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Xiao L, Xiang S, Chen C, Zhu H, Zhou M, Tang Y, Feng L, Hu S. Association of synaptic density and cognitive performance in temporal lobe epilepsy: Humans and animals PET imaging study with [ 18F]SynVesT-1. Psychiatry Clin Neurosci 2024. [PMID: 38804583 DOI: 10.1111/pcn.13682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 04/08/2024] [Accepted: 05/03/2024] [Indexed: 05/29/2024]
Abstract
AIM Cognitive impairment is a common comorbidity in individuals with temporal lobe epilepsy (TLE), yet the underlying mechanisms remain unknown. This study explored the putative association between in vivo synaptic loss and cognitive outcomes in TLE patients by PET imaging of synaptic vesicle glycoprotein 2A (SV2A). METHODS We enrolled 16 TLE patients and 10 cognitively normal controls. All participants underwent SV2A PET imaging using [18F]SynVesT-1 and cognitive assessment. Lithium chloride-pilocarpine-induced rats with status epilepticus (n = 20) and controls (n = 6) rats received levetiracetam (LEV, specifically binds to SV2A), valproic acid (VPA), or saline for 14 days. Then, synaptic density was quantified by [18F]SynVesT-1 micro-PET/CT. The novel object recognition and Morris water maze tests evaluated TLE-related cognitive function. SV2A expression was examined and confirmed by immunohistochemistry. RESULTS Temporal lobe epilepsy patients showed significantly reduced synaptic density in hippocampus, which was associated with cognitive performance. In the rat model of TLE, the expression of SV2A and synaptic density decreased consistently in a wider range of brain regions, including the entorhinal cortex, insula, hippocampus, amygdala, thalamus, and cortex. We treated TLE animal models with LEV or VPA to explore whether synaptic loss contributes to cognitive deficits. It was found that LEV significantly exerted protective effects against brain synaptic deficits and cognitive impairment. CONCLUSION This is the first study to link synaptic loss to cognitive deficits in TLE, suggesting [18F]SynVesT-1 PET could be a promising biomarker for monitoring synaptic loss and cognitive dysfunction. LEV might help reverse synaptic deficits and ameliorate learning and memory impairments in TLE patients.
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Affiliation(s)
- Ling Xiao
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Shijun Xiang
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Chen Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Haoyue Zhu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Ming Zhou
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Yongxiang Tang
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, China
| | - Li Feng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, China
| | - Shuo Hu
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Biological Nanotechnology of National Health Commission, Xiangya Hospital, Central South University, Changsha, China
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Li C, Wang Z, Ren M, Ren S, Wu G, Wang L. Synaptic vesicle protein 2A mitigates parthanatos via apoptosis-inducing factor in a rat model of pharmacoresistant epilepsy. CNS Neurosci Ther 2024; 30:e14778. [PMID: 38801174 PMCID: PMC11129553 DOI: 10.1111/cns.14778] [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: 01/13/2024] [Revised: 04/30/2024] [Accepted: 05/03/2024] [Indexed: 05/29/2024] Open
Abstract
AIMS Synaptic vesicle protein 2A (SV2A) is a unique therapeutic target for pharmacoresistant epilepsy (PRE). As seizure-induced neuronal programmed death, parthanatos was rarely reported in PRE. Apoptosis-inducing factor (AIF), which has been implicated in parthanatos, shares a common cytoprotective function with SV2A. We aimed to investigate whether parthanatos participates in PRE and is mitigated by SV2A via AIF. METHODS An intraperitoneal injection of lithium chloride-pilocarpine was used to establish an epileptic rat model, and phenytoin and phenobarbital sodium were utilized to select PRE and pharmacosensitive rats. The expression of SV2A was manipulated via lentivirus delivery into the hippocampus. Video surveillance was used to assess epileptic ethology. Biochemical tests were employed to test hippocampal tissues following a successful SV2A infection. Molecular dynamic calculations were used to simulate the interaction between SV2A and AIF. RESULTS Parthanatos core index, PARP1, PAR, nuclear AIF and MIF, γ-H2AX, and TUNEL staining were all increased in PRE. SV2A is bound to AIF to form a stable complex, successfully inhibiting AIF and MIF nuclear translocation and parthanatos and consequently mitigating spontaneous recurrent seizures in PRE. Moreover, parthanatos deteriorated after the SV2A reduction. SIGNIFICANCE SV2A protected hippocampal neurons and mitigated epileptic seizures by inhibiting parthanatos via binding to AIF in PRE.
