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Baguma-Nibasheka M, Kablar B. Mechanics of Lung Development. ADVANCES IN ANATOMY, EMBRYOLOGY, AND CELL BIOLOGY 2023; 236:131-150. [PMID: 37955774 DOI: 10.1007/978-3-031-38215-4_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
We summarize how skeletal muscle and lung developmental biology fields have been bridged to benefit from mouse genetic engineering technologies and to explore the role of fetal breathing-like movements (FBMs) in lung development, by using skeletal muscle-specific mutant mice. It has been known for a long time that FBMs are essential for the lung to develop properly. However, the cellular and molecular mechanisms transducing the mechanical forces of muscular activity into specific genetic programs that propel lung morphogenesis (development of the shape, form and size of the lung, its airways, and gas exchange surface) as well as its differentiation (acquisition of specialized cell structural and functional features from their progenitor cells) are only starting to be revealed. This chapter is a brief synopsis of the cumulative findings from that ongoing quest. An update on and the rationale for our recent International Mouse Phenotyping Consortium (IMPC) search is also provided.
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Affiliation(s)
- Mark Baguma-Nibasheka
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada.
| | - Boris Kablar
- Department of Medical Neuroscience, Anatomy and Pathology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
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2
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De Leon N, Tse WH, Ameis D, Keijzer R. Embryology and anatomy of congenital diaphragmatic hernia. Semin Pediatr Surg 2022; 31:151229. [PMID: 36446305 DOI: 10.1016/j.sempedsurg.2022.151229] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Prenatal and postnatal treatment modalities for congenital diaphragmatic hernia (CDH) continue to improve, however patients still face high rates of morbidity and mortality caused by severe underlying persistent pulmonary hypertension and pulmonary hypoplasia. Though the majority of CDH cases are idiopathic, it is believed that CDH is a polygenic developmental defect caused by interactions between candidate genes, as well as environmental and epigenetic factors. However, the origin and pathogenesis of these developmental insults are poorly understood. Further, connections between disrupted lung development and the failure of diaphragmatic closure during embryogenesis have not been fully elucidated. Though several animal models have been useful in identifying candidate genes and disrupted signalling pathways, more studies are required to understand the pathogenesis and to develop effective preventative care. In this article, we summarize the most recent litterature on disrupted embryological lung and diaphragmatic development associated with CDH.
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Affiliation(s)
- Nolan De Leon
- Departments of Surgery, Division of Pediatric Surgery, Pediatrics & Child Health and Physiology and Pathophysiology, University of Manitoba and Biology of Breathing Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada
| | - Wai Hei Tse
- Departments of Surgery, Division of Pediatric Surgery, Pediatrics & Child Health and Physiology and Pathophysiology, University of Manitoba and Biology of Breathing Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada
| | - Dustin Ameis
- Departments of Surgery, Division of Pediatric Surgery, Pediatrics & Child Health and Physiology and Pathophysiology, University of Manitoba and Biology of Breathing Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada
| | - Richard Keijzer
- Departments of Surgery, Division of Pediatric Surgery, Pediatrics & Child Health and Physiology and Pathophysiology, University of Manitoba and Biology of Breathing Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada.
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3
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Burns NG, Kardon G. The role of genes and environment in the etiology of congenital diaphragmatic hernias. Curr Top Dev Biol 2022; 152:115-138. [PMID: 36707209 PMCID: PMC10923182 DOI: 10.1016/bs.ctdb.2022.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Structural birth defects are a common cause of abnormalities in newborns. While there are cases of structural birth defects arising due to monogenic defects or environmental exposures, many birth defects are likely caused by a complex interaction between genes and the environment. A structural birth defect with complex etiology is congenital diaphragmatic hernias (CDH), a common and often lethal disruption in diaphragm development. Mutations in more than 150 genes have been implicated in CDH pathogenesis. Although there is generally less evidence for a role for environmental factors in the etiology of CDH, deficiencies in maternal vitamin A and its derivative embryonic retinoic acid are strongly associated with CDH. However, the incomplete penetrance of CDH-implicated genes and environmental factors such as vitamin A deficiency suggest that interactions between genes and environment may be necessary to cause CDH. In this review, we examine the genetic and environmental factors implicated in diaphragm and CDH development. In addition, we evaluate the potential for gene-environment interactions in CDH etiology, focusing on the potential interactions between the CDH-implicated gene, Gata4, and maternal vitamin A deficiency.
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Affiliation(s)
- Nathan G Burns
- Department of Human Genetics, University of Utah, Salt Lake City, UT, United States
| | - Gabrielle Kardon
- Department of Human Genetics, University of Utah, Salt Lake City, UT, United States.
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4
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Sefton EM, Gallardo M, Tobin CE, Collins BC, Colasanto MP, Merrell AJ, Kardon G. Fibroblast-derived Hgf controls recruitment and expansion of muscle during morphogenesis of the mammalian diaphragm. eLife 2022; 11:e74592. [PMID: 36154712 PMCID: PMC9514848 DOI: 10.7554/elife.74592] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 09/13/2022] [Indexed: 12/01/2022] Open
Abstract
The diaphragm is a domed muscle between the thorax and abdomen essential for breathing in mammals. Diaphragm development requires the coordinated development of muscle, connective tissue, and nerve, which are derived from different embryonic sources. Defects in diaphragm development cause the common and often lethal birth defect, congenital diaphragmatic hernias (CDH). HGF/MET signaling is required for diaphragm muscularization, but the source of HGF and the specific functions of this pathway in muscle progenitors and effects on phrenic nerve have not been explicitly tested. Using conditional mutagenesis in mice and pharmacological inhibition of MET, we demonstrate that the pleuroperitoneal folds (PPFs), transient embryonic structures that give rise to the connective tissue in the diaphragm, are the source of HGF critical for diaphragm muscularization. PPF-derived HGF is directly required for recruitment of MET+ muscle progenitors to the diaphragm and indirectly (via its effect on muscle development) required for phrenic nerve primary branching. In addition, HGF is continuously required for maintenance and motility of the pool of progenitors to enable full muscularization. Localization of HGF at the diaphragm's leading edges directs dorsal and ventral expansion of muscle and regulates its overall size and shape. Surprisingly, large muscleless regions in HGF and Met mutants do not lead to hernias. While these regions are likely more susceptible to CDH, muscle loss is not sufficient to cause CDH.
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Affiliation(s)
- Elizabeth M Sefton
- Department of Human Genetics, University of UtahSalt Lake CityUnited States
| | - Mirialys Gallardo
- Department of Human Genetics, University of UtahSalt Lake CityUnited States
| | - Claire E Tobin
- Department of Human Genetics, University of UtahSalt Lake CityUnited States
| | - Brittany C Collins
- Department of Human Genetics, University of UtahSalt Lake CityUnited States
| | - Mary P Colasanto
- Department of Human Genetics, University of UtahSalt Lake CityUnited States
| | | | - Gabrielle Kardon
- Department of Human Genetics, University of UtahSalt Lake CityUnited States
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5
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Dahl MJ, Lavizzari A, Davis JW, Noble PB, Dellacà R, Pillow JJ. Impact of fetal treatments for congenital diaphragmatic hernia on lung development. Anat Rec (Hoboken) 2022. [PMID: 36065499 DOI: 10.1002/ar.25059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 07/26/2022] [Accepted: 08/08/2022] [Indexed: 11/10/2022]
Abstract
The extent of lung hypoplasia impacts the survival and severity of morbidities associated with congenital diaphragmatic hernia (CDH). The alveoli of CDH infants and in experimental models of CDH have thickened septa with fewer type II pneumocytes and capillaries. Fetal treatments of CDH-risk preterm birth. Therefore, treatments must aim to balance the need for increased gas exchange surface area with the restoration of pulmonary epithelial type II cells and the long-term respiratory and neurodevelopmental consequences of prematurity. Achievement of sufficient lung development in utero for successful postnatal transition requires adequate intra-thoracic space for lung growth, maintenance of sufficient volume and appropriate composition of fetal lung fluid, regular fetal breathing movements, appropriate gas exchange area, and ample surfactant production. The review aims to examine the rationale for current and future therapeutic strategies to improve postnatal outcomes of infants with CDH.
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Affiliation(s)
- Mar Janna Dahl
- School of Human Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - Anna Lavizzari
- NICU, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Jonathan W Davis
- Medical School, University of Western Australia, Perth, Western Australia, Australia
- Telethon Kids Institute, Perth Children's Hospital, Perth, Western Australia, Australia
| | - Peter B Noble
- School of Human Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - Raffaele Dellacà
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - J Jane Pillow
- School of Human Sciences, University of Western Australia, Perth, Western Australia, Australia
- Telethon Kids Institute, Perth Children's Hospital, Perth, Western Australia, Australia
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6
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Davis LA, Fogarty MJ, Brown A, Sieck GC. Structure and Function of the Mammalian Neuromuscular Junction. Compr Physiol 2022; 12:3731-3766. [PMID: 35950651 PMCID: PMC10461538 DOI: 10.1002/cphy.c210022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The mammalian neuromuscular junction (NMJ) comprises a presynaptic terminal, a postsynaptic receptor region on the muscle fiber (endplate), and the perisynaptic (terminal) Schwann cell. As with any synapse, the purpose of the NMJ is to transmit signals from the nervous system to muscle fibers. This neural control of muscle fibers is organized as motor units, which display distinct structural and functional phenotypes including differences in pre- and postsynaptic elements of NMJs. Motor units vary considerably in the frequency of their activation (both motor neuron discharge rate and duration/duty cycle), force generation, and susceptibility to fatigue. For earlier and more frequently recruited motor units, the structure and function of the activated NMJs must have high fidelity to ensure consistent activation and continued contractile response to sustain vital motor behaviors (e.g., breathing and postural balance). Similarly, for higher force less frequent behaviors (e.g., coughing and jumping), the structure and function of recruited NMJs must ensure short-term reliable activation but not activation sustained for a prolonged period in which fatigue may occur. The NMJ is highly plastic, changing structurally and functionally throughout the life span from embryonic development to old age. The NMJ also changes under pathological conditions including acute and chronic disease. Such neuroplasticity often varies across motor unit types. © 2022 American Physiological Society. Compr Physiol 12:1-36, 2022.
