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Gibson JM, Vazquez AH, Yamashiro K, Jakkamsetti V, Ren C, Lei K, Dentel B, Pascual JM, Tsai PT. Cerebellar contribution to autism-relevant behaviors in fragile X syndrome models. Cell Rep 2023; 42:113533. [PMID: 38048226 PMCID: PMC10831814 DOI: 10.1016/j.celrep.2023.113533] [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: 11/21/2022] [Revised: 09/01/2023] [Accepted: 11/17/2023] [Indexed: 12/06/2023] Open
Abstract
Cerebellar dysfunction has been linked to autism spectrum disorders (ASDs). Although cerebellar pathology has been observed in individuals with fragile X syndrome (FXS) and in mouse models of the disorder, a cerebellar functional contribution to ASD-relevant behaviors in FXS has yet to be fully characterized. In this study, we demonstrate a critical cerebellar role for Fmr1 (fragile X messenger ribonucleoprotein 1) in ASD-relevant behaviors. First, we identify reduced social behaviors, sensory hypersensitivity, and cerebellar dysfunction, with loss of cerebellar Fmr1. We then demonstrate that cerebellar-specific expression of Fmr1 is sufficient to impact social, sensory, cerebellar dysfunction, and cerebro-cortical hyperexcitability phenotypes observed in global Fmr1 mutants. Moreover, we demonstrate that targeting the ASD-implicated cerebellar region Crus1 ameliorates behaviors in both cerebellar-specific and global Fmr1 mutants. Together, these results demonstrate a critical role for the cerebellar contribution to FXS-related behaviors, with implications for future therapeutic strategies.
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Affiliation(s)
- Jennifer M Gibson
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Anthony Hernandez Vazquez
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kunihiko Yamashiro
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Vikram Jakkamsetti
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chongyu Ren
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Katherine Lei
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Brianne Dentel
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Juan M Pascual
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Peter T Tsai
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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2
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Lafourcade CA, Sparks FT, Bordey A, Wyneken U, Mohammadi MH. Cannabinoid regulation of neurons in the dentate gyrus during epileptogenesis: Role of CB1R-associated proteins and downstream pathways. Epilepsia 2023. [PMID: 36869624 DOI: 10.1111/epi.17569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 03/05/2023]
Abstract
The hippocampal formation plays a central role in the development of temporal lobe epilepsy (TLE), a disease characterized by recurrent, unprovoked epileptic discharges. TLE is a neurologic disorder characterized by acute long-lasting seizures (i.e., abnormal electrical activity in the brain) or seizures that occur in close proximity without recovery, typically after a brain injury or status epilepticus. After status epilepticus, epileptogenic hyperexcitability develops gradually over the following months to years, resulting in the emergence of chronic, recurrent seizures. Acting as a filter or gate, the hippocampal dentate gyrus (DG) normally prevents excessive excitation from propagating through the hippocampus, and is considered a critical region in the progression of epileptogenesis in pathological conditions. Importantly, lipid-derived endogenous cannabinoids (endocannabinoids), which are produced on demand as retrograde messengers, are central regulators of neuronal activity in the DG circuit. In this review, we summarize recent findings concerning the role of the DG in controlling hyperexcitability and propose how DG regulation by cannabinoids (CBs) could provide avenues for therapeutic interventions. We also highlight possible pathways and manipulations that could be relevant for the control of hyperexcitation. The use of CB compounds to treat epilepsies is controversial, as anecdotal evidence is not always validated by clinical trials. Recent publications shed light on the importance of the DG as a region regulating incoming hippocampal excitability during epileptogenesis. We review recent findings concerning the modulation of the hippocampal DG circuitry by CBs and discuss putative underlying pathways. A better understanding of the mechanisms by which CBs exert their action during seizures may be useful to improve therapies.
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Affiliation(s)
- Carlos A Lafourcade
- Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, Suzhou, China
| | - Fraser T Sparks
- Department of Neuroscience, Columbia University, New York, New York, USA.,Current: Regeneron Pharmaceuticals, Tarrytown, New York, USA
| | - Angelique Bordey
- Department of Neurosurgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Ursula Wyneken
- Centro de Investigación e Innovación Biomédica, Laboratorio de Neurociencias, Universidad de Los Andes, Santiago, Chile.,Center of Interventional Medicine for Precision and Advanced Cellular Therapy, Santiago, Chile
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3
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Armstrong JL, Saraf TS, Bhatavdekar O, Canal CE. Spontaneous seizures in adult Fmr1 knockout mice: FVB.129P2-Pde6b+ Tyr Fmr1/J. Epilepsy Res 2022; 182:106891. [PMID: 35290907 PMCID: PMC9050957 DOI: 10.1016/j.eplepsyres.2022.106891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 02/14/2022] [Accepted: 02/17/2022] [Indexed: 01/26/2023]
Abstract
The prevalence of seizures in individuals with fragile X syndrome (FXS) is ~25%; however, there are no reports of spontaneous seizures in the Fmr1 knockout mouse model of FXS. Herein, we report that 48% of adult (median age P96), Fmr1 knockout mice from our colony were found expired in their home cages. We observed and recorded adult Fmr1 knockout mice having spontaneous convulsions in their home cages. In addition, we captured by electroencephalography an adult Fmr1 knockout mouse having a spontaneous seizure-during preictal, ictal, and postictal phases-which confirmed the presence of a generalized seizure. We did not observe this phenotype in control conspecifics or in juvenile (age <P35) Fmr1 knockout mice. We hypothesized that chronic, random, noise perturbations during development caused the phenotype. We recorded decibels (dB) in our vivarium. The average was 61 dB, but operating the automatic door to the vivarium caused spikes to 95 dB. We modified the door to eliminate noise spikes, which reduced unexpected deaths to 33% in Fmr1 knockout mice raised from birth in this environment (P = 0.07). As the modifications did not eliminate unexpected deaths, we further hypothesized that building vibrations may also be a contributing factor. After installing anti-vibration pads underneath housing carts, unexpected deaths of Fmr1 knockout mice born and raised in this environment decreased to 29% (P < 0.01 compared to the original environment). We also observed significant sex effects, for example, after interventions to reduce sound and vibration, significantly fewer male, but not female, Fmr1 knockout mice died unexpectedly (P < 0.001). The spontaneous seizure phenotype in our Fmr1 knockout mice could serve as a model of seizures observed in individuals with FXS, potentially offering a new translationally-valid phenotype for FXS research. Finally, these observations, although anomalous, serve as a reminder to consider gene-environment interactions when interpreting data derived from Fmr1 knockout mice.
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Affiliation(s)
- Jessica L Armstrong
- Mercer University, College of Pharmacy, Department of Pharmaceutical Sciences, 3001 Mercer University Drive, Atlanta, GA 30341, USA
| | - Tanishka S Saraf
- Mercer University, College of Pharmacy, Department of Pharmaceutical Sciences, 3001 Mercer University Drive, Atlanta, GA 30341, USA
| | - Omkar Bhatavdekar
- Johns Hopkins University, Department of Chemical and Biomolecular Engineering, 3400 North Charles Street, Croft Hall B27, Baltimore, MD 21218, USA
| | - Clinton E Canal
- Mercer University, College of Pharmacy, Department of Pharmaceutical Sciences, 3001 Mercer University Drive, Atlanta, GA 30341, USA.
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4
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Myo-Inositol Limits Kainic Acid-Induced Epileptogenesis in Rats. Int J Mol Sci 2022; 23:ijms23031198. [PMID: 35163126 PMCID: PMC8835653 DOI: 10.3390/ijms23031198] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 01/09/2023] Open
Abstract
Epilepsy is a severe neurological disease characterized by spontaneous recurrent seizures (SRS). A complex pathophysiological process referred to as epileptogenesis transforms a normal brain into an epileptic one. Prevention of epileptogenesis is a subject of intensive research. Currently, there are no clinically approved drugs that can act as preventive medication. Our previous studies have revealed highly promising antiepileptogenic properties of a compound-myo-inositol (MI) and the present research broadens previous results and demonstrates the long-term disease-modifying effect of this drug, as well as the amelioration of cognitive comorbidities. For the first time, we show that long-term treatment with MI: (i) decreases the frequency and duration of electrographic SRS in the hippocampus; (ii) has an ameliorating effect on spatial learning and memory deficit associated with epileptogenesis, and (iii) attenuates cell loss in the hippocampus. MI treatment also alters the expression of the glial fibrillary acidic protein, LRRC8A subunit of volume-regulated anion channels, and protein tyrosine phosphatase receptor type R, all expected to counteract the epileptogenesis. All these effects are still present even 4 weeks after MI treatment ceased. This suggests that MI may exert multiple actions on various epileptogenesis-associated changes in the brain and, therefore, could be considered as a candidate target for prevention of epileptogenesis.
