sirolimus and Epilepsy

Epileptogenesis in infants with tuberous sclerosis complex (TSC) is a gradual and dynamic process, leading to early onset and difficult-to-treat seizures. Several cellular, molecular and pathophysiologic mechanisms, including mammalian target of rapamycin (mTOR) dysregulation, GABAergic dysfunction and abnormal connectivity, may play a role in this epileptogenic process and may also contribute to the associated developmental encephalopathy. Disease-specific antiseizure medications or drugs targeting the mTOR pathway have proved to be effective in TSC-associated epilepsy. Pre-symptomatic administration of vigabatrin, a GABAergic drug, delays seizure onset and reduces the risk of a subsequent epileptic encephalopathy, such as infantile spasms syndrome or Lennox-Gastaut syndrome. Everolimus, a rapamycin-derived mTOR inhibitor, reduces seizure frequency, especially in younger patients. This evidence suggests that everolimus should be considered early in the course of epilepsy. Future trials are needed to optimize the use of everolimus and determine whether earlier correction of mTOR dysregulation can prevent progression to developmental and epileptic encephalopathies or mitigate their severity in infants with TSC. Clinical trials of several other potential antiseizure drugs (cannabidiol and ganaxolone) that target contributing mechanisms are also underway. This review provides an overview of the different biological mechanisms occurring in parallel and interacting throughout the life course, even beyond the epileptogenic process, in individuals with TSC. These complexities highlight the challenges faced in preventing and treating TSC-related developmental and epileptic encephalopathy.

Topics: Anticonvulsants; Epilepsy; Everolimus; Humans; Infant; Seizures; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis

Dysregulation of the mTOR pathway is now well documented in several neurodevelopmental disorders associated with epilepsy. Mutations of mTOR pathway genes are involved in tuberous sclerosis complex (TSC) as well as in a range of cortical malformations from hemimegalencephaly (HME) to type II focal cortical dysplasia (FCD II), leading to the concept of "mTORopathies" (mTOR pathway-related malformations). This suggests that mTOR inhibitors (notably rapamycin (sirolimus), and everolimus) could be used as antiseizure medication. In this review, we provide an overview of pharmacological treatments targeting the mTOR pathway for epilepsy based on lectures from the ILAE French Chapter meeting in October 2022 in Grenoble. There is strong preclinical evidence for the antiseizure effects of mTOR inhibitors in TSC and cortical malformation mouse models. There are also open studies on the antiseizure effects of mTOR inhibitors, as well as one phase III study showing the antiseizure effect of everolimus in TSC patients. Finally, we discuss to which extent mTOR inhibitors might have properties beyond the antiseizure effect on associated neuropsychiatric comorbidities. We also discuss a new way of treatment on the mTOR pathways.

Topics: Animals; Epilepsy; Everolimus; Malformations of Cortical Development, Group I; Mice; MTOR Inhibitors; Sirolimus; TOR Serine-Threonine Kinases

Epilepsy is one of the most common and serious brain syndromes and has adverse consequences on a patient's neurobiological, cognitive, psychological, and social wellbeing, thereby threatening their quality of life. Some patients with epilepsy experience poor treatment effects due to the unclear pathophysiological mechanisms of the syndrome. Dysregulation of the mammalian target of the rapamycin (mTOR) pathway is thought to play an important role in the onset and progression of some epilepsies.. This review summarizes the role of the mTOR signaling pathway in the pathogenesis of epilepsy and the prospects for the use of mTOR inhibitors.. The mTOR pathway functions as a vital mediator in epilepsy development through diverse mechanisms, indicating that the it has great potential as an effective target for epilepsy therapy. The excessive activation of mTOR signaling pathway leads to structural changes in neurons, inhibits autophagy, exacerbates neuron damage, affects mossy fiber sprouting, enhances neuronal excitability, increases neuroinflammation, and is closely associated with tau upregulation in epilepsy. A growing number of studies have demonstrated that mTOR inhibitors exhibit significant antiepileptic effects in both clinical applications and animal models. Specifically, rapamycin, a specific inhibitor of TOR, reduces the intensity and frequency of seizures. Clinical studies in patients with tuberous sclerosis complex have shown that rapamycin has the function of reducing seizures and improving this disease. Everolimus, a chemically modified derivative of rapamycin, has been approved as an added treatment to other antiepileptic medicines. Further explorations are needed to evaluate the therapeutic efficacy and application value of mTOR inhibitors in epilepsy.. Targeting the mTOR signaling pathway provides a promising prospect for the treatment of epilepsy.

Topics: Animals; Anticonvulsants; Epilepsy; Humans; MTOR Inhibitors; Quality of Life; Seizures; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Autophagy is an explicit cellular process to deliver dissimilar cytoplasmic misfolded proteins, lipids and damaged organelles to the lysosomes for degradation and elimination. The mechanistic target of rapamycin (mTOR) is the main negative regulator of autophagy. The mTOR pathway is involved in regulating neurogenesis, synaptic plasticity, neuronal development and excitability. Exaggerated mTOR activity is associated with the development of temporal lobe epilepsy, genetic and acquired epilepsy, and experimental epilepsy. In particular, mTOR complex 1 (mTORC1) is mainly involved in epileptogenesis. The investigation of autophagy's involvement in epilepsy has recently been conducted, focusing on the critical role of rapamycin, an autophagy inducer, in reducing the severity of induced seizures in animal model studies. The induction of autophagy could be an innovative therapeutic strategy in managing epilepsy. Despite the protective role of autophagy against epileptogenesis and epilepsy, its role in status epilepticus (SE) is perplexing and might be beneficial or detrimental. Therefore, the present review aims to revise the possible role of autophagy in epilepsy.

Topics: Animals; Autophagy; Disease Models, Animal; Epilepsy; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Tuberous sclerosis complex (TSC) is a genetic multisystem disease due to the mutation in one of the two genes TSC1 and TSC2, affecting several organs and systems and carrying a significant risk of early onset and refractory seizures. The pathogenesis of this complex disorder is now well known, with most of TSC-related manifestations being a consequence of the overactivation of the mammalian Target of Rapamycin (mTOR) complex. The discovery of this underlying mechanism paved the way for the use of a class of drugs called mTOR inhibitors including rapamycin and everolimus and specifically targeting this pathway. Rapamycin has been widely used in different animal models of TSC-related epilepsy and proved to be able not only to suppress seizures but also to prevent the development of epilepsy, thus demonstrating an antiepileptogenic potential. In some models, it also showed some benefit on neuropsychiatric manifestations associated with TSC. Everolimus has recently been approved by the US Food and Drug Administration and the European Medical Agency for the treatment of refractory seizures associated with TSC starting from the age of 2 years. It demonstrated a clear benefit when compared to placebo on reducing the frequency of different seizure types and exerting a higher effect in younger children. In conclusion, mTOR cascade can be a potentially major cause of TSC-associated epilepsy and neurodevelopmental disability, and additional research should investigate if early suppression of abnormal mTOR signal with mTOR inhibitors before seizure onset can be a more efficient approach and an effective antiepileptogenic and disease-modifying strategy in infants with TSC.

Topics: Animals; Epilepsy; Everolimus; Humans; Mammals; Seizures; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis

Epilepsy is a syndrome specified by frequent seizures and is one of the most prevalent neurological conditions, and that one-third of people of epilepsy are resistant to available drugs. Surgery is supposed to be the main treatment for the remedy of multiple drug-resistant epilepsy, but it is a drastic procedure. Advancement in genomic technologies indicates that gene therapy can make such surgery unnecessary. The considerable number of new studies show the significance of mutation in mammalian target of rapamycin pathway, NMDA receptors, GABA receptors, potassium channels and G-protein coupled receptors. Illustration of the meticulous drug in epilepsy targeting new expression of mutations in SCN8A, GRIN2A, GRIN2D and KCNT1 are conferred. Various methods are utilized to express a gene in a precise area of the brain; Transplantation of cells in an ex vivo approach (fetal cells, fibroblasts, immortalized cells), nonviral vector delivery and viral vector delivery like retrovirus, herpes simplex virus adenovirus and adeno-related virus. Gene therapy has thus been explored to generate anti-epileptogenic, anti-seizure and disease-modifying effects. Specific targeting of the epileptogenic region is facilitated by gene therapy, hence sparing the adjacent healthy tissue and decreasing the adverse effects that frequently go hand in hand with antiepileptic medication.

Topics: Animals; Brain; Disease Models, Animal; Epilepsy; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Humans; Metabolic Networks and Pathways; Mutation; Precision Medicine; Seizures; Sirolimus

Prevention of epilepsy is a great unmet need. Acute central nervous system (CNS) insults such as traumatic brain injury (TBI), cerebrovascular accidents (CVA), and CNS infections account for 15%-20% of all epilepsy. Following TBI and CVA, there is a latency of days to years before epilepsy develops. This allows treatment to prevent or modify postinjury epilepsy. No such treatment exists. In animal models of acquired epilepsy, a number of medications in clinical use for diverse indications have been shown to have antiepileptogenic or disease-modifying effects, including medications with excellent side effect profiles. These include atorvastatin, ceftriaxone, losartan, isoflurane, N-acetylcysteine, and the antiseizure medications levetiracetam, brivaracetam, topiramate, gabapentin, pregabalin, vigabatrin, and eslicarbazepine acetate. In addition, there are preclinical antiepileptogenic data for anakinra, rapamycin, fingolimod, and erythropoietin, although these medications have potential for more serious side effects. However, except for vigabatrin, there have been almost no translation studies to prevent or modify epilepsy using these potentially "repurposable" medications. We may be missing an opportunity to develop preventive treatment for epilepsy by not evaluating these medications clinically. One reason for the lack of translation studies is that the preclinical data for most of these medications are disparate in terms of types of injury, models within different injury type, dosing, injury-treatment initiation latencies, treatment duration, and epilepsy outcome evaluation mode and duration. This makes it difficult to compare the relative strength of antiepileptogenic evidence across the molecules, and difficult to determine which drug(s) would be the best to evaluate clinically. Furthermore, most preclinical antiepileptogenic studies lack information needed for translation, such as dose-blood level relationship, brain target engagement, and dose-response, and many use treatment parameters that cannot be applied clinically, for example, treatment initiation before or at the time of injury and dosing higher than tolerated human equivalent dosing. Here, we review animal and human antiepileptogenic evidence for these medications. We highlight the gaps in our knowledge for each molecule that need to be filled in order to consider clinical translation, and we suggest a platform of preclinical antiepileptogenesis evaluation of potentially repurposable molecu

Topics: Acetylcysteine; Animals; Anticonvulsants; Antioxidants; Atorvastatin; Brain Injuries, Traumatic; Ceftriaxone; Dibenzazepines; Drug Repositioning; Epilepsy; Epilepsy, Post-Traumatic; Erythropoietin; Fingolimod Hydrochloride; GABA Agents; Gabapentin; Humans; Immunologic Factors; Inflammation; Interleukin 1 Receptor Antagonist Protein; Isoflurane; Levetiracetam; Losartan; Neuroprotective Agents; Oxidative Stress; Pregabalin; Pyrrolidinones; Sirolimus; Stroke; Topiramate; Translational Research, Biomedical; Vigabatrin

Tuberous sclerosis complex (TSC) is one of the most common genetic causes of epilepsy. Mutations in the TSC1 or TSC2 genes lead to the dysregulation of the mechanistic target of rapamycin (mTOR) pathway. This mTOR pathway hyperactivation is associated with several processes resulting in epileptic conditions. The occurrence of seizures and their treatment outcomes seem to play a crucial role in cognitive and behavioral developments in patients with TSC. Mechanistic target of rapamycin inhibitors have been proven to be effective in epilepsy treatment in individuals with TSC. Specifically, because of their disease-modifying mechanism of action, they have the capability to prevent epileptogenesis in patients with TSC. This article will provide an overview of the current evidence of and delineate future perspectives for mTOR inhibitors and their role in preventing epileptogenesis.

Topics: Animals; Anticonvulsants; Epilepsy; Forecasting; Humans; Sirolimus; TOR Serine-Threonine Kinases; Treatment Outcome; Tuberous Sclerosis

Between 1993 and 2003, through experiments involving Drosophila sp., cancer biologists identified the protein kinase known as the mammalian target of rapamycin, its pathway, and its relationship to the genes responsible for tuberous sclerosis. Thereafter, clinical research has resulted in regulatory approval of mTOR inhibitors for four distinct manifestations of the disease: giant cell astrocytoma, angiomyolipoma, lymphangioleiomyomatosis, and epilepsy. These developments are summarized and the practical use of mTOR inhibitors to improve the lives of patients with tuberous sclerosis reviewed.

Topics: Angiomyolipoma; Clinical Trials as Topic; Epilepsy; Humans; Lymphangiomyoma; Mucositis; Protein Kinase Inhibitors; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis

An unmet need in the treatment of epilepsy has been targeted therapies that prevent the onset or progression of seizures in the susceptible individual. We have no treatments that target the process of epileptogenesis, through which the genetically predisposed or injured brain becomes capable of generating unprovoked, recurrent seizures. Tuberous Sclerosis Complex (TSC) is a multiorgan disorder caused by a defect in the mTOR (mechanistic/mammalian target of rapamycin) pathway. Epilepsy is a prominent feature of TSC, with seizures often occurring after the diagnosis of TSC has already been made. The mTOR pathway has been studied in animal models, with evidence suggesting that downstream effectors may contribute to the mechanisms leading to seizure generation, making the mTOR pathway an attractive candidate for potentially novel and rational antiepileptogenic therapies.

