Search Results (895)

Human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic neuroinflammatory disorder often leading to demyelination of the spinal cord. Progression to HAM/TSP is closely associated with the high proviral load and the presence of virally infected CD4+ T cells that release extracellular vesicles (EVs). Exosomes, an EV subtype released by many cell types, transport proteins and nucleic acids that regulate intercellular communication and have been implicated in the progression of cancer and neuroinflammatory diseases. Herein, we have studied the effect of exosomes from HTLV-1 infected cells on the Peripheral Blood Mononuclear Cells (PBMCs) of HAM/TSP patients by single-cell sequencing utilizing innovative Honeycomb technology. We observed a distinct transcriptional response in monocyte populations compared with other immune cell types. Given that monocytes remain understudied in HTLV-1 pathogenesis, these findings highlight a potential role for infection-derived exosomes in shaping monocyte-driven immune dysregulation in HAM/TSP. A total of 41 genes were identified to be differentially expressed in HAM/TSP monocytes treated with exosomes; 28 were upregulated and 13 were downregulated. The most significantly altered genes are involved in chemokine activity and signaling, macrophage differentiation, lipid metabolism, and lysosomal function. Overall, our data suggests that exosome-treated HAM/TSP monocytes undergo immune remodeling that favors cell recruitment, activation, and a shift toward a mixed M1/M2-like phenotype. Such a shift may support viral persistence and chronic inflammation. These findings highlight a potential therapeutic pathway for addressing HTLV-1-induced neuroinflammation by modulating exosome-mediated signaling. Full article

JC polyomavirus (JCPyV) is a worldwide-distributed human virus. Primary infection with JCPyV is usually asymptomatic and followed by a lifelong persistent infection. In situations of profound immunosuppression or prolonged treatment with specific immunomodulatory drugs, such as natalizumab, viral reactivation can occur and lead to the development of JCPyV-associated diseases. Progressive multifocal leukoencephalopathy (PML), a severe demyelinating disease of the central nervous system, is the most common clinical manifestation of JCPyV reactivation. Less frequently, viral reactivation may be associated with granule cell neuronopathy, encephalopathy, and meningitis. However, the pathogenesis of these diseases remains a subject of debate. To date, no treatment is available for JCPyV infection. Nevertheless, some therapeutic options have been explored. Despite its ubiquity, the main mode of JCPyV transmission remains unclear. Epidemiological data suggests that primary infection may be acquired in childhood and throughout life, with the involvement of different routes of transmission. In the absence of an effective treatment, the prevention of infection is crucial in risk groups, such as immunosuppressed or natalizumab-treated patients. Therefore, until the achievement of an effective antiviral molecule or a prophylactic vaccine, prevention measures will rely on avoiding transmission, for which it is crucial to understand how transmission occurs. The present review emphasizes the current data on JCPyV transmission routes and associated diseases, including pathogenesis, diagnosis and potential treatment options, highlighting the importance of further studies. Full article

Background/Objectives: Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system characterized by inflammation, demyelination, and axonal loss. Despite available therapies, there is currently no effective cure for MS. Ibudilast (IBD), a phosphodiesterase inhibitor, and 6-shogaol (SH), a bioactive compound from ginger, have independently shown therapeutic potential in MS models. This study aimed to evaluate the therapeutic efficacy of combining SH and IBD in modulating neuroinflammation and improving functional recovery in a cuprizone (CPZ) mouse model of MS. Methods: Male SWR/J mice were exposed to 0.3% CPZ for 5 weeks to induce demyelination, followed by 4 weeks of spontaneous remyelination after CPZ withdrawal. During remyelination, the CPZ group was subdivided into four groups: no therapy, SH (25 mg/kg), IBD (10 mg/kg), and SH + IBD. Behavioral tests were used to assess locomotion, muscle strength, coordination, and memory. Gene expression of proinflammatory and anti-inflammatory cytokines was analyzed in brain tissue. Results: The combined treatment significantly improved locomotor activity, muscle strength, and memory during remyelination phases while suppressing proinflammatory gene expression and enhancing anti-inflammatory pathways in the brain. Conclusions: SH and IBD combination therapy provides enhanced anti-inflammatory and functional benefits compared with monotherapies, supporting its potential as a promising multi-target therapeutic strategy for improving functional recovery and modulating neuroinflammation during the spontaneous remyelination phase following CPZ withdrawal. Full article

