Multi-omics integration and epilepsy: Towards a better understanding of biological mechanisms.

The epilepsies are a group of complex neurological disorders characterised by recurrent seizures. Approximately 30% of patients fail to respond to anti-seizure medications, despite the recent introduction of many new drugs. The molecular processes underlying epilepsy development are not well understood and this knowledge gap impedes efforts to identify effective targets and develop novel therapies against epilepsy. Omics studies allow a comprehensive characterisation of a class of molecules. Omics-based biomarkers have led to clinically validated diagnostic and prognostic tests for personalised oncology, and more recently for non-cancer diseases. We believe that, in epilepsy, the full potential of multi-omics research is yet to be realised and we envisage that this review will serve as a guide to researchers planning to undertake omics-based mechanistic studies.

11ß-HSD1 participates in epileptogenesis and the associated cognitive impairment by inhibiting apoptosis in mice.

BACKGROUND: Glucocorticoid signalling is closely related to both epilepsy and associated cognitive impairment, possibly through mechanisms involving neuronal apoptosis. As a critical enzyme for glucocorticoid action, the role of 11ß-hydroxysteroid dehydrogenase 1 (11ß-HSD1) in epileptogenesis and associated cognitive impairment has not previously been studied. METHODS: We first investigated the expression of 11ß-HSD1 in the pentylenetetrazole (PTZ) kindling mouse model of epilepsy. We then observed the effect of overexpressing 11ß-HSD1 on the excitability of primary cultured neurons in vitro using whole-cell patch clamp recordings. Further, we assessed the effects of adeno-associated virus (AAV)-induced hippocampal 11ß-HSD1 knockdown in the PTZ model, conducting behavioural observations of seizures, assessment of spatial learning and memory using the Morris water maze, and biochemical and histopathological analyses. RESULTS: We found that 11ß-HSD1 was primarily expressed in neurons but not astrocytes, and its expression was significantly (p < 0.05) increased in the hippocampus of PTZ epilepsy mice compared to sham controls. Whole-cell patch clamp recordings showed that overexpression of 11ß-HSD1 significantly decreased the threshold voltage while increasing the frequency of action potential firing in cultured hippocampal neurons. Hippocampal knockdown of 11ß-HSD1 significantly reduced the severity score of PTZ seizures and increased the latent period required to reach the fully kindled state compared to control knockdown. Knockdown of 11ß-HSD1 also significantly mitigated the impairment of spatial learning and memory, attenuated hippocampal neuronal damage and increased the ratio of Bcl-2/Bax, while decreasing the expression of cleaved caspase-3. CONCLUSIONS: 11ß-HSD1 participates in the pathogenesis of both epilepsy and the associated cognitive impairment by elevating neuronal excitability and contributing to apoptosis and subsequent hippocampal neuronal damage. Inhibition of 11ß-HSD1, therefore, represents a promising strategy to treat epilepsy and cognitive comorbidity.

High sucrose diet does not impact spatial cognition in rats using advanced touchscreen technology.

INTRODUCTION: Western diets, including those consisting of saturated fats, simple sugars and processed foods, is rising at an unprecedented rate. These lead to obesity and metabolic diseases, and possibly cognitive deficits. Exploring this, recent studies demonstrate marked impairment in spatial learning in rodents exposed to high-sugar diets. We utilised advanced touchscreen technology to assess several spatial and non-spatial components of cognition in rats chronically exposed to a high sucrose diet. METHODS: Male Wistar rats received 70 ml of 10% sucrose solution each day, or control tap water, persisting for the experiment duration (total n = 32). After 5 weeks of diet, rats performed Pairwise Discrimination, Location Discrimination, or Progressive Ratio tasks on automated touchscreens, and performance compared between groups. RESULTS: Sucrose rats consumed all the sugar solution provided to them, and had significantly increased caloric intake, compared to controls (p < 0.0001). However, in all tests, we found no significant difference in cognitive performance between Sucrose and Control treated rats. This included the number of trials for acquisition, and reversal, in Pairwise Discrimination, and number of trials required to complete Location Discrimination (p > 0.05 for all outcomes). No differences were observed in perseverative behaviour, motivation levels, or processing speed. CONCLUSION: Our study found no evidence to suggest that chronic consumption of sucrose impairs cognition, including both spatial and non-spatial learning tasks. These findings suggest that not all aspects of spatial cognition are negatively impacted by high sugar diet in rodents, and that particular use of touchscreen technology may probe different aspects of cognition than traditional tasks.

