1
|
Oestereicher MA, Wotton JM, Ayabe S, Bou About G, Cheng TK, Choi JH, Clary D, Dew EM, Elfertak L, Guimond A, Haseli Mashhadi H, Heaney JD, Kelsey L, Keskivali-Bond P, Lopez Gomez F, Marschall S, McFarland M, Meziane H, Munoz Fuentes V, Nam KH, Nichtová Z, Pimm D, Bower L, Prochazka J, Rozman J, Santos L, Stewart M, Tanaka N, Ward CS, Willett AME, Wilson R, Braun RE, Dickinson ME, Flenniken AM, Herault Y, Lloyd KCK, Mallon AM, McKerlie C, Murray SA, Nutter LMJ, Sedlacek R, Seong JK, Sorg T, Tamura M, Wells S, Schneltzer E, Fuchs H, Gailus-Durner V, Hrabe de Angelis M, White JK, Spielmann N. Comprehensive ECG reference intervals in C57BL/6N substrains provide a generalizable guide for cardiac electrophysiology studies in mice. Mamm Genome 2023; 34:180-199. [PMID: 37294348 PMCID: PMC10290602 DOI: 10.1007/s00335-023-09995-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/27/2023] [Indexed: 06/10/2023]
Abstract
Reference ranges provide a powerful tool for diagnostic decision-making in clinical medicine and are enormously valuable for understanding normality in pre-clinical scientific research that uses in vivo models. As yet, there are no published reference ranges for electrocardiography (ECG) in the laboratory mouse. The first mouse-specific reference ranges for the assessment of electrical conduction are reported herein generated from an ECG dataset of unprecedented scale. International Mouse Phenotyping Consortium data from over 26,000 conscious or anesthetized C57BL/6N wildtype control mice were stratified by sex and age to develop robust ECG reference ranges. Interesting findings include that heart rate and key elements from the ECG waveform (RR-, PR-, ST-, QT-interval, QT corrected, and QRS complex) demonstrate minimal sexual dimorphism. As expected, anesthesia induces a decrease in heart rate and was shown for both inhalation (isoflurane) and injectable (tribromoethanol) anesthesia. In the absence of pharmacological, environmental, or genetic challenges, we did not observe major age-related ECG changes in C57BL/6N-inbred mice as the differences in the reference ranges of 12-week-old compared to 62-week-old mice were negligible. The generalizability of the C57BL/6N substrain reference ranges was demonstrated by comparison with ECG data from a wide range of non-IMPC studies. The close overlap in data from a wide range of mouse strains suggests that the C57BL/6N-based reference ranges can be used as a robust and comprehensive indicator of normality. We report a unique ECG reference resource of fundamental importance for any experimental study of cardiac function in mice.
Collapse
Affiliation(s)
- Manuela A Oestereicher
- Institute of Experimental Genetics and German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Janine M Wotton
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Shinya Ayabe
- Experimental Animal Division, RIKEN BioResource Research Center, 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074, Japan
| | - Ghina Bou About
- Université de Strasbourg, CNRS, INSERM, Institut de La Clinique de La Souris, PHENOMIN, 1 Rue Laurent Fries, 67404, Illkirch, France
| | - Tsz Kwan Cheng
- The Mary Lyon Centre, MRC Harwell, Harwell Campus, Oxfordshire, OX11 0RD, UK
| | - Jae-Hoon Choi
- Department of Life Science, College of Natural Sciences, Hanyang Institute of Bioscience and Biotechnology, Research Institute for Natural Sciences, Hanyang University, Seoul, 04763, Republic of Korea
| | - Dave Clary
- Mouse Biology Program, University of California, 2795 Second Street Suite 400, Davis, CA, 95618, USA
| | - Emily M Dew
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Lahcen Elfertak
- Université de Strasbourg, CNRS, INSERM, Institut de La Clinique de La Souris, PHENOMIN, 1 Rue Laurent Fries, 67404, Illkirch, France
| | - Alain Guimond
- Université de Strasbourg, CNRS, INSERM, Institut de La Clinique de La Souris, PHENOMIN, 1 Rue Laurent Fries, 67404, Illkirch, France
| | - Hamed Haseli Mashhadi
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SD, UK
| | - Jason D Heaney
- Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Lois Kelsey
- The Centre for Phenogenomics, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5T 3H7, Canada
| | - Piia Keskivali-Bond
- The Mary Lyon Centre, MRC Harwell, Harwell Campus, Oxfordshire, OX11 0RD, UK
| | - Federico Lopez Gomez
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SD, UK
| | - Susan Marschall
- Institute of Experimental Genetics and German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | | | - Hamid Meziane
- Université de Strasbourg, CNRS, INSERM, Institut de La Clinique de La Souris, PHENOMIN, 1 Rue Laurent Fries, 67404, Illkirch, France
| | - Violeta Munoz Fuentes
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SD, UK
| | - Ki-Hoan Nam
- Korea Mouse Phenotyping Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Zuzana Nichtová
- Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Dale Pimm
- The Mary Lyon Centre, MRC Harwell, Harwell Campus, Oxfordshire, OX11 0RD, UK
| | - Lynette Bower
- Mouse Biology Program, University of California, 2795 Second Street Suite 400, Davis, CA, 95618, USA
| | - Jan Prochazka
- Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Rozman
- Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Luis Santos
- The Mary Lyon Centre, MRC Harwell, Harwell Campus, Oxfordshire, OX11 0RD, UK
| | - Michelle Stewart
- The Mary Lyon Centre, MRC Harwell, Harwell Campus, Oxfordshire, OX11 0RD, UK
| | - Nobuhiko Tanaka
- Integrated Bioresource Information Division, RIKEN BioResource Research Center, 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074, Japan
| | - Christopher S Ward
- Integrative Physiology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | | | - Robert Wilson
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SD, UK
| | - Robert E Braun
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Mary E Dickinson
- Integrative Physiology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Ann M Flenniken
- The Centre for Phenogenomics, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5T 3H7, Canada
| | - Yann Herault
- Université de Strasbourg, CNRS, INSERM, Institut de La Clinique de La Souris, PHENOMIN, 1 Rue Laurent Fries, 67404, Illkirch, France
| | - K C Kent Lloyd
- Mouse Biology Program, University of California, 2795 Second Street Suite 400, Davis, CA, 95618, USA
| | - Ann-Marie Mallon
- The Mary Lyon Centre, MRC Harwell, Harwell Campus, Oxfordshire, OX11 0RD, UK
| | - Colin McKerlie
- The Centre for Phenogenomics, The Hospital for Sick Children, Toronto, ON, M5T 3H7, Canada
- Department of Laboratory Medicine & Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Stephen A Murray
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Lauryl M J Nutter
- The Centre for Phenogenomics, The Hospital for Sick Children, Toronto, ON, M5T 3H7, Canada
| | - Radislav Sedlacek
- Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Je Kyung Seong
- Laboratory of Developmental Biology and Genomics, College of Veterinary Medicine, and Interdisciplinary Program for Bioinformatics, Korea Mouse Phenotyping CenterBK21 Plus Program for Advanced Veterinary Science, Research Institute for Veterinary ScienceSeoul National University, 599 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Republic of Korea
| | - Tania Sorg
- Université de Strasbourg, CNRS, INSERM, Institut de La Clinique de La Souris, PHENOMIN, 1 Rue Laurent Fries, 67404, Illkirch, France
| | - Masaru Tamura
- Technology and Development Team for Mouse Phenotype Analysis, RIKEN BioResource Research Center, 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074, Japan
| | - Sara Wells
- The Mary Lyon Centre, MRC Harwell, Harwell Campus, Oxfordshire, OX11 0RD, UK
| | - Elida Schneltzer
- Institute of Experimental Genetics and German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Helmut Fuchs
- Institute of Experimental Genetics and German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Valerie Gailus-Durner
- Institute of Experimental Genetics and German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Martin Hrabe de Angelis
- Institute of Experimental Genetics and German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany.
