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Najafi P, Reimer C, Gilthorpe JD, Jacobsen KR, Ramløse M, Paul NF, Simianer H, Tetens J, Falker-Gieske C. Genomic evidence for the suitability of Göttingen Minipigs with a rare seizure phenotype as a model for human epilepsy. Neurogenetics 2024; 25:103-117. [PMID: 38383918 PMCID: PMC11076379 DOI: 10.1007/s10048-024-00750-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 02/02/2024] [Indexed: 02/23/2024]
Abstract
Epilepsy is a complex genetic disorder that affects about 2% of the global population. Although the frequency and severity of epileptic seizures can be reduced by a range of pharmacological interventions, there are no disease-modifying treatments for epilepsy. The development of new and more effective drugs is hindered by a lack of suitable animal models. Available rodent models may not recapitulate all key aspects of the disease. Spontaneous epileptic convulsions were observed in few Göttingen Minipigs (GMPs), which may provide a valuable alternative animal model for the characterisation of epilepsy-type diseases and for testing new treatments. We have characterised affected GMPs at the genome level and have taken advantage of primary fibroblast cultures to validate the functional impact of fixed genetic variants on the transcriptome level. We found numerous genes connected to calcium metabolism that have not been associated with epilepsy before, such as ADORA2B, CAMK1D, ITPKB, MCOLN2, MYLK, NFATC3, PDGFD, and PHKB. Our results have identified two transcription factor genes, EGR3 and HOXB6, as potential key regulators of CACNA1H, which was previously linked to epilepsy-type disorders in humans. Our findings provide the first set of conclusive results to support the use of affected subsets of GMPs as an alternative and more reliable model system to study human epilepsy. Further neurological and pharmacological validation of the suitability of GMPs as an epilepsy model is therefore warranted.
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Affiliation(s)
- Pardis Najafi
- Department of Animal Sciences, Georg-August-University, Burckhardtweg 2, 37077, Göttingen, Germany
- Center for Integrated Breeding Research, Georg-August-University, Albrecht-Thaer-Weg 3, 37075, Göttingen, Germany
| | - Christian Reimer
- Center for Integrated Breeding Research, Georg-August-University, Albrecht-Thaer-Weg 3, 37075, Göttingen, Germany
- Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Höltystr. 10, 31535, Neustadt, Germany
| | - Jonathan D Gilthorpe
- Department of Integrative Medical Biology, Umeå University, 901 87, Umeå, Sweden
| | - Kirsten R Jacobsen
- Ellegaard Göttingen Minipigs A/S, Sorø Landevej 302, 4261, Dalmose, Denmark
| | - Maja Ramløse
- Ellegaard Göttingen Minipigs A/S, Sorø Landevej 302, 4261, Dalmose, Denmark
| | - Nora-Fabienne Paul
- Department of Animal Sciences, Georg-August-University, Burckhardtweg 2, 37077, Göttingen, Germany
| | - Henner Simianer
- Department of Animal Sciences, Georg-August-University, Burckhardtweg 2, 37077, Göttingen, Germany
- Center for Integrated Breeding Research, Georg-August-University, Albrecht-Thaer-Weg 3, 37075, Göttingen, Germany
| | - Jens Tetens
- Department of Animal Sciences, Georg-August-University, Burckhardtweg 2, 37077, Göttingen, Germany
- Center for Integrated Breeding Research, Georg-August-University, Albrecht-Thaer-Weg 3, 37075, Göttingen, Germany
| | - Clemens Falker-Gieske
- Department of Animal Sciences, Georg-August-University, Burckhardtweg 2, 37077, Göttingen, Germany.
- Center for Integrated Breeding Research, Georg-August-University, Albrecht-Thaer-Weg 3, 37075, Göttingen, Germany.
