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Schmidt A, Kaakinen M, Wenta T, Manninen A. Loss of α6β4 Integrin-Mediated Hemidesmosomes Promotes Prostate Epithelial Cell Migration by Stimulating Focal Adhesion Dynamics. Front Cell Dev Biol 2022; 10:886569. [PMID: 35874837 PMCID: PMC9301336 DOI: 10.3389/fcell.2022.886569] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 06/17/2022] [Indexed: 11/13/2022] Open
Abstract
Epithelial cell adhesion is mediated by actin cytoskeleton-linked focal adhesions (FAs) and intermediate filament-associated hemidesmosomes (HDs). HDs are formed by α6β4-integrins and mediate stable anchoring to the extracellular matrix (ECM) while FAs containing β1-integrins regulate cell migration. Loss of HDs has been reported in various cancers such as prostate cancer where it correlates with increased invasive migration. Here we have studied cell migration properties and FA dynamics in genetically engineered prostate epithelial cell lines with intact or disrupted HDs. Disruption of HDs by depleting α6- or β4-integrin expression promoted collective cell migration and modulated migratory activity. Dynamic analysis of fluorescent protein-tagged FA marker proteins revealed faster FA assembly and disassembly kinetics in HD-depleted cells. FRAP analysis showed that loss of HDs correlated with faster diffusion rates of focal adhesion kinase (FAK) and vinculin in and out of FAs. These data suggest that loss of α6β4-mediated HDs promote cell migration and FA assembly dynamics by influencing the molecular diffusion rates of FAK.
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Affiliation(s)
- Anette Schmidt
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Mika Kaakinen
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Tomasz Wenta
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Gdansk, Poland
- *Correspondence: Tomasz Wenta, ; Aki Manninen,
| | - Aki Manninen
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
- *Correspondence: Tomasz Wenta, ; Aki Manninen,
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2
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Tsakogiannis D, Nikolakopoulou A, Zagouri F, Stratakos G, Syrigos K, Zografos E, Koulouris N, Bletsa G. Update Overview of the Role of Angiopoietins in Lung Cancer. MEDICINA (KAUNAS, LITHUANIA) 2021; 57:medicina57111191. [PMID: 34833409 PMCID: PMC8625006 DOI: 10.3390/medicina57111191] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 12/27/2022]
Abstract
Angiogenesis is a biological process that involves the formation of new blood vessels from the existing vasculature, and it plays a fundamental role in the development and progression of several types of cancer, including lung cancer. The angiopoietin/Tie2 ligand/receptor system orchestrates vascular integrity. In particular, Angiopoietin-1 activates the endothelial cell (EC)-specific receptor tyrosine kinase, Tie2, which is essential for preserving endothelial quiescence. On the other hand, Angiopoietin-2 acts as an inhibitor of the Angiopoietin-1/Tie2 signaling pathways, thus facilitating the destabilization of quiescent endothelium in cases of inflammation and cancer. Clinical studies have proven that high levels of Angiopoietin-2 indicate the development of non-small-cell lung carcinomas (NSCLC), while high levels of Angiopoietin-2 are strongly related to tumor angiogenesis, lymphangiogenesis, metastasis, and poor prognosis. Interestingly, the association of Angiopoietin-2 levels with the type of surgical approach makes Angiopoietin-2 a valuable factor in selecting the most suitable therapeutic strategy for lung cancer patients. The role of the Angiopoietin-1 and Angiopoietin-4 levels in NSCLC development requires further investigation. The present review focuses on the clinical impact of the Angiopoietin-1, Angiopoietin-2, and Angiopoietin-4 levels in patients diagnosed with NSCLC, emphasizing the interaction between them, and how they affect the development, progression, and metastasis of lung disease. Finally, it estimates the role of angiopoietins levels in the effective therapy of lung cancer patients.
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Affiliation(s)
| | - Asimina Nikolakopoulou
- Intensive Care Unit, 1st Department of Respiratory Medicine, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (A.N.); (G.S.); (N.K.)
| | - Flora Zagouri
- Department of Clinical Therapeutics, School of Medicine, Alexandra Hospital, National and Kapodistrian University of Athens, 11528 Athens, Greece; (F.Z.); (E.Z.)
| | - Grigorios Stratakos
- Intensive Care Unit, 1st Department of Respiratory Medicine, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (A.N.); (G.S.); (N.K.)
| | - Konstantinos Syrigos
- Third Department of Internal Medicine, Sotiria Hospital, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Eleni Zografos
- Department of Clinical Therapeutics, School of Medicine, Alexandra Hospital, National and Kapodistrian University of Athens, 11528 Athens, Greece; (F.Z.); (E.Z.)