- Chair of Experimental Genetics, School of Life Science Weihenstephan, Technische 83 Universität München, Alte Akademie 8, 85354, Freising, Germany.
- German Center for Diabetes Research (DZD), Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany.
| | | | - Nadine Spielmann
- Institute of Experimental Genetics and German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| |
Collapse
|
2
|
Bowl MR, Simon MM, Ingham NJ, Greenaway S, Santos L, Cater H, Taylor S, Mason J, Kurbatova N, Pearson S, Bower LR, Clary DA, Meziane H, Reilly P, Minowa O, Kelsey L, Tocchini-Valentini GP, Gao X, Bradley A, Skarnes WC, Moore M, Beaudet AL, Justice MJ, Seavitt J, Dickinson ME, Wurst W, de Angelis MH, Herault Y, Wakana S, Nutter LMJ, Flenniken AM, McKerlie C, Murray SA, Svenson KL, Braun RE, West DB, Lloyd KCK, Adams DJ, White J, Karp N, Flicek P, Smedley D, Meehan TF, Parkinson HE, Teboul LM, Wells S, Steel KP, Mallon AM, Brown SDM. A large scale hearing loss screen reveals an extensive unexplored genetic landscape for auditory dysfunction. Nat Commun 2017; 8:886. [PMID: 29026089 PMCID: PMC5638796 DOI: 10.1038/s41467-017-00595-4] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [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: 11/08/2016] [Accepted: 07/12/2017] [Indexed: 01/27/2023] Open
Abstract
The developmental and physiological complexity of the auditory system is likely reflected in the underlying set of genes involved in auditory function. In humans, over 150 non-syndromic loci have been identified, and there are more than 400 human genetic syndromes with a hearing loss component. Over 100 non-syndromic hearing loss genes have been identified in mouse and human, but we remain ignorant of the full extent of the genetic landscape involved in auditory dysfunction. As part of the International Mouse Phenotyping Consortium, we undertook a hearing loss screen in a cohort of 3006 mouse knockout strains. In total, we identify 67 candidate hearing loss genes. We detect known hearing loss genes, but the vast majority, 52, of the candidate genes were novel. Our analysis reveals a large and unexplored genetic landscape involved with auditory function.The full extent of the genetic basis for hearing impairment is unknown. Here, as part of the International Mouse Phenotyping Consortium, the authors perform a hearing loss screen in 3006 mouse knockout strains and identify 52 new candidate genes for genetic hearing loss.
Collapse
Affiliation(s)
- Michael R Bowl
- Medical Research Council Harwell Institute (Mammalian Genetics Unit and Mary Lyon Centre), Harwell, Oxfordshire, OX11 0RD, UK
| | - Michelle M Simon
- Medical Research Council Harwell Institute (Mammalian Genetics Unit and Mary Lyon Centre), Harwell, Oxfordshire, OX11 0RD, UK
| | - Neil J Ingham
- King's College London, London, SE1 1UL, UK
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Simon Greenaway
- Medical Research Council Harwell Institute (Mammalian Genetics Unit and Mary Lyon Centre), Harwell, Oxfordshire, OX11 0RD, UK
| | - Luis Santos
- Medical Research Council Harwell Institute (Mammalian Genetics Unit and Mary Lyon Centre), Harwell, Oxfordshire, OX11 0RD, UK
| | - Heather Cater
- Medical Research Council Harwell Institute (Mammalian Genetics Unit and Mary Lyon Centre), Harwell, Oxfordshire, OX11 0RD, UK
| | - Sarah Taylor
- Medical Research Council Harwell Institute (Mammalian Genetics Unit and Mary Lyon Centre), Harwell, Oxfordshire, OX11 0RD, UK
| | - Jeremy Mason
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1 SD, UK
| | - Natalja Kurbatova
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1 SD, UK
| | - Selina Pearson
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Lynette R Bower
- Mouse Biology Program, University of California, Davis, California, 95618, USA
| | - Dave A Clary
- Mouse Biology Program, University of California, Davis, California, 95618, USA
| | - Hamid Meziane
- CELPHEDIA, PHENOMIN, Institut Clinique de la Souris (ICS), 1 rue Laurent Fries, Illkirch-Graffenstaden, F-67404, France
| | - Patrick Reilly
- CELPHEDIA, PHENOMIN, Institut Clinique de la Souris (ICS), 1 rue Laurent Fries, Illkirch-Graffenstaden, F-67404, France
| | - Osamu Minowa
- RIKEN BioResource Center, Tsukuba, Ibaraki, 305-0074, Japan
| | - Lois Kelsey
- The Centre for Phenogenomics, Toronto, Ontario, Canada, M5T 3H7
- The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8
- Canada and Mount Sinai Hospital, Toronto, Ontario, Canada, M5G 1X5
| | - Glauco P Tocchini-Valentini
- Monterotondo Mouse Clinic, Italian National Research Council (CNR), Institute of Cell Biology and Neurobiology, I-00015, Monterotondo Scalo, Italy
| | - Xiang Gao
- SKL of Pharmaceutical Biotechnology and Model Animal Research Center, Collaborative Innovation Center for Genetics and Development, Nanjing Biomedical Research Institute, Nanjing University, 210061, Nanjing, China
| | - Allan Bradley
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - William C Skarnes
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Mark Moore
- IMPC, San Anselmo, California, 94960, USA
| | - Arthur L Beaudet
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030, USA
| | - Monica J Justice
- The Centre for Phenogenomics, Toronto, Ontario, Canada, M5T 3H7
- The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8
- Canada and Mount Sinai Hospital, Toronto, Ontario, Canada, M5G 1X5
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030, USA
| | - John Seavitt
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030, USA
| | - Mary E Dickinson
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, 77030, USA
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Ingolstaedter Landstrasse 1, 85764, Neuherberg, Germany
| | - Martin Hrabe de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Ingolstaedter Landstrasse 1, 85764, Neuherberg, Germany
| | - Yann Herault
- CELPHEDIA, PHENOMIN, Institut Clinique de la Souris (ICS), 1 rue Laurent Fries, Illkirch-Graffenstaden, F-67404, France
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 67404, Illkirch, France
- Centre National de la Recherche Scientifique, UMR7104, 67404, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U964, 67404, Illkirch, France
| | | | - Lauryl M J Nutter
- The Centre for Phenogenomics, Toronto, Ontario, Canada, M5T 3H7
- The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8
- Canada and Mount Sinai Hospital, Toronto, Ontario, Canada, M5G 1X5
| | - Ann M Flenniken
- The Centre for Phenogenomics, Toronto, Ontario, Canada, M5T 3H7
- The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8
- Canada and Mount Sinai Hospital, Toronto, Ontario, Canada, M5G 1X5
| | - Colin McKerlie
- The Centre for Phenogenomics, Toronto, Ontario, Canada, M5T 3H7
- The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8
- Canada and Mount Sinai Hospital, Toronto, Ontario, Canada, M5G 1X5
| | | | | | | | - David B West
- Childrens' Hospital Oakland Research Institute, Oakland, California, 94609, USA
| | - K C Kent Lloyd
- Mouse Biology Program, University of California, Davis, California, 95618, USA
| | - David J Adams
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Jacqui White
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Natasha Karp
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Paul Flicek
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1 SD, UK
| | | | - Terrence F Meehan
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1 SD, UK
| | - Helen E Parkinson
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1 SD, UK
| | - Lydia M Teboul
- Medical Research Council Harwell Institute (Mammalian Genetics Unit and Mary Lyon Centre), Harwell, Oxfordshire, OX11 0RD, UK
| | - Sara Wells
- Medical Research Council Harwell Institute (Mammalian Genetics Unit and Mary Lyon Centre), Harwell, Oxfordshire, OX11 0RD, UK
| | - Karen P Steel
- King's College London, London, SE1 1UL, UK
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Ann-Marie Mallon
- Medical Research Council Harwell Institute (Mammalian Genetics Unit and Mary Lyon Centre), Harwell, Oxfordshire, OX11 0RD, UK
| | - Steve D M Brown
- Medical Research Council Harwell Institute (Mammalian Genetics Unit and Mary Lyon Centre), Harwell, Oxfordshire, OX11 0RD, UK.