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Affiliation(s)
- Leah A. Davis
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Matthew J. Fogarty
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Alyssa Brown
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Gary C. Sieck
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
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7
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Fuller DD, Rana S, Smuder AJ, Dale EA. The phrenic neuromuscular system. HANDBOOK OF CLINICAL NEUROLOGY 2022; 188:393-408. [PMID: 35965035 PMCID: PMC11135908 DOI: 10.1016/b978-0-323-91534-2.00012-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The phrenic neuromuscular system consists of the phrenic motor nucleus in the mid-cervical spinal cord, the phrenic nerve, and the diaphragm muscle. This motor system helps sustain breathing throughout life, while also contributing to posture, coughing, swallowing, and speaking. The phrenic nerve contains primarily efferent phrenic axons and afferent axons from diaphragm sensory receptors but is also a conduit for autonomic fibers. On a breath-by-breath basis, rhythmic (inspiratory) depolarization of phrenic motoneurons occurs due to excitatory bulbospinal synaptic pathways. Further, a complex propriospinal network innervates phrenic motoneurons and may serve to coordinate postural, locomotor, and respiratory movements. The phrenic neuromuscular system is impacted in a wide range of neuromuscular diseases and injuries. Contemporary research is focused on understanding how neuromuscular plasticity occurs in the phrenic neuromuscular system and using this information to optimize treatments and rehabilitation strategies to improve breathing and related behaviors.
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Affiliation(s)
- David D Fuller
- Department of Physical Therapy, University of Florida, Gainesville, FL, United States; McKnight Brain Institute, University of Florida, Gainesville, FL, United States; Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, United States.
| | - Sabhya Rana
- Department of Physical Therapy, University of Florida, Gainesville, FL, United States; McKnight Brain Institute, University of Florida, Gainesville, FL, United States; Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, United States
| | - Ashley J Smuder
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, United States; Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States
| | - Erica A Dale
- McKnight Brain Institute, University of Florida, Gainesville, FL, United States; Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, United States; Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States
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8
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Edel GG, Schaaf G, Wijnen RMH, Tibboel D, Kardon G, Rottier RJ. Cellular Origin(s) of Congenital Diaphragmatic Hernia. Front Pediatr 2021; 9:804496. [PMID: 34917566 PMCID: PMC8669812 DOI: 10.3389/fped.2021.804496] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/03/2021] [Indexed: 01/16/2023] Open
Abstract
Congenital diaphragmatic hernia (CDH) is a structural birth defect characterized by a diaphragmatic defect, lung hypoplasia and structural vascular defects. In spite of recent developments, the pathogenesis of CDH is still poorly understood. CDH is a complex congenital disorder with multifactorial etiology consisting of genetic, cellular and mechanical factors. This review explores the cellular origin of CDH pathogenesis in the diaphragm and lungs and describes recent developments in basic and translational CDH research.
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Affiliation(s)
- Gabriëla G. Edel
- Department of Pediatric Surgery and Intensive Care, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
- Department of Cell Biology, Erasmus MC, Rotterdam, Netherlands
| | - Gerben Schaaf
- Department of Clinical Genetics, Erasmus MC, Rotterdam, Netherlands
- Department of Pediatrics, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
- Center for Lysosomal and Metabolic Diseases, Erasmus MC, Rotterdam, Netherlands
| | - Rene M. H. Wijnen
- Department of Pediatric Surgery and Intensive Care, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
| | - Dick Tibboel
- Department of Pediatric Surgery and Intensive Care, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
| | - Gabrielle Kardon
- Department of Human Genetics, University of Utah, Salt Lake City, UT, United States
| | - Robbert J. Rottier
- Department of Pediatric Surgery and Intensive Care, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
- Department of Cell Biology, Erasmus MC, Rotterdam, Netherlands
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9
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Genetics of diaphragmatic hernia. Eur J Hum Genet 2021; 29:1729-1733. [PMID: 34621023 PMCID: PMC8632982 DOI: 10.1038/s41431-021-00972-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 09/09/2021] [Accepted: 09/21/2021] [Indexed: 01/14/2023] Open
Abstract
Congenital diaphragmatic hernia (CDH) is a life-threatening malformation characterised by failure of diaphragmatic development with lung hypoplasia and persistent pulmonary hypertension of the newborn (PPHN). The incidence is 1:2000 corresponding to 8% of all major congenital malformations. Morbidity and mortality in affected newborns are very high and at present, there is no precise prenatal or early postnatal prognostication parameter to predict clinical outcome in CDH patients. Most cases occur sporadically, however, genetic causes have long been discussed to explain a proportion of cases. These range from aneuploidy to complex chromosomal aberrations and specific mutations often causing a complex phenotype exhibiting multiple malformations along with CDH. This review summarises the genetic variations which have been observed in syndromic and isolated cases of congenital diaphragmatic hernia.
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10
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Cannata G, Caporilli C, Grassi F, Perrone S, Esposito S. Management of Congenital Diaphragmatic Hernia (CDH): Role of Molecular Genetics. Int J Mol Sci 2021; 22:ijms22126353. [PMID: 34198563 PMCID: PMC8231903 DOI: 10.3390/ijms22126353] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/04/2021] [Accepted: 06/11/2021] [Indexed: 12/11/2022] Open
Abstract
Congenital diaphragmatic hernia (CDH) is a relatively common major life-threatening birth defect that results in significant mortality and morbidity depending primarily on lung hypoplasia, persistent pulmonary hypertension, and cardiac dysfunction. Despite its clinical relevance, CDH multifactorial etiology is still not completely understood. We reviewed current knowledge on normal diaphragm development and summarized genetic mutations and related pathways as well as cellular mechanisms involved in CDH. Our literature analysis showed that the discovery of harmful de novo variants in the fetus could constitute an important tool for the medical team during pregnancy, counselling, and childbirth. A better insight into the mechanisms regulating diaphragm development and genetic causes leading to CDH appeared essential to the development of new therapeutic strategies and evidence-based genetic counselling to parents. Integrated sequencing, development, and bioinformatics strategies could direct future functional studies on CDH; could be applied to cohorts and consortia for CDH and other birth defects; and could pave the way for potential therapies by providing molecular targets for drug discovery.
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Affiliation(s)
- Giulia Cannata
- Pediatric Clinic, Pietro Barilla Children’s Hospital, University of Parma, Via Gramsci 14, 43126 Parma, Italy; (G.C.); (C.C.); (F.G.)
| | - Chiara Caporilli
- Pediatric Clinic, Pietro Barilla Children’s Hospital, University of Parma, Via Gramsci 14, 43126 Parma, Italy; (G.C.); (C.C.); (F.G.)
| | - Federica Grassi
- Pediatric Clinic, Pietro Barilla Children’s Hospital, University of Parma, Via Gramsci 14, 43126 Parma, Italy; (G.C.); (C.C.); (F.G.)
| | - Serafina Perrone
- Neonatology Unit, Pietro Barilla Children’s Hospital, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy;
| | - Susanna Esposito
- Pediatric Clinic, Pietro Barilla Children’s Hospital, University of Parma, Via Gramsci 14, 43126 Parma, Italy; (G.C.); (C.C.); (F.G.)
- Correspondence: ; Tel.: +39-0521-7047
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11
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Rimington RP, Fleming JW, Capel AJ, Wheeler PC, Lewis MP. Bioengineered model of the human motor unit with physiologically functional neuromuscular junctions. Sci Rep 2021; 11:11695. [PMID: 34083648 PMCID: PMC8175425 DOI: 10.1038/s41598-021-91203-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 05/24/2021] [Indexed: 02/04/2023] Open
Abstract
Investigations of the human neuromuscular junction (NMJ) have predominately utilised experimental animals, model organisms, or monolayer cell cultures that fail to represent the physiological complexity of the synapse. Consequently, there remains a paucity of data regarding the development of the human NMJ and a lack of systems that enable investigation of the motor unit. This work addresses this need, providing the methodologies to bioengineer 3D models of the human motor unit. Spheroid culture of iPSC derived motor neuron progenitors augmented the transcription of OLIG2, ISLET1 and SMI32 motor neuron mRNAs ~ 400, ~ 150 and ~ 200-fold respectively compared to monolayer equivalents. Axon projections of adhered spheroids exceeded 1000 μm in monolayer, with transcription of SMI32 and VACHT mRNAs further enhanced by addition to 3D extracellular matrices in a type I collagen concentration dependent manner. Bioengineered skeletal muscles produced functional tetanic and twitch profiles, demonstrated increased acetylcholine receptor (AChR) clustering and transcription of MUSK and LRP4 mRNAs, indicating enhanced organisation of the post-synaptic membrane. The number of motor neuron spheroids, or motor pool, required to functionally innervate 3D muscle tissues was then determined, generating functional human NMJs that evidence pre- and post-synaptic membrane and motor nerve axon co-localisation. Spontaneous firing was significantly elevated in 3D motor units, confirmed to be driven by the motor nerve via antagonistic inhibition of the AChR. Functional analysis outlined decreased time to peak twitch and half relaxation times, indicating enhanced physiology of excitation contraction coupling in innervated motor units. Our findings provide the methods to maximise the maturity of both iPSC motor neurons and primary human skeletal muscle, utilising cell type specific extracellular matrices and developmental timelines to bioengineer the human motor unit for the study of neuromuscular junction physiology.
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Affiliation(s)
- Rowan P. Rimington
- grid.6571.50000 0004 1936 8542National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU Leicestershire UK
| | - Jacob W. Fleming
- grid.6571.50000 0004 1936 8542National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU Leicestershire UK
| | - Andrew J. Capel
- grid.6571.50000 0004 1936 8542National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU Leicestershire UK
| | - Patrick C. Wheeler
- grid.6571.50000 0004 1936 8542National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU Leicestershire UK
| | - Mark P. Lewis
- grid.6571.50000 0004 1936 8542National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU Leicestershire UK
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12
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Bogenschutz EL, Sefton EM, Kardon G. Cell culture system to assay candidate genes and molecular pathways implicated in congenital diaphragmatic hernias. Dev Biol 2020; 467:30-38. [PMID: 32827499 DOI: 10.1016/j.ydbio.2020.07.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/21/2020] [Accepted: 07/21/2020] [Indexed: 10/23/2022]
Abstract
The mammalian muscularized diaphragm is essential for respiration and defects in the developing diaphragm cause a common and frequently lethal birth defect, congenital diaphragmatic hernia (CDH). Human genetic studies have implicated more than 150 genes and multiple molecular pathways in CDH, but few of these have been validated because of the expense and time to generate mouse mutants. The pleuroperitoneal folds (PPFs) are transient embryonic structures in diaphragm development and defects in PPFs lead to CDH. We have developed a system to culture PPF fibroblasts from E12.5 mouse embryos and show that these fibroblasts, in contrast to the commonly used NIH 3T3 fibroblasts, maintain expression of key genes in normal diaphragm development. Using pharmacological and genetic manipulations that result in CDH in vivo, we also demonstrate that differences in proliferation provide a rapid means of distinguishing healthy and impaired PPF fibroblasts. Thus, the PPF fibroblast cell culture system is an efficient tool for assaying the functional significance of CDH candidate genes and molecular pathways and will be an important resource for elucidating the complex etiology of CDH.
