Sevoflurane (SEV) is widely used in clinical anesthesia, but its exposure is increasingly being linked to neurocognitive dysfunction, particularly in hippocampal neurons. TRIM14, an E3 ubiquitin ligase, is essential for regulating inflammation, apoptosis, and mitochondrial function; however, its involvement in SEV-induced neuronal damage remains unclear. In this study, we investigated the role of TRIM14 in SEV-induced hippocampal neuronal damage, focusing on mitochondrial dysfunction, iron homeostasis, and inflammation. The results show that TRIM14 knockdown significantly increased cell viability, restrained apoptosis, and suppressed inflammatory cytokines in SEV-treated neurons. However, it also alleviated mitochondrial dysfunction, mitigated ferroptosis, and regulated iron homeostasis. Furthermore, silencing TRIM14 suppressed the NF-κB and STAT3 axis. These findings suggest that TRIM14 contributes to SEV-induced neuronal damage.
Central nervous system (CNS) injuries are the leading cause of permanent disability and premature death in adults worldwide, with their incidence continuing to rise amid social development. These injuries not only severely impair the quality of life but also impose a heavy burden on the global public health system. Current clinical interventions, such as decompression and thrombolysis, can alleviate primary injury but fail to effectively reverse the secondary neuroinflammatory damage. Traditional anti-inflammatory therapies, which cannot block the upstream source of the inflammatory cascade, have led to repeated failures in global clinical translation research over the past decades. Gasdermins were first characterized in studies of systemic inflammatory diseases. These proteins form transmembrane pores to drive the release of proinflammatory factors and inflammatory cell death, serving as key mediators of host innate immunity. Recent studies have revealed that gasdermins play critical roles in regulating the initiation and amplification of neuroinflammation following CNS injury. To clarify the therapeutic potential of gasdermins as targets for injury repair, this review systematically summarizes the structure and function of gasdermins, as well as their cell-specific activation and regulatory mechanisms. We further elaborate on their pathological roles in these injuries and the corresponding therapeutic strategies, aiming to provide a theoretical reference for basic research and clinical translation in this field.
Iron is an essential micronutrient for brain development, participating in mitochondrial respiration, myelination, and neurotransmitter synthesis. However, previous studies have demonstrated that excessive iron during early postnatal life induces oxidative reactions, leading to mitochondrial dysfunction and synaptic failure. These alterations compromise energy metabolism and neuronal integrity, contributing to long-lasting cognitive dysfunction and increased brain vulnerability later in life. This study evaluated the effects of cannabidiol (CBD) and cannabigerol (CBG) on behavioral, neuroinflammatory, and blood-brain barrier (BBB) outcomes in rats exposed to early-life iron overload. Male Wistar rats received iron carbonyl (30 mg/kg, intragastrically) from postnatal day 12 to 14. At three months of age, they were treated intraperitoneally with CBD, CBG (both at 10 mg/kg), or vehicle for 21 days. Cognitive performance was assessed in the open field and object recognition tasks. We examined hippocampal levels of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), as proinflammatory markers, and occludin, a protein known to regulate BBB permeability. Iron-exposed animals showed impaired recognition memory, with elevated TNF-α and IL-1β, while CBD reversed memory deficits and reduced IL-1β in iron-treated animals, without affecting TNF-α. CBG restored memory, decreased IL-1β in both iron-treated and controls, and increased TNF-α in controls. Also, iron overload reduced occludin expression in vehicle-treated rats which was reversed by both CBD and CBG. These findings highlight inflammation and BBB disruption as mediators of iron-induced cognitive dysfunction and show that both phytocannabinoids act through distinct but complementary mechanisms, supporting their therapeutic potential in neuroinflammation linked to iron overload.
