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Gerrits T, Dijkstra KL, Bruijn JA, Scharpfenecker M, Bijkerk R, Baelde HJ. Antisense oligonucleotide-mediated terminal intron retention of endoglin: A potential strategy to inhibit renal interstitial fibrosis. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167186. [PMID: 38642778 DOI: 10.1016/j.bbadis.2024.167186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 04/22/2024]
Abstract
TGF-β is considered an important cytokine in the development of interstitial fibrosis in chronic kidney disease. The TGF-β co-receptor endoglin (ENG) tends to be upregulated in kidney fibrosis. ENG has two membrane bound isoforms generated via alternative splicing. Long-ENG was shown to enhance the extent of renal fibrosis in an unilateral ureteral obstruction mouse model, while short-ENG inhibited renal fibrosis. Here we aimed to achieve terminal intron retention of endoglin using antisense-oligo nucleotides (ASOs), thereby shifting the ratio towards short-ENG to inhibit the TGF-β1-mediated pro-fibrotic response. We isolated mRNA from kidney biopsies of patients with chronic allograft disease (CAD) (n = 12) and measured total ENG and short-ENG mRNA levels. ENG mRNA was upregulated 2.3 fold (p < 0.05) in kidneys of CAD patients compared to controls, while the percentage short-ENG of the total ENG mRNA was significantly lower (1.8 fold; p < 0.05). Transfection of ASOs that target splicing regulatory sites of ENG into TK173 fibroblasts led to higher levels of short-ENG (2 fold; p < 0.05). In addition, we stimulated these cells with TGF-β1 and measured a decrease in upregulation of ACTA2, COL1A1 and FN1 mRNA levels, and protein expression of αSMA, collagen type I, and fibronectin. These results show a potential for ENG ASOs as a therapy to reduce interstitial fibrosis in CKD.
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Affiliation(s)
- Tessa Gerrits
- Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands.
| | - Kyra L Dijkstra
- Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Jan Anthonie Bruijn
- Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Marion Scharpfenecker
- Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Roel Bijkerk
- Department of Nephrology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Hans J Baelde
- Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
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Puerto-Camacho P, Díaz-Martín J, Olmedo-Pelayo J, Bolado-Carrancio A, Salguero-Aranda C, Jordán-Pérez C, Esteban-Medina M, Álamo-Álvarez I, Delgado-Bellido D, Lobo-Selma L, Dopazo J, Sastre A, Alonso J, Grünewald TGP, Bernabeu C, Byron A, Brunton VG, Amaral AT, Álava ED. Endoglin and MMP14 Contribute to Ewing Sarcoma Spreading by Modulation of Cell–Matrix Interactions. Int J Mol Sci 2022; 23:ijms23158657. [PMID: 35955799 PMCID: PMC9369355 DOI: 10.3390/ijms23158657] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/14/2022] [Accepted: 07/22/2022] [Indexed: 01/26/2023] Open
Abstract
Endoglin (ENG) is a mesenchymal stem cell (MSC) marker typically expressed by active endothelium. This transmembrane glycoprotein is shed by matrix metalloproteinase 14 (MMP14). Our previous work demonstrated potent preclinical activity of first-in-class anti-ENG antibody-drug conjugates as a nascent strategy to eradicate Ewing sarcoma (ES), a devastating rare bone/soft tissue cancer with a putative MSC origin. We also defined a correlation between ENG and MMP14 expression in ES. Herein, we show that ENG expression is significantly associated with a dismal prognosis in a large cohort of ES patients. Moreover, both ENG/MMP14 are frequently expressed in primary ES tumors and metastasis. To deepen in their functional relevance in ES, we conducted transcriptomic and proteomic profiling of in vitro ES models that unveiled a key role of ENG and MMP14 in cell mechano-transduction. Migration and adhesion assays confirmed that loss of ENG disrupts actin filament assembly and filopodia formation, with a concomitant effect on cell spreading. Furthermore, we observed that ENG regulates cell–matrix interaction through activation of focal adhesion signaling and protein kinase C expression. In turn, loss of MMP14 contributed to a more adhesive phenotype of ES cells by modulating the transcriptional extracellular matrix dynamics. Overall, these results suggest that ENG and MMP14 exert a significant role in mediating correct spreading machinery of ES cells, impacting the aggressiveness of the disease.
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Affiliation(s)
- Pilar Puerto-Camacho
- Institute of Biomedicine of Sevilla (IBiS), Virgen del Rocio University Hospital/CSIC/University of Sevilla/CIBERONC, Molecular Pathology of Sarcomas, 41013 Seville, Spain
| | - Juan Díaz-Martín
- Institute of Biomedicine of Sevilla (IBiS), Virgen del Rocio University Hospital/CSIC/University of Sevilla/CIBERONC, Molecular Pathology of Sarcomas, 41013 Seville, Spain
- Department of Normal and Pathological Cytology and Histology, School of Medicine, University of Seville, 41009 Seville, Spain
| | - Joaquín Olmedo-Pelayo
- Institute of Biomedicine of Sevilla (IBiS), Virgen del Rocio University Hospital/CSIC/University of Sevilla/CIBERONC, Molecular Pathology of Sarcomas, 41013 Seville, Spain
- Department of Normal and Pathological Cytology and Histology, School of Medicine, University of Seville, 41009 Seville, Spain
| | - Alfonso Bolado-Carrancio
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Carmen Salguero-Aranda
- Institute of Biomedicine of Sevilla (IBiS), Virgen del Rocio University Hospital/CSIC/University of Sevilla/CIBERONC, Molecular Pathology of Sarcomas, 41013 Seville, Spain
- Department of Normal and Pathological Cytology and Histology, School of Medicine, University of Seville, 41009 Seville, Spain
| | - Carmen Jordán-Pérez
- Institute of Biomedicine of Sevilla (IBiS), Virgen del Rocio University Hospital/CSIC/University of Sevilla/CIBERONC, Molecular Pathology of Sarcomas, 41013 Seville, Spain
| | - Marina Esteban-Medina
- Clinical Bioinformatics Area, Fundación Progreso y Salud (FPS), CDCA, Hospital Virgen del Rocío, 41013 Seville, Spain
| | - Inmaculada Álamo-Álvarez
- Clinical Bioinformatics Area, Fundación Progreso y Salud (FPS), CDCA, Hospital Virgen del Rocío, 41013 Seville, Spain
| | - Daniel Delgado-Bellido
- Institute of Biomedicine of Sevilla (IBiS), Virgen del Rocio University Hospital/CSIC/University of Sevilla/CIBERONC, Molecular Pathology of Sarcomas, 41013 Seville, Spain
| | - Laura Lobo-Selma
- Institute of Biomedicine of Sevilla (IBiS), Virgen del Rocio University Hospital/CSIC/University of Sevilla/CIBERONC, Molecular Pathology of Sarcomas, 41013 Seville, Spain
- Department of Normal and Pathological Cytology and Histology, School of Medicine, University of Seville, 41009 Seville, Spain
| | - Joaquín Dopazo
- Clinical Bioinformatics Area, Fundación Progreso y Salud (FPS), CDCA, Hospital Virgen del Rocío, 41013 Seville, Spain
| | - Ana Sastre
- Unidad Hemato-oncología Pediátrica, Hospital Infantil Universitario La Paz, 28046 Madrid, Spain
| | - Javier Alonso
- Unidad Hemato-oncología Pediátrica, Hospital Infantil Universitario La Paz, 28046 Madrid, Spain
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras, Instituto de Salud Carlos III (IIER-ISCIII), 28029 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (CB06/07/1009; CIBERER-ISCIII), 28029 Madrid, Spain
| | - Thomas G. P. Grünewald
- Division of Translational Pediatric Sarcoma Research, German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), 69120 Heidelberg, Germany
- Hopp-Children’s Cancer Center Heidelberg (KiTZ), 69120 Heidelberg, Germany
- Institute of Pathology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Carmelo Bernabeu
- Division of Translational Pediatric Sarcoma Research, German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), 69120 Heidelberg, Germany
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Adam Byron
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK
| | - Valerie G. Brunton
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Ana Teresa Amaral
- Institute of Biomedicine of Sevilla (IBiS), Virgen del Rocio University Hospital/CSIC/University of Sevilla/CIBERONC, Molecular Pathology of Sarcomas, 41013 Seville, Spain
- Department of Normal and Pathological Cytology and Histology, School of Medicine, University of Seville, 41009 Seville, Spain
- Correspondence: (A.T.A.); (E.D.Á.)
| | - Enrique De Álava
- Institute of Biomedicine of Sevilla (IBiS), Virgen del Rocio University Hospital/CSIC/University of Sevilla/CIBERONC, Molecular Pathology of Sarcomas, 41013 Seville, Spain
- Department of Normal and Pathological Cytology and Histology, School of Medicine, University of Seville, 41009 Seville, Spain
- Correspondence: (A.T.A.); (E.D.Á.)
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Haarmann A, Zimmermann L, Bieber M, Silwedel C, Stoll G, Schuhmann MK. Regulation and Release of Vasoactive Endoglin by Brain Endothelium in Response to Hypoxia/Reoxygenation in Stroke. Int J Mol Sci 2022; 23:ijms23137085. [PMID: 35806090 PMCID: PMC9267030 DOI: 10.3390/ijms23137085] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 06/21/2022] [Accepted: 06/23/2022] [Indexed: 02/01/2023] Open
Abstract
In large vessel occlusion stroke, recanalization to restore cerebral perfusion is essential but not necessarily sufficient for a favorable outcome. Paradoxically, in some patients, reperfusion carries the risk of increased tissue damage and cerebral hemorrhage. Experimental and clinical data suggest that endothelial cells, representing the interface for detrimental platelet and leukocyte responses, likely play a crucial role in the phenomenon referred to as ischemia/reperfusion (I/R)-injury, but the mechanisms are unknown. We aimed to determine the role of endoglin in cerebral I/R-injury; endoglin is a membrane-bound protein abundantly expressed by endothelial cells that has previously been shown to be involved in the maintenance of vascular homeostasis. We investigated the expression of membranous endoglin (using Western blotting and RT-PCR) and the generation of soluble endoglin (using an enzyme-linked immunosorbent assay of cell culture supernatants) after hypoxia and subsequent reoxygenation in human non-immortalized brain endothelial cells. To validate these in vitro data, we additionally examined endoglin expression in an intraluminal monofilament model of permanent and transient middle cerebral artery occlusion in mice. Subsequently, the effects of recombinant human soluble endoglin were assessed by label-free impedance-based measurement of endothelial monolayer integrity (using the xCELLigence DP system) and immunocytochemistry. Endoglin expression is highly inducible by hypoxia in human brain endothelial monolayers in vitro, and subsequent reoxygenation induced its shedding. These findings were corroborated in mice during MCAO; an upregulation of endoglin was displayed in the infarcted hemispheres under occlusion, whereas endoglin expression was significantly diminished after transient MCAO, which is indicative of shedding. Of note is the finding that soluble endoglin induced an inflammatory phenotype in endothelial monolayers. The treatment of HBMEC with endoglin resulted in a decrease in transendothelial resistance and the downregulation of VE-cadherin. Our data establish a novel mechanism in which hypoxia triggers the initial endothelial upregulation of endoglin and subsequent reoxygenation triggers its release as a vasoactive mediator that, when rinsed into adjacent vascular beds after recanalization, can contribute to cerebral reperfusion injury.
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Affiliation(s)
- Axel Haarmann
- Department of Neurology, University of Würzburg, 97080 Würzburg, Germany; (L.Z.); (M.B.); (G.S.)
