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Sambri I, Ferniani M, Ballabio A. Ragopathies and the rising influence of RagGTPases on human diseases. Nat Commun 2024; 15:5812. [PMID: 38987251 PMCID: PMC11237164 DOI: 10.1038/s41467-024-50034-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 06/27/2024] [Indexed: 07/12/2024] Open
Abstract
RagGTPases (Rags) play an essential role in the regulation of cell metabolism by controlling the activities of both mechanistic target of rapamycin complex 1 (mTORC1) and Transcription factor EB (TFEB). Several diseases, herein named ragopathies, are associated to Rags dysfunction. These diseases may be caused by mutations either in genes encoding the Rags, or in their upstream regulators. The resulting phenotypes may encompass a variety of clinical features such as cataract, kidney tubulopathy, dilated cardiomyopathy and several types of cancer. In this review, we focus on the key clinical, molecular and physio-pathological features of ragopathies, aiming to shed light on their underlying mechanisms.
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Affiliation(s)
- Irene Sambri
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, (NA), Italy
- Scuola Superiore Meridionale (SSM, School of Advanced Studies), Genomics and Experimental Medicine Program (GEM), Naples, Italy
| | - Marco Ferniani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, (NA), Italy.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
- Medical Genetics Unit, Department of Medical and Translational Science, Federico II University, Naples, Italy.
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Singh K, Sethi P, Datta S, Chaudhary JS, Kumar S, Jain D, Gupta JK, Kumar S, Guru A, Panda SP. Advances in gene therapy approaches targeting neuro-inflammation in neurodegenerative diseases. Ageing Res Rev 2024; 98:102321. [PMID: 38723752 DOI: 10.1016/j.arr.2024.102321] [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: 04/14/2024] [Revised: 05/03/2024] [Accepted: 05/03/2024] [Indexed: 05/20/2024]
Abstract
Over the last three decades, neurodegenerative diseases (NDs) have increased in frequency. About 15% of the world's population suffers from NDs in some capacity, which causes cognitive and physical impairment. Neurodegenerative diseases, including Amyotrophic Lateral Sclerosis, Parkinson's disease, Alzheimer's disease, and others represent a significant and growing global health challenge. Neuroinflammation is recognized to be related to all NDs, even though NDs are caused by a complex mix of genetic, environmental, and lifestyle factors. Numerous genes and pathways such as NFκB, p38 MAPK, Akt/mTOR, caspase, nitric oxide, and COX are involved in triggering brain immune cells like astrocytes and microglia to secrete inflammatory cytokines such as tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. In AD, the binding of Aβ with CD36, TLR4, and TLR6 receptors results in activation of microglia which start to produce proinflammatory cytokines and chemokines. Consequently, the pro-inflammatory cytokines worsen and spread neuroinflammation, causing the deterioration of healthy neurons and the impairment of brain functions. Gene therapy has emerged as a promising therapeutic approach to modulate the inflammatory response in NDs, offering potential neuroprotective effects and disease-modifying benefits. This review article focuses on recent advances in gene therapy strategies targeting neuroinflammation pathways in NDs. We discussed the molecular pathways involved in neuroinflammation, highlighted key genes and proteins implicated in these processes, and reviewed the latest preclinical and clinical studies utilizing gene therapy to modulate neuroinflammatory responses. Additionally, this review addressed the prospects and challenges in translating gene therapy approaches into effective treatments for NDs.
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Affiliation(s)
- Kuldeep Singh
- Department of Pharmacology, Institue of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India
| | - Pranshul Sethi
- Department of Pharmacology, College of Pharmacy, Shri Venkateshwara University, Gajraula, Uttar Pradesh, India
| | - Samaresh Datta
- Department of Pharmaceutical Chemistry, Birbhum Pharmacy School, Sadaipur, Dist-Birbhum, West Bengal, India
| | | | - Sunil Kumar
- Faculty of Pharmacy, P. K. University, Village, Thanra, District, Karera, Shivpuri, Madhya Pradesh, India
| | - Divya Jain
- Department of Microbiology, School of Applied and Life Sciences, Uttaranchal University, Dehradun, Uttarakhand, India
| | - Jeetendra Kumar Gupta
- Department of Pharmacology, Institue of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India
| | - Shivendra Kumar
- Department of Pharmacology, Rajiv Academy for Pharmacy, Mathura, Uttar Pradesh, India
| | - Ajay Guru
- Department of Cariology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India
| | - Siva Prasad Panda
- Department of Pharmacology, Institue of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India.
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Goina CA, Goina DM, Farcas SS, Andreescu NI. The Role of Circular RNA for Early Diagnosis and Improved Management of Patients with Cardiovascular Diseases. Int J Mol Sci 2024; 25:2986. [PMID: 38474233 DOI: 10.3390/ijms25052986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/27/2024] [Accepted: 03/02/2024] [Indexed: 03/14/2024] Open
Abstract
Cardiovascular diseases (CVDs) are responsible for approximately 17.9 million deaths every year. There is growing evidence that circular RNAs (circRNAs) may play a significant role in the early diagnosis and treatment of cardiovascular diseases. As regulatory molecules, circular RNAs regulate gene expression, interact with proteins and miRNAs, and are translated into proteins that play a key role in a wide variety of biological processes, including the division and proliferation of cells, as well as the growth and development of individuals. An overview of the properties, expression profiles, classification, and functions of circRNAs is presented here, along with an explanation of their implications in cardiovascular diseases including heart failure, hypertension, ischemia/reperfusion injury, myocardial infarction, cardiomyopathies, atherosclerosis, and arrhythmia.
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Affiliation(s)
- Claudia Alexandrina Goina
- Doctoral School, Discipline of Genetics, "Victor Babes" University of Medicine and Pharmacy, Piata Eftimie Murgu 2, 300041 Timisoara, Romania
| | - Daniela Marcela Goina
- Faculty of Animal Husbandry and Biotechnologies, University of Agricultural Sciences and Veterinary Medicine of Banat, Calea Aradului 119, 300645 Timisoara, Romania
| | - Simona Sorina Farcas
- Department of Microscopic Morphology, Discipline of Genetics, Genomic Medicine Centre, "Victor Babeș" University of Medicine and Pharmacy, Piata Eftimie Murgu 2, 300041 Timisoara, Romania
| | - Nicoleta Ioana Andreescu
- Department of Microscopic Morphology, Discipline of Genetics, Genomic Medicine Centre, "Victor Babeș" University of Medicine and Pharmacy, Piata Eftimie Murgu 2, 300041 Timisoara, Romania
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Du S, Zeng S, Song L, Ma H, Chen R, Luo J, Wang X, Ma T, Xu X, Sun H, Yi P, Guo J, Huang Y, Liu M, Wang T, Liao WP, Zhang L, Liu JY, Tang B. Functional characterization of novel NPRL3 mutations identified in three families with focal epilepsy. SCIENCE CHINA. LIFE SCIENCES 2023; 66:2152-2166. [PMID: 37071290 DOI: 10.1007/s11427-022-2313-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 03/01/2023] [Indexed: 04/19/2023]
Abstract
Focal epilepsy accounts for 60% of all forms of epilepsy, but the pathogenic mechanism is not well understood. In this study, three novel mutations in NPRL3 (nitrogen permease regulator-like 3), c.937_945del, c.1514dupC and 6,706-bp genomic DNA (gDNA) deletion, were identified in three families with focal epilepsy by linkage analysis, whole exome sequencing (WES) and Sanger sequencing. NPRL3 protein is a component of the GATOR1 complex, a major inhibitor of mTOR signaling. These mutations led to truncation of the NPRL3 protein and hampered the binding between NPRL3 and DEPDC5, which is another component of the GATOR1 complex. Consequently, the mutant proteins enhanced mTOR signaling in cultured cells, possibly due to impaired inhibition of mTORC1 by GATOR1. Knockdown of nprl3 in Drosophila resulted in epilepsy-like behavior and abnormal synaptic development. Taken together, these findings expand the genotypic spectrum of NPRL3-associated focal epilepsy and provide further insight into how NPRL3 mutations lead to epilepsy.
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Affiliation(s)
- Shiyue Du
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Sheng Zeng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, China
- Department of Geriatrics, The Second Xiangya Hospital, Central South University, Changsha, 410011, China
| | - Li Song
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Hongying Ma
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Rui Chen
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Junyu Luo
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Xu Wang
- National Reference Laboratory of Veterinary Drug Residues and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, 430070, China
| | - Tingbin Ma
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xuan Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Hao Sun
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ping Yi
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Jifeng Guo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Yaling Huang
- Department of Neurology, Union Hospital of HUST, Wuhan, 430022, China
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Tao Wang
- Department of Neurology, Union Hospital of HUST, Wuhan, 430022, China
| | - Wei-Ping Liao
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou Medical University, Guangzhou, 510260, China
| | - Luoying Zhang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China.
| | - Jing Yu Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, China.
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, 410008, China.
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Neurophysiological assessment of cortical activity in DEPDC5- and NPRL3-related epileptic mTORopathies. Orphanet J Rare Dis 2023; 18:11. [PMID: 36639812 PMCID: PMC9840333 DOI: 10.1186/s13023-022-02600-6] [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: 08/01/2022] [Accepted: 12/19/2022] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Mutations in the GATOR1 complex genes, DEPDC5 and NPRL3, play a major role in the development of lesional and non-lesional focal epilepsy through increased mTORC1 signalling. We aimed to assess the effects of mTORC1 hyperactivation on GABAergic inhibitory circuits, in 3 and 5 individuals carrying DEPDC5 and NPRL3 mutations respectively using a multimodal approach including transcranial magnetic stimulation (TMS), magnetic resonance spectroscopy (MRS), and electroencephalography (EEG). RESULTS Inhibitory functions probed by TMS and MRS showed no effect of mutations on cortical GABAergic receptor-mediated inhibition and GABA concentration, in both cortical and subcortical regions. However, stronger EEG theta oscillations and stronger and more synchronous gamma oscillations were observed in DEPDC5 and NPRL3 mutations carriers. CONCLUSIONS These results suggest that DEPDC5 and NPRL3-related epileptic mTORopathies may not directly modulate GABAergic functions but are nonetheless characterized by a stronger neural entrainment that may be reflective of a cortical hyperexcitability mediated by increased mTORC1 signaling.
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Yin N, Jin G, Ma Y, Zhao H, Zhang G, Li MO, Peng M. SZT2 maintains hematopoietic stem cell homeostasis via nutrient-mediated mTORC1 regulation. J Clin Invest 2022; 132:146272. [PMID: 36250465 PMCID: PMC9566891 DOI: 10.1172/jci146272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 08/19/2022] [Indexed: 11/17/2022] Open
Abstract
The mTORC1 pathway coordinates nutrient and growth factor signals to maintain organismal homeostasis. Whether nutrient signaling to mTORC1 regulates stem cell function remains unknown. Here, we show that SZT2 — a protein required for mTORC1 downregulation upon nutrient deprivation — is critical for hematopoietic stem cell (HSC) homeostasis. Ablation of SZT2 in HSCs decreased the reserve and impaired the repopulating capacity of HSCs. Furthermore, ablation of both SZT2 and TSC1 — 2 repressors of mTORC1 on the nutrient and growth factor arms, respectively — led to rapid HSC depletion, pancytopenia, and premature death of the mice. Mechanistically, loss of either SZT2 or TSC1 in HSCs led to only mild elevation of mTORC1 activity and reactive oxygen species (ROS) production. Loss of both SZT2 and TSC1, on the other hand, simultaneously produced a dramatic synergistic effect, with an approximately 10-fold increase of mTORC1 activity and approximately 100-fold increase of ROS production, which rapidly depleted HSCs. These data demonstrate a critical role of nutrient mTORC1 signaling in HSC homeostasis and uncover a strong synergistic effect between nutrient- and growth factor–mediated mTORC1 regulation in stem cells.