Low prevalence of amyloid and tau pathology in drug-resistant temporal lobe epilepsy.

OBJECTIVE: Cognitive impairment is common in patients with chronic drug-resistant temporal lobe epilepsy (TLE). Hyperphosphorylated tau (pTau) and amyloid-ß (Aß) plaques, pathological hallmarks of Alzheimer disease, have been hypothesized to play a mechanistic role. We investigated Aß plaques and pTau prevalence in TLE patients who underwent resective surgery and correlated their presence with preoperative psychometric test scores and clinical factors. METHODS: Patients were retrospectively selected from the epilepsy surgery register of the Royal Melbourne Hospital, Australia. Sections from the resected temporal lobe were immunostained for pTau and Aß plaques (antibodies: AT8, 1E8). The presence and severity of pathology were correlated with clinical characteristics, and verbal and visual learning functions as measured by the Verbal Pair Associates (VPA) test and Rey Complex Figure Test. RESULTS: Fifty-six patients (55% female) aged 20-68 years (median = 34 years) at surgery were included. Aß plaques were detected in four patients (7%), all at the moderate level. There was no difference in duration, age at onset of epilepsy, or side of resection between patients with and without Aß plaques. Sparse pTau was found in two patients (3.5%). Both had moderate Aß plaques and were >50 years of age. Patients with Aß plaques had a lower median score for the VPA hard assessment compared to those without (0 vs. 4; p = .02). There was otherwise no correlation between pathology and psychometric test scores. SIGNIFICANCE: Aß plaques and pTau were uncommon in the resected brain tissue of patients who have undergone temporal lobectomy, and did not correlate with clinical characteristics or preoperative psychometric test scores, except for a lower VPA median score in patients with Aß plaques. Therefore, considering the low prevalence of Aß plaques and pTau herein observed, it is unlikely that cognitive impairment in TLE is driven by the same mechanisms as in Alzheimer disease.

Antagonism of the ATP-gated P2X7 receptor: a potential therapeutic strategy for cancer.

The P2X receptor 7 (P2X7R) is a plasma membrane receptor sensing extracellular ATP associated with a wide variety of cellular functions. It is most commonly expressed on immune cells and is highly upregulated in a number of human cancers where it can play a trophic role in tumorigenesis. Activation of this receptor leads to the formation of a non-selective cation channel, which has been associated with several cellular functions mediated by the PI3K/Akt pathway and protein kinases. Due to its broad range of functions, the receptor represents a potential therapeutic target for a number of cancers. This review describes the range of mechanisms associated with P2X7R activation in cancer settings and highlights the potential of targeted inhibition of P2X7R as a therapy. It also describes in detail a number of key P2X7R antagonists currently in pre-clinical and clinical development, including oxidised ATP, Brilliant Blue G (BBG), KN-62, KN-04, A740003, A438079, GSK1482160, CE-224535, JNJ-54175446, JNJ-55308942, and AZ10606120. Lastly, it summarises the in vivo studies and clinical trials associated with the use and development of these P2X7R antagonists in different disease contexts.

Inhibition of purinergic P2X receptor 7 (P2X7R) decreases granulocyte-macrophage colony-stimulating factor (GM-CSF) expression in U251 glioblastoma cells.

Glioblastoma is the most aggressive form of primary brain cancer, with a median survival of 12-15 months. The P2X receptor 7 (P2X7R) is upregulated in glioblastoma and is associated with increased tumor cell proliferation. The cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) is also upregulated in glioblastoma and has been shown to have both pro- and anti-tumor functions. This study investigates the potential mechanism linking P2X7R and GM-CSF in the U251 glioblastoma cell line and the therapeutic potential of P2X7R antagonism in this setting. P2X7R protein and mRNA was demonstrated to be expressed in the U251 cell line as assessed by immunocytochemistry and qPCR. Its channel function was intact as demonstrated by live cell confocal imaging using a calcium indicator Fluo-4 AM. Inhibition of P2X7R using antagonist AZ10606120, decreased both GM-CSF mRNA (P < 0.05) and protein (P < 0.01) measured by qPCR and ELISA respectively. Neutralization of GM-CSF with an anti-GM-CSF antibody did not alter U251 cell proliferation, however, P2X7R antagonism with AZ10606120 significantly reduced U251 glioblastoma cell numbers (P < 0.01). This study describes a novel link between P2X7R activity and GM-CSF expression in a human glioblastoma cell line and highlights the potential therapeutic benefit of P2X7R inhibition with AZ10606120 in glioblastoma.

