Search Results (84)

Neurological complications, particularly seizures, represent a significant and often under-recognized clinical challenge in pediatric hematologic malignancies. Distinguishing CNS leukemia-associated epilepsy from chemotherapy-induced neurotoxicity is critical for optimizing therapy but remains difficult due to overlapping clinical presentations. This review highlights the distinct molecular mechanisms underlying these two entities. CNS leukemia-associated seizures are primarily driven by blood–brain barrier (BBB) disruption following leukemic infiltration, which triggers a neuroinflammatory cascade involving pro-inflammatory cytokines such as IL-6 and TNF-α, and impairs glutamate homeostasis. In contrast, chemotherapy-induced seizures, particularly those associated with high-dose methotrexate, arise from disrupted folate metabolism, intracellular oxidative stress, and subsequent N-methyl-D-aspartate (NMDA) receptor-mediated excitotoxicity. We provide a comparative analysis of these pathways, integrating current evidence on pharmacogenomic susceptibility—including polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and drug transporter genes—as well as epigenetic factors. By synthesizing these molecular insights, we propose a mechanistic framework for precise clinical differentiation, which may inform biomarker-driven diagnostic approaches and targeted neuroprotective strategies in this vulnerable population. Full article

Alzheimer’s disease (AD), the leading cause of global dementia, is a multifactorial process that goes beyond the accumulation of β-amyloid (Aβ) plaques and tau protein tangles, including glia cell-mediated neuroinflammation, vascular dysfunction, metabolic alterations, and synaptic loss. Its complex etiology also involves oxidative stress and mitochondrial dysfunction. Multiple neurotransmitter systems involved in the pathogenesis and the various cognitive and non-cognitive symptoms of AD are thus altered. The cholinergic system, historically the first to be associated with AD, suffers early degeneration and loss of neurons/receptors, correlating with cognitive impairment. The glutamatergic system, the main excitatory system, exhibits excitotoxicity due to increased extracellular glutamate and alterations in NMDA/AMPA receptor distribution, exacerbating neuronal damage. The GABAergic system, the main inhibitor, shows alterations in parvalbumin-positive interneurons, leading to hyperexcitability and dysfunction of neuronal networks. Monoaminergic systems (serotonergic, dopaminergic and noradrenergic) undergo early degeneration in key nuclei such as the raphe and locus coeruleus, contributing to the apathy, depression and sleep disturbances characteristic of AD. Other less explored systems, such as histaminergic and purinergic, are also crucial in cognitive modulation and neuroinflammation. The endocannabinoid system acts as a master modulator with neuroprotective and anti-inflammatory effects. These systems do not operate in isolation; their complex interactions generate pathological circuits that amplify neuronal dysfunction. The limited efficacy of current therapies, which are primarily symptomatic, highlights the need for multimodal approaches that may transform AD treatment toward personalized and more effective interventions. Full article

Amyotrophic Lateral Sclerosis (ALS) is a severe, progressive neurodegenerative disorder characterized by the loss of upper and lower motor neurons, affecting 0.5 to 2.6 per 100,000 people, with a median survival of 2 to 5 years. It is increasingly seen as a multisystem disorder, sharing essential clinicopathological features with Frontotemporal Dementia (FTD). This convergence arises from overlapping molecular processes, including severe oxidative stress, glutamate-mediated excitotoxicity, mitochondrial dysfunction, and widespread aggregated TDP-43 proteinopathy in both sporadic and familial cases. Several key genetic factors have been identified, particularly mutations in C9orf72, SOD1, TARDBP, and FUS, which serve as important targets for novel treatments, such as Tofersen, a recently approved SOD1-specific antisense oligonucleotide (ASO) gene therapy. Additionally, there is increasing evidence of the gut–brain connection. Dysbiosis, involving species such as Akkermansia muciniphila, and lower levels of neuroprotective metabolites, such as nicotinamide, may affect the course of the disease. As a result, treatment strategies are shifting toward a personalized approach. This includes using gene therapy, ranging from ASOs and RNA interference (RNAi) to new CRISPR-based genome editing. It also involves exploring microbiome-modulating treatments, such as specific probiotics and Fecal Microbiota Transplantation (FMT). While microbiome and gene therapies remain largely experimental, their potential is promising, as highlighted by the recent approval of Tofersen. These novel approaches could be further enhanced and guided by more robust diagnostic criteria and by investigating early multimodal treatment strategies to slow the progression of this complex disease. Full article