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Li H, Cong X, Sui J, Jiang Z, Fu K, Huan Y, Cao R, Tian W, Feng Y. Baicalin enhances the thermotolerance of mouse blastocysts by activating the ERK1/2 signaling pathway and preventing mitochondrial dysfunction. Theriogenology 2022; 178:85-94. [PMID: 34808561 DOI: 10.1016/j.theriogenology.2021.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 11/05/2021] [Accepted: 11/13/2021] [Indexed: 10/19/2022]
Abstract
Heat stress causes oxidative damage and induces excessive cell apoptosis and thus affects the development and/or even causes the death of preimplantation embryos. The effects of baicalin on the developmental competence of heat-stressed mouse embryos were investigated in this experiment. Two-cell embryos were cultured in the presence of baicalin and subjected to heat stress (42 °C for 1 h) at their blastocyst stage followed by continuous culture at 37 °C until examination. The results showed that heat stress (H group) increased reactive oxygen species (ROS) production, apoptosis and even embryo death, along with reductions in both mitochondrial activity and membrane potential (ΔΨm). Both heat stress (H group) and inhibition of the ERK1/2 signaling pathway (U group) led to significantly reduced expression levels of the genes c-fos, AP-1 and ERK2, and the phosphorylation of ERK1/2 and c-Fos, along with significantly increased c-Jun mRNA expression and phosphorylation levels. These negative effects of heat stress on the ERK1/2 signaling pathway were neutralized by baicalin treatment. To explore the signal transduction mechanism of baicalin in improving embryonic tolerance to heat stress, mitochondrial quality and apoptosis rate in the mouse blastocysts were also examined. Baicalin was found to up-regulate the expression of mtDNA and TFAM mRNA, increased mitochondria activity and ΔΨm, and improved the cellular mitochondria quality of mouse blastocysts undergoing heat stress. Moreover, baicalin decreased Bax transcript abundance in blastocyst, along with an increase in the blastocyst hatching rate, which were negatively affected by heat stress. Our findings suggest that baicalin improves the developmental capacity and quality of heat-stressed mouse embryos via a mechanism whereby mitochondrial quality is improved by activating the ERK1/2 signaling pathway and inducing anti-cellular apoptosis.
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Affiliation(s)
- Huatao Li
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, People's Republic of China
| | - Xia Cong
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, People's Republic of China
| | - Junxia Sui
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, People's Republic of China
| | - Zhongling Jiang
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, People's Republic of China
| | - Kaiqiang Fu
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, People's Republic of China
| | - Yanjun Huan
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, People's Republic of China
| | - Rongfeng Cao
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, People's Republic of China
| | - Wenru Tian
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, People's Republic of China.
| | - Yanni Feng
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, People's Republic of China.
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6
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da Costa Sobral KG, Neuberger B, Mello FK, Mallmann MP, Sampaio TB, Oliveira MS. Anticonvulsant activity of β-caryophyllene in association with pregabalin in a seizure model in rats. Epilepsy Res 2022; 179:106842. [PMID: 34942451 DOI: 10.1016/j.eplepsyres.2021.106842] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 11/15/2021] [Accepted: 12/05/2021] [Indexed: 11/03/2022]
Abstract
Epilepsy is a common chronic neurological disease. The hallmark of epilepsy is recurrent, unprovoked seizures. Unfortunately, drug resistance is frequent in patients with epilepsy, and therefore improved therapeutic strategies are needed. In the present study, we tested the effect of pregabalin in association with beta-caryophyllene, an FDA-approved food additive and naturally occurring agonist of cannabinoid receptor subtype 2 against pentylenetetrazol (PTZ)-induced seizures in rats. In addition, selected neurochemical parameters were evaluated in the cerebral cortex. Adult male Wistar rats received beta-caryophyllene (100 mg/kg), pregabalin (40 mg/kg) or their combination before PTZ (60 mg/kg). Appropriated vehicle-treated control groups were included for each treatment. Animals were monitored by video-EEG and the latency to myoclonic seizures, latency to tonic-clonic seizures, tonic-clonic seizure duration and overall seizure score were measured. Glial fibrillary acidic protein (GFAP) release, erythroid-related factor 2 (Nrf2), c-fos and 3-nitrotyrosine (3-NT) levels were evaluated in the frontal cortex. We found that beta-caryophyllene plus pregabalin increased the latency to PTZ-induced myoclonic and tonic-clonic seizures and decreased the tonic-clonic seizure duration and overall seizure score. Interestingly, lower levels of GFAP, c-Fos and 3-NT were observed in animals receiving beta-caryophyllene and pregabalin treatments. Our results suggest a possible synergic effect of beta-caryophyllene plus pregabalin against PTZ induced-seizures.
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Affiliation(s)
| | - Bruna Neuberger
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil.
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7
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Chuvakova LN, Funikov SY, Rezvykh AP, Davletshin AI, Evgen'ev MB, Litvinova SA, Fedotova IB, Poletaeva II, Garbuz DG. Transcriptome of the Krushinsky-Molodkina Audiogenic Rat Strain and Identification of Possible Audiogenic Epilepsy-Associated Genes. Front Mol Neurosci 2021; 14:738930. [PMID: 34803604 PMCID: PMC8600260 DOI: 10.3389/fnmol.2021.738930] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 10/07/2021] [Indexed: 12/13/2022] Open
Abstract
Audiogenic epilepsy (AE), inherent to several rodent strains is widely studied as a model of generalized convulsive epilepsy. The molecular mechanisms that determine the manifestation of AE are not well understood. In the present work, we compared transcriptomes from the corpora quadrigemina in the midbrain zone, which are crucial for AE development, to identify genes associated with the AE phenotype. Three rat strains without sound exposure were compared: Krushinsky-Molodkina (KM) strain (100% AE-prone); Wistar outbred rat strain (non-AE prone) and “0” strain (partially AE-prone), selected from F2 KM × Wistar hybrids for their lack of AE. The findings showed that the KM strain gene expression profile exhibited a number of characteristics that differed from those of the Wistar and “0” strain profiles. In particular, the KM rats showed increased expression of a number of genes involved in the positive regulation of the MAPK signaling cascade and genes involved in the positive regulation of apoptotic processes. Another characteristic of the KM strain which differed from that of the Wistar and “0” rats was a multi-fold increase in the expression level of the Ttr gene and a significant decrease in the expression of the Msh3 gene. Decreased expression of a number of oxidative phosphorylation-related genes and a few other genes was also identified in the KM strain. Our data confirm the complex multigenic nature of AE inheritance in rodents. A comparison with data obtained from other independently selected AE-prone rodent strains suggests some common causes for the formation of the audiogenic phenotype.
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Affiliation(s)
- Lyubov N Chuvakova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Sergei Yu Funikov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Alexander P Rezvykh
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.,Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Artem I Davletshin
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Michael B Evgen'ev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | | | | | | | - David G Garbuz
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
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8
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Romagnoli A, Di Marino D. The Use of Peptides in the Treatment of Fragile X Syndrome: Challenges and Opportunities. Front Psychiatry 2021; 12:754485. [PMID: 34803767 PMCID: PMC8599826 DOI: 10.3389/fpsyt.2021.754485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/11/2021] [Indexed: 01/17/2023] Open
Abstract
Fragile X Syndrome (FXS) is the most frequent cause of inherited intellectual disabilities and autism spectrum disorders, characterized by cognitive deficits and autistic behaviors. The silencing of the Fmr1 gene and consequent lack of FMRP protein, is the major contribution to FXS pathophysiology. FMRP is an RNA binding protein involved in the maturation and plasticity of synapses and its absence culminates in a range of morphological, synaptic and behavioral phenotypes. Currently, there are no approved medications for the treatment of FXS, with the approaches under study being fairly specific and unsatisfying in human trials. Here we propose peptides/peptidomimetics as candidates in the pharmacotherapy of FXS; in the last years this class of molecules has catalyzed the attention of pharmaceutical research, being highly selective and well-tolerated. Thanks to their ability to target protein-protein interactions (PPIs), they are already being tested for a wide range of diseases, including cancer, diabetes, inflammation, Alzheimer's disease, but this approach has never been applied to FXS. As FXS is at the forefront of efforts to develop new drugs and approaches, we discuss opportunities, challenges and potential issues of peptides/peptidomimetics in FXS drug design and development.
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Affiliation(s)
| | - Daniele Di Marino
- Department of Life and Environmental Sciences, New York-Marche Structural Biology Center (NY-MaSBiC), Polytechnic University of Marche, Ancona, Italy
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9
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Cattelani C, Lesiak D, Liebscher G, Singer II, Stasyk T, Wallnöfer MH, Heberle AM, Corti C, Hess MW, Pfaller K, Kwiatkowski M, Pramstaller PP, Hicks AA, Thedieck K, Müller T, Huber LA, Eca Guimaraes de Araujo M. The SZT2 Interactome Unravels New Functions of the KICSTOR Complex. Cells 2021; 10:2711. [PMID: 34685691 PMCID: PMC8534408 DOI: 10.3390/cells10102711] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/20/2021] [Accepted: 10/05/2021] [Indexed: 12/25/2022] Open
Abstract
Seizure threshold 2 (SZT2) is a component of the KICSTOR complex which, under catabolic conditions, functions as a negative regulator in the amino acid-sensing branch of mTORC1. Mutations in this gene cause a severe neurodevelopmental and epileptic encephalopathy whose main symptoms include epilepsy, intellectual disability, and macrocephaly. As SZT2 remains one of the least characterized regulators of mTORC1, in this work we performed a systematic interactome analysis under catabolic and anabolic conditions. Besides numerous mTORC1 and AMPK signaling components, we identified clusters of proteins related to autophagy, ciliogenesis regulation, neurogenesis, and neurodegenerative processes. Moreover, analysis of SZT2 ablated cells revealed increased mTORC1 signaling activation that could be reversed by Rapamycin or Torin treatments. Strikingly, SZT2 KO cells also exhibited higher levels of autophagic components, independent of the physiological conditions tested. These results are consistent with our interactome data, in which we detected an enriched pool of selective autophagy receptors/regulators. Moreover, preliminary analyses indicated that SZT2 alters ciliogenesis. Overall, the data presented form the basis to comprehensively investigate the physiological functions of SZT2 that could explain major molecular events in the pathophysiology of developmental and epileptic encephalopathy in patients with SZT2 mutations.