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Affiliation(s)
- Eric L Bogenschutz
- Department of Human Genetics, University of Utah, Salt Lake City, UT, 84112, United States
| | - Elizabeth M Sefton
- Department of Human Genetics, University of Utah, Salt Lake City, UT, 84112, United States
| | - Gabrielle Kardon
- Department of Human Genetics, University of Utah, Salt Lake City, UT, 84112, United States.
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13
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Bogenschutz EL, Fox ZD, Farrell A, Wynn J, Moore B, Yu L, Aspelund G, Marth G, Yandell M, Shen Y, Chung WK, Kardon G. Deep whole-genome sequencing of multiple proband tissues and parental blood reveals the complex genetic etiology of congenital diaphragmatic hernias. HGG ADVANCES 2020; 1:100008. [PMID: 33263113 PMCID: PMC7703690 DOI: 10.1016/j.xhgg.2020.100008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 08/07/2020] [Indexed: 12/17/2022] Open
Abstract
The diaphragm is critical for respiration and separation of the thoracic and abdominal cavities, and defects in diaphragm development are the cause of congenital diaphragmatic hernias (CDH), a common and often lethal birth defect. The genetic etiology of CDH is complex. Single-nucleotide variants (SNVs), insertions/deletions (indels), and structural variants (SVs) in more than 150 genes have been associated with CDH, although few genes are recurrently mutated in multiple individuals and mutated genes are incompletely penetrant. This suggests that multiple genetic variants in combination, other not-yet-investigated classes of variants, and/or nongenetic factors contribute to CDH etiology. However, no studies have comprehensively investigated in affected individuals the contribution of all possible classes of variants throughout the genome to CDH etiology. In our study, we used a unique cohort of four individuals with isolated CDH with samples from blood, skin, and diaphragm connective tissue and parental blood and deep whole-genome sequencing to assess germline and somatic de novo and inherited SNVs, indels, and SVs. In each individual we found a different mutational landscape that included germline de novo and inherited SNVs and indels in multiple genes. We also found in two individuals a 343 bp deletion interrupting an annotated enhancer of the CDH-associated gene GATA4, and we hypothesize that this common SV (found in 1%-2% of the population) acts as a sensitizing allele for CDH. Overall, our comprehensive reconstruction of the genetic architecture of four CDH individuals demonstrates that the etiology of CDH is heterogeneous and multifactorial.
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Affiliation(s)
- Eric L. Bogenschutz
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Zac D. Fox
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Andrew Farrell
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- USTAR Center for Genetic Discovery, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Julia Wynn
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Barry Moore
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- USTAR Center for Genetic Discovery, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Lan Yu
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Gudrun Aspelund
- Department of Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Gabor Marth
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- USTAR Center for Genetic Discovery, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Mark Yandell
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- USTAR Center for Genetic Discovery, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Yufeng Shen
- Department of Systems Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Biomedical Informatics, Columbia University Irving Medical Center, New York, NY 10032, USA
- JP Sulzberger Columbia Genome Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wendy K. Chung
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
- Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Gabrielle Kardon
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
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14
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Congenital diaphragmatic eventration with absent left phrenic nerve in the fetal pig. Anat Sci Int 2019; 95:143-152. [PMID: 31414371 DOI: 10.1007/s12565-019-00499-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/05/2019] [Indexed: 10/26/2022]
Abstract
We encountered a fetal pig with eventration of the diaphragm and pulmonary hypoplasia accompanied by phrenic nerve agenesis. The fetal pig was female measuring 34 cm in crown-rump length and about 1500 g in body weight. The diaphragm was a complete continuous sheet, but comprised a translucent membrane with residual muscular tissue only at the dorsolateral area of the right leaf of the diaphragm. The left leaf protruded extraordinarily toward the thoracic cavity. The left phrenic nerve was completely absent, while there was a slight remnant of the right phrenic nerve that supplied the dorsolateral muscular area of the right leaf. Both lungs were small, and the number of smaller bronchioles arising from the bronchioles was decreased to about half of that of the normal lung. Additionally, the right and left subclavius muscles and nerves could not be identified. These findings imply that the diaphragm, the subclavius muscle and nerves innervating them comprise a developmental module, which would secondarily affect lung development. It is considered that the present case is analogous to the animal model of congenital eventration of the diaphragm in humans.
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15
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Pilarski JQ, Leiter JC, Fregosi RF. Muscles of Breathing: Development, Function, and Patterns of Activation. Compr Physiol 2019; 9:1025-1080. [PMID: 31187893 DOI: 10.1002/cphy.c180008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review is a comprehensive description of all muscles that assist lung inflation or deflation in any way. The developmental origin, anatomical orientation, mechanical action, innervation, and pattern of activation are described for each respiratory muscle fulfilling this broad definition. In addition, the circumstances in which each muscle is called upon to assist ventilation are discussed. The number of "respiratory" muscles is large, and the coordination of respiratory muscles with "nonrespiratory" muscles and in nonrespiratory activities is complex-commensurate with the diversity of activities that humans pursue, including sleep (8.27). The capacity for speech and adoption of the bipedal posture in human evolution has resulted in patterns of respiratory muscle activation that differ significantly from most other animals. A disproportionate number of respiratory muscles affect the nose, mouth, pharynx, and larynx, reflecting the vital importance of coordinated muscle activity to control upper airway patency during both wakefulness and sleep. The upright posture has freed the hands from locomotor functions, but the evolutionary history and ontogeny of forelimb muscles pervades the patterns of activation and the forces generated by these muscles during breathing. The distinction between respiratory and nonrespiratory muscles is artificial, as many "nonrespiratory" muscles can augment breathing under conditions of high ventilator demand. Understanding the ontogeny, innervation, activation patterns, and functions of respiratory muscles is clinically useful, particularly in sleep medicine. Detailed explorations of how the nervous system controls the multiple muscles required for successful completion of respiratory behaviors will continue to be a fruitful area of investigation. © 2019 American Physiological Society. Compr Physiol 9:1025-1080, 2019.
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Affiliation(s)
- Jason Q Pilarski
- Department of Biological and Dental Sciences, Idaho State University Pocatello, Idaho, USA
| | - James C Leiter
- Department of Molecular and Systems Biology, The Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA
| | - Ralph F Fregosi
- Departments of Physiology and Neuroscience, The University of Arizona, Tucson, Arizona, USA
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16
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Fogarty MJ, Sieck GC. Evolution and Functional Differentiation of the Diaphragm Muscle of Mammals. Compr Physiol 2019; 9:715-766. [PMID: 30873594 PMCID: PMC7082849 DOI: 10.1002/cphy.c180012] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Symmorphosis is a concept of economy of biological design, whereby structural properties are matched to functional demands. According to symmorphosis, biological structures are never over designed to exceed functional demands. Based on this concept, the evolution of the diaphragm muscle (DIAm) in mammals is a tale of two structures, a membrane that separates and partitions the primitive coelomic cavity into separate abdominal and thoracic cavities and a muscle that serves as a pump to generate intra-abdominal (Pab ) and intrathoracic (Pth ) pressures. The DIAm partition evolved in reptiles from folds of the pleural and peritoneal membranes that was driven by the biological advantage of separating organs in the larger coelomic cavity into separate thoracic and abdominal cavities, especially with the evolution of aspiration breathing. The DIAm pump evolved from the advantage afforded by more effective generation of both a negative Pth for ventilation of the lungs and a positive Pab for venous return of blood to the heart and expulsive behaviors such as airway clearance, defecation, micturition, and child birth. © 2019 American Physiological Society. Compr Physiol 9:715-766, 2019.
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Affiliation(s)
- Matthew J Fogarty
- Mayo Clinic, Department of Physiology & Biomedical Engineering, Rochester, Minnesota, USA
| | - Gary C Sieck
- Mayo Clinic, Department of Physiology & Biomedical Engineering, Rochester, Minnesota, USA
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17
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Chen S, Tian R, Li H, Chen M, Zhang H, Lin D. Optimized methods for rapidly dissecting spinal cords and harvesting spinal motor neurons with high survival and purity from rats at different embryonic stages. J Spinal Cord Med 2018; 41:281-291. [PMID: 28545340 PMCID: PMC6055952 DOI: 10.1080/10790268.2017.1329075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
STUDY DESIGN Experimental study, protocol optimization. OBJECTIVES To investigate and compare the isolation of spinal motor neurons from embryonic rats at different embryonic stages, and develop optimized methods for rapidly dissecting spinal cords and harvesting spinal motor neurons with high survival and purity. SETTING Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China. METHODS Embryonic rats at different embryonic stages (12-18 days) were used to isolate spinal motor neurons. Their shape and corresponding dissection procedures, time needed and skills were compared. After dissecting and dissociating spinal cords, cells were randomly divided into immunopanning group and control group, in which antibodies to p75NTR were used or not. After plating cells, different recipe were added at different stages in serum-free culture media. Morphological features of cells were observed during development. Immunoflurorescence assay was performed to indentify motor neurons and the proportion of motor neurons in both control and immunopanning group were evaluated and compared. RESULTS We summarized the operation essentials for rapid isolation of spinal cords, as well as compared anatomical features and dissection procedures of embryos at different embryonic stages, which help us to better evaluate the developmental profile and isolate cells by adopting corresponding skills. Through the fast isolation procedure and optimized culture media, cells grow in good viability. Moreover, compared with control group, the purity of spinal motor neurons in the immunopanning group was significantly increased, reaching a proportion of over 95%.
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Affiliation(s)
- Shudong Chen
- Guangdong Provincial Hospital of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Ruimin Tian
- Guangdong Provincial Hospital of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Hui Li
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Meihui Chen
- Guangdong Provincial Hospital of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Hu Zhang
- Guangdong Provincial Hospital of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Dingkun Lin
- Guangdong Provincial Hospital of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China,Guangzhou University of Chinese Medicine, Guangzhou, China,Correspondence to: Dingkun Lin, Guangzhou University of Chinese Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, No.111 Dade Road, Yuexiu District, Guangzhou, 510120, China.
