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Waldeck-Weiermair M, Das AA, Covington TA, Yadav S, Kaynert J, Guo R, Balendran P, Thulabandu VR, Pandey AK, Spyropoulos F, Thomas DC, Michel T. An essential role for EROS in redox-dependent endothelial signal transduction. Redox Biol 2024; 73:103214. [PMID: 38805973 PMCID: PMC11153901 DOI: 10.1016/j.redox.2024.103214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/22/2024] [Accepted: 05/24/2024] [Indexed: 05/30/2024] Open
Abstract
The chaperone protein EROS ("Essential for Reactive Oxygen Species") was recently discovered in phagocytes. EROS was shown to regulate the abundance of the ROS-producing enzyme NADPH oxidase isoform 2 (NOX2) and to control ROS-mediated cell killing. Reactive oxygen species are important not only in immune surveillance, but also modulate physiological signaling responses in multiple tissues. The roles of EROS have not been previously explored in the context of oxidant-modulated cell signaling. Here we show that EROS plays a key role in ROS-dependent signal transduction in vascular endothelial cells. We used siRNA-mediated knockdown and developed CRISPR/Cas9 knockout of EROS in human umbilical vein endothelial cells (HUVEC), both of which cause a significant decrease in the abundance of NOX2 protein, associated with a marked decrease in RAC1, a small G protein that activates NOX2. Loss of EROS also attenuates receptor-mediated hydrogen peroxide (H2O2) and Ca2+ signaling, disrupts cytoskeleton organization, decreases cell migration, and promotes cellular senescence. EROS knockdown blocks agonist-modulated eNOS phosphorylation and nitric oxide (NO●) generation. These effects of EROS knockdown are strikingly similar to the alterations in endothelial cell responses that we previously observed following RAC1 knockdown. Proteomic analyses following EROS or RAC1 knockdown in endothelial cells showed that reduced abundance of these two distinct proteins led to largely overlapping effects on endothelial biological processes, including oxidoreductase, protein phosphorylation, and endothelial nitric oxide synthase (eNOS) pathways. These studies demonstrate that EROS plays a central role in oxidant-modulated endothelial cell signaling by modulating NOX2 and RAC1.
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Affiliation(s)
- Markus Waldeck-Weiermair
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA; Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010, Graz, Austria.
| | - Apabrita A Das
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Taylor A Covington
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Shambhu Yadav
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Jonas Kaynert
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Ruby Guo
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Priyanga Balendran
- Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Puddicombe Way, Cambridge, CB2 0AW, UK
| | - Venkata Revanth Thulabandu
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Arvind K Pandey
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Fotios Spyropoulos
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA; Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - David C Thomas
- Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Puddicombe Way, Cambridge, CB2 0AW, UK.
| | - Thomas Michel
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
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Piccoli M, Cirillo F, Ghiroldi A, Rota P, Coviello S, Tarantino A, La Rocca P, Lavota I, Creo P, Signorelli P, Pappone C, Anastasia L. Sphingolipids and Atherosclerosis: The Dual Role of Ceramide and Sphingosine-1-Phosphate. Antioxidants (Basel) 2023; 12:antiox12010143. [PMID: 36671005 PMCID: PMC9855164 DOI: 10.3390/antiox12010143] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/28/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Sphingolipids are bioactive molecules that play either pro- and anti-atherogenic roles in the formation and maturation of atherosclerotic plaques. Among SLs, ceramide and sphingosine-1-phosphate showed antithetic properties in regulating various molecular mechanisms and have emerged as novel potential targets for regulating the development of atherosclerosis. In particular, maintaining the balance of the so-called ceramide/S1P rheostat is important to prevent the occurrence of endothelial dysfunction, which is the trigger for the entire atherosclerotic process and is strongly associated with increased oxidative stress. In addition, these two sphingolipids, together with many other sphingolipid mediators, are directly involved in the progression of atherogenesis and the formation of atherosclerotic plaques by promoting the oxidation of low-density lipoproteins (LDL) and influencing the vascular smooth muscle cell phenotype. The modulation of ceramide and S1P levels may therefore allow the development of new antioxidant therapies that can prevent or at least impair the onset of atherogenesis, which would ultimately improve the quality of life of patients with coronary artery disease and significantly reduce their mortality.
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Affiliation(s)
- Marco Piccoli
- Laboratory of Stem Cells for Tissue Engineering, IRCCS Policlinico San Donato, Piazza Malan 2, San Donato Milanese, 20097 Milan, Italy
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
| | - Federica Cirillo
- Laboratory of Stem Cells for Tissue Engineering, IRCCS Policlinico San Donato, Piazza Malan 2, San Donato Milanese, 20097 Milan, Italy
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
| | - Andrea Ghiroldi
- Laboratory of Stem Cells for Tissue Engineering, IRCCS Policlinico San Donato, Piazza Malan 2, San Donato Milanese, 20097 Milan, Italy
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
| | - Paola Rota
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, 20133 Milan, Italy
| | - Simona Coviello
- Laboratory of Stem Cells for Tissue Engineering, IRCCS Policlinico San Donato, Piazza Malan 2, San Donato Milanese, 20097 Milan, Italy
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
| | - Adriana Tarantino
- Laboratory of Stem Cells for Tissue Engineering, IRCCS Policlinico San Donato, Piazza Malan 2, San Donato Milanese, 20097 Milan, Italy
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
- Faculty of Medicine and Surgery, University Vita-Salute San Raffaele, Via Olgettina 58, 20132 Milan, Italy
| | - Paolo La Rocca
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
- Department of Biomedical Sciences for Health, University of Milan, Via Mangiagalli 31, 20133 Milan, Italy
| | - Ivana Lavota
- Laboratory of Stem Cells for Tissue Engineering, IRCCS Policlinico San Donato, Piazza Malan 2, San Donato Milanese, 20097 Milan, Italy
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
| | - Pasquale Creo
- Laboratory of Stem Cells for Tissue Engineering, IRCCS Policlinico San Donato, Piazza Malan 2, San Donato Milanese, 20097 Milan, Italy
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
| | - Paola Signorelli
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
- Aldo Ravelli Center for Neurotechnology and Experimental Brain Therapeutics, Department of Health Sciences, University of Milan, Via Antonio di Rudinì 8, 20142 Milan, Italy
| | - Carlo Pappone
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
- Faculty of Medicine and Surgery, University Vita-Salute San Raffaele, Via Olgettina 58, 20132 Milan, Italy
- Arrhythmology Department, IRCCS Policlinico San Donato, Piazza Malan 2, San Donato Milanese, 20097 Milan, Italy
| | - Luigi Anastasia
- Laboratory of Stem Cells for Tissue Engineering, IRCCS Policlinico San Donato, Piazza Malan 2, San Donato Milanese, 20097 Milan, Italy
- Institute for Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
- Faculty of Medicine and Surgery, University Vita-Salute San Raffaele, Via Olgettina 58, 20132 Milan, Italy
- Correspondence: ; Tel.: +39-0226437765
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Waldeck-Weiermair M, Yadav S, Kaynert J, Thulabandu VR, Pandey AK, Spyropoulos F, Covington T, Das AA, Krüger C, Michel T. Differential endothelial hydrogen peroxide signaling via Nox isoforms: Critical roles for Rac1 and modulation by statins. Redox Biol 2022; 58:102539. [PMID: 36401888 PMCID: PMC9673117 DOI: 10.1016/j.redox.2022.102539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/08/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
Statins have manifold protective effects on the cardiovascular system. In addition to lowering LDL cholesterol levels, statins also have antioxidant effects on cardiovascular tissues involving intracellular redox pathways that are incompletely understood. Inhibition of HMG-CoA reductase by statins not only modulates cholesterol synthesis, but also blocks the synthesis of lipids necessary for the post-translational modification of signaling proteins, including the GTPase Rac1. Here we studied the mechanisms whereby Rac1 and statins modulate the intracellular oxidant hydrogen peroxide (H2O2) via NADPH oxidase (Nox) isoforms. In live-cell imaging experiments using the H2O2 biosensor HyPer7, we observed robust H2O2 generation in human umbilical vein endothelial cells (HUVEC) following activation of cell surface receptors for histamine or vascular endothelial growth factor (VEGF). Both VEGF- and histamine-stimulated H2O2 responses were abrogated by siRNA-mediated knockdown of Rac1. VEGF responses required the Nox isoforms Nox2 and Nox4, while histamine-stimulated H2O2 signals are independent of Nox4 but still required Nox2. Endothelial H2O2 responses to both histamine and VEGF were completely inhibited by simvastatin. In resting endothelial cells, Rac1 is targeted to the cell membrane and cytoplasm, but simvastatin treatment promotes translocation of Rac1 to the cell nucleus. The effects of simvastatin both on receptor-dependent H2O2 production and Rac1 translocation are rescued by treatment of cells with mevalonic acid, which is the enzymatic product of the HMG-CoA reductase that is inhibited by statins. Taken together, these studies establish that receptor-modulated H2O2 responses to histamine and VEGF involve distinct Nox isoforms, both of which are completely dependent on Rac1 prenylation.
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Affiliation(s)
- Markus Waldeck-Weiermair
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Shambhu Yadav
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jonas Kaynert
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Arvind K Pandey
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Fotios Spyropoulos
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Taylor Covington
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Apabrita Ayan Das
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Christina Krüger
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Thomas Michel
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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Tolksdorf C, Moritz E, Wolf R, Meyer U, Marx S, Bien-Möller S, Garscha U, Jedlitschky G, Rauch BH. Platelet-Derived S1P and Its Relevance for the Communication with Immune Cells in Multiple Human Diseases. Int J Mol Sci 2022; 23:ijms231810278. [PMID: 36142188 PMCID: PMC9499465 DOI: 10.3390/ijms231810278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/02/2022] [Accepted: 09/03/2022] [Indexed: 11/16/2022] Open
Abstract
Sphingosine-1-phosphate (S1P) is a versatile signaling lipid involved in the regulation of numerous cellular processes. S1P regulates cellular proliferation, migration, and apoptosis as well as the function of immune cells. S1P is generated from sphingosine (Sph), which derives from the ceramide metabolism. In particular, high concentrations of S1P are present in the blood. This originates mainly from erythrocytes, endothelial cells (ECs), and platelets. While erythrocytes function as a storage pool for circulating S1P, platelets can rapidly generate S1P de novo, store it in large quantities, and release it when the platelet is activated. Platelets can thus provide S1P in a short time when needed or in the case of an injury with subsequent platelet activation and thereby regulate local cellular responses. In addition, platelet-dependently generated and released S1P may also influence long-term immune cell functions in various disease processes, such as inflammation-driven vascular diseases. In this review, the metabolism and release of platelet S1P are presented, and the autocrine versus paracrine functions of platelet-derived S1P and its relevance in various disease processes are discussed. New pharmacological approaches that target the auto- or paracrine effects of S1P may be therapeutically helpful in the future for pathological processes involving S1P.