Topics: Animals; Anticonvulsants; Epilepsy; Humans; Immunosuppressive Agents; Signal Transduction; Sirolimus; Tuberous Sclerosis

The role of phosphatidylinositol 3-kinase linked mammalian target of rapamycin (mTOR) pathway hyperactivation is well established in cancer pathogenesis. Several molecules inhibiting mTOR pathway, leading to inhibition of protein synthesis responsible for angiogenesis of tumor cells have emerged out to be potential anticancers. Similar hyperactivation of mTOR pathway has also reported in epilepsy during latent phase, following precipitating injury causing reorganization of neuronal networks and ultimately leading to induction of seizures. The mTOR inhibitors have also found to attenuate pathological changes in the brain associated with epilepsy, primarily suppression of mossy fiber sprouting. At the same time, a few antiepileptic molecules which have been studied against cancer showed anticancer activity, apart from their principal mechanism of action. These studies suggest mTOR signaling pathway to be a common pathogenic link between cancer and epilepsy. It has been found that, anticancer molecules acting on different molecular targets, that ultimately down regulate the expression of mTOR, can also be used in case of epilepsy to reduce its hyperactivation. There are several unexplored anticancer molecules that act by inhibiting mTOR directly or indirectly available which can be explored as antiepileptic in future. Majority of the molecules which are tested as anticancer do not reach the final phases of clinical trials due to less potency and efficacy, and ultimately a few of them reach the market. Since a lot of experimental/safety studies have already been conducted on such molecules, hence it is worthwhile to test these molecules for other disorders that share common pathogenic pathway like epilepsy, provided their pitfalls have been addressed, as proposed in the present review.

Topics: Animals; Anticonvulsants; Epilepsy; Humans; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

The mammalian/mechanistic target of rapamycin (mTOR) pathway is a key signaling pathway that has been implicated in genetic epilepsy syndromes, neurodegenerative diseases, and conditions associated with autism spectrum disorder and cognitive impairment. The mTOR pathway has become an exciting treatment target for these various disorders, with mTOR inhibitors such as rapamycin being studied for their potential therapeutic applications. In particular, tuberous sclerosis complex (TSC) is a genetic disorder resulting from overactivation of the mTOR pathway, and pharmacologic therapy with mTOR inhibitors has emerged as a viable treatment option for the systemic manifestations of the disease. In this review, we discuss the approved indications for mTOR inhibitors in TSC, the potential future applications of mTOR inhibitors in TSC and other neurological conditions, and the safety considerations applicable to mTOR therapy in the pediatric population.

Topics: Autism Spectrum Disorder; Child; Enzyme Inhibitors; Epilepsy; Humans; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis

Cortical dysplasia (CD) is a neurodevelopmental disorder due to aberrant cell proliferation and differentiation. Advances in neuroimaging have proven effective in early identification of the more severe lesions and timely surgical removal to treat epilepsy. However, the exact mechanisms of epileptogenesis are not well understood. This review examines possible mechanisms based on anatomical and electrophysiological studies. CD can be classified as CD type I consisting of architectural abnormalities, CD type II with the presence of dysmorphic cytomegalic neurons and balloon cells, and CD type III which occurs in association with other pathologies. Use of freshly resected brain tissue has allowed a better understanding of basic mechanisms of epileptogenesis and has delineated the role of abnormal cells and synaptic activity. In CD type II, it was demonstrated that balloon cells do not initiate epileptic activity, whereas dysmorphic cytomegalic and immature neurons play an important role in generation and propagation of epileptic discharges. An unexpected finding in pediatric CD was that GABA synaptic activity is not reduced, and in fact, it may facilitate the occurrence of epileptic activity. This could be because neuronal circuits display morphological and functional signs of dysmaturity. In consequence, drugs that increase GABA function may prove ineffective in pediatric CD. In contrast, drugs that counteract depolarizing actions of GABA or drugs that inhibit the mammalian target of rapamycin (mTOR) pathway could be more effective.

Topics: Animals; Brain; Epilepsy; gamma-Aminobutyric Acid; Humans; Malformations of Cortical Development, Group II; Neurons; Signal Transduction; Sirolimus

Tuberous sclerosis complex is a multiorgan disease resulting from a mutation of one of two TSC genes. The two gene products form a functional complex that regulates the mTOR signaling pathway (mTOR initially represented mammalian target of rapamycin, but increasingly the term mechanistic target of rapamycin is used to reflect the ubiquitous occurrence of mTOR). Epilepsy is the most common neurological symptom of tuberous sclerosis complex, occurring in 80% to 90% of affected individuals over the course of their lifetimes and causing significant morbidity and mortality. The mechanistic target of rapamycin (mTOR) signaling pathway is intricately involved in multiple cellular functions--including protein synthesis, cell growth and proliferation, and synaptic plasticity--which may influence neuronal excitability and precipitate epileptogenesis. Recent preclinical and clinical studies have increased interest in the potential role of mTOR inhibitors for the treatment of tuberous sclerosis complex-related epilepsy.. Medline and PubMed database searches were used to identify relevant studies and other information on tuberous sclerosis complex-related epilepsies, the mTOR pathway, and current advances in treatment approaches.. Although current management strategies that provide symptomatic relief are effective at reducing the frequency of seizures in individuals with tuberous sclerosis complex, there is further room for the exploration of therapies that directly address hyperactive mTOR signaling--the underlying etiology of the disease. The role of the antiepileptic effect of mTOR inhibition was first demonstrated in knockout TSC1 mouse models. Additionally, several case studies demonstrated a positive effect on seizure frequency and severity in patients with pharmacoresistant epilepsy. In a phase 1/2 clinical trial with 28 patients, clinically relevant reduction in overall seizure frequency was documented in individuals treated with the mTOR inhibitor everolimus. In a phase 3 trial evaluating the role of everolimus in subependymal giant cell astrocytoma, seizures were a secondary end point. Because the median seizure frequency was zero in this study, the analysis was inconclusive.. Various preclinical models provide substantial evidence for the role of mTOR inhibition in the treatment of epilepsy in individuals with tuberous sclerosis complex. Preliminary clinical studies provide supportive evidence for a role of mTOR inhibition in the management of tuberous sclerosis complex-associated epilepsy and pave the way for new randomized placebo-controlled studies. This article reviews current treatment recommendations for the management of tuberous sclerosis complex-associated epilepsy as well as the rationale and evidence to support the use of mTOR inhibitors.

Topics: Animals; Calcium-Binding Proteins; Drug Evaluation, Preclinical; Epilepsy; Humans; Immunosuppressive Agents; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis

The development of new drugs for the treatment of epilepsy is a major challenge for modern neurology and its first steps demand basic research. Preclinical studies on animal models of epilepsy are mainly based on the analysis of brain electrical activity to detect seizures, when they are not just limited to behavioral tests like the Racine scale.. In the present review, we discuss the importance of using time-locked video and EEG recordings (Video-EEG) coupled with behavioral tests as tools to monitor and analyze the effects of anti-epileptic drugs in pre-clinical research. Particularly, we focus on the utility of a multimodal approach based on EEG/behavioral analysis to study the beneficial effects of chronic rapamycin treatment as a potential anti-epileptogenic therapy for a broad spectrum of epilepsy, including both genetic (as in tuberous sclerosis complex) and acquired diseases.. Changes and synchronization of neuronal activity of different areas have been correlated with specific behavior in both physiological and pathological conditions. In the epileptic brain, during a seizure there is an abnormal activation of many cells all at once, altering different networks.. A multimodal approach based on video, EEG analysis and behavioral tests would be the best option in preclinical studies of epilepsy.

Topics: Animals; Anticonvulsants; Brain; Disease Models, Animal; Electroencephalography; Epilepsy; Humans; Outcome Assessment, Health Care; Reproducibility of Results; Sirolimus; Videotape Recording

Tuberous sclerosis complex is an autosomal dominant disease, with variable expressivity and multisystemic involvement, which is characterised by the growth of benign tumours called hamartomas. The organs that are most commonly affected are the brain, skin, kidneys, eyes, heart and lungs. Of all the children with this disease, 85% present neurological manifestations that, due to their severity, are the main cause of morbidity and mortality. The most significant neurological manifestations are epilepsy, autism spectrum disorders and mental retardation. It has been shown that in tuberous sclerosis complex the genes TSC1 and TSC2 alter the mTOR enzyme cascade, which sets off inhibition of this pathway. The possibility of resorting to treatments applied at the origin, thus inhibiting this pathway, is currently being evaluated.

Topics: Anticonvulsants; Astrocytoma; Autistic Disorder; Brain Diseases; Brain Neoplasms; Drug Design; Epilepsy; Everolimus; Glioma, Subependymal; Hamartoma; Humans; Intellectual Disability; Learning Disabilities; Molecular Targeted Therapy; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins

The mTOR signaling network functions as a pivotal regulatory cascade during the development of the cerebral cortex. Aberrant hyperactivation of mTOR as a consequence of loss-of-function gene mutations encoding mTOR inhibitor proteins such as TSC1, TSC2, PTEN and STRADα has been recently linked to developmental cortical malformations associated with epilepsy and neurobehavioral disabilities. Investigation of mTOR signaling in these disorders provides for the first time exciting future avenues for assessment of biomarkers, patient stratification and prognostic measures as well as the opportunity for targeted therapy to regulate mTOR activity across all age groups. As we learn more about mTOR and its activity in the developing brain, many challenges will arise that must be overcome before widespread clinical therapeutics can be implemented.

Topics: Adaptor Proteins, Vesicular Transport; Animals; Autistic Disorder; Biomarkers; Cerebral Cortex; Epilepsy; Humans; Malformations of Cortical Development; Mechanistic Target of Rapamycin Complex 1; Mice; Molecular Targeted Therapy; Multiprotein Complexes; Mutation; Protein Kinase Inhibitors; Proteins; PTEN Phosphohydrolase; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins

Most current treatments for epilepsy are symptomatic therapies that suppress seizures but do not affect the underlying course or prognosis of epilepsy. The need for disease-modifying or "antiepileptogenic" treatments for epilepsy is widely recognized, but no such preventive therapies have yet been established for clinical use. A rational strategy for preventing epilepsy is to target primary signaling pathways that initially trigger the numerous downstream mechanisms mediating epileptogenesis. The mammalian target of rapamycin (mTOR) pathway represents a logical candidate, because mTOR regulates multiple cellular functions that may contribute to epileptogenesis, including protein synthesis, cell growth and proliferation, and synaptic plasticity. The importance of the mTOR pathway in epileptogenesis is best illustrated by tuberous sclerosis complex (TSC), one of the most common genetic causes of epilepsy. In mouse models of TSC, mTOR inhibitors prevent the development of epilepsy and underlying brain abnormalities associated with epileptogenesis. Accumulating evidence suggests that mTOR also participates in epileptogenesis due to a variety of other causes, including focal cortical dysplasia and acquired brain injuries, such as in animal models following status epilepticus or traumatic brain injury. Therefore, mTOR inhibition may represent a potential antiepileptogenic therapy for diverse types of epilepsy, including both genetic and acquired epilepsies.

Topics: Animals; Anticonvulsants; Brain Injuries; Cell Death; Cell Division; Cell Proliferation; Disease Models, Animal; Epilepsy; Gene Expression Regulation; Humans; Intracellular Signaling Peptides and Proteins; Malformations of Cortical Development; Mice; Models, Genetic; Neuronal Plasticity; Protein Serine-Threonine Kinases; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis

Tuberous sclerosis complex (TSC) is a multiorgan genetic disease caused by mutations in the TSC1 or TSC2 genes. TSC has been recognized for many years as an important cause of severe neurological disease with patients suffering from epilepsy, developmental delay, autism, and psychiatric problems. During the last year, there have been enormous advances in basic and translational research pertaining to TSC.. In this review, I discuss the basic science findings that position the TSC1 and TSC2 genes as critical regulators of the mammalian target of rapamycin kinase within mammalian target of rapamycin complex 1. In addition, I will discuss the development of new animal models, translational data, and recent clinical trials using mammalian target of rapamycin complex 1 inhibitors such as rapamycin.. The past few years have seen spectacular advances that have energized TSC-related research and challenged existing symptomatic treatments. Although it remains to be seen whether use of mammalian target of rapamycin complex 1 inhibitors will revolutionize the care of patients with TSC, the application of basic and translational research towards a specific clinical disorder emphasizes the potential and promise of molecular medicine.

Topics: Animals; Clinical Trials as Topic; Disease Models, Animal; Epilepsy; Humans; Signal Transduction; Sirolimus; Transcription Factors; Tuberous Sclerosis

Prevention of epileptogenesis is an unmet need in medicine. During the last 3 years, however, several preclinical studies have demonstrated remarkable favorable effects of novel treatments on genetic and acquired epileptogenesis. These include the use of immunosuppressants and treatments that modify cellular adhesion, proliferation, and/or plasticity. In addition, the use of antiepileptic drugs in rats with genetic epilepsy or proconvulsants in acquired epilepsy models has provided somewhat unexpected favorable effects. This review summarizes these studies, and introduces some caveats when interpreting the data. In particular, the effect of genetic background, the severity of epileptogenic insult, the method and duration of seizure monitoring, and size of animal population are discussed. Furthermore, a novel scheme for defining epileptogenesis-related terms is presented.