- Correspondence: (A.H.); (M.K.S.)
| | - Lena Zimmermann
- Department of Neurology, University of Würzburg, 97080 Würzburg, Germany; (L.Z.); (M.B.); (G.S.)
| | - Michael Bieber
- Department of Neurology, University of Würzburg, 97080 Würzburg, Germany; (L.Z.); (M.B.); (G.S.)
| | - Christine Silwedel
- University Children’s Hospital, University of Würzburg, 97080 Würzburg, Germany;
| | - Guido Stoll
- Department of Neurology, University of Würzburg, 97080 Würzburg, Germany; (L.Z.); (M.B.); (G.S.)
| | - Michael K. Schuhmann
- Department of Neurology, University of Würzburg, 97080 Würzburg, Germany; (L.Z.); (M.B.); (G.S.)
- Correspondence: (A.H.); (M.K.S.)
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Ruiz-Llorente L, Vega MC, Fernández FJ, Langa C, Morrell NW, Upton PD, Bernabeu C. Generation of a Soluble Form of Human Endoglin Fused to Green Fluorescent Protein. Int J Mol Sci 2021; 22:ijms222011282. [PMID: 34681942 PMCID: PMC8539536 DOI: 10.3390/ijms222011282] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 10/08/2021] [Accepted: 10/15/2021] [Indexed: 01/06/2023] Open
Abstract
Endoglin (Eng, CD105) is a type I membrane glycoprotein that functions in endothelial cells as an auxiliary receptor for transforming growth factor β (TGF-β)/bone morphogenetic protein (BMP) family members and as an integrin ligand, modulating the vascular pathophysiology. Besides the membrane-bound endoglin, there is a soluble form of endoglin (sEng) that can be generated by the action of the matrix metalloproteinase (MMP)-14 or -12 on the juxtamembrane region of its ectodomain. High levels of sEng have been reported in patients with preeclampsia, hypercholesterolemia, atherosclerosis and cancer. In addition, sEng is a marker of cardiovascular damage in patients with hypertension and diabetes, plays a pathogenic role in preeclampsia, and inhibits angiogenesis and tumor proliferation, migration, and invasion in cancer. However, the mechanisms of action of sEng have not yet been elucidated, and new tools and experimental approaches are necessary to advance in this field. To this end, we aimed to obtain a fluorescent form of sEng as a new tool for biological imaging. Thus, we cloned the extracellular domain of endoglin in the pEGFP-N1 plasmid to generate a fusion protein with green fluorescent protein (GFP), giving rise to pEGFP-N1/Eng.EC. The recombinant fusion protein was characterized by transient and stable transfections in CHO-K1 cells using fluorescence microscopy, SDS-PAGE, immunodetection, and ELISA techniques. Upon transfection with pEGFP-N1/Eng.EC, fluorescence was readily detected in cells, indicating that the GFP contained in the recombinant protein was properly folded into the cytosol. Furthermore, as evidenced by Western blot analysis, the secreted fusion protein yielded the expected molecular mass and displayed a specific fluorescent signal. The fusion protein was also able to bind to BMP9 and BMP10 in vitro. Therefore, the construct described here could be used as a tool for functional in vitro studies of the extracellular domain of endoglin.
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Affiliation(s)
- Lidia Ruiz-Llorente
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (L.R.-L.); (M.C.V.); (F.J.F.); (C.L.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040 Madrid, Spain
- Biochemistry and Molecular Biology Unit, Department of System Biology, School of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, 28871 Madrid, Spain
| | - M. Cristina Vega
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (L.R.-L.); (M.C.V.); (F.J.F.); (C.L.)
| | - Francisco J. Fernández
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (L.R.-L.); (M.C.V.); (F.J.F.); (C.L.)
| | - Carmen Langa
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (L.R.-L.); (M.C.V.); (F.J.F.); (C.L.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040 Madrid, Spain
| | - Nicholas W. Morrell
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK; (N.W.M.); (P.D.U.)
| | - Paul D. Upton
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK; (N.W.M.); (P.D.U.)
| | - Carmelo Bernabeu
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (L.R.-L.); (M.C.V.); (F.J.F.); (C.L.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040 Madrid, Spain
- Correspondence:
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Endoglin in the Spotlight to Treat Cancer. Int J Mol Sci 2021; 22:ijms22063186. [PMID: 33804796 PMCID: PMC8003971 DOI: 10.3390/ijms22063186] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/06/2021] [Accepted: 03/17/2021] [Indexed: 01/02/2023] Open
Abstract
A spotlight has been shone on endoglin in recent years due to that fact of its potential to serve as both a reliable disease biomarker and a therapeutic target. Indeed, endoglin has now been assigned many roles in both physiological and pathological processes. From a molecular point of view, endoglin mainly acts as a co-receptor in the canonical TGFβ pathway, but also it may be shed and released from the membrane, giving rise to the soluble form, which also plays important roles in cell signaling. In cancer, in particular, endoglin may contribute to either an oncogenic or a non-oncogenic phenotype depending on the cell context. The fact that endoglin is expressed by neoplastic and non-neoplastic cells within the tumor microenvironment suggests new possibilities for targeted therapies. Here, we aimed to review and discuss the many roles played by endoglin in different tumor types, as well as the strong evidence provided by pre-clinical and clinical studies that supports the therapeutic targeting of endoglin as a novel clinical strategy.
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Endoglin: An 'Accessory' Receptor Regulating Blood Cell Development and Inflammation. Int J Mol Sci 2020; 21:ijms21239247. [PMID: 33287465 PMCID: PMC7729465 DOI: 10.3390/ijms21239247] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/01/2020] [Accepted: 12/02/2020] [Indexed: 12/13/2022] Open
Abstract
Transforming growth factor-β1 (TGF-β1) is a pleiotropic factor sensed by most cells. It regulates a broad spectrum of cellular responses including hematopoiesis. In order to process TGF-β1-responses in time and space in an appropriate manner, there is a tight regulation of its signaling at diverse steps. The downstream signaling is mediated by type I and type II receptors and modulated by the ‘accessory’ receptor Endoglin also termed cluster of differentiation 105 (CD105). Endoglin was initially identified on pre-B leukemia cells but has received most attention due to its high expression on activated endothelial cells. In turn, Endoglin has been figured out as the causative factor for diseases associated with vascular dysfunction like hereditary hemorrhagic telangiectasia-1 (HHT-1), pre-eclampsia, and intrauterine growth restriction (IUPR). Because HHT patients often show signs of inflammation at vascular lesions, and loss of Endoglin in the myeloid lineage leads to spontaneous inflammation, it is speculated that Endoglin impacts inflammatory processes. In line, Endoglin is expressed on progenitor/precursor cells during hematopoiesis as well as on mature, differentiated cells of the innate and adaptive immune system. However, so far only pro-monocytes and macrophages have been in the focus of research, although Endoglin has been identified in many other immune system cell subsets. These findings imply a functional role of Endoglin in the maturation and function of immune cells. Aside the functional relevance of Endoglin in endothelial cells, CD105 is differentially expressed during hematopoiesis, arguing for a role of this receptor in the development of individual cell lineages. In addition, Endoglin expression is present on mature immune cells of the innate (i.e., macrophages and mast cells) and the adaptive (i.e., T-cells) immune system, further suggesting Endoglin as a factor that shapes immune responses. In this review, we summarize current knowledge on Endoglin expression and function in hematopoietic precursors and mature hematopoietic cells of different lineages.
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Srivastava A, Shukla V, Tiwari D, Gupta J, Kumar S, Kumar A. Targeted therapy of chronic liver diseases with the inhibitors of angiogenesis. Biomed Pharmacother 2018; 105:256-266. [PMID: 29859468 DOI: 10.1016/j.biopha.2018.05.102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 05/09/2018] [Accepted: 05/21/2018] [Indexed: 01/09/2023] Open
Abstract
Angiogenesis appears to be intrinsically associated with the progression of chronic liver diseases, which eventually leads to the development of cirrhosis and related complications, including hepatocellular carcinoma. Several studies have suggested that this association is relevant for chronic liver disease (CLD) progression, with angiogenesis. The fact that angiogenesis plays a pivotal role in CLDs gives rise to new opportunities for treating CLDs. Inhibitor of angiogenesis has proved effective for the treatment of patients suffering from CLD. However, it is limited in diagnosis. The last decade has witnessed a plethora of publications which elucidate the potential of angiogenesis inhibitors for the therapy of CLD. The close relationship between the progression of CLDs and angiogenesis emphasizes the need for anti-angiogenic therapy to block/slow down CLD progression. The present review summarizes all these discussions, the results of the related studies carried out to date and the future prospects in this field. We discuss liver angiogenesis in normal and pathophysiologic conditions with a focus on the role and future use of angiogenic factors as second-line treatment of CLD. This review compiles relevant findings and offers opinions that have emerged in last few years relating liver angiogenesis and its treatment using anti-angiogenic factors.
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Affiliation(s)
- Ankita Srivastava
- Faculty of Biotechnology, Institute of Biosciences and Technology, Shri Ramswaroop Memorial University, Barabanki, Uttar Pradesh, India
| | - Vanistha Shukla
- Faculty of Biotechnology, Institute of Biosciences and Technology, Shri Ramswaroop Memorial University, Barabanki, Uttar Pradesh, India
| | - Deepika Tiwari
- Faculty of Biotechnology, Institute of Biosciences and Technology, Shri Ramswaroop Memorial University, Barabanki, Uttar Pradesh, India
| | - Jaya Gupta
- Faculty of Biotechnology, Institute of Biosciences and Technology, Shri Ramswaroop Memorial University, Barabanki, Uttar Pradesh, India
| | - Sunil Kumar
- Faculty of Biotechnology, Institute of Biosciences and Technology, Shri Ramswaroop Memorial University, Barabanki, Uttar Pradesh, India.
| | - Awanish Kumar
- Department of Biotechnology, National Institute of Technology, Raipur, Chhattisgarh, India.
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Goumans MJ, Ten Dijke P. TGF-β Signaling in Control of Cardiovascular Function. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a022210. [PMID: 28348036 DOI: 10.1101/cshperspect.a022210] [Citation(s) in RCA: 192] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Genetic studies in animals and humans indicate that gene mutations that functionally perturb transforming growth factor β (TGF-β) signaling are linked to specific hereditary vascular syndromes, including Osler-Rendu-Weber disease or hereditary hemorrhagic telangiectasia and Marfan syndrome. Disturbed TGF-β signaling can also cause nonhereditary disorders like atherosclerosis and cardiac fibrosis. Accordingly, cell culture studies using endothelial cells or smooth muscle cells (SMCs), cultured alone or together in two- or three-dimensional cell culture assays, on plastic or embedded in matrix, have shown that TGF-β has a pivotal effect on endothelial and SMC proliferation, differentiation, migration, tube formation, and sprouting. Moreover, TGF-β can stimulate endothelial-to-mesenchymal transition, a process shown to be of key importance in heart valve cushion formation and in various pathological vascular processes. Here, we discuss the roles of TGF-β in vasculogenesis, angiogenesis, and lymphangiogenesis and the deregulation of TGF-β signaling in cardiovascular diseases.
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Affiliation(s)
- Marie-José Goumans
- Department of Molecular Cell Biology and Cancer Genomics Centre Netherlands, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Peter Ten Dijke
- Department of Molecular Cell Biology and Cancer Genomics Centre Netherlands, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
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Nickel J, Ten Dijke P, Mueller TD. TGF-β family co-receptor function and signaling. Acta Biochim Biophys Sin (Shanghai) 2018; 50:12-36. [PMID: 29293886 DOI: 10.1093/abbs/gmx126] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 11/08/2017] [Indexed: 01/04/2023] Open
Abstract
Transforming growth factor-β (TGF-β) family members, which include TGF-βs, activins and bone morphogenetic proteins, are pleiotropic cytokines that elicit cell type-specific effects in a highly context-dependent manner in many different tissues. These secreted protein ligands signal via single-transmembrane Type I and Type II serine/threonine kinase receptors and intracellular SMAD transcription factors. Deregulation in signaling has been implicated in a broad array of diseases, and implicate the need for intricate fine tuning in cellular signaling responses. One important emerging mechanism by which TGF-β family receptor signaling intensity, duration, specificity and diversity are regulated and/or mediated is through cell surface co-receptors. Here, we provide an overview of the co-receptors that have been identified for TGF-β family members. While some appear to be specific to TGF-β family members, others are shared with other pathways and provide possible ways for signal integration. This review focuses on novel functions of TGF-β family co-receptors, which continue to be discovered.
