Search Results (354)

Background and Clinical Significance: Encephalitis is a rare neurological complication associated with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. In rare cases, focal neuroinflammation can manifest as a mass-like parenchymal lesion, creating profound diagnostic and treatment dilemmas by mimicking primary central nervous system neoplasms. Case Presentation: A 34-year-old female presented with cephalalgia, nausea, confusion, facial palsy, and a new onset of focal impaired awareness seizures (FIAS). Brain magnetic resonance imaging (MRI) revealed a prominent hyperintense lesion within the left temporal lobe with associated vasogenic edema and focal leptomeningeal enhancement highly suspicious of a low-grade glial neoplasm. Although nasopharyngeal RT-PCT was negative, the presence of serum anti-SARS-CoV-2 IgM and IgG suggested recent subclinical SARS-CoV-2 infection. To resolve diagnostic ambiguity and avoid empiric oncological overtreatment, a stereotactic brain biopsy was performed. Histopathology revealed acute neuroinflammation characterized by reactive gliosis, microglial hyperplasia, and perivascular lymphatic cuffing, with no evidence of neoplastic presence. Quantitative tissue RT-PCR confirmed the presence of SARS-CoV-2 (Ct33). Follow-up imaging demonstrated complete resolution of the abnormalities following conservative treatment with corticosteroids and antiepileptics, though mild clinical symptoms persisted for 12 months thereafter. Conclusions: Encephalitis presents a rare yet critical manifestation of SARS-CoV-2. Establishing definitive etiology remains challenging. Stereotactic biopsy is a valuable tool to guide appropriate treatment in cases of ambiguous imaging and clinical findings. Radiographic resolution may precede complete clinical recovery. Full article

Glaucoma is a leading cause of irreversible vision loss characterized by the progressive degeneration of retinal ganglion cells (RGCs) and structural and biochemical remodeling of the optic nerve head. Although lowering intraocular pressure remains the primary clinical intervention, neurodegeneration often persists, highlighting the complexity and multiple mechanisms involved in the disease’s pathophysiology. In the healthy retina, astrocytes and Müller cells maintain structural integrity, homeostatic balance, and metabolic support. However, sustained pathological stress triggers reactive gliosis, a phenomenon with a dichotomous phenotype. Initially, the macroglial response is adaptive and neuroprotective. Persistent biomechanical and ischemic insults shift this profile into a typically deleterious one, characterized by extracellular matrix remodeling, complement system activation, and heightened neuroinflammation, factors that intensify RGC death. Mechanosensitive pathways, notably Piezo1 and various transient receptor potential (TRP) channels, emerge as critical sensors translating physical stress into these reactive cascades within interconnected multicellular networks. This review examines the crucial role of astrocytes and Müller cells in the dynamic modulation of the retinal microenvironment during glaucomatous progression. Finally, it discusses the therapeutic potential of macroglia-directed pharmacological or gene therapies to reprogram the retinal environment. Full article

Monosodium glutamate (E621) is a common flavor enhancer in highly processed food. Although it makes food more enjoyable, chronic intake may lead to excitotoxicity in brain areas. The current study investigates histological and biochemical neurodegenerative alterations in the rat hippocampus following E621 administration and evaluates the potential neuroprotective properties of ascorbic acid (AA) against E621-induced adverse effects. Forty adult male albino rats were divided into four groups: control group (G1), AA group (G2), E621 group (G3), and AA + E621 group (G4). All animals received a daily intraperitoneal (IP) injection for 30 days. Hippocampal samples were processed and stained with hematoxylin and eosin (H&E), immunostained for GFAP, synaptophysin (a synaptic protein), and caspase-3, and biochemically analyzed for oxidative markers, including malondialdehyde (MDA) and superoxide dismutase (SOD). G3 exhibited significant neurodegenerative changes, characterized by pyknotic granular cells and cytoplasmic vacuolation, with significantly elevated GFAP, synaptophysin, and caspase-3 immunoreactivity in the dentate gyrus (DG). These structural deficits correlated with elevated MDA levels and reduced SOD levels in G3. In contrast, simultaneous administration of AA with E621 resulted in substantial preservation of neuronal morphology, a reduction in caspase-3 immunoreactivity, and a restoration of synaptic vesicle density in G4. E621 induces hippocampal injury by increasing ROS levels and dysregulating GFAP, synaptophysin, and caspase-3. At the same time, AA preserves neuronal integrity and synaptic homeostasis, suggesting its potential role as a protective dietary supplement against brain injury induced by the E621 flavor enhancer. Full article

