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Ting KK, Coleman P, Kim HJ, Zhao Y, Mulangala J, Cheng NC, Li W, Gunatilake D, Johnstone DM, Loo L, Neely GG, Yang P, Götz J, Vadas MA, Gamble JR. Vascular senescence and leak are features of the early breakdown of the blood-brain barrier in Alzheimer's disease models. GeroScience 2023; 45:3307-3331. [PMID: 37782439 PMCID: PMC10643714 DOI: 10.1007/s11357-023-00927-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 08/27/2023] [Indexed: 10/03/2023] Open
Abstract
Alzheimer's disease (AD) is an age-related disease, with loss of integrity of the blood-brain barrier (BBB) being an early feature. Cellular senescence is one of the reported nine hallmarks of aging. Here, we show for the first time the presence of senescent cells in the vasculature in AD patients and mouse models of AD. Senescent endothelial cells and pericytes are present in APP/PS1 transgenic mice but not in wild-type littermates at the time of amyloid deposition. In vitro, senescent endothelial cells display altered VE-cadherin expression and loss of cell junction formation and increased permeability. Consistent with this, senescent endothelial cells in APP/PS1 mice are present at areas of vascular leak that have decreased claudin-5 and VE-cadherin expression confirming BBB breakdown. Furthermore, single cell sequencing of endothelial cells from APP/PS1 transgenic mice confirms that adhesion molecule pathways are among the most highly altered pathways in these cells. At the pre-plaque stage, the vasculature shows significant signs of breakdown, with a general loss of VE-cadherin, leakage within the microcirculation, and obvious pericyte perturbation. Although senescent vascular cells were not directly observed at sites of vascular leak, senescent cells were close to the leak area. Thus, we would suggest in AD that there is a progressive induction of senescence in constituents of the neurovascular unit contributing to an increasing loss of vascular integrity. Targeting the vasculature early in AD, either with senolytics or with drugs that improve the integrity of the BBB may be valid therapeutic strategies.
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Affiliation(s)
- Ka Ka Ting
- Vascular Biology Program, Centenary Institute, Camperdown, NSW, Australia.
- School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia.
| | - Paul Coleman
- Vascular Biology Program, Centenary Institute, Camperdown, NSW, Australia
- School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia
| | - Hani Jieun Kim
- Computational Systems Biology Group, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, NSW, 2145, Australia
| | - Yang Zhao
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China
| | - Jocelyne Mulangala
- Vascular Biology Program, Centenary Institute, Camperdown, NSW, Australia
| | - Ngan Ching Cheng
- Vascular Biology Program, Centenary Institute, Camperdown, NSW, Australia
| | - Wan Li
- Department of General Surgery, Jiangsu Province Hospital of Chinese Medicine, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, 210029, China
| | - Dilini Gunatilake
- Vascular Biology Program, Centenary Institute, Camperdown, NSW, Australia
| | - Daniel M Johnstone
- School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia
- School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, NSW, Australia
| | - Lipin Loo
- Charles Perkins Centre, Dr. John and Anne Chong Lab for Functional Genomics, Centenary Institute, & School of Life and Environmental Sciences, University of Sydney, Camperdown, NSW, Australia
| | - G Gregory Neely
- Charles Perkins Centre, Dr. John and Anne Chong Lab for Functional Genomics, Centenary Institute, & School of Life and Environmental Sciences, University of Sydney, Camperdown, NSW, Australia
| | - Pengyi Yang
- Computational Systems Biology Group, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, NSW, 2145, Australia
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Mathew A Vadas
- Vascular Biology Program, Centenary Institute, Camperdown, NSW, Australia
- Heart Research Institute, Sydney, NSW, Australia
| | - Jennifer R Gamble
- Vascular Biology Program, Centenary Institute, Camperdown, NSW, Australia.
- School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia.
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2
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Liu K, Chen J, Zhao Y, Boland J, Ting KK, Lockwood G, McKenzie C, Kench J, Vadas MA, Gamble JR, McCaughan GW. Novel miRNA-based drug CD5-2 reduces liver tumor growth in diethylnitrosamine-treated mice by normalizing tumor vasculature and altering immune infiltrate. Front Immunol 2023; 14:1245708. [PMID: 37795103 PMCID: PMC10545841 DOI: 10.3389/fimmu.2023.1245708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/01/2023] [Indexed: 10/06/2023] Open
Abstract
Introduction Liver cancers exhibit abnormal (leaky) vasculature, hypoxia and an immunosuppressive microenvironment. Normalization of tumor vasculature is an emerging approach to treat many cancers. Blockmir CD5-2 is a novel oligonucleotide-based inhibitor of the miR-27a interaction with VE-Cadherin, the endothelial-specific cadherin. The combination of a vasoactive medication with inhibition of immune checkpoints such as programmed cell death protein 1 (PD1) has been shown to be effective in treating liver cancer in humans. We aimed to study the effect of CD5-2 combined with checkpoint inhibition (using an antibody against PD1) on liver tumor growth, vasculature and immune infiltrate in the diethylnitrosamine (DEN)-induced liver tumor mouse model. Methods We first analyzed human miR-27a and VE-Cadherin expression data from The Cancer Genome Atlas for hepatocellular carcinoma. CD5-2 and/or anti-PD1 antibody were given to the DEN-treated mice from age 7-months until harvest at age 9-months. Tumor and non-tumor liver tissues were analyzed using histology, immunohistochemistry, immunofluorescence and scanning electron microscopy. Results Human data showed high miR-27a and low VE-Cadherin were both significantly associated with poorer prognosis. Mice treated with CD5-2 plus anti-PD1 antibody had significantly smaller liver tumors (50% reduction) compared to mice treated with either agent alone, controls, or untreated mice. There was no difference in tumor number. Histologically, tumors in CD5-2-treated mice had less leaky vessels with higher VE-Cadherin expression and less tumor hypoxia compared to non-CD5-2-treated mice. Only tumors in the combination CD5-2 plus anti-PD1 antibody group exhibited a more favorable immune infiltrate (significantly higher CD3+ and CD8+ T cells and lower Ly6G+ neutrophils) compared to tumors from other groups. Discussion CD5-2 normalized tumor vasculature and reduced hypoxia in DEN-induced liver tumors. CD5-2 plus anti-PD1 antibody reduced liver tumor size possibly by altering the immune infiltrate to a more immunosupportive one.
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Affiliation(s)
- Ken Liu
- AW Morrow Gastroenterology and Liver Centre, Royal Prince Alfred Hospital, Sydney, NSW, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Centenary Institute, University of Sydney, Sydney, NSW, Australia
| | - Jinbiao Chen
- Centenary Institute, University of Sydney, Sydney, NSW, Australia
| | - Yang Zhao
- Centenary Institute, University of Sydney, Sydney, NSW, Australia
| | - Jade Boland
- Centenary Institute, University of Sydney, Sydney, NSW, Australia
| | - Ka Ka Ting
- Centenary Institute, University of Sydney, Sydney, NSW, Australia
| | - Glen Lockwood
- Biogerontology Group, ANZAC Research Institute, Sydney, NSW, Australia
| | - Catriona McKenzie
- New South Wales Health Pathology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - James Kench
- New South Wales Health Pathology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - Mathew A. Vadas
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Centenary Institute, University of Sydney, Sydney, NSW, Australia
| | - Jennifer R. Gamble
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Centenary Institute, University of Sydney, Sydney, NSW, Australia
| | - Geoffrey W. McCaughan
- AW Morrow Gastroenterology and Liver Centre, Royal Prince Alfred Hospital, Sydney, NSW, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Centenary Institute, University of Sydney, Sydney, NSW, Australia
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3
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Chen J, Zhao Y, Zhang F, Li J, Boland JA, Cheng NC, Liu K, Tiffen JC, Bertolino P, Bowen DG, Krueger A, Lisowski L, Alexander IE, Vadas MA, El-Omar E, Gamble JR, McCaughan GW. Liver-specific deletion of miR-181ab1 reduces liver tumour progression via upregulation of CBX7. Cell Mol Life Sci 2022; 79:443. [PMID: 35867177 PMCID: PMC9307539 DOI: 10.1007/s00018-022-04452-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 06/23/2022] [Accepted: 06/26/2022] [Indexed: 11/30/2022]
Abstract
MiR-181 expression levels increased in hepatocellular carcinoma (HCC) compared to non-cancerous tissues. MiR-181 has been widely reported as a possible driver of tumourigenesis but also acts as a tumour suppressor. In addition, the miR-181 family regulates the development and function of immune and vascular cells, which play vital roles in the progression of tumours. More complicatedly, many genes have been identified as miR-181 targets to mediate the effects of miR-181. However, the role of miR-181 in the development of primary tumours remains largely unexplored. We aimed to examine the function of miR-181 and its vital mediators in the progression of diethylnitrosamine-induced primary liver cancers in mice. The size of liver tumours was significantly reduced by 90% in global (GKO) or liver-specific (LKO) 181ab1 knockout mice but not in hematopoietic and endothelial lineage-specific knockout mice, compared to WT mice. In addition, the number of tumours was significantly reduced by 50% in GKO mice. Whole-genome RNA-seq analysis and immunohistochemistry showed that epithelial-mesenchymal transition was partially reversed in GKO tumours compared to WT tumours. The expression of CBX7, a confirmed miR-181 target, was up-regulated in GKO compared to WT tumours. Stable CBX7 expression was achieved with an AAV/Transposase Hybrid-Vector System and up-regulated CBX7 expression inhibited liver tumour progression in WT mice. Hepatic CBX7 deletion restored the progression of LKO liver tumours. MiR-181a expression was the lowest and CBX7 expression the highest in iClust2 and 3 subclasses of human HCC compared to iClust1. Gene expression profiles of GKO tumours overlapped with low-proliferative peri-portal-type HCCs. Liver-specific loss of miR-181ab1 inhibited primary liver tumour progression via up-regulating CBX7 expression, but tumour induction requires both hepatic and non-hepatic miR-181. Also, miR-181ab1-deficient liver tumours may resemble low-proliferative periportal-type human HCC.
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Affiliation(s)
- Jinbiao Chen
- Liver Injury and Cancer Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Yang Zhao
- Vascular Biology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia.,School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, People's Republic of China
| | - Fan Zhang
- UNSW Microbiome Research Centre, School of Clinical Medicine, UNSW Medicine and Health, St George and Sutherland Clinical Campuses, Kogarah, NSW, 2217, Australia
| | - Jia Li
- Vascular Biology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia.,Centre for Motor Neuron Disease, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Jade A Boland
- Liver Injury and Cancer Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Ngan Ching Cheng
- Liver Injury and Cancer Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia.,Vascular Biology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Ken Liu
- Liver Injury and Cancer Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia.,Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW, 2050, Australia
| | - Jessamy C Tiffen
- Melanoma Epigenetics Lab Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Patrick Bertolino
- Liver Immunology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - David G Bowen
- Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW, 2050, Australia.,Liver Immunology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Andreas Krueger
- Molecular Immunology, Faculty of Biology and Chemistry, Justus Liebig University Gießen, Schubertstr 81, 35392, Giessen, Germany.,Institute for Molecular Medicine, Frankfurt Cancer Institute, Goethe-University, Frankfurt, Germany
| | - Leszek Lisowski
- Translational Vectorology Research Unit, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia.,Laboratory of Molecular Oncology and Innovative Therapies, Military Institute of Medicine, Warsaw, Poland
| | - Ian E Alexander
- Gene Therapy Research Unit, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney and Sydney Children's Hospitals Network, Westmead, NSW, 2145, Australia
| | - Mathew A Vadas
- Vascular Biology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Emad El-Omar
- UNSW Microbiome Research Centre, School of Clinical Medicine, UNSW Medicine and Health, St George and Sutherland Clinical Campuses, Kogarah, NSW, 2217, Australia
| | - Jennifer R Gamble
- Vascular Biology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Geoffrey W McCaughan
- Liver Injury and Cancer Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia. .,Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW, 2050, Australia.
