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1.
Neuropeptides ; 96: 102294, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36270032

RESUMO

Understanding the underlying molecular mechanisms involved in epilepsy is critical for the development of more effective therapies. It is believed that mTOR (Mechanistic Target of Rapamycin kinases) activity and the mitochondrial dynamic balance change during epilepsy. mTOR affects mitochondrial fission by stimulating the translation of mitochondrial fission process 1 (MTFP1). In This study, the protective role of N-acetylcysteine was studied in temporal lobe epilepsy (TLE) through the regulation of mTOR and mitochondrial dynamic proteins. Rats received N-acetylcysteine (oral administration) seven days before induction of epilepsy, followed by one day after epilepsy. TLE was induced by microinjection of kainite into the left lateral ventricle. The total mTOR and Drp1 levels in the hippocampus were evaluated by western blotting. MFN1 was assessed using immunohistochemistry, and the expression of Fis.1 and MTFP1 (fission-related proteins) and OPA (fusion-related protein) were detected by real-time PCR. The mitochondrial membrane potential was measured by Rhodamin 123. The results showed that 72 h after induction of epilepsy, the mTOR protein level increased, and the balance of the mitochondrial dynamic was disturbed; however, oral administration of NAC decreased the mTOR protein level and improved the mitochondrial dynamic. These findings indicate that NAC plays a neuroprotective role in temporal lobe epilepsy, probably through decreasing the mTOR protein level, which can improve the imbalance in the mitochondrial dynamic.


Assuntos
Acetilcisteína , Epilepsia do Lobo Temporal , Animais , Ratos , Acetilcisteína/metabolismo , Epilepsia do Lobo Temporal/tratamento farmacológico , Epilepsia do Lobo Temporal/induzido quimicamente , Hipocampo , Dinâmica Mitocondrial , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo
2.
Neurobiol Dis ; 174: 105879, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36183946

RESUMO

GABAergic interneurons play a role in regulating adult neurogenesis within the dentate gyrus (DG) of the hippocampus. Neurogenesis occurs within a stem cell niche in the subgranular zone (SGZ) of the DG. In this niche, populations of neural progenitors give rise to granule cells that migrate radially into the granule cell layer (GCL) of the DG. Altered neurogenesis in temporal lobe epilepsy (TLE) is linked to a transient increase in the proliferation of new neurons and the abnormal inversion of Type 1 progenitors, resulting in ectopic migration of Type 3 progenitors into the hilus of the DG. These ectopic cells mature into granule cells in the hilus that become hyperexcitable and contribute to the development of spontaneous recurrent seizures. To test whether grafts of GABAergic cells in the DG restore synaptic inhibition, prior work focused on transplanting GABAergic progenitors into the hilus of the DG. This cell-based therapeutic approach was shown to alter the disease phenotype by ameliorating spontaneous seizures in mice with pilocarpine-induced TLE. Prior optogenetic and immunohistochemical studies demonstrated that the transplanted GABAergic interneurons increased levels of synaptic inhibition by establishing inhibitory synaptic contacts with adult-born granule cells, consistent with the observed suppression of seizures. Whether GABAergic progenitor transplantation into the DG ameliorates underlying abnormalities in adult neurogenesis caused by TLE is not known. As a first step to address this question, we compared the effects of GABAergic progenitor transplantation on Type 1, Type 2, and Type 3 progenitors in the stem cell niche using cell type-specific molecular markers in naïve, non-epileptic mice. The progenitor transplantation increased GABAergic interneurons in the DG and led to a significant reduction in Type 2 progenitors and a concomitant increase in Type 3 progenitors. Next, we compared the effects of GABAergic interneuron transplantation in epileptic mice. Transplantation of GABAergic progenitors resulted in reductions in inverted Type 1, Type 2, and hilar ectopic Type 3 cells, concomitant with an increase in the radial migration of Type 3 progenitors into the GCL. Thus, in mice with Pilocarpine induced TLE, hilar transplants of GABA interneurons may reverse abnormal patterns of adult neurogenesis, an outcome that may ameliorate seizures.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Camundongos , Animais , Epilepsia do Lobo Temporal/induzido quimicamente , Pilocarpina , Neurogênese/fisiologia , Hipocampo/fisiologia , Convulsões , Giro Denteado/fisiologia
3.
Neuroscience ; 504: 1-9, 2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36122882

