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Martínez-Heredia L, Muñoz-Torres M, Sanabria-de la Torre R, Jiménez-Ortas Á, Andújar-Vera F, González-Cejudo T, Contreras-Bolívar V, González-Salvatierra S, Gómez-Vida JM, García-Fontana C, García-Fontana B. Systemic effects of hypophosphatasia characterization of two novel variants in the ALPL gene. Front Endocrinol (Lausanne) 2024; 14:1320516. [PMID: 38234425 PMCID: PMC10792043 DOI: 10.3389/fendo.2023.1320516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 12/04/2023] [Indexed: 01/19/2024] Open
Abstract
Introduction Hypophosphatasia (HPP) is an inborn metabolic error caused by mutations in the ALPL gene encoding tissue non-specific alkaline phosphatase (TNSALP) and leading to decreased alkaline phosphatase (ALP) activity. Although the main characteristic of this disease is bone involvement, it presents a great genetic and clinical variability, which makes it a systemic disease. Methods Patients were recruited based on biochemical assessments. Diagnosis was made by measuring serum ALP and pyridoxal 5-phosphate levels and finally by Sanger sequencing of the ALPL gene from peripheral blood mononuclear cells. Characterization of the new variants was performed by transfection of the variants into HEK293T cells, where ALP activity and cellular localization were measured by flow cytometry. The dominant negative effect was analyzed by co-transfection of each variant with the wild-type gene, measuring ALP activity and analyzing cellular localization by flow cytometry. Results Two previously undescribed variants were found in the ALPL gene: leucine 6 to serine missense mutation (c.17T>C, L6S) affecting the signal peptide and threonine 167 deletion (c.498_500delCAC, T167del) affecting the vicinity of the active site. These mutations lead mainly to non-pathognomonic symptoms of HPP. Structural prediction and modeling tools indicated the affected residues as critical residues with important roles in protein structure and function. In vitro results demonstrated low TNSALP activity and a dominant negative effect in both mutations. The results of the characterization of these variants suggest that the pleiotropic role of TNSALP could be involved in the systemic effects observed in these patients highlighting digestive and autoimmune disorders associated with TNSALP dysfunction. Conclusions The two new mutations have been classified as pathogenic. At the clinical level, this study suggests that both mutations not only lead to pathognomonic symptoms of the disease, but may also play a role at the systemic level.
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Affiliation(s)
| | - Manuel Muñoz-Torres
- Instituto de Investigación Biosanitaria de Granada, Granada, Spain
- Endocrinology and Nutrition Unit, University Hospital Clínico San Cecilio, Granada, Spain
- Department of Medicine, University of Granada, Granada, Spain
- Biomedical Research Network in Fragility and Healthy Aging (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Raquel Sanabria-de la Torre
- Instituto de Investigación Biosanitaria de Granada, Granada, Spain
- Department of Biochemistry, Molecular Biology III and Immunology, University of Granada, Granada, Spain
| | - Ángela Jiménez-Ortas
- Instituto de Investigación Biosanitaria de Granada, Granada, Spain
- Department of Biochemistry and Molecular Biology II, University of Granada, Granada, Spain
| | - Francisco Andújar-Vera
- Department of Computer Science and Artificial Intelligence, University of Granada, Granada, Spain
- Andalusian Research Institute in Data Science and Computational Intelligence (DaSCI Institute), Granada, Spain
- Bioinformatic Service, Instituto de Investigación Biosanitaria de Granada, Granada, Spain
| | - Trinidad González-Cejudo
- Instituto de Investigación Biosanitaria de Granada, Granada, Spain
- Clinical Analysis Unit, University Hospital Clínico San Cecilio, Granada, Spain
| | | | - Sheila González-Salvatierra
- Instituto de Investigación Biosanitaria de Granada, Granada, Spain
- Endocrinology and Nutrition Unit, University Hospital Clínico San Cecilio, Granada, Spain
- Department of Medicine, University of Granada, Granada, Spain
| | | | - Cristina García-Fontana
- Instituto de Investigación Biosanitaria de Granada, Granada, Spain
- Endocrinology and Nutrition Unit, University Hospital Clínico San Cecilio, Granada, Spain
- Biomedical Research Network in Fragility and Healthy Aging (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Beatriz García-Fontana
- Instituto de Investigación Biosanitaria de Granada, Granada, Spain
- Endocrinology and Nutrition Unit, University Hospital Clínico San Cecilio, Granada, Spain
- Biomedical Research Network in Fragility and Healthy Aging (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
- Department of Cell Biology, University of Granada, Granada, Spain
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Zhan F, Tian W, Cao Y, Wu J, Ni R, Liu T, Yuan Y, Luan X, Cao L. Episodic Neurological Dysfunction in X-Linked Charcot-Marie-Tooth Disease: Expansion of the Phenotypic and Genetic Spectrum. J Clin Neurol 2024; 20:59-66. [PMID: 38179633 PMCID: PMC10782082 DOI: 10.3988/jcn.2023.0104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/10/2023] [Accepted: 05/30/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND AND PURPOSE X-linked Charcot-Marie-Tooth disease type 1 (CMTX1) is characterized by peripheral neuropathy with or without episodic neurological dysfunction. We performed clinical, neuropathological, and genetic investigations of a series of patients with mutations of the gap-junction beta-1 gene (GJB1) to extend the phenotypic and genetic description of CMTX1. METHODS Detailed clinical evaluations, sural nerve biopsy, and genetic analysis were applied to patients with CMTX1. RESULTS We collected 27 patients with CMTX1 with GJB1 mutations from 14 unrelated families. The age at onset (AAO) was 20.9±12.2 years (mean±standard deviation; range, 2-45 years). Walking difficulties, weakness in the legs, and pes cavus were common initial symptoms. Compared