| |
Collapse
|
3
|
Kelsey L, Flenniken AM, Qu D, Funnell APW, Pearson R, Zhou YQ, Voronina I, Berberovic Z, Wood G, Newbigging S, Weiss ES, Wong M, Quach I, Yeh SYS, Deshwar AR, Scott IC, McKerlie C, Henkelman M, Backx P, Simpson J, Osborne L, Rossant J, Crossley M, Bruneau B, Adamson SL. ENU-induced mutation in the DNA-binding domain of KLF3 reveals important roles for KLF3 in cardiovascular development and function in mice. PLoS Genet 2013; 9:e1003612. [PMID: 23874215 PMCID: PMC3708807 DOI: 10.1371/journal.pgen.1003612] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [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: 07/09/2012] [Accepted: 05/22/2013] [Indexed: 12/23/2022] Open
Abstract
KLF3 is a Krüppel family zinc finger transcription factor with widespread tissue expression and no previously known role in heart development. In a screen for dominant mutations affecting cardiovascular function in N-ethyl-N-nitrosourea (ENU) mutagenized mice, we identified a missense mutation in the Klf3 gene that caused aortic valvular stenosis and partially penetrant perinatal lethality in heterozygotes. All homozygotes died as embryos. In the first of three zinc fingers, a point mutation changed a highly conserved histidine at amino acid 275 to arginine (Klf3H275R). This change impaired binding of the mutant protein to KLF3's canonical DNA binding sequence. Heterozygous Klf3H275R mutants that died as neonates had marked biventricular cardiac hypertrophy with diminished cardiac chambers. Adult survivors exhibited hypotension, cardiac hypertrophy with enlarged cardiac chambers, and aortic valvular stenosis. A dominant negative effect on protein function was inferred by the similarity in phenotype between heterozygous Klf3H275R mutants and homozygous Klf3 null mice. However, the existence of divergent traits suggested the involvement of additional interactions. We conclude that KLF3 plays diverse and important roles in cardiovascular development and function in mice, and that amino acid 275 is critical for normal KLF3 protein function. Future exploration of the KLF3 pathway provides a new avenue for investigating causative factors contributing to cardiovascular disorders in humans. Cardiac defects are among the most common malformations in humans. Most causative genetic mutations remain unknown. To discover new causative genes important in cardiovascular development and function, we examined 1770 mice with randomly mutated genes and found a mutant with aortic valvular stenosis, and increased risk of fetal and neonatal death. Using linkage analysis and sequencing, we identified a protein-altering point mutation in the gene regulatory protein KLF3. Mice that survived into adulthood with one mutant copy of the Klf3 gene had low arterial blood pressure, enlarged hearts, and increased mortality due to heart failure. When both copies of the Klf3 gene was mutant, then embryos had heart defects, and all died before birth. KLF3 had no previously known role in heart development so to confirm these findings, we (1) knocked down klf3 expression in zebrafish embryos and (2) examined mice with a mutation that effectively eliminated the KLF3 protein. In both cases, cardiovascular dysfunction was observed. In conclusion, we have discovered that KLF3 plays diverse and important roles in cardiovascular development and function in mice. Future exploration of the KLF3 pathway provides a new avenue for investigating causative factors contributing to cardiovascular disorders in humans.
Collapse
Affiliation(s)
- Lois Kelsey
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Ann M. Flenniken
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Dawei Qu
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Alister P. W. Funnell
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Richard Pearson
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Yu-Qing Zhou
- Mouse Imaging Centre, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Irina Voronina
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Zorana Berberovic
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Geoffrey Wood
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Susan Newbigging
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Edward S. Weiss
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Michael Wong
- Mouse Imaging Centre, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Ivan Quach
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
| | - S. Y. Sandy Yeh
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Ashish R. Deshwar
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Ian C. Scott
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Heart and Stroke Richard Lewar Centre of Excellence, Toronto, Ontario, Canada
| | - Colin McKerlie
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Mark Henkelman
- Mouse Imaging Centre, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Peter Backx
- Heart and Stroke Richard Lewar Centre of Excellence, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Jeremy Simpson
- Heart and Stroke Richard Lewar Centre of Excellence, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Lucy Osborne
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Janet Rossant
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Merlin Crossley
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Benoit Bruneau
- Gladstone Institute of Cardiovascular Disease, Department of Pediatrics, and Cardiovascular Research Institute, University of California, San Francisco, California, United States of America
| | - S. Lee Adamson
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- Heart and Stroke Richard Lewar Centre of Excellence, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
| |
Collapse
|
4
|
Coceani F, Barogi S, Brizzi F, Ackerley C, Seidlitz E, Kelsey L, Ballou LR, Baragatti B. Cyclooxygenase isoenzymes and patency of ductus arteriosus. Prostaglandins Leukot Essent Fatty Acids 2005; 72:71-7. [PMID: 15626588 DOI: 10.1016/j.plefa.2004.10.004] [Citation(s) in RCA: 20] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Prenatal patency of the ductus arteriosus is maintained mainly by prostaglandin (PG) E(2). Accordingly, the vessel is endowed in its muscular component with a complete, cyclooxygenase (COX) and PGE synthase (PGES), system for the synthesis of the compound. COX1 is better expressed than COX2, particularly in the premature, but COX2 is more extensively coupled with microsomal PGES (mPGES). No evidence was obtained of either COX being coupled with cytosolic PGES (cPGES). Functionally, these data translate into a differential constrictor response of the ductus to dual, COX1/COX2, vs. COX2-specific inhibitors (indomethacin vs. L-745,337), with the latter being less effective specifically prior to term. This difference, however, subsides upon treatment with endotoxin and the attendant upregulation of COX2 and mPGES. Furthermore, when studied separately, COX1 and COX2 prove to be unevenly responsive to indomethacin, and an immediate and fast developing contraction of the vessel occurs only when COX2 is inhibited. Deletion of either COX gene results into upregulation of NO synthase, and a similar compensatory reaction is expected when enzymes are suppressed pharmacologically. We conclude that PGE(2) and NO can function synergistically in keeping the ductus patent. This arrangement provides a possible explanation for failures of indomethacin or ibuprofen treatment in the management of the prematurely born infant with persistent ductus. Coincidentally, it opens the way to new therapeutic possibilities being based on interference with the NO effector or a more selective disruption, possibly having mPGES as a target, of the PGE(2) synthetic cascade.