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Affiliation(s)
- Na Yin
- Department of Basic Medical Sciences, School of Medicine, and
- Institute for Immunology, Tsinghua University, Beijing, China
| | - Gang Jin
- Department of Basic Medical Sciences, School of Medicine, and
- Institute for Immunology, Tsinghua University, Beijing, China
| | - Yuying Ma
- Department of Basic Medical Sciences, School of Medicine, and
- Institute for Immunology, Tsinghua University, Beijing, China
| | - Hanfei Zhao
- Department of Basic Medical Sciences, School of Medicine, and
- Institute for Immunology, Tsinghua University, Beijing, China
| | - Guangyue Zhang
- Department of Basic Medical Sciences, School of Medicine, and
- Institute for Immunology, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Ming O. Li
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York, USA
| | - Min Peng
- Department of Basic Medical Sciences, School of Medicine, and
- Institute for Immunology, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
- Beijing Key Laboratory for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, China
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Ververi A, Zagaglia S, Menzies L, Baptista J, Caswell R, Baulac S, Ellard S, Lynch S, Jacques TS, Chawla MS, Heier M, Kulseth MA, Mero IL, Våtevik AK, Kraoua I, Ben Rhouma H, Ben Younes T, Miladi Z, Ben Youssef Turki I, Jones WD, Clement E, Eltze C, Mankad K, Merve A, Parker J, Hoskins B, Pressler R, Sudhakar S, DeVile C, Homfray T, Kaliakatsos M, Robinson R, Keim SMB, Habibi I, Reymond A, Sisodiya SM, Hurst JA. Germline homozygous missense DEPDC5 variants cause severe refractory early-onset epilepsy, macrocephaly and bilateral polymicrogyria. Hum Mol Genet 2022; 32:580-594. [PMID: 36067010 PMCID: PMC9896472 DOI: 10.1093/hmg/ddac225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 08/16/2022] [Accepted: 08/31/2022] [Indexed: 02/07/2023] Open
Abstract
DEPDC5 (DEP Domain-Containing Protein 5) encodes an inhibitory component of the mammalian target of rapamycin (mTOR) pathway and is commonly implicated in sporadic and familial focal epilepsies, both non-lesional and in association with focal cortical dysplasia. Germline pathogenic variants are typically heterozygous and inactivating. We describe a novel phenotype caused by germline biallelic missense variants in DEPDC5. Cases were identified clinically. Available records, including magnetic resonance imaging and electroencephalography, were reviewed. Genetic testing was performed by whole exome and whole-genome sequencing and cascade screening. In addition, immunohistochemistry was performed on skin biopsy. The phenotype was identified in nine children, eight of which are described in detail herein. Six of the children were of Irish Traveller, two of Tunisian and one of Lebanese origin. The Irish Traveller children shared the same DEPDC5 germline homozygous missense variant (p.Thr337Arg), whereas the Lebanese and Tunisian children shared a different germline homozygous variant (p.Arg806Cys). Consistent phenotypic features included extensive bilateral polymicrogyria, congenital macrocephaly and early-onset refractory epilepsy, in keeping with other mTOR-opathies. Eye and cardiac involvement and severe neutropenia were also observed in one or more patients. Five of the children died in infancy or childhood; the other four are currently aged between 5 months and 6 years. Skin biopsy immunohistochemistry was supportive of hyperactivation of the mTOR pathway. The clinical, histopathological and genetic evidence supports a causal role for the homozygous DEPDC5 variants, expanding our understanding of the biology of this gene.
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Affiliation(s)
| | | | | | | | - Richard Caswell
- Exeter Genomics Laboratory, Royal Devon University Healthcare NHS Foundation Trust, Exeter, UK
| | - Stephanie Baulac
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, F-75013 Paris, France
| | - Sian Ellard
- Exeter Genomics Laboratory, Royal Devon University Healthcare NHS Foundation Trust, Exeter, UK
| | - Sally Lynch
- Academic Centre on Rare Diseases, University College Dublin School of Medicine and Medical Science, Dublin, Ireland,Department of Clinical Genetics, Children's Health Ireland (CHI) at Crumlin, Dublin, Ireland
| | | | - Thomas S Jacques
- Developmental Biology and Cancer Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK,Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | | | - Martin Heier
- Department of Clinical Neuroscience for Children, Oslo University Hospital, Oslo, Norway
| | - Mari Ann Kulseth
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Inger-Lise Mero
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | | | - Ichraf Kraoua
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia. Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Hanene Ben Rhouma
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia. Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Thouraya Ben Younes
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia. Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Zouhour Miladi
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia. Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Ilhem Ben Youssef Turki
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia. Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Wendy D Jones
- Department of Clinical Genetics & Genomic Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Emma Clement
- Department of Clinical Genetics & Genomic Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Christin Eltze
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Kshitij Mankad
- Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Ashirwad Merve
- Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Jennifer Parker
- North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Bethan Hoskins
- North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Ronit Pressler
- Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Sniya Sudhakar
- Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Catherine DeVile
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Tessa Homfray
- SW Thames Regional Genetics Service, St George's Hospital, St George's University of London, London, UK
| | - Marios Kaliakatsos
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Ponnudas (Prab) Prabhakar
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Robert Robinson
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | | | - Imen Habibi
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Alexandre Reymond
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Sanjay M Sisodiya
- To whom correspondence should be addressed at: Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK.
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Integrated Analysis of mRNAs and Long Non-Coding RNAs Expression of Oviduct That Provides Novel Insights into the Prolificacy Mechanism of Goat ( Capra hircus). Genes (Basel) 2022; 13:genes13061031. [PMID: 35741792 PMCID: PMC9222479 DOI: 10.3390/genes13061031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 05/27/2022] [Accepted: 06/06/2022] [Indexed: 02/04/2023] Open
Abstract
Artificial directional selection has replaced natural selection and resulted in trait differences across breeds in domestic animal breeding. However, the molecular mechanism by which the oviduct regulates litter size remains largely elusive in goats during the follicular phase. Accumulating data have linked lncRNAs to reproductive activities; however, little is known about the modulation mechanism in the oviduct. Herein, RNA-seq was used to measure mRNA and lncRNA expression levels in low- and high-fecundity goats. We observed distinctive differences in mRNA and lncRNA in terms of different kidding numbers and detected the differential expression of 1640 mRNA transcripts and 271 lncRNA transcripts. Enrichment analysis of differentially expressed mRNAs (DEGs) suggested that multiple pathways, such as the AMPK, PI3K–Akt, calcium signaling pathway, oocyte meiosis, ABC transporter, and ECM–receptor interaction pathways, directly or indirectly affected goat reproduction. Additionally, coexpression of differentially expressed lncRNAs (DEL)-genes analysis showed that XLOC_021615, XLOC_119780, and XLOC_076450 were trans-acting as the DEGs ATAD2, DEPDC5, and TRPM6, respectively, and could regulate embryo development. Moreover, XLOC_020079, XLOC_107361, XLOC_169844, XLOC_252348 were the trans-regulated elements of the DEGs ARHGEF2 and RAPGEF6, and the target DEGs CPEB3 of XLOC_089239, XLOC_090063, XLOC_107409, XLOC_153574, XLOC_211271, XLOC_251687 were associated with prolificacy. Collectively, our study has offered a thorough dissection of the oviduct lncRNA and mRNA landscapes in goats. These results could serve as potential targets of the oviduct affecting fertility in goats.
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9
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Samanta D. DEPDC5-related epilepsy: A comprehensive review. Epilepsy Behav 2022; 130:108678. [PMID: 35429726 DOI: 10.1016/j.yebeh.2022.108678] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/07/2022] [Accepted: 03/21/2022] [Indexed: 11/03/2022]
Abstract
DEPDC5-related epilepsy, caused by pathogenic germline variants(with or without additional somatic variants in the brain) of DEPDC5 (Dishevelled, Egl-10 and Pleckstrin domain-containing protein 5) gene, is a newly discovered predominantly focal epilepsy linked to enhanced mTORC1 pathway. DEPDC5-related epilepsy includes several familial epilepsy syndromes, including familial focal epilepsy with variable foci (FFEVF) and rare sporadic nonlesional focal epilepsy. DEPDC5 has been identified as one of the more common epilepsy genes linked to infantile spasms and sudden unexpected death (SUDEP). Although intelligence usually is unaffected in DEPDC5-related epilepsy, some people have been diagnosed with intellectual disabilities, autism spectrum disorder, and other psychiatric problems. DEPDC5 variants have also been found in 20% of individuals with various brain abnormalities, challenging the traditional distinction between lesional and nonlesional epilepsies. The most exciting development of DEPDC5 variants is the possibility of precision therapeutics using mTOR inhibitors, as evidenced with phenotypic rescue in many animal models. However, more research is needed to better understand the functional impact of diverse (particularly missense or splice-region) variants, the specific involvement of DEPDC5 in epileptogenesis, and the creation and utilization of precision therapies in humans. Precision treatments for DEPDC5-related epilepsy will benefit not only a small number of people with the condition, but they will also pave the way for new therapeutic approaches in epilepsy (including acquired epilepsies in which mTORC1 activation occurs, for example, post-traumatic epilepsy) and other neurological disorders involving a dysfunctional mTOR pathway.
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Affiliation(s)
- Debopam Samanta
- Child Neurology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, United States.
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10
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Ishida S, Zhao D, Sawada Y, Hiraoka Y, Mashimo T, Tanaka K. Dorsal telencephalon-specific Nprl2- and Nprl3-knockout mice: novel mouse models for GATORopathy. Hum Mol Genet 2021; 31:1519-1530. [PMID: 34965576 PMCID: PMC9071434 DOI: 10.1093/hmg/ddab337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 09/28/2021] [Accepted: 11/12/2021] [Indexed: 11/30/2022] Open
Abstract
The most frequent genetic cause of focal epilepsies is variations in the GAP activity toward RAGs 1 complex genes DEP domain containing 5 (DEPDC5), nitrogen permease regulator 2-like protein (NPRL2) and nitrogen permease regulator 3-like protein (NPRL3). Because these variations are frequent and associated with a broad spectrum of focal epilepsies, a unique pathology categorized as GATORopathy can be conceptualized. Animal models recapitulating the clinical features of patients are essential to decipher GATORopathy. Although several genetically modified animal models recapitulate DEPDC5-related epilepsy, no models have been reported for NPRL2- or NPRL3-related epilepsies. Here, we conditionally deleted Nprl2 and Nprl3 from the dorsal telencephalon in mice [Emx1cre/+; Nprl2f/f (Nprl2-cKO) and Emx1cre/+; Nprl3f/f (Nprl3-cKO)] and compared their phenotypes with Nprl2+/−, Nprl3+/− and Emx1cre/+; Depdc5f/f (Depdc5-cKO) mice. Nprl2-cKO and Nprl3-cKO mice recapitulated the major abnormal features of patients—spontaneous seizures, and dysmorphic enlarged neuronal cells with increased mechanistic target of rapamycin complex 1 signaling—similar to Depdc5-cKO mice. Chronic postnatal rapamycin administration dramatically prolonged the survival period and inhibited seizure occurrence but not enlarged neuronal cells in Nprl2-cKO and Nprl3-cKO mice. However, the benefit of rapamycin after withdrawal was less durable in Nprl2- and Nprl3-cKO mice compared with Depdc5-cKO mice. Further studies using these conditional knockout mice will be useful for understanding GATORopathy and for the identification of novel therapeutic targets.
