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Morini E, Chekuri A, Logan EM, Bolduc JM, Kirchner EG, Salani M, Krauson AJ, Narasimhan J, Gabbeta V, Grover S, Dakka A, Mollin A, Jung SP, Zhao X, Zhang N, Zhang S, Arnold M, Woll MG, Naryshkin NA, Weetall M, Slaugenhaupt SA. Development of an oral treatment that rescues gait ataxia and retinal degeneration in a phenotypic mouse model of familial dysautonomia. Am J Hum Genet 2023; 110:531-547. [PMID: 36809767 PMCID: PMC10027479 DOI: 10.1016/j.ajhg.2023.01.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 01/30/2023] [Indexed: 02/22/2023] Open
Abstract
Familial dysautonomia (FD) is a rare neurodegenerative disease caused by a splicing mutation in elongator acetyltransferase complex subunit 1 (ELP1). This mutation leads to the skipping of exon 20 and a tissue-specific reduction of ELP1, mainly in the central and peripheral nervous systems. FD is a complex neurological disorder accompanied by severe gait ataxia and retinal degeneration. There is currently no effective treatment to restore ELP1 production in individuals with FD, and the disease is ultimately fatal. After identifying kinetin as a small molecule able to correct the ELP1 splicing defect, we worked on its optimization to generate novel splicing modulator compounds (SMCs) that can be used in individuals with FD. Here, we optimize the potency, efficacy, and bio-distribution of second-generation kinetin derivatives to develop an oral treatment for FD that can efficiently pass the blood-brain barrier and correct the ELP1 splicing defect in the nervous system. We demonstrate that the novel compound PTC258 efficiently restores correct ELP1 splicing in mouse tissues, including brain, and most importantly, prevents the progressive neuronal degeneration that is characteristic of FD. Postnatal oral administration of PTC258 to the phenotypic mouse model TgFD9;Elp1Δ20/flox increases full-length ELP1 transcript in a dose-dependent manner and leads to a 2-fold increase in functional ELP1 in the brain. Remarkably, PTC258 treatment improves survival, gait ataxia, and retinal degeneration in the phenotypic FD mice. Our findings highlight the great therapeutic potential of this novel class of small molecules as an oral treatment for FD.
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Affiliation(s)
- Elisabetta Morini
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA.
| | - Anil Chekuri
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA; Grousbeck Gene Therapy Center, Schepens Eye Research Institute and Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Emily M Logan
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Jessica M Bolduc
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Emily G Kirchner
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Monica Salani
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Aram J Krauson
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | | | | | | | - Amal Dakka
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | - Anna Mollin
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | | | - Xin Zhao
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | - Nanjing Zhang
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | - Sophie Zhang
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | | | | | | | - Marla Weetall
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | - Susan A Slaugenhaupt
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA.
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ELP1 Splicing Correction Reverses Proprioceptive Sensory Loss in Familial Dysautonomia. Am J Hum Genet 2019; 104:638-650. [PMID: 30905397 DOI: 10.1016/j.ajhg.2019.02.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 02/08/2019] [Indexed: 12/14/2022] Open
Abstract
Familial dysautonomia (FD) is a recessive neurodegenerative disease caused by a splice mutation in Elongator complex protein 1 (ELP1, also known as IKBKAP); this mutation leads to variable skipping of exon 20 and to a drastic reduction of ELP1 in the nervous system. Clinically, many of the debilitating aspects of the disease are related to a progressive loss of proprioception; this loss leads to severe gait ataxia, spinal deformities, and respiratory insufficiency due to neuromuscular incoordination. There is currently no effective treatment for FD, and the disease is ultimately fatal. The development of a drug that targets the underlying molecular defect provides hope that the drastic peripheral neurodegeneration characteristic of FD can be halted. We demonstrate herein that the FD mouse TgFD9;IkbkapΔ20/flox recapitulates the proprioceptive impairment observed in individuals with FD, and we provide the in vivo evidence that postnatal correction, promoted by the small molecule kinetin, of the mutant ELP1 splicing can rescue neurological phenotypes in FD. Daily administration of kinetin starting at birth improves sensory-motor coordination and prevents the onset of spinal abnormalities by stopping the loss of proprioceptive neurons. These phenotypic improvements correlate with increased amounts of full-length ELP1 mRNA and protein in multiple tissues, including in the peripheral nervous system (PNS). Our results show that postnatal correction of the underlying ELP1 splicing defect can rescue devastating disease phenotypes and is therefore a viable therapeutic approach for persons with FD.