RESUMO

Epilepsy is a neurological disorder caused by abnormally elevated neuronal firing and excitability. Spire2, also known as the nucleating factor of F-actin, plays an important role in long-range vesicle transport. This study showed that Spire2 was highly expressed in neurons in the cortex and hippocampus. Its knockdown significantly reduced the initiation current of the evoked action potential and the frequency of action potential, suggesting that Spire2 knockdown inhibits the threshold current of the neuron. In the cortex of patients with refractory temporal lobe epilepsy (TLE), Spire2 expression was significantly reduced. Decreased expression levels of Spire2 were also observed in kainic acid (KA) and pentylenetetrazole (PTZ) animal models. In the KA and PTZ models, Spire2-knockdown mice showed significantly increased seizures and shortened intervals between seizures, with a tendency to increase seizure duration. In contrast, Spire2-overexpressing mice showed reduced numbers of spontaneous seizures. In conclusion, this study revealed a significantly decreased expression of Spire2 in the brain tissues of epileptic individuals and an inhibitory role for this protein in the development of epilepsy. In addition, knockdown of Spire2 aggravated abnormal firing in epileptic mice, while its overexpression had the opposite effect. These findings provide new insights into the mechanism of epileptogenesis.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Animais , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Epilepsia/induzido quimicamente , Epilepsia/metabolismo , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/metabolismo , Pentilenotetrazol/farmacologia , Convulsões/metabolismo , Ácido Caínico , Hipocampo/metabolismo
4.
FASEB J ; 36(10): e22554, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36111973

RESUMO

Mesial temporal lobe epilepsy (MTLE) is one of the most common refractory epilepsies and is usually accompanied by a range of brain pathological changes, such as neuronal injury and astrocytosis. Naïve astrocytes are readily converted to cytotoxic reactive astrocytes (A1) in response to inflammatory stimulation, suppressing the polarization of A1 protects against neuronal death in early central nervous system injury. Our previous study found that pro-inflammatory cytokines and miR-132-3p (hereinafter referred to as "miR-132") expression were upregulated, but how miR-132 affected reactive astrocyte polarization and neuronal damage during epilepsy is not fully understood. Here, we aimed to explore the effect and mechanism of miR-132 on A1 polarization. Our results confirmed that A1 markers were significantly elevated in the hippocampus of MTLE rats and IL-1ß-treated primary astrocytes. In vivo, knockdown of miR-132 by lateral ventricular injection reduced A1 astrocytes, neuronal loss, mossy fiber sprouting, and remitted the severity of status epilepticus and the recurrence of spontaneous recurrent seizures. In vitro, the neuronal cell viability and axon length were reduced by additional treatment with A1 astrocyte conditioned media (ACM), and downregulation of astrocyte miR-132 rescued the inhibition of cell activity by A1 ACM, while the length of axons was further inhibited. The regulation of miR-132 on A1 astrocytes may be related to its target gene expression. Our results show that interfering with astrocyte polarization may be a breakthrough in the treatment of refractory epilepsy, which may extend to the research of other astrocyte polarization-mediated brain injuries.


Assuntos
Epilepsia do Lobo Temporal , MicroRNAs , Estado Epiléptico , Animais , Astrócitos/metabolismo , Meios de Cultivo Condicionados/farmacologia , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/genética , Epilepsia do Lobo Temporal/metabolismo , Hipocampo/metabolismo , Interleucina-1beta/metabolismo , Interleucina-1beta/farmacologia , MicroRNAs/genética , MicroRNAs/metabolismo , Ratos , Convulsões/genética , Convulsões/metabolismo , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/genética , Estado Epiléptico/metabolismo
5.
Neuron ; 110(19): 3121-3138.e8, 2022 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-35987207

RESUMO

The hippocampal CA2 region, an area important for social memory, has been suspected to play a role in temporal lobe epilepsy (TLE) because of its resistance to degeneration observed in neighboring CA1 and CA3 regions in both humans and rodent models of TLE. However, little is known about whether alterations in CA2 properties promote seizure generation or propagation. Here, we addressed the role of CA2 using the pilocarpine-induced status epilepticus model of TLE. Ex vivo electrophysiological recordings from acute hippocampal slices revealed a set of coordinated changes that enhance CA2 PC intrinsic excitability, reduce CA2 inhibitory input, and increase CA2 excitatory output to its major CA1 synaptic target. Moreover, selective chemogenetic silencing of CA2 pyramidal cells caused a significant decrease in the frequency of spontaneous seizures measured in vivo. These findings provide the first evidence that CA2 actively contributes to TLE seizure activity and may thus be a promising therapeutic target.


Assuntos
Epilepsia do Lobo Temporal , Animais , Região CA2 Hipocampal , Modelos Animais de Doenças , Epilepsia do Lobo Temporal/induzido quimicamente , Hipocampo/fisiologia , Humanos , Camundongos , Pilocarpina/toxicidade , Células Piramidais/fisiologia , Convulsões/induzido quimicamente
6.
JCI Insight ; 7(15)2022 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-35938532

