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Cardani S, Janes TA, Betzner W, Pagliardini S. Knockdown of PHOX2B in the retrotrapezoid nucleus reduces the central CO 2 chemoreflex in rats. eLife 2024; 13:RP94653. [PMID: 38727716 PMCID: PMC11087052 DOI: 10.7554/elife.94653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024] Open
Abstract
PHOX2B is a transcription factor essential for the development of different classes of neurons in the central and peripheral nervous system. Heterozygous mutations in the PHOX2B coding region are responsible for the occurrence of Congenital Central Hypoventilation Syndrome (CCHS), a rare neurological disorder characterised by inadequate chemosensitivity and life-threatening sleep-related hypoventilation. Animal studies suggest that chemoreflex defects are caused in part by the improper development or function of PHOX2B expressing neurons in the retrotrapezoid nucleus (RTN), a central hub for CO2 chemosensitivity. Although the function of PHOX2B in rodents during development is well established, its role in the adult respiratory network remains unknown. In this study, we investigated whether reduction in PHOX2B expression in chemosensitive neuromedin-B (NMB) expressing neurons in the RTN altered respiratory function. Four weeks following local RTN injection of a lentiviral vector expressing the short hairpin RNA (shRNA) targeting Phox2b mRNA, a reduction of PHOX2B expression was observed in Nmb neurons compared to both naive rats and rats injected with the non-target shRNA. PHOX2B knockdown did not affect breathing in room air or under hypoxia, but ventilation was significantly impaired during hypercapnia. PHOX2B knockdown did not alter Nmb expression but it was associated with reduced expression of both Task2 and Gpr4, two CO2/pH sensors in the RTN. We conclude that PHOX2B in the adult brain has an important role in CO2 chemoreception and reduced PHOX2B expression in CCHS beyond the developmental period may contribute to the impaired central chemoreflex function.
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Affiliation(s)
- Silvia Cardani
- Department of Physiology, Faculty of Medicine and Dentistry, University of AlbertaEdmontonCanada
- Women and Children’s Health Research Institute, University of AlbertaEdmontonCanada
| | - Tara A Janes
- Department of Physiology, Faculty of Medicine and Dentistry, University of AlbertaEdmontonCanada
- Women and Children’s Health Research Institute, University of AlbertaEdmontonCanada
| | - William Betzner
- Department of Physiology, Faculty of Medicine and Dentistry, University of AlbertaEdmontonCanada
| | - Silvia Pagliardini
- Department of Physiology, Faculty of Medicine and Dentistry, University of AlbertaEdmontonCanada
- Women and Children’s Health Research Institute, University of AlbertaEdmontonCanada
- Neuroscience and Mental Health Institute, University of AlbertaEdmontonCanada
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2
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Tao Y, Li X, Dong Q, Kong L, Petersen AJ, Yan Y, Xu K, Zima S, Li Y, Schmidt DK, Ayala M, Mathivanan S, Sousa AMM, Chang Q, Zhang SC. Generation of locus coeruleus norepinephrine neurons from human pluripotent stem cells. Nat Biotechnol 2023:10.1038/s41587-023-01977-4. [PMID: 37974010 DOI: 10.1038/s41587-023-01977-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 08/30/2023] [Indexed: 11/19/2023]
Abstract
Central norepinephrine (NE) neurons, located mainly in the locus coeruleus (LC), are implicated in diverse psychiatric and neurodegenerative diseases and are an emerging target for drug discovery. To facilitate their study, we developed a method to generate 40-60% human LC-NE neurons from human pluripotent stem cells. The approach depends on our identification of ACTIVIN A in regulating LC-NE transcription factors in dorsal rhombomere 1 (r1) progenitors. In vitro generated human LC-NE neurons display extensive axonal arborization; release and uptake NE; and exhibit pacemaker activity, calcium oscillation and chemoreceptor activity in response to CO2. Single-nucleus RNA sequencing (snRNA-seq) analysis at multiple timepoints confirmed NE cell identity and revealed the differentiation trajectory from hindbrain progenitors to NE neurons via an ASCL1-expressing precursor stage. LC-NE neurons engineered with an NE sensor reliably reported extracellular levels of NE. The availability of functional human LC-NE neurons enables investigation of their roles in psychiatric and neurodegenerative diseases and provides a tool for therapeutics development.
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Affiliation(s)
- Yunlong Tao
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA.
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, China.
| | - Xueyan Li
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Qiping Dong
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Linghai Kong
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Yuanwei Yan
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Ke Xu
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Seth Zima
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Yanru Li
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Melvin Ayala
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Andre M M Sousa
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
- Department of Neuroscience, Department of Neurology, University of Wisconsin-Madison, Madison, WI, USA
| | - Qiang Chang
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
- Department of Neuroscience, Department of Neurology, University of Wisconsin-Madison, Madison, WI, USA
| | - Su-Chun Zhang
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA.
- Department of Neuroscience, Department of Neurology, University of Wisconsin-Madison, Madison, WI, USA.
- Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore, Singapore.
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3
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Slattery SM, Perez IA, Ceccherini I, Chen ML, Kurek KC, Yap KL, Keens TG, Khaytin I, Ballard HA, Sokol EA, Mittal A, Rand CM, Weese-Mayer DE. Transitional care and clinical management of adolescents, young adults, and suspected new adult patients with congenital central hypoventilation syndrome. Clin Auton Res 2023; 33:231-249. [PMID: 36403185 DOI: 10.1007/s10286-022-00908-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 10/31/2022] [Indexed: 11/21/2022]
Abstract
PURPOSE With contemporaneous advances in congenital central hypoventilation syndrome (CCHS), recognition, confirmatory diagnostics with PHOX2B genetic testing, and conservative management to reduce the risk of early morbidity and mortality, the prevalence of identified adolescents and young adults with CCHS and later-onset (LO-) CCHS has increased. Accordingly, there is heightened awareness and need for transitional care of these patients from pediatric medicine into a multidisciplinary adult medical team. Hence, this review summarizes key clinical and management considerations for patients with CCHS and LO-CCHS and emphasizes topics of particular importance for this demographic. METHODS We performed a systematic review of literature on diagnostics, pathophysiology, and clinical management in CCHS and LO-CCHS, and supplemented the review with anecdotal but extensive experiences from large academic pediatric centers with expertise in CCHS. RESULTS We summarized our findings topically for an overview of the medical care in CCHS and LO-CCHS specifically applicable to adolescents and adults. Care topics include genetic and embryologic basis of the disease, clinical presentation, management, variability in autonomic nervous system dysfunction, and clarity regarding transitional care with unique considerations such as living independently, family planning, exposure to anesthesia, and alcohol and drug use. CONCLUSIONS While a lack of experience and evidence exists in the care of adults with CCHS and LO-CCHS, a review of the relevant literature and expert consensus provides guidance for transitional care areas.
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Affiliation(s)
- Susan M Slattery
- Center for Autonomic Medicine in Pediatrics (CAMP), Division of Autonomic Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago and Stanley Manne Children's Research Center, 225 E. Chicago Ave, Box #165, Chicago, IL, 60611, USA.
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| | - Iris A Perez
- Division of Pediatric Pulmonology and Sleep Medicine, Children's Hospital Los Angeles, Los Angeles, CA, USA
- Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - Isabella Ceccherini
- Laboratory of Genetics and Genomics of Rare Diseases, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Maida L Chen
- Division of Pulmonary and Sleep Medicine, Seattle Children's Hospital, Seattle, WA, USA
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA
| | - Kyle C Kurek
- Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada
| | - Kai Lee Yap
- Molecular Diagnostics Laboratory, Department of Pathology & Laboratory Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Thomas G Keens
- Division of Pediatric Pulmonology and Sleep Medicine, Children's Hospital Los Angeles, Los Angeles, CA, USA
- Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - Ilya Khaytin
- Center for Autonomic Medicine in Pediatrics (CAMP), Division of Autonomic Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago and Stanley Manne Children's Research Center, 225 E. Chicago Ave, Box #165, Chicago, IL, 60611, USA
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Heather A Ballard
- Department of Pediatric Anesthesiology, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
- Department of Anesthesia, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Elizabeth A Sokol
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- Division of Hematology/Oncology, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Angeli Mittal
- Center for Autonomic Medicine in Pediatrics (CAMP), Division of Autonomic Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago and Stanley Manne Children's Research Center, 225 E. Chicago Ave, Box #165, Chicago, IL, 60611, USA
| | - Casey M Rand
- Center for Autonomic Medicine in Pediatrics (CAMP), Division of Autonomic Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago and Stanley Manne Children's Research Center, 225 E. Chicago Ave, Box #165, Chicago, IL, 60611, USA
| | - Debra E Weese-Mayer
- Center for Autonomic Medicine in Pediatrics (CAMP), Division of Autonomic Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago and Stanley Manne Children's Research Center, 225 E. Chicago Ave, Box #165, Chicago, IL, 60611, USA
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Etonogestrel Administration Reduces the Expression of PHOX2B and Its Target Genes in the Solitary Tract Nucleus. Int J Mol Sci 2022; 23:ijms23094816. [PMID: 35563209 PMCID: PMC9101578 DOI: 10.3390/ijms23094816] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/15/2022] [Accepted: 04/20/2022] [Indexed: 11/17/2022] Open
Abstract
Heterozygous mutations of the transcription factor PHOX2B are responsible for Congenital Central Hypoventilation Syndrome, a neurological disorder characterized by inadequate respiratory response to hypercapnia and life-threatening hypoventilation during sleep. Although no cure is currently available, it was suggested that a potent progestin drug provides partial recovery of chemoreflex response. Previous in vitro data show a direct molecular link between progestins and PHOX2B expression. However, the mechanism through which these drugs ameliorate breathing in vivo remains unknown. Here, we investigated the effects of chronic administration of the potent progestin drug Etonogestrel (ETO) on respiratory function and transcriptional activity in adult female rats. We assessed respiratory function with whole-body plethysmography and measured genomic changes in brain regions important for respiratory control. Our results show that ETO reduced metabolic activity, leading to an enhanced chemoreflex response and concurrent increased breathing cycle variability at rest. Furthermore, ETO-treated brains showed reduced mRNA and protein expression of PHOX2B and its target genes selectively in the dorsal vagal complex, while other areas were unaffected. Histological analysis suggests that changes occurred in the solitary tract nucleus (NTS). Thus, we propose that the NTS, rich in both progesterone receptors and PHOX2B, is a good candidate for ETO-induced respiratory modulation.