Anxiety disorders are among the most common mental health conditions affecting women of reproductive age, and a significant proportion of pregnant women experience clinically relevant anxiety symptoms. In some cases, pharmacological treatment may be required to manage severe or persistent symptoms; however, concerns remain regarding the potential impact of prenatal exposure to anxiolytic medications on fetal brain development. The developing nervous system undergoes critical processes during gestation, including neuronal proliferation, migration, and synaptic formation, which may be sensitive to pharmacological influences. This review examines available clinical and preclinical evidence regarding the neurodevelopmental consequences of prenatal exposure to commonly used anxiolytic medications, especially benzodiazepines (BZDs) and azapirones (AZPs). Evidence from observational human studies has shown associations between prenatal exposure to BZDs and certain neonatal and neurodevelopmental outcomes. However, results remain inconsistent and may be influenced by confounding factors, including maternal psychiatric conditions, co-medication use, and environmental variables. In contrast, data on prenatal exposure to AZPs, especially buspirone, are relatively limited, with most of the available evidence coming from small cohorts and preclinical models. Experimental studies provide mechanistic insights suggesting that early-life exposure to anxiolytic agents may influence neurotransmitter systems, neuronal morphology, and behavioral development in offspring. However, translating findings from animal models to the human clinical context remains challenging. Overall, the current literature highlights substantial knowledge gaps regarding dose-dependent effects, critical developmental windows, and long-term neurobehavioral outcomes. Further well-controlled longitudinal and translational studies are needed to clarify the potential implications of prenatal exposure and to support evidence-based clinical decision-making during pregnancy. Prenatal exposure to anxiolytic medications may influence fetal brain development and long-term neurobehavioral outcomes. Clinical and preclinical evidence suggests that prenatal benzodiazepine exposure may be associated with structural, neurochemical, and neurobehavioral alterations, although causality remains uncertain. Limited experimental evidence suggests possible neurodevelopmental effects of azapirones such as buspirone, but available data remain sparse. Vigorous translational research and well-controlled clinical studies are needed to justify the safety profile of anxiolytics during pregnancy.
Oxidative stress is an early and important feature of Alzheimer’s disease (AD) that contributes to synaptic dysfunction and neurodegeneration. Soluble amyloid-β oligomers (AβOs) are major contributors to oxidative damage and have been shown to impair neuronal antioxidant defenses. The Nrf2/KEAP1 pathway is a central regulator of cellular redox homeostasis; however, its activity is compromised in AD, increasing neuronal vulnerability to oxidative stress. Metformin (Met), a widely used antidiabetic drug, has emerged as a potential modulator of antioxidant signaling pathways in the nervous system. In the present study, we investigated whether Met enhances antioxidant defenses in primary fetal rat hippocampal neurons exposed to AβOs. Neuronal cultures were treated with Met (2.5 mM for 24 h) prior to exposure to AβOs (500 nM for 6 h). We evaluated Nrf2 and KEAP1 protein levels, Nrf2 nuclear localization, antioxidant enzyme expression and activity, and lipid peroxidation. Met treatment promoted Nrf2 nuclear accumulation, preserved a favorable Nrf2/KEAP1 profile under amyloid stress, and enhanced the expression and activity of key antioxidant enzymes, including superoxide dismutase (SOD1 and SOD2), catalase (CAT), and glutathione peroxidase (GPx1/2). In addition, Met attenuated AβOs-induced lipid peroxidation, supporting its protective effects against amyloid-associated oxidative damage. Collectively, these findings indicate that Met strengthens neuronal antioxidant defenses and promotes redox resilience under amyloid-associated oxidative stress. Our results support modulation of the Nrf2/KEAP1 pathway as a mechanism contributing to the neuroprotective actions of Met and identify the coordinated enhancement of antioxidant defenses and reduction of lipid peroxidation as key components of neuronal redox resilience against AβOs-induced stress. Metformin modulates the Nrf2/KEAP1 pathway and enhances antioxidant defenses in hippocampal neurons. Metformin increases the protein levels and activity of key antioxidant enzymes, including SOD, CAT, and GPx. Metformin attenuates AβOs-induced lipid peroxidation in primary hippocampal cultures.
Tau is a crucial protein involved in many neurodegenerative diseases, including Alzheimer's disease. Natively, Tau is an unfolded protein found predominantly in axons that play a vital role in maintaining and stabilizing microtubules. Under pathological circumstances, Tau disengages from microtubules and forms insoluble intracellular filaments on its own, building neurofibrillary tangles in the brains of Alzheimer's patients. Although Tau exists in aggregates found in the brain and gut of Alzheimer's patients, the function of Tau in the brain is well studied, while the role of Tau in the gut needs further investigation. We have investigated the effects of Tau monomer, oligomer, and aggregates at 10 µM concentration via feeding them to the third instar larvae. To evaluate the genotoxicity, we did 4', 6-diamidino-2-phenylindole staining, while dichloro-dihydro-fluorescein diacetate staining was performed to assess cytotoxicity. Furthermore, we performed a TUNEL assay to detect apoptotic cells. Additionally, we carry out an NBT assay for biochemical estimation of reactive oxygen species by extracting hemolymph. Phenotypes were examined in different stages, i.e., larvae, pupae, and adult flies. Histological studies were performed on eye, gut tissue and reproductive organs of D. melanogaster to check the cytoskeletal alterations. The current study finds that the administration of monomer, oligomer, and aggregate forms causes genotoxicity, cytotoxicity, and cytoskeletal defects in D. melanogaster.
