scholarly journals Rescuing epileptic and behavioral alterations in a Dravet syndrome mouse model by inhibiting eukaryotic elongation factor 2 kinase (eEF2K)

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Stefania Beretta ◽  
Laura Gritti ◽  
Luisa Ponzoni ◽  
Paolo Scalmani ◽  
Massimo Mantegazza ◽  
...  
Keyword(s):  
Mouse Model ◽  
Motor Coordination ◽  
Elongation Factor ◽  
Behavioral Phenotype ◽  
Dravet Syndrome ◽  
Inhibitory Synapses ◽  
Type I ◽  
Behavioral Alterations ◽  
Knock Out ◽  
Pharmacological Inhibition

Abstract Background Dravet Syndrome is a severe childhood pharmaco-resistant epileptic disorder mainly caused by mutations in the SCN1A gene, which encodes for the α1 subunit of the type I voltage-gated sodium channel (NaV1.1), that causes imbalance between excitation and inhibition in the brain. We recently found that eEF2K knock out mice displayed enhanced GABAergic transmission and tonic inhibition and were less susceptible to epileptic seizures. Thus, we investigated the effect of inhibition of eEF2K on the epileptic and behavioral phenotype of Scn1a ± mice, a murine model of Dravet Syndrome. Methods To elucidate the role of eEF2K pathway in the etiopathology of Dravet syndrome we generated a new mouse model deleting the eEF2K gene in Scn1a ± mice. By crossing Scn1a ± mice with eEF2K−/− mice we obtained the three main genotypes needed for our studies, Scn1a+/+ eEF2K+/+ (WT mice), Scn1a ± eEF2K+/+ mice (Scn1a ± mice) and Scn1a ± eEF2K−/− mice, that were fully characterized for EEG and behavioral phenotype. Furthermore, we tested the ability of a pharmacological inhibitor of eEF2K in rescuing EEG alterations of the Scn1a ± mice. Results We showed that the activity of eEF2K/eEF2 pathway was enhanced in Scn1a ± mice. Then, we demonstrated that both genetic deletion and pharmacological inhibition of eEF2K were sufficient to ameliorate the epileptic phenotype of Scn1a ± mice. Interestingly we also found that motor coordination defect, memory impairments, and stereotyped behavior of the Scn1a ± mice were reverted by eEF2K deletion. The analysis of spontaneous inhibitory postsynaptic currents (sIPSCs) suggested that the rescue of the pathological phenotype was driven by the potentiation of GABAergic synapses. Limitations Even if we found that eEF2K deletion was able to increase inhibitory synapses function, the molecular mechanism underlining the inhibition of eEF2K/eEF2 pathway in rescuing epileptic and behavioral alterations in the Scn1a ± needs further investigations. Conclusions Our data indicate that pharmacological inhibition of eEF2K could represent a novel therapeutic intervention for treating epilepsy and related comorbidities in the Dravet syndrome.

scholarly journals Rescuing Epileptic and Behavioral Alterations in a Dravet Syndrome Mouse Model by Inhibiting Eukaryotic Elongation Factor 2 Kinase (eEF2K)

2021 ◽  
Author(s):  
Stefania Beratta ◽  
Luisa Ponzoni ◽  
Laura Gritti ◽  
Paolo Scalmani ◽  
Massimo Mantegazza ◽  
...  
Keyword(s):  
Mouse Model ◽  
Motor Coordination ◽  
Elongation Factor ◽  
Behavioral Phenotype ◽  
Dravet Syndrome ◽  
Inhibitory Synapses ◽  
Type I ◽  
Behavioral Alterations ◽  
Knock Out ◽  
Pharmacological Inhibition