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Ceccherini I, Kurek KC, Weese-Mayer DE. Developmental disorders affecting the respiratory system: CCHS and ROHHAD. HANDBOOK OF CLINICAL NEUROLOGY 2022; 189:53-91. [PMID: 36031316 DOI: 10.1016/b978-0-323-91532-8.00005-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD) and Congenital Central Hypoventilation Syndrome (CCHS) are ultra-rare distinct clinical disorders with overlapping symptoms including altered respiratory control and autonomic regulation. Although both disorders have been considered for decades to be on the same spectrum with necessity of artificial ventilation as life-support, recent acquisition of specific knowledge concerning the genetic basis of CCHS coupled with an elusive etiology for ROHHAD have definitely established that the two disorders are different. CCHS is an autosomal dominant neurocristopathy characterized by alveolar hypoventilation resulting in hypoxemia/hypercarbia and features of autonomic nervous system dysregulation (ANSD), with presentation typically in the newborn period. It is caused by paired-like homeobox 2B (PHOX2B) variants, with known genotype-phenotype correlation but pathogenic mechanism(s) are yet unknown. ROHHAD is characterized by rapid weight gain, followed by hypothalamic dysfunction, then hypoventilation followed by ANSD, in seemingly normal children ages 1.5-7 years. Postmortem neuroanatomical studies, thorough clinical characterization, pathophysiological assessment, and extensive genetic inquiry have failed to identify a cause attributable to a traditional genetic basis, somatic mosaicism, epigenetic mechanism, environmental trigger, or other. To find the key to the ROHHAD pathogenesis and to improve its clinical management, in the present chapter, we have carefully compared CCHS and ROHHAD.
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Affiliation(s)
- Isabella Ceccherini
- Laboratory of Genetics and Genomics of Rare Diseases, IRCCS Istituto Giannina Gaslini, Genova, Italy
| | - Kyle C Kurek
- Department of Pathology & Laboratory Medicine, University of Calgary, Calgary, AB, Canada
| | - Debra E Weese-Mayer
- Division of Autonomic Medicine, Department of Pediatrics, Ann & Robert H Lurie Children's Hospital of Chicago and Stanley Manne Children's Research Institute; and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, United States.
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6
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Levy J, Droz-Bartholet F, Achour M, Facchinetti P, Parratte B, Giuliano F. Parafacial neurons in the human brainstem express specific markers for neurons of the retrotrapezoid nucleus. J Comp Neurol 2021; 529:3313-3320. [PMID: 34008871 DOI: 10.1002/cne.25191] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/08/2021] [Accepted: 05/13/2021] [Indexed: 11/06/2022]
Abstract
The retrotrapezoid nucleus (RTN) is a hub for respiratory chemoregulation in the mammal brainstem that integrates chemosensory information from peripheral sites and central relays. Chemosensitive neurons of the RTN express specific genetic and molecular determinants, which have been used to identify RTN precise location within the brainstem of rodents and nonhuman primates. Based on a comparative approach, we hypothesized that among mammals, neurons exhibiting the same specific molecular and genetic signature would have the same function. The co-expression of preprogalanin (PPGAL) and SLC17A6 (VGluT2) mRNAs with duplex in situ hybridization has been studied in formalin fixed paraffin-embedded postmortem human brainstems. Two specimens were processed and analyzed in line with RTN descriptions in adult rats and macaques. Double-labeled PPGAL+/SLC17A6+ neurons were only identified in the parafacial region of the brainstem. These neurons were found surrounding the nucleus of the facial nerve, located ventrally to the nucleus VII on caudal sections, and slightly more dorsally on rostral sections. The expression of neuromedin B (NMB) mRNA as a single marker of chemosensitive RTN neurons has not been confirmed in humans. The location of the RTN in human adults is provided. This should help to develop investigation tools combining anatomic high-resolution imaging and respiratory functional investigations to explore the pathogenic role of the RTN in congenital or acquired neurodegenerative diseases.
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Affiliation(s)
- Jonathan Levy
- UMR 1179 (Inserm-UVSQ) Neuromuscular Handicap - UFR des sciences de la Santé Simone Veil, Université de Versailles St. Quentin, Montigny-le-Bretonneux, Paris Saclay campus, France.,Service de Médecine Physique et de Réadaptation - APHP, Hôpital Raymond Poincaré, Garches, France.,Fondation Garches - Hôpital Raymond Poincaré, Garches, France
| | - François Droz-Bartholet
- Laboratoire d'Anatomie - Faculté de Médecine de Besançon, Université de Franche-Comté, Besançon, France.,Service de Médecine Physique et de Réadaptation - CHRU Jean Minjoz, Besançon, France
| | - Melyna Achour
- UMR 1179 (Inserm-UVSQ) Neuromuscular Handicap - UFR des sciences de la Santé Simone Veil, Université de Versailles St. Quentin, Montigny-le-Bretonneux, Paris Saclay campus, France
| | - Patricia Facchinetti
- UMR 1179 (Inserm-UVSQ) Neuromuscular Handicap - UFR des sciences de la Santé Simone Veil, Université de Versailles St. Quentin, Montigny-le-Bretonneux, Paris Saclay campus, France
| | - Bernard Parratte
- Laboratoire d'Anatomie - Faculté de Médecine de Besançon, Université de Franche-Comté, Besançon, France.,Service de Médecine Physique et de Réadaptation - CHRU Jean Minjoz, Besançon, France
| | - François Giuliano
- UMR 1179 (Inserm-UVSQ) Neuromuscular Handicap - UFR des sciences de la Santé Simone Veil, Université de Versailles St. Quentin, Montigny-le-Bretonneux, Paris Saclay campus, France.,Service de Médecine Physique et de Réadaptation - APHP, Hôpital Raymond Poincaré, Garches, France
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7
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Mei M, Yang L, Lu Y, Wang L, Cheng G, Cao Y, Chen C, Qian L, Zhou W. Congenital central hypoventilation syndrome in neonates: report of fourteen new cases and a review of the literature. Transl Pediatr 2021; 10:733-745. [PMID: 34012823 PMCID: PMC8107878 DOI: 10.21037/tp-20-303] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Congenital central hypoventilation syndrome (CCHS) is a rare autosomal dominant disorder caused by pathogenic variants in paired-like homeobox 2B (PHOX2B) gene. Characteristics of neonatal-onset CCHS cases have not been well assessed. The aim of this study is to expand current knowledge of clinical and genetic features of neonates with CCHS and provide data on the genotype-phenotype correlation. METHODS We made a retrospective analysis of 14 neonates carrying PHOX2B pathogenic variants from 2014 to 2019 and we reviewed previously published neonatal-onset cases. Clinical and genetic data were analyzed. Moreover, genotype-phenotype correlation analysis was performed. RESULTS We identified a total of 60 neonatal-onset CCHS cases (35 males and 25 females) including 14 novel cases from our local cohort. Nearly 20% (18.2%) of the patients were born prematurely. Nearly half (46.2%) of the patients had abnormal family history. Polyhydramnios was observed in 21.3% (10/47) of the patients. About 90% of the patients manifested symptoms of hypoventilation in the first week of life. Fourteen patients (23.3%) were classified as mild-CCHS and the rest were severe-CCHS. Gastrointestinal manifestations were observed in 71.7% of the patients. Approximately twofold more males than females were affected by Hirschprung disease (HSCR)/variant HSCR (75.8% vs. 35%, P=0.003). Neural crest tumor occurred in 9.1% (4/44) patients. Half patients had polyalanine repeat expansion mutations (PARMs) in PHOX2B (seven with 25 PARM, nine with 26 PARM, twelve with 27 PARM, one with 28 PARM and one with 31 PARM) and the other half patients had 23 distinct non-polyalanine repeat expansion mutations (NPARMs) with one novel pathogenic variant (c.684dup). The prevalence of HSCR and mild-CCHS among patients with NPARMs was significantly greater than that of the patients with PARMs. CONCLUSIONS This report provides a large cohort of neonatal-onset CCHS cases. The results indicate that severe hypoventilation and HSCR are frequently observed in this group. NPARMs accounted for half of the cohort with some genotypes tend to be associated with mild phenotype. Molecular testing in neonates with suspicion of CCHS and genetic counseling for CCHS families are highly recommended.
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Affiliation(s)
- Mei Mei
- Department of Respiratory Medicine, Children's Hospital of Fudan University, Shanghai, China
| | - Lin Yang
- Clinical Genetic Center, Children's Hospital of Fudan University, Shanghai, China.,Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Shanghai, China
| | - Yulan Lu
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Shanghai, China
| | - Laishuan Wang
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China
| | - Guoqiang Cheng
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China
| | - Yun Cao
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China
| | - Chao Chen
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China
| | - Liling Qian
- Department of Respiratory Medicine, Children's Hospital of Fudan University, Shanghai, China
| | - Wenhao Zhou
- Clinical Genetic Center, Children's Hospital of Fudan University, Shanghai, China.,Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Shanghai, China.,Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China
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8
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Di Lascio S, Benfante R, Cardani S, Fornasari D. Research Advances on Therapeutic Approaches to Congenital Central Hypoventilation Syndrome (CCHS). Front Neurosci 2021; 14:615666. [PMID: 33510615 PMCID: PMC7835644 DOI: 10.3389/fnins.2020.615666] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/17/2020] [Indexed: 12/11/2022] Open
Abstract
Congenital central hypoventilation syndrome (CCHS) is a genetic disorder of neurodevelopment, with an autosomal dominant transmission, caused by heterozygous mutations in the PHOX2B gene. CCHS is a rare disorder characterized by hypoventilation due to the failure of autonomic control of breathing. Until now no curative treatment has been found. PHOX2B is a transcription factor that plays a crucial role in the development (and maintenance) of the autonomic nervous system, and in particular the neuronal structures involved in respiratory reflexes. The underlying pathogenetic mechanism is still unclear, although studies in vivo and in CCHS patients indicate that some neuronal structures may be damaged. Moreover, in vitro experimental data suggest that transcriptional dysregulation and protein misfolding may be key pathogenic mechanisms. This review summarizes latest researches that improved the comprehension of the molecular pathogenetic mechanisms responsible for CCHS and discusses the search for therapeutic intervention in light of the current knowledge about PHOX2B function.