| | - Nikolaos Koulouris
- Intensive Care Unit, 1st Department of Respiratory Medicine, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (A.N.); (G.S.); (N.K.)
| | - Garyfalia Bletsa
- Research Center, Hellenic Anticancer Institute, 10680 Athens, Greece;
- Correspondence: or ; Tel./Fax: +30-21-03643723
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3
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Zhang Y, Kontos CD, Annex BH, Popel AS. Angiopoietin-Tie Signaling Pathway in Endothelial Cells: A Computational Model. iScience 2019; 20:497-511. [PMID: 31655061 PMCID: PMC6806670 DOI: 10.1016/j.isci.2019.10.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/21/2019] [Accepted: 09/30/2019] [Indexed: 12/13/2022] Open
Abstract
The angiopoietin-Tie signaling pathway is an important vascular signaling pathway involved in angiogenesis, vascular stability, and quiescence. Dysregulation in the pathway is linked to the impairments in vascular function associated with many diseases, including cancer, ocular diseases, systemic inflammation, and cardiovascular diseases. The present study uses a computational signaling pathway model validated against experimental data to quantitatively study various mechanistic aspects of the angiopoietin-Tie signaling pathway, including receptor activation, trafficking, turnover, and molecular mechanisms of its regulation. The model provides mechanistic insights into the controversial role of Ang2 and its regulators vascular endothelial protein tyrosine phosphatase (VE-PTP) and Tie1 and predicts synergistic effects of inhibition of VE-PTP, Tie1, and Tie2 cleavage on enhancing the vascular protective actions of Tie2.
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Affiliation(s)
- Yu Zhang
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA.
| | - Christopher D Kontos
- Department of Medicine, Division of Cardiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Brian H Annex
- Department of Medicine and the Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Aleksander S Popel
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
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4
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Boscher C, Gaonac'h-Lovejoy V, Delisle C, Gratton JP. Polarization and sprouting of endothelial cells by angiopoietin-1 require PAK2 and paxillin-dependent Cdc42 activation. Mol Biol Cell 2019; 30:2227-2239. [PMID: 31141452 PMCID: PMC6743454 DOI: 10.1091/mbc.e18-08-0486] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Binding of angiopoietin-1 (Ang-1) to its receptor Tie2 on endothelial cells (ECs) promotes vessel barrier integrity and angiogenesis. Here, we identify PAK2 and paxillin as critical targets of Ang-1 responsible for EC migration, polarization, and sprouting. We found that Ang-1 increases PAK2-dependent paxillin phosphorylation and remodeling of focal adhesions and that PAK2 and paxillin are required for EC polarization, migration, and angiogenic sprouting in response to Ang-1. Our findings show that Ang-1 triggers Cdc42 activation at the leading edges of migrating ECs, which is dependent on PAK2 and paxillin expression. We also established that the polarity protein Par3 interacts with Cdc42 in response to Ang-1 in a PAK2- and paxillin-dependent manner. Par3 is recruited at the leading edges of migrating cells and in focal adhesion, where it forms a signaling complex with PAK2 and paxillin in response to Ang-1. These results show that Ang-1 triggers EC polarization and angiogenic sprouting through PAK2-dependent paxillin activation and remodeling of focal adhesions, which are necessary for local activation of Cdc42 and the associated polarity complex. We have shown that PAK2 controls a signaling pathway important for angiogenic sprouting that links focal adhesions to polarity signaling in ECs.
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Affiliation(s)
- Cécile Boscher
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, QC H3C 3J7, Canada
| | - Vanda Gaonac'h-Lovejoy
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, QC H3C 3J7, Canada
| | - Chantal Delisle
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, QC H3C 3J7, Canada
| | - Jean-Philippe Gratton
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, QC H3C 3J7, Canada
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5
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Elamaa H, Kihlström M, Kapiainen E, Kaakinen M, Miinalainen I, Ragauskas S, Cerrada-Gimenez M, Mering S, Nätynki M, Eklund L. Angiopoietin-4-dependent venous maturation and fluid drainage in the peripheral retina. eLife 2018; 7:37776. [PMID: 30444491 PMCID: PMC6239434 DOI: 10.7554/elife.37776] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 10/22/2018] [Indexed: 01/09/2023] Open
Abstract
The maintenance of fluid homeostasis is necessary for function of the neural retina; however, little is known about the significance of potential fluid management mechanisms. Here, we investigated angiopoietin-4 (Angpt4, also known as Ang3), a poorly characterized ligand for endothelial receptor tyrosine kinase Tie2, in mouse retina model. By using genetic reporter, fate mapping, and in situ hybridization, we found Angpt4 expression in a specific sub-population of astrocytes at the site where venous morphogenesis occurs and that lower oxygen tension, which distinguishes peripheral and venous locations, enhances Angpt4 expression. Correlating with its spatiotemporal expression, deletion of Angpt4 resulted in defective venous development causing impaired venous drainage and defects in neuronal cells. In vitro characterization of angiopoietin-4 proteins revealed both ligand-specific and redundant functions among the angiopoietins. Our study identifies Angpt4 as the first growth factor for venous-specific development and its importance in venous remodeling, retinal fluid clearance and neuronal function.
