sirolimus and Epilepsies--Partial

The most frequent genetic cause of focal epilepsies is variations in the GAP activity toward RAGs 1 complex genes DEP domain containing 5 (DEPDC5), nitrogen permease regulator 2-like protein (NPRL2) and nitrogen permease regulator 3-like protein (NPRL3). Because these variations are frequent and associated with a broad spectrum of focal epilepsies, a unique pathology categorized as GATORopathy can be conceptualized. Animal models recapitulating the clinical features of patients are essential to decipher GATORopathy. Although several genetically modified animal models recapitulate DEPDC5-related epilepsy, no models have been reported for NPRL2- or NPRL3-related epilepsies. Here, we conditionally deleted Nprl2 and Nprl3 from the dorsal telencephalon in mice [Emx1cre/+; Nprl2f/f (Nprl2-cKO) and Emx1cre/+; Nprl3f/f (Nprl3-cKO)] and compared their phenotypes with Nprl2+/-, Nprl3+/- and Emx1cre/+; Depdc5f/f (Depdc5-cKO) mice. Nprl2-cKO and Nprl3-cKO mice recapitulated the major abnormal features of patients-spontaneous seizures, and dysmorphic enlarged neuronal cells with increased mechanistic target of rapamycin complex 1 signaling-similar to Depdc5-cKO mice. Chronic postnatal rapamycin administration dramatically prolonged the survival period and inhibited seizure occurrence but not enlarged neuronal cells in Nprl2-cKO and Nprl3-cKO mice. However, the benefit of rapamycin after withdrawal was less durable in Nprl2- and Nprl3-cKO mice compared with Depdc5-cKO mice. Further studies using these conditional knockout mice will be useful for understanding GATORopathy and for the identification of novel therapeutic targets.

Topics: Animals; Disease Models, Animal; Epilepsies, Partial; Epilepsy; GTPase-Activating Proteins; Membrane Transport Proteins; Mice; Mice, Knockout; Mutation; Nitrogen; Seizures; Sirolimus; Telencephalon; Tumor Suppressor Proteins

Mechanistic target of rapamycin (mTOR) regulates cell proliferation, growth and survival, and is activated in cancer and neurological disorders, including epilepsy. The rapamycin derivative ("rapalog") everolimus, which allosterically inhibits the mTOR pathway, is approved for the treatment of partial epilepsy with spontaneous recurrent seizures (SRS) in individuals with tuberous sclerosis complex (TSC). In contrast to the efficacy in TSC, the efficacy of rapalogs on SRS in other types of epilepsy is equivocal. Furthermore, rapalogs only poorly penetrate into the brain and are associated with peripheral adverse effects, which may compromise their therapeutic efficacy. Here we compare the antiseizure efficacy of two novel, brain-permeable ATP-competitive and selective mTORC1/2 inhibitors, PQR620 and PQR626, and the selective dual pan-PI3K/mTORC1/2 inhibitor PQR530 in two mouse models of chronic epilepsy with SRS, the intrahippocampal kainate (IHK) mouse model of acquired temporal lobe epilepsy and Tsc1

Topics: Animals; Disease Models, Animal; Epilepsies, Partial; Everolimus; Immunosuppressive Agents; Male; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Mice; Mice, Knockout; Sirolimus; Treatment Outcome; Tuberous Sclerosis

Mutations in DEPDC5 are causal factors for a broad spectrum of focal epilepsies, but the underlying pathogenic mechanisms are still largely unknown. To address this question, a zebrafish depdc5 knockout model showing spontaneous epileptiform events in the brain, increased drug-induced seizure susceptibility, general hypoactivity, premature death at 2-3 weeks post-fertilization, as well as the expected hyperactivation of mTOR signaling was developed. Using this model, the role of DEPDC5 in brain development was investigated using an unbiased whole-transcriptomic approach. Surprisingly, in addition to mTOR-associated genes, many genes involved in synaptic function, neurogenesis, axonogenesis, and GABA network activity were found to be dysregulated in larval brains. Although no gross defects in brain morphology or neuron loss were observed, immunostaining of depdc5