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Affiliation(s)
- Simona Di Lascio
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy
| | - Roberta Benfante
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy.,CNR-Institute of Neuroscience, Milan, Italy.,NeuroMi-Milan Center for Neuroscience, University of Milano Bicocca, Milan, Italy
| | - Silvia Cardani
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy
| | - Diego Fornasari
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy.,CNR-Institute of Neuroscience, Milan, Italy
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9
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Blackburn J, Chapur VF, Stephens JA, Zhao J, Shepler A, Pierson CR, Otero JJ. Revisiting the Neuropathology of Sudden Infant Death Syndrome (SIDS). Front Neurol 2020; 11:594550. [PMID: 33391159 PMCID: PMC7773837 DOI: 10.3389/fneur.2020.594550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 11/10/2020] [Indexed: 01/08/2023] Open
Abstract
Background: Sudden infant death syndrome (SIDS) is one of the leading causes of infant mortality in the United States (US). The extent to which SIDS manifests with an underlying neuropathological mechanism is highly controversial. SIDS correlates with markers of poor prenatal and postnatal care, generally rooted in the lack of access and quality of healthcare endemic to select racial and ethnic groups, and thus can be viewed in the context of health disparities. However, some evidence suggests that at least a subset of SIDS cases may result from a neuropathological mechanism. To explain these issues, a triple-risk hypothesis has been proposed, whereby an underlying biological abnormality in an infant facing an extrinsic risk during a critical developmental period SIDS is hypothesized to occur. Each SIDS decedent is thus thought to have a unique combination of these risk factors leading to their death. This article reviews the neuropathological literature of SIDS and uses machine learning tools to identify distinct subtypes of SIDS decedents based on epidemiological data. Methods: We analyzed US Period Linked Birth/Infant Mortality Files from 1990 to 2017 (excluding 1992–1994). Using t-SNE, an unsupervised machine learning dimensionality reduction algorithm, we identified clusters of SIDS decedents. Following identification of these groups, we identified changes in the rates of SIDS at the state level and across three countries. Results: Through t-SNE and distance based statistical analysis, we identified three groups of SIDS decedents, each with a unique peak age of death. Within the US, SIDS is geographically heterogeneous. Following this, we found low birth weight and normal birth weight SIDS rates have not been equally impacted by implementation of clinical guidelines. We show that across countries with different levels of cultural heterogeneity, reduction in SIDS rates has also been distinct between decedents with low vs. normal birth weight. Conclusions: Different epidemiological and extrinsic risk factors exist based on the three unique SIDS groups we identified with t-SNE and distance based statistical measurements. Clinical guidelines have not equally impacted the groups, and normal birth weight infants comprise more of the cases of SIDS even though low birth weight infants have a higher SIDS rate.
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Affiliation(s)
- Jessica Blackburn
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, United States.,Division of Anatomy, Department of Biomedical Education & Anatomy, The Ohio State University College of Medicine, Columbus, OH, United States
| | - Valeria F Chapur
- Instituto de Ecoregiones Andinas (INECOA)/Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Instituto de Biología de la Altura (INBIAL)/Universidad Nacional de Jujuy (UNJU), San Salvador de Jujuy, Argentina
| | - Julie A Stephens
- Department of Biomedical Informatics, Center for Biostatistics, The Ohio State University College of Medicine, Columbus, OH, United States
| | - Jing Zhao
- Department of Biomedical Informatics, Center for Biostatistics, The Ohio State University College of Medicine, Columbus, OH, United States
| | - Anne Shepler
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, United States.,Franklin County Forensic Science Center, Columbus, OH, United States
| | - Christopher R Pierson
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, United States.,Division of Anatomy, Department of Biomedical Education & Anatomy, The Ohio State University College of Medicine, Columbus, OH, United States.,Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus, OH, United States
| | - José Javier Otero
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, United States
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10
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Alzate-Correa D, Mei-Ling Liu J, Jones M, Silva TM, Alves MJ, Burke E, Zuñiga J, Kaya B, Zaza G, Aslan MT, Blackburn J, Shimada MY, Fernandes-Junior SA, Baer LA, Stanford KI, Kempton A, Smith S, Szujewski CC, Silbaugh A, Viemari JC, Takakura AC, Garcia AJ, Moreira TS, Czeisler CM, Otero JJ. Neonatal apneic phenotype in a murine congenital central hypoventilation syndrome model is induced through non-cell autonomous developmental mechanisms. Brain Pathol 2020; 31:84-102. [PMID: 32654284 PMCID: PMC7881415 DOI: 10.1111/bpa.12877] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 05/10/2020] [Accepted: 06/11/2020] [Indexed: 12/19/2022] Open
Abstract
Congenital central hypoventilation syndrome (CCHS) represents a rare genetic disorder usually caused by mutations in the homeodomain transcription factor PHOX2B. Some CCHS patients suffer mainly from deficiencies in CO2 and/or O2 respiratory chemoreflex, whereas other patients present with full apnea shortly after birth. Our goal was to identify the neuropathological mechanisms of apneic presentations in CCHS. In the developing murine neuroepithelium, Phox2b is expressed in three discrete progenitor domains across the dorsal-ventral axis, with different domains responsible for producing unique autonomic or visceral motor neurons. Restricting the expression of mutant Phox2b to the ventral visceral motor neuron domain induces marked newborn apnea together with a significant loss of visceral motor neurons, RTN ablation, and preBötzinger complex dysfunction. This finding suggests that the observed apnea develops through non-cell autonomous developmental mechanisms. Mutant Phox2b expression in dorsal rhombencephalic neurons did not generate significant respiratory dysfunction, but did result in subtle metabolic thermoregulatory deficiencies. We confirm the expression of a novel murine Phox2b splice variant which shares exons 1 and 2 with the more widely studied Phox2b splice variant, but which differs in exon 3 where most CCHS mutations occur. We also show that mutant Phox2b expression in the visceral motor neuron progenitor domain increases cell proliferation at the expense of visceral motor neuron development. We propose that visceral motor neurons may function as organizers of brainstem respiratory neuron development, and that disruptions in their development result in secondary/non-cell autonomous maldevelopment of key brainstem respiratory neurons.
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Affiliation(s)
- Diego Alzate-Correa
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jillian Mei-Ling Liu
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Mikayla Jones
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Talita M Silva
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Michele Joana Alves
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Elizabeth Burke
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jessica Zuñiga
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Behiye Kaya
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Giuliana Zaza
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Mehmet Tahir Aslan
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jessica Blackburn
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Marina Y Shimada
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Silvio A Fernandes-Junior
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Lisa A Baer
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Kristin I Stanford
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Amber Kempton
- Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Sakima Smith
- Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Caroline C Szujewski
- Institute for Integrative Physiology, Grossman Institute for Neuroscience Quantitative Biology and Human Behavior, The Committee on Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Abby Silbaugh
- Institute for Integrative Physiology, Grossman Institute for Neuroscience Quantitative Biology and Human Behavior, The Committee on Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Jean-Charles Viemari
- P3M Team, Institut de Neurosciences de la Timone, UMR 7289 AMU-CNRS, Marseille, France
| | - Ana C Takakura
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Alfredo J Garcia
- Institute for Integrative Physiology, Grossman Institute for Neuroscience Quantitative Biology and Human Behavior, The Committee on Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Thiago S Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Catherine M Czeisler
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - José J Otero
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
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11
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Liu N, Fu C, Yu H, Wang Y, Shi L, Hao Y, Yuan F, Zhang X, Wang S. Respiratory Control by Phox2b-expressing Neurons in a Locus Coeruleus-preBötzinger Complex Circuit. Neurosci Bull 2020; 37:31-44. [PMID: 32468398 DOI: 10.1007/s12264-020-00519-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 03/12/2020] [Indexed: 02/06/2023] Open
Abstract
The locus coeruleus (LC) has been implicated in the control of breathing. Congenital central hypoventilation syndrome results from mutation of the paired-like homeobox 2b (Phox2b) gene that is expressed in LC neurons. The present study was designed to address whether stimulation of Phox2b-expressing LC (Phox2bLC) neurons affects breathing and to reveal the putative circuit mechanism. A Cre-dependent viral vector encoding a Gq-coupled human M3 muscarinic receptor (hM3Dq) was delivered into the LC of Phox2b-Cre mice. The hM3Dq-transduced neurons were pharmacologically activated while respiratory function was measured by plethysmography. We demonstrated that selective stimulation of Phox2bLC neurons significantly increased basal ventilation in conscious mice. Genetic ablation of these neurons markedly impaired hypercapnic ventilatory responses. Moreover, stimulation of Phox2bLC neurons enhanced the activity of preBötzinger complex neurons. Finally, axons of Phox2bLC neurons projected to the preBötzinger complex. Collectively, Phox2bLC neurons contribute to the control of breathing most likely via an LC-preBötzinger complex circuit.
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Affiliation(s)
- Na Liu
- Department of Physiology, Hebei Medical University, Shijiazhuang, 050017, China.,Department of Physiology, Cangzhou Medical College, Cangzhou, 061000, China
| | - Congrui Fu
- School of Nursing, Hebei Medical University, Shijiazhuang, 050000, China
| | - Hongxiao Yu
- Department of Physiology, Hebei Medical University, Shijiazhuang, 050017, China
| | - Yakun Wang
- Department of Physiology, Hebei Medical University, Shijiazhuang, 050017, China
| | - Luo Shi
- Department of Physiology, Hebei Medical University, Shijiazhuang, 050017, China
| | - Yinchao Hao
- Department of Physiology, Hebei Medical University, Shijiazhuang, 050017, China
| | - Fang Yuan
- Department of Physiology, Hebei Medical University, Shijiazhuang, 050017, China
| | - Xiangjian Zhang
- Hebei Key laboratory of Vascular Homeostasis and Hebei Collaborative Innovation Center for Cardio-cerebrovascular Disease, Shijiazhuang, 050000, China
| | - Sheng Wang
- Department of Physiology, Hebei Medical University, Shijiazhuang, 050017, China.