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Bai S, Chen L, Yan Y, Wang X, Jiang A, Li R, Kang H, Feng Z, Li G, Ma W, Zhang J, Ren J. Identification of Hypoxia-Immune-Related Gene Signatures and Construction of a Prognostic Model in Kidney Renal Clear Cell Carcinoma. Front Cell Dev Biol 2022; 9:796156. [PMID: 35211477 PMCID: PMC8860910 DOI: 10.3389/fcell.2021.796156] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 12/23/2021] [Indexed: 12/24/2022] Open
Abstract
Introduction: Kidney renal clear cell carcinoma (KIRC), a kind of malignant disease, is a severe threat to public health. Tracking the information of tumor progression and conducting a related dynamic prognosis model are necessary for KIRC. It is crucial to identify hypoxia-immune-related genes and construct a prognostic model due to immune interaction and the influence of hypoxia in the prognosis of patients with KIRC. Methods: The hypoxia and immune status of KIRC patients were identified by utilizing t-SNE and ImmuCellAI for gene expression data. COX and Lasso regression were used to identify some hypoxia-immune-related signature genes and further construct a prognostic risk model based on these genes. Internal and external validations were also conducted to construct a prognostic model. Finally, some potentially effective drugs were screened by the CMap dataset. Results: We found that high-hypoxia and low-immune status tend to induce poor overall survival (OS). Six genes, including PLAUR, UCN, PABPC1L, SLC16A12, NFE2L3, and KCNAB1, were identified and involved in our hypoxia-immune-related prognostic risk model. Internal verification showed that the area under the curve (AUC) for the constructed models for 1-, 3-, 4-, and 5-year OS were 0.768, 0.754, 0.775, and 0.792, respectively. For the external verification, the AUC for 1-, 3-, 4-, and 5-year OS were 0.768, 0.739, 0.763, and 0.643 respectively. Furthermore, the decision curve analysis findings demonstrated excellent clinical effectiveness. Finally, we found that four drugs (including vorinostat, fludroxycortide, oxolinic acid, and flutamide) might be effective and efficient in alleviating or reversing the status of severe hypoxia and poor infiltration of immune cells. Conclusion: Our constructed prognostic model, based on hypoxia-immune-related genes, has excellent effectiveness and clinical application value. Moreover, some small-molecule drugs are screened to alleviate severe hypoxia and poor infiltration of immune cells.
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Affiliation(s)
- Shuheng Bai
- Department of Radiotherapy, Oncology Department, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Ling Chen
- Department of Chemotherapy, Oncology Department, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Yanli Yan
- Department of Radiotherapy, Oncology Department, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Xuan Wang
- Department of Radiotherapy, Oncology Department, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Aimin Jiang
- Department of Chemotherapy, Oncology Department, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Rong Li
- Department of Radiotherapy, Oncology Department, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Haojing Kang
- Department of Radiotherapy, Oncology Department, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Zhaode Feng
- Department of Radiotherapy, Oncology Department, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Guangzu Li
- Department of Radiotherapy, Oncology Department, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Wen Ma
- Medical School, Xi'an Jiaotong University Xi'an, Xi'an, China
| | - Jiangzhou Zhang
- Medical School, Xi'an Jiaotong University Xi'an, Xi'an, China
| | - Juan Ren
- Department of Radiotherapy, Oncology Department, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
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Nikitin ES, Vinogradova LV. Potassium channels as prominent targets and tools for the treatment of epilepsy. Expert Opin Ther Targets 2021; 25:223-235. [PMID: 33754930 DOI: 10.1080/14728222.2021.1908263] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION K+ channels are of great interest to epilepsy research as mutations in their genes are found in humans with inherited epilepsy. At the level of cellular physiology, K+ channels control neuronal intrinsic excitability and are the main contributors to membrane repolarization of active neurons. Recently, a genetically modified voltage-dependent K+ channel has been patented as a remedy for epileptic seizures. AREAS COVERED We review the role of potassium channels in excitability, clinical and experimental evidence for the association of potassium channelopathies with epilepsy, the targeting of K+ channels by drugs, and perspectives of gene therapy in epilepsy with the expression of extra K+ channels in the brain. EXPERT OPINION Control over K+ conductance is of great potential benefit for the treatment of epilepsy. Nowadays, gene therapy affecting K+ channels is one of the most promising approaches to treat pharmacoresistant focal epilepsy.
