Camila Vicencio Esguerra

• Marszałek-Grabska, Marta; Hułas-Stasiak, Monika; Bekenova, Saadat; Grenda, Anna; Szulc, Michał & Esguerra, Camila [Vis alle 9 forfattere av denne artikkelen] (2026). Lithium pretreatment does not affect pilocarpine-induced seizure-like activity in zebrafish larvae. Pharmacological Reports. ISSN 1734-1140. doi: 10.1007/s43440-026-00905-y. Fulltekst i vitenarkiv Vis sammendrag

  Background Recently, it has been reported that pilocarpine (PILO) induces seizures in zebrafish larvae. It has also been shown that acute PILO-induced convulsions result in unprovoked seizure-like discharges 24 hours later. Since lithium (Li) pretreatment potentiates the convulsions induced by PILO in rodents, this study was undertaken to evaluate the effect of Li on PILO-induced seizures in zebrafish larvae. Methods Experiments were conducted on zebrafish larvae up to 5 days post-fertilization. Larvae were pre-exposed to Li and then exposed to PILO. Local field potentials from the optic tectum were recorded and subjected to quantitative spectral analysis, including power spectral density estimation, band-specific power analysis, and automated ictal-event detection based on root mean square thresholding. Locomotor activity, followed by quartile-based population analysis as a potential behavioral correlate of seizure activity, was investigated. TUNEL-based apoptosis quantification and mRNA expression of neuronal activity markers npas4α and c-fos were examined. Results It was found, that pre-exposure to Li does not affect PILO-induced seizures. PILO induced seizure-like discharges in Li-pretreated larvae comparable to those evoked by PILO alone, and similarly to PILO, resulted in spontaneous, unprovoked paroxysmal brain activity 24 hours post-exposure. Spectral analysis revealed persistent increases in theta, alpha, and beta band power at the 24-hour time point, accompanied by brain apoptosis. At this time, an increase in npas4α expression was found in naïve larvae exposed to PILO. Results of quartile-based locomotor analysis, but not aggregate distance measures, correlate with seizure-like activity. Conclusions Both PILO and Li+PILO zebrafish paradigms offer a reproducible, ethically advantageous platform for conducting research related to early-onset epilepsy and for antiseizure medication screening targeting this age group.

• Nieoczym, Dorota; Marszalek-Grabska, Marta; Szalak, Radoslaw; Kundap, Uday; Kaczor, Agnieszka A. & Wrobel, Tomasz M. [Vis alle 16 forfattere av denne artikkelen] (2024). A comprehensive assessment of palmatine as anticonvulsant agent – In vivo and in silico studies. Biomedicine & Pharmacotherapy. ISSN 0753-3322. 172. doi: 10.1016/j.biopha.2024.116234. Fulltekst i vitenarkiv
• Shojaeinia, Elham; Mastracci, Teresa L.; Soliman, Remon; Devinsky, Orrin; Esguerra, Camila & Crawford, Alexander Dettmar (2024). Deoxyhypusine synthase deficiency syndrome zebrafish model: aberrant morphology, epileptiform activity, and reduced arborization of inhibitory interneurons. Molecular Brain. 17. doi: 10.1186/s13041-024-01139-w. Fulltekst i vitenarkiv Vis sammendrag

  DHPS deficiency syndrome is an ultra-rare neurodevelopmental disorder (NDD) which results from biallelic mutations in the gene encoding the enzyme deoxyhypusine synthase (DHPS). DHPS is essential to synthesize hypusine, a rare amino acid formed by post-translational modification of a conserved lysine in eukaryotic initiation factor 5 A (eIF5A). DHPS deficiency syndrome causes epilepsy, cognitive and motor impairments, and mild facial dysmorphology. In mice, a brain-specific genetic deletion of Dhps at birth impairs eIF5AHYP-dependent mRNA translation. This alters expression of proteins required for neuronal development and function, and phenotypically models features of human DHPS deficiency. We studied the role of DHPS in early brain development using a zebrafish loss-of-function model generated by knockdown of dhps expression with an antisense morpholino oligomer (MO) targeting the exon 2/intron 2 (E2I2) splice site of the dhps pre-mRNA. dhps knockdown embryos exhibited dose-dependent developmental delay and dysmorphology, including microcephaly, axis truncation, and body curvature. In dhps knockdown larvae, electrophysiological analysis showed increased epileptiform activity, and confocal microscopy analysis revealed reduced arborisation of GABAergic neurons. Our findings confirm that hypusination of eIF5A by DHPS is needed for early brain development, and zebrafish with an antisense knockdown of dhps model features of DHPS deficiency syndrome.

• Gawel, Kinga Aurelia; Hulas-Stasiak, Monika; Marszalek-Grabska, Marta; Grenda, Anna; Siekierska, Aleksandra & Kosheva, Nataliia [Vis alle 10 forfattere av denne artikkelen] (2024). Induction of seizures and initiation of epileptogenesis by pilocarpine in zebrafish larvae. Frontiers in Molecular Neuroscience. 17. doi: 10.3389/fnmol.2024.1418606. Fulltekst i vitenarkiv Vis sammendrag

  Objective: Preclinical models of seizures and epilepsy in rodents contributed substantially to the discovery of currently available antiseizure medications. These were also broadly used for investigation of processes of epileptogenesis. Nevertheless, rodent models pose some limitations, thus, new models using alternative species are in high demand. The aim of this study was to describe a new model of seizures/epilepsy induced by the cholinomimetic agent, pilocarpine (PILO), in larval zebrafish. Methods: Local field potential (LFP) recordings were conducted to analyze electroencephalographic discharges and correlate it with larval behavior. Hematoxylin and eosin (H&E) staining, as well as TUNEL staining were performed to analyze morphology and apoptosis, respectively. Real-time quantitative polymerase chain reaction (qRT-PCR) was undertaken for gene expression analysis. Results: Acute exposure to PILO, in a concentration-dependent manner, induces electroencephalographic discharges in larval zebrafish, which behaviorally manifest as decreased locomotion and moving time, but enhanced movement velocity. The PILO-induced seizure-like activity is behaviorally distinct from this induced by the application of chemoconvulsant pentylenetetrazole (PTZ). Zebrafish larvae previously exposed to PILO (2 h), after a washing out period, exhibit spontaneous, unprovoked discharges and apoptotic changes in their brains. Significance: Here, we comprehensively investigated a new model of PILO-induced seizures/epilepsy in larval zebrafish. We propose that this model may be used to study epileptogenesis and for antiseizure drug screening purposes.