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4
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Chen Q, Wang W, Xia MF, Lu YL, Bian H, Yu C, Li XY, Vadas MA, Gao X, Lin HD, Xia P. Identification of circulating sphingosine kinase-related metabolites for prediction of type 2 diabetes. J Transl Med 2021; 19:393. [PMID: 34530846 PMCID: PMC8447705 DOI: 10.1186/s12967-021-03066-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 09/02/2021] [Indexed: 12/23/2022] Open
Abstract
Background Sphingosine Kinase (SphK) that catalyzes sphingosine (Sph) to sphingosine 1-phosphate (S1P), plays a key role in both sphingolipid metabolism and cellular signaling. While SphK has been implicated in type 2 diabetes mellitus (T2DM), it is unexplored in humans. Herein, we investigated whether circulating SphK-related metabolites are associated with T2DM incidence in an established prospective cohort. Methods Levels of SphK-related sphingolipid metabolites, including Sph, S1P, dihydrosphingosine (dhSph) and dihydro-S1P (dhS1P) in serum were measured by targeted-lipidomic analyses. By accessing to an established prospective cohort that involves a total of 2486 non-diabetic adults at baseline, 100 subjects who developed T2DM after a mean follow-up of 4.2-years, along with 100 control subjects matched strictly with age, sex, BMI and fasting glucose, were randomly enrolled for the present study. Results Comparison with the control group, medians of serum dhS1P and dhS1P/dhSph ratio at baseline were elevated significantly prior to the onset of T2DM. Each SD increment of dhS1P and dhS1P/dhSph ratio was associated with 53.5% and 54.1% increased risk of incident diabetes, respectively. The predictive effect of circulating dhS1P and dhS1P/dhSph ratio on T2DM incidence was independent of conventional risk factors in multivariate regression models. Furthermore, combination of serum dhS1P and dhS1P/dhSph ratio with conventional clinical indices significantly improved the accuracy of T2DM prediction (AUROC, 0.726), especially for normoglycemic subjects (AUROC, 0.859). Conclusion Circulating levels of dhS1P and dhS1P/dhSph ratio are strongly associated with increased risk of T2DM, and could serve as a useful biomarker for prediction of incident T2DM in normoglycemic populations.
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Affiliation(s)
- Qi Chen
- Department of Endocrinology and Metabolism, Fudan Institute for Metabolic Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Wei Wang
- Department of Endocrinology and Metabolism, Fudan Institute for Metabolic Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Ming-Feng Xia
- Department of Endocrinology and Metabolism, Fudan Institute for Metabolic Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - You-Li Lu
- Central Laboratory, Xuhui Central Hospital, Shanghai, China
| | - Hua Bian
- Department of Endocrinology and Metabolism, Fudan Institute for Metabolic Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Chen Yu
- Central Laboratory, Xuhui Central Hospital, Shanghai, China
| | - Xiao-Ying Li
- Department of Endocrinology and Metabolism, Fudan Institute for Metabolic Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Mathew A Vadas
- Centenary Institute, The University of Sydney, Sydney, Australia
| | - Xin Gao
- Department of Endocrinology and Metabolism, Fudan Institute for Metabolic Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Huan-Dong Lin
- Department of Endocrinology and Metabolism, Fudan Institute for Metabolic Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
| | - Pu Xia
- Department of Endocrinology and Metabolism, Fudan Institute for Metabolic Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
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Abstract
Cellular senescence is now recognized as one of the hallmarks of aging. Herein, we examine current findings on senescence of the vascular endothelium and its impacts on age-related vascular diseases. Endothelial senescence can result in systemic metabolic changes, implicating senescence in chronic diseases such as diabetes, obesity and atherosclerosis. Senolytics, drugs that eliminate senescent cells, afford new therapeutic strategies for control of these chronic diseases.
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Affiliation(s)
- Ka Ka Ting
- Centre for the Endothelium Vascular Biology Program Centenary Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Paul Coleman
- Centre for the Endothelium Vascular Biology Program Centenary Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Yang Zhao
- Centre for the Endothelium Vascular Biology Program Centenary Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Mathew A Vadas
- Centre for the Endothelium Vascular Biology Program Centenary Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Jennifer R Gamble
- Centre for the Endothelium Vascular Biology Program Centenary Institute, The University of Sydney, Sydney, New South Wales, Australia
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6
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Zhao Y, Li J, Ting KK, Chen J, Coleman P, Liu K, Wan L, Moller T, Vadas MA, Gamble JR. The VE-Cadherin/β-catenin signalling axis regulates immune cell infiltration into tumours. Cancer Lett 2020; 496:1-15. [PMID: 32991950 DOI: 10.1016/j.canlet.2020.09.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/14/2020] [Accepted: 09/24/2020] [Indexed: 12/20/2022]
Abstract
Vascular normalisation, the process that reverses the structural and functional abnormalities seen in tumour-associated vessels, is also accompanied by changes in leucocyte trafficking. Our previous studies have shown the normalisation effects of the agent CD5-2 which acts to stabilise VE-Cadherin leading to increased penetration of CD8+ T cells but decreased infiltration of neutrophils (CD11b+Gr1hi) into tumour parenchyma. In the present study, we demonstrate that VE-Cadherin stabilisation through CD5-2 treatment of purified endothelial cells (ECs) results in a similar leucocyte-selective regulation of transmigration, suggesting the existence of an endothelial specific intrinsic mechanism. Further, we show by RNA sequencing (RNA-seq)-based transcriptomic analysis, that treatment of ECs with CD5-2 regulates chemokines known to be involved in leucocyte transmigration, including upregulation of CCL2 and CXCL10 that facilitate CD8+ T cell transmigration. Both in vitro and in vivo mechanistic studies revealed that the increased CCL2 expression was dependent on expression of VE-Cadherin and downstream activation of the AKT/GSK3β/β-catenin/TCF4 signalling pathway. CD5-2 treatment also contributed to the reorganisation of the cytoskeleton, inducing reorganisation of stress fibres to circumferential actin, which previously has been described as associated with the stabilisation of the endothelial barrier, and amplification of the transcellular migration of CD8+ T cells. Thus, we propose that promotion of endothelial junctional integrity during vascular normalisation not only inhibits vascular leak but also resets the endothelial dependent regulation of immune cell infiltration.
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Affiliation(s)
- Yang Zhao
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, 2050, Australia
| | - Jia Li
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, 2050, Australia
| | - Ka Ka Ting
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, 2050, Australia
| | - Jinbiao Chen
- Liver Injury and Cancer Program, Centenary Institute, The University of Sydney, Sydney, 2050, Australia
| | - Paul Coleman
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, 2050, Australia
| | - Ken Liu
- Liver Injury and Cancer Program, Centenary Institute, The University of Sydney, Sydney, 2050, Australia
| | - Li Wan
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, 2050, Australia
| | | | - Mathew A Vadas
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, 2050, Australia
| | - Jennifer R Gamble
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, 2050, Australia.
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7
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Li J, Zhao Y, Choi J, Ting KK, Coleman P, Chen J, Cogger VC, Wan L, Shi Z, Moller T, Zheng X, Vadas MA, Gamble JR. Targeting miR-27a/VE-cadherin interactions rescues cerebral cavernous malformations in mice. PLoS Biol 2020; 18:e3000734. [PMID: 32502201 PMCID: PMC7299406 DOI: 10.1371/journal.pbio.3000734] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/17/2020] [Accepted: 05/20/2020] [Indexed: 12/13/2022] Open
Abstract
Cerebral cavernous malformations (CCMs) are vascular lesions predominantly developing in the central nervous system (CNS), with no effective treatments other than surgery. Loss-of-function mutation in CCM1/krev interaction trapped 1 (KRIT1), CCM2, or CCM3/programmed cell death 10 (PDCD10) causes lesions that are characterized by abnormal vascular integrity. Vascular endothelial cadherin (VE-cadherin), a major regulator of endothelial cell (EC) junctional integrity is strongly disorganized in ECs lining the CCM lesions. We report here that microRNA-27a (miR-27a), a negative regulator of VE-cadherin, is elevated in ECs isolated from mouse brains developing early CCM lesions and in cultured ECs with CCM1 or CCM2 depletion. Furthermore, we show miR-27a acts downstream of kruppel-like factor (KLF)2 and KLF4, two known key transcription factors involved in CCM lesion development. Using CD5-2 (a target site blocker [TSB]) to prevent the miR-27a/VE-cadherin mRNA interaction, we present a potential therapy to increase VE-cadherin expression and thus rescue the abnormal vascular integrity. In CCM1- or CCM2-depleted ECs, CD5-2 reduces monolayer permeability, and in Ccm1 heterozygous mice, it restores dermal vessel barrier function. In a neonatal mouse model of CCM disease, CD5-2 normalizes vasculature and reduces vascular leakage in the lesions, inhibits the development of large lesions, and significantly reduces the size of established lesions in the hindbrain. Furthermore, CD5-2 limits the accumulation of inflammatory cells in the lesion area. Our work has established that VE-cadherin is a potential therapeutic target for normalization of the vasculature and highlights that targeting miR-27a/VE-cadherin interaction by CD5-2 is a potential novel therapy for the devastating disease, CCM. Cerebral cavernous malformation (CCM) is a disease for which, hitherto, surgery has been the only option. This study shows that a potential therapeutic, CD5-2, inhibits lesion development and vascular leak in the brains of CCM neonatal mice by targeting the endothelial cell–specific adhesion molecule VE-cadherin and restoring the vascular integrity of CCM lesions.
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Affiliation(s)
- Jia Li
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, Australia
- Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
| | - Yang Zhao
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, Australia
| | - Jaesung Choi
- Laboratory of Cardiovascular Signaling, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, Australia
| | - Ka Ka Ting
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, Australia
| | - Paul Coleman
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, Australia
| | - Jinbiao Chen
- Liver Injury and Cancer Program, Centenary Institute, The University of Sydney, Sydney, Australia
| | - Victoria C. Cogger
- Aging and Alzheimers Institute and ANZAC Research Institute and Concord Hospital, Charles Perkins Centre, The University of Sydney, Sydney, Australia
| | - Li Wan
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, Australia
| | - Zhongsong Shi
- Department of Neurosurgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | | | - Xiangjian Zheng
- Laboratory of Cardiovascular Signaling, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, Australia
| | - Mathew A. Vadas
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, Australia
| | - Jennifer R. Gamble
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney, Australia
- * E-mail:
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8
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Coleman PR, Lay AJ, Ting KK, Zhao Y, Li J, Jarrah S, Vadas MA, Gamble JR. YAP and the RhoC regulator ARHGAP18, are required to mediate flow-dependent endothelial cell alignment. Cell Commun Signal 2020; 18:18. [PMID: 32013974 PMCID: PMC6998144 DOI: 10.1186/s12964-020-0511-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 01/04/2020] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Vascular endothelial cell alignment in the direction of flow is an adaptive response that protects against aortic diseases such as atherosclerosis. The RhoGTPases are known to regulate this alignment. We have shown previously that ARHGAP18 in endothelial cells is a negative regulator of RhoC and its expression is essential in flow-mediated alignment. Depletion of ARHGAP18 inhibits alignment and results in the induction of a pro-inflammatory phenotype. In embryogenesis, ARHGAP18 was identified as a downstream effector of the Yes-associated protein, YAP, which regulates cell shape and size. METHODS We have used siRNA technology to deplete either ARHGAP18 or YAP in human endothelial cells. The in vitro studies were performed under athero-protective, laminar flow conditions. The analysis of YAP activity was also investigated, using high performance confocal imaging, in our ARHGAP18 knockout mutant mice. RESULTS We show here that loss of ARHGAP18, although decreasing the expression of YAP results in its nuclear localisation consistent with activation. We further show that depletion of YAP itself results in its activation as defined by an in increase in its nuclear localisation and an increase in the YAP target gene, CyR61. Depletion of YAP, similar to that observed for ARHGAP18 depletion, results in loss of endothelial cell alignment under high shear stress mediated flow and also in the activation of NFkB, as determined by p65 nuclear localisation. In contrast, ARHGAP18 overexpression results in upregulation of YAP, its phosphorylation, and a decrease in the YAP target gene Cyr61, consistent with YAP inactivation. Finally, in ARHGAP18 deleted mice, in regions where there is a loss of endothelial cell alignment, a situation associated with a priming of the cells to a pro-inflammatory phenotype, YAP shows nuclear localisation. CONCLUSION Our results show that YAP is downstream of ARHGAP18 in mature endothelial cells and that this pathway is involved in the athero-protective alignment of endothelial cells under laminar shear stress. ARHGAP18 depletion leads to a disruption of the junctions as seen by loss of VE-Cadherin localisation to these regions and a concomitant localisation of YAP to the nucleus.
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Affiliation(s)
- Paul R Coleman
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Locked Bag 6, Newtown, Sydney, 2042, Australia
| | - Angelina J Lay
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Locked Bag 6, Newtown, Sydney, 2042, Australia
| | - Ka Ka Ting
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Locked Bag 6, Newtown, Sydney, 2042, Australia
| | - Yang Zhao
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Locked Bag 6, Newtown, Sydney, 2042, Australia
| | - Jia Li
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Locked Bag 6, Newtown, Sydney, 2042, Australia
| | - Sorour Jarrah
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Locked Bag 6, Newtown, Sydney, 2042, Australia
| | - Mathew A Vadas
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Locked Bag 6, Newtown, Sydney, 2042, Australia
| | - Jennifer R Gamble
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, The University of Sydney, Locked Bag 6, Newtown, Sydney, 2042, Australia.