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Affiliation(s)
- E S Nikitin
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
| | - L V Vinogradova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
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Thakran S, Guin D, Singh P, Singh P, Kukal S, Rawat C, Yadav S, Kushwaha SS, Srivastava AK, Hasija Y, Saso L, Ramachandran S, Kukreti R. Genetic Landscape of Common Epilepsies: Advancing towards Precision in Treatment. Int J Mol Sci 2020; 21:E7784. [PMID: 33096746 PMCID: PMC7589654 DOI: 10.3390/ijms21207784] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/09/2020] [Accepted: 10/14/2020] [Indexed: 12/15/2022] Open
Abstract
Epilepsy, a neurological disease characterized by recurrent seizures, is highly heterogeneous in nature. Based on the prevalence, epilepsy is classified into two types: common and rare epilepsies. Common epilepsies affecting nearly 95% people with epilepsy, comprise generalized epilepsy which encompass idiopathic generalized epilepsy like childhood absence epilepsy, juvenile myoclonic epilepsy, juvenile absence epilepsy and epilepsy with generalized tonic-clonic seizure on awakening and focal epilepsy like temporal lobe epilepsy and cryptogenic focal epilepsy. In 70% of the epilepsy cases, genetic factors are responsible either as single genetic variant in rare epilepsies or multiple genetic variants acting along with different environmental factors as in common epilepsies. Genetic testing and precision treatment have been developed for a few rare epilepsies and is lacking for common epilepsies due to their complex nature of inheritance. Precision medicine for common epilepsies require a panoramic approach that incorporates polygenic background and other non-genetic factors like microbiome, diet, age at disease onset, optimal time for treatment and other lifestyle factors which influence seizure threshold. This review aims to comprehensively present a state-of-art review of all the genes and their genetic variants that are associated with all common epilepsy subtypes. It also encompasses the basis of these genes in the epileptogenesis. Here, we discussed the current status of the common epilepsy genetics and address the clinical application so far on evidence-based markers in prognosis, diagnosis, and treatment management. In addition, we assessed the diagnostic predictability of a few genetic markers used for disease risk prediction in individuals. A combination of deeper endo-phenotyping including pharmaco-response data, electro-clinical imaging, and other clinical measurements along with genetics may be used to diagnose common epilepsies and this marks a step ahead in precision medicine in common epilepsies management.
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Affiliation(s)
- Sarita Thakran
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Debleena Guin
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Department of Bioinformatics, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042, India;
| | - Pooja Singh
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Priyanka Singh
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Samiksha Kukal
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Chitra Rawat
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Saroj Yadav
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Suman S. Kushwaha
- Department of Neurology, Institute of Human Behaviour and Allied Sciences, Dilshad Garden, Delhi 110095, India;
| | - Achal K. Srivastava
- Department of Neurology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India;
| | - Yasha Hasija
- Department of Bioinformatics, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042, India;
| | - Luciano Saso
- Department of Physiology and Pharmacology “Vittorio Erspamer”, Sapienza University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy;
| | - Srinivasan Ramachandran
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
- G N Ramachandran Knowledge Centre, Council of Scientific and Industrial Research (CSIR)—Institute of Genomics and Integrative Biology (IGIB), New Delhi 110007, India
| | - Ritushree Kukreti
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
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Ibrahim O, Sutherland HG, Maksemous N, Smith R, Haupt LM, Griffiths LR. Exploring Neuronal Vulnerability to Head Trauma Using a Whole Exome Approach. J Neurotrauma 2020; 37:1870-1879. [PMID: 32233732 PMCID: PMC7462038 DOI: 10.1089/neu.2019.6962] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Brain injuries are associated with oxidative stress and a need to restore neuronal homeostasis. Mutations in ion channel genes, in particular CACNA1A, have been implicated in familial hemiplegic migraine (FHM) and in the development of concussion-related symptoms in response to trivial head trauma. The aim of this study was to explore the potential role of variants in other ion channel genes in the development of such responses. We conducted whole exome sequencing (WES) on16 individuals who developed a range of neurological and concussion-related symptoms following minor or trivial head injuries. All individuals were initially tested and shown to be negative for mutations in known FHM genes. Variants identified from the WES results were filtered to identify rare variants (minor allele frequency [MAF] <0.01) in genes related to neural processes as well as genes highly expressed in the brain using a combination of in silico prediction tools (SIFT, PolyPhen, PredictSNP, Mutation Taster, and Mutation Assessor). Rare (MAF <0.001) or novel heterozygous variants in 7 ion channel genes were identified in 37.5% (6/16) of the cases (CACNA1I, CACNA1C, ATP10A, ATP7B, KCNAB1, KCNJ10, and SLC26A4), rare variants in neurotransmitter genes were found in 2 cases (GABRG1 and GRIK1), and rare variants in 3 ubiquitin-related genes identified in 4 cases (SQSTM1, TRIM2, and HECTD1). In this study, the largest proportion of potentially pathogenic variants in individuals with severe responses to minor head trauma were identified in genes previously implicated in migraine and seizure-related autosomal recessive neurological disorders. Together with results implicating variants in the hemiplegic migraine genes, CACNA1A and ATP1A2, in severe head trauma response, our results support a role for heterozygous deleterious mutations in genes implicated in neurological dysfunction and potentially increasing the risk of poor response to trivial head trauma.
