Using biochemical approaches and superresolution microscopy, we show that estrogen drives membrane ERα into endosomes in breast cancer cells and that its fate is determined by the presence of fibronectin (FN) in the extracellular matrix; it is trafficked to lysosomes in the absence of FN and avoids the lysosomal compartment in its presence. In this context, FN prolongs ERα half-life and strengthens its transcriptional activity. We show that ERα is associated with β1-integrin at the membrane, and this integrin follows the same endocytosis and subcellular trafficking pathway triggered by estrogen. Moreover, ERα+ vesicles are present within human breast tissues, and colocalization with β1-integrin is detected primarily in tumors. Our work unravels a key, clinically relevant mechanism of microenvironmental regulation of ERα signaling.
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Affiliation(s)
- Rocío G Sampayo
- Universidad de Buenos Aires, Instituto de Oncología "Ángel H. Roffo", Área Investigación, Buenos Aires, Argentina .,Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Ciudad Universitaria, Buenos Aires, Argentina.,Universidad Nacional de San Martín, Instituto de Nanosistemas, Campus Miguelete, San Martín, Argentina
| | - Andrés M Toscani
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, IQUIBICEN UBA-CONICET y Universidad Nacional de Luján, Departamento de Ciencias Básicas, Buenos Aires, Argentina
| | - Matthew G Rubashkin
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA
| | - Kate Thi
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Luciano A Masullo
- Centro de Investigaciones en Bionanociencias, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.,Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ianina L Violi
- Centro de Investigaciones en Bionanociencias, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Jonathon N Lakins
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA
| | - Alfredo Cáceres
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, Córdoba, Argentina
| | - William C Hines
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Federico Coluccio Leskow
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, IQUIBICEN UBA-CONICET y Universidad Nacional de Luján, Departamento de Ciencias Básicas, Buenos Aires, Argentina
| | - Fernando D Stefani
- Centro de Investigaciones en Bionanociencias, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.,Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Dante R Chialvo
- Center for Complex Systems and Brain Sciences, Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín and Consejo Nacional de Investigaciones Científicas y Tecnológicas, San Martín, Argentina
| | - Mina J Bissell
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Valerie M Weaver
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA
| | - Marina Simian
- Universidad de Buenos Aires, Instituto de Oncología "Ángel H. Roffo", Área Investigación, Buenos Aires, Argentina .,Universidad Nacional de San Martín, Instituto de Nanosistemas, Campus Miguelete, San Martín, Argentina
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6
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Sánchez-Sánchez BJ, Urbano JM, Comber K, Dragu A, Wood W, Stramer B, Martín-Bermudo MD. Drosophila Embryonic Hemocytes Produce Laminins to Strengthen Migratory Response. Cell Rep 2018; 21:1461-1470. [PMID: 29117553 PMCID: PMC5695906 DOI: 10.1016/j.celrep.2017.10.047] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 09/05/2017] [Accepted: 10/11/2017] [Indexed: 12/28/2022] Open
Abstract
The most prominent developmental function attributed to the extracellular matrix (ECM) is cell migration. While cells in culture can produce ECM to migrate, the role of ECM in regulating developmental cell migration is classically viewed as an exogenous matrix presented to the moving cells. In contrast to this view, we show here that Drosophila embryonic hemocytes deposit their own laminins in streak-like structures to migrate efficiently throughout the embryo. With the help of transplantation experiments, live microscopy, and image quantification, we demonstrate that autocrine-produced laminin regulates hemocyte migration by controlling lamellipodia dynamics, stability, and persistence. Proper laminin deposition is regulated by the RabGTPase Rab8, which is highly expressed and required in hemocytes for lamellipodia dynamics and migration. Our results thus support a model in which, during embryogenesis, the Rab8-regulated autocrine deposition of laminin reinforces directional and effective migration by stabilizing cellular protrusions and strengthening otherwise transient adhesion states. Drosophila embryonic hemocytes use autocrine-produced laminins for their migration Autocrine laminins regulate lamellipodia dynamics, stability, and persistence Rab8 regulates laminin deposition and lamellipodia dynamics in migrating hemocytes Laminins deposit in tracks around hemocytes and in a fibrillar mesh over the VNC
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Affiliation(s)
- Besaiz J Sánchez-Sánchez
- CABD (CSIC-Universidad Pablo de Olavide-JA), Sevilla 41013, Spain; Randall Centre for Cell and Molecular Biophysics, King's College London, London SE5 9AP, UK
| | - José M Urbano
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Kate Comber
- Department of Cellular and Molecular Medicine, Biomedical Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Anca Dragu
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE5 9AP, UK
| | - Will Wood
- Department of Cellular and Molecular Medicine, Biomedical Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Brian Stramer
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE5 9AP, UK
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7
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Dysregulated fibronectin trafficking by Hsp90 inhibition restricts prostate cancer cell invasion. Sci Rep 2018; 8:2090. [PMID: 29391407 PMCID: PMC5794796 DOI: 10.1038/s41598-018-19871-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 01/08/2018] [Indexed: 12/17/2022] Open
Abstract