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Affiliation(s)
- Chen Li
- School of Clinical MedicineGuizhou Medical UniversityGuiyangGuizhouChina
| | - Ziqi Wang
- School of Clinical MedicineGuizhou Medical UniversityGuiyangGuizhouChina
| | - Mianmian Ren
- School of Clinical MedicineGuizhou Medical UniversityGuiyangGuizhouChina
| | - Siying Ren
- The Affiliated Hospital of Guizhou Medical UniversityGuiyangGuizhouChina
| | - Guofeng Wu
- The Affiliated Hospital of Guizhou Medical UniversityGuiyangGuizhouChina
| | - Likun Wang
- The Affiliated Hospital of Guizhou Medical UniversityGuiyangGuizhouChina
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3
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Löscher W, White HS. Animal Models of Drug-Resistant Epilepsy as Tools for Deciphering the Cellular and Molecular Mechanisms of Pharmacoresistance and Discovering More Effective Treatments. Cells 2023; 12:cells12091233. [PMID: 37174633 PMCID: PMC10177106 DOI: 10.3390/cells12091233] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/28/2023] [Accepted: 04/18/2023] [Indexed: 05/15/2023] Open
Abstract
In the last 30 years, over 20 new anti-seizure medicines (ASMs) have been introduced into the market for the treatment of epilepsy using well-established preclinical seizure and epilepsy models. Despite this success, approximately 20-30% of patients with epilepsy have drug-resistant epilepsy (DRE). The current approach to ASM discovery for DRE relies largely on drug testing in various preclinical model systems that display varying degrees of ASM drug resistance. In recent years, attempts have been made to include more etiologically relevant models in the preclinical evaluation of a new investigational drug. Such models have played an important role in advancing a greater understanding of DRE at a mechanistic level and for hypothesis testing as new experimental evidence becomes available. This review provides a critical discussion of the pharmacology of models of adult focal epilepsy that allow for the selection of ASM responders and nonresponders and those models that display a pharmacoresistance per se to two or more ASMs. In addition, the pharmacology of animal models of major genetic epilepsies is discussed. Importantly, in addition to testing chemical compounds, several of the models discussed here can be used to evaluate other potential therapies for epilepsy such as neurostimulation, dietary treatments, gene therapy, or cell transplantation. This review also discusses the challenges associated with identifying novel therapies in the absence of a greater understanding of the mechanisms that contribute to DRE. Finally, this review discusses the lessons learned from the profile of the recently approved highly efficacious and broad-spectrum ASM cenobamate.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Bünteweg 17, 30559 Hannover, Germany
- Center for Systems Neuroscience, 30559 Hannover, Germany
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA 98195, USA
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Rossi R, Arjmand S, Bærentzen SL, Gjedde A, Landau AM. Synaptic Vesicle Glycoprotein 2A: Features and Functions. Front Neurosci 2022; 16:864514. [PMID: 35573314 PMCID: PMC9096842 DOI: 10.3389/fnins.2022.864514] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/05/2022] [Indexed: 01/05/2023] Open
Abstract
In recent years, the field of neuroimaging dramatically moved forward by means of the expeditious development of specific radioligands of novel targets. Among these targets, the synaptic vesicle glycoprotein 2A (SV2A) is a transmembrane protein of synaptic vesicles, present in all synaptic terminals, irrespective of neurotransmitter content. It is involved in key functions of neurons, focused on the regulation of neurotransmitter release. The ubiquitous expression in gray matter regions of the brain is the basis of its candidacy as a marker of synaptic density. Following the development of molecules derived from the structure of the anti-epileptic drug levetiracetam, which