A long journey to treat epilepsy with the gut microbiota.

Epilepsy is a common neurological disorder that affects approximately 10.5 million children worldwide. Approximately 33% of affected patients exhibit resistance to all available antiseizure medications, but the underlying mechanisms are unknown and there is no effective treatment. Increasing evidence has shown that an abnormal gut microbiota may be associated with epilepsy. The gut microbiota can influence the function of the brain through multiple pathways, including the neuroendocrine, neuroimmune, and autonomic nervous systems. This review discusses the interactions between the central nervous system and the gastrointestinal tract (the brain-gut axis) and the role of the gut microbiota in the pathogenesis of epilepsy. However, the exact gut microbiota involved in epileptogenesis is unknown, and no consistent results have been obtained based on current research. Moreover, the target that should be further explored to identify a novel antiseizure drug is unclear. The role of the gut microbiota in epilepsy will most likely be uncovered with the development of genomics technology.

Clinical phenotypes of developmental and epileptic encephalopathy-related recurrent KCNH5 missense variant p.R327H in Chinese children.

KCNH5 gene encodes for the voltage-gated potassium channel protein Kv10.2. Here, we investigated the clinical features of developmental and epileptic encephalopathy (DEE) in five Chinese pediatric patients with a missense mutation (p.R327H) in KCNH5 gene. These patients had undergone video EEG to evaluate background features and epileptiform activity, as well as 3.0 T MRI scans for structural analysis and intelligence assessments using the Gesell Developmental Observation or Wechsler Intelligence Scale for Children. Seizure onset occurs between 4 and 10 months of age, with focal and generalized tonic-clonic seizures being common. Initial EEG findings showed multiple multifocal sharp waves, sharp slow waves or spike slow waves, and spike waves. Brain MRI revealed widened extracerebral space in only one patient. Mechanistically, the KCNH5 mutation disrupts the two hydrogen bonds between Arg327 and Asp304 residues, potentially altering the protein's structural stability and function. Almost 80 % of patients receiving add-on valproic acid (VPA) therapy experienced a reduction in epileptic seizure frequency. Altogether, this study presents the first Chinese cohort of pediatric DEE patients with the KCNH5 p.R327H mutation, highlighting focal seizures as the predominant seizure type and incomplete mutation penetrance. Add-on VPA therapy was likely effective in the early stages of DEE pathogenesis.

Astrocyte-derived complement C3 is activated in patients with tuberous sclerosis complex and mediates immune injury: an integrated bioinformatics analysis.

Background: Tuberous sclerosis complex (TSC) is a genetic disorder associated with multiple neurological manifestations. Cortical tubers (CT) are recognized as the hallmark brain lesions of TSC and contribute to neurological and psychiatric symptoms. To understand the molecular mechanism of neuropsychiatric features of TSC, the differentially expressed genes (DEGs) in CT from patients with TSC and those in normal cortex (NC) from participants acting as healthy controls were investigated. Methods: The dataset of GSE16969, which had already been published and described (https://onlinelibrary.wiley.com/doi/10.1111/j.1750-3639.2009.00341.x), was downloaded from the Gene Expression Omnibus (GEO), including samples of 4 CT and 4 NC. The R package "limma" was used to screen DEGs in CT and NC. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analyses of the DEGs were conducted using the R package "clusterProfiler". The online software Ingenuity Pathway Analysis (IPA) was used to explore activation/inaction of canonical pathways. The hub gene was selected based on the protein-protein interaction (PPI) network constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database and Cytoscape software. Subsequently, the hub genes at messenger (mRNA) and transcriptional levels were tested. We also explored immune cell-type enrichment using the online database xCell, and assessed the correlation between cell types and C3 expression. Then, we verified the source of C3 by constructing TSC2 knockout cells in the U87 astrocyte cell line. The human neuronal cell line SH-SY5Y was used to examine the effects of excessive complement C3 levels. Results: A total of 455 DEGs were identified. A large number of pathways were involved in the immune response process based on the results of GO, KEGG, and IPA. C3 was identified as a hub gene. Complement C3 was also upregulated in the human CT and peripheral blood. Furthermore, based on the enrichment of functions and signaling pathways, complement C3 played a critical role in immune injury in CT of TSC. In the in vitro experiments, we found that excessive complement C3 was derived from TSC2 knockout U87 cells, and there was an increased intracellular reactive oxygen species (ROS) level in SH-SY5Y cells. Conclusions: Complement C3 is activated in patients with TSC and can mediate immune injury.

