Neuroprotective agents ineffective in mitigating autonomic dysreflexia following experimental spinal cord injury.

BACKGROUND AND OBJECTIVES: Loss of supraspinal cardiovascular control and secondary damage following spinal cord injury (SCI) lead to cardiovascular dysfunction, where autonomic dysreflexia (AD), triggered by stimuli below the injury, can cause uncontrolled blood pressure (BP) surges, posing severe health risks such as stroke and seizures. While anti-inflammatory neuroprotective agents have been studied for motor recovery, their impact on cardiovascular function remains under investigated. The objective was to assess the efficacy of four clinically approved neuroprotective agents in promoting cardiovascular recovery following SCI. METHODS: Male Wistar rats received contusion at the third thoracic spinal segment (T3). Fluoxetine, Glyburide, Valproic acid, and Indomethacin were first administered at 1 h or 6 h post-SCI, and every 12 h for two weeks thereafter. Four weeks following SCI, hemodynamics were measured at rest and during colorectal distension. Locomotor function was assessed prior to SCI and weekly for four weeks after SCI, using the Basso-Beattie-Bresnahan (BBB) locomotor scale. Quantitative comparisons of lesion area were performed. RESULTS: Contrary to the published literature, Indomethacin and Valproic acid resulted in high morbidity and mortality rates 60 % and 40 % respectively) within 2-3 days of administration. Fluoxetine, and Glyburide were well-tolerated. There were no differences in change in systolic BP with colorectal distension compared to control i.e., all experimental groups experienced severe episodes of AD [F(6, 67) = 0.94, p = 0.47]. There was no significant difference in BBB scores in any experimental group compared to control [F(18, 252) = 0.3, p = 0.99]. No between-group differences were observed in tissue sparing at the lesion epicentre [F(6, 422) = 6.98, p = 0.29]. DISCUSSION: Despite promising beneficial effect reported in previous studies, none of the drugs demonstrated improvement in cardiovascular or motor function. Indomethacin and Valproic acid exhibited unexpected high mortality at doses deemed safe in the literature. This emphasizes the necessity for reproducibility studies in pre-clinical research and underscores the importance of publishing null findings to guide future investigations.

Transient CSF1R inhibition ameliorates behavioral deficits in Cntnap2 knockout and valproic acid-exposed mouse models of autism.

Microglial abnormality and heterogeneity are observed in autism spectrum disorder (ASD) patients and animal models of ASD. Microglial depletion by colony stimulating factor 1-receptor (CSF1R) inhibition has been proved to improve autism-like behaviors in maternal immune activation mouse offspring. However, it is unclear whether CSF1R inhibition has extensive effectiveness and pharmacological heterogeneity in treating autism models caused by genetic and environmental risk factors. Here, we report pharmacological functions and cellular mechanisms of PLX5622, a small-molecule CSF1R inhibitor, in treating Cntnap2 knockout and valproic acid (VPA)-exposed autism model mice. For the Cntnap2 knockout mice, PLX5622 can improve their social ability and reciprocal social behavior, slow down their hyperactivity in open field and repetitive grooming behavior, and enhance their nesting ability. For the VPA model mice, PLX5622 can enhance their social ability and social novelty, and alleviate their anxiety behavior, repetitive and stereotyped autism-like behaviors such as grooming and marble burying. At the cellular level, PLX5622 restores the morphology and/or number of microglia in the somatosensory cortex, striatum, and hippocampal CA1 regions of the two models. Specially, PLX5622 corrects neurophysiological abnormalities in the striatum of the Cntnap2 knockout mice, and in the somatosensory cortex, striatum, and hippocampal CA1 regions of the VPA model mice. Incidentally, microglial dynamic changes in the VPA model mice are also reported. Our study demonstrates that microglial depletion and repopulation by transient CSF1R inhibition is effective, and however, has differential pharmacological functions and cellular mechanisms in rescuing behavioral deficits in the two autism models.

Soluble form of Lingo2, an autism spectrum disorder-associated molecule, functions as an excitatory synapse organizer in neurons.

