Search Results (328)

The Tau protein is traditionally recognized for stabilizing axonal microtubules in neurons. However, emerging evidence indicates that astrocytes also show basal expression of the microtubule-associated protein Tau (MAPT) gene, with potential implications for central nervous system (CNS) homeostasis. Under physiological conditions, astrocytes support functions essential to CNS integrity, including metabolic support, neurotransmitter uptake, blood–brain barrier maintenance, and immune surveillance, all of which may be influenced by endogenous Tau expression. This review examines the current literature on the mechanisms that govern astrocytic Tau regulation, mainly in primary tauopathies with glial cytopathology. Available data indicate that Tau accumulation in these glial cells arises from endogenous synthesis, uptake from neighboring neurons, or a combination of these pathways, while failed extracellular clearance may favor this process by increasing Tau availability in the extracellular space. Once internalized, Tau can be processed, degraded through proteolytic and autophagic-lysosomal pathways, or re-released into the extracellular space, potentially facilitating its propagation; insufficient degradation, in contrast, promotes reactive astrogliosis and disrupts vital processes such as metabolic support and neurotransmitter handling. Taken together, this evidence suggests that distinguishing endogenous synthesis from neuronal uptake is essential to define glial-mediated pathology and recognize astrocytic Tau as a relevant contributor to neurodegenerative disease progression. Full article

Background/Objectives: Antenatal corticosteroids (ACSs) are widely used to improve outcomes in preterm infants, but their effects in the context of fetal growth restriction (FGR) remain incompletely understood. This study investigated the impact of ACSs on pulmonary and neurodevelopmental outcomes using a rabbit mod (K.Z.el) of FGR. Methods: FGR was induced at a gestational age (GA) of 25 days (term 31.5 days) by partial uteroplacental vessel ligation (UPVL) in one uterine horn, with the contralateral horn serving as a control. Dams received intramuscular betamethasone (0.1 mg/kg) or saline 24 and 12 h before expected delivery. At GA 30 days, offspring were delivered by caesarean section and allocated to four groups for pulmonary function testing or neurobehavioral assessment on postnatal day 1, followed by histological analyses of the brain, lungs, and placenta. Results: ACSs improved respiratory mechanics, particularly static and dynamic compliance, in FGR offspring. PND 1 survival showed a concerning pattern, with numerically lower model-estimated survival in both ACS-exposed groups, although the only statistically significant adjusted comparison was between Control/NoACS and FGR/ACS offspring. Neurobehavioral testing showed lower neurosensory performance after ACS exposure within both control and FGR offspring. Lung morphometry and apoptosis were not significantly altered, while neuronal density and astrogliosis showed isolated regional differences. Placental histology showed a higher junctional zone proportion in untreated FGR placentas than in untreated controls. Conclusions: ACSs improved short-term respiratory mechanics without detectable alveolar structural benefit. The observed PND 1 survival pattern and lower neurobehavioral performance warrant cautious interpretation, and these animal findings should not be directly extrapolated to clinical ACS decision-making in FGR pregnancies. Full article

Transplanted neural precursor cells (NPCs) can support repair after spinal cord injury (SCI) but often face poor survival and limited differentiation within the hostile post-injury microenvironment. We tested whether subacute activation of Sonic hedgehog (Shh) signaling improves NPC engraftment and functional recovery over the duration of 6 weeks. Female Wistar rats underwent T9/T10 clip-contusion SCI and were assigned to vehicle, Shh-only, NPC-only, Shh + NPC, or sham groups (n = 8 per SCI arm, n = 5 sham, total n = 37). GFP + NPCs (4 × 10⁵) were grafted at 7 days post injury. Recombinant Shh or vehicle was delivered intrathecally via osmotic pumps for 7 days thereafter. Outcome measures included pathway activation (GLI1, SMO), NPC differentiation (NeuN, Olig2, Nestin, GFAP), astrogliosis (GFAP), CSPG deposition, immune cell infiltration (CD3, Iba1), apoptosis (cleaved Caspase-3), and locomotion (BBB, Gridwalk, CatWalk) over 6 weeks. Shh delivery increased GLI1/SMO expression and, when combined with NPCs, significantly elevated NPC-derived neurons and oligodendrocytes while preserving undifferentiated NPCs. Combined therapy reduced astrogliosis, CSPG deposition, T-cell and macrophage/microglial densities, cyst size and apoptotic cells compared with controls. These histological benefits were accompanied by improved locomotor scores in BBB, Gridwalk and selected CatWalk parameters. Our findings highlight the synergistic effects of Shh pathway activation and NPC transplantation in promoting neuroregeneration after SCI. The data support Shh as an adjunct to NPC transplantation for SCI repair. Full article