The molecular chaperone Hsp90 is overexpressed in prostate cancer (PCa) and is responsible for the folding, stabilization and maturation of multiple oncoproteins, which are implicated in PCa progression. Compared to first-in-class Hsp90 inhibitors such as 17-allylamino-demethoxygeldanamycin (17-AAG) that were clinically ineffective, second generation inhibitor AUY922 has greater solubility and efficacy. Here, transcriptomic and proteomic analyses of patient-derived PCa explants identified cytoskeletal organization as highly enriched with AUY922 treatment. Validation in PCa cell lines revealed that AUY922 caused marked alterations to cell morphology, and suppressed cell motility and invasion compared to vehicle or 17-AAG, concomitant with dysregulation of key extracellular matrix proteins such as fibronectin (FN1). Interestingly, while the expression of FN1 was increased by AUY922, FN1 secretion was significantly decreased. This resulted in cytosolic accumulation of FN1 protein within late endosomes, suggesting that AUY922 disrupts vesicular secretory trafficking pathways. Depletion of FN1 by siRNA knockdown markedly reduced the invasive capacity of PCa cells, phenocopying AUY922. These results highlight a novel mechanism of action for AUY922 beyond its established effects on cellular mitosis and survival and, furthermore, identifies extracellular matrix cargo delivery as a potential therapeutic target for the treatment of aggressive PCa.
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8
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Navratil AM, Dozier MG, Whitesell JD, Clay CM, Roberson MS. Role of cortactin in dynamic actin remodeling events in gonadotrope cells. Endocrinology 2014; 155:548-57. [PMID: 24274984 PMCID: PMC3891938 DOI: 10.1210/en.2012-1924] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
GnRH induces marked activation of the actin cytoskeleton in gonadotropes; however, the physiological consequences and cellular mechanisms responsible have yet to be fully elucidated. The current studies focus on the actin scaffolding protein cortactin. Using the gonadotrope-derived αT3-1 cell line, we found that cortactin is phosphorylated at Y(421), S(405), and S(418) in a time-dependent manner in response to the GnRH agonist buserelin (GnRHa). GnRHa induced translocation of cortactin to the leading edge of the plasma membrane where it colocalizes with actin and actin-related protein 3 (Arp3). Incubation of αT3-1 cells with the c-src inhibitor phosphoprotein phosphatase 1, blocked tyrosine phosphorylation of cortactin, reduced cortactin association with Arp3, and blunted actin reorganization in response to GnRHa. Additionally, we used RNA silencing strategies to knock down cortactin in αT3-1 cells. Knockdown of cortactin blocked the ability of αT3-1 cells to generate filopodia, lamellipodia, and membrane ruffles in response to GnRHa. We show that lamellipodia and filopodia are capable of LHβ mobilization in primary pituitary culture after GnRHa treatment, and disruption of these structures using jasplakinolide reduces LH secretion. Collectively, our findings suggest that after GnRHa activation, src activity leads to tyrosine phosphorylation of cortactin, which facilitates its association with Arp3 to engage the actin cytoskeleton. The reorganization of actin by cortactin potentially underlies GnRHa-induced secretory events within αT3-1 cells.
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Affiliation(s)
- Amy M Navratil
- College of Arts and Sciences, Department of Zoology and Physiology (A.M.N., M.G.D.), University of Wyoming, Laramie, Wyoming 82071; College of Veterinary Medicine and Biomedical Science, Departments of Microbiology, Immunology, and Pathology (J.D.W.) and Biomedical Sciences (C.M.C.), Colorado State University, Ft Collins, Colorado, 80523; and College of Veterinary Medicine, Department of Biomedical Sciences (M.S.R.), Cornell University, Ithaca, New York 14853
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9
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Wong MS, Sidik SM, Mahmud R, Stanslas J. Molecular targets in the discovery and development of novel antimetastatic agents: current progress and future prospects. Clin Exp Pharmacol Physiol 2013; 40:307-19. [PMID: 23534409 DOI: 10.1111/1440-1681.12083] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 03/18/2013] [Accepted: 03/21/2013] [Indexed: 01/08/2023]
Abstract
Tumour invasion and metastasis have been recognized as major causal factors in the morbidity and mortality among cancer patients. Many advances in the knowledge of cancer metastasis have yielded an impressive array of attractive drug targets, including enzymes, receptors and multiple signalling pathways. The present review summarizes the molecular pathogenesis of metastasis and the identification of novel molecular targets used in the discovery of antimetastatic agents. Several promising targets have been highlighted, including receptor tyrosine kinases, effector molecules involved in angiogenesis, matrix metalloproteinases (MMPs), urokinase plasminogen activator, adhesion molecules and their receptors, signalling pathways (e.g. phosphatidylinositol 3-kinase, phospholipase Cγ1, mitogen-activated protein kinases, c-Src kinase, c-Met kinases and heat shock protein. The discovery and development of potential novel therapeutics for each of the targets are also discussed in this review. Among these, the most promising agents that have shown remarkable clinical outcome are anti-angiogenic agents (e.g. bevacizumab). Newer agents, such as c-Met kinase inhibitors, are still undergoing preclinical studies and are yet to have their clinical efficacy proven. Some therapeutics, such as first-generation MMP inhibitors (MMPIs; e.g. marimastat) and more selective versions of them (e.g. prinomastat, tanomastat), have undergone clinical trials. Unfortunately, these drugs produced serious adverse effects that led to the premature termination of their development. In the future, third-generation MMPIs and inhibitors of signalling pathways and adhesion molecules could form valuable novel classes of drugs in the anticancer armamentarium to combat metastasis.