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Affiliation(s)
- Omar Ibrahim
- Genomics Research Centre, Institute of Health and Biomedical Innovation, School of Biomedical Science, Queensland University of Technology (QUT), Kelvin Grove, Queensland, Australia
| | - Heidi G Sutherland
- Genomics Research Centre, Institute of Health and Biomedical Innovation, School of Biomedical Science, Queensland University of Technology (QUT), Kelvin Grove, Queensland, Australia
| | - Neven Maksemous
- Genomics Research Centre, Institute of Health and Biomedical Innovation, School of Biomedical Science, Queensland University of Technology (QUT), Kelvin Grove, Queensland, Australia
| | - Robert Smith
- Genomics Research Centre, Institute of Health and Biomedical Innovation, School of Biomedical Science, Queensland University of Technology (QUT), Kelvin Grove, Queensland, Australia
| | - Larisa M Haupt
- Genomics Research Centre, Institute of Health and Biomedical Innovation, School of Biomedical Science, Queensland University of Technology (QUT), Kelvin Grove, Queensland, Australia
| | - Lyn R Griffiths
- Genomics Research Centre, Institute of Health and Biomedical Innovation, School of Biomedical Science, Queensland University of Technology (QUT), Kelvin Grove, Queensland, Australia
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Zhang Y, Kong W, Gao Y, Liu X, Gao K, Xie H, Wu Y, Zhang Y, Wang J, Gao F, Wu X, Jiang Y. Gene Mutation Analysis in 253 Chinese Children with Unexplained Epilepsy and Intellectual/Developmental Disabilities. PLoS One 2015; 10:e0141782. [PMID: 26544041 PMCID: PMC4636363 DOI: 10.1371/journal.pone.0141782] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 10/13/2015] [Indexed: 12/18/2022] Open
Abstract
Objective Epilepsy and intellectual/developmental disabilities (ID/DD) have a high rate of co-occurrence. Here, we investigated gene mutations in Chinese children with unexplained epilepsy and ID/DD. Methods We used targeted next-generation sequencing to detect mutations within 300 genes related to epilepsy and ID/DD in 253 Chinese children with unexplained epilepsy and ID/DD. A series of filtering criteria was used to find the possible pathogenic variations. Validation and parental origin analyses were performed by Sanger sequencing. We reviewed the phenotypes of patients with each mutated gene. Results We identified 32 novel and 16 reported mutations within 24 genes in 46 patients. The detection rate was 18% (46/253) in the whole group and 26% (17/65) in the early-onset (before three months after birth) epilepsy group. To our knowledge, we are the first to report KCNAB1 is a disease-causing gene of epilepsy by identifying a novel de novo mutation (c.1062dupCA p.Leu355HisfsTer5) within this gene in one patient with early infantile epileptic encephalopathy (EIEE). Patients with an SCN1A mutation accounted for the largest proportion, 17% (8/46). A total of 38% (9/24) of the mutated genes re-occurred at least 2 times and 63% (15/24) occurred only one time. Ion channel genes are the most common (8/24) and genes related to synapse are the next most common to occur (5/24). Significance We have established genetic diagnosis for 46 patients of our cohort. Early-onset epilepsy had the highest detection rate. KCNAB1 mutation was first identified in EIEE patient. We expanded the phenotype and mutation spectrum of the genes we identified. The mutated genes in this cohort are mostly isolated. This suggests that epilepsy and ID/DD phenotypes occur as a consequence of brain dysfunction caused by a highly diverse population of mutated genes. Ion channel genes and genes related to synapse were more common mutated in this patient cohort.