selectively binds to SV2A, several radiolabeled markers have been synthetized to allow the study of SV2A distribution with positron emission tomography (PET). These radioligands permit the evaluation of in vivo changes of SV2A distribution held to be a potential measure of synaptic density in physiological and pathological conditions. The use of SV2A as a biomarker of synaptic density raises important questions. Despite numerous studies over the last decades, the biological function and the expressional properties of SV2A remain poorly understood. Some functions of SV2A were claimed, but have not been fully elucidated. While the expression of SV2A is ubiquitous, stronger associations between SV2A and Υ amino butyric acid (GABA)-ergic rather than glutamatergic synapses were observed in some brain structures. A further issue is the unclear interaction between SV2A and its tracers, which reflects a need to clarify what really is detected with neuroimaging tools. Here, we summarize the current knowledge of the SV2A protein and we discuss uncertain aspects of SV2A biology and physiology. As SV2A expression is ubiquitous, but likely more strongly related to a certain type of neurotransmission in particular circumstances, a more extensive knowledge of the protein would greatly facilitate the analysis and interpretation of neuroimaging results by allowing the evaluation not only of an increase or decrease of the protein level, but also of the type of neurotransmission involved.
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Affiliation(s)
- Rachele Rossi
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Shokouh Arjmand
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Simone Larsen Bærentzen
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Albert Gjedde
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Anne M Landau
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
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Finnema SJ, Toyonaga T, Detyniecki K, Chen MK, Dias M, Wang Q, Lin SF, Naganawa M, Gallezot JD, Lu Y, Nabulsi NB, Huang Y, Spencer DD, Carson RE. Reduced synaptic vesicle protein 2A binding in temporal lobe epilepsy: A [ 11 C]UCB-J positron emission tomography study. Epilepsia 2020; 61:2183-2193. [PMID: 32944949 DOI: 10.1111/epi.16653] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVE In this positron emission tomography (PET) study with [11 C]UCB-J, we evaluated synaptic vesicle glycoprotein 2A (SV2A) binding, which is decreased in resected brain tissues from epilepsy patients, in subjects with temporal lobe epilepsy (TLE) and compared the regional binding pattern to [18 F]fluorodeoxyglucose (FDG) uptake. METHODS Twelve TLE subjects and 12 control subjects were examined. Regional [11 C]UCB-J binding potential (BPND ) values were estimated using the centrum semiovale as a reference region. [18 F]FDG uptake in TLE subjects was quantified using mean radioactivity values. Asymmetry in outcome measures was assessed by comparison of ipsilateral and contralateral regions. Partial volume correction (PVC) with the iterative Yang algorithm was applied based on the FreeSurfer segmentation. RESULTS In 11 TLE subjects with medial temporal lobe sclerosis (MTS), the hippocampal volumetric asymmetry was 25 ± 11%. After PVC, [11 C]UCB-J BPND asymmetry indices were 37 ± 19% in the hippocampus, with very limited asymmetry in other brain regions. Reductions in [11 C]UCB-J BPND values were restricted to the sclerotic hippocampus when compared to control subjects. The corresponding asymmetry in hippocampal [18 F]FDG uptake was 22 ± 7% and correlated with that of [11 C]UCB-J BPND across subjects (R2 = .38). Hippocampal asymmetries in [11 C]UCB-J binding were 1.7-fold larger than those of [18 F]FDG uptake. SIGNIFICANCE [11 C]UCB-J binding is reduced in the seizure onset zone of TLE subjects with MTS. PET imaging of SV2A may be a promising biomarker approach in the presurgical selection and evaluation of TLE patients and may improve the sensitivity of molecular imaging for seizure focus detection.