Abstract Background: Dravet Syndrome is a severe childhood pharmaco-resistant epileptic disorder mainly caused by mutations in the SCN1A gene, which encodes for the α1 subunit of the type I voltage-gated sodium channel (NaV1.1), that cause imbalance between excitation and inhibition in the brain. We recently found that eEF2K knock out mice displayed enhanced GABAergic transmission and tonic inhibition and were less susceptible to epileptic seizures. Thus, we investigated the effect of inhibition of eEF2K on the epileptic and behavioral phenotype of Scn1a+/- mice, a murine model of Dravet Syndrome.Methods: To elucidate the role of eEF2K pathway in the etiopathology of Dravet syndrome we generated a new mouse model deleting the eEF2K gene in Scn1a+/- mice. By crossing Scn1a+/- mice with eEF2K-/- mice we obtained the three main genotypes needed for our studies, Scn1a+/+eEF2K+/+ (WT mice), Scn1a+/-eEF2K+/+ mice (Scn1a+/- mice) and Scn1a+/-eEF2K-/- mice, that were fully characterized for EEG and behavioral phenotype. Furthermore, we tested the ability of a pharmacological inhibitor of eEF2K in rescuing EEG alterations of the Scn1a+/- mice.Results: We showed that the activity of eEF2K/eEF2 pathway was enhanced in Scn1a+/- mice. Then, we demonstrated that both genetic deletion and pharmacological inhibition of eEF2K were sufficient to ameliorate the epileptic phenotype of Scn1a+/- mice. Interestingly we also found that motor coordination defect, memory impairments, and stereotyped behavior of the Scn1a+/- mice were reverted by eEF2K deletion. The analysis of spontaneous inhibitory postsynaptic currents (sIPSCs) suggested that the rescue of the pathological phenotype was driven by the potentiation of GABAergic synapses. Limitations: Even if we found that eEF2K deletion was able to increase inhibitory synapses function, the molecular mechanism underlining the inhibition of eEF2K/eEF2 pathway in rescuing epileptic and behavioral alterations in the Scn1a+/- needs further investigations.Conclusions: Our data indicate that pharmacological inhibition of eEF2K could represent a novel therapeutic intervention for treating epilepsy and related comorbidities in the Dravet syndrome.

scholarly journals Rescuing epileptic and behavioral alterations in a Dravet syndrome mouse model by inhibiting eEF2K

2021 ◽  
Author(s):  
Stefania Beretta ◽  
Luisa Ponzoni ◽  
Laura Gritti ◽  
Paolo Scalmani ◽  
Massimo Mantegazza ◽  
...  
Keyword(s):  
Mouse Model ◽  
Motor Coordination ◽  
Epileptic Seizures ◽  
Stereotyped Behavior ◽  
Dravet Syndrome ◽  
Type I ◽  
Behavioral Alterations ◽  
Knock Out ◽  
Memory Impairments ◽  
Pharmacological Inhibition

Dravet Syndrome is a severe childhood pharmacoresistant epileptic disorder caused mainly by mutations in the SCN1A gene, which encodes for the α1 subunit of the type I voltage-gated sodium channel (NaV1.1), that cause imbalance between excitation and inhibition in the brain. We recently found that eEF2K knock out mice displayed enhanced GABAergic transmission and tonic inhibition and were less susceptible to epileptic seizures. In Scn1a+/- mice, a mouse model of the Dravet syndrome, we found that the activity of eEF2K/eEF2 pathway was enhanced. Then, we demonstrated that both genetic deletion and pharmacological inhibition of eEF2K were able to reduce the epileptic phenotype of Scn1a+/- mice. Interestingly we also found that motor coordination defect, memory impairments, and stereotyped behavior of the Scn1a+/- mice were reverted by eEF2K deletion. The analysis of spontaneous inhibitory postsynaptic currents (sIPSCs) suggested that the rescue of the pathological phenotype was driven by the potentiation of GABAergic synapses. Our data indicate that pharmacological inhibition of eEF2K could represent a novel therapeutic intervention for treating epilepsy and related comorbidities in the Dravet syndrome.

scholarly journals Inhibitory synaptic transmission is impaired at higher extracellular Ca2+ concentrations in Scn1a+/− mouse model of Dravet syndrome

