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Asfour H, Hirsinger E, Rouco R, Zarrouki F, Hayashi S, Swist S, Braun T, Patel K, Relaix F, Andrey G, Stricker S, Duprez D, Stantzou A, Amthor H. Inhibitory SMAD6 interferes with BMP dependent generation of muscle progenitor cells and perturbs proximodistal pattern of murine limb muscles. Development 2023:310501. [PMID: 37218515 DOI: 10.1242/dev.201504] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 05/02/2023] [Indexed: 05/24/2023]
Abstract
The mechanism of pattern formation during limb muscle development remains poorly understood. The canonical view holds that naïve limb muscle progenitor cells (MPCs) invade a pre-established pattern of muscle connective tissue, thereby forming individual muscles. Here we show that early murine embryonic limb MPCs highly accumulate pSMAD1/5/9, demonstrating active signaling of bone morphogenetic proteins (BMP) in these cells. Overexpression of inhibitory SMAD6 in limb MPCs abrogated BMP signaling, impaired their migration and proliferation, and accelerated myogenic lineage progression. Fewer primary myofibers developed, causing an aberrant proximodistal muscle pattern. Patterning was not disturbed when SMAD6 was overexpressed in differentiated muscle, implying that the proximodistal muscle pattern depends on BMP-mediated expansion of MPCs prior to their differentiation. We show that limb MPCs differentially express Hox genes, and Hox-expressing MPCs displayed active BMP signaling. SMAD6 overexpression caused loss of HOXA11 in early limb MPCs. In conclusion, our data show that BMP signaling controls expansion of embryonic limb MPC as a prerequisite for establishing the proximodistal muscle pattern, a process that involves expression of Hox genes.
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Affiliation(s)
- Hasan Asfour
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000 Versailles, France
| | - Estelle Hirsinger
- Sorbonne Université, Institut Biologie Paris Seine, CNRS UMR7622, Developmental Biology Laboratory, Inserm U1156, 75005 Paris, France
| | - Raquel Rouco
- University of Geneva, Faculty of Medicine, Department of Genetic Medicine and Development, 1211 Geneva 4, Switzerland
| | - Faouzi Zarrouki
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000 Versailles, France
| | - Shinichiro Hayashi
- National Center of Neurology and Psychiatry (NCNP), National Institute of Neuroscience, Department of Neuromuscular Research, Tokyo 187-8502, Japan
| | - Sandra Swist
- Max-Planck-Institute for Heart and Lung Research, Department of Cardiac Development and Remodeling, 61231 Bad Nauheim, Germany
| | - Thomas Braun
- Max-Planck-Institute for Heart and Lung Research, Department of Cardiac Development and Remodeling, 61231 Bad Nauheim, Germany
| | - Ketan Patel
- University of Reading, School of Biological Sciences, Reading RG6 6AH, UK
| | - Frédéric Relaix
- Université Paris Est Créteil, INSERM, EnvA, EFS, AP-HP, IMRB, 94010 Créteil, France
| | - Guillaume Andrey
- University of Geneva, Faculty of Medicine, Department of Genetic Medicine and Development, 1211 Geneva 4, Switzerland
| | - Sigmar Stricker
- Freie Universität Berlin, Institute for Chemistry and Biochemistry, 14195 Berlin, Germany
| | - Delphine Duprez
- Sorbonne Université, Institut Biologie Paris Seine, CNRS UMR7622, Developmental Biology Laboratory, Inserm U1156, 75005 Paris, France
| | - Amalia Stantzou
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000 Versailles, France
| | - Helge Amthor
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000 Versailles, France
- AP-HP, Hôpital Raymond Poincaré, Service de Pédiatrie, 92380 Garches, France