• Melikishvili, Gia; Striano, Pasquale; Shojaeinia, Elham; Gachechiladze, Tamar; Kurua, Ekaterine & Tabatadze, Nazhi [Vis alle 18 forfattere av denne artikkelen] (2024). Effectiveness of add-on acetazolamide in children with drug-resistant CHD2-related epilepsy and in a zebrafish CHD2 model. Epilepsia Open. 9(5). doi: 10.1002/epi4.13034. Fulltekst i vitenarkiv Vis sammendrag

  CHD2-related epilepsy is characterized by early-onset photosensitive myoclonic epilepsy with developmental delay and a high rate of pharmacoresistance. We sought to evaluate the efficacy of acetazolamide (ACZ) in CHD2-related epilepsy, due to ACZ's unexpected efficacy in our first patient harboring a pathogenic CHD2 variant. We collected patients from different Eastern European countries with drug-resistant CHD2-related epilepsy who were then treated with ACZ. Patients underwent video EEG before and during ACZ treatment. In a zebrafish model of CHD2-related epilepsy, ictal-like events were recorded 5 days post-fertilization after overnight ACZ exposure. Developmental delay preceded the onset of seizures in 10 of the 12 patients. Four had ataxia, and 6 exhibited autistic features. Seizures, primarily myoclonic, began at an average age of 3.4 years and were photosensitive in all 12 patients. Add-on ACZ treatment controlled photosensitive seizures in all patients: 6 became seizure-free, and in the remaining 6, seizure frequency decreased by over 75%. Four patients transitioned to ACZ monotherapy. The median follow-up was 13 months. In the zebrafish model, ACZ exposure reduced ictal-like events by 72%. ACZ, a well-tolerated and cost-effective medication, could be a good option for CHD2-related epilepsy, predominantly manifesting with myoclonic seizures and photosensitivity.

• Nieoczym, Dorota; Banono, Nancy Saana; Stępnik, Katarzyna; Kaczor, Agnieszka A.; Szybkowski, Przemysław & Esguerra, Camila [Vis alle 8 forfattere av denne artikkelen] (2023). In Silico Analysis, Anticonvulsant Activity, and Toxicity Evaluation of Schisandrin B in Zebrafish Larvae and Mice. International Journal of Molecular Sciences. ISSN 1661-6596. 24(16). doi: 10.3390/ijms241612949. Fulltekst i vitenarkiv Vis sammendrag

  The aim of this study is to evaluate the anticonvulsant potential of schisandrin B, a main ingredient of Schisandra chinensis extracts. Schisandrin B showed anticonvulsant activity in the zebrafish larva pentylenetetrazole acute seizure assay but did not alter seizure thresholds in the intravenous pentylenetetrazole test in mice. Schisandrin B crosses the blood–brain barrier, which we confirmed in our in silico and in vivo analyses; however, the low level of its unbound fraction in the mouse brain tissue may explain the observed lack of anticonvulsant activity. Molecular docking revealed that the anticonvulsant activity of the compound in larval zebrafish might have been due to its binding to a benzodiazepine site within the GABAA receptor and/or the inhibition of the glutamate NMDA receptor. Although schisandrin B showed a beneficial anticonvulsant effect, toxicological studies revealed that it caused serious developmental impairment in zebrafish larvae, underscoring its teratogenic properties. Further detailed studies are needed to precisely identify the properties, pharmacological effects, and safety of schisandrin B.

• Skiba, Adrianna; Kozioł, Ewelina; Luca, Simon Vlad; Budzyńska, Barbara; Podlasz, Piotr & Ent, Wietske van der [Vis alle 12 forfattere av denne artikkelen] (2023). Evaluation of the Antiseizure Activity of Endemic Plant Halfordia kendack Guillaumin and Its Main Constituent, Halfordin, on a Zebrafish Pentylenetetrazole (PTZ)-Induced Seizure Model. International Journal of Molecular Sciences. ISSN 1661-6596. 24(3). doi: 10.3390/ijms24032598. Fulltekst i vitenarkiv Vis sammendrag

  Epilepsy is a neurological disease that burdens over 50 million people worldwide. Despite the considerable number of available antiseizure medications, it is estimated that around 30% of patients still do not respond to available treatment. Herbal medicines represent a promising source of new antiseizure drugs. This study aimed to identify new drug lead candidates with antiseizure activity from endemic plants of New Caledonia. The crude methanolic leaf extract of Halfordia kendack Guillaumin (Rutaceae) significantly decreased (75 μg/mL and 100 μg/mL) seizure-like behaviour compared to sodium valproate in a zebrafish pentylenetetrazole (PTZ)-induced acute seizure model. The main coumarin compound, halfordin, was subsequently isolated by liquid-liquid chromatography and subjected to locomotor, local field potential (LFP), and gene expression assays. Halfordin (20 μM) significantly decreased convulsive-like behaviour in the locomotor and LFP analysis (by 41.4% and 60%, respectively) and significantly modulated galn, and penka gene expression.