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Affiliation(s)
- Sjoerd J Finnema
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Kamil Detyniecki
- Department of Neurology, Yale University, New Haven, Connecticut, USA
| | - Ming-Kai Chen
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Mark Dias
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Qianyu Wang
- Department of Neurology, Yale University, New Haven, Connecticut, USA
| | - Shu-Fei Lin
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Mika Naganawa
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Jean-Dominique Gallezot
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Yihuan Lu
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Nabeel B Nabulsi
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Dennis D Spencer
- Department of Neurosurgery, Yale University, New Haven, Connecticut, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA.,Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
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6
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Huang Y, Wang L, Ren S, Wu G, Wu J. The Expression of ZnT3 and GFAP Is Potentiated in the Hippocampus of Drug-Resistant Epileptic Rats Induced by Amygdala Kindling. Neuroimmunomodulation 2020; 27:104-112. [PMID: 33161399 DOI: 10.1159/000510399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 07/19/2020] [Indexed: 01/29/2023] Open
Abstract
OBJECTIVE The first-line treatment for epilepsy, a chronic neurological disorder characterized by spontaneous seizures, includes the application of anticonvulsant drug therapy. Only one-third of patients are incapable of complete controlling of their seizures after the administration of ≥2 pharmaceuticals. Here, we aimed to observe the ultrastructure changes and the expression of ZnT3 and GFAP in the hippocampus of drug-resistant epileptic rats. METHODS A total of 50 healthy adult male SD rats were used to generate the model ofepilepsy by amygdala kindling. After the rats were successfully kindled, pharmacoresistant epileptic (PRE) rats were selected according to their response to phenobarbital and phenytoin. The ultrastructure as well as the expression of zinc transporter 3 (ZnT3, a member of a growing family of mammalian zinc transporters) and glial fibrillary acidic protein (GFAP) were compared among PRE, pharmacosensitive epileptic (PRE), and normal (NRC) rats. RESULTS The PRE rats displayed severe synapses, neuronal degeneration, and necrosis. Moreover, the expression of ZnT3 and GFAP was significantly increased in both PRE and PSE rats; compared with NRC rats, the promotion of this expression was more pronounced in the PRE rats. CONCLUSIONS Taken together, obvious synapses, neuronal degeneration, necrosis, mossy fiber sprouting, and astrogliosis were found in the drug-resistant epileptic rat model induced by amygdala kindling.
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Affiliation(s)
- Yuanxin Huang
- Department of Pain, the Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Lin Wang
- Department of Pain, the Affiliated Hospital of Guizhou Medical University, Guiyang, China,
| | - Siying Ren
- Department of Emergency, the Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Guofeng Wu
- Department of Emergency, the Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Jing Wu
- Graduate School of Guizhou Medical University, Guiyang, China
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Stout KA, Dunn AR, Hoffman C, Miller GW. The Synaptic Vesicle Glycoprotein 2: Structure, Function, and Disease Relevance. ACS Chem Neurosci 2019; 10:3927-3938. [PMID: 31394034 DOI: 10.1021/acschemneuro.9b00351] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The synaptic vesicle glycoprotein 2 (SV2) family is comprised of three paralogues: SV2A, SV2B, and SV2C. In vertebrates, SV2s are 12-transmembrane proteins present on every secretory vesicle, including synaptic vesicles, and are critical to neurotransmission. Structural and functional studies suggest that SV2 proteins may play several roles to promote proper vesicular function. Among these roles are their potential to stabilize the transmitter content of vesicles, to maintain and orient the releasable pool of vesicles, and to regulate vesicular calcium sensitivity to ensure efficient, coordinated release of the transmitter. The SV2 family is highly relevant to human health in a number of ways. First, SV2A plays a role in neuronal excitability and as such is the specific target for the antiepileptic drug levetiracetam. SV2 proteins also act as the target by which potent neurotoxins, particularly botulinum, gain access to neurons and exert their toxicity. Both SV2B and SV2C are increasingly implicated in diseases such as Alzheimer's disease and Parkinson's disease. Interestingly, despite decades of intensive research, their exact function remains elusive. Thus, SV2 proteins are intriguing in their potentially diverse roles within the presynaptic terminal, and several recent developments have enhanced our understanding and appreciation of the protein family. Here, we review the structure and function of SV2 proteins as well as their relevance to disease and therapeutic development.