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Wang L, Rice M, Swist S, Kubin T, Wu F, Wang S, Kraut S, Weissmann N, Böttger T, Wheeler M, Schneider A, Braun T. BMP9 and BMP10 Act Directly on Vascular Smooth Muscle Cells for Generation and Maintenance of the Contractile State. Circulation 2020; 143:1394-1410. [PMID: 33334130 DOI: 10.1161/circulationaha.120.047375] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Vascular smooth muscle cells (VSMCs) show a remarkable phenotypic plasticity, allowing acquisition of contractile or synthetic states, but critical information is missing about the physiologic signals, promoting formation, and maintenance of contractile VSMCs in vivo. BMP9 and BMP10 (bone morphogenetic protein) are known to regulate endothelial quiescence after secretion from the liver and right atrium, whereas a direct role in the regulation of VSMCs was not investigated. We studied the role of BMP9 and BMP10 for controlling formation of contractile VSMCs. METHODS We generated several cell type-specific loss- and gain-of-function transgenic mouse models to investigate the physiologic role of BMP9, BMP10, ALK1 (activin receptor-like kinase 1), and SMAD7 in vivo. Morphometric assessments, expression analysis, blood pressure measurements, and single molecule fluorescence in situ hybridization were performed together with analysis of isolated pulmonary VSMCs to unravel phenotypic and transcriptomic changes in response to absence or presence of BMP9 and BMP10. RESULTS Concomitant genetic inactivation of Bmp9 in the germ line and Bmp10 in the right atrium led to dramatic changes in vascular tone and diminution of the VSMC layer with attenuated contractility and decreased systemic as well as right ventricular systolic pressure. On the contrary, overexpression of Bmp10 in endothelial cells of adult mice dramatically enhanced formation of contractile VSMCs and increased systemic blood pressure as well as right ventricular systolic pressure. Likewise, BMP9/10 treatment induced an ALK1-dependent phenotypic switch from synthetic to contractile in pulmonary VSMCs. Smooth muscle cell-specific overexpression of Smad7 completely suppressed differentiation and proliferation of VSMCs and reiterated defects observed in adult Bmp9/10 double mutants. Deletion of Alk1 in VSMCs recapitulated the Bmp9/10 phenotype in pulmonary but not in aortic and coronary arteries. Bulk expression analysis and single molecule RNA-fluorescence in situ hybridization uncovered vessel bed-specific, heterogeneous expression of BMP type 1 receptors, explaining phenotypic differences in different Alk1 mutant vessel beds. CONCLUSIONS Our study demonstrates that BMP9 and BMP10 act directly on VSMCs for induction and maintenance of their contractile state. The effects of BMP9/10 in VSMCs are mediated by different combinations of BMP type 1 receptors in a vessel bed-specific manner, offering new opportunities to manipulate blood pressure in the pulmonary circulation.
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Affiliation(s)
- Lei Wang
- Departments of Cardiac Development and Remodeling (L.W., M.R., S.S., F.W., T.B., M.W., A.S., T.B.)
| | - Megan Rice
- Departments of Cardiac Development and Remodeling (L.W., M.R., S.S., F.W., T.B., M.W., A.S., T.B.)
| | - Sandra Swist
- Departments of Cardiac Development and Remodeling (L.W., M.R., S.S., F.W., T.B., M.W., A.S., T.B.)
| | | | - Fan Wu
- Departments of Cardiac Development and Remodeling (L.W., M.R., S.S., F.W., T.B., M.W., A.S., T.B.)
| | - Shengpeng Wang
- Cardiac Surgery (S.W.), Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Simone Kraut
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany (S.K., N.W.)
| | - Norbert Weissmann
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany (S.K., N.W.).,German Centre for Lung Research (DZL), Partner site Giessen, Germany (N.W.)
| | - Thomas Böttger
- Departments of Cardiac Development and Remodeling (L.W., M.R., S.S., F.W., T.B., M.W., A.S., T.B.)
| | - Matthew Wheeler
- Departments of Cardiac Development and Remodeling (L.W., M.R., S.S., F.W., T.B., M.W., A.S., T.B.)
| | - Andre Schneider
- Departments of Cardiac Development and Remodeling (L.W., M.R., S.S., F.W., T.B., M.W., A.S., T.B.)
| | - Thomas Braun
- Departments of Cardiac Development and Remodeling (L.W., M.R., S.S., F.W., T.B., M.W., A.S., T.B.).,German Centre for Cardiovascular Research (DZHK), Partner site Rhein-Main, Frankfurt am Main, Germany (T.B.)