• Desalegn, Anteneh Assefa; Ent, Wietske van der; Lenters, Virissa Claire; Torcelino-Iszatt, Nina Louise; Stigum, Hein & Lyche, Jan Ludvig [Vis alle 10 forfattere av denne artikkelen] (2023). Perinatal exposure to potential endocrine disrupting chemicals and autism spectrum disorder: From Norwegian birth cohort to zebrafish studies. Environment International. ISSN 0160-4120. 181. doi: 10.1016/j.envint.2023.108271. Fulltekst i vitenarkiv Vis sammendrag

  Background The etiology of autism spectrum disorder (ASD) is multifactorial, involving genetic and environmental contributors such as endocrine-disrupting chemicals (EDCs). Objective To evaluate the association between perinatal exposure to 27 potential EDCs and ASD among Norwegian children, and to further examine the neurodevelopmental toxicity of associated chemicals using zebrafish embryos and larvae. Method 1,199 mothers enrolled in the prospective birth-cohort (HUMIS, 2002–2009) study. Breastmilk levels of 27 chemicals were measured: polychlorinated biphenyls, organochlorine pesticides, polybrominated diphenyl ethers, and perfluoroalkyl substances as a proxy for perinatal exposure. We employed multivariable logistic regression to determine association, utilized elastic net logistic regression as variable selection method, and conducted an in vivo study with zebrafish larvae to confirm the neurodevelopmental effect. Results A total of 20 children had specialist confirmed diagnosis of autism among 1,199 mother–child pairs in this study. β-Hexachlorocyclohexane (β-HCH) was the only chemical associated with ASD, after adjusting for 26 other chemicals. Mothers with the highest levels of β-HCH in their milk had a significant increased risk of having a child with ASD (OR = 1.82, 95 % CI: 1.20, 2.77 for an interquartile range increase in ln-transformed β-HCH concentration). The median concentration of β-HCH in breast milk was 4.37 ng/g lipid (interquartile range: 2.92–6.47), and the estimated daily intake (EDI) for Norwegian children through breastfeeding was 0.03 µg/kg of body weight. The neurodevelopmental and social behavioral effects of β-HCH were established in zebrafish embryos and larvae across various concentrations, with further analysis suggesting that perturbation of dopaminergic neuron development may underlie the neurotoxicity associated with β-HCH. Conclusions Prenatal exposure to β-HCH was associated with an increased risk of specialist-confirmed diagnoses of ASD among Norwegian children, and the EDI surpasses the established threshold. Zebrafish experiments confirm β-HCH neurotoxicity, suggesting dopaminergic neuron disruption as a potential underlying mechanism.

• Abram, Michał; Jakubiec, Marcin; Reeb, Katelyn; Cheng, Mary Hongying; Gedschold, Robin & Rapacz, Anna [Vis alle 22 forfattere av denne artikkelen] (2022). Discovery of (R)- N-Benzyl-2-(2,5-dioxopyrrolidin-1-yl)propanamide [ (R)-AS-1 ], a Novel Orally Bioavailable EAAT2 Modulator with Drug-like Properties and Potent Antiseizure Activity in Vivo. Journal of Medicinal Chemistry. ISSN 0022-2623. 65(17), s. 11703–11725. doi: 10.1021/acs.jmedchem.2c00534. Fulltekst i vitenarkiv Vis sammendrag

  (R)-7 [(R)-AS-1] showed broad-spectrum antiseizure activity across in vivo mouse seizure models: maximal electroshock (MES), 6 Hz (32/44 mA), acute pentylenetetrazol (PTZ), and PTZ-kindling. A remarkable separation between antiseizure activity and CNS-related adverse effects was also observed. In vitro studies with primary glia cultures and COS-7 cells expressing the glutamate transporter EAAT2 showed enhancement of glutamate uptake, revealing a stereoselective positive allosteric modulator (PAM) effect, further supported by molecular docking simulations. (R)-7 [(R)-AS-1] was not active in EAAT1 and EAAT3 assays and did not show significant off-target activity, including interactions with targets reported for marketed antiseizure drugs, indicative of a novel and unprecedented mechanism of action. Both in vivo pharmacokinetic and in vitro absorption, distribution, metabolism, excretion, toxicity (ADME-Tox) profiles confirmed the favorable drug-like potential of the compound. Thus, (R)-7 [(R)-AS-1] may be considered as the first-in-class small-molecule PAM of EAAT2 with potential for further preclinical and clinical development in epilepsy and possibly other CNS disorders.