RESUMO

Dysregulation of excitatory amino acid transporter 2 (EAAT2) contributes to the development of temporal lobe epilepsy (TLE). Several strategies for increasing total EAAT2 levels have been proposed. However, the mechanism underlying the oligomeric assembly of EAAT2, impairment of which inhibits the formation of functional oligomers by EAAT2 monomers, is still poorly understood. In the present study, we identified E3 ubiquitin ligase AMFR as an EAAT2-interacting protein. AMFR specifically increased the level of EAAT2 oligomers rather than inducing protein degradation through K542-specific ubiquitination. By using tissues from humans with TLE and epilepsy model mice, we observed that AMFR and EAAT2 oligomer levels were simultaneously decreased in the hippocampus. Screening of 2386 FDA-approved drugs revealed that the most common analgesic/antipyretic medicine, acetaminophen (APAP), can induce AMFR transcriptional activation via transcription factor SP1. Administration of APAP protected against pentylenetetrazol-induced epileptogenesis. In mice with chronic epilepsy, APAP treatment partially reduced the occurrence of spontaneous seizures and greatly enhanced the antiepileptic effects of 17AAG, an Hsp90 inhibitor that upregulates total EAAT2 levels, when the 2 compounds were administered together. In summary, our studies reveal an essential role for AMFR in regulating the oligomeric state of EAAT2 and suggest that APAP can improve the efficacy of EAAT2-targeted antiepileptic treatments.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Acetaminofen , Animais , Anticonvulsivantes/farmacologia , Anticonvulsivantes/uso terapêutico , Epilepsia/induzido quimicamente , Epilepsia/tratamento farmacológico , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/tratamento farmacológico , Epilepsia do Lobo Temporal/metabolismo , Transportador 2 de Aminoácido Excitatório/metabolismo , Humanos , Camundongos , Receptores do Fator Autócrino de Motilidade/metabolismo , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico
7.
PLoS One ; 17(8): e0271995, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35972937

RESUMO

OBJECTIVE: Inflammation of brain structures, in particular the hippocampal formation, can induce neuronal degeneration and be associated with increased excitability manifesting as propensity for repetitive seizures. An increase in the abundance of individual proinflammatory molecules including interleukin 1 beta has been observed in brain tissue samples of patients with pharmacoresistant temporal lobe epilepsy (TLE) and corresponding animal models. The NLRP3-inflammasome, a cytosolic protein complex, acts as a key regulator in proinflammatory innate immune signalling. Upon activation, it leads to the release of interleukin 1 beta and inflammation-mediated neurodegeneration. Transient brain insults, like status epilepticus (SE), can render hippocampi chronically hyperexcitable and induce segmental neurodegeneration. The underlying mechanisms are referred to as epileptogenesis. Here, we have tested the hypothesis that distinct NLRP3-dependent transcript and protein signalling dynamics are induced by SE and whether they differ between two classical SE models. We further correlated the association of NLRP3-related transcript abundance with convulsive activity in human TLE hippocampi of patients with and without associated neurodegenerative damage. METHODS: Hippocampal mRNA- and protein-expression of NLRP3 and associated signalling molecules were analysed longitudinally in pilocarpine- and kainic acid-induced SE TLE mouse models. Complementarily, we studied NLRP3 inflammasome-associated transcript patterns in epileptogenic hippocampi with different damage patterns of pharmacoresistant TLE patients that had undergone epilepsy surgery for seizure relief. RESULTS: Pilocarpine- and kainic acid-induced SE elicit distinct hippocampal Nlrp3-associated molecular signalling. Transcriptional activation of NLRP3 pathway elements is associated with seizure activity but independent of the particular neuronal damage phenotype in KA-induced and in human TLE hippocampi. SIGNIFICANCE: These data suggest highly dynamic inflammasome signalling in SE-induced TLE and highlight a vicious cycle associated with seizure activity. Our results provide promising perspectives for the inflammasome signalling pathway as a target for anti-epileptogenic and -convulsive therapeutic strategies. The latter may even applicable to a particularly broad spectrum of TLE patients with currently pharmacoresistant disease.


Assuntos
Epilepsia do Lobo Temporal , Proteína 3 que Contém Domínio de Pirina da Família NLR , Doenças Neuroinflamatórias , Estado Epiléptico , Animais , Modelos Animais de Doenças , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/patologia , Hipocampo/metabolismo , Humanos , Inflamassomos/metabolismo , Interleucina-1beta/metabolismo , Ácido Caínico , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Doenças Neuroinflamatórias/patologia , Pilocarpina , Convulsões/metabolismo , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/patologia
8.
Prog Neurobiol ; 217: 102335, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35931355