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12
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Souza GMPR, Kanbar R, Stornetta DS, Abbott SBG, Stornetta RL, Guyenet PG. Breathing regulation and blood gas homeostasis after near complete lesions of the retrotrapezoid nucleus in adult rats. J Physiol 2019; 596:2521-2545. [PMID: 29667182 DOI: 10.1113/jp275866] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 04/04/2018] [Indexed: 12/16/2022] Open
Abstract
KEY POINTS The retrotrapezoid nucleus (RTN) drives breathing proportionally to brain PCO2 but its role during various states of vigilance needs clarification. Under normoxia, RTN lesions increased the arterial PCO2 set-point, lowered the PO2 set-point and reduced alveolar ventilation relative to CO2 production. Tidal volume was reduced and breathing frequency increased to a comparable degree during wake, slow-wave sleep and REM sleep. RTN lesions did not produce apnoeas or disordered breathing during sleep. RTN lesions in rats virtually eliminated the central respiratory chemoreflex (CRC) while preserving the cardiorespiratory responses to hypoxia; the relationship between CRC and number of surviving RTN Nmb neurons was an inverse exponential. The CRC does not function without the RTN. In the quasi-complete absence of the RTN and CRC, alveolar ventilation is reduced despite an increased drive to breathe from the carotid bodies. ABSTRACT The retrotrapezoid nucleus (RTN) is one of several CNS nuclei that contribute, in various capacities (e.g. CO2 detection, neuronal modulation) to the central respiratory chemoreflex (CRC). Here we test how important the RTN is to PCO2 homeostasis and breathing during sleep or wake. RTN Nmb-positive neurons were killed with targeted microinjections of substance P-saporin conjugate in adult rats. Under normoxia, rats with large RTN lesions (92 ± 4% cell loss) had normal blood pressure and arterial pH but were hypoxic (-8 mmHg PaO2 ) and hypercapnic (+10 mmHg ). In resting conditions, minute volume (VE ) was normal but breathing frequency (fR ) was elevated and tidal volume (VT ) reduced. Resting O2 consumption and CO2 production were normal. The hypercapnic ventilatory reflex in 65% FiO2 had an inverse exponential relationship with the number of surviving RTN neurons and was decreased by up to 92%. The hypoxic ventilatory reflex (HVR; FiO2 21-10%) persisted after RTN lesions, hypoxia-induced sighing was normal and hypoxia-induced hypotension was reduced. In rats with RTN lesions, breathing was lowest during slow-wave sleep, especially under hyperoxia, but apnoeas and sleep-disordered breathing were not observed. In conclusion, near complete RTN destruction in rats virtually eliminates the CRC but the HVR persists and sighing and the state dependence of breathing are unchanged. Under normoxia, RTN lesions cause no change in VE but alveolar ventilation is reduced by at least 21%, probably because of increased physiological dead volume. RTN lesions do not cause sleep apnoea during slow-wave sleep, even under hyperoxia.
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Affiliation(s)
- George M P R Souza
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Roy Kanbar
- Department of Pharmaceutical Sciences, Lebanese American University, Beyrouth, Lebanon
| | - Daniel S Stornetta
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Stephen B G Abbott
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Ruth L Stornetta
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Patrice G Guyenet
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
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13
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Sex differences in breathing. Comp Biochem Physiol A Mol Integr Physiol 2019; 238:110543. [PMID: 31445081 DOI: 10.1016/j.cbpa.2019.110543] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 01/15/2023]
Abstract
Breathing is a vital behavior that ensures both the adequate supply of oxygen and the elimination of CO2, and it is influenced by many factors. Despite that most of the studies in respiratory physiology rely heavily on male subjects, there is much evidence to suggest that sex is an important factor in the respiratory control system, including the susceptibility for some diseases. These different respiratory responses in males and females may be related to the actions of sex hormones, especially in adulthood. These hormones affect neuromodulatory systems that influence the central medullary rhythm/pontine pattern generator and integrator, sensory inputs to the integrator and motor output to the respiratory muscles. In this article, we will first review the sex dependence on the prevalence of some respiratory-related diseases. Then, we will discuss the role of sex and gonadal hormones in respiratory control under resting conditions and during respiratory challenges, such as hypoxia and hypercapnia, and whether hormonal fluctuations during the estrous/menstrual cycle affect breathing control. We will then discuss the role of the locus coeruleus, a sexually dimorphic CO2/pH-chemosensitive nucleus, on breathing regulation in males and females. Next, we will highlight the studies that exist regarding sex differences in respiratory control during development. Finally, the few existing studies regarding the influence of sex on breathing control in non-mammalian vertebrates will be discussed.
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14
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Levy J, Facchinetti P, Jan C, Achour M, Bouvier C, Brunet JF, Delzescaux T, Giuliano F. Tridimensional mapping of Phox2b expressing neurons in the brainstem of adult Macaca fascicularis and identification of the retrotrapezoid nucleus. J Comp Neurol 2019; 527:2875-2884. [PMID: 31071232 DOI: 10.1002/cne.24713] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/29/2019] [Accepted: 04/29/2019] [Indexed: 11/08/2022]
Abstract
Chemosensitivity is a key mechanism for the regulation of breathing in vertebrates. The retrotrapezoid nucleus is a crucial hub for respiratory chemoreception within the brainstem. It integrates chemosensory information that are both peripheral from the carotid bodies (via the nucleus of the solitary tract) and central through the direct sensing of extracellular protons. To date, the location of a genetically defined RTN has only been ascertained in rodents. We first demonstrated that Phox2b, a key determinant for the development of the visceral nervous system and branchiomotor nuclei in the brainstem including the RTN, had a similar distribution in the brainstem of adult macaques compared to adult rats. Second, based on previous description of a specific molecular signature for the RTN in rats, and on an innovative technique for duplex in situ hybridization, we identified parafacial neurons which coexpressed Phox2b and ppGal mRNAs. They were located ventrally to the nucleus of the facial nerve and extended from the caudal part of the nucleus of the superior olive to the rostral tip of the inferior olive. Using the previously described blockface technique, deformations were corrected to allow the proper alignment and stacking of digitized sections, hence providing for the first time a 3D reconstruction of the macaque brainstem, Phox2b distribution and the primate retrotrapezoid nucleus. This description should help bridging the gap between rodents and humans for the description of key respiratory structures in the brainstem.
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Affiliation(s)
- Jonathan Levy
- INSERM UMR1179-Handicap Neuromusculaire, Université de Versailles Saint-Quentin-en-Yvelines, Montigny-le-Bretonneux, France.,Service de Médecine Physique et de Réadaptation-APHP, Hôpital Raymond Poincaré, Garches, France.,Fondation Garches-APHP, Hôpital Raymond Poincaré, Garches, France
| | - Patricia Facchinetti
- INSERM UMR1179-Handicap Neuromusculaire, Université de Versailles Saint-Quentin-en-Yvelines, Montigny-le-Bretonneux, France
| | - Caroline Jan
- Molecular Imaging Research Center (MIRCen)-Commissariat à l'Énergie Atomique (CEA), Fontenay-aux-Roses, France.,CNRS-CEA UMR9199-Neurodegenerative Diseases Laboratory, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Mélyna Achour
- INSERM UMR1179-Handicap Neuromusculaire, Université de Versailles Saint-Quentin-en-Yvelines, Montigny-le-Bretonneux, France
| | - Clément Bouvier
- Molecular Imaging Research Center (MIRCen)-Commissariat à l'Énergie Atomique (CEA), Fontenay-aux-Roses, France.,NEOXIA, Paris, France
| | - Jean-François Brunet
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université, Paris, France
| | - Thierry Delzescaux
- Molecular Imaging Research Center (MIRCen)-Commissariat à l'Énergie Atomique (CEA), Fontenay-aux-Roses, France.,CNRS-CEA UMR9199-Neurodegenerative Diseases Laboratory, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - François Giuliano
- INSERM UMR1179-Handicap Neuromusculaire, Université de Versailles Saint-Quentin-en-Yvelines, Montigny-le-Bretonneux, France.,Service de Médecine Physique et de Réadaptation-APHP, Hôpital Raymond Poincaré, Garches, France
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15
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Czeisler CM, Silva TM, Fair SR, Liu J, Tupal S, Kaya B, Cowgill A, Mahajan S, Silva PE, Wang Y, Blissett AR, Göksel M, Borniger JC, Zhang N, Fernandes‐Junior SA, Catacutan F, Alves MJ, Nelson RJ, Sundaresean V, Rekling J, Takakura AC, Moreira TS, Otero JJ. The role of PHOX2B-derived astrocytes in chemosensory control of breathing and sleep homeostasis. J Physiol 2019; 597:2225-2251. [PMID: 30707772 PMCID: PMC6462490 DOI: 10.1113/jp277082] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 01/28/2019] [Indexed: 01/07/2023] Open
Abstract
KEY POINTS The embryonic PHOX2B-progenitor domain generates neuronal and glial cells which together are involved in chemosensory control of breathing and sleep homeostasis. Ablating PHOX2B-derived astrocytes significantly contributes to secondary hypoxic respiratory depression as well as abnormalities in sleep homeostasis. PHOX2B-derived astrocyte ablation results in axonal pathologies in the retrotrapezoid nucleus. ABSTRACT We identify in mice a population of ∼800 retrotrapezoid nucleus (RTN) astrocytes derived from PHOX2B-positive, OLIG3-negative progenitor cells, that interact with PHOX2B-expressing RTN chemosensory neurons. PHOX2B-derived astrocyte ablation during early life results in adult-onset O2 chemoreflex deficiency. These animals also display changes in sleep homeostasis, including fragmented sleep and disturbances in delta power after sleep deprivation, all without observable changes in anxiety or social behaviours. Ultrastructural evaluation of the RTN demonstrates that PHOX2B-derived astrocyte ablation results in features characteristic of degenerative neuro-axonal dystrophy, including abnormally dilated axon terminals and increased amounts of synapses containing autophagic vacuoles/phagosomes. We conclude that PHOX2B-derived astrocytes are necessary for maintaining a functional O2 chemosensory reflex in the adult, modulate sleep homeostasis, and are key regulators of synaptic integrity in the RTN region, which is necessary for the chemosensory control of breathing. These data also highlight how defects in embryonic development may manifest as neurodegenerative pathology in an adult.