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Affiliation(s)
- Kristen A Stout
- Department of Physiology , Northwestern University, Feinberg School of Medicine , Chicago , Illinois , United States
| | - Amy R Dunn
- The Jackson Laboratory , Bar Harbor , Maine , United States
| | - Carlie Hoffman
- Department of Environmental Health, Rollins School of Public Health , Emory University , Atlanta , Georgia , United States
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailman School of Public Health , Columbia University , New York , New York , United States
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Wang L, Shi H, Kang Y, Guofeng W. Hippocampal low-frequency stimulation improves cognitive function in pharmacoresistant epileptic rats. Epilepsy Res 2019; 168:106194. [PMID: 31521425 DOI: 10.1016/j.eplepsyres.2019.106194] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 08/05/2019] [Accepted: 08/28/2019] [Indexed: 01/30/2023]
Abstract
OBJECTIVE The aims of the present study were to observe the changes of cognitive function in a pilocarpine-induced rat model of epilepsy, and to investigate the effects of hippocampal low-frequency stimulation (Hip-LFS) on cognitive function in rats with pharmacoresistant epilepsy. METHODS A total of 100 male Sprague Dawley rats were randomly selected to establish an epilepsy model. Rats with successfully induced epilepsy were injected intraperitoneally with phenobarbital and phenytoin for pharmacoresistance selection. The selected pharmacoresistant epileptic (PRE) rats were assigned to a pharmacoresistant control group (PRC group), or a group that received Hip-LFS (LFS group). The same number of rats with pharmacosensitive epilepsy formed the PSC group, and a normal control (NCR) group was included. A novel object recognition (NOR) test, and a Morris water maze (MWM) task were used to assess cognitive function in all groups. RESULTS The epileptic rats showed decreased abilities of learning and memory compared with normal control. The rats in the LFS group displayed significantly shorter escape latency in place navigation, spent longer times in the target quadrant, and traveled longer distances on the platform in the spatial probe test than PRC group. In the NOR test, compared with the PRC group, the discrimination index of the LFS group was significantly increased. Compared with the PRC group, the average frequency and duration of seizures were also decreased in the LFS group. CONCLUSIONS The present pilocarpine-induced rat model of epilepsy showed impaired cognitive function, especially in rats with PRE. The Hip-LFS treatment could effectively improve the cognitive function of rats with PRE.
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Affiliation(s)
- Likun Wang
- Emergency Department, Affiliated Hospital of Guizhou Medical University, Guiyang City, 550004, PR China.
| | - Haiyan Shi
- Emergency Department, Affiliated Hospital of Guizhou Medical University, Guiyang City, 550004, PR China.
| | - Yangting Kang
- Emergency Department, Affiliated Hospital of Guizhou Medical University, Guiyang City, 550004, PR China.
| | - Wu Guofeng
- Emergency Department, Affiliated Hospital of Guizhou Medical University, Guiyang City, 550004, PR China.