Illicit psychostimulant use during pregnancy represents a major public health issue due to its detrimental effects on offspring neurodevelopment. Prenatal exposure to smokable cocaine derivatives such as crack cocaine and coca paste (CP) is particularly concerning, as it has been associated with an increased risk of impairments in learning, memory, and social behavior from birth through early childhood. CP's low cost, wide availability, high toxicity, and strong addictive potential heighten its danger. While CP use during pregnancy is well documented, its specific neurodevelopmental consequences remain poorly understood compared to those of crack. Here, we used a rat model to examine the effects of chronic prenatal exposure to a street-grade CP sample obtained from police seizures on hippocampal neuronal morphogenesis, synaptogenesis, and function, as well as hippocampus-dependent recognition memory. Primary hippocampal neurons from neonates prenatally exposed to CP once daily from gestational day (GD) 8 until GD21 showed reduced neuronal survival, impaired neurite outgrowth, and decreased dendritic complexity, together with reduced synaptic vGlut1 abundance. These structural alterations were accompanied by significant deficits in recognition memory in the novel object recognition task in juvenile offspring. Our findings suggest that prenatal CP exposure disrupts hippocampal development and function, leading to cognitive deficits. This study supports the severe neurodevelopmental risks associated with prenatal CP exposure and underscores the importance of preventive strategies addressing drug use during pregnancy.
Motor neuron (MN) diseases such as amyotrophic lateral sclerosis (ALS) are characterized by the loss of cortical and spinal MNs. Although the precise mechanisms of MN degeneration are still unknown, downregulation of GABAergic circuits has been identified in both ALS patients and transgenic models of the disease. GABA synthesis depends on the activity of the enzyme glutamate decarboxylase (GAD), of which two isoforms are known: GAD65 and GAD67. To study the effects of decreased GABA synthesis on spinal cord motor function, we analyzed the effects of administering three selective inhibitors of GAD: 3-mercaptopropionic acid (MPA), a competitive inhibitor of GAD, thiosemicarbazide (TSC), and pyridoxal phosphate γ-glutamyl hydrazone (PLPGH), two GAD cofactor blockers. A single dose of any of these inhibitors did not affect motor behavior or MN morphology. However, subchronic (3 days) and chronic (10 days) administration of MPA, TSC or PLPGH in rats caused motor alterations and cellular changes, including episodic myoclonus-like movements, flaccidity in the ipsilateral phalanges, loss of 35–50
Chlorpyrifos (CPF) is a broad-spectrum chlorinated organophosphate insecticide. It was classified as a persistent organic pollutant under the Stockholm Convention in 2024 due to its harmful effects on the environment and human health, including neurotoxicity. The classical mechanism of CPF-induced neurotoxicity is attributed to acetylcholinesterase inhibition by its metabolite, chlorpyrifos-oxon (CPO), in cholinergic neurons. Emerging studies indicate that CPF also induces toxicity in dopaminergic neurons through mitochondrial dysfunction. In this study, the molecular mechanisms and targets associated with CPF-induced neurotoxicity in humans were investigated using network toxicology, molecular docking, molecular dynamics, and in vitro study. Comprehensive database analyses identified 271 potential targets associated with CPF-induced neurotoxicity. Gene ontology enrichment and gene-gene interaction analyses revealed significant enrichment related to mitochondria and oxidative phosphorylation. Protein-protein interaction and centrality analyses identified 15 hub targets. Molecular docking and molecular dynamics simulations demonstrated that CPF and CPO bind to mitochondrial Complex I, especially with NDUFA2, more strongly than rotenone, a known Complex I inhibitor. In vitro analysis in SH-SY5Y cells demonstrated that CPF impaired mitochondrial complex I-associated activity in a concentration-dependent manner, with significant inhibition observed at concentrations of 75 µM and higher. These findings suggest that CPF, and to a lesser extent CPO, may exert inhibitory effects on mitochondrial complex I in neurons, thereby contributing to neurotoxicity in humans. Overall, these results are in line with previous experimental reports and highlight the effectiveness of integrated computational approaches in identifying key mitochondrial mechanisms involved in CPF-induced neurotoxicity.