Chronic stress is increasingly recognized as a major contributor to Alzheimer’s disease (AD)-related neurodegeneration through mechanisms involving neuroinflammation, oxidative stress, mitochondrial dysfunction, excitotoxicity, and amyloidogenic processing. Here, we investigated the neuroprotective effects of Sesamum indicum whole paste extract (SIPE) using 2D neuron–astrocyte-like cell (ALC) co-cultures and 3D neuron–ALC spheroids exposed to a TNF-α/glutamate/cortisol (TGC) chronic stress paradigm. TGC exposure induced mitochondrial dysfunction, mitochondrial superoxide generation, astrocytic reactivity, NF-κB activation, reduced pro-BDNF expression, intracellular and extracellular Aβ42 accumulation, Tau phosphorylation, and caspase-3 activation, reproducing key hallmarks associated with chronic stress-related neurodegeneration. Among sesame-derived preparations evaluated, SIPE exhibited the strongest neuroprotective effects, preserving mitochondrial membrane potential, reducing oxidative stress, preventing neuronal loss, attenuating gliosis, and suppressing inflammatory, amyloidogenic, and apoptotic signaling. These effects were consistently reproduced in 3D spheroids. Phytochemical analysis revealed that SIPE contained the highest enrichment of sesamin, representing approximately 25% of the detected relative composition. Molecular docking analyses demonstrated favorable sesamin binding affinity toward TNF-α, DJ-1, Aβ42, and caspase-3. Collectively, these findings identify SIPE as a promising multitarget neuroprotective strategy against chronic stress-associated AD-related pathology. Full article

Glutamate excitotoxicity is a key contributor to the pathogenesis of glaucoma, a leading cause of irreversible blindness worldwide; however, the molecular events driving progressive retinal ganglion cell (RGC) loss and axonal degeneration remain incompletely understood, and effective neuroprotective therapies are lacking. Here, we evaluated the preventive potential of K9-C-peptide, a biopolymer-conjugated human C-peptide, in a mouse model of N-methyl-D-aspartate (NMDA)-induced retinal neurodegeneration and optic nerve axonal transport impairment, and examined potential mechanisms underlying its protective effects. In NMDA-induced excitotoxic mouse retinas, intracellular Ca²⁺ elevation mediated NMDA-induced oxidative stress, including both intracellular and mitochondrial reactive oxygen species (ROS) generation and lipid peroxidation. NMDA exposure induced activation of Müller glia and microglia and upregulation of inflammatory cytokines, ultimately leading to RGC death; these effects were attenuated by prolonged intraocular delivery of ROS scavengers. K9-C-peptide significantly reduced NMDA-induced retinal degeneration, including RGC loss and retinal thinning, and preserved optic nerve axonal transport function in both whole-mount retinas and optic nerve longitudinal sections. These protective effects were associated with suppression of NMDA-induced oxidative stress, mitochondrial dysfunction, and inflammation and reactive gliosis, without altering intracellular Ca²⁺ levels. Notably, sustained intraocular delivery of human C-peptide conferred robust neuroprotection for at least 3 weeks against NMDA-induced retinal degeneration and optic nerve axonal transport impairment. These findings suggest that K9-C-peptide acts as a long-acting neuroprotective agent that mitigates oxidative stress-driven retinal damage and axonal dysfunction, highlighting its translational potential as a C-peptide-based neuroprotective strategy for retinal glutamate excitotoxicity. Full article