Background/Objectives: Adverse neurological events caused by imipenem are usually more frequent in patients with epilepsy. This study investigates the effects of imipenem on hippocampal neurogenesis, astroglial activation, and behaviour in animals with pro-epileptogenic alterations. Methods: Five-month-old Wistar rats were divided into four groups: control (CT), pentylenetetrazol (PTZ), imipenem-treated group (IM), and imipenem after PTZ-kindling (IM-PTZ). Epileptogenesis was induced by PTZ-kindling for 28 days, followed by 10 days of imipenem (40 mg/kg) or saline injections. Rats underwent memory and anxiety tests followed by immunohistochemical analyses of doublecortin (DCX) and glial fibrillary acidic protein (GFAP) in the hippocampus. Results: Both kindled groups displayed comparable impairments in spatial learning and working memory, while imipenem alone did not alter behaviour. The IM-PTZ group failed to reach control-level performance only in the final Morris Water Maze acquisition trials, suggesting a deficit in memory consolidation rather than a total loss of retention, as the probe trial remained comparable across all groups. Although PTZ increased anxiety-like behaviour, no locomotor differences were observed in open-field test, confirming cognitive impairments were not due to motor deficits. These behavioural changes mirrored distinct cellular alterations: while PTZ alone triggered a compensatory increase in DCX neuronal density and astrocytic branching, imipenem co-administration suppressed this neurogenic response, bringing DCX to baseline. Furthermore, combined treatment induced an uncoupling of astrocytic response, marked by increased astrocyte density and reduced process complexity in dentate hilus and Cornus Ammonis 3 (CA3). Conclusions: These results suggest that imipenem modulates the cellular substrate of the pre-sensitized brain, interfering with hippocampal plasticity and glial compensatory mechanisms, rather than directly driving further behavioural deterioration. Full article

We aimed to investigate the therapeutic effects of alpha-pinene (α-pinene), a major component of phytoncide, in in vitro and in vivo models of mild traumatic brain injury (mTBI), raising the possibility of treating mTBI, a condition currently lacking adequate therapies. An in vitro model was established using SH-SY5Y cells and a cell injury controller, and was treated with α-pinene (0.5 g/mL). An in vivo model was induced by a stereotaxic impactor in male C57BL/6J mice and treated with α-pinene intravenously (50 mg/kg and 100 mg/kg) for 3 days post-injury. Histopathological and immunohistochemical comparisons were conducted alongside cognitive function tests to evaluate -pinene treatment. In vitro analysis showed that alpha-pinene treatment significantly increased TUNEL-positive cells. Elevated NOX4 and p22phox mRNA expressions and a high Bax/Bcl-2 protein expression ratio were noted following alpha-pinene treatment. mTBI mice treated with alpha-pinene exhibited a notable decrease in brain water content with fewer FJB-positive neurons and lower protein expression of Bax and Bcl-2 compared to untreated mTBI mice. Immunofluorescence staining for NOX4 and GFAP-positive or Iba-1-positive cells demonstrated that the increased oxidative stress and astrogliosis or activated microglia triggered by mTBI were alleviated after alpha-pinene treatment. Cognitive function testing revealed a general improvement in mTBI mice treated with alpha-pinene, with statistical significance observed in the NOR test. Alpha-pinene appears to be beneficial for neuroprotection and enhancing cognitive function in the early phases of mTBI. Full article