A Ketogenic Diet and the Treatment of Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is characterized by stereotyped behavior and deficits in communication and social interaction. There are no curative treatments for children with ASD. The ketogenic diet (KD) is a high-fat, appropriate-protein, and low-carbohydrate diet that mimics the fasting state of the body and is proven beneficial in drug-resistant epilepsy and some other brain diseases. An increasing number of studies demonstrated that a KD improved autistic behavior, but the underlying mechanisms are not known. We reviewed the neuroprotective role of a KD in ASD, which is likely mediated via improvements in energy metabolism, reductions in antioxidative stress levels, control of neurotransmitters, inhibition of the mammalian target of rapamycin (mTOR) signaling pathway, and modulation of the gut microbiota. A KD is likely a safe and effective treatment for ASD.

Pediatric Autoimmune Encephalitis and Its Relationship With Infection.

Autoimmune encephalitis (AE) is an increasingly recognized inflammatory disorder of the central nervous system and is most often characterized by antibodies against intracellular and neuronal surface antigens. AE is a devastating disease that may result in developmental delay or regression in children. However, the pathogenesis of AE is not clear, and immune system disorders after infection likely play an important role in AE. Many studies have reported that patients with herpes simplex virus encephalitis develop anti-N-methyl-d-aspartate receptor encephalitis after antiviral treatment. It is critical to recognize pediatric AE early and to distinguish it from infectious forms because AE is treatable and responsive to immunotherapies. In this review, we discuss the clinical features of pediatric AE and focus on the relationship between AE and postinfection status. In addition, we review the probable mechanisms underlying infection-triggered AE, which include molecular mimicry, bystander activation, epitope spreading, immune system disorder, and genetic susceptibility.

The Role of Microtubule Associated Serine/Threonine Kinase 3 Variants in Neurodevelopmental Diseases: Genotype-Phenotype Association.

Objective: To prove microtubule associated serine/threonine kinase 3 (MAST3) gene is associated with neurodevelopmental diseases (NDD) and the genotype-phenotype correlation. Methods: Trio exome sequencing (trio ES) was performed on four NDD trios. Bioinformatic analysis was conducted based on large-scale genome sequencing data and human brain transcriptomic data. Further in vivo zebrafish studies were performed. Results: In our study, we identified four de novo MAST3 variants (NM_015016.1: c.302C > T:p.Ser101Phe; c.311C > T:p.Ser104Leu; c.1543G > A:p.Gly515Ser; and c.1547T > C:p.Leu516Pro) in four patients with developmental and epileptic encephalopathy (DEE) separately. Clinical heterogeneities were observed in patients carrying variants in domain of unknown function (DUF) and serine-threonine kinase (STK) domain separately. Using the published large-scale exome sequencing data, higher CADD scores of missense variants in DUF domain were found in NDD cohort compared with gnomAD database. In addition, we obtained an excess of missense variants in DUF domain when compared autistic spectrum disorder (ASD) cohort with gnomAD database, similarly an excess of missense variants in STK domain when compared DEE cohort with gnomAD database. Based on Brainspan datasets, we showed that MAST3 expression was significantly upregulated in ASD and DEE-related brain regions and was functionally linked with DEE genes. In zebrafish model, abnormal morphology of central nervous system was observed in mast3a/b crispants. Conclusion: Our results support the possibility that MAST3 is a novel gene associated with NDD which could expand the genetic spectrum for NDD. The genotype-phenotype correlation may contribute to future genetic counseling.

Characterization of Intestinal Microbiota and Probiotics Treatment in Children With Autism Spectrum Disorders in China.