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Affiliation(s)
- Céline Tolksdorf
- Division of Pharmacology and Toxicology, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany
- Department of General Pharmacology, University Medicine Greifswald, 17489 Greifswald, Germany
| | - Eileen Moritz
- Department of General Pharmacology, University Medicine Greifswald, 17489 Greifswald, Germany
| | - Robert Wolf
- Department of General Pharmacology, University Medicine Greifswald, 17489 Greifswald, Germany
| | - Ulrike Meyer
- Division of Pharmacology and Toxicology, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany
| | - Sascha Marx
- Department of Neurosurgery, University Medicine Greifswald, 17489 Greifswald, Germany
| | - Sandra Bien-Möller
- Department of General Pharmacology, University Medicine Greifswald, 17489 Greifswald, Germany
- Department of Neurosurgery, University Medicine Greifswald, 17489 Greifswald, Germany
| | - Ulrike Garscha
- Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany
| | - Gabriele Jedlitschky
- Department of General Pharmacology, University Medicine Greifswald, 17489 Greifswald, Germany
| | - Bernhard H. Rauch
- Division of Pharmacology and Toxicology, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany
- Correspondence:
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5
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Giri H, Srivastava AK, Naik UP. Apoptosis signal-regulating kinase-1 regulates thrombin-induced endothelial permeability. Vascul Pharmacol 2022; 145:107088. [DOI: 10.1016/j.vph.2022.107088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/17/2022] [Accepted: 06/29/2022] [Indexed: 11/16/2022]
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Ouellette MM, Zhou S, Yan Y. Cell Signaling Pathways That Promote Radioresistance of Cancer Cells. Diagnostics (Basel) 2022; 12:diagnostics12030656. [PMID: 35328212 PMCID: PMC8947583 DOI: 10.3390/diagnostics12030656] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/26/2022] [Accepted: 03/02/2022] [Indexed: 12/20/2022] Open
Abstract
Radiation therapy (RT) is a standard treatment for solid tumors and about 50% of patients with cancer, including pediatric cancer, receive RT. While RT has significantly improved the overall survival and quality of life of cancer patients, its efficacy has still been markedly limited by radioresistance in a significant number of cancer patients (intrinsic or acquired), resulting in failure of the RT control of the disease. Radiation eradicates cancer cells mainly by causing DNA damage. However, radiation also concomitantly activates multiple prosurvival signaling pathways, which include those mediated by ATM, ATR, AKT, ERK, and NF-κB that promote DNA damage checkpoint activation/DNA repair, autophagy induction, and/or inhibition of apoptosis. Furthermore, emerging data support the role of YAP signaling in promoting the intrinsic radioresistance of cancer cells, which occurs through its activation of the transcription of many essential genes that support cell survival, DNA repair, proliferation, and the stemness of cancer stem cells. Together, these signaling pathways protect cancer cells by reducing the magnitude of radiation-induced cytotoxicity and promoting radioresistance. Thus, targeting these prosurvival signaling pathways could potentially improve the radiosensitivity of cancer cells. In this review, we summarize the contribution of these pathways to the radioresistance of cancer cells.
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Affiliation(s)
- Michel M. Ouellette
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Sumin Zhou
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Ying Yan
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE 68198, USA;
- Correspondence:
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Hashimoto Y, Campbell M, Tachibana K, Okada Y, Kondoh M. Claudin-5: A Pharmacological Target to Modify the Permeability of the Blood-Brain Barrier. Biol Pharm Bull 2021; 44:1380-1390. [PMID: 34602546 DOI: 10.1248/bpb.b21-00408] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Claudin-5 is the dominant tight junction protein in brain endothelial cells and exclusively limits the paracellular permeability of molecules larger than 400 Da across the blood-brain barrier (BBB). Its pathological impairment or sustained down-regulation has been shown to lead to the progression of psychiatric and neurological disorders, whereas its expression under physiological conditions prevents the passage of drugs across the BBB. While claudin-5 enhancers could potentially act as vascular stabilizers to treat neurological diseases, claudin-5 inhibitors could function as delivery systems to enhance the brain uptake of hydrophilic small-molecular-weight drugs. Therefore, the effects of claudin-5 manipulation on modulating the BBB in different neurological diseases requires further examination. To manipulate claudin-5 expression levels and function, several claudin-5 modulating molecules have been developed. In this review, we first describe the molecular, cellular and pathological aspects of claudin-5 to highlight the mechanisms of claudin-5 enhancers/inhibitors. We then discuss recently developed claudin-5 enhancers/inhibitors and new methods to discover these molecules.
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Affiliation(s)
| | | | | | - Yoshiaki Okada
- Graduate School of Pharmaceutical Sciences, Osaka University
| | - Masuo Kondoh
- Graduate School of Pharmaceutical Sciences, Osaka University
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Pleiotropic and Potentially Beneficial Effects of Reactive Oxygen Species on the Intracellular Signaling Pathways in Endothelial Cells. Antioxidants (Basel) 2021; 10:antiox10060904. [PMID: 34205032 PMCID: PMC8229098 DOI: 10.3390/antiox10060904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 02/06/2023] Open
Abstract
Endothelial cells (ECs) are exposed to molecular dioxygen and its derivative reactive oxygen species (ROS). ROS are now well established as important signaling messengers. Excessive production of ROS, however, results in oxidative stress, a significant contributor to the development of numerous diseases. Here, we analyze the experimental data and theoretical concepts concerning positive pro-survival effects of ROS on signaling pathways in endothelial cells (ECs). Our analysis of the available experimental data suggests possible positive roles of ROS in induction of pro-survival pathways, downstream of the Gi-protein-coupled receptors, which mimics insulin signaling and prevention or improvement of the endothelial dysfunction. It is, however, doubtful, whether ROS can contribute to the stabilization of the endothelial barrier.
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Maltas J, Reed H, Porter A, Malliri A. Mechanisms and consequences of dysregulation of the Tiam family of Rac activators in disease. Biochem Soc Trans 2020; 48:2703-2719. [PMID: 33200195 DOI: 10.1042/bst20200481] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/16/2020] [Accepted: 10/16/2020] [Indexed: 12/14/2022]
Abstract
The Tiam family proteins - Tiam1 and Tiam2/STEF - are Rac1-specific Guanine Nucleotide Exchange Factors (GEFs) with important functions in epithelial, neuronal, immune and other cell types. Tiam GEFs regulate cellular migration, proliferation and survival, mainly through activating and directing Rac1 signalling. Dysregulation of the Tiam GEFs is significantly associated with human diseases including cancer, immunological and neurological disorders. Uncovering the mechanisms and consequences of dysregulation is therefore imperative to improving the diagnosis and treatment of diseases. Here we compare and contrast the subcellular localisation and function of Tiam1 and Tiam2/STEF, and review the evidence for their dysregulation in disease.
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Affiliation(s)
- Joe Maltas
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park SK10 4TG, U.K
| | - Hannah Reed
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park SK10 4TG, U.K
| | - Andrew Porter
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park SK10 4TG, U.K
| | - Angeliki Malliri
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park SK10 4TG, U.K
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Engelbrecht E, MacRae CA, Hla T. Lysolipids in Vascular Development, Biology, and Disease. Arterioscler Thromb Vasc Biol 2020; 41:564-584. [PMID: 33327749 DOI: 10.1161/atvbaha.120.305565] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Membrane phospholipid metabolism forms lysophospholipids, which possess unique biochemical and biophysical properties that influence membrane structure and dynamics. However, lysophospholipids also function as ligands for G-protein-coupled receptors that influence embryonic development, postnatal physiology, and disease. The 2 most well-studied species-lysophosphatidic acid and S1P (sphingosine 1-phosphate)-are particularly relevant to vascular development, physiology, and cardiovascular diseases. This review summarizes the role of lysophosphatidic acid and S1P in vascular developmental processes, endothelial cell biology, and their roles in cardiovascular disease processes. In addition, we also point out the apparent connections between lysophospholipid biology and the Wnt (int/wingless family) pathway, an evolutionarily conserved fundamental developmental signaling system. The discovery that components of the lysophospholipid signaling system are key genetic determinants of cardiovascular disease has warranted current and future research in this field. As pharmacological approaches to modulate lysophospholipid signaling have entered the clinical sphere, new findings in this field promise to influence novel therapeutic strategies in cardiovascular diseases.
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Affiliation(s)
- Eric Engelbrecht
- Vascular Biology Program, Boston Children's Hospital, Department of Surgery (E.E., T.H.), Harvard Medical School, Boston, MA
| | - Calum A MacRae
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, Department of Medicine (C.A.M.), Harvard Medical School, Boston, MA
| | - Timothy Hla
- Vascular Biology Program, Boston Children's Hospital, Department of Surgery (E.E., T.H.), Harvard Medical School, Boston, MA
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11
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Chi F, Sharpley MS, Nagaraj R, Roy SS, Banerjee U. Glycolysis-Independent Glucose Metabolism Distinguishes TE from ICM Fate during Mammalian Embryogenesis. Dev Cell 2020; 53:9-26.e4. [PMID: 32197068 DOI: 10.1016/j.devcel.2020.02.015] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/26/2019] [Accepted: 02/19/2020] [Indexed: 01/01/2023]
Abstract
The mouse embryo undergoes compaction at the 8-cell stage, and its transition to 16 cells generates polarity such that the outer apical cells are trophectoderm (TE) precursors and the inner cell mass (ICM) gives rise to the embryo. Here, we report that this first cell fate specification event is controlled by glucose. Glucose does not fuel mitochondrial ATP generation, and glycolysis is dispensable for blastocyst formation. Furthermore, glucose does not help synthesize amino acids, fatty acids, and nucleobases. Instead, glucose metabolized by the hexosamine biosynthetic pathway (HBP) allows nuclear localization of YAP1. In addition, glucose-dependent nucleotide synthesis by the pentose phosphate pathway (PPP), along with sphingolipid (S1P) signaling, activates mTOR and allows translation of Tfap2c. YAP1, TEAD4, and TFAP2C interact to form a complex that controls TE-specific gene transcription. Glucose signaling has no role in ICM specification, and this process of developmental metabolism specifically controls TE cell fate.
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Affiliation(s)
- Fangtao Chi
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Mark S Sharpley
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Raghavendra Nagaraj
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Shubhendu Sen Roy
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Utpal Banerjee
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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12
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Ouellette MM, Yan Y. Radiation‐activated prosurvival signaling pathways in cancer cells. PRECISION RADIATION ONCOLOGY 2019. [DOI: 10.1002/pro6.1076] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Michel M. Ouellette
- Department of Internal MedicineUniversity of Nebraska Medical Center Omaha Nebraska USA
| | - Ying Yan
- Department of Radiation OncologyUniversity of Nebraska Medical Center Omaha Nebraska USA
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Cho SM, Lee HK, Liu Q, Wang MW, Kwon HJ. A Guanidine-Based Synthetic Compound Suppresses Angiogenesis via Inhibition of Acid Ceramidase. ACS Chem Biol 2019; 14:11-19. [PMID: 30507149 DOI: 10.1021/acschembio.8b00558] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Angiogenesis generates new blood vessels from pre-existing vessels. Tumors induce the formation of new blood vessels to ensure sufficient oxygen and nutrients for their growth. Normally, angiogenesis is induced by various pro-angiogenesis factors, including vascular endothelial growth factor (VEGF). Inhibition of VEGF is a promising approach to cancer treatment. A guanidine-based synthetic compound, E2, was identified as a potent hit from 68 guanidine-based derivatives by screening for angiogenesis inhibitors showing antiproliferative activity in human umbilical vein endothelial cells (HUVECs). To explore the mode of action of E2, target proteins were investigated using phage display biopanning, and acid ceramidase 1 (ASAH1) was identified as an E2-binding protein. Drug affinity responsive target stability (DARTS) and ASAH1 activity assays revealed the direct binding of E2 to ASAH1. Moreover, siRNA knockdown of ASAH1 demonstrated its role as an angiogenesis factor. Consequently, E2 inhibited chemoinvasion and tube formation of HUVECs in a dose-dependent manner. E2 also potently suppressed neo-vascularization of chorioallantoic membranes in vivo. Collectively, these data suggest that E2 is a novel angiogenesis inhibitor and ASAH1 is proposed to be a new antiangiogenesis target.
