1
|
Tixeira R, Phan TK, Caruso S, Shi B, Atkin-Smith GK, Nedeva C, Chow JDY, Puthalakath H, Hulett MD, Herold MJ, Poon IKH. ROCK1 but not LIMK1 or PAK2 is a key regulator of apoptotic membrane blebbing and cell disassembly. Cell Death Differ 2019; 27:102-116. [PMID: 31043701 DOI: 10.1038/s41418-019-0342-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 04/15/2019] [Accepted: 04/17/2019] [Indexed: 12/31/2022] Open
Abstract
Many cell types are known to undergo a series of morphological changes during the progression of apoptosis, leading to their disassembly into smaller membrane-bound vesicles known as apoptotic bodies (ApoBDs). In particular, the formation of circular bulges called membrane blebs on the surface of apoptotic cells is a key morphological step required for a number of cell types to generate ApoBDs. Although apoptotic membrane blebbing is thought to be regulated by kinases including ROCK1, PAK2 and LIMK1, it is unclear whether these kinases exhibit overlapping roles in the disassembly of apoptotic cells. Utilising both pharmacological and CRISPR/Cas9 gene editing based approaches, we identified ROCK1 but not PAK2 or LIMK1 as a key non-redundant positive regulator of apoptotic membrane blebbing as well as ApoBD formation. Functionally, we have established an experimental system to either inhibit or enhance ApoBD formation and demonstrated the importance of apoptotic cell disassembly in the efficient uptake of apoptotic materials by various phagocytes. Unexpectedly, we also noted that ROCK1 could play a role in regulating the onset of secondary necrosis. Together, these data shed light on both the mechanism and function of cell disassembly during apoptosis.
Collapse
Affiliation(s)
- Rochelle Tixeira
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Thanh Kha Phan
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Sarah Caruso
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Bo Shi
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Georgia K Atkin-Smith
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Christina Nedeva
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Jenny D Y Chow
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Hamsa Puthalakath
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Mark D Hulett
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Marco J Herold
- The Walter and Eliza Hall Institute for Medical Research, Parkville, VIC, 3052, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Ivan K H Poon
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
| |
Collapse
|
2
|
Poon IKH, Parkes MAF, Jiang L, Atkin-Smith GK, Tixeira R, Gregory CD, Ozkocak DC, Rutter SF, Caruso S, Santavanond JP, Paone S, Shi B, Hodge AL, Hulett MD, Chow JDY, Phan TK, Baxter AA. Moving beyond size and phosphatidylserine exposure: evidence for a diversity of apoptotic cell-derived extracellular vesicles in vitro. J Extracell Vesicles 2019; 8:1608786. [PMID: 31069027 PMCID: PMC6493268 DOI: 10.1080/20013078.2019.1608786] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [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: 05/28/2018] [Revised: 04/08/2019] [Accepted: 04/12/2019] [Indexed: 12/16/2022] Open
Abstract
Apoptosis is a form of programmed cell death that occurs throughout life as part of normal development as well as pathologic processes including chronic inflammation and infection. Although the death of a cell is often considered as the only biological outcome of a cell committed to apoptosis, it is becoming increasingly clear that the dying cell can actively communicate with other cells via soluble factors as well as membrane-bound extracellular vesicles (EVs) to regulate processes including cell clearance, immunity and tissue repair. Compared to EVs generated from viable cells such as exosomes and microvesicles, apoptotic cell-derived EVs (ApoEVs) are less well defined and the basic criteria for ApoEV characterization have not been established in the field. In this study, we will examine the current understanding of ApoEVs, in particular, the ApoEV subtype called apoptotic bodies (ApoBDs). We described that a subset of ApoBDs can be larger than 5 μm and smaller than 1 μm based on flow cytometry and live time-lapse microscopy analysis, respectively. We also described that a subset of ApoBDs can expose a relatively low level of phosphatidylserine on its surface based on annexin A5 staining. Furthermore, we characterized the presence of caspase-cleaved proteins (in particular plasma membrane-associated or cytoplasmic proteins) in samples enriched in ApoBDs. Lastly, using a combination of biochemical-, live imaging- and flow cytometry-based approaches, we characterized the progressive lysis of ApoBDs. Taken together, these results extended our understanding of ApoBDs.
