Application of induced pluripotent stem cells in epilepsy.

Epilepsy is among the most common neurological disorders, affecting approximately 50 million people worldwide. Importantly, epilepsy is genetically and etiologically heterogenous, but several epilepsy types exhibit similar clinical presentations. Epilepsy-associated genes are being identified. However, the molecular pathomechanisms remain largely unknown. Approximately one-third of epilepsy is refractory to multiple conventional anti-epileptic drugs (AEDs). Induced pluripotent stem cells (iPSCs) provide an excellent tool to study the pathomechanisms underlying epilepsy and to develop novel treatments. Indeed, disease-specific iPSCs have been established for several genetic epilepsies. In particular, the molecular mechanisms underlying certain developmental and epileptic encephalopathies, such as Dravet syndrome, have been revealed. Modeling epilepsy with iPSCs enables new drug development based on the elucidated pathomechanisms. This can also be used to evaluate conventional AEDs and drug repurposing. Furthermore, transplanting neuronal cells derived from iPSCs into the brain has great potential to treat refractory epilepsies. Recent advances in iPSC technology have enabled the generation of neuronal organoids, or "mini brains." These organoids demonstrate electrophysiological activities similar to those of the brain and have the potential for extensive epilepsy research opportunities. Thus, the application of iPSCs in epilepsy provides insight into novel treatments based on the molecular pathomechanisms of epilepsy. In this review, we comprehensively discuss the studies conducted on iPSCs established for genetic epilepsy or epilepsies without major structural dysmorphic features.

SCN8A encephalopathy: Research progress and prospects.

On April 21, 2015, the first SCN8A Encephalopathy Research Group convened in Washington, DC, to assess current research into clinical and pathogenic features of the disorder and prepare an agenda for future research collaborations. The group comprised clinical and basic scientists and representatives of patient advocacy groups. SCN8A encephalopathy is a rare disorder caused by de novo missense mutations of the sodium channel gene SCN8A, which encodes the neuronal sodium channel Nav 1.6. Since the initial description in 2012, approximately 140 affected individuals have been reported in publications or by SCN8A family groups. As a result, an understanding of the severe impact of SCN8A mutations is beginning to emerge. Defining a genetic epilepsy syndrome goes beyond identification of molecular etiology. Topics discussed at this meeting included (1) comparison between mutations of SCN8A and the SCN1A mutations in Dravet syndrome, (2) biophysical properties of the Nav 1.6 channel, (3) electrophysiologic effects of patient mutations on channel properties, (4) cell and animal models of SCN8A encephalopathy, (5) drug screening strategies, (6) the phenotypic spectrum of SCN8A encephalopathy, and (7) efforts to develop a bioregistry. A panel discussion of gaps in bioregistry, biobanking, and clinical outcomes data was followed by a planning session for improved integration of clinical and basic science research. Although SCN8A encephalopathy was identified only recently, there has been rapid progress in functional analysis and phenotypic classification. The focus is now shifting from identification of the underlying molecular cause to the development of strategies for drug screening and prioritized patient care.

Treatment with Oral ATP decreases alternating hemiplegia of childhood with de novo ATP1A3 Mutation.

BACKGROUND: Alternating hemiplegia of childhood is an intractable neurological disorder characterized by recurrent episodes of alternating hemiplegia accompanied by other paroxysmal symptoms. Recent research has identified mutations in the ATP1A3 gene as the underlying cause. Adenosine-5'-triphosphate has a vasodilatory effect, can enhance muscle strength and physical performance, and was hypothesized to improve the symptoms of paroxysmal hemiplegia. METHODS: A 7-year-old boy with alternating hemiplegia of childhood who was positive for a de novo ATP1A3 mutation was treated with adenosine- 5'- triphosphate supplementation orally as an innovative therapy for 2 years. Outcome was evaluated through the follow-up of improvement of hemiplegic episodes and psychomotor development. Side effects and safety were monitored in regularity. RESULTS: With the dosage of adenosine-5'-triphosphate administration increased, the patient showed significantly less frequency and shorter duration of hemiplegic episodes. Treatment with adenosine-5'-triphosphate was correlated with a marked amelioration of alternating hemiplegia of childhood episodes, and psychomotor development has improved. The maximum dose of oral administration of adenosine-5'-triphosphate reached 25 mg/kg per day. Adenosine-5'-triphosphate therapy was well tolerated without complaint of discomfort and side effects. CONCLUSIONS: The 2-year follow-up outcome of adenosine-5'-triphosphate therapy for alternating hemiplegia of childhood was successful.

Successful treatment of an infected wound in infants by a combination of negative pressure wound therapy and arginine supplementation.