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Affiliation(s)
- Sung Min Cho
- Chemical Genomics Global Research Laboratory, Department of Biotechnology, College of Life Science & Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
| | - Hyung Keun Lee
- Chemical Genomics Global Research Laboratory, Department of Biotechnology, College of Life Science & Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
| | - Qing Liu
- The National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Ming-Wei Wang
- The National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
- School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Ho Jeong Kwon
- Chemical Genomics Global Research Laboratory, Department of Biotechnology, College of Life Science & Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
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14
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Yagci ZB, Esvap E, Ozkara HA, Ulgen KO, Olmez EO. Inflammatory response and its relation to sphingolipid metabolism proteins: Chaperones as potential indirect anti-inflammatory agents. MOLECULAR CHAPERONES IN HUMAN DISORDERS 2019; 114:153-219. [DOI: 10.1016/bs.apcsb.2018.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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15
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Fu P, Shaaya M, Harijith A, Jacobson JR, Karginov A, Natarajan V. Sphingolipids Signaling in Lamellipodia Formation and Enhancement of Endothelial Barrier Function. CURRENT TOPICS IN MEMBRANES 2018; 82:1-31. [PMID: 30360778 DOI: 10.1016/bs.ctm.2018.08.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sphingolipids, first described in the brain in 1884, are important structural components of biological membranes of all eukaryotic cells. In recent years, several lines of evidence support the critical role of sphingolipids such as sphingosine, sphingosine-1-phosphate (S1P), and ceramide as anti- or pro-inflammatory bioactive lipid mediators in a variety of human pathologies including pulmonary and vascular disorders. Among the sphingolipids, S1P is a naturally occurring agonist that exhibits potent barrier enhancing property in the endothelium by signaling via G protein-coupled S1P1 receptor. S1P, S1P analogs, and other barrier enhancing agents such as HGF, oxidized phospholipids, and statins also utilize the S1P/S1P1 signaling pathway to generate membrane protrusions or lamellipodia, which have been implicated in resealing of endothelial gaps and maintenance of barrier integrity. A better understanding of sphingolipids mediated regulation of lamellipodia formation and barrier enhancement of the endothelium will be critical for the development of sphingolipid-based therapies to alleviate pulmonary disorders such as sepsis-, radiation-, and mechanical ventilation-induced acute lung injury.
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Affiliation(s)
- Panfeng Fu
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States
| | - Mark Shaaya
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States
| | - Anantha Harijith
- Department of Pediatrics, University of Illinois at Chicago, Chicago, IL, United States
| | - Jeffrey R Jacobson
- Department of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Andrei Karginov
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States
| | - Viswanathan Natarajan
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States; Department of Medicine, University of Illinois at Chicago, Chicago, IL, United States.
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16
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Cheng Y, Desse S, Martinez A, Worthen RJ, Jope RS, Beurel E. TNFα disrupts blood brain barrier integrity to maintain prolonged depressive-like behavior in mice. Brain Behav Immun 2018; 69:556-567. [PMID: 29452218 PMCID: PMC5963697 DOI: 10.1016/j.bbi.2018.02.003] [Citation(s) in RCA: 158] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 01/18/2018] [Accepted: 02/12/2018] [Indexed: 12/15/2022] Open
Abstract
Recovery from major depressive disorder is difficult, particularly in patients who are refractory to antidepressant treatments. To examine factors that regulate recovery, we developed a prolonged learned helplessness depression model in mice. After the induction of learned helplessness, mice were separated into groups that recovered or did not recover within 4 weeks. Comparisons were made between groups in hippocampal proteins, inflammatory cytokines, and blood brain barrier (BBB) permeability. Compared with mice that recovered and control mice, non-recovered mice displaying prolonged learned helplessness had greater hippocampal activation of glycogen synthase kinase-3 (GSK3), higher levels of tumor necrosis factor-α (TNFα), interleukin-17A, and interleukin-23, increased permeability of the blood brain barrier (BBB), and lower levels of the BBB tight junction proteins occludin, ZO1, and claudin-5. Treatment with the GSK3 inhibitor TDZD-8 reduced inflammatory cytokine levels, increased tight junction protein levels, and reversed impaired recovery from learned helplessness, demonstrating that prolonged learned helplessness is reversible and is maintained by abnormally active GSK3. In non-recovered mice with prolonged learned helpless, stimulation of sphingosine 1-phosphate receptors by Fingolimod or administration of the TNFα inhibitor etanercept repaired the BBB and reversed impaired recovery from prolonged learned helplessness. Thus, disrupted BBB integrity mediated in part by TNFα contributes to blocking recovery from prolonged learned helplessness depression-like behavior. Overall, this report describes a new model of prolonged depression-like behavior and demonstrates that stress-induced GSK3 activation contributes to disruption of BBB integrity mediated by inflammation, particularly TNFα, which contributes to impaired recovery from prolonged learned helplessness.
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Affiliation(s)
- Yuyan Cheng
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136,Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Sachi Desse
- Department of Biology, University of Miami, Coral Gables, FL 33146
| | - Ana Martinez
- Centro de Investigaciones Biologicas-CSIC, 28040 Madrid, Spain
| | - Ryan J. Worthen
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136,Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Richard S. Jope
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136,Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136,Corresponding author: Richard S. Jope, Miller School of Medicine, University of Miami, 1011 NW 15th Street, Gautier Building room 416, Miami, Florida 33136 USA, phone: 305-243-0262,
| | - Eleonore Beurel
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136,Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136
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17
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Abstract
Enterohemorrhagic Escherichia coli (EHEC) is a diarrheagenic pathogen that colonizes the gut mucosa and induces attaching-and-effacing lesions. EHEC employs a type III secretion system (T3SS) to translocate 50 effector proteins that hijack and manipulate host cell signaling pathways, which allow bacterial colonization and subversion of immune responses and disease progression. The aim of this study was to characterize the T3SS effector EspW. We found espW in the sequenced O157:H7 and non-O157 EHEC strains as well as in Shigella boydii. Furthermore, a truncated version of EspW, containing the first 206 residues, is present in EPEC strains belonging to serotype O55:H7. Screening a collection of clinical EPEC isolates revealed that espW is present in 52% of the tested strains. We report that EspW modulates actin dynamics in a Rac1-dependent manner. Ectopic expression of EspW results in formation of unique membrane protrusions. Infection of Swiss cells with an EHEC espW deletion mutant induces a cell shrinkage phenotype that could be rescued by Rac1 activation via expression of the bacterial guanine nucleotide exchange factor, EspT. Furthermore, using a yeast two-hybrid screen, we identified the motor protein Kif15 as a potential interacting partner of EspW. Kif15 and EspW colocalized in cotransfected cells, while ectopically expressed Kif15 localized to the actin pedestals following EHEC infection. The data suggest that Kif15 recruits EspW to the site of bacterial attachment, which in turn activates Rac1, resulting in modifications of the actin cytoskeleton that are essential to maintain cell shape during infection.
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18
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Komarova YA, Kruse K, Mehta D, Malik AB. Protein Interactions at Endothelial Junctions and Signaling Mechanisms Regulating Endothelial Permeability. Circ Res 2017; 120:179-206. [PMID: 28057793 DOI: 10.1161/circresaha.116.306534] [Citation(s) in RCA: 303] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 10/04/2016] [Accepted: 10/06/2016] [Indexed: 12/31/2022]
Abstract
The monolayer of endothelial cells lining the vessel wall forms a semipermeable barrier (in all tissue except the relatively impermeable blood-brain and inner retinal barriers) that regulates tissue-fluid homeostasis, transport of nutrients, and migration of blood cells across the barrier. Permeability of the endothelial barrier is primarily regulated by a protein complex called adherens junctions. Adherens junctions are not static structures; they are continuously remodeled in response to mechanical and chemical cues in both physiological and pathological settings. Here, we discuss recent insights into the post-translational modifications of junctional proteins and signaling pathways regulating plasticity of adherens junctions and endothelial permeability. We also discuss in the context of what is already known and newly defined signaling pathways that mediate endothelial barrier leakiness (hyperpermeability) that are important in the pathogenesis of cardiovascular and lung diseases and vascular inflammation.
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Affiliation(s)
- Yulia A Komarova
- From the Department of Pharmacology and the Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago
| | - Kevin Kruse
- From the Department of Pharmacology and the Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago
| | - Dolly Mehta
- From the Department of Pharmacology and the Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago
| | - Asrar B Malik
- From the Department of Pharmacology and the Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago.
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19
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Hein AL, Post CM, Sheinin YM, Lakshmanan I, Natarajan A, Enke CA, Batra SK, Ouellette MM, Yan Y. RAC1 GTPase promotes the survival of breast cancer cells in response to hyper-fractionated radiation treatment. Oncogene 2016; 35:6319-6329. [PMID: 27181206 PMCID: PMC5112160 DOI: 10.1038/onc.2016.163] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 03/08/2016] [Accepted: 03/29/2016] [Indexed: 01/22/2023]
Abstract
Radiation therapy is a staple approach for cancer treatment, whereas radioresistance of cancer cells remains a substantial clinical problem. In response to ionizing radiation (IR) induced DNA-damage, cancer cells can sustain/activate pro-survival signaling pathways, leading to apoptotic resistance and induction of cell cycle checkpoint/DNA repair. Previous studies show that Rac1 GTPase is overexpressed/hyperactivated in breast cancer cells and is associated with poor prognosis. Studies from our laboratory reveal that Rac1 activity is necessary for G2/M checkpoint activation and cell survival in response to IR exposure of breast and pancreatic cancer cells. In the present study, we investigated the effect of Rac1 on the survival of breast cancer cells treated with hyper-fractionated radiation (HFR), which is used clinically for cancer treatment. Results in this report indicate that Rac1 protein expression is increased in the breast cancer cells that survived HFR compared to parental cells. Furthermore, this increase of Rac1 is associated with enhanced activities of ERK1/2 and NF-κB signaling pathways and increased levels of anti-apoptotic protein Bcl-xL and Mcl-1, which are downstream targets of ERK1/2 and NF-κB signaling pathways. Using Rac1 specific inhibitor and dominant negative mutant N17Rac1, here we demonstrate that Rac1 inhibition decreases the phosphorylation of ERK1/2 and IκBα, as well as the levels of Bcl-xL and Mcl-1 protein in the HFR-selected breast cancer cells. Moreover, inhibition of Rac1 using either small molecule inhibitor or dominant negative N17Rac1 abrogates clonogenic survival of HFR-selected breast cancer cells and decreases the level of intact PARP, which is indicative of apoptosis induction. Collectively, results in this report suggest that Rac1 signaling is essential for the survival of breast cancer cells subjected to HFR and implicate Rac1 in radioresistance of breast cancer cells. These studies also provide the basis to explore Rac1 as a therapeutic target for radioresistant breast cancer cells.