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Affiliation(s)
| | - Talita M. Silva
- Department of Physiology and BiophysicsInstitute of Biomedical ScienceUniversity of Sao PauloSao PauloBrazil
| | - Summer R. Fair
- Department of PathologyThe Ohio State University College of MedicineColumbusOHUSA
| | - Jillian Liu
- Department of PathologyThe Ohio State University College of MedicineColumbusOHUSA
| | - Srinivasan Tupal
- Department of PathologyThe Ohio State University College of MedicineColumbusOHUSA
| | - Behiye Kaya
- Department of PathologyThe Ohio State University College of MedicineColumbusOHUSA
| | - Aaron Cowgill
- Department of PathologyThe Ohio State University College of MedicineColumbusOHUSA
| | - Salil Mahajan
- Department of PathologyThe Ohio State University College of MedicineColumbusOHUSA
| | - Phelipe E. Silva
- Department of Physiology and BiophysicsInstitute of Biomedical ScienceUniversity of Sao PauloSao PauloBrazil
| | - Yangyang Wang
- Department of NeuroscienceThe Ohio State University College of MedicineColumbusOHUSA
- The Ohio State University Mathematical Biosciences InstituteColumbusOHUSA
| | - Angela R. Blissett
- Department of Mechanical and Aerospace EngineeringThe Ohio State University College of EngineeringColumbusOHUSA
| | - Mustafa Göksel
- Department of PathologyThe Ohio State University College of MedicineColumbusOHUSA
| | - Jeremy C. Borniger
- Department of NeuroscienceThe Ohio State University College of MedicineColumbusOHUSA
| | - Ning Zhang
- Department of NeuroscienceWest Virginia UniversityWVUSA
| | - Silvio A. Fernandes‐Junior
- The Ohio State University Campus Microscopy and Imaging FacilityColumbusOHUSA
- Department of PharmacologyInstitute of Biomedical ScienceUniversity of São PauloSao PauloBrazil
| | - Fay Catacutan
- Department of PathologyThe Ohio State University College of MedicineColumbusOHUSA
| | - Michele J. Alves
- Department of PathologyThe Ohio State University College of MedicineColumbusOHUSA
| | | | - Vishnu Sundaresean
- Department of PathologyThe Ohio State University College of MedicineColumbusOHUSA
| | - Jens Rekling
- Department of NeuroscienceUniversity of CopenhagenCopenhagenDenmark
| | - Ana C. Takakura
- Department of PharmacologyInstitute of Biomedical ScienceUniversity of São PauloSao PauloBrazil
| | - Thiago S. Moreira
- Department of Physiology and BiophysicsInstitute of Biomedical ScienceUniversity of Sao PauloSao PauloBrazil
| | - José J. Otero
- Department of PathologyThe Ohio State University College of MedicineColumbusOHUSA
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16
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Bardanzellu F, Pintus MC, Fanos V, Marcialis MA. Neonatal Congenital Central Hypoventilation Syndrome: Why We Should not Sleep on it. Literature Review of Forty-two Neonatal Onset Cases. Curr Pediatr Rev 2019; 15:139-153. [PMID: 31223092 DOI: 10.2174/1573396315666190621103954] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/18/2019] [Accepted: 03/25/2019] [Indexed: 12/31/2022]
Abstract
Congenital Central Hypoventilation Syndrome (CCHS), also referred with the expression "Ondine's Curse", is a rare genetic life-long disease resulting from the mutation of PHOX2B gene on chromosome 4p12.3. CCHS represents an autonomic nervous system disorder; its more fearsome manifestation is central hypoventilation, due to a deficient response of chemoreceptors to hypercapnia and hypoxia. Several associated symptoms can occur, such as pupillary anomalies, arrhythmias, reduced heart rate variability, esophageal dysmotility, and structural comorbidities (Hirschsprung's Disease or neural crest tumours). CCHS typical onset is during the neonatal period, but cases of delayed diagnosis have been reported; moreover, both sporadic or familial cases can occur. In preterm newborns, asphyxia and typical prematurity-related findings may overlap CCHS clinical manifestations and make it harder to formulate a correct diagnosis. The early recognition of CCHS allows appropriate management, useful to reduce immediate and long- term consequences.
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Affiliation(s)
- Flaminia Bardanzellu
- Neonatal Intensive Care Unit, AOU and University of Cagliari, SS 554 km 4,500, 09042 Monserrato, Italy
| | - Maria Cristina Pintus
- Neonatal Intensive Care Unit, AOU and University of Cagliari, SS 554 km 4,500, 09042 Monserrato, Italy
| | - Vassilios Fanos
- Neonatal Intensive Care Unit, AOU and University of Cagliari, SS 554 km 4,500, 09042 Monserrato, Italy
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17
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Bishara J, Keens TG, Perez IA. The genetics of congenital central hypoventilation syndrome: clinical implications. APPLICATION OF CLINICAL GENETICS 2018; 11:135-144. [PMID: 30532577 PMCID: PMC6241683 DOI: 10.2147/tacg.s140629] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Congenital central hypoventilation syndrome (CCHS) is a rare genetic disorder of the autonomic nervous system (ANS) and respiratory control. This disorder, formerly referred to as Ondine’s curse, is due to a mutation in the PHOX2B gene that affects the development of the neural crest cells. CCHS has an autosomal dominant pattern of inheritance. Majority of the patients have a polyalanine repeat mutation (PARM) of the PHOX2B, while a small group has non-PARM (NPARM). Knowledge of the patient’s PHOX2B gene mutation helps predict a patient’s clinical presentation and outcome and aids in anticipatory management of the respiratory and ANS dysfunction.
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Affiliation(s)
- John Bishara
- Division of Pediatric Pulmonology and Sleep Medicine, Children's Hospital Los Angeles, Los Angeles, CA, USA,
| | - Thomas G Keens
- Division of Pediatric Pulmonology and Sleep Medicine, Children's Hospital Los Angeles, Los Angeles, CA, USA, .,Department of Pediatrics, Keck School of Medicine of USC, Los Angeles, CA, USA,
| | - Iris A Perez
- Division of Pediatric Pulmonology and Sleep Medicine, Children's Hospital Los Angeles, Los Angeles, CA, USA, .,Department of Pediatrics, Keck School of Medicine of USC, Los Angeles, CA, USA,
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18
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Di Lascio S, Benfante R, Cardani S, Fornasari D. Advances in the molecular biology and pathogenesis of congenital central hypoventilation syndrome—implications for new therapeutic targets. Expert Opin Orphan Drugs 2018. [DOI: 10.1080/21678707.2018.1540978] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Simona Di Lascio
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy
| | - Roberta Benfante
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy
- CNR- Neuroscience Institute, Milan, Italy
| | - Silvia Cardani
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy
| | - Diego Fornasari
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy
- CNR- Neuroscience Institute, Milan, Italy
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19
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Cardani S, Di Lascio S, Belperio D, Di Biase E, Ceccherini I, Benfante R, Fornasari D. Desogestrel down-regulates PHOX2B and its target genes in progesterone responsive neuroblastoma cells. Exp Cell Res 2018; 370:671-679. [PMID: 30036539 DOI: 10.1016/j.yexcr.2018.07.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 10/28/2022]
Abstract
The paired-like homeobox 2B gene (PHOX2B) encodes a key transcription factor that plays a role in the development of the autonomic nervous system and the neural structures involved in controlling breathing. In humans, PHOX2B over-expression plays a role in the pathogenesis of tumours arising from the sympathetic nervous system such as neuroblastomas, and heterozygous PHOX2B mutations cause Congenital Central Hypoventilation Syndrome (CCHS), a life-threatening neurocristopathy characterised by the defective autonomic control of breathing and involving altered CO2/H+ chemosensitivity. The recovery of CO2/H+ chemosensitivity and increased ventilation have been observed in two CCHS patients using the potent contraceptive progestin desogestrel. Given the central role of PHOX2B in the pathogenesis of CCHS, and the progesterone-mediated effects observed in the disease, we generated progesterone-responsive neuroblastoma cells, and evaluated the effects of 3-Ketodesogestrel (3-KDG), the biologically active metabolite of desogestrel, on the expression of PHOX2B and its target genes. Our findings demonstrate that, through progesterone nuclear receptor PR-B, 3-KDG down-regulates PHOX2B gene expression, by a post-transcriptional mechanism, and its target genes and open up the possibility that this mechanism may contribute to the positive effects observed in some CCHS patients.
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Affiliation(s)
- Silvia Cardani
- Dept. of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, via Vanvitelli 32, 2019 Milan, Italy
| | - Simona Di Lascio
- Dept. of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, via Vanvitelli 32, 2019 Milan, Italy
| | - Debora Belperio
- Dept. of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, via Vanvitelli 32, 2019 Milan, Italy
| | - Erika Di Biase
- Dept. of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, via Vanvitelli 32, 2019 Milan, Italy
| | - Isabella Ceccherini
- Laboratorio di Genetica Molecolare, Istituto Giannina Gaslini, Largo G. Gaslini 5, 16148 Genoa, Italy
| | - Roberta Benfante
- Dept. of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, via Vanvitelli 32, 2019 Milan, Italy; CNR -Neuroscience Institute, via Vanvitelli 32, 20129 Milan, Italy.
| | - Diego Fornasari
- Dept. of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, via Vanvitelli 32, 2019 Milan, Italy; CNR -Neuroscience Institute, via Vanvitelli 32, 20129 Milan, Italy.
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20
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Byers HM, Chen M, Gelfand AS, Ong B, Jendras M, Glass IA. Expanding the phenotype of congenital central hypoventilation syndrome impacts management decisions. Am J Med Genet A 2018; 176:1398-1404. [PMID: 29696799 DOI: 10.1002/ajmg.a.38726] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 04/01/2018] [Accepted: 04/04/2018] [Indexed: 11/10/2022]
Abstract
Congenital central hypoventilation syndrome (CCHS) is a neurocristopathy caused by pathogenic heterozygous variants in the gene paired-like homeobox 2b (PHOX2B). It is characterized by severe infantile alveolar hypoventilation. Individuals may also have diffuse autonomic nervous system dysfunction, Hirschsprung disease and neural crest tumors. We report three individuals with CCHS due to an 8-base pair duplication in PHOX2B; c.691_698dupGGCCCGGG (p.Gly234Alafs*78) with a predominant enteral and neural crest phenotype and a relatively mild respiratory phenotype. The attenuated respiratory phenotype reported here and elsewhere suggests an emergent genotype:phenotype correlation which challenges the current paradigm of invoking mechanical ventilation for all infants diagnosed with CCHS. Best treatment requires careful clinical judgment and ideally the assistance of a care team with expertise in CCHS.