Melatonin has been extensively studied for its antioxidant activity, yet its safety profile and concentration-dependent effects remain only partially understood, particularly in aquatic experimental systems. Here, we investigated the effects of melatonin on behavioral and physiological responses in a pilocarpine (PILO)-induced seizure-like model using zebrafish (Danio rerio) larvae. A multibiomarker framework was employed, combining embryo–larval toxicity assessments up to 144 h post-fertilization with behavioral and biochemical endpoints related to seizure-like activity. Across the tested concentration range (0.14–18 µg/mL), melatonin did not affect mortality or hatching rates. However, exposure to higher concentrations (9.0 and 18 µg/mL) resulted in altered spontaneous contractions and increased embryonic heart rate, indicating measurable physiological changes during early development. At lower concentrations (2.25 and 4.50 µg/mL), melatonin was associated with reduced PILO-induced hyperlocomotion, increased latency to seizure-like onset, and reduced progression to more severe behavioral stages. These responses were accompanied by a reduction in reactive oxygen species (ROS) levels at both 72 and 144 hpf. Collectively, the data reveal a concentration-dependent response profile, with distinct behavioral and physiological outcomes emerging across exposure levels. This study contributes to the characterization of melatonin effects in zebrafish larvae and underscores the importance of dose selection in experimental seizure models.
Lead (Pb) neurotoxicity is characterized by persistent cognitive and motor impairments that arise from converging disturbances in mitochondrial function, oxidative balance, and neuroinflammatory signaling. Increasing evidence suggests that these pathological outcomes are closely linked to disruption of Transcription Factor EB (TFEB), a key regulator of autophagy-lysosomal pathways and mitochondrial quality control. Impaired TFEB function can promote the accumulation of dysfunctional mitochondria and perpetuate oxidative and inflammatory cascades, thereby exacerbating Pb-induced neurodegeneration. The present study evaluated whether caffeic acid (CFA) protects against Pb-induced neurotoxicity and investigated the involvement of TFEB signaling in its neuroprotective effects. Wistar rats were exposed to lead acetate (100 mg/kg, p.o.) for 30 days, followed by treatment with caffeic acid (CFA; 20 and 40 mg/kg). To validate the mechanistic role of TFEB, eltrombopag, a TFEB inhibitor, was co-administered in dedicated groups. Behavioral outcomes were assessed using the Morris Water Maze and rota rod tests, and hippocampal and cerebellar tissues were examined for mitochondrial complex I–III activities, oxidative stress indices (TBARS, GSH), and inflammatory mediators (TNF-α, IL-1β, NF-κB). Pb exposure produced marked spatial memory deficits, motor impairment, suppression of mitochondrial complex activities, oxidative imbalance, and enhanced inflammatory signaling. CFA treatment attenuated these alterations; however, these benefits were lost upon TFEB inhibition. Collectively, these findings demonstrate that CFA attenuates Pb-induced behavioral and biochemical alterations and suggest that its neuroprotective effects are mediated, at least in part, through TFEB-associated pathways.
Neuroinflammation is recognized as a central mechanism in Parkinson’s disease (PD) pathogenesis. The C-terminal domain of the heavy-chain of tetanus toxin (Hc-TeTx) has shown neuroprotective effects in toxin-based PD models, but its efficacy in inflammatory-induced PD conditions remain unexplored. To test this possibility, we used the hemiparkinsonism model induced by central injection of lipopolysaccharide (LPS) to evaluate potential antiinflammatory effects of Hc-TeTx in adult male Wistar rats. Seven days post LPS-injection motor coordination and gait maintenance were assessed using elevated beam test. The day after, that is 8 days post LPS-injection, the cylinder test was used to assess forelimb motor asymmetry during spontaneous vertical exploration. Immediately after this test the animals were sacrificed for tissue collection. Dopaminergic degeneration was assessed by immunohistochemical quantification of tyrosine hydroxylase in substantia nigra pars compacta. Astroglial activation, reflective of neuroinflammation was evaluated by glial fibrillary acidic protein in the striatum. LPS administration caused forelimb motor asymmetry, which was significantly attenuated by Hc-TeTx treatment. Hc-TeTx also tended to attenuate LPS-induced dopaminergic neurodegeneration reflected by a reduced TH ipsilateral/contralateral ratio, as well as astroglial activation that was markedly increased after LPS administration. Beam test parameters showed no significant differences among groups. Although further verification and mechanistic studies are needed, current results support potential utility of Hc-TeTx in an inflammatory model of PD.