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9
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Lay AJ, Coleman PR, Formaz-Preston A, Ting KK, Roediger B, Weninger W, Schwartz MA, Vadas MA, Gamble JR. ARHGAP18: A Flow-Responsive Gene That Regulates Endothelial Cell Alignment and Protects Against Atherosclerosis. J Am Heart Assoc 2020; 8:e010057. [PMID: 30630384 PMCID: PMC6497359 DOI: 10.1161/jaha.118.010057] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background Vascular endothelial cell (EC) alignment in the direction of flow is an adaptive response that protects against aortic diseases, such as atherosclerosis. The Rho GTPases are known to regulate this alignment. Herein, we analyze the effect of ARHGAP18 on the regulation of EC alignment and examine the effect of ARHGAP18 deficiency on the development of atherosclerosis in mice. Methods and Results We used in vitro analysis of ECs under flow conditions together with apolipoprotein E−/−Arhgap18−/− double‐mutant mice to study the function of ARHGAP18 in a high‐fat diet–induced model of atherosclerosis. Depletion of ARHGAP18 inhibited the alignment of ECs in the direction of flow and promoted inflammatory phenotype, as evidenced by disrupted junctions and increased expression of nuclear factor‐κB and intercellular adhesion molecule‐1 and decreased endothelial nitric oxide synthase. Mice with double deletion in ARHGAP18 and apolipoprotein E and fed a high‐fat diet show early onset of atherosclerosis, with lesions developing in atheroprotective regions. Conclusions ARHGAP18 is a protective gene that maintains EC alignments in the direction of flow. Deletion of ARHGAP18 led to loss of EC ability to align and promoted atherosclerosis development.
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Affiliation(s)
- Angelina J Lay
- 1 Vascular Biology Program Centre for the Endothelium Centenary Institute The University of Sydney Newtown Australia
| | - Paul R Coleman
- 1 Vascular Biology Program Centre for the Endothelium Centenary Institute The University of Sydney Newtown Australia
| | - Ann Formaz-Preston
- 1 Vascular Biology Program Centre for the Endothelium Centenary Institute The University of Sydney Newtown Australia
| | - Ka Ka Ting
- 1 Vascular Biology Program Centre for the Endothelium Centenary Institute The University of Sydney Newtown Australia
| | - Ben Roediger
- 2 Immune Imaging Program, Centenary Institute The University of Sydney Newtown Australia
| | - Wolfgang Weninger
- 2 Immune Imaging Program, Centenary Institute The University of Sydney Newtown Australia
| | - Martin A Schwartz
- 3 Department of Internal Medicine Yale Cardiovascular Research Center Yale University New Haven CT
| | - Mathew A Vadas
- 1 Vascular Biology Program Centre for the Endothelium Centenary Institute The University of Sydney Newtown Australia
| | - Jennifer R Gamble
- 1 Vascular Biology Program Centre for the Endothelium Centenary Institute The University of Sydney Newtown Australia
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10
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Li J, Zhao Y, Coleman P, Chen J, Ting KK, Choi JP, Zheng X, Vadas MA, Gamble JR. Low fluid shear stress conditions contribute to activation of cerebral cavernous malformation signalling pathways. Biochim Biophys Acta Mol Basis Dis 2019; 1865:165519. [DOI: 10.1016/j.bbadis.2019.07.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 06/18/2019] [Accepted: 07/27/2019] [Indexed: 02/07/2023]
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11
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Ting KK, Zhao Y, Shen W, Coleman P, Yam M, Chan-Ling T, Li J, Moller T, Gillies M, Vadas MA, Gamble JR. Therapeutic regulation of VE-cadherin with a novel oligonucleotide drug for diabetic eye complications using retinopathy mouse models. Diabetologia 2019; 62:322-334. [PMID: 30443753 DOI: 10.1007/s00125-018-4770-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 10/03/2018] [Indexed: 02/06/2023]
Abstract
AIMS/HYPOTHESIS A major feature of diabetic retinopathy is breakdown of the blood-retinal barrier, resulting in macular oedema. We have developed a novel oligonucleotide-based drug, CD5-2, that specifically increases expression of the key junctional protein involved in barrier integrity in endothelial cells, vascular-endothelial-specific cadherin (VE-cadherin). CD5-2 prevents the mRNA silencing by the pro-angiogenic microRNA, miR-27a. CD5-2 was evaluated in animal models of ocular neovascularisation and vascular leak to determine its potential efficacy for diabetic retinopathy. METHODS CD5-2 was tested in three mouse models of retinal dysfunction: conditional Müller cell depletion, streptozotocin-induced diabetes and oxygen-induced retinopathy. Vascular permeability in the Müller cell-knockout model was assessed by fluorescein angiography. The Evans Blue leakage method was used to determine vascular permeability in streptozotocin- and oxygen-induced retinopathy models. The effects of CD5-2 on retinal neovascularisation, inter-endothelial junctions and pericyte coverage in streptozotocin- and oxygen-induced retinopathy models were determined by staining for isolectin-B4, VE-cadherin and neural/glial antigen 2 (NG2). Blockmir CD5-2 localisation in diseased retina was determined using fluorescent in situ hybridisation. The effects of CD5-2 on VE-cadherin expression and in diabetic retinopathy-associated pathways, such as the transforming growth factor beta (TGF-β) and wingless/integrated (WNT) pathway, were confirmed using western blot of lysates from HUVECs, a mouse brain endothelial cell line and a VE-cadherin null mouse endothelial cell line. RESULTS CD5-2 penetrated the vasculature of the eye in the oxygen-induced retinopathy model. Treatment of diseased mice with CD5-2 resulted in reduced vascular leak in all three animal models, enhanced expression of VE-cadherin in the microvessels of the eye and improved pericyte coverage of the retinal vasculature in streptozotocin-induced diabetic models and oxygen-induced retinopathy models. Further, CD5-2 reduced the activation of retinal microglial cells in the streptozotocin-induced diabetic model. The positive effects of CD5-2 seen in vivo were further confirmed in vitro by increased protein expression of VE-cadherin, SMAD2/3 activity, and platelet-derived growth factor B (PDGF-B). CONCLUSIONS/INTERPRETATION CD5-2 has therapeutic potential for individuals with vascular-leak-associated retinal diseases based on its ease of delivery and its ability to reverse vascular dysfunction and inflammatory aspects in three animal models of retinopathy.
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Affiliation(s)
- Ka Ka Ting
- Centre for the Endothelium Vascular Biology Program Centenary Institute, The University of Sydney, Locked bag #6, Newtown, NSW, 2042, Australia
| | - Yang Zhao
- Centre for the Endothelium Vascular Biology Program Centenary Institute, The University of Sydney, Locked bag #6, Newtown, NSW, 2042, Australia
| | - Weiyong Shen
- Save Sight Institute, The University of Sydney, Sydney, NSW, Australia
| | - Paul Coleman
- Centre for the Endothelium Vascular Biology Program Centenary Institute, The University of Sydney, Locked bag #6, Newtown, NSW, 2042, Australia
| | - Michelle Yam
- Save Sight Institute, The University of Sydney, Sydney, NSW, Australia
| | - Tailoi Chan-Ling
- Discipline of Anatomy and Histology, School of Medical Sciences Bosch Institute, The University of Sydney, Sydney, NSW, Australia
| | - Jia Li
- Centre for the Endothelium Vascular Biology Program Centenary Institute, The University of Sydney, Locked bag #6, Newtown, NSW, 2042, Australia
| | | | - Mark Gillies
- Save Sight Institute, The University of Sydney, Sydney, NSW, Australia
| | - Mathew A Vadas
- Centre for the Endothelium Vascular Biology Program Centenary Institute, The University of Sydney, Locked bag #6, Newtown, NSW, 2042, Australia.
| | - Jennifer R Gamble
- Centre for the Endothelium Vascular Biology Program Centenary Institute, The University of Sydney, Locked bag #6, Newtown, NSW, 2042, Australia.
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12
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Chen J, Qi Y, Zhao Y, Kaczorowski D, Couttas TA, Coleman PR, Don AS, Bertolino P, Gamble JR, Vadas MA, Xia P, McCaughan GW. Deletion of sphingosine kinase 1 inhibits liver tumorigenesis in diethylnitrosamine-treated mice. Oncotarget 2018; 9:15635-15649. [PMID: 29643998 PMCID: PMC5884653 DOI: 10.18632/oncotarget.24583] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 02/21/2018] [Indexed: 12/20/2022] Open
Abstract
Primary liver cancer is the 3rd leading cause of cancer deaths worldwide with very few effective treatments. Sphingosine kinase 1 (SphK1), a key regulator of sphingolipid metabolites, is over-expressed in human hepatocellular carcinoma (HCC) and our previous studies have shown that SphK1 is important in liver injury. We aimed to explore the role of SphK1 specifically in liver tumorigenesis using the SphK1 knockout (SphK1-/-) mouse. SphK1 deletion significantly reduced the number and the size of DEN-induced liver cancers in mice. Mechanistically, fewer proliferating but more apoptotic and senescent cells were detected in SphK1 deficient tumors compared to WT tumors. There was an increase in sphingosine rather than a decrease in sphingosine 1-phosphate (S1P) in SphK1 deficient tumors. Furthermore, the STAT3-S1PR pathway that has been reported previously to mediate the effect of SphK1 on colorectal cancers was not altered by SphK1 deletion in liver cancer. Instead, c-Myc protein expression was down-regulated by SphK1 deletion. In conclusion, this is the first in vivo evidence that SphK1 contributes to hepatocarcinogenesis. However, the downstream signaling pathways impacting on the development of HCC via SphK1 are organ specific providing further evidence that simply transferring known oncogenic molecular pathway targeting into HCC is not always valid.
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Affiliation(s)
- Jinbiao Chen
- Liver Injury and Cancer, Camperdown, NSW 2050, Australia.,Sydney Medical School, University of Sydney, Camperdown, NSW 2050, Australia
| | - Yanfei Qi
- Vascular Biology, Camperdown, NSW 2050, Australia
| | - Yang Zhao
- Vascular Biology, Camperdown, NSW 2050, Australia
| | | | | | | | - Anthony S Don
- ACRF Centenary Cancer Research, Camperdown, NSW 2050, Australia
| | - Patrick Bertolino
- Liver Immunology in Centenary Institute, Camperdown, NSW 2050, Australia
| | | | | | - Pu Xia
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Geoffrey W McCaughan
- Liver Injury and Cancer, Camperdown, NSW 2050, Australia.,A.W. Morrow Gastroenterology and Liver Center, Australian Liver Transplant Unit, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia.,Sydney Medical School, University of Sydney, Camperdown, NSW 2050, Australia
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13
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Liu R, Lo L, Lay AJ, Zhao Y, Ting KK, Robertson EN, Sherrah AG, Jarrah S, Li H, Zhou Z, Hambly BD, Richmond DR, Jeremy RW, Bannon PG, Vadas MA, Gamble JR. ARHGAP18 Protects Against Thoracic Aortic Aneurysm Formation by Mitigating the Synthetic and Proinflammatory Smooth Muscle Cell Phenotype. Circ Res 2017; 121:512-524. [DOI: 10.1161/circresaha.117.310692] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 07/06/2017] [Accepted: 07/11/2017] [Indexed: 12/11/2022]
Abstract
Rationale:
Thoracic aortic aneurysm (TAA) is a potentially lethal condition, which can affect individuals of all ages. TAA may be complicated by the sudden onset of life-threatening dissection or rupture. The underlying mechanisms leading to TAA formation, particularly in the nonsyndromal idiopathic group of patients, are not well understood. Thus, identification of new genes and targets that are involved in TAA pathogenesis are required to help prevent and reverse the disease phenotype.
Objective:
Here we explore the role of ARHGAP18, a novel Rho GAP expressed by smooth muscle cells (SMCs), in the pathogenesis of TAA.
Methods and Results:
Using human and mouse aortic samples, we report that ARHGAP18 levels were significantly reduced in the SMC layer of aortic aneurysms.
Arhgap18
global knockout (
Arhgap18
−/
−
) mice exhibited a highly synthetic, proteolytic, and proinflammatory smooth muscle phenotype under basal conditions and when challenged with angiotensin II, developed TAA with increased frequency and severity compared with littermate controls. Chromatin immunoprecipitation studies revealed this phenotype is partly associated with strong enrichment of H3K4me3 and depletion of H3K27me3 at the
MMP2
and
TNF-α
promoters in
Arhgap18
-deficient SMC. We further show that TAA formation in the
Arhgap18
−/−
mice is associated with loss of Akt activation. The abnormal SMC phenotype observed in the
Arhgap18
−/−
mice can be partially rescued by pharmacological treatment with the mTORC1 inhibitor rapamycin, which reduces the synthetic and proinflammatory phenotype of
Arhgap18
-deficient SMC.