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Affiliation(s)
- A L Hein
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE, USA
| | - C M Post
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Y M Sheinin
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - I Lakshmanan
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - A Natarajan
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
| | - C A Enke
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE, USA
| | - S K Batra
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - M M Ouellette
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Y Yan
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE, USA.,Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
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20
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Beta2-adrenergic activity modulates vascular tone regulation in lecithin:cholesterol acyltransferase knockout mice. Vascul Pharmacol 2015; 74:114-121. [PMID: 26254103 PMCID: PMC4675083 DOI: 10.1016/j.vph.2015.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 07/28/2015] [Accepted: 08/03/2015] [Indexed: 11/22/2022]
Abstract
Lecithin:cholesterol acyltransferase (LCAT) deficiency is associated with hypoalphalipoproteinemia, generally a predisposing factor for premature coronary heart disease. The evidence of accelerated atherosclerosis in LCAT-deficient subjects is however controversial. In this study, the effect of LCAT deficiency on vascular tone and endothelial function was investigated in LCAT knockout mice, which reproduce the human lipoprotein phenotype. Aortas from wild-type (Lcatwt) and LCAT knockout (LcatKO) mice exposed to noradrenaline showed reduced contractility in LcatKO mice (P < 0.005), whereas acetylcholine exposure showed a lower NO-dependent relaxation in LcatKO mice (P < 0.05). Quantitative PCR and Western blotting analyses suggested an adequate eNOS expression in LcatKO mouse aortas. Real-time PCR analysis indicated increased expression of β2-adrenergic receptors vs wild-type mice. Aorta stimulation with noradrenaline in the presence of propranolol, to abolish the β-mediated relaxation, showed the same contractile response in the two mouse lines. Furthermore, propranolol pretreatment of mouse aortas exposed to L-NAME prevented the difference in responses between Lcatwt and LcatKO mice. The results indicate that LCAT deficiency leads to increased β2-adrenergic relaxation and to a consequently decreased NO-mediated vasodilation that can be reversed to guarantee a correct vascular tone. The present study suggests that LCAT deficiency is not associated with an impaired vascular reactivity.
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21
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Inhibition of RAC1 GTPase sensitizes pancreatic cancer cells to γ-irradiation. Oncotarget 2015; 5:10251-70. [PMID: 25344910 PMCID: PMC4279370 DOI: 10.18632/oncotarget.2500] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 09/16/2014] [Indexed: 12/31/2022] Open
Abstract
Radiation therapy is a staple treatment for pancreatic cancer. However, owing to the intrinsic radioresistance of pancreatic cancer cells, radiation therapy often fails to increase survival of pancreatic cancer patients. Radiation impedes cancer cells by inducing DNA damage, which can activate cell cycle checkpoints. Normal cells possess both a G1 and G2 checkpoint. However, cancer cells are often defective in G1 checkpoint due to mutations/alterations in key regulators of this checkpoint. Accordingly, our results show that normal pancreatic ductal cells respond to ionizing radiation (IR) with activation of both checkpoints whereas pancreatic cancer cells respond to IR with G2/M arrest only. Overexpression/hyperactivation of Rac1 GTPase is detected in the majority of pancreatic cancers. Rac1 plays important roles in survival and Ras-mediated transformation. Here, we show that Rac1 also plays a critical role in the response of pancreatic cancer cells to IR. Inhibition of Rac1 using specific inhibitor and dominant negative Rac1 mutant not only abrogates IR-induced G2 checkpoint activation, but also increases radiosensitivity of pancreatic cancer cells through induction of apoptosis. These results implicate Rac1 signaling in the survival of pancreatic cancer cells following IR, raising the possibility that this pathway contributes to the intrinsic radioresistance of pancreatic cancer.
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22
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Weise M, Vettel C, Spiger K, Gilsbach R, Hein L, Lorenz K, Wieland T, Aktories K, Orth JHC. A systemic Pasteurella multocida toxin aggravates cardiac hypertrophy and fibrosis in mice. Cell Microbiol 2015; 17:1320-31. [PMID: 25759205 DOI: 10.1111/cmi.12436] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 02/20/2015] [Accepted: 03/06/2015] [Indexed: 11/30/2022]
Abstract
Pasteurella multocida toxin (PMT) persistently activates heterotrimeric G proteins of the Gαq/11 , Gα12/13 and Gαi family without interaction with G protein-coupled receptors (GPCRs). We show that PMT acts on heart tissue in vivo and on cardiomyocytes and cardiac fibroblasts in vitro by deamidation of heterotrimeric G proteins. Increased normalized ventricle weights and fibrosis were detected after intraperitoneal administration of PMT in combination with the GPCR agonist phenylephrine. In neonatal rat cardiomyocytes, PMT stimulated the mitogen-activated protein kinase pathway, which is crucial for the development of cellular hypertrophy. The toxin induced phosphorylation of the canonical phosphorylation sites of the extracellular-regulated kinase 1/2 and, additionally, caused phosphorylation of the recently recognized autophosphorylation site, which appears to be important for the development of cellular hypertrophy. Moreover, PMT stimulated the small GTPases Rac1 and RhoA. Both switch proteins are involved in cardiomyocyte hypertrophy. In addition, PMT stimulated RhoA and Rac1 in neonatal rat cardiac fibroblasts. RhoA and Rac1 have been implicated in the regulation of connective tissue growth factor (CTGF) secretion and expression. Accordingly, we show that PMT treatment increased secretion and expression of CTGF in cardiac fibroblasts. Altogether, the data indicate that PMT is an inducer of pathological remodelling of cardiac cells and identifies the toxin as a promising tool for studying heterotrimeric G protein-dependent signalling in cardiac cells.
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Affiliation(s)
- Markus Weise
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Dept. I, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, Freiburg, 79104, Germany
| | - Christiane Vettel
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Katharina Spiger
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Ralf Gilsbach
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Dept. II, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Lutz Hein
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Dept. II, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Kristina Lorenz
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany.,Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Thomas Wieland
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Dept. I, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, Freiburg, 79104, Germany.,BIOSS Centre for Biological Signalling Studies, Universität Freiburg, Freiburg, Germany
| | - Joachim H C Orth
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Dept. I, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, Freiburg, 79104, Germany
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23
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Schäker K, Bartsch S, Patry C, Stoll SJ, Hillebrands JL, Wieland T, Kroll J. The bipartite rac1 Guanine nucleotide exchange factor engulfment and cell motility 1/dedicator of cytokinesis 180 (elmo1/dock180) protects endothelial cells from apoptosis in blood vessel development. J Biol Chem 2015; 290:6408-18. [PMID: 25586182 DOI: 10.1074/jbc.m114.633701] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Engulfment and cell motility 1/dedicator of cytokinesis 180 (Elmo1/Dock180) is a bipartite guanine nucleotide exchange factor for the monomeric GTPase Ras-related C3 botulinum toxin substrate 1 (Rac1). Elmo1/Dock180 regulates Rac1 activity in a specific spatiotemporal manner in endothelial cells (ECs) during zebrafish development and acts downstream of the Netrin-1/Unc5-homolog B (Unc5B) signaling cascade. However, mechanistic details on the pathways by which Elmo1/Dock180 regulates endothelial function and vascular development remained elusive. In this study, we aimed to analyze the vascular function of Elmo1 and Dock180 in human ECs and during vascular development in zebrafish embryos. In vitro overexpression of Elmo1 and Dock180 in ECs reduced caspase-3/7 activity and annexin V-positive cell number upon induction of apoptosis. This protective effect of Elmo1 and Dock180 is mediated by activation of Rac1, p21-activated kinase (PAK) and AKT/protein kinase B (AKT) signaling. In zebrafish, Elmo1 and Dock180 overexpression reduced the total apoptotic cell and apoptotic EC number and promoted the formation of blood vessels during embryogenesis. In conclusion, Elmo1 and Dock180 protect ECs from apoptosis by the activation of the Rac1/PAK/AKT signaling cascade in vitro and in vivo. Thus, Elmo1 and Dock180 facilitate blood vessel formation by stabilization of the endothelium during angiogenesis.
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Affiliation(s)
- Kathrin Schäker
- From the Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM) and Division of Vascular Oncology and Metastasis, German Cancer Research Center (DKFZ-ZMBH Alliance), 69120 Heidelberg, Germany, and
| | - Susanne Bartsch
- From the Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM) and
| | - Christian Patry
- From the Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM) and
| | - Sandra J Stoll
- From the Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM) and
| | - Jan-Luuk Hillebrands
- Department of Pathology and Medical Biology, Division of Pathology, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
| | - Thomas Wieland
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim of Heidelberg University, 68167 Mannheim, Germany
| | - Jens Kroll
- From the Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM) and Division of Vascular Oncology and Metastasis, German Cancer Research Center (DKFZ-ZMBH Alliance), 69120 Heidelberg, Germany, and
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24
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Feng H, Li Y, Yin Y, Zhang W, Hou Y, Zhang L, Li Z, Xie B, Gao WQ, Sarkaria JN, Raizer JJ, James CD, Parsa AT, Hu B, Cheng SY. Protein kinase A-dependent phosphorylation of Dock180 at serine residue 1250 is important for glioma growth and invasion stimulated by platelet derived-growth factor receptor α. Neuro Oncol 2014; 17:832-42. [PMID: 25468898 DOI: 10.1093/neuonc/nou323] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Accepted: 10/30/2014] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Dedicator of cytokinesis 1 (Dock1 or Dock180), a bipartite guanine nucleotide exchange factor for Rac1, plays critical roles in receptor tyrosine kinase-stimulated cancer growth and invasion. Dock180 activity is required in cell migration cancer tumorigenesis promoted by platelet derived growth factor receptor (PDGFR) and epidermal growth factor receptor. METHODS To demonstrate whether PDGFRα promotes tumor malignant behavior through protein kinase A (PKA)-dependent serine phosphorylation of Dock180, we performed cell proliferation, viability, migration, immunoprecipitation, immunoblotting, colony formation, and in vivo tumorigenesis assays using established and short-term explant cultures of glioblastoma cell lines. RESULTS Stimulation of PDGFRα results in phosphorylation of Dock180 at serine residue 1250 (S1250), whereas PKA inhibitors H-89 and KT5720 oppose this phosphorylation. S1250 locates within the Rac1-binding Dock homology region 2 domain of Dock180, and its phosphorylation activates Rac1, p-Akt, and phosphorylated extracellular signal-regulated kinase 1/2, while promoting cell migration, in vitro. By expressing RNA interference (RNAi)-resistant wild-type Dock180, but not mutant Dock180 S1250L, we were able to rescue PDGFRα-associated signaling and biological activities in cultured glioblastoma multiforme (GBM) cells that had been treated with RNAi for suppression of endogenous Dock180. In addition, expression of the same RNAi-resistant Dock180 rescued an invasive phenotype of GBM cells following intracranial engraftment in immunocompromised mice. CONCLUSION These data describe an important mechanism by which PDGFRα promotes glioma malignant phenotypes through PKA-dependent serine phosphorylation of Dock180, and the data thereby support targeting the PDGFRα-PKA-Dock180-Rac1 axis for treating GBM with molecular profiles indicating PDGFRα signaling dependency.