Background and Clinical Significance: Lambert–Eaton myasthenic syndrome (LEMS) is mediated by antibodies against P/Q-type voltage-gated calcium channels (VGCCs) and is classified as paraneoplastic (T-LEMS) or non-paraneoplastic (NT-LEMS). Cerebellar degeneration is recognized in T-LEMS, but pathological confirmation in NT-LEMS has not been reported. Case Presentation: A 79-year-old man developed progressive ataxic gait and dysarthria at age 76 and was diagnosed with LEMS based on repetitive nerve stimulation findings and anti-P/Q-type VGCC antibodies. No malignancy was identified during more than 40 months of surveillance, and comprehensive autopsy revealed no occult tumor. After hospitalization for erythroderma and pneumonia, he died of respiratory failure. Postmortem examination revealed severe Purkinje cell loss with Bergmann gliosis in the anterior lobe and tuber vermis, accompanied by torpedoes and empty baskets, without significant inflammation. These findings indicate that NT-LEMS can reach the same VGCC-associated Purkinje cell endpoint previously documented only in paraneoplastic LEMS, despite different upstream triggers. Conclusions: This first autopsy-confirmed case of NT-LEMS with cerebellar degeneration supports a shared, non-inflammatory VGCC-mediated pathway of Purkinje cell injury across LEMS subtypes. Full article

Background and Clinical Significance: Beta-propeller protein–associated neurodegeneration (BPAN), also known as static encephalopathy of childhood with neurodegeneration in adulthood (SENDA), is a subtype of neurodegeneration with brain iron accumulation caused by pathogenic variants in WDR45. Although its clinical course and neuroimaging features are increasingly recognized, detailed neuropathological characterization, especially at its terminal stage, remains limited. Case presentation: We report a 68-year-old woman with a heterozygous WDR45 splice-site variant (NM_007075.4:c.830+1G>A), representing the longest-surviving case of SENDA/BPAN described to date. After static developmental delay in childhood, she rapidly developed progressive parkinsonism, dystonia, and cognitive decline in early adulthood, ultimately becoming bedridden with profound motor and autonomic dysfunction. Serial MRI demonstrated progressive cerebral and cerebellar atrophy with iron-related signal changes in the globus pallidus and substantia nigra. She died of sepsis at the age of 68 and was subjected to an autopsy including the brain. Neuropathological findings: Autopsy revealed severe, diffuse neuronal loss and gliosis throughout the central nervous system, with marked iron deposition and complete neuronal loss in the globus pallidus and substantia nigra. Immunohistochemistry demonstrated widespread tau pathology. Notably, neuronal tau inclusions contained both four-repeat (4R) and three-repeat (3R) isoforms, whereas glial tau was predominantly 4R-positive, indicating a mixed neuronal 4R/3R and glial 4R-dominant tauopathy. Perivascular and subpial 4R-tau–dominant deposits consistent with aging-related tau astrogliopathy were also present. LC3-positive and ferritin-positive cells suggested impaired autophagic flux, supporting the proposed autophagy-related pathogenesis of SENDA/BPAN. Conclusions: This case provides comprehensive clinicopathological insight into end-stage SENDA/BPAN, highlighting distinctive tau isoform patterns in neurons versus glia and pathological evidence of autophagy dysfunction. These findings expand the neuropathological spectrum of SENDA/BPAN and may inform future mechanistic and therapeutic research. Full article