Topics: Animals; Anticonvulsants; Epilepsy; Epilepsy, Post-Traumatic; Humans; Imidazoles; Immunosuppressive Agents; Piperidines; Pyrazoles; Rats; Rimonabant; Sirolimus; Status Epilepticus; Terminology as Topic

To determine whether sirolimus, a mechanistic target of rapamycin (mTOR) inhibitor, reduces epileptic seizures associated with focal cortical dysplasia (FCD) type II.. Sixteen patients (aged 6-57 years) with FCD type II received sirolimus at an initial dose of 1 or 2 mg/day based on body weight (FCDS-01). In 15 patients, the dose was adjusted to achieve target trough ranges of 5-15 ng/mL, followed by a 12-week maintenance therapy period. The primary endpoint was a lower focal seizure frequency during the maintenance therapy period. Further, we also conducted a prospective cohort study (RES-FCD) in which 60 patients with FCD type II were included as an external control group.. The focal seizure frequency reduced by 25% in all patients during the maintenance therapy period and by a median value of 17%, 28%, and 23% during the 1-4-, 5-8-, and 9-12-week periods. The response rate was 33%. The focal seizure frequency in the external control group reduced by 0.5%. However, the background characteristics of external and sirolimus-treated groups differed. Adverse events were consistent with those of mTOR inhibitors reported previously. The blood KL-6 level was elevated over time.. The reduction of focal seizures did not meet the predetermined level of statistical significance. The safety profile of the drug was tolerable. The potential for a reduction of focal seizures over time merit further investigations.

Topics: Adolescent; Adult; Child; Epilepsy; Humans; Malformations of Cortical Development, Group I; Middle Aged; Outcome Assessment, Health Care; Protein Kinase Inhibitors; Seizures; Sirolimus; TOR Serine-Threonine Kinases; Young Adult

To evaluate the efficacy and side effects of oral mammalian target of rapamycin (mTOR) inhibitors in children and adolescents with tuberous sclerosis complex (TSC) and intractable epilepsy or subependymal giant cell astrocytoma (SEGA).. Single-center series of 13 children and adolescents with TSC who received sirolimus or everolimus (mTOR inhibitors). The anticonvulsant response was evaluated in 7 patients with TSC and refractory seizures. Six patients with SEGAs were treated with either sirolimus or everolimus for nonsurgical management. SEGA volumes were assessed longitudinally using 1.5-T magnetic resonance imaging.. Of the intractable seizure group (7 patients), 1 patient had >90% reduction, 4 had 50%-90% reduction, and 2 had <50% reduction. Three reported subjective improvements in learning. By 12 months of treatment, there were statistically significant reductions in the SEGA volumes in 4 patients who received mTOR inhibitors (P < .04). The mean SEGA volume after 6 months of treatment was 2.18 cm(3), which represents 33% reduction in the mean baseline volume of 3.26 cm(3). The mTOR inhibitors were well tolerated. Adverse effects include dyslipidaemia (3 of 13), gingivitis (1 of 13), anorexia (1 of 13), and mild gastrointestinal side effects (1 of 13).. This case series suggests that mTOR inhibitors can improve seizures in those with TSC and refractory epilepsy. They are also an effective treatment for reducing the volume of SEGAs in patients with TSC not amenable to surgery with an acceptable side effect profile.

Topics: Adolescent; Anticonvulsants; Antineoplastic Agents; Astrocytoma; Child; Child, Preschool; Epilepsy; Everolimus; Female; Humans; Male; Prospective Studies; Sirolimus; TOR Serine-Threonine Kinases; Treatment Outcome; Tuberous Sclerosis

Epilepsy is a major manifestation of tuberous sclerosis complex (TSC). Everolimus is an mammalian target of rapamycin complex 1 inhibitor with demonstrated benefit in several aspects of TSC. We report the first prospective human clinical trial to directly assess whether everolimus will also benefit epilepsy in TSC patients.. The effect of everolimus on seizure control was assessed using a prospective, multicenter, open-label, phase I/II clinical trial. Patients≥2 years of age with confirmed diagnosis of TSC and medically refractory epilepsy were treated for a total of 12 weeks. The primary endpoint was percentage of patients with a ≥50% reduction in seizure frequency over a 4-week period before and after treatment. Secondary endpoints assessed impact on electroencephalography (EEG), behavior, and quality of life.. Twenty-three patients were enrolled, and 20 patients were treated with everolimus. Seizure frequency was reduced by ≥50% in 12 of 20 subjects. Overall, seizures were reduced in 17 of the 20 by a median reduction of 73% (p<0.001). Seizure frequency was also reduced during 23-hour EEG monitoring (p=0.007). Significant reductions in seizure duration and improvement in parent-reported behavior and quality of life were also observed. There were 83 reported adverse events that were thought to be treatment-related, all of which were mild or moderate in severity.. Seizure control improved in the majority of TSC patients with medically refractory epilepsy following treatment with everolimus. Everolimus demonstrated additional benefits on behavior and quality of life. Treatment was safe and well tolerated. Everolimus may be a therapeutic option for refractory epilepsy in this population.

Topics: Adolescent; Anticonvulsants; Brain; Child; Child, Preschool; Electroencephalography; Epilepsy; Everolimus; Female; Humans; Male; Quality of Life; Sirolimus; Treatment Outcome; Tuberous Sclerosis; Young Adult

Hyperactivation of the mechanistic target of rapamycin (mTOR) signaling pathway is linked to more than a dozen neurologic diseases, causing a range of pathologies, including excess neuronal growth, disrupted neuronal migration, cortical dysplasia, epilepsy and autism. The mTOR pathway also regulates angiogenesis. For the present study, therefore, we queried whether loss of

Topics: Animals; Epilepsy; Mice; Neurons; Prosencephalon; PTEN Phosphohydrolase; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

The efficacy of the mechanistic target of rapamycin inhibitor, sirolimus, was recently reported for patients more than 6 years of age by Kato et al. We evaluated the efficacy and safety of sirolimus in a 2-year-old patient with recurrent focal seizures with impaired consciousness after focal cortical dysplasia (FCD) type IIa resection.. The patient was a 2-year-old girl who had recurrent seizures after undergoing FCD resection at 4 months of age. The initial dose of sirolimus was 0.5 mg/day and was gradually increased using the trough blood concentration before oral administration as an index, and evaluation was performed at 92 weeks.. The trough blood level of sirolimus was increased to 6.1 ng/mL and maintenance therapy was started at 40 weeks. Focal seizures with impairment of consciousness with tonic extension of the limbs decreased. No critically serious adverse events occurred.. Sirolimus was effective against epileptic seizures from FCD type II even for a child under 5 years of age. There were no critically serious adverse events and administration could be continued.

Topics: Child; Child, Preschool; Epilepsy; Epilepsy, Generalized; Female; Focal Cortical Dysplasia; Humans; Magnetic Resonance Imaging; Malformations of Cortical Development; Seizures; Sirolimus

Epilepsy can seriously affect children's cognitive and behavioral development. The mechanistic target of rapamycin(mTOR) pathway plays an important role in neurodevelopment and epilepsy, but the mechanism of mechanistic target of rapamycin complex 2 (mTORC2) in epilepsy is still unclear. Here, we compared the similarities and differences of the mechanisms of action of mechanistic target of rapamycin complex 1 (mTORC1) and mTORC2 complex in the pathogenesis of epilepsy. Our research results show that the levels of apoptosis in cortical and hippocampal neurons were upregulated in epileptic rats (F = 32.15, 30.96; both P < 0.01), and epilepsy caused neuronal damage (F = 8.13, 9.43; both P < 0.01). The mTORC2-Akt pathway was activated in the cortex and hippocampus of epileptic rats. Inhibition of mTORC2 resulted in decreased levels of apoptosis and reduced neuronal damage in the cortex and hippocampus of epileptic rats. In the hippocampus, selective inhibition of mTORC2 increased lysosome-associated membrane protein 2 A (LAMP2A) protein expression compared with the control group, and the difference was statistically significant (F = 3.02, P < 0.05). Finally, we concluded that in the hippocampus, selective inhibition of mTORC2 can improve epileptic brain injury in rats by increasing chaperone-mediated autophagy (CMA) levels.

Topics: Animals; Autophagy; Brain Injuries; Chaperone-Mediated Autophagy; Epilepsy; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Rats; Sirolimus

The mechanistic target of rapamycin (mTOR) pathway is a signaling system integral to neural growth and migration. In both patients and rodent models, mutations to the phosphatase and tensin homolog gene (PTEN) on chromosome 10 results in hyperactivation of the mTOR pathway, as well as seizures, intellectual disabilities and autistic behaviors. Rapamycin, an inhibitor of mTOR, can reverse the epileptic phenotype of neural subset specific Pten knockout (NS-Pten KO) mice, but its impact on behavior is not known. To determine the behavioral effects of rapamycin, male and female NS-Pten KO and wildtype (WT) mice were assigned as controls or administered 10 mg/kg of rapamycin for 2 weeks followed by behavioral testing. Rapamycin improved social behavior in both genotypes and stereotypic behaviors in NS-Pten KO mice. Rapamycin treatment resulted in a reduction of several measures of activity in the open field test in both genotypes. Rapamycin did not reverse the reduced anxiety behavior in KO mice. These data show the potential clinical use of mTOR inhibitors by showing its administration can reduce the production of autistic-like behaviors in NS-Pten KO mice.

Topics: Animals; Epilepsy; Female; Male; Mice; Neurons; PTEN Phosphohydrolase; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Sudden Unexpected Death in Epilepsy (SUDEP) is primarily linked with the cardiac irregularities that occur due to recurrent seizures. Our previous studies found a role of mTOR pathway activation in seizures-linked cardiac damage in a rat model. In continuation to the earlier work, the present study was devised to explore the role of rapamycin (mTOR inhibitor and clinically used immunosuppressive agent) in a zebrafish kindling model and associated cardiac damage. Adult zebrafish were incubated with increasing concentrations of rapamycin (1, 2 and, 4 μM), followed by pentylenetetrazole (PTZ) exposure to record seizure latency and severity. In another experiment, zebrafish were subjected to a standardized PTZ kindling protocol. The kindled fish were treated daily with rapamycin for up to 25 days, along with PTZ to record seizure severity. At the end, zebrafish heart was excised for carbonylation assay, gene expression, and protein quantification studies. In the acute PTZ convulsion test, treatment with rapamycin showed a significant increase in seizure latency and decreased seizure severity without any change in seizure incidence. Treatment with rapamycin also reduced the severity of seizures in kindled fish. The cardiac expressions of gpx, nppb, kcnh2, scn5a, mapk8, stat3, rps6 and ddit were decreased, whereas the levels of trxr2 and beclin 1 were increased following rapamycin treatment in kindled fish. Furthermore, rapamycin treatment also decreased p-mTOR expression and protein carbonyls level in the fish cardiac tissue. The present study concluded that rapamycin reduces seizures and associated cardiac damage by inhibiting mTOR activation in the zebrafish kindling model.

Topics: Animals; Epilepsy; Mammals; Rats; Seizures; Sirolimus; TOR Serine-Threonine Kinases; Zebrafish

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

Sirolimus is confirmed to be effective in the treatment of tuberous sclerosis complex (TSC) and related disorders. The study aims to establish a population pharmacokinetic model of oral sirolimus for children with TSC and provide an evidence-based approach for individualization of sirolimus dosing in the pediatric population. A total of 64 children were recruited in this multicenter, retrospective pharmacokinetic study. Whole-blood concentrations of sirolimus, demographic, and clinical information were collected and analyzed using a nonlinear mixed-effects population modeling method. The final model was internally and externally validated. Then Monte Carlo simulations were performed to evaluate and optimize the dosing regimens. In addition, the efficacy and safety of sirolimus therapy was assessed retrospectively in patients with epilepsy or cardiac rhabdomyomas associated with TSC. Finally, the sirolimus pharmacokinetic profile was described by a 1-compartment model with first-order absorption and elimination along with body weight and total daily dose as significant covariates. The typical population parameter estimates of apparent volume of distribution and apparent clearance were 69.48 L and 2.79 L/h, respectively. Simulations demonstrated that dosage regimens stratified by body surface area may be more appropriate for children with TSC. These findings could be used to inform individualized dosing strategies of sirolimus for pediatric patients with TSC.