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Xu K, Liu F, Xu W, Liu J, Chen S, Wu G. Transplanting GABAergic Neurons Differentiated from Neural Stem Cells into Hippocampus Inhibits Seizures and Epileptiform Discharges in Pilocarpine-Induced Temporal Lobe Epilepsy Model. World Neurosurg 2019; 128:e1-e11. [PMID: 30790741 DOI: 10.1016/j.wneu.2019.01.245] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 01/23/2019] [Accepted: 01/24/2019] [Indexed: 11/24/2022]
Abstract
OBJECTIVE This study aimed to explore whether intrahippocampal transplantation of GABAergic neurons generated in vitro ameliorated seizures and epileptiform discharges via increasing γ-aminobutyric acid (GABA)-associated inhibition mediated by the addition of new GABAergic neurons. METHODS Neural stem cells (NSCs) isolated from newborn rats were induced and differentiated into GABAergic neurons. A total of 36 Pilocarpine-induced pharmacoresistant epileptic rats were divided into 3 groups: PBS (phosphate-buffered saline) group, NSCs group, and GABAergic neurons group (GABA group), with an additional 10 normal rats used (normal rat control group). The effects of grafting on spontaneous recurrent seizures (SRS) were examined and hippocampal GABA content was measured after grafting. RESULTS In the GABA group, the frequency of electroencephalography decreased significantly compared with the PBS group (P < 0.001), but there was no significant difference between the GABA group and NSCs group. Compared with the PBS group, the overall frequency and duration of SRS significantly decreased in the transplantation group, especially in the GABA group (P < 0.01). The number of GABAergic neurons was highest in the GABA group compared with the other groups (P < 0.001). Furthermore, hippocampal GABA concentrations significantly increased in the GABA group. CONCLUSIONS We show that GABAergic neurons generated in vitro from NSCs and grafted into the hippocampi of chronically epileptic rats can significantly reduce the frequency of electroencephalography and frequency and duration of SRS via increasing GABA-associated inhibition mediated by the addition of new GABAergic neurons.
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Affiliation(s)
- Kaya Xu
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guizhou, Guiyang City, China
| | - Feng Liu
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guizhou, Guiyang City, China
| | - Wei Xu
- Public Health School, Guizhou Medical University, Guizhou, Guiyang City, China
| | - Jian Liu
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guizhou, Guiyang City, China
| | - Shuxuan Chen
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guizhou, Guiyang City, China
| | - Guofeng Wu
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guizhou, Guiyang City, China.
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10
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Cai Z, Li S, Matuskey D, Nabulsi N, Huang Y. PET imaging of synaptic density: A new tool for investigation of neuropsychiatric diseases. Neurosci Lett 2019; 691:44-50. [PMID: 30075287 PMCID: PMC6339829 DOI: 10.1016/j.neulet.2018.07.038] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 07/25/2018] [Accepted: 07/26/2018] [Indexed: 12/14/2022]
Abstract
Synaptic vesicle glycoprotein 2A (SV2A) is expressed ubiquitously in neurons of the central nervous system, and is the binding target of the anti-epileptic drug levetiracetam. Because of the availability of positron emission tomography (PET) ligands targeting SV2A, there is increasing enthusiasm on the use of SV2A PET to study a variety of neuropsychiatric diseases. This review discusses the recent development of radioligands for PET imaging of SV2A and their potential use in the research and diagnosis of CNS diseases.
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Affiliation(s)
- Zhengxin Cai
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA.