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Affiliation(s)
- Haizhong Feng
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Yanxin Li
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Yuhua Yin
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Weiwei Zhang
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Yanli Hou
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Lei Zhang
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Zuoqing Li
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Baoshu Xie
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Wei-Qiang Gao
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Jann N Sarkaria
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Jeffery J Raizer
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - C David James
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Andrew T Parsa
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Bo Hu
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
| | - Shi-Yuan Cheng
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (H.F., W.Z., Y.H., L.Z., Z.L., W.-Q.G., S.-Y.C.); Department of Neurology, Northwestern Brain Tumor Institute, Center for Genetic Medicine, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (H.F., J.J.R., B.H., S.-Y.C.); Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.L.); Department of Neurological Surgery (Y.Y., B.X.); Department of Radiotherapy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China (Y.H.); Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (J.N.S.); Department of Neurological Surgery, Northwestern Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (C.D.J., A.T.P.)
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25
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Abstract
BACKGROUND Defects in cardiac septation are the most common form of congenital heart disease, but the mechanisms underlying these defects are still poorly understood. The small GTPase Rac1 is implicated in planar cell polarity of epithelial cells in Drosophila; however, its role in mammalian cardiomyocyte polarity is not clear. We tested the hypothesis that Rac1 signaling in the second heart field regulates cardiomyocyte polarity, chamber septation, and right ventricle development during embryonic heart development. METHODS AND RESULTS Mice with second heart field-specific deficiency of Rac1 (Rac1(SHF)) exhibited ventricular and atrial septal defects, a thinner right ventricle myocardium, and a bifid cardiac apex. Fate-mapping analysis showed that second heart field contribution to the interventricular septum and right ventricle was deficient in Rac1(SHF) hearts. Notably, cardiomyocytes had a spherical shape with disrupted F-actin filaments in Rac1(SHF) compared with elongated and well-aligned cardiomyocytes in littermate controls. Expression of Scrib, a core protein in planar cell polarity, was lost in Rac1(SHF) hearts with decreased expression of WAVE and Arp2/3, leading to decreased migratory ability. In addition, Rac1-deficient neonatal cardiomyocytes displayed defects in cell projections, lamellipodia formation, and cell elongation. Furthermore, apoptosis was increased and the expression of Gata4, Tbx5, Nkx2.5, and Hand2 transcription factors was decreased in the Rac1(SHF) right ventricle myocardium. CONCLUSIONS Deficiency of Rac1 in the second heart field impairs elongation and cytoskeleton organization of cardiomyocytes and results in congenital septal defects, thin right ventricle myocardium, and a bifid cardiac apex. Our study suggests that Rac1 signaling is critical to cardiomyocyte polarity and embryonic heart development.
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Affiliation(s)
- Carmen Leung
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada (C.L., X.L., Q.F.) Collaborative Program in Developmental Biology, The University of Western Ontario, London, Ontario, Canada (C.L.)
| | - Xiangru Lu
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada (C.L., X.L., Q.F.)
| | - Murong Liu
- Lawson Health Research Institute, The University of Western Ontario, London, Ontario, Canada (M.L., Q.F.)
| | - Qingping Feng
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada (C.L., X.L., Q.F.) Department of Medicine, Schulich School of Medicine and Dentistry The University of Western Ontario, London, Ontario, Canada (Q.F.) Lawson Health Research Institute, The University of Western Ontario, London, Ontario, Canada (M.L., Q.F.)
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26
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Genetic dissection of the vav2-rac1 signaling axis in vascular smooth muscle cells. Mol Cell Biol 2014; 34:4404-19. [PMID: 25288640 DOI: 10.1128/mcb.01066-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vascular smooth muscle cells (vSMCs) are key in the regulation of blood pressure and the engagement of vascular pathologies, such as hypertension, arterial remodeling, and neointima formation. The role of the Rac1 GTPase in these cells remains poorly characterized. To clarify this issue, we have utilized genetically engineered mice to manipulate the signaling output of Rac1 in these cells at will using inducible, Cre-loxP-mediated DNA recombination techniques. Here, we show that the expression of an active version of the Rac1 activator Vav2 exclusively in vSMCs leads to hypotension as well as the elimination of the hypertension induced by the systemic loss of wild-type Vav2. Conversely, the specific depletion of Rac1 in vSMCs causes defective nitric oxide vasodilation responses and hypertension. Rac1, but not Vav2, also is important for neointima formation but not for hypertension-driven vascular remodeling. These animals also have allowed us to dismiss etiological connections between hypertension and metabolic disease and, most importantly, identify pathophysiological programs that cooperate in the development and consolidation of hypertensive states caused by local vascular tone dysfunctions. Finally, our results suggest that the therapeutic inhibition of Rac1 will be associated with extensive cardiovascular system-related side effects and identify pharmacological avenues to circumvent them.
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27
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Wilkerson BA, Argraves KM. The role of sphingosine-1-phosphate in endothelial barrier function. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1841:1403-1412. [PMID: 25009123 PMCID: PMC4169319 DOI: 10.1016/j.bbalip.2014.06.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 06/19/2014] [Accepted: 06/26/2014] [Indexed: 02/08/2023]
Abstract
Loss of endothelial barrier function is implicated in the etiology of metastasis, atherosclerosis, sepsis and many other diseases. Studies suggest that sphingosine-1-phosphate (S1P), particularly HDL-bound S1P (HDL-S1P) is essential for endothelial barrier homeostasis and that HDL-S1P may be protective against the loss of endothelial barrier function in disease. This review summarizes evidence providing mechanistic insights into how S1P maintains endothelial barrier function, highlighting the recent findings that implicate the major S1P carrier, HDL, in the maintenance of the persistent S1P-signaling needed to maintain endothelial barrier function. We review the mechanisms proposed for HDL maintenance of persistent S1P-signaling, the evidence supporting these mechanisms and the remaining fundamental questions.
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Affiliation(s)
- Brent A Wilkerson
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, 173 Ashley Ave., BSB650, Charleston, SC 29425, USA
| | - Kelley M Argraves
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, 173 Ashley Ave., BSB650, Charleston, SC 29425, USA.
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28
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Tian X, Tian Y, Moldobaeva N, Sarich N, Birukova AA. Microtubule dynamics control HGF-induced lung endothelial barrier enhancement. PLoS One 2014; 9:e105912. [PMID: 25198505 PMCID: PMC4157766 DOI: 10.1371/journal.pone.0105912] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 07/29/2014] [Indexed: 01/11/2023] Open
Abstract
Microtubules (MT) play a vital role in many cellular functions, but their role in peripheral actin cytoskeletal dynamics which is essential for control of endothelial barrier and monolayer integrity is less understood. We have previously described the enhancement of lung endothelial cell (EC) barrier by hepatocyte growth factor (HGF) which was associated with Rac1-mediated remodeling of actin cytoskeleton. This study investigated involvement of MT-dependent mechanisms in the HGF-induced enhancement of EC barrier. HGF-induced Rac1 activation was accompanied by phosphorylation of stathmin, a regulator of MT dynamics. HGF also stimulated MT peripheral growth monitored by time lapse imaging and tracking analysis of EB-1-decorated MT growing tips, and increased the pool of acetylated tubulin. These effects were abolished by EC pretreatment with HGF receptor inhibitor, downregulation of Rac1 pathway, or by expression of a stathmin-S63A phosphorylation deficient mutant. Expression of stathmin-S63A abolished the HGF protective effects against thrombin-induced activation of RhoA cascade, permeability increase, and EC barrier dysfunction. These results demonstrate a novel MT-dependent mechanism of HGF-induced EC barrier regulation via Rac1/PAK1/stathmin-dependent control of MT dynamics.
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Affiliation(s)
- Xinyong Tian
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
| | - Yufeng Tian
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
| | - Nurgul Moldobaeva
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
| | - Nicolene Sarich
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
| | - Anna A. Birukova
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
- * E-mail:
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29
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Igarashi J, Hashimoto T, Kubota Y, Shoji K, Maruyama T, Sakakibara N, Takuwa Y, Ujihara Y, Katanosaka Y, Mohri S, Naruse K, Yamashita T, Okamoto R, Hirano K, Kosaka H, Takata M, Konishi R, Tsukamoto I. Involvement of S1P1 receptor pathway in angiogenic effects of a novel adenosine-like nucleic acid analog COA-Cl in cultured human vascular endothelial cells. Pharmacol Res Perspect 2014; 2:e00068. [PMID: 25505610 PMCID: PMC4186426 DOI: 10.1002/prp2.68] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 07/11/2014] [Indexed: 12/13/2022] Open
Abstract
COA-Cl (2Cl-C.OXT-A) is a recently developed adenosine-like nucleic acid analog that promotes angiogenesis via the mitogen-activated protein (MAP) kinases ERK1/2. Endothelial S1P1 receptor plays indispensable roles in developmental angiogenesis. In this study, we examined the functions of S1P1 in COA-Cl-induced angiogenic responses. Antagonists for S1P1, W146, and VPC23019, substantially but still partly inhibited the effects of COA-Cl with regard to ERK1/2 activation and tube formation in cultured human umbilical vein endothelial cells (HUVEC). Antagonists for adenosine A1 receptor and purinergic P2Y1 receptor were without effect. Genetic knockdown of S1P1 with siRNA, but not that of S1P3, attenuated COA-Cl-elicited ERK1/2 responses. The signaling properties of COA-Cl showed significant similarities to those of sphingosine 1-phosphate, an endogenous S1P1 ligand, in that both induced responses sensitive to pertussis toxin (Gα i/o inhibitor), 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis (acetoxymethyl ester) (BAPTA-AM), (calcium chelator), and PP2 (c-Src tyrosine kinase inhibitor). COA-Cl elevated intracellular Ca2+ concentration and induced tyrosine phosphorylation of p130Cas, a substrate of c-Src, in HUVEC. COA-Cl displaced [3H]S1P in a radioligand-binding competition assay in chem-1 cells overexpressing S1P1. However, COA-Cl activated ERK1/2 in CHO-K1 cells that lack functional S1P1 receptor, suggesting the presence of additional yet-to-be-defined COA-Cl target in these cells. The results thus suggest the major contribution of S1P1 in the angiogenic effects of COA-Cl. However, other mechanism such as that seen in CHO-K1 cells may also be partly involved. Collectively, these findings may lead to refinement of the design of this nucleic acid analog and ultimately to development of small molecule-based therapeutic angiogenesis.