Collapse
Affiliation(s)
- Ivan K H Poon
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Michael A F Parkes
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Lanzhou Jiang
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Georgia K Atkin-Smith
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Rochelle Tixeira
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Christopher D Gregory
- MRC Centre for inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Dilara C Ozkocak
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Stephanie F Rutter
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Sarah Caruso
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Jascinta P Santavanond
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Stephanie Paone
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Bo Shi
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Amy L Hodge
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Mark D Hulett
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Jenny D Y Chow
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Thanh Kha Phan
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Amy A Baxter
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| |
Collapse
|
3
|
Van Sinderen M, Steinberg G, Jorgensen SB, Honeyman J, Chow JDY, Simpson ER, Jones MEE, Boon WC. Sexual dimorphism in the glucose homeostasis phenotype of the Aromatase Knockout (ArKO) mice. J Steroid Biochem Mol Biol 2017; 170:39-48. [PMID: 27353462 DOI: 10.1016/j.jsbmb.2016.05.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [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: 06/16/2015] [Revised: 05/04/2016] [Accepted: 05/12/2016] [Indexed: 02/08/2023]
Abstract
We investigated the effects of estrogens on glucose homeostasis using the Aromatase Knockout (ArKO) mouse, which is unable to convert androgens into estrogens. The ArKO mouse is a model of total estrogen ablation which develops symptoms of metabolic syndrome. To determine the development and progression of whole body state of insulin resistance of ArKO mice, comprehensive whole body tolerance tests were performed on WT, ArKO and estrogen administrated mice at 3 and 12 months of age. The absence of estrogens in the male ArKO mice leads to hepatic insulin resistance, glucose and pyruvate intolerance from 3 to 12 months with consistent improvement upon estrogen treatment. Estrogen absence in the female ArKO mice leads to glucose intolerance without pyruvate intolerance or insulin resistance. The replacement of estrogens in the female WT and ArKO mice exhibited both insulin sensitizing and resistance effects depending on age and dosage. In conclusion, this study presents information on the sexually dimorphic roles of estrogens on glucose homeostasis regulation.
Collapse
Affiliation(s)
- Michelle Van Sinderen
- Hudson Institute of Medical Research, Clayton, Vic 3180, Australia; Dept of Anatomy and Developmental Biology, Monash University, Clayton, Vic 3800, Australia
| | - Gregory Steinberg
- St. Vincent's Institute of Medical Research and Dept of Medicine, University of Melbourne, Fitzroy, Vic 3065, Australia; Division of Endocrinology and Metabolism, Dept of Medicine, McMaster University, ON, Canada
| | - Sebastian B Jorgensen
- St. Vincent's Institute of Medical Research and Dept of Medicine, University of Melbourne, Fitzroy, Vic 3065, Australia; Diabetes Research Unit, Novo Nordisk A/S, Maaloev, Denmark
| | - Jane Honeyman
- St. Vincent's Institute of Medical Research and Dept of Medicine, University of Melbourne, Fitzroy, Vic 3065, Australia
| | - Jenny D Y Chow
- Dept of Anatomy and Developmental Biology, Monash University, Clayton, Vic 3800, Australia
| | - Evan R Simpson
- Hudson Institute of Medical Research, Clayton, Vic 3180, Australia
| | | | - Wah Chin Boon
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Vic 3000, Australia; Dept of Anatomy and Developmental Biology, Monash University, Clayton, Vic 3800, Australia.