Diabetic neuropathy (DN) is a multifactorial complication of diabetes mellitus driven by chronic hyperglycemia, insulin resistance, and disturbed metabolic homeostasis, leading to progressive injury of both the peripheral and central nervous systems. This study investigated whether L-serine supplementation could attenuate DN through dose-dependent metabolic and neuroprotective mechanisms in a high-fat diet (HFD) plus streptozotocin (STZ)-induced diabetic rat model. Male Wistar rats (n = 8 per group) were allocated to five groups: normal control (NC), diabetic control (DC), pioglitazone (PIO; 1.5 mg/kg/day), low-dose L-serine (S1; 200 mg/kg/day), and high-dose L-serine (S2; 400 mg/kg/day). After 60 days of oral gavage, behavioural testing, glucose and insulin profiling, HOMA-IR calculation, brain histopathology, nerve growth factor (NGF) immunohistochemistry, and LC–MS/MS-based proteomic analysis of cerebral tissue were performed. Diabetic rats exhibited marked hyperglycaemia (355.33 ± 4.72 mg/dL), hyperinsulinaemia, severe insulin resistance (HOMA-IR 16.8 ± 3.2; a 14-fold increase), impaired thermal nociception, motor dysfunction, and pronounced neuronal degeneration. L-serine supplementation significantly improved metabolic status: S1 reduced HOMA-IR by 77.4% and S2 by 87.5% relative to diabetic controls (p < 0.001). High-dose L-serine produced greater improvements in thermal sensitivity, motor coordination (rotarod latency 26.67 ± 1.52 s vs. 16.1 ± 0.85 s in DC; p < 0.05), and NGF expression (8.6-fold increase vs. DC). Histopathology confirmed attenuation of neuronal injury and gliosis in both treatment groups. Exploratory, group-level proteomic profiling identified dose-specific molecular signatures: S1 was predominantly associated with carbohydrate, lipid, and biosynthetic pathways, whereas S2 was associated with synaptic, neurotransmission-related, and proteostasis pathways. Within the constraints of an exploratory design—group-level pooled proteomics, analysis of cerebral rather than peripheral-nerve tissue, and only two doses—these findings indicate that L-serine attenuates the metabolic and behavioural features of experimental diabetic neuropathy and generates the testable hypothesis of dose-dependent neuro-metabolic remodelling. The proteomic signatures are hypothesis-generating and require orthogonal validation before any mechanistic or translational inference can be drawn. Full article

Temporal lobe epilepsy (TLE) is a common drug-resistant epilepsy characterized by recurrent seizures, cognitive impairment, aberrant adult hippocampal neurogenesis, inhibitory circuit disruption, and persistent inflammatory remodeling. Current anti-seizure medications primarily offer symptomatic control and do not target the progressive structural and functional deterioration of epileptic hippocampal networks. Here, we investigated whether local nerve growth factor (NGF)-hydrogel delivery during the latent phase after status epilepticus could mitigate hippocampal pathological remodeling and improve long-term outcomes in a kainic acid (KA)-induced mouse model (utilizing C57BL/6J and Nestin-CreERT2 mice). Animals were randomly assigned to three groups: the saline control group, the untreated KA epilepsy group, and the KA + NGF-hydrogel treatment group. NGF-hydrogel was administered into hippocampal Cornu Ammonis 1 (CA1) beginning 3 days post-kainic acid and repeated every 15 days. Histological, immunofluorescence, circuit-tracing, electrophysiology, electroencephalography (EEG), and behavioral assessments were used to evaluate neurogenesis, microenvironment, circuit readouts, seizure burden, and cognition. NGF-hydrogel treatment was associated with preserved dentate gyrus neural stem cell populations, improved newborn granule cell localization and maturation, attenuated neuroinflammation and gliosis, and partial recovery of inhibitory interneuron markers. These changes were accompanied by improved hippocampal circuit readouts, reduced chronic spontaneous seizure burden, and enhanced recognition and spatial memory. Our findings indicate that local NGF-hydrogel delivery following status epilepticus is associated with improved hippocampal remodeling and functional outcomes, and suggest that biomaterial-based neurotrophic support may be a promising strategy for providing targeted neuroprotection and facilitating excitatory/inhibitory (E/I) balance reconstruction in the epileptic hippocampus. Full article

Spinal cord injury (SCI) triggers a secondary injury cascade characterized by neuroinflammation, reactive gliosis, and neuronal apoptosis. While many pro-inflammatory cytokines contributing to this cascade reach peak upregulation within 24 h, Interleukin-18 (IL-18) exhibits a delayed upregulation profile, typically peaking 7 days post-injury. This review examines the temporal regulation and cell-specific roles contributing to the rise in IL-18 after SCI. Following primary insult, damage-associated molecular patterns prime and activate the NLRP3 inflammasome, which in turn drives latent IL-18 secretion. Cellularly, microglia function as the primary producers of IL-18 via the TLR4/p38-MAPK pathway, while astrocytes serve as the primary responders through IL-18R/p65-NF-κβ signaling. The microglia-astrocyte cross-talk propagates reactive gliosis, drives neuropathic pain, facilitates neuronal loss, and potentially contributes to the formation of the astrocytic border. Targeted therapeutic interventions such as upstream inhibition of NLRP3 inflammasome assembly or direct IL-18 neutralization successfully mitigate neuroinflammation. By either inhibiting NLRP3 inflammasome activation or directly neutralizing IL-18, these treatments shift the microglial toward a protective state, restrict histological damage, and significantly improve functional recovery. Full article