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Affiliation(s)
- Saeko Ishida
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, 113-8510, Japan
- Division of Animal Genetics, Laboratory Animal Research Center, The Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan
| | - Di Zhao
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, 113-8510, Japan
- Division of Animal Genetics, Laboratory Animal Research Center, The Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan
| | - Yuta Sawada
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, 113-8510, Japan
| | - Yuichi Hiraoka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, 113-8510, Japan
- Laboratory of Genome Editing for Biomedical Research, MRI, TMDU, Tokyo, 101-0062, Japan
| | - Tomoji Mashimo
- Division of Animal Genetics, Laboratory Animal Research Center, The Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, 113-8510, Japan
- Center for Brain Integration Research (CBIR), TMDU, Tokyo, 113-8510, Japan
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11
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Moloney PB, Cavalleri GL, Delanty N. Epilepsy in the mTORopathies: opportunities for precision medicine. Brain Commun 2021; 3:fcab222. [PMID: 34632383 PMCID: PMC8495134 DOI: 10.1093/braincomms/fcab222] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/23/2021] [Accepted: 08/30/2021] [Indexed: 01/16/2023] Open
Abstract
The mechanistic target of rapamycin signalling pathway serves as a ubiquitous regulator of cell metabolism, growth, proliferation and survival. The main cellular activity of the mechanistic target of rapamycin cascade funnels through mechanistic target of rapamycin complex 1, which is inhibited by rapamycin, a macrolide compound produced by the bacterium Streptomyces hygroscopicus. Pathogenic variants in genes encoding upstream regulators of mechanistic target of rapamycin complex 1 cause epilepsies and neurodevelopmental disorders. Tuberous sclerosis complex is a multisystem disorder caused by mutations in mechanistic target of rapamycin regulators TSC1 or TSC2, with prominent neurological manifestations including epilepsy, focal cortical dysplasia and neuropsychiatric disorders. Focal cortical dysplasia type II results from somatic brain mutations in mechanistic target of rapamycin pathway activators MTOR, AKT3, PIK3CA and RHEB and is a major cause of drug-resistant epilepsy. DEPDC5, NPRL2 and NPRL3 code for subunits of the GTPase-activating protein (GAP) activity towards Rags 1 complex (GATOR1), the principal amino acid-sensing regulator of mechanistic target of rapamycin complex 1. Germline pathogenic variants in GATOR1 genes cause non-lesional focal epilepsies and epilepsies associated with malformations of cortical development. Collectively, the mTORopathies are characterized by excessive mechanistic target of rapamycin pathway activation and drug-resistant epilepsy. In the first large-scale precision medicine trial in a genetically mediated epilepsy, everolimus (a synthetic analogue of rapamycin) was effective at reducing seizure frequency in people with tuberous sclerosis complex. Rapamycin reduced seizures in rodent models of DEPDC5-related epilepsy and focal cortical dysplasia type II. This review outlines a personalized medicine approach to the management of epilepsies in the mTORopathies. We advocate for early diagnostic sequencing of mechanistic target of rapamycin pathway genes in drug-resistant epilepsy, as identification of a pathogenic variant may point to an occult dysplasia in apparently non-lesional epilepsy or may uncover important prognostic information including, an increased risk of sudden unexpected death in epilepsy in the GATORopathies or favourable epilepsy surgery outcomes in focal cortical dysplasia type II due to somatic brain mutations. Lastly, we discuss the potential therapeutic application of mechanistic target of rapamycin inhibitors for drug-resistant seizures in GATOR1-related epilepsies and focal cortical dysplasia type II.
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Affiliation(s)
- Patrick B Moloney
- FutureNeuro, the Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, Dublin, D02 VN51, Ireland
| | - Gianpiero L Cavalleri
- FutureNeuro, the Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, Dublin, D02 VN51, Ireland
| | - Norman Delanty
- FutureNeuro, the Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, Dublin, D02 VN51, Ireland
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12
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Loissell-Baltazar YA, Dokudovskaya S. SEA and GATOR 10 Years Later. Cells 2021; 10:cells10102689. [PMID: 34685669 PMCID: PMC8534245 DOI: 10.3390/cells10102689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/30/2021] [Accepted: 10/03/2021] [Indexed: 12/17/2022] Open
Abstract
The SEA complex was described for the first time in yeast Saccharomyces cerevisiae ten years ago, and its human homologue GATOR complex two years later. During the past decade, many advances on the SEA/GATOR biology in different organisms have been made that allowed its role as an essential upstream regulator of the mTORC1 pathway to be defined. In this review, we describe these advances in relation to the identification of multiple functions of the SEA/GATOR complex in nutrient response and beyond and highlight the consequence of GATOR mutations in cancer and neurodegenerative diseases.
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13
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Klofas LK, Short BP, Zhou C, Carson RP. Prevention of premature death and seizures in a Depdc5 mouse epilepsy model through inhibition of mTORC1. Hum Mol Genet 2021; 29:1365-1377. [PMID: 32280987 DOI: 10.1093/hmg/ddaa068] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/31/2020] [Accepted: 04/06/2020] [Indexed: 11/13/2022] Open
Abstract
Mutations in DEP domain containing 5 (DEPDC5) are increasingly appreciated as one of the most common causes of inherited focal epilepsy. Epilepsies due to DEPDC5 mutations are often associated with brain malformations, tend to be drug-resistant, and have been linked to an increased risk of sudden unexplained death in epilepsy (SUDEP). Generation of epilepsy models to define mechanisms of epileptogenesis remains vital for future therapies. Here, we describe a novel mouse model of Depdc5 deficiency with a severe epilepsy phenotype, generated by conditional deletion of Depdc5 in dorsal telencephalic neuroprogenitor cells. In contrast to control and heterozygous mice, Depdc5-Emx1-Cre conditional knockout (CKO) mice demonstrated macrocephaly, spontaneous seizures and premature death. Consistent with increased mTORC1 activation, targeted neurons were enlarged and both neurons and astrocytes demonstrated increased S6 phosphorylation. Electrophysiologic characterization of miniature inhibitory post-synaptic currents in excitatory neurons was consistent with impaired post-synaptic response to GABAergic input, suggesting a potential mechanism for neuronal hyperexcitability. mTORC1 inhibition with rapamycin significantly improved survival of CKO animals and prevented observed seizures, including for up to 40 days following rapamycin withdrawal. These data not only support a primary role for mTORC1 hyperactivation in epilepsy following homozygous loss of Depdc5, but also suggest a developmental window for treatment which may have a durable benefit for some time even after withdrawal.
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Affiliation(s)
- Lindsay K Klofas
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA
| | - Brittany P Short
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Robert P Carson
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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14
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Xu L, Zhang X, Xin Y, Ma J, Yang C, Zhang X, Hou G, Dong XC, Sun Z, Xiong X, Cao X. Depdc5 deficiency exacerbates alcohol-induced hepatic steatosis via suppression of PPARα pathway. Cell Death Dis 2021; 12:710. [PMID: 34267188 PMCID: PMC8282792 DOI: 10.1038/s41419-021-03980-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/16/2022]
Abstract
Alcohol-related liver disease (ALD), a condition caused by alcohol overconsumption, occurs in three stages of liver injury including steatosis, hepatitis, and cirrhosis. DEP domain-containing protein 5 (DEPDC5), a component of GAP activities towards Rags 1 (GATOR1) complex, is a repressor of amino acid-sensing branch of the mammalian target of rapamycin complex 1 (mTORC1) pathway. In the current study, we found that aberrant activation of mTORC1 was likely attributed to the reduction of DEPDC5 in the livers of ethanol-fed mice or ALD patients. To further define the in vivo role of DEPDC5 in ALD development, we generated Depdc5 hepatocyte-specific knockout mouse model (Depdc5-LKO) in which mTORC1 pathway was constitutively activated through loss of the inhibitory effect of GATOR1. Hepatic Depdc5 ablation leads to mild hepatomegaly and liver injury and protects against diet-induced liver steatosis. In contrast, ethanol-fed Depdc5-LKO mice developed severe hepatic steatosis and inflammation. Pharmacological intervention with Torin 1 suppressed mTORC1 activity and remarkably ameliorated ethanol-induced hepatic steatosis and inflammation in both control and Depdc5-LKO mice. The pathological effect of sustained mTORC1 activity in ALD may be attributed to the suppression of peroxisome proliferator activated receptor α (PPARα), the master regulator of fatty acid oxidation in hepatocytes, because fenofibrate (PPARα agonist) treatment reverses ethanol-induced liver steatosis and inflammation in Depdc5-LKO mice. These findings provide novel insights into the in vivo role of hepatic DEPDC5 in the development of ALD.
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Affiliation(s)
- Lin Xu
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, PR China
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, 453003, PR China
| | - Xinge Zhang
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, 453003, PR China
- Xinxiang Key Laboratory of Metabolism and Integrative Physiology, Xinxiang Medical University, Xinxiang, Henan, 453003, PR China
| | - Yue Xin
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, 453003, PR China
- Xinxiang Key Laboratory of Metabolism and Integrative Physiology, Xinxiang Medical University, Xinxiang, Henan, 453003, PR China
| | - Jie Ma
- Department of Human Anatomy & Histoembryology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan, 453003, PR China
| | - Chenyan Yang
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, 453003, PR China
- Xinxiang Key Laboratory of Metabolism and Integrative Physiology, Xinxiang Medical University, Xinxiang, Henan, 453003, PR China
| | - Xi Zhang
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, PR China
| | - Guoqing Hou
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, PR China
| | - Xiaocheng Charlie Dong
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Zhaoli Sun
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Xiwen Xiong
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, 453003, PR China.
- Xinxiang Key Laboratory of Metabolism and Integrative Physiology, Xinxiang Medical University, Xinxiang, Henan, 453003, PR China.
| | - Xuan Cao
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, PR China.
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15
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Weston M. Getting Sucker Punched by Depdc5 Really Hurts. Epilepsy Curr 2021; 20:378-380. [PMID: 34025259 PMCID: PMC7818211 DOI: 10.1177/1535759720956992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
[Box: see text]
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16
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Garcia-Rosa S, de Freitas Brenha B, Felipe da Rocha V, Goulart E, Araujo BHS. Personalized Medicine Using Cutting Edge Technologies for Genetic Epilepsies. Curr Neuropharmacol 2021; 19:813-831. [PMID: 32933463 PMCID: PMC8686309 DOI: 10.2174/1570159x18666200915151909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/08/2020] [Accepted: 08/28/2020] [Indexed: 11/22/2022] Open
Abstract
Epilepsy is the most common chronic neurologic disorder in the world, affecting 1-2% of the population. Besides, 30% of epilepsy patients are drug-resistant. Genomic mutations seem to play a key role in its etiology and knowledge of strong effect mutations in protein structures might improve prediction and the development of efficacious drugs to treat epilepsy. Several genetic association studies have been undertaken to examine the effect of a range of candidate genes for resistance. Although, few studies have explored the effect of the mutations into protein structure and biophysics in the epilepsy field. Much work remains to be done, but the plans made for exciting developments will hold therapeutic potential for patients with drug-resistance. In summary, we provide a critical review of the perspectives for the development of individualized medicine for epilepsy based on genetic polymorphisms/mutations in light of core elements such as transcriptomics, structural biology, disease model, pharmacogenomics and pharmacokinetics in a manner to improve the success of trial designs of antiepileptic drugs.
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Affiliation(s)
- Sheila Garcia-Rosa
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Bianca de Freitas Brenha
- Laboratory of Embryonic Genetic Regulation, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Vinicius Felipe da Rocha
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Ernesto Goulart
- Human Genome and Stem-Cell Research Center (HUG-CEL), Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, SP, Brazil
| | - Bruno Henrique Silva Araujo
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
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17
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Nicotinic Receptors in Sleep-Related Hypermotor Epilepsy: Pathophysiology and Pharmacology. Brain Sci 2020; 10:brainsci10120907. [PMID: 33255633 PMCID: PMC7761363 DOI: 10.3390/brainsci10120907] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/19/2020] [Accepted: 11/21/2020] [Indexed: 12/12/2022] Open
Abstract
Sleep-related hypermotor epilepsy (SHE) is characterized by hyperkinetic focal seizures, mainly arising in the neocortex during non-rapid eye movements (NREM) sleep. The familial form is autosomal dominant SHE (ADSHE), which can be caused by mutations in genes encoding subunits of the neuronal nicotinic acetylcholine receptor (nAChR), Na+-gated K+ channels, as well as non-channel signaling proteins, such as components of the gap activity toward rags 1 (GATOR1) macromolecular complex. The causative genes may have different roles in developing and mature brains. Under this respect, nicotinic receptors are paradigmatic, as different pathophysiological roles are exerted by distinct nAChR subunits in adult and developing brains. The widest evidence concerns α4 and β2 subunits. These participate in heteromeric nAChRs that are major modulators of excitability in mature neocortical circuits as well as regulate postnatal synaptogenesis. However, growing evidence implicates mutant α2 subunits in ADSHE, which poses interpretive difficulties as very little is known about the function of α2-containing (α2*) nAChRs in the human brain. Planning rational therapy must consider that pharmacological treatment could have different effects on synaptic maturation and adult excitability. We discuss recent attempts towards precision medicine in the mature brain and possible approaches to target developmental stages. These issues have general relevance in epilepsy treatment, as the pathogenesis of genetic epilepsies is increasingly recognized to involve developmental alterations.
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18
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Castello MA, Gleeson JG. Insight into developmental mechanisms of global and focal migration disorders of cortical development. Curr Opin Neurobiol 2020; 66:77-84. [PMID: 33099181 DOI: 10.1016/j.conb.2020.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 10/02/2020] [Accepted: 10/05/2020] [Indexed: 12/20/2022]
Abstract
Cortical development involves neurogenesis followed by migration, maturation, and myelination of immature neurons. Disruptions in these processes can cause malformations of cortical development (MCD). Radial glia (RG) are the stem cells of the brain, both generating neurons and providing the scaffold upon which immature neurons radially migrate. Germline mutations in genes required for cell migration, or cell-cell contact, often lead to global MCDs. Somatic mutations in RG in genes involved in homeostatic function, like mTOR signaling, often lead to focal MCDs. Two different mutations occurring in the same patient can combine in ways we are just beginning to understand. Our growing knowledge about MCD suggests mTOR inhibitors may have expanded utility in treatment-resistant epilepsy, while imaging techniques can better delineate the type and extent of these lesions.
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Affiliation(s)
- Michael A Castello
- Department of Neurosciences, Division of Child Neurology, University of California San Diego, San Diego, CA, USA
| | - Joseph G Gleeson
- Department of Neurosciences, Rady Children's Institute for Genomic Medicine, University of California San Diego, San Diego, CA, USA.
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19
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Gawel K, Langlois M, Martins T, van der Ent W, Tiraboschi E, Jacmin M, Crawford AD, Esguerra CV. Seizing the moment: Zebrafish epilepsy models. Neurosci Biobehav Rev 2020; 116:1-20. [PMID: 32544542 DOI: 10.1016/j.neubiorev.2020.06.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/20/2020] [Accepted: 06/05/2020] [Indexed: 12/14/2022]
Abstract
Zebrafish are now widely accepted as a valuable animal model for a number of different central nervous system (CNS) diseases. They are suitable both for elucidating the origin of these disorders and the sequence of events culminating in their onset, and for use as a high-throughput in vivo drug screening platform. The availability of powerful and effective techniques for genome manipulation allows the rapid modelling of different genetic epilepsies and of conditions with seizures as a core symptom. With this review, we seek to summarize the current knowledge about existing epilepsy/seizures models in zebrafish (both pharmacological and genetic) and compare them with equivalent rodent and human studies. New findings obtained from the zebrafish models are highlighted. We believe that this comprehensive review will highlight the value of zebrafish as a model for investigating different aspects of epilepsy and will help researchers to use these models to their full extent.
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Affiliation(s)
- Kinga Gawel
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway; Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego St. 8b, 20-090, Lublin, Poland
| | | | - Teresa Martins
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg
| | - Wietske van der Ent
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway
| | - Ettore Tiraboschi
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway; Neurophysics Group, Center for Mind/Brain Sciences, University of Trento, Piazza Manifattura 1, Building 14, 38068, Rovereto, TN, Italy
| | - Maxime Jacmin
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg
| | - Alexander D Crawford
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg; Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Oslo, Norway
| | - Camila V Esguerra
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway.
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20
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Yuskaitis CJ, Rossitto LA, Gurnani S, Bainbridge E, Poduri A, Sahin M. Chronic mTORC1 inhibition rescues behavioral and biochemical deficits resulting from neuronal Depdc5 loss in mice. Hum Mol Genet 2020; 28:2952-2964. [PMID: 31174205 DOI: 10.1093/hmg/ddz123] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/31/2019] [Accepted: 06/04/2019] [Indexed: 01/05/2023] Open
Abstract
DEPDC5 is now recognized as one of the genes most often implicated in familial/inherited focal epilepsy and brain malformations. Individuals with pathogenic variants in DEPDC5 are at risk for epilepsy, associated neuropsychiatric comorbidities and sudden unexplained death in epilepsy. Depdc5flox/flox-Syn1Cre (Depdc5cc+) neuronal-specific Depdc5 knockout mice exhibit seizures and neuronal mTORC1 hyperactivation. It is not known if Depdc5cc+ mice have a hyperactivity/anxiety phenotype, die early from terminal seizures or whether mTOR inhibitors rescue DEPDC5-related seizures and associated comorbidities. Herein, we report that Depdc5cc+ mice were hyperactive in open-field testing but did not display anxiety-like behaviors on the elevated-plus maze. Unlike many other mTOR-related models, Depdc5cc+ mice had minimal epileptiform activity and rare seizures prior to seizure-induced death, as confirmed by video-EEG monitoring. Treatment with the mTORC1 inhibitor rapamycin starting after 3 weeks of age significantly prolonged the survival of Depdc5cc+ mice and partially rescued the behavioral hyperactivity. Rapamycin decreased the enlarged brain size of Depdc5cc+ mice with corresponding decrease in neuronal soma size. Loss of Depdc5 led to a decrease in the other GATOR1 protein levels (NPRL2 and NPRL3). Rapamycin failed to rescue GATOR1 protein levels but rather rescued downstream mTORC1 hyperactivity as measured by phosphorylation of S6. Collectively, our data provide the first evidence of behavioral alterations in mice with Depdc5 loss and support mTOR inhibition as a rational therapeutic strategy for DEPDC5-related epilepsy in humans.
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Affiliation(s)
- Christopher J Yuskaitis
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Leigh-Ana Rossitto
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Sarika Gurnani
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Elizabeth Bainbridge
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Annapurna Poduri
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Mustafa Sahin
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
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21
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De Fusco A, Cerullo MS, Marte A, Michetti C, Romei A, Castroflorio E, Baulac S, Benfenati F. Acute knockdown of Depdc5 leads to synaptic defects in mTOR-related epileptogenesis. Neurobiol Dis 2020; 139:104822. [PMID: 32113911 DOI: 10.1016/j.nbd.2020.104822] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 02/02/2020] [Accepted: 02/26/2020] [Indexed: 12/17/2022] Open
Abstract
DEP-domain containing 5 (DEPDC5) is part of the GATOR1 complex that functions as key inhibitor of the mechanistic target of rapamycin complex 1 (mTORC1). Loss-of-function mutations in DEPDC5 leading to mTOR hyperactivation have been identified as the most common cause of either lesional or non-lesional focal epilepsy. However, the precise mechanisms by which DEPDC5 loss-of-function triggers neuronal and network hyperexcitability are still unclear. In this study, we investigated the cellular mechanisms of hyperexcitability by comparing the constitutive heterozygous Depdc5 knockout mouse versus different levels of acute Depdc5 deletion (≈40% and ≈80% neuronal knockdown of Depdc5 protein) by RNA interference in primary cortical cultures. While heterozygous Depdc5+/- neurons have only a subtle phenotype, acutely knocked-down neurons exhibit a strong dose-dependent phenotype characterized by mTOR hyperactivation, increased soma size, dendritic arborization, excitatory synaptic transmission and intrinsic excitability. The robust synaptic phenotype resulting from the acute knockdown Depdc5 deficiency highlights the importance of the temporal dynamics of Depdc5 knockdown in triggering the phenotypic changes, reminiscent of the somatic second-hit mechanism in patients with focal cortical dysplasia. These findings uncover a novel synaptic phenotype that is causally linked to Depdc5 knockdown, highlighting the developmental role of Depdc5. Interestingly, the synaptic defect appears to affect only excitatory synapses, while inhibitory synapses develop normally. The increased frequency and amplitude of mEPSCs, paralleled by increased density of excitatory synapses and expression of glutamate receptors, may generate an excitation/inhibition imbalance that triggers epileptogenesis.
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Affiliation(s)
- Antonio De Fusco
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Maria Sabina Cerullo
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Antonella Marte
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCSS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Caterina Michetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; IRCSS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Alessandra Romei
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Enrico Castroflorio
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Stephanie Baulac
- Sorbonne Université, UPMC Univ Paris 06, UMR S 1127, INSERM, U1127, CNRS, UMR 7225, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, F-75013 Paris, France
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; IRCSS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy.
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22
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Garcia CAB, Carvalho SCS, Yang X, Ball LL, George RD, James KN, Stanley V, Breuss MW, Thomé U, Santos MV, Saggioro FP, Neder Serafini L, Silva WA, Gleeson JG, Machado HR. mTOR pathway somatic variants and the molecular pathogenesis of hemimegalencephaly. Epilepsia Open 2020; 5:97-106. [PMID: 32140648 PMCID: PMC7049797 DOI: 10.1002/epi4.12377] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 12/16/2019] [Accepted: 01/02/2020] [Indexed: 12/28/2022] Open
Abstract
Objectives Recently, defects in the protein kinase mTOR (mammalian target of rapamycin) and its associated pathway have been correlated with hemimegalencephaly (HME). mTOR acts as a central regulator of important physiological cellular functions such as growth and proliferation, metabolism, autophagy, death, and survival. This study was aimed at identifying specific variants in mTOR signaling pathway genes in patients diagnosed with HME. Methods Using amplicon and whole exome sequencing (WES) of resected brain and paired blood samples from five HME patients, we were able to identify pathogenic mosaic variants in the mTOR pathway genes MTOR, PIK3CA, and DEPDC5. Results These results strengthen the hypothesis that somatic variants in PI3K-Akt-mTOR pathway genes contribute to HME. We also describe one patient presenting with a pathogenic variant on DEPDC5 gene, which reinforces the role of DEPDC5 on cortical structural changes due to mTORC1 hyperactivation. These findings also provide insights into when in brain development these variants occurred. An early developmental variant is expected to affect a larger number of cells and to result in a larger malformation, whereas the same variant occurring later in development would cause a minor malformation. Significance In the future, numerous somatic variants in known or new genes will undoubtedly be revealed in resected brain samples, making it possible to draw correlations between genotypes and phenotypes and allow for a genetic clinical diagnosis that may help to predict a given patient's outcome.
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Affiliation(s)
- Camila A B Garcia
- Department of Surgery and Anatomy Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil
| | - Simone C S Carvalho
- Department of Genetics Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil
| | - Xiaoxu Yang
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Laurel L Ball
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Renee D George
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Kiely N James
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Valentina Stanley
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Martin W Breuss
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Ursula Thomé
- Department of Neurosciences and Behavioral Sciences Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil
| | - Marcelo V Santos
- Department of Surgery and Anatomy Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil
| | - Fabiano P Saggioro
- Department of Pathology Ribeirão Preto School of Medicine University of São Paulo USP Ribeirao Preto SP Brazil
| | - Luciano Neder Serafini
- Department of Pathology Ribeirão Preto School of Medicine University of São Paulo USP Ribeirao Preto SP Brazil
| | - Wilson A Silva
- Department of Genetics Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil.,Center for Medical Genomics University Hospital of Ribeirão Preto Medical School (USP) Ribeirao Preto SP Brazil
| | - Joseph G Gleeson
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Hélio R Machado
- Department of Surgery and Anatomy Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil
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23
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Circular RNA Expression Profiles in Plasma from Patients with Heart Failure Related to Platelet Activity. Biomolecules 2020; 10:biom10020187. [PMID: 31991759 PMCID: PMC7072558 DOI: 10.3390/biom10020187] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 01/23/2020] [Indexed: 12/17/2022] Open
Abstract
Heart failure (HF) is a deadly disease that is difficult to accurately diagnose. Circular RNAs (circRNAs) are a novel class of noncoding RNAs that might play important roles in many cardiovascular diseases. However, their role in HF remains unclear. CircRNA microarrays were performed on plasma samples obtained from three patients with HF and three healthy controls. The profiling results were validated by quantitative reverse transcription polymerase chain reaction. The diagnostic value of circRNAs for HF was evaluated by receiver operating characteristic (ROC) curves. The expression profiles indicated that 477 circRNAs were upregulated and 219 were downregulated in the plasma of patients with HF compared with healthy controls. Among the dysregulated circRNAs, hsa_circ_0112085 (p = 0.0032), hsa_circ_0062960 (p = 0.0006), hsa_circ_0053919 (p = 0.0074) and hsa_circ_0014010 (p = 0.025) showed significantly higher expression in patients with HF compared with healthy controls. The area under the ROC curve for hsa_circ_0062960 for HF diagnosis was 0.838 (p < 0.0001). Correlation analysis showed that the expression of hsa_circ_0062960 was highly correlated with B-type natriuretic peptide (BNP) serum levels. Some differential circRNAs were found to be related to platelet activity by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. The landscape of circRNA expression profiles may play a role in HF pathogenesis and improve our understanding of platelet function in HF. Moreover, hsa_circ_0062960 has potential as a novel diagnostic biomarker for HF.