Conclusion:
We have identified
ARHGAP18
as a novel protective gene against TAA formation and define an additional target for the future development of treatments to limit TAA pathogenesis.
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Affiliation(s)
- Renjing Liu
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Lisa Lo
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Angelina J. Lay
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Yang Zhao
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Ka Ka Ting
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Elizabeth N. Robertson
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Andrew G. Sherrah
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Sorour Jarrah
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Haibo Li
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Zhaoxiong Zhou
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Brett D. Hambly
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - David R. Richmond
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Richmond W. Jeremy
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Paul G. Bannon
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Mathew A. Vadas
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
| | - Jennifer R. Gamble
- From the Agnes Ginges Laboratory for Diseases of the Aorta, Vascular Biology Program (R.L., L.L., H.L.) and Centre for the Endothelium, Vascular Biology Program (A.J.L., Y.Z., K.K.T., S.J., Z.Z., M.A.V., J.R.G.), Centenary Institute, Camperdown, New South Wales, Australia; Discipline of Pathology and Bosch Institute, Charles Perkins Center (E.N.R., B.D.H.) and Sydney Medical School (R.L., E.N.R., R.W.J., P.G.B., M.A.V., J.R.G.), University of Sydney, New South Wales, Australia; The Baird Institute
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Zhao Y, Ting KK, Li J, Cogger VC, Chen J, Johansson-Percival A, Ngiow SF, Holst J, Grau G, Goel S, Muller T, Dejana E, McCaughan G, Smyth MJ, Ganss R, Vadas MA, Gamble JR. Targeting Vascular Endothelial-Cadherin in Tumor-Associated Blood Vessels Promotes T-cell–Mediated Immunotherapy. Cancer Res 2017; 77:4434-4447. [DOI: 10.1158/0008-5472.can-16-3129] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/12/2017] [Accepted: 06/14/2017] [Indexed: 11/16/2022]
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15
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Lovelace MD, Powter EE, Coleman PR, Zhao Y, Parker A, Chang GH, Lay AJ, Hunter J, McGrath AP, Jormakka M, Bertolino P, McCaughan G, Kavallaris M, Vadas MA, Gamble JR. The RhoGAP protein ARHGAP18/SENEX localizes to microtubules and regulates their stability in endothelial cells. Mol Biol Cell 2017; 28:1066-1078. [PMID: 28251925 PMCID: PMC5391183 DOI: 10.1091/mbc.e16-05-0285] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 02/10/2017] [Accepted: 02/17/2017] [Indexed: 11/17/2022] Open
Abstract
Localization of a regulator of RhoGTPases (ARHGAP18) is important for microtubule stability and endothelial cell function. The localization is demonstrated by advanced imaging and biochemical techniques. RhoGTPases are important regulators of the cell cytoskeleton, controlling cell shape, migration and proliferation. Previously we showed that ARHGAP18 in endothelial cells is important in cell junctions. Here we show, using structured illumination microscopy (SIM), ground-state depletion (GSD), and total internal reflection fluorescence microscopy (TIRF) that a proportion of ARHGAP18 localizes to microtubules in endothelial cells, as well as in nonendothelial cells, an association confirmed biochemically. In endothelial cells, some ARHGAP18 puncta also colocalized to Weibel–Palade bodies on the microtubules. Depletion of ARHGAP18 by small interfering RNA or analysis of endothelial cells isolated from ARHGAP18-knockout mice showed microtubule destabilization, as evidenced by altered morphology and decreased acetylated α-tubulin and glu-tubulin. The destabilization was rescued by inhibition of ROCK and histone deacetylase 6 but not by a GAP-mutant form of ARHGAP18. Depletion of ARHGAP18 resulted in a failure to secrete endothelin-1 and a reduction in neutrophil transmigration, both known to be microtubule dependent. Thrombin, a critical regulator of the Rho-mediated barrier function of endothelial cells through microtubule destabilization, enhanced the plasma membrane–bound fraction of ARHGAP18. Thus, in endothelial cells, ARHGAP18 may act as a significant regulator of vascular homeostasis.
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Affiliation(s)
- Michael D Lovelace
- Centre for the Endothelium, Vascular Biology Program, University of Sydney, Sydney, NSW 2050, Australia
| | - Elizabeth E Powter
- Centre for the Endothelium, Vascular Biology Program, University of Sydney, Sydney, NSW 2050, Australia
| | - Paul R Coleman
- Centre for the Endothelium, Vascular Biology Program, University of Sydney, Sydney, NSW 2050, Australia
| | - Yang Zhao
- Centre for the Endothelium, Vascular Biology Program, University of Sydney, Sydney, NSW 2050, Australia
| | - Amelia Parker
- Tumour Biology and Targeting Program, Children's Cancer Institute, Lowy Cancer Research Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Garry H Chang
- Centre for the Endothelium, Vascular Biology Program, University of Sydney, Sydney, NSW 2050, Australia
| | - Angelina J Lay
- Centre for the Endothelium, Vascular Biology Program, University of Sydney, Sydney, NSW 2050, Australia
| | - Julie Hunter
- Centre for the Endothelium, Vascular Biology Program, University of Sydney, Sydney, NSW 2050, Australia
| | - Aaron P McGrath
- Structural Biology Laboratory, University of Sydney, Sydney, NSW 2050, Australia
| | - Mika Jormakka
- Structural Biology Laboratory, University of Sydney, Sydney, NSW 2050, Australia
| | - Patrick Bertolino
- Liver Immunology Laboratory, University of Sydney, Sydney, NSW 2050, Australia
| | - Geoffrey McCaughan
- Liver Biology and Cancer Laboratory, Centenary Institute, University of Sydney, Sydney, NSW 2050, Australia
| | - Maria Kavallaris
- Tumour Biology and Targeting Program, Children's Cancer Institute, Lowy Cancer Research Centre, University of New South Wales, Sydney, NSW 2052, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and Australian Centre for NanoMedicine, University of New South Wales, Sydney, NSW 2052, Australia
| | - Mathew A Vadas
- Centre for the Endothelium, Vascular Biology Program, University of Sydney, Sydney, NSW 2050, Australia
| | - Jennifer R Gamble
- Centre for the Endothelium, Vascular Biology Program, University of Sydney, Sydney, NSW 2050, Australia
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16
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Li J, Zhao Y, Lu Y, Ritchie W, Grau G, Vadas MA, Gamble JR. The Poly-cistronic miR-23-27-24 Complexes Target Endothelial Cell Junctions: Differential Functional and Molecular Effects of miR-23a and miR-23b. Mol Ther Nucleic Acids 2016; 5:e354. [PMID: 27741223 PMCID: PMC5023406 DOI: 10.1038/mtna.2016.62] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/20/2016] [Indexed: 01/09/2023]
Abstract
The regulation of function of endothelial cell-cell junctions is fundamental in sustaining vascular integrity. The polycistronic microRNA (miR) complexes containing miR-23a-27a-24-2, and 23b-27b-24-1 are predicted to target the majority of major endothelial junctional proteins. We focus on miR-23a and miR-23b, and investigate the functional effects of these miRs on junctions. While miR-23a and 23b only differ by 1 nucleotide (g19) outside the seed region and thus are predicted to have the same targets, they function differently with miR-23a inhibiting permeability and miR-23b inhibiting angiogenesis. Both miRs target the junctional attractive molecule (tight junction protein 2) ZO-2 and the repulsive molecule junctional adhesion molecule C (JAM-C), although the inhibition of JAM-C by miR-23a is more profound than by miR-23b. The difference in potency is attributable to differences at g19 since a mutation of the t17, the g19 binding site of miR-23b in the 3'UTR of JAM-C restores identity. We also show that the pattern of expression of miR-23a and miR-23b and their targets are different. Thus, the paralogues miR-23a and miR-23b can have profoundly different effects on endothelial cell function due at least partially to selective effects on target proteins and differences in expression patterns of the miRs. This work exposes a hitherto unappreciated complexity in therapeutically targeting miRs.
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Affiliation(s)
- Jia Li
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, University of Sydney, Sydney, Australia
| | - Yang Zhao
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, University of Sydney, Sydney, Australia
| | - Ying Lu
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, University of Sydney, Sydney, Australia
| | - William Ritchie
- Bioinformatics Laboratory, Centenary Institute, University of Sydney, Sydney, Australia
| | - Georges Grau
- Department of Pathology, Faculty of Medicine, School of Medical Sciences, University of Sydney, Sydney, Australia
| | - Mathew A Vadas
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, University of Sydney, Sydney, Australia
| | - Jennifer R Gamble
- Centre for the Endothelium, Vascular Biology Program, Centenary Institute, University of Sydney, Sydney, Australia
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17
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Chen J, Wang W, Qi Y, Kaczorowski D, McCaughan GW, Gamble JR, Don AS, Gao X, Vadas MA, Xia P. Deletion of sphingosine kinase 1 ameliorates hepatic steatosis in diet-induced obese mice: Role of PPARγ. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1861:138-147. [PMID: 26615875 DOI: 10.1016/j.bbalip.2015.11.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 10/03/2015] [Accepted: 11/09/2015] [Indexed: 12/19/2022]
Abstract
Sphingolipid metabolites have emerged playing important roles in the pathogenesis of nonalcoholic fatty liver disease, whereas the underlying mechanism remains largely unknown. In the present study, we provide both in vitro and in vivo evidence showing a pathogenic role of sphingosine kinase 1 (SphK1) in hepatocellular steatosis. We found that levels of SphK1 expression were significantly increased in steatotic hepatocytes. Enforced overexpression of SphK1 or treatment with sphingosine 1-phosphate (S1P) markedly enhanced hepatic lipid accumulation. In contrast, the siRNA-mediated knockdown of SphK1 or S1P receptors, S1P2 and S1P3, profoundly inhibited lipid accumulation in hepatocytes. Moreover, Sphk1(-/-) mice exhibited a significant amelioration of hepatosteatosis under diet-induced obese (DIO) conditions, compared to wild-type littermates. In addition, DIO-induced up-regulation of PPARγ and its target genes were significantly reduced by SphK1 deficiency. Furthermore, treatment of hepatocytes with S1P induces a dose-dependent increase in PPARγ expression at the transcriptional level. Blockage of S1P receptors and the Akt-mTOR signaling profoundly inhibited S1P-induced PPARγ expression. Notably, down-regulation of PPARγ by using its siRNA significantly diminished the pro-steatotic effect of SphK1/S1P. Thus, the study demonstrates a new pathway connecting SphK1 and PPARγ involved in the pathogenesis of hepatocellular steatosis.
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Affiliation(s)
- Jinbiao Chen
- Centenary Institute, The University of Sydney, Sydney, Australia
| | - Wei Wang
- Department of Endocrinology and Metabolism, Zhongshan Hospital, and Institute of Chronic Metabolic Diseases, Fudan University, Shanghai, China
| | - Yanfei Qi
- Centenary Institute, The University of Sydney, Sydney, Australia
| | | | | | | | - Anthony S Don
- Lowy Cancer Research Centre and Prince of Wales Clinical School, University of New South Wales, Sydney, Australia
| | - Xin Gao
- Department of Endocrinology and Metabolism, Zhongshan Hospital, and Institute of Chronic Metabolic Diseases, Fudan University, Shanghai, China
| | - Mathew A Vadas
- Centenary Institute, The University of Sydney, Sydney, Australia
| | - Pu Xia
- Centenary Institute, The University of Sydney, Sydney, Australia; Department of Endocrinology and Metabolism, Zhongshan Hospital, and Institute of Chronic Metabolic Diseases, Fudan University, Shanghai, China.
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18
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Chang GHK, Lay AJ, Ting KK, Zhao Y, Coleman PR, Powter EE, Formaz-Preston A, Jolly CJ, Bower NI, Hogan BM, Rinkwitz S, Becker TS, Vadas MA, Gamble JR. ARHGAP18: an endogenous inhibitor of angiogenesis, limiting tip formation and stabilizing junctions. Small GTPases 2015; 5:1-15. [PMID: 25425145 DOI: 10.4161/21541248.2014.975002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The formation of the vascular network requires a tightly controlled balance of pro-angiogenic and stabilizing signals. Perturbation of this balance can result in dysregulated blood vessel morphogenesis and drive pathologies including cancer. Here, we have identified a novel gene, ARHGAP18, as an endogenous negative regulator of angiogenesis, limiting pro-angiogenic signaling and promoting vascular stability. Loss of ARHGAP18 promotes EC hypersprouting during zebrafish and murine retinal vessel development and enhances tumor vascularization and growth. Endogenous ARHGAP18 acts specifically on RhoC and relocalizes to the angiogenic and destabilized EC junctions in a ROCK dependent manner, where it is important in reaffirming stable EC junctions and suppressing tip cell behavior, at least partially through regulation of tip cell genes, Dll4, Flk-1 and Flt-4. These findings highlight ARHGAP18 as a specific RhoGAP to fine tune vascular morphogenesis, limiting tip cell formation and promoting junctional integrity to stabilize the angiogenic architecture.