Collapse
|
5
|
Adeagbo ASO, Kelsey L, Coceani F. Endothelin-induced constriction of the ductus venosus in fetal sheep: developmental aspects and possible interaction with vasodilatory prostaglandin. Br J Pharmacol 2004; 142:727-36. [PMID: 15172962 PMCID: PMC1575056 DOI: 10.1038/sj.bjp.0705849] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
1. The ductus venosus is actively regulated in the fetus, but questions remain on the presence of a functional sphincter at its inlet. Using fetal sheep (0.6-0.7 gestation onwards), we have examined the morphology of the vessel and have also determined whether endothelin-1 (ET-1) qualifies as a natural constrictor being modulated by prostaglandins (PGs). 2. Masson's staining and alpha-actin immunohistochemistry showed a muscular, sphincter-like formation at the ductus inlet and a muscle layer within the wall of the vessel proper. This muscle cell component increased with age. 3. ET-1 contracted dose-dependently isolated sphincter and extrasphincter preparations of the ductus from term fetus. This ET-1 effect also occurred in the premature, but its threshold was higher. 4. BQ123 (1 microm) caused a rightward shift in the ET-1 dose-response curve, while indomethacin at a threshold concentration (28 nm) tended to have an opposite effect. 5. Big ET-1 also contracted the ductus sphincter but differed from ET-1 for its lesser potency and inhibition by phosphoramidon (50 microm). 6. The ductus sphincter (term and preterm) and extrasphincter (term) released 6-keto-PGF(1alpha) (hence PGI(2)) and, to a lesser degree, PGE(2) at rest and their release increased dose-dependently upon ET-1 treatment. Both basal and stimulated release was curtailed by endothelium removal. 7. BQ123 and phosphoramidon reduced slightly the contraction of ductus sphincter to indomethacin (2.8 microm). 8. We conclude that the ductus contains a contractile mechanism in the sphincter and extrasphincter regions. ET-1 lends itself to a role in the generation of contractile tone and its action may be modulated by prostaglandins.
Collapse
Affiliation(s)
- A S O Adeagbo
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - L Kelsey
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - F Coceani
- Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
- Author for correspondence:
| |
Collapse
|
6
|
Abstract
Endothelin-1 (ET-1) is a putative messenger of oxygen in the ductus arteriosus. Since the ability of the vessel to contract to oxygen increases with gestation, we wished to ascertain whether ET-1 action is also developmentally regulated. A corollary objective was to assess whether any gestational variation in the ET-1 contraction is due to a change in the ET(A)-mediated action or to a shift in the balance between opposing, contractile (ET(A) - mediated) and relaxant (ET(B)-mediated), actions. Experiments were performed with isolated ductal strips from preterm (0.7 gestation) and near-term fetal lambs. ET-1 contracted the ductus dose-dependently (10(-10)-10(-7) M) at both ages; however, the peak contraction was about double in magnitude at term. Regardless of age, ET-1 contraction was greater with preparations kept in the dark compared to those exposed to light. This effect of light was not seen after removing the endothelium or when treating the intact tissue with the ET(B) antagonist BQ788 (1 microM). In the dark, however, BQ788 did not modify significantly the ET-1 response at either age. We conclude that ET-1 becomes a stronger ductus constrictor with fetal age, conceivably by acting on ET(A) receptors. Hence, the concept of ET-1 mediating the oxygen contraction is further validated. Peculiarly, the ET-1 contraction is curtailed by light through a hitherto undefined ET(B) receptor-linked process.
Collapse
Affiliation(s)
- Flavio Coceani
- Integrative Biology Programme, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada.
| | | | | |
Collapse
|
7
|
Hirai M, LaFace D, Robinson S, Kelsey L, Johnson R, Wen SF, Warkentin P, Mills K, Vaillancourt M, Chavez J, Leutzinger C, Sumegi J, Neugebauer S, Lehman J, Talmadge C, Maneval D, Talmadge J. Ex vivo purging by adenoviral p53 gene therapy does not affect NOD-SCID repopulating activity of human CD34+ cells. Cancer Gene Ther 2001; 8:936-47. [PMID: 11781656 DOI: 10.1038/sj.cgt.7700390] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2001] [Indexed: 11/09/2022]
Abstract
Co-incubation of a replication-deficient, recombinant adenovirus carrying the wild-type p53 gene (rAd-p53) and hematopoietic stem cell (HSC) products from patients with breast cancer can significantly reduce tumor cell contamination. Whereas this approach provides a powerful tumor cell purging strategy, potential detrimental effects on the HSC population have not been investigated. The ability of human HSC to reconstitute hematopoiesis in severe combined immunodeficient (SCID) mice and to undergo secondary transplantation provides the only nonclinical measure of self-renewing, stem cell function. The objective of this study was to investigate whether co-incubation with rAd-p53 compromised the SCID repopulating activity (SRA) of HSC. Granulocyte colony-stimulating factor-mobilized human CD34+ cells were co-cultured with rAd-p53 at our targeted clinical dose, and the ability of these cells to establish multilineage hematopoiesis in sublethally irradiated, nonobese diabetic (NOD)-SCID mice was investigated. The persistence of human cells in the mice was investigated by flow cytometry, granulocyte-macrophage colony-forming unit assay, and polymerase chain reaction of human Alu sequences. Further, limiting dilution analysis provided a quantitative comparison between the SRA of CD34+ cells co-incubated with rAd-p53 and control CD34+ cells (no rAd-p53 co-incubation). We conclude that co-incubation with rAd-p53 has little effect on the SRA of HSC.
Collapse
Affiliation(s)
- M Hirai
- University of Nebraska Medical Center, Omaha, Nebraska 68198-7660, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Coceani F, Ackerley C, Seidlitz E, Kelsey L. Function of cyclo-oxygenase-1 and cyclo-oxygenase-2 in the ductus arteriosus from foetal lamb: differential development and change by oxygen and endotoxin. Br J Pharmacol 2001; 132:241-51. [PMID: 11156583 PMCID: PMC1572537 DOI: 10.1038/sj.bjp.0703779] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
1. Prenatal patency of the ductus arteriosus is maintained mainly by prostaglandin(PG) E(2). Here we have examined the relative importance of cyclo-oxygenase-1 (COX1) and cyclo-oxygenase-2 (COX2) for PGE(2) formation in the foetal lamb ductus (0.65 gestation onwards). 2. Using fluorescence microscopy and immunogold staining, COX1 appeared more abundant than COX2 in endothelial and smooth muscle cells, and this difference was greater before-term. Inside muscle cells, COX1 and COX2 immunoreactivity was located primarily in the perinuclear region. Endotoxin, given to the lamb in utero (approximately 0.1 microg kg(-1)), caused COX2 upregulation, while an opposite effect with disappearance of the enzyme followed endotoxin treatment in vitro (100 ng ml(-1)). COX1 immunoreactivity remained virtually unchanged with either treatment; however, this isoform as well as any induced COX2 migrated towards the outer cytoplasm. 3. The COX2 inhibitor L-745,337 (1--10 microM) contracted the isolated ductus at term, the response being almost as high as that to indomethacin (dual COX1/COX2 inhibitor) over the same dose-range. Conversely, L-745,337 was relatively less effective in the premature. 4. Pretreatment of the premature in vivo with endotoxin enhanced the contraction of the ductus to L-745,337, while in vitro endotoxin had a variable effect. 5. The premature ductus exhibited a stronger contraction to L-745,337 following exposure to oxygen. On the other hand, the oxygen contraction, which is modest before-term, was enhanced by L-745,337. 6. We conclude that COX1 and COX2 develop unevenly in the ductus. While both enzymes contribute to PGE(2) formation at term, COX1 is the major isoform in the premature. COX2, however, may acquire greater importance before-term following physiological and pathophysiological stimuli.