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Affiliation(s)
- Cecilia Cattelani
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy; (C.C.); (P.P.P.); (A.A.H.)
| | - Dominik Lesiak
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
| | - Gudrun Liebscher
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
| | - Isabel I. Singer
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
| | - Taras Stasyk
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
| | - Moritz H. Wallnöfer
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
| | - Alexander M. Heberle
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, 6020 Innsbruck, Austria; (A.M.H.); (M.K.); (K.T.)
- Laboratory of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
| | - Corrado Corti
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy; (C.C.); (P.P.P.); (A.A.H.)
| | - Michael W. Hess
- Institute of Histology and Embryology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.W.H.); (K.P.)
| | - Kristian Pfaller
- Institute of Histology and Embryology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.W.H.); (K.P.)
| | - Marcel Kwiatkowski
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, 6020 Innsbruck, Austria; (A.M.H.); (M.K.); (K.T.)
| | - Peter P. Pramstaller
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy; (C.C.); (P.P.P.); (A.A.H.)
| | - Andrew A. Hicks
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy; (C.C.); (P.P.P.); (A.A.H.)
| | - Kathrin Thedieck
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, 6020 Innsbruck, Austria; (A.M.H.); (M.K.); (K.T.)
- Laboratory of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
- Department for Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany
| | - Thomas Müller
- Department of Pediatrics I, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - Lukas A. Huber
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
- Austrian Drug Screening Institute, ADSI, 6020 Innsbruck, Austria
| | - Mariana Eca Guimaraes de Araujo
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
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10
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Khayachi A, Schorova L, Alda M, Rouleau GA, Milnerwood AJ. Posttranslational modifications & lithium's therapeutic effect-Potential biomarkers for clinical responses in psychiatric & neurodegenerative disorders. Neurosci Biobehav Rev 2021; 127:424-445. [PMID: 33971223 DOI: 10.1016/j.neubiorev.2021.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 03/14/2021] [Accepted: 05/03/2021] [Indexed: 01/03/2023]
Abstract
Several neurodegenerative diseases and neuropsychiatric disorders display aberrant posttranslational modifications (PTMs) of one, or many, proteins. Lithium treatment has been used for mood stabilization for many decades, and is highly effective for large subsets of patients with diverse neurological conditions. However, the differential effectiveness and mode of action are not fully understood. In recent years, studies have shown that lithium alters several protein PTMs, altering their function, and consequently neuronal physiology. The impetus for this review is to outline the links between lithium's therapeutic mode of action and PTM homeostasis. We first provide an overview of the principal PTMs affected by lithium. We then describe several neuropsychiatric disorders in which PTMs have been implicated as pathogenic. For each of these conditions, we discuss lithium's clinical use and explore the putative mechanism of how it restores PTM homeostasis, and thereby cellular physiology. Evidence suggests that determining specific PTM patterns could be a promising strategy to develop biomarkers for disease and lithium responsiveness.
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Affiliation(s)
- A Khayachi
- Montreal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, Montréal, Quebec, Canada.
| | - L Schorova
- McGill University Health Center Research Institute, Montréal, Quebec, Canada
| | - M Alda
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - G A Rouleau
- Montreal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, Montréal, Quebec, Canada; Department of Human Genetics, McGill University, Montréal, Quebec, Canada.
| | - A J Milnerwood
- Montreal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, Montréal, Quebec, Canada.
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11
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Abstract
Fragile X syndrome (FXS) is the most common inherited form of intellectual disability and the leading monogenic cause of autism. The condition stems from loss of fragile X mental retardation protein (FMRP), which regulates a wide range of ion channels via translational control, protein-protein interactions and second messenger pathways. Rapidly increasing evidence demonstrates that loss of FMRP leads to numerous ion channel dysfunctions (that is, channelopathies), which in turn contribute significantly to FXS pathophysiology. Consistent with this, pharmacological or genetic interventions that target dysregulated ion channels effectively restore neuronal excitability, synaptic function and behavioural phenotypes in FXS animal models. Recent studies further support a role for direct and rapid FMRP-channel interactions in regulating ion channel function. This Review lays out the current state of knowledge in the field regarding channelopathies and the pathogenesis of FXS, including promising therapeutic implications.
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12
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Lo AC, Rajan N, Gastaldo D, Telley L, Hilal ML, Buzzi A, Simonato M, Achsel T, Bagni C. Absence of RNA-binding protein FXR2P prevents prolonged phase of kainate-induced seizures. EMBO Rep 2021; 22:e51404. [PMID: 33779029 PMCID: PMC8024897 DOI: 10.15252/embr.202051404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 01/26/2021] [Accepted: 01/29/2021] [Indexed: 12/26/2022] Open
Abstract
Status epilepticus (SE) is a condition in which seizures are not self-terminating and thereby pose a serious threat to the patient's life. The molecular mechanisms underlying SE are likely heterogeneous and not well understood. Here, we reveal a role for the RNA-binding protein Fragile X-Related Protein 2 (FXR2P) in SE. Fxr2 KO mice display reduced sensitivity specifically to kainic acid-induced SE. Immunoprecipitation of FXR2P coupled to next-generation sequencing of associated mRNAs shows that FXR2P targets are enriched in genes that encode glutamatergic post-synaptic components. Of note, the FXR2P target transcriptome has a significant overlap with epilepsy and SE risk genes. In addition, Fxr2 KO mice fail to show sustained ERK1/2 phosphorylation induced by KA and present reduced burst activity in the hippocampus. Taken together, our findings show that the absence of FXR2P decreases the expression of glutamatergic proteins, and this decrease might prevent self-sustained seizures.
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Affiliation(s)
- Adrian C Lo
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Nicholas Rajan
- Department of Neurosciences and Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Denise Gastaldo
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Ludovic Telley
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Muna L Hilal
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Andrea Buzzi
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
| | - Michele Simonato
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy.,Division of Neuroscience, IRCCS San Raffaele Hospital, Milan, Italy
| | - Tilmann Achsel
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland.,Department of Neurosciences and Leuven Brain Institute, KU Leuven, Leuven, Belgium.,Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
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13
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Naumova AA, Oleynik EA, Chernigovskaya EV, Glazova MV. Glutamatergic Fate of Neural Progenitor Cells of Rats with Inherited Audiogenic Epilepsy. Brain Sci 2020; 10:brainsci10050311. [PMID: 32455746 PMCID: PMC7288135 DOI: 10.3390/brainsci10050311] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/15/2020] [Accepted: 05/19/2020] [Indexed: 01/08/2023] Open
Abstract
Epilepsy is associated with aberrant neurogenesis in the hippocampus and may underlie the development of hereditary epilepsy. In the present study, we analyzed the differentiation fate of neural progenitor cells (NPC), which were isolated from the hippocampus of embryos of Krushinsky-Molodkina (KM) rats genetically prone to audiogenic epilepsy. NPCs from embryos of Wistar rats were used as the control. We found principal differences between Wistar and KM NPC in unstimulated controls: Wistar NPC culture contained both gamma-aminobutyric acid (GABA) and glutamatergic neurons; KM NPC culture was mainly represented by glutamatergic cells. The stimulation of glutamatergic differentiation of Wistar NPC resulted in a significant increase in glutamatergic cell number that was accompanied by the activation of protein kinase A. The stimulation of KM NPC led to a decrease in immature glutamatergic cell number and was associated with the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and protein kinase B/ glycogen synthase kinase 3 beta (Akt/GSK3β), which indicates the activation of glutamatergic cell maturation. These results suggest genetically programmed abnormalities in KM rats that determine the glutamatergic fate of NPC and contribute to the development of audiogenic epilepsy.
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14
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Garcia-Gomes MDSA, Zanatto DA, Galvis-Alonso OY, Mejia J, Antiorio ATFB, Yamamoto PK, Olivato MCM, Sandini TM, Flório JC, Lebrun I, Massironi SMG, Alexandre-Ribeiro SR, Bernardi MM, Ienne S, de Souza TA, Dagli MLZ, Mori CMC. Behavioral and neurochemical characterization of the spontaneous mutation tremor, a new mouse model of audiogenic seizures. Epilepsy Behav 2020; 105:106945. [PMID: 32109856 DOI: 10.1016/j.yebeh.2020.106945] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 01/08/2020] [Accepted: 01/24/2020] [Indexed: 11/18/2022]
Abstract
The tremor mutant phenotype results from an autosomal recessive spontaneous mutation arisen in a Swiss-Webster mouse colony. The mutant mice displayed normal development until three weeks of age when they began to present motor impairment comprised by whole body tremor, ataxia, and decreased exploratory behavior. These features increased in severity with aging suggesting a neurodegenerative profile. In parallel, they showed audiogenic generalized clonic seizures. Results from genetic mapping identified the mutation tremor on chromosome 14, in an interval of 5 cM between D14Mit37 (33.21 cM) and D14Mit115 (38.21 cM), making Early Growth Response 3 (Egr3) the main candidate gene. Comparing with wild type (WT) mice, the tremor mice showed higher hippocampal gene expression of Egr3 and Gabra1 and increased concentrations of noradrenalin (NOR; p = .0012), serotonin (5HT; p = .0083), 5-hydroxyindoleacetic acid (5-HIAA; p = .0032), γ-amino butyric acid (GABA; p = .0123), glutamate (p = .0217) and aspartate (p = .0124). In opposition, the content of glycine (p = .0168) and the vanillylmandelic acid (VMA)/NOR ratio (p = .032) were decreased. Regarding to dopaminergic system, neither dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) contents nor the turnover rate of DA showed statistically significant differences between WT and mutant mice. Data demonstrated that audiogenic seizures of tremor mice are associated with progressive motor impairment as well as to hippocampal alterations of the Egr3 and Gabra1 gene expression and amino acid and monoamine content. In addition, the tremor mice could be useful for study of neurotransmission pathways as modulators of epilepsy and the pathogenesis of epilepsies occurring with generalized clonic seizures.