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder whose origins extend beyond the brain. Chronic periodontitis has emerged as a modifiable risk factor, and extracellular vesicles (EVs) have recently been proposed as important mediators of the periodontal–brain axis. Periodontal pathogens such as Porphyromonas gingivalis (P. gingivalis) release bacterial EVs enriched with virulence factors including gingipains, lipopolysaccharide, and regulatory RNAs. These vesicles can enter systemic circulation, interact with the blood–brain barrier, activate microglia, and trigger inflammatory signaling pathways such as NF-κB and NLRP3. These processes contribute to neuroinflammation, amyloid-β accumulation, and tau hyperphosphorylation, hallmarks of AD pathology. Host-derived EVs further contribute to this complex signaling network by facilitating intercellular communication and potentially propagating pathogenic proteins while also carrying protective molecules. Preclinical studies suggest that periodontal-derived vesicles can reach the hippocampus and impair cognition, while clinical studies have detected P. gingivalis DNA and gingipains in AD brain tissues. EV–associated biomarkers in blood or cerebrospinal fluid and engineered therapeutic vesicles represent promising tools for early diagnosis and intervention. Targeting oral microbial EVs may therefore offer novel avenues for AD prevention and therapy.
Synthetic cannabinoids (SCs) are chemical and inhomogeneous broad group of new psychoactive substances associated with severe toxicity and death. This study aims to characterize neurotoxicological profile of ADB-FUBIATA, third-generation indole-3-acetamide-type SCRA, applying 3D human stem-cell-derived neuronal (3D-hNLCs) spheroids testing at different concentrations (25-2000 nM) and exposure times. i)Single exposure to ADB-FUBIATA induced decrease of: cell viability (2000 nM after 24-h and ≥ 800 nM after 48-h), spheroid compactness (≥ 1600 nM after 24-h and ≥ 200 nM after 48-h), collagen I fibre content (25–35
Heavy alcohol consumption has multiple negative cognitive, psychological, and neurobiological consequences for people with epilepsy. However, the psychopharmacological interactions remain unclear with limited therapeutic interventions. In this study, we investigated the diverse impact of alcohol on experimental simulated pentylenetetrazol-induced seizures and alcohol-use disorder, and the effects of silymarin, a polyphenolic compound with neuroprotective properties. Following seven days of ethanol binge exposure (2 g/kg, oral gavage) in mice, maximal and sub-convulsive pentylenetetrazol-induced seizures were administered from days 8 to 14, alongside silymarin (50 and 100 mg/kg) or diazepam (3 mg/kg) oral administration. This study evaluated the interplay between ethanol and pentylenetetrazol-induced seizures, assessing behavioural comorbidities, dysregulation of the hypothalamic-pituitary-adrenal (HPA)-axis, neurochemical and neurotrophic alterations, oxidative stress, and neuroinflammation in the hippocampus, prefrontal-cortex, and striatum, which are involved in the disease. Ethanol increased seizure severity and frequency caused by pentylenetetrazol, and worsened anxiety-like and depressive behaviours, along with spatial working memory deficits linked to higher alcohol preference. These effects were reduced by silymarin. Ethanol also increased corticosterone release and reduced GABA-dependent glutamic acid decarboxylase activity, raising glutamate levels, while decreasing serotonin and brain-derived neurotrophic factor across the studied brain regions. Silymarin significantly reduced neuroinflammatory markers such as myeloperoxidase, TNF-α, IL-6, nitrite, and malondialdehyde, while enhancing IL-10 levels and antioxidant defenses, including catalase, superoxide dismutase and glutathione in the brain regions. These findings suggest alcoholism with alcohol-use disorders worsens epilepsy, notably involving neurochemical imbalance, neurotropic, HPA-axis upregulation, oxidative stress, and neuroinflammation, which were reversed by silymarin.