Background: Most previous studies have found that human intestinal microbiota affect the symptoms of autism spectrum disorder (ASD), especially gastrointestinal (GI) symptoms, but regarding this, there is limited data of non-western ethnicity. Probiotics can reconstitute the host intestinal microbiota and strengthen gastrointestinal function, however, clinical data proving the effect of probiotics treatment on ASD is lacking. Methods: This study explored the significant differences between ASD and neurotypical (NT), and the improvement of applied behavior analysis (ABA) training in combination with probiotics, vs. ABA training only. Results: We found significant differences between the ASD group and the NT group in the evenness of the intestinal microbiota and the relative abundance of the bacterial phyla and genus. At the phylum level, relative abundance of Bacteroidetes in the ASD group was significantly lower than in the NT group. At the genus level, the relative abundance of Bacteroides, Bifidobacterium, Ruminococcus, Roseburia, and Blautia in the ASD group was significantly lower than that in the NT group. After a 4-week ABA training program in combination with probiotics treatment, the ATEC and GI scores decreased more than the control group with ABA training only. Conclusion: Our findings suggest that intestinal microbiota is different between the NT children and the ASD children with or without GI problems. In combination with ABA training, probiotics treatment can bring more benefit to ASD children. Clinical trials with a more rigorous design and larger sample size are indispensable for further validation.

Corrigendum: Prevalence of Anemia and Its Associated Risk Factors Among 6-Months-Old Infants in Beijing.

[This corrects the article DOI: 10.3389/fped.2019.00286.].

Prevalence of Anemia and Its Associated Risk Factors Among 6-Months-Old Infants in Beijing.

Objective: The worldwide prevalence of anemia is ~24.8%. Iron deficiency anemia is common in children and women and associated with sensory, motor, cognitive, language, and socioemotional deficits. Therefore, detection and early intervention strategies for anemia in infants are urgently needed. To prevent the occurrence of iron deficiency anemia, we aimed to identify risk factors associated with anemia in infants. Methods: This investigation involved a cross-sectional study of 6-months-old infants discharged between April 2014 and September 2017 from Peking University First Hospital. We assessed birth information, maternal age, and maternal educational level as well as data on feeding style, complementary foods and primary caregivers. The infants were assessed with the Denver Developmental Screening Test (DDST). Results: A total of 1,127 6-months-old infants were enrolled at the hospital. We found that the prevalence of anemia among infants in Beijing was ~11.8%. Premature infants had a higher rate of anemia than full-term infants (χ2 = 40.103, P < 0.001). Infants born in autumn or winter were at an elevated risk of developing anemia (χ2 = 22.949, P < 0.001). Birth weight had no effect on the rate of anemia in infants (χ2 = 0.023, P = 0.568). Infants who were exclusively breastfeeding had higher anemia rates than those who were fed formula (χ2 = 38.466, P < 0.001). Infants whose caregivers added no complementary foods had higher anemia rates (24.7%) than those whose caregivers added more than two kinds of complementary food (8.2%). The type of caregiver had no effect on the anemia rate in infants (χ2 = 0.031, P = 1.000). Conclusions: The following factors resulted in a higher prevalence of anemia in our study a gestational age at birth of <37 weeks, exclusive breastfeeding, a lack of supplementation with complementary foods and a spring birth date. No significant differences in DDST pass rates were evident between infants with and without anemia.

Inhibition of TRIB3 Protects Against Neurotoxic Injury Induced by Kainic Acid in Rats.

Epilepsy refers to a group of neurological disorders of varying etiologies characterized by recurrent seizures, resulting in brain dysfunction. Endoplasmic reticulum (ER) stress is highly activated in the process of epilepsy-related brain injury. However, the mechanisms by which ER stress triggers neuronal apoptosis remain to be fully elucidated. Tribbles pseudokinase 3 (TRIB3) is a pseudokinase that affects a number of cellular functions, and its expression is increased during ER stress. Here, we sought to clarify the role of TRIB3 in neuronal apoptosis mediated by ER stress. In the kainic acid (KA) (10 mg/kg)-induced rat seizure model, we characterized neuronal injury and apoptosis after KA injection. KA induced an ER stress response, as indicated by elevated expression of glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP). TRIB3 protein was upregulated concomitantly with the downregulation of phosphorylated-protein kinase B (p-AKT) in rats following KA administration. In rat cortical neurons treated with KA, TRIB3 knockdown by siRNA reduced the number of dying neurons, decreased the induction of GRP78 and CHOP and the activation of caspase-3, and blocked the dephosphorylation of AKT after KA treatment. Our findings indicate that TRIB3 is involved in neuronal apoptosis occurring after KA-induced seizure. The knockdown of TRIB3 effectively protects against neuronal apoptosis in vitro, suggesting that TRIB3 may be a potential therapeutic target for the treatment of epilepsy.