Relapsing–remitting multiple sclerosis (RRMS) is characterized by neuroaxonal damage, astrogliosis and inflammation. These mechanisms may already be active from early disease stages, underscoring the need for sensitive biomarkers capable of capturing treatment-related biological effects beyond conventional clinical measures. In this multicenter, ambispective, observational real-world study, the longitudinal effects of ozanimod on serum biomarkers were evaluated, during the first year of treatment in patients with low-to-moderate activity RRMS. Serum neurofilament light chain (sNfL), glial fibrillary acidic protein (sGFAP) and cytokines associated with immune activity (IFN-γ, IL-17, IL-6, IL-10, and IL-1β) were quantified at baseline, 6 months, and 12 months using an ultrasensitive single-molecule array (SIMOA). Ozanimod was associated with significant reductions in sNfLs and sGFAP at 12 months. Concomitantly, significant decreases in IFN-γ and IL-1β were observed. IL-17 levels remained unchanged in the overall cohort but decreased in patients with higher baseline IL-17 levels. These findings demonstrate coordinated modulation of biomarkers reflecting neuroaxonal damage, astroglial activation, and inflammatory activity under ozanimod treatment in early RRMS in real-world conditions. These results highlight the biological relevance of early intervention within a therapeutic window of opportunity and support the potential utility of serum biomarkers for monitoring biological treatment effects in clinical practice. 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

Alexander disease (AxD) is a rare and fatal neurodegenerative disorder caused by dominant mutations in the gfap gene, which encodes glial fibrillary acidic protein (GFAP), a major intermediate filament in astrocytes. As a primary astrogliopathy, AxD is marked by white matter abnormalities, the formation of GFAP-containing Rosenthal fibers, astrocyte dysfunction, and progressive neurodegeneration. While GFAP mutations are known to cause toxic gain-of-function effects, the precise mechanisms by which mutant GFAP drives astrocyte dysfunction and central nervous system pathology remain unclear. To address this, we developed a novel rat model of AxD harboring the R237H mutation in the endogenous gfap locus, which mirrors the R239H mutation commonly associated with early-onset AxD in humans. This model recapitulates key AxD pathologies, including GFAP aggregation, widespread astrogliosis, white matter abnormalities, and motor deficits. Using homozygous mutant rats, we dissected the distinct contributions of mutant GFAP and elevated GFAP expression to astrocyte dysfunction and neurodegeneration. Our findings reveal that AxD pathogenesis results from a synergistic interaction between the toxic gain-of-function properties of mutant GFAP and its elevated expression, which together drive GFAP aggregation, proteostatic stress, and astrocyte dysfunction. These insights provide a deeper understanding of AxD mechanisms and a foundation for developing targeted therapies for this devastating disease. Full article

Background: The management of persistent post-concussive symptoms (PPCS) is limited by the absence of objective biomarkers to guide treatment. We examined the early effects of a mild hyperbaric oxygen protocol on serum biomarkers of neuronal injury (neurofilament light chain, NfL), astrogliosis (glial fibrillary acidic protein, GFAP), acute neuronal injury (ubiquitin C-terminal hydrolase L1, UCH-L1), and axonal stability (total tau) in patients with PPCS. Methods: In this single-center, randomized, placebo-controlled trial, we enrolled adults with PPCS lasting from 3 months to 5 years after mild traumatic brain injury. Participants received 40 sessions of either active treatment (≥99% O₂ at 1.5 atmospheres absolute, ATA) or a true chamber placebo (21% O₂ with simulated pressure changes). Serum samples were collected at baseline and 13 weeks after treatment. The primary outcome was the difference between groups in serum NfL levels. Analysis was performed on an intention-to-treat basis using a two-way ANOVA with Šídák’s multiple comparison test. Findings: Of 84 individuals assessed, 20 were randomized (Placebo, n = 9; Intervention, n = 11). Eight from each group received their respective interventions. At 13 weeks, one participant from each group was lost to follow-up, leaving seven per group for analysis. We found no significant differences in serum levels of GFAP, NfL, total tau, or UCH-L1 between the intervention and placebo groups from baseline to 13 weeks. Conclusions: A 40-session mild hyperbaric oxygen protocol at 1.5 ATA did not significantly change serum biomarkers of neuronal injury, astrogliosis, or acute neuronal damage at 13 weeks post-treatment in individuals with PPCS. This early-phase analysis, at the highest point of participant retention, provides no evidence of a treatment effect on these pathophysiological markers. Full article