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Affiliation(s)
- Joachim Nickel
- Universitätsklinikum Würzburg, Lehrstuhl für Tissue Engineering und Regenerative Medizin und Fraunhofer Institut für Silicatforschung (ISC), Translationszentrum "Regenerative Therapien", Röntgenring 11, D-97070 Würzburg, Germany
| | - Peter Ten Dijke
- Department of Molecular and Cell Biology and Cancer Genomics Centre Netherlands, Leiden University Medical Center, Einthovenweg 20, 2300 RC Leiden, The Netherlands
| | - Thomas D Mueller
- Lehrstuhl für molekulare Pflanzenphysiologie und Biophysik, Julius-von-Sachs Institut für Biowissenschaften, Universität Würzburg, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany
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10
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Varejckova M, Gallardo-Vara E, Vicen M, Vitverova B, Fikrova P, Dolezelova E, Rathouska J, Prasnicka A, Blazickova K, Micuda S, Bernabeu C, Nemeckova I, Nachtigal P. Soluble endoglin modulates the pro-inflammatory mediators NF-κB and IL-6 in cultured human endothelial cells. Life Sci 2017; 175:52-60. [DOI: 10.1016/j.lfs.2017.03.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 03/17/2017] [Accepted: 03/19/2017] [Indexed: 01/01/2023]
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Núñez-Gómez E, Pericacho M, Ollauri-Ibáñez C, Bernabéu C, López-Novoa JM. The role of endoglin in post-ischemic revascularization. Angiogenesis 2016; 20:1-24. [PMID: 27943030 DOI: 10.1007/s10456-016-9535-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 11/29/2016] [Indexed: 12/12/2022]
Abstract
Following arterial occlusion, blood vessels respond by forming a new network of functional capillaries (angiogenesis), by reorganizing preexisting capillaries through the recruitment of smooth muscle cells to generate new arteries (arteriogenesis) and by growing and remodeling preexisting collateral arterioles into physiologically relevant arteries (collateral development). All these processes result in the recovery of organ perfusion. The importance of endoglin in post-occlusion reperfusion is sustained by several observations: (1) endoglin expression is increased in vessels showing active angiogenesis/remodeling; (2) genetic endoglin haploinsufficiency in humans causes deficient angiogenesis; and (3) the reduction of endoglin expression by gene disruption or the administration of endoglin-neutralizing antibodies reduces angiogenesis and revascularization. However, the precise role of endoglin in the several processes associated with revascularization has not been completely elucidated and, in some cases, the function ascribed to endoglin by different authors is controversial. The purpose of this review is to organize in a critical way the information available for the role of endoglin in several phenomena (angiogenesis, arteriogenesis and collateral development) associated with post-ischemic revascularization.
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Affiliation(s)
- Elena Núñez-Gómez
- Renal and Cardiovascular Research Unit, Department of Physiology and Pharmacology, University of Salamanca, Salamanca, Spain.,Biomedical Research Institute of Salamanca (IBSAL), Salamanca, Spain
| | - Miguel Pericacho
- Renal and Cardiovascular Research Unit, Department of Physiology and Pharmacology, University of Salamanca, Salamanca, Spain.,Biomedical Research Institute of Salamanca (IBSAL), Salamanca, Spain
| | - Claudia Ollauri-Ibáñez
- Renal and Cardiovascular Research Unit, Department of Physiology and Pharmacology, University of Salamanca, Salamanca, Spain.,Biomedical Research Institute of Salamanca (IBSAL), Salamanca, Spain
| | - Carmelo Bernabéu
- Centro de Investigaciones Biológicas, Spanish National Research Council (CIB, CSIC), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - José M López-Novoa
- Renal and Cardiovascular Research Unit, Department of Physiology and Pharmacology, University of Salamanca, Salamanca, Spain. .,Biomedical Research Institute of Salamanca (IBSAL), Salamanca, Spain.
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12
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Farrokh S, Brillen AL, Haendeler J, Altschmied J, Schaal H. Critical regulators of endothelial cell functions: for a change being alternative. Antioxid Redox Signal 2015; 22:1212-29. [PMID: 25203279 DOI: 10.1089/ars.2014.6023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
SIGNIFICANCE The endothelium regulates vessel dilation and constriction, balances hemostasis, and inhibits thrombosis. In addition, pro- and anti-angiogenic molecules orchestrate proliferation, survival, and migration of endothelial cells. Regulation of all these processes requires fine-tuning of signaling pathways, which can easily be tricked into running the opposite direction when exogenous or endogenous signals get out of hand. Surprisingly, some critical regulators of physiological endothelial functions can turn malicious by mere alternative splicing, leading to the expression of protein isoforms with opposite functions. RECENT ADVANCES While reviewing the evidence of alternative splicing on cellular physiology, it became evident that expression of splice factors and their activities are regulated by externally triggered signaling cascades. Furthermore, genome-wide identification of RNA-binding sites of splicing regulatory proteins now offer a glimpse into the splicing code responsible for alternative splicing of molecules regulating endothelial functions. CRITICAL ISSUES Due to the constantly growing number of transcript and protein isoforms, it will become more and more important to identify and characterize all transcripts and proteins regulating endothelial cell functions. One critical issue will be a non-ambiguous nomenclature to keep consistency throughout different laboratories. FUTURE DIRECTIONS RNA-deep sequencing focusing on exon-exon junction needs to more reliably identify alternative splicing events combined with functional analyses that will uncover more splice variants contributing to or inhibiting proper endothelial functions. In addition, understanding the signals mediating alternative splicing and its regulation might allow us to derive new strategies to preserve endothelial function by suppressing or upregulating specific protein isoforms. Antioxid. Redox Signal. 22, 1212-1229.
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Affiliation(s)
- Sabrina Farrokh
- 1 Heisenberg-Group-Environmentally-Induced Cardiovascular Degeneration, IUF-Leibniz Research Institute for Environmental Medicine , Düsseldorf, Germany
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13
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Rossi E, Lopez-Novoa JM, Bernabeu C. Endoglin involvement in integrin-mediated cell adhesion as a putative pathogenic mechanism in hereditary hemorrhagic telangiectasia type 1 (HHT1). Front Genet 2015; 5:457. [PMID: 25709613 PMCID: PMC4285797 DOI: 10.3389/fgene.2014.00457] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 12/12/2014] [Indexed: 12/11/2022] Open
Abstract
Mutations in the endoglin gene (ENG) are responsible for ∼50% of all cases with hereditary hemorrhagic telangiectasia (HHT). Because of the absence of effective treatments for HHT symptoms, studies aimed at identifying novel biological functions of endoglin which could serve as therapeutic targets of the disease are needed. Endoglin is an endothelial membrane protein, whose most studied function has been its role as an auxiliary receptor in the TGF-β receptor complex. However, several lines of evidence suggest the involvement of endoglin in TGF-β-independent functions. Endoglin displays, within its zona pellucida domain, an RGD motif, which is a prototypic sequence involved in integrin-based interactions with other proteins. Indeed, we have recently described a novel role for endothelial endoglin in leukocyte trafficking and extravasation via its interaction with leukocyte integrins. In addition, functional, as well as protein and gene expression analysis have shown that ectopic endoglin represses the synthesis of several members of the integrin family and modulates integrin-mediated cell adhesions. This review focuses on the tight link between endoglin and integrins and how the role of endothelial endoglin in integrin-dependent cell adhesion processes can provide a better understanding of the pathogenic mechanisms leading to vascular lesions in endoglin haploinsufficient HHT1 patients.
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Affiliation(s)
- Elisa Rossi
- INSERM, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, UMR-S 1140 Paris, France
| | - José M Lopez-Novoa
- Renal and Cardiovascular Research Unit, Department of Physiology and Pharmacology, University of Salamanca, and Institute of Biomedical Research of Salamanca Salamanca, Spain
| | - Carmelo Bernabeu
- Centro de Investigaciones Biológicas - Consejo Superior de Investigaciones Científicas and Centro de Investigación Biomédica en Red de Enfermedades Raras Madrid, Spain
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14
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Abstract
Tubulointerstitial fibrosis and glomerulosclerosis, are a major feature of end stage chronic kidney disease (CKD), characterised by an excessive accumulation of extracellular matrix (ECM) proteins. Transforming growth factor beta-1 (TGF-β1) is a cytokine with an important role in many steps of renal fibrosis such as myofibroblast activation and proliferation, ECM protein synthesis and inflammatory cell infiltration. Endoglin is a TGF-β co-receptor that modulates TGF-β responses in different cell types. In numerous cells types, such as mesangial cells or myoblasts, endoglin regulates negatively TGF-β-induced ECM protein expression. However, recently it has been demonstrated that 'in vivo' endoglin promotes fibrotic responses. Furthermore, several studies have demonstrated an increase of endoglin expression in experimental models of renal fibrosis in the kidney and other tissues. Nevertheless, the role of endoglin in renal fibrosis development is unclear and a question arises: Does endoglin protect against renal fibrosis or promotes its development? The purpose of this review is to critically analyse the recent knowledge relating to endoglin and renal fibrosis. Knowledge of endoglin role in this pathology is necessary to consider endoglin as a possible therapeutic target against renal fibrosis.
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15
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Aristorena M, Blanco FJ, de Las Casas-Engel M, Ojeda-Fernandez L, Gallardo-Vara E, Corbi A, Botella LM, Bernabeu C. Expression of endoglin isoforms in the myeloid lineage and their role during aging and macrophage polarization. J Cell Sci 2014; 127:2723-35. [PMID: 24777481 DOI: 10.1242/jcs.143644] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Endoglin plays a crucial role in pathophysiological processes such as hereditary hemorrhagic telangiectasia (HHT), preeclampsia and cancer. Endoglin expression is upregulated during the monocyte-to-macrophage transition, but little is known about its regulation and function in these immune cells. Two different alternatively spliced isoforms of endoglin have been reported, L-endoglin and S-endoglin. Although L-endoglin is the predominant variant, here, we found that there was an increased expression of the S-endoglin isoform during senescence of the myeloid lineage in human and murine models. We performed a stable isotope labelling of amino acids in cell culture (SILAC) analysis of both L-endoglin and S-endoglin transfectants in the human promonocytic cell line U937. Analysis of differentially expressed protein clusters allowed the identification of cellular activities affected during aging. S-endoglin expression led to decreased cellular proliferation and a decreased survival response to granulocyte-macrophage colony-stimulating factor (GM-CSF)-induced apoptosis, as well as increased oxidative stress. Gene expression and functional studies suggested that there was a non-redundant role for each endoglin isoform in monocyte biology. In addition, we found that S-endoglin impairs the monocytic differentiation into the pro-inflammatory M1 phenotype and contributes to the compromised status of macrophage functions during aging.