The effects of cell therapy on seizures in animal models of epilepsy: protocol for systematic review and meta-analysis of preclinical studies.

BACKGROUND: Epilepsy is one of the most common and serious brain conditions, characterised by recurrent unprovoked seizures. It affects about 1% of the population worldwide. Despite a range of antiepileptic drugs being available, one third of the patients do not achieve adequate seizure control. Only a minority of these patients may be suitable to undergo surgical resection of the seizure focus, but this is an invasive and not always successful procedure. There is an urgent need to develop more effective treatment options for uncontrolled seizures. With the recent advances in regenerative and translational medicine, cell therapies could prove to be beneficial. Here we describe the protocol for a proposed systematic review and meta-analysis to assess the effects for cell transplantation in animal models of epilepsy. METHODS: We will include all preclinical animal models of epilepsy that evaluate the effects of cell transplantation compared to the untreated control. The primary outcome will be the change in frequency and duration of seizures from baseline measured by video electroencephalography (EEG). The secondary outcomes will include histological and neurobehavioural assessments. We will perform an electronic search of MEDLINE via PubMed, Web of Science, and EMBASE. Search results will be screened independently by two reviewers and confirmed by a third reviewer. Data from eligible studies will be extracted and pooled, and the summary estimate of effect size will be calculated using DerSimonian and Laird random effects meta-analysis. Heterogeneity will be explored using sub-group meta-analysis, and meta-regression risk of bias will be assessed by using the CAMARADES checklist for study quality tool. DISCUSSION: The purpose of this systematic review is to assess and summarise the existing literature in the field of cell transplantation as a treatment for epilepsy in animal models. Efficacy will be measured by evaluating the reduction in seizure intervals, number, and duration, within animal models of epilepsy. Analysis of the existing literature will mark the achievement made in the field and locate the existing gaps, a process that will aid in the search for the next needed step. SYSTEMATIC REVIEW REGISTRATION: CRD42018103628.

Raloxifene recovers effects of prenatal immune activation on cognitive task-induced gamma power.

There is currently no treatment available for the cognitive symptoms of schizophrenia, but evidence suggests that selective estrogen receptor modulators (SERMs) may provide relief. Our recent animal model data showed that a lack of female sex hormones in mice impairs the ability of hippocampal neurons to synchronise and generate oscillations within the frequency range of 30-80 Hz (gamma power) leading to cognitive impairment, while both estradiol and the SERM, raloxifene, recovered this. Given that cognitive impairment is accompanied by abnormal gamma power in schizophrenia, this study aimed to determine the effects of raloxifene on gamma power during spatial memory tasks in the prenatal immune challenged (poly-I:C) mouse model with relevance to schizophrenia. Pregnant dams received the viral mimetic poly-I:C (20 mg/kg, i.p.) at gestational day 17. Male and female offspring were treated with placebo or raloxifene implants at adulthood. Local field potentials from the CA1 hippocampus were simultaneously recorded during the Y-maze test of short term spatial memory and the cheeseboard maze test of long-term spatial learning and memory and cognitive flexibility. In female but not male mice, poly I:C exposure reduced gamma power during decision making and prolonged the time spent in the centre (decision making phase) during the Y-maze task. Female poly-I:C exposed mice also showed increased gamma power during acquisition of the cheeseboard long term memory task and perseverative behaviour. Treatment with raloxifene recovered gamma power and decision making deficits in the Y-maze and restored gamma power changes during the cheeseboard maze task as well as perseverative behaviour. Male mice showed no electrophysiological or behavioural effects of poly-I:C or raloxifene treatment. In summary, poly-I:C exposure induced female specific cognitive impairments accompanied by altered neural oscillations in the gamma frequency and raloxifene recovered these abnormalities.