Autism Spectrum Disorder (ASD) is a developmental disorder characterized by impaired social communication and repetitive behaviors. In recent years, a pharmacological mouse model of ASD involving maternal administration of valproic acid (VPA) has become widely used. Newborn pups in this model show an abnormal balance between excitatory and inhibitory (E/I) signaling in neurons and exhibit ASD-like behavior. However, the molecular basis of this model and its implications for the pathogenesis of ASD in humans remain unknown. Using quantitative secretome analysis, we found that the level of leucine-rich repeat and immunoglobulin domain-containing protein 2 (Lingo2) was upregulated in the conditioned medium of VPA model neurons. This upregulation was associated with excitatory synaptic organizer activity. The secreted form of the extracellular domain of Lingo2 (sLingo2) is produced by the transmembrane metalloprotease ADAM10 through proteolytic processing. sLingo2 was found to induce the formation of excitatory synapses in both mouse and human neurons, and treatment with sLingo2 resulted in an increased frequency of miniature excitatory postsynaptic currents in human neurons. These findings suggest that sLingo2 is an excitatory synapse organizer involved in ASD, and further understanding of the mechanisms by which sLingo2 induces excitatory synaptogenesis is expected to advance our understanding of the pathogenesis of ASD.

MSC Exosomes Containing Valproic Acid Promote Wound Healing by Modulating Inflammation and Angiogenesis.

PURPOSE: Chronic wounds that are difficult to heal pose a major challenge for clinicians and researchers. Currently, common treatment methods focus on isolating the wound from the outside world, relying on the tissue at the wound site to grow and heal unaided. Umbilical cord mesenchymal stem cell (MSC) exosomes can promote wound healing by enhancing new blood vessel growth at the wound site. Valproic acid (VPA) reduces the inflammatory response and acts on macrophages to accelerate wound closure. In this study, VPA was loaded into umbilical cord MSC exosomes to form a drug carrier exosome (VPA-EXO) with the aim of investigating the effect of VPA-EXO on wound healing. METHODS: This study first isolated and obtained umbilical cord MSC exosomes, then added VPA to the exosomes and explored the ability of VPA-EXO to promote the proliferation and migration of human skin fibroblasts (HSFs) and human umbilical vein endothelial cells (HUVECs), as well as the ability to promote the angiogenesis of HUVECs, by using scratch, Transwell, and angiogenesis assays. An in vitro cell model was established and treated with VPA-EXO, and the expression levels of inflammation and pro-angiogenesis-related proteins and genes were examined using Western blot and qRT-PCR. The therapeutic effect of VPA-EXO on promoting wound healing in a whole skin wound model was investigated using image analysis of the wound site, H&E staining, and immunohistochemical staining experiments in a mouse wound model. RESULTS: The in vitro model showed that VPA-EXO effectively promoted the proliferation and migration of human skin fibroblast cells and human umbilical vein endothelial cells; significantly inhibited the expression of MMP-9, IL-1ß, IL-8, TNF-α, and PG-E2; and promoted the expression of vascular endothelial growth factors. In the mouse wound model, VPA-EXO reduced inflammation at the wound site, accelerated wound healing, and significantly increased the collagen content of tissue at the wound site. CONCLUSIONS: As a complex with dual efficacy in simultaneously promoting tissue regeneration and inhibiting inflammation, VPA-EXO has potential applications in tissue wound healing and vascular regeneration. In future studies, we will further investigate the mechanism of action and application scenarios of drug-loaded exosome complexes in different types of wound healing and vascular regeneration.

Microglia inversely regulate the level of perineuronal nets with the treatment of lipopolysaccharide and valproic acid.

Perineuronal nets (PNNs) are extracellular matrix which mostly surround the inhibitory neurons. They are changed in several brain diseases, such as autism spectrum disorder, but the mechanism of PNNs degradation is still unclear. In this study, we investigated the role of microglial cells in regulating PNNs levels. Specifically, 1 day or 3 days after a single dose of lipopolysaccharide (LPS, 0.25 mg/kg) increased the density of microglia and further reduced the density of PNNs in both hippocampus CA1 and visual cortex. Minocycline, an inhibitor of microglia activation, took effect time-dependently. Minocycline for 7 days before a single LPS injection (0.25 mg/kg) inhibited microglia increase and PNNs loss, but minocycline for 3 days did not work. Finally, in a valproic acid (VPA)-treated autism mouse model, microglia were reduced while PNNs+ cells were increased in both hippocampus CA1 and visual cortex. In summary, the microglia are involved in the balanced level of PNNs, while in the autism model, the altered level of PNNs might be due to the microglia hypofunction.