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Affiliation(s)
- Mikel Aristorena
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040 Madrid, Spain
| | - Francisco J Blanco
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040 Madrid, Spain
| | - Mateo de Las Casas-Engel
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Luisa Ojeda-Fernandez
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040 Madrid, Spain
| | - Eunate Gallardo-Vara
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040 Madrid, Spain
| | - Angel Corbi
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Luisa M Botella
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040 Madrid, Spain
| | - Carmelo Bernabeu
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040 Madrid, Spain
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Paauwe M, ten Dijke P, Hawinkels LJAC. Endoglin for tumor imaging and targeted cancer therapy. Expert Opin Ther Targets 2013; 17:421-35. [PMID: 23327677 DOI: 10.1517/14728222.2013.758716] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Although cancer treatment has evolved substantially in the past decades, cancer-related mortality rates are still increasing. Therapies targeting tumor angiogenesis, crucial for the growth of solid tumors, mainly target vascular endothelial growth factor (VEGF) and have been clinically applied during the last decade. However, these therapies have not met high expectations, which were based on therapeutic efficacy in animal models. This can partly be explained by the upregulation of alternative angiogenic pathways. Therefore, additional therapies targeting other pro-angiogenic pathways are needed. AREAS COVERED The transforming growth factor (TGF)-β signaling pathway plays an important role in (tumor) angiogenesis. Therefore, components of this pathway are interesting candidates for anti-angiogenic therapy. Endoglin, a co-receptor for various TGF-β family members, is specifically overexpressed in tumor vessels and endoglin expression is associated with metastasis and patient survival. Therefore, endoglin might be a good candidate for anti-angiogenic therapy. In this review, we discuss the potential of using endoglin to target the tumor vasculature for imaging and therapeutic purposes. EXPERT OPINION Considering the promising results from various in vitro studies, in vivo animal models and the first clinical trial targeting endoglin, we are convinced that endoglin is a valuable tool for the diagnosis, visualization and ultimately treatment of solid cancers.
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Affiliation(s)
- Madelon Paauwe
- Cancer Genomics Centre Netherlands and Centre for BioMedical Genetics, Department of Molecular Cell Biology, Leiden University Medical Center, Building-2, S1-P, PO-box 9600, 2300 RC Leiden, The Netherlands
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17
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Endoglin - a marker of vascular endothelial cell proliferation in cancer. Contemp Oncol (Pozn) 2012; 16:68-71. [PMID: 23788858 PMCID: PMC3687377 DOI: 10.5114/wo.2012.27340] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 11/26/2011] [Accepted: 12/02/2011] [Indexed: 11/17/2022] Open
Abstract
Endoglin (CD105) is an accessory receptor of transforming growth factor B. The highest synthesis, as well as expression, of endoglin has been found in vascular endothelial cells. The involvement of endoglin in angiogenesis and in angiogenesis-dependent processes has been observed. Endoglin promotes angiogenesis not only by activation of vascular endothelial cell proliferation but also by induction of the antiapoptotic pathway in hypoxic endothelial cells. The potential application of endoglin as a tumour angiogenesis marker, useful for cancer diagnostics and clinical application, is anticipated. Endoglin expression may be useful as an indicator of disease progression and helpful for estimation of recurrence and metastasis risk.
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18
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Rossi E, Langa C, Gilsanz A, Blanco FJ, Ayllón J, Villar E, Botella LM, Cabañas C, Shaw M, Bernabeu C. Characterization of chicken endoglin, a member of the zona pellucida family of proteins, and its tissue expression. Gene 2012; 491:31-9. [DOI: 10.1016/j.gene.2011.09.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 09/08/2011] [Accepted: 09/14/2011] [Indexed: 10/17/2022]
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19
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Angiogenesis regulation by TGFβ signalling: clues from an inherited vascular disease. Biochem Soc Trans 2011; 39:1659-66. [DOI: 10.1042/bst20110664] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Studies of rare genetic diseases frequently reveal genes that are fundamental to life, and the familial vascular disorder HHT (hereditary haemorrhagic telangiectasia) is no exception. The majority of HHT patients are heterozygous for mutations in either the ENG (endoglin) or the ACVRL1 (activin receptor-like kinase 1) gene. Both genes are essential for angiogenesis during development and mice that are homozygous for mutations in Eng or Acvrl1 die in mid-gestation from vascular defects. Recent development of conditional mouse models in which the Eng or Acvrl1 gene can be depleted in later life have confirmed the importance of both genes in angiogenesis and in the maintenance of a normal vasculature. Endoglin protein is a co-receptor and ACVRL1 is a signalling receptor, both of which are expressed primarily in endothelial cells to regulate TGFβ (transforming growth factor β) signalling in the cardiovasculature. The role of ACVRL1 and endoglin in TGFβ signalling during angiogenesis is now becoming clearer as interactions between these receptors and additional ligands of the TGFβ superfamily, as well as synergistic relationships with other signalling pathways, are being uncovered. The present review aims to place these recent findings into the context of a better understanding of HHT and to summarize recent evidence that confirms the importance of endoglin and ACVRL1 in maintaining normal cardiovascular health.
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20
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Ali BR, Ben-Rebeh I, John A, Akawi NA, Milhem RM, Al-Shehhi NA, Al-Ameri MM, Al-Shamisi SA, Al-Gazali L. Endoplasmic reticulum quality control is involved in the mechanism of endoglin-mediated hereditary haemorrhagic telangiectasia. PLoS One 2011; 6:e26206. [PMID: 22022569 PMCID: PMC3194820 DOI: 10.1371/journal.pone.0026206] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 09/22/2011] [Indexed: 02/05/2023] Open
Abstract
Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant genetic condition affecting the vascular system and is characterised by epistaxis, arteriovenous malformations and mucocutaneous and gastrointestinal telangiectases. This disorder affects approximately 1 in 8,000 people worldwide. Significant morbidity is associated with this condition in affected individuals, and anaemia can be a consequence of repeated haemorrhages from telangiectasia in the gut and nose. In the majority of the cases reported, the condition is caused by mutations in either ACVRL1 or endoglin genes, which encode components of the TGF-beta signalling pathway. Numerous missense mutations in endoglin have been reported as causative defects for HHT but the exact underlying cellular mechanisms caused by these mutations have not been fully established despite data supporting a role for the endoplasmic reticulum (ER) quality control machinery. For this reason, we examined the subcellular trafficking of twenty-five endoglin disease-causing missense mutations. The mutant proteins were expressed in HeLa and HEK293 cell lines, and their subcellular localizations were established by confocal fluorescence microscopy alongside the analysis of their N-glycosylation profiles. ER quality control was found to be responsible in eight (L32R, V49F, C53R, V125D, A160D, P165L, I271N and A308D) out of eleven mutants located on the orphan extracellular domain in addition to two (C363Y and C382W) out of thirteen mutants in the Zona Pellucida (ZP) domain. In addition, a single intracellular domain missense mutant was examined and found to traffic predominantly to the plasma membrane. These findings support the notion of the involvement of the ER's quality control in the mechanism of a significant number, but not all, missense endoglin mutants found in HHT type 1 patients. Other mechanisms including loss of interactions with signalling partners as well as adverse effects on functional residues are likely to be the cause of the mutant proteins' loss of function.
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MESH Headings
- Antigens, CD/chemistry
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Cell Membrane/metabolism
- Endoglin
- Endoplasmic Reticulum/metabolism
- Glycoside Hydrolases/metabolism
- HeLa Cells
- Humans
- Models, Molecular
- Mutant Proteins/chemistry
- Mutant Proteins/metabolism
- Mutation, Missense/genetics
- Protein Structure, Tertiary
- Protein Transport
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Subcellular Fractions/metabolism
- Telangiectasia, Hereditary Hemorrhagic/genetics
- Telangiectasia, Hereditary Hemorrhagic/metabolism
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Affiliation(s)
- Bassam R Ali
- Department of Pathology, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.
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21
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Meurer SK, Tihaa L, Borkham-Kamphorst E, Weiskirchen R. Expression and functional analysis of endoglin in isolated liver cells and its involvement in fibrogenic Smad signalling. Cell Signal 2010; 23:683-99. [PMID: 21146604 DOI: 10.1016/j.cellsig.2010.12.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 11/29/2010] [Accepted: 12/02/2010] [Indexed: 12/17/2022]
Abstract
Endoglin is an accessory component of the TGF-β-binding receptor complex that differentially modulates TGF-β and BMP responses. The existence of two splice variants L- and S-endoglin which differ in their cytoplasmic domain has already been shown in human and mice. Endoglin is located on the cell surfaces of cultured hepatic stellate cells and transdifferentiated myofibroblasts suggesting that this receptor might be associated with the profibrogenic attributes of these liver cell subpopulations. We now show that endoglin expression is increased in transdifferentiating hepatic stellate cells and in two models of liver fibrosis (i.e. bile duct ligation and carbon tetrachloride model) and further detectable in cultured portal fibroblasts representing another important fibrogenic cell type but not in hepatocytes. In respect to TGF-β1-signalling, we demonstrate that endoglin interacts with and is phosphorylated by TβRII. In hepatic stellate cells, TGF-β1 upregulates endoglin expression most likely via the ALK5 pathway and requires the SP1 transcription factor. We further identified a novel rat splice variant that is structurally and functionally different from that identified in human and mouse. Transient overexpression of endoglin resulted in a strong increase of TGF-β1-driven Smad1/5 phosphorylation and α-smooth muscle actin expression in a hepatic stellate cell line. In supernatants of respective cultures, we could detect the ectodomain of endoglin suggesting that shedding is a further key process involved in the regulation of this surface receptor.
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Affiliation(s)
- Steffen K Meurer
- Institute of Clinical Chemistry and Pathobiochemistry, RWTH-University Hospital, Aachen, Germany.
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22
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Santibanez JF, Pérez-Gómez E, Fernandez-L A, Garrido-Martin EM, Carnero A, Malumbres M, Vary CPH, Quintanilla M, Bernabéu C. The TGF-beta co-receptor endoglin modulates the expression and transforming potential of H-Ras. Carcinogenesis 2010; 31:2145-54. [PMID: 20884686 DOI: 10.1093/carcin/bgq199] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Endoglin is a coreceptor for transforming growth factor-β (TGF-β) that acts as a suppressor of malignancy during mouse skin carcinogenesis. Because in this model system H-Ras activation drives tumor initiation and progression, we have assessed the effects of endoglin on the expression of H-Ras in transformed keratinocytes. We found that TGF-β1 increases the expression of H-Ras at both messenger RNA and protein levels. The TGF-β1-induced H-Ras promoter transactivation was Smad4 independent but mediated by the activation of the TGF-β type I receptor ALK5 and the Ras-mitogen-activated protein kinase (MAPK) pathway. Endoglin attenuated stimulation by TGF-β1 of both MAPK signaling activity and H-Ras gene expression. Moreover, endoglin inhibited the Ras/MAPK pathway in transformed epidermal cells containing an H-Ras oncogene, as evidenced by the levels of Ras-guanosine triphosphate, phospho-MAPK kinase (MEK) and phospho-extracellular signal-regulated kinase (ERK) as well as the expression of c-fos, a MAPK downstream target gene. Interestingly, in spindle carcinoma cells, that have a hyperactivated Ras/MAPK pathway, endoglin inhibited ERK phosphorylation without affecting MEK or Ras activity. The mechanism for this effect is unknown but strongly depends on the endoglin extracellular domain. Because the MAPK pathway is a downstream mediator of the transforming potential of Ras, the effect of endoglin on the oncogenic function of H-Ras was assessed. Endoglin inhibited the transforming capacity of H-Ras(Q61K) and H-Ras(G12V) oncogenes in a NIH3T3 focus formation assay. The ability to interfere with the expression and oncogenic potential of H-Ras provides a new face of the suppressor role exhibited by endoglin in H-Ras-driven carcinogenesis.
