Search Results (40)

Multiple sclerosis is a chronic, immune-mediated neurodegenerative disorder of the central nervous system, characterized by widespread demyelination, axonal injury, and progressive neurological impairment. The pathophysiology of multiple sclerosis involves complex interactions between immune cells and central nervous system resident cells, with oligodendrocytes (the myelin-producing glial cells) occupying a central role in both the disease’s onset and progression. Oligodendrocyte dysfunction, including diminished regenerative capacity, heightened vulnerability to inflammatory cytokines, and increased susceptibility to oxidative stress, contributes significantly to the failure of remyelination observed in chronic multiple sclerosis lesions. Key factors such as microglial activation, T-cell-mediated cytotoxicity, and altered signaling pathways affecting oligodendrocyte progenitor cell maturation are explored in depth. Some therapeutic strategies under investigation encompass the use of pharmacological agents, cell-based interventions, and modulation of both the extracellular matrix and the immune microenvironment. Advancing our understanding of oligodendrocyte biology, along with the intrinsic and extrinsic factors that impede effective remyelination, is critical for the development of innovative, targeted therapies aimed at attenuating neurodegeneration and enhancing long-term clinical outcomes in patients with multiple sclerosis. Full article

Amyotrophic lateral sclerosis (ALS) is characterized by upper and lower motor neuron failure and poor prognosis. This study performed a meta-analysis of gene expression datasets that compared bulk-processed post-mortem spinal cord from ALS and control (CTL) patients. The analysis included 569 samples (454 ALS, 115 CTL) from 348 individuals (262 ALS, 86 CTL). Patterns of differential expression bias, related to mRNA abundance, gene length and GC content, were discernable from individual studies but attenuated by meta-analysis. A total of 213 differentially expressed genes (DEGs) were identified (144 ALS-increased, 69 ALS-decreased). ALS-increased DEGs were most highly expressed by microglia and associated with MHC class II, immune response and leukocyte activation. ALS-decreased DEGs were abundantly expressed by mature oligodendrocytes (e.g., the MOL5 phenotype) and associated with myelin production, plasma membrane and sterol metabolism. Comparison to spatial transcriptomics data showed that DEGs were prominently expressed in white matter, with increased DEG expression strongest in the ventral/lateral white matter. These results highlight white matter as the spinal cord region most strongly associated with the shifts in mRNA abundance observed in bulk-processed tissues. These shifts can be explained by attrition of mature oligodendrocytes and an ALS-emergent microglia phenotype that is partly shared among neurodegenerative conditions. Full article

Glioblastoma (GBM) often exhibits distinct anatomical patterns of relapse after radiotherapy. Tumour cell migration along myelinated white matter tracts is a key driver of disease progression. The failure of conventional imaging to capture subclinical infiltration has driven interest in advanced imaging biomarkers capable of quantifying tumour–brain interactions. Diffusion tensor imaging (DTI), radiomics, and connectomics represent a triad of innovative, non-invasive approaches that map white matter architecture, predict recurrence risk, and inform biologically guided treatment strategies. This review examines the biological rationale and clinical applications of DTI-based metrics, radiomic signatures, and tractography-informed connectomics in GBM. We discuss the integration of these modalities into machine learning frameworks and radiotherapy/surgical planning, supported by landmark studies and multi-institutional data. The implications for personalised neuro-oncology are profound, marking a shift towards risk-adaptive, tract-aware treatment strategies that may improve local control and preserve neurocognitive function. Full article

Stress-induced demyelination resulting from oligodendrocyte (OLG) dysfunction is one of the key pathological mechanisms of depression, yet its dynamic regulatory network remains unclear. This study integrates single-cell transcriptomics, lineage tracing, and functional interventions to uncover a temporally disordered OLG cholesterol metabolism in a restraint stress mouse model: After 3 days of stress, upregulation of efflux genes Abca1/Abcg1 triggers a compensatory response; however, by day 14, persistent suppression of transport genes (Apoe, Apod) and homeostatic regulatory genes (Dhcr24, Srebf2, etc.) leads to intracellular accumulation of “ineffective cholesterol”, with compensatory activation of the AMPK pathway unable to restore cholesterol conversion into myelin. Pseudotime analysis further reveals that stress alters OLG differentiation trajectories, decreasing the proportion of mature OLGs and causing immature precursors to abnormally stall at the late pre-differentiation stage, resulting in myelin regeneration failure. Moreover, an immune OLG_C10 subpopulation expressing complement component C3 and P2ry12 is identified, indicating that OLGs may contribute to neuroinflammatory cascades through immune reprogramming. In summary, these findings reveal a novel mechanism from the dynamic perspective of OLGs, in which the interplay of “metabolic imbalance, differentiation blockade, and immune activation” collaboratively drives stress-induced demyelination, providing a theoretical foundation for depression treatment targeting OLG functional restoration. Full article