with female patients, males tended to have a younger AAO (males vs. females=15.4±9.6 vs. 32.0±8.8 years, p=0.002), a longer disease course (16.8±16.1 vs. 5.5±3.8 years, p=0.034), and more-severe electrophysiological results. Besides peripheral neuropathy, six of the patients had special episodic central nervous system (CNS) evidence from symptoms, signs, and/or reversible white-matter lesions. Neuropathology revealed the loss of large myelinated fibers, increased number of regenerated axon clusters with abnormally thin myelin sheaths, and excessively folded myelin. Genetic analysis identified 14 GJB1 variants, 6 of which were novel. CONCLUSIONS These findings expand the phenotypic and genetic spectrum of CMTX1. Although CMTX1 was found to have high phenotypic and CNS involvement variabilities, detailed neurological examinations and nerve conduction studies will provide critical clues for accurate diagnoses. Further exploration of the underlying mechanisms of connexin 32 involvement in neuropathy or CNS dysfunction is warranted to develop promising therapies.
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Affiliation(s)
- Feixia Zhan
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wotu Tian
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuwen Cao
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jingying Wu
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ruilong Ni
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- School of Medicine, Anhui University of Science and Technology, Huainan, China
| | - Taotao Liu
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- School of Medicine, Anhui University of Science and Technology, Huainan, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Xinghua Luan
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Li Cao
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- School of Medicine, Anhui University of Science and Technology, Huainan, China.
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Yao S, Mo X, Luo C, Qu C. MYRF-related mild encephalopathy with reversible myelin vacuolization: a case report and literature review. Front Genet 2023; 14:1284060. [PMID: 38155716 PMCID: PMC10753760 DOI: 10.3389/fgene.2023.1284060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 11/13/2023] [Indexed: 12/30/2023] Open
Abstract
Background: MYRF-related mild encephalopathy with reversible myelin vacuolization (MMERV) is an inherited neurological disorder characterized by dysfunction in the central nervous system and widespread reversible leukoencephalopathy. This paper presents a confirmed case of familial MMERV and summarizes pertinent features to offer guidance for future diagnosis and treatment of MMERV. Case Introduction: We have diagnosed a case of MMERV based on a history of seizures during early childhood and recurrent speech fluency issues in adulthood, reversible abnormal intensities in bilateral white matter in the centrum semiovale and corpus callosum, and the identification of myelin regulatory factor (MYRF) heterozygous variants. Conclusion: MYRF-related mild encephalopathy with reversible myelin vacuolization is a rare autosomal dominant genetic disease, with early clinical manifestations often being seizures. The definitive diagnosis of MMERV can be confirmed through genetic analysis. Minimizing infections can help reduce disease recurrence. However, future research should explore the impact of MYRF heterozygous variants in the wider MMERV population.
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Affiliation(s)
- Shumei Yao
- Department of Neurology, Shandong Provincial Hospital, Shandong University, Jinan, China
| | - Xiufeng Mo
- Department of Neurology, Jinan Shizhong District People’s Hospital, Jinan, China
| | - Changjiang Luo
- Department of Neurology, Jinan Shizhong District People’s Hospital, Jinan, China
| | - Chuanqiang Qu
- Department of Neurology, Shandong Provincial Hospital, Shandong University, Jinan, China
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
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Record CJ, Skorupinska M, Laura M, Rossor AM, Pareyson D, Pisciotta C, Feely SME, Lloyd TE, Horvath R, Sadjadi R, Herrmann DN, Li J, Walk D, Yum SW, Lewis RA, Day J, Burns J, Finkel RS, Saporta MA, Ramchandren S, Weiss MD, Acsadi G, Fridman V, Muntoni F, Poh R, Polke JM, Zuchner S, Shy ME, Scherer SS, Reilly MM. Genetic analysis and natural history of Charcot-Marie-Tooth disease CMTX1 due to GJB1 variants. Brain 2023; 146:4336-4349. [PMID: 37284795 PMCID: PMC10545504 DOI: 10.1093/brain/awad187] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/05/2023] [Accepted: 05/20/2023] [Indexed: 06/08/2023] Open
Abstract
Charcot-Marie-Tooth disease (CMT) due to GJB1 variants (CMTX1) is the second most common form of CMT. It is an X-linked disorder characterized by progressive sensory and motor neuropathy with males affected more severely than females. Many reported GJB1 variants remain classified as variants of uncertain significance (VUS). In this large, international, multicentre study we prospectively collected demographic, clinical and genetic data on patients with CMT associated with GJB1 variants. Pathogenicity for each variant was defined using adapted American College of Medical Genetics criteria. Baseline and longitudinal analyses were conducted to study genotype-phenotype correlations, to calculate longitudinal change using the CMT Examination Score (CMTES), to compare males versus females, and pathogenic/likely pathogenic (P/LP) variants versus VUS. We present 387 patients from 295 families harbouring 154 variants in GJB1. Of these, 319 patients (82.4%) were deemed to have P/LP variants, 65 had VUS (16.8%) and three benign variants (0.8%; excluded from analysis); an increased proportion of patients with P/LP variants compared with using ClinVar's classification (74.6%). Male patients (166/319, 52.0%, P/LP only) were more severely affected at baseline. Baseline measures in patients with P/LP variants and VUS showed no significant differences, and regression analysis suggested the disease groups were near identical at baseline. Genotype-phenotype analysis suggested c.