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Affiliation(s)
| | - Dennis Albert Zanatto
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Brazil
| | | | - Jorge Mejia
- Hospital Israelita Albert Einstein, São Paulo, Brazil
| | | | - Pedro Kenzo Yamamoto
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Brazil
| | | | - Thaísa Meira Sandini
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Brazil
| | - Jorge Camilo Flório
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Brazil
| | - Ivo Lebrun
- Laboratory of Biochemistry and Biophysics, Butantan Institute, Brazil
| | - Silvia Maria Gomes Massironi
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Brazil; Department of Immunology, Institute of Biomedical Sciences, University of São Paulo (USP), Brazil
| | | | | | - Susan Ienne
- Core Facility for Scientific Research - University of São Paulo (CEFAP-USP/GENIAL (Genome Investigation and Analysis Laboratory), Brazil
| | - Tiago Antonio de Souza
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo (USP), Brazil
| | - Maria Lúcia Zaidan Dagli
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Brazil
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15
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Gonzalez D, Tomasek M, Hays S, Sridhar V, Ammanuel S, Chang CW, Pawlowski K, Huber KM, Gibson JR. Audiogenic Seizures in the Fmr1 Knock-Out Mouse Are Induced by Fmr1 Deletion in Subcortical, VGlut2-Expressing Excitatory Neurons and Require Deletion in the Inferior Colliculus. J Neurosci 2019; 39:9852-9863. [PMID: 31666356 PMCID: PMC6891051 DOI: 10.1523/jneurosci.0886-19.2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 09/06/2019] [Accepted: 10/16/2019] [Indexed: 02/07/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and the leading monogenetic cause of autism. One symptom of FXS and autism is sensory hypersensitivity (also called sensory over-responsivity). Perhaps related to this, the audiogenic seizure (AGS) is arguably the most robust behavioral phenotype in the FXS mouse model-the Fmr1 knock-out (KO) mouse. Therefore, the AGS may be considered a mouse model of sensory hypersensitivity. Hyperactive circuits are hypothesized to underlie dysfunction in a number of brain regions in patients with FXS and Fmr1 KO mice, and the AGS may be a result of this. But the specific cell types and brain regions underlying AGSs in the Fmr1 KO are unknown. We used conditional deletion or expression of Fmr1 in different cell populations to determine whether Fmr1 deletion in those cells was sufficient or necessary, respectively, for the AGS phenotype in males. Our data indicate that Fmr1 deletion in glutamatergic neurons that express vesicular glutamate transporter 2 (VGlut2) and are located in subcortical brain regions is sufficient and necessary to cause AGSs. Furthermore, the deletion of Fmr1 in glutamatergic neurons of the inferior colliculus is necessary for AGSs. When we demonstrate necessity, we show that Fmr1 expression in either the larger population of VGlut2-expressing glutamatergic neurons or the smaller population of inferior collicular glutamatergic neurons-in an otherwise Fmr1 KO mouse-eliminates AGSs. Therefore, targeting these neuronal populations in FXS and autism may be part of a therapeutic strategy to alleviate sensory hypersensitivity.SIGNIFICANCE STATEMENT Sensory hypersensitivity in fragile X syndrome (FXS) and autism patients significantly interferes with quality of life. Audiogenic seizures (AGSs) are arguably the most robust behavioral phenotype in the FXS mouse model-the Fmr1 knockout-and may be considered a model of sensory hypersensitivity in FXS. We provide the clearest and most precise genetic evidence to date for the cell types and brain regions involved in causing AGSs in the Fmr1 knockout and, more broadly, for any mouse mutant. The expression of Fmr1 in these same cell types in an otherwise Fmr1 knockout eliminates AGSs indicating possible cellular targets for alleviating sensory hypersensitivity in FXS and other forms of autism.
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Affiliation(s)
| | | | - Seth Hays
- Department of Neuroscience, Dallas, and
| | | | | | | | - Karen Pawlowski
- Department of Otolaryngology and Biomedical Engineering Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9035
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16
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Chernigovskaya EV, Korotkov AA, Dorofeeva NA, Gorbacheva EL, Kulikov AA, Glazova MV. Delayed audiogenic seizure development in a genetic rat model is associated with overactivation of ERK1/2 and disturbances in glutamatergic signaling. Epilepsy Behav 2019; 99:106494. [PMID: 31493733 DOI: 10.1016/j.yebeh.2019.106494] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/13/2019] [Accepted: 08/13/2019] [Indexed: 02/05/2023]
Abstract
Krushinsky-Molodkina (KM) rats genetically prone to audiogenic seizure are characterized by age-dependent expression of audiogenic seizures (AGS). It is known that the critical period of enhanced seizure susceptibility in rodents occurs at 2nd-3rd weeks of postnatal development. However, KM rats do not express AGS at this time-point, but start to demonstrate a stable AGS only after the age of 3 months. We hypothesized that this delay in AGS susceptibility in KM rats is genetically determined and may depend on some alterations in the development of the hippocampal glutamatergic system during the early postnatal period. We analyzed the expression and activity of seizure-related proteins, such as vesicular glutamate transporter 2 (VGLUT2), extracellular signal-regulated kinases 1 and 2 (ERK1/2), synapsin I, and NR2B subunit of the N-methyl-d-aspartate (NMDA) receptor (NR2B) in the hippocampus of KM rats during postnatal development. A significantly higher activity of ERK1/2 in KM rats was observed at 14th, 30th, and 60th days of postnatal development (P14, P30, P60) in comparison with control Wistar rats of the corresponding ages, while in adult (P120) KM rats it was at the same level with Wistar rats. Despite the increased activity of ERK1/2 at P14 and P30, the phosphorylation of synapsin I at Ser62/67 was significantly lower in the hippocampus of KM rats than in Wistar rats of the same ages; however, at P60 and P120, the phosphorylation of synapsin I was enhanced. Our data also revealed the increase of VGLUT2 and NR2B expression at P14, which dramatically decreased at the later stages. Our data indicate that a genetically determined increase in ERK1/2 kinase activity during postnatal ontogenesis in KM rats may be associated with the disturbances in synthesis and activity of the proteins, which are responsible for glutamatergic transmission in the KM rat hippocampus during the seizure susceptibility development.
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Affiliation(s)
- Elena V Chernigovskaya
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, 44 Thorez pr., 194223 St. Petersburg, Russia
| | - Anatoly A Korotkov
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, 44 Thorez pr., 194223 St. Petersburg, Russia
| | - Nadezhda A Dorofeeva
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, 44 Thorez pr., 194223 St. Petersburg, Russia
| | - Evgenia L Gorbacheva
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, 44 Thorez pr., 194223 St. Petersburg, Russia
| | - Alexey A Kulikov
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, 44 Thorez pr., 194223 St. Petersburg, Russia
| | - Margarita V Glazova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, 44 Thorez pr., 194223 St. Petersburg, Russia.
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17
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Yang X, Hei C, Liu P, Li PA. Prevention of post-ischemic seizure by rapamycin is associated with deactivation of mTOR and ERK1/2 pathways in hyperglycemic rats. Biochem Biophys Res Commun 2019; 520:47-53. [PMID: 31564412 DOI: 10.1016/j.bbrc.2019.09.096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 09/22/2019] [Indexed: 12/11/2022]
Abstract
Pre-ischemic hyperglycemia increases the occurrence of post-ischemic seizures both in experimental and clinical settings. The underlying mechanisms are not fully delineated; however, activation of mammalian target of rapamycin (mTOR) has been shown to be engaged in the pathogenesis of epilepsy, in which seizures are a regular occurrence. Therefore, we wanted to explore specifically the capacity of an mTOR inhibitor, rapamycin, in preventing post-ischemic seizures in hyperglycemic rats and to explore the underlying molecular mechanisms. The results showed that none of the rats in the sham control, EG ischemic, or within 3 h of I/R in hyperglycemic ischemic groups experienced seizures. Generalized tonic-clonic seizures were observed in all 8/8 of hyperglycemic ischemic rats at 16 h of I/R. Treatment with rapamycin successfully blocked post-ischemic seizures in 7/8 hyperglycemic ischemic animals. Rapamycin also lessened the neuronal death extraordinarily in hyperglycemic ischemic animals as revealed by histopathological studies. Protein analysis revealed that transient ischemia resulted in increases in p-mTOR and p-S6, especially in the hippocampi of the hyperglycemic ischemic rats. Rapamycin treatment completely blocked mTOR activation. Furthermore, hyperglycemic ischemia induced a much prominent rise of p-ERK1/2 both in the cortex and the hippocampi compared with EG counterparts; whereas rapamycin suppressed it. We conclude that the development of post-ischemic seizures in the hyperglycemic animals may be associated with activations of mTOR and ERK1/2 pathways and that rapamycin treatment inhibited the post-ischemic seizures effectively by suppressing the mTOR and ERK1/2 signaling.