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Affiliation(s)
- Heather M Byers
- Division of Medical Genetics, Department of Pediatrics, Stanford University, Palo Alto, California
| | - Maida Chen
- Department of Pediatrics, University of Washington, Seattle, Washington.,Division of Pulmonary Medicine, Seattle Children's Hospital, Seattle, Washington
| | | | - Bruce Ong
- Division of Pediatric Pulmonology, Tripler Army Medical Center, Honolulu, Hawaii
| | | | - Ian A Glass
- Department of Pediatrics, University of Washington, Seattle, Washington.,Division of Medical Genetics, Seattle Children's Hospital, Seattle, Washington
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21
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Zelko FA, Stewart TM, Brogadir CD, Rand CM, Weese-Mayer DE. Congenital central hypoventilation syndrome: Broader cognitive deficits revealed by parent controls. Pediatr Pulmonol 2018; 53:492-497. [PMID: 29327497 DOI: 10.1002/ppul.23939] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 12/06/2017] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To investigate neurocognitive deficits in children with Congenital Central Hypoventilation Syndrome (CCHS) by comparing them to their parents, since parents comprise a particularly suitable control group matched on disease-extrinsic factors that can influence neurocognitive functioning. We compared CCHS patients to their parents and to population norms, hypothesizing that they would obtain lower intelligence test scores than both groups. We also compared patient-parent differences against patient-normative differences, to determine whether the two analytic approaches would yield different results. METHODS We administered an intelligence screening, the Shipley-2, to 21 school-aged patients (age 14.2 ± 5.5 years) with PHOX2B mutation-confirmed CCHS and their parents. Patients also received detailed clinical intellectual assessments using the Wechsler scales. RESULTS CCHS patients scored significantly below parents on Shipley-2 indices of intelligence, vocabulary, and abstraction, with a trend for perceptual reasoning. The CCHS patients scored significantly below population norms on indices of abstraction and perceptual reasoning. Patient-parent differences were significantly larger than patient-normative differences for vocabulary scores. CCHS patients scored significantly below population norms on Wechsler indices of intelligence, perceptual reasoning, working memory, and processing speed. CONCLUSIONS CCHS may affect a broader range of cognitive abilities than previous research based on comparisons to population norms has indicated. Comparisons of CCHS children to their parents reveal deficits of vocabulary and abstract reasoning which have not been previously identified. A full understanding of the neurocognitive impact of CCHS requires comparisons between patients and other individuals such as friends, parents, or siblings who closely resemble them on disease-extrinsic characteristics.
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Affiliation(s)
- Frank A Zelko
- Department of Child and Adolescent Psychiatry, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois.,Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Tracey M Stewart
- Department of Pediatrics, Center for Autonomic Medicine in Pediatrics (CAMP), The Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
| | - Cindy D Brogadir
- Department of Pediatrics, Center for Autonomic Medicine in Pediatrics (CAMP), The Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
| | - Casey M Rand
- Department of Pediatrics, Center for Autonomic Medicine in Pediatrics (CAMP), The Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
| | - Debra E Weese-Mayer
- Northwestern University Feinberg School of Medicine, Chicago, Illinois.,Department of Pediatrics, Center for Autonomic Medicine in Pediatrics (CAMP), The Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
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22
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Patrone LGA, Biancardi V, Marques DA, Bícego KC, Gargaglioni LH. Brainstem catecholaminergic neurones and breathing control during postnatal development in male and female rats. J Physiol 2018; 596:3299-3325. [PMID: 29479699 DOI: 10.1113/jp275731] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 02/21/2018] [Indexed: 01/23/2023] Open
Abstract
KEY POINTS The brainstem catecholaminergic (CA) modulation on ventilation changes with development. We determined the role of the brainstem CA system in ventilatory control under normocapnic and hypercapnic conditions during different phases of development [postnatal day (P)7-8, P14-15 and P20-21] in male and female Wistar rats. Brainstem CA neurones produce a tonic inhibitory drive that affects breathing frequency in P7-8 rats and provide an inhibitory drive during hypercapnic conditions in both males and females at P7-8 and P14-15. In pre-pubertal rats, brainstem CA neurones become excitatory for the CO2 ventilatory response in males but remain inhibitory in females. Diseases such as sudden infant death syndrome, congenital central hypoventilation syndrome and Rett syndrome have been associated with abnormalities in the functioning of CA neurones; therefore, the results of the present study contribute to a better understanding of this system. ABSTRACT The respiratory network undergoes significant development during the postnatal phase, including the maturation of the catecholaminergic (CA) system. However, postnatal development of this network and its effect on the control of pulmonary ventilation ( V̇E ) is not fully understood. We investigated the involvement of brainstem CA neurones in respiratory control during postnatal development [postnatal day (P)7-8, P14-15 and P20-21], in male and female rats, through chemical injury with conjugated saporin anti-dopamine β-hydroxylase (DβH-SAP). Thus, DβH-SAP (420 ng μL-1 ), saporin (SAP) or phosphate buffered solution (PBS) was injected into the fourth ventricle of neonatal Wistar rats of both sexes. V̇E and oxygen consumption were recorded 1 week after the injections in unanaesthetized neonatal and juvenile rats during room air and hypercapnia. The resting ventilation was higher in both male and female P7-8 lesioned rats by 33%, with a decrease in respiratory variability being observed in males. The hypercapnic ventilatory response (HCVR) was altered in male and female lesioned rats at all postnatal ages. At P7-8, the HCVR for males and females was increased by 37% and 30%, respectively. For both sexes at P14-15 rats, the increase in V̇E during hypercapnia was 37% higher for lesioned rats. A sex-specific difference in HCRV was observed at P20-21, with lesioned males showing a 33% decrease, and lesioned females showing an increase of 33%. We conclude that brainstem CA neurones exert a tonic inhibitory effect on V̇E in the early postnatal days of the life of a rat, increase variability in P7-8 males and modulate HCRV during the postnatal phase.
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Affiliation(s)
- Luis Gustavo A Patrone
- Department of Animal Morphology and Physiology, Sao Paulo State University - UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Vivian Biancardi
- Department of Animal Morphology and Physiology, Sao Paulo State University - UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Danuzia A Marques
- Department of Animal Morphology and Physiology, Sao Paulo State University - UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Kênia C Bícego
- Department of Animal Morphology and Physiology, Sao Paulo State University - UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Luciane H Gargaglioni
- Department of Animal Morphology and Physiology, Sao Paulo State University - UNESP/FCAV at Jaboticabal, SP, Brazil
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23
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Congenital heart disease and aortic arch variants associated with mutation in PHOX2B. Genet Med 2018. [DOI: 10.1038/gim.2018.34] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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24
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Loiseau C, Cayetanot F, Joubert F, Perrin-Terrin AS, Cardot P, Fiamma MN, Frugiere A, Straus C, Bodineau L. Current Perspectives for the use of Gonane Progesteronergic Drugs in the Treatment of Central Hypoventilation Syndromes. Curr Neuropharmacol 2018; 16:1433-1454. [PMID: 28721821 PMCID: PMC6295933 DOI: 10.2174/1570159x15666170719104605] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/30/2017] [Accepted: 07/12/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Central alveolar hypoventilation syndromes (CHS) encompass neurorespiratory diseases resulting from congenital or acquired neurological disorders. Hypercapnia, acidosis, and hypoxemia resulting from CHS negatively affect physiological functions and can be lifethreatening. To date, the absence of pharmacological treatment implies that the patients must receive assisted ventilation throughout their lives. OBJECTIVE To highlight the relevance of determining conditions in which using gonane synthetic progestins could be of potential clinical interest for the treatment of CHS. METHODS The mechanisms by which gonanes modulate the respiratory drive were put into the context of those established for natural progesterone and other synthetic progestins. RESULTS The clinical benefits of synthetic progestins to treat respiratory diseases are mixed with either positive outcomes or no improvement. A benefit for CHS patients has only recently been proposed. We incidentally observed restoration of CO2 chemosensitivity, the functional deficit of this disease, in two adult CHS women by desogestrel, a gonane progestin, used for contraception. This effect was not observed by another group, studying a single patient. These contradictory findings are probably due to the complex nature of the action of desogestrel on breathing and led us to carry out mechanistic studies in rodents. Our results show that desogestrel influences the respiratory command by modulating the GABAA and NMDA signaling in the respiratory network, medullary serotoninergic systems, and supramedullary areas. CONCLUSION Gonanes show promise for improving ventilation of CHS patients, although the conditions of their use need to be better understood.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Laurence Bodineau
- Address correspondence to this author at the Sorbonne Universités, UPMC Univ. Paris 06, INSERM, UMR_S1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75013, Paris, France; Tel: 33 1 40 77 97 15; Fax: 33 1 40 77 97 89; E-mail:
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25
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Di Lascio S, Benfante R, Di Zanni E, Cardani S, Adamo A, Fornasari D, Ceccherini I, Bachetti T. Structural and functional differences in PHOX2B frameshift mutations underlie isolated or syndromic congenital central hypoventilation syndrome. Hum Mutat 2017; 39:219-236. [PMID: 29098737 PMCID: PMC5846889 DOI: 10.1002/humu.23365] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/24/2017] [Accepted: 10/29/2017] [Indexed: 12/13/2022]
Abstract
Heterozygous mutations in the PHOX2B gene are causative of congenital central hypoventilation syndrome (CCHS), a neurocristopathy characterized by defective autonomic control of breathing due to the impaired differentiation of neural crest cells. Among PHOX2B mutations, polyalanine (polyAla) expansions are almost exclusively associated with isolated CCHS, whereas frameshift variants, although less frequent, are often more severe than polyAla expansions and identified in syndromic CCHS. This article provides a complete review of all the frameshift mutations identified in cases of isolated and syndromic CCHS reported in the literature as well as those identified by us and not yet published. These were considered in terms of both their structure, whether the underlying indels induced frameshifts of either 1 or 2 steps ("frame 2" and "frame 3" mutations respectively), and clinical associations. Furthermore, we evaluated the structural and functional effects of one "frame 3" mutation identified in a patient with isolated CCHS, and one "frame 2" mutation identified in a patient with syndromic CCHS, also affected with Hirschsprung's disease and neuroblastoma. The data thus obtained confirm that the type of translational frame affects the severity of the transcriptional dysfunction and the predisposition to isolated or syndromic CCHS.