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Affiliation(s)
- Harri Elamaa
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Minna Kihlström
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Emmi Kapiainen
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Mika Kaakinen
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | | | | | | | - Satu Mering
- R&D Department, Experimentica Ltd, Kuopio, Finland
| | - Marjut Nätynki
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Lauri Eklund
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
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6
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Kangas J, Nätynki M, Eklund L. Development of Molecular Therapies for Venous Malformations. Basic Clin Pharmacol Toxicol 2018; 123 Suppl 5:6-19. [DOI: 10.1111/bcpt.13027] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 04/09/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Jaakko Kangas
- Life Science Center of Tsukuba Advanced Research Alliance; University of Tsukuba; Tsukuba Japan
| | - Marjut Nätynki
- Oulu Center for Cell-Matrix Research; Faculty of Biochemistry and Molecular Medicine; Biocenter Oulu University of Oulu; Oulu Finland
| | - Lauri Eklund
- Oulu Center for Cell-Matrix Research; Faculty of Biochemistry and Molecular Medicine; Biocenter Oulu University of Oulu; Oulu Finland
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7
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Review of the endothelial pathogenic mechanism of TIE2-related venous malformation. J Vasc Surg Venous Lymphat Disord 2017; 5:740-748. [DOI: 10.1016/j.jvsv.2017.05.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 03/11/2017] [Indexed: 11/20/2022]
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8
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Angiopoietin-Tie signalling in the cardiovascular and lymphatic systems. Clin Sci (Lond) 2017; 131:87-103. [PMID: 27941161 PMCID: PMC5146956 DOI: 10.1042/cs20160129] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 06/23/2016] [Accepted: 07/07/2016] [Indexed: 12/30/2022]
Abstract
Endothelial cells that form the inner layer of blood and lymphatic vessels are important regulators of vascular functions and centrally involved in the pathogenesis of vascular diseases. In addition to the vascular endothelial growth factor (VEGF) receptor pathway, the angiopoietin (Ang)-Tie system is a second endothelial cell specific ligand-receptor signalling system necessary for embryonic cardiovascular and lymphatic development. The Ang-Tie system also regulates postnatal angiogenesis, vessel remodelling, vascular permeability and inflammation to maintain vascular homoeostasis in adult physiology. This system is implicated in numerous diseases where the vasculature has an important contribution, such as cancer, sepsis, diabetes, atherosclerosis and ocular diseases. Furthermore, mutations in the TIE2 signalling pathway cause defects in vascular morphogenesis, resulting in venous malformations and primary congenital glaucoma. Here, we review recent advances in the understanding of the Ang-Tie signalling system, including cross-talk with the vascular endothelial protein tyrosine phosphatase (VE-PTP) and the integrin cell adhesion receptors, focusing on the Ang-Tie system in vascular development and pathogenesis of vascular diseases.
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9
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Saharinen P, Eklund L, Alitalo K. Therapeutic targeting of the angiopoietin-TIE pathway. Nat Rev Drug Discov 2017; 16:635-661. [PMID: 28529319 DOI: 10.1038/nrd.2016.278] [Citation(s) in RCA: 342] [Impact Index Per Article: 48.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The endothelial angiopoietin (ANG)-TIE growth factor receptor pathway regulates vascular permeability and pathological vascular remodelling during inflammation, tumour angiogenesis and metastasis. Drugs that target the ANG-TIE pathway are in clinical development for oncological and ophthalmological applications. The aim is to complement current vascular endothelial growth factor (VEGF)-based anti-angiogenic therapies in cancer, wet age-related macular degeneration and macular oedema. The unique function of the ANG-TIE pathway in vascular stabilization also renders this pathway an attractive target in sepsis, organ transplantation, atherosclerosis and vascular complications of diabetes. This Review covers key aspects of the function of the ANG-TIE pathway in vascular disease and describes the recent development of novel therapeutics that target this pathway.