| |
Collapse
|
4
|
Healy ME, Lahiri S, Hargett SR, Chow JDY, Byrne FL, Breen DS, Kenwood BM, Taddeo EP, Lackner C, Caldwell SH, Hoehn KL. Dietary sugar intake increases liver tumor incidence in female mice. Sci Rep 2016; 6:22292. [PMID: 26924712 PMCID: PMC4770276 DOI: 10.1038/srep22292] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [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: 09/30/2015] [Accepted: 02/11/2016] [Indexed: 12/21/2022] Open
Abstract
Overnutrition can promote liver cancer in mice and humans that have liver damage caused by alcohol, viruses, or carcinogens. However, the mechanism linking diet to increased liver tumorigenesis remains unclear in the context of whether tumorigenesis is secondary to obesity, or whether nutrients like sugar or fat drive tumorigenesis independent of obesity. In male mice, liver tumor burden was recently found to correlate with sugar intake, independent of dietary fat intake and obesity. However, females are less susceptible to developing liver cancer than males, and it remains unclear how nutrition affects tumorigenesis in females. Herein, female mice were exposed to the liver carcinogen diethylnitrosamine (DEN) and fed diets with well-defined sugar and fat content. Mice fed diets with high sugar content had the greatest liver tumor incidence while dietary fat intake was not associated with tumorigenesis. Diet-induced postprandial hyperglycemia and fasting hyperinsulinemia significantly correlated with tumor incidence, while tumor incidence was not associated with obesity and obesity-related disorders including liver steatosis, glucose intolerance, or elevated serum levels of estrogen, ALT, and lipids. These results simplify the pathophysiology of diet-induced liver tumorigenesis by focusing attention on the role of sugar metabolism and reducing emphasis on the complex milieu associated with obesity.
Collapse
Affiliation(s)
- Marin E Healy
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Sujoy Lahiri
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Stefan R Hargett
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Jenny D Y Chow
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Frances L Byrne
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - David S Breen
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Brandon M Kenwood
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Evan P Taddeo
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Carolin Lackner
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Stephen H Caldwell
- Department of Medicine, University of Virginia, Charlottesville, VA, USA.,Emily Couric Clinical Cancer Center, University of Virginia, Charlottesville, VA, USA
| | - Kyle L Hoehn
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA.,Department of Medicine, University of Virginia, Charlottesville, VA, USA.,Emily Couric Clinical Cancer Center, University of Virginia, Charlottesville, VA, USA.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| |
Collapse
|
5
|
Byrne FL, Poon IKH, Modesitt SC, Tomsig JL, Chow JDY, Healy ME, Baker WD, Atkins KA, Lancaster JM, Marchion DC, Moley KH, Ravichandran KS, Slack-Davis JK, Hoehn KL. Metabolic vulnerabilities in endometrial cancer. Cancer Res 2014; 74:5832-45. [PMID: 25205105 DOI: 10.1158/0008-5472.can-14-0254] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Women with metabolic disorders, including obesity and diabetes, have an increased risk of developing endometrial cancer. However, the metabolism of endometrial tumors themselves has been largely understudied. Comparing human endometrial tumors and cells with their nonmalignant counterparts, we found that upregulation of the glucose transporter GLUT6 was more closely associated with the cancer phenotype than other hallmark cancer genes, including hexokinase 2 and pyruvate kinase M2. Importantly, suppression of GLUT6 expression inhibited glycolysis and survival of endometrial cancer cells. Glycolysis and lipogenesis were also highly coupled with the cancer phenotype in patient samples and cells. To test whether targeting endometrial cancer metabolism could be exploited as a therapeutic strategy, we screened a panel of compounds known to target diverse metabolic pathways in endometrial cells. We identified that the glycolytic inhibitor, 3-bromopyruvate, is a powerful antagonist of lipogenesis through pyruvylation of CoA. We also provide evidence that 3-bromopyruvate promotes cell death via a necrotic mechanism that does not involve reactive oxygen species and that 3-bromopyruvate impaired the growth of endometrial cancer xenografts.
