1
|
Gao H, Li J, Li Q, Lin Y. Identification of hub genes significantly linked to subarachnoid hemorrhage and epilepsy via bioinformatics analysis. Front Neurol 2023; 14:1061860. [PMID: 36741285 PMCID: PMC9893862 DOI: 10.3389/fneur.2023.1061860] [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: 10/05/2022] [Accepted: 01/02/2023] [Indexed: 01/20/2023] Open
Abstract
Background Although epilepsy has been linked to subarachnoid hemorrhage (SAH), the underlying mechanism has not been fully elucidated. This study aimed to further explore the potential mechanisms in epilepsy and SAH through genes. Methods Gene expression profiles for subarachnoid hemorrhage (GSE36791) and epilepsy (GSE143272) were downloaded from the Gene Expression Omnibus (GEO) database. Differential expression analysis was performed to identify the common differentially expressed genes (DEGs) to epilepsy and SAH, which were further analyzed by functional enrichment analysis. Single-sample gene set enrichment analysis (ssGSEA) and weighted correlation network analysis (WGCNA) were used to identify common module genes related to the infiltration of immune cells in epilepsy and SAH. Hub module genes were identified using a protein-protein interaction (PPI) network. Finally, the most relevant genes were obtained by taking the intersection points between the DEGs and hub module genes. We performed validation by retrospectively analyzing the RT-PCR levels of the most relevant genes in patients with pure SAH and patients with SAH complicated with epilepsy. Our experiments verified that the SAH and SAH+epilepsy groups were significantly different from the normal control group. In addition, significant differences were observed between the SAH and SAH+epilepsy groups. Results In total, 159 common DEGs-85 downregulated genes and 74 upregulated genes-were identified. Functional analysis emphasized that the immune response was a common feature to epilepsy and SAH. The results of ssGSEA and WGCNA revealed changes in immunocyte recruitment and the related module genes. Finally, MMP9 and C3aR1 were identified as hub genes, and RT-PCR confirmed that the expression levels of the hub genes were higher in epilepsy and SAH samples than in normal samples. Conclusions Our study revealed the pathogenesis of SAH complicated with epilepsy and identified hub genes that might provide new ideas for further mechanistic studies.
Collapse
Affiliation(s)
- Hong Gao
- Department of Neurosurgery, The First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, China,Department of Neurosurgery, Zhongshan Hospital (Xiamen), Fudan University, Xiamen, Fujian, China
| | - Jie Li
- Department of Medical Intensive Care Unit, Tongji Medical College, Maternal and Child Health Hospital of Hubei Province, Hua Zhong University of Science and Technology, Wuhan, Hubei, China
| | - Qiuping Li
- Department of Neurosurgery, Zhongshan Hospital (Xiamen), Fudan University, Xiamen, Fujian, China
| | - Yuanxiang Lin
- Department of Neurosurgery, The First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, China,*Correspondence: Yuanxiang Lin ✉
| |
Collapse
|
2
|
Shen L, Yang Q, He Y, Zou X, Cao Z. BmK NT1-induced neurotoxicity is mediated by PKC/CaMKⅡ-dependent ERK1/2 and p38 activation in primary cultured cerebellar granule cells. Toxicology 2019; 421:22-29. [PMID: 30940546 DOI: 10.1016/j.tox.2019.03.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 03/01/2019] [Accepted: 03/28/2019] [Indexed: 01/08/2023]
Abstract
Voltage-gated sodium channels (VGSCs) represent molecular targets for a number of potent neurotoxins that affect the ion permeation or gating kinetics. BmK NT1, an α-scorpion toxin purified from Buthus martensii Karch (BMK), induces excitatory neurotoxicity by activation of VGSCs with subsequent overloading of intracellular Ca2+ in cerebellar granule cells (CGCs). In the current study, we further investigated signaling pathways responsible for BmK NT1-induced neurotoxicity in CGCs. BmK NT1 exposure induced neuronal death in different development stages of CGCs with similar potencies ranging from 0.21-0.48 μM. The maximal neuronal death induced by BmK NT1 gradually increased from 25.6% at 7 days in vitro (DIVs) to 42.1%, 47.8%, and 67.2% at 10, 13, and 16 DIVs, respectively, suggesting that mature CGCs are more vulnerable to BmK NT1 exposure. Application of Ca2+/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) inhibitors, KN-62 or KN-93, but not Ca2+/calmodulin-dependent protein kinase kinase (CaMKK) inhibitor, STO-609, completely abolished BmK NT1-induced neuronal death. Moreover, BmK NT1 exposure stimulated CaMKⅡ phosphorylation. BmK NT1 also stimulated extracellular regulated protein kinases 1/2 (ERK1/2) and p38 phosphorylation which was abolished by tetrodotoxin demonstrating the role of VGSCs on BmK NT1-induced ERK1/2 and p38 phosphorylation. However, BmK NT1 didn't affect c-Jun N-terminal kinase (JNK) phosphorylation. In addition, both ERK1/2 inhibitor, U0126 and p38 inhibitor, SB203580 attenuated BmK NT1-induced neuronal death. Both PKC inhibitor, Gö 6983 and CaMKⅡ inhibitor, KN-62 abolished BmK NT1-induced ERK1/2 and p38 phosphorylation. Considered together, these data demonstrate that BmK NT1-induced neurotoxicity is through PKC/CaMKⅡ mediated ERK1/2 and p38 activation.