Failure in the proliferation, recruitment, mobilization, and/or differentiation of oligodendrocyte precursor cells (OPCs) impedes remyelination in central nervous system (CNS) demyelinating diseases. Our group has recently achieved the generation of functional oligodendroglia through direct lineage conversion by expressing Sox10, Olig2, and Zfp536 genes in adult rat adipose tissue-derived stromal cells. The present study aimed to determine whether various repurposed drugs or molecules could enhance the myelinating capacities of these induced OPCs (iOPCs). We report that kainate, benztropine, miconazole, clobetasol, and baclofen promote in vitro iOPCs migration, differentiation, and ensheathing abilities through mechanisms similar to those observed in rat neural stem cell-derived OPCs. This research supports the potential use of iOPCs as they provide an alternative and reliable cell source for testing the effects of in vitro promyelinating repurposed drugs and for assessing the molecular and cellular mechanisms involved in therapeutic strategies for demyelinating diseases. Full article

Recovery from traumatic spinal cord injury (tSCI) is challenging due to the limited regenerative capacity of the central nervous system to restore cells, myelin, and neural connections. At the clinical level, the fundamental pillars of treatment are the reduction in secondary damage (neuroprotection) and rehabilitation; these are the tools we have to mitigate the disability caused by spinal cord injury (SCI). To date, the treatments on which neuroprotection has been based are the prevention of acute respiratory failure to avoid hypoxia, early hemodynamic control, neuroprotective drugs and surgical management. Optimizing early hemodynamic control to ensure adequate spinal cord perfusion may be key to the management of SCI. While neuroprotective agents like methylprednisolone have fallen into disuse, several promising therapies are currently being tested in clinical trials. In terms of surgical treatment, although their impact on neurological recovery remains debated, appropriate early bone decompression followed by duroplasty in selected cases is increasingly recommended. Advances in cell therapies hold significant potential for enhancing both clinical and functional outcomes in SCI patients. Moreover, emerging neuromodulation techniques, such as transcutaneous and epidural stimulation, along with innovations in rehabilitation technologies—such as robotic systems and exoskeletons—are becoming indispensable tools for improving locomotion and overall mobility in individuals with SCI. This article provides an update on the advances in neuroprotection against secondary damage caused by tSCI, in cellular therapies, and in new rehabilitation therapies. Full article

The failure of endogenous repair mechanisms is a key characteristic of neurological diseases, leading to the inability to restore damaged nerves and resulting in functional impairments. Since the endogenously regenerative capacity of damaged nerves is limited, the enhancement of regenerative potential of quiescent neural stem cells (NSCs) presents as a therapeutic option for neural diseases. Our previous studies have shown exciting progress in treating sciatic nerve injury in mice and rats using NSCs in conjunction with neurotrophic factors such as fibroblast growth factor 1 (FGF1). Additionally, a recently discovered neurotrophic factor, IL12p80, has shown significant therapeutic effects in sciatic nerve injury repair via myelinating oligodendrocytes. IL12p80 induces oligodendrocyte differentiation from NSCs through phosphorylation of Stat3. Therefore, it might be possible to alleviate the myelination defects of oligodendrocytes in neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), and even schizophrenia through the administration of IL12p80. These applications could shed light on IL12p80 and FGF1, not only in damaged nerve repair, but also in rectifying the oligodendrocytes’ defects in neurodegenerative diseases, such as ALS and MS. Finally, the synergistic effects of neurogenesis-induced FGF1 and myelination-induced IL12 might be able to supplant the need of NSCs for nerve repair and neuroregeneration. Full article

Neurodegeneration is preeminent in many neurological diseases, and still a major burden we fail to manage in patient’s care. Its pathogenesis is complicated, intricate, and far from being completely understood. Taking multiple sclerosis as an example, we propose that neurodegeneration is neither a cause nor a consequence by itself. Mitochondrial dysfunction, leading to energy deficiency and ion imbalance, plays a key role in neurodegeneration, and is partly caused by the oxidative stress generated by microglia and astrocytes. Nodal and paranodal disruption, with or without myelin alteration, is further involved. Myelin loss exposes the axons directly to the inflammatory and oxidative environment. Moreover, oligodendrocytes provide a singular metabolic and trophic support to axons, but do not emerge unscathed from the pathological events, by primary myelin defects and cell apoptosis or secondary to neuroinflammation or axonal damage. Hereby, trophic failure might be an overlooked contributor to neurodegeneration. Thus, a complex interplay between neuroinflammation, demyelination, and neurodegeneration, wherein each is primarily and secondarily involved, might offer a more comprehensive understanding of the pathogenesis and help establishing novel therapeutic strategies for many neurological diseases and beyond. Full article