RESUMO

The infiltration of immune cells is observed in the epileptogenic zone; however, the relationship between epilepsy and regulatory T cells (Tregs) remains only partially understood. We aimed to investigate brain-infiltrating Tregs to reveal their underlying role in epilepsy. We analyzed the infiltration of Tregs in the epileptogenic zones from patients with epilepsy and a pilocarpine-induced temporal lobe epilepsy (TLE) model. Next, we evaluated the effects of brain Treg depletion on neuroinflammation, neuronal loss, oxidative stress, seizure activity and behavioral changes in the pilocarpine model. We also explored the impact of Treg expansion in the brain on seizure activity. There were a large number of Tregs in the epileptogenic zones of human and experimental epilepsy. The number of brain Tregs was negatively correlated with the frequency of seizures in patients with epilepsy. Our further findings demonstrated that brain Treg depletion promoted astrocytosis, microgliosis, inflammatory cytokine production, oxidative stress, and neuronal loss in the hippocampus after status epilepticus (SE). Moreover, brain Treg depletion increased seizure activity and contributed to behavioral impairments in experimental chronic TLE. Interestingly, intracerebroventricular injection of CCL20 amplified Tregs in brain tissue, thereby inhibiting seizure activity. Taken together, our study highlights the therapeutic potential of regulating Tregs in epileptic brain tissue.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Animais , Encéfalo , Modelos Animais de Doenças , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/tratamento farmacológico , Hipocampo , Humanos , Pilocarpina/efeitos adversos , Convulsões/induzido quimicamente , Linfócitos T Reguladores
9.
Sci Rep ; 12(1): 14690, 2022 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-36038626

RESUMO

The molecular mechanisms underlying circuit re-wiring in the mature brain remains ill-defined. An eloquent example of adult circuit remodelling is the hippocampal mossy fiber (MF) sprouting found in diseases such as temporal lobe epilepsy. The molecular determinants underlying this retrograde re-wiring remain unclear. This may involve signaling system(s) controlling axon specification/growth during neurodevelopment reactivated during epileptogenesis. Since adenosine A2A receptors (A2AR) control axon formation/outgrowth and synapse stabilization during development, we now examined the contribution of A2AR to MF sprouting. A2AR blockade significantly attenuated status epilepticus(SE)-induced MF sprouting in a rat pilocarpine model. This involves A2AR located in dentate granule cells since their knockdown selectively in dentate granule cells reduced MF sprouting, most likely through the ability of A2AR to induce the formation/outgrowth of abnormal secondary axons found in rat hippocampal neurons. These A2AR should be activated by extracellular ATP-derived adenosine since a similar prevention/attenuation of SE-induced hippocampal MF sprouting was observed in CD73 knockout mice. These findings demonstrate that A2AR contribute to epilepsy-related MF sprouting, most likely through the reactivation of the ability of A2AR to control axon formation/outgrowth observed during neurodevelopment. These results frame the CD73-A2AR axis as a regulator of circuit remodeling in the mature brain.


Assuntos
Adenosina , Epilepsia do Lobo Temporal , Receptor A2A de Adenosina/metabolismo , Animais , Epilepsia do Lobo Temporal/induzido quimicamente , Camundongos , Fibras Musgosas Hipocampais , Pilocarpina/farmacologia , Ratos , Sinapses/fisiologia
10.
Neural Plast ; 2022: 8511066, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35860309

RESUMO

Temporal lobe epilepsy (TLE) is a chronic neurological disorder that is often resistant to antiepileptic drugs. The pathogenesis of TLE is extremely complicated and remains elusive. Understanding the molecular mechanisms underlying TLE is crucial for its diagnosis and treatment. In the present study, a lithium-pilocarpine-induced TLE model was employed to reveal the pathological changes of hippocampus in rats. Hippocampal samples were taken for proteomic analysis at 2 weeks after the onset of spontaneous seizure (a chronic stage of epileptogenesis). Isobaric tag for relative and absolute quantization (iTRAQ) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique was applied for proteomic analysis of hippocampus. A total of 4173 proteins were identified from the hippocampi of epileptic rats and its control, of which 27 differentially expressed proteins (DEPs) were obtained with a fold change > 1.5 and P < 0.05. Bioinformatics analysis indicated 27 DEPs were mainly enriched in "regulation of synaptic plasticity and structure" and "calmodulin-dependent protein kinase activity," which implicate synaptic remodeling may play a vital role in the pathogenesis of TLE. Consequently, the synaptic plasticity-related proteins and synaptic structure were investigated to verify it. It has been demonstrated that CaMKII-α, CaMKII-ß, and GFAP were significant upregulated coincidently with proteomic analysis in the hippocampus of TLE rats. Moreover, the increased dendritic spines and hippocampal sclerosis further proved that synaptic plasticity involves in the development of TLE. The present study may help to understand the molecular mechanisms underlying epileptogenesis and provide a basis for further studies on synaptic plasticity in TLE.


Assuntos
Epilepsia do Lobo Temporal , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Cromatografia Líquida , Modelos Animais de Doenças , Epilepsia do Lobo Temporal/induzido quimicamente , Hipocampo/metabolismo , Plasticidade Neuronal , Pilocarpina , Proteômica , Ratos , Espectrometria de Massas em Tandem
11.
Neurochem Int ; 158: 105383, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35787395