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Affiliation(s)
- Simona Di Lascio
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Roberta Benfante
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy.,CNR- Neuroscience Institute, Milan, Italy
| | | | - Silvia Cardani
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Annalisa Adamo
- UOC Genetica Medica, Istituto Giannina Gaslini, Genoa, Italy
| | - Diego Fornasari
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy.,CNR- Neuroscience Institute, Milan, Italy
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26
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Sun JJ, Huang TW, Neul JL, Ray RS. Embryonic hindbrain patterning genes delineate distinct cardio-respiratory and metabolic homeostatic populations in the adult. Sci Rep 2017; 7:9117. [PMID: 28831138 PMCID: PMC5567350 DOI: 10.1038/s41598-017-08810-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/10/2017] [Indexed: 12/21/2022] Open
Abstract
Previous studies based on mouse genetic mutations suggest that proper partitioning of the hindbrain into transient, genetically-defined segments called rhombomeres is required for normal respiratory development and function in neonates. Less clear is what role these genes and the neurons they define play in adult respiratory circuit organization. Several Cre drivers are used to access and study developmental rhombomeric domains (Eng1Cre, HoxA2-Cre, Egr2Cre, HoxB1Cre, and HoxA4-Cre) in the adult. However, these drivers show cumulative activity beyond the brainstem while being used in intersectional genetic experiments to map central respiratory circuitry. We crossed these drivers to conditional DREADD mouse lines to further characterize the functional contributions of Cre defined populations. In the adult, we show that acute DREADD inhibition of targeted populations results in a variety of not only respiratory phenotypes but also metabolic and temperature changes that likely play a significant role in the observed respiratory alterations. DREADD mediated excitation of targeted domains all resulted in death, with unique differences in the patterns of cardio-respiratory failure. These data add to a growing body of work aimed at understanding the role of early embryonic patterning genes in organizing adult respiratory homeostatic networks that may be perturbed in congenital pathophysiologies.
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Affiliation(s)
- Jenny J Sun
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
| | - Teng-Wei Huang
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas, USA
| | - Jeffrey L Neul
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA.,Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
| | - Russell S Ray
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA. .,Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA. .,Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA. .,Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, USA. .,McNair Medical Institute, TX-77030, Houston, USA.
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27
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Di Zanni E, Bianchi G, Ravazzolo R, Raffaghello L, Ceccherini I, Bachetti T. Targeting of PHOX2B expression allows the identification of drugs effective in counteracting neuroblastoma cell growth. Oncotarget 2017; 8:72133-72146. [PMID: 29069774 PMCID: PMC5641117 DOI: 10.18632/oncotarget.19922] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 07/18/2017] [Indexed: 11/25/2022] Open
Abstract
The pathogenic role of the PHOX2B gene in neuroblastoma is indicated by heterozygous mutations in neuroblastoma patients and by gene overexpression in both neuroblastoma cell lines and tumor samples. PHOX2B encodes a transcription factor which is crucial for the correct development and differentiation of sympathetic neurons. PHOX2B overexpression is considered a prognostic marker for neuroblastoma and it is also used by clinicians to monitor minimal residual disease. Furthermore, it has been observed that neuronal differentiation in neuroblastoma is dependent on down-regulation of PHOX2B expression, which confirms that PHOX2B expression may be considered a target in neuroblastoma. Here, PHOX2B promoter or 3′ untranslated region were used as molecular targets in an in vitro high-throughput approach that led to the identification of molecules able to decrease PHOX2B expression at transcriptional and likely even at post-transcriptional levels. Further functional investigations carried out on PHOX2B mRNA levels and biological consequences, such as neuroblastoma cell apoptosis and growth, showed that chloroquine and mycophenolate mofetil are most promising agents for neuroblastoma therapy based on down-regulation of PHOX2B expression. Finally, a strong correlation between the effect of drugs in terms of down-regulation of PHOX2B expression and of biological consequences in neuroblastoma cells confirms the role of PHOX2B as a potential molecular target in neuroblastoma.
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Affiliation(s)
- Eleonora Di Zanni
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Genova, Italy.,Present Address: Istituto di Biofisica, CNR, Genova, Italy
| | | | - Roberto Ravazzolo
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Genova, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health and CEBR, Università degli Studi di Genova, Genova, Italy
| | | | | | - Tiziana Bachetti
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Genova, Italy
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28
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Fu C, Xue J, Wang R, Chen J, Ma L, Liu Y, Wang X, Guo F, Zhang Y, Zhang X, Wang S. Chemosensitive Phox2b-expressing neurons are crucial for hypercapnic ventilatory response in the nucleus tractus solitarius. J Physiol 2017; 595:4973-4989. [PMID: 28488367 DOI: 10.1113/jp274437] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 05/04/2017] [Indexed: 02/03/2023] Open
Abstract
KEY POINTS Central hypercapnic hypoventilation is highly prevalent in children suffering from congenital central hypoventilation syndrome (CCHS). Mutations of the gene for paired-like homeobox 2b (Phox2b) are aetiologically associated with CCHS and Phox2b is present in central components of respiratory chemoreflex, such as the nucleus tractus solitarius (NTS). Injection of the neurotoxin substance P-saporin into NTS destroys Phox2b-expressing neurons. Impaired hypercapnic ventilatory response caused by this neurotoxin is attributable to a loss of CO2 -sensitive Phox2b-expressing NTS neurons. A subgroup of Phox2b-expressing neurons exhibits intrinsic chemosensitivity. A background K+ channel-like current is partially responsible for such chemosensitivity in Phox2b-expressing neurons. The present study helps us better understand the mechanism of respiratory deficits in CCHS and potentially locates a brainstem site for development of precise clinical intervention. ABSTRACT The nucleus tractus solitarius (NTS) neurons have been considered to function as central respiratory chemoreceptors. However, the common molecular marker defined for these neurons remains unknown. The present study investigated whether paired-like homeobox 2b (Phox2b)-expressing NTS neurons are recruited in hypercapnic ventilatory response (HCVR) and whether these neurons exhibit intrinsic chemosensitivity. HCVR was assessed using whole body plethysmography and neuronal chemosensitivity was examined by patch clamp recordings in brainstem slices or dissociated neurons from Phox2b-EGFP transgenic mice. Injection of the neurotoxin substance P-saporin (SSP-SAP) into NTS destroyed Phox2b-expressing neurons. Minute ventilation and tidal volume were both reduced by 13% during exposure to 8% CO2 in inspired air when ∼13% of the Phox2b-expressing neurons were eliminated. However, a loss of ∼18% of these neurons was associated with considerable decreases in minute ventilation by ≥18% and in tidal volume by≥22% when challenged by ≥4% CO2 . In both cases, breathing frequency was unaffected. Most CO2 -activated neurons were immunoreactive to Phox2b. In brainstem slices, ∼43% of Phox2b-expressing neurons from Phox2b-EGFP mice displayed a sustained or transient increase in firing rate during physiological acidification (pH 7.0 or 8% CO2 ). Such a response was also present in dissociated neurons in favour of an intrinsic property. In voltage clamp recordings, a background K+ channel-like current was found in a subgroup of Phox2b-expressing neurons. Thus, the respiratory deficits caused by injection of SSP-SAP into the NTS are attributable to proportional lesions of CO2 /H+ -sensitive Phox2b-expressing neurons.
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Affiliation(s)
- Congrui Fu
- Department of Physiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Jinyu Xue
- Department of Respiration, Hebei Chest Hospital, Shijiazhuang, Hebei, China
| | - Ri Wang
- Department of Physiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Jinting Chen
- Department of Physiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Lan Ma
- Department of Physiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yixian Liu
- Department of Physiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xuejiao Wang
- Department of Physiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Fang Guo
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yi Zhang
- Department of Physiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xiangjian Zhang
- Department of Neurology, Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China.,Hebei Key Laboratory of Vascular Homeostasis and Hebei Collaborative Innovation Center for Cardio-cerebrovascular Disease, Shijiazhuang, Hebei, China
| | - Sheng Wang
- Department of Physiology, Hebei Medical University, Shijiazhuang, Hebei, China.,Hebei Key Laboratory of Vascular Homeostasis and Hebei Collaborative Innovation Center for Cardio-cerebrovascular Disease, Shijiazhuang, Hebei, China
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29
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Congenital central hypoventilation syndrome: a bedside-to-bench success story for advancing early diagnosis and treatment and improved survival and quality of life. Pediatr Res 2017; 81:192-201. [PMID: 27673423 DOI: 10.1038/pr.2016.196] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 08/15/2016] [Indexed: 01/13/2023]
Abstract
The "bedside-to-bench" Congenital Central Hypoventilation Syndrome (CCHS) research journey has led to increased phenotypic-genotypic knowledge regarding autonomic nervous system (ANS) regulation, and improved clinical outcomes. CCHS is a neurocristopathy characterized by hypoventilation and ANS dysregulation. Initially described in 1970, timely diagnosis and treatment remained problematic until the first large cohort report (1992), delineating clinical presentation and treatment options. A central role of ANS dysregulation (2001) emerged, precipitating evaluation of genes critical to ANS development, and subsequent 2003 identification of Paired-Like Homeobox 2B (PHOX2B) as the disease-defining gene for CCHS. This breakthrough engendered clinical genetic testing, making diagnosis exact and early tracheostomy/artificial ventilation feasible. PHOX2B genotype-CCHS phenotype relationships were elucidated, informing early recognition and timely treatment for phenotypic manifestations including Hirschsprung disease, prolonged sinus pauses, and neural crest tumors. Simultaneously, cellular models of CCHS-causing PHOX2B mutations were developed to delineate molecular mechanisms. In addition to new insights regarding genetics and neurobiology of autonomic control overall, new knowledge gained has enabled physicians to anticipate and delineate the full clinical CCHS phenotype and initiate timely effective management. In summary, from an initial guarantee of early mortality or severe neurologic morbidity in survivors, CCHS children can now be diagnosed early and managed effectively, achieving dramatically improved quality of life as adults.