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Kazachkov M, Palma JA, Norcliffe-Kaufmann L, Bar-Aluma BE, Spalink CL, Barnes EP, Amoroso NE, Balou SM, Bess S, Chopra A, Condos R, Efrati O, Fitzgerald K, Fridman D, Goldenberg RM, Goldhaber A, Kaufman DA, Kothare SV, Levine J, Levy J, Lubinsky AS, Maayan C, Moy LC, Rivera PJ, Rodriguez AJ, Sokol G, Sloane MF, Tan T, Kaufmann H. Respiratory care in familial dysautonomia: Systematic review and expert consensus recommendations. Respir Med 2018; 141:37-46. [PMID: 30053970 PMCID: PMC6084453 DOI: 10.1016/j.rmed.2018.06.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 05/14/2018] [Accepted: 06/18/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Familial dysautonomia (Riley-Day syndrome, hereditary sensory autonomic neuropathy type-III) is a rare genetic disease caused by impaired development of sensory and afferent autonomic nerves. As a consequence, patients develop neurogenic dysphagia with frequent aspiration, chronic lung disease, and chemoreflex failure leading to severe sleep disordered breathing. The purpose of these guidelines is to provide recommendations for the diagnosis and treatment of respiratory disorders in familial dysautonomia. METHODS We performed a systematic review to summarize the evidence related to our questions. When evidence was not sufficient, we used data from the New York University Familial Dysautonomia Patient Registry, a database containing ongoing prospective comprehensive clinical data from 670 cases. The evidence was summarized and discussed by a multidisciplinary panel of experts. Evidence-based and expert recommendations were then formulated, written, and graded using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. RESULTS Recommendations were formulated for or against specific diagnostic tests and clinical interventions. Diagnostic tests reviewed included radiological evaluation, dysphagia evaluation, gastroesophageal evaluation, bronchoscopy and bronchoalveolar lavage, pulmonary function tests, laryngoscopy and polysomnography. Clinical interventions and therapies reviewed included prevention and management of aspiration, airway mucus clearance and chest physical therapy, viral respiratory infections, precautions during high altitude or air-flight travel, non-invasive ventilation during sleep, antibiotic therapy, steroid therapy, oxygen therapy, gastrostomy tube placement, Nissen fundoplication surgery, scoliosis surgery, tracheostomy and lung lobectomy. CONCLUSIONS Expert recommendations for the diagnosis and management of respiratory disease in patients with familial dysautonomia are provided. Frequent reassessment and updating will be needed.
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Affiliation(s)
- Mikhail Kazachkov
- Department of Pediatric Pulmonology, New York University School of Medicine, New York, NY, United States; Gastroesophageal, Upper Airway and Respiratory Diseases Center, New York University School of Medicine, New York, NY, United States
| | - Jose-Alberto Palma
- Department of Neurology, Dysautonomia Center, New York University School of Medicine, New York, NY, United States
| | - Lucy Norcliffe-Kaufmann
- Department of Neurology, Dysautonomia Center, New York University School of Medicine, New York, NY, United States
| | - Bat-El Bar-Aluma
- Pediatric Pulmonary Unit, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Israel
| | - Christy L Spalink
- Department of Neurology, Dysautonomia Center, New York University School of Medicine, New York, NY, United States
| | - Erin P Barnes
- Department of Neurology, Dysautonomia Center, New York University School of Medicine, New York, NY, United States
| | - Nancy E Amoroso
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine. New York University School of Medicine, New York, NY, United States
| | - Stamatela M Balou
- Department of Otolaryngology-Head and Neck Surgery, New York University School of Medicine, New York, NY, United States
| | - Shay Bess
- Department of Orthopedic Surgery, New York University School of Medicine, New York, NY, United States
| | - Arun Chopra
- Department of Pediatrics, Division of Pediatric Critical Care, New York University School of Medicine, New York, NY, United States
| | - Rany Condos
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine. New York University School of Medicine, New York, NY, United States
| | - Ori Efrati
- Pediatric Pulmonary Unit, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Israel
| | - Kathryn Fitzgerald
- Department of Pediatric Pulmonology, New York University School of Medicine, New York, NY, United States
| | - David Fridman
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine. New York University School of Medicine, New York, NY, United States