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3
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Swist S, Unger A, Li Y, Vöge A, von Frieling-Salewsky M, Skärlén Å, Cacciani N, Braun T, Larsson L, Linke WA. Maintenance of sarcomeric integrity in adult muscle cells crucially depends on Z-disc anchored titin. Nat Commun 2020; 11:4479. [PMID: 32900999 PMCID: PMC7478974 DOI: 10.1038/s41467-020-18131-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 08/04/2020] [Indexed: 12/14/2022] Open
Abstract
The giant protein titin is thought to be required for sarcomeric integrity in mature myocytes, but direct evidence for this hypothesis is limited. Here, we describe a mouse model in which Z-disc-anchored TTN is depleted in adult skeletal muscles. Inactivation of TTN causes sarcomere disassembly and Z-disc deformations, force impairment, myocyte de-stiffening, upregulation of TTN-binding mechanosensitive proteins and activation of protein quality-control pathways, concomitant with preferential loss of thick-filament proteins. Interestingly, expression of the myosin-bound Cronos-isoform of TTN, generated from an alternative promoter not affected by the targeting strategy, does not prevent deterioration of sarcomere formation and maintenance. Finally, we demonstrate that loss of Z-disc-anchored TTN recapitulates muscle remodeling in critical illness ‘myosinopathy’ patients, characterized by TTN-depletion and loss of thick filaments. We conclude that full-length TTN is required to integrate Z-disc and A-band proteins into the mature sarcomere, a function that is lost when TTN expression is pathologically lowered. Titin is considered an integrator of muscle cell proteins but direct evidence is limited. Here, titin is inactivated in adult mouse muscles, which causes sarcomere disassembly, protein mis-expression and force impairment, recapitulating key alterations in critical illness myopathy patient muscles.
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Affiliation(s)
- Sandra Swist
- Department of Systems Physiology, Ruhr University Bochum, D-44780, Bochum, Germany.
| | - Andreas Unger
- Institute of Physiology II, University of Munster, D-48149, Munster, Germany
| | - Yong Li
- Institute of Physiology II, University of Munster, D-48149, Munster, Germany
| | - Anja Vöge
- Department of Systems Physiology, Ruhr University Bochum, D-44780, Bochum, Germany
| | | | - Åsa Skärlén
- Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska Institute, SE-171 77, Stockholm, Sweden
| | - Nicola Cacciani
- Department of Physiology and Pharmacology, Karolinska Institute, SE-171 77, Stockholm, Sweden
| | - Thomas Braun
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, D-61231, Bad Nauheim, Germany
| | - Lars Larsson
- Department of Physiology and Pharmacology, Karolinska Institute, SE-171 77, Stockholm, Sweden
| | - Wolfgang A Linke
- Institute of Physiology II, University of Munster, D-48149, Munster, Germany.
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4
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Stantzou A, Schirwis E, Swist S, Alonso-Martin S, Polydorou I, Zarrouki F, Mouisel E, Beley C, Julien A, Le Grand F, Garcia L, Colnot C, Birchmeier C, Braun T, Schuelke M, Relaix F, Amthor H. BMP signaling regulates satellite cell-dependent postnatal muscle growth. Development 2017; 144:2737-2747. [PMID: 28694257 DOI: 10.1242/dev.144089] [Citation(s) in RCA: 28] [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] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 06/21/2017] [Indexed: 02/03/2023]
Abstract
Postnatal growth of skeletal muscle largely depends on the expansion and differentiation of resident stem cells, the so-called satellite cells. Here, we demonstrate that postnatal satellite cells express components of the bone morphogenetic protein (BMP) signaling machinery. Overexpression of noggin in postnatal mice (to antagonize BMP ligands), satellite cell-specific knockout of Alk3 (the gene encoding the BMP transmembrane receptor) or overexpression of inhibitory SMAD6 decreased satellite cell proliferation and accretion during myofiber growth, and ultimately retarded muscle growth. Moreover, reduced BMP signaling diminished the adult satellite cell pool. Abrogation of BMP signaling in satellite cell-derived primary myoblasts strongly diminished cell proliferation and upregulated the expression of cell cycle inhibitors p21 and p57 In conclusion, these results show that BMP signaling defines postnatal muscle development by regulating satellite cell-dependent myofiber growth and the generation of the adult muscle stem cell pool.