Pairing tones with vagus nerve stimulation improves brain stem responses to speech in the valproic acid model of autism.

Receptive language deficits and aberrant auditory processing are often observed in individuals with autism spectrum disorders (ASD). Symptoms associated with ASD are observed in rodents prenatally exposed to valproic acid (VPA), including deficits in speech sound discrimination ability. These perceptual difficulties are accompanied by changes in neural activity patterns. In both cortical and subcortical levels of the auditory pathway, VPA-exposed rats have impaired responses to speech sounds. Developing a method to improve these neural deficits throughout the auditory pathway is necessary. The purpose of this study was to investigate the ability of vagus nerve stimulation (VNS) paired with sounds to restore degraded inferior colliculus (IC) responses in VPA-exposed rats. VNS paired with the speech sound "dad" was presented to a group of VPA-exposed rats 300 times per day for 20 days. Another group of VPA-exposed rats were presented with VNS paired with multiple tone frequencies for 20 days. The IC responses were recorded from 19 saline-exposed control rats and 18 VPA-exposed with no VNS, 8 VNS-speech paired VPA-exposed, and 7 VNS-tone paired VPA-exposed female and male rats. Pairing VNS with tones increased the IC response strength to speech sounds by 44% compared to VPA-exposed rats alone. Contrarily, VNS-speech pairing significantly decreased the IC response to speech compared with VPA-exposed rats by 5%. The present research indicates that pairing VNS with tones improved sound processing in rats exposed to VPA and suggests that auditory processing can be improved through targeted plasticity.NEW & NOTEWORTHY Pairing vagus nerve stimulation (VNS) with sounds has improved auditory processing in the auditory cortex of normal-hearing rats and autism models of rats. This study tests the ability of VNS-sound pairing to restore auditory processing in the inferior colliculus (IC) of valproic acid (VPA)-exposed rats. Pairing VNS with tones significantly reversed the degraded sound processing in the IC in VPA-exposed rats. The findings provide evidence that auditory processing in autism rat models can be improved through VNS.

Preconditioning of Human Umbilical Cord Mesenchymal Stem Cells with a Histone Deacetylase Inhibitor: Valproic Acid.

Background: Mesenchymal stem cells (MSCs) play a key role in regenerative medicine due to their capacity to differentiate into multiple cell lines, regulate the immune system, and exert paracrine effects. The therapeutic impact of MSCs is primarily mediated through their secretome. The secretory and therapeutic potential of MSCs can be improved through preconditioning, which entails the application of hypoxic environments, 3-dimensional cell cultures, and pharmacological agents. Valproic acid (VPA) is a histone deacetylase inhibitor that is employed in medical practice for treating epilepsy and bipolar disorder. Hence, preconditioning MSCs with VPA is expected to induce histone acetylation, enhance gene expression, and beneficially modify the cells' secretomes. Aims: To assess the effectiveness of VPA in enhancing and regulating the therapeutic potential of cells as well as its impact on MSC secretome profiles and ultrastructural morphologies. Study Design: Expiremental study. Methods: Human umbilical cord MSCs were preconditioned with 2 mM VPA for 24 and 48 hours; untreated MSCs served as controls. The secretome secreted by the cells was assessed for its total protein content. Subsequently, interferon-gamma (IFN-γ), interleukin-17 (IL-17), IL-10, vascular endothelial growth factor, nerve growth factor (NGF), glial cell line-derived neurotrophic factor, and brain-derived neurotrophic factor (BDNF) levels in the secretome were analyzed using the ELISA method. The ultrastructural properties of the cells were studied under transmission electron microscopy. Results: Ultrastructural examinations revealed that the chromatin content of VPA-treated cells was reduced. VPA-preconditioned cells exhibited a higher density of rough endoplasmic reticulum, autophagic vesicles, and myelin figures on cytoplasmic structure analysis, which was indicative of increased secretion. Protein secretion was elevated in those cells, with notable increases in NGF and BDNF levels. Furthermore, the cytoskeletal rearrangement and elevated autophagic activity observed in the 48-hour preconditioned cells could indicate the initiation of neuronal differentiation. IL-10, IL-17, and IFN-γ were not detected in the secretome. Conclusion: This study indicate that preconditioning with VPA enhances MSC activity and subsequently modifies the secretome content.