| | - Ronald M Goldenberg
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine. New York University School of Medicine, New York, NY, United States
| | - Ayelet Goldhaber
- Department of Pediatrics, Pediatric Gastroenterology Unit, New York University School of Medicine, New York, NY, United States
| | - David A Kaufman
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine. New York University School of Medicine, New York, NY, United States
| | - Sanjeev V Kothare
- Department of Neurology, Pediatric Sleep Medicine Unit, New York University School of Medicine, New York, NY, United States
| | - Jeremiah Levine
- Department of Pediatrics, Pediatric Gastroenterology Unit, New York University School of Medicine, New York, NY, United States
| | - Joseph Levy
- Department of Pediatrics, Pediatric Gastroenterology Unit, New York University School of Medicine, New York, NY, United States
| | - Anthony S Lubinsky
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine. New York University School of Medicine, New York, NY, United States
| | - Channa Maayan
- Department of Pediatrics. Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Libia C Moy
- Department of Pediatrics, Pediatric Gastroenterology Unit, New York University School of Medicine, New York, NY, United States
| | - Pedro J Rivera
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine. New York University School of Medicine, New York, NY, United States
| | - Alcibiades J Rodriguez
- Department of Neurology, Sleep Laboratory, New York University School of Medicine, New York, NY, United States
| | - Gil Sokol
- Pediatric Pulmonary Unit, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Israel
| | - Mark F Sloane
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine. New York University School of Medicine, New York, NY, United States
| | - Tina Tan
- Gastroesophageal, Upper Airway and Respiratory Diseases Center, New York University School of Medicine, New York, NY, United States
| | - Horacio Kaufmann
- Department of Neurology, Dysautonomia Center, New York University School of Medicine, New York, NY, United States.
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Elhennawy K, Reda S, Finke C, Graul-Neumann L, Jost-Brinkmann PG, Bartzela T. Oral manifestations, dental management, and a rare homozygous mutation of the PRDM12 gene in a boy with hereditary sensory and autonomic neuropathy type VIII: a case report and review of the literature. J Med Case Rep 2017; 11:233. [PMID: 28807049 PMCID: PMC5556355 DOI: 10.1186/s13256-017-1387-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 07/11/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hereditary sensory and autonomic neuropathy type VIII is a rare autosomal recessive inherited disorder. Chen et al. recently identified the causative gene and characterized biallelic mutations in the PR domain-containing protein 12 gene, which plays a role in the development of pain-sensing nerve cells. Our patient's family was included in Chen and colleagues' study. We performed a literature review of the PubMed library (January 1985 to December 2016) on hereditary sensory and autonomic neuropathy type I to VIII genetic disorders and their orofacial manifestations. This case report is the first to describe the oral manifestations, and their treatment, of the recently discovered hereditary sensory and autonomic neuropathy type VIII in the medical and dental literature. CASE PRESENTATION We report on the oral manifestations and dental management of an 8-month-old white boy with hereditary sensory and autonomic neuropathy-VIII over a period of 16 years. Our patient was homozygous for a mutation of PR domain-containing protein 12 gene and was characterized by insensitivity to pain and thermal stimuli, self-mutilation behavior, reduced sweat and tear production, absence of corneal reflexes, and multiple skin and bone infections. Oral manifestations included premature loss of teeth, associated with dental traumata and self-mutilation, severe soft tissue injuries, dental caries and submucosal abscesses, hypomineralization of primary teeth, and mandibular osteomyelitis. CONCLUSIONS The lack of scientific knowledge on hereditary sensory and autonomic neuropathy due to the rarity of the disease often results in a delay in diagnosis, which is of substantial importance for the prevention of many complications and symptoms. Interdisciplinary work of specialized medical and dental teams and development of a standardized treatment protocols are essential for the management of the disease. There are many knowledge gaps concerning the management of patients with hereditary sensory and autonomic neuropathy-VIII, therefore more research on an international basis is needed.