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Affiliation(s)
- Juan F Santibanez
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC) and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040 Madrid, Spain
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23
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López-Novoa JM, Bernabeu C. The physiological role of endoglin in the cardiovascular system. Am J Physiol Heart Circ Physiol 2010; 299:H959-74. [PMID: 20656886 DOI: 10.1152/ajpheart.01251.2009] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Endoglin (CD105) is an integral membrane glycoprotein that serves as a coreceptor for members of the transforming growth factor-β superfamily of proteins. A major role for endoglin in regulating transforming growth factor-β-dependent vascular remodeling and angiogenesis has been postulated based on the following: 1) endoglin is the gene mutated in hereditary hemorrhagic telangiectasia type 1, a disease characterized by vascular malformations; 2) endoglin knockout mice die at midgestation because of defective angiogenesis; 3) endoglin is overexpressed in neoangiogenic vessels, during inflammation, and in solid tumors; and 4) endoglin regulates the expression and activity of endothelial nitric oxide synthase, which is involved in angiogenesis and vascular tone. Besides the predominant form of the endoglin receptor (long endoglin isoform), two additional forms of endoglin have been recently reported to play a role in the vascular pathology and homeostasis: the alternatively spliced short endoglin isoform and a soluble endoglin form that is proteolytically cleaved from membrane-bound endoglin. The purpose of this review is to underline the role that the different forms of endoglin play in regulating angiogenesis, vascular remodeling, and vascular tone, as well as to analyze the molecular and cellular mechanisms supporting these effects.
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Affiliation(s)
- José M López-Novoa
- Instituto Reina Sofía de Investigación Nefrológica, Departamento de Fisiologia y Farmacologia, Universidad de Salamanca, and Red de Investigación Renal, Instituto de Salud Carlos III, Salamanca, Spain.
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Tumor angiogenesis: insights and innovations. JOURNAL OF ONCOLOGY 2010; 2010:132641. [PMID: 20445741 PMCID: PMC2860112 DOI: 10.1155/2010/132641] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Revised: 02/12/2010] [Accepted: 02/12/2010] [Indexed: 12/21/2022]
Abstract
Angiogenesis is a vital process resulting in the formation of new blood vessels. It is normally a highly regulated process that occurs during human development, reproduction, and wound repair. However, angiogenesis can also become a fundamental pathogenic process found in cancer and several other diseases. To date, the inhibition of angiogenesis has been researched at both the bench and the bedside. While several studies have found moderate improvements when treating with angiogenesis inhibitors, greater success is being seen when the inhibition of angiogenesis is combined with other traditional forms of available therapy. This review summarizes several important angiogenic factors, examines new research and ongoing clinical trials for such factors, and attempts to explain how this new knowledge may be applied in the fight against cancer and other angiogenic-related diseases.
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25
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Ray BN, Lee NY, How T, Blobe GC. ALK5 phosphorylation of the endoglin cytoplasmic domain regulates Smad1/5/8 signaling and endothelial cell migration. Carcinogenesis 2009; 31:435-41. [PMID: 20042635 DOI: 10.1093/carcin/bgp327] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Endoglin, an endothelial cell-specific transforming growth factor-beta (TGF-beta) superfamily coreceptor, has an essential role in angiogenesis. Endoglin-null mice have an embryonic lethal phenotype due to defects in angiogenesis and mutations in endoglin result in the vascular disease hereditary hemorrhagic telangiectasia type I. Increased endoglin expression in the proliferating endothelium of tumors has been correlated with metastasis, tumor grade and decreased survival. Although endoglin is thought to regulate TGF-beta superfamily signaling in endothelial cells through regulating the balance between two TGF-beta-responsive pathways, the activin receptor-like kinase 5 (ALK5)/Smad2/3 pathway and the activin receptor-like kinase 1 (ALK1)/Smad1/5/8 pathway, the mechanism by which endoglin regulates angiogenesis has not been defined. Here, we investigate the role of the cytoplasmic domain of endoglin and its phosphorylation by ALK5 in regulating endoglin function in endothelial cells. We demonstrate that the cytoplasmic domain of endoglin is basally phosphorylated by ALK5, primarily on serines 646 and 649, in endothelial cells. Functionally, the loss of phosphorylation at serine 646 resulted in a loss of endoglin-mediated inhibition of Smad1/5/8 signaling in response to TGF-beta and endothelial cell migration, whereas loss of phosphorylation at both serines 646 and 649 resulted in a loss of endoglin-mediated inhibition of Smad1/5/8 signaling in response to bone morphogenetic protein-9. Taken together, these results support endoglin phosphorylation by ALK5 as an important mechanism for regulating TGF-beta superfamily signaling and migration in endothelial cells.
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Affiliation(s)
- Bridgette N Ray
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27708, USA
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Fonsatti E, Nicolay HJM, Altomonte M, Covre A, Maio M. Targeting cancer vasculature via endoglin/CD105: a novel antibody-based diagnostic and therapeutic strategy in solid tumours. Cardiovasc Res 2009; 86:12-9. [PMID: 19812043 DOI: 10.1093/cvr/cvp332] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Endoglin/CD105 is well acknowledged as being the most reliable marker of proliferation of endothelial cells, and it is overexpressed on tumour neovasculature. Our current knowledge of its structure, physiological role, and tissue distribution suggests that targeting of endoglin/CD105 is a novel and powerful diagnostic and therapeutic strategy in human malignancies, through the imaging of tumour-associated angiogenesis and the inhibition of endothelial cell functions related to tumour angiogenesis. Among biotherapeutic agents, monoclonal antibodies have shown a major impact on the clinical course of human malignancies of different histotypes. Along this line, the potential efficacy of anti-endoglin/CD105 antibodies and their derivatives for clinical purposes in cancer is supported by a large body of available pre-clinical in vitro and in vivo data. In this review, the main findings supporting the translation of antibody-based endoglin/CD105 targeting from pre-clinical studies to clinical applications in human cancer are summarized and discussed.
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Affiliation(s)
- Ester Fonsatti
- Division of Medical Oncology and Immunotherapy, Department of Oncology, Istituto Toscano Tumori, University Hospital of Siena, Strada delle Scotte 14, 53100 Siena, Italy
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Bernabeu C, Lopez-Novoa JM, Quintanilla M. The emerging role of TGF-beta superfamily coreceptors in cancer. Biochim Biophys Acta Mol Basis Dis 2009; 1792:954-73. [PMID: 19607914 DOI: 10.1016/j.bbadis.2009.07.003] [Citation(s) in RCA: 195] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2009] [Revised: 07/02/2009] [Accepted: 07/06/2009] [Indexed: 12/23/2022]
Abstract
The transforming growth factor beta (TGF-beta) signaling pathway plays a key role in different physiological processes such as development, cellular proliferation, extracellular matrix synthesis, angiogenesis or immune responses and its deregulation may result in tumor development. The TGF-beta coreceptors endoglin and betaglycan are emerging as modulators of the TGF-beta response with important roles in cancer. Endoglin is highly expressed in the tumor-associated vascular endothelium with prognostic significance in selected neoplasias and with potential to be a prime vascular target for antiangiogenic cancer therapy. On the other hand, the expression of endoglin and betaglycan in tumor cells themselves appears to play an important role in the progression of cancer, influencing cell proliferation, motility, invasiveness and tumorigenicity. In addition, experiments in vitro and in vivo in which endoglin or betaglycan expression is modulated have provided evidence that they act as tumor suppressors. The purpose of this review was to highlight the potential of membrane and soluble forms of the endoglin and betaglycan proteins as molecular targets in cancer diagnosis and therapy.
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Affiliation(s)
- Carmelo Bernabeu
- Centro de Investigaciones Biologicas, Consejo Superior de Investigaciones Cientificas (CSIC), and CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), 28040 Madrid, Spain.
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28
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Pizarro CB, Oliveira MC, Pereira-Lima JFS, Leães CGS, Kramer CK, Schuch T, Barbosa-Coutinho LM, Ferreira NP. Evaluation of angiogenesis in 77 pituitary adenomas using endoglin as a marker. Neuropathology 2008; 29:40-4. [PMID: 18673444 DOI: 10.1111/j.1440-1789.2008.00937.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Angiogenesis, a fundamental process for the development and growth of a tumor, is less expressive in adenomas than in the normal pituitary tissue. There is controversy about the behavior of angiogenesis as a function of hormonal secretion or other characteristics of pituitary tumors. Endoglin (CD105) is a proliferation-associated antigen on endothelial cells, as well as an endothelial progenitor cell marker. We used the anti-endoglin antibody, a glycoprotein expressed in endothelial cells and conjunctive tissue, as a new marker particularly associated with neovascularization, in order to determine microvascular density (MVD) in pituitary adenomas. There were 77 samples, 31 males and 46 females, carriers of micro- (n = 24) or macroadenomas (n = 53). No significant difference was found in MVD concerning the variables of age, clinical presentation, and immunohistochemical phenotype or tumor size. MVD in males (median 5.4) was significantly higher (P = 0.001) than in females (median 3.0). Cell proliferation, as evaluated by the MIB-1 antibody (a cellular proliferation index [Ki-67 antigen], which is present in all stages of the cellular cycle except for the resting cells), ranged from 0% to 19.58%. No correlation was found between MIB-1 and MVD. It is possible to infer that the lower MVD found in pituitary adenomas in females reflects an inhibitory estrogen action on TGF-beta1, a protein involved in vascular remodeling. Because of its role as a TGF receptor ligand, endoglin proved to be sensitive in detecting this gender difference in pituitary tumor angiogenesis.
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Affiliation(s)
- Cristina B Pizarro
- Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil
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29
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Bernabeu C, Conley BA, Vary CPH. Novel biochemical pathways of endoglin in vascular cell physiology. J Cell Biochem 2008; 102:1375-88. [PMID: 17975795 DOI: 10.1002/jcb.21594] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The broad role of the transforming growth factor beta (TGFbeta) signaling pathway in vascular development, homeostasis, and repair is well appreciated. Endoglin is emerging as a novel, complex, and poorly understood regulatory component of the TGFbeta receptor complex, whose importance is underscored by its recognition as the site of mutations causing hereditary hemorrhagic telangiectasia (HHT) [McAllister et al., 1994]. Extensive analyses of endoglin function in normal developmental mouse models [Bourdeau et al., 1999; Li et al., 1999; Arthur et al., 2000] and in HHT animal models [Bourdeau et al., 2000; Torsney et al., 2003] exemplify the importance of understanding endoglin's biochemical functions. However, novel mechanisms underlying the regulation of these pathways continue to emerge. These mechanisms include modification of TGFbeta receptor signaling at the ligand and receptor activation level, direct effects of endoglin on cell adhesion and migration, and emerging roles for endoglin in the determination of stem cell fate and tissue patterning. The purpose of this review is to highlight the cellular and molecular studies that underscore the central role of endoglin in vascular development and disease.
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Affiliation(s)
- Carmelo Bernabeu
- Centro de Investigaciones Biologicas, Consejo Superior de Investigaciones Cientificas (CSIC), 28040 Madrid, Spain
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30
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Velasco S, Alvarez-Muñoz P, Pericacho M, Dijke PT, Bernabéu C, López-Novoa JM, Rodríguez-Barbero A. L- and S-endoglin differentially modulate TGFbeta1 signaling mediated by ALK1 and ALK5 in L6E9 myoblasts. J Cell Sci 2008; 121:913-9. [PMID: 18303046 DOI: 10.1242/jcs.023283] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
TGFbeta regulates cellular processes by binding to type I and type II TGFbeta receptors (TbetaRI and TbetaRII, respectively). In addition to these signaling receptors, endoglin is an accessory TGFbeta receptor that regulates TGFbeta signaling. Although there are two different alternatively spliced isoforms of endoglin, L-endoglin (L, long) and S-endoglin (S, short), little is known about the effects of S-endoglin isoform on TGFbeta signaling. Here, we have analyzed the TGFbeta1 signaling pathways and the effects of L- and S-endoglin in endoglin-deficient L6E9 cells. We found that TGFbeta activates two distinct TbetaRI-Smad signaling pathways: ALK1-Smad1-Id1 and ALK5-Smad2-PAI1, in these cells. Interestingly, L-endoglin enhanced the ALK1-Id1 pathway, while S-endoglin promoted the ALK5-PAI1 route. These effects on signaling are supported by biological effects on TGFbeta1-induced collagen I expression and inhibition of cell proliferation. Thus, while L-endoglin decreased TGFbeta1-induced collagen I and CTGF expression and increased TGFbeta1-induced proliferation, S-endoglin strongly increased TGFbeta1-induced collagen I and CTGF expression, and reduced TGFbeta1-induced cell proliferation.