• Silvennoinen, Katri; Gawel, Kinga Aurelia; Tsortouktzidis, Despina; Pitsch, Julika; Alhusaini, Saud & Loo, Karen M. J. van [Vis alle 26 forfattere av denne artikkelen] (2022). SCN1A overexpression, associated with a genomic region marked by a risk variant for a common epilepsy, raises seizure susceptibility. Acta Neuropathologica. ISSN 0001-6322. 144(1), s. 107–127. doi: 10.1007/s00401-022-02429-0. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Mesial temporal lobe epilepsy with hippocampal sclerosis and a history of febrile seizures is associated with common variation at rs7587026, located in the promoter region of SCN1A. We sought to explore possible underlying mechanisms. SCN1A expression was analysed in hippocampal biopsy specimens of individuals with mesial temporal lobe epilepsy with hippocampal sclerosis who underwent surgical treatment, and hippocampal neuronal cell loss was quantitatively assessed using immunohistochemistry. In healthy individuals, hippocampal volume was measured using MRI. Analyses were performed stratified by rs7587026 type. To study the functional consequences of increased SCN1A expression, we generated, using transposon-mediated bacterial artificial chromosome transgenesis, a zebrafish line expressing exogenous scn1a , and performed EEG analysis on larval optic tecta at 4 day post-fertilization. Finally, we used an in vitro promoter analysis to study whether the genetic motif containing rs7587026 influences promoter activity. Hippocampal SCN1A expression differed by rs7587026 genotype (Kruskal–Wallis test P  = 0.004). Individuals homozygous for the minor allele showed significantly increased expression compared to those homozygous for the major allele (Dunn’s test P  = 0.003), and to heterozygotes (Dunn’s test P  = 0.035). No statistically significant differences in hippocampal neuronal cell loss were observed between the three genotypes. Among 597 healthy participants, individuals homozygous for the minor allele at rs7587026 displayed significantly reduced mean hippocampal volume compared to major allele homozygotes (Cohen’s D  = − 0.28, P  = 0.02), and to heterozygotes (Cohen’s D  = − 0.36, P  = 0.009). Compared to wild type, scn1lab -overexpressing zebrafish larvae exhibited more frequent spontaneous seizures [one-way ANOVA F (4,54) = 6.95 ( P  < 0.001)]. The number of EEG discharges correlated with the level of scn1lab overexpression [one-way ANOVA F (4,15) = 10.75 ( P  < 0.001]. Finally, we showed that a 50 bp promoter motif containing rs7587026 exerts a strong regulatory role on SCN1A expression, though we could not directly link this to rs7587026 itself. Our results develop the mechanistic link between rs7587026 and mesial temporal lobe epilepsy with hippocampal sclerosis and a history of febrile seizures. Furthermore, we propose that quantitative precision may be important when increasing SCN1A expression in current strategies aiming to treat seizures in conditions involving SCN1A haploinsufficiency, such as Dravet syndrome.

• Gawel, Kinga Aurelia; Kukula-Koch, Wirginia; Banono, Nancy Saana; Nieoczym, Dorota; Targowska-Duda, Katarzyna M & Czernicka, Lidia [Vis alle 8 forfattere av denne artikkelen] (2021). 6-Gingerol, a Major Constituent of Zingiber officinale Rhizoma, Exerts Anticonvulsant Activity in the Pentylenetetrazole-Induced Seizure Model in Larval Zebrafish. International Journal of Molecular Sciences. ISSN 1661-6596. 22(14), s. 1–22. doi: 10.3390/ijms22147745. Fulltekst i vitenarkiv Vis sammendrag

  Zingiber officinale is one of the most frequently used medicinal herbs in Asia. Using rodent seizure models, it was previously shown that Zingiber officinale hydroethanolic extract exerts antiseizure activity, but the active constituents responsible for this effect have not been determined. In this paper, we demonstrated that Zingiber officinale methanolic extract exerts anticonvulsant activity in the pentylenetetrazole (PTZ)-induced hyperlocomotion assay in larval zebrafish. Next, we isolated 6-gingerol (6-GIN)—a major constituent of Zingiber officinale rhizoma. We observed that 6-GIN exerted potent dose-dependent anticonvulsant activity in the PTZ-induced hyperlocomotion seizure assay in zebrafish, which was confirmed electroencephalographically. To obtain further insight into the molecular mechanisms of 6-GIN antiseizure activity, we assessed the concentration of two neurotransmitters in zebrafish, i.e., inhibitory γ-aminobutyric acid (GABA) and excitatory glutamic acid (GLU), and their ratio after exposure to acute PTZ dose. Here, 6-GIN decreased GLU level and reduced the GLU/GABA ratio in PTZ-treated fish compared with only PTZ-bathed fish. This activity was associated with the decrease in grin2b, but not gabra1a, grin1a, gria1a, gria2a, and gria3b expression in PTZ-treated fish. Molecular docking to the human NR2B-containing N-methyl-D-aspartate (NMDA) receptor suggests that 6-GIN might act as an inhibitor and interact with the amino terminal domain, the glutamate-binding site, as well as within the ion channel of the NR2B-containing NMDA receptor. In summary, our study reveals, for the first time, the anticonvulsant activity of 6-GIN. We suggest that this effect might at least be partially mediated by restoring the balance between GABA and GLU in the epileptic brain; however, more studies are needed to prove our hypothesis.

• Banono, Nancy Saana & Esguerra, Camila (2020). Pharmacological validation of the prepulse inhibition of startle response in larval zebrafish using a commercial automated system and software. Journal of Visualized Experiments. 161. doi: 10.3791/61423. Fulltekst i vitenarkiv Vis sammendrag

  Tamoxifen is the most prescribed selective estrogen receptor (ER) modulator in patients with ER-positive breast cancers. Tamoxifen requires the transcription factor paired box 2 protein (PAX2) to repress the transcription of ERBB2/HER2. Now, we identified that PAX2 inhibits cell growth of ER+/HER2− tumor cells in a dose-dependent manner. Moreover, we have identified that cell growth inhibition can be achieved by expressing moderate levels of PAX2 in combination with tamoxifen treatment. Global run-on sequencing of cells overexpressing PAX2, when coupled with PAX2 ChIP-seq, identified common targets regulated by both PAX2 and tamoxifen. The data revealed that PAX2 can inhibit estrogen-induced gene transcription and this effect is enhanced by tamoxifen, suggesting that they converge on repression of the same targets. Moreover, PAX2 and tamoxifen have an additive effect and both induce coding genes and enhancer RNAs (eRNAs). PAX2–tamoxifen upregulated genes are also enriched with PAX2 eRNAs. The enrichment of eRNAs is associated with the highest expression of genes that positivity regulate apoptotic processes. In luminal tumors, the expression of a subset of these proapoptotic genes predicts good outcome and their expression are significantly reduced in tumors of patients with relapse to tamoxifen treatment. Mechanistically, PAX2 and tamoxifen coexert an antitumoral effect by maintaining high levels of transcription of tumor suppressors that promote cell death. The apoptotic effect is mediated in large part by the gene interferon regulatory factor 1. Altogether, we conclude that PAX2 contributes to better clinical outcome in tamoxifen treated ER-positive breast cancer patients by repressing estrogen signaling and inducing cell death related pathways.