Topics: Child; Epilepsy; Humans; Monte Carlo Method; Retrospective Studies; Sirolimus; Tuberous Sclerosis

Mutations in nitrogen permease regulator-like 3 (NPRL3), a component of the GATOR1 complex within the mTOR pathway, are associated with epilepsy and malformations of cortical development. Little is known about the effects of NPRL3 loss on neuronal mTOR signalling and morphology, or cerebral cortical development and seizure susceptibility. We report the clinical phenotypic spectrum of a founder NPRL3 pedigree (c.349delG, p.Glu117LysFS; n = 133) among Old Order Mennonites dating to 1727. Next, as a strategy to define the role of NPRL3 in cortical development, CRISPR/Cas9 Nprl3 knockout in Neuro2a cells in vitro and in foetal mouse brain in vivo was used to assess the effects of Nprl3 knockout on mTOR activation, subcellular mTOR localization, nutrient signalling, cell morphology and aggregation, cerebral cortical cytoarchitecture and network integrity. The NPRL3 pedigree exhibited an epilepsy penetrance of 28% and heterogeneous clinical phenotypes with a range of epilepsy semiologies, i.e. focal or generalized onset, brain imaging abnormalities, i.e. polymicrogyria, focal cortical dysplasia or normal imaging, and EEG findings, e.g. focal, multi-focal or generalized spikes, focal or generalized slowing. Whole exome analysis comparing a seizure-free group (n = 37) to those with epilepsy (n = 24) to search for gene modifiers for epilepsy did not identify a unique genetic modifier that explained the variability in seizure penetrance in this cohort. Nprl3 knockout in vitro caused mTOR pathway hyperactivation, cell soma enlargement and the formation of cellular aggregates seen in time-lapse videos that were prevented with the mTOR inhibitors rapamycin or torin1. In Nprl3 knockout cells, mTOR remained localized on the lysosome in a constitutively active conformation, as evidenced by phosphorylation of ribosomal S6 and 4E-BP1 proteins, even under nutrient starvation (amino acid-free) conditions, demonstrating that Nprl3 loss decouples mTOR activation from neuronal metabolic state. To model human malformations of cortical development associated with NPRL3 variants, we created a focal Nprl3 knockout in foetal mouse cortex by in utero electroporation and found altered cortical lamination and white matter heterotopic neurons, effects which were prevented with rapamycin treatment. EEG recordings showed network hyperexcitability and reduced seizure threshold to pentylenetetrazol treatment. NPRL3 variants are linked to a highly variable clinical phenotype which we propose

Topics: Animals; Epilepsy; GTPase-Activating Proteins; Humans; Malformations of Cortical Development; Mice; Neurons; Seizures; Sirolimus; TOR Serine-Threonine Kinases

To evaluate whether sirolimus treatment could relieve the later burden of new-onset seizures in patients with tuberous sclerosis complex (TSC) prior to epilepsy.. A real-world matched case-control study was nested in another registry cohort study. Infants with TSC (<12 months old) without seizures whose parents agreed on sirolimus treatment for other symptoms were eligible for inclusion to the early sirolimus (ES) group. These patients were enrolled from 2015 to 2018. Controls in the late sirolimus (LS) group were matched from the registry cohort database for 2015-2018. Age and genotype were used as the initial stratifying criteria and other symptoms as the greedy matching criteria at a matching ratio of 1:4. None of the preventive drugs were introduced before seizure onset or before 2 years of age in the LS group. Both groups were followed up until June 2020. The primary objective was a comparison of the characteristics of the first seizure between the two groups. The secondary objective was the assessment of the final seizure status at the endpoint.. There were 42 and 168 patients with TSC in the ES and LS groups, respectively. Early sirolimus treatment significantly reduced the seizure onset, especially in the patients aged <6 months. The mean onset-age was significantly delayed by sirolimus treatment (11.34±7.93 months vs. 6.94±6.03 months, P<0.001). The subtype of seizures that benefited the most was spastic (onset) seizures (all were infantile spasms) [5/42 (11.90%) vs. 73/168 (43.45%), P<0.001]; these seizures were either eliminated or alleviated. The sirolimus treatment addition prior to seizures was more effective than its addition after seizures in reducing drug-resistant epilepsy [10/42 (23.81%) vs. 70/147 (47.62%), P=0.004].. Early sirolimus treatment for TSC effectively modified the disease by preventing infantile spasms, delaying seizure onset, and relieving its severity. The anti-epileptogenic effect of sirolimus may be time- and dose-dependent.

Topics: Case-Control Studies; Child, Preschool; Cohort Studies; Epilepsy; Humans; Infant; Registries; Seizures; Sirolimus; Spasms, Infantile; Tuberous Sclerosis

To assess the safety of inactivated coronavirus 2019 disease (COVID-19) vaccine in tuberous sclerosis complex (TSC) patients with epilepsy.. All patients with epilepsy were selected from Efficacy and Safety of Sirolimus in Pediatric Patients with Tuberous Sclerosis (ESOSPIT) project and younger than 17 years old. The patients were treated with mTOR inhibitors (rapamycin). A total of 44 patients who completed the two-dose inactivated COVID-19 vaccine between July 7, 2021, and January 1, 2022, were enrolled.. The median age of seizure onset was 23 months. About two-thirds of patients have focal seizures. Thirty-three patients use antiseizure medications. The mean duration of rapamycin treatment was 55.59 ± 18.42 months. Adverse reactions within 28 days after injection occurred in 11 patients (25%), all were under 12 years old. Injection site pain was the most reported event (20.45%), which was mild in severity and improved within one day. All patients had no seizure-related changes after vaccination.. This study shows that the inactivated COVID-19 vaccine was well tolerated and safe in TSC patients with epilepsy, as well as for those treated with mTOR inhibitors.

Topics: Adolescent; Child; Child, Preschool; COVID-19; COVID-19 Vaccines; Epilepsy; Humans; Infant; MTOR Inhibitors; Seizures; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis

To assess whether prenatal diagnosis and early intervention are beneficial for developmental outcomes and epilepsy prognosis in individuals with tuberous sclerosis complex (TSC).. This retrospective study originated from a single-centre TSC-specific cohort. We enrolled 273 individuals (138 males, 145 females; 2 years-7 years 6 months, mean 4 years 5 months, SD 1 year 6 months) with definitive TSC who completed TSC1/TSC2 genetic testing and were followed up to 2 years of age. The benefits of early attention and intervention were assessed by comparing epilepsy and developmental outcomes between groups with or without a prenatal diagnosis and with or without presymptomatic preventive intervention.. The epilepsy occurrence rate was significantly lower in individuals diagnosed prenatally than in individuals diagnosed postnatally (p = 0.027). In individuals diagnosed prenatally, the epilepsy rate in the preventive intervention subgroup was significantly lower than that in the subgroup without preventive intervention (p = 0.008). Significant improvements in cognitive, language, and motor development were observed in individuals diagnosed prenatally compared to individuals diagnosed postnatally and in the preventive intervention subgroup compared to the subgroup without preventive intervention (p < 0.05).. Based on this study, we cautiously speculate that early postpartum intervention may reduce the incidence of epilepsy and intractable epilepsy and improve developmental outcomes. Prophylactic intervention with sirolimus and vigabatrin may reduce the incidence of epilepsy. Larger prospective randomized controlled studies are required to support these findings.. Prenatal diagnosis and early intervention may improve developmental outcomes in children with tuberous sclerosis complex (TSC). Prophylactic intervention with sirolimus and vigabatrin may reduce the incidence of epilepsy. Cardiac and/or intracranial lesions combined with genetic testing can be used to diagnose TSC prenatally.

Topics: Child; Epilepsy; Female; Humans; Male; Pregnancy; Prenatal Diagnosis; Prognosis; Prospective Studies; Retrospective Studies; Sirolimus; Tuberous Sclerosis; Vigabatrin

Tuberous sclerosis complex (TSC) is a genetic disorder involving a variety of physical manifestations, and is associated with epilepsy and multiple serious neuropsychiatric symptoms. These symptoms are collectively known as TSC-associated neuropsychiatric disorders (TAND), which is a severe burden for patients and their families. Overactivation of the mechanistic target of rapamycin complex 1 (mTORC1) by mutations in TSC1 or TSC2 is thought to cause TSC, and mTORC1 inhibitors such as sirolimus and everolimus are reported to be effective against various tumor types of TSC. However, there are various reports on the effect of mTORC1 inhibitor therapy on TAND in patients with TSC, which may or may not be effective. In our previous investigations, we generated TSC2 conditional knockout mice (Mitf-Cre, Tsc2 KO; Tsc2 cKO). These mice developed spontaneous epileptic activity. In the current study, we further analyzed the detailed behaviors of Tsc2 cKO mice and confirmed that they exhibited phenotypes of TAND as well as epileptic seizures, indicating that Tsc2 cKO mice are a useful model for TAND. Furthermore, the olfactory bulb and piriform cortex caused epilepsy and TAND in Tsc2 cKO mice, and neurodegeneration was observed. Immunohistology and immunophenotypic analysis of cells, and quantitative RT-PCR suggested that changes in microglial polarity were involved in the onset of TSC epilepsy and neuropsychiatric symptoms. Although the effect of mTORC1 inhibitors on TAND has not been established, the results of this study might help elucidate the mechanism of TAND pathogenesis and suggest that sirolimus may be a valuable therapeutic tool for TAND.

Topics: Animals; Epilepsy; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Knockout; Microglia; Seizures; Sirolimus; Tuberous Sclerosis

In previous studies, we found that dynorphin exerts antiepileptic effect by activating the kappa opioid receptor (KOR). However, the role of neuronal autophagy in dynorphin/KOR-mediated antiepileptic is still unclear. This study aimed to investigate the molecular mechanism of dynorphin's antiepileptic effect by inhibiting autophagy and reducing neuronal apoptosis. Here, a pilocarpine-induced rat model of epilepsy was established and hippocampal neurons were treated with Mg

Topics: Animals; Anticonvulsants; Apoptosis; Autophagy; Biotin; Dynorphins; Epilepsy; Green Fluorescent Proteins; Mammals; Pilocarpine; Rats; Rats, Sprague-Dawley; Receptors, Opioid, kappa; RNA, Messenger; Seizures; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Hemimegalencephaly (HME) is a rare hamartomatous congenital malformation of the brain characterized by dysplastic overgrowth of either one of the cerebral hemispheres. HME is associated with early onset seizures, abnormal neurological findings, and with subsequent cognitive and behavioral disabilities. Seizures associated with HME are often refractory to antiepileptic medications. Hemispherectomy is usually necessary to provide effective seizure control. The exact etiology of HME is not fully understood, but involves a disturbance in early brain development and likely involves genes responsible for patterning and symmetry of the brain. We present a female newborn who had refractory seizures due to HME. Whole genome sequencing revealed a novel, likely pathogenic, maternally inherited, 3Kb deletion encompassing exon 5 of the NPRL3 gene (chr16:161898-164745x1). The NPRL3 gene encodes for a nitrogen permease regulator 3-like protein, a subunit of the GATOR complex, which regulates the mTOR signaling pathway. A trial of mTOR inhibitor drug, Sirolimus, did not improve her seizure control. Functional hemispherectomy at 3 months of age resulted in total abatement of clinical seizures.

Topics: Brain; Epilepsy; Female; Genetic Predisposition to Disease; GTPase-Activating Proteins; Hemimegalencephaly; Humans; Infant, Newborn; Seizures; Sirolimus; TOR Serine-Threonine Kinases

Epilepsy is one of the most common neurological disorders, with individuals having an increased susceptibility of seizures in the first few years of life, making children at risk of developing a multitude of cognitive and behavioral comorbidities throughout development. The present study examined the role of PI3K/Akt/mTOR pathway activity and neuroinflammatory signaling in the development of autistic-like behavior following seizures in the neonatal period. Male and female C57BL/6J mice were administered 3 flurothyl seizures on postnatal (PD) 10, followed by administration of minocycline, the mTOR inhibitor rapamycin, or a combined treatment of both therapeutics. On PD12, isolation-induced ultrasonic vocalizations (USVs) of mice were examined to determine the impact of seizures and treatment on communicative behaviors, a component of the autistic-like phenotype. Seizures on PD10 increased the quantity of USVs in female mice and reduced the amount of complex call types emitted in males compared to controls. Inhibition of mTOR with rapamycin significantly reduced the quantity and duration of USVs in both sexes. Changes in USVs were associated with increases in mTOR and astrocyte levels in male mice, however, three PD10 seizures did not result in enhanced proinflammatory cytokine expression in either sex. Beyond inhibition of mTOR activity by rapamycin, both therapeutics did not demonstrate beneficial effects. These findings emphasize the importance of differences that may exist across preclinical seizure models, as three flurothyl seizures did not induce as drastic of changes in mTOR activity or inflammation as observed in other rodent models.

Topics: Animals; Convulsants; Disease Models, Animal; Epilepsy; Female; Flurothyl; Immunologic Factors; Male; Mice; Mice, Inbred C57BL; Minocycline; MTOR Inhibitors; Seizures; Sex Factors; Sirolimus; Vocalization, Animal

Epileptic seizures are core symptoms in focal cortical dysplasia (FCD), a disease that often develops in infancy. Such seizures are refractory to conventional antiepileptic drugs (AED) and temporarily disappear in response to AED in only 17% of patients. Currently, surgical resection is an important option for the treatment of epileptic seizures in FCD. In 2015, Korean and Japanese groups independently reported that FCD is caused by somatic mosaic mutation of the MTOR gene in the brain tissue. Based on these results we decided to test a novel treatment using sirolimus, an mTOR inhibitor, for epileptic seizures in patients with FCD type II. A single arm open-label clinical trial for FCD type II patients is being conducted in order to evaluate the efficacy and safety of sirolimus. The dose of sirolimus is fixed for the first 4 weeks and dose adjustment is achieved to maintain a blood level of 5 to 15 ng/mL during 8 to 24 weeks after initiation of administration, and it is kept within this level during a maintenance therapy period of 12 weeks. Primary endpoint is a reduction in the rate of incidence of focal seizures (including focal to bilateral tonic-clonic seizures) per 28 days during the maintenance therapy period from the observation period. To evaluate the frequency of epileptic seizures, registry data will be used as an external control group. We hope that the results of this trial will lead to future innovative treatments for FCD type II patients.

Topics: Clinical Trials as Topic; Epilepsy; Humans; Malformations of Cortical Development; Malformations of Cortical Development, Group I; Seizures; Sirolimus; TOR Serine-Threonine Kinases

Infantile spasms may evolve into persistent epilepsies including Lennox-Gastaut syndrome. We compared adult epilepsy outcomes in models of infantile spasms due to structural etiology (multiple-hit model) or focal cortical inflammation and determined the anti-epileptogenic effects of pulse-rapamycin, previously shown to stop spasms in multiple-hit rats.. Spasms were induced in 3-day-old male rats via right intracerebral doxorubicin/lipopolysaccharide (multiple-hit model) infusions. Controls and sham rats were used. Separate multiple-hit rats received pulse-rapamycin or vehicle intraperitoneally between postnatal days 4 and 6. In adult mice, video-EEG (electroencephalography) scoring for seizures and sleep and histology were done blinded to treatment.. Motor-type seizures developed in 66.7% of multiple-hit rats, usually from sleep, but were reduced in the pulse-rapamycin-treated group (20%, p = .043 vs multiple-hit) and rare in other groups (0-9.1%, p < .05 vs multiple-hit). Spike-and-wave bursts had a slower frequency in multiple-hit rats (5.4-5.8Hz) than in the other groups (7.6-8.3Hz) (p < .05); pulse rapamycin had no effect on the hourly spike-and-wave burst rates in adulthood. Rapamycin, however, reduced the time spent in slow-wave-sleep (17.2%), which was increased in multiple-hit rats (71.6%, p = .003). Sham rats spent more time in wakefulness (43.7%) compared to controls (30.6%, p = .043). Multiple-hit rats, with or without rapamycin treatment, had right more than left corticohippocampal, basal ganglia lesions. There was no macroscopic pathology in the other groups.. Structural corticohippocampal/basal ganglia lesions increase the risk for post-infantile spasms epilepsy, Lennox-Gastaut syndrome features, and sleep dysregulation. Pulse rapamycin treatment for infantile spasms has anti-epileptogenic effects, despite the structural lesions, and decreases the time spent in slow wave sleep.