Role of endoplasmic reticulum stress-associated gene TRIB3 in rats following kainic acid-induced seizures.

TRIB3 (tribblespseudokinase 3) is a pseudokinase that affects several cellular functions, and its expression is increased during endoplasmic reticulum stress (ER stress). How recurrent seizures affect the regulation of TRIB3 in the hippocampus during epilepsy remains unclear. In this study, we investigated the role of TRIB3 in the kainic acid (KA)-induced seizures and related brain injury. In a rat model of kainic acid-induced seizures, neuronal excitotoxic injury and apoptosis, and increases in the expression of TRIB3 and ER stress markers glucose-regulated protein 78 (GRP78) and C/EBP homologous binding protein (CHOP) were observed in the hippocampus by 24 h to 30 d after KA administration. Furthermore, phosphorylation of AKT, which is inhibited by TRIB3, was decreased in the hippocampus after KA-evoked seizure. These results indicate that ER stress, TRIB3 and AKT signaling are involved in the acute and prolonged hippocampal injury following KA induced seizure, suggesting that the ER stress-associated gene TRIB3 plays an important role in neuronal apoptosis after seizure.

Endogenous sulfur dioxide regulates hippocampal neuron apoptosis in developing epileptic rats and is associated with the PERK signaling pathway.

Epilepsy is among the most common neurological diseases in children. Recurrent seizures can result in hippocampal damage and seriously impair learning and memory functions in children. However, the mechanisms underlying epilepsy-related brain injury are unclear. Neuronal apoptosis is among the most common neuropathological manifestations of brain injury. Endogenous sulfur dioxide (SO2) has been shown to be involved in seizures and related neuron apoptosis. However, the role of endogenous SO2 in epilepsy remains unclear. This study assessed whether endogenous SO2 is involved in epilepsy and its underlying mechanisms. Using a rat epilepsy model induced by an intraperitoneal injection of kainic acid (KA), we found that hippocampal neuron apoptosis was induced in epileptic rats, and the SO2 content and aspartate aminotransferase (AAT) activity in the plasma were increased compared to those in the control group. However, the inhibition of SO2 production by l-aspartate-ß-hydroxamate (HDX) can subvert this response 72h after an epileptic seizure. No difference in apoptosis was observed 7 d after the epileptic seizure in the KA and KA+HDX groups. The protein expression levels of AAT2, glucose-regulated protein 78 (GRP78), pancreatic eIF2 kinase-like ER kinase (PERK) and phospho-PERK (p-PERK) were remarkably elevated in the hippocampi of the epileptic rats, while the HDX treatment was capable of reversing this process 7 d after the epileptic seizure. These results indicate that the inhibition of endogenous SO2 production can alleviate neuronal apoptosis and is associated with the PERK signaling pathway during the initial stages after epileptic seizure, but inhibiting SO2 production only delayed the occurrence of apoptosis and did not prevent neuronal apoptosis in the epileptic rats.

Recombinant Human Erythropoietin Protects Against Hippocampal Damage in Developing Rats with Seizures by Modulating Autophagy via the S6 Protein in a Time-Dependent Manner.

Epilepsy is among the most common neurological disorders. Recurrent seizures result in neuronal death, cognitive deficits and intellectual disabilities in children. Currently, recombinant human erythropoietin (rhEPO) is considered to play a neuroprotective role in nervous system disorders. However, the precise mechanisms through which rhEPO modulates epilepsy remain unknown. Based on results from numerous studies, we hypothesized that rhEPO protects against hippocampal damage in developing rats with seizures probably by modulating autophagy via the ribosomal protein S6 (S6) in a time-dependent manner. First, we observed that rats with recurrent seizures displayed neuronal loss in the hippocampal CA1 region. Second, rhEPO injection reduced neuronal loss and decreased the number of apoptotic cells in the hippocampal CA1 region. Moreover, rhEPO increased the Bcl-2 protein expression levels and decreased the ratio of cleaved caspase-3/caspase-3 in the hippocampus. Finally, rhEPO modulated autophagy in the hippocampus in a time-dependent manner, probably via the S6 protein. In summary, rhEPO protects against hippocampal damage in developing rats with seizures by modulating autophagy in a time-dependent manner, probably via the S6 protein. Consequently, rhEPO is a likely drug candidate that is capable of attenuating brain injury.