RESUMO

VIP binding sites are upregulated in mesial temporal lobe epilepsy (MTLE) patients, also suffering from severe cognitive deficits. Although altered VIP and VIP receptor levels were described in rodent models of epilepsy, the VIP receptor subtype(s) were never identified. We now investigated how VPAC1 and VPAC2 receptor levels change in the Li2+-pilocarpine rat model of MTLE. Cognitive decline and altered synaptic plasticity as estimated from phosphorylation of AMPA GluA1 subunit on Ser831 and Ser845 and AMPA GluA1/GluA2 ratio was also probed. Animals showing spontaneous recurrent seizures (SRSs) for at least 4 weeks showed impaired learning in the radial arm maze (RAM) and presented decreased VPAC1 and increased VPAC2 receptor levels. In addition, SRSs rats showed increased AMPA GluA1 phosphorylation in Ser831 and Ser845, marked decrease in GluA1 levels and a milder decrease in GluA2 levels. Consequently, the GluA1/GluA2 ratio was also decreased in SRSs rats. Altered VIP receptor levels may differentially prevent or contribute to MTLE pathology, since VPAC1 receptors promote the endogenous control of LTP, mediate endogenous VIP neuroprotection against altered synaptic plasticity following epileptiform activity, and mediate anti-inflammatory actions in microglia, while VPAC2 receptors mediate VIP endogenous neuroprotection against neonatal excitotoxicity and prevent reactive astrogliosis. This discovery imposes a different mindset for considering VIP receptors as therapeutic targets in MTLE, allowing a differential targeting of the cellular events contributing to epileptogenesis.


Assuntos
Epilepsia do Lobo Temporal , Receptores de Peptídeo Intestinal Vasoativo , Animais , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/metabolismo , Hipocampo/metabolismo , Pilocarpina/toxicidade , Ratos , Receptores de Peptídeo Intestinal Vasoativo/metabolismo , Convulsões/metabolismo , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico
12.
Free Radic Biol Med ; 188: 45-61, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35714846

RESUMO

Neuronal nitric oxide synthase (nNOS) plays a pivotal role in the pathological process of neuronal injury in the development of epilepsy. Our previous study has demonstrated that nitric oxide (NO) derived from nNOS in the epileptic brain is neurotoxic due to its reaction with the superoxide radical with the formation of peroxynitrite. Neuropeptide Y (NPY) is widely expressed in the mammalian brain, which has been implicated in energy homeostasis and neuroprotection. Recent studies suggest that nNOS may act as a mediator of NPY signaling. Here in this study, we sought to determine whether NPY expression is regulated by nNOS, and if so, whether the regulation of NPY by nNOS is associated with the neuronal injuries in the hippocampus of epileptic brain. Our results showed that pilocarpine-induced temporal lobe epilepsy (TLE) mice exhibited an increased level of nNOS expression and a decreased level of NPY expression along with hippocampal neuronal injuries and cognition deficit. Genetic deletion of nNOS gene, however, significantly upregulated hippocampal NPY expression and reduced TLE-induced hippocampal neuronal injuries and cognition decline. Knockdown of NPY abolished nNOS depletion-induced neuroprotection and cognitive improvement in the TLE mice, suggesting that inhibition of nNOS protects against hippocampal neuronal injuries by increasing neuropeptide Y expression in TLE mice. Targeting nNOS-NPY signaling pathway in the epileptic brain might provide clinical benefit by attenuating neuronal injuries and preventing cognitive deficits in epilepsy patients.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Animais , Epilepsia/metabolismo , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/genética , Epilepsia do Lobo Temporal/metabolismo , Hipocampo/metabolismo , Mamíferos/metabolismo , Camundongos , Neuropeptídeo Y/genética , Neuropeptídeo Y/metabolismo , Neuropeptídeo Y/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo I/genética , Óxido Nítrico Sintase Tipo I/metabolismo
13.
J Chem Neuroanat ; 124: 102121, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35718291

RESUMO

Temporal lobe epilepsy (TLE) is presented the most common form of focal epilepsy with involvement of oxidative stress and neuroinflammation as important factors in its development. About one third of epileptic patients are intractable to currently available medications. Paeonol isolated from some herbs with traditional and medicinal uses has shown anti-oxidative and anti-inflammatory effects in different models of neurological disorders. In this research, we tried to evaluate the possible protective effect of paeonol in intrahippocampal kainate murine model of TLE. To induce TLE, kainate was microinjected into CA3 area of the hippocampus and paeonol was administered at two doses of 30 or 50 mg/kg. The results of this study showed that paeonol at the higher dose significantly reduces incidence of status epilepticus, hippocampal aberrant mossy fiber sprouting and also preserves neuronal density. Beneficial protective effect of paeonol was in parallel with partial reversal of some hippocampal oxidative stress markers (reactive oxygen species and malondialdehyde), caspase 1, glial fibrillary acidic protein, heme oxygenase 1, DNA fragmentation, and inflammation-associated factors (nuclear factor-kappa B, toll-like receptor 4, and tumor necrosis factor α). Our obtained data indicated anticonvulsant and neuroprotective effects of paeonol which is somewhat attributed to its anti-oxidative and anti-inflammation properties besides its attenuation of apoptosis, pyroptosis, and astrocyte activity.


