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Zahradka P, Taylor CG, Tworek L, Perrault R, M’Seffar S, Murali M, Loader T, Wigle JT. Thrombin-Mediated Formation of Globular Adiponectin Promotes an Increase in Adipose Tissue Mass. Biomolecules 2022; 13:biom13010030. [PMID: 36671414 PMCID: PMC9855379 DOI: 10.3390/biom13010030] [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: 10/22/2022] [Revised: 11/15/2022] [Accepted: 11/23/2022] [Indexed: 12/24/2022] Open
Abstract
A decrease in the circulating levels of adiponectin in obesity increases the risk of metabolic complications, but the role of globular adiponectin, a truncated form produced by proteolytic cleavage, has not been defined. The objective of this investigation was to determine how globular adiponectin is generated and to determine whether this process impacts obesity. The cleavage of recombinant full-length adiponectin into globular adiponectin by plasma in vitro was used to identify Gly-93 as the N-terminal residue after proteolytic processing. The amino acid sequence of the cleavage site suggested thrombin was the protease responsible for cleavage, and inhibitors confirmed its likely involvement. The proteolytic site was modified, and this thrombin-resistant mutant protein was infused for 4 weeks into obese adiponectin-knockout mice that had been on a high-fat diet for 8 weeks. The mutation of the cleavage site ensured that globular adiponectin was not generated, and thus did not confound the actions of the full-length adiponectin. Mice infused with the mutant adiponectin accumulated less fat and had smaller adipocytes compared to mice treated with globular adiponectin, and concurrently had elevated fasting glucose. The data demonstrate that generation of globular adiponectin through the action of thrombin increases both adipose tissue mass and adipocyte size, but it has no effect on fasting glucose levels in the context of obesity.
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Affiliation(s)
- Peter Zahradka
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Canadian Centre for Agri-food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Correspondence: ; Tel.: +1-204-235-3507
| | - Carla G. Taylor
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Canadian Centre for Agri-food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Leslee Tworek
- Canadian Centre for Agri-food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Raissa Perrault
- Canadian Centre for Agri-food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Sofia M’Seffar
- Canadian Centre for Agri-food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Megha Murali
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Tara Loader
- Canadian Centre for Agri-food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Jeffrey T. Wigle
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
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2
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Nagalingam RS, Chattopadhyaya S, Al-Hattab DS, Cheung DYC, Schwartz LY, Jana S, Aroutiounova N, Ledingham DA, Moffatt TL, Landry NM, Bagchi RA, Dixon IMC, Wigle JT, Oudit GY, Kassiri Z, Jassal DS, Czubryt MP. Scleraxis and fibrosis in the pressure-overloaded heart. Eur Heart J 2022; 43:4739-4750. [PMID: 36200607 DOI: 10.1093/eurheartj/ehac362] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 06/02/2022] [Accepted: 06/23/2022] [Indexed: 01/05/2023] Open
Abstract
AIMS In response to pro-fibrotic signals, scleraxis regulates cardiac fibroblast activation in vitro via transcriptional control of key fibrosis genes such as collagen and fibronectin; however, its role in vivo is unknown. The present study assessed the impact of scleraxis loss on fibroblast activation, cardiac fibrosis, and dysfunction in pressure overload-induced heart failure. METHODS AND RESULTS Scleraxis expression was upregulated in the hearts of non-ischemic dilated cardiomyopathy patients, and in mice subjected to pressure overload by transverse aortic constriction (TAC). Tamoxifen-inducible fibroblast-specific scleraxis knockout (Scx-fKO) completely attenuated cardiac fibrosis, and significantly improved cardiac systolic function and ventricular remodelling, following TAC compared to Scx+/+ TAC mice, concomitant with attenuation of fibroblast activation. Scleraxis deletion, after the establishment of cardiac fibrosis, attenuated the further functional decline observed in Scx+/+ mice, with a reduction in cardiac myofibroblasts. Notably, scleraxis knockout reduced pressure overload-induced mortality from 33% to zero, without affecting the degree of cardiac hypertrophy. Scleraxis directly regulated transcription of the myofibroblast marker periostin, and cardiac fibroblasts lacking scleraxis failed to upregulate periostin synthesis and secretion in response to pro-fibrotic transforming growth factor β. CONCLUSION Scleraxis governs fibroblast activation in pressure overload-induced heart failure, and scleraxis knockout attenuated fibrosis and improved cardiac function and survival. These findings identify scleraxis as a viable target for the development of novel anti-fibrotic treatments.
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Affiliation(s)
- Raghu S Nagalingam
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.,Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
| | - Sikta Chattopadhyaya
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.,Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
| | - Danah S Al-Hattab
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.,Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
| | - David Y C Cheung
- Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
| | - Leah Y Schwartz
- Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
| | - Sayantan Jana
- Department of Physiology, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Canada
| | - Nina Aroutiounova
- Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
| | - D Allison Ledingham
- Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
| | - Teri L Moffatt
- Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
| | - Natalie M Landry
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.,Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
| | - Rushita A Bagchi
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Ian M C Dixon
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.,Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
| | - Jeffrey T Wigle
- Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada.,Department of Biochemistry and Medical Genetics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Gavin Y Oudit
- Department of Physiology, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Canada.,Division of Cardiology, Department of Medicine, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
| | - Zamaneh Kassiri
- Department of Physiology, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Canada
| | - Davinder S Jassal
- Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada.,Department of Internal Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Michael P Czubryt
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.,Institute of Cardiovascular Sciences, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
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3
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Sabbir MG, Wigle JT, Taylor CG, Zahradka P. Growth State-Dependent Expression of Arachidonate Lipoxygenases in the Human Endothelial Cell Line EA.hy926. Cells 2022; 11:cells11162478. [PMID: 36010555 PMCID: PMC9406857 DOI: 10.3390/cells11162478] [Citation(s) in RCA: 2] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 08/05/2022] [Accepted: 08/07/2022] [Indexed: 11/30/2022] Open
Abstract
Endothelial cells regulate vascular homeostasis through the secretion of various paracrine molecules, including bioactive lipids, but little is known regarding the enzymes responsible for generating these lipids under either physiological or pathophysiological conditions. Arachidonate lipoxygenase (ALOX) expression was therefore investigated in confluent and nonconfluent EA.h926 endothelial cells, which represent the normal quiescent and proliferative states, respectively. mRNAs for ALOX15, ALOX15B, and ALOXE3 were detected in EA.hy926 cells, with the highest levels present in confluent cells compared to nonconfluent cells. In contrast, ALOX5, ALOX12, and ALOX12B mRNAs were not detected. At the protein level, only ALOX15B and ALOXE3 were detected but only in confluent cells. ALOXE3 was also observed in confluent human umbilical artery endothelial cells (HUAEC), indicating that its expression, although previously unreported, may be a general feature of endothelial cells. Exposure to laminar flow further increased ALOXE3 levels in EA.hy926 cells and HUAECs. The evidence obtained in this study indicates that proliferative status and shear stress are both important factors that mediate endothelial ALOX gene expression. The presence of ALOX15B and ALOXE3 exclusively in quiescent human endothelial cells suggests their activity likely contributes to the maintenance of a healthy endothelium.
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Affiliation(s)
- Mohammad G. Sabbir
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Jeffrey T. Wigle
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Carla G. Taylor
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Peter Zahradka
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
- Correspondence: ; Tel.: +204-235-3507; Fax: +204-237-4018
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4
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Leung RF, George AM, Roussel EM, Faux MC, Wigle JT, Eisenstat DD. Genetic Regulation of Vertebrate Forebrain Development by Homeobox Genes. Front Neurosci 2022; 16:843794. [PMID: 35546872 PMCID: PMC9081933 DOI: 10.3389/fnins.2022.843794] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 03/14/2022] [Indexed: 01/19/2023] Open
Abstract
Forebrain development in vertebrates is regulated by transcription factors encoded by homeobox, bHLH and forkhead gene families throughout the progressive and overlapping stages of neural induction and patterning, regional specification and generation of neurons and glia from central nervous system (CNS) progenitor cells. Moreover, cell fate decisions, differentiation and migration of these committed CNS progenitors are controlled by the gene regulatory networks that are regulated by various homeodomain-containing transcription factors, including but not limited to those of the Pax (paired), Nkx, Otx (orthodenticle), Gsx/Gsh (genetic screened), and Dlx (distal-less) homeobox gene families. This comprehensive review outlines the integral role of key homeobox transcription factors and their target genes on forebrain development, focused primarily on the telencephalon. Furthermore, links of these transcription factors to human diseases, such as neurodevelopmental disorders and brain tumors are provided.
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Affiliation(s)
- Ryan F. Leung
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
| | - Ankita M. George
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
| | - Enola M. Roussel
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
| | - Maree C. Faux
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
- Department of Surgery, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | - Jeffrey T. Wigle
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
| | - David D. Eisenstat
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
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5
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Lieben Louis X, Raj P, Meikle Z, Yu L, Susser SE, MacInnis S, Duhamel TA, Wigle JT, Netticadan T. Resveratrol prevents palmitic-acid-induced cardiomyocyte contractile impairment. Can J Physiol Pharmacol 2019; 97:1132-1140. [PMID: 31374178 DOI: 10.1139/cjpp-2019-0051] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Long-chain saturated fatty acids, especially palmitic acid (PA), contribute to cardiomyocyte lipotoxicity. This study tests the effects of PA on adult rat cardiomyocyte contractile function and proteins associated with calcium regulating cardiomyocyte contraction and relaxation. Adult rat cardiomyocytes were pretreated with resveratrol (Resv) and then treated with PA. For the reversal study, cardiomyocytes were incubated with PA prior to treatment with Resv. Cardiomyocyte contractility, ratio of rod- to round-shaped cardiomyocytes, and Hoechst staining were used to measure functional and morphological changes in cardiomyocytes. Protein expression of sarco-endoplasmic reticulum ATPase 2a (SERCA2a), native phospholamban (PLB) and phosphorylated PLB (pPLB ser16 and pPLB thr17), and troponin I (TnI) and phosphorylated TnI (pTnI) were measured. SERCA2a activity was also measured. Our results show that PA (200 μM) decreased the rate of cardiomyocyte relaxation, reduced the number of rod-shaped cardiomyocytes, and increased the number of cells with condensed nuclei; pre-treating cardiomyocytes with Resv significantly prevented these changes. Post-treatment with Resv did not reverse morphological changes induced by PA. Protein expression levels of SERCA2a, PLB, pPLBs, TnI, and pTnI were unchanged by PA or Resv. SERCA2a activity assay showed that Vmax and Iono ratio were increased with PA and pre-treatment with Resv prevented this increase. In conclusion, our results show that Resv protect cardiomyocytes from contractile dysfunction induced by PA.