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Affiliation(s)
- Pipsa Saharinen
- Wihuri Research Institute and Translational Cancer Biology Program, Biomedicum Helsinki, University of Helsinki, Haartmaninkatu 8, P.O. Box 63, FI-00014 Helsinki, Finland
| | - Lauri Eklund
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, Aapistie 5A, University of Oulu, 90220 Oulu, Finland
| | - Kari Alitalo
- Wihuri Research Institute and Translational Cancer Biology Program, Biomedicum Helsinki, University of Helsinki, Haartmaninkatu 8, P.O. Box 63, FI-00014 Helsinki, Finland
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10
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Abstract
The endothelial cell (EC)-specific receptor tyrosine kinases Tie1 and Tie2 are necessary for the remodeling and maturation of blood and lymphatic vessels. Angiopoietin-1 (Ang1) growth factor is a Tie2 agonist, whereas Ang2 functions as a context-dependent agonist/antagonist. The orphan receptor Tie1 modulates Tie2 activation, which is induced by association of angiopoietins with Tie2 in cis and across EC-EC junctions in trans Except for the binding of the C-terminal angiopoietin domains to the Tie2 ligand-binding domain, the mechanisms for Tie2 activation are poorly understood. We report here the structural basis of Ang1-induced Tie2 dimerization in cis and provide mechanistic insights on Ang2 antagonism, Tie1/Tie2 heterodimerization, and Tie2 clustering. We find that Ang1-induced Tie2 dimerization and activation occurs via the formation of an intermolecular β-sheet between the membrane-proximal (third) Fibronectin type III domains (Fn3) of Tie2. The structures of Tie2 and Tie1 Fn3 domains are similar and compatible with Tie2/Tie1 heterodimerization by the same mechanism. Mutagenesis of the key interaction residues of Tie2 and Tie1 Fn3 domains decreased Ang1-induced Tie2 phosphorylation and increased the basal phosphorylation of Tie1, respectively. Furthermore, the Tie2 structures revealed additional interactions between the Fn 2 (Fn2) domains that coincide with a mutation of Tie2 in primary congenital glaucoma that leads to defective Tie2 clustering and junctional localization. Mutagenesis of the Fn2-Fn2 interface increased the basal phosphorylation of Tie2, suggesting that the Fn2 interactions are essential in preformed Tie2 oligomerization. The interactions of the membrane-proximal domains could provide new targets for modulation of Tie receptor activity.
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11
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Nätynki M, Kangas J, Miinalainen I, Sormunen R, Pietilä R, Soblet J, Boon LM, Vikkula M, Limaye N, Eklund L. Common and specific effects of TIE2 mutations causing venous malformations. Hum Mol Genet 2015; 24:6374-89. [PMID: 26319232 DOI: 10.1093/hmg/ddv349] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 08/24/2015] [Indexed: 01/09/2023] Open
Abstract
Venous malformations (VMs) are localized defects in vascular morphogenesis frequently caused by mutations in the gene for the endothelial tyrosine kinase receptor TIE2. Here, we report the analysis of a comprehensive collection of 22 TIE2 mutations identified in patients with VM, either as single amino acid substitutions or as double-mutations on the same allele. Using endothelial cell (EC) cultures, mouse models and ultrastructural analysis of tissue biopsies from patients, we demonstrate common as well as mutation-specific cellular and molecular features, on the basis of which mutations cluster into categories that correlate with data from genetic studies. Comparisons of double-mutants with their constituent single-mutant forms identified the pathogenic contributions of individual changes, and their compound effects. We find that defective receptor trafficking and subcellular localization of different TIE2 mutant forms occur via a variety of mechanisms, resulting in attenuated response to ligand. We also demonstrate, for the first time, that TIE2 mutations cause chronic activation of the MAPK pathway resulting in loss of normal EC monolayer due to extracellular matrix (ECM) fibronectin deficiency and leading to upregulation of plasminogen/plasmin proteolytic pathway. Corresponding EC and ECM irregularities are observed in affected tissues from mouse models and patients. Importantly, an imbalance between plasminogen activators versus inhibitors would also account for high d-dimer levels, a major feature of unknown cause that distinguishes VMs from other vascular anomalies.