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18
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Sefton EM, Gallardo M, Kardon G. Developmental origin and morphogenesis of the diaphragm, an essential mammalian muscle. Dev Biol 2018; 440:64-73. [PMID: 29679560 DOI: 10.1016/j.ydbio.2018.04.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/14/2018] [Accepted: 04/14/2018] [Indexed: 11/17/2022]
Abstract
The diaphragm is a mammalian skeletal muscle essential for respiration and for separating the thoracic and abdominal cavities. Development of the diaphragm requires the coordinated development of muscle, muscle connective tissue, tendon, nerves, and vasculature that derive from different embryonic sources. However, defects in diaphragm development are common and the cause of an often deadly birth defect, Congenital Diaphragmatic Hernia (CDH). Here we comprehensively describe the normal developmental origin and complex spatial-temporal relationship between the different developing tissues to form a functional diaphragm using a developmental series of mouse embryos genetically and immunofluorescently labeled and analyzed in whole mount. We find that the earliest developmental events are the emigration of muscle progenitors from cervical somites followed by the projection of phrenic nerve axons from the cervical neural tube. Muscle progenitors and phrenic nerve target the pleuroperitoneal folds (PPFs), transient pyramidal-shaped structures that form between the thoracic and abdominal cavities. Subsequently, the PPFs expand across the surface of the liver to give rise to the muscle connective tissue and central tendon, and the leading edge of their expansion precedes muscle morphogenesis, formation of the vascular network, and outgrowth and branching of the phrenic nerve. Thus development and morphogenesis of the PPFs is critical for diaphragm formation. In addition, our data indicate that the earliest events in diaphragm development are critical for the etiology of CDH and instrumental to the evolution of the diaphragm. CDH initiates prior to E12.5 in mouse and suggests that defects in the early PPF formation or their ability to recruit muscle are an important source of CDH. Also, the recruitment of muscle progenitors from cervical somites to the nascent PPFs is uniquely mammalian and a key developmental innovation essential for the evolution of the muscularized diaphragm.
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Affiliation(s)
- Elizabeth M Sefton
- Department of Human Genetics University of Utah, Salt Lake City, UT 84112, USA
| | - Mirialys Gallardo
- Department of Human Genetics University of Utah, Salt Lake City, UT 84112, USA
| | - Gabrielle Kardon
- Department of Human Genetics University of Utah, Salt Lake City, UT 84112, USA
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19
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Fogarty MJ, Mantilla CB, Sieck GC. Breathing: Motor Control of Diaphragm Muscle. Physiology (Bethesda) 2018; 33:113-126. [PMID: 29412056 PMCID: PMC5899234 DOI: 10.1152/physiol.00002.2018] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 01/05/2018] [Indexed: 12/12/2022] Open
Abstract
Breathing occurs without thought but is controlled by a complex neural network with a final output of phrenic motor neurons activating diaphragm muscle fibers (i.e., motor units). This review considers diaphragm motor unit organization and how they are controlled during breathing as well as during expulsive behaviors.
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Affiliation(s)
- Matthew J Fogarty
- Department of Physiology and Biomedical Engineering, Mayo Clinic , Rochester, Minnesota
- School of Biomedical Sciences, The University of Queensland , Brisbane , Australia
| | - Carlos B Mantilla
- Department of Physiology and Biomedical Engineering, Mayo Clinic , Rochester, Minnesota
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic , Rochester, Minnesota
| | - Gary C Sieck
- Department of Physiology and Biomedical Engineering, Mayo Clinic , Rochester, Minnesota
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic , Rochester, Minnesota
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20
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Bordoni B, Marelli F, Morabito B, Sacconi B, Caiazzo P, Castagna R. Low back pain and gastroesophageal reflux in patients with COPD: the disease in the breath. Int J Chron Obstruct Pulmon Dis 2018; 13:325-334. [PMID: 29403270 PMCID: PMC5777378 DOI: 10.2147/copd.s150401] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
COPD is a worsening condition that leads to a pathologic degeneration of the respiratory system. It represents one of the most important causes of mortality and morbidity in the world, and it is characterized by the presence of associated comorbidity. This article analyzes gastroesophageal reflux disease (GERD) and low back pain (LBP) in patients with COPD and tries to produce anatomo-clinical considerations on the reasons of the presence of these comorbidities. The considerations of the authors are based on the anatomic functions and characteristics of the respiratory diaphragm that are not always considered, from which elements useful to comprehend the symptomatic status of the patient can be deduced, finally improving the therapeutic approach. The information contained in the article can be of help to the clinician and for physiotherapy, and to all health professionals who gravitate around the patient’s care, improving the approach to the diaphragm muscle.
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Affiliation(s)
- Bruno Bordoni
- Foundation Don Carlo Gnocchi IRCCS, Department of Cardiology, Scientific Institute of Hospitalization and Care, Milan
| | - Fabiola Marelli
- Department of Fascial Osteopathic Research, CRESO, School of Osteopathic Centre for Research and Studies, Gorla Minore.,Department of Fascial Osteopathic Research, CRESO, School of Osteopathic Centre for Research and Studies, Fano
| | - Bruno Morabito
- Department of Fascial Osteopathic Research, CRESO, School of Osteopathic Centre for Research and Studies, Gorla Minore.,Department of Fascial Osteopathic Research, CRESO, School of Osteopathic Centre for Research and Studies, Fano
| | - Beatrice Sacconi
- Department of Radiological, Oncological and Anatomopathological Sciences, Sapienza University of Rome.,Department of Radiological, Oncological and Anatomopathological Sciences, Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Rome
| | - Philippe Caiazzo
- Department of Osteopathic Research, AITOP, Italian Academy of Postural Osteopathic Therapy, Levizzano Rangone - Castelvetro, Italy
| | - Roberto Castagna
- Department of Fascial Osteopathic Research, CRESO, School of Osteopathic Centre for Research and Studies, Gorla Minore
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21
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Landry-Truchon K, Houde N, Boucherat O, Joncas FH, Dasen JS, Philippidou P, Mansfield JH, Jeannotte L. HOXA5 plays tissue-specific roles in the developing respiratory system. Development 2017; 144:3547-3561. [PMID: 28827394 DOI: 10.1242/dev.152686] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 08/16/2017] [Indexed: 12/20/2022]
Abstract
Hoxa5 is essential for development of several organs and tissues. In the respiratory system, loss of Hoxa5 function causes neonatal death due to respiratory distress. Expression of HOXA5 protein in mesenchyme of the respiratory tract and in phrenic motor neurons of the central nervous system led us to address the individual contribution of these Hoxa5 expression domains using a conditional gene targeting approach. Hoxa5 does not play a cell-autonomous role in lung epithelium, consistent with lack of HOXA5 expression in this cell layer. In contrast, ablation of Hoxa5 in mesenchyme perturbed trachea development, lung epithelial cell differentiation and lung growth. Further, deletion of Hoxa5 in motor neurons resulted in abnormal diaphragm innervation and musculature, and lung hypoplasia. It also reproduced the neonatal lethality observed in null mutants, indicating that the defective diaphragm is the main cause of impaired survival at birth. Thus, Hoxa5 possesses tissue-specific functions that differentially contribute to the morphogenesis of the respiratory tract.
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Affiliation(s)
- Kim Landry-Truchon
- Centre de Recherche sur le Cancer de l'Université Laval, CRCHU de Québec, L'Hôtel-Dieu de Québec, Québec G1R 3S3, Canada
| | - Nicolas Houde
- Centre de Recherche sur le Cancer de l'Université Laval, CRCHU de Québec, L'Hôtel-Dieu de Québec, Québec G1R 3S3, Canada
| | - Olivier Boucherat
- Centre de Recherche sur le Cancer de l'Université Laval, CRCHU de Québec, L'Hôtel-Dieu de Québec, Québec G1R 3S3, Canada
| | - France-Hélène Joncas
- Centre de Recherche sur le Cancer de l'Université Laval, CRCHU de Québec, L'Hôtel-Dieu de Québec, Québec G1R 3S3, Canada
| | - Jeremy S Dasen
- NYU Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY 10036, USA
| | - Polyxeni Philippidou
- NYU Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY 10036, USA
| | - Jennifer H Mansfield
- Department of Biology, Barnard College-Columbia University, New York, NY 10027, USA
| | - Lucie Jeannotte
- Centre de Recherche sur le Cancer de l'Université Laval, CRCHU de Québec, L'Hôtel-Dieu de Québec, Québec G1R 3S3, Canada
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22
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Kardon G, Ackerman KG, McCulley DJ, Shen Y, Wynn J, Shang L, Bogenschutz E, Sun X, Chung WK. Congenital diaphragmatic hernias: from genes to mechanisms to therapies. Dis Model Mech 2017; 10:955-970. [PMID: 28768736 PMCID: PMC5560060 DOI: 10.1242/dmm.028365] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Congenital diaphragmatic hernias (CDHs) and structural anomalies of the diaphragm are a common class of congenital birth defects that are associated with significant morbidity and mortality due to associated pulmonary hypoplasia, pulmonary hypertension and heart failure. In ∼30% of CDH patients, genomic analyses have identified a range of genetic defects, including chromosomal anomalies, copy number variants and sequence variants. The affected genes identified in CDH patients include transcription factors, such as GATA4, ZFPM2, NR2F2 and WT1, and signaling pathway components, including members of the retinoic acid pathway. Mutations in these genes affect diaphragm development and can have pleiotropic effects on pulmonary and cardiac development. New therapies, including fetal endoscopic tracheal occlusion and prenatal transplacental fetal treatments, aim to normalize lung development and pulmonary vascular tone to prevent and treat lung hypoplasia and pulmonary hypertension, respectively. Studies of the association between particular genetic mutations and clinical outcomes should allow us to better understand the origin of this birth defect and to improve our ability to predict and identify patients most likely to benefit from specialized treatment strategies.
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Affiliation(s)
- Gabrielle Kardon
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Kate G Ackerman
- Departments of Pediatrics (Critical Care) and Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - David J McCulley
- Department of Pediatrics, University of Wisconsin, Madison, WI 53792, USA
| | - Yufeng Shen
- Department of Systems Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - Julia Wynn
- Departments of Pediatrics, Columbia University Medical Center, New York, NY 10032, USA
| | - Linshan Shang
- Departments of Pediatrics, Columbia University Medical Center, New York, NY 10032, USA
| | - Eric Bogenschutz
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Xin Sun
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Wendy K Chung
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
- Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
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23
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Developmental plasticity of phrenic motoneuron and diaphragm properties with the inception of inspiratory drive transmission in utero. Exp Neurol 2016; 287:137-143. [PMID: 27181410 DOI: 10.1016/j.expneurol.2016.05.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 05/06/2016] [Accepted: 05/11/2016] [Indexed: 11/23/2022]
Abstract
The review outlines data consistent with the hypothesis that inspiratory drive transmission that generates fetal breathing movements (FBMs) is essential for the developmental plasticity of phrenic motoneurons (PMNs) and diaphragm musculature prior to birth. A systematic examination during the perinatal period demonstrated a very marked transformation of PMN and diaphragm properties coinciding with the onset and strengthening of inspiratory drive and FBMs in utero. This included studies of age-dependent changes of: i) morphology, neuronal coupling, passive and electrophysiological properties of PMNs; ii) rhythmic inspiratory activity in vitro; iii) FBMs generated in vivo detected by ultrasonography; iv) contractile and end-plate potential properties of diaphragm musculature. We also propose how the hypothesis can be further evaluated with studies of perinatal hypoglossal motoneuron-tongue musculature and the use of Dbx1 null mice that provide an experimental model lacking descending inspiratory drive transmission in utero.