• Banono, Nancy Saana; Gawel, Kinga Aurelia; Witte, Linus De & Esguerra, Camila (2020). Zebrafish Larvae Carrying a Splice Variant Mutation in cacna1d: A New Model for Schizophrenia-Like Behaviours? Molecular Neurobiology. ISSN 0893-7648. 58, s. 877–894. doi: 10.1007/s12035-020-02160-5. Fulltekst i vitenarkiv Vis sammendrag

  Persons with certain single nucleotide polymorphisms (SNPs) in the CACNA1D gene (encoding voltage-gated calcium channel subunit alpha 1-D) have increased risk of developing neuropsychiatric disorders such as bipolar, schizophrenia and autism. The molecular consequences of SNPs on gene expression and protein function are not well understood. Thus, the use of animal models to determine genotype-phenotype correlations is critical to understanding disease pathogenesis. Here, we describe the behavioural changes in larval zebrafish carrying an essential splice site mutation (sa17298) in cacna1da. Heterozygous mutation resulted in 50% reduction of splice variants 201 and 202 (haploinsufficiency), while homozygosity increased transcript levels of variant 201 above wild type (WT; gain-of-function, GOF). Due to low homozygote viability, we focused primarily on performing the phenotypic analysis on heterozygotes. Indeed, cacna1dasa17298/WT larvae displayed hyperlocomotion—a behaviour characterised in zebrafish as a surrogate phenotype for epilepsy, anxiety or psychosis-like behaviour. Follow-up tests ruled out anxiety or seizures, however, as neither thigmotaxis defects nor epileptiform-like discharges in larval brains were observed. We therefore focused on testing for potential “psychosis-like” behaviour by assaying cacna1dasa17298/WT larval locomotor activity under constant light, during light-dark transition and in startle response to dark flashes. Furthermore, exposure of larvae to the antipsychotics, risperidone and haloperidol reversed cacna1da-induced hyperactivity to WT levels while valproate decreased but did not reverse hyperactivity. Together, these findings demonstrate that cacna1da haploinsufficiency induces behaviours in larval zebrafish analogous to those observed in rodent models of psychosis. Future studies on homozygous mutants will determine how cacna1d GOF alters behaviour in this context.

• Gawel, Kinga Aurelia; Kukula-Koch, Wirginia; Nieoczym, Dorota; Stępnik, Katarzyna; Ent, Wietske van der & Banono, Nancy Saana [Vis alle 9 forfattere av denne artikkelen] (2020). The Influence of Palmatine Isolated from Berberis sibirica Radix on Pentylenetetrazole-Induced Seizures in Zebrafish. Cells. 9(5). doi: 10.3390/cells9051233. Fulltekst i vitenarkiv Vis sammendrag

  Palmatine (PALM) and berberine (BERB) are widely identified isoquinoline alkaloids among the representatives of the Berberidaceae botanical family. The antiseizure activity of BERB was shown previously in experimental epilepsy models. We assessed the effect of PALM in a pentylenetetrazole (PTZ)-induced seizure assay in zebrafish, with BERB as an active reference compound. Both alkaloids were isolated from the methanolic root extract of Berberis sibirica by counter-current chromatography, and their ability to cross the blood-brain barrier was determined via quantitative structure-activity relationship assay. PALM exerted antiseizure activity, as confirmed by electroencephalographic analysis, and decreased c-fos and bdnf levels in PTZ-treated larvae. In a behavioral assay, PALM dose-dependently decreased PTZ-induced hyperlocomotion. The combination of PALM and BERB in ED16 doses revealed hyperadditive activity towards PTZ-induced hyperlocomotion. Notably, we have indicated that both alkaloids may exert their anticonvulsant activity through different mechanisms of action. Additionally, the combination of both alkaloids in a 1:2.17 ratio (PALM: BERB) mimicked the activity of the pure extract, which indicates that these two active compounds are responsible for its anticonvulsive activity. In conclusion, our study reveals for the first time the anticonvulsant activity of PALM and suggests the combination of PALM and BERB may have higher therapeutic value than separate usage of these compounds.