Collapse
Affiliation(s)
- Liping Shen
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Qundi Yang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Yuwei He
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Xiaohan Zou
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China.
| | - Zhengyu Cao
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China.
| |
Collapse
|
3
|
Wang J, Ou SW, Wang YJ. Distribution and function of voltage-gated sodium channels in the nervous system. Channels (Austin) 2017; 11:534-554. [PMID: 28922053 DOI: 10.1080/19336950.2017.1380758] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Voltage-gated sodium channels (VGSCs) are the basic ion channels for neuronal excitability, which are crucial for the resting potential and the generation and propagation of action potentials in neurons. To date, at least nine distinct sodium channel isoforms have been detected in the nervous system. Recent studies have identified that voltage-gated sodium channels not only play an essential role in the normal electrophysiological activities of neurons but also have a close relationship with neurological diseases. In this study, the latest research findings regarding the structure, type, distribution, and function of VGSCs in the nervous system and their relationship to neurological diseases, such as epilepsy, neuropathic pain, brain tumors, neural trauma, and multiple sclerosis, are reviewed in detail.
Collapse
Affiliation(s)
- Jun Wang
- a Department of Neurosurgery , The First Hospital of China Medical University , Shenyang , P.R. China
| | - Shao-Wu Ou
- a Department of Neurosurgery , The First Hospital of China Medical University , Shenyang , P.R. China
| | - Yun-Jie Wang
- a Department of Neurosurgery , The First Hospital of China Medical University , Shenyang , P.R. China
| |
Collapse
|
4
|
Saxena S, Hillis AE. An update on medications and noninvasive brain stimulation to augment language rehabilitation in post-stroke aphasia. Expert Rev Neurother 2017; 17:1091-1107. [PMID: 28847186 DOI: 10.1080/14737175.2017.1373020] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Aphasia is among the most debilitating outcomes of stroke. Aphasia is a language disorder occurring in 10-30% of stroke survivors. Speech and Language Therapy (SLT) is the gold standard, mainstay treatment for aphasia, but gains from SLT may be incomplete. Pharmaceutical and noninvasive brain stimulation (NIBS) techniques may augment the effectiveness of SLT. Areas covered: Herein reviewed are studies of the safety and efficacy of these adjunctive interventions for aphasia, including randomized placebo-controlled and open-label trials, as well as case series from Pubmed, using search terms 'pharmacological,' 'tDCS' or 'TMS' combined with 'aphasia' and 'stroke.' Expert commentary: Relatively small studies have included participants with a range of aphasia types and severities, using inconsistent interventions and outcome measures. Results to-date have provided promising, but weak to moderate evidence that medications and/or NIBS can augment the effects of SLT for improving language outcomes. We end with recommendations for future approaches to studying these interventions, with multicenter, double-blind, randomized controlled trials.
Collapse
Affiliation(s)
- Sadhvi Saxena
- a Department of Neurology , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | - Argye E Hillis
- a Department of Neurology , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| |
Collapse
|
5
|
Liang W, Zhang W, Zhao S, Liang H, Zhang J, Wang L. Alterations of Caspr2 and Nav1.6 on myelinated axon damage in a rat model of chronic cerebral hypoperfusion. Exp Ther Med 2017; 13:2468-2472. [PMID: 28565865 PMCID: PMC5443296 DOI: 10.3892/etm.2017.4228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 01/11/2017] [Indexed: 11/19/2022] Open
Abstract
Myelinated axons require the correct localization of key proteins that are essential for nerve conduction and cognitive function. Little is known regarding the altered expression of contactin-associated protein 2 (Caspr2) at the juxtaparanodal regions and Nav1.6 at the node of Ranvier in response to chronic cerebral hypoperfusion (CCH). The aim of the present study was to examine the alterations in the key protein of myelinated axons and the potential mechanisms that may follow CCH. We established a rat model of CCH by controllable partial narrowing of bilateral common carotid arteries. Then, we detected cerebral blood flow (CBF) after surgery. We also evaluated motor-evoked potentials (MEPs), assessed the Morris water maze test, analyzed Caspr2 expression through immunohistochemistry and Nav1.6 protein expression through western blot analysis at 2, 4 and 12 weeks. The results revealed that the mean CBF value was significantly decreased to 33.90±5.48%. The MEP latencies and the escaping latencies were significantly prolonged. There was also an elongation of the first time passing of the hidden platform with a reduction of crossing platform times in spatial probing. Furthermore, the Caspr2 immunoreactivity demonstrated that the Caspr2 level was significantly downregulated with abnormal locations in the corpus callosum. The western blot analysis of Nav1.6 protein revealed that the level was reduced significantly over time. The results demonstrate that CCH leads to central conductive function loss, cognitive function damage and alterations in the key protein of myelinated axons, which may provide a molecular basis and key link for white matter damage.