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Key Words
- AJ, Adherens junctions
- ARHGAP18
- DLL4, Delta-like ligand 4
- EC, Endothelial cell
- GAP, GTPase activating protein
- GDI, Guanine nucleotide dissociation inhibitor
- GEF, Guanine nucleotide exchange factor
- HUVEC, Human umbilical vein endothelial cell
- ISV, Intersegmental vessel
- MO, Morpholino
- SC, Stalk cell
- SENEX
- Sp, Splice
- TC, Tip cell
- Tr, Translational
- WT, Wildtype
- angiogenesis
- cell junctions
- hpf, Hours post fertilization
- sprouting
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Affiliation(s)
- Garry H K Chang
- a Centre for the Endothelium; Vascular Biology Program; Centenary Institute ; Newtown , NSW , Australia
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Powter EE, Coleman PR, Tran MH, Lay AJ, Bertolino P, Parton RG, Vadas MA, Gamble JR. Caveolae control the anti-inflammatory phenotype of senescent endothelial cells. Aging Cell 2015; 14:102-11. [PMID: 25407919 PMCID: PMC4326911 DOI: 10.1111/acel.12270] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2014] [Indexed: 02/03/2023] Open
Abstract
Senescent endothelial cells (EC) have been identified in cardiovascular disease, in angiogenic tumour associated vessels and in aged individuals. We have previously identified a novel anti-inflammatory senescent phenotype of EC. We show here that caveolae are critical in the induction of this anti-inflammatory senescent state. Senescent EC induced by either the overexpression of ARHGAP18/SENEX or by H₂O₂ showed significantly increased numbers of caveolae and associated proteins Caveolin-1, cavin-1 and cavin-2. Depletion of these proteins by RNA interference decreased senescence induced by ARHGAP18 and by H₂O₂. ARHGAP18 overexpression induced a predominantly anti-inflammatory senescent population and depletion of the caveolae-associated proteins resulted in the preferential reduction in this senescent population as measured by neutrophil adhesion and adhesion protein expression after TNFα treatment. In confirmation, EC isolated from the aortas of CAV-1(-/-) mice failed to induce this anti-inflammatory senescent cell population upon expression of ARHGAP18, whereas EC from wild-type mice showed a significant increase. NF-κB is one of the major transcription factors mediating the induction of E-selectin and VCAM-1 expression, adhesion molecules responsible for leucocyte attachment to EC. TNFα-induced activation of NF-κB was suppressed in ARHGAP18-induced senescent EC, and this inhibition was reversed by Caveolin-1 knock-down. Thus, out results demonstrate that an increase in caveolae and its component proteins in senescent ECs is associated with inhibition of the NF-kB signalling pathway and promotion of the anti-inflammatory senescent pathway.
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Affiliation(s)
- Elizabeth E. Powter
- Centre for the Endothelium Vascular Biology Program Centenary Institute Sydney Australia
- The University of Sydney NSW 2006Australia
| | - Paul R. Coleman
- Centre for the Endothelium Vascular Biology Program Centenary Institute Sydney Australia
- The University of Sydney NSW 2006Australia
| | - Mai H. Tran
- Centre for the Endothelium Vascular Biology Program Centenary Institute Sydney Australia
- The University of Sydney NSW 2006Australia
| | - Angelina J. Lay
- Centre for the Endothelium Vascular Biology Program Centenary Institute Sydney Australia
- The University of Sydney NSW 2006Australia
| | - Patrick Bertolino
- Liver Immunology Group Centenary Institute Sydney Australia
- The University of Sydney NSW 2006Australia
| | - Robert G. Parton
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis The University of Queensland University of St. Lucia Qld 4072Australia
| | - Mathew A. Vadas
- Centre for the Endothelium Vascular Biology Program Centenary Institute Sydney Australia
- The University of Sydney NSW 2006Australia
| | - Jennifer R. Gamble
- Centre for the Endothelium Vascular Biology Program Centenary Institute Sydney Australia
- The University of Sydney NSW 2006Australia
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20
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Shackel NA, Vadas MA, Gamble JR, McCaughan GW. Beyond liver fibrosis: hepatic stellate cell senescence links obesity to liver cancer by way of the microbiome. Hepatology 2014; 59:2413-5. [PMID: 24273014 DOI: 10.1002/hep.26932] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 10/17/2013] [Accepted: 11/11/2013] [Indexed: 02/03/2023]
Affiliation(s)
- Nicholas A Shackel
- Liver Injury and Cancer Group, Centenary Institute, Sydney, NSW, Australia; A.W. Morrow Gastroenterology and Liver Centre, Royal Prince Alfred Hospital, Sydney, NSW, Australia
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21
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Lichtenstein I, Charleston MA, Caetano TS, Gamble JR, Vadas MA. Active subnetwork recovery with a mechanism-dependent scoring function; with application to angiogenesis and organogenesis studies. BMC Bioinformatics 2013; 14:59. [PMID: 23432934 PMCID: PMC3663784 DOI: 10.1186/1471-2105-14-59] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Accepted: 01/21/2013] [Indexed: 11/10/2022] Open
Abstract
Background The learning active subnetworks problem involves finding subnetworks of a bio-molecular network that are active in a particular condition. Many approaches integrate observation data (e.g., gene expression) with the network topology to find candidate subnetworks. Increasingly, pathway databases contain additional annotation information that can be mined to improve prediction accuracy, e.g., interaction mechanism (e.g., transcription, microRNA, cleavage) annotations. We introduce a mechanism-based approach to active subnetwork recovery which exploits such annotations. We suggest that neighboring interactions in a network tend to be co-activated in a way that depends on the “correlation” of their mechanism annotations. e.g., neighboring phosphorylation and de-phosphorylation interactions may be more likely to be co-activated than neighboring phosphorylation and covalent bonding interactions. Results Our method iteratively learns the mechanism correlations and finds the most likely active subnetwork. We use a probabilistic graphical model with a Markov Random Field component which creates dependencies between the states (active or non-active) of neighboring interactions, that incorporates a mechanism-based component to the function. We apply a heuristic-based EM-based algorithm suitable for the problem. We validated our method’s performance using simulated data in networks downloaded from GeneGO against the same approach without the mechanism-based component, and two other existing methods. We validated our methods performance in correctly recovering (1) the true interaction states, and (2) global network properties of the original network against these other methods. We applied our method to networks generated from time-course gene expression studies in angiogenesis and lung organogenesis and validated the findings from a biological perspective against current literature. Conclusions The advantage of our mechanism-based approach is best seen in networks composed of connected regions with a large number of interactions annotated with a subset of mechanisms, e.g., a regulatory region of transcription interactions, or a cleavage cascade region. When applied to real datasets, our method recovered novel and biologically meaningful putative interactions, e.g., interactions from an integrin signaling pathway using the angiogenesis dataset, and a group of regulatory microRNA interactions in an organogenesis network.
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Affiliation(s)
- Ilana Lichtenstein
- School of Information Technologies, University of Sydney, Sydney, NSW 2006, Australia.
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22
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Xia P, Wang L, Moretti PA, Albanese N, Chai F, Pitson SM, D'Andrea RJ, Gamble JR, Vadas MA. Sphingosine kinase interacts with TRAF2 and dissects tumor necrosis factor-α signaling. J Biol Chem 2011. [DOI: 10.1074/jbc.a111.111423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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23
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Xia P, Wang L, Moretti PA, Albanese N, Chai F, Pitson SM, D'Andrea RJ, Gamble JR, Vadas MA. Sphingosine kinase interacts with TRAF2 and dissects tumor necrosis factor-α signaling. J Biol Chem 2011. [DOI: 10.1074/jbc.a110.111423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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24
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Williams SL, Milne IR, Bagley CJ, Gamble JR, Vadas MA, Pitson SM, Khew-Goodall Y. A proinflammatory role for proteolytically cleaved annexin A1 in neutrophil transendothelial migration. J Immunol 2010; 185:3057-63. [PMID: 20679535 DOI: 10.4049/jimmunol.1000119] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Neutrophil extravasation, a critical component of innate immunity must be tightly regulated to prevent inadvertent or prolonged inflammation and subsequent tissue damage. We have shown previously that endothelial ERK1/2 signaling essential for neutrophil transendothelial migration is induced by a soluble factor produced by activated neutrophils. In this study, we demonstrate that the soluble neutrophil factor is a truncated form of annexin A1 (AnxA1) that can be generated by calpain 1 cleavage of the N terminus, thus identifying a novel proinflammatory function to AnxA1. In contrast, neither the full-length protein nor the N-terminal 26 aa peptide, previously shown to be antiinflammatory, were able to activate Erk. Our data suggest that two different fragments of AnxA1 have opposing functions in inflammation. We also provide evidence that C-terminal AnxA1 functions by increasing ICAM1 clustering around adherent neutrophils to anchor them to the endothelium and promote transmigration through the transcellular route.
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Affiliation(s)
- Samantha L Williams
- Division of Human Immunology, Centre for Cancer Biology, SA Pathology, Adelaide, South Australia, Australia
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25
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Gamble JR, Sun WY, Li X, Hahn CN, Pitson SM, Vadas MA, Bonder CS. Sphingosine kinase-1 associates with integrin {alpha}V{beta}3 to mediate endothelial cell survival. Am J Pathol 2009; 175:2217-25. [PMID: 19815712 DOI: 10.2353/ajpath.2009.090076] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Sphingosine kinase (SK)-1 promotes endothelial cell (EC) survival through the cell junction molecule CD31 (platelet endothelial cell adhesion molecule-1). The integrin alpha(v)beta(3) is also essential for EC survival; inhibition of alpha(v)beta(3) ligation promotes apoptosis. Herein we demonstrate that under basal conditions, SK-1, alpha(v)beta(3), and CD31 exist as a heterotrimeric complex. Under conditions that affect EC survival such as loss of contact with the extracellular matrix or growth factor activation, more of this heterotrimeric complex forms. Overexpression studies demonstrate a requirement for SK-1 phosphorylation at serine 225 for increased heterotrimeric complex formation, activation of alpha(v)beta(3), and EC survival signals, including Bcl-X and nuclear factor-kappaB pathways. Moreover, beta(3) integrin depletion confirmed the requirement for this heterotrimeric complex in SK-1-mediated EC survival. Thus, with alpha(v)beta(3) integrin being identifiable primarily on angiogenic ECs and SK-1 being highly expressed in tumors, targeting SK-1 may affect multiple survival pathways, and its inhibition may be highly efficacious in controlling pathological EC survival.
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Affiliation(s)
- Jennifer R Gamble
- Centenary Institute for Cancer Medicine and Cell Biology, University of Sydney, Australia
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26
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Sukocheva O, Wang L, Verrier E, Vadas MA, Xia P. Restoring endocrine response in breast cancer cells by inhibition of the sphingosine kinase-1 signaling pathway. Endocrinology 2009; 150:4484-92. [PMID: 19706837 DOI: 10.1210/en.2009-0391] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We previously demonstrated that sphingosine kinase-1 (SphK1) is an important mediator in the cytoplasmic signaling of estrogens, including Ca(2+) mobilization, ERK1/2 activation, and the epidermal growth factor receptor transactivation. Here we report for the first time that SphK1 activity is causally associated with endocrine resistance in MCF-7 human breast cancer cells. Enforced overexpression of human SphK1 in MCF-7 cells resulted in enhanced cell proliferation and resistance to tamoxifen-induced cell growth arrest and apoptosis. Tamoxifen-resistant (TamR) MCF-7 cells selected by prolonged exposure to 4-hydroxytamoxifen, exhibited higher levels in SphK1 expression and activity, compared with the control cells. Inhibition of SphK1 activity by either specific pharmaceutical inhibitors or the dominant-negative mutant SphK1(G82D) restored the antiproliferative and proapoptotic effects of tamoxifen in the TamR cells. Furthermore, silencing of SphK1, but not SphK2, expression by the specific small interference RNA also restored the tamoxifen responsiveness in the TamR cells. Thus, blockade of the SphK1 signaling pathway may reprogram cellular responsiveness to tamoxifen and abrogate antiestrogen resistance in human breast cancer cells.