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Affiliation(s)
- Xavier Lieben Louis
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.,Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.,Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen, Research Centre, Winnipeg, MB R2H 2A6, Canada.,Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Pema Raj
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.,Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen, Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Zach Meikle
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.,Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Liping Yu
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen, Research Centre, Winnipeg, MB R2H 2A6, Canada.,Agriculture and Agri-Food Canada, Winnipeg, MB R2H 2A6, Canada
| | - Shannel E Susser
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.,Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Shayla MacInnis
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Todd A Duhamel
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.,Health, Leisure & Human Performance Research Institute, Faculty of Kinesiology & Recreation Management, University of Manitoba, MB R3E 0J9, Canada
| | - Jeffrey T Wigle
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.,Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Thomas Netticadan
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.,Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen, Research Centre, Winnipeg, MB R2H 2A6, Canada.,Agriculture and Agri-Food Canada, Winnipeg, MB R2H 2A6, Canada
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6
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Morissette MP, Susser SE, Stammers AN, Moffatt TL, Wigle JT, Wigle TJ, Netticadan T, Premecz S, Jassal DS, O’Hara KA, Duhamel TA. Exercise-induced increases in the expression and activity of cardiac sarcoplasmic reticulum calcium ATPase 2 is attenuated in AMPKα2kinase-dead mice. Can J Physiol Pharmacol 2019; 97:786-795. [DOI: 10.1139/cjpp-2018-0737] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Exercise enhances cardiac sarcoplasmic reticulum Ca2+-ATPase 2a (SERCA2a) function through unknown mechanisms. The present study tested the hypothesis that the positive effects of exercise on SERCA2a expression and function in the left ventricle is dependent on adenosine-monophosphate-activated protein kinase (AMPK) α2 function. AMPKα2kinase-dead (KD) transgenic mice, which overexpress inactivated AMPKα2subunit, and wild-type C57Bl/6 (WT) mice were randomized into sedentary groups or groups with access to running wheels. After 5 months, exercised KD mice exhibited shortened deceleration time compared with sedentary KD mice. In left ventricular tissue, the ratio of phosphorylated AMPKαThr172:total AMPKα was 65% lower (P < 0.05) in KD mice compared with WT mice. The left ventricle of KD mice had 37% lower levels of SERCA2a compared with WT mice. Although exercise increased SERCA2a protein levels in WT mice by 53%, this response of exercise was abolished in exercised KD mice. Exercise training reduced total phospholamban protein content by 23% in both the WT and KD mice but remained 20% higher overall in KD mice. Collectively, these data suggest that AMPKα influences SERCA2a and phospholamban protein content in the sedentary and exercised heart, and that exercise-induced changes in SERCA2a protein are dependent on AMPKα function.
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Affiliation(s)
- Marc P. Morissette
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
- Health, Leisure, and Human Performance Research Institute, Faculty of Kinesiology and Recreation Management, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Shanel E. Susser
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
- Health, Leisure, and Human Performance Research Institute, Faculty of Kinesiology and Recreation Management, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Andrew N. Stammers
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
- Health, Leisure, and Human Performance Research Institute, Faculty of Kinesiology and Recreation Management, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Teri L. Moffatt
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
- Health, Leisure, and Human Performance Research Institute, Faculty of Kinesiology and Recreation Management, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Jeffrey T. Wigle
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
- Department of Biochemistry and Medical Genetics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R2E 3N4, Canada
| | - Theodore J. Wigle
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
- Health, Leisure, and Human Performance Research Institute, Faculty of Kinesiology and Recreation Management, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Thomas Netticadan
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Agriculture and Agri-Food Canada, Winnipeg, MB R3C 3G7, Canada
| | - Sheena Premecz
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
| | - Davinder S. Jassal
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Section of Cardiology, Department of Internal Medicine, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB R3A 1R9, Canada
| | - Kimberley A. O’Hara
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
- Health, Leisure, and Human Performance Research Institute, Faculty of Kinesiology and Recreation Management, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Todd A. Duhamel
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
- Health, Leisure, and Human Performance Research Institute, Faculty of Kinesiology and Recreation Management, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
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7
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Lieben Louis X, Meikle Z, Chan L, DeGagne G, Cummer R, Meikle S, Krishnan S, Yu L, Netticadan T, Wigle JT. Divergent Effects of Resveratrol on Rat Cardiac Fibroblasts and Cardiomyocytes. Molecules 2019; 24:molecules24142604. [PMID: 31319579 PMCID: PMC6680709 DOI: 10.3390/molecules24142604] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 11/27/2022] Open
Abstract
In this study, we tested the potential cardioprotective effects of the phytoalexin resveratrol (Rsv) on primary adult rat cardiac fibroblasts (CF), myofibroblasts (MF) and cardiomyocytes. Adult rat CF and cardiomyocytes were isolated from male 10-week old Sprague–Dawley rats, cultured for either 24 h (cardiomyocytes) or 48 h (CF) before treatments. To isolate MF, CF were trypsinized after 48 h in culture, seeded in fresh plates and cultured for 24 h prior to treatment. All three cells were then treated for a further 24 h with a range of Rsv doses. In CF and MF, cell proliferation, viability, apoptosis assays were performed with or without Rsv treatment for 24 h. In cardiomyocytes, cell viability and apoptosis assay were performed 24 h after treatment. In separate experiments, CF was pre-incubated with estrogen, tamoxifen and fulvestrant for 30 min prior to Rsv treatment. Rsv treatment decreased proliferation of both fibroblasts and myofibroblasts. Rsv treatment also increased the proportion of dead CF and MF in a dose dependent manner. However, treatment with Rsv did not induce cell death in adult cardiomyocytes. There was an increase in the percentage of cells with condensed nuclei with Rsv treatment in both CF and MF, but not in cardiomyocytes. Treatment with estrogen, tamoxifen and fulvestrant alone or in combination with Rsv did not have any additional effects on CF survival. Our results demonstrate that treatment with Rsv can inhibit cell proliferation and induce cell death in rat CF and MF, while not affecting cardiomyocyte survival. We also demonstrated that the induction of cell death in CF with Rsv treatment was independent of estrogen receptor alpha (ERα) signaling.
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Affiliation(s)
- Xavier Lieben Louis
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Zach Meikle
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Laura Chan
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Garret DeGagne
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Rebecca Cummer
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Shannon Meikle
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Sampath Krishnan
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Liping Yu
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada
- Agriculture and Agri-Food Canada, Winnipeg Winnipeg, MB R2H 2A6, Canada
| | - Thomas Netticadan
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.
- Agriculture and Agri-Food Canada, Winnipeg Winnipeg, MB R2H 2A6, Canada.
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Jeffrey T Wigle
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
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8
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Louis XL, Raj P, Chan L, Zieroth S, Netticadan T, Wigle JT. Are the cardioprotective effects of the phytoestrogen resveratrol sex-dependent? 1. Can J Physiol Pharmacol 2018; 97:503-514. [PMID: 30576226 DOI: 10.1139/cjpp-2018-0544] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [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: 12/26/2022]
Abstract
Cardiovascular disease (CVD) is the number one cause of death in both men and women. Younger women have a lower risk for CVD, but their risk increases considerably after menopause when estrogen levels decrease. The cardiovascular protective properties of estrogen are mediated through decreasing vascular inflammation and progression of atherosclerosis, decreasing endothelial cell damage by preventing apoptosis and anti-hypertrophic mechanisms. Estrogen also regulates glucose and lipid levels, which are 2 important risk factors for CVD. Resveratrol (RES), a cardioprotective polyphenolic compound, is classified as a phytoestrogen due its capacity to bind to and modulate estrogen receptor signalling. Due to its estrogen-like property, we speculate that the cardioprotective effects of RES treatment could be sex-dependent. Based on earlier reports and more recent data from our lab presented here, we found that RES treatment may have more favourable cardiovascular outcomes in females than in males. This review will discuss estrogen- and phytoestrogen-mediated cardioprotection, with a specific focus on sex-dependent effects reported in preclinical and clinical studies.
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Affiliation(s)
- Xavier Lieben Louis
- a Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.,b Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R2E 3N4, Canada
| | - Pema Raj
- c Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R2E 0J9, Canada.,d Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen, Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Laura Chan
- a Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.,b Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R2E 3N4, Canada
| | - Shelley Zieroth
- c Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R2E 0J9, Canada.,e Section of Cardiology, Department of Medicine, University of Manitoba, Winnipeg, MB R3A 1R9, Canada
| | - Thomas Netticadan
- d Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen, Research Centre, Winnipeg, MB R2H 2A6, Canada.,f Agriculture and Agri-Food Canada, Winnipeg, MB R3C 3G7, Canada
| | - Jeffrey T Wigle
- a Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.,b Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R2E 3N4, Canada
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9
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Zeglinski MR, Moghadam AR, Ande SR, Sheikholeslami K, Mokarram P, Sepehri Z, Rokni H, Mohtaram NK, Poorebrahim M, Masoom A, Toback M, Sareen N, Saravanan S, Jassal DS, Hashemi M, Marzban H, Schaafsma D, Singal P, Wigle JT, Czubryt MP, Akbari M, Dixon IM, Ghavami S, Gordon JW, Dhingra S. Myocardial Cell Signaling During the Transition to Heart Failure. Compr Physiol 2018; 9:75-125. [DOI: 10.1002/cphy.c170053] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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10
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Aloud BM, Raj P, McCallum J, Kirby C, Louis XL, Jahan F, Yu L, Hiebert B, Duhamel TA, Wigle JT, Blewett H, Netticadan T. Cyanidin 3-O-glucoside prevents the development of maladaptive cardiac hypertrophy and diastolic heart dysfunction in 20-week-old spontaneously hypertensive rats. Food Funct 2018; 9:3466-3480. [PMID: 29878020 DOI: 10.1039/c8fo00730f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The present study investigated the effects of cyanidin 3-O-glucoside (C3G) in cardiomyocytes (CM) and fibroblasts exposed to endothelin 1 (ET1), as well as in the spontaneously hypertensive rat (SHR) model, alone or in combination with hydrochlorothiazide (HCT). Adult rat CM and cardiac fibroblasts (CF) were pretreated with C3G and co-incubated with ET1 (10-7 M) for 24 hours. Five-week-old male SHR and their normotensive controls, Wistar-Kyoto rats (WKY), received one of 4 treatments via oral gavage daily for 15 weeks: (1) water (control); (2) C3G (10 mg per kg per day); (3) HCT (10 mg per kg per day); (4) C3G + HCT (10 mg per kg per day each). Blood pressure (BP) was measured at 1, 8 and 15 weeks. Echocardiography measurements were performed at 15 weeks. C3G prevented ET1-induced CM death and hypertrophy. Stimulating CF with ET1 did not induce their phenoconversion; nevertheless, C3G inhibited un-stimulated CF differentiation. HCT slowed the rise of systolic BP (SBP) in the SHR over time (week 1: SHRs control = 161 ± 6.3 mmHg, SHRs HCT = 129 ± 6.3 mmHg; week 15: SHRs control = 201 ± 7.3 mmHg, SHRs HCT = 168 ± 7.3 mmHg), but C3G had no effect on SBP (week 1: SHRs control = 161 ± 6.3 mmHg, SHRs C3G = 126 ± 6.3 mmHg; week 15: SHRs control = 201 ± 7.3 mmHg, SHRs C3G = 186 ± 7.3 mmHg). SHRs treated with C3G, HCT, and C3G + HCT had lower left ventricular mass and shorter isovolumetric relaxation time compared to control SHRs. C3G ameliorated cardiac hypertrophy and diastolic dysfunction in SHRs.