The mammalian brain fundamentally relies on precise lipid homeostasis to maintain structural integrity and complex neural signaling. Emerging evidence positions lipid metabolism reprogramming not merely as a secondary pathological byproduct but as a core initiating driver of age-related neurodegenerative diseases. This review systematically evaluates the mechanisms of cerebral lipid dyshomeostasis during brain aging, highlighting glial cells as the central mediators of this pathological cascade. We comprehensively dissect the age-associated “lipid drift”, emphasizing apolipoprotein E (APOE)-induced cholesterol transport defects and lipid raft pathology, the accumulation of lipid droplets that triggers microglial metabolic stress (LDAMs), and ceramide-driven neuronal apoptosis coupled with the exosome-mediated propagation of pathogenic proteins. Furthermore, we map these aberrant lipid networks to specific pathological signatures in Alzheimer’s, Parkinson’s, and demyelinating diseases. Finally, we critically evaluate promising therapeutic interventions, including nutritional strategies, LXR/RXR agonists, and nanotechnology-enabled delivery systems designed to bypass the blood–brain barrier. By integrating high-throughput lipidomics for early diagnostic biomarker discovery, we underscore the translational imperative of restoring cerebral lipid homeostasis as a disease-modifying strategy for neurodegeneration. Full article

Multiple sclerosis (MS) is a neuro-inflammatory disease characterized by demyelination in the central nervous system (CNS). Although a substantial endogenous capacity for remyelination has been demonstrated, this process is frequently incomplete and exhibits marked intra- and inter-individual heterogeneity. Several factors influence the extent of spontaneous myelin regeneration, including age, sex, disease course, and lesion localization. Oligodendrocytes (OL), derived from oligodendrocyte progenitor cells (OPCs), are the principal myelinating cells of the CNS. The regenerative cascade involves several key stages, including OPC activation, recruitment, differentiation into oligodendrocytes (OL), and myelin deposition. This process is orchestrated in a spatiotemporal manner by a complex interplay of intracellular signaling pathways, genetic determinants, and dynamic microenvironmental cues, which together balance inhibitory and pro-remyelinating influences. Several lines of evidence indicate that chronically demyelinated axons are vulnerable to degeneration, whereas successful remyelination may confer neuroprotection. These observations underscore remyelination as a promising neuroprotective therapeutic target for preventing or slowing disability progression in MS, a condition in which gradual neuroaxonal degeneration is believed to underlie irreversible disability progression. In this review, we aim to bridge the gap between fundamental biological mechanisms of remyelination and their clinical relevance. We examine recent advances in in vivo techniques for assessing remyelination and discuss how these measures correlate with clinical and disability outcomes. In addition, we review recent clinical trials of remyelination-promoting therapies and analyze the challenges that have limited their advancement beyond phase II. Overall, we seek to provide a comprehensive overview of the remyelination process from bench to bedside, highlighting both the obstacles and the therapeutic potential of remyelination strategies in MS. Full article

Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system characterized by demyelination, neuroinflammation, and progressive neurodegeneration. While there is a small component of genetic susceptibility to MS risk, environmental factors, including infectious exposures, are gaining increased recognition as playing a critical role in MS initiation and progression. Viral infections, especially by Epstein–Barr virus (EBV), have emerged as strong candidates and triggers of MS symptoms, through antibody-mediated molecular mimicry and B-cell dysregulation. In contrast, parasitic infections, including helminths and select protozoa, appear to exert neuroprotective effects by skewing immune responses toward regulation and tolerance. In this review, we examine antibody-driven mechanisms by which viral pathogens promote autoimmunity in MS and contrast these with parasite-induced immunoregulatory pathways that suppress pathogenic inflammation. We further discuss diagnostic and therapeutic implications, highlighting how insights from infectious immunology may inform novel strategies for MS treatment. Full article

Background and Clinical Significance: Tumefactive Multiple Sclerosis (TMS) represents a rare and diagnostically challenging form of demyelinating disease characterized by large space-occupying lesions that can closely mimic intracranial neoplasms, abscesses, and other inflammatory or vascular conditions. Case Presentation: The case highlights the overlapping radiologic features that frequently lead to diagnostic uncertainty and underscores the importance of careful interpretation of multimodal imaging and ancillary studies. Overall a comprehensive multidisciplinary evaluation is essential to reduce the risk of misdiagnosis and avoid unnecessary invasive interventions. Conclusions: This review summarizes current evidence regarding the diagnostic approach, imaging characteristics, and therapeutic strategies for tumefactive demyelinating lesions. Additionally, we present a clinical case that illustrates the diagnostic complexity of this entity, in which neuroimaging findings and cerebrospinal fluid analysis supported a demyelinating rather than neoplastic process. Full article