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Affiliation(s)
- Olga Sukocheva
- Signal Transduction Laboratory, Centenary Institute, Newtown, New South Wales 2042, Australia
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27
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Li X, Stankovic M, Lee BPL, Aurrand-Lions M, Hahn CN, Lu Y, Imhof BA, Vadas MA, Gamble JR. JAM-C induces endothelial cell permeability through its association and regulation of {beta}3 integrins. Arterioscler Thromb Vasc Biol 2009; 29:1200-6. [PMID: 19461049 DOI: 10.1161/atvbaha.109.189217] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE The molecular mechanisms regulating vascular permeability are only now being elucidated. The junctional adhesion molecule (JAM) JAM-C has been linked to the induction of vascular permeability. We sought to understand the mechanism whereby JAM-C may disrupt junctional integrity in endothelial cells (ECs). METHODS AND RESULTS We show here that JAM-C alters permeability through modulation of integrin activity. JAM-C overexpression results in an increase in JAM-C at junctions and an increase in permeability. Conversely, knockdown of JAM-C by siRNA results in a reduction in permeability. JAM-C associates with alphavbeta3 integrin and regulates its localization and activity. JAM-C also inhibits the activation state of the beta(1) integrin although it does not associate with this integrin. These changes induced on the integrins are mediated through regulation of the small GTPase, Rap1b but not Rap1a. Thrombin, a powerful inductor of vascular leak, causes localization of JAM-C into the junctions, whereas angiopoietin-1, an inhibitor of permeability, prevents JAM-C translocation. CONCLUSIONS The regulation of EC junctional integrity involves the coordinated and dynamic modification of localization and activity of junctional stabilizers such as the integrin beta(3) and the destabilizer, JAM-C.
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Affiliation(s)
- Xiaochun Li
- Centenary Institute of Cancer Medicine and Cell Biology, Locked bag#6, Newtown, NSW, Australia
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28
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Affiliation(s)
- Jennifer R Gamble
- Vascular Biology Program, Centenary Institute, University of Sydney, New South Wales, Australia
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29
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Zebol JR, Hewitt NM, Moretti PAB, Lynn HE, Lake JA, Li P, Vadas MA, Wattenberg BW, Pitson SM. The CCT/TRiC chaperonin is required for maturation of sphingosine kinase 1. Int J Biochem Cell Biol 2008; 41:822-7. [PMID: 18775504 DOI: 10.1016/j.biocel.2008.08.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 08/07/2008] [Accepted: 08/11/2008] [Indexed: 11/17/2022]
Abstract
Sphingosine kinase 1 (SK1) catalyses the generation of sphingosine 1-phosphate (S1P), a bioactive phospholipid that influences a diverse range of cellular processes, including proliferation, survival, adhesion, migration, morphogenesis and differentiation. SK1 is controlled by various mechanisms, including transcriptional regulation, and post-translational activation by phosphorylation and protein-protein interactions which can regulate both the activity and localisation of this enzyme. To gain a better understanding of the regulatory mechanisms controlling SK1 activity and function we performed a yeast two-hybrid screen to identify SK1-interacting proteins. Using this approach we identified that SK1 interacts with subunit 7 (eta) of cytosolic chaperonin CCT (chaperonin containing t-complex polypeptide, also called TRiC for TCP-1 ring complex), a hexadecameric chaperonin that binds unfolded polypeptides and mediates their folding and release in an ATP-dependent manner. Further analysis of the SK1-CCTeta interaction demonstrated that other CCT/TRiC subunits also associated with SK1 in HEK293T cell lysates in an ATP-sensitive manner, suggesting that the intact, functional, multimeric CCT/TRiC complex associated with SK1. Furthermore, pulse-chase studies indicated that CCT/TRiC binds specifically to newly translated SK1. Finally, depletion of functional CCT/TRiC through the use of RNA interference in HeLa cells or temperature sensitive CCT yeast mutants reduced cellular SK1 activity. Thus, combined this data suggests that SK1 is a CCT/TRiC substrate, and that this chaperonin facilitates folding of newly translated SK1 into its mature active form.
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Affiliation(s)
- Julia R Zebol
- Hanson Institute, Division of Human Immunology, Institute of Medical and Veterinary Science, Frome Road, Adelaide, SA 5000, Australia
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30
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Leclercq TM, Moretti PAB, Vadas MA, Pitson SM. Eukaryotic elongation factor 1A interacts with sphingosine kinase and directly enhances its catalytic activity. J Biol Chem 2008; 283:9606-14. [PMID: 18263879 PMCID: PMC2442288 DOI: 10.1074/jbc.m708782200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Revised: 01/23/2008] [Indexed: 01/07/2023] Open
Abstract
Sphingosine 1-phosphate (S1P) has many important roles in mammalian cells, including contributing to the control of cell survival and proliferation. S1P is generated by sphingosine kinases (SKs), of which two mammalian isoforms have been identified (SK1 and SK2). To gain a better understanding of SK regulation, we have used a yeast two-hybrid screen to identify SK1-interacting proteins and established elongation factor 1A (eEF1A) as one such protein that associates with both SK1 and SK2. We show the direct interaction of eEF1A with the SKs in vitro, whereas the physiological relevance of this association was demonstrated by co-immunoprecipitation of the endogenous proteins from cell lysates. Although the canonical role of eEF1A resides in protein synthesis, it has also been implicated in other roles, including regulating the activity of some signaling enzymes. Thus, we examined the potential role of eEF1A in regulation of the SKs and show that eEF1A is able to directly increase the activity of SK1 and SK2 approximately 3-fold in vitro. Substrate kinetics demonstrated that eEF1A increased the catalytic rate of both SKs, while having no observable effect on substrate affinities of these enzymes for either ATP or sphingosine. Overexpression of eEF1A in quiescent Chinese hamster ovary cells increased cellular SK activity, whereas a small interfering RNA-mediated decrease in eEF1A levels in MCF7 cells substantially reduced cellular SK activity and S1P levels, supporting the in vivo physiological relevance of this interaction. Thus, this study has established a novel mechanism of regulation of both SK1 and SK2 that is mediated by their interaction with eEF1A.
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Affiliation(s)
- Tamara M Leclercq
- Hanson Institute, Division of Human Immunology, Institute of Medical and Veterinary Science, Frome Road, Adelaide, South Australia 5000, Australia
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31
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Gregory PA, Bert AG, Paterson EL, Barry SC, Tsykin A, Farshid G, Vadas MA, Khew-Goodall Y, Goodall GJ. The miR-200 family and miR-205 regulate epithelial to mesenchymal transition by targeting ZEB1 and SIP1. Nat Cell Biol 2008; 10:593-601. [PMID: 18376396 DOI: 10.1038/ncb1722] [Citation(s) in RCA: 2984] [Impact Index Per Article: 186.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 03/10/2008] [Indexed: 11/09/2022]
Abstract
Epithelial to mesenchymal transition (EMT) facilitates tissue remodelling during embryonic development and is viewed as an essential early step in tumour metastasis. We found that all five members of the microRNA-200 family (miR-200a, miR-200b, miR-200c, miR-141 and miR-429) and miR-205 were markedly downregulated in cells that had undergone EMT in response to transforming growth factor (TGF)-beta or to ectopic expression of the protein tyrosine phosphatase Pez. Enforced expression of the miR-200 family alone was sufficient to prevent TGF-beta-induced EMT. Together, these microRNAs cooperatively regulate expression of the E-cadherin transcriptional repressors ZEB1 (also known as deltaEF1) and SIP1 (also known as ZEB2), factors previously implicated in EMT and tumour metastasis. Inhibition of the microRNAs was sufficient to induce EMT in a process requiring upregulation of ZEB1 and/or SIP1. Conversely, ectopic expression of these microRNAs in mesenchymal cells initiated mesenchymal to epithelial transition (MET). Consistent with their role in regulating EMT, expression of these microRNAs was found to be lost in invasive breast cancer cell lines with mesenchymal phenotype. Expression of the miR-200 family was also lost in regions of metaplastic breast cancer specimens lacking E-cadherin. These data suggest that downregulation of the microRNAs may be an important step in tumour progression.
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Affiliation(s)
- Philip A Gregory
- Hanson Institute and Division of Human Immunology, Institute of Medical and Veterinary Science, Adelaide, SA 5000, Australia
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32
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Hahn CN, Su ZJ, Vadas MA, Gamble JR. Angiogenesis, VasGAP and the actin cytoskeleton. Vascul Pharmacol 2006. [DOI: 10.1016/j.vph.2006.08.311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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33
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Abstract
Dicistronic reporter plasmids, such as the dual luciferase-containing pR-F plasmid, have been widely used to assay cellular and viral 5' untranslated regions (UTRs) for IRES activity. We found that the pR-F dicistronic reporter containing the 5' UTRs from HIF-1alpha, VEGF, c-myc, XIAP, VEGFR-1, or Egr-1 UTRs all produce the downstream luciferase predominantly as a result of cryptic promoter activity that is activated by the SV40 enhancer elements in the plasmid. RNA transfection experiments using dicistronic or uncapped RNAs, which avoid the complication of cryptic promoter activity, indicate that the HIF-1alpha, VEGF, c-myc, and XIAP UTRs do have some IRES activity, although the activity was much less than that of the viral EMCV IRES. The translation of transfected monocistronic RNAs containing these cellular UTRs was greatly enhanced by the presence of a 5' cap, raising questions as to the strength or mechanism of IRES-mediated translation in these assays.
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Affiliation(s)
- Andrew G Bert
- Division of Human Immunology, Hanson Institute, Institute of Medical and Veterinary Science (IMVS), Adelaide, SA, Australia
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34
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Gamble JR, Xia P, Hahn CN, Drew JJ, Drogemuller CJ, Brown D, Vadas MA. Phenoxodiol, an experimental anticancer drug, shows potent antiangiogenic properties in addition to its antitumour effects. Int J Cancer 2006; 118:2412-20. [PMID: 16353157 DOI: 10.1002/ijc.21682] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Phenoxodiol (2H-1-benzopyran-7-0,1, 3-[4-hydroxyphenyl], PXD) is a synthetic analogue of the naturally-occurring plant isoflavone and anticancer agent, genistein. PXD directly induces mitotic arrest and apoptosis in most cancer cells and is currently undergoing clinical trials, as a chemotherapeutic in ovarian and prostate cancers. We show here that PXD also exhibits potent antiangiogenic properties. Thus, it inhibited endothelial cell proliferation, migration and capillary tube formation and inhibited expression of the matrix metalloproteinase MMP-2, a major matrix degrading enzyme. Importantly, we demonstrate that PXD is functional in vivo since it inhibited the extent of capillary tube invasion in an in vivo model of angiogenesis. We show that phenoxodiol inhibits hallmarks of endothelial cell activation, namely TNF or IL-1 induced E-selectin and VCAM-1 expression and IL-8 secretion. However, PXD had no effect on unstimulated endothelial cells. We also describe that PXD inhibits the lipid kinase sphingosine kinase, which recently has been implicated in endothelial cell activation and angiogenesis as well as oncogenesis. Thus, our results suggest that PXD may be an effective anticancer drug targeting the two drivers of tumour growth--the proliferation of the tumour cells themselves and the angiogenic and inflammatory stimulation of the vasculature.
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Affiliation(s)
- Jennifer R Gamble
- Division of Human Immunology, Hanson Institute, Institute of Medical and Veterinary Science, and Division of Human Immunology, the University of Adelaide 5000, Australia.
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35
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Sukocheva O, Wadham C, Holmes A, Albanese N, Verrier E, Feng F, Bernal A, Derian CK, Ullrich A, Vadas MA, Xia P. Estrogen transactivates EGFR via the sphingosine 1-phosphate receptor Edg-3: the role of sphingosine kinase-1. J Cell Biol 2006; 173:301-10. [PMID: 16636149 PMCID: PMC2063820 DOI: 10.1083/jcb.200506033] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The transactivation of enhanced growth factor receptor (EGFR) by G protein-coupled receptor (GPCR) ligands is recognized as an important signaling mechanism in the regulation of complex biological processes, such as cancer development. Estrogen (E2), which is a steroid hormone that is intimately implicated in breast cancer, has also been suggested to function via EGFR transactivation. In this study, we demonstrate that E2-induced EGFR transactivation in human breast cancer cells is driven via a novel signaling system controlled by the lipid kinase sphingosine kinase-1 (SphK1). We show that E2 stimulates SphK1 activation and the release of sphingosine 1-phosphate (S1P), by which E2 is capable of activating the S1P receptor Edg-3, resulting in the EGFR transactivation in a matrix metalloprotease-dependent manner. Thus, these findings reveal a key role for SphK1 in the coupling of the signals between three membrane-spanning events induced by E2, S1P, and EGF. They also suggest a new signal transduction model across three individual ligand-receptor systems, i.e., "criss-cross" transactivation.