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Affiliation(s)
- Basma Milad Aloud
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB, Canada
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11
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Raj P, McCallum JL, Kirby C, Grewal G, Yu L, Wigle JT, Netticadan T. Effects of cyanidin 3-0-glucoside on cardiac structure and function in an animal model of myocardial infarction. Food Funct 2018; 8:4089-4099. [PMID: 28990610 DOI: 10.1039/c7fo00709d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cyanidin 3-0-glucoside (CG) is a polyphenol with potential health benefits. In this study, we investigated, for the first time, the cardioprotective effects of CG in an animal model of myocardial infarction (MI), a major cause of death worldwide. Sham and MI rats were administered CG (10 mg kg-1 day-1) daily for one week prior to surgery, and 8 weeks post-surgery. Echocardiography was performed to assess cardiac structure and function at 4 and 8 weeks. At 4 weeks, MI rats had significantly lower body mass when compared to control rats, and CG administration significantly prevented this decrease. Four-week MI rats also showed significantly increased left ventricle dilation, end systolic and end diastolic volumes in comparison to controls, and CG significantly prevented these adverse changes. Ejection fraction was significantly lower in 4-week MI rats in comparison to controls, and CG had no effect on this parameter. At 8 weeks, body mass was significantly lower in MI rats when compared to control rats, and CG significantly prevented this decrease. At 8 weeks, MI rats showed a significant increase in left ventricle dilation and isovolumic relaxation time, while ejection fraction was significantly lower when compared to controls; these parameters were not altered by CG treatment. Eight-week MI rats had significantly higher level of oxidative stress in heart tissue in comparison to controls, and CG administration did not prevent this increase. In conclusion, administration of CG was able to significantly preserve body mass in both 4 and 8 weeks MI rats, as well as significantly prevent cardiac dilation in 4 weeks MI rats. However, CG was unable to sustain this cardioprotection, as cardiac structure and function were not significantly improved in 8 weeks MI rats.
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Affiliation(s)
- Pema Raj
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Canada.
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12
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Nagalingam RS, Safi HA, Al-Hattab DS, Bagchi RA, Landry NM, Dixon IMC, Wigle JT, Czubryt MP. Regulation of cardiac fibroblast MMP2 gene expression by scleraxis. J Mol Cell Cardiol 2018; 120:64-73. [PMID: 29750994 DOI: 10.1016/j.yjmcc.2018.05.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 04/19/2018] [Accepted: 05/07/2018] [Indexed: 12/20/2022]
Abstract
Remodeling of the cardiac extracellular matrix is responsible for a number of the detrimental effects on heart function that arise secondary to hypertension, diabetes and myocardial infarction. This remodeling consists both of an increase in new matrix protein synthesis, and an increase in the expression of matrix metalloproteinases (MMPs) that degrade existing matrix structures. Previous studies utilizing knockout mice have demonstrated clearly that MMP2 plays a pathogenic role during matrix remodeling, thus it is important to understand the mechanisms that regulate MMP2 gene expression. We have shown that the transcription factor scleraxis is an important inducer of extracellular matrix gene expression in the heart that may also control MMP2 expression. In the present study, we demonstrate that scleraxis directly transactivates the proximal MMP2 gene promoter, resulting in increased histone acetylation, and identify a specific E-box sequence in the promoter to which scleraxis binds. Cardiac myo-fibroblasts isolated from scleraxis knockout mice exhibited dramatically decreased MMP2 expression; however, scleraxis over-expression in knockout cells could rescue this loss. We further show that regulation of MMP2 gene expression by the pro-fibrotic cytokine TGFβ occurs via a scleraxis-dependent mechanism: TGFβ induces recruitment of scleraxis to the MMP2 promoter, and TGFβ was unable to up-regulate MMP2 expression in cells lacking scleraxis due to either gene knockdown or knockout. These results reveal that scleraxis can exert control over both extracellular matrix synthesis and breakdown, and thus may contribute to matrix remodeling in wound healing and disease.
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Affiliation(s)
- Raghu S Nagalingam
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Manitoba, Canada
| | - Hamza A Safi
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Manitoba, Canada
| | - Danah S Al-Hattab
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Manitoba, Canada
| | - Rushita A Bagchi
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Manitoba, Canada
| | - Natalie M Landry
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Manitoba, Canada
| | - Ian M C Dixon
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Manitoba, Canada
| | - Jeffrey T Wigle
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Manitoba, Canada; Department of Biochemistry and Medical Genetics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Michael P Czubryt
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Manitoba, Canada.
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13
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Gupta SS, Zeglinski MR, Rattan SG, Landry NM, Ghavami S, Wigle JT, Klonisch T, Halayko AJ, Dixon IMC. Inhibition of autophagy inhibits the conversion of cardiac fibroblasts to cardiac myofibroblasts. Oncotarget 2018; 7:78516-78531. [PMID: 27705938 PMCID: PMC5346657 DOI: 10.18632/oncotarget.12392] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [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: 08/04/2016] [Accepted: 09/20/2016] [Indexed: 11/29/2022] Open
Abstract
The incidence of heart failure with concomitant cardiac fibrosis is very high in developed countries. Fibroblast activation in heart is causal to cardiac fibrosis as they convert to hypersynthetic cardiac myofibroblasts. There is no known treatment for cardiac fibrosis. Myofibroblasts contribute to the inappropriate remodeling of the myocardial interstitium, which leads to reduced cardiac function and ultimately heart failure. Elevated levels of autophagy have been linked to stress-induced ventricular remodeling and other cardiac diseases. Previously, we had shown that TGF-β1 treatment of human atrial fibroblasts both induced autophagy and enhanced the fibrogenic response supporting a linkage between the myofibroblast phenotype and autophagy. We now demonstrate that with in vitro culture of primary rat cardiac fibroblasts, inhibition of autophagy represses fibroblast to myofibroblast phenoconversion. Culturing unpassaged cardiac fibroblasts for 72 hours on plastic tissue culture plates is associated with elevated α-smooth muscle actin (α-SMA) expression. This activation parallels increased microtubule-associated protein 1A/1B-light chain 3 (LC-3β II) protein expression. Inhibition of autophagy with bafilomycin-A1 (Baf-A1) and chloroquine (CQ) in cardiac fibroblasts significantly reduces α-SMA and extracellular domain A fibronectin (ED-A FN) protein vs untreated controls. Myofibroblast cell migration and contractility were significantly reduced following inhibition of autophagy. These data support the possibility of a causal link between cardiac fibroblast-to-myofibroblast phenoconversion and autophagy.
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Affiliation(s)
- Shivika S Gupta
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Matthew R Zeglinski
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Sunil G Rattan
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Natalie M Landry
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Saeid Ghavami
- Department of Human Anatomy and Cell Science, Basic Medical Sciences Building, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.,Children's Hospital Research Institute of Manitoba, John Buhler Research Centre, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jeffrey T Wigle
- Department of Biochemistry and Medical Genetics, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Thomas Klonisch
- Department of Human Anatomy and Cell Science, Basic Medical Sciences Building, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Andrew J Halayko
- Children's Hospital Research Institute of Manitoba, John Buhler Research Centre, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.,Department of Physiology and Pathophysiology, Internal Medicine and Pediatrics and Child Health, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ian M C Dixon
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
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14
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Northcott JM, Czubryt MP, Wigle JT. Vascular senescence and ageing: a role for the MEOX proteins in promoting endothelial dysfunction. Can J Physiol Pharmacol 2017; 95:1067-1077. [PMID: 28727928 DOI: 10.1139/cjpp-2017-0149] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [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: 01/02/2023]
Abstract
In the vascular system, ageing is accompanied by the accrual of senescent cells and is associated with an increased risk of vascular disease. Endothelial cell (EC) dysfunction is a hallmark of vascular disease and is characterized by decreased angiogenic potential, reduced nitric oxide bioavailability, impaired vasodilation, increased production of ROS, and enhanced inflammation. In ECs, the major producer of nitric oxide is the endothelial nitric oxide synthase (eNOS) enzyme that is encoded by the NOS3 gene. NOS3/eNOS function is tightly regulated at both the transcriptional and post-transcriptional levels to maintain normal vascular function. A key transcriptional regulator of eNOS expression is p53, which has been shown to play a central role in mediating cellular senescence and thereby vascular dysfunction. Herein, we show that, in ECs, the MEOX homeodomain transcription factors decrease the expression of genes involved in angiogenesis, repress eNOS expression at the mRNA and protein levels, and increase the expression of p53. These findings support a role for the MEOX proteins in promoting endothelial dysfunction.