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Affiliation(s)
- Soraya Velasco
- Instituto Reina Sofía de Investigación Nefrológica, Departamento de Fisiología y Farmacología, Universidad de Salamanca, and Red de Investigación en Enfermedades Renales (RedinRen), Salamanca, Spain
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31
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Endoglin expression in metastatic breast cancer cells enhances their invasive phenotype. Oncogene 2008; 27:3567-75. [DOI: 10.1038/sj.onc.1211025] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Blaha M, Cermanova M, Blaha V, Jarolim P, Andrys C, Blazek M, Maly J, Smolej L, Zajic J, Masin V, Zimova R, Rehacek V. Elevated serum soluble endoglin (sCD105) decreased during extracorporeal elimination therapy for familial hypercholesterolemia. Atherosclerosis 2007; 224:4-11. [PMID: 17540382 DOI: 10.1016/j.atherosclerosis.2012.03.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Revised: 02/21/2012] [Accepted: 03/01/2012] [Indexed: 12/29/2022]
Abstract
Extracorporeal elimination is a method of LDL-lowering therapy that is used in severe familial hypercholesterolemia (FH) after other therapeutic approaches have failed. There are currently no universally accepted biomarkers that would allow determining necessary intensity of therapy and frequency of future therapeutic interventions. An ideal tool for immediate evaluation would be a readily measurable serum marker. We hypothesized that soluble endoglin (sCD105), a recently described indicator of endothelial dysfunction, may represent such a tool. Eleven patients with FH (three homozygous, eight heterozygous; Fredrickson type IIa, IIb) that have been monitored for 4.5+/-2.8 years were treated; eight by LDL-apheresis and three by hemorheopheresis. 40 sCD105 measurements were done, before and after two consecutive elimination procedures. Baseline serum sCD105 levels were significantly higher in the patients (5.74+/-1.47 microg/l in series I, 6.85+/-1.85 microg/l in series II) than in the control group (3.85+/-1.25 microg/l). They decreased to normal after LDL-elimination (p=0.0003) in all except for one patient. This return to normal was not due to a non-specific capture of endoglin in adsorption or filtration columns as demonstrated by measurement of sCD105 before and after passage through the elimination media. We conclude that the soluble endoglin levels in patients with severe FH remain elevated despite long-term intensive therapy and that they decrease after extracorporeal elimination. Endoglin can therefore serve as a marker for evaluation of the treatment efficacy and of the decreased atherosclerotic activity in patients with FH treated by extracorporeal LDL-cholesterol elimination.
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Affiliation(s)
- Milan Blaha
- 2nd Internal Clinic, Charles University School of Medicine and the Faculty Hospital, Hradec Kralove, Czech Republic.
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33
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Koleva RI, Conley BA, Romero D, Riley KS, Marto JA, Lux A, Vary CPH. Endoglin structure and function: Determinants of endoglin phosphorylation by transforming growth factor-beta receptors. J Biol Chem 2006; 281:25110-23. [PMID: 16785228 DOI: 10.1074/jbc.m601288200] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Determination of the functional relationship between the transforming growth factor-beta (TGFbeta) receptor proteins endoglin and ALK1 is essential to the understanding of the human vascular disease, hereditary hemorrhagic telangiectasia. TGFbeta1 caused recruitment of ALK1 into a complex with endoglin in human umbilical vein endothelial cells (HUVECs). Therefore, we examined TGFbeta receptor-dependent phosphorylation of endoglin by the constitutively active forms of the TGFbeta type I receptors ALK1, ALK5, and the TGFbeta type II receptor, TbetaRII. Of these receptors, TbetaRII preferentially phosphorylated endoglin on cytosolic domain serine residues Ser(634) and Ser(635). Removal of the carboxyl-terminal tripeptide of endoglin, which comprises a putative PDZ-liganding motif, dramatically increased endoglin serine phosphorylation by all three receptors, suggesting that the PDZ-liganding motif is important for the regulation of endoglin phosphorylation. Constitutively active (ca)ALK1, but not caALK5, phosphorylated endoglin on cytosolic domain threonine residues. caALK1-mediated threonine phosphorylation required prior serine phosphorylation, suggesting a sequential mechanism of endoglin phosphorylation. Wild-type, but not a threonine phosphorylation-defective endoglin mutant blocked cell detachment and the antiproliferative effects of caALK1 expressed in HUVECs. These results suggest that ALK1 is a preferred TGFbeta receptor kinase for endoglin threonine phosphorylation in HUVECs and indicate a role for endoglin phosphorylation in the regulation of endothelial cell adhesion and growth by ALK1.
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MESH Headings
- Activin Receptors, Type II/metabolism
- Amino Acid Sequence
- Antigens, CD/chemistry
- Antigens, CD/physiology
- Cells, Cultured
- Cytosol/metabolism
- Endoglin
- Endothelium, Vascular/cytology
- Humans
- Molecular Sequence Data
- Phosphorylation
- Protein Structure, Tertiary
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/physiology
- Receptors, Transforming Growth Factor beta/metabolism
- Sequence Homology, Amino Acid
- Structure-Activity Relationship
- Umbilical Veins/cytology
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Affiliation(s)
- Rositsa I Koleva
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
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34
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Kirkbride KC, Ray BN, Blobe GC. Cell-surface co-receptors: emerging roles in signaling and human disease. Trends Biochem Sci 2005; 30:611-21. [PMID: 16185874 DOI: 10.1016/j.tibs.2005.09.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Revised: 08/10/2005] [Accepted: 09/12/2005] [Indexed: 12/28/2022]
Abstract
Extracellular signals are transmitted to cells through two classes of cell-surface receptors: signaling receptors that directly transduce signals and signaling co-receptors that bind ligand but that, traditionally, have not been thought to signal directly. Signaling co-receptors modulate the ligand binding and signaling of their respective signaling receptors. In recent years, roles for co-receptors have expanded to include essential functions in morphogen gradient formation, localizing signaling, signaling independently, regulating cell adhesion and orchestrating the signaling of several pathways. The importance of signaling co-receptors is demonstrated by their ubiquitous expression, their conservation during evolution, their prominent role in signaling cascades, their indispensable role during development and their frequent mutation or altered expression in human disease.
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Affiliation(s)
- Kellye C Kirkbride
- Duke University Medical Center, Department of Medicine, Durham, NC 27710, USA
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35
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Pérez-Gómez E, Eleno N, López-Novoa JM, Ramirez JR, Velasco B, Letarte M, Bernabéu C, Quintanilla M. Characterization of murine S-endoglin isoform and its effects on tumor development. Oncogene 2005; 24:4450-61. [PMID: 15806144 DOI: 10.1038/sj.onc.1208644] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Endoglin is a transmembrane glycoprotein that acts as an auxiliary receptor for transforming growth factor-beta (TGF-beta) and modulates cellular responses to this pleiotropic cytokine. Endoglin is strongly expressed in endothelial cells, where it appears to exert a crucial role in vascular development and angiogenesis. Two endoglin isoforms (L and S), differing in their cytoplasmic domains, have been previously characterized in human tissues. We now demonstrate the existence of similar L- and S-endoglin variants in murine tissues with 47 and 35 amino acids, respectively, in their cytoplasmic tail. RT-PCR analysis showed that L is the predominant endoglin isoform expressed in mouse tissues, although S-endoglin mRNA is significantly expressed in liver and lung, as well as in endothelial cell lines. Furthermore, a protein of size equivalent to recombinant S-endoglin expressed in mammalian cells was detected in mouse endothelial cells by Western blot analysis. L- and S-endoglin isoforms can form disulfide-linked heterodimers, as demonstrated by cotransfection of L- and S-endoglin constructs. To address the role of S-endoglin in vivo, an S-Eng(+) transgenic mouse model that targets S-endoglin expression to the endothelium was generated. The lethal phenotype of endoglin-null (Eng(-/-)) mice was not rescued by breeding S-Eng(+) transgenic mice into the endoglin-null background. S-Eng(+) mice exhibited reduced tumor growth and neovascularization after transplantation of Lewis lung carcinoma cells. In addition, S-Eng(+) mice showed a drastic inhibition of benign papilloma formation when subjected to two-stage chemical skin carcinogenesis. These results point to S-endoglin as an antiangiogenic molecule, in contrast to L-endoglin which is proangiogenic. Oncogene (2005) 24, 4450-4461. doi:10.1038/sj.onc.1208644 Published online 4 April 2005.
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Affiliation(s)
- Eduardo Pérez-Gómez
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad Autónoma de Madrid (UAM), Arturo Duperier 4, 28029 Madrid, Spain
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36
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Abdalla SA, Letarte M. Hereditary haemorrhagic telangiectasia: current views on genetics and mechanisms of disease. J Med Genet 2005; 43:97-110. [PMID: 15879500 PMCID: PMC2603035 DOI: 10.1136/jmg.2005.030833] [Citation(s) in RCA: 257] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterised by epistaxis, telangiectases, and multiorgan vascular dysplasia. The two major types of disease, HHT1 and HHT2, are caused by mutations in the ENG (endoglin) and ACVRL1 genes, respectively. The corresponding endoglin and ALK-1 proteins are specific endothelial receptors of the transforming growth factor beta superfamily essential for maintaining vascular integrity. Many mutations have been identified in ENG and ACVRL1 genes and support the haploinsufficiency model for HHT. Two more genes have recently been implicated in HHT: MADH4 mutated in a combined syndrome of juvenile polyposis and HHT (JPHT), and an unidentified HHT3 gene linked to chromosome 5. Current knowledge on the genetics of HHT is summarised, including the pathways that link the genes responsible for HHT and the potential mechanisms underlying the pathogenesis of the disease.
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Affiliation(s)
- S A Abdalla
- Department of Laboratory Medicine and Pathobiology, St Michael's Hospital, Toronto, Canada.
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37
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Tang H, Low B, Rutherford SA, Hao Q. Thrombin induces endocytosis of endoglin and type-II TGF-beta receptor and down-regulation of TGF-beta signaling in endothelial cells. Blood 2004; 105:1977-85. [PMID: 15522964 DOI: 10.1182/blood-2004-08-3308] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thrombin activates protease-activated receptor 1 (PAR1) on endothelial cells (ECs) and is critical for angiogenesis and vascular development. However, the mechanism underlying the proangiogenic effect of thrombin has not been elucidated yet. Here, we report the discovery of a novel functional link between thrombin-PAR1 and transforming growth factor-beta (TGF-beta) signaling pathways. We showed that thrombin via PAR1 induced the internalization of endoglin and type-II TGF-beta receptor (TbetaRII) but not type-I receptors in human ECs. This effect was mediated by protein kinase C-zeta (PKC-zeta) since specific inhibition of PKC-zeta caused an aggregation of endoglin or TbetaRII on cell surface and blocked their internalization by thrombin. Furthermore, acute and long-term pretreatment of ECs with thrombin or PAR1 peptide agonist suppressed the TGF-beta-induced serine phosphorylation of Smad2, a critical mediator of TGF-beta signaling. Moreover, activation of PAR1 led to a profound and spread cytosolic clustering formation of Smad2/3 and markedly prevented Smad2/3 nuclear translocation evoked by TGF-beta1. Since TGF-beta plays a crucial role in the resolution phase of angiogenesis, the down-regulation of TGF-beta signaling by thrombin-PAR1 pathway may provide a new insight into the mechanism of the proangiogenic effect of thrombin.