OBJECTIVE: Wound dehiscence caused by surgical site infection (SSI) presents a complicated problem. Negative pressure wound therapy (NPWT) was developed to treat wound dehiscence. Nutritional treatment using arginine has also been recently shown to be effective for the treatment of pressure ulcers. Therefore, wound complications due to SSI were treated using NPWT combined with nutritional therapy with an arginine-rich supplement (ARS). METHODS: Six pediatric patients with wound dehiscence due to SSI received this combined therapy. RESULTS: The average age of the patients was 12.2 mo. The operations that these patients underwent included laryngotracheal separation, radical operation for spinal bifida, gastrostomy, colostomy, anorectoplasty, and tumor extirpation. A local wound infection induced wound dehiscence in all patients. Therefore, NPWT was introduced with an enteral administration of ARS. All wounds completely healed within 1 mo after the introduction of this combined therapy without any other complications from the NPWT or ARS. A follow-up study at 6 mo after this therapy was completed showed no complications associated with the wounds. CONCLUSION: This combination therapy using NPWT and ARS administration was effective in inducing early healing of infected wound complications after surgery.

Rats harboring S284L Chrna4 mutation show attenuation of synaptic and extrasynaptic GABAergic transmission and exhibit the nocturnal frontal lobe epilepsy phenotype.

Mutations of genes encoding alpha4, beta2, or alpha2 subunits (CHRNA4, CHRNB2, or CHRNA2, respectively) of nAChR [neuronal nicotinic ACh (acetylcholine) receptor] cause nocturnal frontal lobe epilepsy (NFLE) in human. NFLE-related seizures are seen exclusively during sleep and are characterized by three distinct seizure phenotypes: "paroxysmal arousals," "paroxysmal dystonia," and "episodic wandering." We generated transgenic rat strains that harbor a missense mutation S284L, which had been identified in CHRNA4 in NFLE. The transgenic rats were free of biological abnormalities, such as dysmorphology in the CNS, and behavioral abnormalities. The mRNA level of the transgene (mutant Chrna4) was similar to the wild type, and no distorted expression was detected in the brain. However, the transgenic rats showed epileptic seizure phenotypes during slow-wave sleep (SWS) similar to those in NFLE exhibiting three characteristic seizure phenotypes and thus fulfilled the diagnostic criteria of human NFLE. The therapeutic response of these rats to conventional antiepileptic drugs also resembled that of NFLE patients with the S284L mutation. The rats exhibited two major abnormalities in neurotransmission: (1) attenuation of synaptic and extrasynaptic GABAergic transmission and (2) abnormal glutamate release during SWS. The currently available genetically engineered animal models of epilepsy are limited to mice; thus, our transgenic rats offer another dimension to the epilepsy research field.

Late-onset ornithine transcarbamylase deficiency in male patients: prognostic factors and characteristics of plasma amino acid profile.

BACKGROUND: The occurrence of male patients with ornithine transcarbamylase (OTC) deficiency during adolescence or in adulthood has now been recognized. The aim of this study was to determine the prognostic factors that affect the prognosis of life, to explore a basis for therapeutic strategy. METHODS: In 10 patients, nine of whom carried the R40H mutation and the other one carrying the Y55D mutation in the OTC gene, 32 demographic and laboratory data were first compared between survivors and non-survivors, using the unpaired t-test. The factors with significant difference were then subjected to multiple regression analysis. RESULTS: The factors that exhibited significant difference were: age at onset, concentration of plasma ammonium, blood pH, and concentrations of six amino acids in plasma. The multiple regression analysis then revealed concentrations of ammonium, leucine, lysine, isoleucine, phenylalanine, glutamine and proline to be significant prognostic factors. The amino acid profile in the 10 patients showed increases in glutamine, proline, lysine, valine and methionine, and decreases in serine, ornithine and arginine. There was an inverse correlation between the age at onset and the level of the residual hepatic OTC activity. CONCLUSION: The results implied that: (i) the plasma amino acid profile was unique, in comparison to other liver diseases; (ii) the plasma concentration of each of the (mentioned above) six amino acids was a significant predictor of prognosis; and (iii) suppression of protein catabolism, as suggested by the higher concentrations in isoleucine and leucine in the non-survivors, prevention of glutamine-induced brain edema, correction of alkalosis, and supplementation with ornithine or arginine may improve the prognosis of life.

Molecular genetics of human familial epilepsy syndromes.

Genetic defects have been recently identified in certain inherited epilepsy syndromes in which the phenotypes are similar to those of common idiopathic epilepsies. Mutations in the neuronal nicotinic acetylcholine receptor alpha4 and beta2 subunit genes have been detected in families with autosomal dominant nocturnal frontal lobe epilepsy. Both receptors are components of neuronal acetylcholine receptor, a ligand-gated ion channel in the brain. Furthermore, mutations of two K+ channel genes also were identified as the underlying genetic abnormalities of benign familial neonatal convulsions. Mutations in the voltage-gated Na+-channel alpha1 and beta1 subunit genes were found as the cause of generalized epilepsy with febrile seizures plus, a clinical subset of febrile convulsions. Mutation of a voltage-gated K+-channel gene can cause partial seizures associated with periodic ataxia type 1 and some forms of juvenile myoclonic epilepsy can result from mutations of a Ca2+ channel. This line of evidence suggests the involvement of channels expressed in the brain in the pathogenesis of certain types of epilepsy. Our working hypothesis is to view certain idiopathic epilepsies as disorders of ion channels (i.e., "channelopathies"). Such a hypothesis should provide a new insight into our understanding of the genetic background of epilepsy.