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kouya Uchino ◽  
Hiroyuki Kawano ◽  
Yasuyoshi Tanaka ◽  
Yuna Adaniya ◽  
Ai Asahara ◽  
...  
Keyword(s):  
Mouse Model ◽  
Dravet Syndrome ◽  
Inhibitory Synapses ◽  
Wild Type ◽  
Inhibitory Synaptic Transmission ◽  
Postsynaptic Currents ◽  
Vesicular Release ◽  
A Subunit ◽  
Proportional Increase ◽  
The Brain

AbstractDravet syndrome (DS) is an intractable form of childhood epilepsy that occurs in infancy. More than 80% of all patients have a heterozygous abnormality in the SCN1A gene, which encodes a subunit of Na+ channels in the brain. However, the detailed pathogenesis of DS remains unclear. This study investigated the synaptic pathogenesis of this disease in terms of excitatory/inhibitory balance using a mouse model of DS. We show that excitatory postsynaptic currents were similar between Scn1a knock-in neurons (Scn1a+/− neurons) and wild-type neurons, but inhibitory postsynaptic currents were significantly lower in Scn1a+/− neurons. Moreover, both the vesicular release probability and the number of inhibitory synapses were significantly lower in Scn1a+/− neurons compared with wild-type neurons. There was no proportional increase in inhibitory postsynaptic current amplitude in response to increased extracellular Ca2+ concentrations. Our study revealed that the number of inhibitory synapses is significantly reduced in Scn1a+/− neurons, while the sensitivity of inhibitory synapses to extracellular Ca2+ concentrations is markedly increased. These data suggest that Ca2+ tethering in inhibitory nerve terminals may be disturbed following the synaptic burst, likely leading to epileptic symptoms.

scholarly journals Scn1a gene reactivation after symptom onset rescues pathological phenotypes in a mouse model of Dravet syndrome

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Nicholas Valassina ◽  
Simone Brusco ◽  
Alessia Salamone ◽  
Linda Serra ◽  
Mirko Luoni ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mouse Model ◽  
Symptom Onset ◽  
Epileptic Encephalopathy ◽  
Dravet Syndrome ◽  
Neurological Deficits ◽  
Behavioral Alterations ◽  
Unexpected Death ◽  
Physiological Level ◽  
Behavioral Abnormalities

AbstractDravet syndrome is a severe epileptic encephalopathy caused primarily by haploinsufficiency of the SCN1A gene. Repetitive seizures can lead to endurable and untreatable neurological deficits. Whether this severe pathology is reversible after symptom onset remains unknown. To address this question, we generated a Scn1a conditional knock-in mouse model (Scn1a Stop/+) in which Scn1a expression can be re-activated on-demand during the mouse lifetime. Scn1a gene disruption leads to the development of seizures, often associated with sudden unexpected death in epilepsy (SUDEP) and behavioral alterations including hyperactivity, social interaction deficits and cognitive impairment starting from the second/third week of age. However, we showed that Scn1a gene re-activation when symptoms were already manifested (P30) led to a complete rescue of both spontaneous and thermic inducible seizures, marked amelioration of behavioral abnormalities and normalization of hippocampal fast-spiking interneuron firing. We also identified dramatic gene expression alterations, including those associated with astrogliosis in Dravet syndrome mice, that, accordingly, were rescued by Scn1a gene expression normalization at P30. Interestingly, regaining of Nav1.1 physiological level rescued seizures also in adult Dravet syndrome mice (P90) after months of repetitive attacks. Overall, these findings represent a solid proof-of-concept highlighting that disease phenotype reversibility can be achieved when Scn1a gene activity is efficiently reconstituted in brain cells.

scholarly journals A Mouse Model of PPRV Infection for Elucidating Protective and Pathological Roles of Immune Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Yashu Sharma ◽  
Roman Sarkar ◽  
Ayush Jain ◽  
Sudhakar Singh ◽  
Chander Shekhar ◽  
...  
Keyword(s):  
T Cells ◽  
Mouse Model ◽  
Immune Cells ◽  
High Dose ◽  
Type I ◽  
Knock Out ◽  
Cell Responses ◽  
Type I Ifns ◽  
Immune Mediators ◽  
Body Weights