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24
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Bagheri-Fam S, Chen H, Wilson S, Ayers K, Hughes J, Sloan-Bena F, Calvel P, Robevska G, Puisac B, Kusz-Zamelczyk K, Gimelli S, Spik A, Jaruzelska J, Warenik-Szymankiewicz A, Faradz S, Nef S, Pié J, Thomas P, Sinclair A, Wilhelm D. The gene encoding the ketogenic enzyme HMGCS2 displays a unique expression during gonad development in mice. PLoS One 2020; 15:e0227411. [PMID: 31910233 PMCID: PMC6946174 DOI: 10.1371/journal.pone.0227411] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 12/18/2019] [Indexed: 11/26/2022] Open
Abstract
Disorders/differences of sex development (DSD) cause profound psychological and reproductive consequences for the affected individuals, however, most are still unexplained at the molecular level. Here, we present a novel gene, 3-hydroxy-3-methylglutaryl coenzyme A synthase 2 (HMGCS2), encoding a metabolic enzyme in the liver important for energy production from fatty acids, that shows an unusual expression pattern in developing fetal mouse gonads. Shortly after gonadal sex determination it is up-regulated in the developing testes following a very similar spatial and temporal pattern as the male-determining gene Sry in Sertoli cells before switching to ovarian enriched expression. To test if Hmgcs2 is important for gonad development in mammals, we pursued two lines of investigations. Firstly, we generated Hmgcs2-null mice using CRISPR/Cas9 and found that these mice had gonads that developed normally even on a sensitized background. Secondly, we screened 46,XY DSD patients with gonadal dysgenesis and identified two unrelated patients with a deletion and a deleterious missense variant in HMGCS2 respectively. However, both variants were heterozygous, suggesting that HMGCS2 might not be the causative gene. Analysis of a larger number of patients in the future might shed more light into the possible association of HMGCS2 with human gonadal development.
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Affiliation(s)
- Stefan Bagheri-Fam
- Department of Anatomy & Neuroscience, The University of Melbourne, Melbourne, Australia
| | - Huijun Chen
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Sean Wilson
- Murdoch Children’s Research Institute, Melbourne, Australia
| | - Katie Ayers
- Murdoch Children’s Research Institute, Melbourne, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, Australia
| | - James Hughes
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
| | | | - Pierre Calvel
- Department of Genetics, Medicine & Development, University of Geneva, Geneva, Switzerland
| | - Gorjana Robevska
- Murdoch Children’s Research Institute, Melbourne, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, Australia
| | - Beatriz Puisac
- Unit of Clinical Genetics and Functional Genomics, Department of Pharmacology-Physiology, School of Medicine, University of Zaragoza, CIBERER-GCV02 and ISS-Aragon, Zaragoza, Spain
| | | | - Stefania Gimelli
- Service of Genetic Medicine, University Geneva Hospitals, Geneva, Switzerland
| | - Anna Spik
- Institute of Human Genetics, Polish Academy of Sciences, Poznań, Poland
| | | | | | - Sultana Faradz
- Center for Biomedical Research Faculty of Medicine Diponegoro University (FMDU), Semarang, Indonesia
| | - Serge Nef
- Service of Genetic Medicine, University Geneva Hospitals, Geneva, Switzerland
| | - Juan Pié
- Unit of Clinical Genetics and Functional Genomics, Department of Pharmacology-Physiology, School of Medicine, University of Zaragoza, CIBERER-GCV02 and ISS-Aragon, Zaragoza, Spain
| | - Paul Thomas
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
| | - Andrew Sinclair
- Murdoch Children’s Research Institute, Melbourne, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, Australia
| | - Dagmar Wilhelm
- Department of Anatomy & Neuroscience, The University of Melbourne, Melbourne, Australia
- * E-mail:
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25
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Iffland PH, Carson V, Bordey A, Crino PB. GATORopathies: The role of amino acid regulatory gene mutations in epilepsy and cortical malformations. Epilepsia 2019; 60:2163-2173. [PMID: 31625153 PMCID: PMC7155771 DOI: 10.1111/epi.16370] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 09/20/2019] [Accepted: 09/20/2019] [Indexed: 12/11/2022]
Abstract
The mechanistic target of rapamycin (mTOR) pathway has been implicated in a growing number of malformations of cortical development (MCD) associated with intractable epilepsy. Mutations in single genes encoding mTOR pathway regulatory proteins have been linked to MCD such as focal cortical dysplasia (FCD) types IIa and IIb, hemimegalencephaly (HME), and megalencephaly. Recent studies have demonstrated that the GATOR1 protein complex, comprised of DEPDC5, NPRL3, and NPRL2, plays a pivotal role in regulating mTOR signaling in response to cellular amino acid levels and that mutations in DEPDC5, NPRL3, or NPRL2 are linked to FCD, HME, and seizures. Histopathological analysis of FCD and HME tissue specimens resected from individuals harboring DEPDC5, NPRL3, or NPRL2 gene mutations reveals hyperactivation of mTOR pathway signaling. Family pedigrees carrying mutations in either DEPDC5 or NPRL3 share clinical phenotypes of epilepsy and MCD, as well as intellectual and neuropsychiatric disabilities. Interestingly, some individuals with seizures associated with DEPDC5, NPRL3, or NPRL2 variants exhibit normal brain imaging suggesting either occult MCD or a role for these genes in non-lesional neocortical epilepsy. Mouse models resulting from knockdown or knockout of either Depdc5 or Nprl3 exhibit altered cortical lamination, neuronal dysmorphogenesis, and enhanced neuronal excitability as reported in models resulting from direct mTOR activation through expression of its canonical activator RHEB. The role of the GATOR1 proteins in regulating mTOR signaling suggest plausible options for mTOR inhibition in the treatment of epilepsy associated with mutations in DEPDC5, NPRL3, or NPRL2.
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Affiliation(s)
- Philip H. Iffland
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Vincent Carson
- The Clinic for Special Children, Strasburg, Pennsylvania
| | - Angelique Bordey
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
| | - Peter B. Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland
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26
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Dawson RE, Nieto Guil AF, Robertson LJ, Piltz SG, Hughes JN, Thomas PQ. Functional screening of GATOR1 complex variants reveals a role for mTORC1 deregulation in FCD and focal epilepsy. Neurobiol Dis 2019; 134:104640. [PMID: 31639411 DOI: 10.1016/j.nbd.2019.104640] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 10/07/2019] [Accepted: 10/13/2019] [Indexed: 12/20/2022] Open
Abstract
Mutations in the GAP activity toward RAGs 1 (GATOR1) complex genes (DEPDC5, NPRL2 and NPRL3) have been associated with focal epilepsy and focal cortical dysplasia (FCD). GATOR1 functions as an inhibitor of the mTORC1 signalling pathway, indicating that the downstream effects of mTORC1 deregulation underpin the disease. However, the vast majority of putative disease-causing variants have not been functionally assessed for mTORC1 repression activity. Here, we develop a novel in vitro functional assay that enables rapid assessment of GATOR1-gene variants. Surprisingly, of the 17 variants tested, we show that only six showed significantly impaired mTORC1 inhibition. To further investigate variant function in vivo, we generated a conditional Depdc5 mouse which modelled a 'second-hit' mechanism of disease. Generation of Depdc5 null 'clones' in the embryonic brain resulted in mTORC1 hyperactivity and modelled epilepsy and FCD symptoms including large dysmorphic neurons, defective migration and lower seizure thresholds. Using this model, we validated DEPDC5 variant F164del to be loss-of-function. We also show that Q542P is not functionally compromised in vivo, consistent with our in vitro findings. Overall, our data show that mTORC1 deregulation is the central pathological mechanism for GATOR1 variants and also indicates that a significant proportion of putative disease variants are pathologically inert, highlighting the importance of GATOR1 variant functional assessment.
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Affiliation(s)
- Ruby E Dawson
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Alvaro F Nieto Guil
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Louise J Robertson
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Sandra G Piltz
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - James N Hughes
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Paul Q Thomas
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia; Precision Medicine Theme, South Australia Health and Medical Research Institute, Adelaide, SA 5000, Australia.
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27
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Kim JK, Lee JH. Mechanistic Target of Rapamycin Pathway in Epileptic Disorders. J Korean Neurosurg Soc 2019; 62:272-287. [PMID: 31085953 PMCID: PMC6514310 DOI: 10.3340/jkns.2019.0027] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 03/12/2019] [Indexed: 12/19/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) pathway coordinates the metabolic activity of eukaryotic cells through environmental signals, including nutrients, energy, growth factors, and oxygen. In the nervous system, the mTOR pathway regulates fundamental biological processes associated with neural development and neurodegeneration. Intriguingly, genes that constitute the mTOR pathway have been found to be germline and somatic mutation from patients with various epileptic disorders. Hyperactivation of the mTOR pathway due to said mutations has garnered increasing attention as culprits of these conditions : somatic mutations, in particular, in epileptic foci have recently been identified as a major genetic cause of intractable focal epilepsy, such as focal cortical dysplasia. Meanwhile, epilepsy models with aberrant activation of the mTOR pathway have helped elucidate the role of the mTOR pathway in epileptogenesis, and evidence from epilepsy models of human mutations recapitulating the features of epileptic patients has indicated that mTOR inhibitors may be of use in treating epilepsy associated with mutations in mTOR pathway genes. Here, we review recent advances in the molecular and genetic understanding of mTOR signaling in epileptic disorders. In particular, we focus on the development of and limitations to therapies targeting the mTOR pathway to treat epileptic seizures. We also discuss future perspectives on mTOR inhibition therapies and special diagnostic methods for intractable epilepsies caused by brain somatic mutations.
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Affiliation(s)
- Jang Keun Kim
- Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
| | - Jeong Ho Lee
- Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea.,Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
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28
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Raikwar SP, Kikkeri NS, Sakuru R, Saeed D, Zahoor H, Premkumar K, Mentor S, Thangavel R, Dubova I, Ahmed ME, Selvakumar GP, Kempuraj D, Zaheer S, Iyer SS, Zaheer A. Next Generation Precision Medicine: CRISPR-mediated Genome Editing for the Treatment of Neurodegenerative Disorders. J Neuroimmune Pharmacol 2019; 14:608-641. [PMID: 31011884 DOI: 10.1007/s11481-019-09849-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 03/29/2019] [Indexed: 12/13/2022]
Abstract
Despite significant advancements in the field of molecular neurobiology especially neuroinflammation and neurodegeneration, the highly complex molecular mechanisms underlying neurodegenerative diseases remain elusive. As a result, the development of the next generation neurotherapeutics has experienced a considerable lag phase. Recent advancements in the field of genome editing offer a new template for dissecting the precise molecular pathways underlying the complex neurodegenerative disorders. We believe that the innovative genome and transcriptome editing strategies offer an excellent opportunity to decipher novel therapeutic targets, develop novel neurodegenerative disease models, develop neuroimaging modalities, develop next-generation diagnostics as well as develop patient-specific precision-targeted personalized therapies to effectively treat neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, Huntington's disease, Amyotrophic lateral sclerosis, Frontotemporal dementia etc. Here, we review the latest developments in the field of CRISPR-mediated genome editing and provide unbiased futuristic insights regarding its translational potential to improve the treatment outcomes and minimize financial burden. However, despite significant advancements, we would caution the scientific community that since the CRISPR field is still evolving, currently we do not know the full spectrum of CRISPR-mediated side effects. In the wake of the recent news regarding CRISPR-edited human babies being born in China, we urge the scientific community to maintain high scientific and ethical standards and utilize CRISPR for developing in vitro disease in a dish model, in vivo testing in nonhuman primates and lower vertebrates and for the development of neurotherapeutics for the currently incurable neurodegenerative disorders. Graphical Abstract.
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Affiliation(s)
- Sudhanshu P Raikwar
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA.,U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Nidhi S Kikkeri
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Ragha Sakuru
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Daniyal Saeed
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Haris Zahoor
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Keerthivaas Premkumar
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Shireen Mentor
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA.,Department of Medical Biosciences, University of the Western Cape, Bellville, 7535, Republic of South Africa
| | - Ramasamy Thangavel
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA.,U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Iuliia Dubova
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA.,U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Mohammad Ejaz Ahmed
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA.,U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Govindhasamy P Selvakumar
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA.,U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Duraisamy Kempuraj
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA.,U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Smita Zaheer
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Shankar S Iyer
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA.,U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Asgar Zaheer
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA. .,U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA.
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29
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Marsan E, Baulac S. Review: Mechanistic target of rapamycin (mTOR) pathway, focal cortical dysplasia and epilepsy. Neuropathol Appl Neurobiol 2019; 44:6-17. [PMID: 29359340 DOI: 10.1111/nan.12463] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/17/2018] [Indexed: 12/19/2022]
Abstract
Over the last decade, there has been increasing evidence that hyperactivation of the mechanistic target of rapamycin (mTOR) pathway is a hallmark of malformations of cortical development such as focal cortical dysplasia (FCD) or hemimegalencephaly. The mTOR pathway governs protein and lipid synthesis, cell growth and proliferation as well as metabolism and autophagy. The molecular genetic aetiology of mTOR hyperactivation has only been recently clarified. This article will review the current and still evolving genetic advances in the elucidation of the molecular basis of FCD. Activating somatic mutations in the MTOR gene are to date the most frequent mutations found in FCD brain specimens.
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Affiliation(s)
- E Marsan
- Department of Genetics and Cytogenetics, AP-HP, Institut du Cerveau et de la Moelle Epinière (ICM) - Hôpital Pitié-Salpêtrière, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Inserm U1127, CNRS UMR 7225, Paris, France
| | - S Baulac
- Department of Genetics and Cytogenetics, AP-HP, Institut du Cerveau et de la Moelle Epinière (ICM) - Hôpital Pitié-Salpêtrière, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Inserm U1127, CNRS UMR 7225, Paris, France
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30
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Fullard JF, Charney AW, Voloudakis G, Uzilov AV, Haroutunian V, Roussos P. Assessment of somatic single-nucleotide variation in brain tissue of cases with schizophrenia. Transl Psychiatry 2019; 9:21. [PMID: 30655504 PMCID: PMC6336839 DOI: 10.1038/s41398-018-0342-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/15/2018] [Accepted: 11/13/2018] [Indexed: 12/20/2022] Open
Abstract
The genetic architecture of schizophrenia (SCZ) includes numerous risk loci across a range of frequencies and sizes, including common and rare single-nucleotide variants and insertions/deletions (indels), as well as rare copy number variants (CNVs). Despite the clear heritability of the disease, monozygotic twins are discordant for SCZ at a significant rate. Somatic variants-genetic changes that arise after fertilization rather than through germline inheritance-are widespread in the human brain and known to contribute to risk for both rare and common neuropsychiatric conditions. The contribution of somatic variants in the brain to risk of SCZ remains to be determined. In this study, we surveyed somatic single-nucleotide variants (sSNVs) in the brains of controls and individuals with SCZ (n = 10 and n = 9, respectively). From each individual, whole-exome sequencing (WES) was performed on DNA from neuronal and non-neuronal nuclei isolated by fluorescence activated nuclear sorting (FANS) from frozen postmortem prefrontal cortex (PFC) samples, as well as DNA extracted from temporal muscle as a reference. We identified an increased burden of sSNVs in cases compared to controls (SCZ rate = 2.78, control rate = 0.70; P = 0.0092, linear mixed effects model), that included a higher rate of non-synonymous and loss-of-function variants (SCZ rate = 1.33, control rate = 0.50; P = 0.047, linear mixed effects model). Our findings suggest sSNVs in the brain may constitute an additional component of the complex genetic architecture of SCZ. This perspective argues for the need to further investigate somatic variation in the brain as an explanation of the discordance in monozygotic twins and a potential guide to the identification of novel therapeutic targets.
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Affiliation(s)
- John F. Fullard
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA ,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, Institute for Genomics and Multiscale Biology, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Alexander W. Charney
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA ,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, Institute for Genomics and Multiscale Biology, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Georgios Voloudakis
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Andrew V. Uzilov
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, Institute for Genomics and Multiscale Biology, One Gustave L. Levy Place, New York, NY 10029 USA ,Sema4, 333 Ludlow Street, Stamford, CT 06902 USA
| | - Vahram Haroutunian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA ,0000 0004 0420 1184grid.274295.fMental Illness Research, Education, and Clinical Center (VISN 2 South), James J. Peters VA Medical Center, Bronx, NY 10468 USA
| | - Panos Roussos
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA. .,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, Institute for Genomics and Multiscale Biology, One Gustave L. Levy Place, New York, NY, 10029, USA. .,Mental Illness Research, Education, and Clinical Center (VISN 2 South), James J. Peters VA Medical Center, Bronx, NY, 10468, USA.
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Graber TG, Fry CS, Brightwell CR, Moro T, Maroto R, Bhattarai N, Porter C, Wakamiya M, Rasmussen BB. Skeletal muscle-specific knockout of DEP domain containing 5 protein increases mTORC1 signaling, muscle cell hypertrophy, and mitochondrial respiration. J Biol Chem 2019; 294:4091-4102. [PMID: 30635399 DOI: 10.1074/jbc.ra118.005970] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 01/09/2019] [Indexed: 11/06/2022] Open
Abstract
mTORC1 regulates protein synthesis and in turn is regulated by growth factors, energy status, and amino acid availability. In kidney cell (HEK293-T) culture, the GAP activity toward RAG (GATOR1) protein complex suppresses activation of the RAG A/B-RAG C/D heterodimer when amino acids are insufficient. During amino acid sufficiency, the RAG heterodimer recruits mTORC1 to the lysosomal membrane where its interaction with Ras homolog enriched in brain (Rheb) stimulates mTORC1's kinase activity. The DEP domain containing 5 (DEPDC5) protein, a GATOR1 subunit, causes familial focal epilepsy when mutated, and global knockout of the Depdc5 gene is embryonically lethal. To study the function of DEPDC5 in skeletal muscle, we generated a muscle-specific inducible Depdc5 knockout mouse, hypothesizing that knocking out Depdc5 in muscle would make mTORC1 constitutively active, causing hypertrophy and improving muscle function. Examining mTORC1 signaling, morphology, mitochondrial respiratory capacity, contractile function, and applied physical function (e.g. rotarod, treadmill, grip test, and wheel running), we observed that mTORC1 activity was significantly higher in knockout (KO) mice, indicated by the increased phosphorylation of mTOR and its downstream effectors (by 118% for p-mTOR/mTOR, 114% for p-S6K1/S6K1, and 35% for p-4E-BP1/4E-BP1). The KO animals also exhibited soleus muscle cell hypertrophy and a 2.5-fold increase in mitochondrial respiratory capacity. However, contrary to our hypothesis, neither physical nor contractile function improved. In conclusion, DEPDC5 depletion in adult skeletal muscle removes GATOR1 inhibition of mTORC1, resulting in muscle hypertrophy and increased mitochondrial respiration, but does not improve overall muscle quality and function.
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Affiliation(s)
- Ted G Graber
- From the Division of Rehabilitation Sciences.,the Department of Nutrition and Metabolism
| | | | | | | | | | | | | | - Maki Wakamiya
- the Transgenics Core Facility, University of Texas Medical Branch, Galveston, Texas 77555
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Abstract
Epilepsy is one of the most frequent neurological disorders characterized by spontaneous and recurrent seizures. Most seizures last for the lifetime and the patients require long term therapies. However, about 30% of the patients are refractory to antiepileptic drugs. Therefore, the need for newer and more effective therapies is urgent. Focal epilepsies, in which the abnormal electrical discharges occur within neuronal networks limited to one hemisphere, accounts for about 60% of all adult idiopathic epilepsy cases. Recently, mutations of DEPDC5 gene has been reported in wide spectrum of focal epilepsy syndromes. Most epilepsy genes encode ion channel or transmitter receptor, but DEPDC5 has no homology with them. DEPDC5 forms a complex, named GATOR1, together with other focal epilepsy related proteins NPRL2 and NPRL3. GATOR1 inhibits the mTORC1 pathway, regulating multiple cellular processes including cell growth and proliferation. The role of DEPDC5 in neuronal system is becoming clear from recent studies using the animal models. Because DEPDC5 is the most common causative gene in focal epilepsies and different from other epilepsy genes, DEPDC5 will be a key to understand epileptogenesis of various epilepsies, and provide new insight to develop new versatile therapies.
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Affiliation(s)
- Saeko Ishida
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU)
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Bourdeau Julien I, Sephton CF, Dutchak PA. Metabolic Networks Influencing Skeletal Muscle Fiber Composition. Front Cell Dev Biol 2018; 6:125. [PMID: 30324104 PMCID: PMC6172607 DOI: 10.3389/fcell.2018.00125] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 09/10/2018] [Indexed: 12/19/2022] Open
Abstract
Advancements in metabolomic and genomic research tools are revealing new insights into how metabolic networks can influence skeletal muscle fiber composition. In this mini-review, we summarize the recent progress of metabolite-dependent signaling pathways and transcriptional regulators that control glycolytic and oxidative metabolism and ultimately influence the type of fibers in muscle depots. These mechanisms expand the role of metabolites beyond that of basic building blocks of cellular components, and illustrate how particular metabolites can take an active role in regulating metabolic homeostasis and fiber adaptation. As new metabolite-dependent mechanisms emerge, ongoing metabolomic studies have begun to help explain why distinct metabolic pathways are used in different biological contexts and widen the view of seminal observations like the Warburg effect.
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Affiliation(s)
- Isabelle Bourdeau Julien
- Department of Psychiatry and Neuroscience, Université Laval, Quebec, QC, Canada.,CERVO Brain Research Centre, Quebec, QC, Canada
| | - Chantelle F Sephton
- Department of Psychiatry and Neuroscience, Université Laval, Quebec, QC, Canada.,CERVO Brain Research Centre, Quebec, QC, Canada
| | - Paul A Dutchak
- Department of Psychiatry and Neuroscience, Université Laval, Quebec, QC, Canada.,CERVO Brain Research Centre, Quebec, QC, Canada
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Loss of Leucyl-tRNA synthetase b leads to ILFS1-like symptoms in zebrafish. Biochem Biophys Res Commun 2018; 505:378-384. [PMID: 30262142 DOI: 10.1016/j.bbrc.2018.09.133] [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: 09/14/2018] [Accepted: 09/20/2018] [Indexed: 12/13/2022]
Abstract
Leucyl-tRNA synthetase (LARS) is a kind of aminoacyl-tRNA synthetases (aaRSs), which is important for protein synthesis. Following the discovery of three clinical cases which carry LARS mutations, it has been designated as the infantile liver failure syndrome type 1 (ILFS1) gene. ILFS1 is a kind of infantile hepatopathy, which is difficult to diagnose and manage. As the mechanism underlying this disease is poorly understood and LARS is conserved among vertebrates, we obtained zebrafish larsbcq68 mutant via CRISPR/Cas9 technology to investigate the role of larsb in vivo. In mutant, the proliferation ability of liver was drastically decreased at later stages accompanied with severe DNA damage. Further studies demonstrated that the mTORC1 signaling was hyperactivated in larsbcq68 mutant. Inhibition of mTORC1 signaling pathway by Rapamycin or mTORC1 morpholino can partially rescue the liver failure of the mutants. These data revealed that larsb mutation caused ILFS1-like phenotype in zebrafish, and indicated this mutant may serve as a potential model for ILFS1. Furthermore, we demonstrated that rapamycin treatment can partially rescue the liver defect in mutants, thus providing a practicable therapeutic plan for ILFS1.