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Affiliation(s)
- Xiao Yang
- Neuroscience Center, General Hospital of Ningxia Medical University, Key Laboratory for Craniocerebral Diseases of Ningxia Hui Autonomous Region, Yinchuan, China; Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Technology Enterprise (BRITE), College of Arts and Sciences, North Carolina Central University, Durham, USA
| | - Changchun Hei
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Technology Enterprise (BRITE), College of Arts and Sciences, North Carolina Central University, Durham, USA; Department of Human Anatomy, Histology and Embryology, Ningxia Medical University, Yinchuan, China
| | - Ping Liu
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Technology Enterprise (BRITE), College of Arts and Sciences, North Carolina Central University, Durham, USA; Department of Endocrinology, General Hospital of Ningxia Medical University, Yinchuan, China
| | - P Andy Li
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Technology Enterprise (BRITE), College of Arts and Sciences, North Carolina Central University, Durham, USA.
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18
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Modulators of Kv3 Potassium Channels Rescue the Auditory Function of Fragile X Mice. J Neurosci 2019; 39:4797-4813. [PMID: 30936239 DOI: 10.1523/jneurosci.0839-18.2019] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 03/15/2019] [Accepted: 03/26/2019] [Indexed: 11/21/2022] Open
Abstract
Fragile X syndrome (FXS) is characterized by hypersensitivity to sensory stimuli, including environmental sounds. We compared the auditory brainstem response (ABR) recorded in vivo in mice lacking the gene (Fmr1 -/y ) for fragile X mental retardation protein (FMRP) with that in wild-type animals. We found that ABR wave I, which represents input from the auditory nerve, is reduced in Fmr1 -/y animals, but only at high sound levels. In contrast, wave IV, which represents the activity of auditory brainstem nuclei is enhanced at all sound levels, suggesting that loss of FMRP alters the central processing of auditory signals. Current-clamp recordings of neurons in the medial nucleus of the trapezoid body in the auditory brainstem revealed that, in contrast to neurons from wild-type animals, sustained depolarization triggers repetitive firing rather than a single action potential. In voltage-clamp recordings, K+ currents that activate at positive potentials ("high-threshold" K+ currents), which are required for high-frequency firing and are carried primarily by Kv3.1 channels, are elevated in Fmr1 -/y mice, while K+ currents that activate near the resting potential and inhibit repetitive firing are reduced. We therefore tested the effects of AUT2 [((4-({5-[(4R)-4-ethyl-2,5-dioxo-1-imidazolidinyl]-2-pyridinyl}oxy)-2-(1-methylethyl) benzonitrile], a compound that modulates Kv3.1 channels. AUT2 reduced the high-threshold K+ current and increased the low-threshold K+ currents in neurons from Fmr1 -/y animals by shifting the activation of the high-threshold current to more negative potentials. This reduced the firing rate and, in vivo, restored wave IV of the ABR. Our results from animals of both sexes suggest that the modulation of the Kv3.1 channel may have potential for the treatment of sensory hypersensitivity in patients with FXS.SIGNIFICANCE STATEMENT mRNA encoding the Kv3.1 potassium channel was one of the first described targets of the fragile X mental retardation protein (FMRP). Fragile X syndrome is caused by loss of FMRP and, in humans and mice, causes hypersensitivity to auditory stimuli. We found that components of the auditory brain response (ABR) corresponding to auditory brainstem activity are enhanced in mice lacking FMRP. This is accompanied by hyperexcitability and altered potassium currents in auditory brainstem neurons. Treatment with a drug that alters the voltage dependence of Kv3.1 channels normalizes the imbalance of potassium currents, as well as ABR responses in vivo, suggesting that such compounds may be effective in treating some symptoms of fragile X syndrome.
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19
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Ma T, Wu Y, Chen B, Zhang W, Jin L, Shen C, Wang Y, Liu Y. D-Serine Contributes to Seizure Development via ERK Signaling. Front Neurosci 2019; 13:254. [PMID: 30971878 PMCID: PMC6443828 DOI: 10.3389/fnins.2019.00254] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/04/2019] [Indexed: 12/22/2022] Open
Abstract
A seizure is one of the leading neurological disorders. NMDA receptor-mediated neuronal excitation has been thought to be essential for epileptogenesis. As an endogenous co-agonist of the NMDA receptor, D-serine has been suggested to play a role in epileptogenesis. However, the underlying mechanisms remain unclear. In the current study, we investigated the effects of antagonizing two key enzymes in D-serine metabolism on the development of seizures and the downstream signaling. Our results showed that serine racemase (SR), a key enzyme in regulating the L-to-D-serine conversion, was significantly up-regulated in hippocampal astrocytes in rats and patients who experienced seizure, in comparison with control rats and patients. L-aspartic acid β-hydroxamate (LaaβH), an inhibitor of SR, significantly prolonged the latencies of seizures, shortened the durations of seizures, and decreased the total EEG power in rats. In contrast, D-amino acid oxidase inhibitor 5-chlorobenzo[d]isoxazol-3-ol (CBIO), which can increase D-serine levels, showed the opposite effects. Furthermore, our data showed that LaaβH and CBIO significantly affected the phosphorylation of Extracellular Signal-regulated Kinase (ERK). Antagonizing or activating ERK could significantly block the effects of LaaβH/CBIO on the occurrence of seizures. In summary, our study revealed that D-serine is involved in the development of epileptic seizures, partially through ERK signaling, indicating that the metabolism of D-serine may be targeted for the treatment of epilepsy.
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Affiliation(s)
- Tie Ma
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China.,Department of Neurology, The Seventh Medical Center of PLA General Hospital, Beijing, China
| | - Yin Wu
- Department of Pharmacy, Xi'an High-tech Hospital, Xi'an, China
| | - Beibei Chen
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China
| | - Wenjuan Zhang
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China
| | - Lang Jin
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China
| | - Chenxi Shen
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China
| | - Yazhou Wang
- Department of Neurobiology and Institute of Neurosciences, School of Basic Medicine, Air Force Medical University, Xi'an, China
| | - Yonghong Liu
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China
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20
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Down-Regulation of Astrocytic Kir4.1 Channels during the Audiogenic Epileptogenesis in Leucine-Rich Glioma-Inactivated 1 ( Lgi1) Mutant Rats. Int J Mol Sci 2019; 20:ijms20051013. [PMID: 30813600 PMCID: PMC6429235 DOI: 10.3390/ijms20051013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/14/2019] [Accepted: 02/21/2019] [Indexed: 02/07/2023] Open
Abstract
The dysfunction of astrocytic inwardly rectifying potassium (Kir) 4.1 channels, which mediate the spatial potassium-buffering function of astrocytes, is known to be involved in the development of epilepsy. Here, we analyzed the Kir4.1 expressional changes in Leucine-Rich Glioma-Inactivated 1 (Lgi1) mutant rats, which is a model of autosomal dominant lateral temporal lobe epilepsy in humans, to clarify the role of astrocytic Kir4.1 channels in Lgi1-related epileptogenesis. Priming acoustic stimulation (at postnatal day 16) conferred seizure susceptibility on Lgi1 mutant rats, which evoked audiogenic seizures with test stimulation at eight weeks. In the seizure-susceptible Lgi1 mutant rats (before test stimulation), astrocytic Kir4.1 expression was down-regulated region-specifically in the cerebral cortex, hippocampus, and amygdala. In addition, prophylactic treatments of Lgi1 mutant rats with valproic acid (VPA, 30 mg/kg and 200 mg/kg) for two weeks prevented both the development of seizure susceptibility and the down-regulation of Kir4.1 expression in astrocytes. The present study demonstrated for the first time that the astrocytic Kir4.1 expression was reduced in the Lgi1-related seizure model, suggesting that the down-regulation of Kir4.1 channels in astrocytes is involved in audiogenic epileptogenesis caused by Lgi1 mutation. In addition, VPA seemed to have a prophylactic effect on Lgi1-related seizures.
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21
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Jarero-Basulto JJ, Gasca-Martínez Y, Rivera-Cervantes MC, Ureña-Guerrero ME, Feria-Velasco AI, Beas-Zarate C. Interactions Between Epilepsy and Plasticity. Pharmaceuticals (Basel) 2018; 11:ph11010017. [PMID: 29414852 PMCID: PMC5874713 DOI: 10.3390/ph11010017] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/01/2018] [Accepted: 02/06/2018] [Indexed: 02/06/2023] Open
Abstract
Undoubtedly, one of the most interesting topics in the field of neuroscience is the ability of the central nervous system to respond to different stimuli (normal or pathological) by modifying its structure and function, either transiently or permanently, by generating neural cells and new connections in a process known as neuroplasticity. According to the large amount of evidence reported in the literature, many stimuli, such as environmental pressures, changes in the internal dynamic steady state of the organism and even injuries or illnesses (e.g., epilepsy) may induce neuroplasticity. Epilepsy and neuroplasticity seem to be closely related, as the two processes could positively affect one another. Thus, in this review, we analysed some neuroplastic changes triggered in the hippocampus in response to seizure-induced neuronal damage and how these changes could lead to the establishment of temporal lobe epilepsy, the most common type of focal human epilepsy.