Comparative effect of atorvastatin and risperidone on modulation of TLR4/NF-κB/NOX-2 in a rat model of valproic acid-induced autism.

BACKGROUND: Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that is significantly increasing, resulting in severe distress. The approved treatment for ASD only partially improves the sympoms, but it does not entirely reverse the symptoms. Developing novel disease-modifying drugs is essential for the continuous improvement of ASD. Because of its pleiotropic effect, atorvastatin has been garnered attention for treating neuronal degeneration. The present study aimed to investigate the therapeutic effects of atorvastatin in autism and compare it with an approved autism drug (risperidone) through the impact of these drugs on TLR4/NF-κB/NOX-2 and the apoptotic pathway in a valproic acid (VPA) induced rat model of autism. METHODS: On gestational day 12.5, pregnant rats received a single IP injection of VPA (500 mg/kg), for VPA induced autism, risperidone and atorvastatin groups, or saline for control normal group. At postnatal day 21, male offsprings were randomly divided into four groups (n = 6): control, VPA induced autism, risperidone, and atorvastatin. Risperidone and atorvastatin were administered from postnatal day 21 to day 51. The study evaluated autism-like behaviors using the three-chamber test, the dark light test, and the open field test at the end of the study. Biochemical analysis of TLR4, NF-κB, NOX-2, and ROS using ELISA, RT-PCR, WB, histological examination with hematoxylin and eosin and immunohistochemical study of CAS-3 were performed. RESULTS: Male offspring of prenatal VPA-exposed female rats exhibited significant autism-like behaviors and elevated TLR4, NF-κB, NOX-2, ROS, and caspase-3 expression. Histological analysis revealed structural alterations. Both risperidone and atorvastatin effectively mitigated the behavioral, biochemical, and structural changes associated with VPA-induced rat model of autism. Notably, atorvastatin group showed a more significant improvement than risperidone group. CONCLUSIONS: The research results unequivocally demonstrated that atorvastatin can modulate VPA-induced autism by suppressing inflammation, oxidative stress, and apoptosis through TLR4/NF-κB/NOX-2 signaling pathway. Atorvastatin could be a potential treatment for ASD.

Aprepitant's roles in abating seizures, behavioral, and cognitive deficits in mice model of epilepsy.

BACKGROUND: Aprepitant (APR), a neurokinin 1 receptor antagonist, is an approved drug for treating chemotherapy-induced nausea and vomiting. OBJECTIVES: Investigate the beneficial roles of APR alone or in combination with sodium valproate (VPA) against lithium pilocarpine [li-pilo]-induced seizures, behavioral changes, and cognitive deficits. METHODS: Thirty male mice were divided into five groups, each containing 6. "Vehicle Group I," "Control Group II "li-pilo, " Valproate (VPA) group III (400 mg/kg/i.p.), "APR group IV, " and "Combination Group V." Videos of mice were recorded, and they were watched for episodes of spontaneous recurring seizures (SRS). Behavioral Tests were performed. At the end of the study, animal brains were taken for biochemical assays and gene expression studies. RESULTS: APR partially protected against SRS with partial restoration of average behavioral and standard cognitive skills associated with a significant increase in brain SOD activity and a significant decrease in MDA, IL-1ß, NF-КB, and SP-3 levels in relation to the control group. Interestingly, a combination of APR with VPA in epileptic mice showed complete protection against li-pilo-induced behavioral changes and cognitive deficits, a significant increase in brain SOD activity, and a considerable decrease in MDA, IL-1ß, NF-ΚB, and SP levels to normal. CONCLUSION: Using APR as an adjuvant to VPA is more effective in protecting against li-pilo-induced seizures, behavioral changes, and cognitive deficits due to its antioxidant, anti-inflammatory, and NK1 antagonist effects than using APR alone as drug therapy.