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Affiliation(s)
- Olga Sukocheva
- Signal Transduction Laboratory, Division of Human Immunology, Hanson Institute, Institute of Medical and Veterinary Science, Adelaide SA 5000, Australia
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36
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Sutherland CM, Moretti PAB, Hewitt NM, Bagley CJ, Vadas MA, Pitson SM. The calmodulin-binding site of sphingosine kinase and its role in agonist-dependent translocation of sphingosine kinase 1 to the plasma membrane. J Biol Chem 2006; 281:11693-701. [PMID: 16522638 DOI: 10.1074/jbc.m601042200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Sphingosine kinases catalyze the formation of sphingosine 1-phosphate, a bioactive lipid involved in many aspects of cellular regulation, including the fundamental biological processes of cell growth and survival. A diverse range of cell agonists induce activation of human sphingosine kinase 1 (hSK1) and, commonly, its translocation to the plasma membrane. Although the activation of hSK1 in response to at least some agonists occurs directly via its phosphorylation at Ser225 by ERK1/2, many aspects governing the regulation of this phosphorylation and subsequent translocation remain unknown. Here, in an attempt to understand some of these processes, we have examined the known interaction of hSK1 with calmodulin (CaM). By using a combination of limited proteolysis, peptide interaction analysis, and site-directed mutagenesis, we have identified that the CaM-binding site of hSK1 resides in the region spanned by residues 191-206. Specifically, Phe197 and Leu198 are critically involved in the interaction because a version of hSK1 incorporating mutations of both Phe197 --> Ala and Leu198 --> Gln failed to bind CaM. We have also shown for the first time that human sphingosine kinase 2 (hSK2) binds CaM, and does so via a CaM binding region that is conserved with hSK1 because comparable mutations in hSK2 also ablate CaM binding to this protein. By using the CaM-binding-deficient version of hSK1, we have begun to elucidate the role of CaM in hSK1 regulation by demonstrating that disruption of the CaM-binding site ablates agonist-induced translocation of hSK1 from the cytoplasm to the plasma membrane, while having no effect on hSK1 phosphorylation and catalytic activation.
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Affiliation(s)
- Catherine M Sutherland
- Hanson Institute, Division of Human Immunology, Institute of Medical and Veterinary Science, Frome Road, University of Adelaide, Adelaide, South Australia 5000, Australia
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37
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Wang L, Xing XP, Holmes A, Wadham C, Gamble JR, Vadas MA, Xia P. Activation of the sphingosine kinase-signaling pathway by high glucose mediates the proinflammatory phenotype of endothelial cells. Circ Res 2005; 97:891-9. [PMID: 16179586 DOI: 10.1161/01.res.0000187469.82595.15] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Vascular endothelial cells are key targets for hyperglycemic damage that facilitates vascular inflammation and the vasculopathy associated with diabetes mellitus. However, the mechanisms underlying this damage remain undefined. We now demonstrate that hyperglycemia induces activation of sphingosine kinase (SphK), which represents a novel signaling pathway that mediates endothelial damage under ambient high glucose conditions. SphK activity was significantly increased in aorta and heart of streptozotocin-induced diabetic rats. Interestingly, this increase in SphK activity was prevented by insulin treatment, which achieved euglycemia in the diabetic animals. Hyperglycemia-induced increase in SphK activity was also evident in endothelial cells that received long-term exposure to high glucose (22 mmol/L). Studies using a small interfering RNA strategy demonstrated that endogenous SphK1, but not SphK2, is the major isoenzyme that was activated by high glucose. In addition, an increase in SphK1 phosphorylation was detected in a protein kinase C- and extracellular signal-regulated kinase 1/2-dependent manner, which accounts for the high glucose-induced increases in SphK activity. Importantly, inhibition of SphK1 by either a chemical inhibitor (N',N'-dimethylsphingosine) or expression of a dominant-negative mutant of SphK1 (SphK(G82D)), or SphK1-specific small interfering RNA, strongly protected endothelial cells against high glucose-induced damage, as characterized by an attenuation in the expression of proinflammatory adhesion molecules, adhesion of leukocytes to endothelial cells, and nuclear factor kappaB activation. Thus, interventions that target the SphK-signaling pathway may have the potential to prevent vascular lesions under hyperglycemic conditions.
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Affiliation(s)
- Lijun Wang
- Division of Human Immunology, Hanson Institute, Institute of Medical and Veterinary Science, Adelaide, Australia
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38
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Coles LS, Lambrusco L, Burrows J, Hunter J, Diamond P, Bert AG, Vadas MA, Goodall GJ. Phosphorylation of cold shock domain/Y-box proteins by ERK2 and GSK3β and repression of the human VEGF promoter. FEBS Lett 2005; 579:5372-8. [PMID: 16198352 DOI: 10.1016/j.febslet.2005.08.075] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Revised: 07/05/2005] [Accepted: 08/29/2005] [Indexed: 10/25/2022]
Abstract
The hypoxia responsive region (HRR) of the VEGF promoter plays a key role in regulating VEGF expression. We found that the cold shock domain (Y-box) repressor proteins, dbpA and dbpB/YB-1, bind distinct strands of the human VEGF HRR. We find both dbpA and dbpB are phosphorylated by ERK2 and GSK3beta in vitro, and the binding of dbpB to single-strand VEGF HRR DNA is regulated by this phosphorylation. These findings suggest the ERK/MAPK and PI3K pathways may regulate VEGF expression in part through regulating the action of these repressor proteins.
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Affiliation(s)
- Leeanne S Coles
- Division of Human Immunology, Hanson Institute, Institute of Medical and Veterinary Science, Adelaide, SA , Australia
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39
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Hahn CN, Su ZJ, Drogemuller CJ, Tsykin A, Waterman SR, Brautigan PJ, Yu S, Kremmidiotis G, Gardner A, Solomon PJ, Goodall GJ, Vadas MA, Gamble JR. Expression profiling reveals functionally important genes and coordinately regulated signaling pathway genes during in vitro angiogenesis. Physiol Genomics 2005; 22:57-69. [PMID: 15840639 DOI: 10.1152/physiolgenomics.00278.2004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Angiogenesis is a complex multicellular process requiring the orchestration of many events including migration, alignment, proliferation, lumen formation, remodeling, and maturation. Such complexity indicates that not only individual genes but also entire signaling pathways will be crucial in angiogenesis. To define an angiogenic blueprint of regulated genes, we utilized our well-characterized three-dimensional collagen gel model of in vitro angiogenesis, in which the majority of cells synchronously progress through defined morphological stages culminating in the formation of capillary tubes. We developed a comprehensive three-tiered approach using microarray analysis, which allowed us to identify genes known to be involved in angiogenesis and genes hitherto unlinked to angiogenesis as well as novel genes and has proven especially useful for genes where the magnitude of change is small. Of interest is the ability to recognize complete signaling pathways that are regulated and genes clustering into ontological groups implicating the functional importance of particular processes. We have shown that consecutive members of the mitogen-activated protein kinase and leukemia inhibitory factor signaling pathways are altered at the mRNA level during in vitro angiogenesis. Thus, at least for the mitogen-activated protein kinase pathway, mRNA changes as well as the phosphorylation changes of these gene products may be important in the control of blood vessel morphogenesis. Furthermore, in this study, we demonstrated the power of virtual Northern blot analysis, as an alternative to quantitative RT-PCR, for measuring the magnitudes of differential gene expression.
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Affiliation(s)
- C N Hahn
- Vascular Biology Laboratory, Human Immunology, Hanson Institute, Adelaide, Australia.
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40
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Roberts JL, Moretti PAB, Darrow AL, Derian CK, Vadas MA, Pitson SM. An assay for sphingosine kinase activity using biotinylated sphingosine and streptavidin-coated membranes. Anal Biochem 2005; 331:122-9. [PMID: 15246004 DOI: 10.1016/j.ab.2004.03.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2004] [Indexed: 11/15/2022]
Abstract
Sphingosine kinase catalyses the phosphorylation of sphingosine to generate sphingosine 1-phosphate, a lipid signaling molecule implicated in roles in a diverse range of mammalian cell processes through its action as both a ligand for G-protein-coupled cell-surface receptors and an apparent intracellular second messenger. This paper describes a rapid, sensitive, and reproducible assay for sphingosine kinase activity using biotinylated sphingosine (biotinyl-Sph) as a substrate and capturing the phosphorylated product with streptavidin-coated membranes. We have shown that both human sphingosine kinase 1 and 2 (hSK1 and hSK2) can efficiently phosphorylate biotinyl-Sph, with K(m) values similar to those of sphingosine. The assay utilizing this substrate has high sensitivity for hSK1 and hSK2, with detection limits in the low-femtomole range for both purified recombinant enzymes. Importantly, we have also demonstrated the capacity of this assay to measure endogenous sphingosine kinase activity in crude cell extracts and to follow changes in this activity following sphingosine kinase activation. Together, these results demonstrate the potential utility of this assay in both cell-based analysis of sphingosine kinase signaling pathways and high-throughput screens for agents affecting sphingosine kinase activity in vitro.
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Affiliation(s)
- Jane L Roberts
- Hanson Institute, Division of Human Immunology, Institute of Medical and Veterinary Science, Frome Road, Adelaide, SA 5000, Australia
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41
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Limaye V, Li X, Hahn C, Xia P, Berndt MC, Vadas MA, Gamble JR. Sphingosine kinase-1 enhances endothelial cell survival through a PECAM-1-dependent activation of PI-3K/Akt and regulation of Bcl-2 family members. Blood 2005; 105:3169-77. [PMID: 15632208 DOI: 10.1182/blood-2004-02-0452] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Sphingosine-1-phosphate (S1P), the bioactive product of sphingosine kinase (SK) activation, is a survival factor for endothelial cells. The mechanism of SK-mediated survival was investigated in endothelial cells with moderately raised intracellular SK activity. Overexpression of SK mediated survival primarily through the activation of the phosphatidyl inositol 3-kinase (PI-3K)/protein kinase B (Akt/PKB) pathway and an associated up-regulation of the antiapoptotic protein B cell lymphoma gene 2 (Bcl-2) and down-regulation of the proapoptotic protein bisindolylmaleimide (Bcl-2 interacting mediator of cell death; Bim). In addition there was an up-regulation and dephosphorylation of the junctional molecule platelet endothelial cell adhesion molecule-1 (PECAM-1), which was obligatory for activation of the PI-3K/Akt pathway, for SK-induced cell survival, and for the changes in the apoptosis-related proteins. Thus, raised intracellular SK activity induced a molecule involved in cell-cell interactions to augment cell survival through a PI-3K/Akt-dependent pathway. This is distinct from the activation of both PI-3K/Akt and mitogen-activated protein kinase (MAPK) pathways seen with exogenously added S1P. Cells overexpressing SK showed enhanced survival under conditions of serum deprivation and absence of attachment to extracellular matrix, suggesting a role for SK in the regulation of vascular phenomena that occur under conditions of stress, such as angiogenesis and survival in unattached states, as would be required for a circulating endothelial cell.
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Affiliation(s)
- Vidya Limaye
- Hanson Institute, Institute of Medical and Veterinary Science, Adelaide, SA, Australia
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42
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Pitson SM, Xia P, Leclercq TM, Moretti PAB, Zebol JR, Lynn HE, Wattenberg BW, Vadas MA. Phosphorylation-dependent translocation of sphingosine kinase to the plasma membrane drives its oncogenic signalling. ACTA ACUST UNITED AC 2004; 201:49-54. [PMID: 15623571 PMCID: PMC2212769 DOI: 10.1084/jem.20040559] [Citation(s) in RCA: 223] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Sphingosine kinase (SK) 1 catalyzes the formation of the bioactive lipid sphingosine 1-phosphate, and has been implicated in several biological processes in mammalian cells, including enhanced proliferation, inhibition of apoptosis, and oncogenesis. Human SK (hSK) 1 possesses high instrinsic catalytic activity which can be further increased by a diverse array of cellular agonists. We have shown previously that this activation occurs as a direct consequence of extracellular signal-regulated kinase 1/2-mediated phosphorylation at Ser225, which not only increases catalytic activity, but is also necessary for agonist-induced translocation of hSK1 to the plasma membrane. In this study, we report that the oncogenic effects of overexpressed hSK1 are blocked by mutation of the phosphorylation site despite the phosphorylation-deficient form of the enzyme retaining full instrinsic catalytic activity. This indicates that oncogenic signaling by hSK1 relies on a phosphorylation-dependent function beyond increasing enzyme activity. We demonstrate, through constitutive localization of the phosphorylation-deficient form of hSK1 to the plasma membrane, that hSK1 translocation is the key effect of phosphorylation in oncogenic signaling by this enzyme. Thus, phosphorylation of hSK1 is essential for oncogenic signaling, and is brought about through phosphorylation-induced translocation of hSK1 to the plasma membrane, rather than from enhanced catalytic activity of this enzyme.