• Tiraboschi, Ettore; Martina, Silvia; Ent, Wietske van der; Grzyb, Kamil; Gawel, Kinga Aurelia & Cordero-Maldonado, Maria Lorena [Vis alle 14 forfattere av denne artikkelen] (2020). New insights into the early mechanisms of epileptogenesis in a zebrafish model of Dravet syndrome. Epilepsia. ISSN 0013-9580. 61(3), s. 549–560. doi: 10.1111/epi.16456. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Objective: To pinpoint the earliest cellular defects underlying seizure onset (epileptogenic period) during perinatal brain development in a new zebrafish model of Dravet syndrome (DS) and to investigate potential disease-modifying activity of the 5HT2 receptor agonist fenfluramine. Methods: We used CRISPR/Cas9 mutagenesis to introduce a missense mutation, designed to perturb ion transport function in all channel isoforms, into scn1lab, the zebrafish orthologue of SCN1A (encoding voltage-gated sodium channel alpha subunit 1). We performed behavioral analysis and electroencephalographic recordings to measure convulsions and epileptiform discharges, followed by single-cell RNA-Seq, morphometric analysis of transgenic reporter-labeled γ-aminobutyric acidergic (GABAergic) neurons, and pharmacological profiling of mutant larvae. Results: Homozygous mutant (scn1labmut/mut ) larvae displayed spontaneous seizures with interictal, preictal, and ictal discharges (mean = 7.5 per 20-minute recording; P < .0001; one-way analysis of variance). Drop-Seq analysis revealed a 2:1 shift in the ratio of glutamatergic to GABAergic neurons in scn1labmut/mut larval brains versus wild type (WT), with dynamic changes in neuronal, glial, and progenitor cell populations. To explore disease pathophysiology further, we quantified dendritic arborization in GABAergic neurons and observed a 40% reduction in arbor number compared to WT (P < .001; n = 15 mutant, n = 16 WT). We postulate that the significant reduction in inhibitory arbors causes an inhibitory to excitatory neurotransmitter imbalance that contributes to seizures and enhanced electrical brain activity in scn1labmut/mut larvae (high-frequency range), with subsequent GABAergic neuronal loss and astrogliosis. Chronic fenfluramine administration completely restored dendritic arbor numbers to normal in scn1labmut/mut larvae, whereas similar treatment with the benzodiazepine diazepam attenuated seizures, but was ineffective in restoring neuronal cytoarchitecture. BrdU labeling revealed cell overproliferation in scn1labmut/mut larval brains that were rescued by fenfluramine but not diazepam. Significance: Our findings provide novel insights into early mechanisms of DS pathogenesis, describe dynamic cell population changes in the scn1labmut/mut brain, and present first-time evidence for potential disease modification by fenfluramine. Keywords: Dravet syndrome; epileptogenesis; fenfluramine; sodium channel; zebrafish.

• Sisodiya, Sanjay M.; Fowler, Hayley J.; Lake, Iain; Nanji, Rosemary Ogwen; Gawel, Kinga Aurelia & Esguerra, Camila Vicencio [Vis alle 8 forfattere av denne artikkelen] (2019). Climate change and epilepsy: Time to take action. Epilepsia Open. 4(4), s. 524–536. doi: 10.1002/epi4.12359. Fulltekst i vitenarkiv Vis sammendrag

  Climate change is the biggest challenge facing humanity today. The associated global warming and humidification, increases in the severity and frequency of extreme climate events, extension of the ranges of vector‐borne diseases, and the consequent social and economic stresses and disruption will have major negative consequences on many aspects of health care. People whose resilience to change is already impaired may suffer disproportionately from these environmental changes, which are of unprecedented reach and magnitude. There has been little connection made so far between climate change and epilepsy. We briefly review the history of climate change science and the subsequent response of the global scientific community. We consider how climate change effects might in general affect health and disease. We consider some of the underlying complex interactions that, for example, favor the spread of vector‐borne diseases and how climate models operate and may help plan for global and local changes. We then speculate specifically on how these generic ideas may apply specifically to epilepsy. We consider these impacts at levels from molecular to the epidemiological. Data are sparse, and there is undoubtedly a need for more information to enable better estimation of possible effects of climate change on care in epilepsy. We also consider how the professional activities of those involved in epilepsy health care might contribute to global carbon emissions, for example, through flying for conference attendance. Healthcare organizations across the world are already considering, and responding to, many of these issues. We argue for more research in this area, but also for action today. Actions today are likely to generate cobenefits for health care, including care in epilepsy, resulting from efforts to decarbonize, mitigate effects of climate change that has already happened, and plan for adaptation to climate change.

• Abudu, Yakubu Princely; Pankiv, Serhiy; Mathai, Benan John; Lystad, Alf Håkon; Bindesbøll, Christian & Brenne, Hanne Britt [Vis alle 14 forfattere av denne artikkelen] (2019). NIPSNAP1 and NIPSNAP2 act as “eat-me signal” for mitophagy. Developmental Cell. ISSN 1534-5807. 49(4), s. 509–525.e12. doi: 10.1016/j.devcel.2019.03.013. Fulltekst i vitenarkiv Vis sammendrag

  The clearance of damaged or dysfunctional mitochondria by selective autophagy (mitophagy) is important for cellular homeostasis and prevention of disease. Our understanding of the mitochondrial signals that trigger their recognition and targeting by mitophagy is limited. Here, we show that the mitochondrial matrix proteins 4-Nitrophenylphosphatase domain and non-neuronal SNAP25-like protein homolog 1 (NIPSNAP1) and NIPSNAP2 accumulate on the mitochondria surface upon mitochondrial depolarization. There, they recruit proteins involved in selective autophagy, including autophagy receptors and ATG8 proteins, thereby functioning as an “eat me” signal for mitophagy. NIPSNAP1 and NIPSNAP2 have a redundant function in mitophagy and are predominantly expressed in different tissues. Zebrafish lacking a functional Nipsnap1 display reduced mitophagy in the brain and parkinsonian phenotypes, including loss of tyrosine hydroxylase (Th1)-positive dopaminergic (DA) neurons, reduced motor activity, and increased oxidative stress.

• Copmans, Daniëlle; Kildgaard, Sara; Rasmussen, Silas A.; Ślęzak, Monika; Dirkx, Nina & Partoens, Michèle [Vis alle 10 forfattere av denne artikkelen] (2019). Zebrafish-based discovery of antiseizure compounds from the north sea: Isoquinoline alkaloids TMC-120A and TMC-120B. Marine Drugs. 17:607(11), s. 1–20. doi: 10.3390/md17110607. Fulltekst i vitenarkiv Vis sammendrag

  There is a high need for the development of new and improved antiseizure drugs (ASDs) to treat epilepsy. Despite the potential of marine natural products (MNPs), the EU marine biodiscovery consortium PharmaSea has made the only effort to date to perform ASD discovery based on large-scale screening of MNPs. To this end, the embryonic zebrafish photomotor response assay and the larval zebrafish pentylenetetrazole (PTZ) model were used to screen MNP extracts for neuroactivity and antiseizure activity, respectively. Here we report the identification of the two known isoquinoline alkaloids TMC-120A and TMC-120B as novel antiseizure compounds, which were isolated by bioactivity-guided purification from the marine-derived fungus Aspergillus insuetus. TMC-120A and TMC-120B were observed to significantly lower PTZ-induced seizures and epileptiform brain activity in the larval zebrafish PTZ seizure model. In addition, their structural analogues TMC-120C, penicisochroman G, and ustusorane B were isolated and also significantly lowered PTZ-induced seizures. Finally, TMC-120A and TMC-120B were investigated in a mouse model of drug-resistant focal seizures. Compound treatment significantly shortened the seizure duration, thereby confirming their antiseizure activity. These data underscore the possibility to translate findings in zebrafish to mice in the field of epilepsy and the potential of the marine environment for ASD discovery.