Collapse
Affiliation(s)
- Weihua Liang
- No. 263 Clinic of PLA Army General Hospital, Beijing 101149, P.R. China.,Department of Neurology, Xinqiao Hospital, The Third Military Medical University, Chongqing 400038, P.R. China
| | - Weiwei Zhang
- PLA Army General Hospital, Beijing 100700, P.R. China
| | - Shifu Zhao
- Department of Neurology, Xinqiao Hospital, The Third Military Medical University, Chongqing 400038, P.R. China
| | - Hua Liang
- The 66083rd of PLA, Beijing 102488, P.R. China
| | - Jinli Zhang
- No. 263 Clinic of PLA Army General Hospital, Beijing 101149, P.R. China
| | - Luyan Wang
- No. 263 Clinic of PLA Army General Hospital, Beijing 101149, P.R. China
| |
Collapse
|
6
|
Ren L, Fang YN, Zhang AW, Li XL, Wang XJ, Yin Z, Miao JY. Effect of electroacupuncture on the expression of Nav1·1 in rat after acute cerebral ischemia. Neurol Res 2013; 32:763-9. [DOI: 10.1179/016164109x12445616596481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
7
|
Zha F, Li M, Guo W, Chen J, Wang P. Sodium ion channel optical model: Depolarization spatial distribution and local potential dynamic spatiotemporal processes. Neurocomputing 2013. [DOI: 10.1016/j.neucom.2012.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
8
|
Interleukin-1β Inhibits Voltage-Gated Sodium Currents in a Time- and Dose-Dependent Manner in Cortical Neurons. Neurochem Res 2011; 36:1116-23. [DOI: 10.1007/s11064-011-0456-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2011] [Indexed: 01/21/2023]
|
9
|
Mao Q, Jia F, Zhang XH, Qiu YM, Ge JW, Bao WJ, Luo QZ, Jiang JY. The up-regulation of voltage-gated sodium channel Nav1.6 expression following fluid percussion traumatic brain injury in rats. Neurosurgery 2010; 66:1134-9; discussion 1139. [PMID: 20421839 DOI: 10.1227/01.neu.0000369612.31946.a2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The influx of Na and the depolarization mediated by voltage-gated sodium channels (VGSCs) is an early event in traumatic brain injury (TBI) induced cellular abnormalities and is therefore well positioned as an upstream target for pharmacologic modulation of the pathological responses to TBI. Alteration in the expression of the VGSC alpha-subunit has occurred in a variety of neuropathological states including focal cerebral ischemia, spinal injury, and epilepsy. OBJECTIVE In this study, changes in Nav1.6 mRNA and protein expression were investigated in rat hippocampus after TBI. METHODS Forty-eight adult male Sprague Dawley rats were randomly assigned to control or TBI groups. TBI was induced with a lateral fluid percussion device. Expression of mRNA and protein for Nav1.6 in the bilateral hippocampus was examined at 2, 12, 24, and 72 hours after injury by real-time quantitative polymerase chain reaction and Western blot. Immunofluorescence was performed to localize the expression of Nav1.6 protein in the hippocampus. RESULTS Expression of >Nav1.6 mRNA was significantly up-regulated in the bilateral hippocampus at 2 and 12 hours post-TBI. Significant up-regulation of Nav1.6 protein was identified in the ipsilateral hippocampus from 2 to 72 hours post-TBI and in the contralateral hippocampus from 2 to 24 hours post-TBI. Expression of Nav1.6 occurred predominantly in neurons in the hippocampus. CONCLUSION Results of the study showed significant up-regulation of mRNA and protein for Nav1.6 in rat hippocampal neurons after TBI.