Topics: Animals; Disease Models, Animal; Epilepsies, Partial; Gene Knockout Techniques; Intracellular Signaling Peptides and Proteins; Loss of Function Mutation; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Zebrafish; Zebrafish Proteins

Epilepsy is a frequent comorbidity in patients with focal cortical dysplasia (FCD). Recent studies utilizing massive sequencing data identified subsets of genes that are associated with epilepsy and FCD. AKT and mTOR-related signals have been recently implicated in the pathogenic processes of epilepsy and FCD. To clarify the functional roles of the AKT-mTOR pathway in the hippocampal neurons, we generated conditional knockout mice harboring the deletion of Pten (Pten-cKO) in Proopiomelanocortin-expressing neurons. The Pten-cKO mice developed normally until 8 weeks of age, then presented generalized seizures at 8-10 weeks of age. Video-monitored electroencephalograms detected paroxysmal discharges emerging from the cerebral cortex and hippocampus. These mice showed progressive hypertrophy of the dentate gyrus (DG) with increased expressions of excitatory synaptic markers (Psd95, Shank3 and Homer). In contrast, the expression of inhibitory neurons (Gad67) was decreased at 6-8 weeks of age. Immunofluorescence studies revealed the abnormal sprouting of mossy fibers in the DG of the Pten-cKO mice prior to the onset of seizures. The treatment of these mice with an mTOR inhibitor rapamycin successfully prevented the development of seizures and reversed these molecular phenotypes. These data indicate that the mTOR pathway regulates hippocampal excitability in the postnatal brain.

Topics: Animals; Craniofacial Abnormalities; Dentate Gyrus; Disease Models, Animal; Electroencephalography; Epilepsies, Partial; Epilepsy; Hippocampus; Humans; Malformations of Cortical Development; Mice; Mice, Knockout; Neurons; Pro-Opiomelanocortin; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

We are reporting on a 13.5-year-old girl with tuberous sclerosis complex (TSC) who was treated with everolimus because of giant cell astrocytoma and bilateral angiomyolipoma. She suffered from pharmacoresistant partial epilepsy with clusters of tonic and tonic-clonic seizures. Treatment with carbamazepine and sulthiame had led to a stable situation for more than 2.5 years. The dosage of everolimus had to be increased and refractory status epilepticus followed after 12 days. In the absence of any other possible cause, we believe that the status epilepticus was provoked by everolimus. So far, only a few cases of possible seizure aggravation by everolimus have been reported. The clinical relevance of possible negative effects in epileptic patients remains unclear. Similar observations should be documented and reported.

Topics: Adolescent; Antineoplastic Agents; Astrocytoma; Epilepsies, Partial; Everolimus; Female; Humans; Seizures; Sirolimus; Status Epilepticus; Tuberous Sclerosis