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Affiliation(s)
- Mei S Wong
- Pharmacotherapeutics Unit, Department of Medicine, University Putra Malaysia, Serdang, Selangor, Malaysia
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10
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Bouétard A, Besnard AL, Vassaux D, Lagadic L, Coutellec MA. Impact of the redox-cycling herbicide diquat on transcript expression and antioxidant enzymatic activities of the freshwater snail Lymnaea stagnalis. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 126:256-265. [PMID: 23237706 DOI: 10.1016/j.aquatox.2012.11.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 11/06/2012] [Accepted: 11/17/2012] [Indexed: 06/01/2023]
Abstract
The presence of pesticides in the environment results in potential unwanted effects on non-target species. Freshwater organisms inhabiting water bodies adjacent to agricultural areas, such as ditches, ponds and marshes, are good models to test such effects as various pesticides may reach these habitats through several ways, including aerial drift, run-off, and drainage. Diquat is a non-selective herbicide used for crop protection or for weed control in such water bodies. In this study, we investigated the effects of diquat on a widely spread aquatic invertebrate, the holarctic freshwater snail Lymnaea stagnalis. Due to the known redox-cycling properties of diquat, we studied transcript expression and enzymatic activities relative to oxidative and general stress in the haemolymph and gonado-digestive complex (GDC). As diquat is not persistent, snails were exposed for short times (5, 24, and 48 h) to ecologically relevant concentrations (22.2, 44.4, and 222.2 μg l(-1)) of diquat dibromide. RT-qPCR was used to quantify the transcription of genes encoding catalase (cat), a cytosolic superoxide dismutase (Cu/Zn-sod), a selenium-dependent glutathione peroxidase (gpx), a glutathione reductase (gred), the retinoid X receptor (rxr), two heat shock proteins (hsp40 and hsp70), cortactin (cor) and the two ribosomal genes r18S and r28s. Enzymatic activities of SOD, Gpx, Gred and glutathione S-transferase (GST) were investigated in the GDC using spectrophoto/fluorometric methods. Opposite trends were obtained in the haemolymph depending on the herbicide concentration. At the lowest concentration, effects were mainly observed after 24 h of exposure, with over-transcription of cor, hsp40, rxr, and sod, whereas higher concentrations down-regulated the expression of most of the studied transcripts, especially after 48 h of exposure. In the GDC, earlier responses were observed and the fold-change magnitude was generally much higher: transcription of all target genes increased significantly (or non-significantly for cat) after 5 h of exposure, and went back to control levels afterwards, suggesting the onset of an early response to oxidative stress associated to the unbalance of reactive oxygen species (ROS) in hepatocytes. Although increases obtained for Gred and SOD activities were globally consistent with their respective transcript expressions, up-regulation of transcription was not always correlated with increase of enzymatic activity, indicating that diquat might affect steps downstream of transcription. However, constitutive levels of enzymatic activities were at least maintained. In conclusion, diquat was shown to affect expression of the whole set of studied transcripts, reflecting their suitability as markers of early response to oxidative stress in L. stagnalis.
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Affiliation(s)
- Anthony Bouétard
- INRA, UMR INRA-Agrocampus Ouest ESE, Equipe Ecotoxicologie et Qualité des Milieux Aquatiques, Rennes, France.
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Gunning P. BioArchitecture: the organization and regulation of biological space. BIOARCHITECTURE 2012; 2:200-3. [PMID: 23267413 PMCID: PMC3527313 DOI: 10.4161/bioa.22726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BioArchitecture is a term used to describe the organization and regulation of biological space. It applies to the principles which govern the structure of molecules, polymers and mutiprotein complexes, organelles, membranes and their organization in the cytoplasm and the nucleus. It also covers the integration of cells into their three dimensional environment at the level of cell-matrix, cell-cell interactions, integration into tissue/organ structure and function and finally into the structure of the organism. This review will highlight studies at all these levels which are providing a new way to think about the relationship between the organization of biological space and the function of biological systems.
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Affiliation(s)
- Peter Gunning
- School of Medical Sciences, University of New South Wales, Sydney, Australia.
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