Sortilin is associated with progranulin deficiency and autism-like behaviors in valproic acid-induced autism rats.

INTRODUCTION: Neuroinflammation and microglial activation-related dendritic injury contribute to the pathogenesis of Autism Spectrum Disorder (ASD). Previous studies show that Progranulin (PGRN) is a growth factor associated with inflammation and synaptic development, but the role of PGRN in autism and the mechanisms underlying changes in PGRN expression remain unclear. AIMS: To investigate the impact of PGRN in autism, we stereotactically injected recombinant PGRN into the hippocampus of ASD model rats. Additionally, we explored the possibility that sortilin may be the factor behind the alterations in PGRN by utilizing SORT1 knockdown. Ultimately, we aimed to identify potential targets for the treatment of autism. RESULTS: PGRN could alleviate inflammatory responses, protect neuronal dendritic spines, and ameliorate autism-like behaviors. Meanwhile, elevated expression of sortilin and decreased levels of PGRN were observed in both ASD patients and rats. Enhanced sortilin levels facilitated PGRN internalization into lysosomes. Notably, suppressing SORT1 expression amplified PGRN levels, lessened microglial activation, and mitigated inflammation, thereby alleviating autism-like behaviors. CONCLUSION: Collectively, our findings highlight elevated sortilin levels in ASD rat brains, exacerbating dendrite impairment by affecting PGRN expression. PGRN supplementation and SORT1 knockdown hold potential as therapeutic strategies for ASD.

The epigenetic changes are affected by sex and valproic acid treatment in a rat model of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) presents distinct sex-specific differences in both symptom expression and treatment outcomes, with the underlying biological mechanisms still remain unclear. Epigenetic modifications, particularly histone acetylation, have been increasingly recognized as critical factors in the pathophysiology of PTSD. Valproic acid (VPA), a potent histone deacetylase (HDAC) inhibitor, has shown promise in modulating epigenetic responses and improving therapeutic outcomes is PTSD, though its effect may differ between sexes. This study aimed to explore the sex-specific epigenetic changes in response to trauma and the impact of VPA treatment in a rat model of PTSD induced by predator scent stress. Sprague-Dawley rats of both sexes were randomly assigned to stressed and non-stressed groups and treated with either VPA (100 mg/kg) or vehicle. Anxiety levels were assessed using the elevated plus maze, followed by analysis of histone H3 and H4 acetylation, HDAC activity, and c-fos expression in the hippocampus. Our findings revealed that traumatic stress led to increased freezing time and anxiety levels, with more pronounced effects observed in females. Additionally, we have identified sex-specific differences in hippocampal epigenetic modifications; stressed females exhibited higher H3 acetylation, and VPA-treated stressed males showed increased H4 acetylation. These results highlight the importance of considering sex differences in the epigenetic mechanism underlying PTSD and suggest that personalized therapeutic approaches may be necessary to address these complexities.

An alpha 5-GABAA receptor positive allosteric modulator attenuates social and cognitive deficits without changing dopamine system hyperactivity in rats exposed to valproic acid in utero.

Autism spectrum disorders (ASDs) are characterized by core behavioral symptoms in the domains of sociability, language/communication, and repetitive or stereotyped behaviors. Deficits in the prefrontal and hippocampal excitatory/inhibitory balance due to a functional loss of GABAergic interneurons are proposed to underlie these symptoms. Increasing the postsynaptic effects of GABA with compounds that selectively modulate GABAergic receptors could be a potential target for treating ASD symptoms. In addition, deficits in GABAergic interneurons have been linked to dopamine (DA) system dysregulation, and, despite conflicting evidence, abnormalities in the DA system activity may underly some ASD symptoms. Here, we investigated whether the positive allosteric modulator of α5-containing GABAA receptors (α5-GABAARs) SH-053-2'F-R-CH3 (10 mg/kg) attenuates behavioral abnormalities in rats exposed to valproic acid (VPA) in utero, an established risk factor for autism. We also evaluated if animals exposed to VPA in utero present changes in the ventral tegmental area (VTA) DA system activity using in vivo electrophysiology and if SH-053-2'F-R-CH3 could attenuate these changes. SH-053-2'F-R-CH3 was administered intraperitoneally 30 min before each behavioral test and electrophysiology. In utero VPA exposure caused male and female rats to present increased repetitive behavior (self-grooming) in early adolescence and deficits in social interaction in adulthood. Male, but not female VPA rats, also presented deficits in recognition memory as adults. SH-053-2'F-R-CH3 attenuated the impairments in sociability and cognitive function in male VPA-exposed rats without attenuating the decreased social interaction in females. Adult male and female VPA-exposed rats also showed an increased VTA DA neuron population activity, which was not changed by SH-053-2'F-R-CH3. Despite sex differences, our findings indicate that α5-GABAARs positive allosteric modulators may effectively attenuate some core ASD symptoms.