Topics: Animals; Disease Models, Animal; Electroencephalography; Epilepsy; Lennox Gastaut Syndrome; Male; Mice; Rats; Seizures; Sirolimus; Spasm

Topics: Cognition; Epilepsy; Humans; Intellectual Disability; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis

To clarify the complex mechanism underlying epileptogeneis, a novel animal model was generated.. In our previous research, we have generated a melanocyte-lineage mTOR hyperactivation mouse model (Mitf-M-Cre Tsc2 KO mice; cKO mice) to investigate mTOR pathway in melanogenesis regulation, markedly reduced skin pigmentation was observed. Very unexpectedly, spontaneous recurrent epilepsy was also developed in this mouse model.. Compared with control littermates, no change was found in either brain size or brain mass in cKO mice. Hematoxylin staining revealed no obvious aberrant histologic features in the whole brains of cKO mice. Histoimmunofluorescence staining and electron microscopy examination revealed markedly increased mTOR signaling and hyperproliferation of mitochondria in cKO mice, especially in the hippocampus. Furthermore, rapamycin treatment reversed these abnormalities.. This study suggests that our melanocyte-lineage mTOR hyperactivation mouse is a novel animal model of epilepsy, which may promote the progress of both epilepsy and neurophysiology research.

Topics: Animals; Brain; Cells, Cultured; Disease Models, Animal; Electroencephalography; Epilepsy; Hippocampus; Melanocytes; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitochondria; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis Complex 2 Protein

This study aimed to analyze the therapeutic effect of sirolimus on seizures in pediatric patients with tuberous sclerosis.. We first compared the efficacy of controlling seizures in all patients after they had taken sirolimus for one year, and then we performed a subgroup analysis based on whether the administered antiepileptic drugs were changed to determine whether the efficacy was associated with changes of antiepileptic drugs.. A total of 91 eligible children were enrolled. The response rate was 78.0 % (71/91), and 47.2 % (43/91) of all patients were became seizure-free. The improvement in seizure control before and after treatment with sirolimus was significant (p < 0.001). In the AEDs unaltered group, 34 were responders (34/45, 75.6 %, 95 % CI 17.4-88.3), of which 24 were seizure-free (24/34, 70.6 %). In the AEDs-altered group, 37 were responders (37/46, 80.4 %, 95 % CI 56.7-88.1), of which 19 were seizure-free (19/37, 51.4 %). There was no significant difference between the two groups for reductions in rate of seizure frequency (p = 0.308). In the patients with refractory epilepsy, treatment with sirolimus was also effective (p = 0.01). Logistic regression analysis showed that age was an important factor affecting outcome of epilepsy (p = 0.003, 95 % CI 2.05-38.31). No Grade 3 or 4 adverse events were noted during the follow-up.. Sirolimus has a significant effect on seizures associated with tuberous sclerosis complex (TSC), with no or only moderate adverse events after long-term administration. Sirolimus could be used as the first-line medication for pediatric patients with TSC-associated epilepsy.

Topics: Adolescent; Anticonvulsants; Child; Child, Preschool; Epilepsy; Female; Humans; Infant; Male; Outcome Assessment, Health Care; Prospective Studies; Protein Kinase Inhibitors; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis

DEPDC5 is now recognized as one of the genes most often implicated in familial/inherited focal epilepsy and brain malformations. Individuals with pathogenic variants in DEPDC5 are at risk for epilepsy, associated neuropsychiatric comorbidities and sudden unexplained death in epilepsy. Depdc5flox/flox-Syn1Cre (Depdc5cc+) neuronal-specific Depdc5 knockout mice exhibit seizures and neuronal mTORC1 hyperactivation. It is not known if Depdc5cc+ mice have a hyperactivity/anxiety phenotype, die early from terminal seizures or whether mTOR inhibitors rescue DEPDC5-related seizures and associated comorbidities. Herein, we report that Depdc5cc+ mice were hyperactive in open-field testing but did not display anxiety-like behaviors on the elevated-plus maze. Unlike many other mTOR-related models, Depdc5cc+ mice had minimal epileptiform activity and rare seizures prior to seizure-induced death, as confirmed by video-EEG monitoring. Treatment with the mTORC1 inhibitor rapamycin starting after 3 weeks of age significantly prolonged the survival of Depdc5cc+ mice and partially rescued the behavioral hyperactivity. Rapamycin decreased the enlarged brain size of Depdc5cc+ mice with corresponding decrease in neuronal soma size. Loss of Depdc5 led to a decrease in the other GATOR1 protein levels (NPRL2 and NPRL3). Rapamycin failed to rescue GATOR1 protein levels but rather rescued downstream mTORC1 hyperactivity as measured by phosphorylation of S6. Collectively, our data provide the first evidence of behavioral alterations in mice with Depdc5 loss and support mTOR inhibition as a rational therapeutic strategy for DEPDC5-related epilepsy in humans.

Topics: Animals; Disease Models, Animal; Electroencephalography; Epilepsy; Fluorescent Antibody Technique; Genes, Lethal; Genetic Association Studies; Genetic Predisposition to Disease; Genotype; GTPase-Activating Proteins; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Knockout; Neurons; Phenotype; Signal Transduction; Sirolimus

An epilepsy mouse model for Tuberous Sclerosis Complex (TSC) was developed and validated to investigate the mechanisms underlying epileptogenesis. Furthermore, the possible antiepileptogenic properties of commonly used antiepileptic drugs (AEDs) and new compounds were assessed.. Tsc1 deletion was induced in CAMK2A-expressing neurons of adult mice. The antiepileptogenic properties of commonly used AEDs and inhibitors of the mTOR pathways were assessed by EEG recordings and by molecular read outs.. Mice developed epilepsy in a narrow time window (10 ± 2 days) upon Tsc1 gene deletion. Seizure frequency but not duration increased over time. Seizures were lethal within 18 days, were unpredictable, and did not correlate to seizure onset, length or frequency, reminiscent of sudden unexpected death in epilepsy (SUDEP). Tsc1 gene deletion resulted in a strong activation of the mTORC1 pathway, and both epileptogenesis and lethality could be entirely prevented by RHEB1 gene deletion or rapamycin treatment. However, other inhibitors of the mTOR pathway such as AZD8055 and PF4708671 were ineffective. Except for ketogenic diet, none of commonly used AEDs showed an effect on mTORC1 activity. Vigabatrin and ketogenic diet treatment were able to significantly delay seizure onset. In contrast, survival was shortened by lamotrigine.. This novel Tsc1 mouse model is highly suitable to assess the efficacy of antiepileptic and -epileptogenic drugs to treat mTORC1-dependent epilepsy. Additionally, it allows us to study the mechanisms underlying mTORC1-mediated epileptogenesis and SUDEP. We found that early treatment with vigabatrin was not able to prevent epilepsy, but significantly delayed seizure onset.

Topics: Animals; Anticonvulsants; Brain; Diet, Ketogenic; Epilepsy; Female; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Inbred C57BL; Mice, Knockout; Morpholines; Ras Homolog Enriched in Brain Protein; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tumor Suppressor Proteins; Vigabatrin

Autophagy alterations have been observed in a variety of neurological disorders, however, very few studies have focused on autophagy alterations in epilepsy. The ketogenic diet (KD) likely ameliorates neuronal loss in several seizure models. However, whether this neuroprotective function occurs via starvation-induced autophagy and its prevalence in chronic kindled seizures remains unknown. The aim of this study was to determine the role of autophagy following seizure under KD, and the potential mechanism involved. Pentylenetetrazol (PTZ)-kindled rats, which were fed a Normal diet (ND) or KD, were pretreated with intraventricular infusions of saline, autophagy inducer rapamycin (RAP), or inhibitor 3-methyladenine (3-MA). KD alleviated seizure severity, decreased the number of Fluoro-jade B (FJB)-positive cells in the hippocampus of kindled rats. These effects were abolished by 3-MA pretreatment. RAP pretreatment did not affect seizure severity, but decreased the number of FJB-positive cells in ND group. KD decreased the percentage of damaged mitochondria in kindled group. Hippocampal Beclin-1 was increased by KD in vehicle group. The autophagy proteins Atg5, Beclin-1 and the ratio of microtubule-associated protein 1 light chain 3 (LC3) II to LC3-I in kindled KD-fed rats were higher, and the autophagy substrate P62 was lower than those in the kindled ND-fed rats, indicating an increase in autophagy following KD. Pretreatment with RAP increased the level of LC3-II/LC3-I, and pretreatment with 3-MA increased the level of P62 in KD-fed rats. To further clarify the mechanism of autophagy protection, the levels of key mitochondria related molecules were examed. The results showed that mitochondrial cytochrome c was up-regulated, cytosolic cytochrome c and the downstream cleaved caspase-3 was down-regulated in KD-fed rats, indicating a decrease in mitochondrial apoptosis. Taken together, our results indicated that KD activates autophagic pathways and reduces brain injury during PTZ-kindled seizures. The neuroprotective effect of KD is likely exerted via a reduction of mitochondrial cytochrome c release.

Topics: Adenine; Animals; Apoptosis; Autophagy; Caspase 3; Cytochromes c; Diet, Ketogenic; Epilepsy; Hippocampus; Male; Mitochondria; Neurons; Neuroprotective Agents; Pentylenetetrazole; Rats; Rats, Sprague-Dawley; Seizures; Sirolimus

Cortical dysplasia (CD) is a common cause for intractable epilepsy. Hyperactivation of the mechanistic target of rapamycin (mTOR) pathway has been implicated in CD; however, the mechanisms by which mTOR hyperactivation contribute to the epilepsy phenotype remain elusive. Here, we investigated whether constitutive mTOR hyperactivation in the hippocampus is associated with altered voltage-gated ion channel expression in the neuronal subset-specific Pten knockout (NS-Pten KO) mouse model of CD with epilepsy. We found that the protein levels of Kv1.1, but not Kv1.2, Kv1.4, or Kvβ2, potassium channel subunits were increased, along with altered Kv1.1 distribution, within the hippocampus of NS-Pten KO mice. The aberrant Kv1.1 protein levels were present in young adult (≥postnatal week 6) but not juvenile (≤postnatal week 4) NS-Pten KO mice. No changes in hippocampal Kv1.1 mRNA levels were found between NS-Pten KO and WT mice. Interestingly, mTOR inhibition with rapamycin treatment at early and late stages of the pathology normalized Kv1.1 protein levels in NS-Pten KO mice to WT levels. Together, these studies demonstrate altered Kv1.1 protein expression in association with mTOR hyperactivation in NS-Pten KO mice and suggest a role for mTOR signaling in the modulation of voltage-gated ion channel expression in this model.

Topics: Animals; Disease Models, Animal; Epilepsy; Gene Expression Regulation; Hippocampus; Humans; Kv1.1 Potassium Channel; Kv1.2 Potassium Channel; Kv1.4 Potassium Channel; Malformations of Cortical Development; Mice; Mice, Knockout; PTEN Phosphohydrolase; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

The mTOR signaling pathway has emerged as a possible therapeutic target for epilepsy. Clinical trials have shown that mTOR inhibitors such as everolimus reduce seizures in tuberous sclerosis complex patients with intractable epilepsy. Furthermore, accumulating preclinical data suggest that mTOR inhibitors may have anti-seizure or anti-epileptogenic actions in other types of epilepsy. However, the chronic use of rapalogs such as everolimus is limited by poor tolerability, particularly by immunosuppression, poor brain penetration and induction of feedback loops which might contribute to their limited therapeutic efficacy. Here we describe two novel, brain-permeable and well tolerated small molecule 1,3,5-triazine derivatives, the catalytic mTORC1/C2 inhibitor PQR620 and the dual pan-PI3K/mTOR inhibitor PQR530. These derivatives were compared with the mTORC1 inhibitors rapamycin and everolimus as well as the anti-seizure drugs phenobarbital and levetiracetam. The anti-seizure potential of these compounds was determined by evaluating the electroconvulsive seizure threshold in normal and epileptic mice. Rapamycin and everolimus only poorly penetrated into the brain (brain:plasma ratio 0.0057 for rapamycin and 0.016 for everolimus). In contrast, the novel compounds rapidly entered the brain, reaching brain:plasma ratios of ∼1.6. Furthermore, they significantly decreased phosphorylation of S6 ribosomal protein in the hippocampus of normal and epileptic mice, demonstrating effective mTOR inhibition. PQR620 and PQR530 significantly increased seizure threshold at tolerable doses. The effect of PQR620 was more marked in epileptic vs. nonepileptic mice, matching the efficacy of levetiracetam. Overall, the novel compounds described here have the potential to overcome the disadvantages of rapalogs for treatment of epilepsy and mTORopathies directly connected to mutations in the mTOR signaling cascade.