Assuntos
Epilepsia do Lobo Temporal , Ácido Caínico , Acetofenonas/metabolismo , Acetofenonas/farmacologia , Acetofenonas/uso terapêutico , Animais , Anticonvulsivantes/farmacologia , Anticonvulsivantes/uso terapêutico , Modelos Animais de Doenças , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/tratamento farmacológico , Epilepsia do Lobo Temporal/metabolismo , Hipocampo/metabolismo , Humanos , Ácido Caínico/metabolismo , Ácido Caínico/farmacologia , Ácido Caínico/uso terapêutico , Camundongos
14.
J Pharm Pharmacol ; 74(11): 1640-1650, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-35704277

RESUMO

OBJECTIVES: Temporal lobe epilepsy (TLE) is a common and intractable form of epilepsy. There is a strong need to better understand molecular events underlying TLE and to find novel therapeutic agents. Here we aimed to investigate the role of Clock and ferroptosis in regulating TLE. METHODS: TLE model was established by treating mice with kainic acid (KA). Regulatory effects of the Clock gene on KA-induced seizures and ferroptosis were evaluated using Clock knockout (Clock-/-) mice. mRNA and protein levels were determined by quantitative real-time PCR and western blotting, respectively. Ferroptosis was assessed by measuring the levels of iron, GSH and ROS. Transcriptional regulation was studied using a combination of luciferase reporter, mobility shift and chromatin immunoprecipitation (ChIP) assays. KEY FINDINGS: We found that Clock ablation exacerbated KA-induced seizures in mice, accompanied by enhanced ferroptosis in the hippocampus. Clock ablation reduced the hippocampal expression of GPX4 and PPAR-γ, two ferroptosis-inhibitory factors, in mice and in N2a cells. Moreover, Clock regulates diurnal expression of GPX4 and PPAR-γ in mouse hippocampus and rhythmicity in KA-induced seizures. Consistent with this finding, Clock overexpression up-regulated GPX4 and PPAR-γ and protected against ferroptosis in N2a cells. In addition, luciferase reporter, mobility shift and ChIP assays showed that CLOCK trans-activated Gpx4 and Ppar-γ through direct binding to the E-box elements in the gene promoters. CONCLUSION: CLOCK protects against KA-induced seizures through increased expression of GPX4 and PPAR-γ and inhibition of ferroptosis.


Assuntos
Proteínas CLOCK , Epilepsia do Lobo Temporal , Ferroptose , Animais , Camundongos , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/genética , Epilepsia do Lobo Temporal/metabolismo , Ácido Caínico/efeitos adversos , PPAR gama , Convulsões/induzido quimicamente , Convulsões/genética , Proteínas CLOCK/genética , Camundongos Knockout
15.
J Neuroinflammation ; 19(1): 121, 2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35624482

RESUMO

BACKGROUND: The complex pathophysiology of epilepsy hampers the development of effective treatments. Although more than ten kinds of anti-seizures drugs (ASDs) have good effects on seizure control worldwide, about 30% of patients still display pharmacoresistance against ASDs. Neuroinflammation seems to play a crucial role in disease progression. G protein-coupled receptor 120 (GPR120) has been shown to negatively regulate inflammation and apoptosis. However, the role of GPR120 in epilepsy remains unclear. In this study, we aimed to explore the mechanism of GPR120 in epilepsy. METHODS: Male adult C57BL/6 mice were intracranially injected with kainic acid (KA) to establish epilepsy model, and the adeno associated virus (AAV) was administered intracranially at 3 weeks before KA injection. VX765 was administered by intragastric administration at 30 min before KA induced and an equal dose administrated twice a day (10 a.m. and 4 p.m.) lasting 7 days until the mice were killed. Western blot analysis, immunofluorescence staining, video monitoring of seizure, LFP recording, Nissl staining were performed. RESULTS: GPR120 was increased in both the hippocampus and cortex in the KA-induced model with temporal lobe epilepsy (TLE), and both were most highly expressed at 7 days after KA injection. Overexpression of GPR120 significantly alleviated epileptic activity, reduced neuronal death after status epilepticus (SE), downregulated the expression of IL-1ß, IL-6, IL-18, and pyrin domain-containing protein 3 (NLRP3) inflammasome, whereas knockdown GPR120 showed the opposite effect. The effects of GPR120 knockdown were reversed by VX765 inhibition cysteinyl aspartate specific proteinase-1 (Caspase-1). CONCLUSION: GPR120 modulates epileptic seizure activity and affects neuronal survival in KA-induced mouse model of temporal lobe epilepsy. Furthermore, GPR120 regulated neuroinflammation in epileptic animals through NLRP3/Caspase-1/IL-1ß signaling pathway.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Estado Epiléptico , Animais , Caspases , Epilepsia/induzido quimicamente , Epilepsia do Lobo Temporal/induzido quimicamente , Humanos , Inflamassomos , Ácido Caínico/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Doenças Neuroinflamatórias , Receptores Acoplados a Proteínas G/genética , Estado Epiléptico/induzido quimicamente
16.
Hippocampus ; 32(7): 517-528, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35621370