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Affiliation(s)
- José J Jarero-Basulto
- Cellular Neurobiology Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
| | - Yadira Gasca-Martínez
- Cellular Neurobiology Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
| | - Martha C Rivera-Cervantes
- Cellular Neurobiology Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
| | - Mónica E Ureña-Guerrero
- Neurotransmission Biology Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
| | - Alfredo I Feria-Velasco
- Cellular Neurobiology Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
| | - Carlos Beas-Zarate
- Development and Neural Regeneration Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
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Genome-wide profiling reveals functional diversification of ∆FosB gene targets in the hippocampus of an Alzheimer's disease mouse model. PLoS One 2018; 13:e0192508. [PMID: 29408867 PMCID: PMC5800686 DOI: 10.1371/journal.pone.0192508] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 01/24/2018] [Indexed: 01/20/2023] Open
Abstract
The activity-induced transcription factor ∆FosB has been implicated in Alzheimer’s disease (AD) as a critical regulator of hippocampal function and cognition downstream of seizures and network hyperexcitability. With its long half-life (> 1 week), ∆FosB is well-poised to modulate hippocampal gene expression over extended periods of time, enabling effects to persist even during seizure-free periods. However, the transcriptional mechanisms by which ∆FosB regulates hippocampal function are poorly understood due to lack of identified hippocampal gene targets. To identify putative ∆FosB gene targets, we employed high-throughput sequencing of genomic DNA bound to ∆FosB after chromatin immunoprecipitation (ChIP-sequencing). We compared ChIP-sequencing results from hippocampi of transgenic mice expressing mutant human amyloid precursor protein (APP) and nontransgenic (NTG) wild-type littermates. Surprisingly, only 52 ∆FosB gene targets were shared between NTG and APP mice; the vast majority of targets were unique to one genotype or the other. We also found a functional shift in the repertoire of ∆FosB gene targets between NTG and APP mice. A large number of targets in NTG mice are involved in neurodevelopment and/or cell morphogenesis, whereas in APP mice there is an enrichment of targets involved in regulation of membrane potential and neuronal excitability. RNA-sequencing and quantitative PCR experiments confirmed that expression of putative ∆FosB gene targets were altered in the hippocampus of APP mice. This study provides key insights into functional domains regulated by ∆FosB in the hippocampus, emphasizing remarkably different programs of gene regulation under physiological and pathological conditions.
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Chernigovskaya EV, Lebedenko OO, Nidenfyur AV, Nikitina LS, Glazova MV. Analysis of ERK1/2 kinases in the inferior colliculus of rats genetically prone to audiogenic seizures during postnatal development. DOKL BIOCHEM BIOPHYS 2017; 476:296-298. [DOI: 10.1134/s1607672917050015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Indexed: 11/23/2022]
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Lucchi C, Costa AM, Giordano C, Curia G, Piat M, Leo G, Vinet J, Brunel L, Fehrentz JA, Martinez J, Torsello A, Biagini G. Involvement of PPARγ in the Anticonvulsant Activity of EP-80317, a Ghrelin Receptor Antagonist. Front Pharmacol 2017; 8:676. [PMID: 29018345 PMCID: PMC5614981 DOI: 10.3389/fphar.2017.00676] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/08/2017] [Indexed: 02/03/2023] Open
Abstract
Ghrelin, des-acyl ghrelin and other related peptides possess anticonvulsant activities. Although ghrelin and cognate peptides were shown to physiologically regulate only the ghrelin receptor, some of them were pharmacologically proved to activate the peroxisome proliferator-activated receptor gamma (PPARγ) through stimulation of the scavenger receptor CD36 in macrophages. In our study, we challenged the hypothesis that PPARγ could be involved in the anticonvulsant effects of EP-80317, a ghrelin receptor antagonist. For this purpose, we used the PPARγ antagonist GW9662 to evaluate the modulation of EP-80317 anticonvulsant properties in two different models. Firstly, the anticonvulsant effects of EP-80317 were studied in rats treated with pilocarpine to induce status epilepticus (SE). Secondly, the anticonvulsant activity of EP-80317 was ascertained in the repeated 6-Hz corneal stimulation model in mice. Behavioral and video electrocorticographic (ECoG) analyses were performed in both models. We also characterized levels of immunoreactivity for PPARγ in the hippocampus of 6-Hz corneally stimulated mice. EP-80317 predictably antagonized seizures in both models. Pretreatment with GW9662 counteracted almost all EP-80317 effects both in mice and rats. Only the effects of EP-80317 on power spectra of ECoGs recorded during repeated 6-Hz corneal stimulation were practically unaffected by GW9662 administration. Moreover, GW9662 alone produced a decrease in the latency of tonic-clonic seizures and accelerated the onset of SE in rats. Finally, in the hippocampus of mice treated with EP-80317 we found increased levels of PPARγ immunoreactivity. Overall, these results support the hypothesis that PPARγ is able to modulate seizures and mediates the anticonvulsant effects of EP-80317.
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Affiliation(s)
- Chiara Lucchi
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Anna M Costa
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Carmela Giordano
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Giulia Curia
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Marika Piat
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Giuseppina Leo
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Jonathan Vinet
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Luc Brunel
- Centre National de la Recherche Scientifique, Max Mousseron Institute of Biomolecules, National School of Chemistry Montpellier, University of MontpellierMontpellier, France
| | - Jean-Alain Fehrentz
- Centre National de la Recherche Scientifique, Max Mousseron Institute of Biomolecules, National School of Chemistry Montpellier, University of MontpellierMontpellier, France
| | - Jean Martinez
- Centre National de la Recherche Scientifique, Max Mousseron Institute of Biomolecules, National School of Chemistry Montpellier, University of MontpellierMontpellier, France
| | - Antonio Torsello
- School of Medicine and Surgery, University of Milano-BicoccaMilan, Italy
| | - Giuseppe Biagini
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy.,Center for Neuroscience and Neurotechnology, University of Modena and Reggio EmiliaModena, Italy
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25
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Erickson CA, Davenport MH, Schaefer TL, Wink LK, Pedapati EV, Sweeney JA, Fitzpatrick SE, Brown WT, Budimirovic D, Hagerman RJ, Hessl D, Kaufmann WE, Berry-Kravis E. Fragile X targeted pharmacotherapy: lessons learned and future directions. J Neurodev Disord 2017; 9:7. [PMID: 28616096 PMCID: PMC5467059 DOI: 10.1186/s11689-017-9186-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 01/18/2017] [Indexed: 01/04/2023] Open
Abstract
Our understanding of fragile X syndrome (FXS) pathophysiology continues to improve and numerous potential drug targets have been identified. Yet, current prescribing practices are only symptom-based in order to manage difficult behaviors, as no drug to date is approved for the treatment of FXS. Drugs impacting a diversity of targets in the brain have been studied in recent FXS-specific clinical trials. While many drugs have focused on regulation of enhanced glutamatergic or deficient GABAergic neurotransmission, compounds studied have not been limited to these mechanisms. As a single-gene disorder, it was thought that FXS would have consistent drug targets that could be modulated with pharmacotherapy and lead to significant improvement. Unfortunately, despite promising results in FXS animal models, translational drug treatment development in FXS has largely failed. Future success in this field will depend on learning from past challenges to improve clinical trial design, choose appropriate outcome measures and age range choices, and find readily modulated drug targets. Even with many negative placebo-controlled study results, the field continues to move forward exploring both the new mechanistic drug approaches combined with ways to improve trial execution. This review summarizes the known phenotype and pathophysiology of FXS and past clinical trial rationale and results, and discusses current challenges facing the field and lessons from which to learn for future treatment development efforts.
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Affiliation(s)
- Craig A Erickson
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Department of Psychiatry, College of Medicine, University of Cincinnati, Cincinnati, OH USA
| | - Matthew H Davenport
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Department of Biomedical Engineering, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH USA
| | - Tori L Schaefer
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Logan K Wink
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Department of Psychiatry, College of Medicine, University of Cincinnati, Cincinnati, OH USA
| | - Ernest V Pedapati
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Department of Psychiatry, College of Medicine, University of Cincinnati, Cincinnati, OH USA
| | - John A Sweeney
- Department of Psychiatry, College of Medicine, University of Cincinnati, Cincinnati, OH USA
| | - Sarah E Fitzpatrick
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - W Ted Brown
- Institute for Basic Research in Developmental Disabilities, New York, NY USA
| | - Dejan Budimirovic
- Clinical Research Center, Clinical Trials Unit, Fragile X Clinic, Kennedy Krieger Institute, The Johns Hopkins Medical Institutions, Baltimore, MD USA.,Departments of Psychiatry & Behavioral Sciences, Child Psychiatry, The Johns Hopkins Medical Institutions, Baltimore, MD USA
| | - Randi J Hagerman
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Davis Medical Center, University of California, Sacramento, CA USA.,Department of Pediatrics, Davis Medical Center, University of California, Sacramento, California USA
| | - David Hessl
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Davis Medical Center, University of California, Sacramento, CA USA.,Department of Psychiatry and Behavioral Sciences, Davis Medical Center, University of California, Sacramento, California USA
| | - Walter E Kaufmann
- Greenwood Genetic Center, Greenwood, SC USA.,Boston Children's Hospital, Boston, Massachusetts USA
| | - Elizabeth Berry-Kravis
- Departments of Pediatrics, Neurological Sciences, Biochemistry, Rush University Medical Center, Chicago, Illinois USA
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26
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Giordano C, Costa AM, Lucchi C, Leo G, Brunel L, Fehrentz JA, Martinez J, Torsello A, Biagini G. Progressive Seizure Aggravation in the Repeated 6-Hz Corneal Stimulation Model Is Accompanied by Marked Increase in Hippocampal p-ERK1/2 Immunoreactivity in Neurons. Front Cell Neurosci 2016; 10:281. [PMID: 28018175 PMCID: PMC5159434 DOI: 10.3389/fncel.2016.00281] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/24/2016] [Indexed: 12/13/2022] Open
Abstract
The 6-Hz corneal stimulation test is used to screen novel antiepileptic molecules to overcome the problem of drug refractoriness. Although recognized as a standard test, it has been evaluated only recently in the attempt to characterize the putative neuronal networks involved in seizures caused by corneal stimulation. In particular, by recording from the CA1 region we previously established that the hippocampus participates to propagation of seizure activity. However, these findings were not corroborated by using markers of neuronal activation such as FosB/ΔFosB antigens. In view of this discrepancy, we performed new experiments to characterize the changes in levels of phosphorylated extracellular signal-regulated kinases1/2 (p-ERK1/2), which are also used as markers of neuronal activation. To this aim, mice underwent corneal stimulation up to three different times, in three sessions separated by an interval of 3 days. To characterize a group in which seizures could be prevented by pharmacological treatment, we also considered pretreatment with the ghrelin receptor antagonist EP-80317 (330 μg/kg). Control mice were sham-treated. Video electrocorticographic (ECoG) recordings were obtained from mice belonging to each group of treatment. Animals were finally used to characterize the immunoreactivity for FosB/ΔFosB and p-ERK1/2 in the hippocampus. As previously shown, FosB/ΔFosB levels were highly increased throughout the hippocampus by the first induced seizure but, in spite of the progressively increased seizure severity, they were restored to control levels after the third stimulation. At variance, corneal stimulation caused a progressive increase in p-ERK1/2 immunoreactivity all over the hippocampus, especially in CA1, peaking in the third session. Predictably, EP-80317 administration reduced both duration and severity of seizures, prevented the increase in FosB/ΔFosB levels in the first session, and partially counteracted the increase in p-ERK1/2 levels in the third session. The vast majority of p-ERK1/2 immunopositive cells were co-labeled with FosB/ΔFosB antibodies, suggesting the existence of a relationship between the investigated markers in a subpopulation of neurons activated by seizures. These findings suggest that p-ERK1/2 are useful markers to define the aggravation of seizures and the response to anticonvulsant treatments. In particular, p-ERK1/2 expression clearly identified the involvement of hippocampal regions during seizure aggravation in the 6-Hz model.