Collapse
Affiliation(s)
- F Coceani
- Integrative Biology Programme, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | | | | | | |
Collapse
|
9
|
Coceani F, Liu YA, Seidlitz E, Kelsey L, Kuwaki T, Ackerley C, Yanagisawa M. Deletion of the endothelin-A-receptor suppresses oxygen-induced constriction but not postnatal closure of the ductus arteriosus. J Cardiovasc Pharmacol 2000; 36:S75-7. [PMID: 11078341 DOI: 10.1097/00005344-200036051-00025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Experiments were carried out in mutant 129/SvEv mice lacking the endothelin-A (ET(A))-receptor to determine whether endothelin-1 (ET-1), acting as a messenger for oxygen constriction, is responsible for closure of the ductus arteriosus at birth. The isolated ductus from ET(A) -/- fetuses, unlike that from ET(A) +/+ littermates, contracted marginally to oxygen and ET-1 but responded to a thromboxane analog. In vivo, reduction in ductus lumen was equally pronounced in tracheotomized ET(A) -/- and ET(A) +/+ newborns. Conversely, no such vessel narrowing was seen in hyperoxic ET(A), -/- fetuses, although it occurred in ET(A) +/+ littermates. Notwithstanding the uneven behaviour of the ductus in vitro and in vivo, no ET(A) genotype-related difference was noted in the morphology of the vessel on both light and electron microscopy. We conclude that ET-1 mediates the ductus constriction to oxygen. Without ET-1, however, the vessel still closes postnatally probably as a result of the withdrawal of the relaxing influence of prostaglandin E2 (PGE2).
Collapse
Affiliation(s)
- F Coceani
- Integrative Biology Programme, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
10
|
Pisarev VM, Parajuli P, Mosley RL, Sublet J, Kelsey L, Sarin PS, Zimmerman DH, Winship MD, Talmadge JE. Flt3 ligand enhances the immunogenicity of a gag-based HIV-1 vaccine. Int J Immunopharmacol 2000; 22:865-76. [PMID: 11090695 DOI: 10.1016/s0192-0561(00)00048-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Liposomes and Flt3 ligand (Flt3L), a ligand for the fms-like tyrosine kinase receptor Flt3/ FLK2, can augment the immune response to an HIV peptide vaccine. The HGP-30 peptide used in these studies is a synthetic peptide that corresponds to a highly conserved region of HIV-1 p17 gag (amino acids 86-115). Mice were immunized with HGP-30 or HGP-30 conjugated to keyhole limpet hemocyanin (KLH) and delayed-type hypersensitivity (DTH) responses, antibody (IgG) amount and antigen-specific proliferative responses by spleen cells were used to monitor the immune response. Daily injections of Flt3L prior to HGP-30 administration enhanced significantly an antigen-specific lymphocyte proliferation response when compared with Flt3L, HGP-30 alone or HGP-30 containing liposomes. Intravenous administration of HGP-30 was superior to intramuscular (i.m.) immunization for the induction of DTH responses. The HGP-30/KLH containing liposomes enhanced both DTH and antibody responses, while liposomes containing HGP-30 peptide elicited only T cell responses. In these studies, either Flt3L or liposomes increased DTH responses compared with the i.m. injection of the HGP-30 vaccine alone.
Collapse
Affiliation(s)
- V M Pisarev
- Laboratory of Transplantation Immunology, Department of Pathology/Microbiology, 985660 Nebraska Medical Center, Omaha, NE 68198-5660, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
We have proposed that endothelin-1 (ET-1), formed through the activation of a cytochrome P450 (CYP450)-based monooxygenase reaction, is important for generation of contractile tone in the ductus arteriosus and, consequently, for closure of the vessel at birth. The present investigation was undertaken to ascertain, using an isolated ductus preparation from near-term fetal lambs, whether carbon monoxide (CO) and nitric oxide (NO) qualify as regulators of the CYP450/ET-1 system. Preparations released ET-1 at rest and its amount showed no significant reduction following removal of the endothelium. Basal release was not changed by the NO synthesis inhibitor, N(G)-nitro-L-arginine methylester (L-NAME, 100 microM), nor by agents altering cyclic GMP content (i.e. increase; ONO-1505, 1 microM) and action (i.e. decrease; LY-83583, 10 microM). These findings extend previous work showing no effect of the CO synthesis inhibitor zinc protoporphyrin IX (ZnPP, 10 microM) under the same conditions (10). Conversely, both CO (65 microM) and the NO donor, sodium nitroprusside (SNP, 10 microM), curtailed ET-1 release. ET-1 release was increased by oxygen and reduced by pyrogens (endotoxin and IL-1, both at 100 ng mL(-1)). The endotoxin effect tended to be reversed by L-NAME and ZnPP, used singly or in combination. We conclude that ET-1 is formed naturally in the ductus and that its formation may change in response to physiological (oxygen) and pathophysiological (pyrogens) stimuli. Endogenous CO and NO, however, appear to have little or no role as ET-1 regulators.
Collapse
Affiliation(s)
- F Coceani
- Integrative Biology Programme, Research Institute, The Hospital for Sick Children, Toronto, Ont., Canada.
| | | |
Collapse
|
12
|
Coceani F, Liu Y, Seidlitz E, Kelsey L, Kuwaki T, Ackerley C, Yanagisawa M. Endothelin A receptor is necessary for O(2) constriction but not closure of ductus arteriosus. Am J Physiol 1999; 277:H1521-31. [PMID: 10516191 DOI: 10.1152/ajpheart.1999.277.4.h1521] [Citation(s) in RCA: 31] [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] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In vitro and in vivo techniques were developed with genetically modified mice to determine whether endothelin-1 (ET-1) functions as an O(2) mediator in closure of the ductus arteriosus (DA) at birth. Wild-type CD-1 and 129/SvEv mice with ET(A) receptor -/-, +/-, and +/+ genotypes were used. Isolated DA from term ET(A) +/+ fetuses contracted to O(2) (5-95%) and a thromboxane A(2) analog (ONO-11113, 0.1 microM). Instead, ET-1 elicited a dual response with weak relaxation (0.1 nM) preceding contraction (1-100 nM). Indomethacin (2.8 microM) was also a constrictor. ET(A) -/- DA, unlike ET(A) +/+ DA, contracted marginally to O(2) and ET-1 but responded to ONO-11113. O(2) contraction was also reduced in ET(A) +/- DA. In vivo, DA constricted equally in tracheotomized ET(A) -/- and ET(A) +/+ newborns. Conversely, no DA constriction was seen in hyperoxic ET(A) -/- fetuses in utero, although it occurred in ET(A) +/+ and +/- littermates. We conclude that ET-1 mediates the DA constrictor response to O(2). Without ET-1, however, the vessel still closes postnatally, conceivably caused by the withdrawal of relaxing influence(s).