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Affiliation(s)
- Marjut Nätynki
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Jaakko Kangas
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | | | - Raija Sormunen
- Biocenter Oulu, University of Oulu, Oulu, Finland, Department of Pathology and Oulu University Hospital, University of Oulu, Oulu, Finland
| | - Riikka Pietilä
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Julie Soblet
- Human Molecular Genetics, de Duve Institute, and
| | - Laurence M Boon
- Human Molecular Genetics, de Duve Institute, and Center for Vascular Anomalies, Division of Plastic Surgery, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium
| | | | - Nisha Limaye
- Human Molecular Genetics, de Duve Institute, and
| | - Lauri Eklund
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland,
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12
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Abstract
The endothelial TIE1 and TIE2 receptor tyrosine kinases form a distinct subfamily characterized by their unique extracellular domains. Together with the angiopoietin growth factors (ANGPT1, ANGPT2, ANGPT4, also abbreviated as ANG), the TIE receptors form an endothelial specific signaling pathway with important functions in the regulation of lymphatic and cardiovascular development and vascular homeostasis. Angiopoietins exist in multimeric forms that activate the TIE receptors via unique mechanism. In endothelial cell–cell contacts, angiopoietins induce the formation of homomeric in trans TIE receptor complexes extending across the cell junctions, whereas matrix-bound angiopoietin-1 (ANG1) activates the TIE receptors in a cis configuration. In comparison to the vascular endothelial growth factor receptors, the TIE receptors undergo little ubiquitin-mediated degradation after activation, whereas TIE2 signaling is negatively regulated by the vascular endothelial protein tyrosine phosphatase, VE-PTP. ANG1 activation of TIE2 supports vascular stabilization, whereas angiopoietin-2 (ANG2), a context-dependent weak TIE2 agonist/antagonist, promotes pathological tumor angiogenesis, vascular permeability, and inflammation. Recently, ANG2 has been found to mediate some of its vascular destabilizing and angiogenic functions via integrin signalling. The circulating levels of ANG2 are increased in cancer, and in several human diseases associated with inflammation and vascular leak, for example, in sepsis. Blocking of ANG2 has emerged as a potential novel therapeutic strategy for these diseases. In addition, preclinical results demonstrate that genetic TIE1 deletion in mice inhibits the vascularization and growth of tumor isografts and protects from atherosclerosis, with little effect on normal vascular homeostasis in adult mice. The ability of the ANG-TIE pathway to control vessel stability and angiogenesis makes it an interesting vascular target for the treatment of the various diseases.
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13
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Endothelial destabilization by angiopoietin-2 via integrin β1 activation. Nat Commun 2015; 6:5962. [PMID: 25635707 PMCID: PMC4316742 DOI: 10.1038/ncomms6962] [Citation(s) in RCA: 192] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 11/24/2014] [Indexed: 02/07/2023] Open
Abstract
Angiopoietins regulate vascular homeostasis via the endothelial Tie receptor tyrosine kinases. Angiopoietin-1 (Ang1) supports endothelial stabilization via Tie2 activation. Angiopoietin-2 (Ang2) functions as a context-dependent Tie2 agonist/antagonist promoting pathological angiogenesis, vascular permeability and inflammation. Elucidating Ang2-dependent mechanisms of vascular destablization is critical for rational design of angiopoietin antagonists that have demonstrated therapeutic efficacy in cancer trials. Here, we report that Ang2, but not Ang1, activates β1-integrin, leading to endothelial destablization. Autocrine Ang2 signalling upon Tie2 silencing, or in Ang2 transgenic mice, promotes β1-integrin-positive elongated matrix adhesions and actin stress fibres, regulating vascular endothelial-cadherin-containing cell–cell junctions. The Tie2-silenced monolayer integrity is rescued by β1-integrin, phosphoinositide-3 kinase or Rho kinase inhibition, and by re-expression of a membrane-bound Tie2 ectodomain. Furthermore, Tie2 silencing increases, whereas Ang2 blocking inhibits transendothelial tumour cell migration in vitro. These results establish Ang2-mediated β1-integrin activation as a promoter of endothelial destablization, explaining the controversial vascular functions of Ang1 and Ang2. Angiopoietin-1 (Ang1) and angiopoietin-2 (Ang2) have opposing effects on vascular stability through their receptor Tie2, but there is evidence for Tie2-independent functions of Ang2. Here, Hakanpaa et al. show that Ang2 directly activates β1-integrin, leading to rearrangement of the actin cytoskeleton and decreased VE-cadherin in cell–cell junctions.