Traumatic brain injury (TBI) is a common and important cause of morbidity and mortality among pediatric patients, affecting 47–280 per 100,000 children every year. Head trauma can affect the brain not only by the injury itself but also via a neuroinflammatory process, which leads to blood–brain barrier (BBB) disruption, leukocyte infiltration, and edema formation. This process is regulated by several immune mediators, including interleukins (ILs), which are molecules that are currently investigated in both adult and pediatric TBI. In pediatric patients, IL-1β, IL-6, and IL-8 have mainly been investigated, while IL-10 and IL-17 also play a role in the neuroinflammatory cascade. Therefore, the purpose of this review was to examine the role of the aforementioned cytokines in the pathophysiology of pediatric TBI, as well as their role in determining clinical outcome and prognosis. IL-1β is a key pro-inflammatory cytokine in glutamate excitotoxicity post-TBI and in upregulating the expression of additional pro-inflammatory cytokines. Its high levels in cerebrospinal fluid (CSF) are correlated with injury severity and poor outcomes. IL-6 is an anti-inflammatory cytokine, and its concentration rises rapidly after the injury. Current data show that it can be useful in predicting severe TBI (sTBI) in addition to clinical parameters. IL-8 is a cytokine with several pro- and anti-inflammatory properties. On the one hand, it is a potent chemotactic agent, attracting inflammatory cells to the injured area, and it plays a role in BBB disruption. On the other hand, it promotes the survival of cholinergic and hippocampal neurons via the secretion of nerve growth factor (NGF). These cytokines are important in predicting the outcome of pediatric patients with TBI, as well as in predicting several post-TBI conditions such as fatigue and epilepsy, thus improving diagnostic ability and timely treatment. Further research, unraveling the complex mechanisms via which post-TBI neuroinflammation occurs, will lead to targeted therapies and better outcomes overall. Full article

Ishige okamurae Yendo (I. okamurae) is a brown macroalga with diverse biological activities. Recently, its ameliorative effects against dementia progression have been demonstrated in various in vitro and in vivo models of Alzheimer’s disease (AD), glutamate excitotoxicity, and bacterial-driven neuroinflammation. I. okamurae extract (IOE) inhibited AD progression by regulating amyloid beta–induced neuronal death and cognitive impairments. Moreover, IOE attenuated glutamate-induced neurodegeneration by modulating the mitogen-activated protein kinases/Nrf2/heme oxygenase-1 signaling pathway. Furthermore, IOE effectively suppressed lipopolysaccharide-mediated neuroinflammation and memory deficits by downregulating the Toll-like receptor 4/MyD88-dependent signaling pathway. Collectively, these findings highlight the potential of IOE as a natural multi-target, anti-dementia agent. In this review, we summarize the neuroprotective and cognition-enhancing properties of IOE, discuss the molecular mechanisms underlying its action, and consider the advantages of I. okamurae as a promising natural resource for effective therapeutic developments that are capable of targeting multiple pathogenic causes of dementia. Full article

Traumatic brain injury (TBI) results in a cascade of neuropathological events, which can significantly disrupt synaptic integrity. This review explores the acute, subacute and chronic phases of synaptic dysfunction and loss in trauma which commence post-TBI, and their contribution to the subsequent neurological sequelae. Central to these disruptions is the loss of dendritic spines and impaired synaptic plasticity, which compromise neuronal connectivity and signal transmission. During the acute phase of TBI, mechanical injury triggers presynaptic glutamate secretion and Ca²⁺ ion-mediated excitotoxic injury, accompanied by cerebral edema, mitochondrial dysfunction and the loss of the mushroom-shaped architecture of the dendritic spines. The subacute phase is marked by continued glutamate excitotoxicity and GABAergic disruption, along with neuroinflammatory pathology and autophagy. In the chronic phase, long-term structural remodeling and reduced synaptic densities are evident. These chronic alterations underlie persistent cognitive and memory deficits, mood disturbances and the development of post-traumatic epilepsy. Understanding the phase-specific progression of TBI-related synaptic dysfunction is essential for targeted interventions. Novel therapeutic strategies primarily focus on how to effectively counter acute excitotoxicity and neuroinflammatory cascades. Future approaches may benefit from boosting synaptic repair and modulating neurotransmitter systems in a phase-specific manner, thereby mitigating the long-term impact of TBI on neuronal function. Full article