-17G>A produces the most severe phenotype of the five most common variants, and missense variants in the intracellular domain are less severe than other domains. Progression of disease was seen with increasing CMTES over time up to 8 years follow-up. Standard response mean (SRM), a measure of outcome responsiveness, peaked at 3 years with moderate responsiveness [change in CMTES (ΔCMTES) = 1.3 ± 2.6, P = 0.00016, SRM = 0.50]. Males and females progressed similarly up to 8 years, but baseline regression analysis suggested that over a longer period, females progress more slowly. Progression was most pronounced for mild phenotypes (CMTES = 0-7; 3-year ΔCMTES = 2.3 ± 2.5, P = 0.001, SRM = 0.90). Enhanced variant interpretation has yielded an increased proportion of GJB1 variants classified as P/LP and will aid future variant interpretation in this gene. Baseline and longitudinal analysis of this large cohort of CMTX1 patients describes the natural history of the disease including the rate of progression; CMTES showed moderate responsiveness for the whole group at 3 years and higher responsiveness for the mild group at 3, 4 and 5 years. These results have implications for patient selection for upcoming clinical trials.
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Affiliation(s)
- Christopher J Record
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Mariola Skorupinska
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Matilde Laura
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Alexander M Rossor
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Davide Pareyson
- Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Chiara Pisciotta
- Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Shawna M E Feely
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Thomas E Lloyd
- Departments of Neurology and Neuroscience, John Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, UK
| | - Reza Sadjadi
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - David N Herrmann
- Department of Neurology, University of Rochester, Rochester, NY 14618, USA
| | - Jun Li
- Department of Neurology, Houston Methodist Hospital, Houston, TX 77030, USA
| | - David Walk
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sabrina W Yum
- Department of Neurology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Richard A Lewis
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - John Day
- Department of Neurology, Stanford University, Stanford, CA 94304, USA
| | - Joshua Burns
- University of Sydney School of Health Sciences, Faculty of Medicine and Health; Paediatric Gait Analysis Service of New South Wales, Sydney Children’s Hospitals Network, Sydney, 2145Australia
| | - Richard S Finkel
- Department of Neurology, Nemours Children’s Hospital, Orlando, FL 32827, USA
| | - Mario A Saporta
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Sindhu Ramchandren
- Department of Neurology, Wayne State University, Detroit, MI 48201, USA
- The Janssen Pharmaceutical Companies of Johnson & Johnson, Titusville, NJ 08560, USA
| | - Michael D Weiss
- Department of Neurology, University of Washington, Seattle, WA, 98195USA
| | - Gyula Acsadi
- Connecticut Children’s Medical Center, Hartford, CT 06106, USA
| | - Vera Fridman
- Department of Neurology, University of Colorado Denver School of Medicine, Aurora, CO 80045, USA
| | - Francesco Muntoni
- The Dubowitz Neuromuscular Centre, NIHR Great Ormond Street Hospital Biomedical Research Centre, Great Ormond Street Institute of Child Health University College London, and Great Ormond Street Hospital Trust, London, WC1N 1EH, UK
| | - Roy Poh
- Neurogenetics Laboratory, National Hospital for Neurology and Neurosurgery, London, WC1N 3BG, UK
| | - James M Polke
- Neurogenetics Laboratory, National Hospital for Neurology and Neurosurgery, London, WC1N 3BG, UK
| | - Stephan Zuchner
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Michael E Shy
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Steven S Scherer
- Department of Neurology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mary M Reilly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
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Dale N, Butler J, Dospinescu VM, Nijjar S. Channel-mediated ATP release in the nervous system. Neuropharmacology 2023; 227:109435. [PMID: 36690324 DOI: 10.1016/j.neuropharm.2023.109435] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/10/2023] [Accepted: 01/19/2023] [Indexed: 01/21/2023]
Abstract
ATP is well established as a transmitter and modulator in the peripheral and central nervous system. While conventional exocytotic release of ATP at synapses occurs, this transmitter is unusual in also being released into the extracellular space via large-pored plasma membrane channels. This review considers the channels that are known to be permeable to ATP and some of the functions of channel-mediated ATP release. While the possibility of ATP release via channels mediating volume transmission has been known for some time, localised ATP release via channels at specialised synapses made by taste cells to the afferent nerve has recently been documented in taste buds. This raises the prospect that "channel synapses" may occur in other contexts. However, volume transmission and channel synapses are not necessarily mutually exclusive. We suggest that certain glial cells in the brain stem and hypothalamus, which possess long processes and are known to release ATP, may be candidates for both modes of ATP release -channel-mediated volume transmission in the region of their somata and more localised transmission possibly via either conventional or channel synapses from their processes at distal targets. Finally, we consider the different characteristics of vesicular and channel synapses and suggest that channel synapses may be advantageous in requiring less energy than their conventional vesicular counterparts. This article is part of the Special Issue on "Purinergic Signaling: 50 years".