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Affiliation(s)
- Karim Elhennawy
- Center for Dental and Craniofacial Sciences, Department of Orthodontics, Dentofacial Orthopedics and Pedodontics, Charité - Universitätsmedizin Berlin, Aßmannshauser Str. 4-6, 14197, Berlin, Germany
| | - Seif Reda
- Center for Dental and Craniofacial Sciences, Department of Orthodontics, Dentofacial Orthopedics and Pedodontics, Charité - Universitätsmedizin Berlin, Aßmannshauser Str. 4-6, 14197, Berlin, Germany
| | - Christian Finke
- Center for Dental and Craniofacial Sciences, Department of Orthodontics, Dentofacial Orthopedics and Pedodontics, Charité - Universitätsmedizin Berlin, Aßmannshauser Str. 4-6, 14197, Berlin, Germany
| | - Luitgard Graul-Neumann
- Ambulantes Gesundheitszentrum, Campus Virchow Clinic, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Charité Campus Virchow, Department of Human Genetics, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Paul-Georg Jost-Brinkmann
- Center for Dental and Craniofacial Sciences, Department of Orthodontics, Dentofacial Orthopedics and Pedodontics, Charité - Universitätsmedizin Berlin, Aßmannshauser Str. 4-6, 14197, Berlin, Germany
| | - Theodosia Bartzela
- Center for Dental and Craniofacial Sciences, Department of Orthodontics, Dentofacial Orthopedics and Pedodontics, Charité - Universitätsmedizin Berlin, Aßmannshauser Str. 4-6, 14197, Berlin, Germany.
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Hilz MJ, Moeller S, Buechner S, Czarkowska H, Ayappa I, Axelrod FB, Rapoport DM. Obstructive Sleep-Disordered Breathing Is More Common than Central in Mild Familial Dysautonomia. J Clin Sleep Med 2016; 12:1607-1614. [PMID: 27655467 DOI: 10.5664/jcsm.6342] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 07/19/2016] [Indexed: 01/22/2023]
Abstract
STUDY OBJECTIVES In familial dysautonomia (FD) patients, sleep-disordered breathing (SDB) might contribute to their high risk of sleep-related sudden death. Prevalence of central versus obstructive sleep apneas is controversial but may be therapeutically relevant. We, therefore, assessed sleep structure and SDB in FD-patients with no history of SDB. METHODS 11 mildly affected FD-patients (28 ± 11 years) without clinically overt SDB and 13 controls (28 ± 10 years) underwent polysomnographic recording during one night. We assessed sleep stages, obstructive and central apneas (≥ 90% air flow reduction) and hypopneas (> 30% decrease in airflow with ≥ 4% oxygen-desaturation), and determined obstructive (oAI) and central (cAI) apnea indices and the hypopnea index (HI) as count of respective apneas/hypopneas divided by sleep time. We obtained the apnea-hypopnea index (AHI4%) from the total of apneas and hypopneas divided by sleep time. We determined differences between FD-patients and controls using the U-test and within-group differences between oAIs, cAIs, and HIs using the Friedman test and Wilcoxon test. RESULTS Sleep structure was similar in FD-patients and controls. AHI4% and HI were significantly higher in patients than controls. In patients, HIs were higher than oAIs and oAIs were higher than cAIs. In controls, there was no difference between HIs, oAIs, and cAIs. Only patients had apneas and hypopneas during slow wave sleep. CONCLUSIONS In our FD-patients, obstructive apneas were more common than central apneas. These findings may be related to FD-specific pathophysiology. The potential ramifications of SDB in FD-patients suggest the utility of polysomnography to unveil SDB and initiate treatment. COMMENTARY A commentary on this article appears in this issue on page 1583.