Reactive astrocytes are a hallmark of several neurological diseases in multiple sclerosis and experimental demyelination models. Their morphological alterations are commonly assessed by qualitative histopathology, yet quantitative tools are required to better capture astrocytic heterogeneity and to allow correlations with imaging-derived biomarkers. Here, we present a workflow for the quantitative analysis of Glial Fibrillary Acidic Protein (GFAP) network remodeling in astrocytes in the cuprizone model of demyelination. C57BL/6 mice were intoxicated with cuprizone for 3 or 5 weeks to induce progressive demyelination, microglial activation, and reactive astrogliosis. Brain sections were processed for anti-GFAP immunohistochemistry, and individual astrocytes from the stratum oriens of the hippocampus were digitally reconstructed. Diverse parameters of GFAP topology, including soma size, process length, branching order, convex hull area, and ramification index, were extracted using either the commercial Neurolucida^® 360 software or the open-source Simple Neurite Tracer (SNT) plugin in ImageJ. Principal component analysis revealed clear differences between control astrocytes and astrocytes in cuprizone-intoxicated animals, with reactive astrocytes displaying increased numbers of primary processes, enhanced bifurcation, and process complexity. Comparative evaluation of Neurolucida^® 360 and SNT demonstrated that both tools are suitable for astrocyte reconstruction, although Neurolucida^® 360 enabled faster and more detailed tracing. This protocol provides a reproducible pipeline for the quantitative assessment of astrocyte morphology under control and pathological conditions, thereby supporting future efforts to link cellular remodeling to functional outcomes in neuroinflammatory disease models. Full article

Retinal neurovascular unit (RNVU) dysfunction underlies major blinding and neurodegenerative conditions including glaucoma, diabetic retinopathy (DR), age-related macular degeneration (AMD), retinal ischemia–reperfusion (RIR) injury, and Alzheimer’s disease (AD)-associated retinopathy. Within the RNVU, calcium ions coordinate neurotransmission, glial activation, vascular tone, and blood–retinal barrier maintenance, and calcium dysregulation is emerging as a unifying pathogenic hub across these conditions. Although upstream triggers differ, including mechanical stress in glaucoma, hyperglycemia in DR, oxidative damage in AMD, ischemic energy failure in RIR, and amyloid-β–driven endoplasmic reticulum stress in AD, all converge on disruption of intracellular calcium homeostasis, producing shared downstream consequences including excitotoxic injury of retinal ganglion cells (RGCs), Müller cell reactive gliosis, and pericyte hypercontraction. Broad-spectrum calcium channel blockade has shown limited clinical success, underscoring the need for cell-type-specific and pathway-selective approaches. This review therefore catalogs key interventional nodes, including transient receptor potential (TRP) channel antagonists, T-type calcium channel inhibitors, calcium/calmodulin-dependent protein kinase II (CaMKII) suppressors, and mitochondrial permeability transition pore (mPTP) inhibitors, and discusses how precision targeting of these pathways may restore RNVU homeostasis and open a therapeutic window into central nervous system (CNS) degenerative disorders. Full article