Background/Objectives: Stroke is the second leading cause of death worldwide. There is an unmet need to manage stroke pathophysiology, including L-glutamate (L-Glu)-mediated neurotoxicity. The acai berry (Euterpe sp.) contains phytochemicals with potentially nutraceutical content. The aim of this study was to assess the ability of acai berry extracts to counter L-Glu neurotoxicity using human differentiated TE671 cells. Methods: The cytotoxicity of L-Glu and acai berry extracts was quantified using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. Mitochondrial function was examined by a quantitation of cellular ATP levels, the maintenance of the mitochondrial membrane potential (MMP), and the production of reactive oxygen species (ROS). Whole-cell patch-clamp recordings monitored the activation of N-methyl-D-aspartate receptors (NMDARs). Candidate phytochemicals from acai berry extracts were modeled in silico for NMDAR binding. Results: L-Glu significantly reduced cell viability, ATP levels, the MMP, and increased cellular ROS. Generally, acai berry extracts alone were not cytotoxic, although high concentrations were detrimental to ATP production, maintenance of the MMP, and elevated ROS levels. Whole-cell patch-clamp recordings revealed that the combined addition of 300 µM L-Glu and 10 µM glycine activated currents in differentiated TE671 cells, consistent with triggering NMDAR activity. Acai berry extracts ameliorated the L-Glu-induced cytotoxicity, mitochondrial dysfunction, elevated ROS levels, and limited the NMDAR-mediated excitotoxicity (p < 0.001–0.0001). Several virtual ligands from acai berry extracts exhibited high-affinity NMDAR binding (arginine, 2,5-dihydroxybenzoic acid, threonine, protocatechuic acid, and histidine) as possible candidate receptor antagonists. Conclusions: Acai berry phytochemicals could be exploited to reduce the L-Glu-induced neurotoxicity often observed in stroke and other neurodegenerative diseases. Full article

Glutamate is an excitatory neurotransmitter in the central nervous system (CNS) that mediates synaptic transmission. However, glutamate homeostasis among neural cells is broken in cerebral ischemia. Excessive glutamate triggers N-methyl-d-aspartate receptors (NMDARs) in postsynaptic neurons, leading to intracellular calcium (Ca²⁺) overload and excitoneurotoxicity. At this moment, L-lactate may affect NMDARs and play a protective role in cerebral ischemia. This work proposes that L-lactate regulates glutamate signaling among neural cells. But, dysregulation of L-lactate in glutamate signaling cascades contributes to glutamate excitotoxicity in cerebral ischemia. In detail, L-lactate regulates the glutamine(Gln)-glutamate cycle between astrocytes and presynaptic neurons, which triggers the astroglial L-lactate-sensitive receptor (LLR)-cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway, coordinating astroglial glutamate uptake and neuronal glutamate transmission. L-lactate mediates glutamate signaling and synaptic transmission among neural cells. In addition, L-lactate promotes the function of mitochondrial calcium uniporter complex (MCUC), which quickly depletes intracellular Ca²⁺ in postsynaptic neurons. In addition, L-lactate can promote the conversion of microglia from the pro-inflammatory (M1) to anti-inflammatory (M2) phenotype. Therefore, regulation of L-lactate in glutamate signaling in the CNS might become a preventive target for cerebral ischemia. Full article

Traumatic brain injury (TBI) in the elderly is frequently associated with worsened neurological outcomes and prolonged recovery, yet the age-specific molecular mechanisms driving this vulnerability remain poorly understood. Aging is characterized by increased oxidative stress and chronic neuro-inflammation, both of which may amplify the brain’s susceptibility to injury. In this study, we identify spermine oxidase (SMOX), a polyamine-catabolizing enzyme that produces reactive oxygen species, as a key mediator linking oxidative stress and neuro-inflammation to age-dependent TBI susceptibility. Using a mouse model of controlled cortical impact (CCI), we found that SMOX expression was significantly upregulated in aged brains, primarily in neurons and microglia, and this increase correlated with greater microglial activation, elevated pro-inflammatory cytokine expression, and widespread neuronal degeneration. Notably, SMOX upregulation also impaired astrocytic glutamate clearance by disrupting the membrane localization of the transporter GLT-1, contributing to excitotoxic stress. Importantly, analysis of postmortem human brain samples and transcriptomic data revealed a parallel age-related increase in SMOX expression, supporting its translational relevance. The pharmacological inhibition of SMOX with JNJ-9350 in aged mice reduced oxidative and inflammatory markers, preserved neuronal viability, and improved motor, cognitive, and emotional outcomes up to 30 days post-injury. These findings establish SMOX as a critical molecular driver of age-related vulnerability to TBI and highlight its inhibition as a promising therapeutic strategy for improving outcomes in elderly TBI patients. Full article