The study was aimed at developing an accessible laboratory animal model to elucidate protective and pathological roles of immune mediators during Peste des petits ruminants virus (PPRV) infection. It is because of the critical roles of type I IFNs in anti-viral defense, we assessed the susceptibility of IFN receptor knock out (IFNR KO) mice to PPRV infection. IFNR KO mice were exceedingly susceptible to the infection but WT animals efficiently controlled PPRV. Accordingly, the PPRV infected IFNR KO mice gradually reduced their body weights and succumbed to the infection within 10 days irrespective of the dose and route of infection. The lower infecting doses predominantly induced immunopathological lesions. The viral antigens as well as the replicating PPRV were abundantly present in most of the critical organs such as brain, lungs, heart and kidneys of IFNR KO mice infected with high dose of the virus. Neutrophils and macrophages transported the replicating virus to central nervous system (CNS) and contributed to pathology while the elevated NK and T cell responses directly correlated with the resolution of PPRV infection in WT animals. Using an array of fluorescently labeled H-2Kb tetramers, we discovered four immunogenic epitopes of PPRV. The PPRV-peptides interacted well with H-2Kb in acellular and cellular assay as well as expanded the virus-specific CD8+ T cells in immunized or infected mice. Adoptively transferred CD8+ T cells helped control PPRV in infected mice. Our study therefore established and employed a mouse model for investigating the pathogenesis of PPRV. The model could be useful for elucidating the contribution of immune cells in disease progression as well as to test anti-viral agents.

scholarly journals The Excitatory/Inhibitory Balance of Synaptic Transmission Is Impaired at Higher Extracellular Ca2+ Concentrations in Scn1a+/− Mouse Model of Dravet Syndrome

2021 ◽  
Author(s):  
Kouya Uchino ◽  
Hiroyuki Kawano ◽  
Yasuyoshi Tanaka ◽  
Yuna Adaniya ◽  
Ai Asahara ◽  
...  
Keyword(s):  
Mouse Model ◽  
Dravet Syndrome ◽  
Inhibitory Synapses ◽  
Nerve Terminals ◽  
Wild Type ◽  
Postsynaptic Currents ◽  
Vesicular Release ◽  
A Subunit ◽  
Proportional Increase ◽  
The Brain

Abstract Dravet syndrome (DS) is an intractable form of childhood epilepsy that occurs in infancy. More than 80% of all patients have a heterozygous abnormality in the SCN1A gene, which encodes a subunit of Na+ channels in the brain. However, the detailed pathogenesis of DS remains unclear. This study investigated the synaptic pathogenesis of this disease in terms of excitatory/inhibitory balance using a mouse model of DS. We show that excitatory postsynaptic currents were similar between Scn1a knock-in neurons (Scn1a+/− neurons) and wild-type neurons, but inhibitory postsynaptic currents were significantly lower in Scn1a+/− neurons. Moreover, both the vesicular release probability and the number of inhibitory synapses were significantly lower in Scn1a+/− neurons compared with wild-type neurons. There was no proportional increase in inhibitory postsynaptic current amplitude in response to increased extracellular Ca2+ concentrations. Our study revealed that the number of inhibitory synapses is significantly reduced in Scn1a+/− neurons, while the sensitivity of inhibitory synapses to extracellular Ca2+ concentrations is markedly increased. These data suggest that Ca2+ tethering in inhibitory nerve terminals may be disturbed following the synaptic burst, likely leading to epileptic symptoms.

scholarly journals The excitatory/inhibitory balance of synaptic transmission is impaired at higher extracellular Ca2+ concentrations in Scn1a+/− mouse model of Dravet syndrome