Collapse
Affiliation(s)
- F Coceani
- Integrative Biology Programme, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8.
| | | | | | | | | | | | | |
Collapse
|
13
|
Seberger PJ, Scholar EM, Kelsey L, Chaney WG, Talmadge JE. N-linked oligosaccharides and metastatic propensity in in vivo selected mouse mammary adenocarcinoma cells. Clin Exp Metastasis 1999; 17:437-44. [PMID: 10651311 DOI: 10.1023/a:1006629119030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Studies using metastatic variant selected in vivo from a cloned parental cell line demonstrate that the expression of beta1-6 branched, N-linked carbohydrates and sialic acid were positively associated with in vitro invasiveness and inversely associated with metastatic potential, adherence, and in vivo growth rate. These results suggest that at least within one tumor model, a negative association occurs between metastatic potential and 1-6 branched oligosaccharide expression. In these studies two metastatic variants, Cl-66M1 and Cl-66M2, were selected following serial in vivo passage of Cl-66, a clonal cell line obtained from a mouse mammary adenocarcinoma cell line. The parent cell line and the two metastatic variants were approximately equal in their adherence to fibronectin, laminin, and collagen type IV coated plastic. In contrast, both Cl-66M1 and Cl-66M2 had a significantly increased ability to invade through matrigel invasion chambers and expressed significantly increased levels of beta1-6 branched, N-linked carbohydrates, and sialic acid compared to the clonal parental cell line, Cl-66. Furthermore, the in vivo tumor growth rates of these selected variants were decreased compared to Cl-66 with the longest tumor volume doubling time observed with Cl-66M2.
Collapse
Affiliation(s)
- P J Seberger
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha 68198-5660, USA
| | | | | | | | | |
Collapse
|
14
|
Sarin PS, Talmadge JE, Heseltine P, Murcar N, Gendelman HE, Coleman R, Kelsey L, Beckner S, Winship D, Kahn J. Booster immunization of HIV-1 negative volunteers with HGP-30 vaccine induces protection against HIV-1 virus challenge in SCID mice. Vaccine 1999; 17:64-71. [PMID: 10078609 DOI: 10.1016/s0264-410x(98)00119-4] [Citation(s) in RCA: 9] [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] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Eleven HIV-1 seronegative subjects previously injected with an HIV-1 p17 synthetic peptide vaccine (HGP-30) were given two booster immunizations to evaluate memory cell responses and the ability to boost cellular and humoral immune responses. Five of 11 subjects showed a significant increase in their antibody titres to HGP-30 or p17 and 6/11 had T-cell proliferation responses to either HGP-30 or p17. HIV-1 virus challenge studies in SCID mice demonstrated that 39 of 50 mice (78%) receiving PBMC from 5 of the HGP-30 immunized subjects were protected from infection with a different strain of HIV-1 compared to 4 of 30 mice (13%) that received PBMC from 3 non-immunized subjects (p < 0.001). These studies show that booster immunizations with HGP-30 vaccine are safe and non-toxic and induce protective cell mediated immune responses.
Collapse
Affiliation(s)
- P S Sarin
- CEL-SCI Corporation, Vienna, VA 22182, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Watanabe T, Kelsey L, Ageitos A, Kuszynski C, Ino K, Heimann DG, Varney MT, Shepard HM, Vaillancourt MT, Maneval DC, Talmadge JE. Enhancement of adenovirus-mediated gene transfer to human bone marrow cells. Leuk Lymphoma 1998; 29:439-51. [PMID: 9643558 DOI: 10.3109/10428199809050904] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Adenovirus infection of CD34+ hematopoietic stem/progenitor cells is dependent on the multiplicity of infection (MOI), time of incubation, the volume in which the co-incubation occurs and the presence or absence of growth factors. Studies revealed that a brief co-incubation (1-8 hours), resulted in low levels of transgene expression, suggesting that adenovirus infection of CD34+ cells occurs slowly, and optimal transduction requires a 24 hour exposure to adenovirus. Infection by Ad/beta-gal or Ad/p53 at a MOI of 500:1 provided a high transduction efficiency but inhibited hematopoietic function. However, treatment at a MOI of 50-100 resulted in efficient transduction (10.7-15.7% positive) without detectable toxicity. Secondary proof of adenovirus transgene expression was demonstrated by detection of mRNA for p53 in Ad/p53 infected stem cells. We conclude that a 24 hour exposure to recombinant adenovirus encoding p53 or beta-gal, at a MOI of 50-100 is optimal for in vitro gene transfer to BM cells and has no significant effect on hematopoietic function. Adenovirus-mediated transduction of BM cells can also be modulated by growth factors (IL-3, GM-CSF and G-CSF) with improved gene delivery and maintenance of hematopoietic function. In summary, adenovirus vectors can be used to transiently transduce stem cells, and conditions have been defined to maximize expression and limit inhibitory effects on CD34+ cells. These data support continued investigation of this vector for local cytokine delivery and purging of stem cell products.
Collapse
Affiliation(s)
- T Watanabe
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Coceani F, Kelsey L, Seidlitz E, Marks GS, McLaughlin BE, Vreman HJ, Stevenson DK, Rabinovitch M, Ackerley C. Carbon monoxide formation in the ductus arteriosus in the lamb: implications for the regulation of muscle tone. Br J Pharmacol 1997; 120:599-608. [PMID: 9051297 PMCID: PMC1564507 DOI: 10.1038/sj.bjp.0700947] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
1. We have previously shown that carbon monoxide (CO) potently relaxes the lamb ductus arteriosus and have ascribed this response to inhibition of a cytochrome P450-based mono-oxygenase reaction controlling the formation of endothelin-1 (ET-1). In the present study, we have examined whether CO is formed naturally in the vessel. 2. The CO-forming enzyme, haem oxygenase (HO), was identified in ductal tissue in its constitutive (HO-2) and inducible (HO-1) isoforms by Western immunoblotting and immunological staining procedures (both light and electron microscopy). HO-1 was localized to endothelial and muscle cells, while HO-2 was found only in muscle cells. Inside the muscle cells, HO-1 and HO-2 immunoreactivity was limited to the perinuclear region, and the Golgi apparatus in particular. However, upon exposure to endotoxin, HO-1 became more abundant, and both HO isoforms migrated towards the outer region of the cytoplasm close to the sarcolemma. 3. CO was formed enzymatically from added substrate (hemin, 50 microM) in the 10,000 g supernatant of the ductus and its formation was inhibited by zinc protoporphyrin IX (ZnPP, 200 microM). 4. ZnPP (10 microM) had no effect on the tone of the ductus under normal conditions (2.5 to 95% O2), but it contracted the endotoxin-treated ductus (at 2.5% O2). At the same concentration, ZnPP also tended to contract the hypoxic vessel (zero O2). 5. ZnPP (10 microM) curtailed the relaxant response of the oxygen (30%)/indomethacin (2.8 microM)-contracted ductus to bradykinin (35 nM), while it left the sodium nitroprusside (35 nM) relaxation unchanged. 6. We conclude that CO is formed in the ductus and may exert a relaxing influence when its synthesis is upregulated by an appropriate stimulus.