Delving into the Complexity of Valproate-Induced Autism Spectrum Disorder: The Use of Zebrafish Models.

Autism spectrum disorder (ASD) is a multifactorial neurodevelopmental condition with several identified risk factors, both genetic and non-genetic. Among these, prenatal exposure to valproic acid (VPA) has been extensively associated with the development of the disorder. The zebrafish, a cost- and time-effective model, is useful for studying ASD features. Using validated VPA-induced ASD zebrafish models, we aimed to provide new insights into VPA exposure effects during embryonic development and to identify new potential biomarkers associated with ASD-like features. Dose-response analyses were performed in vivo to study larval phenotypes and mechanisms underlying neuroinflammation, mitochondrial dysfunction, oxidative stress, microglial cell status, and motor behaviour. Wild-type and transgenic Tg(mpeg1:EGFP) zebrafish were water-exposed to VPA doses (5 to 500 µM) from 6 to 120 h post-fertilisation (hpf). Embryos and larvae were monitored daily to assess survival and hatching rates, and numerous analyses and tests were conducted from 24 to 120 hpf. VPA doses higher than 50 µM worsened survival and hatching rates, while doses of 25 µM or more altered morphology, microglial status, and larval behaviours. VPA 50 µM also affected mRNA expression of inflammatory cytokines and neurogenesis-related genes, mitochondrial respiration, and reactive oxygen species accumulation. The study confirmed that VPA alters brain homeostasis, synaptic interconnections, and neurogenesis-related signalling pathways, contributing to ASD aetiopathogenesis. Further studies are essential to identify novel ASD biomarkers for developing new drug targets and tailored therapeutic interventions for ASD.

Assessment of the potential protective effects of culture filtrate of Trichoderma harzianum to ameliorate the damaged histoarchitecture of brain in epileptic rats.

The simultaneous hyperexcitability of the neural network is the most well-known manifestation of epilepsy that causes recurrent seizures. The current study was aimed to examine any potential safety benefits of the culture filtrate of Trichoderma harzianum (ThCF) to ameliorate damaged histoarchitecture of the brain in epileptic rats by assessing seizure intensity scale and behavioral impairments and follow up the spontaneous motor seizures during status epilepticus phases in rats. Twenty-four rats were divided into four groups; control (C), epileptic (EP) valproic acid-treated epileptic (EP-VPA), and epileptic treated with T. harzianum cultured filtrate (ThCF). In addition to a seizure intensity score and behavioral tests, routine H&E and Golgi-Copsch histopathology, were used to examine the cell somas, dendrites, axons, and neural spines. ThCF treatment increased activity and recorded movements during grooming, rearing, and ambulation frequency. Brain tissues of epileptic rats exhibited detached meninges, hypercellularity, mild edema in the cortex and markedly degenerated neurons, degenerated glial cells, and microcyst formation in the hippocampus. Moreover, brains of EP-ThCF were noticed with average blood vessels, and increased dendritogenesis. The current data revealed some of negative effects of epileptogenesis brought on by seizure intensity score and retarded histopathological alterations in the hippocampus. Therefore, the study is forecasting to identify novel active components from the metabolites of T. harzianum with a crucial therapeutic role in various disorders.

Continuous exercise training rescues hippocampal long-term potentiation in the VPA rat model of Autism: Uncovering sex-specific effects.