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Affiliation(s)
- Josette M Northcott
- a Institute of Cardiovascular Sciences, St. Boniface Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.,b Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Michael P Czubryt
- a Institute of Cardiovascular Sciences, St. Boniface Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.,c Department of Physiology and Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Jeffrey T Wigle
- a Institute of Cardiovascular Sciences, St. Boniface Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada.,b Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
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15
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Zhang Q, Zagozewski J, Cheng S, Dixit R, Zhang S, de Melo J, Mu X, Klein WH, Brown NL, Wigle JT, Schuurmans C, Eisenstat DD. Regulation of Brn3b by DLX1 and DLX2 is required for retinal ganglion cell differentiation in the vertebrate retina. Development 2017; 144:1698-1711. [PMID: 28356311 PMCID: PMC5450843 DOI: 10.1242/dev.142042] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 03/17/2017] [Indexed: 12/24/2022]
Abstract
Regulated retinal ganglion cell (RGC) differentiation and axonal guidance is required for a functional visual system. Homeodomain and basic helix-loop-helix transcription factors are required for retinogenesis, as well as patterning, differentiation and maintenance of specific retinal cell types. We hypothesized that Dlx1, Dlx2 and Brn3b homeobox genes function in parallel intrinsic pathways to determine RGC fate and therefore generated Dlx1/Dlx2/Brn3b triple-knockout mice. A more severe retinal phenotype was found in the Dlx1/Dlx2/Brn3b-null retinas than was predicted by combining features of the Brn3b single- and Dlx1/Dlx2 double-knockout retinas, including near total RGC loss with a marked increase in amacrine cells in the ganglion cell layer. Furthermore, we discovered that DLX1 and DLX2 function as direct transcriptional activators of Brn3b expression. Knockdown of Dlx2 expression in primary embryonic retinal cultures and Dlx2 gain of function in utero strongly support that DLX2 is both necessary and sufficient for Brn3b expression in vivo. We suggest that ATOH7 specifies RGC-committed progenitors and that Dlx1 and Dlx2 function both downstream of ATOH7 and in parallel, but cooperative, pathways that involve regulation of Brn3b expression to determine RGC fate. Summary:Dlx1/2 homeobox genes regulate retinal ganglion cell (RGC) differentiation by directly activating Brn3b expression; accordingly, Dlx1/Dlx2/Brn3b triple-knockout mice exhibit near complete RGC loss.
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Affiliation(s)
- Qi Zhang
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada R3E 0J9
| | - Jamie Zagozewski
- Department of Medical Genetics, University of Alberta, Edmonton, Canada T6G 2H7
| | - Shaohong Cheng
- Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Canada R3A 1S1
| | - Rajiv Dixit
- Hotchkiss Brain Institute, University of Calgary, Canada T2N 4N1
| | - Shunzhen Zhang
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Canada R3E 3J7
| | - Jimmy de Melo
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada R3E 0J9
| | - Xiuqian Mu
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | - William H Klein
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Nadean L Brown
- Department of Cell Biology and Human Anatomy, University of California, Davis, CA 95616, Canada
| | - Jeffrey T Wigle
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Canada R3E 3J7
| | - Carol Schuurmans
- Hotchkiss Brain Institute, University of Calgary, Canada T2N 4N1
| | - David D Eisenstat
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada R3E 0J9 .,Department of Medical Genetics, University of Alberta, Edmonton, Canada T6G 2H7.,Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Canada R3A 1S1.,Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Canada R3E 3J7.,Department of Ophthalmology, University of Manitoba, Winnipeg, Canada R3T 2N2
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16
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Roche PL, Nagalingam RS, Bagchi RA, Aroutiounova N, Belisle BMJ, Wigle JT, Czubryt MP. Role of scleraxis in mechanical stretch-mediated regulation of cardiac myofibroblast phenotype. Am J Physiol Cell Physiol 2016; 311:C297-307. [PMID: 27357547 DOI: 10.1152/ajpcell.00333.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [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: 11/24/2015] [Accepted: 06/27/2016] [Indexed: 12/21/2022]
Abstract
The phenotype conversion of fibroblasts to myofibroblasts plays a key role in the pathogenesis of cardiac fibrosis. Numerous triggers of this conversion process have been identified, including plating of cells on solid substrates, cytokines such as transforming growth factor-β, and mechanical stretch; however, the underlying mechanisms remain incompletely defined. Recent studies from our laboratory revealed that the transcription factor scleraxis is a key regulator of cardiac fibroblast phenotype and extracellular matrix expression. Here we report that mechanical stretch induces type I collagen expression and morphological changes indicative of cardiac myofibroblast conversion, as well as scleraxis expression via activation of the scleraxis promoter. Scleraxis causes phenotypic changes similar to stretch, and the effect of stretch is attenuated in scleraxis null cells. Scleraxis was also sufficient to upregulate expression of vinculin and F-actin, to induce stress fiber and focal adhesion formation, and to attenuate both cell migration and proliferation, further evidence of scleraxis-mediated regulation of fibroblast to myofibroblast conversion. Together, these data confirm that scleraxis is sufficient to promote the myofibroblast phenotype and is a required effector of stretch-mediated conversion. Scleraxis may thus represent a potential target for the development of novel antifibrotic therapies aimed at inhibiting myofibroblast formation.
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Affiliation(s)
- Patricia L Roche
- St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada; and
| | - Raghu S Nagalingam
- St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada; and
| | - Rushita A Bagchi
- St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada; and
| | - Nina Aroutiounova
- St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Breanna M J Belisle
- St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jeffrey T Wigle
- St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada; Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Michael P Czubryt
- St. Boniface Hospital Albrechtsen Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada; and
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17
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Bagchi RA, Wang R, Jahan F, Wigle JT, Czubryt MP. Regulation of scleraxis transcriptional activity by serine phosphorylation. J Mol Cell Cardiol 2016; 92:140-8. [PMID: 26883788 DOI: 10.1016/j.yjmcc.2016.02.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 02/12/2016] [Accepted: 02/13/2016] [Indexed: 10/22/2022]
Abstract
Cardiac fibroblasts are the major extracellular matrix producing cells in the heart. Our laboratory was the first to demonstrate that the transcription factor scleraxis induces collagen 1α2 expression in both cardiac fibroblasts and myofibroblasts. Here we identify a novel post-translational mechanism by which scleraxis activity is regulated and determine its effect on transcription of genes targeted by scleraxis. Putative serine phosphorylation sites on scleraxis were revealed by in silico analysis using motif prediction software. Mutation of key serine residues to alanine, which cannot be phosphorylated, significantly attenuated the expression of fibrillar type I collagen and myofibroblast marker genes that are normally induced by scleraxis. Down-regulation of collagen 1α2 expression was due to reduced binding of the non-phosphorylated scleraxis mutant to specific E-box DNA-binding sites within the promoter as determined by chromatin immunoprecipitation in human cardiac myofibroblast cells and by electrophoretic mobility shift assay. This is the first evidence suggesting that scleraxis is phosphorylated under basal conditions. The phosphorylation sequence matched that targeted by Casein Kinase 2, and inhibition of this kinase activity disrupted the ability of scleraxis to modulate the expression of its target genes while also attenuating TGFβ-induced expression of type I collagen and myofibroblast phenotype conversion marker genes. These results demonstrate a novel mechanism for regulation of scleraxis activity, which may prove to be tractable for pharmacologic manipulation.
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Affiliation(s)
- Rushita A Bagchi
- St. Boniface Albrechtsen Research Centre, Winnipeg, Manitoba, Canada; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ryan Wang
- St. Boniface Albrechtsen Research Centre, Winnipeg, Manitoba, Canada; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Fahmida Jahan
- St. Boniface Albrechtsen Research Centre, Winnipeg, Manitoba, Canada; Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jeffrey T Wigle
- St. Boniface Albrechtsen Research Centre, Winnipeg, Manitoba, Canada; Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Michael P Czubryt
- St. Boniface Albrechtsen Research Centre, Winnipeg, Manitoba, Canada; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada.
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Zeglinski MR, Roche P, Hnatowich M, Jassal DS, Wigle JT, Czubryt MP, Dixon IMC. TGFβ1 regulates Scleraxis expression in primary cardiac myofibroblasts by a Smad-independent mechanism. Am J Physiol Heart Circ Physiol 2016; 310:H239-49. [DOI: 10.1152/ajpheart.00584.2015] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [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: 07/23/2015] [Accepted: 11/10/2015] [Indexed: 11/22/2022]
Abstract
In cardiac wound healing following myocardial infarction (MI), relatively inactive resident cardiac fibroblasts phenoconvert to hypersynthetic/secretory myofibroblasts that produce large quantities of extracellular matrix (ECM) and fibrillar collagen proteins. Our laboratory and others have identified TGFβ1 as being a persistent stimulus in the chronic and inappropriate wound healing phase that is marked by hypertrophic scarring and eventual stiffening of the entire myocardium, ultimately leading to the pathogenesis of heart failure following MI. Ski is a potent negative regulator of TGFβ/Smad signaling with known antifibrotic effects. Conversely, Scleraxis is a potent profibrotic basic helix-loop-helix transcription factor that stimulates fibrillar collagen expression. We hypothesize that TGFβ1 induces Scleraxis expression by a novel Smad-independent pathway. Our data support the hypothesis that Scleraxis expression is induced by TGFβ1 through a Smad-independent pathway in the cardiac myofibroblast. Specifically, we demonstrate that TGFβ1 stimulates p42/44 (Erk1/2) kinases, which leads to increased Scleraxis expression. Inhibition of MEK1/2 using U0126 led to a sequential temporal reduction of phospho-p42/44 and subsequent Scleraxis expression. We also found that adenoviral Ski expression in primary myofibroblasts caused a significant repression of endogenous Scleraxis expression at both the mRNA and protein levels. Thus we have identified a novel TGFβ1-driven, Smad-independent, signaling cascade that may play an important role in regulating the fibrotic response in activated cardiac myofibroblasts following cardiac injury.
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Affiliation(s)
- Matthew R. Zeglinski
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Patricia Roche
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Mark Hnatowich
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Davinder S. Jassal
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Internal Medicine, College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jeffrey T. Wigle
- Department of Biochemistry and Medical Genetics, Institute of Cardiovascular Sciences, College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada; and
| | - Michael P. Czubryt
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ian M. C. Dixon
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
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Zagozewski JL, Zhang Q, Pinto VI, Wigle JT, Eisenstat DD. The role of homeobox genes in retinal development and disease. Dev Biol 2014; 393:195-208. [PMID: 25035933 DOI: 10.1016/j.ydbio.2014.07.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [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: 03/24/2014] [Revised: 07/02/2014] [Accepted: 07/08/2014] [Indexed: 11/18/2022]
Abstract
Homeobox genes are an evolutionarily conserved class of transcription factors that are critical for development of many organ systems, including the brain and eye. During retinogenesis, homeodomain-containing transcription factors, which are encoded by homeobox genes, play essential roles in the regionalization and patterning of the optic neuroepithelium, specification of retinal progenitors and differentiation of all seven of the retinal cell classes that derive from a common progenitor. Homeodomain transcription factors control retinal cell fate by regulating the expression of target genes required for retinal progenitor cell fate decisions and for terminal differentiation of specific retinal cell types. The essential role of homeobox genes during retinal development is demonstrated by the number of human eye diseases, including colobomas and anophthalmia, which are attributed to homeobox gene mutations. In the following review, we highlight the role of homeodomain transcription factors during retinogenesis and regulation of their gene targets. Understanding the complexities of vertebrate retina development will enhance our ability to drive differentiation of specific retinal cell types towards novel cell-based replacement therapies for retinal degenerative diseases.