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Affiliation(s)
- Amalia Stantzou
- Versailles Saint-Quentin-en-Yvelines University, INSERM U1179, LIA BAHN CSM, Montigny-le-Bretonneux 78180, France.,Department of Neuropediatrics and NeuroCure Clinical Research Center, Charité University-Medicine, Berlin 10117, Germany.,Pierre et Marie Curie University, Paris Sorbonne, INSERM, UMRS974, CNRS FRE3617, Center for Research in Myology, Paris 75013, France
| | - Elija Schirwis
- Versailles Saint-Quentin-en-Yvelines University, INSERM U1179, LIA BAHN CSM, Montigny-le-Bretonneux 78180, France.,Pierre et Marie Curie University, Paris Sorbonne, INSERM, UMRS974, CNRS FRE3617, Center for Research in Myology, Paris 75013, France.,Developmental Biology/Signal Transduction Group, Max Delbruck Center for Molecular Medicine, Berlin 13092, Germany
| | - Sandra Swist
- Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim 61231, Germany.,Department of Cardiovascular Physiology, Ruhr University Bochum, D-44780 Bochum, Germany
| | - Sonia Alonso-Martin
- Pierre et Marie Curie University, Paris Sorbonne, INSERM, UMRS974, CNRS FRE3617, Center for Research in Myology, Paris 75013, France.,INSERM, Paris Est University, IMRB U955-E10, Créteil 94010, France
| | - Ioanna Polydorou
- Versailles Saint-Quentin-en-Yvelines University, INSERM U1179, LIA BAHN CSM, Montigny-le-Bretonneux 78180, France.,Department of Neuropediatrics and NeuroCure Clinical Research Center, Charité University-Medicine, Berlin 10117, Germany
| | - Faouzi Zarrouki
- Versailles Saint-Quentin-en-Yvelines University, INSERM U1179, LIA BAHN CSM, Montigny-le-Bretonneux 78180, France
| | - Etienne Mouisel
- Pierre et Marie Curie University, Paris Sorbonne, INSERM, UMRS974, CNRS FRE3617, Center for Research in Myology, Paris 75013, France.,Paul Sabatier University, Inserm UMR 1048, Toulouse 31432, France
| | | | - Anaïs Julien
- Paris Descartes-Sorbonne Paris Cité University, Inserm UMR1163, Imagine Institute, Paris 75015, France
| | - Fabien Le Grand
- Pierre et Marie Curie University, Paris Sorbonne, INSERM, UMRS974, CNRS FRE3617, Center for Research in Myology, Paris 75013, France
| | - Luis Garcia
- Versailles Saint-Quentin-en-Yvelines University, INSERM U1179, LIA BAHN CSM, Montigny-le-Bretonneux 78180, France
| | - Céline Colnot
- Paris Descartes-Sorbonne Paris Cité University, Inserm UMR1163, Imagine Institute, Paris 75015, France
| | - Carmen Birchmeier
- Developmental Biology/Signal Transduction Group, Max Delbruck Center for Molecular Medicine, Berlin 13092, Germany
| | - Thomas Braun
- Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim 61231, Germany
| | - Markus Schuelke
- Department of Neuropediatrics and NeuroCure Clinical Research Center, Charité University-Medicine, Berlin 10117, Germany
| | - Frédéric Relaix
- Pierre et Marie Curie University, Paris Sorbonne, INSERM, UMRS974, CNRS FRE3617, Center for Research in Myology, Paris 75013, France.,INSERM, Paris Est University, IMRB U955-E10, Créteil 94010, France
| | - Helge Amthor
- Versailles Saint-Quentin-en-Yvelines University, INSERM U1179, LIA BAHN CSM, Montigny-le-Bretonneux 78180, France .,Pediatric Department, University Hospital Raymond Poincaré, Garches 92380, France
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5
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Hinson JT, Chopra A, Nafissi N, Polacheck WJ, Benson CC, Swist S, Gorham J, Yang L, Schafer S, Sheng CC, Haghighi A, Homsy J, Hubner N, Church G, Cook SA, Linke WA, Chen CS, Seidman JG, Seidman CE. HEART DISEASE. Titin mutations in iPS cells define sarcomere insufficiency as a cause of dilated cardiomyopathy. Science 2016; 349:982-6. [PMID: 26315439 DOI: 10.1126/science.aaa5458] [Citation(s) in RCA: 415] [Impact Index Per Article: 51.9] [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
Human mutations that truncate the massive sarcomere protein titin [TTN-truncating variants (TTNtvs)] are the most common genetic cause for dilated cardiomyopathy (DCM), a major cause of heart failure and premature death. Here we show that cardiac microtissues engineered from human induced pluripotent stem (iPS) cells are a powerful system for evaluating the pathogenicity of titin gene variants. We found that certain missense mutations, like TTNtvs, diminish contractile performance and are pathogenic. By combining functional analyses with RNA sequencing, we explain why truncations in the A-band domain of TTN cause DCM, whereas truncations in the I band are better tolerated. Finally, we demonstrate that mutant titin protein in iPS cell-derived cardiomyocytes results in sarcomere insufficiency, impaired responses to mechanical and β-adrenergic stress, and attenuated growth factor and cell signaling activation. Our findings indicate that titin mutations cause DCM by disrupting critical linkages between sarcomerogenesis and adaptive remodeling.