Collapse
Affiliation(s)
- Frances L Byrne
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia. School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Ivan K H Poon
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia. Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Victoria, Australia
| | - Susan C Modesitt
- Department of Obstetrics and Gynecology, University of Virginia, Charlottesville, Virginia
| | - Jose L Tomsig
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia
| | - Jenny D Y Chow
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia
| | - Marin E Healy
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia
| | - William D Baker
- Department of Obstetrics and Gynecology, University of Virginia, Charlottesville, Virginia
| | - Kristen A Atkins
- Department of Pathology, University of Virginia, Charlottesville, Virginia
| | - Johnathan M Lancaster
- Departments of Women's Oncology and Experimental Therapeutics Program, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - Douglas C Marchion
- Departments of Women's Oncology and Experimental Therapeutics Program, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - Kelle H Moley
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, Missouri
| | - Kodi S Ravichandran
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia. Center for Cell Clearance, University of Virginia, Charlottesville, Virginia
| | - Jill K Slack-Davis
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia. Cancer Center, University of Virginia, Charlottesville, Virginia
| | - Kyle L Hoehn
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia. School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia. Cancer Center, University of Virginia, Charlottesville, Virginia. Department of Medicine, University of Virginia, Charlottesville, Virginia.
| |
Collapse
|
6
|
Chow JDY, Lawrence RT, Healy ME, Dominy JE, Liao JA, Breen DS, Byrne FL, Kenwood BM, Lackner C, Okutsu S, Mas VR, Caldwell SH, Tomsig JL, Cooney GJ, Puigserver PB, Turner N, James DE, Villén J, Hoehn KL. Genetic inhibition of hepatic acetyl-CoA carboxylase activity increases liver fat and alters global protein acetylation. Mol Metab 2014; 3:419-31. [PMID: 24944901 PMCID: PMC4060285 DOI: 10.1016/j.molmet.2014.02.004] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 02/19/2014] [Accepted: 02/21/2014] [Indexed: 02/05/2023] Open
Abstract
Lipid deposition in the liver is associated with metabolic disorders including fatty liver disease, type II diabetes, and hepatocellular cancer. The enzymes acetyl-CoA carboxylase 1 (ACC1) and ACC2 are powerful regulators of hepatic fat storage; therefore, their inhibition is expected to prevent the development of fatty liver. In this study we generated liver-specific ACC1 and ACC2 double knockout (LDKO) mice to determine how the loss of ACC activity affects liver fat metabolism and whole-body physiology. Characterization of LDKO mice revealed unexpected phenotypes of increased hepatic triglyceride and decreased fat oxidation. We also observed that chronic ACC inhibition led to hyper-acetylation of proteins in the extra-mitochondrial space. In sum, these data reveal the existence of a compensatory pathway that protects hepatic fat stores when ACC enzymes are inhibited. Furthermore, we identified an important role for ACC enzymes in the regulation of protein acetylation in the extra-mitochondrial space.
Collapse
Affiliation(s)
- Jenny D Y Chow
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Robert T Lawrence
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Marin E Healy
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - John E Dominy
- Department of Cancer Biology, Dana-Faber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA ; Department of Cell Biology, Dana-Faber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jason A Liao
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - David S Breen
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Frances L Byrne
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Brandon M Kenwood
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Carolin Lackner
- Institute of Pathology, Medical University Graz, Graz, Austria
| | - Saeko Okutsu
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Valeria R Mas
- Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Stephen H Caldwell
- Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Jose L Tomsig
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Gregory J Cooney
- Diabetes and Obesity Program, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia
| | - Pere B Puigserver
- Department of Cancer Biology, Dana-Faber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA ; Department of Cell Biology, Dana-Faber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Nigel Turner
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - David E James
- Diabetes and Obesity Program, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia
| | - Judit Villén
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Kyle L Hoehn
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA ; Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA ; School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| |
Collapse
|
7
|
Poon IKH, Goodall KJ, Phipps S, Chow JDY, Pagler EB, Andrews DM, Conlan CL, Ryan GF, White JA, Wong MKL, Horan C, Matthaei KI, Smyth MJ, Hulett MD. Mice deficient in heparanase exhibit impaired dendritic cell migration and reduced airway inflammation. Eur J Immunol 2014; 44:1016-30. [PMID: 24532362 DOI: 10.1002/eji.201343645] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 11/29/2013] [Accepted: 01/07/2014] [Indexed: 01/15/2023]
Abstract
Heparanase is a β-d-endoglucuronidase that cleaves heparan sulphate, a key component of the ECM and basement membrane. The remodelling of the ECM by heparanase has been proposed to regulate both normal physiological and pathological processes, including wound healing, inflammation, tumour angiogenesis and cell migration. Heparanase is also known to exhibit non-enzymatic functions by regulating cell adhesion, cell signalling and differentiation. In this study, constitutive heparanase-deficient (Hpse(-/-) ) mice were generated on a C57BL/6 background using the Cre/loxP recombination system, with a complete lack of heparanase mRNA, protein and activity. Although heparanase has been implicated in embryogenesis and development, Hpse(-/-) mice are anatomically normal and fertile. Interestingly, consistent with the suggested function of heparanase in cell migration, the trafficking of dendritic cells from the skin to the draining lymph nodes was markedly reduced in Hpse(-/-) mice. Furthermore, the ability of Hpse(-/-) mice to generate an allergic inflammatory response in the airways, a process that requires dendritic cell migration, was also impaired. These findings establish an important role for heparanase in immunity and identify the enzyme as a potential target for regulation of an immune response.