RESUMO

Temporal lobe epilepsy is characterized by hippocampal neuronal death in CA1 and hilus. Dentate gyrus granule cells survive but show dispersion of the compact granule cell layer. This is associated with decrease of the glycoprotein Reelin, which regulates neuron migration and dendrite outgrow. Reelin-deficient (reeler) mice show no layering, their granule cells are dispersed throughout the dentate gyrus. We studied granule cell dendritic orientation and distribution of postsynaptic spines in reeler mice and two mouse models of temporal lobe epilepsy, namely the p35 knockout mice, which show Reelin-independent neuronal migration defects, and mice with unilateral intrahippocampal kainate injection. Granule cells were Golgi-stained and analyzed, using a computerized camera lucida system. Granule cells in naive controls exhibited a vertically oriented dendritic arbor with a small bifurcation angle if positioned proximal to the hilus and a wider dendritic bifurcation angle, if positioned distally. P35 knockout- and kainate-injected mice showed a dispersed granule cell layer, granule cells showed basal dendrites with wider bifurcation angles, which lost position-specific differences. Reeler mice lacked dendritic orientation. P35 knockout- and kainate-injected mice showed increased dendritic spine density in the granule cell layer. Molecular layer dendrites showed a reduced spine density in kainate-injected mice only, whereas in p35 knockouts no reduced spine density was seen. Reeler mice showed a homogenous high spine density. We hypothesize that granule cells migrate in temporal lobe epilepsy, develop new dendrites which show a spread of the dendritic tree, create new spines in areas proximal to mossy fiber sprouting, which is present in p35 knockout- and kainate-injected mice and loose spines on distal dendrites if mossy cell death is present, as it was in kainate-injected mice only. These results are in accordance with findings in epilepsy patients.


Assuntos
Epilepsia do Lobo Temporal , Animais , Dendritos/metabolismo , Giro Denteado , Modelos Animais de Doenças , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/metabolismo , Humanos , Ácido Caínico/toxicidade , Camundongos , Camundongos Mutantes Neurológicos , Neurônios/metabolismo
17.
Epilepsy Res ; 183: 106926, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35526328

RESUMO

Synaptic Vesicle Glycoprotein 2A (SV2A) has been proposed as a presynaptic marker in several neurological disorders. Not only is SV2A the target for the antiepileptic drug levetiracetam, but also considered a marker of mature pre-synapses. In this study, we aimed to assess the binding of [3H]UCB-J as a selective radioligand for SV2A to visualize and determine changes during different stages of epileptogenesis by in-vitro autoradiography in rat models of temporal lobe epilepsy. Two different kainic acid (KA) injection routes were used to model temporal lobe epilepsy in the rat; a systemic (10 mg/kg KA injected intraperitoneally) and a local model (1.875 mM KA injected intrahippocampally). Brain tissue was sampled at different time points after the initial status epilepticus and semi-quantitative [3H]UCB-J autoradiography was performed to determine temporal and spatial changes under the progression of epileptogenesis. A decrease in [3H]UCB-J binding was observed in many brain areas in the acute phases after both types of kainic acid administration. Peak reductions occurred slightly before in systemic-treated animals (within 3-10 days) than after local-treated animals (within 5-15 days). Interestingly in the systemic model, we observed a full restoration in the binding level 30 days after the treatment in most areas probably reflecting neuronal reorganization. However, after the local injection in the hippocampus, the binding in the hippocampus, and in temporal and piriform cortices did not return to basal levels. The time-course profile displayed lateralization in the local model. These results demonstrate changes in the amount of a presynaptic SV2A binding site after seizures and suggest that SV2A may have importance in eliciting spontaneous seizures and/or be a biomarker for epileptogenesis. The present study shows that SV2A is a biomarker of acute phase epileptogenesis in specific brain regions.


Assuntos
Epilepsia do Lobo Temporal , Estado Epiléptico , Animais , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/metabolismo , Ácido Caínico/toxicidade , Glicoproteínas de Membrana , Proteínas do Tecido Nervoso/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Ratos , Estado Epiléptico/metabolismo , Vesículas Sinápticas/metabolismo
18.
Int J Mol Sci ; 23(5)2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35269897