Cognitive decline is a hallmark of neurodegenerative diseases. The complex pathophysiology of these diseases has limited the efficacy of current therapies. The co-administration of epidermal growth factor (EGF) and growth hormone-releasing peptide 6 (GHRP6) emerges as a promising neuroprotective candidate. The present study evaluated the therapeutic potential of this combination in two preclinical models of cognitive impairment: (i) age-related decline and (ii) impairment induced by intracerebroventricular administration of streptozotocin (STZ). In both experiments, C57BL/6 mice were used and distributed into three experimental groups, each comprising 14–15 animals per group. Cognitive and motor function was assessed through gait pattern, Y-maze and novel object recognition tests. Differential gene expression was analyzed using qPCR. Both models reproduced hallmark features of cognitive decline, including deficits in working and spatial memory and changes in the expression of genes associated with oxidative stress, neuroinflammation and synaptic plasticity. In aged animals, EGF + GHRP6 treatment increased step length (p = 0.04). In the forced alternation Y-maze test, aged-EGF + GHRP6 animals made more visits to the novel arm than to the familiar arm 1 (p = 0.001) or to the familiar arm 2 (p = 0.04). Cognitive benefits were also observed in the STZ-induced model. STZ-EGF + GHRP6 group exhibited an alternation percentage higher than the STZ-vehicle group (p = 0.03). Moreover, EGF + GHRP6 treatment significantly increased the expression of genes associated with antioxidant defense (Hmox1), synaptic plasticity (Creb1), and oligodendrocyte differentiation (Olig1) while concurrently reducing the expression of Nfkb1. These findings highlight the therapeutic potential of EGF + GHRP6 co-administration as a neuroprotective strategy to mitigate neurodegeneration and preserve cognitive function.
Atorvastatin is a widely prescribed statin used for its cholesterol-lowering effects; however, it also exerts known pleiotropic effects, including antioxidant and anti-inflammatory properties. Atorvastatin´s impact on mitochondrial function remains controversial, with reports of toxicity in skeletal muscle and liver, while exhibiting beneficial effects on the brain. Atorvastatin has a neuroprotective effect, modulating glutamatergic transmission and reducing oxidative stress. Additionally, we previously showed that atorvastatin treatment in vivo increases mitochondrial capacity in the mouse hippocampus. Nonetheless, the bioenergetic impact of atorvastatin on the prefrontal cortex, a critical region for cognitive function, remains underexplored. This study investigated whether short-term administration of atorvastatin alters mitochondrial respiration and redox status in the prefrontal cortex of adult mice. Male Swiss mice received atorvastatin (10 mg/kg/day) or vehicle orally (p.o., in a voluntary consumption protocol) for 7 days. A behavioral analysis showed that atorvastatin slightly increased spontaneous locomotor activity and does not compromise short- (90 min) and long-term (24 h) memory in the object recognition task. The evaluation of cellular viability, cell membrane integrity, reactive oxygen species (ROS) production, and mitochondrial membrane potential in slices from the prefrontal cortex showed that atorvastatin did not induce oxidative stress, cell damage, or mitochondrial depolarization. High-resolution respirometry (HRR) was used to assess oxygen consumption rates (OCR) in prefrontal cortex homogenates, and we observed no significant alterations in any of the mitochondrial respiratory states: basal, LEAK, phosphorylating, maximal electron transfer system (ETS) capacity, or coupling efficiency. Furthermore, direct analysis of the enzymatic activity of respiratory chain complexes I and II also showed no alterations. These findings indicate that short-term atorvastatin administration is bioenergetically neutral in the murine prefrontal cortex under basal conditions, and does not compromise cognition, mitochondrial function, or cellular viability.