| | - Songye Li
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - David Matuskey
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Nabeel Nabulsi
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Yiyun Huang
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
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11
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Skarpaas TL, Tcheng TK, Morrell MJ. Clinical and electrocorticographic response to antiepileptic drugs in patients treated with responsive stimulation. Epilepsy Behav 2018; 83:192-200. [PMID: 29719278 DOI: 10.1016/j.yebeh.2018.04.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 04/07/2018] [Accepted: 04/07/2018] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The objective of this study was to explore whether chronic electrocorticographic (ECoG) data recorded by a responsive neurostimulation system could be used to assess clinical responses to antiepileptic drugs (AEDs). METHODS Antiepileptic drugs initiated and maintained for ≥3 months by patients participating in clinical trials of the RNS® System were identified. Such "AED Starts" that produced an additional ≥50% reduction in patient-reported clinical seizure frequency were categorized as clinically beneficial, and the remaining as not beneficial. Electrocorticographic features recorded by the RNS® Neurostimulator were analyzed during three periods: 3 months before the AED Start, first month after the AED Start, and the first 3 months after the AED Start. RESULTS The most commonly added medications were clobazam (n = 41), lacosamide (n = 96), levetiracetam (n = 31), and pregabalin (n = 25). Across all four medications, there were sufficient clinical data for 193 AED Starts to be included in the analyses, and 59 AED Starts were considered clinically beneficial. The proportion of AED Starts that qualified as clinically beneficial was higher for clobazam (53.7%) and levetiracetam (51.6%) than for lacosamide (18.8%) and pregabalin (12%). Across all AED Starts for which RNS ECoG detection settings were held constant, the clinically beneficial AED Starts were associated with a significantly greater reduction in the detection of epileptiform activity (p < 0.001) at 1 (n = 33) and 3 months (n = 30) compared with AED Starts that were not beneficial at 1 (n = 71) and 3 months (n = 60). Furthermore, there was a significant reduction in interictal spike rate and spectral power (1-125 Hz) associated with a clinically beneficial response to an AED Start at 1 (n = 32) and 3 months (n = 35) (p < 0.001). These reductions were not observed at either 1 (n = 59) or 3 months (n = 60) for AED Starts that were not clinically beneficial. CONCLUSIONS Significant quantitative changes in ECoG data recorded by the RNS System were observed in patients who experienced an additional clinical response to a new AED. While there was variability across patients in the changes observed, the results suggest that quantitative ECoG data may provide useful information when assessing whether a patient may have a favorable clinical response to an AED.
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Affiliation(s)
- Tara L Skarpaas
- NeuroPace, Inc., Mountain View, CA, Clinical and Research Departments, United States.
| | - Thomas K Tcheng
- NeuroPace, Inc., Mountain View, CA, Clinical and Research Departments, United States.
| | - Martha J Morrell
- NeuroPace, Inc., Mountain View, CA, Clinical and Research Departments, United States; Stanford University School of Medicine, Stanford, CA, Neurology Department, United States.
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Dunn AR, Hoffman CA, Stout KA, Ozawa M, Dhamsania RK, Miller GW. Immunochemical analysis of the expression of SV2C in mouse, macaque and human brain. Brain Res 2017; 1702:85-95. [PMID: 29274878 DOI: 10.1016/j.brainres.2017.12.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 11/30/2017] [Accepted: 12/19/2017] [Indexed: 11/17/2022]
Abstract
The synaptic vesicle glycoprotein 2C (SV2C) is an undercharacterized protein with enriched expression in phylogenetically old brain regions. Its precise role within the brain is unclear, though various lines of evidence suggest that SV2C is involved in the function of synaptic vesicles through the regulation of vesicular trafficking, calcium-induced exocytosis, or synaptotagmin function. SV2C has been linked to multiple neurological disorders, including Parkinson's disease and psychiatric conditions. SV2C is expressed in various cell types-primarily dopaminergic, GABAergic, and cholinergic cells. In mice, it is most highly expressed in nuclei within the basal ganglia, though it is unknown if this pattern of expression is consistent across species. Here, we use a custom SV2C-specific antiserum to describe localization within the brain of mouse, nonhuman primate, and human, including cell-type localization. We found that the immunoreactivity with this antiserum is consistent with previously-published antibodies, and confirmed localization of SV2C in the basal ganglia of rodent, rhesus macaque, and human. We observed strongest expression of SV2C in the substantia nigra, ventral tegmental area, dorsal striatum, pallidum, and nucleus accumbens of each species. Further, we demonstrate colocalization between SV2C and markers of dopaminergic, GABAergic, and cholinergic neurons within these brain regions. SV2C has been increasingly linked to dopamine and basal ganglia function. These antisera will be an important resource moving forward in our understanding of the role of SV2C in vesicle dynamics and neurological disease.