Long-term potentiation (LTP) impairment has been reported in many studies of autistic models. The aim of the present study was to investigate the effects of interval training (IT) and continuous training (CT) exercises on LTP in the hippocampal dentate gyrus (DG) neurons of valproic acid (VPA) rat model of autism. To induce an autism-like model, pregnant rats were injected 500 mg/kg NaVPA (intraperitoneal) on the embryonic day 12.5. IT and CT aerobic exercises started on postnatal day 56 in the offspring. Four weeks after IT and/or CT exercises, the offspring were urethane-anesthetized and placed into a stereotaxic apparatus for surgery, electrode implantation, and field potential recording. In the DG region, excitatory post synaptic potentials (EPSP) slope and population spike (PS) amplitude were measured. Sex differences in LTP were evident for control rats but not for VPA-exposed offspring. LTP was significantly smaller in VPA-exposed male offspring compared with control male rats. In contrast to males, there was no difference between VPA-exposed female offspring and control female rats. Interestingly, we observed a sex difference in the response to exercise between VPA-exposed male and female offspring. CT exercise training (but not IT) increased LTP in VPA-exposed male offspring. Both IT and CT exercise trainings had no effect on intact LTP in VPA-exposed female offspring. Our work suggests that there may be differences in the benefits of exercise interventions based on sex, and CT exercise training could be more beneficial for LTP improvements.

Spontaneous Calcium Transients Recorded from Striatal Astrocytes in a Preclinical Model of Autism.

Autism spectrum disorder (ASD) is known as a group of neurodevelopmental conditions including stereotyped and repetitive behaviors, besides social and sensorimotor deficits. Anatomical and functional evidence indicates atypical maturation of the striatum. Astrocytes regulate the maturation and plasticity of synaptic circuits, and impaired calcium signaling is associated with repetitive behaviors and atypical social interaction. Spontaneous calcium transients (SCT) recorded in the striatal astrocytes of the rat were investigated in the preclinical model of ASD by prenatal exposure to valproic acid (VPA). Our results showed sensorimotor delay, augmented glial fibrillary acidic protein -a typical intermediate filament protein expressed by astrocytes- and diminished expression of GABAA-ρ3 through development, and increased frequency of SCT with a reduced latency that resulted in a diminished amplitude in the VPA model. The convulsant picrotoxin, a GABAA (γ-aminobutyric acid type A) receptor antagonist, reduced the frequency of SCT in both experimental groups but rescued this parameter to control levels in the preclinical ASD model. The amplitude and latency of SCT were decreased by picrotoxin in both experimental groups. Nipecotic acid, a GABA uptake inhibitor, reduced the mean amplitude only for the control group. Nevertheless, nipecotic acid increased the frequency but diminished the latency in both experimental groups. Thus, we conclude that striatal astrocytes exhibit SCT modulated by GABAA-mediated signaling, and prenatal exposure to VPA disturbs this tuning.

Epigenetic insights into GABAergic development in Dravet Syndrome iPSC and therapeutic implications.

Dravet syndrome (DS) is a devastating early-onset refractory epilepsy syndrome caused by variants in the SCN1A gene. A disturbed GABAergic interneuron function is implicated in the progression to DS but the underlying developmental and pathophysiological mechanisms remain elusive, in particularly at the chromatin level. Induced pluripotent stem cells (iPSCs) derived from DS cases and healthy donors were used to model disease-associated epigenetic abnormalities of GABAergic development. Chromatin accessibility was assessed at multiple time points (Day 0, Day 19, Day 35, and Day 65) of GABAergic differentiation. Additionally, the effects of the commonly used anti-seizure drug valproic acid (VPA) on chromatin accessibility were elucidated in GABAergic cells. The distinct dynamics in the chromatin profile of DS iPSC predicted accelerated early GABAergic development, evident at D19, and diverged further from the pattern in control iPSC with continued differentiation, indicating a disrupted GABAergic maturation. Exposure to VPA at D65 reshaped the chromatin landscape at a variable extent in different iPSC-lines and rescued the observed dysfunctional development of some DS iPSC-GABA. The comprehensive investigation on the chromatin landscape of GABAergic differentiation in DS-patient iPSC offers valuable insights into the epigenetic dysregulations associated with interneuronal dysfunction in DS. Moreover, the detailed analysis of the chromatin changes induced by VPA in iPSC-GABA holds the potential to improve the development of personalized and targeted anti-epileptic therapies.