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Affiliation(s)
- Jamie L Zagozewski
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada T6G 2H7
| | - Qi Zhang
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada R3E 0J9
| | - Vanessa I Pinto
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada R3E 0J9
| | - Jeffrey T Wigle
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada R3E 0J9; Institute of Cardiovascular Sciences, St. Boniface Hospital Research Institute, Winnipeg, MB, Canada R2H 2A6
| | - David D Eisenstat
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada T6G 2H7; Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada R3E 0J9; Department of Pediatrics, University of Alberta, Edmonton, AB, Canada T6G 1C9.
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20
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Santiago JJ, McNaughton LJ, Koleini N, Ma X, Bestvater B, Nickel BE, Fandrich RR, Wigle JT, Freed DH, Arora RC, Kardami E. High molecular weight fibroblast growth factor-2 in the human heart is a potential target for prevention of cardiac remodeling. PLoS One 2014; 9:e97281. [PMID: 24827991 PMCID: PMC4020823 DOI: 10.1371/journal.pone.0097281] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [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: 08/08/2013] [Accepted: 04/18/2014] [Indexed: 11/18/2022] Open
Abstract
Fibroblast growth factor 2 (FGF-2) is a multifunctional protein synthesized as high (Hi-) and low (Lo-) molecular weight isoforms. Studies using rodent models showed that Hi- and Lo-FGF-2 exert distinct biological activities: after myocardial infarction, rat Lo-FGF-2, but not Hi-FGF-2, promoted sustained cardioprotection and angiogenesis, while Hi-FGF-2, but not Lo-FGF-2, promoted myocardial hypertrophy and reduced contractile function. Because there is no information regarding Hi-FGF-2 in human myocardium, we undertook to investigate expression, regulation, secretion and potential tissue remodeling-associated activities of human cardiac (atrial) Hi-FGF-2. Human patient-derived atrial tissue extracts, as well as pericardial fluid, contained Hi-FGF-2 isoforms, comprising, respectively, 53%(±20 SD) and 68% (±25 SD) of total FGF-2, assessed by western blotting. Human atrial tissue-derived primary myofibroblasts (hMFs) expressed and secreted predominantly Hi-FGF-2, at about 80% of total. Angiotensin II (Ang II) up-regulated Hi-FGF-2 in hMFs, via activation of both type 1 and type 2 Ang II receptors; the ERK pathway; and matrix metalloprotease-2. Treatment of hMFs with neutralizing antibodies selective for human Hi-FGF-2 (neu-AbHi-FGF-2) reduced accumulation of proteins associated with fibroblast-to-myofibroblast conversion and fibrosis, including α-smooth muscle actin, extra-domain A fibronectin, and procollagen. Stimulation of hMFs with recombinant human Hi-FGF-2 was significantly more potent than Lo-FGF-2 in upregulating inflammation-associated proteins such as pro-interleukin-1β and plasminogen-activator-inhibitor-1. Culture media conditioned by hMFs promoted cardiomyocyte hypertrophy, an effect that was prevented by neu-AbHi-FGF-2 in vitro. In conclusion, we have documented that Hi-FGF-2 represents a substantial fraction of FGF-2 in human cardiac (atrial) tissue and in pericardial fluid, and have shown that human Hi-FGF-2, unlike Lo-FGF-2, promotes deleterious (pro-fibrotic, pro-inflammatory, and pro-hypertrophic) responses in vitro. Selective targeting of Hi-FGF-2 production may, therefore, reduce pathological remodelling in the human heart.
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Affiliation(s)
- Jon-Jon Santiago
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Leslie J. McNaughton
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Navid Koleini
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Xin Ma
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Human Anatomy & Cell Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Brian Bestvater
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Barbara E. Nickel
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Robert R. Fandrich
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Human Anatomy & Cell Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jeffrey T. Wigle
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Darren H. Freed
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Surgery, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Rakesh C. Arora
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Surgery, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Elissavet Kardami
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Human Anatomy & Cell Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada
- * E-mail:
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Cunnington RH, Northcott JM, Ghavami S, Filomeno KL, Jahan F, Kavosh MS, Davies JJL, Wigle JT, Dixon IMC. The Ski-Zeb2-Meox2 pathway provides a novel mechanism for regulation of the cardiac myofibroblast phenotype. Development 2014. [DOI: 10.1242/dev.107359] [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: 11/20/2022]
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Cunnington RH, Northcott JM, Ghavami S, Filomeno KL, Jahan F, Kavosh MS, Davies JJL, Wigle JT, Dixon IMC. The Ski-Zeb2-Meox2 pathway provides a novel mechanism for regulation of the cardiac myofibroblast phenotype. J Cell Sci 2013; 127:40-9. [PMID: 24155330 DOI: 10.1242/jcs.126722] [Citation(s) in RCA: 33] [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] [Indexed: 11/20/2022] Open
Abstract
Cardiac fibrosis is linked to fibroblast-to-myofibroblast phenoconversion and proliferation but the mechanisms underlying this are poorly understood. Ski is a negative regulator of TGF-β-Smad signaling in myofibroblasts, and might redirect the myofibroblast phenotype back to fibroblasts. Meox2 could alter TGF-β-mediated cellular processes and is repressed by Zeb2. Here, we investigated whether Ski diminishes the myofibroblast phenotype by de-repressing Meox2 expression and function through repression of Zeb2 expression. We show that expression of Meox1 and Meox2 mRNA and Meox2 protein is reduced during phenoconversion of fibroblasts to myofibroblasts. Overexpression of Meox2 shifts the myofibroblasts into fibroblasts, whereas the Meox2 DNA-binding mutant has no effect on myofibroblast phenotype. Overexpression of Ski partially restores Meox2 mRNA expression levels to those in cardiac fibroblasts. Expression of Zeb2 increased during phenoconversion and Ski overexpression reduces Zeb2 expression in first-passage myofibroblasts. Furthermore, expression of Meox2 is decreased in scar following myocardial infarction, whereas Zeb2 protein expression increases in the infarct scar. Thus Ski modulates the cardiac myofibroblast phenotype and function through suppression of Zeb2 by upregulating the expression of Meox2. This cascade might regulate cardiac myofibroblast phenotype and presents therapeutic options for treatment of cardiac fibrosis.
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Affiliation(s)
- Ryan H Cunnington
- Department of Physiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
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23
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Northcott JM, Yeganeh A, Taylor CG, Zahradka P, Wigle JT. Adipokines and the cardiovascular system: mechanisms mediating health and disease. Can J Physiol Pharmacol 2012; 90:1029-59. [DOI: 10.1139/y2012-053] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review focuses on the role of adipokines in the maintenance of a healthy cardiovascular system, and the mechanisms by which these factors mediate the development of cardiovascular disease in obesity. Adipocytes are the major cell type comprising the adipose tissue. These cells secrete numerous factors, termed adipokines, into the blood, including adiponectin, leptin, resistin, chemerin, omentin, vaspin, and visfatin. Adipose tissue is a highly vascularised endocrine organ, and different adipose depots have distinct adipokine secretion profiles, which are altered with obesity. The ability of many adipokines to stimulate angiogenesis is crucial for adipose tissue expansion; however, excessive blood vessel growth is deleterious. As well, some adipokines induce inflammation, which promotes cardiovascular disease progression. We discuss how these 7 aforementioned adipokines act upon the various cardiovascular cell types (endothelial progenitor cells, endothelial cells, vascular smooth muscle cells, pericytes, cardiomyocytes, and cardiac fibroblasts), the direct effects of these actions, and their overall impact on the cardiovascular system. These were chosen, as these adipokines are secreted predominantly from adipocytes and have known effects on cardiovascular cells.
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Affiliation(s)
- Josette M. Northcott
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E OJ9, Canada
- Institute of Cardiovascular Sciences, and Medicine, St. Boniface Hospital Research Centre, Winnipeg, MB R2H 2A6, Canada
| | - Azadeh Yeganeh
- Department of Physiology, University of Manitoba, Winnipeg, MB R3E OJ9, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Research Centre, Winnipeg, MB R3T 2N2, Canada
| | - Carla G. Taylor
- Department of Physiology, University of Manitoba, Winnipeg, MB R3E OJ9, Canada
- Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3E OJ9, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Research Centre, Winnipeg, MB R3T 2N2, Canada
| | - Peter Zahradka
- Department of Physiology, University of Manitoba, Winnipeg, MB R3E OJ9, Canada
- Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3E OJ9, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Research Centre, Winnipeg, MB R3T 2N2, Canada
| | - Jeffrey T. Wigle
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E OJ9, Canada
- Institute of Cardiovascular Sciences, and Medicine, St. Boniface Hospital Research Centre, Winnipeg, MB R2H 2A6, Canada
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24
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Dixon IMC, Cunnington RH, Douville JM, Bathe KL, Rattan SG, Freed DH, Wigle JT. Identifying novel mechanisms of cardiac myofibroblast phenotype modulation. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1059.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | | | | | - Jeffrey T Wigle
- Biochemistry and Medical GeneticsU of ManitobaWinnipegMBCanada
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25
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Douville JM, Cheung DYC, Herbert KL, Moffatt T, Wigle JT. Mechanisms of MEOX1 and MEOX2 regulation of the cyclin dependent kinase inhibitors p21 and p16 in vascular endothelial cells. PLoS One 2011; 6:e29099. [PMID: 22206000 PMCID: PMC3243699 DOI: 10.1371/journal.pone.0029099] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [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: 07/19/2011] [Accepted: 11/21/2011] [Indexed: 12/31/2022] Open
Abstract
Senescence, the state of permanent cell cycle arrest, has been associated
with endothelial cell dysfunction and atherosclerosis. The cyclin dependent
kinase inhibitors p21CIP1/WAF1 and p16INK4a govern the
G1/S cell cycle checkpoint and are essential for determining whether
a cell enters into an arrested state. The homeodomain transcription factor
MEOX2 is an important regulator of vascular cell proliferation and is a direct
transcriptional activator of both p21CIP1/WAF1 and p16INK4a.