Alterations of apoptosis and autophagy in developing brain of rats with epilepsy: Changes in LC3, P62, Beclin-1 and Bcl-2 levels.

Current studies have indicated that apoptotic and autophagic signaling pathways are triggered by epileptic seizures, but the precise roles of these processes in epilepsy-induced neuronal loss remain unclear. Identifying a concrete molecular mechanism may help researchers develop relevant epilepsy therapies that are more effective than existing treatments. Autophagy is a type of conserved degradation that contributes to cellular homeostasis. The involved signaling pathways allow us to observe alterations in autophagy and apoptosis during epileptic seizures over time. This study investigated the time-dependent changes in autophagy, apoptosis and neuronal morphology in developing brain of epilepsy model rats. At 48h after epileptic seizure onset, the number of neurons in neocortex decreased, and the number of apoptotic cells in neocortex increased. The ratio of microtubule-associated protein 1 light chain 3 (LC3) II to LC3 I and Beclin-1 protein levels increased from 12h to 48h after epileptic seizure onset. P62 protein and Bcl-2 protein levels decreased from 24h to 48h after epileptic seizure onset. The changes in the levels of these autophagy and apoptosis markers indicate that autophagy starts before apoptosis in rats with epilepsy, demonstrating a potential role of autophagy in epilepsy-induced neuronal loss in developing brain.

Recombinant human erythropoietin protects against brain injury through blunting the mTORC1 pathway in the developing brains of rats with seizures.

AIMS: Recurrent seizures can result in neuronal death, cognitive deficits and intellectual disability, which causes devastating damage in children. Recombinant human erythropoietin (rhEPO) is considered a neuroprotective factor in many nervous system diseases. However, the precise mechanisms through which rhEPO exerts its neuroprotective effects on epilepsy remain unknown. Thus, in this study, we determined whether rhEPO protects against brain injury by inducing cortical neuronal autophagy through blunting the mammalian target of rapamycin complex 1 (mTORC1) pathway in the developing brains of rats with seizures. MAIN METHODS: We used kainic acid to induce recurrent seizures in rats. Nissl staining and TUNEL analysis were used to evaluate the neuronal damage and apoptotic cells. Western blot analysis was employed to evaluate the phospho-mammalian target of rapamycin (p-mTOR)/mTOR protein ratio, the phospho-ribosomal protein S6 (S6)/S6 protein ratio, the microtubule-associated protein light chain 3 (LC3) II/I protein ratio and sequestosome 1 (P62/SQSTM1) protein expression levels. KEY FINDINGS: rhEPO reversed the decrease in the number of Nissl-positive neurons and the increase in the number of apoptotic cells in the kainic acid group. Notably, rhEPO induced autophagy and inhibited the mTORC1 pathway to protect against brain injury in rats with seizures. Treating rats with rapamycin blocked the mTORC1 pathway and masked the abovementioned effects of rhEPO. SIGNIFICANCE: Based on these results, rhEPO protects against brain injury by activating autophagy through blunting the mTORC1 pathway in developing rats with seizures.

The Influence of Different Caregivers on Infant Growth and Development in China.

OBJECTIVE: An increasing number of parents in China ask grandparents or babysitters to care for their children. Modern parents are often the only child in their family because of China's One-Child Policy and thus may lack interaction with siblings. Accordingly, the present study aimed to explore whether different caregivers affect the physical and development of infants in China. METHODS: In total, 2,514 infants were enrolled in our study. We assessed their weight-for-age, supine length-for-age, weight-for-length, occipital-frontal circumference, and Denver Developmental Screening Test (DDST) results and recorded their general parental information and their primary caregivers. RESULTS: The weights and lengths of 12-month-old infants under the care of babysitters were significantly lower than those of infants under the care of parents or grandparents (P < 0.05). Additionally, 12-month-old infants under the care of babysitters had the lowest DDST pass rate (75%) among the three groups (χ2 = 11.819, P = 0.012), especially for the fine motor-adaptive and language domains. Compared to 12-month-old infants under the care of parents and babysitters, infants under the care of grandparents were more likely to be overweight or obese (P < 0.001). CONCLUSION: The study showed that caregivers had a dominant role in the physical and cognitive development of the infants. Specifically, compared with infants raised by grandparents and parents, 12-month-old infants under the care of babysitters had partially suppressed lengths and weights and lagged cognitively. The 12-month-old infants under the care of grandparents were more overweight than those cared for by parents and babysitters.