Targeting high-mobility group box protein 1 (HMGB1) in pediatric traumatic brain injury: Chronic neuroinflammatory, behavioral, and epileptogenic consequences.

High mobility group box protein-1 (HMGB1) has been implicated as a key mediator of neuroinflammation and neurodegeneration in a range of neurological conditions including traumatic brain injury (TBI) and epilepsy. To date, however, most studies have examined only acute outcomes, and the adult brain. We have recently demonstrated HMGB1 release after experimental TBI in the pediatric mouse. This study therefore examined the chronic consequences of acute HMGB1 inhibition in the same model, to test the hypothesis that HMGB1 is a pivotal mediator of neuropathological, neurobehavioral, and epilepsy outcomes in pediatric TBI. HMGB1 was inhibited by treatment with 50 mg/kg i.p. Glycyrrhizin (Gly), compared to vehicle controls, commencing 1 h prior to moderate TBI or sham surgery in post-natal day 21 mice. We first demonstrated that Gly reduced brain HMGB1 levels and brain edema at an acute time point of 3 days post-injury. Subsequent analysis over a chronic time course found that pediatric TBI resulted in short-term spatial memory and motor learning deficits alongside an apparent increase in hippocampal microglial reactivity, which was prevented in Gly-treated TBI mice. In contrast, Gly treatment did not reduce the severity of evoked seizures, the proportion of animals exhibiting chronic spontaneous seizure activity, or cortical tissue loss. Together, our findings contribute to a growing appreciation for HMGB1's role in neuropathology and associated behavioral outcomes after TBI. However, further work is needed to fully elucidate the contribution of HMGB1 to epileptogenesis in this context.

Targeting Glioma Stem Cells by Functional Inhibition of Dynamin 2: A Novel Treatment Strategy for Glioblastoma.

Glioma stem cells (GSCs) play major roles in drug resistance, tumour maintenance and recurrence of glioblastoma. We investigated inhibition of the GTPase dynamin 2 as a therapy for glioblastoma. Glioma cell lines and patient-derived GSCs were treated with dynamin inhibitors, Dynole 34-2 and CyDyn 4-36. We studied about cell viability, and GSC neurosphere formation in vitro and orthotopic tumour growth in vivo. Dynamin inhibition reduced glioblastoma cell line viability and suppressed neurosphere formation and migration of GSCs. Tumour growth was reduced by CyDyn 4-36 treatment. Dynamin 2 inhibition therefore represents a novel approach for stem cell-directed Glioblastoma therapy.

Somatic GNAQ mutation in the forme fruste of Sturge-Weber syndrome.

OBJECTIVE: To determine whether the GNAQ R183Q mutation is present in the forme fruste cases of Sturge-Weber syndrome (SWS) to establish a definitive molecular diagnosis. METHODS: We used sensitive droplet digital PCR (ddPCR) to detect and quantify the GNAQ mutation in tissues from epilepsy surgery in 4 patients with leptomeningeal angiomatosis; none had ocular or cutaneous manifestations. RESULTS: Low levels of the GNAQ mutation were detected in the brain tissue of all 4 cases-ranging from 0.42% to 7.1% frequency-but not in blood-derived DNA. Molecular evaluation confirmed the diagnosis in 1 case in which the radiologic and pathologic data were equivocal. CONCLUSIONS: We detected the mutation at low levels, consistent with mosaicism in the brain or skin (1.0%-18.1%) of classic cases. Our data confirm that the forme fruste is part of the spectrum of SWS, with the same molecular mechanism as the classic disease and that ddPCR is helpful where conventional diagnosis is uncertain.

Estradiol and raloxifene modulate hippocampal gamma oscillations during a spatial memory task.