Tuberous sclerosis complex (TSC) is frequently accompanied by difficult-to-treat epilepsy, which conditions these patients' quality of life and cognitive level. AIM. To describe the epidemiological and clinical characteristics, as well as the treatment of patients affected by TSC with epilepsy.. A retrospective review was carried out of the medical records of 30 patients aged under 18 registered in our database, who had been diagnosed with TSC and epilepsy.. The age at onset of epilepsy in the patients with TSC in our series ranged from one month to four years. All of them began with partial crises. Two presented West's syndrome and four others had infantile spasms without hypsarrhythmia. In 19 of the patients, the epilepsy was medication resistant. As regards treatment with antiepileptic drugs, 11 are in monotherapy, 10 in bitherapy, seven in tritherapy and one with four drugs. Two were given ACTH, two carry an implanted vagal nerve stimulator, four receive treatment with everolimus and eight have undergone surgery.. Epilepsy is a very common problem and begins in the early years of life in TSC. There are currently a large number of therapeutic options available, although 63.3% of patients have non-controlled epilepsy and most of them present crises on a daily basis. Poor control of their crises is correlated with mental retardation and autism spectrum disorder. The positive response obtained with other therapeutic possibilities, such as mTOR pathway inhibitors, surgery and vagal nerve stimulator, should be noted.. Posibilidades terapeuticas en la epilepsia refractaria en el complejo esclerosis tuberosa.. Introduccion. El complejo esclerosis tuberosa (CET) cursa frecuentemente con epilepsia de dificil control, lo que condiciona la calidad de vida y el nivel cognitivo de estos pacientes. Objetivo. Describir las caracteristicas epidemiologicas, clinicas y el tratamiento de los pacientes afectos de CET con epilepsia. Pacientes y metodos. Se han revisado retrospectivamente las historias clinicas de 30 pacientes menores de 18 años, diagnosticados de CET y epilepsia registrados en nuestra base de datos. Resultados. La edad de inicio de la epilepsia en los pacientes con CET en nuestra serie esta comprendida entre el primer mes de vida y los 4 años. Todos comenzaron con crisis parciales. Dos presentaron sindrome de West y cuatro, espasmos infantiles sin hipsarritmia. En 19 de los pacientes, la epilepsia se comporto como farmacorresistente. Respecto al tratamiento con farmacos antiepilepticos, 11 estan en monoterapia, 10 en biterapia, siete en triterapia y uno con cuatro farmacos. Dos recibieron ACTH, dos tienen implantado un estimulador del nervio vago, cuatro reciben tratamiento con everolimus y ocho han sido sometidos a cirugia. Conclusiones. La epilepsia es un problema muy frecuente y de inicio en los primeros años de vida en el CET. Las opciones terapeuticas actuales son muchas, sin embargo el 63,3% de los pacientes tiene una epilepsia no controlada y la mayoria de ellos presenta crisis diarias. El mal control de las crisis se correlaciona con retraso mental y trastorno del espectro autista. Señalar la respuesta positiva obtenida con otras posibilidades terapeuticas: inhibidores de la via mTOR, cirugia y el estimulador del nervio vago.

Topics: Adrenocorticotropic Hormone; Age of Onset; Anticonvulsants; Astrocytoma; Brain Neoplasms; Child; Child Development Disorders, Pervasive; Child, Preschool; Combined Modality Therapy; Drug Resistance; Drug Therapy, Combination; Epilepsies, Partial; Everolimus; Female; Humans; Infant; Infant, Newborn; Intellectual Disability; Male; Retrospective Studies; Sirolimus; Spasms, Infantile; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Vagus Nerve Stimulation

Focal malformations of cortical development are highly associated with intractable epilepsy in children and adults. Most patients with focal cortical malformations and epilepsy will require epilepsy surgery. Recent studies have provided new insights into the developmental pathogenesis of cortical malformations specifically relating to alterations in cell signaling though the mammalian target of rapamycin (mTOR) pathway. Focal cortical dysplasias, hemimegalencephaly, and tubers in tuberous sclerosis complex all exhibit evidence for hyperactive mTOR signaling, suggesting that these disorders form a spectrum of malformations or "TORopathies" characterized by disorganized cortical lamination, cytomegaly, and intractable seizures. Alterations in mTOR activity in focal brain malformations provide a potential pathogenic pathway to investigate for gene mutations and to exploit for animal models. Most importantly, however, if select focal cortical malformations result from enhanced mTOR signaling, new therapeutic antiepileptic compounds, such as rapamycin, can be designed and tested that specifically target mTOR signaling.

Topics: Adult; Animals; Anticonvulsants; Disease Models, Animal; Drug Design; Epilepsies, Partial; Gene Expression; Humans; Malformations of Cortical Development; Mice; Mutation; Protein Kinases; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins