1
|
Liu J, Hu D, Zhang Z, Tang F, Yan Y, Ma Y. Autosomal dominant lateral temporal epilepsy in a family exhibiting a rare heterozygous mutation and deletion in the leucine-rich glioma inactivated 1 gene. Neurosci Lett 2022; 782:136698. [PMID: 35643238 DOI: 10.1016/j.neulet.2022.136698] [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: 02/13/2022] [Revised: 05/08/2022] [Accepted: 05/23/2022] [Indexed: 11/24/2022]
Abstract
Autosomal dominant lateral temporal epilepsy (ADLTE) is an inherited syndrome caused by mutations in the leucine-rich glioma inactivated 1 (LGI1) gene. In a family with six ADLTE patients spanning four generations, our linkage and exome sequencing investigations revealed a rare frameshift heterozygous mutation in LGI1 (c.1494del(p.Phe498LeufsTer15)). Gene cloning methods were used to create plasmids with wild-type and mutant LGI1 alleles. Through transfection of HEK293 cells and primary neurons, they were utilized to assess the subcellular location of wild-type and mutant LGI1. Moreover, the plasmid-transfected primary neurons were analyzed for neuronal complexity and density of dendritic spines. According to our results. the mutation decreased LGI1 secretion in transfected HEK293 cells. In primary neurons, mutant LGI1 affected neuronal polarity and complexity. Our findings have broadened the phenotypic spectrum of LGI1 mutations and provided evidence regarding the pathogenicity of this mutation. In addition, we discovered new information about the role of LGI1 in the development of temporal lobe epilepsy, along with a possible link between neuronal polarity disorder and ADLTE.
Collapse
Affiliation(s)
- Jie Liu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Danmei Hu
- Department of Neurology, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan 030032, China
| | - Zhijuan Zhang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Fenglin Tang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Yin Yan
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China
| | - Yuanlin Ma
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China.
| |
Collapse
|
2
|
Li Y, Zhao X, Wang S, Xu K, Zhao X, Huang S, Zhu S. A Novel Loss-of-Function Mutation in the NPRL3 Gene Identified in Chinese Familial Focal Epilepsy with Variable Foci. Front Genet 2021; 12:766354. [PMID: 34868250 PMCID: PMC8633433 DOI: 10.3389/fgene.2021.766354] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 10/20/2021] [Indexed: 11/18/2022] Open
Abstract
Familial focal epilepsy with variable foci is an autosomal dominant disorder characterized by partial epilepsy with variable foci. In this study, we report a six-generation with segregation of the mutation present in four generations Chinese family presenting with focal epilepsy with variable foci. Whole exome sequencing confirms a novel pathogenic mutation in the NPRL3 gene (c316C>T; p. Q106*). PCR, Western blotting, and immunohistochemistry were conducted to analyze the gene transcription, protein expression, and subcellular localization of NPRL3 and related signaling molecules in peripheral blood cells from family members. As compared with healthy family members, both mRNA level and protein expression of NPRL3 are decreased in peripheral blood cells of the mutation carrier. In addition, the expression of downstream molecular Phospho-p70 S6 kinase (P-s6k) are increased consequently. Our findings expand the genotypic and phenotypic spectrum of the NPRL3-associated epilepsy and reveal the mechanisms of mTOR pathway signaling and GATOR1 pathogenesis in focal epilepsies, providing exciting potential for future diagnostic and therapeutic interventions. However, further in vitro and animal experiments are still needed to evaluate the role of NPRL3 loss-of-function mutation in epileptogensis.
Collapse
Affiliation(s)
- Youzhi Li
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xu Zhao
- Department of Radiology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shanshan Wang
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ke Xu
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xin Zhao
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shanshan Huang
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Suiqiang Zhu
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| |
Collapse
|
3
|
Abstract
INTRODUCTION Focal cortical dysplasias (FCDs) represent the most common etiology in pediatric drug-resistant focal epilepsies undergoing surgical treatment. The localization, extent and histopathological features of FCDs are considerably variable. Somatic mosaic mutations of genes that encode proteins in the PI3K-AKTmTOR pathway, which also includes the tuberous sclerosis associated genes TSC1 and TSC2, have been implicated in FCD type II in a substantial subset of patients. Surgery is the principal therapeutic option for FCD-related epilepsy. Advanced neurophysiological and neuroimaging techniques have improved surgical outcome and reduced the risk of postsurgical deficits. Pharmacological MTOR inhibitors are being tested in clinical trials and might represent an example of personalized treatment of epilepsy based on the known mechanisms of disease, used alone or in combination with surgery. AREAS COVERED This review will critically analyze the advances in the diagnosis and treatment of FCDs, with a special focus on the novel therapeutic options prompted by a better understanding of their pathophysiology. EXPERT OPINION Focal cortical dysplasia is a main cause of drug-resistant epilepsy, especially in children. Novel, personalized approaches are needed to more effectively treat FCD-related epilepsy and its cognitive consequences.
Collapse
Affiliation(s)
- Renzo Guerrini
- Neuroscience Department, Children's Hospital Meyer-University of Florence, Florence, Italy
| | - Carmen Barba
- Neuroscience Department, Children's Hospital Meyer-University of Florence, Florence, Italy
| |
Collapse
|
4
|
Yamagata A, Fukai S. Insights into the mechanisms of epilepsy from structural biology of LGI1-ADAM22. Cell Mol Life Sci 2020; 77:267-274. [PMID: 31432233 PMCID: PMC11104983 DOI: 10.1007/s00018-019-03269-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 08/05/2019] [Accepted: 08/09/2019] [Indexed: 01/05/2023]
Abstract
Epilepsy is one of the most common brain disorders, which can be caused by abnormal synaptic transmissions. Many epilepsy-related mutations have been identified in synaptic ion channels, which are main targets for current antiepileptic drugs. One of the novel potential targets for therapy of epilepsy is a class of non-ion channel-type epilepsy-related proteins. The leucine-rich repeat glioma-inactivated protein 1 (LGI1) is a neuronal secreted protein, and has been extensively studied as a product of a causative gene for autosomal dominant lateral temporal lobe epilepsy (ADLTE; also known as autosomal dominant partial epilepsy with auditory features [ADPEAF]). At least 43 mutations of LGI1 have been found in ADLTE families. Additionally, autoantibodies against LGI1 in limbic encephalitis are associated with amnesia, seizures, and cognitive dysfunction. Although the relationship of LGI1 with synaptic transmission and synaptic disorders has been studied genetically, biochemically, and clinically, the structural mechanism of LGI1 remained largely unknown until recently. In this review, we introduce insights into pathogenic mechanisms of LGI1 from recent structural studies on LGI1 and its receptor, ADAM22. We also discuss the mechanism for pathogenesis of autoantibodies against LGI1, and the potential of chemical correctors as novel drugs for epilepsy, with structural aspects of LGI1-ADAM22.
Collapse
Affiliation(s)
- Atsushi Yamagata
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.
- Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8561, Japan.
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa, 230-0045, Japan.
| | - Shuya Fukai
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.
- Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8561, Japan.
| |
Collapse
|
5
|
Matsushima N, Takatsuka S, Miyashita H, Kretsinger RH. Leucine Rich Repeat Proteins: Sequences, Mutations, Structures and Diseases. Protein Pept Lett 2019; 26:108-131. [PMID: 30526451 DOI: 10.2174/0929866526666181208170027] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 11/26/2018] [Accepted: 11/26/2018] [Indexed: 12/18/2022]
Abstract
Mutations in the genes encoding Leucine Rich Repeat (LRR) containing proteins are associated with over sixty human diseases; these include high myopia, mitochondrial encephalomyopathy, and Crohn's disease. These mutations occur frequently within the LRR domains and within the regions that shield the hydrophobic core of the LRR domain. The amino acid sequences of fifty-five LRR proteins have been published. They include Nod-Like Receptors (NLRs) such as NLRP1, NLRP3, NLRP14, and Nod-2, Small Leucine Rich Repeat Proteoglycans (SLRPs) such as keratocan, lumican, fibromodulin, PRELP, biglycan, and nyctalopin, and F-box/LRR-repeat proteins such as FBXL2, FBXL4, and FBXL12. For example, 363 missense mutations have been identified. Replacement of arginine, proline, or cysteine by another amino acid, or the reverse, is frequently observed. The diverse effects of the mutations are discussed based on the known structures of LRR proteins. These mutations influence protein folding, aggregation, oligomerization, stability, protein-ligand interactions, disulfide bond formation, and glycosylation. Most of the mutations cause loss of function and a few, gain of function.