Previous work suggests that estradiol regulates the expression of hippocampal parvalbumin as well as hippocampus-dependent spatial memory in mice. Parvalbumin interneurons generate neuronal oscillatory activity in the gamma frequency range (30-80Hz) and gamma oscillations are closely linked with higher cognitive functions. Raloxifene, a selective estrogen receptor modulator, shows beneficial effects on human cognitive performance, and has few peripheral side effects unlike estradiol, but the biological mechanisms which underpin these benefits are not clear. This study aimed to investigate whether estradiol and raloxifene modulate hippocampal gamma-band oscillations during spatial memory performance. Prepubescent female mice were ovariectomized (OVX) and implanted with a subcutaneous pellet of either estradiol (E2), raloxifene or placebo. During adulthood, local field potentials were recorded from the dorsal hippocampus while mice were performing the Y-maze hippocampus-dependent spatial memory task. Ovariectomy caused deficits in spatial memory, accompanied by a significant reduction in hippocampal gamma oscillations, specifically during decision making. Estradiol as well as raloxifene rescued both behavioural and electrophysiological deficits. These data have significant implications for disorders of cognitive impairment where altered gamma oscillations are apparent, such as schizophrenia.

Mutations of the Sonic Hedgehog Pathway Underlie Hypothalamic Hamartoma with Gelastic Epilepsy.

Hypothalamic hamartoma (HH) with gelastic epilepsy is a well-recognized drug-resistant epilepsy syndrome of early life.(1) Surgical resection allows limited access to the small deep-seated lesions that cause the disease. Here, we report the results of a search for somatic mutations in paired hamartoma- and leukocyte-derived DNA samples from 38 individuals which we conducted by using whole-exome sequencing (WES), chromosomal microarray (CMA), and targeted resequencing (TRS) of candidate genes. Somatic mutations were identified in genes involving regulation of the sonic hedgehog (Shh) pathway in 14/38 individuals (37%). Three individuals had somatic mutations in PRKACA, which encodes a cAMP-dependent protein kinase that acts as a repressor protein in the Shh pathway, and four subjects had somatic mutations in GLI3, an Shh pathway gene associated with HH. In seven other individuals, we identified two recurrent and three single brain-tissue-specific, large copy-number or loss-of-heterozygosity (LOH) variants involving multiple Shh genes, as well as other genes without an obvious biological link to the Shh pathway. The Shh pathway genes in these large somatic lesions include the ligand itself (SHH and IHH), the receptor SMO, and several other Shh downstream pathway members, including CREBBP and GLI2. Taken together, our data implicate perturbation of the Shh pathway in at least 37% of individuals with the HH epilepsy syndrome, consistent with the concept of a developmental pathway brain disease.

Neuregulin 1 expression and electrophysiological abnormalities in the Neuregulin 1 transmembrane domain heterozygous mutant mouse.

BACKGROUND: The Neuregulin 1 transmembrane domain heterozygous mutant (Nrg1 TM HET) mouse is used to investigate the role of Nrg1 in brain function and schizophrenia-like behavioural phenotypes. However, the molecular alterations in brain Nrg1 expression that underpin the behavioural observations have been assumed, but not directly determined. Here we comprehensively characterise mRNA Nrg1 transcripts throughout development of the Nrg1 TM HET mouse. In addition, we investigate the regulation of high-frequency (gamma) electrophysiological oscillations in this mutant mouse to associate molecular changes in Nrg1 with a schizophrenia-relevant neurophysiological profile. METHODS: Using exonic probes spanning the cysteine-rich, epidermal growth factor (EGF)-like, transmembrane and intracellular domain encoding regions of Nrg1, mRNA levels were measured using qPCR in hippocampus and frontal cortex from male and female Nrg1 TM HET and wild type-like (WT) mice throughout development. We also performed electrophysiological recordings in adult mice and analysed gamma oscillatory at baseline, in responses to auditory stimuli and to ketamine. RESULTS: In both hippocampus and cortex, Nrg1 TM HET mice show significantly reduced expression of the exon encoding the transmembrane domain of Nrg1 compared with WT, but unaltered mRNA expression encoding the extracellular bioactive EGF-like and the cysteine-rich (type III) domains, and development-specific and region-specific reductions in the mRNA encoding the intracellular domain. Hippocampal Nrg1 protein expression was not altered, but NMDA receptor NR2B subunit phosphorylation was lower in Nrg1 TM HET mice. We identified elevated ongoing and reduced sensory-evoked gamma power in Nrg1 TM HET mice. INTERPRETATION: We found no evidence to support the claim that the Nrg1 TM HET mouse represents a simple haploinsufficient model. Further research is required to explore the possibility that mutation results in a gain of Nrg1 function.

Memory impairment in rats after desflurane anesthesia is age and dose dependent.

Post-operative cognitive dysfunction (POCD) predominantly affects the elderly who suffer memory and concentration deficits after anesthesia and surgery. Animal studies have demonstrated anesthetic alone may contribute to POCD but results are variable and little is known about common anesthetics other than isoflurane. The present study investigated dose-dependence of desflurane anesthesia in young adult and aged rats. We hypothesize higher concentrations of desflurane will result in memory impairment in the water maze and that impairment will be worse in aged rats. Effects of anesthesia (1 or 1.5 MAC, 4 h) desflurane, or sham exposure on cognition were investigated in young adult (3 months) and aged (20-24 months) rats at 1, 4, and 12 weeks post-exposure. The Morris water maze was used to assess acquisition and retention of spatial reference memory. Latency to find the hidden platform and swimming speed were compared between treatments. Aged rats showed significant impairment in task acquisition after exposure to 1.5 MAC, but not 1.0 MAC desflurane anesthetic when tested 1 week following exposure. Latency to find the platform and distance travelled were significantly longer in aged rats given 1.5 MAC desflurane (latency: F(1,108) = 19.71, p < 0.0001; distance: F(1,108) = 5.79, p = 0.018). Deficits were not long-lasting and were no longer present at 4 or 12 weeks. In contrast, young adult rats performed equally as well as sham-exposed control rats irrespective of desflurane dose. This study showed the effects of desflurane on learning and memory in the water maze are age and dose dependent and are brief in duration.

Granulocyte-macrophage colony-stimulating factor is neuroprotective in experimental traumatic brain injury.

Traumatic brain injury (TBI) is an international health concern with a complex pathogenesis resulting in major long-term neurological, neurocognitive, and neuropsychiatric outcomes. Although neuroinflammation has been identified as an important pathophysiological process resulting from TBI, the function of specific inflammatory mediators in the aftermath of TBI remains poorly understood. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is an inflammatory cytokine that has been reported to have neuroprotective effects in various animal models of neurodegenerative disease that share pathological similarities with TBI. The importance of GM-CSF in TBI has yet to be studied, however. We examined the role of GM-CSF in TBI by comparing the effects of a lateral fluid percussion (LFP) injury or sham injury in GM-CSF gene deficient (GM-CSF(-/-)) versus wild-type (WT) mice. After a 3-month recovery interval, mice were assessed using neuroimaging and behavioral outcomes. All mice given a LFP injury displayed significant brain atrophy and behavioral impairments compared with those given sham-injuries; however, this was significantly worse in the GM-CSF(-/-) mice compared with the WT mice. GM-CSF(-/-) mice given LFP injury also had reduced astrogliosis compared with their WT counterparts. These novel findings indicate that the inflammatory mediator, GM-CSF, may have significant protective properties in the chronic sequelae of experimental TBI and suggest that further research investigating GM-CSF and its potential benefits in the injured brain is warranted.

Hyperphosphorylated tau is implicated in acquired epilepsy and neuropsychiatric comorbidities.

Epilepsy is a common group of neurological diseases. Acquired epilepsy can be caused by brain insults, such as trauma, infection or tumour, and followed by a latent period from several months to years before the emergence of recurrent spontaneous seizures. More than 50% of epilepsy cases will develop chronic neurodegenerative, neurocognitive and neuropsychiatric comorbidities. It is important to understand the mechanisms by which a brain insult results in acquired epilepsy and comorbidities in order to identify targets for novel therapeutic interventions that may mitigate these outcomes. Recent studies have implicated the hyperphosphorylated tubulin-associated protein (tau) in rodent models of epilepsy and Alzheimer's disease, and in experimental and clinical studies of traumatic brain injury. This potentially represents a novel target to mitigate epilepsy and associated neurocognitive and psychiatric disorders post-brain injury. This article reviews the potential role of tau-based mechanisms in the pathophysiology of acquired epilepsy and its neurocognitive and neuropsychiatric comorbidities, and the potential to target these for novel disease-modifying treatments.

Targeting hyperphosphorylated tau with sodium selenate suppresses seizures in rodent models.

Tau hyperphosphorylation has been implicated in the pathogenesis of a variety of forms of human epilepsy. Here we investigated whether treatment with sodium selenate, a drug which reduces pathological hyperphosphorylated tau by enhancement of PP2A activity, would inhibit seizures in rodent models. In vitro, sodium selenate reduced tau phosphorylation in human neuroblastoma cells and reversed the increase in tau phosphorylation induced by the PP2A inhibitor, okadaic acid. Sodium selenate treatment was then tested against three different rodent seizure models. Firstly the propensity of 6-Hz electrical corneal stimulation to induce seizures in adult mice was assessed following acute treatment with different doses of sodium selenate. Secondly, the number of seizures induced by pentylenetetrazole (PTZ) was quantified in rats following chronic sodium selenate treatment via drinking water. Finally, amygdala kindled rats were chronically treated with sodium selenate in drinking water and the length and the severity of the seizures evoked by stimulation of the amygdala recorded. The results demonstrated a dose-dependent protection of sodium selenate against 6-Hz stimulation induced seizures, and significant reduction in the total number of seizures following PTZ injection. Amygdala kindled rats chronically treated with sodium selenate had significantly shorter seizure duration compared controls, with more pronounced effects observed as the duration of treatment increased. The results of this study indicate that targeting hyperphosphorylated tau by treatment with sodium selenate has anti-seizure effects in a broad range of rodent models, and may represent a novel approach to treatment of patients with epilepsy.

Inhibition of dynamin by dynole 34-2 induces cell death following cytokinesis failure in cancer cells.

Inhibitors of mitotic proteins such as Aurora kinase and polo-like kinase have shown promise in preclinical or early clinical development for cancer treatment. We have reported that the MiTMAB class of dynamin small molecule inhibitors are new antimitotic agents with a novel mechanism of action, blocking cytokinesis. Here, we examined 5 of the most potent of a new series of dynamin GTPase inhibitors called dynoles. They all induced cytokinesis failure at the point of abscission, consistent with inhibition of dynamin while not affecting other cell cycle stages. All 5 dynoles inhibited cell proliferation (MTT and colony formation assays) in 11 cancer cell lines. The most potent GTPase inhibitor, dynole 34-2, also induced apoptosis, as revealed by cell blebbing, DNA fragmentation, and PARP cleavage. Cell death was induced specifically following cytokinesis failure, suggesting that dynole 34-2 selectively targets dividing cells. Dividing HeLa cells were more sensitive to the antiproliferative properties of all 5 dynoles compared with nondividing cells, and nontumorigenic fibroblasts were less sensitive to cell death induced by dynole 34-2. Thus, the dynoles are a second class of dynamin GTPase inhibitors, with dynole 34-2 as the lead compound, that are novel antimitotic compounds acting specifically at the abscission stage.

Experimental traumatic brain injury induces a pervasive hyperanxious phenotype in rats.

Mood disturbances, including depression and anxiety disorders, are common and disabling long-term sequelae of traumatic brain injury (TBI). These psychiatric conditions have generally been considered psychosocial consequences of the trauma, but neurobiological alterations and causes have also been implicated. Using a rat model of TBI (lateral fluid-percussion injury), this longitudinal study seeks to assess anxiety and depression-like behaviors following experimental TBI. Male Wistar rats (n = 20) received a severe (approximately 3.5 atmosphere) pressure pulse directed to the right sensorimotor cortex, or sham surgery (n = 15). At 1, 3, and 6 months following injury, all rats underwent four assessments of anxiety and depression-like behaviors: exposure to an open field, elevated plus maze test, the forced swim test, and the sucrose preference test. Injured animals displayed increased anxiety-like behaviors throughout the study, as evidenced by reduced time spent (p = 0.014) and reduced entries (p < 0.001) into the center area of the open field, and reduced proportion of time in the open arms of the plus maze (p = 0.015), compared to sham-injured controls. These striking changes were particularly evident 1 and 3 months after injury. No differences were observed in depression-like behaviors in the forced swim test (a measure of behavioral despair) and the sucrose preference test (a measure of anhedonia). This report provides the first evidence of persistent anxiety-like disturbances in an experimental model of TBI. This finding indicates that the common occurrence of these symptoms in human sufferers is likely to have, at least in part, a neurobiological basis. Studies in this model could provide insight into the mechanisms underlying affective disturbance in brain-injured patients.