Oligodendrocytes (OLs) are essential for myelin formation in the central nervous system, and their loss or dysfunction is a hallmark of various demyelinating and neurodegenerative disorders. Although oligodendrocyte precursor cells (OPCs) represent a promising cell source for remyelination therapies, existing protocols for generating OPCs from human-induced pluripotent stem cells (iPSCs) are often limited by prolonged culture duration, low efficiency, and cellular heterogeneity. Here, we report an efficient and reproducible platform for generating OPCs from iPSC-derived neural progenitor cells (iNPCs) through stage-specific modulation of developmental signaling pathways. Directed differentiation of iNPCs recapitulated key developmental transitions, progressing through OLIG2⁺/NKX2.2⁺ progenitors to CD140a⁺/O4⁺ OPCs within a significantly shortened timeframe compared to conventional approaches. Notably, iNPC-derived spheres functioned as a progenitor-like niche, enabling sustained OPC production through serial replating. Purified OPCs could differentiate into MBP⁺ oligodendrocytes and demonstrated myelination capacity both in vitro, via nanofiber ensheathment and in vivo following transplantation into shiverer (shi/shi) mice, where they formed myelin sheaths around host axons. Despite these advances, OPC differentiation and maturation efficiencies remained suboptimal, highlighting the need for further optimization. Collectively, our findings establish a scalable and time-efficient strategy for iPSC-derived OPC generation and underscore their potential for disease modeling and cell-based remyelination therapies. Full article

Demyelinating diseases are characterized by loss of myelin and impaired neuronal function. Differentiation of oligodendrocyte progenitor cells (OPCs) and neural stem and progenitor cells is regulated by intracellular kinase signaling pathways. PI3K/Akt/mTOR and Wnt/GSK-3β signaling are involved in oligodendrocyte maturation and neurogenesis, and pharmacological modulation of these pathways affects myelin formation and neuronal differentiation. Small-molecule compounds targeting these pathways influence protein synthesis, lipid production, and β-catenin-dependent transcription. Activation of Akt and mTOR is associated with increased myelin-related protein expression, whereas inhibition of mTOR reduces oligodendrocyte differentiation. In contrast, inhibition of GSK-3β affects β-catenin stability and is associated with oligodendrocyte differentiation. These pathways also affect proliferation and differentiation of neural stem and progenitor cells. However, effects observed in experimental demyelination models have not been established as direct evidence of remyelination in patients. In addition, pharmacological agents act on multiple cell populations in the central nervous system (CNS), which complicates interpretation of their effects on specific cell types. This review examines pharmacological targeting of PI3K/Akt/mTOR and Wnt/GSK-3β signaling and describes intracellular mechanisms involved in oligodendrocyte and neuronal differentiation, with consideration of therapeutic application in demyelinating diseases. Full article

Multiple sclerosis (MS) is a chronic, immune-mediated demyelinating disease of the central nervous system whose heterogeneous clinical, radiological, and biological course has long resisted precise individual-level prediction. The recent convergence of large longitudinal datasets, advanced computational methods, and increasingly informative biomarkers has created conditions in which artificial intelligence (AI) and machine learning (ML) can begin to address that problem substantively. This review surveys the current evidence for AI/ML applications across the MS care continuum, with particular focus on the literature from 2022 through early 2026. Nine domains are examined: automated MRI lesion segmentation and quantification, fluid biomarker interpretation, unsupervised disease subtyping, disability progression prediction, treatment response stratification, drug repurposing and molecular discovery, digital biomarker monitoring, mechanistic interpretability, and integrated clinical management protocols. Notable recent contributions include the SuStaIn-based identification of two biologically distinct MS trajectories distinguished by early versus late serum neurofilament light chain elevation, the MindGlide deep learning platform enabling longitudinal analysis of archived routine clinical MRI data, the T-cell morphological classifier predicting natalizumab treatment response before drug initiation, and the fenebrutinib Phase III program that produced the first Bruton’s tyrosine kinase inhibitor results meeting primary endpoints in both relapsing and primary progressive MS. A proposed AI-Enhanced Management Protocol (AMP-26) reflecting 2026 clinical standards is included as an appendix. Throughout, emphasis is placed on mechanistic interpretability: the distinction between models that correlate features with outcomes and models whose decision logic reflects established MS pathobiology is considered a prerequisite for clinical credibility and regulatory readiness. 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