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Affiliation(s)
- Max J Hilz
- Department of Neurology, University of Erlangen-Nürnberg, Erlangen, Germany.,Autonomic Unit, University Colloge of London, Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Sebastian Moeller
- Department of Neurology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Susanne Buechner
- Department of Neurology, General Hospital of Bozen/Bolzano, Bozen/Bolzano, Italy
| | - Hanna Czarkowska
- Cushing Neuroscience Institute, NS-LIJ Health System, Great Neck, NY
| | - Indu Ayappa
- Division of Pulmonary, Critical Care and Sleep Medicine, New York University School of Medicine, New York, NY
| | - Felicia B Axelrod
- Dysautonomia Center, New York University Langone School of Medicine, New York, NY
| | - David M Rapoport
- Division of Pulmonary, Critical Care and Sleep Medicine, New York University School of Medicine, New York, NY
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Dietrich P, Dragatsis I. Familial Dysautonomia: Mechanisms and Models. Genet Mol Biol 2016; 39:497-514. [PMID: 27561110 PMCID: PMC5127153 DOI: 10.1590/1678-4685-gmb-2015-0335] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 03/16/2016] [Indexed: 11/22/2022] Open
Abstract
Hereditary Sensory and Autonomic Neuropathies (HSANs) compose a heterogeneous group of genetic disorders characterized by sensory and autonomic dysfunctions. Familial Dysautonomia (FD), also known as HSAN III, is an autosomal recessive disorder that affects 1/3,600 live births in the Ashkenazi Jewish population. The major features of the disease are already present at birth and are attributed to abnormal development and progressive degeneration of the sensory and autonomic nervous systems. Despite clinical interventions, the disease is inevitably fatal. FD is caused by a point mutation in intron 20 of the IKBKAP gene that results in severe reduction in expression of IKAP, its encoded protein. In vitro and in vivo studies have shown that IKAP is involved in multiple intracellular processes, and suggest that failed target innervation and/or impaired neurotrophic retrograde transport are the primary causes of neuronal cell death in FD. However, FD is far more complex, and appears to affect several other organs and systems in addition to the peripheral nervous system. With the recent generation of mouse models that recapitulate the molecular and pathological features of the disease, it is now possible to further investigate the mechanisms underlying different aspects of the disorder, and to test novel therapeutic strategies.
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Affiliation(s)
- Paula Dietrich
- Department of Physiology, The University of Tennessee, Memphis, TN, USA
| | - Ioannis Dragatsis
- Department of Physiology, The University of Tennessee, Memphis, TN, USA
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Jackson MZ, Gruner KA, Qin C, Tourtellotte WG. A neuron autonomous role for the familial dysautonomia gene ELP1 in sympathetic and sensory target tissue innervation. Development 2014; 141:2452-61. [PMID: 24917501 DOI: 10.1242/dev.107797] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Familial dysautonomia (FD) is characterized by severe and progressive sympathetic and sensory neuron loss caused by a highly conserved germline point mutation of the human ELP1/IKBKAP gene. Elp1 is a subunit of the hetero-hexameric transcriptional elongator complex, but how it functions in disease-vulnerable neurons is unknown. Conditional knockout mice were generated to characterize the role of Elp1 in migration, differentiation and survival of migratory neural crest (NC) progenitors that give rise to sympathetic and sensory neurons. Loss of Elp1 in NC progenitors did not impair their migration, proliferation or survival, but there was a significant impact on post-migratory sensory and sympathetic neuron survival and target tissue innervation. Ablation of Elp1 in post-migratory sympathetic neurons caused highly abnormal target tissue innervation that was correlated with abnormal neurite outgrowth/branching and abnormal cellular distribution of soluble tyrosinated α-tubulin in Elp1-deficient primary sympathetic and sensory neurons. These results indicate that neuron loss and physiologic impairment in FD is not a consequence of abnormal neuron progenitor migration, differentiation or survival. Rather, loss of Elp1 leads to neuron death as a consequence of failed target tissue innervation associated with impairments in cytoskeletal regulation.