Collapse
Affiliation(s)
- Ivan K H Poon
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Chow JDY, Jones MEE, Prelle K, Simpson ER, Boon WC. A selective estrogen receptor α agonist ameliorates hepatic steatosis in the male aromatase knockout mouse. J Endocrinol 2011; 210:323-34. [PMID: 21705395 DOI: 10.1530/joe-10-0462] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [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: 12/25/2022]
Abstract
Male aromatase knockout mice (ArKO; an estrogen-deficient model) present with male-specific hepatic steatosis that is reversible upon 17β-estradiol replacement. This study aims to elucidate which estrogen receptor (ER) subtype, ERα or ERβ, is involved in the regulation of triglyceride (TG) homeostasis in the liver. Nine-month-old male ArKO mice were treated with vehicle, ERα- or ERβ-specific agonists via s.c. injection, daily for 6 weeks. Male ArKO mice treated with ERα agonist had normal liver histology and TG contents compared with vehicle-treated ArKO; omental (gonadal) and infra-renal (visceral) fat pad weights were normalized to those of vehicle-treated wild-type (WT). In contrast, ERβ agonist treatment did not result in the similar reversal of these ArKO phenotypes. In vehicle-treated ArKO mice, hepatic transcript expression of fatty acid synthase (Fasn) and stearoyl-coenzyme A desaturase 1 (key enzymes in de novo FA synthesis) were significantly elevated compared with vehicle-treated WT, but only Fasn expression was lowered to WT level after ERα agonist treatment. There were no significant changes in the transcript levels of carnitine palmitoyl transferase 1 (required for transfer of FA residues into the mitochondria for β-oxidation) and sterol regulatory element-binding factor 1c (the upstream regulator of de novo FA synthesis). We also confirmed by RT-PCR that only ERα is expressed in the mouse liver. There were no changes in hepatic androgen receptor transcript level across all treatment groups. Our data suggest that estrogens act via ERα to regulate TG homeostasis in the ArKO liver. Since the liver, adipose tissue and arcuate nucleus express mainly ERα, estrogens could regulate hepatic functions via peripheral and central pathways.