Collapse
Affiliation(s)
- F Coceani
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Coceani F, Kelsey L, Seidlitz E. Carbon monoxide-induced relaxation of the ductus arteriosus in the lamb: evidence against the prime role of guanylyl cyclase. Br J Pharmacol 1996; 118:1689-96. [PMID: 8842433 PMCID: PMC1909852 DOI: 10.1111/j.1476-5381.1996.tb15593.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.6] [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: 02/02/2023] Open
Abstract
1. We have previously found that carbon monoxide (CO) potently relaxes the lamb ductus arteriosus and have ascribed this response to inhibition of a cytochrome P450-based mono-oxygenase reaction which sustains contractile tone. Our proposal, however, has been questioned on the evidence of findings in other blood vessels implicating the guanylyl cyclase-based relaxing mechanism as the target for CO. To investigate this issue further, we have carried out experiments in the isolated ductus from near-term foetal lambs and have examined the effect of CO concomitantly on muscle tone and cyclic GMP content, both in the absence and presence of guanylyl inhibitors, or during exposure to monochromatic light at 450 nm. 2. CO (65 microM) reversed completely, or nearly completely, the tone developed by the vessel in the presence of oxygen (30%) and indomethacin (2.8 microM). Cyclic GMP content tended to increase with the relaxation, but the change did not reach significance. Sodium nitroprusside (SNP), a NO donor, mimicked CO in relaxing the ductus. Contrary to CO, however, SNP caused a marked accumulation of cyclic GMP with levels being positively correlated with the relaxation. 3. Methylene blue (10 microM) reduced marginally the CO relaxation, whilst LY-83583 (10 microM) had an obvious, albeit variable, inhibitory effect. Basal cyclic GMP content was lower in tissues treated with either compound and rose upon exposure to CO. However, the levels attained were still within the range of values for tissues prior to any treatment. Furthermore, the elevation in cyclic GMP was not related to the magnitude of the CO relaxation. 4. Illumination of the ductus with monochromatic light at 450 nm reversed the CO relaxation and any concomitant increase in cyclic GMP. In the absence of CO, light by itself had no effect. 5. Ductal preparation with only muscle behaved as the intact preparations in reacting to CO, both in the absence and presence of guanylyl cyclase inhibitors, or during illumination. 6. We conclude that the primary action of CO in the ductus arteriosus is not exerted on the guanylyl cyclase heme and that cyclic GMP may only have an accessory role in the relaxation to this agent. This finding reasserts the importance of a cytochrom P450-based mono-oxygenase reaction for generation of tone and as a target for CO in the ductus.
Collapse
Affiliation(s)
- F Coceani
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | |
Collapse
|
18
|
Coceani F, Kelsey L, Seidlitz E, Korzekwa K. Inhibition of the contraction of the ductus arteriosus to oxygen by 1-aminobenzotriazole, a mechanism-based inactivator of cytochrome P450. Br J Pharmacol 1996; 117:1586-92. [PMID: 8730758 PMCID: PMC1909445 DOI: 10.1111/j.1476-5381.1996.tb15325.x] [Citation(s) in RCA: 33] [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: 02/01/2023] Open
Abstract
1. We have proposed that contractile tension of the ductus arteriosus is sustained by a cytochrome P450-linked mechanism acting as a limiting step in the synthesis of endothelin-1 (ET-1). In the present study, we have used the isolated ductus from near-term foetal lambs and guinea-pigs to investigate the effect on both muscle tone and ET-1 formation of 1-aminobenzotriazole (ABT), a suicide substrate for mono-oxygenase reactions. 2. ABT relaxed the lamb ductus at rest (2.5% O2) and during the oxygen contraction (15 to 95% O2). The effect was seen at 40 microM, and at 0.8 mM active tone was almost completely abolished. ABT (1 mM) also reversed the oxygen contraction in the guinea-pig ductus. 3. In the lamb ductus, the ABT response was not affected by removal of the endothelium or by treatment with 2.8 microM indomethacin (at 2.5% O2) and the ensuing contraction. 4. At both low and high concentration, ABT relaxed marginally, or not at all, the potassium-contracted (55 mM) ductus from either species. 5. ET-1 release from either the intact or endothelium-denuded lamb ductus tended to decrease in the presence of ABT (1 mM), whilst during the same treatment cyclic GMP content of the tissue remained unchanged. 6. We conclude that ABT relaxation is due to suppression of a contractile mechanism and not to activation of prostaglandin- and NO-mediated relaxing mechanisms. This contractile mechanism has a cytochrome P450-based mono-oxygenase reaction as a key component.
Collapse
Affiliation(s)
- F Coceani
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | |
Collapse
|
19
|
Coceani F, Kelsey L, Ackerley C, Rabinovitch M, Gelboin H. Cytochrome P450 during ontogenic development: occurrence in the ductus arteriosus and other tissues. Can J Physiol Pharmacol 1994; 72:217-26. [PMID: 8069768 DOI: 10.1139/y94-034] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Our previous investigations have implicated a cytochrome P450 mechanism in the oxygen contraction of the ductus arteriosus and, by extension, in the closure of the vessel at birth. This study was undertaken in fetal and newborn sheep to characterize the ductal cytochrome and gather insight into its operation. Other tissues, vascular and extravascular, were used as a reference. Benzo[a]pyrene hydroxylation (a marker for the 3-methylcholanthrene-inducible isozyme) and aminopyrine N-demethylation (a marker for the glucocorticoid-inducible isozyme) had insignificant activity in the ductus and aorta from fetal sheep, and no increase was noted after exposing the animal in utero to beta-naphthoflavone or dexamethasone, both alone and in combination with phenobarbital. However, dexamethasone and, particularly, dexamethasone plus phenobarbital produced a variable constriction of the fetal ductus. No monooxygenase activity was found in the naturally closing ductus of the newborn. Conversely, both enzyme reactions were measurable in the fetal liver, and they became more active after treatment with the inducers or at birth. Scanning immunoelectron microscopy of cultured endothelial and muscle cells from both ductus and aorta showed specific gold labelling for the glucocorticoid-inducible cytochrome P450 only in ductal muscle. By transmission electron microscopy, this immunoreactivity was located along the sarcolemma and in the sarcoplasmic reticulum. These findings indicate the presence in the ductus arteriosus of a cytochrome P450 belonging to the 3A subfamily. However, considering the uneven action of the inducers on enzyme activity in ductal tissue and muscle tone, the role of this cytochrome in closure of the vessel at birth remains to be ascertained.