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14
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Martín-Vílchez S, Rodríguez-Muñoz Y, López-Rodríguez R, Hernández-Bartolomé Á, Borque-Iñurrita MJ, Molina-Jiménez F, García-Buey L, Moreno-Otero R, Sanz-Cameno P. Inhibition of tyrosine kinase receptor Tie2 reverts HCV-induced hepatic stellate cell activation. PLoS One 2014; 9:e106958. [PMID: 25302785 PMCID: PMC4193738 DOI: 10.1371/journal.pone.0106958] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 08/12/2014] [Indexed: 01/18/2023] Open
Abstract
Background Hepatitis C virus (HCV) infection is a major cause of chronic liver disease (CLD) and is frequently linked to intrahepatic microvascular disorders. Activation of hepatic stellate cells (HSC) is a central event in liver damage, due to their contribution to hepatic renewal and to the development of fibrosis and hepatocarcinoma. During the progression of CLDs, HSC attempt to restore injured tissue by stimulating repair processes, such as fibrosis and angiogenesis. Because HSC express the key vascular receptor Tie2, among other angiogenic receptors and mediators, we analyzed its involvement in the development of CLD. Methods Tie2 expression was monitored in HSC cultures that were exposed to media from HCV-expressing cells (replicons). The effects of Tie2 blockade on HSC activation by either neutralizing antibody or specific signaling inhibitors were also examined. Results Media from HCV-replicons enhanced HSC activation and invasion and upregulated Tie2 expression. Notably, the blockade of Tie2 receptor (by a specific neutralizing antibody) or signaling (by selective AKT and MAPK inhibitors) significantly reduced alpha-smooth muscle actin (α-SMA) expression and the invasive potential of HCV-conditioned HSC. Conclusions These findings ascribe a novel profibrogenic function to Tie2 receptor in the progression of chronic hepatitis C, highlighting the significance of its dysregulation in the evolution of CLDs and its potential as a novel therapeutic target.
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Affiliation(s)
- Samuel Martín-Vílchez
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Yolanda Rodríguez-Muñoz
- Unidad de Hepatología, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBER-ehd), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Rosario López-Rodríguez
- Unidad de Hepatología, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBER-ehd), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Ángel Hernández-Bartolomé
- Unidad de Hepatología, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain
| | - María Jesús Borque-Iñurrita
- Unidad de Biología Molecular, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain
| | - Francisca Molina-Jiménez
- Unidad de Biología Molecular, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain
| | - Luisa García-Buey
- Unidad de Hepatología, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBER-ehd), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Ricardo Moreno-Otero
- Unidad de Hepatología, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBER-ehd), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Paloma Sanz-Cameno
- Unidad de Hepatología, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBER-ehd), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- * E-mail:
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15
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Sie M, den Dunnen WF, Hoving EW, de Bont ES. Anti-angiogenic therapy in pediatric brain tumors: An effective strategy? Crit Rev Oncol Hematol 2014; 89:418-32. [DOI: 10.1016/j.critrevonc.2013.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 08/10/2013] [Accepted: 09/27/2013] [Indexed: 12/15/2022] Open
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16
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Jeltsch M, Leppänen VM, Saharinen P, Alitalo K. Receptor tyrosine kinase-mediated angiogenesis. Cold Spring Harb Perspect Biol 2013; 5:5/9/a009183. [PMID: 24003209 DOI: 10.1101/cshperspect.a009183] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The endothelial cell is the essential cell type forming the inner layer of the vasculature. Two families of receptor tyrosine kinases (RTKs) are almost completely endothelial cell specific: the vascular endothelial growth factor (VEGF) receptors (VEGFR1-3) and the Tie receptors (Tie1 and Tie2). Both are key players governing the generation of blood and lymphatic vessels during embryonic development. Because the growth of new blood and lymphatic vessels (or the lack thereof) is a central element in many diseases, the VEGF and the Tie receptors provide attractive therapeutic targets in various diseases. Indeed, several drugs directed to these RTK signaling pathways are already on the market, whereas many are in clinical trials. Here we review the VEGFR and Tie families, their involvement in developmental and pathological angiogenesis, and the different possibilities for targeting them to either block or enhance angiogenesis and lymphangiogenesis.
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Affiliation(s)
- Michael Jeltsch
- Wihuri Research Institute, Biomedicum Helsinki, University of Helsinki, FIN-00014 Helsinki, Finland
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17
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αV-integrins are required for mechanotransduction in MDCK epithelial cells. PLoS One 2013; 8:e71485. [PMID: 23977051 PMCID: PMC3747215 DOI: 10.1371/journal.pone.0071485] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 06/29/2013] [Indexed: 01/12/2023] Open
Abstract
The properties of epithelial cells within tissues are regulated by their immediate microenvironment, which consists of neighboring cells and the extracellular matrix (ECM). Integrin heterodimers orchestrate dynamic assembly and disassembly of cell-ECM connections and thereby convey biochemical and mechanical information from the ECM into cells. However, the specific contributions and functional hierarchy between different integrin heterodimers in the regulation of focal adhesion dynamics in epithelial cells are incompletely understood. Here, we have studied the functions of RGD-binding αV-integrins in a Madin Darby Canine Kidney (MDCK) cell model and found that αV-integrins regulate the maturation of focal adhesions (FAs) and cell spreading. αV-integrin-deficient MDCK cells bound collagen I (Col I) substrate via α2β1-integrins but failed to efficiently recruit FA components such as talin, focal adhesion kinase (FAK), vinculin and integrin-linked kinase (ILK). The apparent inability to mature α2β1-integrin-mediated FAs and link them to cellular actin cytoskeleton led to disrupted mechanotransduction in αV-integrin deficient cells seeded onto Col I substrate.