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24
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Hirasawa T, Fujimoto S, Kuratani S. Expansion of the neck reconstituted the shoulder-diaphragm in amniote evolution. Dev Growth Differ 2015; 58:143-53. [PMID: 26510533 DOI: 10.1111/dgd.12243] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 09/24/2015] [Accepted: 09/26/2015] [Indexed: 02/01/2023]
Abstract
The neck acquired flexibility through modifications of the head-trunk interface in vertebrate evolution. Although developmental programs for the neck musculoskeletal system have attracted the attention of evolutionary developmental biologists, how the heart, shoulder and surrounding tissues are modified during development has remained unclear. Here we show, through observation of the lateral plate mesoderm at cranial somite levels in chicken-quail chimeras, that the deep part of the lateral body wall is moved concomitant with the caudal transposition of the heart, resulting in the infolding of the expanded cervical lateral body wall into the thorax. Judging from the brachial plexus pattern, an equivalent infolding also appears to take place in mammalian and turtle embryos. In mammals, this infolding process is particularly important because it separates the diaphragm from the shoulder muscle mass. In turtles, the expansion of the cervical lateral body wall affects morphogenesis of the shoulder. Our findings highlight the cellular expansion in developing amniote necks that incidentally brought about the novel adaptive traits.
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Affiliation(s)
- Tatsuya Hirasawa
- Evolutionary Morphology Laboratory, RIKEN, 2-2-3 Minatojima-minami, Chuo-ku, Kobe, 650-0047, Japan
| | - Satoko Fujimoto
- Evolutionary Morphology Laboratory, RIKEN, 2-2-3 Minatojima-minami, Chuo-ku, Kobe, 650-0047, Japan
| | - Shigeru Kuratani
- Evolutionary Morphology Laboratory, RIKEN, 2-2-3 Minatojima-minami, Chuo-ku, Kobe, 650-0047, Japan
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25
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Tintignac LA, Brenner HR, Rüegg MA. Mechanisms Regulating Neuromuscular Junction Development and Function and Causes of Muscle Wasting. Physiol Rev 2015; 95:809-52. [DOI: 10.1152/physrev.00033.2014] [Citation(s) in RCA: 224] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The neuromuscular junction is the chemical synapse between motor neurons and skeletal muscle fibers. It is designed to reliably convert the action potential from the presynaptic motor neuron into the contraction of the postsynaptic muscle fiber. Diseases that affect the neuromuscular junction may cause failure of this conversion and result in loss of ambulation and respiration. The loss of motor input also causes muscle wasting as muscle mass is constantly adapted to contractile needs by the balancing of protein synthesis and protein degradation. Finally, neuromuscular activity and muscle mass have a major impact on metabolic properties of the organisms. This review discusses the mechanisms involved in the development and maintenance of the neuromuscular junction, the consequences of and the mechanisms involved in its dysfunction, and its role in maintaining muscle mass during aging. As life expectancy is increasing, loss of muscle mass during aging, called sarcopenia, has emerged as a field of high medical need. Interestingly, aging is also accompanied by structural changes at the neuromuscular junction, suggesting that the mechanisms involved in neuromuscular junction maintenance might be disturbed during aging. In addition, there is now evidence that behavioral paradigms and signaling pathways that are involved in longevity also affect neuromuscular junction stability and sarcopenia.
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Affiliation(s)
- Lionel A. Tintignac
- Biozentrum, University of Basel, Basel, Switzerland; Department of Biomedicine, University of Basel, Basel, Switzerland; and INRA, UMR866 Dynamique Musculaire et Métabolisme, Montpellier, France
| | - Hans-Rudolf Brenner
- Biozentrum, University of Basel, Basel, Switzerland; Department of Biomedicine, University of Basel, Basel, Switzerland; and INRA, UMR866 Dynamique Musculaire et Métabolisme, Montpellier, France
| | - Markus A. Rüegg
- Biozentrum, University of Basel, Basel, Switzerland; Department of Biomedicine, University of Basel, Basel, Switzerland; and INRA, UMR866 Dynamique Musculaire et Métabolisme, Montpellier, France
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26
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Muscle connective tissue controls development of the diaphragm and is a source of congenital diaphragmatic hernias. Nat Genet 2015; 47:496-504. [PMID: 25807280 PMCID: PMC4414795 DOI: 10.1038/ng.3250] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 02/23/2015] [Indexed: 12/14/2022]
Abstract
The diaphragm is an essential mammalian skeletal muscle, and defects in diaphragm development are the cause of congenital diaphragmatic hernias (CDH), a common and often lethal birth defect. The diaphragm is derived from multiple embryonic sources, but how these give rise to the diaphragm is unknown and, despite the identification of many CDH-associated genes, the etiology of CDH is incompletely understood. Using mouse genetics, we show that the pleuroperitoneal folds (PPFs), transient embryonic structures, are the source of the diaphragm’s muscle connective tissue, regulate muscle development, and their striking migration controls diaphragm morphogenesis. Furthermore, Gata4 mosaic mutations in PPF-derived muscle connective tissue fibroblasts result in the development of localized amuscular regions that are biomechanically weaker and more compliant and lead to CDH. Thus the PPFs and muscle connective tissue are critical for diaphragm development and mutations in PPF-derived fibroblasts are a source of CDH.
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27
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Stifani N. Motor neurons and the generation of spinal motor neuron diversity. Front Cell Neurosci 2014; 8:293. [PMID: 25346659 PMCID: PMC4191298 DOI: 10.3389/fncel.2014.00293] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Accepted: 09/02/2014] [Indexed: 11/13/2022] Open
Abstract
Motor neurons (MNs) are neuronal cells located in the central nervous system (CNS) controlling a variety of downstream targets. This function infers the existence of MN subtypes matching the identity of the targets they innervate. To illustrate the mechanism involved in the generation of cellular diversity and the acquisition of specific identity, this review will focus on spinal MNs (SpMNs) that have been the core of significant work and discoveries during the last decades. SpMNs are responsible for the contraction of effector muscles in the periphery. Humans possess more than 500 different skeletal muscles capable to work in a precise time and space coordination to generate complex movements such as walking or grasping. To ensure such refined coordination, SpMNs must retain the identity of the muscle they innervate. Within the last two decades, scientists around the world have produced considerable efforts to elucidate several critical steps of SpMNs differentiation. During development, SpMNs emerge from dividing progenitor cells located in the medial portion of the ventral neural tube. MN identities are established by patterning cues working in cooperation with intrinsic sets of transcription factors. As the embryo develop, MNs further differentiate in a stepwise manner to form compact anatomical groups termed pools connecting to a unique muscle target. MN pools are not homogeneous and comprise subtypes according to the muscle fibers they innervate. This article aims to provide a global view of MN classification as well as an up-to-date review of the molecular mechanisms involved in the generation of SpMN diversity. Remaining conundrums will be discussed since a complete understanding of those mechanisms constitutes the foundation required for the elaboration of prospective MN regeneration therapies.
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Affiliation(s)
- Nicolas Stifani
- Medical Neuroscience, Dalhousie University Halifax, NS, Canada
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28
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Machado CB, Kanning KC, Kreis P, Stevenson D, Crossley M, Nowak M, Iacovino M, Kyba M, Chambers D, Blanc E, Lieberam I. Reconstruction of phrenic neuron identity in embryonic stem cell-derived motor neurons. Development 2014; 141:784-94. [PMID: 24496616 PMCID: PMC3912827 DOI: 10.1242/dev.097188] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Air breathing is an essential motor function for vertebrates living on land. The rhythm that drives breathing is generated within the central nervous system and relayed via specialised subsets of spinal motor neurons to muscles that regulate lung volume. In mammals, a key respiratory muscle is the diaphragm, which is innervated by motor neurons in the phrenic nucleus. Remarkably, relatively little is known about how this crucial subtype of motor neuron is generated during embryogenesis. Here, we used direct differentiation of motor neurons from mouse embryonic stem cells as a tool to identify genes that direct phrenic neuron identity. We find that three determinants, Pou3f1, Hoxa5 and Notch, act in combination to promote a phrenic neuron molecular identity. We show that Notch signalling induces Pou3f1 in developing motor neurons in vitro and in vivo. This suggests that the phrenic neuron lineage is established through a local source of Notch ligand at mid-cervical levels. Furthermore, we find that the cadherins Pcdh10, which is regulated by Pou3f1 and Hoxa5, and Cdh10, which is controlled by Pou3f1, are both mediators of like-like clustering of motor neuron cell bodies. This specific Pcdh10/Cdh10 activity might provide the means by which phrenic neurons are assembled into a distinct nucleus. Our study provides a framework for understanding how phrenic neuron identity is conferred and will help to generate this rare and inaccessible yet vital neuronal subtype directly from pluripotent stem cells, thus facilitating subsequent functional investigations.
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Abstract
Breathing movements have been demonstrated in the fetuses of every mammalian species investigated and are a critical component of normal fetal development. The classic sheep preparations instrumented for chronic fetal monitoring determined that fetal breathing movements (FBMs) occur in aggregates interspersed with long periods of quiescence that are strongly associated with neurophysiological state. The fetal sheep model also provided data regarding the neurochemical modulation of behavioral state and FBMs under a variety of in utero conditions. Subsequently, in vitro rodent models have been developed to advance our understanding of cellular, synaptic, network, and more detailed neuropharmacological aspects of perinatal respiratory neural control. This includes the ontogeny of the inspiratory rhythm generating center, the preBötzinger complex (preBötC), and the anatomical and functional development of phrenic motoneurons (PMNs) and diaphragm during the perinatal period. A variety of newborn animal models and studies of human infants have provided insights into age-dependent changes in state-dependent respiratory control, responses to hypoxia/hypercapnia and respiratory pathologies.