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Affiliation(s)
- Junsuke Igarashi
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan
| | - Takeshi Hashimoto
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan
| | - Yasuo Kubota
- Department of Dermatology, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan
| | - Kazuyo Shoji
- Department of Dermatology, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan
| | - Tokumi Maruyama
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University 1314-1 Shido, Sanuki, Kagawa, 769-2193, Japan
| | - Norikazu Sakakibara
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University 1314-1 Shido, Sanuki, Kagawa, 769-2193, Japan
| | - Yoh Takuwa
- Department of Cardiovascular Physiology, Kanazawa University School of Medicine 13-1 Takara-machi, Kanazawa, Ishikawa, 920-8640, Japan
| | - Yoshihiro Ujihara
- Department of Physiology, Kawasaki Medical School 577 Matsushima, Kurashiki, 701-0192, Japan
| | - Yuki Katanosaka
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shitada-Cho 2-5-1, Kita-Ku, Okayama, 700-0914, Japan
| | - Satoshi Mohri
- Department of Physiology, Kawasaki Medical School 577 Matsushima, Kurashiki, 701-0192, Japan
| | - Keiji Naruse
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shitada-Cho 2-5-1, Kita-Ku, Okayama, 700-0914, Japan
| | - Tetsuo Yamashita
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan
| | - Ryuji Okamoto
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan
| | - Katsuya Hirano
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan
| | - Hiroaki Kosaka
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan
| | - Maki Takata
- Department of Pharmaco-Bio-Informatics, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan
| | - Ryoji Konishi
- Department of Pharmaco-Bio-Informatics, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan
| | - Ikuko Tsukamoto
- Department of Pharmaco-Bio-Informatics, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan
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Higginbotham K, Tian Y, Gawlak G, Moldobaeva N, Shah A, Birukova AA. Hepatocyte growth factor triggers distinct mechanisms of Asef and Tiam1 activation to induce endothelial barrier enhancement. Cell Signal 2014; 26:2306-16. [PMID: 25101856 DOI: 10.1016/j.cellsig.2014.07.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/11/2014] [Accepted: 07/28/2014] [Indexed: 10/24/2022]
Abstract
Previous reports described an important role of hepatocyte growth factor (HGF) in mitigation of pulmonary endothelial barrier dysfunction and cell injury induced by pathologic agonists and mechanical forces. HGF protective effects have been associated with Rac-GTPase signaling pathway activated by Rac-specific guanine nucleotide exchange factor Tiam1 and leading to enhancement of intercellular adherens junctions. This study tested involvement of a novel Rac-specific activator, Asef, in endothelial barrier enhancement by HGF and investigated a mechanism of HGF-induced Asef activation. Si-RNA-based knockdown of Tiam1 and Asef had an additive effect on attenuation of HGF-induced Rac activation and endothelial cell (EC) barrier enhancement. Tiam1 and Asef activation was abolished by pharmacologic inhibitors of HGF receptor and PI3-kinase. In contrast to Tiam1, Asef interacted with APC and associated with microtubule fraction upon HGF stimulation. EC treatment by low dose nocodazole to inhibit peripheral microtubule dynamics partially attenuated HGF-induced Asef peripheral translocation, but had negligible effect on Tiam1 translocation. These effects were associated with attenuation of HGF-induced barrier enhancement in EC pretreated with low ND dose and activation of Rac and its cytoskeletal effectors PAK1 and cortactin. These data demonstrate, that in addition to microtubule-independent Tiam1 activation, HGF engages additional microtubule- and APC-dependent pathway of Asef activation. These mechanisms may complement each other to provide the fine tuning of Rac signaling and endothelial barrier enhancement in response to various agonists.
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Affiliation(s)
- Katherine Higginbotham
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Yufeng Tian
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Grzegorz Gawlak
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Nurgul Moldobaeva
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Alok Shah
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Anna A Birukova
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA.
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Shen L, Yang A, Yao P, Sun X, Chen C, Mo C, Shi L, Chen Y, Liu Q. Gadolinium promoted proliferation in mouse embryo fibroblast NIH3T3 cells through Rac and PI3K/Akt signaling pathways. Biometals 2014; 27:753-62. [DOI: 10.1007/s10534-014-9769-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 06/25/2014] [Indexed: 11/25/2022]
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Kratzer A, Giral H, Landmesser U. High-density lipoproteins as modulators of endothelial cell functions: alterations in patients with coronary artery disease. Cardiovasc Res 2014; 103:350-61. [DOI: 10.1093/cvr/cvu139] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Zhang H, An F, Tang L, Qiu R. Multiple Effects of a Novel Epothilone Analog on Cellular Processes and Signaling Pathways Regulated by Rac1 GTPase in the Human Breast Cancer Cells. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2014; 18:109-20. [PMID: 24757372 PMCID: PMC3994297 DOI: 10.4196/kjpp.2014.18.2.109] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 02/20/2014] [Accepted: 02/26/2014] [Indexed: 01/09/2023]
Abstract
The epothilones are a class of microtubule inhibitors that exhibit a strong antitumor activity. UTD2 is a novel epothilone analog generated by genetic manipulation of the polyketide biosynthetic gene cluster. This study investigated the effects of UTD2 on the actin cytoskeleton and its critical regulators, and the signaling pathways which are essential for cell motility, growth and survival in MCF-7 breast cancer cells. Results showed that UTD2 inhibited the cellular functions of actin cytoskeleton, such as wound-closure, migration and invasion, as well as adhesion. Our study further demonstrated that UTD2 suppressed Rac1 GTPase activation and reduced the activity of PAK1, which is a downstream effector of Rac1, while the activity of Cdc42 was not affected. Additionally, the phosphorylation of p38 and ERK were significantly inhibited, but the phosphorylation of JNK remained the same after UTD2 treatment. Moreover, UTD2 inhibited the activity and mRNA expression of MMP-2, which plays a key role in cell motility. UTD2 also reduced the phosphorylation of Akt, which is an important signaling kinase regulating the cell survival through Rac1. Furthermore, UTD2 interrupted the synergy between Rac1 and Raf in focus formation assays. Taken together, these results indicated that UTD2 exerted multiple effects on the actin cytoskeleton and signaling pathways associated with Rac1. This study provided novel insights into the molecular mechanism of the antineoplastic and antimetastatic activities of epothilones. Our findings also suggest that the signaling pathways regulated by Rac1 may be evaluated as biomarkers for the response to therapy in clinical trials of epothilones.
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Affiliation(s)
- Hong Zhang
- Research Center for Molecular Medicine, Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116023, China
| | - Fan An
- Research Center for Molecular Medicine, Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116023, China
| | - Li Tang
- Research Center for Molecular Medicine, Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116023, China
| | - Rongguo Qiu
- Research Center for Molecular Medicine, Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116023, China
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Birukova AA, Tian X, Tian Y, Higginbotham K, Birukov KG. Rap-afadin axis in control of Rho signaling and endothelial barrier recovery. Mol Biol Cell 2013; 24:2678-88. [PMID: 23864716 PMCID: PMC3756920 DOI: 10.1091/mbc.e13-02-0098] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
This study describes the novel role of Rap1 as a molecular switch for down-regulation of the Rho-dependent pathway of agonist-induced endothelial hyperpermeability. The Rho-Rap-Rac autoregulation loop may represent a fundamental mechanism of homeostasis and be critical for reestablishment of cell monolayer integrity in pathological conditions. Activation of the Rho GTPase pathway determines endothelial cell (EC) hyperpermeability after injurious stimuli. To date, feedback mechanisms of Rho down-regulation critical for barrier restoration remain poorly understood. We tested a hypothesis that Rho down-regulation and barrier recovery of agonist-stimulated ECs is mediated by the Ras family GTPase Rap1. Thrombin-induced EC permeability driven by rapid activation of the Rho GTPase pathway was followed by Src kinase–dependent phosphorylation of the Rap1-specific guanine nucleotide exchange factor (GEF) C3G, activation of Rap1, and initiation of EC barrier recovery. Knockdown experiments showed that Rap1 activation was essential for down-regulation of Rho signaling and actin stress fiber dissolution. Rap1 activation also enhanced interaction between adherens junction (AJ) proteins VE-cadherin and p120-catenin and stimulated AJ reannealing mediated by the Rap1 effector afadin. This mechanism also included Rap1-dependent membrane translocation of the Rac1-specific GEF Tiam1 and activation of Rac1-dependent peripheral cytoskeletal dynamics, leading to resealing of intercellular gaps. These data demonstrate that activation of the Rap1-afadin axis is a physiological mechanism driving restoration of barrier integrity in agonist-stimulated EC monolayers via negative-feedback regulation of Rho signaling, stimulation of actin peripheral dynamics, and reestablishment of cell–cell adhesive complexes.
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Affiliation(s)
- Anna A Birukova
- Department of Medicine, Section of Pulmonary and Critical Medicine, Lung Injury Center, University of Chicago, Chicago, IL 60637, USA
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Cuvillier O, Ader I, Bouquerel P, Brizuela L, Gstalder C, Malavaud B. Hypoxia, therapeutic resistance, and sphingosine 1-phosphate. Adv Cancer Res 2013; 117:117-41. [PMID: 23290779 DOI: 10.1016/b978-0-12-394274-6.00005-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hypoxia, defined as a poor oxygenation, has been long recognized as a hallmark of solid tumors and a negative prognostic factor for response to therapeutics and survival of patients. Cancer cells have evolved biochemical mechanisms that allow them to react and adapt to hypoxia. At the cellular level, this adaptation is under the control of two related transcription factors, HIF-1 and HIF-2 (hypoxia-inducible factor), that respond rapidly to decreased oxygen levels to activate the expression of a broad range of genes promoting neoangiogenesis, glycolysis, metastasis, increased tumor growth, and resistance to treatments. Recent studies have identified the sphingosine kinase 1/sphingosine 1-phosphate (SphK1/S1P) signaling pathway-which elicits various cellular processes including cell proliferation, cell survival, or angiogenesis-as a new regulator of HIF-1 or HIF-2 activity. In this review, we will focus on how the inhibition/neutralization of the SphK1/S1P signaling could be exploited for cancer therapy.
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Affiliation(s)
- Olivier Cuvillier
- CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse, France; Université de Toulouse, Toulouse, France.
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Igarashi J, Hashimoto T, Shoji K, Yoneda K, Tsukamoto I, Moriue T, Kubota Y, Kosaka H. Dexamethasone induces caveolin-1 in vascular endothelial cells: implications for attenuated responses to VEGF. Am J Physiol Cell Physiol 2013; 304:C790-800. [DOI: 10.1152/ajpcell.00268.2012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Steroids exert direct actions on cardiovascular cells, although underlying molecular mechanisms remain incompletely understood. We examined if steroids modulate abundance of caveolin-1, a regulatory protein of cell-surface receptor pathways that regulates the magnitudes of endothelial response to vascular endothelial growth factor (VEGF). Dexamethasone, a synthetic glucocorticoid, induces caveolin-1 at both levels of protein and mRNA in a time- and dose-dependent manner in pharmacologically relevant concentrations in cultured bovine aortic endothelial cells. Aldosterone, a mineralocorticoid, but not the sex steroids 17β-estradiol, testosterone, or progesterone, elicits similar caveolin-1 induction. Caveolin-1 induction by dexamethasone and that by aldosterone were abrogated by RU-486, an inhibitor of glucocorticoid receptor, and by spironolactone, a mineralocorticoid receptor inhibitor, respectively. Dexamethasone attenuates VEGF-induced responses at the levels of protein kinases Akt and ERK1/2, small-G protein Rac1, nitric oxide production, and migration. When induction of caveolin-1 by dexamethasone is attenuated either by genetically by transient transfection with small interfering RNA or pharmacologically by RU-486, kinase responses to VEGF are rescued. Dexamethasone also increases expression of caveolin-1 protein in cultured human umbilical vein endothelial cells, associated with attenuated tube formation responses of these cells when cocultured with normal fibroblasts. Immunohistochemical analyses revealed that intraperitoneal injection of dexamethasone induces endothelial caveolin-1 protein in thoracic aorta and in lung artery in healthy male rats. Thus steroids functionally attenuate endothelial responses to VEGF via caveolin-1 induction at the levels of signal transduction, migration, and tube formation, identifying a novel point of cross talk between nuclear and cell-surface receptor signaling pathways.