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Baldassari S, Picard F, Verbeek NE, van Kempen M, Brilstra EH, Lesca G, Conti V, Guerrini R, Bisulli F, Licchetta L, Pippucci T, Tinuper P, Hirsch E, de Saint Martin A, Chelly J, Rudolf G, Chipaux M, Ferrand-Sorbets S, Dorfmüller G, Sisodiya S, Balestrini S, Schoeler N, Hernandez-Hernandez L, Krithika S, Oegema R, Hagebeuk E, Gunning B, Deckers C, Berghuis B, Wegner I, Niks E, Jansen FE, Braun K, de Jong D, Rubboli G, Talvik I, Sander V, Uldall P, Jacquemont ML, Nava C, Leguern E, Julia S, Gambardella A, d'Orsi G, Crichiutti G, Faivre L, Darmency V, Benova B, Krsek P, Biraben A, Lebre AS, Jennesson M, Sattar S, Marchal C, Nordli DR, Lindstrom K, Striano P, Lomax LB, Kiss C, Bartolomei F, Lepine AF, Schoonjans AS, Stouffs K, Jansen A, Panagiotakaki E, Ricard-Mousnier B, Thevenon J, de Bellescize J, Catenoix H, Dorn T, Zenker M, Müller-Schlüter K, Brandt C, Krey I, Polster T, Wolff M, Balci M, Rostasy K, Achaz G, Zacher P, Becher T, Cloppenborg T, Yuskaitis CJ, Weckhuysen S, Poduri A, Lemke JR, Møller RS, Baulac S. The landscape of epilepsy-related GATOR1 variants. Genet Med 2018; 21:398-408. [PMID: 30093711 PMCID: PMC6292495 DOI: 10.1038/s41436-018-0060-2] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/02/2018] [Indexed: 01/28/2023] Open
Abstract
Purpose To define the phenotypic and mutational spectrum of epilepsies related to DEPDC5, NPRL2 and NPRL3 genes encoding the GATOR1 complex, a negative regulator of the mTORC1 pathway Methods We analyzed clinical and genetic data of 73 novel probands (familial and sporadic) with epilepsy-related variants in GATOR1-encoding genes and proposed new guidelines for clinical interpretation of GATOR1 variants. Results The GATOR1 seizure phenotype consisted mostly in focal seizures (e.g., hypermotor or frontal lobe seizures in 50%), with a mean age at onset of 4.4 years, often sleep-related and drug-resistant (54%), and associated with focal cortical dysplasia (20%). Infantile spasms were reported in 10% of the probands. Sudden unexpected death in epilepsy (SUDEP) occurred in 10% of the families. Novel classification framework of all 140 epilepsy-related GATOR1 variants (including the variants of this study) revealed that 68% are loss-of-function pathogenic, 14% are likely pathogenic, 15% are variants of uncertain significance and 3% are likely benign. Conclusion Our data emphasize the increasingly important role of GATOR1 genes in the pathogenesis of focal epilepsies (>180 probands to date). The GATOR1 phenotypic spectrum ranges from sporadic early-onset epilepsies with cognitive impairment comorbidities to familial focal epilepsies, and SUDEP.
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Affiliation(s)
- Sara Baldassari
- Sorbonne Université, UPMC Univ Paris 06, UMR S 1127, F-75013, Paris, France.,INSERM, U1127, F-75013, Paris, France.,CNRS, UMR 7225, F-75013, Paris, France.,Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, F-75013, Paris, France.,Department of Genetics, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Fabienne Picard
- Department of Clinical Neurosciences, University Hospitals and Medical School of Geneva, Geneva, Switzerland
| | - Nienke E Verbeek
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marjan van Kempen
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Eva H Brilstra
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Gaetan Lesca
- Service de Génétique, Hospices Civils de Lyon - GHE; CNRS UMR 5292, INSERM U1028, CNRL, et Université Claude Bernard Lyon 1, GHE, Lyon, France
| | - Valerio Conti
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, A. Meyer Children's Hospital, Florence, Italy
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, A. Meyer Children's Hospital, Florence, Italy
| | - Francesca Bisulli
- IRCCS, Istituto delle Scienze Neurologiche of Bologna; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Laura Licchetta
- IRCCS, Istituto delle Scienze Neurologiche of Bologna; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Tommaso Pippucci
- Medical Genetics Unit, Polyclinic Sant' Orsola-Malpighi University Hospital, Bologna, Italy
| | - Paolo Tinuper
- IRCCS, Istituto delle Scienze Neurologiche of Bologna; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Edouard Hirsch
- Department of Neurology-centre de référence des épilepsies rares, University Hospital of Strasbourg, Strasbourg, France
| | - Anne de Saint Martin
- Department of Pediatrics - centre de référence des épilepsies rares, University Hospital of Strasbourg, Strasbourg, France
| | - Jamel Chelly
- IGBMC, INSERM, CNRS, Strasbourg University, Strasbourg, France
| | | | - Mathilde Chipaux
- Department of Pediatric Neurosurgery, Fondation Rothschild, F-75019, Paris, France
| | | | - Georg Dorfmüller
- Department of Pediatric Neurosurgery, Fondation Rothschild, F-75019, Paris, France
| | - Sanjay Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, WC1N 3BG, and Chalfont Centre for Epilepsy, Bucks, UK
| | - Simona Balestrini
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, WC1N 3BG, and Chalfont Centre for Epilepsy, Bucks, UK
| | - Natasha Schoeler
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, WC1N 3BG, and Chalfont Centre for Epilepsy, Bucks, UK
| | - Laura Hernandez-Hernandez
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, WC1N 3BG, and Chalfont Centre for Epilepsy, Bucks, UK
| | - S Krithika
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, WC1N 3BG, and Chalfont Centre for Epilepsy, Bucks, UK
| | - Renske Oegema
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Eveline Hagebeuk
- Stichting Epilepsie Instellingen Nederland, Zwolle/Heemstede, The Netherlands
| | - Boudewijn Gunning
- Stichting Epilepsie Instellingen Nederland, Zwolle/Heemstede, The Netherlands
| | - Charles Deckers
- Stichting Epilepsie Instellingen Nederland, Zwolle/Heemstede, The Netherlands
| | - Bianca Berghuis
- Stichting Epilepsie Instellingen Nederland, Zwolle/Heemstede, The Netherlands
| | - Ilse Wegner
- Stichting Epilepsie Instellingen Nederland, Zwolle/Heemstede, The Netherlands
| | - Erik Niks
- Leiden University Medical Center, Leiden, The Netherlands
| | - Floor E Jansen
- Department of Child Neurology, Brain Center Rudolf Magnus, University Medical Center, Utrecht, The Netherlands
| | - Kees Braun
- Department of Child Neurology, Brain Center Rudolf Magnus, University Medical Center, Utrecht, The Netherlands
| | - Daniëlle de Jong
- Department of Neurology, Academic Center for Epileptology Kempenhaeghe, Heeze, The Netherlands
| | - Guido Rubboli
- Danish Epilepsy Centre, Dianalund, University of Copenhagen, Copenhagen, Denmark
| | - Inga Talvik
- Department of Neurology and Rehabilitation, Tallinn Children's Hospital, Tallinn, Estonia
| | - Valentin Sander
- Department of Neurology and Rehabilitation, Tallinn Children's Hospital, Tallinn, Estonia
| | | | | | - Caroline Nava
- Sorbonne Université, UPMC Univ Paris 06, UMR S 1127, F-75013, Paris, France.,INSERM, U1127, F-75013, Paris, France.,CNRS, UMR 7225, F-75013, Paris, France.,Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, F-75013, Paris, France.,Department of Genetics, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Eric Leguern
- Sorbonne Université, UPMC Univ Paris 06, UMR S 1127, F-75013, Paris, France.,INSERM, U1127, F-75013, Paris, France.,CNRS, UMR 7225, F-75013, Paris, France.,Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, F-75013, Paris, France.,Department of Genetics, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Sophie Julia
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan CHU Toulouse, Toulouse, France
| | - Antonio Gambardella
- Institute of Neurology, Department of Medical and Surgical Sciences, University Magna Græcia, Catanzaro, Italy
| | - Giuseppe d'Orsi
- Epilepsy Center, Clinic of Nervous System Diseases, University of Foggia, Riuniti Hospital, Foggia, Italy
| | - Giovanni Crichiutti
- Department of Pediatrics, Institute of Medicine, University Hospital of Udine, Udine, Italy
| | - Laurence Faivre
- Centre de Référence Anomalies du Développement et Syndromes Malformatifs et FHU TRANSLAD, CHU de Dijon et Université de Bourgogne, Dijon, France
| | | | - Barbora Benova
- Department of Paediatric Neurology, Motol University Hospital, 2nd faculty of medicine Charles University, Prague, Czech Republic
| | - Pavel Krsek
- Department of Paediatric Neurology, Motol University Hospital, 2nd faculty of medicine Charles University, Prague, Czech Republic
| | - Arnaud Biraben
- Centre Hospitalier Universitaire de Rennes, F-35000, Rennes, France
| | - Anne-Sophie Lebre
- CHU Reims, Hôpital Maison Blanche, Pôle de Biologie, Service de Génétique, Reims, F-51092, France
| | - Mélanie Jennesson
- CHU Reims, American Memorial Hospital, Service de Pédiatrie, REIMS, F-51092, France
| | - Shifteh Sattar
- Department of Pediatric Neurology, Rady Children's Hospital/University of California, San Diego, California, USA
| | - Cécile Marchal
- Service d'Epileptologie Clinique, CHU de Bordeaux, France
| | - Douglas R Nordli
- Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Kristin Lindstrom
- Division of Genetics and Metabolism, Phoenix Children's Hospital, Phoenix, Arizona, USA
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, "G. Gaslini" Institute, Genova, Italy
| | - Lysa Boissé Lomax
- Department of Medicine, Divisions of Neurology and Respirology, Queen's University, Kingston, Ontario, Canada.,Kingston Health Sciences Centre, Kingston, Ontario, K7L 2V7, Canada
| | - Courtney Kiss
- Kingston Health Sciences Centre, Kingston, Ontario, K7L 2V7, Canada
| | - Fabrice Bartolomei
- Pediatric Neurology Department, Timone Hospital, APHM, Marseille, France
| | | | - An-Sofie Schoonjans
- Department of Pediatric Neurology, Antwerp University Hospital, Edegem, Belgium
| | - Katrien Stouffs
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Neurogenetics Research Group, Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Anna Jansen
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Neurogenetics Research Group, Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Eleni Panagiotakaki
- Paediatric Clinical Epileptology, Sleep disorders and Functional Neurology, University Hospitals of Lyon (HCL), Lyon, France
| | | | - Julien Thevenon
- Inserm UMR 1231 GAD Team, Genetics of Developmental Anomalies, et FHU-TRANSLAD, CHU/Université de Bourgogne-Franche Comté, Dijon, France
| | - Julitta de Bellescize
- Paediatric Clinical Epileptology, Sleep disorders and Functional Neurology, University Hospitals of Lyon (HCL), Lyon, France
| | - Hélène Catenoix
- Paediatric Clinical Epileptology, Sleep disorders and Functional Neurology, University Hospitals of Lyon (HCL), Lyon, France
| | - Thomas Dorn
- Clinique Bernoise, Crans-, Montana, Switzerland
| | - Martin Zenker
- Institute of Human Genetics, University Hospital, Magdeburg, Germany
| | - Karen Müller-Schlüter
- Epilepsy Center for Children, Brandenburg Medical School, University Hospital, Neuruppin, Germany
| | | | - Ilona Krey
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany
| | | | - Markus Wolff
- Department of Pediatric Neurology and Developmental Medicine, University Children's Hospital, Tübingen, Germany
| | - Meral Balci
- Department of Pediatric Neurology, Children's Hospital Datteln, Witten/Herdecke University, Datteln, Germany
| | - Kevin Rostasy
- Department of Pediatric Neurology, Children's Hospital Datteln, Witten/Herdecke University, Datteln, Germany
| | - Guillaume Achaz
- Institut de Systématique, Evolution, Biodiversité, ISYEB, UMR 7205 CNRS MNHN UPMC EPHE, Paris, France
| | - Pia Zacher
- The Saxon Epilepsy Center Kleinwachau, Radeberg, Germany
| | - Thomas Becher
- Kinderneurologisches Zentrum, Düsseldorf-Gerresheim, Sana Kliniken, Düsseldorf, Germany
| | | | - Christopher J Yuskaitis
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts, USA.,Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Neurology, Harvard Medical School, Boston, Massachusetts, USA
| | - Sarah Weckhuysen
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium
| | - Annapurna Poduri
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts, USA.,Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Neurology, Harvard Medical School, Boston, Massachusetts, USA
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany
| | - Rikke S Møller
- Danish Epilepsy Centre, Dianalund; Institute for Regional Health research, University of Southern Denmark, Odense, Denmark
| | - Stéphanie Baulac
- Sorbonne Université, UPMC Univ Paris 06, UMR S 1127, F-75013, Paris, France. .,INSERM, U1127, F-75013, Paris, France. .,CNRS, UMR 7225, F-75013, Paris, France. .,Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, F-75013, Paris, France. .,Department of Genetics, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, F-75013, Paris, France.