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Affiliation(s)
- Carmela Giordano
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSLModena, Italy
| | - Anna M Costa
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSLModena, Italy
| | - Chiara Lucchi
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSLModena, Italy
| | - Giuseppina Leo
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSLModena, Italy
| | - Luc Brunel
- Max Mousseron Institute of Biomolecules, Centre National de la Recherche Scientifique (CNRS), University of Montpellier, École Nationale Supérieure de Chimie de Montpellier (ENSCM) Montpellier, France
| | - Jean-Alain Fehrentz
- Max Mousseron Institute of Biomolecules, Centre National de la Recherche Scientifique (CNRS), University of Montpellier, École Nationale Supérieure de Chimie de Montpellier (ENSCM) Montpellier, France
| | - Jean Martinez
- Max Mousseron Institute of Biomolecules, Centre National de la Recherche Scientifique (CNRS), University of Montpellier, École Nationale Supérieure de Chimie de Montpellier (ENSCM) Montpellier, France
| | - Antonio Torsello
- Department of Medicine and Surgery, University of Milano-Bicocca Monza, Italy
| | - Giuseppe Biagini
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSLModena, Italy
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27
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Davenport MH, Schaefer TL, Friedmann KJ, Fitzpatrick SE, Erickson CA. Pharmacotherapy for Fragile X Syndrome: Progress to Date. Drugs 2016; 76:431-45. [PMID: 26858239 DOI: 10.1007/s40265-016-0542-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
To date, no drug is approved for the treatment of Fragile X Syndrome (FXS) although many drugs are used to manage challenging behaviors from a symptomatic perspective in this population. While our understanding of FXS pathophysiology is expanding, efforts to devise targeted FXS-specific treatments have had limited success in placebo-controlled trials. Compounds aimed at rectifying excessive glutamate and deficient gamma-aminobutyric acid (GABA) neurotransmission, as well as other signaling pathways known to be affected by Fragile X Mental Retardation Protein (FMRP) are under various phases of development in FXS. With the failure of several metabotropic glutamate receptor subtype 5 (mGlur5) selective antagonists under clinical investigation, no clear single treatment appears to be greatly effective. These recent challenges call into question various aspects of clinical study design in FXS. More objective outcome measures are under development and validation. Future trials will likely be aimed at correcting multiple pathways known to be disrupted by the loss of FMRP. This review offers a brief summary of the prevalence, phenotypic characteristics, genetic causes and molecular functions of FMRP in the brain (as these have been extensively reviewed elsewhere), discusses the most recent finding in FXS drug development, and summarizes FXS trials utilizing symptomatic treatment.
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Affiliation(s)
- Matthew H Davenport
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA
- Department of Biomedical Engineering, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Tori L Schaefer
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA
| | - Katherine J Friedmann
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA
| | | | - Craig A Erickson
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA.
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28
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mTOR and MAPK: from localized translation control to epilepsy. BMC Neurosci 2016; 17:73. [PMID: 27855659 PMCID: PMC5114760 DOI: 10.1186/s12868-016-0308-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 11/09/2016] [Indexed: 01/03/2023] Open
Abstract
Background Epilepsy is one of the most common neurological diseases characterized by excessive hyperexcitability of neurons. Molecular mechanisms of epilepsy are diverse and not really understood. All in common is the misregulation of proteins that determine excitability such as potassium and sodium channels as well as GABA receptors; which are all known as biomarkers for epilepsy. Two recently identified key pathways involve the kinases mechanistic target of rapamycin (mTOR) and mitogen-activated protein kinases (MAPK). Interestingly, mRNAs coding for those biomarkers are found to be localized at or near synapses indicating a local misregulation of synthesis and activity. Results Research in the last decade indicates that RNA-binding proteins (RBPs) responsible for mRNA localization, stability and translation mediate local expression control. Among others, they are affected by mTOR and MAPK to guide expression of epileptic factors. These results suggest that mTOR/MAPK act on RBPs to regulate the fate of mRNAs, indicating a misregulation of protein expression at synapses in epilepsy. Conclusion We propose that mTOR and MAPK regulate RBPs, thereby guiding the local expression of their target-mRNAs encoding for markers of epilepsy. Thus, misregulated mTOR/MAPK-RBP interplay may result in excessive local synthesis of ion channels and receptors thereby leading to hyperexcitability. Continuous stimulation of synapses further activates mTOR/MAPK pathway reinforcing their effect on RBP-mediated expression control establishing the basis for epilepsy. Here, we highlight findings showing the tight interplay between mTOR as well as MAPK with RBPs to control expression for epileptic biomarkers.
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Chernigovskaya EV, Korotkov AA, Nikitina LS, Dorofeeva NA, Glazova MV. The expression and distribution of seizure-related and synaptic proteins in the insular cortex of rats genetically prone to audiogenic seizures. Neurol Res 2016; 37:1108-17. [PMID: 26923581 DOI: 10.1080/01616412.2015.1114288] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
It is known that perirhinal/insular cortices participate in the transmission of sensory stimuli to the motor cortex, thus coordinating motor activity during seizures. In the present study we analysed seizure-related proteins, such as GABA, glutamate, ERK1/2 and the synaptic proteins in the insular cortex of Krushinsky-Molodkina (KM) rats genetically prone to audiogenic seizures (AGS). We compared seizure-naïve and seizure-experienced KM rats with control Wistar rats in order to distinguish whether seizure-related protein changes are associated with seizure event or representing an inhered pathological abnormality that determines predisposition to AGS. Our data demonstrated an increased level of vesicular glutamate transporter VGLUT2 in naïve and seizure-experienced KM rats, while glutamic acid decarboxylases GAD65 and GAD67 levels were unchanged. Evaluation of the synaptic proteins showed a decrease in SNAP-25 and upregulation of synapsin I phosphorylation in both groups of KM rats in comparison to Wistar rats. However, when phosphorylation level of ERK1/2 in naïve KM rats was significantly increased, several episodes of AGS diminished ERK1/2 activity. Obtained data indicate that changes in ERK1/2 phosphorylation status and glutamate release controlling synaptic proteins in the insular cortex of KM rats could contribute to the AGS susceptibility.
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Affiliation(s)
- Elena V Chernigovskaya
- 1 Department of Comparative Biochemistry of cellular functions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences , Saint-Petersburg, Russia
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30
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Vahdatpour C, Dyer AH, Tropea D. Insulin-Like Growth Factor 1 and Related Compounds in the Treatment of Childhood-Onset Neurodevelopmental Disorders. Front Neurosci 2016; 10:450. [PMID: 27746717 PMCID: PMC5043261 DOI: 10.3389/fnins.2016.00450] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 09/20/2016] [Indexed: 12/17/2022] Open
Abstract
Insulin-Like Growth Factor 1 (IGF-1) is a neurotrophic polypeptide with crucial roles to play in Central Nervous System (CNS) growth, development and maturation. Following interrogation of the neurobiology underlying several neurodevelopmental disorders and Autism Spectrum Disorders (ASD), both recombinant IGF-1 (mecasermin) and related derivatives, such as (1-3)IGF-1, have emerged as potential therapeutic approaches. Clinical pilot studies and early reports have supported the safety/preliminary efficacy of IGF-1 and related compounds in the treatment of Rett Syndrome, with evidence mounting for its use in Phelan McDermid Syndrome and Fragile X Syndrome. In ASD, clinical trials are ongoing. Here, we review the role of IGF-1 in the molecular etiologies of these conditions in addition to the accumulating evidence from early clinical studies highlighting the possibility of IGF-1 and related compounds as potential treatments for these childhood-onset neurodevelopmental disorders.