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Affiliation(s)
- Nicholas Dale
- School of Life Sciences, University of Warwick, Coventry, CV4, AL, UK.
| | - Jack Butler
- School of Life Sciences, University of Warwick, Coventry, CV4, AL, UK
| | | | - Sarbjit Nijjar
- School of Life Sciences, University of Warwick, Coventry, CV4, AL, UK
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Karakaya T, Turkyilmaz A, Sager G, Inan R, Yarali O, Cebi AH, Akin Y. Molecular characterization of Turkish patients with demyelinating Charcot-Marie-Tooth disease. Neurogenetics 2022; 23:213-221. [DOI: 10.1007/s10048-022-00693-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 05/04/2022] [Indexed: 10/18/2022]
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Yalcouyé A, Diallo SH, Cissé L, Karembé M, Diallo S, Coulibaly T, Diarra S, Coulibaly D, Keita M, Guinto CO, Fischbeck KH, Wonkam A, Landouré G. GJB1 variants in Charcot-Marie-Tooth disease X-linked type 1 in Mali. J Peripher Nerv Syst 2022; 27:113-119. [PMID: 35383424 PMCID: PMC11000073 DOI: 10.1111/jns.12486] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 02/22/2022] [Accepted: 02/25/2022] [Indexed: 11/30/2022]
Abstract
X-linked Charcot-Marie-Tooth type 1 (CMTX1) disease is one of the most common subtypes of inherited neuropathies and is caused by mutations in the GJB1 gene. To date, more than 400 mutations have been reported in GJB1 worldwide but none in sub-Saharan Africa (SSA). We aimed to clinically characterize patients with CMTX1 and identify the genetic defects. All patients were examined thoroughly, and Nerve Conduction Studies (NCS) were done. EEG and pure tone audiometry (PTA) were also done in select individuals having additional symptoms. DNA was extracted for CMT gene panel testing (50 genes + mtDNA and PMP22 duplication), and putative variants were screened in available relatives. The predominant starting symptom was tingling, and the chief complaint was gait difficulty. Neurological examination found a distal muscle weakness and atrophy, and sensory loss, skeletal deformities, decreased or absent reflexes and steppage gait. The inheritance pattern was consistent with dominant X-linked. NCS showed no response in most of the tested nerves in lower limbs, and normal or reduced amplitudes in upper limbs. A severe sensorineural hearing impairment and a focal epileptic seizure were observed in one patient each. A high intra and inter-familial clinical variability was observed. Genetic testing found three pathogenic missense variants in GJB1, one in each of the families (Val91Met, Arg15Trp, and Phe235Cys). This is the first report of genetically confirmed cases of CMTX1 in SSA, and confirms its clinical and genetic heterogeneity.