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Affiliation(s)
- Marisa Z Jackson
- Department of Pathology (Division of Neuropathology), Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611, USA Northwestern University Integrated Neuroscience (NUIN) Program, Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611, USA
| | - Katherine A Gruner
- Department of Pathology (Division of Neuropathology), Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611, USA
| | - Charles Qin
- Department of Pathology (Division of Neuropathology), Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611, USA
| | - Warren G Tourtellotte
- Department of Pathology (Division of Neuropathology), Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611, USA Northwestern University Integrated Neuroscience (NUIN) Program, Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611, USA Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611, USA
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George L, Chaverra M, Wolfe L, Thorne J, Close-Davis M, Eibs A, Riojas V, Grindeland A, Orr M, Carlson GA, Lefcort F. Familial dysautonomia model reveals Ikbkap deletion causes apoptosis of Pax3+ progenitors and peripheral neurons. Proc Natl Acad Sci U S A 2013; 110:18698-703. [PMID: 24173031 PMCID: PMC3831979 DOI: 10.1073/pnas.1308596110] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Familial dysautonomia (FD) is a devastating developmental and progressive peripheral neuropathy caused by a mutation in the gene inhibitor of kappa B kinase complex-associated protein (IKBKAP). To identify the cellular and molecular mechanisms that cause FD, we generated mice in which Ikbkap expression is ablated in the peripheral nervous system and identify the steps in peripheral nervous system development that are Ikbkap-dependent. We show that Ikbkap is not required for trunk neural crest migration or pathfinding, nor for the formation of dorsal root or sympathetic ganglia, or the adrenal medulla. Instead, Ikbkap is essential for the second wave of neurogenesis during which the majority of tropomyosin-related kinase A (TrkA(+)) nociceptors and thermoreceptors arise. In its absence, approximately half the normal complement of TrkA(+) neurons are lost, which we show is partly due to p53-mediated premature differentiation and death of mitotically-active progenitors that express the paired-box gene Pax3 and give rise to the majority of TrkA(+) neurons. By the end of sensory development, the number of TrkC neurons is significantly increased, which may result from an increase in Runx3(+) cells. Furthermore, our data demonstrate that TrkA(+) (but not TrkC(+)) sensory and sympathetic neurons undergo exacerbated Caspase 3-mediated programmed cell death in the absence of Ikbkap and that this death is not due to a reduction in nerve growth factor synthesis. In summary, these data suggest that FD does not result from a failure in trunk neural crest migration, but rather from a critical function for Ikbkap in TrkA progenitors and TrkA(+) neurons.
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Affiliation(s)
- Lynn George
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717
- Department of Biological and Physical Sciences, Montana State University Billings, Billings, MT 59101; and
| | - Marta Chaverra
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717
| | - Lindsey Wolfe
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717
| | - Julian Thorne
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717
| | - Mattheson Close-Davis
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717
| | - Amy Eibs
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717
| | - Vickie Riojas
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717
| | | | - Miranda Orr
- McLaughlin Research Institute, Great Falls, MT 59405
| | | | - Frances Lefcort
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717
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Abstract
LEARNING OBJECTIVES After studying this article, the participant should be able to: 1. Describe the historical origins of modern cephalometry. 2. Identify common landmark points on the lateral cephalogram. 3. Describe multiple common clinical uses for cephalometry. 4. Exhibit knowledge of developments in imaging and analysis alternatives. BACKGROUND Interest in the dimensions of the human head has been present since antiquity. Proportional analysis and measures from cadaveric specimens led to the development of radiologic image capture and analysis on living subjects. These techniques were originally applied to establishing normative values, documenting growth, and diagnosing dentofacial disharmonies. This article reviews the origins of cephalometric methodology and current developments and applications. METHODS The authors conducted a MEDLINE search and review of all English language articles using the keywords "cephalometric" and "cephalometrics." RESULTS Cephalometrics have undergone substantial use and development since the introduction of radiologic imaging on living human subjects in 1931. Although frequently associated with orthognathic surgery, cephalometrics have been applied to a number of conditions involving altered craniofacial morphology. Advances in imaging and computing have led to increased interest in three-dimensional and non-x-ray-based assessment of the human head. Mathematical models have been applied to standard cephalometric information to increase the descriptive accuracy of the complex shapes involved. CONCLUSIONS Cephalometric techniques and analyses are versatile tools that can be applied to a wide variety of clinical scenarios involving the craniofacial region. New technologies and expanded applications promise to continue the development and use of this well-established methodology.
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