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18
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Eklund L, Saharinen P. Angiopoietin signaling in the vasculature. Exp Cell Res 2013; 319:1271-80. [PMID: 23500414 DOI: 10.1016/j.yexcr.2013.03.011] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Revised: 03/03/2013] [Accepted: 03/04/2013] [Indexed: 01/26/2023]
Abstract
The angiopoietin (Ang) growth factors and the endothelial Tie receptors regulate blood and lymphatic vessel development, and vascular permeability, inflammation, angiogenic remodeling and tumor vascularization in adult tissues. The angiopoietins activate the Tie receptors in unique in trans complexes at endothelial cell-cell and cell-matrix contacts. In addition, integrins have been implicated in the regulation of Ang-Tie signaling. Recent interest has focused on the function of angiopoietin-2 and its inhibition in the tumor vasculature and also in other pathological conditions associated with endothelial dysfunction. Here we review the current understanding of the signaling functions of the Ang-Tie pathway and its potential for future development of targeted vascular therapeutics.
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Affiliation(s)
- Lauri Eklund
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, and Department of Medical Biochemistry and Molecular Biology, University of Oulu, Finland
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19
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Marteau L, Valable S, Divoux D, Roussel SA, Touzani O, MacKenzie ET, Bernaudin M, Petit E. Angiopoietin-2 is vasoprotective in the acute phase of cerebral ischemia. J Cereb Blood Flow Metab 2013; 33:389-95. [PMID: 23211963 PMCID: PMC3587809 DOI: 10.1038/jcbfm.2012.178] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Most forms of cerebral ischemia are characterized by damage to the entire neurovascular unit, which leads to an increase in the permeability of the blood-brain barrier (BBB). In response to permanent focal cerebral ischemia in mice, we detected an early concomitant increase in the expression of the vascular endothelial growth factor (VEGF), a key inducer of vascular leakage and pathological blood vessel growth, and of angiopoietin-2 (Ang2), which is closely associated with VEGF in vascular remodeling. Thus, the aim of this study was to evaluate the role of Ang2 alone, or in combination with VEGF, in the acute phase of cerebral ischemia. The effect of these angiogenic factors on the ischemic lesion volume was evaluated by magnetic resonance imaging. We observed that timely administration of VEGF exacerbates ischemic damage. In contrast, Ang2 decreases the ischemic volume and this beneficial effect is maintained in the presence of VEGF. This investigation reports, for the first time, a protective role of Ang2 following cerebral ischemia, an action associated with a reduced BBB permeability. We propose that Ang2 represents a pertinent molecular target for the treatment of cerebral ischemia since acute brain damage may be limited by a pharmacological protection of the vascular compartment.
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Affiliation(s)
- Léna Marteau
- CNRS, UMR 6301 ISTCT, CERVOxy Group, GIP CYCERON, CAEN Cedex, France
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20
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Thomas M, Kienast Y, Scheuer W, Bähner M, Kaluza K, Gassner C, Herting F, Brinkmann U, Seeber S, Kavlie A, Welschof M, Ries S, Weidner KM, Regula JT, Klein C. A novel angiopoietin-2 selective fully human antibody with potent anti-tumoral and anti-angiogenic efficacy and superior side effect profile compared to Pan-Angiopoietin-1/-2 inhibitors. PLoS One 2013; 8:e54923. [PMID: 23405099 PMCID: PMC3566157 DOI: 10.1371/journal.pone.0054923] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 12/19/2012] [Indexed: 11/29/2022] Open
Abstract
There is increasing experimental evidence for an important role of Angiopoietin-2 (Ang-2) in tumor angiogenesis and progression. In addition, Ang-2 is up-regulated in many cancer types and correlated with poor prognosis. To investigate the functional role of Ang-2 inhibition in tumor development and progression, we generated novel fully human antibodies that neutralize specifically the binding of Ang-2 to its receptor Tie2. The selected antibodies LC06 and LC08 recognize both rodent and human Ang-2 with high affinity, but LC06 shows a higher selectivity for Ang-2 over Ang-1 compared to LC08 which can be considered an Ang-2/Ang-1 cross-reactive antibody. Our data demonstrate that Ang-2 blockade results in potent tumor growth inhibition and pronounced tumor necrosis in subcutaneous and orthotopic tumor models. These effects are attended with a reduction of intratumoral microvessel density and tumor vessels characterized by fewer branches and increased pericyte coverage. Furthermore, anti-Ang-2 treatment strongly inhibits the dissemination of tumor cells to the lungs. Interestingly, in contrast to the Ang-2/Ang-1 cross-reactive antibody LC08 that leads to a regression of physiological vessels in the mouse trachea, the inhibition with the selective anti-Ang-2 antibody LC06 appears to be largely restricted to tumor vasculature without obvious effects on normal vasculature. Taken together, these data provide strong evidence for the selective Ang-2 antibody LC06 as promising new therapeutic agent for the treatment of various cancers.