Topics: Animals; Anticonvulsants; Azabicyclo Compounds; Blood-Brain Barrier; Catalysis; Electroshock; Enzyme Inhibitors; Epilepsy; Everolimus; Female; Hippocampus; Levetiracetam; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Mice; Morpholines; Phenobarbital; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Pyridines; Ribosomal Proteins; Seizures; Sirolimus; Triazines

Topics: Adolescent; Child; Epilepsy; Everolimus; Humans; Seizures; Sirolimus; Tuberous Sclerosis

The purpose of this study was to evaluate the long-term results of eight cases diagnosed with tuberous sclerosis complex (TSC) and receiving rapamycin therapy because of epileptic seizures and/or accompanying TSC findings.. Rapamycin therapy was initiated at a dose of 1.5 mg/m. Four girls and four boys aged 4-16 years at the start of rapamycin therapy and now aged 9-24 years were evaluated. Duration of rapamycin therapy was 1-5 years, and the monitoring period after commencement of rapamycin therapy lasted 5-8 years. Positive effects were observed at 9-12 months in three out of six cases of renal angiomyolipoma (AML) and in the second year of treatment in one. An increase in AML dimensions was observed in three cases after treatment was stopped. Seizure control was established in the first year of rapamycin therapy in all cases. An increased frequency of seizures was observed in three cases after the second year of treatment. No seizure recurrence was determined in the second year of treatment with rapamycin in five out of eight cases. Recurrence of seizure was observed in 6-12 months after the discontinuation of rapamycin in three cases.. Rapamycin therapy exhibits positive effects on epileptic seizures in cases of TSC in 1-2 years but these positive effects on seizure control of rapamycin therapy decline after the second year. Larger case series are still needed to determine the duration and effectiveness of treatment in childhood.

Topics: Adolescent; Adult; Child; Electroencephalography; Epilepsy; Female; Humans; Male; Neoplasm Recurrence, Local; Retrospective Studies; Seizures; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Young Adult

To investigate the efficacy of brain-targeted rapamycin (T-Rap) in treatment of epilepsy in rats.. Rapamycin nanoparticles targeting brain were prepared. The epilepsy model was induced by injection of pilocarpine in rats. The rats with pilocarpine-induced epilepsy were treated with rapamycin (Rap group) or brain-targeted rapamycin (T-Rap group). Seizure activity was observed by electroencephalography; the effect on mTOR signaling pathway was detected by Western blot; neuronal death and moss fiber sprouting were analyzed by Fluoro-Jade B (FJB) and Timm's staining, respectively.. Electroencephalography showed that both preparation of rapamycin significantly reduced the frequency of spontaneous seizures in rats, and the effect of T-Rap was stronger than that of conventional rapamycin (. T-Rap has a better therapeutic effect on epilepsy than conventional rapamycin with a less adverse effects in rats.

Topics: Animals; Brain; Disease Models, Animal; Epilepsy; Neurons; Pilocarpine; Rats; Rats, Sprague-Dawley; Signal Transduction; Sirolimus; Treatment Outcome

Focal cortical dysplasia (FCD) is a major cause of the sporadic form of intractable focal epilepsies that require surgical treatment. It has recently been reported that brain somatic mutations in MTOR account for 15%-25% of FCD type II (FCDII), characterized by cortical dyslamination and dysmorphic neurons. However, the genetic etiologies of FCDII-affected individuals who lack the MTOR mutation remain unclear. Here, we performed deep hybrid capture and amplicon sequencing (read depth of 100×-20,012×) of five important mTOR pathway genes-PIK3CA, PIK3R2, AKT3, TSC1, and TSC2-by using paired brain and saliva samples from 40 FCDII individuals negative for MTOR mutations. We found that 5 of 40 individuals (12.5%) had brain somatic mutations in TSC1 (c.64C>T [p.Arg22Trp] and c.610C>T [p.Arg204Cys]) and TSC2 (c.4639G>A [p.Val1547Ile]), and these results were reproducible on two different sequencing platforms. All identified mutations induced hyperactivation of the mTOR pathway by disrupting the formation or function of the TSC1-TSC2 complex. Furthermore, in utero CRISPR-Cas9-mediated genome editing of Tsc1 or Tsc2 induced the development of spontaneous behavioral seizures, as well as cytomegalic neurons and cortical dyslamination. These results show that brain somatic mutations in TSC1 and TSC2 cause FCD and that in utero application of the CRISPR-Cas9 system is useful for generating neurodevelopmental disease models of somatic mutations in the brain.

Topics: Adolescent; Animals; Brain; Cell Line, Tumor; Child; Class I Phosphatidylinositol 3-Kinases; Cloning, Molecular; CRISPR-Cas Systems; Disease Models, Animal; Epilepsy; Female; HEK293 Cells; Humans; Male; Malformations of Cortical Development, Group I; Mice; Mutation; Neurons; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Saliva; Sequence Analysis, DNA; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins

Topics: Child; Epilepsy; Humans; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis

Topics: Child; Epilepsy; Humans; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis

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

Saikosaponin a (SSa), which is one major bioactive compound isolated from radix bupleuri, has been demonstrated to exhibit the properties of anticonvulsant and antiepileptic in few reports. This study aims to clarify the molecular mechanism by which SSa protects against pentylenetetrazol (PTZ) induced epileptic seizure.. PTZ induced rat and hippocampal neuron were established. Treated rats or hippocampal neuron with SSa, and mTOR, P70S6K, IL-1β and TNF-α were then determined.. In PTZ induced rat, SSa significantly reduced seizure severity and duration while markedly elevated seizure latency, and it also down-regulated hippocampal p-mTOR, p-70S6K, L-1β and TNF-α expression. In hippocampal neurons exposed to PTZ, p-mTOR and p-70S6K expression levels were also decreased by SSa. Pre-incubated hippocampal neurons with leucine, an mTOR agonist, reversed the effects of SSa on decreasing cytokines expression and inhibiting cell apoptosis. The treatment of mTOR inhibitor rapamycin prevented against the increase of cytokines expression and hippocampal neuron apoptosis induced by PTZ. Leucine also canceled the alleviation of seizures and induction of hippocampal caspase-3 activity in PTZ induced rat with the treatment of SSa.. SSa protects against PTZ induced epileptic seizure and hippocampal neuron apoptosis through inhibiting mTOR signaling pathway.

Topics: Animals; Apoptosis; Down-Regulation; Epilepsy; Hippocampus; Interleukin-1beta; Leucine; Male; Neurons; Neuroprotective Agents; Oleanolic Acid; Pentylenetetrazole; Phosphorylation; Rats, Wistar; Ribosomal Protein S6 Kinases, 70-kDa; Saponins; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tumor Necrosis Factor-alpha

Topics: Child; Enzyme Inhibitors; Epilepsy; Humans; Mechanistic Target of Rapamycin Complex 1; Sirolimus; Tuberous Sclerosis

The proteasome is a multisubunit enzyme complex involved in protein degradation, which is essential for many cellular processes. During inflammation, the constitutive subunits are replaced by their inducible counterparts, resulting in the formation of the immunoproteasome.. We investigated the expression pattern of constitutive (β1, β5) and immunoproteasome (β1i, β5i) subunits using immunohistochemistry in malformations of cortical development (MCD; focal cortical dysplasia (FCD) IIa and b, cortical tubers from patients with tuberous sclerosis complex (TSC), and mild MCD (mMCD)). Glial cells in culture were used to elucidate the mechanisms regulating immunoproteasome subunit expression.. Increased expression was observed in both FCD II and TSC; β1, β1i, β5, and β5i were detected (within cytosol and nucleus) in dysmorphic neurons, balloon/giant cells, and reactive astrocytes. Glial and neuronal nuclear expression positively correlated with seizure frequency. Positive correlation was also observed between the glial expression of constitutive and immunoproteasome subunits and IL-1β. Accordingly, the proteasome subunit expression was modulated by IL-1β in human astrocytes in vitro. Expression of both constitutive and immunoproteasome subunits in FCD II-derived astroglial cultures was negatively regulated by treatment with the immunomodulatory drug rapamycin (inhibitor of the mammalian target of rapamycin (mTOR) pathway, which is activated in both TSC and FCD II).. These observations support the dysregulation of the proteasome system in both FCD and TSC and provide new insights on the mechanism of regulation the (immuno)proteasome in astrocytes and the molecular links between inflammation, mTOR activation, and epilepsy.

Topics: Adolescent; Adult; Astrocytes; Cells, Cultured; Cerebral Cortex; Child; Child, Preschool; Cytokines; Epilepsy; Female; Fetus; Humans; Lipopolysaccharides; Male; Malformations of Cortical Development; Malformations of Cortical Development, Group I; Middle Aged; Nerve Tissue Proteins; Proteasome Endopeptidase Complex; Signal Transduction; Sirolimus; Tuberous Sclerosis; Young Adult

BACKGROUND The aim of this study was to determine whether activation of mammalian target of rapamycin (mTOR) is a key epileptogenic mechanism in the development of alcohol-related seizure. MATERIAL AND METHODS C57BL/6 mice were administered 10% ethanol in drinking water for 9 weeks. Video-electroencephalography (EEG) monitoring was then used to assess seizure frequency after alcohol and rapamycin treatment. In addition, mouse neuroblastoma NG108-15 cells were treated ethanol for 3 days and subsequently treated with AKT inhibitor LY294002 for 2-12 h. The in vitro kinase assay was performed for determining mTOR activity. Western blot analysis was used to determine the expression of P-AKT, P-S6K, and P-S6. RESULTS Long-term ethanol treatment markedly increased the seizure frequency of C57/BL6 mice over time. Moreover, ethanol treatment increased the expression level of P-S6 over time. Ethanol-induced seizure can be reversed by rapamycin. In addition, the in vitro kinase assay showed mTOR activity was activated by ethanol. Compared with NG108-15 cells treated without both ethanol and LY294002, ethanol increased the expression level of P-AKT, P-S6K, and P-S6, whereas LY294002 had opposite effects on expression levels of these proteins. CONCLUSIONS Our findings indicate that long-term alcohol intake increases the risk of epilepsy via activation of mTOR signaling. Moreover, ethanol-induced mTOR activation may be dependent on the AKT-mTOR signaling pathway. The key molecules involved in AKT-mTOR signaling pathway may serve as potential targets in the treatment of epilepsy.

Topics: Animals; Chromones; Enzyme Inhibitors; Epilepsy; Ethanol; Mice; Mice, Inbred C57BL; Morpholines; Phosphorylation; Proto-Oncogene Proteins c-akt; Risk Factors; Seizures; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Epilepsy and autism spectrum disorder (ASD) are common comorbidities of one another. Despite the prevalent correlation between the two disorders, few studies have been able to elucidate a mechanistic link. We demonstrate that forebrain specific Tsc1 deletion in mice causes epilepsy and autism-like behaviors, concomitant with disruption of 5-HT neurotransmission. We find that epileptiform activity propagates to the raphe nuclei, resulting in seizure-dependent hyperactivation of mTOR in 5-HT neurons. To dissect whether mTOR hyperactivity in 5-HT neurons alone was sufficient to recapitulate an autism-like phenotype we utilized Tsc1flox/flox;Slc6a4-cre mice, in which mTOR is restrictively hyperactivated in 5-HT neurons. Tsc1flox/flox;Slc6a4-cre mice displayed alterations of the 5-HT system and autism-like behaviors, without causing epilepsy. Rapamycin treatment in these mice was sufficient to rescue the phenotype. We conclude that the spread of seizure activity to the brainstem is capable of promoting hyperactivation of mTOR in the raphe nuclei, which in turn promotes autism-like behaviors. Thus our study provides a novel mechanism describing how epilepsy can contribute to the development of autism-like behaviors, suggesting new therapeutic strategies for autism.

Topics: Animals; Autistic Disorder; Behavior, Animal; Disease Models, Animal; Epilepsy; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neurons; Protein Kinase Inhibitors; Raphe Nuclei; Serotonin; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis Complex 1 Protein; Tumor Suppressor Proteins

Hyperactivation of the mechanistic target of rapamycin (mTOR; also known as mammalian target of rapamycin) pathway has been demonstrated in human cortical dysplasia (CD) as well as in animal models of epilepsy. Although inhibition of mTOR signaling early in epileptogenesis suppressed epileptiform activity in the neuron subset-specific Pten knockout (NS-Pten KO) mouse model of CD, the effects of mTOR inhibition after epilepsy is fully established were not previously examined in this model. Here, we investigated whether mTOR inhibition suppresses epileptiform activity and other neuropathological correlates in adult NS-Pten KO mice with severe and well-established epilepsy.. The progression of epileptiform activity, mTOR pathway dysregulation, and associated neuropathology with age in NS-Pten KO mice were evaluated using video-electroencephalography (EEG) recordings, Western blotting, and immunohistochemistry. A cohort of NS-Pten KO mice was treated with the mTOR inhibitor rapamycin (10 mg/kg i.p., 5 days/week) starting at postnatal week 9 and video-EEG monitored for epileptiform activity. Western blotting and immunohistochemistry were performed to evaluate the effects of rapamycin on the associated pathology.. Epileptiform activity worsened with age in NS-Pten KO mice, with parallel increases in the extent of hippocampal mTOR complex 1 and 2 (mTORC1 and mTORC2, respectively) dysregulation and progressive astrogliosis and microgliosis. Rapamycin treatment suppressed epileptiform activity, improved baseline EEG activity, and increased survival in severely epileptic NS-Pten KO mice. At the molecular level, rapamycin treatment was associated with a reduction in both mTORC1 and mTORC2 signaling and decreased astrogliosis and microgliosis.. These findings reveal a wide temporal window for successful therapeutic intervention with rapamycin in the NS-Pten KO mouse model, and they support mTOR inhibition as a candidate therapy for established, late-stage epilepsy associated with CD and genetic dysregulation of the mTOR pathway.