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Affiliation(s)
- John J Greer
- Department of Physiology, Centre for Neuroscience, Women and Children Health Research Institute, University of Alberta, Edmonton, Alberta, Canada.
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30
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Abstract
Striated respiratory muscles are necessary for lung ventilation and to maintain the patency of the upper airway. The basic structural and functional properties of respiratory muscles are similar to those of other striated muscles (both skeletal and cardiac). The sarcomere is the fundamental organizational unit of striated muscles and sarcomeric proteins underlie the passive and active mechanical properties of muscle fibers. In this respect, the functional categorization of different fiber types provides a conceptual framework to understand the physiological properties of respiratory muscles. Within the sarcomere, the interaction between the thick and thin filaments at the level of cross-bridges provides the elementary unit of force generation and contraction. Key to an understanding of the unique functional differences across muscle fiber types are differences in cross-bridge recruitment and cycling that relate to the expression of different myosin heavy chain isoforms in the thick filament. The active mechanical properties of muscle fibers are characterized by the relationship between myoplasmic Ca2+ and cross-bridge recruitment, force generation and sarcomere length (also cross-bridge recruitment), external load and shortening velocity (cross-bridge cycling rate), and cross-bridge cycling rate and ATP consumption. Passive mechanical properties are also important reflecting viscoelastic elements within sarcomeres as well as the extracellular matrix. Conditions that affect respiratory muscle performance may have a range of underlying pathophysiological causes, but their manifestations will depend on their impact on these basic elemental structures.
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Affiliation(s)
- Gary C Sieck
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
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31
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Coles GL, Ackerman KG. Kif7 is required for the patterning and differentiation of the diaphragm in a model of syndromic congenital diaphragmatic hernia. Proc Natl Acad Sci U S A 2013; 110:E1898-905. [PMID: 23650387 PMCID: PMC3666741 DOI: 10.1073/pnas.1222797110] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Congenital diaphragmatic hernia (CDH) is a common birth defect that results in a high degree of neonatal morbidity and mortality, but its pathological mechanisms are largely unknown. Therefore, we performed a forward genetic screen in mice to identify unique genes, models, and mechanisms of abnormal diaphragm development. We identified a mutant allele of kinesin family member 7 (Kif7), the disorganized diaphragm (dd). Embryos homozygous for the dd allele possess communicating diaphragmatic hernias, central tendon patterning defects, and increased cell proliferation with diaphragmatic tissue hyperplasia. Because the patterning of the central tendon is undescribed, we analyzed the expression of genes regulating tendonogenesis in dd/dd mutant embryos, and we determined that retinoic acid (RA) signaling was misregulautted. To further investigate the role of Kif7 and RA signaling in the development of the embryonic diaphragm, we established primary mesenchymal cultures of WT embryonic day 13.5 diaphragmatic cells. We determined that RA signaling is necessary for the expression of tendon markers as well as the expression of other CDH-associated genes. Knockdown of Kif7, and retinoic acid receptors alpha (Rara), beta (Rarb), and gamma (Rarg) indicated that RA signaling is dependent on these genes to promote tendonogenesis within the embryonic diaphragm. Taken together, our results provide evidence for a model in which inhibition of RA receptor signaling promotes CDH pathogenesis through a complex gene network.
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Affiliation(s)
| | - Kate G. Ackerman
- Department of Biomedical Genetics and
- Department of Pediatrics, Center for Pediatric Biomedical Research, University of Rochester Medical Center, Rochester, NY 14642
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32
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Merrell AJ, Kardon G. Development of the diaphragm -- a skeletal muscle essential for mammalian respiration. FEBS J 2013; 280:4026-35. [PMID: 23586979 DOI: 10.1111/febs.12274] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 03/27/2013] [Accepted: 03/28/2013] [Indexed: 12/26/2022]
Abstract
The mammalian diaphragm muscle is essential for respiration, and thus is one of the most critical skeletal muscles in the human body. Defects in diaphragm development leading to congenital diaphragmatic hernias (CDH) are common birth defects and result in severe morbidity or mortality. Given its functional importance and the frequency of congenital defects, an understanding of diaphragm development, both normally and during herniation, is important. We review current knowledge of the embryological origins of the diaphragm, diaphragm development and morphogenesis, as well as the genetic and developmental aetiology of diaphragm birth defects.
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Affiliation(s)
- Allyson J Merrell
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
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33
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Hirasawa T, Kuratani S. A new scenario of the evolutionary derivation of the mammalian diaphragm from shoulder muscles. J Anat 2013; 222:504-17. [PMID: 23448284 PMCID: PMC3633340 DOI: 10.1111/joa.12037] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2013] [Indexed: 12/30/2022] Open
Abstract
The evolutionary origin of the diaphragm remains unclear, due to the lack of a comparable structure in other extant taxa. However, recent researches into the developmental mechanism of this structure have yielded new insights into its origin. Here we summarize current understanding regarding the development of the diaphragm, and present a possible scenario for the evolutionary acquisition of this uniquely mammalian structure. Recent developmental analyses indicate that the diaphragm and forelimb muscles are derived from a shared cell population during embryonic development. Therefore, the embryonic positions of forelimb muscle progenitors, which correspond to the position of the brachial plexus, likely played an important role in the evolution of the diaphragm. We surveyed the literature to reexamine the position of the brachial plexus among living amniotes and confirmed that the cervico-thoracic transition in ribs reflects the brachial plexus position. Using this osteological correlate, we concluded that the anterior borders of the brachial plexuses in the stem synapsids were positioned at the level of the fourth spinal nerve, suggesting that the forelimb buds were laid in close proximity of the infrahyoid muscles. The topology of the phrenic and suprascapular nerves of mammals is similar to that of subscapular and supracoracoid nerves, respectively, of the other amniotes, suggesting that the diaphragm evolved from a muscle positioned medial to the pectoral girdle (cf. subscapular muscle). We hypothesize that the diaphragm was acquired in two steps: first, forelimb muscle cells were incorporated into tissues to form a primitive diaphragm in the stem synapsid grade, and second, the diaphragm in cynodonts became entrapped in the region controlled by pulmonary development.
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Affiliation(s)
- Tatsuya Hirasawa
- Laboratory for Evolutionary Morphology, RIKEN Center for Developmental Biology, Kobe, Japan.
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34
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Buchholtz EA, Bailin HG, Laves SA, Yang JT, Chan MY, Drozd LE. Fixed cervical count and the origin of the mammalian diaphragm. Evol Dev 2012; 14:399-411. [PMID: 22947313 DOI: 10.1111/j.1525-142x.2012.00560.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Why is mammalian cervical count fixed across the historically long and ecologically broad mammalian radiation? Multiple lines of evidence, considered together, suggest a link between fixed cervical count and the muscularization of the diaphragm, a key innovation in mammalian history. We test this hypothesis by documenting the anteroposterior (AP) movement of the diaphragm, a lateral plate derivative, relative to that of the somitic thoracolumbar transition in unusually patterned mammals, by comparing the temporal occurrence of an osteological proxy for the diaphragm and fixed cervical counts in the fossil record, and by quantifying morphological differentiation within the mammalian cervical series. We then integrate these anatomical observations with details of diaphragm function and development to propose a sequence of innovations in mammalian evolution that could have led to fixed cervical count. We argue that the novel commitment of migratory muscle precursor cells (MMPs) of mid-cervical somites to a fate in the abaxial diaphragm defined these somites as a new and uniquely mammalian modular subunit. We further argue that the coordination of primaxial abaxial patterning constrained subsequent AP migration of the forelimb, thereby secondarily fixing cervical count.
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Affiliation(s)
- Emily A Buchholtz
- Department of Biological Sciences, Wellesley College, Wellesley, MA 02481, USA.
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35
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Sustained Hox5 gene activity is required for respiratory motor neuron development. Nat Neurosci 2012; 15:1636-44. [PMID: 23103965 PMCID: PMC3676175 DOI: 10.1038/nn.3242] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 09/18/2012] [Indexed: 01/01/2023]
Abstract
Respiration in mammals relies on the rhythmic firing of neurons within the Phrenic Motor Column (PMC), a motor neuron group that provides the sole source of diaphragm innervation. Despite their essential role in breathing, the specific determinants of PMC identity and patterns of connectivity are largely unknown. We show that two Hox genes, Hoxa5 and Hoxc5, control diverse aspects of PMC development including their clustering, intramuscular branching, and survival. In mice lacking Hox5 genes in motor neurons, axons extend to the diaphragm but fail to arborize, leading to respiratory failure. Genetic rescue of cell death fails to restore columnar organization and branching patterns, indicating these defects are independent of neuronal loss. Unexpectedly, late Hox5 removal preserves columnar organization but depletes PMC number and branches, demonstrating a continuous requirement for Hox function in motor neurons. These findings indicate that Hox5 genes orchestrate PMC development through deployment of temporally distinct wiring programs.
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36
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Veenma DCM, de Klein A, Tibboel D. Developmental and genetic aspects of congenital diaphragmatic hernia. Pediatr Pulmonol 2012; 47:534-45. [PMID: 22467525 DOI: 10.1002/ppul.22553] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 02/17/2012] [Indexed: 12/21/2022]
Abstract
Congenital diaphragmatic hernia (CDH) is a frequent occurring cause of neonatal respiratory distress and occurs 1 in every 3,000 liveborns. Ventilatory support and pharmaceutical treatment of the co-occurring lung hypoplasia and pulmonary hypertension are insufficient in, respectively, 20% of isolated cases and 60% of complex ones leading to early perinatal death. The exact cause of CDH remains to be identified in the majority of human CDH patients and prognostic factors predicting treatment refraction are largely unknown. Their identification is hampered by the multifactorial and heterogenic nature of this congenital anomaly. However, application of high-resolution molecular cytogenetic techniques to patients' DNA now enables detection of chromosomal aberrations in 30% of the patients. Furthermore, recent insights in rodent embryogenesis pointed to a specific disruption of the early mesenchymal structures in the primordial diaphragm of CDH-induced offspring. Together, these data allowed for the introduction of new hypotheses on CDH pathogenesis, although many issues remain to be resolved. In this review, we have combined these new insights and remaining questions on diaphragm pathogenesis with a concise overview of the clinical, embryological, and genetic data available.