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30
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Moreira TS, Takakura AC, Czeisler C, Otero JJ. Respiratory and autonomic dysfunction in congenital central hypoventilation syndrome. J Neurophysiol 2016; 116:742-52. [PMID: 27226447 PMCID: PMC6208311 DOI: 10.1152/jn.00026.2016] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 05/25/2016] [Indexed: 12/22/2022] Open
Abstract
The developmental lineage of the PHOX2B-expressing neurons in the retrotrapezoid nucleus (RTN) has been extensively studied. These cells are thought to function as central respiratory chemoreceptors, i.e., the mechanism by which brain Pco2 regulates breathing. The molecular and cellular basis of central respiratory chemoreception is based on the detection of CO2 via intrinsic proton receptors (TASK-2, GPR4) as well as synaptic input from peripheral chemoreceptors and other brain regions. Murine models of congenital central hypoventilation syndrome designed with PHOX2B mutations have suggested RTN neuron agenesis. In this review, we examine, through human and experimental animal models, how a restricted number of neurons that express the transcription factor PHOX2B play a crucial role in the control of breathing and autonomic regulation.
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Affiliation(s)
- Thiago S Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil;
| | - Ana C Takakura
- Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil; and
| | - Catherine Czeisler
- The Ohio State University, College of Medicine, Department of Pathology, Division of Neuropathology, Columbus, Ohio
| | - Jose J Otero
- The Ohio State University, College of Medicine, Department of Pathology, Division of Neuropathology, Columbus, Ohio
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31
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Oliveira LM, Moreira TS, Kuo FS, Mulkey DK, Takakura AC. α1- and α2-adrenergic receptors in the retrotrapezoid nucleus differentially regulate breathing in anesthetized adult rats. J Neurophysiol 2016; 116:1036-48. [PMID: 27306670 DOI: 10.1152/jn.00023.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 06/09/2016] [Indexed: 02/07/2023] Open
Abstract
Norepinephrine (NE) is a potent modulator of breathing that can increase/decrease respiratory activity by α1-/α2-adrenergic receptor (AR) activation, respectively. The retrotrapezoid nucleus (RTN) is known to contribute to central chemoreception, inspiration, and active expiration. Here we investigate the sources of catecholaminergic inputs to the RTN and identify respiratory effects produced by activation of ARs in this region. By injecting the retrograde tracer Fluoro-Gold into the RTN, we identified back-labeled catecholaminergic neurons in the A7 region. In urethane-anesthetized, vagotomized, and artificially ventilated male Wistar rats unilateral injection of NE or moxonidine (α2-AR agonist) blunted diaphragm muscle activity (DiaEMG) frequency and amplitude, without changing abdominal muscle activity. Those inhibitory effects were reduced by preapplication of yohimbine (α2-AR antagonist) into the RTN. Conversely, unilateral RTN injection of phenylephrine (α1-AR agonist) increased DiaEMG amplitude and frequency and facilitated active expiration. This response was blocked by prior RTN injection of prazosin (α1-AR antagonist). Interestingly, RTN injection of propranolol (β-AR antagonist) had no effect on respiratory inhibition elicited by applications of NE into the RTN; however, the combined blockade of α2- and β-ARs (coapplication of propranolol and yohimbine) revealed an α1-AR-dependent excitatory response to NE that resulted in increase in DiaEMG frequency and facilitation of active expiration. However, blockade of α1-, α2-, or β-ARs in the RTN had minimal effect on baseline respiratory activity, on central or peripheral chemoreflexes. These results suggest that NE signaling can modulate RTN chemoreceptor function; however, endogenous NE signaling does not contribute to baseline breathing or the ventilatory response to central or peripheral chemoreceptor activity in urethane-anesthetized rats.
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Affiliation(s)
- Luiz M Oliveira
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Thiago S Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil; and
| | - Fu-Shan Kuo
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut
| | - Daniel K Mulkey
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut
| | - Ana C Takakura
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil;
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Sarnat HB, Flores-Sarnat L. Synaptogenesis and Myelination in the Nucleus/Tractus Solitarius: Potential Role in Apnea of Prematurity, Congenital Central Hypoventilation, and Sudden Infant Death Syndrome. J Child Neurol 2016; 31:722-32. [PMID: 26661483 DOI: 10.1177/0883073815615227] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 09/26/2015] [Indexed: 12/14/2022]
Abstract
Fetuses as early as 15 weeks' gestation exhibit rhythmical respiratory movements shown by real-time ultrasonography. The nucleus/tractus solitarius is the principal brainstem respiratory center; other medullary nuclei also participate. The purpose was to determine temporal maturation of synaptogenesis. Delayed synaptic maturation may explain neurogenic apnea or hypoventilation of prematurity and some cases of sudden infant death syndrome. Sections of medulla oblongata were studied from 30 human fetal and neonatal brains 9 to 41 weeks' gestation. Synaptophysin demonstrated the immunocytochemical sequence of synaptogenesis. Other neuronal markers and myelin stain also were applied. The nucleus/tractus solitarius was similarly studied in fetuses with chromosomopathies, metabolic encephalopathies, and brain malformations. Synapse formation in the nucleus solitarius begins at about 12 weeks' gestation and matures by 15 weeks; myelination initiated at 33 weeks. Synaptogenesis was delayed in 3 fetuses with different conditions, but was not specific for only nucleus solitarius. Delayed synaptogenesis or myelination in the nucleus solitarius may play a role in neonatal hypoventilation, especially in preterm infants and in some sudden infant death syndrome cases.
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Affiliation(s)
- Harvey B Sarnat
- Departments of Paediatrics, Pathology (Neuropathology) and Clinical Neurosciences, University of Calgary and Alberta Children's Hospital Research Institute, Calgary Alberta, Canada
| | - Laura Flores-Sarnat
- Departments of Paediatrics, Pathology (Neuropathology) and Clinical Neurosciences, University of Calgary and Alberta Children's Hospital Research Institute, Calgary Alberta, Canada
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Di Lascio S, Belperio D, Benfante R, Fornasari D. Alanine Expansions Associated with Congenital Central Hypoventilation Syndrome Impair PHOX2B Homeodomain-mediated Dimerization and Nuclear Import. J Biol Chem 2016; 291:13375-93. [PMID: 27129232 PMCID: PMC4933246 DOI: 10.1074/jbc.m115.679027] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Indexed: 11/30/2022] Open
Abstract
Heterozygous mutations of the human PHOX2B gene, a key regulator of autonomic nervous system development, lead to congenital central hypoventilation syndrome (CCHS), a neurodevelopmental disorder characterized by a failure in the autonomic control of breathing. Polyalanine expansions in the 20-residues region of the C terminus of PHOX2B are the major mutations responsible for CCHS. Elongation of the alanine stretch in PHOX2B leads to a protein with altered DNA binding, transcriptional activity, and nuclear localization and the possible formation of cytoplasmic aggregates; furthermore, the findings of various studies support the idea that CCHS is not due to a pure loss of function mechanism but also involves a dominant negative effect and/or toxic gain of function for PHOX2B mutations. Because PHOX2B forms homodimers and heterodimers with its paralogue PHOX2A in vitro, we tested the hypothesis that the dominant negative effects of the mutated proteins are due to non-functional interactions with the wild-type protein or PHOX2A using a co-immunoprecipitation assay and the mammalian two-hybrid system. Our findings show that PHOX2B forms homodimers and heterodimerizes weakly with mutated proteins, exclude the direct involvement of the polyalanine tract in dimer formation, and indicate that mutated proteins retain partial ability to form heterodimers with PHOX2A. Moreover, in this study, we investigated the effects of the longest polyalanine expansions on the homeodomain-mediated nuclear import, and our data clearly show that the expanded C terminus interferes with this process. These results provide novel insights into the effects of the alanine tract expansion on PHOX2B folding and activity.
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Affiliation(s)
- Simona Di Lascio
- From the Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, 20129 Milan, Italy and
| | - Debora Belperio
- From the Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, 20129 Milan, Italy and
| | - Roberta Benfante
- From the Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, 20129 Milan, Italy and the National Research Council (CNR) Neuroscience Institute, 20129 Milan, Italy
| | - Diego Fornasari
- From the Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, 20129 Milan, Italy and the National Research Council (CNR) Neuroscience Institute, 20129 Milan, Italy
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Gokozan HN, Baig F, Corcoran S, Catacutan FP, Gygli PE, Takakura AC, Moreira TS, Czeisler C, Otero JJ. Area postrema undergoes dynamic postnatal changes in mice and humans. J Comp Neurol 2015; 524:1259-69. [PMID: 26400711 DOI: 10.1002/cne.23903] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 09/15/2015] [Accepted: 09/15/2015] [Indexed: 12/29/2022]
Abstract
The postnatal period in mammals represents a developmental epoch of significant change in the autonomic nervous system (ANS). This study focuses on postnatal development of the area postrema, a crucial ANS structure that regulates temperature, breathing, and satiety, among other activities. We find that the human area postrema undergoes significant developmental changes during postnatal development. To characterize these changes further, we used transgenic mouse reagents to delineate neuronal circuitry. We discovered that, although a well-formed ANS scaffold exists early in embryonic development, the area postrema shows a delayed maturation. Specifically, postnatal days 0-7 in mice show no significant change in area postrema volume or synaptic input from PHOX2B-derived neurons. In contrast, postnatal days 7-20 show a significant increase in volume and synaptic input from PHOX2B-derived neurons. We conclude that key ANS structures show unexpected dynamic developmental changes during postnatal development. These data provide a basis for understanding ANS dysfunction and disease predisposition in premature and postnatal humans.
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Affiliation(s)
- Hamza Numan Gokozan
- The Ohio State University, College of Medicine, Department of Pathology, Division of Neuropathology, Columbus, Ohio, 43210
| | - Faisal Baig
- The Ohio State University, College of Medicine, Department of Pathology, Division of Neuropathology, Columbus, Ohio, 43210
| | - Sarah Corcoran
- The Ohio State University, College of Medicine, Department of Pathology, Division of Neuropathology, Columbus, Ohio, 43210
| | - Fay Patsy Catacutan
- The Ohio State University, College of Medicine, Department of Pathology, Division of Neuropathology, Columbus, Ohio, 43210
| | - Patrick Edwin Gygli
- The Ohio State University, College of Medicine, Department of Pathology, Division of Neuropathology, Columbus, Ohio, 43210
| | - Ana C Takakura
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, 05508-900, São Paulo, Brazil
| | - Thiago S Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, 05508-900, São Paulo, Brazil
| | - Catherine Czeisler
- The Ohio State University, College of Medicine, Department of Pathology, Division of Neuropathology, Columbus, Ohio, 43210
| | - José J Otero
- The Ohio State University, College of Medicine, Department of Pathology, Division of Neuropathology, Columbus, Ohio, 43210
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