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Affiliation(s)
- Hua Tang
- Department of Biochemistry, The University of Texas Health Center at Tyler, 11937 US Highway 271, Tyler, TX 75708, USA.
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38
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Fonsatti E, Maio M. Highlights on endoglin (CD105): from basic findings towards clinical applications in human cancer. J Transl Med 2004; 2:18. [PMID: 15193152 PMCID: PMC441416 DOI: 10.1186/1479-5876-2-18] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2004] [Accepted: 06/11/2004] [Indexed: 11/19/2022] Open
Abstract
Antibody targeting of tumor-associated vasculature is a promising therapeutic approach in human cancer; however, a specific cell membrane marker for endothelial cells of tumor vasculature has not been discovered yet. Endoglin (CD105) is a cell-surface glycoprotein most recently identified as an optimal indicator of proliferation of human endothelial cells. The finding that CD105 is over-expressed on vascular endothelium in angiogenetic tissues has prompted several pre-clinical studies designed to get a deeper understanding on the role of CD105 in angiogenesis, and to evaluate the most appropriate clinical setting(s) to utilize CD105 as a therapeutic target. In this review, the foreseeable clinical applications of CD105 in human cancer are discussed.
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Affiliation(s)
- Ester Fonsatti
- Cancer Bioimmunotherapy Unit, Department of Medical Oncology, Centro di Riferimento Oncologico, I.R.C.C.S., 33081 Aviano, Italy
| | - Michele Maio
- Cancer Bioimmunotherapy Unit, Department of Medical Oncology, Centro di Riferimento Oncologico, I.R.C.C.S., 33081 Aviano, Italy
- Division of Medical Oncology and Immunotherapy, Department of Oncology, University Hospital of Siena, 53100 Siena, Italy
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39
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Conley BA, Koleva R, Smith JD, Kacer D, Zhang D, Bernabéu C, Vary CPH. Endoglin controls cell migration and composition of focal adhesions: function of the cytosolic domain. J Biol Chem 2004; 279:27440-9. [PMID: 15084601 DOI: 10.1074/jbc.m312561200] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in the human endoglin gene result in hereditary hemorrhagic telangiectasia type 1, a vascular disorder characterized by multisystemic vascular dysplasia, arteriovenous malformations, and focal dilatation of postcapillary venules. Previous studies have implicated endoglin in the inhibition of cell migration in vivo and in vitro. In the course of studies to address the relationship of the conserved cytosolic domain to endoglin function, we identified zyxin, a LIM domain protein that is concentrated at focal adhesions, as an interactor with endoglin in human umbilical vein vascular endothelial cells. This interaction is localized within the 47-amino acid carboxyl-terminal cytosolic domain of endoglin, and maps within zyxin residues 326-572. The endoglin-zyxin interaction was found to be largely mediated by the third LIM domain of zyxin, and is specific for endoglin because the homologous cytosolic domain of the transforming growth factor-beta type III receptor, betaglycan, fails to interact with zyxin. Expression of endoglin is associated with reduction of zyxin, as well as its interacting proteins p130(cas) and CrkII, from a focal adhesion protein fraction, and this reduction is correlated with inhibition of cell migration. We also show that endoglin-dependent: (i) inhibition of cell migration, (ii) reduction of focal adhesion-associated p130(cas)/CrkII protein levels, (iii) tyrosine phosphorylation of p130(cas), and (iv) focal adhesion-associated endoglin levels are mediated by the cytosolic domain of endoglin. These results suggest a novel mechanism of endoglin function involving its interaction with LIM domain-containing proteins, and associated adapter proteins, affecting sites of focal adhesion.
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Affiliation(s)
- Barbara A Conley
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
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40
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Fonsatti E, Altomonte M, Nicotra MR, Natali PG, Maio M. Endoglin (CD105): a powerful therapeutic target on tumor-associated angiogenetic blood vessels. Oncogene 2003; 22:6557-63. [PMID: 14528280 DOI: 10.1038/sj.onc.1206813] [Citation(s) in RCA: 180] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Among surface molecules expressed on endothelial cells, endoglin (CD105) is emerging as a prime vascular target for antiangiogenetic cancer therapy. CD105 is a cell membrane glycoprotein mainly expressed on endothelial cells and overexpressed on tumor-associated vascular endothelium, which functions as an accessory component of the transforming growth factor -beta receptor complex and is involved in vascular development and remodelling. Quantification of intratumoral microvessel density by CD105 staining and of circulating soluble CD105 has been suggested to have prognostic significance in selected neoplasias. In addition, the potential usefulness of CD105 in tumor imaging and antiangiogenetic therapy has been well documented utilizing different animal models.
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Affiliation(s)
- Ester Fonsatti
- Cancer Bioimmunotherapy Unit, Department of Medical Oncology, Centro di Riferimento Oncologico, Istituto di Ricovero e Cura a Carattere Scientific, Aviano 33081, Italy
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41
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Duff SE, Li C, Garland JM, Kumar S. CD105 is important for angiogenesis: evidence and potential applications. FASEB J 2003; 17:984-92. [PMID: 12773481 DOI: 10.1096/fj.02-0634rev] [Citation(s) in RCA: 363] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Angiogenesis is the propelling force for tumor growth and metastasis, and antiangiogenic therapy represents one of the most promising modalities for cancer treatment. CD105 (endoglin) is a proliferation-associated and hypoxia-inducible protein abundantly expressed in angiogenic endothelial cells (EC). It is a receptor for transforming growth factor (TGF) -beta1 and -beta3 and modulates TGF-beta signaling by interacting with TGF-beta receptors I and/or II. Immunohistochemistry studies have revealed that CD105 is strongly expressed in blood vessels of tumor tissues. Intratumoral microvessel density (MVD) determined using antibodies to CD105 has been found to be an independent prognostic indicator, wherein increased MVD correlates with shorter survival. CD105 is able to be shed into the circulation, with elevated levels detected in patients with various types of cancer and positively correlated with tumor metastasis. Tangible evidence of its proangiogenic role comes from knockout studies in which CD105 null mice die in utero as a result of impaired angiogenesis in the yolk sac and heart defects. The potential usefulness of CD105 for tumor imaging has been evaluated in tumor-bearing mice and dogs that have shown the rapid accumulation of radiolabeled anti-CD105 monoclonal antibody in the tumors with a high tumor-to-background ratio. The anti-CD105 antibody conjugated with immunotoxins and immunoradioisotopes efficiently suppressed/abrogated tumor growth in murine models bearing breast and colon carcinoma without any significant systemic side effects. Immunoscintigraphy in patients with renal cell carcinomas has shown specific localization of 99Tcm-labeled CD105 mab in tumor endothelial cells. Thus, CD105 is a promising vascular target that can be used for tumor imaging, prognosis, and bears therapeutic potential in patients with solid tumors and other angiogenic diseases.
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Affiliation(s)
- Sarah E Duff
- Department of Pathology, Medical School, University of Manchester, M13 9PT, UK
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Liu Y, Jovanovic B, Pins M, Lee C, Bergan RC. Over expression of endoglin in human prostate cancer suppresses cell detachment, migration and invasion. Oncogene 2002; 21:8272-81. [PMID: 12447690 DOI: 10.1038/sj.onc.1206117] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2002] [Revised: 07/11/2002] [Accepted: 10/07/2002] [Indexed: 11/09/2022]
Abstract
The regulation of cell adhesion and motility in human prostate is not well understood. We have previously shown that the endoglin gene is differently expressed during changes in prostate cell adhesion. Endoglin is a transmembrane transforming growth factor beta binding protein typically expressed by endothelial cells. In this report we demonstrate that endoglin over expression increases prostate cell attachment, while decreasing migration and invasion. Engineered decreases in endoglin expression have opposite effects. While endoglin exerted only relatively small effects upon cell adhesion, large effects upon cell migration and invasion were observed. Endoglin was shown to localize to focal adhesion plaques, consistent with its role in regulating cell adhesion and motility. Loss of endoglin expression in cancer, as compared to normal prostate, was seen in human prostate cell lines. Suppression of endoglin expression in a panel of normal human prostate cell lines led to cell detachment. Endoglin is identified as a regulator of cell adhesion, motility and invasion in human prostate. Loss of endoglin expression appears to be associated with prostate cancer progression, at least in vitro.
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Affiliation(s)
- Yuequin Liu
- Division of Hematology/Oncology, Department of Medicine, Northwestern University Medical School and the Robert H. Lurie Cancer Center of Northwestern University, Olson 8524, 710 N. Fairbanks, Chicago, Illinois, IL 60611, USA
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43
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Guerrero-Esteo M, Sanchez-Elsner T, Letamendia A, Bernabeu C. Extracellular and cytoplasmic domains of endoglin interact with the transforming growth factor-beta receptors I and II. J Biol Chem 2002; 277:29197-209. [PMID: 12015308 DOI: 10.1074/jbc.m111991200] [Citation(s) in RCA: 172] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Endoglin is an auxiliary component of the transforming growth factor-beta (TGF-beta) receptor system, able to associate with the signaling receptor types I (TbetaRI) and II (TbetaRII) in the presence of ligand and to modulate the cellular responses to TGF-beta1. Endoglin cannot bind ligand on its own but requires the presence of the signaling receptors, supporting a critical role for the interaction between endoglin and TbetaRI or TbetaRII. This study shows that full-length endoglin interacts with both TbetaRI and TbetaRII, independently of their kinase activation state or the presence of exogenous TGF-beta1. Truncated constructs encoding either the extracellular or the cytoplasmic domains of endoglin demonstrated that the association with the signaling receptors occurs through both extracellular and cytoplasmic domains. However, a more specific mapping revealed that the endoglin/TbetaRI interaction was different from that of endoglin/TbetaRII. TbetaRII interacts with the amino acid region 437-558 of the extracellular domain of endoglin, whereas TbetaRI interacts not only with the region 437-558 but also with the protein region located between amino acid 437 and the N terminus. Both TbetaRI and TbetaRII interact with the cytoplasmic domain of endoglin, but TbetaRI only interacts when the kinase domain is inactive, whereas TbetaRII remains associated in its active and inactive forms. Upon association, TbetaRI and TbetaRII phosphorylate the endoglin cytoplasmic domain, and then TbetaRI, but not TbetaRII, kinase dissociates from the complex. Conversely, endoglin expression results in an altered phosphorylation state of TbetaRII, TbetaRI, and downstream Smad proteins as well as a modulation of TGF-beta signaling, as measured by the reporter gene expression. These results suggest that by interacting through its extracellular and cytoplasmic domains with the signaling receptors, endoglin might affect TGF-beta responses.