Astrocytes are now recognized as active and essential participants in neural circuit function, extending far beyond their traditional roles as passive support cells. Emerging evidence highlights their critical involvement in synaptic modulation, information processing, and complex behaviors, making them key targets for understanding cognitive dysfunction in psychiatric disorders. This narrative review synthesizes current findings from rodent models to elucidate the relationship between astrocytic networks and multidomain cognitive performance. We first outline the morphological and physiological features of astrocytes, followed by a comprehensive overview of the modern experimental toolkit, including observational markers and advanced interventional strategies. Next, we evaluate commonly used behavioral assays that capture distinct cognitive domains, ranging from basic spatial and recognition memory to higher-order executive functions, cognitive flexibility, and social cognition. By integrating recent experimental evidence, we detail the specific mechanistic pathways, such as intracellular calcium signaling, gliotransmission, and neuroinflammatory reactivity, through which astrocytes directly govern these cognitive processes. Finally, we highlight critical knowledge gaps stemming from methodological limitations, arguing for the integration of more ethologically relevant, high-throughput behavioral tasks alongside highly specific targeting tools to better capture the functional heterogeneity of astrocytes in cognitive health and disease. Full article

Background: Neurodegenerative diseases (NDs) are mainly considered disorders marked by severe immunometabolic imbalance, characterized by ongoing neuroinflammation and glial activation. While mitochondrial dysfunction and oxidative stress are well-known features, the upstream metabolic factors linking these pathological processes remain poorly understood. Methods: In this review, we examined recent preclinical and clinical studies exploring the connections between lipid metabolism, glial immunometabolism, and regulated cell death pathways. Our focus was on how long-chain fatty acids (LCFAs) facilitate communication among mitochondria, reactive oxygen species (ROS), and ferroptosis in Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS). Results: New evidence shifts LCFAs from merely being passive indicators of cellular damage to active, upstream regulators of the neuroimmune response. Existing research shows that excess LCFA intake can overload astrocytic mitochondrial oxidative phosphorylation, leading to abnormal lipid droplet buildup and reactive astrogliosis. This lipid-driven reactivity promotes microglial polarization toward a persistent pro-inflammatory state. Notably, high levels of specific LCFAs, especially arachidonic acid, increase ROS production and lipid peroxidation. This lipotoxic environment ultimately triggers ferroptosis, an iron-dependent form of cell death shared across multiple NDs. Conclusions: The harmful interaction among mitochondrial dysfunction, lipid peroxidation, and ferroptosis is driven by an imbalance in LCFA levels. Addressing current challenges, such as the complex effects of polyunsaturated fatty acid supplementation, requires advanced techniques like single-cell multi-omics and artificial intelligence. Understanding this intricate lipidomic-transcriptomic crosstalk is crucial for moving toward personalized neuroimmunometabolism and developing new treatments to prevent ferroptosis. Full article

Alzheimer’s disease (AD) is the leading cause of dementia, responsible for approximately 60–70% of cases globally. AD is a gradually progressive neurodegenerative disorder that is characterized by widespread deposition of β-amyloid (Aβ) plaques, followed by aggregation of tau protein in the neocortex, neurodegeneration, and cognitive decline. Within these complex pathological interactions, Aβ and tau proteins, together with astrogliosis, neuroinflammation, and other factors, play a key role in the development of clinical AD. Accumulating evidence indicates that the formation of protein oligomers, followed by their aggregation into pathological fibrils, constitutes an early and critical step in the pathogenesis of the disease. Specific pathological proteins are often treated as biomarkers of particular diseases because their presence, concentration, or altered structure reflects an underlying disease process. It is well established that the Aβ and tau proteins are the key hallmarks of AD, and their mutual interaction may significantly influence the pathology of the disease. Early diagnosis is crucial for maximizing the therapeutic benefits of currently available symptomatic treatments, which can alleviate symptoms and modestly delay clinical deterioration in patients with AD. This review highlights the mechanisms involved in protein-dependent neurodegeneration and describes both traditional and novel approaches for the cure of AD. The most important aspect of this publication is the integration of the two key proteins: Aβ and tau, and the resulting shift toward a new therapeutic approach. Full article