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Affiliation(s)
- Abdoulaye Yalcouyé
- Division of Human Genetics, Department of Pathology, University of Cape Town, Cape Town, South Africa
- Faculté de Médecine et d’Odontostomatologie, USTTB, Bamako, Mali
| | - Seybou H. Diallo
- Faculté de Médecine et d’Odontostomatologie, USTTB, Bamako, Mali
- Service de Neurologie, Centre Hospitalier Universitaire Gabriel Touré, Bamako, Mali
| | - Lassana Cissé
- Service de Neurologie, Centre Hospitalier Universitaire du Point “G”, Bamako, Mali
| | - Mamadou Karembé
- Service de Neurologie, Centre Hospitalier Universitaire du Point “G”, Bamako, Mali
| | - Salimata Diallo
- Service de Neurologie, Centre Hospitalier Universitaire Gabriel Touré, Bamako, Mali
| | - Thomas Coulibaly
- Faculté de Médecine et d’Odontostomatologie, USTTB, Bamako, Mali
- Service de Neurologie, Centre Hospitalier Universitaire du Point “G”, Bamako, Mali
| | - Salimata Diarra
- Faculté de Médecine et d’Odontostomatologie, USTTB, Bamako, Mali
- Neurogenetics Branch, National Institutes of Neurological Disorders and Stroke, Bethesda, Maryland, USA
| | - Dramane Coulibaly
- Service de Médecine, Centre Hospitalier Universitaire Mère-Enfant le “Luxembourg”, Bamako, Mali
| | - Mohamed Keita
- Faculté de Médecine et d’Odontostomatologie, USTTB, Bamako, Mali
- Service d’ORL, Centre Hospitalier Universitaire Gabriel Touré, Bamako, Mali
| | - Cheick O. Guinto
- Faculté de Médecine et d’Odontostomatologie, USTTB, Bamako, Mali
- Service de Neurologie, Centre Hospitalier Universitaire du Point “G”, Bamako, Mali
| | - Kenneth H. Fischbeck
- Neurogenetics Branch, National Institutes of Neurological Disorders and Stroke, Bethesda, Maryland, USA
| | - Ambroise Wonkam
- Division of Human Genetics, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Guida Landouré
- Faculté de Médecine et d’Odontostomatologie, USTTB, Bamako, Mali
- Service de Neurologie, Centre Hospitalier Universitaire du Point “G”, Bamako, Mali
- Neurogenetics Branch, National Institutes of Neurological Disorders and Stroke, Bethesda, Maryland, USA
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Rawat A, Morrison BM. Metabolic Transporters in the Peripheral Nerve-What, Where, and Why? Neurotherapeutics 2021; 18:2185-2199. [PMID: 34773210 PMCID: PMC8804006 DOI: 10.1007/s13311-021-01150-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2021] [Indexed: 12/18/2022] Open
Abstract
Cellular metabolism is critical not only for cell survival, but also for cell fate, function, and intercellular communication. There are several different metabolic transporters expressed in the peripheral nervous system, and they each play important roles in maintaining cellular energy. The major source of energy in the peripheral nervous system is glucose, and glucose transporters 1 and 3 are expressed and allow blood glucose to be imported and utilized by peripheral nerves. There is also increasing evidence that other sources of energy, particularly monocarboxylates such as lactate that are transported primarily by monocarboxylate transporters 1 and 2 in peripheral nerves, can be efficiently utilized by peripheral nerves. Finally, emerging evidence supports an important role for connexins and possibly pannexins in the supply and regulation of metabolic energy. In this review, we will first define these critical metabolic transporter subtypes and then examine their localization in the peripheral nervous system. We will subsequently discuss the evidence, which comes both from experiments in animal models and observations from human diseases, supporting critical roles played by these metabolic transporters in the peripheral nervous system. Despite progress made in understanding the function of these transporters, many questions and some discrepancies remain, and these will also be addressed throughout this review. Peripheral nerve metabolism is fundamentally important and renewed interest in these pathways should help to answer many of these questions and potentially provide new treatments for neurologic diseases that are partly, or completely, caused by disruption of metabolism.
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Affiliation(s)
- Atul Rawat
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Brett M Morrison
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Jiang H, Guo C, Xie J, Pan J, Huang Y, Li M, Guo Y. Case report: exome sequencing achieved a definite diagnosis in a Chinese family with muscle atrophy. BMC Neurol 2021; 21:96. [PMID: 33653295 PMCID: PMC7923504 DOI: 10.1186/s12883-021-02093-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 02/04/2021] [Indexed: 11/25/2022] Open
Abstract
Background Due to large genetic and phenotypic heterogeneity, the conventional workup for Charcot-Marie-Tooth (CMT) diagnosis is often underpowered, leading to diagnostic delay or even lack of diagnosis. In the present study, we explored how bioinformatics analysis on whole-exome sequencing (WES) data can be used to diagnose patients with CMT disease efficiently. Case presentation The proband is a 29-year-old female presented with a severe amyotrophy and distal skeletal deformity that plagued her family for over 20 years since she was 5-year-old. No other aberrant symptoms were detected in her speaking, hearing, vision, and intelligence. Similar symptoms manifested in her younger brother, while her parents and her older brother showed normal. To uncover the genetic causes of this disease, we performed exome sequencing for the proband and her parents. Subsequent bioinformatics analysis on the KGGSeq platform and further Sanger sequencing identified a novel homozygous GDAP1 nonsense mutation (c.218C > G, p.Ser73*) that responsible for the family. This genetic finding then led to a quick diagnosis of CMT type 4A (CMT4A), confirmed by nerve conduction velocity and electromyography examination of the patients. Conclusions The patients with severe muscle atrophy and distal skeletal deformity were caused by a novel homozygous nonsense mutation in GDAP1 (c.218C > G, p.Ser73*), and were diagnosed as CMT4A finally. This study expanded the mutation spectrum of CMT disease and demonstrated how affordable WES could be effectively employed for the clinical diagnosis of unexplained phenotypes. Supplementary Information The online version contains supplementary material available at 10.1186/s12883-021-02093-z.