Fragile X Syndrome: Prevalence, Treatment, and Prevention in China.

Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability and the leading monogenic cause of autism spectrum disorder. Although FXS has been studied for several decades, there is relatively little basic science or clinical research being performed on FXS in China. Indeed, there is a large gap between China and Western countries in the FXS field. China has a potentially large number of FXS patients. However, many of them are underdiagnosed or even misdiagnosed, and treatments are not always administered in the Chinese population. This review discusses the prevalence, treatment, and prevention of FXS in China to facilitate an understanding of this disease in the Chinese population.

Autism Symptoms in Fragile X Syndrome.

Fragile X syndrome (FXS) is recognized as the most common genetic cause of intellectual disability and autism spectrum disorder (ASD). Although symptoms of ASD are frequently observed in patients with FXS, researchers have not yet clearly determined whether the symptoms in patients with FXS differ from the symptoms in patients without ASD or nonsyndromic ASD. Behavioral similarities and differences between FXS and ASD are important to improve our understanding of the causes and correlations of ASD with FXS. Based on the evidence presented in this review, individuals with FXS and comorbid ASD have more severe behavioral problems than individuals with FXS alone. However, patients with FXS and comorbid ASD exhibit less severe impairments in the social and communication symptoms than patients with nonsyndromic ASD. Individuals with FXS also present with anxiety and seizures in addition to comorbid ASD symptoms, and differences in these conditions are noted in patients with FXS and ASD. This review also discusses the role of fragile X mental retardation 1 protein (FMRP) in FXS and ASD phenotypes.

The Gut Microbiota and Autism Spectrum Disorders.

Gastrointestinal (GI) symptoms are a common comorbidity in patients with autism spectrum disorder (ASD), but the underlying mechanisms are unknown. Many studies have shown alterations in the composition of the fecal flora and metabolic products of the gut microbiome in patients with ASD. The gut microbiota influences brain development and behaviors through the neuroendocrine, neuroimmune and autonomic nervous systems. In addition, an abnormal gut microbiota is associated with several diseases, such as inflammatory bowel disease (IBD), ASD and mood disorders. Here, we review the bidirectional interactions between the central nervous system and the gastrointestinal tract (brain-gut axis) and the role of the gut microbiota in the central nervous system (CNS) and ASD. Microbiome-mediated therapies might be a safe and effective treatment for ASD.

Reduced AKT phosphorylation contributes to endoplasmic reticulum stress-mediated hippocampal neuronal apoptosis in rat recurrent febrile seizure.

AIMS: Febrile seizure (FS) is one of the most common types of seizures in childhood. Recurrent FS can result in hippocampus injury and thus impair learning capacity and memory, while the underlying molecular mechanisms are still elusive. Studies indicated that endoplasmic reticulum stress (ERS), involved in many diseases including some neurodegenerative diseases, can increase the expression of tribbles-related protein 3 (TRIB3), which thus inhibits the activity of AKT. The current study assessed whether ERS, TRIB3 and AKT signalling is involved in the hippocampus injury following recurrent FS. MAIN METHODS: Recurrent FS was induced in Sprague-Dawley (SD) rats by using a heated water-bath. TdT-mediated dUTP nick-end labeling (TUNEL) assay was performed to assess hippocampus apoptosis, and electron microscopy was used to examine ultrastructural changes. Protein expression and localization of TRIB3, glucose-regulated protein 78(GRP78) and CCAAT/enhancer-binding protein homologous protein (CHOP) as well as AKT were examined by using western blot and double immunofluorescence staining. Knockdown of TRIB3 was studied in primary cultured neurons treated with hyperthermia. KEY FINDINGS: As compared with control, apoptosis of hippocampus was significantly induced in FS group. Abundance of TRIB3, GRP78 and CHOP was remarkably elevated, while phosphor-AKT decreased significantly in hippocampus of rats with recurrent FS. Double immunofluorescence indicated that phosphor-AKT was not detected in cells with induction of TRIB3 in FS rats. Hyperthermia-treated cells showed up-regulates TRIB3 expression and that TRIB3 reduces AKT phosphorylation. SIGNIFICANCE: These results show that recurrent FS may induce injury of hippocampal cell by interfering with AKT activation through ERS-mediated up-regulation of TRIB3.