Spinocerebellar Ataxia type 2 (SCA2) and Amyotrophic Lateral Sclerosis type 13 (ALS13) are triggered by polyglutamine expansion in Ataxin-2 (ATXN2). To understand these neurodegenerative disorders at the molecular level, the brains of 10-month-old Atxn2-CAG100-knockin mice were analyzed as microglial, astroglial and neuronal fractions via global RNA sequencing. Data were validated by comparison with the spinal cord oligonucleotide microarray profile or filtered by RNA-seq consistency. Here, we show that the mutation causes a massive inflammatory response in microglia and a reciprocal loss of neuronal transcripts in glial fractions, suggesting severe synapse loss. Beyond these general neurodegenerative signs, we identify pathognomonic changes in the machinery for protein translation and RNA splicing. Glial fractions showed upregulation of Gpnmb (to 2082%), Cst7, Clec7a, Axl, Csf1, Lgals3, Lgals3bp, Slc11a1, and Usp18 as an unspecific neuroinflammatory signature, versus downregulation of axonal Nefh (to <19%), and synaptic Scn4b, Camk2b, Rab15, and Grin1 mRNAs correlating with circuit disconnection. In all fractions, reductions in Kif5a, Rph3a, and Cplx1 were noted versus disease-specific inductions of ribosomal subunits, presumably mirroring the partial loss-of-function of ATXN2 as RNA translation modulator. Selective accumulations of embryonic factors Rnu1b2 and Eef1a1 versus downregulation of adult Eef1a2 specify the mutation impact on splicing and translation elongation. As a potential underpinning of toxic gain-of-function, the proteostasis transcript Rnf213 appeared increased in astroglial and microglial fractions. These transcriptome data suggest altered ribosomal and spliceosome machinery, with massive microgliosis versus mild astrogliosis, at the core of SCA2 and ALS13. Full article

Neuroimplants represent an emerging medical technology, offering new therapeutic approaches for severe neurological and psychiatric disorders. One of the key limitations to long-term neuroimplant performance is the foreign body response elicited by intracortical implantation. Among the contributing cell types, astrocytes play a central role in glial scar formation around the implant, which can compromise device functionality. Immunofluorescence of glial fibrillary acidic protein (GFAP) provides a well-established marker of astrogliosis (neuroinflammation), yet quantitative and reproducible assessment of astrocyte morphology remains challenging due to the complexity and variability of image analysis approaches. Here, we aimed to quantitatively assess implantation-induced astrogliosis and to determine how classifier training strategy influences segmentation outcomes and morphometric measurements. We present a machine learning-assisted pipeline based on the LabKit plugin in Fiji for segmentation and morphometric analysis of GFAP-positive astrocytes in peri-implant scar versus distant cortical regions. Using this approach, we demonstrate an increase in GFAP expression, cell area, and astrocytic process length as well as the redistribution of GFAP signal along astrocytic processes within scar regions. We show that different classifier training strategies produce systematically distinct segmentation outcomes, with rule-compliant annotation improving agreement with manually defined ground truth. These findings highlight the critical role of annotation strategy in shallow learning-based segmentation and provide a practical framework for improving reproducibility of astrocyte morphometry in studies of neuroinflammation and neuroimplant biocompatibility. Full article

Neuroinflammation is a hallmark of multiple sclerosis (MS). MS is marked by glial cell activation, autoreactive T cells, and the release of pro-inflammatory cytokines and free radicals. Current therapeutic strategies aim to modulate the immune response using disease-modifying therapies, to slow disease progression. The specific aims of this study were: (a) to investigate the effect of cannabinoid acids on the release of glial neuroinflammatory mediators, (b) to examine the effect of intraperitoneally administered cannabinoid acids on symptoms of MS, and (c) to evaluate their effects on microglial and astrocyte activation and CD4⁺ T cell infiltration into the spinal cords of MS mice. Exposure of BV2 microglia to cannabinoid acids attenuated lipopolysaccharide (LPS)-induced expression of inducible nitric oxide synthase by 40–90% it also reduced the release of nitric oxide and interleukin-17A. Among the cannabinoid acids tested, cannabidiolic acid (CBDA) significantly increased tumor necrosis factor alpha (TNFα) secretion by up to 40% in LPS-stimulated BV2 cells. Intraperitoneal administration of CBDA also resulted in a twofold increase in TNFα secretion in splenocytes isolated from MS mice, compared to untreated MS controls. This study provides evidence that CBDA significantly reduces neurological scores, while both cannabinoid acids attenuate microgliosis, astrogliosis, and CD4+ T cell migration in lumbar spinal cord sections of MS mice. These compounds cross the blood–brain barrier (BBB) and act directly within the central nervous system. The consistent elevation of TNFα in the presence of CBDA across three experimental models suggests a distinctive immunomodulatory role for CBDA, with potential therapeutic implications in MS. Full article