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Affiliation(s)
- Junsuke Igarashi
- Department of Cardiovascular Physiology, Kagawa University, Kagawa, Japan
| | - Takeshi Hashimoto
- Department of Cardiovascular Physiology, Kagawa University, Kagawa, Japan
| | - Kazuyo Shoji
- Department of Dermatology, Kagawa University, Kagawa, Japan; and
| | - Kozo Yoneda
- Department of Dermatology, Kagawa University, Kagawa, Japan; and
| | - Ikuko Tsukamoto
- Department of Pharmaco-Bio-Informatics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Tetsuya Moriue
- Department of Dermatology, Kagawa University, Kagawa, Japan; and
| | - Yasuo Kubota
- Department of Dermatology, Kagawa University, Kagawa, Japan; and
| | - Hiroaki Kosaka
- Department of Cardiovascular Physiology, Kagawa University, Kagawa, Japan
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Goyal P, Brunnert D, Ehrhardt J, Bredow M, Piccenini S, Zygmunt M. Cytokine IL-6 secretion by trophoblasts regulated via sphingosine-1-phosphate receptor 2 involving Rho/Rho-kinase and Rac1 signaling pathways. Mol Hum Reprod 2013; 19:528-38. [DOI: 10.1093/molehr/gat023] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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38
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Zhan H, Liang H, Liu X, Deng J, Wang B, Hao X. Expression of Rac1, HIF-1α, and VEGF in gastric carcinoma: correlation with angiogenesis and prognosis. ACTA ACUST UNITED AC 2013; 36:102-7. [PMID: 23485997 DOI: 10.1159/000348525] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND The aim of this study was to investigate the relationship between the expression of hypoxia-inducible factor-1α (HIF-1α), Ras-related C3 botulinum toxin substrate 1 (Rac1), and vascular endothelial growth factor (VEGF), as well as their correlation with angiogenesis and prognosis in gastric carcinoma. MATERIAL AND METHODS The expression of Rac1, HIF-1α, VEGF, and CD34 (described in terms of microvessel density, MVD) was determined by immunohistochemical staining of tissues from 60 radically resected gastric cancer specimens. RESULTS The proportion of specimens expressing Rac1, HIF-1α, and VEGF was 37/60 (61.7%), 35/60 (58.3%), and 40/60 (66.7%), respectively. The levels of Rac1, HIF-1α, and VEGF expression were significantly correlated with Lauren's classification, lymph node metastasis, and pathologic staging (p < 0.05). There were positive correlations between MVD and the expression of Rac1, HIF-1α, and VEGF. The mean survival time and 5-year survival rate in cases with positive Rac1, HIF-1α, and VEGF expression and MVD ≥ 26.3 were significantly shorter than those with negative Rac1, HIF-1α, and VEGF expression and MVD < 26.3. CONCLUSION Rac1, HIF-1α, and VEGF play an important role in tumor invasion and metastasis, especially in tumor angiogenesis. Thus, testing the expression of Rac1, HIF-1α, and VEGF may be a useful index for treatment and prognosis.
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Affiliation(s)
- Hongjie Zhan
- Department of Gastric Cancer Surgery, Tianjin Medical University Cancer Hospital and City Key Laboratory of Tianjin Cancer Center, Tianjin, China
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Richmond JM, Lee J, Green DS, Kornfeld H, Cruikshank WW. Mannose-capped lipoarabinomannan from Mycobacterium tuberculosis preferentially inhibits sphingosine-1-phosphate-induced migration of Th1 cells. THE JOURNAL OF IMMUNOLOGY 2012; 189:5886-95. [PMID: 23129756 DOI: 10.4049/jimmunol.1103092] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Chemokine receptor cross-desensitization provides an important mechanism to regulate immune cell recruitment at sites of inflammation. We previously reported that the mycobacterial cell wall glycophospholipid mannose-capped lipoarabinomannan (ManLAM) could induce human peripheral blood T cell chemotaxis. Therefore, we examined the ability of ManLAM to desensitize T cells to other chemoattractants as a potential mechanism for impaired T cell homing and delayed lung recruitment during mycobacterial infection. We found that ManLAM pretreatment inhibited in vitro migration of naive human or mouse T cells to the lymph node egress signal sphingosine-1-phosphate (S1P). Intratracheal administration of ManLAM in mice resulted in significant increases in T cells, primarily CCR5(+) (Th1) cells, in lung-draining lymph nodes. To investigate the selective CCR5 effect, mouse T cells were differentiated into Th1 or Th2 populations in vitro, and their ability to migrate to S1P with or without ManLAM pretreatment was analyzed. ManLAM pretreatment of Th1 populations inhibited S1P-induced migration but had no effect on Th2 cell S1P-directed migration, suggesting a differential effect by S1P on the two subsets. The PI3K/AKT inhibitor Ly294002 inhibited S1P-directed migration by Th1 cells, whereas the ERK inhibitor U0126 inhibited Th2 cell S1P-directed migration. These observations demonstrate that S1P-induced migratory responses in Th1 and Th2 lymphocytes occurs via different signaling pathways and suggests further that the production of ManLAM during Mycobacterium tuberculosis infection may function to sequester Th1 cells in lung-draining lymph nodes, thereby delaying their recruitment to the lung.
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Affiliation(s)
- Jillian M Richmond
- Pulmonary Center, Boston University School of Medicine, Boston, MA 02118, USA
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40
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MARCKS protein mediates hydrogen peroxide regulation of endothelial permeability. Proc Natl Acad Sci U S A 2012; 109:14864-9. [PMID: 22927426 DOI: 10.1073/pnas.1204974109] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Impairment of endothelial barrier function is implicated in many vascular and inflammatory disorders. One prevalent mechanism of endothelial dysfunction is an increase in reactive oxygen species under oxidative stress. Previous reports have demonstrated that hydrogen peroxide (H(2)O(2)), a highly stable reactive oxygen species that modulates physiological signaling pathways, also enhances endothelial permeability, but the mechanism of this effect is unknown. Here, we identify the actin-binding protein myristoylated alanine-rich C-kinase substrate (MARCKS) as a key mediator of the H(2)O(2)-induced permeability change in bovine aortic endothelial cells. MARCKS knockdown and H(2)O(2) treatment alter the architecture of the actin cytoskeleton in endothelial cells, and H(2)O(2) induces the phosphorylation and translocation of MARCKS from the cell membrane to the cytosol. Using pharmacological inhibitors and small interference RNA constructs directed against specific proteins, we uncover a signaling cascade from Rac1 to Abl1, phospholipase Cγ1, and PKCδ that is triggered by H(2)O(2) and leads to MARCKS phosphorylation. Our findings establish a distinct role for MARCKS in the regulation of H(2)O(2)-induced permeability change in endothelial cells, and suggest potential new therapeutic targets for the treatment of disorders involving oxidative stress and altered endothelial permeability.
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Kalwa H, Sartoretto JL, Sartoretto SM, Michel T. Angiotensin-II and MARCKS: a hydrogen peroxide- and RAC1-dependent signaling pathway in vascular endothelium. J Biol Chem 2012; 287:29147-58. [PMID: 22773836 DOI: 10.1074/jbc.m112.381517] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MARCKS is an actin-binding protein that modulates vascular endothelial cell migration and cytoskeleton signaling (Kalwa, H., and Michel, T. (2011) J. Biol. Chem. 286, 2320-2330). Angiotensin-II is a vasoactive peptide implicated in vascular physiology as well as pathophysiology; the pathways connecting angiotensin-II and cytoskeletal remodeling are incompletely understood. Here we show that MARCKS is expressed in intact arterial preparations, with prominent staining of the endothelium. In endothelial cells, angiotensin-II-promoted MARCKS phosphorylation is abrogated by PEG-catalase, implicating endogenous H(2)O(2) in the angiotensin-II response. Studies using the H(2)O(2) biosensor HyPer2 reveal that angiotensin-II promotes increases in intracellular H(2)O(2). We used a Rac1 FRET biosensor to show that angiotensin-II promotes Rac1 activation that is attenuated by PEG-catalase. siRNA-mediated Rac1 knockdown blocks angiotensin-II-stimulated MARCKS phosphorylation. Cell imaging studies using a phosphoinositide 4,5-bisphosphate (PIP(2)) biosensor revealed that angiotensin-II PIP(2) regulation depends on MARCKS and H(2)O(2). siRNA-mediated knockdown of MARCKS or Rac1 attenuates receptor-mediated activation of the tyrosine kinase c-Abl and disrupts actin fiber formation. These studies establish a critical role for H(2)O(2) in angiotensin-II signaling to the endothelial cytoskeleton in a novel pathway that is critically dependent on MARCKS, Rac1, and c-Abl.
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Affiliation(s)
- Hermann Kalwa
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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A novel player in cellular hypertrophy: Giβγ/PI3K-dependent activation of the RacGEF TIAM-1 is required for α₁-adrenoceptor induced hypertrophy in neonatal rat cardiomyocytes. J Mol Cell Cardiol 2012; 53:165-75. [PMID: 22564263 DOI: 10.1016/j.yjmcc.2012.04.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 04/25/2012] [Accepted: 04/26/2012] [Indexed: 01/08/2023]
Abstract
Activation of α(1)-adrenoceptors (α(1)-AR) by high catecholamine levels, e.g. in heart failure, is thought to be a driving force of cardiac hypertrophy. In this context several downstream mediators and cascades have been identified to potentially play a role in cardiomyocyte hypertrophy. One of these proteins is the monomeric G protein Rac1. However, until now it is unclear how this essential G protein is activated by α(1)-AR agonists and what are the downstream targets inducing cellular growth. By using protein-based as well as pharmacological inhibitors and the shRNA technique, we demonstrate that in neonatal rat cardiomyocytes (NRCM) Rac1 is activated via a cascade involving the α(1A)-AR subtype, G(i)βγ, the phosphoinositide-3'-kinase and the guanine nucleotide exchange factor Tiam1. We further demonstrate that this signaling induces an increase in protein synthesis, cell size and atrial natriuretic peptide expression. We identified the p21-activated kinase 2 (PAK2) as a downstream effector of Rac1 and were able to link this cascade to the activation of the pro-hypertrophic kinases ERK1/2 and p90RSK. Our data thus reveal a prominent role of the α(1A)-AR/G(i)βγ/Tiam1-mediated activation of Rac1 and its effector PAK2 in the induction of hypertrophy in NRCM.
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Abstract
Germinal centers (GCs) are sites of rapid B-cell proliferation and somatic mutation. These ovoid structures develop within the center of follicles and grow to a stereotypic size. The cell migration and interaction dynamics underlying GC B-cell selection events are currently under intense scrutiny. In recent study, we identified a role for a migration inhibitory receptor, S1PR2, in promoting GC B-cell confinement to GCs. S1PR2 also dampens Akt activation and deficiency in S1PR2 or components of its signaling pathway result in a loss of growth control in chronically stimulated mucosal GCs. Herein, we detail present understanding of S1PR2 and S1P biology as it pertains to GC B cells and place this information in the context of a current model of GC function.
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Affiliation(s)
- Jesse A Green
- Department of Microbiology and Immunology, Howard Hughes Medical Institute, University of California, San Francisco, CA 94143-0414, USA
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Synergistic Regulation of Angiogenic Sprouting by Biochemical Factors and Wall Shear Stress. Cell Mol Bioeng 2011; 4:547-559. [PMID: 22247741 DOI: 10.1007/s12195-011-0208-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The process of sprouting angiogenesis involves activating endothelial cells in a quiescent monolayer of an existing vessel to degrade and migrate into the underlying matrix to form new blood vessels. While the roles of biochemical factors in angiogenic sprouting have been well characterized, the roles of fluid forces have received much less attention. This review summarizes results that support a role for wall shear stress in post-capillary venules as a mechanical factor capable of synergizing with biochemical factors to stimulate pro-angiogenic signaling in endothelial cells and promote sprout formation.