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Affiliation(s)
- Mercedes Guerrero-Esteo
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Cientificas, Velázquez 144, Madrid 28006, Spain
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Caterson EJ, Nesti LJ, Li WJ, Danielson KG, Albert TJ, Vaccaro AR, Tuan RS. Three-dimensional cartilage formation by bone marrow-derived cells seeded in polylactide/alginate amalgam. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2001; 57:394-403. [PMID: 11523034 DOI: 10.1002/1097-4636(20011205)57:3<394::aid-jbm1182>3.0.co;2-9] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Bone marrow-derived cells are considered as candidate cells for cartilage tissue engineering by virtue of their ability to undergo chondrogenesis in vitro when cultured in high density or when embedded within a three-dimensional matrix in the presence of growth factors. This study evaluated the potential of human bone marrow-derived cells for cartilage tissue engineering by examining their chondrogenic properties within a three-dimensional amalgam scaffold consisting of the biodegradable polymer, poly-L-lactic acid (PLA) alone, and with the polysaccharide gel, alginate. Cells were suspended either in alginate or medium and loaded into porous PLA blocks. Alginate was used to improve cell loading and retention within the construct, whereas the PLA polymeric scaffold provided appropriate mechanical support and stability to the composite culture. Cells seeded in the PLA/alginate amalgams and the plain PLA constructs were treated with different concentrations of recombinant human transforming growth factor-beta1 (TGF-beta 1) either continuously (10 ng/mL) or only for the initial 3 days of culture (50 ng/mL). Chondrogenesis was assessed at weekly intervals with cultures maintained for up to 3 weeks. Histological and immunohistochemical analysis of the TGF-beta 1-treated PLA/alginate amalgam and PLA constructs showed development of a cartilaginous phenotype from day 7 to day 21 as demonstrated by colocalization of Alcian blue staining with collagen type II and cartilage proteoglycan link protein. Expression of cartilage specific genes, including collagen types II and IX, and aggrecan, was detected in TGF-beta 1-treated cultures by reverse transcription-polymerase chain reaction analysis. The initiation and progression of chondrogenic differentiation within the polymeric macrostructure occurred with both continuous and the initial 3-day TGF-beta 1 treatment regimens, suggesting that key regulatory events of chondrogenesis take place during the early period of cell growth and proliferation. Scanning electron microscopy revealed abundant cells with a rounded morphology in the PLA/alginate amalgam. These findings suggest that the three-dimensional PLA/alginate amalgam is a potential candidate bioactive scaffold for cartilage tissue engineering applications.
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Affiliation(s)
- E J Caterson
- Department of Orthopaedic Surgery, Thomas Jefferson University Hospital, 1015 Walnut Street, Philadelphia, Pennsylvania 19107, USA
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Fonsatti E, Del Vecchio L, Altomonte M, Sigalotti L, Nicotra MR, Coral S, Natali PG, Maio M. Endoglin: An accessory component of the TGF-beta-binding receptor-complex with diagnostic, prognostic, and bioimmunotherapeutic potential in human malignancies. J Cell Physiol 2001; 188:1-7. [PMID: 11382917 DOI: 10.1002/jcp.1095] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Endoglin (CD105) is a cell membrane glycoprotein over-expressed on highly proliferating endothelial cells in culture, and on endothelial cells of angiogenetic blood vessels within benign and malignant tissues. CD105 binds several factors of the Transforming Growth Factor (TGF)-beta superfamily, and its over-expression modulates cellular responses to TGF-beta1. The complex of experimental findings accumulated in the last few years strongly indicate that CD105 is a powerful marker of angiogenesis, and that it might play a critical role in the pathogenesis of vascular diseases and in tumor progression. In this paper, we will review the structural, biological and functional features of CD105, as well as its distribution within normal and neoplastic tissues, emphasizing its foreseeable role as a molecular target for new diagnostic and bioimmunotherapeutic approaches in human malignancies.
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Affiliation(s)
- E Fonsatti
- Advanced Immunotherapy Unit, Centro di Riferimento Oncologico, I.R.C.C.S., Via Pedemontana Occ.le.12, Aviano, Italy 33081
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Abstract
The progression of breast cancer depends on the establishment of a neovasculature, by a process called angiogenesis. Angiogenesis is an invasive cellular event that requires the co-ordination of numerous molecules including growth factors and their receptors, extracellular proteins, adhesion molecules, and proteolytic enzymes. TGFbeta has emerged to be a major modulator of angiogenesis by regulating endothelial cell proliferation, migration, extracellular matrix (ECM) metabolism, and the expression of adhesion molecules. It is a potent growth inhibitor of normal mammary epithelial cells and a number of breast cancer cell lines. It seems that TGFbeta exerts pleiotropic effects in the oncogenesis of breast cancers in a contextual manner, i.e., it suppresses tumourigenesis at an early stage by direct inhibition of angiogenesis and tumour cell growth. However, over-production of TGFbeta by an advanced tumour may accelerate disease progression through indirect stimulation of angiogenesis and immune suppression. The cell membrane antigen CD105 (endoglin) binds TGFbeta1 and TGFbeta3 and is preferentially expressed in angiogenic vascular endothelial cells. The reduction of CD105 levels in HUVEC leads to in vitro angiogenesis inhibition and massive cell mortality in the presence of TGFbeta1. CD105 null mice die in utero with impaired vasculature, indicating the pivotal role of CD105 in vascular development. The administration of an immunotoxin-conjugate, mab to CD105, induces long-term and complete regression of breast cancer growth in SCID mice. Therefore, CD105 is a promising vascular target for antiangiogenic therapy.
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Affiliation(s)
- C Li
- Department of Pathological Sciences, Medical School, The University of Manchester, M13 9PT, United Kingdom.
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Conley BA, Smith JD, Guerrero-Esteo M, Bernabeu C, Vary CP. Endoglin, a TGF-beta receptor-associated protein, is expressed by smooth muscle cells in human atherosclerotic plaques. Atherosclerosis 2000; 153:323-35. [PMID: 11164421 DOI: 10.1016/s0021-9150(00)00422-6] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Endoglin is a transmembrane protein that is found in association with transforming growth factor-beta (TGF-beta) superfamily receptor complexes and has an expression pattern that appears to be restricted primarily to endothelial cells, activated macrophages, trophoblasts, and fibroblasts. Since mutations in endoglin have been shown to be linked to hereditary hemorrhagic telangiectasia type 1, a disease manifested as vascular malformations characterized by excessive layers of vascular smooth muscle cells (VSMC), the expression of endoglin was investigated in VSMC. In vivo, the majority of SMC in human atherosclerotic plaques expressed high levels of endoglin, while endoglin was not detected in SMC from samples of the normal arterial wall. In vitro studies demonstrate that human aortic smooth muscle cells (HASMC) express the L-isoform of endoglin. Like endothelial cells, HASMC express endoglin protein as a dimer on the cell surface that binds TGF-beta1. In vitro, endoglin expression by HASMC is upregulated in response to TGF-beta1, suggesting that the presence of this factor in the atherosclerotic plaque might be responsible for the increased expression of endoglin. The demonstration of increased levels of endoglin in VSMC in human atherosclerotic plaques suggests a role for SMC endoglin in the maintenance of vascular integrity and in the response of the vessel wall to injury.
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Affiliation(s)
- B A Conley
- Center for Molecular Medicine, Maine Medical Center Research Institute, South Portland 04106, USA
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Li C, Hampson IN, Hampson L, Kumar P, Bernabeu C, Kumar S. CD105 antagonizes the inhibitory signaling of transforming growth factor beta1 on human vascular endothelial cells. FASEB J 2000; 14:55-64. [PMID: 10627280 DOI: 10.1096/fasebj.14.1.55] [Citation(s) in RCA: 186] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
CD105 (endoglin), a receptor for transforming growth factor beta (TGFbeta), is highly expressed in tissue-cultured, activated endothelial cells in vitro and in tissues undergoing angiogenesis in vivo. The absence of CD105 in knockout mice leads to their death from defective vascular development, but the role of CD105 in the modulation of angiogenesis has not been elucidated. TGFbeta1 is a well-recognized regulator of angiogenesis. Using an antisense approach, we have shown that inhibition of CD105 protein translation in cultured human endothelial cells enhances the ability of TGFbeta1 to suppress growth and migration in these cells. The ability of endothelial cells to form capillary tubes was evaluated by the use of a 3-dimensional collagen matrix system where TGFbeta1 not only reduced the length of capillary-like structures, but also caused massive mortality in CD105-deficient cells compared to control cultures. These results provide direct evidence that CD105 antagonizes the inhibitory effects of TGFbeta1 on human vascular endothelial cells and that normal cellular levels of CD105 are required for the formation of new blood vessels.
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Affiliation(s)
- C Li
- Department of Pathological Sciences, Medical School, University of Manchester, Manchester M13 9PT, U.K
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Guerrero-Esteo M, Lastres P, Letamendía A, Pérez-Alvarez MJ, Langa C, López LA, Fabra A, García-Pardo A, Vera S, Letarte M, Bernabéu C. Endoglin overexpression modulates cellular morphology, migration, and adhesion of mouse fibroblasts. Eur J Cell Biol 1999; 78:614-23. [PMID: 10535303 DOI: 10.1016/s0171-9335(99)80046-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Endoglin is the gene mutated in hereditary hemorrhagic telangiectasia type 1 (HHT1), a dominantly inherited vascular disorder. Endoglin glycoprotein is a component of the transforming growth factor type beta (TGF-beta) receptor system which is highly expressed by endothelial cells, and at lower levels on fibroblasts and smooth muscle cells, suggesting the involvement of these lineages in the HHT1 vascular dysplasia. Overexpression of endoglin in mouse NCTC929 fibroblasts led to decreased migration in chemotactic and wound healing assays, as well as changes in the cellular morphology. When plated on uncoated surfaces, endoglin transfectants formed intercellular clusters, endoglin being not specifically localized to the cell-cell junctions, but homogenously distributed on the cellular surface. Although the expression of alpha5beta1 integrin and of an activation epitope of beta1 integrin were unchanged, a polyclonal antibody to alpha5beta1 integrin was able to inhibit cluster formation, suggesting the involvement of integrin ligand/s. In fact, coating with fibronectin, laminin, or an RGD-containing 80 kDa fragment of fibronectin were able to prevent the cellular clustering. Furthermore, synthesis of plasminogen activator inhibitor 1 (PAI-1), and to a weak extent that of fibronectin, were inhibited in endoglin transfectants. Thus, the presence of endoglin in mouse NCTC929 fibroblasts is associated with reduced production of certain extracellular matrix (ECM) components, which might explain their altered morphology, migration and intercellular cluster formation.
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Affiliation(s)
- M Guerrero-Esteo
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid/Spain
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Lux A, Attisano L, Marchuk DA. Assignment of transforming growth factor beta1 and beta3 and a third new ligand to the type I receptor ALK-1. J Biol Chem 1999; 274:9984-92. [PMID: 10187774 DOI: 10.1074/jbc.274.15.9984] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Germ line mutations in one of two distinct genes, endoglin or ALK-1, cause hereditary hemorrhagic telangiectasia (HHT), an autosomal dominant disorder of localized angiodysplasia. Both genes encode endothelial cell receptors for the transforming growth factor beta (TGF-beta) ligand superfamily. Endoglin has homology to the type III receptor, betaglycan, although its exact role in TGF-beta signaling is unclear. Activin receptor-like kinase 1 (ALK-1) has homology to the type I receptor family, but its ligand and corresponding type II receptor are unknown. In order to identify the ligand and type II receptor for ALK-1 and to investigate the role of endoglin in ALK-1 signaling, we devised a chimeric receptor signaling assay by exchanging the kinase domain of ALK-1 with either the TGF-beta type I receptor or the activin type IB receptor, both of which can activate an inducible PAI-1 promoter. We show that TGF-beta1 and TGF-beta3, as well as a third unknown ligand present in serum, can activate chimeric ALK-1. HHT-associated missense mutations in the ALK-1 extracellular domain abrogate signaling. The ALK-1/ligand interaction is mediated by the type II TGF-beta receptor for TGF-beta and most likely through the activin type II or type IIB receptors for the serum ligand. Endoglin is a bifunctional receptor partner since it can bind to ALK-1 as well as to type I TGF-beta receptor. These data suggest that HHT pathogenesis involves disruption of a complex network of positive and negative angiogenic factors, involving TGF-beta, a new unknown ligand, and their corresponding receptors.
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Affiliation(s)
- A Lux
- Department of Genetics, Duke University Medical Center, Durham, North Carolina 27710, USA
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