Topics: Animals; Disease Models, Animal; Epilepsy; Female; Male; Malformations of Cortical Development; Mice; Mice, Knockout; PTEN Phosphohydrolase; Sirolimus; TOR Serine-Threonine Kinases

Focal cortical dysplasia type II (FCDII) is a sporadic developmental malformation of the cerebral cortex characterized by dysmorphic neurons, dyslamination and medically refractory epilepsy. It has been hypothesized that FCD is caused by somatic mutations in affected regions. Here, we used deep whole-exome sequencing (read depth, 412-668×) validated by site-specific amplicon sequencing (100-347,499×) in paired brain-blood DNA from four subjects with FCDII and uncovered a de novo brain somatic mutation, mechanistic target of rapamycin (MTOR) c.7280T>C (p.Leu2427Pro) in two subjects. Deep sequencing of the MTOR gene in an additional 73 subjects with FCDII using hybrid capture and PCR amplicon sequencing identified eight different somatic missense mutations found in multiple brain tissue samples of ten subjects. The identified mutations accounted for 15.6% of all subjects with FCDII studied (12 of 77). The identified mutations induced the hyperactivation of mTOR kinase. Focal cortical expression of mutant MTOR by in utero electroporation in mice was sufficient to disrupt neuronal migration and cause spontaneous seizures and cytomegalic neurons. Inhibition of mTOR with rapamycin suppressed cytomegalic neurons and epileptic seizures. This study provides, to our knowledge, the first evidence that brain somatic activating mutations in MTOR cause FCD and identifies mTOR as a treatment target for intractable epilepsy in FCD.

Topics: Algorithms; Amino Acid Sequence; Animals; Brain; Child; Child, Preschool; DNA; Electroporation; Epilepsy; Exome; Exons; Female; HEK293 Cells; Humans; Infant; Male; Malformations of Cortical Development, Group I; Mice; Molecular Sequence Data; Mutagenesis; Mutation; Neurons; Phosphorylation; Polymerase Chain Reaction; Sequence Homology, Amino Acid; Sirolimus; TOR Serine-Threonine Kinases

Tuberous sclerosis complex (TSC) is a genetic disorder characterized by the formation of hamartomas in various organ systems. We would like share our experience from 86 patients and the results of rapamycin treatment in seven children with TSC.. Eighty-six children with TSC were enrolled into this retrospective study. The clinical features of seven children treated with oral rapamycin were presented in detail.. The most common complaint of administration was convulsion in 77 children (89.5%). Hypopigmented skin lesions, adenoma sebaceum, resistant epilepsy, intracardiac mass, renal angiomyolipomas, and West syndrome were detected (n = 83, 96.5%; n = 47, 54.7%; n = 36, 41.9%; n = 27, 31.4%; n = 18, 20.9%; and n = 13, 15.1%, respectively). Subependymal nodules were the most frequent finding in cranial imaging followed by cortical tubers and subependymal giant cell astrocytomas (n = 75, 87.2%; n = 71, 82.6%; and n = 8, 9.3%, respectively). Of the seven patients treated with rapamycin, the lesions of six children with facial adenoma sebaceum showed regression in various degrees. The frequency of convulsions decreased in five patients with resistant epilepsy within the first 6 months of the treatment, and complete control of convulsion for all patients was achieved in the second 6 months.. This is the first study that showed that rapamycin is an effective agent for controlling epilepsy without any significant side effect in children with TSC. Rapamycin seems to be effective after 6 months of therapy, and we recommend tapering the dosage after successful management of epilepsy.

Topics: Antibiotics, Antineoplastic; Child; Child, Preschool; Epilepsy; Female; Humans; Infant; Male; Retrospective Studies; Sirolimus; Treatment Outcome; Tuberous Sclerosis; Young Adult

Topics: Anticonvulsants; Brain; Epilepsy; Female; Humans; Male; Quality of Life; Sirolimus; Tuberous Sclerosis

Topics: Anticonvulsants; Brain; Epilepsy; Female; Humans; Male; Quality of Life; Sirolimus; Tuberous Sclerosis

To evaluate the therapeutic effect and safety of rapamycin in treatment of children with tuberous sclerosis complex (TSC) complicated with epilepsy.. This was an open-label, prospective, self-controlled study. From Sep. 2011 to Sep. 2013, 52 patients with the diagnosis of tuberous sclerosis complicated with epilepsy receiving rapamycin treatment for at least 24 weeks were enrolled.. Of the 52 children, 34 were male and 18 female. The median age at onset of epilepsy was 4.8 months (4 days-49 months), the median age for treatment with rapamycin was 27 months (4.5-172.5 months). Ten children had a family history of TSC. In 24 children TSC gene detection was carried out, among whom TSC1 mutation was detected in 4 cases and TSC2 mutation in 20. Before rapamycin therapy, 59.62%, (31/52) patients took more than 3 antiepileptic drugs, of whom 10 cases even took more than 5 kinds of antiepileptic drugs. Fifty-two patients received rapamycin treatment for 24 weeks, seizure free rate was 25.00% (13 cases), the total effective rate was 73.08% (38 cases); 31 cases received treatment for 48 weeks, seizure free 6 cases, total effective 23 cases; 17 cases accepted treatment for 72 weeks, seizure free 5 cases, total effective 13 cases; 12 cases received treatment for 96 weeks, seizure free 3 cases, total effective 9 cases. With the decrease of seizure attacks, use of antiepileptic drug types were reduced simultaneously, they had a negative correlation. Before rapamycin therapy, the average frequency of seizures was 70.27 times/d, the number of antiepileptic drug kinds was 1.30. After 24, 48, 72, 96 weeks' treatment, the average seizure frequency was reduced to 1.94-2.80 times /d and the antiepileptic drugs were reduced to 0.83-0.97 kinds. On every visit during the follow-up, blood and urine routine tests, liver and kidney function test showed no abnormality in the 52 cases. The drug dosage was 1 mg/(m(2)×d), average 0.7 mg/d (0.35-1.20 mg/d). Blood concentrations of rapamycin remained below 10 µg/L (average 6.5 µg/L). The main side effect was oral ulcer which happened in 23.08% (12/52). The oral ulcer would disappeared 2-3 days later. 17.31% (9/52 cases) had upper respiratory infection.. Rapamycin was effective in children with tuberous sclerosis and epilepsy with few adverse reactions. The daily dose of rapamycin for children patients is 1 mg/m(2), which has a certain effect on seizures and a good safety profile.

Topics: Adolescent; Anticonvulsants; Child; Child, Preschool; Epilepsy; Female; Humans; Infant; Male; Prospective Studies; Seizures; Sirolimus; Treatment Outcome; Tuberous Sclerosis

Tuberous sclerosis complex (TSC) is a genetic disorder characterized by increased mammalian target of rapamycin (mTOR) activation and growth of benign tumors in several organs throughout the body. In young children with TSC, drug-resistant epilepsy and subependymal giant cell astrocytomas (SEGAs) present the most common causes of mortality and morbidity. There are also some reports on the antiepileptic and antiepileptogenic potential of mTOR inhibitors in TSC. However, the data on everolimus efficacy and safety in young children are very limited.. To show the long-term safety data and the effect of everolimus treatment on epilepsy in children under the age of 3 who received everolimus for SEGAs associated with TSC.. We present the results of everolimus treatment in 8 children under the age of 3 who participated in EXIST-1 study. Five patients presented with active, drug-resistant epilepsy at baseline. The mean follow-up is 35 months (33-38 months) and all children are still on treatment.. In 6 out of 8 children, at least a 50% reduction in SEGA volume was observed. In 1 child with drug-resistant epilepsy, everolimus treatment resulted in cessation of seizures and in 2 other children, at least a 50% reduction in the number of seizures was noted. The incidence of adverse events (AE) was similar to that observed in older children and adults.. This study suggests that everolimus is effective and safe in infants and young children with epilepsy and SEGA associated with TSC and offers a valuable treatment option.

Topics: Anticonvulsants; Astrocytoma; Child, Preschool; Epilepsy; Everolimus; Female; Follow-Up Studies; Humans; Male; Sirolimus; Time; TOR Serine-Threonine Kinases; Treatment Outcome; Tuberous Sclerosis

Seizure development in tuberous sclerosis complex (TSC) correlates with the presence of specific lesions called cortical tubers. Moreover, heterozygous TSC animal models do not show gross brain pathology and are seizure-free, suggesting that such pathology is a prerequisite for the development of epilepsy. However, cells within TSC lesions show increased activity of the target of rapamycin complex 1 (TORC1) pathway, and recent studies have implicated this pathway in non-TSC-related animal models of epilepsy and neuronal excitability. These findings imply a direct role for TORC1 in epilepsy. Here, we investigate the effect of increased TORC1 signaling induced by acute biallelic deletion of Tsc1 in healthy adult mice.. Biallelic Tsc1 gene deletion was induced in adult Tsc1 heterozygous and wild-type mice. Seizures were monitored by electroencephalographic and video recordings. Molecular and cellular changes were investigated by Western blot analysis, immunohistochemistry, and electrophysiology.. Mice developed epilepsy a few days after biallelic Tsc1 deletion. Acute gene deletion was not accompanied by any obvious histological changes, but resulted in activation of the TORC1 pathway, enhanced neuronal excitability, and a decreased threshold for protein-synthesis-dependent long-term potentiation preceding the onset of seizures. Rapamycin treatment after seizure onset reduced TORC1 activity and fully abolished the seizures.. Our data indicate a direct role for TORC1 signaling in epilepsy development, even in the absence of major brain pathology. This suggests that TORC1 is a promising target for treating seizures not only in TSC but also in other forms of epilepsy that result from increased TORC1 activation.

Topics: Animals; Carrier Proteins; Disease Models, Animal; Dose-Response Relationship, Drug; Electroencephalography; Epilepsy; Gene Expression Regulation; Hippocampus; Immunosuppressive Agents; Long-Term Potentiation; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Transgenic; Multiprotein Complexes; Neurons; ras Proteins; Receptors, Estrogen; Sequence Deletion; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis Complex 1 Protein; Tumor Suppressor Proteins

Tuberous sclerosis complex (TSC) is a dominantly inherited disease with high penetrance and morbidity, and is caused by mutations in either of two genes, TSC1 or TSC2. Most affected individuals display severe neurological manifestations - such as intractable epilepsy, mental retardation and autism - that are intimately associated with peculiar CNS lesions known as cortical tubers (CTs). The existence of a significant genotype-phenotype correlation in individuals bearing mutations in either TSC1 or TSC2 is highly controversial. Similar to observations in humans, mouse modeling has suggested that a more severe phenotype is associated with mutation in Tsc2 rather than in Tsc1. However, in these mutant mice, deletion of either gene was achieved in differentiated astrocytes. Here, we report that loss of Tsc1 expression in undifferentiated radial glia cells (RGCs) early during development yields the same phenotype detected upon deletion of Tsc2 in the same cells. Indeed, the same aberrations in cortical cytoarchitecture, hippocampal disturbances and spontaneous epilepsy that have been detected in RGC-targeted Tsc2 mutants were observed in RGC-targeted Tsc1 mutant mice. Remarkably, thorough characterization of RGC-targeted Tsc1 mutants also highlighted subventricular zone (SVZ) disturbances as well as STAT3-dependent and -independent developmental-stage-specific defects in the differentiation potential of ex-vivo-derived embryonic and postnatal neural stem cells (NSCs). As such, deletion of either Tsc1 or Tsc2 induces mostly overlapping phenotypic neuropathological features when performed early during neurogenesis, thus suggesting that the timing of mTOR activation is a key event in proper neural development.

Topics: Animals; Animals, Newborn; Cell Differentiation; Cell Proliferation; Cell Size; Cerebral Cortex; Disease Models, Animal; Embryo, Mammalian; Embryonic Development; Enzyme Activation; Epilepsy; Gene Silencing; Longevity; Megalencephaly; Mice; Mutagenesis; Myelin Sheath; Neuroglia; Neurons; Sirolimus; STAT3 Transcription Factor; Time Factors; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tumor Suppressor Proteins

Tuberous Sclerosis Complex (TSC) is an often severe neurodevelopmental disorder caused by overactivation of the mTOR pathway due to mutations in either the TSC1 or TSC2 genes. Seizures are the primary cause of neurologic morbidity and often refractory. The mTOR inhibitor everolimus was recently approved for the treatment of giant cell astrocytomas and renal angiomyolipomas in TSC. Whether everolimus has any direct effect on epilepsy in TSC is not known.. Within the framework of a compassionate use trial, we evaluated the safety and efficacy of everolimus in seven patients with TSC and intractable epilepsy. We evaluated seizure frequency, seizure-free days and adverse effects including standard laboratory parameters. Seizure frequency was analysed in each patient using a non-parametric test for trend and using a Generalized Estimating Equations Model in the total patient group. The observation period was continued for nine months.. One patient discontinued the medication at the beginning of the observation period due to side effects (flushing). In the remaining 6 patients, we observed a reduction of seizures in 4/6 patients with a reduction of 25-100%. In addition, the percentage of seizure-free days increased in 3/4 of these patients. In 2/6 patients, no alteration of seizure frequency was noted. We observed an increase of mild infections and an increase of triglycerides and various liver function tests. We did not encounter life-threatening infections or other side effects of everolimus.. In some patients with TSC, everolimus may have an anticonvulsant effect with a reduction in seizure frequency and increase of seizure-free days. Everolimus was well tolerated, with adverse effects similar to those reported in previous studies.