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Affiliation(s)
| | - Adam H. Dyer
- School of Medicine, Trinity College DublinDublin, Ireland
| | - Daniela Tropea
- Department of Psychiatry, Trinity College DublinDublin, Ireland
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Giordano C, Vinet J, Curia G, Biagini G. Repeated 6-Hz Corneal Stimulation Progressively Increases FosB/ΔFosB Levels in the Lateral Amygdala and Induces Seizure Generalization to the Hippocampus. PLoS One 2015; 10:e0141221. [PMID: 26555229 PMCID: PMC4640822 DOI: 10.1371/journal.pone.0141221] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 10/06/2015] [Indexed: 11/30/2022] Open
Abstract
Exposure to repetitive seizures is known to promote convulsions which depend on specific patterns of network activity. We aimed at evaluating the changes in seizure phenotype and neuronal network activation caused by a modified 6-Hz corneal stimulation model of psychomotor seizures. Mice received up to 4 sessions of 6-Hz corneal stimulation with fixed current amplitude of 32 mA and inter-stimulation interval of 72 h. Video-electroencephalography showed that evoked seizures were characterized by a motor component and a non-motor component. Seizures always appeared in frontal cortex, but only at the fourth stimulation they involved the hippocampus, suggesting the establishment of an epileptogenic process. Duration of seizure non-motor component progressively decreased after the second session, whereas convulsive seizures remained unchanged. In addition, a more severe seizure phenotype, consisting of tonic-clonic generalized convulsions, was predominant after the second session. Immunohistochemistry and double immunofluorescence experiments revealed a significant increase in neuronal activity occurring in the lateral amygdala after the fourth session, most likely due to activity of principal cells. These findings indicate a predominant role of amygdala in promoting progressively more severe convulsions as well as the late recruitment of the hippocampus in the seizure spread. We propose that the repeated 6-Hz corneal stimulation model may be used to investigate some mechanisms of epileptogenesis and to test putative antiepileptogenic drugs.
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MESH Headings
- Animals
- Basolateral Nuclear Complex/metabolism
- Basolateral Nuclear Complex/physiopathology
- Cornea/physiopathology
- Disease Models, Animal
- Electric Stimulation/adverse effects
- Electrodes, Implanted
- Electroencephalography
- Epilepsy, Complex Partial/etiology
- Epilepsy, Complex Partial/genetics
- Epilepsy, Complex Partial/physiopathology
- Epilepsy, Generalized/etiology
- Epilepsy, Generalized/genetics
- Epilepsy, Generalized/physiopathology
- Epilepsy, Tonic-Clonic/etiology
- Epilepsy, Tonic-Clonic/genetics
- Epilepsy, Tonic-Clonic/physiopathology
- Gene Expression Regulation
- Hippocampus/physiopathology
- Male
- Mice
- Microglia/pathology
- Nerve Net/physiopathology
- Nerve Tissue Proteins/biosynthesis
- Nerve Tissue Proteins/genetics
- Neurons/metabolism
- Neurons/pathology
- Phenotype
- Proto-Oncogene Proteins c-fos/biosynthesis
- Proto-Oncogene Proteins c-fos/genetics
- Severity of Illness Index
- Single-Blind Method
- Video Recording
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Affiliation(s)
- Carmela Giordano
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
| | - Jonathan Vinet
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
| | - Giulia Curia
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
- Department of Neurosciences, NOCSAE Hospital, AUSL Modena, Italy
- * E-mail:
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32
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Séjourné J, Llaneza D, Kuti OJ, Page DT. Social Behavioral Deficits Coincide with the Onset of Seizure Susceptibility in Mice Lacking Serotonin Receptor 2c. PLoS One 2015; 10:e0136494. [PMID: 26308619 PMCID: PMC4550412 DOI: 10.1371/journal.pone.0136494] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 07/15/2015] [Indexed: 11/19/2022] Open
Abstract
The development of social behavior is strongly influenced by the serotonin system. Serotonin 2c receptor (5-HT2cR) is particularly interesting in this context considering that pharmacological modulation of 5-HT2cR activity alters social interaction in adult rodents. However, the role of 5-HT2cR in the development of social behavior is unexplored. Here we address this using Htr2c knockout mice, which lack 5-HT2cR. We found that these animals exhibit social behavior deficits as adults but not as juveniles. Moreover, we found that the age of onset of these deficits displays similar timing as the onset of susceptibility to spontaneous death and audiogenic-seizures, consistent with the hypothesis that imbalanced excitation and inhibition (E/I) may contribute to social behavioral deficits. Given that autism spectrum disorder (ASD) features social behavioral deficits and is often co-morbid with epilepsy, and given that 5-HT2cR physically interacts with Pten, we tested whether a second site mutation in the ASD risk gene Pten can modify these phenotypes. The age of spontaneous death is accelerated in mice double mutant for Pten and Htr2c relative to single mutants. We hypothesized that pharmacological antagonism of 5-HT2cR activity in adult animals, which does not cause seizures, might modify social behavioral deficits in Pten haploinsufficient mice. SB 242084, a 5-HT2cR selective antagonist, can reverse the social behavior deficits observed in Pten haploinsufficient mice. Together, these results elucidate a role of 5-HT2cR in the modulation of social behavior and seizure susceptibility in the context of normal development and Pten haploinsufficiency.
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Affiliation(s)
- Julien Séjourné
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida, 33458, United States of America
| | - Danielle Llaneza
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida, 33458, United States of America
| | - Orsolya J. Kuti
- Department of Brain and Cognitive Sciences and Picower Institute for Learning and Memory, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139, United States of America
| | - Damon T. Page
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida, 33458, United States of America
- * E-mail:
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33
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Dorofeeva NA, Glazova MV, Khudik KA, Nikitina LS, Kirillova OD, Chernigovskaya EV. Comparative analysis of the nigrostriatal system in Wistar rats and rats prone to seizures. J EVOL BIOCHEM PHYS+ 2015. [DOI: 10.1134/s0022093015030088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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34
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Wang H, Pati S, Pozzo-Miller L, Doering LC. Targeted pharmacological treatment of autism spectrum disorders: fragile X and Rett syndromes. Front Cell Neurosci 2015; 9:55. [PMID: 25767435 PMCID: PMC4341567 DOI: 10.3389/fncel.2015.00055] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 02/05/2015] [Indexed: 12/27/2022] Open
Abstract
Autism spectrum disorders (ASDs) are genetically and clinically heterogeneous and lack effective medications to treat their core symptoms. Studies of syndromic ASDs caused by single gene mutations have provided insights into the pathophysiology of autism. Fragile X and Rett syndromes belong to the syndromic ASDs in which preclinical studies have identified rational targets for drug therapies focused on correcting underlying neural dysfunction. These preclinical discoveries are increasingly translating into exciting human clinical trials. Since there are significant molecular and neurobiological overlaps among ASDs, targeted treatments developed for fragile X and Rett syndromes may be helpful for autism of different etiologies. Here, we review the targeted pharmacological treatment of fragile X and Rett syndromes and discuss related issues in both preclinical studies and clinical trials of potential therapies for the diseases.
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Affiliation(s)
- Hansen Wang
- Faculty of Medicine, University of Toronto, 1 King's College Circle Toronto, ON, Canada
| | - Sandipan Pati
- Department of Neurology, Epilepsy Division, The University of Alabama at Birmingham Birmingham, AL, USA
| | - Lucas Pozzo-Miller
- Department of Neurobiology, Civitan International Research Center, The University of Alabama at Birmingham Birmingham, AL, USA
| | - Laurie C Doering
- Faculty of Health Sciences, Department of Pathology and Molecular Medicine, McMaster University Hamilton, ON, Canada
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35
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Glazova MV, Nikitina LS, Hudik KA, Kirillova OD, Dorofeeva NA, Korotkov AA, Chernigovskaya EV. Inhibition of ERK1/2 signaling prevents epileptiform behavior in rats prone to audiogenic seizures. J Neurochem 2014; 132:218-29. [PMID: 25351927 DOI: 10.1111/jnc.12982] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 10/14/2014] [Accepted: 10/22/2014] [Indexed: 01/24/2023]
Abstract
It has recently been proposed that extracellular signal-regulated kinases 1 and 2 (ERK1/2) are one of the factors mediating seizure development. We hypothesized that inhibition of ERK1/2 activity could prevent audiogenic seizures by altering GABA and glutamate release mechanisms. Krushinsky-Molodkina rats, genetically prone to audiogenic seizure, were recruited in the experiments. Animals were i.p. injected with an inhibitor of ERK1/2 SL 327 at different doses 60 min before audio stimulation. We demonstrated for the first time that inhibition of ERK1/2 activity by SL 327 injections prevented seizure behavior and this effect was dose-dependent and correlated with ERK1/2 activity. The obtained data also demonstrated unchanged levels of GABA production, and an increase in the level of vesicular glutamate transporter 2. The study of exocytosis protein expression showed that SL 327 treatment leads to downregulation of vesicle-associated membrane protein 2 and synapsin I, and accumulation of synaptosomal-associated protein 25 (SNAP-25). The obtained data indicate that the inhibition of ERK1/2 blocks seizure behavior presumably by altering the exocytosis machinery, and identifies ERK1/2 as a potential target for the development of new strategies for seizure treatment. Extracellular signal-regulated kinases 1 and 2 (ERK1/2) are one of the factors mediating seizure development. Here we report that inhibition of ERK1/2 by SL 327 prevented seizure behavior and this effect was dose-dependent and correlated with ERK1/2 activity. Accumulation of VGLUT2 was associated with differential changing of synaptic proteins VAMP2, SNAP-25 and synapsin I. The obtained data indicate that the inhibition of ERK1/2 alters neurotransmitter release by changing the exocytosis machinery, thus preventing seizures.
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Affiliation(s)
- Margarita V Glazova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint-Petersburg, Russia
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