Collapse
Affiliation(s)
- Qing Mao
- Department of Neurosurgery, Shanghai RenJi hospital, Shanghai Jiaotong University, School of Medicine, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Yao C, Williams AJ, Ottens AK, Lu XCM, Liu MC, Hayes RL, Wang KK, Tortella FC, Dave JR. P43/pro-EMAPII: a potential biomarker for discriminating traumatic versus ischemic brain injury. J Neurotrauma 2009; 26:1295-305. [PMID: 19317603 PMCID: PMC2850301 DOI: 10.1089/neu.2008.0811] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
To gain additional insights into the pathogenic cellular and molecular mechanisms underlying different types of brain injury (e.g., trauma versus ischemia), recently attention has focused on the discovery and study of protein biomarkers. In previous studies, using a high-throughput immunoblotting (HTPI) technique, we reported changes in 29 out of 998 proteins following acute injuries to the rat brain (penetrating traumatic versus focal ischemic). Importantly, we discovered that one protein, endothelial monocyte-activating polypeptide II precursor (p43/pro-EMAPII), was differentially expressed between these two types of brain injury. Among other functions, p43/pro-EMAPII is a known pro-inflammatory cytokine involved in the progression of apoptotic cell death. Our current objective was to verify the changes in p43/pro-EMAPII expression, and to evaluate the potentially important implications that the differential regulation of this protein has on injury development. At multiple time points following either a penetrating ballistic-like brain injury (PBBI), or a transient middle cerebral artery occlusion (MCAo) brain injury, tissue samples (6-72 h), CSF samples (24 h), and blood samples (24 h) were collected from rats for analysis. Changes in protein expression were assessed by Western blot analysis and immunohistochemistry. Our results indicated that p43/pro-EMAPII was significantly increased in brain tissues, CSF, and plasma following PBBI, but decreased after MCAo injury compared to their respective sham control samples. This differential expression of p43/pro-EMAPII may be a useful injury-specific biomarker associated with the underlying pathologies of traumatic versus ischemic brain injury, and provide valuable information for directing injury-specific therapeutics.
Collapse
Affiliation(s)
- Changping Yao
- Department of Applied Neurobiology, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Anthony J. Williams
- Department of Applied Neurobiology, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Andrew K. Ottens
- Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia
| | - X.-C. May Lu
- Department of Applied Neurobiology, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Ming Cheng Liu
- Center of Innovative Research, Banyan Biomarkers Inc., Alachua, Florida
| | - Ronald L. Hayes
- Department of Anesthesiology, The University of Florida, Gainesville, Florida.,Center of Innovative Research, Banyan Biomarkers Inc., Alachua, Florida
| | - Kevin K. Wang
- Department of Psychiatry, The University of Florida, Gainesville, Florida.,Center of Innovative Research, Banyan Biomarkers Inc., Alachua, Florida
| | - Frank C. Tortella
- Department of Applied Neurobiology, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Jitendra R. Dave
- Department of Applied Neurobiology, Walter Reed Army Institute of Research, Silver Spring, Maryland
| |
Collapse
|
11
|
The effects of lead exposure on placental NF-κB expression and the consequences for gestation. Reprod Toxicol 2009; 27:190-5. [DOI: 10.1016/j.reprotox.2008.12.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2008] [Revised: 11/27/2008] [Accepted: 12/19/2008] [Indexed: 02/04/2023]
|
12
|
Yao C, Williams AJ, Ottens A, Lu XCM, Liu MC, Hayes RL, Wang KK, Tortella FC, Dave JR. P43/pro-EMAP-II: A POTENTIAL BIOMARKER FOR DISCRIMINATING TRAUMATIC VERSUS ISCHEMIC BRAIN INJURY. J Neurotrauma 2009. [DOI: 10.1089/neu.2008-0811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
13
|
Dave JR, Williams AJ, Yao C, Lu XCM, Tortella FC. Modeling cerebral ischemia in neuroproteomics. Methods Mol Biol 2009; 566:25-40. [PMID: 20058162 DOI: 10.1007/978-1-59745-562-6_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Protein changes induced by traumatic or ischemic brain injury can serve as diagnostic markers as well as therapeutic targets for neuroprotection. The focus of this chapter is to provide a representative overview of preclinical brain injury and proteomics analysis protocols for evaluation and discovery of novel biomarkers. Detailed surgical procedures have been provided for inducing MCAo and implantation of chronic indwelling cannulas for drug delivery. Sample collection and tissue processing techniques for collection of blood, CSF, and brain are also described including standard biochemical methodology for the proteomic analysis of these tissues.The dynamics of proteomic analysis is a multistep process comprising sample preparation, separation, quantification, and identification of proteins. Our approach is to separate proteins first by two-dimensional gel electrophoresis according to charge and molecular mass. Proteins are then fragmented and analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Identification of proteins can be achieved by comparing the mass-to-charge data to protein sequences in respective databases.