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Maruyama S, Shibata R, Ohashi K, Ohashi T, Daida H, Walsh K, Murohara T, Ouchi N. Adiponectin ameliorates doxorubicin-induced cardiotoxicity through Akt protein-dependent mechanism. J Biol Chem 2011; 286:32790-800. [PMID: 21784858 DOI: 10.1074/jbc.m111.245985] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Accumulating evidence shows that obesity is associated with doxorubicin cardiac toxicity in the heart, but the molecular mechanisms that contribute to this pathological response are not understood. Adiponectin is an adipose-derived, cardioprotective factor that is down-regulated in obesity. Here, we investigated the effect of adiponectin on doxorubicin (DOX)-induced cardiotoxicity and assessed the mechanisms of this effect. A single dose of DOX was intraperitoneally injected into the abdomen of adiponectin knock-out (APN-KO) and wild-type (WT) mice. APN-KO mice had increased mortality and exacerbated contractile dysfunction of left ventricle compared with WT mice. APN-KO mice also showed increased apoptotic activity and diminished Akt signaling in the failing myocardium. Systemic delivery of adenoviral vector expressing adiponectin improved left ventricle dysfunction and myocardial apoptosis following DOX injection in WT and APN-KO mice but not in Akt1 heterozygous KO mice. In cultured rat neonatal cardiomyocytes, adiponectin stimulated Akt phosphorylation and inhibited DOX-stimulated apoptosis. Treatment with sphingosine kinase-1 inhibitor or sphingosine 1-phosphate receptor antagonist diminished adiponectin-induced Akt phosphorylation and reversed the inhibitory effects of adiponectin on myocyte apoptosis. Pretreatment with anti-calreticulin antibody reduced the binding of adiponectin to cardiac myocytes and blocked the adiponectin-stimulated increase in Akt activation and survival in cardiomyocytes. Interference of the LRP1/calreticulin co-receptor system by siRNA or blocking antibodies diminished the stimulatory actions of adiponectin on Akt activation and myocyte survival. These data show that adiponectin protects against DOX-induced cardiotoxicity by its ability to promote Akt signaling.
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Affiliation(s)
- Sonomi Maruyama
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
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Thennes T, Mehta D. Heterotrimeric G proteins, focal adhesion kinase, and endothelial barrier function. Microvasc Res 2011; 83:31-44. [PMID: 21640127 DOI: 10.1016/j.mvr.2011.05.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 05/04/2011] [Accepted: 05/12/2011] [Indexed: 12/18/2022]
Abstract
Ligands by binding to G protein coupled receptors (GPCRs) stimulate dissociation of heterotrimeric G proteins into Gα and Gβγ subunits. Released Gα and Gβγ subunits induce discrete signaling cues that differentially regulate focal adhesion kinase (FAK) activity and endothelial barrier function. Activation of G proteins downstream of receptors such as protease activated receptor 1 (PAR1) and histamine receptors rapidly increases endothelial permeability which reverses naturally within the following 1-2 h. However, activation of G proteins coupled to the sphingosine-1-phosphate receptor 1 (S1P1) signal cues that enhance basal barrier endothelial function and restore endothelial barrier function following the increase in endothelial permeability by edemagenic agents. Intriguingly, both PAR1 and S1P1 activation stimulates FAK activity, which associates with alteration in endothelial barrier function by these agonists. In this review, we focus on the role of the G protein subunits downstream of PAR1 and S1P1 in regulating FAK activity and endothelial barrier function.
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Affiliation(s)
- Tracy Thennes
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612, USA
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Lin CH, Cheng HW, Ma HP, Wu CH, Hong CY, Chen BC. Thrombin induces NF-kappaB activation and IL-8/CXCL8 expression in lung epithelial cells by a Rac1-dependent PI3K/Akt pathway. J Biol Chem 2011; 286:10483-94. [PMID: 21266580 DOI: 10.1074/jbc.m110.112433] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
We previously showed that thrombin induces interleukin (IL)-8/CXCL8 expression via the protein kinase C (PKC)α/c-Src-dependent IκB kinase α/β (IKKα/β)/NF-κB signaling pathway in human lung epithelial cells. In this study, we further investigated the roles of Rac1, phosphoinositide 3-kinase (PI3K), and Akt in thrombin-induced NF-κB activation and IL-8/CXCL8 expression. Thrombin-induced IL-8/CXCL8 release and IL-8/CXCL8-luciferase activity were attenuated by a PI3K inhibitor (LY294002), an Akt inhibitor (1-L-6-hydroxymethyl-chiro-inositol-2-((R)-2-O-methyl-3-O-octadecylcarbonate)), and the dominant negative mutants of Rac1 (RacN17) and Akt (AktDN). Treatment of cells with thrombin caused activation of Rac and Akt. The thrombin-induced increase in Akt activation was inhibited by RacN17 and LY294002. Stimulation of cells with thrombin resulted in increases in IKKα/β activation and κB-luciferase activity; these effects were inhibited by RacN17, LY294002, an Akt inhibitor, and AktDN. Treatment of cells with thrombin induced Gβγ, p85α, and Rac1 complex formation in a time-dependent manner. These results imply that thrombin activates the Rac1/PI3K/Akt pathway through formation of the Gβγ, Rac1, and p85α complex to induce IKKα/β activation, NF-κB transactivation, and IL-8/CXCL8 expression in human lung epithelial cells.
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Affiliation(s)
- Chien-Huang Lin
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
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Kalwa H, Michel T. The MARCKS protein plays a critical role in phosphatidylinositol 4,5-bisphosphate metabolism and directed cell movement in vascular endothelial cells. J Biol Chem 2010; 286:2320-30. [PMID: 21097841 DOI: 10.1074/jbc.m110.196022] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The MARCKS protein (myristoylated alanine-rich C kinase substrate) is an actin- and calmodulin-binding protein that is expressed in many mammalian tissues. The role of MARCKS in endothelial signaling responses is incompletely understood. We found that siRNA-mediated knockdown of MARCKS in cultured endothelial cells abrogated directed cell movement in a wound healing assay. We used biochemical and cell imaging approaches to explore the role of MARCKS in endothelial signal transduction pathways activated by insulin. Insulin treatment of vascular endothelial cells promoted the dose- and time-dependent phosphorylation of MARCKS. Cell imaging and hydrodynamic approaches revealed that MARCKS is targeted to plasmalemmal caveolae and undergoes subcellular translocation in response to insulin. Insulin treatment promoted an increase in levels of the signaling phospholipid phosphatidylinositol 4,5-bisphosphate (PIP(2)) in plasmalemmal caveolae. The insulin-stimulated increase in caveolar PIP(2) was blocked by siRNA-mediated knockdown of MARCKS, as determined using both biochemical assays and imaging studies using FRET-based PIP(2) biosensors. The critical role of PIP(2) in MARCKS responses was explored by examining the PIP(2)- and actin-binding proteins Arp2/3 and N-WASP. Insulin promoted the rapid and robust phosphorylation of both N-WASP and Arp2/3, but these phosphorylation responses were markedly attenuated by siRNA-mediated MARCKS knockdown. Moreover, MARCKS knockdown effectively abrogated N-WASP activation in response to insulin, as determined using a FRET-based N-WASP activity biosensor. Taken together, these studies show that MARCKS plays a key role in insulin-dependent endothelial signaling to PIP(2) and is a critical determinant of actin assembly and directed cell movement in the vascular endothelium.
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Affiliation(s)
- Hermann Kalwa
- Cardiovascular Medicine Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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Becker S, von Otte S, Robenek H, Diedrich K, Nofer JR. Follicular fluid high-density lipoprotein-associated sphingosine 1-phosphate (S1P) promotes human granulosa lutein cell migration via S1P receptor type 3 and small G-protein RAC1. Biol Reprod 2010; 84:604-12. [PMID: 20980685 DOI: 10.1095/biolreprod.110.084152] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Coordinated migration and progesterone production by granulosa cells is critical to the development of the corpus luteum, but the underlying mechanisms remain obscure. Sphingosine 1-phosphate (S1P), which is associated with follicular fluid high-density lipoprotein (FF-HDL), was previously shown to regulate ovarian angiogenesis. We herein examined the effects of S1P and FF-HDL on the function of granulosa lutein cells. Both FF-HDL and S1P induced migration of primary human granulosa lutein cells (hGCs) and the granulosa lutein cell line HGL5. In addition, FF-HDL but not S1P promoted progesterone synthesis, and neither of the two compounds stimulated proliferation of granulosa lutein cells. Polymerase chain reaction and Western blot experiments demonstrated the expression of S1P receptor type 1 (S1PR1), S1PR2, S1PR3, and S1PR5 but not S1PR4 in hGCs and HGL5 cells. The FF-HDL- and S1P-induced granulosa lutein cell migration was emulated by FTY720, an agonist of S1PR1, S1PR3, S1PR4, and S1PR5, and by VPC24191, an agonist of S1PR1 and S1PR3, but not by SEW2871 and phytosphingosine 1-phosphate, agonists of S1PR1 and S1PR4, respectively. In addition, blockade of S1PR3 with CAY1044, suramine, or pertussis toxin inhibited hGC and HGL5 cell migration toward FF-HDL or S1P, while blockade of S1PR1 and S1PR2 with W146 and JTE013, respectively, had no effect. Both FF-HDL and S1P triggered activation of small G-protein RAC1 and actin polymerization in granulosa cells, and RAC1 inhibition with Clostridium difficile toxin B or NSC23766 abolished FF-HDL- and S1P-induced migration. The FF-HDL-associated S1P promotes granulosa lutein cell migration via S1PR3 and RAC1 activation. This may represent a novel mechanism contributing to the development of the corpus luteum.
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Affiliation(s)
- Steffi Becker
- Department of Obstetrics and Gynecology, University of Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
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Su SC, Maxwell SA, Bayless KJ. Annexin 2 regulates endothelial morphogenesis by controlling AKT activation and junctional integrity. J Biol Chem 2010; 285:40624-34. [PMID: 20947498 DOI: 10.1074/jbc.m110.157271] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sprouting angiogenesis is a multistep process that involves endothelial cell activation, basement membrane degradation, proliferation, lumen formation, and stabilization. In this study, we identified annexin 2 as a regulator of endothelial morphogenesis using a three-dimensional in vitro model where sprouting angiogenesis was driven by sphingosine 1-phosphate and angiogenic growth factors. We observed that sphingosine 1-phosphate triggered annexin 2 translocation from the cytosol to the plasma membrane and its association with vascular endothelial (VE)-cadherin. In addition, annexin 2 depletion attenuated Akt activation, which was associated with increased phosphorylation of VE-cadherin and endothelial barrier leakage. Disrupting homotypic VE-cadherin interactions with EGTA, antibodies to the extracellular domain of VE-cadherin, or gene silencing all resulted in decreased Akt (but not Erk1/2) activation. Furthermore, expression of constitutively active Akt restored reduced endothelial sprouting responses observed with annexin 2 and VE-cadherin knockdown. Collectively, we report that annexin 2 regulates endothelial morphogenesis through an adherens junction-mediated pathway upstream of Akt.
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Affiliation(s)
- Shih-Chi Su
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas 77843-1114, USA
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