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Affiliation(s)
- Amy R Dunn
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Carlie A Hoffman
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Kristen A Stout
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Minagi Ozawa
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Rohan K Dhamsania
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Gary W Miller
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States; Center for Neurodegenerative Disease, Emory University, Atlanta, GA 30322, United States.
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13
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Wu G, Wang L, Hong Z, Ren S, Zhou F. Hippocampal low-frequency stimulation inhibits afterdischarge and increases GABA (A) receptor expression in amygdala-kindled pharmacoresistant epileptic rats. Neurol Res 2017; 39:733-743. [PMID: 28502217 DOI: 10.1080/01616412.2017.1325120] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Guofeng Wu
- Department of Neurology, Affiliated Hospital, Guizhou Medical University, Guiyang, P.R. China
- Department of Neurology, Affiliated Huashan Hospital, Fudan University, Shanghai, P.R. China
| | - Likun Wang
- Department of Neurology, Affiliated Hospital, Guizhou Medical University, Guiyang, P.R. China
| | - Zhen Hong
- Department of Neurology, Affiliated Huashan Hospital, Fudan University, Shanghai, P.R. China
| | - Siying Ren
- Department of Neurology, Affiliated Hospital, Guizhou Medical University, Guiyang, P.R. China
| | - Feng Zhou
- Department of Neurology, Affiliated Hospital, Guizhou Medical University, Guiyang, P.R. China
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Löscher W, Gillard M, Sands ZA, Kaminski RM, Klitgaard H. Synaptic Vesicle Glycoprotein 2A Ligands in the Treatment of Epilepsy and Beyond. CNS Drugs 2016; 30:1055-1077. [PMID: 27752944 PMCID: PMC5078162 DOI: 10.1007/s40263-016-0384-x] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The synaptic vesicle glycoprotein SV2A belongs to the major facilitator superfamily (MFS) of transporters and is an integral constituent of synaptic vesicle membranes. SV2A has been demonstrated to be involved in vesicle trafficking and exocytosis, processes crucial for neurotransmission. The anti-seizure drug levetiracetam was the first ligand to target SV2A and displays a broad spectrum of anti-seizure activity in various preclinical models. Several lines of preclinical and clinical evidence, including genetics and protein expression changes, support an important role of SV2A in epilepsy pathophysiology. While the functional consequences of SV2A ligand binding are not fully elucidated, studies suggest that subsequent SV2A conformational changes may contribute to seizure protection. Conversely, the recently discovered negative SV2A modulators, such as UCB0255, counteract the anti-seizure effect of levetiracetam and display procognitive properties in preclinical models. More broadly, dysfunction of SV2A may also be involved in Alzheimer's disease and other types of cognitive impairment, suggesting potential novel therapies for levetiracetam and its congeners. Furthermore, emerging data indicate that there may be important roles for two other SV2 isoforms (SV2B and SV2C) in the pathogenesis of epilepsy, as well as other neurodegenerative diseases. Utilization of recently developed SV2A positron emission tomography ligands will strengthen and reinforce the pharmacological evidence that SV2A is a druggable target, and will provide a better understanding of its role in epilepsy and other neurological diseases, aiding in further defining the full therapeutic potential of SV2A modulation.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Bünteweg 17, 30559, Hannover, Germany.
- Center for Systems Neuroscience, Hannover, Germany.
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Xi Z, Deng W, Wang L, Xiao F, Li J, Wang Z, Wang X, Mi X, Wang N, Wang X. Association of Alpha-Soluble NSF Attachment Protein with Epileptic Seizure. J Mol Neurosci 2015; 57:417-25. [DOI: 10.1007/s12031-015-0596-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 06/02/2015] [Indexed: 01/02/2023]
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