Collapse
Affiliation(s)
- Jitendra R Dave
- Department of Applied Neurobiology, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
| | | | | | | | | |
Collapse
|
14
|
Zhan RZ, Nadler JV, Schwartz-Bloom RD. Impaired firing and sodium channel function in CA1 hippocampal interneurons after transient cerebral ischemia. J Cereb Blood Flow Metab 2007; 27:1444-52. [PMID: 17228331 DOI: 10.1038/sj.jcbfm.9600448] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although interneurons in area CA1 of the hippocampus are less vulnerable to cerebral ischemia than CA1 pyramidal cells, it is not clear whether their relatively intact cellular morphology implies preservation of normal function. As maintenance of cellular excitability and firing properties is essential for interneurons to regulate neural networks, we investigated these aspects of interneuronal function after transient cerebral ischemia in rats. Cerebral ischemia in rats was induced for 8 mins by a combination of bilateral common carotid artery occlusion and hypovolemic hypotension, and whole cell patch clamp recordings were made in hippocampal slices prepared 24 h after reperfusion. Interneurons located within stratum pyramidale of area CA1 exhibited normal membrane properties and action potentials under these conditions. However, their excitability had declined, as evidenced by an increased action potential threshold and a rightward shift in the relationship between injected depolarizing current and firing rate. Voltage-clamp experiments revealed that transient cerebral ischemia reduced the peak Na(+) current and shifted Na(+) channel activation to more depolarized values, but did not alter steady-state inactivation of the channel. Double immunofluorescence cytochemistry showed that transient cerebral ischemia also reduced Na(v)1.1 subunit immunoreactivity in interneurons that coexpressed parvalbumin. We conclude that transient cerebral ischemia renders CA1 interneurons less excitable, that depressed excitability involves impaired Na(+) channel activation and that Na(+) channel dysfunction is explained, at least in part, by reduced expression of the Na(v)1.1 subunit. These changes may promote interneuron survival, but might also contribute to pyramidal cell death.
Collapse
Affiliation(s)
- Ren-Zhi Zhan
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, USA
| | | | | |
Collapse
|
15
|
Dai X, Chen L, Sokabe M. Neurosteroid estradiol rescues ischemia-induced deficit in the long-term potentiation of rat hippocampal CA1 neurons. Neuropharmacology 2007; 52:1124-38. [PMID: 17258238 DOI: 10.1016/j.neuropharm.2006.11.012] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2006] [Revised: 11/28/2006] [Accepted: 11/29/2006] [Indexed: 02/03/2023]
Abstract
Increasing evidence indicates that neurosteroid 17beta-Estradiol (E2), a type of female sex hormone, has a neuroprotective effect against cerebral injury. However, it remains unknown whether E2 can also protect the hippocampal CA1 neurons from functional deficits in synaptic transmission and plasticity caused by ischemia. To address this issue, adult male Wistar rats were subjected to mild global cerebral ischemia created by four-vessel occlusion (4VO) for 10min, and the effects of E2 administration against the ischemic injury were investigated. The electrophysiological properties of Schaffer collateral-CA1 synapses were examined 7days after ischemia by applying a real-time optical recording technique to the hippocampal slices stained with a voltage-sensitive dye (RH482). The ischemic brain showed a decreased basal synaptic transmission and an impairment of LTP induction, but no alteration in paired-pulse facilitation. The administration of E2 (1mg/kg) 3h before ischemia was able to protect CA1 neurons from these ischemia-induced synaptic dysfunctions. The estrogen receptor-alpha (ERalpha) selective agonist, propyl pyrazole triol (PPT, 2mg/kg), exerted a similar protective effect, but the estrogen receptor-beta (ERbeta) agonist, diarylpropiolnitrile (DPN, 8mg/kg), failed to do so. A histological examination revealed that the transient global cerebral ischemia markedly reduced the density of pyramidal neurons in the CA1 region. The cell loss was significantly attenuated by E2 and PPT but not by DPN, as observed in synaptic functions. These findings suggest that E2 can protect neurons not only from cell death but also from functional damages due to a relatively mild degree of transient cerebral ischemia, and this effect is mediated by ERalpha, but not by ERbeta.
Collapse
Affiliation(s)
- Xiaoniu Dai
- Department of Physiology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Nagoya 466-8550, Japan
| | | | | |
Collapse
|