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Affiliation(s)
- Yujia Zhang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
- Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
| | - Weijing Kong
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Yang Gao
- Department of Neurosurgery, the Second Hospital of Dalian Medical University, Dalian, China
| | - Xiaoyan Liu
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Kai Gao
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Han Xie
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Ye Wu
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Jingmin Wang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Feng Gao
- The Children’s Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Xiru Wu
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Yuwu Jiang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, China
- Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
- * E-mail:
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Genetic association of KCNA5 and KCNJ3 polymorphisms in Korean children with epilepsy. Mol Cell Toxicol 2014. [DOI: 10.1007/s13273-014-0024-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Differential neuronal targeting of a new and two known calcium channel β4 subunit splice variants correlates with their regulation of gene expression. J Neurosci 2014; 34:1446-61. [PMID: 24453333 DOI: 10.1523/jneurosci.3935-13.2014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The β subunits of voltage-gated calcium channels regulate surface expression and gating of CaV1 and CaV2 α1 subunits and thus contribute to neuronal excitability, neurotransmitter release, and calcium-induced gene regulation. In addition, certain β subunits are targeted into the nucleus, where they interact directly with the epigenetic machinery. Whereas their involvement in this multitude of functions is reflected by a great molecular heterogeneity of β isoforms derived from four genes and abundant alternative splicing, little is known about the roles of individual β variants in specific neuronal functions. In the present study, an alternatively spliced β4 subunit lacking the variable N terminus (β4e) is identified. It is highly expressed in mouse cerebellum and cultured cerebellar granule cells (CGCs) and modulates P/Q-type calcium currents in tsA201 cells and CaV2.1 surface expression in neurons. Compared with the other two known full-length β4 variants (β4a and β4b), β4e is most abundantly expressed in the distal axon, but lacks nuclear-targeting properties. To determine the importance of nuclear targeting of β4 subunits for transcriptional regulation, we performed whole-genome expression profiling of CGCs from lethargic (β4-null) mice individually reconstituted with β4a, β4b, and β4e. Notably, the number of genes regulated by each β4 splice variant correlated with the rank order of their nuclear-targeting properties (β4b > β4a > β4e). Together, these findings support isoform-specific functions of β4 splice variants in neurons, with β4b playing a dual role in channel modulation and gene regulation, whereas the newly detected β4e variant serves exclusively in calcium-channel-dependent functions.
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Chen WD, Zhang Y. Regulation of aldo-keto reductases in human diseases. Front Pharmacol 2012; 3:35. [PMID: 22408622 PMCID: PMC3297832 DOI: 10.3389/fphar.2012.00035] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 02/20/2012] [Indexed: 01/20/2023] Open
Abstract
The aldo-keto reductases (AKRs) are a superfamily of NAD(P)H-linked oxidoreductases, which reduce aldehydes and ketones to their respective primary and secondary alcohols. AKR enzymes are increasingly being recognized to play an important role in the transformation and detoxification of aldehydes and ketones generated during drug detoxification and xenobiotic metabolism. Many transcription factors have been identified to regulate the expression of human AKR genes, which could have profound effects on the metabolism of endogenous mediators and detoxication of chemical carcinogens. This review summarizes the current knowledge on AKR regulation by transcription factors and other mediators in human diseases.
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Affiliation(s)
- Wei-Dong Chen
- Department of Integrative Medical Sciences, Northeast Ohio Medical University Rootstown, OH, USA
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