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Affiliation(s)
- Hui Jiang
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Diseases Control (SYSU), Sun Yat-sen University, Guangzhou, 510080, China.,Center for Precision Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Chunmiao Guo
- Department of Neurology, The Second Affiliated Hospital, Fujian University of Medical Science, Quanzhou, 362000, China
| | - Jie Xie
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Diseases Control (SYSU), Sun Yat-sen University, Guangzhou, 510080, China.,Center for Precision Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Jingxin Pan
- Department of Hematology, The Second Affiliated Hospital, Fujian University of Medical Science, Quanzhou, 362000, China
| | - Ying Huang
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Diseases Control (SYSU), Sun Yat-sen University, Guangzhou, 510080, China.,Center for Precision Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Miaoxin Li
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China. .,Key Laboratory of Tropical Diseases Control (SYSU), Sun Yat-sen University, Guangzhou, 510080, China. .,Center for Precision Medicine, Sun Yat-sen University, Guangzhou, 510080, China. .,The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, 519000, Guangdong, China. .,State Key Laboratory for Cognitive and Brain Sciences, The University of Hong Kong, Hong Kong SAR, China.
| | - Yibin Guo
- Key Laboratory of Tropical Diseases Control (SYSU), Sun Yat-sen University, Guangzhou, 510080, China. .,Center for Precision Medicine, Sun Yat-sen University, Guangzhou, 510080, China. .,School of Medicine, Sun Yat-sen University, Shenzhen, 518107, Guangdong, China.
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10
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Moss KR, Bopp TS, Johnson AE, Höke A. New evidence for secondary axonal degeneration in demyelinating neuropathies. Neurosci Lett 2021; 744:135595. [PMID: 33359733 PMCID: PMC7852893 DOI: 10.1016/j.neulet.2020.135595] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 10/31/2020] [Accepted: 12/19/2020] [Indexed: 12/28/2022]
Abstract
Development of peripheral nervous system (PNS) myelin involves a coordinated series of events between growing axons and the Schwann cell (SC) progenitors that will eventually ensheath them. Myelin sheaths have evolved out of necessity to maintain rapid impulse propagation while accounting for body space constraints. However, myelinating SCs perform additional critical functions that are required to preserve axonal integrity including mitigating energy consumption by establishing the nodal architecture, regulating axon caliber by organizing axonal cytoskeleton networks, providing trophic and potentially metabolic support, possibly supplying genetic translation materials and protecting axons from toxic insults. The intermediate steps between the loss of these functions and the initiation of axon degeneration are unknown but the importance of these processes provides insightful clues. Prevalent demyelinating diseases of the PNS include the inherited neuropathies Charcot-Marie-Tooth Disease, Type 1 (CMT1) and Hereditary Neuropathy with Liability to Pressure Palsies (HNPP) and the inflammatory diseases Acute Inflammatory Demyelinating Polyneuropathy (AIDP) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). Secondary axon degeneration is a common feature of demyelinating neuropathies and this process is often correlated with clinical deficits and long-lasting disability in patients. There is abundant electrophysiological and histological evidence for secondary axon degeneration in patients and rodent models of PNS demyelinating diseases. Fully understanding the involvement of secondary axon degeneration in these diseases is essential for expanding our knowledge of disease pathogenesis and prognosis, which will be essential for developing novel therapeutic strategies.
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Affiliation(s)
- Kathryn R Moss
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Taylor S Bopp
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Anna E Johnson
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Ahmet Höke
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States.
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11
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Michaelidou K, Tsiverdis I, Erimaki S, Papadimitriou D, Amoiridis G, Papadimitriou A, Mitsias P, Zaganas I. Whole exome sequencing establishes diagnosis of Charcot-Marie-Tooth 4J, 1C, and X1 subtypes. Mol Genet Genomic Med 2020; 8:e1141. [PMID: 32022442 PMCID: PMC7196464 DOI: 10.1002/mgg3.1141] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 01/01/2020] [Accepted: 01/03/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Charcot-Marie-Tooth (CMT) hereditary polyneuropathies pose a diagnostic challenge. Our aim here is to describe CMT patients diagnosed by whole exome sequencing (WES) following years of fruitless testing. METHODS/RESULTS Three patients with polyneuropathy suspected to be genetic in origin, but not harboring PMP22 gene deletion/duplication, were offered WES. The first patient, a 66-year-old man, had been suffering from progressive weakness and atrophies in the lower and upper extremities for 20 years. Due to ambiguous electrophysiological findings, immune therapies were administered to no avail. Twelve years after PMP22 deletion/duplication testing, WES revealed two pathogenic variants in the FIG4 gene (p.Ile41Thr and p.Phe598fs, respectively), as a cause of CMT 4J. The second patient, a 19-year-old man, had been suffering from hearing and gait impairment since at least his infancy, and recently presented with weakness and dystonia of the lower extremities. In this patient, WES identified the p.Leu122Val LITAF gene variant in heterozygous state, suggesting the diagnosis of CMT 1C, several years after initial genetic analyses. The third patient, a 44-year-old man, presented with progressive weakness and atrophies of the lower and upper extremities since the age of 17 years old. In this patient, WES identified the hemizygous p.Arg164Gln pathogenic variant in the GJB1 gene, establishing the diagnosis of CMT X1, 8 years after testing for PMP22 deletion/duplication. CONCLUSION Novel diagnostic techniques, such as WES, offer the possibility to decipher the cause of CMT subtypes, ending the diagnostic Odyssey of the patients and sparing them from unnecessary and potentially harmful treatments.