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Affiliation(s)
- John T Hinson
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA.
| | - Anant Chopra
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA. The Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA 02115, USA
| | - Navid Nafissi
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - William J Polacheck
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA. The Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA 02115, USA
| | - Craig C Benson
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Sandra Swist
- Department of Cardiovascular Physiology, Ruhr University Bochum, MA 3/56 D-44780, Bochum, Germany
| | - Joshua Gorham
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Luhan Yang
- The Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA 02115, USA. Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Sebastian Schafer
- Cardiovascular and Metabolic Sciences, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Calvin C Sheng
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Alireza Haghighi
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA. Department of Genetics, Harvard Medical School, Boston, MA 02115, USA. Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Jason Homsy
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Norbert Hubner
- Cardiovascular and Metabolic Sciences, Max Delbrück Center for Molecular Medicine, Berlin, Germany. DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
| | - George Church
- The Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA 02115, USA. Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Stuart A Cook
- National Institute for Health Research (NIHR) Biomedical Research Unit in Cardiovascular Disease at Royal Brompton and Harefield National Health Service (NHS) Foundation Trust, Imperial College London, London, UK. National Heart Centre and Duke-National University, Singapore, Singapore
| | - Wolfgang A Linke
- Department of Cardiovascular Physiology, Ruhr University Bochum, MA 3/56 D-44780, Bochum, Germany
| | - Christopher S Chen
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA. The Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA 02115, USA
| | - J G Seidman
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Christine E Seidman
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA. Department of Genetics, Harvard Medical School, Boston, MA 02115, USA. Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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6
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Swist S, Linke WA. Untangling regulatory networks to spot drivers and modulators of cardiac disease. J Mol Cell Cardiol 2013; 63:1-3. [PMID: 23859767 DOI: 10.1016/j.yjmcc.2013.07.003] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 07/05/2013] [Accepted: 07/07/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Sandra Swist
- Dept. of Cardiovascular Physiology, Ruhr University Bochum, MA 3/56, D-44780 Bochum, Germany
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Abstract
Inherited osteopetrosis was identified in cattle herds in Wyoming, Nebraska, and Missouri in 2008 to 2010. Ten affected Red Angus calves were examined to characterize lesions in brain, teeth, and skull. Six affected aborted or stillborn calves were homozygous for the recently characterized deletion mutation in SLC4A2. Four affected calves were heterozygous for the SLC4A2 mutation and survived 1 to 7 days after birth. Gross lesions were similar in all 10 calves. Brains were rectangular and dorsoventrally compressed, with concave depressions in the parietal cortex owing to thickened parietal bone. Cerebellar hemispheres were compressed with herniation of the cerebellar vermis into the foramen magnum. Moderate bilateral chromatolysis affected multiple cranial nerve nuclei and, in some calves, the red nucleus. There was loss of retinal ganglion cells with severe atrophy of optic nerves. Periventricular corpora amylacea were in the thalamus, caudate nucleus, and midbrain. Vessels and neuropil in the dorsomedial aspect of the thalamus were mineralized. Dysplastic change in premolar and molar teeth comprised intra-alveolar intermingling of dentin, enamel, cementum, and bone, contributing to dental ankylosis. Changes in the heads of osteopetrotic calves are similar to those in children with malignant forms of homozygous recessive osteopetrosis.
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Affiliation(s)
- D O'Toole
- Department of Veterinary Sciences, 1174 Snowy Range Road, University of Wyoming, Laramie, WY 82070, USA.
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