RESUMO

Preventing epileptogenesis in people at risk is an unmet medical need. Metabotropic glutamate receptors (mGluRs) are promising targets for such therapy. However, drugs acting on mGluRs are not used in the clinic due to limited knowledge of the involvement of mGluRs in epileptogenesis. This study aimed to analyze the changes in gene expression of mGluR subtypes (1-5, 7, 8) in various rat brain regions in the latent and chronic phases of a lithium-pilocarpine model of epilepsy. For this study, multiplex test systems were selected and optimized to analyze mGluR gene expression using RT-qPCR. Region- and phase-specific changes in expression were revealed. During the latent phase, mGluR5 mRNA levels were increased in the dorsal and ventral hippocampus, and expression of group III genes was decreased in the hippocampus and temporal cortex, which could contribute to epileptogenesis. Most of the changes in expression detected in the latent stage were absent in the chronic stage, but mGluR8 mRNA production remained reduced in the hippocampus. Moreover, we found that gene expression of group II mGluRs was altered only in the chronic phase. The study deepened our understanding of the mechanisms of epileptogenesis and suggested that agonists of group III mGluRs are the most promising targets for preventing epilepsy.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Animais , Encéfalo/metabolismo , Epilepsia/metabolismo , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/genética , Epilepsia do Lobo Temporal/metabolismo , Expressão Gênica , Hipocampo/metabolismo , Humanos , Lítio/farmacologia , Pilocarpina , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos
19.
Comput Math Methods Med ; 2022: 1938205, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35256888

RESUMO

Objective: To explore the effect of miR-136 on temporal lobe epilepsy (Ep) and its mechanism of action. Methods: 30 male rats were injected intraperitoneally with 30 mg/kg pilocarpine to construct a rat temporal lobe epilepsy model, and they were randomly divided into 5 groups (n = 6 per group): control group, Ep group, agomir NC group, miR-136 agomir group, and miR-136+LiCl group. The brain tissues of the rats were collected 7 days after the treatment. The expression of miR-136 in the hippocampus tissue was detected by qRT-PCR. H&E and Nissl staining were used to observe the histopathological changes and neuron damage in the hippocampus tissue. IL-1ß, IL-6, and TNF-α levels in the hippocampus tissue were detected by ELISA. Flow cytometry was used to detect the apoptosis rate in the hippocampus tissue. Western blot was used to detect the expression levels of c-Caspase-3, Bcl-2, ß-catenin, Cyclin D1, and c-myc protein in the hippocampus. Results: The expression of miR-136 was significantly downregulated in the hippocampus tissue of epileptic rats. After overexpression of miR-136, the number of seizures and the duration of epilepsy in rats were significantly reduced. At the same time, hippocampal tissue damage was improved considerably, and the degree of neuronal damage decreased. Overexpression of miR-136 also significantly reduced the apoptosis rate in the hippocampus tissue and inhibited the levels of inflammatory factors. Meanwhile, miR-136 downregulates the expression of Wnt/ß-catenin signaling pathway-related proteins. However, Wnt pathway activator LiCl could destroy the protective effect of miR-136. Conclusion: miR-136 could exert its neuroprotective influence on temporal lobe epilepsy rats by inhibiting the Wnt/ß-catenin signaling pathway.


Assuntos
Epilepsia do Lobo Temporal/prevenção & controle , MicroRNAs/genética , MicroRNAs/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Biologia Computacional , Modelos Animais de Doenças , Regulação para Baixo , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Inflamação/genética , Inflamação/metabolismo , Inflamação/prevenção & controle , Mediadores da Inflamação/metabolismo , Masculino , Fármacos Neuroprotetores/metabolismo , Fármacos Neuroprotetores/farmacologia , Pilocarpina/toxicidade , Ratos , Ratos Sprague-Dawley , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/metabolismo
20.
J Mol Neurosci ; 72(6): 1224-1233, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35320462

RESUMO

The most well-known type of focal epilepsy that is resistant to existing treatments is temporal lobe epilepsy (TLE), with seizure foci in various structures including temporal lobe, hippocampus, amygdala, entorhinal cortex, and subcortex. The most significant processes involved in the pathophysiology of temporal lobe epilepsy (TLE) are oxidative stress, inflammation, and pyroptosis. There are evidences indicating that acetyl-l-carnitine (ALC) has anti-oxidative, anti-inflammatory, and anti-pyroptotic effects. In the present study, rat model of TLE was induced by intrahippocampal kainate and animals received ALC (100 mg/kg, p.o.). ALC properly attenuated intensity of seizures and also incidence of kainate-induced status epilepticus (SE). As well, obtained findings showed that ALC can partially reverse hippocampal levels of MDA, ROS, SOD, TNFa, NF-kB, TLR4, GFAP, and caspase 1. Besides, treatment of kainate group with ALC exerted a protective effect against CA1 neuronal loss and abnormal mossy fiber sprouting (MFS). Conclusively, these results suggest that ALC is capable to attenuate kainate-induced SE which is somewhat mediated through its lowering of oxidative stress, neuroinflammation, and pyroptosis that are related to its neuroprotective effect.


Assuntos
Epilepsia do Lobo Temporal , Estado Epiléptico , Acetilcarnitina/efeitos adversos , Animais , Anticonvulsivantes/farmacologia , Anticonvulsivantes/uso terapêutico , Modelos Animais de Doenças , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/tratamento farmacológico , Hipocampo , Ácido Caínico/toxicidade , Camundongos , Ratos , Convulsões/tratamento farmacológico , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/tratamento farmacológico
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