• Gawel, Kinga Aurelia; Banono, Nancy Saana; Michalak, Agnieszka & Esguerra, Camila Vicencio (2019). A critical review of zebrafish schizophrenia models: Time for validation? Neuroscience and Biobehavioral Reviews. ISSN 0149-7634. 107, s. 6–22. doi: 10.1016/j.neubiorev.2019.08.001. Fulltekst i vitenarkiv
• Nieoczym, Dorota; Socala, Katarzyna; Gawel, Kinga Aurelia; Esguerra, Camila Vicencio; Wyska, Elzbieta & Wlaz, Piotr (2019). Anticonvulsant Activity of Pterostilbene in Zebrafish and Mouse Acute Seizure Tests. Neurochemical Research. ISSN 0364-3190. 44(5), s. 1043–1055. doi: 10.1007/s11064-019-02735-2. Fulltekst i vitenarkiv Vis sammendrag

  Pterostilbene (PTE), a natural dimethylated analog of resveratrol, possesses numerous health-beneficial properties. The ability of PTE to cross the blood–brain barrier raised the possibility that this compound may modulate central nervous system functions, including seizure activity. The aim of our study was to investigate the activity of PTE in the larval zebrafish pentylenetetrazole (PTZ) seizure assay and three acute seizure tests in mice, i.e., in the maximal electroshock seizure threshold (MEST), 6 Hz-induced psychomotor seizure threshold and intravenous (iv) PTZ tests. Additionally, potential antidepressant activity of PTE was estimated in the forced swim test in mice. The chimney test was used to determine the influence of PTE on motor coordination in mice, while its influence on neuromuscular strength was assessed in the grip strength test in mice. Locomotor activity was determined to verify the results from the forced swim test. PTE revealed an evident anticonvulsant effect both in zebrafish larvae (10 µM; 2 h-incubation) and mice (at doses of 100 and 200 mg/kg, intraperitoneally) but it did not exhibit antidepressant potential in the forced swim test. Furthermore, it did not cause any statistically significant changes in motor coordination, neuromuscular strength and locomotor activity in mice. In conclusion, our present findings demonstrate for the first time the anticonvulsant potential of PTE. The aforementioned results suggest that it might be employed in epilepsy treatment, however, further precise studies are required to verify its activity in other experimental seizure and epilepsy models and its precise mechanism of action should be determined.

• Leclercq, K; Afrikanova, Tatiana; Langlois, M.; Prins, A De; Buenafe, OE & Rospo, CC [Vis alle 12 forfattere av denne artikkelen] (2015). Cross-species pharmacological characterization of the allylglycine seizure model in mice and larval zebrafish. Epilepsy & Behavior. ISSN 1525-5050. 45, s. 53–63. doi: 10.1016/j.yebeh.2015.03.019. Fulltekst i vitenarkiv
• Schubert, Julian; Siekierska, Aleksandra; Langlois, Melanie; May, Patrick; Huneau, Clément & Becker, Felicitas [Vis alle 47 forfattere av denne artikkelen] (2014). Mutations in STX1B, encoding a presynaptic protein, cause fever-associated epilepsy syndromes. Nature Genetics. ISSN 1061-4036. 46, s. 1327–1332. doi: 10.1038/ng.3130. Fulltekst i vitenarkiv