Collapse
Affiliation(s)
- Jenny D Y Chow
- Prince Henry's Institute, Clayton, Victoria 3168, Australia
| | | | | | | | | |
Collapse
|
9
|
Chow JDY, Price JT, Bills MM, Simpson ER, Boon WC. A doxycycline-inducible, tissue-specific aromatase-expressing transgenic mouse. Transgenic Res 2011; 21:415-28. [PMID: 21614586 DOI: 10.1007/s11248-011-9525-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [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: 12/06/2010] [Accepted: 05/13/2011] [Indexed: 11/24/2022]
Abstract
Aromatase converts androgens to estrogens and it is expressed in gonads and non-reproductive tissues (e.g. brain and adipose tissues). As circulating levels of estrogens in males are low, we hypothesize that local estrogen production is important for the regulation of physiological functions (e.g. metabolism) and pathological development (e.g. breast and prostate cancers) by acting in a paracrine and/or intracrine manner. We generated a tissue-specific doxycycline-inducible, aromatase transgenic mouse to test this hypothesis. The transgene construct (pTetOAROM) consists of a full-length human aromatase cDNA (hAROM) and a luciferase gene under the control of a bi-directional tetracycline-responsive promoter (pTetO), which is regulated by transactivators (rtTA or tTA) and doxycycline. Our in vitro studies using MBA-MB-231tet cells stably expressing rtTA, showed that doxycycline treatment induced transgene expression of hAROM transcripts by 17-fold (P = 0.01), aromatase activity by 26-fold, (P = 0.0008) and luciferase activity by 9.6-fold (P = 0.0006). Pronuclear microinjection of the transgene generated four pTetOAROM founder mice. A male founder was bred with a female mammary gland-specific rtTA mouse (MMTVrtTA) to produce MMTVrtTA-pTetOAROM double-transgenic mice. Upon doxycycline treatment via drinking water, human aromatase expression was detected by RT-PCR, specifically in mammary glands, salivary glands and seminal vesicles of double-stransgenic mice. Luciferase expression and activity was detected in these tissues by in vivo bioluminescence imaging, in vitro luciferase assay and RT-PCR. In summary, we generated a transgenic mouse model that expresses the human aromatase transgene in a temporal- and spatial-specific manner, which will be a useful model to study the physiological importance of local estrogen production.
Collapse
MESH Headings
- Animals
- Aromatase/genetics
- Aromatase/metabolism
- Cell Line, Tumor
- Cloning, Molecular
- DNA, Complementary/genetics
- DNA, Complementary/metabolism
- Doxycycline/administration & dosage
- Doxycycline/pharmacology
- Enzyme Activation
- Enzyme Assays
- Female
- Gene Expression Regulation, Enzymologic
- Genetic Vectors/genetics
- Genetic Vectors/metabolism
- Humans
- Luciferases, Firefly/genetics
- Luciferases, Firefly/metabolism
- Luminescent Measurements/methods
- Male
- Mammary Glands, Human/cytology
- Mammary Glands, Human/metabolism
- Mice
- Mice, Transgenic
- Microinjections
- Plasmids/genetics
- Plasmids/metabolism
- Promoter Regions, Genetic
- Reverse Transcriptase Polymerase Chain Reaction
- Salivary Glands/cytology
- Salivary Glands/metabolism
- Seminal Vesicles/cytology
- Seminal Vesicles/metabolism
- Transgenes
Collapse
|
10
|
Chow JDY, Simpson ER, Boon WC. Alternative 5'-untranslated first exons of the mouse Cyp19A1 (aromatase) gene. J Steroid Biochem Mol Biol 2009; 115:115-25. [PMID: 19500729 DOI: 10.1016/j.jsbmb.2009.03.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [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] [Received: 01/29/2009] [Revised: 03/24/2009] [Accepted: 03/26/2009] [Indexed: 10/20/2022]
Abstract
The human aromatase gene (CYP19A1) has eleven tissue-specific untranslated first exons, while only three have been described in the mouse Cyp19A1 namely brain-, ovary- and testis-specific exons 1. The present study aims to elucidate the complete structure of the mouse Cyp19A1 gene. We detected aromatase transcripts in mouse bone, aorta, hypothalamus, adipose, gonads and placenta, but not nulliparous mammary fat pad. BestFit algorithm analysis against the human CYP19A1 has identified ten putative first exons upstream of mouse Cyp19A1. Based on these putative sequences, we were able to design specific primers for RT-PCR and detected for the first time, the presence of exons I.4 and I.3 in murine fat and gonads, respectively. These are novel 5'UTRs of mouse Cyp19A1. Using RT-PCR and 5' RACE, we confirmed the expression of exon 1f in the hypothalamus and proximal exon P2 in the ovary. The testis-specific exon 1 begins 217bp further upstream than previously reported. Putative exons 2a, I.5, I.7, I.6 and I.2 were not detected in mouse tissues. Therefore, we showed that mouse Cyp19A1 contains more tissue-specific first exons than previously thought and displays a similar genomic organization to human CYP19A1.
Collapse
|