MEOX1 and MEOX2 have been shown to be partially functionally redundant during
development, suggesting that they regulate similar target genes in
vivo. We compared the ability of MEOX1 and MEOX2 to activate p21CIP1/WAF1
and p16INK4a expression and induce endothelial cell cycle arrest.
Our results demonstrate for the first time that MEOX1 regulates the MEOX2
target genes p21CIP1/WAF1 and p16INK4a. In addition,
increased expression of either of the MEOX homeodomain transcription factors
leads to cell cycle arrest and endothelial cell senescence. Furthermore, we
show that the mechanism of transcriptional activation of these cyclin dependent
kinase inhibitor genes by MEOX1 and MEOX2 is distinct. MEOX1 and MEOX2 activate
p16INK4a in a DNA binding dependent manner, whereas they induce
p21CIP1/WAF1 in a DNA binding independent manner.
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Affiliation(s)
- Josette M. Douville
- Institute of Cardiovascular Sciences,
St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada
- Department of Biochemistry and Medical
Genetics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - David Y. C. Cheung
- Institute of Cardiovascular Sciences,
St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada
| | - Krista L. Herbert
- Institute of Cardiovascular Sciences,
St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada
| | - Teri Moffatt
- Institute of Cardiovascular Sciences,
St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada
| | - Jeffrey T. Wigle
- Institute of Cardiovascular Sciences,
St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada
- Department of Biochemistry and Medical
Genetics, University of Manitoba, Winnipeg, Manitoba, Canada
- * E-mail:
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26
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Cunnington RH, Douville JM, Bathe KL, Wigle JT, Dixon IM. c‐Ski upregulation of Meox2 diminishes cardiac myofibroblast phenotype. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.1032.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Jeffrey T. Wigle
- Biochemistry and Medical GeneticsUniversity of ManitobaWinnipegMBCanada
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Baxter SA, Cheung DY, Bocangel P, Kim HK, Herbert K, Douville JM, Jangamreddy JR, Zhang S, Eisenstat DD, Wigle JT. Regulation of the lymphatic endothelial cell cycle by the PROX1 homeodomain protein. Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 2011; 1813:201-12. [DOI: 10.1016/j.bbamcr.2010.10.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 10/01/2010] [Accepted: 10/25/2010] [Indexed: 11/28/2022]
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Guo J, Massaeli H, Xu J, Jia Z, Wigle JT, Mesaeli N, Zhang S. Extracellular K+ concentration controls cell surface density of IKr in rabbit hearts and of the HERG channel in human cell lines. J Clin Invest 2009; 119:2745-57. [PMID: 19726881 DOI: 10.1172/jci39027] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Accepted: 06/10/2009] [Indexed: 12/19/2022] Open
Abstract
Although the modulation of ion channel gating by hormones and drugs has been extensively studied, much less is known about how cell surface ion channel expression levels are regulated. Here, we demonstrate that the cell surface density of both the heterologously expressed K+ channel encoded by the human ether-a-go-go-related gene (HERG) and its native counterpart, the rapidly activating delayed rectifier K+ channel (IKr), in rabbit hearts in vivo is precisely controlled by extracellular K+ concentration ([K+]o) within a physiologically relevant range. Reduction of [K+]o led to accelerated internalization and degradation of HERG channels within hours. Confocal analysis revealed colocalization between HERG and ubiquitin during the process of HERG internalization, and overexpression of ubiquitin facilitated HERG degradation under low [K+]o. The HERG channels colocalized with a marker of multivesicular bodies during internalization, and the internalized HERG channels were targeted to lysosomes. Our results provide the first evidence to our knowledge that the cell surface density of a voltage-gated K+ channel, HERG, is regulated by a biological factor, extracellular K+. Because hypokalemia is known to exacerbate long QT syndrome (LQTS) and Torsades de pointes tachyarrhythmias, our findings provide a potential mechanistic link between hypokalemia and LQTS.
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Affiliation(s)
- Jun Guo
- Department of Physiology, Queen's University, Kingston, Ontario, Canada
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29
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Baxter SA, Herbert K, Kim H, Cheung DY, Wigle JT. PROX1 regulation of endothelial cell cycle progression. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.660.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shannon A Baxter
- Biochemistry and Medical GeneticsUniversity of ManitobaWinnipegMBCanada
- Institute of Cardiovascular SciencesSt. Boniface General Hospital Research CentreWinnipegMBCanada
| | - Krista Herbert
- Biochemistry and Medical GeneticsUniversity of ManitobaWinnipegMBCanada
- Institute of Cardiovascular SciencesSt. Boniface General Hospital Research CentreWinnipegMBCanada
| | - Hae‐Kwang Kim
- Biochemistry and Medical GeneticsUniversity of ManitobaWinnipegMBCanada
- Institute of Cardiovascular SciencesSt. Boniface General Hospital Research CentreWinnipegMBCanada
| | - David Y.C. Cheung
- Biochemistry and Medical GeneticsUniversity of ManitobaWinnipegMBCanada
- Institute of Cardiovascular SciencesSt. Boniface General Hospital Research CentreWinnipegMBCanada
| | - Jeffrey T. Wigle
- Biochemistry and Medical GeneticsUniversity of ManitobaWinnipegMBCanada
- Institute of Cardiovascular SciencesSt. Boniface General Hospital Research CentreWinnipegMBCanada
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Abstract
Homeobox genes are an evolutionarily conserved class of transcription factors that are key regulators of developmental processes such as regional specification, patterning, migration and differentiation. In both mouse and humans, the developing forebrain is marked by distinct boundaries of homeobox gene expression at different developmental time points. These genes regulate the patterning of the forebrain along the dorsal/ventral and rostral/caudal axes and are also essential for the differentiation of specific neuronal subtypes. Inhibitory interneurons that arise from the ganglionic eminences and migrate tangentially to the neocortex and hippocampus are dramatically affected by mutations in several homeobox genes. In this review, we discuss the identification, expression patterns, loss- and/or gain-of-function models, and confirmed transcriptional targets for a set of homeobox genes required for the correct development of the forebrain in the mouse. In humans, mutations of homeobox genes expressed in the forebrain have been shown to result in mental retardation, epilepsy or movement disorders. The number of homeobox genes currently linked to human nervous system disease is surprisingly low, perhaps reflecting the essential functions of these genes throughout embryogenesis or the degree of functional redundancy during central nervous system development.
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Affiliation(s)
- J T Wigle
- Department of Biochemistry & Medical Genetics; Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Winnipeg, Manitoba, Canada
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31
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de Melo J, Zhou QP, Zhang Q, Zhang S, Fonseca M, Wigle JT, Eisenstat DD. Dlx2 homeobox gene transcriptional regulation of Trkb neurotrophin receptor expression during mouse retinal development. Nucleic Acids Res 2007; 36:872-84. [PMID: 18086710 PMCID: PMC2241891 DOI: 10.1093/nar/gkm1099] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Dlx homeobox genes are first expressed in embryonic retina at E11.5. The Dlx1/Dlx2 null retina has a reduced ganglion cell layer (GCL), with loss of late-born differentiated retinal ganglion cells (RGCs) due to increased apoptosis. TrkB signaling is proposed to regulate the dynamics of RGC apoptosis throughout development. DLX2 expression markedly precedes the onset of TrkB expression in the GCL; TrkB co-expression with Dlx2 and RGC markers is well-established by E13.5. In the Dlx1/Dlx2 null retina, TrkB expression is significantly reduced by E16.5. We demonstrated that DLX2 binds to a specific region of the TrkB promoter in retinal neuroepithelium during embryogenesis. In vitro confirmation and the functional consequences of DLX2 binding to this TrkB regulatory region support TrkB as a Dlx2 transcriptional target. Furthermore, ectopic Dlx2 expression in retinal explants activates TrkB expression and Dlx2 knockdown in primary retinal cultures results in reduced TrkB expression. RGC differentiation and survival require the coordinated expression of transcription factors. This study establishes a direct transcriptional relationship between a homeodomain protein involved in RGC differentiation and a neurotrophin receptor implicated in RGC survival. Signaling mediated by TrkB may contribute to survival of late-born RGCs whose terminal differentiation is regulated by Dlx gene function.
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Affiliation(s)
- Jimmy de Melo
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada
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Abstract
During embryonic development, the cardiovascular system first forms and then gives rise to the lymphatic vascular system. Homeobox genes are essential for both the development of the blood and lymphatic vascular systems, as well as for their maintenance in the adult. These genes all encode proteins that are transcription factors that contain a well conserved DNA binding motif, the homeodomain. It is through the homeodomain that these transcription factors bind to the promoters of target genes and regulate their expression. Although many homeodomain proteins have been found to be expressed within the vascular systems, little is known about their downstream target genes. This review highlights recent advances made in the identification of novel genes downstream of the homeodomain proteins that are necessary for regulating vascular cellular processes such as proliferation, migration, and endothelial tube formation. Factors known to regulate the functions of vascular cells via modulating the expression of homeobox genes will be discussed. We will also review current methods used to identify and characterize downstream target genes of homeodomain proteins.
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Affiliation(s)
- Josette M Douville
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre and Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R2H 2A6, Canada
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Hurtado C, Wigle JT, Dibrov E, Maddaford TG, Pierce GN. A comparison of adenovirally delivered molecular methods to inhibit Na+/Ca2+ exchange. J Mol Cell Cardiol 2007; 43:49-53. [PMID: 17540404 DOI: 10.1016/j.yjmcc.2007.04.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [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: 12/21/2006] [Revised: 03/21/2007] [Accepted: 04/17/2007] [Indexed: 11/21/2022]
Abstract
The ability to use molecular biology tools to down-regulate Na+/Ca2+ exchanger (NCX) expression will allow us to better understand the regulation of Ca(i)2+ and contractility in heart. Three different techniques to deplete NCX expression were compared: short hairpin RNA (shRNA), antisense RNA and exchanger inhibitory peptide expression via adenoviral transfection. Our results demonstrate that the most efficient method to deplete NCX expression and activity from cardiomyocytes is shRNA. It is also possible to replace the endogenous NCX with alternative isoforms or mutant forms of the NCX. Adenovirally delivered shRNA is an efficient tool for the study of the NCX and could be adapted for many other cardiac proteins.