Acetyl-l-carnitine alleviates valproate-induced autism-like behaviors through attenuation of hippocampal mitochondrial dysregulation.

This study aimed to evaluate the potential benefits of acetyl-L-carnitine (ALCAR) in the context of valproate-induced autism. After prenatal exposure to valproate (VPA; 600 mg/kg, i.p.) on embryonic day 12.5, followed by ALCAR treatment (300 mg/kg on postnatal days 21-49, p.o.), assessment of oxidative stress, mitochondrial membrane potential (MMP), mitochondrial biogenesis, parvalbumin interneurons, and hippocampal volume was conducted. These assessments were carried out subsequent to the evaluation of autism-like behaviors. Hippocampal analysis of oxidative factors (reactive oxygen species and malondialdehyde) and antioxidants (superoxide dismutase, catalase, and glutathione) revealed a burden of oxidative stress in VPA rats. Additionally, mitochondrial biogenesis and MMP were elevated, while the number of parvalbumin interneurons decreased. These changes were accompanied by autism-like behaviors observed in the three-chamber maze, marble burring test, and Y-maze, as well as a learning deficit in the Barnes maze. In contrast, administrating ALCAR attenuated behavioral deficits, reduced oxidative stress, improved parvalbumin-positive neuronal population, and properly modified MMP and mitochondrial biogenesis. Collectively, our results indicate that oral administration of ALCAR ameliorates autism-like behaviors, partly through its targeting oxidative stress and mitochondrial biogenesis. This suggests that ALCAR may have potential benefits ASD managing.

Neuroprotective effect of PPAR gamma agonist in rat model of autism spectrum disorder: Role of Wnt/ß-catenin pathway.

BACKGROUND: The clinical manifestation of autism spectrum disorder (ASD) is linked to the disruption of fundamental neurodevelopmental pathways. Emerging evidences claim to have an upregulation of canonical Wnt/ß-catenin pathway while downregulation of PPARγ pathway in ASD. This study aims to investigate the therapeutic potential of pioglitazone, a PPARγ agonist, in rat model of ASD. The study further explores the possible role of PPARγ and Wnt/ß-catenin pathway and their interaction in ASD by using their modulators. MATERIAL AND METHODS: Pregnant female Wistar rats received 600 mg/kg of valproic acid (VPA) to induce autistic symptoms in pups. Pioglitazone (10 mg/kg) was used to evaluate neurobehaviors, relative mRNA expression of inflammatory (IL-1ß, IL-6, IL-10, TNF-α), apoptotic markers (Bcl-2, Bax, & Caspase-3) and histopathology (H&E, Nissl stain, Immunohistochemistry). Effect of pioglitazone was evaluated on Wnt pathway and 4 µg/kg dose of 6-BIO (Wnt modulator) was used to study the PPARγ pathway. RESULTS: ASD model was established in pups as indicated by core autistic symptoms, increased neuroinflammation, apoptosis and histopathological neurodegeneration in cerebellum, hippocampus and amygdala. Pioglitazone significantly attenuated these alterations in VPA-exposed rats. The expression study results indicated an increase in key transcription factor, ß-catenin in VPA-rats suggesting an upregulation of canonical Wnt pathway in them. Pioglitazone significantly downregulated the Wnt signaling by suppressing the expression of Wnt signaling-associated proteins. The inhibiting effect of Wnt pathway on PPARγ activity was indicated by downregulation of PPARγ-associated protein in VPA-exposed rats and those administered with 6-BIO. CONCLUSION: In the present study, upregulation of canonical Wnt/ß-catenin pathway was demonstrated in ASD rat model. Pioglitazone administration significantly ameliorated these symptoms potentially through its neuroprotective effect and its ability to downregulate the Wnt/ß-catenin pathway. The antagonism between the PPARγ and Wnt pathway offers a promising therapeutic approach for addressing ASD.