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Affiliation(s)
- D C M Veenma
- Department of Paediatric Surgery, Erasmus MC-Sophia, Rotterdam, The Netherlands
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37
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Liu Y, Sugiura Y, Wu F, Mi W, Taketo MM, Cannon S, Carroll T, Lin W. β-Catenin stabilization in skeletal muscles, but not in motor neurons, leads to aberrant motor innervation of the muscle during neuromuscular development in mice. Dev Biol 2012; 366:255-67. [PMID: 22537499 DOI: 10.1016/j.ydbio.2012.04.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 04/04/2012] [Accepted: 04/05/2012] [Indexed: 01/22/2023]
Abstract
β-Catenin, a key component of the Wnt signaling pathway, has been implicated in the development of the neuromuscular junction (NMJ) in mice, but its precise role in this process remains unclear. Here we use a β-catenin gain-of-function mouse model to stabilize β-catenin selectively in either skeletal muscles or motor neurons. We found that β-catenin stabilization in skeletal muscles resulted in increased motor axon number and excessive intramuscular nerve defasciculation and branching. In contrast, β-catenin stabilization in motor neurons had no adverse effect on motor innervation pattern. Furthermore, stabilization of β-catenin, either in skeletal muscles or in motor neurons, had no adverse effect on the formation and function of the NMJ. Our findings demonstrate that β-catenin levels in developing muscles in mice are crucial for proper muscle innervation, rather than specifically affecting synapse formation at the NMJ, and that the regulation of muscle innervation by β-catenin is mediated by a non-cell autonomous mechanism.
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Affiliation(s)
- Yun Liu
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA
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38
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Simpson SJ, Flecknoe SJ, Clugston RD, Greer JJ, Hooper SB, Frappell PB. Structural and functional development of the respiratory system in a newborn marsupial with cutaneous gas exchange. Physiol Biochem Zool 2011; 84:634-49. [PMID: 22030856 DOI: 10.1086/662557] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Marsupials are born with structurally immature lungs and rely, to varying degrees, on cutaneous gas exchange. With a gestation of 13 d and a birth weight of 13 mg, the fat-tailed dunnart (Sminthopsis crassicaudata) is one of the smallest and most immature marsupial newborns. We determined that the skin is almost solely responsible for gas exchange in the early neonatal period. Indeed, fewer than 35% of newborn dunnarts were observed to make any respiratory effort on the day of birth, with pulmonary ventilation alone not meeting the demand for oxygen until approximately 35 d postpartum. Despite the lack of pulmonary ventilation, the phrenic nerve had made contact with the diaphragm, and the respiratory epithelium was sufficiently developed to support gas exchange on the day of birth. Both type I and type II (surfactant-producing) alveolar epithelial cells were present, with fewer than 7% of the cells resembling undifferentiated alveolar epithelial precursor cells. The type I epithelial cells did, however, display thickened cytoplasmic extensions, leading to a high diffusion distance for oxygen. In addition, the architecture of the lung was immature, resembling the early canalicular stage, with alveolarization not commencing until 45 d postpartum. The pulmonary vasculature was also immature, with a centrally positioned single-capillary layer not evident until 100 d postbirth. These structural limitations may impede efficient pulmonary gas exchange, forcing the neonatal fat-tailed dunnart to rely predominately on its skin, a phenomenon supported by a low metabolic rate and small size.
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Affiliation(s)
- Shannon J Simpson
- Adaptational and Evolutionary Respiratory Physiology Laboratory, School of Zoology, University of Tasmania, Hobart, Tasmania 7005, Australia
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39
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Axonal regeneration and neuronal function are preserved in motor neurons lacking ß-actin in vivo. PLoS One 2011; 6:e17768. [PMID: 21445349 PMCID: PMC3062555 DOI: 10.1371/journal.pone.0017768] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 02/14/2011] [Indexed: 12/31/2022] Open
Abstract
The proper localization of ß-actin mRNA and protein is essential for growth cone guidance and axon elongation in cultured neurons. In addition, decreased levels of ß-actin mRNA and protein have been identified in the growth cones of motor neurons cultured from a mouse model of Spinal Muscular Atrophy (SMA), suggesting that ß-actin loss-of-function at growth cones or pre-synaptic nerve terminals could contribute to the pathogenesis of this disease. However, the role of ß-actin in motor neurons in vivo and its potential relevance to disease has yet to be examined. We therefore generated motor neuron specific ß-actin knock-out mice (Actb-MNsKO) to investigate the function of ß-actin in motor neurons in vivo. Surprisingly, ß-actin was not required for motor neuron viability or neuromuscular junction maintenance. Skeletal muscle from Actb-MNsKO mice showed no histological indication of denervation and did not significantly differ from controls in several measurements of physiologic function. Finally, motor axon regeneration was unimpaired in Actb-MNsKO mice, suggesting that ß-actin is not required for motor neuron function or regeneration in vivo.
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40
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Mundell NA, Labosky PA. Neural crest stem cell multipotency requires Foxd3 to maintain neural potential and repress mesenchymal fates. Development 2011; 138:641-52. [PMID: 21228004 DOI: 10.1242/dev.054718] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Neural crest (NC) progenitors generate a wide array of cell types, yet molecules controlling NC multipotency and self-renewal and factors mediating cell-intrinsic distinctions between multipotent versus fate-restricted progenitors are poorly understood. Our earlier work demonstrated that Foxd3 is required for maintenance of NC progenitors in the embryo. Here, we show that Foxd3 mediates a fate restriction choice for multipotent NC progenitors with loss of Foxd3 biasing NC toward a mesenchymal fate. Neural derivatives of NC were lost in Foxd3 mutant mouse embryos, whereas abnormally fated NC-derived vascular smooth muscle cells were ectopically located in the aorta. Cranial NC defects were associated with precocious differentiation towards osteoblast and chondrocyte cell fates, and individual mutant NC from different anteroposterior regions underwent fate changes, losing neural and increasing myofibroblast potential. Our results demonstrate that neural potential can be separated from NC multipotency by the action of a single gene, and establish novel parallels between NC and other progenitor populations that depend on this functionally conserved stem cell protein to regulate self-renewal and multipotency.
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Affiliation(s)
- Nathan A Mundell
- Center for Stem Cell Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-0494, USA
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41
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Liu Y, Sugiura Y, Padgett D, Lin W. Postsynaptic development of the neuromuscular junction in mice lacking the gamma-subunit of muscle nicotinic acetylcholine receptor. J Mol Neurosci 2009; 40:21-6. [PMID: 19672725 DOI: 10.1007/s12031-009-9248-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 07/20/2009] [Indexed: 12/22/2022]
Abstract
The mammalian muscle nicotinic acetylcholine receptor (AChR) is composed of five membrane-spanning subunits and its composition differs between embryonic and adult muscles. In embryonic muscles, it is composed of two alpha-, one beta-, one delta-, and one gamma-subunit; the gamma-subunit is later replaced by the epsilon-subunit during postnatal development. This unique temporal expression pattern of the gamma-subunit suggests it may play specific roles in embryonic muscles. To address this issue, we examined the formation and function of the neuromuscular junction in mouse embryos deficient in the gamma-subunit. At embryonic day 15.5, AChR clusters were absent and the spontaneous miniature endplate potentials were undetectable in the mutant muscles. However, electrical stimulation of the nerves triggered muscle contraction and elicited postsynaptic endplate potential (EPP) in the mutant muscles, although the magnitude of the muscle contraction and the amplitudes of the EPPs were smaller in the mutant compared to the wild-type muscles. Reintroducing a wild-type gamma-subunit into the mutant myotubes restored the formation of AChR clusters in vitro. Together, these results have demonstrated that functional AChRs were present in the mutant muscle membrane, but at reduced levels. Thus, in the absence of the gamma-subunit, a combination of alpha, beta, and delta subunits may assemble into functional receptors in vivo. These results also suggest that the gamma-subunit maybe involved in interacting with rapsyn, a cytoplasmic protein required for AChR clustering.
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Affiliation(s)
- Yun Liu
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390-9111, USA
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42
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Liu Y, Oppenheim RW, Sugiura Y, Lin W. Abnormal development of the neuromuscular junction in Nedd4-deficient mice. Dev Biol 2009; 330:153-66. [PMID: 19345204 DOI: 10.1016/j.ydbio.2009.03.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 03/23/2009] [Accepted: 03/25/2009] [Indexed: 11/28/2022]
Abstract
Nedd4 (neural precursor cell expressed developmentally down-regulated gene 4) is an E3 ubiquitin ligase highly conserved from yeast to humans. The expression of Nedd4 is developmentally down-regulated in the mammalian nervous system, but the role of Nedd4 in mammalian neural development remains poorly understood. Here we show that a null mutation of Nedd4 in mice leads to perinatal lethality: mutant mice were stillborn and many of them died in utero before birth (between E15.5-E18.5). In Nedd4 mutant embryos, skeletal muscle fiber sizes and motoneuron numbers are significantly reduced. Surviving motoneurons project axons to their target muscles on schedule, but motor nerves defasciculate upon reaching the muscle surface, suggesting that Nedd4 plays a critical role in fine-tuning the interaction between the nerve and the muscle. Electrophysiological analyses of the neuromuscular junction (NMJ) demonstrate an increased spontaneous miniature endplate potential (mEPP) frequency in Nedd4 mutants. However, the mutant neuromuscular synapses are less responsive to membrane depolarization, compared to the wildtypes. Ultrastructural analyses further reveal that the pre-synaptic nerve terminal branches at the NMJs of Nedd4 mutants are increased in number, but decreased in diameter compared to the wildtypes. These ultrastructural changes are consistent with functional alternation of the NMJs in Nedd4 mutants. Unexpectedly, Nedd4 is not expressed in motoneurons, but is highly expressed in skeletal muscles and Schwann cells. Together, these results demonstrate that Nedd4 is involved in regulating the formation and function of the NMJs through non-cell autonomous mechanisms.
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Affiliation(s)
- Yun Liu
- Department of Neuroscience, UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX 75390-9111, USA
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43
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Montedonico S, Nakazawa N, Puri P. Congenital diaphragmatic hernia and retinoids: searching for an etiology. Pediatr Surg Int 2008; 24:755-61. [PMID: 18401587 PMCID: PMC2440969 DOI: 10.1007/s00383-008-2140-x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/13/2008] [Indexed: 12/19/2022]
Abstract
Congenital diaphragmatic hernia (CDH) is a major life-threatening cause of respiratory failure in the newborn. Recent data reveal the role of a retinoid-signaling pathway disruption in the pathogenesis of CDH. We describe the epidemiology and pathophysiology of human CDH, the metabolism of retinoids and the implications of retinoids in the development of the diaphragm and lung. Finally, we describe the existing evidence of a disruption of the retinoid-signaling pathway in CDH.