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• Banono, Nancy Saana; Gawel, Kinga Aurelia; Mäki-Marttunen, Tuomo; Ent, Wietske van der; Kukula-Koch, Wirginia & Fyhn, Marianne [Vis alle 10 forfattere av denne artikkelen] (2023). Novel zebrafish model for studying neurodevelopment in Timothy syndrome. Fulltekst i vitenarkiv
• Connors, Craig; Mastracci, Teresa; Devinsky, Orrin; Shojaeinia, Elham; Esguerra, Camila Vicencio & Crawford, Alexander Dettmar (2023). Zebrafish embryos with reduced deoxyhypusine synthase exhibit dysmorphology, epileptiform activity, and reduced GABAergic neuronal arborization. Fulltekst i vitenarkiv
• Ent, Wietske van der; Kirstein-Smardzewska, Karolina Joanna; Gawel, Kinga Aurelia; Banono, Nancy Saana; Eggesbø, Merete Åse & Esguerra, Camila Vicencio (2023). Evaluation of Developmental Neurotoxicity in Zebrafish (Danio rerio) by Endocrine Disrupting Chemical β-HCH. Fulltekst i vitenarkiv
• Ent, Wietske van der; Kirstein-Smardzewska, Karolina Joanna; Gawel, Kinga Aurelia; Banono, Nancy Saana; Eggesbø, Merete Åse & Esguerra, Camila Vicencio (2023). Evaluation of Developmental Neurotoxicity in Zebrafish (Danio rerio) by Endocrine Disrupting Chemical β-HCH. Fulltekst i vitenarkiv
• Christou, Maria; Hultman, Maria Thérése; Esguerra, Camila Vicencio; Lillicrap, Adam David & Song, You (2023). Using Automated Size Measurement Software as a Possible New Approach Methodology to Support Adverse Outcome Pathway. Fulltekst i vitenarkiv
• Shojaeinia, Elham; Melikishvili, Gia; Kurua, Ekaterine; Tabatadze, Nazhi; Gachechiladze, Tamar & Melikishvili, Mariam [Vis alle 10 forfattere av denne artikkelen] (2023). Acetazolamide – an old drug but potentially also a first precision medicine for CHD2-related epilepsy? Fulltekst i vitenarkiv
• Song, You; Lillicrap, Adam David; Esguerra, Camila Vicencio; Villeneuve, Daniel L.; Ng, Daniel & Rundberget, Jan Thomas [Vis alle 15 forfattere av denne artikkelen] (2022). Quantitative Adverse Outcome Pathways Assisted Next Generation Risk Assessment of Mitochondrial Toxicants. Fulltekst i vitenarkiv
• Christou, Maria; Hultman, Maria Thérése; Esguerra, Camila Vicencio; Lillicrap, Adam David & Song, You (2022). Adverse outcome pathway guided hazard assessment of mitochondrial uncouplers: a tiered testing strategy using zebrafish in vitro assays and embryo toxicity assays. Fulltekst i vitenarkiv
• Esguerra, Camila (2022). Altered brain activity and neuronal morphology in larval zebrafish carrying mutations in Syntaxin binding protein 1. Fulltekst i vitenarkiv
• Song, You; Villeneuve, Daniel L.; Moe, Jannicke; Cao, Yang; Hultman, Maria Thérése & Christou, Maria [Vis alle 21 forfattere av denne artikkelen] (2021). Development of quantitative Adverse Outcome Pathways to facilitate next generation risk assessment of mitochondrial toxicants. Fulltekst i vitenarkiv
• Hultman, Maria Thérése; Christou, Maria; Rundberget, Jan Thomas; Esguerra, Camila Vicencio; Edhlund, Ian & Kamstra, Jorke [Vis alle 8 forfattere av denne artikkelen] (2021). Adverse outcome pathway (AOP) guided high-throughput in vitro and in vivo assessment of mitochondrial toxicants. Fulltekst i vitenarkiv
• Hultman, Maria Thérése; Christou, Maria; Rundberget, Jan Thomas; Esguerra, Camila Vicencio; Edhlund, Ian & Kamstra, Jorke Harmen [Vis alle 8 forfattere av denne artikkelen] (2021). Adverse outcome pathway (AOP) guided high-throughput in vitro and in vivo assessment of mitochondrial toxicants. Fulltekst i vitenarkiv
• Song, You; Villeneuve, Daniel; Moe, Jannicke; Cao, Yang; Hultman, Maria Thérése & Christou, Maria [Vis alle 21 forfattere av denne artikkelen] (2021). Development of quantitative Adverse Outcome Pathways to facilitate next generation risk assessment of mitochondrial toxicants. Fulltekst i vitenarkiv
• Banono, Nancy Saana; Ent, Wietske van der; Gawel, Kinga Aurelia; Mäki-Marttunen, Tuomo; Kukula-Koch, Wirginia & Einevoll, Gaute [Vis alle 9 forfattere av denne artikkelen] (2021). Functional characterisation of cacna1c mutations in zebrafish larvae. Fulltekst i vitenarkiv
• Song, You; Hultman, Maria Thérése; Moe, Jannicke; Petersen, Karina; Rundberget, Jan Thomas & Xie, Li [Vis alle 18 forfattere av denne artikkelen] (2020). The RiskAOP project - Quantitative Adverse Outcome Pathway assisted risk assessment of mitochondrial toxicants. Fulltekst i vitenarkiv
• Banono, Nancy Saana; Gawel, Kinga Aurelia; Witte, Linus De & Esguerra, Camila (2020). Zebrafish larvae carrying a mutation in cacna1d display schizophrenia-like behaviours. Fulltekst i vitenarkiv
• Banono, Nancy Saana & Esguerra, Camila (2018). Phenotypic analysis and small-molecule drug screening in genetic zebrafish models of schizophrenia. Fulltekst i vitenarkiv
• Banono, Nancy Saana; Esguerra, Camila; Fyhn, Marianne & Andreassen, Ole (2021). Functional analysis of psychiatric risk genes in zebrafish (Danio rerio): a focus on the L-type voltage-gated calcium channel subtypes CaV1.2 and CaV1.3. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  CACNA1C and CACNA1D are voltage-gated calcium channel genes that have been repeatedly associated with psychiatric disorders by various genomic studies. These genes are involved in gene expression regulation, neurotransmitter release and integration of dendritic information in the brain, but the mechanisms through which they cause disease are poorly understood. The goal of this thesis was to characterise the effects of mutations in CACNA1C and CACNA1D on early brain function using three zebrafish mutant lines (one cacna1d and two cacna1c mutants) that were characterised through an arsenal of molecular, behavioural, neurophysiological and pharmacological methods. Larval zebrafish with global cacna1da haploinsufficiency showed a hyperlocomotor phenotype that could be improved or reversed using the antipsychotics haloperidol and risperidone and the mood stabiliser, valproate. Furthermore, larvae with global loss-of-function (LOF) of cacna1c was associated with observable dysmorphologies, changes in downstream molecular targets, compensatory overexpression of cacna1d, and deficits in sensorimotor gating. In addition, spectral analysis of local field potential recordings and neurotransmitter analysis revealed gross neural excitability in the cacna1c LOF mutants. Together, we have shown that mutations that alter the function of cacna1da and cacna1c lead to a wide-range of phenotypes reminiscent of relevant functional domains observed in psychiatric disorders.

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