Multiple Sclerosis (MS) is a chronic, immune-mediated disorder of the central nervous system characterized by leukocyte infiltration, inflammation, demyelination, and progressive neurodegeneration. Susceptibility to MS is influenced by genetic factors, including variants within the human leukocyte antigen (HLA) region, (notably HLA-DR15), and multiple single nucleotide polymorphisms that modulate T cell function and immune regulation. Clinically, early manifestations such as visual disturbances, sensory deficits, fatigue, and impaired coordination often precede more advanced features, including cognitive decline and bladder or bowel dysfunction. Although experimental and genetic models of neuroinflammation have facilitated the development of therapies that reduce relapse rates and slow disease progression, the underlying pathological mechanisms remain incompletely understood. Emerging evidence points to the importance of cytoskeletal organization and membrane-associated signaling platforms in maintaining neuronal and immune cell function. Disruption of these systems may contribute to demyelination and neuroinflammatory cascades. Within this context, a systems biology perspective is particularly valuable, as it emphasizes the integration of multiple, interdependent pathways rather than isolated mechanisms. Caveolin-1 (Cav-1), an integral membrane protein of caveolae, has gained attention as a potential central regulator due to its role in coordinating signaling processes across diverse cellular compartments. In this review, we examine the potential genetic and functional contributions of Cav-1 to MS pathophysiology, with a focus on its involvement in oxidative stress, inflammation, blood–brain barrier integrity, and autophagy. By framing these processes as components of an interconnected network, we highlight Cav-1 as a context-dependent modulator that may influence both disease progression and severity. However, despite its mechanistic relevance, the translational potential of Cav-1 remains uncertain, and further studies are required to clarify its precise role and evaluate its suitability as a therapeutic target in MS. Full article

Demyelinating disorders such as multiple sclerosis are characterized by oligodendrocyte loss and insufficient remyelination. The cuprizone model provides a well-established experimental system for studying these processes. The apelinergic system, including the apelin receptor (APLNR), has been implicated in neuroprotection and central nervous system homeostasis. However, its role in white matter demyelination and repair remains incompletely understood. This study aimed to characterize the spatial and temporal dynamics of APLNR expression in relation to oligodendrocyte lineage cells in the corpus callosum (CC) during demyelination and remyelination. Demyelination was induced in 8-week-old C57BL/6 mice by 0.2% cuprizone supplementation in their drinking water for 5 weeks, followed by 5 weeks remyelination phase after toxin withdrawal. Histological assessment using Luxol Fast Blue/Cresyl violet staining was performed to evaluate structural changes in the CC. Immunohistochemistry and confocal microscopy were used to analyze APLNR expression, GST-π⁺ cells, and NG2⁺ cells, including their spatial distribution and co-localization. Quantitative analyses and correlation tests were conducted to assess relationships between cellular markers and CC area. Demyelination resulted in significant reduction in CC area and a marked decrease in GST-π⁺ cells, accompanied by a robust increase in NG2⁺ cells, while remyelination led to partial structural and cellular recovery. APLNR expression increased progressively from control to demyelination and further during remyelination, exhibiting pronounced regional heterogeneity with higher levels in lateral CC regions. Confocal analysis demonstrated increasing co-localization of APLNR with NG2⁺ cells, particularly during remyelination. Correlation analyses identified GST-π⁺ cell density as the strongest predictor of CC area, whereas APLNR showed phase-dependent associations, including a positive correlation with GST-π⁺ cells during remyelination and a negative relationship with NG2⁺ cells during demyelination. APLNR expression is dynamically regulated during cuprizone-induced demyelination and remyelination and is closely associated with oligodendrocyte lineage cell responses. Its increased expression and enhanced co-localization with NG2⁺ cells during remyelination suggest a potential role in endogenous repair processes. However, as the findings are based on descriptive analyses, further functional studies are required to determine the mechanistic contribution of APLNR signaling and its potential as a therapeutic target in demyelinating diseases. Full article

This study investigated the role of microglia-derived insulin-like growth factor 1 (IGF-1) in modulating host defense and disease progression in a viral model of neuroinflammation and demyelination. Intracranial infection of susceptible mice with the glial-tropic JHM strain of mouse hepatitis virus (JHMV) induces acute encephalomyelitis, followed by an immune-mediated demyelinating disease that mimics many clinical and histologic features of multiple sclerosis (MS). Utilizing an inducible fractalkine receptor (Cx3cr1) promoter-driven Cre-loxP recombinant system, we performed timed ablation of Igf1 in microglia to assess its impact on the central nervous system (CNS) response to JHMV. While the loss of microglial IGF-1 did not impair the control of viral replication, it significantly exacerbated spinal cord demyelination. CyTOF and imaging mass cytometry analysis of spinal cords indicated increased myelin damage was associated with increased accumulation of CD8⁺Ly6C⁺ effector T cells and reduced expression of TREM2 that impaired transition into a disease-associated microglia (DAM) phenotype capable of sensing and potentially mitigating myelin damage. Collectively, these findings argue that microglial IGF-1 is a non-redundant coordinator of the CNS immune responses that occur in response to CNS viral infection. Full article