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Affiliation(s)
- Cecilia Hurtado
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, and Departments of Physiology, Faculties of Medicine and Pharmacy, University of Manitoba, Winnipeg, MB Canada R2H 2A6
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Le TN, Du G, Fonseca M, Zhou QP, Wigle JT, Eisenstat DD. Dlx homeobox genes promote cortical interneuron migration from the basal forebrain by direct repression of the semaphorin receptor neuropilin-2. J Biol Chem 2007; 282:19071-81. [PMID: 17259176 DOI: 10.1074/jbc.m607486200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [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: 01/31/2023] Open
Abstract
Dlx homeobox genes play an important role in vertebrate forebrain development. Dlx1/Dlx2 null mice die at birth with an abnormal cortical phenotype, including impaired differentiation and migration of GABAergic interneurons to the neocortex. However, the molecular basis for these defects downstream of loss of Dlx1/Dlx2 function is unknown. Neuropilin-2 (NRP-2) is a receptor for Class III semaphorins, which inhibit neuronal migration. Herein, we show that Neuropilin-2 is a specific DLX1 and DLX2 transcriptional target by applying chromatin immunoprecipitation to embryonic forebrain tissues. Both homeobox proteins repress Nrp-2 expression in vitro, confirming the functional significance of DLX binding. Furthermore, the homeodomain of DLX1 and DLX2 is necessary for DNA binding and this binding is essential for Dlx repression of Nrp-2 expression. Of importance, there is up-regulated and aberrant expression of NRP-2 in the forebrains of Dlx1/Dlx2 null mice. This is the first report that DLX1 or DLX2 can function as transcriptional repressors. Our data show that DLX proteins specifically mediate the repression of Neuropilin-2 in the developing forebrain. As well, our results support the hypothesis that down-regulation of Neuropilin-2 expression may facilitate tangential interneuron migration from the basal forebrain.
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Affiliation(s)
- Trung N Le
- Department of Biochemistry and Medical Genetics, Manitoba Institute of Cell Biology, University of Manitoba, Winnipeg, Manitoba R3E 0V9, Canada
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Dupasquier CMC, Weber AM, Ander BP, Rampersad PP, Steigerwald S, Wigle JT, Mitchell RW, Kroeger EA, Gilchrist JSC, Moghadasian MM, Lukas A, Pierce GN. Effects of dietary flaxseed on vascular contractile function and atherosclerosis during prolonged hypercholesterolemia in rabbits. Am J Physiol Heart Circ Physiol 2006; 291:H2987-96. [PMID: 16844912 DOI: 10.1152/ajpheart.01179.2005] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [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: 01/12/2023]
Abstract
Dietary flaxseed has significant anti-atherogenic effects. However, the limits of this action and its effects on vascular contractile function are not known. We evaluated the effects of flaxseed supplementation on atherosclerosis and vascular function under prolonged hypercholesterolemic conditions in New Zealand White rabbits assigned to one of four groups for 6, 8, or 16 wk of feeding: regular diet (RG), 10% flaxseed-supplemented diet (FX), 0.5% cholesterol-supplemented diet (CH), and 0.5% cholesterol- and 10% flaxseed-supplemented diet (CF). Cholesterol feeding resulted in elevated plasma cholesterol levels and the development of atherosclerosis. The CF group had significantly less atherosclerotic lesions in the aorta and carotid arteries after 6 and 8 wk than the CH animals. However, the anti-atherogenic effect of flaxseed supplementation was completely attenuated by 16 wk. Maximal tension induced in aortic rings either by KCl or norepinephrine was not impaired by dietary cholesterol until 16 wk. This functional impairment was not prevented by including flaxseed in the high-cholesterol diet. Aortic rings from the cholesterol-fed rabbits exhibited an impaired relaxation response to acetylcholine at all time points examined. Including flaxseed in the high-cholesterol diet completely normalized the relaxation response at 6 and 8 wk and partially restored it at 16 wk. No significant changes in the relaxation response induced by sodium nitroprusside were observed in any of the groups. In summary, dietary flaxseed is a valuable strategy to limit cholesterol-induced atherogenesis as well as abnormalities in endothelial-dependent vasorelaxation. However, these beneficial effects were attenuated during prolonged hypercholesterolemic conditions.
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Affiliation(s)
- C M C Dupasquier
- Canadian Centre for Agri-Food Research in Health and Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
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Lin J, Friesen MT, Bocangel P, Cheung D, Rawszer K, Wigle JT. Characterization of Mesenchyme Homeobox 2 (MEOX2) transcription factor binding to RING finger protein 10. Mol Cell Biochem 2005; 275:75-84. [PMID: 16335786 DOI: 10.1007/s11010-005-0823-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [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: 11/29/2022]
Abstract
The molecular mechanisms by which Mesenchyme Homeobox 2 (Meox2) regulates the proliferation, differentiation and migration of vascular smooth muscle cells and cardiomyocytes are not known. The discovery of MEOX2 binding proteins will aid in understanding how MEOX2 functions as a regulator of these key cellular processes. To identify MEOX2 binding proteins, a yeast two-hybrid screen of a human heart cDNA library was performed using a deleted MEOX2 bait protein that does not contain the histidine/glutamine rich region (MEOX2deltaHQ). Eleven putative interacting proteins were identified including RING finger protein 10 (RNF10). In vitro pull-down assays and co-immunoprecipitation studies in mammalian cells further supported the yeast data demonstrating RNF10 bound to MEOX2. The minimal RNF10 binding region of MEOX2 was determined to be a central region between the histidine/glutamine rich domain and the homeodomain (amino acids 101-185). The amino terminal region of RNF10, containing the RING finger domain, was not essential for the binding to MEOX2. Our results also demonstrated that MEOX2 activation of the p21WAF1 promoter was enhanced by RNF10 co-expression.
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Affiliation(s)
- Jijin Lin
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba
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Lin J, Guo J, Gang H, Wojciechowski P, Wigle JT, Zhang S. Intracellular K+ is required for the inactivation-induced high-affinity binding of cisapride to HERG channels. Mol Pharmacol 2005; 68:855-65. [PMID: 15967876 DOI: 10.1124/mol.105.012278] [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: 11/22/2022] Open
Abstract
Many commonly used medications can cause long QT syndrome and thus increase the risk of life-threatening arrhythmias. High-affinity human Ether-à-go-go-related gene (HERG) potassium channel blockade by structurally diverse compounds is almost exclusively responsible for this side effect. Understanding drug-HERG channel interactions is an important step in avoiding drug-induced long QT syndromes. Previous studies have found that disrupting HERG inactivation reduces the degree of drug block and have suggested that the inactivated state is the preferential state for drug binding to HERG channels. However, recent studies have also shown that inactivation does not dictate drug sensitivity of HERG channels. In the present study, we examined the effect of inactivation gating on cisapride block of HERG. Modulation of HERG inactivation was achieved by either changing extracellular K+ or Cs+ concentrations or by mutations of the channel. We found that although inactivation facilitated cisapride block of the HERG K+ current, it was not coupled with cisapride block of HERG when the Cs+ current was recorded. Furthermore, cisapride block of the HERG K+ current was not linked with inactivation in the mutant HERG channels F656V and F656M. Our results suggest that inactivation facilitates cisapride block of HERG channels through affecting the positioning of Phe-656.
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Affiliation(s)
- Jijin Lin
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre and Department of Physiology, Faculty of Medicine, University of Manitoba, 351 Tache Avenue, Winnipeg, Manitoba, Canada R2H 2A6
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Wigle JT, Harvey N, Detmar M, Lagutina I, Grosveld G, Gunn MD, Jackson DG, Oliver G. An essential role for Prox1 in the induction of the lymphatic endothelial cell phenotype. EMBO J 2002; 21:1505-13. [PMID: 11927535 PMCID: PMC125938 DOI: 10.1093/emboj/21.7.1505] [Citation(s) in RCA: 669] [Impact Index Per Article: 30.4] [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] [Indexed: 12/24/2022] Open
Abstract
The process of angiogenesis has been well documented, but little is known about the biology of lymphatic endothelial cells and the molecular mechanisms controlling lymphangiogenesis. The homeobox gene Prox1 is expressed in a subpopulation of endothelial cells that, after budding from veins, gives rise to the mammalian lymphatic system. In Prox1(-)(/-) embryos, this budding becomes arrested at around embryonic day (E)11.5, resulting in embryos without lymphatic vasculature. Unlike the endothelial cells that bud off in E11.5 wild-type embryos, those of Prox1-null embryos did not co-express any lymphatic markers such as VEGFR-3, LYVE-1 or SLC. Instead, the mutant cells appeared to have a blood vascular phenotype, as determined by their expression of laminin and CD34. These results suggest that Prox1 activity is required for both maintenance of the budding of the venous endothelial cells and differentiation toward the lymphatic phenotype. On the basis of our findings, we propose that a blood vascular phenotype is the default fate of budding embryonic venous endothelial cells; upon expression of Prox1, these budding cells adopt a lymphatic vasculature phenotype.