Collapse
Affiliation(s)
- Norio Matsushima
- Center for Medical Education, Sapporo Medical University, Sapporo 060-8556, Japan.,Institute of Tandem Repeats, Noboribetsu 059-0464, Japan
| | - Shintaro Takatsuka
- Center for Medical Education, Sapporo Medical University, Sapporo 060-8556, Japan
| | - Hiroki Miyashita
- Institute of Tandem Repeats, Noboribetsu 059-0464, Japan.,Hokubu Rinsho Co., Ltd, Sapporo 060-0061, Japan
| | - Robert H Kretsinger
- Department of Biology, University of Virginia, Charlottesville, VA 22904, United States
| |
Collapse
|
6
|
Zhang L, Zhu X, Zou X, Chen L. Factors predicting uncontrolled seizures in epilepsy with auditory features. Seizure 2019; 65:55-61. [PMID: 30612076 DOI: 10.1016/j.seizure.2018.12.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 12/21/2018] [Accepted: 12/24/2018] [Indexed: 02/05/2023] Open
Abstract
PURPOSE To analyse the factors predicting uncontrolled seizures in epilepsy with auditory features (EAF). METHODS We analysed individual data from EAF patients who were previously reported. Two authors independently reviewed the titles and abstracts identified and extracted data from each eligible study using a standardized form. The outcome measure was uncontrolled seizures. The odds ratio (OR) and 95% confidence interval (CI) were used. RESULTS A total of 27 studies including 181 patients with familial and sporadic EAF met our inclusion criteria. None of the clinical factors appeared to affect seizure outcomes significantly except that treatment with carbamazepine was a protective factor against uncontrolled seizures (OR = 0.399, 95% CI: 0.195-0.820, p = 0.012), and polytherapy was associated with uncontrolled seizures. Treatment with carbamazepine was also a protective factor against uncontrolled seizures for families with LGI1 mutations (OR = 0.248, 95% CI: 0.085-0.724, p = 0.011). Carbamazepine might have a better efficacy in patients with frequent seizures (p = 0.041). Low-dose carbamazepine might completely control seizures in some EAF patients, although other effective doses of antiepileptic drugs might not. Patients without carbamazepine treatment were more likely to use new antiepileptic drugs, which might be due to the higher rate of uncontrolled seizures. CONCLUSIONS Carbamazepine treatment is a protective factor against uncontrolled seizures for EAF. However, this evidence is not strong enough to state that carbamazepine is the first choice drug for EAF.
Collapse
Affiliation(s)
- Lin Zhang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Xi Zhu
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaoyi Zou
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Lei Chen
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China.
| |
Collapse
|
7
|
Structural basis of epilepsy-related ligand-receptor complex LGI1-ADAM22. Nat Commun 2018; 9:1546. [PMID: 29670100 PMCID: PMC5906670 DOI: 10.1038/s41467-018-03947-w] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 03/23/2018] [Indexed: 01/17/2023] Open
Abstract
Epilepsy is a common brain disorder throughout history. Epilepsy-related ligand–receptor complex, LGI1–ADAM22, regulates synaptic transmission and has emerged as a determinant of brain excitability, as their mutations and acquired LGI1 autoantibodies cause epileptic disorders in human. Here, we report the crystal structure of human LGI1–ADAM22 complex, revealing a 2:2 heterotetrameric assembly. The hydrophobic pocket of the C-terminal epitempin-repeat (EPTP) domain of LGI1 binds to the metalloprotease-like domain of ADAM22. The N-terminal leucine-rich repeat and EPTP domains of LGI1 mediate the intermolecular LGI1–LGI1 interaction. A pathogenic R474Q mutation of LGI1, which does not exceptionally affect either the secretion or the ADAM22 binding, is located in the LGI1–LGI1 interface and disrupts the higher-order assembly of the LGI1–ADAM22 complex in vitro and in a mouse model for familial epilepsy. These studies support the notion that the LGI1–ADAM22 complex functions as the trans-synaptic machinery for precise synaptic transmission. LGI1 is an epilepsy-related gene that encodes a secreted neuronal protein. Here the authors present the crystal structure of LGI1 bound to its receptor ADAM22, which provides structural insights into epilepsy-causing LGI1 mutations and might facilitate the development of novel anti-epilepsy drugs.
Collapse
|
8
|
Lascano AM, Korff CM, Picard F. Seizures and Epilepsies due to Channelopathies and Neurotransmitter Receptor Dysfunction: A Parallel between Genetic and Immune Aspects. Mol Syndromol 2016; 7:197-209. [PMID: 27781030 DOI: 10.1159/000447707] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Despite intensive research activity leading to many important discoveries, the pathophysiological mechanisms underlying seizures and epilepsy remain poorly understood. An important number of specific gene defects have been related to various forms of epilepsies, and autoimmunity and epilepsy have been associated for a long time. Certain central nervous system proteins have been involved in epilepsy or acute neurological diseases with seizures either due to underlying gene defects or immune dysfunction. Here, we focus on 2 of them that have been the object of particular attention and in-depth research over the past years: the N-methyl-D-aspartate receptor and the leucin-rich glioma-inactivated protein 1 (LGI1). We also describe illustrative examples of situations in which genetics and immunology meet in the complex pathways that underlie seizures and epilepsy.
Collapse
Affiliation(s)
- Agustina M Lascano
- EEG and Epilepsy Exploration Unit, University Hospitals Geneva, Geneva, Switzerland
| | - Christian M Korff
- Pediatric Neurology Unit, Child and Adolescent Department, University Hospitals Geneva, Geneva, Switzerland
| | - Fabienne Picard
- EEG and Epilepsy Exploration Unit, University Hospitals Geneva, Geneva, Switzerland
| |
Collapse
|