Topics: Anticonvulsants; Child; Child, Preschool; Epilepsy; Everolimus; Female; Humans; Immunosuppressive Agents; Male; Sirolimus; Statistics, Nonparametric; Tuberous Sclerosis; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins

To investigate the effect of rapamycin, an mTOR inhibitor, on learning and memory ability of mice with pilocarpine (PILO)-induced seizure.. One hundred and sixty male adult ICR mice were randomly grouped as vehicle control (n=20), rapamycin control (n=20), PILO model (n=40), rapamycin pre-treatment (n=40) and rapamycin post-treatment (n=40). PILO model and rapamycin treatment groups were injected with PILO to induce temporal lobe seizure. Rapamycin was administrated for 3 days before or after seizure. Morris water maze, Y maze and open field were used for the assessment of learning and memory, and FJB and Timm staining were conducted to detect the neuronal cell death and mossy fiber sprouting, respectively.. No significant cell death was observed in the mice with PILO-induced seizure. The learning and memory were impaired in mice 7 to 10 days after PILO-induced seizure, which was evident by prolongation of avoiding latency (P<0.05), decrease in number of correct reaction (P<0.01) and number of crossing (P<0.05). Treatment with rapamycin both pre-and post- PILO injection reversed seizure-induced cognitive impairment. In addition, rapamycin inhibited the mossy fiber sprouting after seizure (P<0.001).. Rapamycin improves learning and memory ability in ICR mice after PILO-induced seizure, and its mechanism needs to be further studied.

Topics: Animals; Cell Death; Disease Models, Animal; Epilepsy; Learning; Memory; Mice; Mice, Inbred ICR; Neurons; Pilocarpine; Sirolimus

We present successful everolimus treatment of a huge subependymal giant cell astrocytoma in a 10-year old boy with tuberous sclerosis complex. The patient underwent several partial tumor resections complicated by intraoperative cardiac arrest. The tumor has been regrowing and produced severe clinical symptoms. Everolimus treatment resulted in marked tumor regression, significant improvement in patient's ambulation and cessation of seizures. Moreover, the therapy was well tolerated. These findings indicate that everolimus treatment should be considered as a therapeutic option alternative to surgery in patients with tuberous sclerosis complex.

Topics: Antineoplastic Agents; Astrocytoma; Cerebral Ventricle Neoplasms; Child; Epilepsy; Everolimus; Humans; Male; Sirolimus; Tuberous Sclerosis

The dentate gyrus is hypothesized to function as a "gate," limiting the flow of excitation through the hippocampus. During epileptogenesis, adult-generated granule cells (DGCs) form aberrant neuronal connections with neighboring DGCs, disrupting the dentate gate. Hyperactivation of the mTOR signaling pathway is implicated in driving this aberrant circuit formation. While the presence of abnormal DGCs in epilepsy has been known for decades, direct evidence linking abnormal DGCs to seizures has been lacking. Here, we isolate the effects of abnormal DGCs using a transgenic mouse model to selectively delete PTEN from postnatally generated DGCs. PTEN deletion led to hyperactivation of the mTOR pathway, producing abnormal DGCs morphologically similar to those in epilepsy. Strikingly, animals in which PTEN was deleted from ≥ 9% of the DGC population developed spontaneous seizures in about 4 weeks, confirming that abnormal DGCs, which are present in both animals and humans with epilepsy, are capable of causing the disease.

Topics: Animals; Animals, Newborn; Carrier Proteins; Cation Transport Proteins; Dentate Gyrus; Disease Models, Animal; Disks Large Homolog 4 Protein; Electroencephalography; Epilepsy; Gene Expression Regulation; Gliosis; Green Fluorescent Proteins; Guanylate Kinases; Immunosuppressive Agents; Kruppel-Like Transcription Factors; Membrane Proteins; Membrane Transport Proteins; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mossy Fibers, Hippocampal; Neurons; Olfactory Pathways; Phosphopyruvate Hydratase; PTEN Phosphohydrolase; Sirolimus; Time Factors; TOR Serine-Threonine Kinases; Zinc Finger Protein GLI1

Increased activity of mTOR Complex 1 (mTORC1) has been demonstrated in cortical dysplasia and tuberous sclerosis complex, as well as in animal models of epilepsy. Recent studies in such models revealed that inhibiting mTORC1 with rapamycin effectively suppressed seizure activity. However, seizures can recur after treatment cessation, and continuous rapamycin exposure can adversely affect animal growth and health. Here, we evaluated the efficacy of an intermittent rapamycin treatment protocol on epilepsy progression using neuron subset-specific-Pten (NS-Pten) conditional knockout mice.. NS-Pten knockouts were treated with a single course of rapamycin during postnatal weeks 4 and 5, or intermittently over a period of 5 months. Epileptiform activity was monitored using video-electroencephalography (EEG) recordings, and mossy fiber sprouting was evaluated using Timm staining. Survival and body weight were assessed in parallel.. NS-Pten knockouts treated with a single course of rapamycin had recurrence of epilepsy 4-7 weeks after treatment ended. In contrast, epileptiform activity remained suppressed, and survival increased if knockout mice received additional rapamycin during weeks 10-11 and 16-17. Aberrant mossy fiber sprouting, present by 4 weeks of age and progressing in parallel with epileptiform activity, was also blocked by rapamycin.. These findings demonstrate that a single course of rapamycin treatment suppresses epileptiform activity and mossy fiber sprouting for several weeks before epilepsy recurs. However, additional intermittent treatments with rapamycin prevented this recurrence and enhanced survival without compromising growth. Therefore, these studies add to the growing body of evidence implicating an important role for mTORC1 signaling in epilepsy.

Topics: Animals; Dentate Gyrus; Disease Progression; Electroencephalography; Epilepsy; Female; Male; Mice; Nerve Fibers; PTEN Phosphohydrolase; Sirolimus; TOR Serine-Threonine Kinases

Inhibition of mTOR by rapamycin has been shown to suppress seizures in TSC/PTEN genetic models. Rapamycin, when applied immediately before or after a neurological insult, also prevents the development of spontaneous recurrent seizures (epileptogenesis) in an acquired model. In the present study, we examined the mTOR pathway in rats that had already developed chronic spontaneous seizures in a pilocarpine model. We found that mTOR is aberrantly activated in brain tissues from rats with chronic seizures. Furthermore, inhibition of mTOR by rapamycin treatment significantly reduces seizure activity. Finally, mTOR inhibition also significantly suppresses mossy fiber sprouting. Our findings suggest the possibility for a much broader window for intervention for some acquired epilepsies by targeting the mTOR pathway.

Topics: Animals; Convulsants; Disease Models, Animal; Epilepsy; Hippocampus; Male; Mossy Fibers, Hippocampal; Neuronal Plasticity; Pilocarpine; Rats; Rats, Sprague-Dawley; Seizures; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Topics: Animals; Disease Models, Animal; Epilepsy; Humans; Mice; Mice, Knockout; Models, Biological; Phosphatidylinositol 3-Kinases; PTEN Phosphohydrolase; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Topics: Animals; Brain; Cognition Disorders; Epilepsy; Humans; Mental Disorders; Neurons; Protein Kinases; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins

Focal cortical dysplasia (FCD) and related malformations of cortical development (MCDs) represent an increasingly recognized cause of medically intractable epilepsy. However, the underlying mechanisms of epileptogenesis are poorly understood, and treatments for epilepsy due to various cortical malformations are often limited or ineffective. Animal models offer a number of advantages for investigating cellular and molecular mechanisms of epileptogenesis and developing novel, rational therapies for MCD-related epilepsy. This review highlights specific examples of how animal models have been useful in addressing several clinically relevant issues about epilepsy due to FCDs and related cortical malformations, including the pathologic and clinical features, etiologic factors, localization of the epileptogenic zone, neuronal and astrocytic contributions to epileptogenesis, and the development of antiepileptogenic therapies.

Topics: Animals; Anticonvulsants; Cerebral Cortex; Disease Models, Animal; Drug Design; Epilepsy; Humans; Malformations of Cortical Development; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Knockout; Multiprotein Complexes; Proteins; Rats; Sirolimus; TOR Serine-Threonine Kinases; Transcription Factors; Tuberous Sclerosis

Topics: Action Potentials; Animals; Apoptosis; Autophagy; Brain Diseases; Disease Models, Animal; Epilepsy; Neuroprotective Agents; Protein Kinases; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Up-Regulation

Cortical tubers are epileptogenic lesions in patients with tuberous sclerosis complex (TSC). Giant cells and dysplastic neurons are pathological hallmarks of cortical tubers. Severe astrogliosis, which is invariably present in tubers, has attracted much less attention. We hypothesize that the development of astrogliosis in cortical tubers constitutes a primary pathology of astrocytes and is directly related to TSC 1/2 mutations.. To begin to test this hypothesis, we performed immunohistochemical and electron microscopic analysis of brain tuber tissue resected from epileptic TSC patients. We compared alterations in tuber astrocytes to those found in other acute and chronic human epilepsy pathologies.. We found that astrogliosis in tubers is comprised of a mixture of "gliotic" and "reactive" astrocytes. The majority of tuber astrocytes are "gliotic" astrocytes that are morphologically and immunophenotypically similar to astrocytes in areas of gliosis in hippocampal sclerosis (HS). However, specific immunostaining features differentiate TSC gliosis from HS gliosis. "Reactive" tuber astrocytes are large-sized, vimentin positive cells in the vicinity of giant cells that show activation of the mammalian target of rapamycin (mTOR) pathway, consistent with mutated TSC gene function. These cells resemble acutely reactive human astrocytes seen in tissue resected from depth electrode implantation patients. Oligodendrocytes and NG2 expressing glial cells do not have any detectable alterations within tubers.. We conclude that astrocytes are the type of glial cell selectively impacted in cortical tuber pathology. We propose that tubers may be dynamic lesions, with progression of astrocytes over time from "reactive" to "gliotic." Tuber astrogliosis in TSC may represent a genetic "model" of gliosis that is phenotypically similar to gliosis seen in acquired human pathologies.

Topics: Antigens; Astrocytes; Cerebral Cortex; Epilepsy; Giant Cells; Gliosis; Hippocampus; Humans; Immunohistochemistry; Microscopy, Electron; Models, Genetic; Mutation; Neuroglia; Phenotype; Proteoglycans; Sclerosis; Sirolimus; Tuberous Sclerosis; Vimentin

Topics: Animals; Epilepsy; Humans; Polynesia; Sirolimus; Tuberous Sclerosis

Tuberous sclerosis complex (TSC) represents one of the most common genetic causes of epilepsy. TSC gene inactivation leads to hyperactivation of the mammalian target of rapamycin signaling pathway, raising the intriguing possibility that mammalian target of rapamycin inhibitors might be effective in preventing or treating epilepsy in patients with TSC. Mice with conditional inactivation of the Tsc1 gene primarily in glia (Tsc1(GFAP)CKO mice) develop glial proliferation, progressive epilepsy, and premature death. Here, we tested whether rapamycin could prevent or reverse epilepsy, as well as other cellular and molecular brain abnormalities in Tsc1(GFAP)CKO mice.. Tsc1(GFAP)CKO mice and littermate control animals were treated with rapamycin or vehicle starting at postnatal day 14 (early treatment) or 6 weeks of age (late treatment), corresponding to times before and after onset of neurological abnormalities in Tsc1(GFAP)CKO mice. Mice were monitored for seizures by serial video-electroencephalogram and for long-term survival. Brains were examined histologically for astrogliosis and neuronal organization. Expression of phospho-S6 and other molecular markers correlating with epileptogenesis was measured by Western blotting.. Early treatment with rapamycin prevented the development of epilepsy and premature death observed in vehicle-treated Tsc1(GFAP)CKO mice. Late treatment with rapamycin suppressed seizures and prolonged survival in Tsc1(GFAP)CKO mice that had already developed epilepsy. Correspondingly, rapamycin inhibited the abnormal activation of the mammalian target of rapamycin pathway, astrogliosis, and neuronal disorganization, and increased brain size in Tsc1(GFAP)CKO mice.. Rapamycin has strong efficacy for preventing seizures and prolonging survival in Tsc1(GFAP)CKO mice.

Topics: Animals; Disease Models, Animal; Epilepsy; Mice; Mice, Knockout; Sirolimus; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tumor Suppressor Proteins

Neurological complications are common in transplant recipients treated with immunosuppressant calcineurin inhibitors. Rapamycin, a macrolide antibiotic, was suggested as an alternative agent in patients who develop calcineurin inhibitor associated neurotoxicity, including seizure attacks. The aim of the present study was to test the effect of rapamycin on the bioelectrical activity and evoked field excitatory postsynaptic potentials (fEPSP) in CA1 area of hippocampal tissues and compare its effect with FK506, a calcineurin inhibitor agent. Application of rapamycin at different concentrations neither affected the bioelectrical activity nor changed fEPSP magnitude. In contrast, FK506 elicited epileptiform burst discharges and significantly enhanced fEPSP magnitude. This study supports the suggestion that rapamycin could be used as an alternative to calcineurin inhibitors in the event of neurotoxicity.

Topics: Animals; Brain; Calcineurin; Calcineurin Inhibitors; Dose-Response Relationship, Drug; Epilepsy; Evoked Potentials; Excitatory Postsynaptic Potentials; Graft Rejection; Hippocampus; Immunosuppressive Agents; In Vitro Techniques; Neurons; Neurotoxicity Syndromes; Rats; Seizures; Sirolimus; Tacrolimus; Transplantation

Topics: Epilepsy; Everolimus; Humans; Immunosuppressive Agents; Nervous System Diseases; Protein Kinases; Sirolimus; TOR Serine-Threonine Kinases; Treatment Outcome; Tuberous Sclerosis