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Affiliation(s)
- Jeffrey T. Wigle
- Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105, Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA and MRC Human Immunology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK Present address: Division of Stroke and Vascular Disease and Department of Biochemistry and Medical Genetics, St Boniface General Hospital Research Centre, Winnipeg, Canada Corresponding author e-mail:
| | - Natasha Harvey
- Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105, Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA and MRC Human Immunology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK Present address: Division of Stroke and Vascular Disease and Department of Biochemistry and Medical Genetics, St Boniface General Hospital Research Centre, Winnipeg, Canada Corresponding author e-mail:
| | - Michael Detmar
- Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105, Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA and MRC Human Immunology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK Present address: Division of Stroke and Vascular Disease and Department of Biochemistry and Medical Genetics, St Boniface General Hospital Research Centre, Winnipeg, Canada Corresponding author e-mail:
| | - Irina Lagutina
- Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105, Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA and MRC Human Immunology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK Present address: Division of Stroke and Vascular Disease and Department of Biochemistry and Medical Genetics, St Boniface General Hospital Research Centre, Winnipeg, Canada Corresponding author e-mail:
| | - Gerard Grosveld
- Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105, Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA and MRC Human Immunology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK Present address: Division of Stroke and Vascular Disease and Department of Biochemistry and Medical Genetics, St Boniface General Hospital Research Centre, Winnipeg, Canada Corresponding author e-mail:
| | - Michael D. Gunn
- Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105, Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA and MRC Human Immunology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK Present address: Division of Stroke and Vascular Disease and Department of Biochemistry and Medical Genetics, St Boniface General Hospital Research Centre, Winnipeg, Canada Corresponding author e-mail:
| | - David G. Jackson
- Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105, Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA and MRC Human Immunology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK Present address: Division of Stroke and Vascular Disease and Department of Biochemistry and Medical Genetics, St Boniface General Hospital Research Centre, Winnipeg, Canada Corresponding author e-mail:
| | - Guillermo Oliver
- Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105, Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA and MRC Human Immunology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK Present address: Division of Stroke and Vascular Disease and Department of Biochemistry and Medical Genetics, St Boniface General Hospital Research Centre, Winnipeg, Canada Corresponding author e-mail:
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Wielowieyski PA, Wigle JT, Salih M, Hum P, Tuana BS. Alternative splicing in intracellular loop connecting domains II and III of the alpha 1 subunit of Cav1.2 Ca2+ channels predicts two-domain polypeptides with unique C-terminal tails. J Biol Chem 2001; 276:1398-406. [PMID: 11010971 DOI: 10.1074/jbc.m006868200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Novel splice variants of the alpha(1) subunit of the Ca(v)1.2 voltage-gated Ca(2+) channel were identified that predicted two truncated forms of the alpha(1) subunit comprising domains I and II generated by alternative splicing in the intracellular loop region linking domains II and III. In rabbit heart splice variant 1 (RH-1), exon 19 was deleted, which resulted in a reading frameshift of exon 20 with a premature termination codon and a novel 19-amino acid carboxyl-terminal tail. In the RH-2 variant, exons 17 and 18 were deleted, leading to a reading frameshift of exons 19 and 20 with a premature stop codon and a novel 62-amino acid carboxyl-terminal tail. RNase protection assays with RH-1 and RH-2 cRNA probes confirmed the expression in cardiac and neuronal tissue but not skeletal muscle. The deduced amino acid sequence from full-length cDNAs encoding the two variants predicted polypeptides of 99.0 and 99.2 kDa, which constituted domains I and II of the alpha(1) subunit of the Ca(v)1.2 channel. Antipeptide antibodies directed to sequences in the second intracellular loop between domains II and III identified the 240-kDa Ca(v)1.2 subunit in sarcolemmal and heavy sarcoplasmic reticulum (HSR) membranes and a 99-kDa polypeptide in the HSR. An antipeptide antibody raised against unique sequences in the RH-2 variant also identified a 99-kDa polypeptide in the HSR. These data reveal the expression of additional Ca(2+) channel structural units generated by alternative splicing of the Ca(v)1.2 gene.
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Affiliation(s)
- P A Wielowieyski
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
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Wielowieyski PA, Sevinc S, Guzzo R, Salih M, Wigle JT, Tuana BS. Alternative splicing, expression, and genomic structure of the 3' region of the gene encoding the sarcolemmal-associated proteins (SLAPs) defines a novel class of coiled-coil tail-anchored membrane proteins. J Biol Chem 2000; 275:38474-81. [PMID: 10986292 DOI: 10.1074/jbc.m007682200] [Citation(s) in RCA: 26] [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] [Indexed: 11/06/2022] Open
Abstract
The sarcolemmal associated proteins (SLAPs) are encoded by multiple mRNAs that are presumably generated by alternative splicing mechanisms. The amino acid sequence of the SLAP1 isoform exhibited 76% identity with TOP(AP), a topographically graded antigen of the chick visual system. The regions of coiled-coil structure including an 11-heptad acidic amphipathic alpha-helical segment was conserved with a major divergence in sequence noted in the hydrophobic C termini predicted to be transmembrane domains in the two polypeptides. The genomic organization of the 3' region of the SLAP gene indicated that SLAP1 and TOP(AP) are generated by alternative splicing mechanisms, which are conserved among mammalian and avian species. SLAP1/TOP(AP) were encoded by 11 exons distributed over a minimum of 35 kilobase pairs of continuous DNA; 9 of the exons were constitutively expressed, and 2 were alternatively spliced. The exons range in size from 60 to 321 base pairs, and the predicted functional domains within the polypeptides were encompassed by single exons. The introns vary from 0.2 to 10 kilobase pairs and conform to consensus dinucleotide splicing signals. Reverse transcriptase-polymerase chain reaction studies demonstrated that alternative exons (IV and X) of SLAP were expressed in a tissue-specific fashion and developmentally regulated. The alternatively spliced exon X, which encodes the putative transmembrane anchor in TOP(AP), and a constitutively expressed exon XI, which encodes the putative transmembrane domain in SLAP, were found to target these polypeptides to membrane structures. The presence and conservation of termination codons in exons X and XI render expression of the two SLAP1/TOP(AP) transmembrane domains mutually exclusive. These data reveal that TOP(AP) and SLAP are alternatively spliced products of a single gene that encodes a unique class of tail-anchored membrane proteins.
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Affiliation(s)
- P A Wielowieyski
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario K1H 8M5, Canada
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Abstract
Several genes are required during the early phases of liver specification, proliferation and differentiation. Here we report that Prox1 is required for hepatocyte migration. Loss of Prox1 leads to formation of a smaller liver with a reduced population of clustered hepatocytes surrounded by a laminin-rich basal membrane.
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Affiliation(s)
- B Sosa-Pineda
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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42
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Abstract
The lack of specific markers has raised problems in documenting the precise manner by which the lymphatic system develops. Here we report that the homeobox gene Prox1 is expressed in a subpopulation of endothelial cells that by budding and sprouting give rise to the lymphatic system. The initial localization of these cells in the veins and their subsequent budding are both polarized, suggesting that unidentified guidance signals regulate this process. In Prox1 null mice, budding and sprouting is arrested, although vasculogenesis and angiogenesis of the vascular system is unaffected. These findings suggest that Prox1 is a specific and required regulator of the development of the lymphatic system and that the vascular and lymphatic systems develop independently.
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Affiliation(s)
- J T Wigle
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
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Abstract
Although insights have emerged regarding genes controlling the early stages of eye formation, little is known about lens-fibre differentiation and elongation. The expression pattern of the Prox1 homeobox gene suggests it has a role in a variety of embryonic tissues, including lens. To analyse the requirement for Prox1 during mammalian development, we inactivated the locus in mice. Homozygous Prox1-null mice die at mid-gestation from multiple developmental defects; here we describe the specific effect on lens development. Prox1 inactivation causes abnormal cellular proliferation, downregulated expression of the cell-cycle inhibitors Cdkn1b (also known as p27KIP1) and Cdkn1c (also known as p57KIP2), misexpression of E-cadherin and inappropriate apoptosis. Consequently, mutant lens cells fail to polarize and elongate properly, resulting in a hollow lens. Our data provide evidence that the progression of terminal fibre differentiation and elongation is dependent on Prox1 activity during lens development.
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Affiliation(s)
- J T Wigle
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
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Wigle JT, Demchyshyn L, Pratt MA, Staines WA, Salih M, Tuana BS. Molecular cloning, expression, and chromosomal assignment of sarcolemmal-associated proteins. A family of acidic amphipathic alpha-helical proteins associated with the membrane. J Biol Chem 1997; 272:32384-94. [PMID: 9405447 DOI: 10.1074/jbc.272.51.32384] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [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: 02/05/2023] Open
Abstract
Two overlapping cDNAs encoding a novel sarcolemmal associated protein (SLAP) were isolated from a cardiac cDNA expression library by immunoscreening with anti-sarcolemmal antibodies. Further characterization of these clones showed that they belonged to a family of related cDNAs that potentially encode polypeptides of 37, 46, and 74 kDa designated SLAP1, SLAP2, and SLAP3, respectively. The SLAP3 transcript was ubiquitously expressed, whereas SLAP1 and SLAP2 transcripts were predominantly expressed in cardiac, soleus, and smooth muscle. SLAP was encoded by a single gene that mapped to chromosome 3p14.3-21.2, and the various transcripts are likely generated by alternative splicing. The primary structure of SLAP predicted that it would have large regions of coiled-coil structure including an 11-heptad acidic amphipathic alpha-helical segment. The carboxyl-terminal region of the SLAP proteins was predicted to have a transmembrane domain, although there was no discernible signal sequence. SLAPs could only be solubilized from cardiac membrane with detergents suggesting that they were integral membrane proteins. Subcellular distribution studies showed that MYC epitope-tagged SLAP localized to regions of juxtaposition between neighboring cell membranes although an intracellular pool of the protein was also present in cells undergoing apparent cleavage. Immunohistochemical localization of SLAP in cardiac muscle revealed that SLAP associated with the sarcolemma and also displayed a reticular pattern of staining that resembled the transverse tubules and the sarcoplasmic reticulum. The SLAPs define a new family of tail-anchored membrane proteins that exhibit tissue-specific expression and are uniquely situated to serve a variety of roles through their coiled-coil motifs.
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Affiliation(s)
- J T Wigle
- Departments of Pharmacology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
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Ray A, Kyselovic J, Leddy JJ, Wigle JT, Jasmin BJ, Tuana BS. Regulation of dihydropyridine and ryanodine receptor gene expression in skeletal muscle. Role of nerve, protein kinase C, and cAMP pathways. J Biol Chem 1995; 270:25837-44. [PMID: 7592768 DOI: 10.1074/jbc.270.43.25837] [Citation(s) in RCA: 32] [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] [Indexed: 01/26/2023] Open
Abstract
The dihydropyridine (DHP) and ryanodine (RY) receptors play a critical role in depolarization-induced calcium release in skeletal muscle, yet the factors which govern their expression remain unknown. We investigated the roles of electrical activity and trophic factors in the regulation of the genes encoding the alpha 1, alpha 2, and beta subunits of the DHP receptor as well as the RY receptor in rat skeletal muscle in vivo. Muscle paralysis, induced by denervation, had no effect on the DHP receptor mRNA levels while the RY receptor mRNA was decreased. In contrast, chronic superfusion of tetrodotoxin onto the sciatic nerve resulted in a marked increase in mRNA levels and transcriptional activity of both DHP and RY receptor genes. Since nerve can induce changes in second messenger pathways which modulate muscle gene expression, we attempted to identify factors which regulate DHP and RY receptor expression using cultured myotubes. Elevated cAMP levels specifically inhibited the expression of RY receptor mRNA while 12-O-tetradecanoylphorbol-13-acetate, an activator of protein kinase C, increased the transcripts encoding the RY receptor and the alpha 1 subunit of the DHP receptor. Changes in the level of mRNAs were paralleled by altered receptor numbers. Neither cAMP nor protein kinase C altered transcriptional activity of the DHP and RY receptor genes. These results demonstrate that neural factor(s) regulate DHP and RY receptor mRNA levels in vivo via transcriptional mechanisms while protein kinase C and cAMP can modulate DHP and RY receptor transcript levels by a transcription-independent process.
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Affiliation(s)
- A Ray
- Department of Pharmacology, Faculty of Medicine, University of Ottawa, Canada
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