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Affiliation(s)
- Kleita Michaelidou
- Neurogenetics LaboratoryMedical SchoolUniversity of CreteHeraklion, CreteGreece
| | - Ioannis Tsiverdis
- Neurology DepartmentUniversity Hospital of CreteHeraklion, CreteGreece
| | - Sophia Erimaki
- Neurophysiology UnitUniversity Hospital of CreteHeraklion, CreteGreece
| | | | | | | | - Panayiotis Mitsias
- Neurogenetics LaboratoryMedical SchoolUniversity of CreteHeraklion, CreteGreece
- Neurology DepartmentUniversity Hospital of CreteHeraklion, CreteGreece
- Neurophysiology UnitUniversity Hospital of CreteHeraklion, CreteGreece
- Department of NeurologyHenry Ford Hospital/Wayne State UniversityDetroitMIUSA
| | - Ioannis Zaganas
- Neurogenetics LaboratoryMedical SchoolUniversity of CreteHeraklion, CreteGreece
- Neurology DepartmentUniversity Hospital of CreteHeraklion, CreteGreece
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12
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Liu Y, Xue J, Li Z, Linpeng S, Tan H, Teng Y, Liang D, Wu L. A novel GJB1 mutation associated with X-linked Charcot-Marie-Tooth disease in a large Chinese family pedigree. Mol Genet Genomic Med 2020; 8:e1127. [PMID: 31943912 PMCID: PMC7057093 DOI: 10.1002/mgg3.1127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 12/19/2019] [Accepted: 01/02/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Charcot-Marie-Tooth (CMT) disease is a group of hereditary neuropathies with high phenotypic and genetic heterogeneity. In this study, we report a large family with X-linked CMT (CMTX) caused by a novel GJB1 mutation. METHODS A family with the clinical diagnosis of CMTX was investigated. For mutation analysis, the coding region of GJB1 was sequenced using DNA from 15 family members. The identified GJB1 mutation was investigated by DHPLC in 120 normal controls. Mutation reanalysis was performed based on whole-exome sequencing (WES). Cell transfection studies were performed to characterize the function of the novel mutation. RESULTS A missense mutation (c.605T>A) in GJB1 was detected in five patients and eight female carriers but not in two unaffected members of the family. The mutation was not found in 120 healthy controls and has not been previously reported. WES excluded other pathogenic mutations in the family. The pathogenicity of the mutation was confirmed by disrupting the membrane localization of the encoded proteins. CONCLUSION Our findings demonstrate that a novel mutation (c.605T>A) in GJB1 is associated with CMTX and adds to the repertoire of GJB1 mutations related to CMTX.
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Affiliation(s)
- Yingdi Liu
- Center for Medical Genetics & Hunan Key Laboratory of Medical GeneticsSchool of Life SciencesCentral South UniversityChangshaChina
| | - Jinjie Xue
- Center for Medical Genetics & Hunan Key Laboratory of Medical GeneticsSchool of Life SciencesCentral South UniversityChangshaChina
- Children's Hospital of ShanxiWomen Health Center of ShanxiTaiyuanChina
| | - Zhuo Li
- Center for Medical Genetics & Hunan Key Laboratory of Medical GeneticsSchool of Life SciencesCentral South UniversityChangshaChina
| | - Siyuan Linpeng
- Center for Medical Genetics & Hunan Key Laboratory of Medical GeneticsSchool of Life SciencesCentral South UniversityChangshaChina
| | - Hu Tan
- Center for Medical Genetics & Hunan Key Laboratory of Medical GeneticsSchool of Life SciencesCentral South UniversityChangshaChina
| | | | - Desheng Liang
- Center for Medical Genetics & Hunan Key Laboratory of Medical GeneticsSchool of Life SciencesCentral South UniversityChangshaChina
| | - Lingqian Wu
- Center for Medical Genetics & Hunan Key Laboratory of Medical GeneticsSchool of Life SciencesCentral South UniversityChangshaChina
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13
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Hsu Y, Lin K, Guo Y, Tsai Y, Liao Y, Lee Y. Mutation spectrum of Charcot-Marie-Tooth disease among the Han Chinese in Taiwan. Ann Clin Transl Neurol 2019; 6:1090-1101. [PMID: 31211173 PMCID: PMC6562034 DOI: 10.1002/acn3.50797] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/25/2019] [Accepted: 05/02/2019] [Indexed: 12/25/2022] Open
Abstract
Objective Charcot‐Marie‐Tooth disease (CMT) is a clinically and genetically heterogeneous group of inherited neuropathies. Mutations in more than 90 genes have been implicated in CMT; however, the mutational spectrum of CMT in Chinese population remains obscure. This study aims to provide a comprehensive overview of the frequency of mutations in Taiwanese patients with CMT and look for genotype‐phenotype correlations. Methods Mutational analyses were performed on 427 unrelated Taiwanese patients with CMT by polymorphic microsatellite markers analysis or real‐time fluorescent PCR for PMP22 duplication, Sanger sequencing for GJB1 mutations, and targeted sequencing covering 124 genes causing or relevant to inherited neuropathies. We also correlated the genotypes with the phenotypic features, such as age at disease onset and ulnar motor nerve conduction velocity. Results Pathogenic mutations were identified in 312 patients (73.1%; 312/427), including 208 patients with a PMP22 duplication, 40 patients with a GJB1 mutation, and 64 patients with a mutation in one of other 18 CMT genes. A confirmed molecular diagnosis was achieved in 84.4% (266/315) of the patients with demyelinating CMT and 41.1% (46/112) of the patients with axonal CMT. Mutations in MPZ, MFN2, or NEFL are the most frequent disease causes in patients with infantile‐onset CMT (≤2 years), while PMP22 duplications and mutations in GJB1, MFN2, or MPZ are the frequent causes among patients with childhood‐ or adolescence‐onset CMT (3–9 years). Interpretation This study provides a genotype‐phenotype landscape of CMT in Taiwan and highlights the unique spectrum of CMT genes frequencies among patients of Chinese origin.