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Affiliation(s)
- Sandra Montedonico
- The Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin 12, Ireland ,Centro de Investigación en Biología de la Reproducción, Escuela de Medicina, Universidad de Valparaíso, Valparaiso, Chile
| | - Nana Nakazawa
- The Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin 12, Ireland
| | - Prem Puri
- The Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin 12, Ireland
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44
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Mantilla CB, Sieck GC. Key aspects of phrenic motoneuron and diaphragm muscle development during the perinatal period. J Appl Physiol (1985) 2008; 104:1818-27. [PMID: 18403452 DOI: 10.1152/japplphysiol.01192.2007] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
At the time of birth, respiratory muscles must be activated to sustain ventilation. The perinatal development of respiratory motor units (comprising an individual motoneuron and the muscle fibers it innervates) shows remarkable features that enable mammals to transition from in utero conditions to the air environment in which the remainder of their life will occur. In addition, significant postnatal maturation is necessary to provide for the range of motor behaviors necessary during breathing, swallowing, and speech. As the main inspiratory muscle, the diaphragm muscle (and the phrenic motoneurons that innervate it) plays a key role in accomplishing these behaviors. Considerable diversity exists across diaphragm motor units, but the determinant factors for this diversity are unknown. In recent years, the mechanisms underlying the development of respiratory motor units have received great attention, and this knowledge may provide the opportunity to design appropriate interventions for the treatment of respiratory disease not only in the perinatal period but likely also in the adult.
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45
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Clugston RD, Zhang W, Greer JJ. Gene expression in the developing diaphragm: significance for congenital diaphragmatic hernia. Am J Physiol Lung Cell Mol Physiol 2008; 294:L665-75. [PMID: 18263670 DOI: 10.1152/ajplung.00027.2008] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Congenital diaphragmatic hernia (CDH) is a frequently occurring birth defect and a source of potentially fatal neonatal respiratory distress. Recently, through the application of detailed karyotyping methods, several CDH-critical regions within the human genome have been identified. These regions typically contain several genes. Here we focused on genes from 15q26, the best-characterized CDH-critical region, as well as FOG2 and GATA4, genes singled out from CDH-critical regions at 8q22-8q23 and 8p23.1, respectively. We tested the hypothesis that these putative CDH-related genes are expressed within the developing diaphragm at the time of the hypothesized initial defect. Our results show that 15q26 contains a cluster of genes that are expressed in the developing rodent diaphragm, consistent with an association between deletions in this region and CDH. We then examined the protein expression pattern of positively identified genes within the developing diaphragm. Two major themes emerged. First, those factors strongly associated with CDH are expressed only in the nonmuscular, mesenchymal component of the diaphragm, supporting the hypothesis that CDH has its origins in a mesenchymal defect. Second, these factors are all coexpressed in the same cells. This suggests that cases of CDH with unique genetic etiology may lead to a common defect in these cells and supports the hypothesis that these factors may be members of a common pathway. This study is the first to provide a detailed examination of how genes associated with CDH are expressed in the developing diaphragm and provides an important foundation for understanding how the deletion of specific genes may contribute to abnormal diaphragm formation.
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Affiliation(s)
- Robin D Clugston
- University of Alberta, Department of Physiology, Edmonton, Alberta, Canada
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46
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Baertschi S, Zhuang L, Trueb B. Mice with a targeted disruption of the Fgfrl1 gene die at birth due to alterations in the diaphragm. FEBS J 2007; 274:6241-53. [DOI: 10.1111/j.1742-4658.2007.06143.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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47
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Turgut HB, Peker T, Karaköse M, Anil A, Gülekon N, Demirtaş K. Phrenic nerve distribution in the rabbit diaphragm and morphometric analysis of nerve branches. Anat Histol Embryol 2007; 35:357-60. [PMID: 17156087 DOI: 10.1111/j.1439-0264.2006.00688.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The best method to evaluate the pathogenesis of diaphragmatic disorders is to demonstrate the distribution pattern of the phrenic nerve in the diaphragm. For this purpose the branching pattern and the microanatomic features of the phrenic nerve were observed in six rabbits. All diaphragms were stained by using Sihler's stain method. The phrenic nerve divided into three to four branches when entering the diaphragm. These branches were classified as sternal, anterolateral, posterolateral and crural. The crural branches were the thickest whereas the anterolateral branches were the thinnest. Knowledge about the distribution pattern of the phrenic nerve may be important in surgical approach to the diaphragm.
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Affiliation(s)
- H B Turgut
- Department of Anatomy, Faculty of Medicine, Gazi University, Beşevler, Ankara, Turkey.
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48
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Mousavi K, Jasmin BJ. BDNF is expressed in skeletal muscle satellite cells and inhibits myogenic differentiation. J Neurosci 2006; 26:5739-49. [PMID: 16723531 PMCID: PMC6675269 DOI: 10.1523/jneurosci.5398-05.2006] [Citation(s) in RCA: 131] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In skeletal muscle, brain-derived neurotrophic factor (BDNF) has long been thought to serve as a retrograde trophic factor for innervating motor neurons throughout their lifespan. However, its localization in mature muscle fibers has remained elusive. Given the postulated roles of BDNF in skeletal muscle, we performed a series of complementary experiments aimed at defining the localization of BDNF and its transcripts in adult muscle. By reverse transcription-PCR, in situ hybridization, and immunofluorescence, we show that BDNF, along with the receptor p75NTR, is not expressed at significant levels within mature myofibers and that it does not accumulate preferentially within subsynaptic regions of neuromuscular junctions. Interestingly, expression of BDNF correlated with that of Pax3, a marker of muscle progenitor cells, in several different adult skeletal muscles. Additionally, BDNF was expressed in Pax7+ satellite cells where it colocalized with p75NTR. In complementary cell culture experiments, we detected high levels of BDNF and p75NTR in myoblasts. During myogenic differentiation, expression of BDNF became drastically reduced. Using small interfering RNA (siRNA) technology to knock down BDNF expression, we demonstrate enhanced myogenic differentiation of myoblasts. This accelerated rate of myogenic differentiation seen in myoblasts expressing BDNF siRNA was normalized by administration of recombinant BDNF. Collectively, these findings show that BDNF plays an important regulatory function during myogenic differentiation. In addition, the expression of BDNF in satellite cells is coherent with the notion that BDNF serves a key role in maintaining the population of muscle progenitors in adult muscle.
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49
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Fisher JC, Bodenstein L. Computer simulation analysis of normal and abnormal development of the mammalian diaphragm. Theor Biol Med Model 2006; 3:9. [PMID: 16483386 PMCID: PMC1434728 DOI: 10.1186/1742-4682-3-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Accepted: 02/17/2006] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Congenital diaphragmatic hernia (CDH) is a birth defect with significant morbidity and mortality. Knowledge of diaphragm morphogenesis and the aberrations leading to CDH is limited. Although classical embryologists described the diaphragm as arising from the septum transversum, pleuroperitoneal folds (PPF), esophageal mesentery and body wall, animal studies suggest that the PPF is the major, if not sole, contributor to the muscular diaphragm. Recently, a posterior defect in the PPF has been identified when the teratogen nitrofen is used to induce CDH in fetal rodents. We describe use of a cell-based computer modeling system (Nudge++) to study diaphragm morphogenesis. METHODS AND RESULTS Key diaphragmatic structures were digitized from transverse serial sections of paraffin-embedded mouse embryos at embryonic days 11.5 and 13. Structure boundaries and simulated cells were combined in the Nudge++ software. Model cells were assigned putative behavioral programs, and these programs were progressively modified to produce a diaphragm consistent with the observed anatomy in rodents. Homology between our model and recent anatomical observations occurred under the following simulation conditions: (1) cell mitoses are restricted to the edge of growing tissue; (2) cells near the chest wall remain mitotically active; (3) mitotically active non-edge cells migrate toward the chest wall; and (4) movement direction depends on clonal differentiation between anterior and posterior PPF cells. CONCLUSION With the PPF as the sole source of mitotic cells, an early defect in the PPF evolves into a posteromedial diaphragm defect, similar to that of the rodent nitrofen CDH model. A posterolateral defect, as occurs in human CDH, would be more readily recreated by invoking other cellular contributions. Our results suggest that recent reports of PPF-dominated diaphragm morphogenesis in the rodent may not be strictly applicable to man. The ability to recreate a CDH defect using a combination of experimental data and testable hypotheses gives impetus to simulation modeling as an adjunct to experimental analysis of diaphragm morphogenesis.
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Affiliation(s)
- Jason C Fisher
- Division of Pediatric Surgery, Morgan Stanley Children's Hospital of New York-Presbyterian and Department of Surgery, College of Physicians and Surgeons, Columbia University, 3959 Broadway, 216B, New York, NY 10032, USA
| | - Lawrence Bodenstein
- Division of Pediatric Surgery, Morgan Stanley Children's Hospital of New York-Presbyterian and Department of Surgery, College of Physicians and Surgeons, Columbia University, 3959 Broadway, 216B, New York, NY 10032, USA
- Olana Technologies, Inc., 5424 Arlington Avenue, H51, Bronx, NY 10471, USA
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Gallot D, Marceau G, Coste K, Hadden H, Robert-Gnansia E, Laurichesse H, Déchelotte PJ, Labbé A, Dastugue B, Lémery D, Sapin V. Congenital diaphragmatic hernia: a retinoid-signaling pathway disruption during lung development? ACTA ACUST UNITED AC 2005; 73:523-31. [PMID: 15981190 DOI: 10.1002/bdra.20151] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Congenital diaphragmatic hernia (CDH) usually occurs sporadically. The prognosis remains poor, with a 50% perinatal mortality rate. Most deaths result from hypoxemia due to lung hypoplasia and abnormal development of pulmonary vasculature that results in persistent pulmonary hypertension. Our current understanding of the pathogenesis of CDH is based on an assumption linking herniation of abdominal viscera into the thorax with compression of the developing lung. Pulmonary hypoplasia, however, can also result from reduced distension of the developing lung secondary to impaired fetal breathing movements. Moreover, a nitrofen-induced CDH model shows that lung hypoplasia precedes the diaphragmatic defect, leading to a "dual-hit hypothesis." Recent data reveal the role of a retinoid-signaling pathway disruption in the pathogenesis of CDH. We describe the clinical and epidemiological aspects of human CDH, the metabolic and molecular aspects of the retinoid-signaling pathway, and the implications of retinoids in the development of the diaphragm and the lung. Finally, we highlight the existing links between CDH and disruption of the retinoid-signaling pathway, which may suggest an eventual use of retinoids in the treatment of CDH.
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Affiliation(s)
- Denis Gallot
- Maternal Fetal Medicine Unit, Maternité Hôtel-Dieu, Centre Hospitalier Universitaire, Clermont-Ferrand, France
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