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease associated with damage to motor neurons and leading to severe muscle weakness and, eventually, death. Over the past decade, understanding of the key pathogenetic links of ALS, including glutamate-mediated excitotoxicity and oxidative stress, has significantly advanced. This review considers the recent evidence on molecular mechanisms of these processes, as well as the therapeutic strategies aimed at their modulation. Special attention is paid to antiglutamatergic and antioxidant drugs as approaches to the ALS pathogenetic therapy. Full article

Multiple sclerosis (MS) is a chronic autoimmune disease characterised by inflammation, demyelination, and neurodegeneration within the central nervous system. The pathogenesis of MS involves an immune-mediated attack on myelin and neurons, accompanied by blood–brain barrier dysfunction and chronic CNS inflammation. Central to MS pathology is dysregulation of the kynurenine pathway, which metabolises tryptophan into neuroactive compounds. Kynurenine pathway (KP) activation, driven by inflammatory cytokines, leads to the production of both neuroprotective (e.g., kynurenic acid, KYNA) and neurotoxic (e.g., quinolinic acid, QUIN) metabolites. Imbalance between these metabolites, particularly increased QUIN production, exacerbates glutamate excitotoxicity, oxidative stress, and mitochondrial dysfunction, contributing to neuronal and oligodendrocyte damage. Mitochondrial dysfunction plays a critical role in the pathophysiology of MS, exacerbating neurodegeneration through impaired energy metabolism and oxidative stress. This review integrates the current understanding of KP dysregulation in multiple sclerosis across disease stages. In RRMS, heightened KP activity correlates with inflammation and neuroprotection attempts through increased KYNA production. In contrast, SPMS and PPMS are associated with a shift towards a more neurotoxic KP profile, marked by elevated QUIN levels and reduced KYNA, exacerbating neurodegeneration and disability progression. Understanding these mechanisms offers insights into potential biomarkers and therapeutic targets for MS, emphasising the need for strategies to rebalance KP metabolism and mitigate neurotoxicity in progressive disease stages. Full article

Brain ischemia-reperfusion (IR) injury is a critical pathological process that leads to extensive neuronal death, with hippocampal pyramidal cells, particularly those in the cornu Ammonis 1 (CA1) subfield, being highly vulnerable. Until now, human olfactory mitral cell resistance to IR injury has not been directly studied, but olfactory dysfunction in humans is frequently reported in systemic vascular conditions such as ischemic heart failure and may serve as an early clinical marker of neurological or cardiovascular disease. Mitral cells, the principal neurons of the olfactory bulb (OB), exhibit remarkable resistance to IR injury, suggesting the presence of unique molecular adaptations that support their survival under ischemic stress. Several factors may contribute to the resilience of mitral cells. They have a lower susceptibility to excitotoxicity, mitigating the harmful effects of excessive glutamate signaling. Additionally, they maintain efficient calcium homeostasis, preventing calcium overload—a major trigger for cell death in vulnerable neurons. Mitral cells may also express high baseline levels of antioxidant enzymes and their activities, counteracting oxidative stress. Their robust mitochondrial function enhances energy production and reduces susceptibility to metabolic failure. Furthermore, neuroprotective signaling pathways, including phosphatidylinositol-3-kinase (PI3K)/Akt, mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), and nuclear factor erythroid-2-related factor 2 (Nrf2)-mediated antioxidative responses, further bolster their resistance. In addition to these intrinsic mechanisms, the unique microvascular architecture and metabolic support within the olfactory bulb provide an extra layer of protection. By comparing mitral cells to ischemia-sensitive neurons, key vulnerabilities—such as oxidative stress, excitotoxicity, calcium dysregulation, and mitochondrial dysfunction—can be identified and potentially mitigated in other brain regions. Understanding these molecular determinants of neuronal survival may offer valuable insights for developing novel neuroprotective strategies to combat IR injury in highly vulnerable areas, such as the hippocampus and cortex. Full article