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Affiliation(s)
- Yun‐Hsin Hsu
- Division of Neurology, Department of Internal MedicineTaipei Veterans General Hospital Su‐Ao BranchYilanTaiwan
- Neurological Institute, Taichung Veterans General HospitalTaichungTaiwan
| | - Kon‐Ping Lin
- Neurological Institute, Taipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang‐Ming University School of MedicineTaipeiTaiwan
| | - Yuh‐Cherng Guo
- Institute of Clinical MedicineNational Yang‐Ming UniversityTaipeiTaiwan
- Department of NeurologyChina Medical University HospitalTaichungTaiwan
- School of Medicine, College of MedicineChina Medical UniversityTaichungTaiwan
| | - Yu‐Shuen Tsai
- Institute of Biomedical InformaticsNational Yang‐Ming UniversityTaipeiTaiwan
- Center for Systems and Synthetic BiologyNational Yang‐Ming UniversityTaipeiTaiwan
| | - Yi‐Chu Liao
- Neurological Institute, Taipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang‐Ming University School of MedicineTaipeiTaiwan
- Brain Research CenterNational Yang‐Ming University School of MedicineTaipeiTaiwan
| | - Yi‐Chung Lee
- Neurological Institute, Taipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang‐Ming University School of MedicineTaipeiTaiwan
- Brain Research CenterNational Yang‐Ming University School of MedicineTaipeiTaiwan
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14
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Castranio EL, Mounier A, Wolfe CM, Nam KN, Fitz NF, Letronne F, Schug J, Koldamova R, Lefterov I. Gene co-expression networks identify Trem2 and Tyrobp as major hubs in human APOE expressing mice following traumatic brain injury. Neurobiol Dis 2017; 105:1-14. [PMID: 28502803 DOI: 10.1016/j.nbd.2017.05.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 05/01/2017] [Accepted: 05/10/2017] [Indexed: 01/09/2023] Open
Abstract
Traumatic brain injury (TBI) is strongly linked to an increased risk of developing dementia, including chronic traumatic encephalopathy and possibly Alzheimer's disease (AD). APOEε4 allele of human Apolipoprotein E (APOE) gene is the major genetic risk factor for late onset AD and has been associated with chronic traumatic encephalopathy and unfavorable outcome following TBI. To determine if there is an APOE isoform-specific response to TBI we performed controlled cortical impact on 3-month-old mice expressing human APOE3 or APOE4 isoforms. Following injury, we used several behavior paradigms to test for anxiety and learning and found that APOE3 and APOE4 targeted replacement mice demonstrate cognitive impairments following moderate TBI. Transcriptional profiling 14days following injury revealed a significant effect of TBI, which was similar in both genotypes. Significantly upregulated by injury in both genotypes were mRNA expression and protein level of ABCA1 transporter and APOJ, but not APOE. To identify gene-networks correlated to injury and APOE isoform, we performed Weighted Gene Co-expression Network Analysis. We determined that the network mostly correlated to TBI in animals expressing both isoforms is immune response with major hub genes including Trem2, Tyrobp, Clec7a and Cd68. We also found a significant increase of TREM2, IBA-1 and GFAP protein levels in the brains of injured mice. We identified a network representing myelination that correlated significantly with APOE isoform in both injury groups. This network was significantly enriched in oligodendrocyte signature genes, such as Mbp and Plp1. Our results demonstrate unique and distinct gene networks at this acute time point for injury and APOE isoform, as well as a network driven by APOE isoform across TBI groups.
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Affiliation(s)
- Emilie L Castranio
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Anais Mounier
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Cody M Wolfe
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Kyong Nyon Nam
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Nicholas F Fitz
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Florent Letronne
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Jonathan Schug
- Functional Genomics Core, Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Radosveta Koldamova
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA.
| | - Iliya Lefterov
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA.
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