2021 ◽  
Author(s):  
Kouya Uchino ◽  
Hiroyuki Kawano ◽  
Yasuyoshi Tanaka ◽  
Yuna Adaniya ◽  
Ai Asahara ◽  
...  
Keyword(s):  
Mouse Model ◽  
Dravet Syndrome ◽  
Inhibitory Synapses ◽  
Nerve Terminals ◽  
Wild Type ◽  
Postsynaptic Currents ◽  
Vesicular Release ◽  
A Subunit ◽  
Proportional Increase ◽  
The Brain

AbstractDravet syndrome (DS) is an intractable form of childhood epilepsy that occurs in infancy. More than 80% of all patients have a heterozygous abnormality in the SCN1A gene, which encodes a subunit of Na+ channels in the brain. However, the detailed pathogenesis of DS remains unclear. This study investigated the synaptic pathogenesis of this disease in terms of excitatory/inhibitory balance using a mouse model of DS. We show that excitatory postsynaptic currents were similar between Scn1a knock-in neurons (Scn1a+/− neurons) and wild-type neurons, but inhibitory postsynaptic currents were significantly lower in Scn1a+/− neurons. Moreover, both the vesicular release probability and the number of inhibitory synapses were significantly lower in Scn1a+/− neurons compared with wild-type neurons. There was no proportional increase in inhibitory postsynaptic current amplitude in response to increased extracellular Ca2+ concentrations. Our study revealed that the number of inhibitory synapses is significantly reduced in Scn1a+/− neurons, while the sensitivity of inhibitory synapses to extracellular Ca2+ concentrations is markedly increased. These data suggest that Ca2+ tethering in inhibitory nerve terminals may be disturbed following the synaptic burst, likely leading to epileptic symptoms.

Dysregulation of DNA methylation during development as a potential mechanisms contributing to obsessive compulsive disorders and autism

2019 ◽  
Author(s):  
German I. Todorov ◽  
Karthikeyan Mayilvahanan ◽  
David Ashurov ◽  
Catarina Cunha
Keyword(s):  
Mouse Model ◽  
Autism Spectrum ◽  
Obsessive Compulsive ◽  
Cancer Treatments ◽  
Knock Out ◽  
Treatment Priority ◽  
Underlying Mechanisms ◽  
Knock Out Mice ◽  
Obsessive Compulsive Disorders ◽  
Compulsive Disorders

Autism Spectrum Disorder (ASD) is a pervasive developmental disorder, that is raising at a concerning rate. However, underlying mechanisms are still to be discovered. Obsessions and compulsions are the most debilitating aspect of these disorders (OCD), and they are the treatment priority for patients. SAPAP3 knock out mice present a reliable mouse model for repetitive compulsive behavior and are mechanistically closely related to the ASD mouse model Shank3 on a molecular level and AMPA receptor net effect. The phenotype of SAPAP3 knock out mice is obsessive grooming that leads to self-inflicted lesions by 4 months of age. Recent studies have accumulated evidence, that epigenetic mechanisms are important effectors in psychiatric conditions such as ASD and OCD. Methylation is the most studied mechanism, that recently lead to drug developments for more precise cancer treatments. We injected SAPAP3 mice with an epigenetic demethylation drug RG108 during pregnancy and delayed the onset of the phenotype in the offspring by 4 months. This result gives us clues about possible mechanism involved in OCD and ASD. Additionally, it shows that modulation of methylation mechanisms during development might be explored as a preventative treatment in the cases of high inherited risk of certain mental health conditions.

Adolescent behavioral abnormalities in a Scn1a+/− mouse model of Dravet syndrome

2020 ◽  
Vol 103 ◽  
pp. 106842
Author(s):  
Dilara Bahceci ◽  
Lyndsey Leigh Anderson ◽  
Cassandra Veronica Occelli Hanbury Brown ◽  
Cilla Zhou ◽  
Jonathon Carl Arnold
Keyword(s):  
Mouse Model ◽  
Dravet Syndrome ◽  
Behavioral Abnormalities
Sign in / Sign up

Export Citation Format

Share Document