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Affiliation(s)
- Markus Thomas
- Discovery Oncology, Pharma Research and Early Development, Roche Diagnostics GmbH, Penzberg, Germany.
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21
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Das S, Sudarsan R, Sivakami S, Sharma S. Erythrocytic stage-dependent regulation of oligomerization of Plasmodium ribosomal protein P2. J Biol Chem 2012; 287:41499-513. [PMID: 23060439 DOI: 10.1074/jbc.m112.384388] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The eukaryotic 60 S-ribosomal stalk consists of P0, P1, and P2 proteins, which associate in a pentameric structure (P1(2)-P0-P2(2)). The Plasmodium falciparum protein P2 (PfP2) appears to play nonribosomal roles. It gets exported to the infected erythrocyte (IE) surface at 30 h post-merozoite invasion (PMI), concomitant with extensive oligomerization. Here we present certain biophysical properties of PfP2. Recombinant P2 (rPfP2) protein showed SDS-resistant oligomerization, which could be significantly abolished under reducing conditions. However, the protein continued to oligomerize even when both cysteine residues were mutated, and with up to 40 amino acids (aa) deleted from the C-terminal end. CD analysis of P2 showed largely α-helical and random coil domains. The SDS- and DTT-resistant oligomerization was studied further as it occurred in a development-specific manner in Plasmodium. In a synchronized erythrocytic culture of P. falciparum, the PfP2 protein was detected as part of the ribosomal complex (∼96 kDa) at 18 and 30 h PMI, and was SDS sensitive. However, at 30 h, large amounts of SDS-sensitive aggregates of >600 kDa were also seen. At 30 h PMI, each of the parasites, IE cytosol and IE ghost contained 60-80-kDa PfP2 complexes, which resolved to a single 65-kDa species on SDS-PAGE. Tetramethylrhodamine-labeled rPfP2 protein exhibited DTT- and SDS-resistant oligomerization when treated with P. falciparum parasite extracts only from 24 to 36 h PMI, and multiple proteins appeared to be required for this oligomerization. Understanding the regulation of oligomerization of PfP2 may help in the elucidation of the novel structure-function relationship in the export of PfP2 to the red cell surface.
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Affiliation(s)
- Sudipta Das
- Department of Biological Sciences, Tata Institute of Fundamental Research, 400005 Mumbai, India
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Formation of a PKCζ/β-catenin complex in endothelial cells promotes angiopoietin-1-induced collective directional migration and angiogenic sprouting. Blood 2012; 120:3371-81. [PMID: 22936663 DOI: 10.1182/blood-2012-03-419721] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Angiogenic sprouting requires that cell-cell contacts be maintained during migration of endothelial cells. Angiopoietin-1 (Ang-1) and vascular endothelial growth factor act oppositely on endothelial cell junctions. We found that Ang-1 promotes collective and directional migration and, in contrast to VEGF, induces the formation of a complex formed of atypical protein kinase C (PKC)-ζ and β-catenin at cell-cell junctions and at the leading edge of migrating endothelial cells. This complex brings Par3, Par6, and adherens junction proteins at the front of migrating cells to locally activate Rac1 in response to Ang-1. The colocalization of PKCζ and β-catenin at leading edge along with PKCζ-dependent stabilization of cell-cell contacts promotes directed and collective endothelial cell migration. Consistent with these results, down-regulation of PKCζ in endothelial cells alters Ang-1-induced sprouting in vitro and knockdown in developing zebrafish results in intersegmental vessel defects caused by a perturbed directionality of tip cells and by loss of cell contacts between tip and stalk cells. These results reveal that PKCζ and β-catenin function in a complex at adherens junctions and at the leading edge of migrating endothelial cells to modulate collective and directional migration during angiogenesis.
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