Collapse
Affiliation(s)
- F Coceani
- Research Institute, Hospital for Sick Children, Toronto, ON, Canada
| | | | | | | | | |
Collapse
|
20
|
Abstract
To determine whether the ductus arteriosus can form endothelium-derived relaxing factor--nitric oxide, we used isolated ductal strips from near-term fetal lamb and examined their response to bradykinin (a nitric oxide stimulator), L-arginine (a nitric oxide precursor), and agents interfering with the synthesis (N omega-nitro-L-arginine) and action (methylene blue) of nitric oxide. Bradykinin relaxed the indomethacin-contracted ductus dose dependently from a threshold of about 10(-10) M, and peak relaxation was greater at high (176-210 mmHg; 1 mmHg = 133.3 Pa) than low (15-25 mmHg) PO2. Bradykinin relaxation was nearly completely or completely abolished in endothelium-denuded preparations and, in its place, there was often a small contraction. Pretreatment with nitric oxide inhibitors also prevented, in part (methylene blue, 1 microM) or in full (N omega-nitro-L-arginine, 100 microM), the relaxant effect of bradykinin. Paradoxically, L-arginine (10 microM) had an inhibiting rather than an enhancing effect on the bradykinin relaxation. N omega-Nitro-L-arginine (100 microM) and methylene blue (1-100 microM) contracted by themselves the untreated ductus, and their action persisted after removal of the endothelium. These findings indicate the presence in the ductus arteriosus of a nitric oxide based relaxing mechanism, which may supplement prostaglandin E2 in keeping the vessel patent in the fetus. This mechanism may, on one hand, afford protection against nonsteroidal anti-inflammatory drugs in utero and may, on the other hand, complicate the management of prematures with persistent ductus and account for failures of the indomethacin therapy.
Collapse
Affiliation(s)
- F Coceani
- Research Institute, Hospital for Sick Children, Toronto, ON, Canada
| | | | | |
Collapse
|
21
|
Talmadge JE, Jackson JD, Kelsey L, Borgeson CD, Faltynek C, Perry GA. T-cell reconstitution by molecular, phenotypic, and functional analysis in the thymus, bone marrow, spleen, and blood following split-dose polychemotherapy and therapeutic activity for metastatic breast cancer in mice. J Immunother Emphasis Tumor Immunol 1993; 14:258-68. [PMID: 7506577 DOI: 10.1097/00002371-199311000-00002] [Citation(s) in RCA: 11] [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] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We examined the effect of a maximum tolerated, split-dose chemotherapy protocol of cyclophosphamide, cisplatin, and 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) on neutrophil and lymphocyte subpopulations in the peripheral blood leukocytes (PBLs), thymus, bone marrow, and spleen. It was found that this protocol of polychemotherapy, modeled after the induction protocol used with autologous bone marrow transplantation (AuBMT) for breast cancer, suppressed both B- and T-cell populations and T-cell function at times when the absolute neutrophil count had returned to normal or supernormal numbers. We observed an organ- and phenotype-specific T- and B-cell recovery to normal levels following chemotherapy. However, despite normalization of cellularity and phenotype frequency, splenic lymphocytes remained unable to respond to normally concanavalin A (ConA). This polychemotherapy protocol in mice with an extensive experimental metastasis mammary tumor burden, was a dose lethal to 20% of the test group, which could be overcome with treatment by BMT and rHu interleukin (IL)-7. Furthermore, therapy with the T-cell augmenting agent rHu IL-7 had additive therapeutic activity and significantly prolonged survival beyond that of chemotherapy and BMT although it did not cure any mice with a heavy tumor burden. In summary, these studies demonstrate an organ-specific and selective polymorphonuclear neutrophil and T- and B-cell reconstitution following multidrug, split-dose chemotherapy on tissue and PBL populations, and a chronic depression in T-cell function, which when modified can result in significant therapeutic activity.
Collapse
Affiliation(s)
- J E Talmadge
- University of Nebraska Medical Center, Department of Pathology/Microbiology, Omaha 68198-5660
| | | | | | | | | | | |
Collapse
|
22
|
Abstract
The ductus arteriosus is a special muscular shunt that in the fetus allows blood to bypass the unexpanded lungs. It closes rapidly after birth and this event is initiated by the physiologic rise in blood oxygen tension. Endothelin-1 has been proposed by us as a local mediator for oxygen after demonstrating that it is formed within the ductus and is a potent ductus constrictor. To confirm this possibility, we have now measured the release of endothelin-1 from the isolated ductus of near-term fetal lambs at different oxygen concentrations of the medium. In addition, using the same preparation, we have examined the effect on contractile tone of compounds interfering with the synthesis (phosphoramidon, 50 microM) and action (BQ123, 1 microM) of endothelin-1. We report that release of endothelin-1 from the ductus tends to increase with the oxygen concentration up to a value mimicking the neonatal condition. Phosphoramidon and, to a greater degree, BQ123 inhibit the contraction of the vessel to oxygen. These results implicate endothelin-1 as the effector agent for oxygen in the ductus and, by extension, assign to this peptide a critical role in the closure of the vessel at birth.
Collapse
Affiliation(s)
- F Coceani
- Research Institute, Hospital for Sick Children, Toronto, Ont., Canada
| | | | | |
Collapse
|
23
|
Abstract
Recent studies suggest an improved survival in patients who undergo radical lymph node dissection for the curative treatment of gastric carcinoma. We have undertaken a retrospective review to compare morbidity and mortality between patients who underwent radical lymph node dissection and those who underwent resections of lesser scope. Of the surgically related events compared, only the amount of postoperative abdominal drainage was significantly different in the group that underwent radical lymph node dissection Forty-four percent of patients who underwent radical lymph node dissection and 35% of patients who underwent a procedure of lesser scope developed a major complication. There was also no significant difference in the postoperative death rate, with a total of two 30-day in-hospital deaths (1.1%). Our observations indicate that radical lymph node dissection can be performed as safely as lesser operations for gastric carcinoma, and should not be avoided because of the fear of complications.
Collapse
Affiliation(s)
- J W Smith
- Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY 10021
| | | | | | | |
Collapse
|
24
|
Abstract
Our previous investigations have shown that endothelin-1 (ET-1) is a singularly potent constrictor of the ductus arteriosus and that a cytochrome P-450 system located in the sarcolemma is crucial for the contractile response of the vessel to oxygen. We have now studied the release of ET-1 from isolated ductus arteriosus preparations of near-term fetal lambs. Preparations produced measurable amounts of ET-1 under basal conditions (about 0.04 pg/100 mg wet weight.min) both in the presence and absence of the endothelium. Anisomycin (10(-4) M) reduced this release by 50%, while thrombin (1 U/mL) doubled the release. Treatment with a CO mixture (CO/O2 ratio, 0.27) inhibited ET-1 release from intact and endothelium-denuded preparations. We propose that oxygen triggers closure of the ductus arteriosus at birth by causing a conformational change in a specific cytochrome P-450, which, in turn, provides the signal for the synthesis of the constrictor ET-1.
Collapse
Affiliation(s)
- F Coceani
- Research Institute, Hospital for Sick Children, Toronto, Ont., Canada
| | | |
Collapse
|
25
|
Abstract
Endothelin was tested on isolated ductus arteriosus preparations from mature fetal lambs. At low PO2 (18-24 Torr; 1 Torr = 133.3 Pa), the compound constricted the vessel dose-dependently over the range from about 10(-10) to 10(-7) M. The contraction was sustained and did not subside even after an extended period of washing. Endothelin was also effective on tissues (PO2,217-231 Torr; indomethacin, 2.8 X 10(-6) M) that had been completely relaxed with CO (CO/O2 ratio, 0.28). CO treatment interferes with a cytochrome P-450 mechanism, which is considered crucial for the contractile response of the vessel to oxygen. These findings are consistent with a role of endothelin in the closure of the ductus arteriosus at birth.
Collapse
Affiliation(s)
- F Coceani
- Research Institute, Hospital for Sick Children, Toronto, Ont., Canada
| | | | | |
Collapse
|