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Affiliation(s)
- Stuart M Pitson
- Hanson Institute and Division of Human Immunology, Institute of Medical and Veterinary Science, Adelaide SA 5000, Australia.
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43
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Li X, Hahn CN, Parsons M, Drew J, Vadas MA, Gamble JR. Role of protein kinase Cζ in thrombin-induced endothelial permeability changes: inhibition by angiopoietin-1. Blood 2004; 104:1716-24. [PMID: 15172966 DOI: 10.1182/blood-2003-11-3744] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
AbstractEndothelial cell leakiness is regulated by mediators such as thrombin, which promotes endothelial permeability, and anti-inflammatory agents, such as angiopoietin-1. Here we define a new pathway involved in thrombin-induced permeability that involves the atypical protein kinase C isoform, PKCζ. Chemical inhibitor studies implicated the involvement of an atypical PKC isoform in thrombin-induced permeability changes in human umbilical vein endothelial cells. Thrombin stimulation resulted in PKCζ, but not the other atypical PKC isoform, PKCλ, translocating to the membrane, an event known to be critical to enzyme activation. The involvement of PKCζ was confirmed by overexpression of constitutively active PKCζ, resulting in enhanced basal permeability. Dominant-negative PKCζ prevented the thrombin-mediated effects on endothelial cell permeability and inhibited thrombin-induced activation of PKCζ. Rho activation does not appear to play a role, either upstream or downstream of PKCζ, as C3 transferase does not block thrombin-induced PKCζ activation and dominant-negative PKCζ does not block thrombin-induced Rho activation. Finally, we show that angiopoietin-1 inhibits thrombin-induced PKCζ activation, Rho activation, and Ca++ flux, thus demonstrating that the powerful antipermeability action of angiopoietin-1 is mediated by its action on a number of signaling pathways induced by thrombin and implicated in permeability changes. (Blood. 2004; 104:1716-1724)
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Affiliation(s)
- Xiaochun Li
- Vascular Biology Laboratory, Division of Human Immunology, Hanson Institute, Institute of Medical and Veterinary Science, Frome Road, Adelaide, South Australia 5000
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44
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Su ZJ, Hahn CN, Goodall GJ, Reck NM, Leske AF, Davy A, Kremmidiotis G, Vadas MA, Gamble JR. A vascular cell-restricted RhoGAP, p73RhoGAP, is a key regulator of angiogenesis. Proc Natl Acad Sci U S A 2004; 101:12212-7. [PMID: 15302923 PMCID: PMC514459 DOI: 10.1073/pnas.0404631101] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Angiogenesis is a major therapeutic target. Ideal drug targets are genes expressed only in endothelial cells (ECs) or only during the angiogenic process. Here, we describe a gene, p73RhoGAP (p73), that has both of these properties. By using a PCR-based subtraction-hybridization approach to clone cDNAs from ECs undergoing capillary-tube formation, we identified a RhoGAP member, p73. p73 displays GTPase activity to Rho but not to Rac or Cdc42. Knockdown of p73 protein, achieved by adenovirus delivery of p73 antisense and by small interfering RNA into ECs, demonstrated the importance of this protein in EC function. Under such conditions, EC migration, proliferation, and capillary-tube formation were inhibited. Furthermore, angiogenesis in vivo was also inhibited by antisense p73. A mutant R82A alteration achieved a similar phenotype in vitro to the antisense, demonstrating the importance of the GTPase-activating protein activity to p73 function. Expression profiling of p73 shows that it is vascular cell-selective, being highly expressed in ECs and smooth-muscle cells but not in other cell types. Finally, we show that the mRNA of p73 is up-regulated in an angiogenic milieu with little or no regulation seen under nonangiogenic conditions. p73, a vascular cell-specific GTPase-activating protein, is an important modulator of angiogenesis and displays many of features that make it worthy of being a drug target.
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Affiliation(s)
- Zhi-Jian Su
- Vascular Biology Laboratory, Division of Human Immunology, Hanson Institute, Institute of Medical and Veterinary Science, Adelaide, SA 5000, Australia
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45
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Wadham C, Albanese N, Roberts J, Wang L, Bagley CJ, Gamble JR, Rye KA, Barter PJ, Vadas MA, Xia P. High-Density Lipoproteins Neutralize C-Reactive Protein Proinflammatory Activity. Circulation 2004; 109:2116-22. [PMID: 15078800 DOI: 10.1161/01.cir.0000127419.45975.26] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
C-reactive protein (CRP), a well-recognized marker of atherosclerosis, has recently been suggested to have a direct proinflammatory effect. The constitutive expression of low levels of CRP in normal plasma suggests the likelihood that a natural factor exists to neutralize the effect of CRP. This factor(s) has not yet been identified.
Method and Results—
The proinflammatory effect of CRP was measured by the induction of inflammatory adhesion molecules in human umbilical vein endothelial cells (HUVECs). We show that CRP significantly induced upregulation of adhesion molecules in both protein and mRNA levels. The CRP-induced expression of these inflammatory adhesion molecules was completely suppressed when the cells were preincubated with a physiological concentration (1 mg/mL apolipoprotein A-I) of HDLs derived from human plasma (native HDL) or reconstituted HDL (rHDL) at a very low concentration (0.01 mg/mL apolipoprotein A-I). A novel mechanism of HDL inhibition is likely to operate, because (1) rHDL was 100 times more potent than native HDL, (2) preincubation with HDL and its sustained presence were obligatory, and (3) oxidized 1-palmitoyl-2-linoleoyl-
sn
-glycero-3-phosphocholine was the fundamental active component.
Conclusions—
The CRP-induced upregulation of inflammatory adhesion molecules in HUVECs was completely prevented by HDL via their oxidized phospholipid components.
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Affiliation(s)
- Carol Wadham
- Division of Human Immunology, Hanson Institute, Institute of Medical and Veterinary Science, Adelaide, South Australia, Australia
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Verrier E, Wang L, Wadham C, Albanese N, Hahn C, Gamble JR, Chatterjee VKK, Vadas MA, Xia P. PPARgamma agonists ameliorate endothelial cell activation via inhibition of diacylglycerol-protein kinase C signaling pathway: role of diacylglycerol kinase. Circ Res 2004; 94:1515-22. [PMID: 15117825 DOI: 10.1161/01.res.0000130527.92537.06] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Subject- Peroxisome proliferator-activated receptor (PPAR)-gamma agonists are emerging as potential protectors against inflammatory cardiovascular diseases including atherosclerosis and diabetic complications. However, their molecular mechanism of action within vasculature remains unclear. We report here that PPARgamma agonists, thiazolidinedione class drugs (TZDs), or 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) were capable of activating diacylglycerol (DAG) kinase (DGK), resulting in attenuation of DAG levels and inhibition of protein kinase C (PKC) activation. The PPARgamma agonist-induced DGK was completely blocked by a dominant-negative mutant of PPARgamma, indicating an essential receptor-dependent action. Importantly, the suppression of DAG-PKC signaling pathway was functional linkage to the anti-inflammatory properties of PPARgamma agonists in endothelial cells (EC), characterized by the inhibition of proinflammatory adhesion molecule expression and adherence of monocytes to the activated EC induced by high glucose. These findings thus demonstrate a novel molecular action of PPARgamma agonists to suppress the DAG-PKC signaling pathway via upregulation of an endogenous attenuator, DGK.
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Affiliation(s)
- Emily Verrier
- Signal Transduction Laboratory, Hanson Institute, Adelaide, SA, Australia
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Coles LS, Bartley MA, Bert A, Hunter J, Polyak S, Diamond P, Vadas MA, Goodall GJ. A multi-protein complex containing cold shock domain (Y-box) and polypyrimidine tract binding proteins forms on the vascular endothelial growth factor mRNA. Potential role in mRNA stabilization. ACTA ACUST UNITED AC 2004; 271:648-60. [PMID: 14728692 DOI: 10.1111/j.1432-1033.2003.03968.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis and post-transcriptional regulation plays a major role in VEGF expression. Both the 5'- and 3'-UTR are required for VEGF post-transcriptional regulation but factors binding to functional sequences within the 5'-UTR have not been fully characterized. We report here the identification of complexes, binding to the VEGFmRNA 5'- and 3'-UTR, that contain cold shock domain (CSD) and polypyrimidine tract binding (PTB) RNA binding proteins. Analysis of the CSD/PTB binding sites revealed a potential role in VEGF mRNA stability, in both noninduced and induced conditions, demonstrating a general stabilizing function. Such a stabilizing mechanism had not been reported previously for the VEGF gene. We further found that the CSD/PTB-containing complexes are large multiprotein complexes that are most likely preformed in solution and we demonstrate that PTB is associated with the VEGF mRNA in vivo. Complex formation between CSD proteins and PTB has not been reported previously. Analysis of the CSD/PTB RNA binding sites revealed a novel CSD protein RNA recognition site and also demonstrated that CSD proteins may direct the binding of CSD/PTB complexes. We found the same complexes binding to an RNA-stabilizing element of another growth factor gene, suggesting a broader functional role for the CSD/PTB complexes. Finally, as the VEGF gene is also regulated at the transcriptional level by CSD proteins, we propose a combined transcriptional/post-transcriptional role for these proteins in VEGF and other growth factor gene regulation.
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Affiliation(s)
- Leeanne S Coles
- Division of Human Immunology, The Hanson Institute, Institute of Medical and Veterinary Science, Adelaide, South Australia, Australia.
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Stein BN, Gamble JR, Pitson SM, Vadas MA, Khew-Goodall Y. Activation of endothelial extracellular signal-regulated kinase is essential for neutrophil transmigration: potential involvement of a soluble neutrophil factor in endothelial activation. J Immunol 2004; 171:6097-104. [PMID: 14634124 DOI: 10.4049/jimmunol.171.11.6097] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
During an inflammatory response induced by infection or injury, leukocytes traverse the endothelial barrier into the tissue space. Extravasation of leukocytes is a multistep process involving rolling, tethering, firm adhesion to the endothelium, and finally, transendothelial migration, the least characterized step in the process. The resting endothelium is normally impermeable to leukocytes; thus, during inflammation, intracellular signals that modulate endothelial permeability are activated to facilitate the paracellular passage of leukocytes. Using a static in vitro assay of neutrophil transmigration across human umbilical vein endothelium, a panel of inhibitors of intracellular signaling was screened for their ability to inhibit transmigration. PD98059, a specific inhibitor of extracellular signal-regulated kinase (ERK) 1/2 activation, inhibited both transmigration across TNF-alpha-activated endothelium and transmigration induced by the chemoattractant fMLP in a dose-dependent manner. PD98059 did not inhibit neutrophil chemotaxis in the absence of an endothelial barrier nor neutrophil adhesion to the endothelium, suggesting that its effect was on the endothelium, and furthermore, that endothelial ERK activation may be important for transmigration. We demonstrate in this study that endothelial ERK is indeed activated during neutrophil transmigration and that its activation is dependent on the addition of neutrophils to the endothelium. Further characterization showed that the trigger for endothelial ERK activation is a soluble protein of molecular mass approximately 30 kDa released from neutrophils after activation.
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Affiliation(s)
- Brian N Stein
- Hanson Institute, Institute of Medical and Veterinary Science, and Department of Medicine, University of Adelaide, Adelaide, Australia
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Abstract
Sphingosine kinase 1 is an agonist-activated signalling enzyme that catalyses the formation of sphingosine 1-phosphate, a lipid second messenger that has been implicated in a number of agonist-driven cellular responses, including stimulation of cell proliferation, inhibition of apoptosis and expression of inflammatory molecules. Although agonist-induced stimulation of sphingosine kinase activity is critical in a number of signalling pathways, nothing has been known of the molecular mechanism of this activation. Here we show that this activation results directly from phosphorylation of sphingosine kinase 1 at Ser225, and present several lines of evidence to show compellingly that the activating kinase is ERK1/2 or a close relative. Furthermore, we show that phosphorylation of sphingosine kinase 1 at Ser225 results not only in an increase in enzyme activity, but is also necessary for translocation of the enzyme from the cytosol to the plasma membrane. Thus, these studies have elucidated the mechanism of agonist-mediated sphingosine kinase activation, and represent a key finding in understanding the regulation of sphingosine kinase/sphingosine 1-phosphate-controlled signalling pathways.
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Affiliation(s)
- Stuart M Pitson
- Hanson Institute, Division of Human Immunology, Institute of Medical and Veterinary Science, Frome Road, Adelaide, SA 5000, Australia.
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50
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Imhof BA, Vadas MA. New therapeutic targets in vascular biology. Thromb Haemost 2003; 90:557-9. [PMID: 14515170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
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