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37
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Ribierre T, Deleuze C, Bacq A, Baldassari S, Marsan E, Chipaux M, Muraca G, Roussel D, Navarro V, Leguern E, Miles R, Baulac S. Second-hit mosaic mutation in mTORC1 repressor DEPDC5 causes focal cortical dysplasia-associated epilepsy. J Clin Invest 2018; 128:2452-2458. [PMID: 29708508 PMCID: PMC5983335 DOI: 10.1172/jci99384] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/06/2018] [Indexed: 01/04/2023] Open
Abstract
DEP domain-containing 5 protein (DEPDC5) is a repressor of the recently recognized amino acid-sensing branch of the mTORC1 pathway. So far, its function in the brain remains largely unknown. Germline loss-of-function mutations in DEPDC5 have emerged as a major cause of familial refractory focal epilepsies, with case reports of sudden unexpected death in epilepsy (SUDEP). Remarkably, a fraction of patients also develop focal cortical dysplasia (FCD), a neurodevelopmental cortical malformation. We therefore hypothesized that a somatic second-hit mutation arising during brain development may support the focal nature of the dysplasia. Here, using postoperative human tissue, we provide the proof of concept that a biallelic 2-hit - brain somatic and germline - mutational mechanism in DEPDC5 causes focal epilepsy with FCD. We discovered a mutation gradient with a higher rate of mosaicism in the seizure-onset zone than in the surrounding epileptogenic zone. Furthermore, we demonstrate the causality of a Depdc5 brain mosaic inactivation using CRISPR-Cas9 editing and in utero electroporation in a mouse model recapitulating focal epilepsy with FCD and SUDEP-like events. We further unveil a key role of Depdc5 in shaping dendrite and spine morphology of excitatory neurons. This study reveals promising therapeutic avenues for treating drug-resistant focal epilepsies with mTORC1-targeting molecules.
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Affiliation(s)
- Théo Ribierre
- Institut du Cerveau et de la Moelle épinière (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Charlotte Deleuze
- Institut du Cerveau et de la Moelle épinière (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Alexandre Bacq
- Institut du Cerveau et de la Moelle épinière (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Sara Baldassari
- Institut du Cerveau et de la Moelle épinière (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Elise Marsan
- Institut du Cerveau et de la Moelle épinière (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Mathilde Chipaux
- Department of Pediatric Neurosurgery, Fondation Rothschild, Paris, France
| | - Giuseppe Muraca
- Institut du Cerveau et de la Moelle épinière (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Delphine Roussel
- Institut du Cerveau et de la Moelle épinière (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Vincent Navarro
- Institut du Cerveau et de la Moelle épinière (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
- Epileptology Unit, and
| | - Eric Leguern
- Institut du Cerveau et de la Moelle épinière (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
- Department of Genetics, Assistance Publique – Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, Paris, France
| | - Richard Miles
- Institut du Cerveau et de la Moelle épinière (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Stéphanie Baulac
- Institut du Cerveau et de la Moelle épinière (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
- Department of Genetics, Assistance Publique – Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, Paris, France
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38
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Swaminathan A, Hassan-Abdi R, Renault S, Siekierska A, Riché R, Liao M, de Witte PAM, Yanicostas C, Soussi-Yanicostas N, Drapeau P, Samarut É. Non-canonical mTOR-Independent Role of DEPDC5 in Regulating GABAergic Network Development. Curr Biol 2018; 28:1924-1937.e5. [PMID: 29861134 DOI: 10.1016/j.cub.2018.04.061] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 02/13/2018] [Accepted: 04/17/2018] [Indexed: 01/19/2023]
Abstract
Mutations in DEPDC5 are causal factors for a broad spectrum of focal epilepsies, but the underlying pathogenic mechanisms are still largely unknown. To address this question, a zebrafish depdc5 knockout model showing spontaneous epileptiform events in the brain, increased drug-induced seizure susceptibility, general hypoactivity, premature death at 2-3 weeks post-fertilization, as well as the expected hyperactivation of mTOR signaling was developed. Using this model, the role of DEPDC5 in brain development was investigated using an unbiased whole-transcriptomic approach. Surprisingly, in addition to mTOR-associated genes, many genes involved in synaptic function, neurogenesis, axonogenesis, and GABA network activity were found to be dysregulated in larval brains. Although no gross defects in brain morphology or neuron loss were observed, immunostaining of depdc5-/- brains for several GABAergic markers revealed specific defects in the fine branching of the GABAergic network. Consistently, some defects in depdc5-/- could be compensated for by treatment with GABA, corroborating that GABA signaling is indeed involved in DEPDC5 pathogenicity. Further, the mTOR-independent nature of these neurodevelopmental defects was demonstrated by the inability of rapamycin to rescue the GABAergic network defects observed in depdc5-/- brains and, conversely, the inability of GABA to rescue the hypoactivity in another genetic model showing mTOR hyperactivation. This study hence provides the first in vivo evidence that DEPDC5 plays previously unknown roles apart from its canonical function as an mTOR inhibitor. Moreover, these results propose that defective neurodevelopment of GABAergic networks could be a key factor in epileptogenesis when DEPDC5 is mutated.
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Affiliation(s)
- Amrutha Swaminathan
- Department of Neurosciences, Research Center of the University of Montréal Hospital Center (CRCHUM), Université de Montréal, Montréal, QC, Canada H2X 0A9
| | - Rahma Hassan-Abdi
- Inserm, U1141, F-75019 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, UMRS 1141, F-75019 Paris, France
| | - Solène Renault
- Inserm, U1141, F-75019 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, UMRS 1141, F-75019 Paris, France
| | - Aleksandra Siekierska
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, 3000 Leuven, Belgium
| | - Raphaëlle Riché
- Department of Neurosciences, Research Center of the University of Montréal Hospital Center (CRCHUM), Université de Montréal, Montréal, QC, Canada H2X 0A9
| | - Meijiang Liao
- Department of Neurosciences, Research Center of the University of Montréal Hospital Center (CRCHUM), Université de Montréal, Montréal, QC, Canada H2X 0A9
| | - Peter A M de Witte
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, 3000 Leuven, Belgium
| | - Constantin Yanicostas
- Inserm, U1141, F-75019 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, UMRS 1141, F-75019 Paris, France
| | - Nadia Soussi-Yanicostas
- Inserm, U1141, F-75019 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, UMRS 1141, F-75019 Paris, France
| | - Pierre Drapeau
- Department of Neurosciences, Research Center of the University of Montréal Hospital Center (CRCHUM), Université de Montréal, Montréal, QC, Canada H2X 0A9; DanioDesign, Montréal, QC, Canada.
| | - Éric Samarut
- Department of Neurosciences, Research Center of the University of Montréal Hospital Center (CRCHUM), Université de Montréal, Montréal, QC, Canada H2X 0A9; DanioDesign, Montréal, QC, Canada.
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39
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de Calbiac H, Dabacan A, Marsan E, Tostivint H, Devienne G, Ishida S, Leguern E, Baulac S, Muresan RC, Kabashi E, Ciura S. Depdc5 knockdown causes mTOR-dependent motor hyperactivity in zebrafish. Ann Clin Transl Neurol 2018; 5:510-523. [PMID: 29761115 PMCID: PMC5945968 DOI: 10.1002/acn3.542] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 01/18/2018] [Indexed: 12/18/2022] Open
Abstract
Objective DEPDC5 was identified as a major genetic cause of focal epilepsy with deleterious mutations found in a wide range of inherited forms of focal epilepsy, associated with malformation of cortical development in certain cases. Identification of frameshift, truncation, and deletion mutations implicates haploinsufficiency of DEPDC5 in the etiology of focal epilepsy. DEPDC5 is a component of the GATOR1 complex, acting as a negative regulator of mTOR signaling. Methods Zebrafish represents a vertebrate model suitable for genetic analysis and drug screening in epilepsy-related disorders. In this study, we defined the expression of depdc5 during development and established an epilepsy model with reduced Depdc5 expression. Results Here we report a zebrafish model of Depdc5 loss-of-function that displays a measurable behavioral phenotype, including hyperkinesia, circular swimming, and increased neuronal activity. These phenotypic features persisted throughout embryonic development and were significantly reduced upon treatment with the mTORC1 inhibitor, rapamycin, as well as overexpression of human WT DEPDC5 transcript. No phenotypic rescue was obtained upon expression of epilepsy-associated DEPDC5 mutations (p.Arg487* and p.Arg485Gln), indicating that these mutations cause a loss of function of the protein. Interpretation This study demonstrates that Depdc5 knockdown leads to early-onset phenotypic features related to motor and neuronal hyperactivity. Restoration of phenotypic features by WT but not epilepsy-associated Depdc5 mutants, as well as by mTORC1 inhibition confirm the role of Depdc5 in the mTORC1-dependent molecular cascades, defining this pathway as a potential therapeutic target for DEPDC5-inherited forms of focal epilepsy.
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Affiliation(s)
- Hortense de Calbiac
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France.,Institut Imagine UMR Inserm 1163 University Paris Descartes Hospital Necker-Enfants Malades 24 Boulevard du Montparnasse Paris 75015 France
| | - Adriana Dabacan
- Transylvanian Institute of Neuroscience (TINS) Str. Ploiesti 33 Cluj-Napoca 400157 Romania
| | - Elise Marsan
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France
| | - Hervé Tostivint
- Evolution des Régulations Endocriniennes UMR 7221 CNRS and Muséum National d'Histoire Naturelle Paris France
| | - Gabrielle Devienne
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France
| | - Saeko Ishida
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France
| | - Eric Leguern
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France
| | - Stéphanie Baulac
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France
| | - Raul C Muresan
- Transylvanian Institute of Neuroscience (TINS) Str. Ploiesti 33 Cluj-Napoca 400157 Romania
| | - Edor Kabashi
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France.,Institut Imagine UMR Inserm 1163 University Paris Descartes Hospital Necker-Enfants Malades 24 Boulevard du Montparnasse Paris 75015 France
| | - Sorana Ciura
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France.,Institut Imagine UMR Inserm 1163 University Paris Descartes Hospital Necker-Enfants Malades 24 Boulevard du Montparnasse Paris 75015 France
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