Methylmalonic acidemia is an inherited neurometabolic disorder characterized by accumulation of methylmalonic acid (MMA) in different tissues, particularly in the brain. As a result, patients frequently exhibit progressive neurological deterioration, accompanied by episodes of acute encephalopathy following metabolic decompensation. Astrocytes are glial cells that maintain the central nervous system homeostasis and may be important cellular targets of MMA-induced dysfunction. However, most in vitro experimental models for the study of methylmalonic acidemia are based on short-term exposure to the toxic metabolites that accumulate in patients. In this study, we used a prolonged experimental model, which has not been yet explored in the context of glial cells, focusing on the inflammatory response, glutamate metabolism, and putative signaling pathways that can contribute to understanding cellular damage observed in methylmalonic acidemia. It is emphasized that MMA is persistently elevated in the brain of the affected patients. Prolonged MMA exposure induced inflammation with significant increase in gene expression of cyclooxygenase 2, interleukin (IL)-1β and its receptor (IL1R1), and IL-6, accompanied by a decrease in IL-10 expression. MMA also increased glutamate uptake and the activity and gene expression of the enzyme glutamine synthetase, while it downregulated glial cell-derived neurotrophic factor (GDNF). The expression of NFκB, p38 MAPK, Nrf2, heme oxygenase 1, PGC-1α, and sirtuin 1 were also modulated by MMA treatment, indicating the critical role of these signaling pathways in the MMA-induced persistent gliotoxicity. Finally, it is conceivable that these changes may significantly contribute to clarify the pathogenesis of methylmalonic acidemia.
The present study aimed to investigate the effects of chronic mild stress (CMS) on neurotrophic factors in the brains of rats subjected to the cecal ligation and puncture (CLP) model of sepsis. After 30 days of the CLP procedure, the animals were subjected to CMS. Twenty-four hours after the last stressor, the animals were euthanized, their blood was collected, and their brains were dissected in the frontal cortex and hippocampus. Then, the levels of brain-derived neurotrophic factor, neurotrophin-3, neurotrophin-4, nerve growth factor, and glial cell line-derived neurotrophic factor were evaluated in the brain structures. The levels of adrenocorticotropic hormone and corticosterone were evaluated in the serum of the rats. The four experimental groups of the present study were: (1) Sham + Non-stressed; (2) Sepsis + Non-stressed; (3) Sham + CMS; (4) Sepsis + CMS. CMS increased adrenocorticotropic hormone and corticosterone levels, whereas sepsis alone did not significantly alter these hormones. Regarding neurotrophic factors, CMS reduced the levels of BDNF, NT-3, NT-4, and NGF in both the hippocampus and frontal cortex, regardless of prior sepsis exposure. Sepsis alone was also associated with reduced levels of these neurotrophins, although the magnitude of the effect varied depending on the specific neurotrophin and brain region, with greater reductions observed for BDNF and NGF. No interaction between sepsis and CMS was detected for these neurotrophins, suggesting independent effects. Our findings suggest that sepsis and CMS independently affect most neurotrophin levels, with no clear evidence that prior sepsis potentiates the effects of subsequent CMS. GDNF represents an exception, pointing to potential region-specific mechanisms that warrant further investigation.
The Na⁺,K⁺-ATPase plays a fundamental role in memory formation by regulating neuronal excitability and NMDA receptor-dependent synaptic plasticity. While this enzyme’s dysfunction is broadly linked to cognitive disorders, its specific contribution to fear memory consolidation, particularly within the key brain structure of the basolateral amygdala (BLA), remains undefined. We investigate whether Na+,K+-ATPase inhibition disrupts contextual fear conditioning (CFC) memory consolidation and examine downstream molecular, oxidative, and inflammatory responses in interconnected brain regions. Fifty-day-old male Wistar rats received bilateral cerebral infusions of the Na+,K+-ATPase inhibitor ouabain (1 μm) or vehicle immediately after CFC training. Memory retention was assessed 24 h later. Additional cohorts were euthanized 6–24 h after infusion for biochemical analysis of Na+,K+-ATPase activity, expression of Na+,K+-ATPase isoforms (α1, α2, α3, β1), oxidative stress markers, and pro-inflammatory cytokines in the amygdala, hippocampus, and prefrontal cortex. Post-training Na+,K+-ATPase inhibition in the BLA selectively impaired fear memory consolidation. Ouabain induced changes in Na⁺,K⁺-ATPase activity in the hippocampus and prefrontal cortex, and induces time-dependent upregulation of α1 and β1 isoforms. Six hours after infusion, ouabain triggered oxidative imbalance – characterized by reduced CAT activity. Pro-inflammatory cytokine expression was markedly elevated in the hippocampus and prefrontal cortex, while D-serine co-administration failed to rescue memory deficits. These findings establish a previously unrecognized role for Na⁺,K⁺-ATPase signaling in the BLA in coordinating the neurobiological processes essential for fear memory consolidation, indicating that its precise regulation is required for adaptive fear memory formation.