: Alzheimer’s disease (AD) is a neurodegenerative disorder closely associated with aging, and its pathogenesis involves the interaction of multidimensional pathophysiologic processes. This review outlines the core mechanisms linking aging and AD. The amyloid cascade hypothesis emphasizes that abnormal deposition of amyloid-β (Aβ) triggers neuronal damage and synaptic dysfunction, which is exacerbated by aging-associated declines in protein clearance. Neuroinflammation, a synergistic pathogenetic factor in AD, is mediated by microglia activation, creating a vicious cycle with Aβ and tau pathology. The cholinergic hypothesis states that the degeneration of cholinergic neurons in the basal forebrain can lead to acetylcholine deficiency, which is directly associated with cognitive decline. Endothelial disorders promote neuroinflammation and metabolic waste accumulation through blood–brain barrier dysfunction and cerebral vascular abnormalities. In addition, glutamate-mediated excitotoxicity and mitochondrial dysfunction (e.g., oxidative stress and energy metabolism imbalance) further lead to neuronal death, and aging-associated declines in mitochondrial autophagy exacerbate such damage. This review also explores the application of animal models that mimic AD and aging in studying these mechanisms and summarizes therapeutic strategies targeting these pathways. Future studies need to integrate multi-targeted therapies and focus on the role of the aging microenvironment in regulating AD pathology in order to develop more effective early diagnosis and treatment options. Full article

Epilepsy is a chronic neurological disorder marked by recurrent seizures, significantly impacting individuals worldwide. Current treatments are often ineffective for a third of patients and can cause severe side effects, necessitating new therapeutic approaches. Glial cells, particularly astrocytes, microglia, and oligodendrocytes, are emerging as crucial targets in epilepsy management. Astrocytes regulate neuronal homeostasis, excitability, and synaptic plasticity, playing key roles in maintaining the blood–brain barrier (BBB) and mediating neuroinflammatory responses. Dysregulated astrocyte functions, such as reactive astrogliosis, can lead to abnormal neuronal activity and seizure generation. They release gliotransmitters, cytokines, and chemokines that may exacerbate or mitigate seizures. Microglia, the innate immune cells of the CNS, contribute to neuroinflammation, glutamate excitotoxicity, and the balance between excitatory and inhibitory neurotransmission, underscoring their dual role in seizure promotion and protection. Meanwhile, oligodendrocytes, primarily involved in myelination, also modulate axonal excitability and contribute to the neuron–glia network underlying seizure pathogenesis. Understanding the dynamic interactions of glial cells with neurons provides promising avenues for novel epilepsy therapies. Targeting these cells may lead to improved seizure control and better clinical outcomes, offering hope for patients with refractory epilepsy. Full article

Traumatic brain injury (TBI) results from external biomechanical forces that cause structural and physiological disturbances in the brain, leading to neuronal, axonal, and vascular damage. TBIs are predominantly mild (65%), with moderate (10%) and severe (25%) cases also prevalent. TBI significantly impacts health, increasing the risk of neurodegenerative diseases such as dementia, post injury. The initial phase of TBI involves acute disruption of the blood–brain barrier (BBB) due to vascular shear stress, leading to ischemic damage and amyloid-beta accumulation. Among the acute cerebrovascular changes after trauma are early progressive hemorrhage, micro bleeding, coagulopathy, neurovascular unit (NVU) uncoupling, changes in the BBB, changes in cerebral blood flow (CBF), and cerebral edema. The secondary phase is characterized by metabolic dysregulation and inflammation, mediated by oxidative stress and reactive oxygen species (ROS), which contribute to further neurodegeneration. The cerebrovascular changes and neuroinflammation include excitotoxicity from elevated extracellular glutamate levels, coagulopathy, NVU, immune responses, and chronic vascular changes after TBI result in neurodegeneration. Severe TBI often leads to dysfunction in organs outside the brain, which can significantly impact patient care and outcomes. The vascular component of systemic inflammation after TBI includes immune dysregulation, hemodynamic dysfunction, coagulopathy, respiratory failure, and acute kidney injury. There are differences in how men and women acquire traumatic brain injuries, how their brains respond to these injuries at the cellular and molecular levels, and in their brain repair and recovery processes. Also, the patterns of cerebrovascular dysfunction and stroke vulnerability after TBI are different in males and females based on animal studies. Full article