Background/Objectives: Inflammation is a critical contributor to the development of diabetic retinopathy (DR). In the early stages of DR, the compromised permeability of the blood–retina barrier facilitates the infiltration of macrophages and the activation of microglia. These specific retinal immune cells can adopt morphologies M1 or M2, linked to pro- or anti-inflammatory responses, respectively. This dual response represents a new therapeutic target against DR progression. This study aimed to investigate the modulation of the response M1/M2 and the molecular mechanism of two algal diterpenoids, rugukadiol A (RK) and ruguloptone A (RL), in the early inflammatory events associated with DR. Methods: LPS-stimulated microglial (Bv.2) and macrophage (RAW264.7) cells and an ex vivo physiological model of DR were used to analyze the effects of RK and RL on M1 and M2 inflammatory markers. Results: Compounds RK and RL, besides decreasing the expression of the M1 pro-inflammatory factors iNOS, Il6 mRNA, and NLRP3 in LPS-stimulated Bv.2 cells, caused enhancements in Arg-1 mRNA and Il10 mRNA expression consistent with the induction of an M2 anti-inflammatory response. RK promoted p38α-MAPK phosphorylation, suggesting a non-classical activation of p38α related to the induction of anti-inflammatory responses. Consistently, treatment of retinal explants of BB rats in the early stages of DR with RL decreased M1 pro-inflammatory mediators and induced M2 anti-inflammatory markers, with a reduction in gliosis and a phenotype switch from activated to resting microglia. Conclusions: This study provides the first evidence of algal diterpenoids attenuating pro-inflammatory mediators and promoting the resolution of inflammation in a diabetic retinopathy context, thus opening the way to further explore this class of marine natural products and analogs for early DR management. Full article

Alzheimer’s disease (AD) is increasingly recognized as a multisystem neurodegenerative disorder in which sensory dysfunction accompanies cognitive decline. As an accessible extension of the central nervous system, the retina provides a valuable window for investigating early neurodegenerative processes; however, the cellular mechanisms underlying AD-associated retinal pathology remain incompletely understood. Here, using the APP/PS1 mouse model, we systematically examined structural, functional, and glial alterations in the retina across disease stages. Despite robust age-dependent amyloid plaque accumulation in visual-related brain regions, no plaque-like β-amyloid (Aβ) deposits were detected in the retina even at advanced ages. Nevertheless, young APP/PS1 mice exhibited early thinning of inner retinal layers, impaired retinal electrophysiological responses, and reduced excitatory synaptic inputs to retinal ganglion cells (RGCs), preceding overt neuronal loss. These neuronal changes were accompanied by pronounced Müller glial activation, characterized by upregulation of gliosis markers and extensive morphological remodeling. Functional analyses further revealed dynamic alterations in glial homeostasis, including early elevation followed by age-dependent decline of glutamine synthetase activity, together with increased expression and disrupted perivascular polarity of aquaporin-4. Consistently, transcriptomic profiling of young AD retinas identified coordinated dysregulation of genes involved in amino acid metabolism, transport, and oxidative stress responses. Together, our findings identify Müller glial remodeling as an early feature of AD-associated retinal pathology that coincides with synaptic vulnerability of RGCs and occurs independently of local Aβ plaque deposition, highlighting retinal glia as potential early indicators and modulators of neurodegeneration. Full article

Glial cells, particularly astrocytes and microglia, are central to maintaining CNS homeostasis and coordinating responses to injury through tightly regulated metabolic, inflammatory, and mechanosensitive processes. Emerging evidence identifies the Hippo signaling pathway and its downstream effectors YAP/TAZ as key regulators of glial functions, influencing proliferation, polarization, intercellular communication, and the balance between neuroprotection and neurotoxicity. This review discusses the Hippo signaling pathway and its transcriptional co-activators YAP/TAZ as context-dependent hubs integrating mechanical, metabolic, and immune cues in astrocytes and microglia. Particular attention is given to MST1/2- and YAP/TAZ-dependent signaling in microglia, which governs inflammatory states, redox balance, mitophagy, and mechanosensing. In astrocytes, Hippo–YAP signaling emerges as a bidirectional regulator of reactive gliosis and neuroprotection, capable of constraining excessive scar formation. However, when chronically suppressed, it impairs glutamate clearance, metabolic support, and resistance to neurodegeneration. Disruption of Hippo signaling in glial tumors is also considered, with YAP/TAZ–TEAD complexes driving glioblastoma stemness, infiltrative growth, immune evasion, and therapy resistance. Finally, therapeutic perspectives are outlined that emphasize context-selective modulation of Hippo signaling in the CNS. Overall, Hippo–YAP/TAZ signaling is presented as a highly context-dependent regulator at the interface of glial inflammation, neurodegeneration, and glioma biology and as a promising but demanding target for future CNS therapies. Full article