Failure of myelin regeneration by oligodendrocytes contributes to progressive decline in many neurological diseases. Here, using in vitro and in vivo rodent models, functional blockade, and mouse brain demyelination, we demonstrate that Sonic hedgehog (Shh) expression in a subset of oligodendrocyte progenitor cells precedes the expression of myelin basic protein (MBP), a major myelin sheath protein. Primary cultures of rodent cortical oligodendrocytes show that Shh mRNA and protein are upregulated during oligodendrocyte maturation before the upregulation of MBP expression. Importantly, almost all MBP-positive cells are Shh positive during differentiation. During remyelination, we identify a rapid induction of Shh mRNA and peptide in oligodendroglial cells present in the demyelinated corpus callosum of mice, including a population of PDGFRα-expressing cells. Shh invalidation by an adeno-associated virus strategy demonstrates that the downregulation of Shh impairs the differentiation of oligodendrocytes in vitro and decreases MBP and myelin proteolipid protein expression in the demyelinated mouse brain at late stages of remyelination. We also report a parallel expression of Shh and MBP in oligodendroglial cells during early post-natal myelination of the mouse brain. Thus, we identify a crucial Shh signal involved in oligodendroglial cell differentiation and remyelination, with potential interest in the design of better-targeted remyelinating therapeutic strategies. Full article

In 2024, over 775 million cases of COVID-19 were recorded, including approximately 7 million deaths, indicating its widespread and dangerous nature. The disease is caused by the SARS-CoV-2 virus, which can manifest a wide spectrum of symptoms, from mild infection to respiratory failure and even death. Neurological symptoms, such as headaches, confusion, and impaired consciousness, have also been reported in some COVID-19 patients. These observations suggest the potential of SARS-CoV-2 to invade the central nervous system and induce neuroinflammation during infection. This review specifically explores the relationship between SARS-CoV-2 infection and selected neurological diseases such as multiple sclerosis (MS), ischemic stroke (IS), and Alzheimer’s disease (AD). It has been observed that the SARS-CoV-2 virus increases the production of cytokines whose action can cause the destruction of the myelin sheaths of nerve cells. Subsequently, the body may synthesize autoantibodies that attack nerve cells, resulting in damage to the brain’s anatomical elements, potentially contributing to the onset of multiple sclerosis. Additionally, SARS-CoV-2 exacerbates inflammation, worsening the clinical condition in individuals already suffering from MS. Moreover, the secretion of pro-inflammatory cytokines may lead to an escalation in blood clot formation, which can result in thrombosis, obstructing blood flow to the brain and precipitating an ischemic stroke. AD is characterized by intense inflammation and heightened oxidative stress, both of which are exacerbated during SARS-CoV-2 infection. It has been observed that the SARS-CoV-2 demonstrates enhanced cell entry in the presence of both the ACE2 receptor, which is already elevated in AD and the ApoE ε4 allele. Consequently, the condition worsens and progresses more rapidly, increasing the mortality rate among AD patients. The above information underscores the numerous connections between SARS-CoV-2 infection and neurological diseases. Full article

Immuno-neurology is an emerging therapeutic strategy for dementia and neurodegeneration designed to address immune surveillance failure in the brain. Microglia, as central nervous system (CNS)-resident myeloid cells, routinely perform surveillance of the brain and support neuronal function. Loss-of-function (LOF) mutations causing decreased levels of progranulin (PGRN), an immune regulatory protein, lead to dysfunctional microglia and are associated with multiple neurodegenerative diseases, including frontotemporal dementia caused by the progranulin gene (GRN) mutation (FTD-GRN), Alzheimer’s disease (AD), Parkinson’s disease (PD), limbic-predominant age-related transactivation response deoxyribonucleic acid binding protein 43 (TDP-43) encephalopathy (LATE), and amyotrophic lateral sclerosis (ALS). Immuno-neurology targets immune checkpoint-like proteins, offering the potential to convert aging and dysfunctional microglia into disease-fighting cells that counteract multiple disease pathologies, clear misfolded proteins and debris, promote myelin and synapse repair, optimize neuronal function, support astrocytes and oligodendrocytes, and maintain brain vasculature. Several clinical trials are underway to elevate PGRN levels as one strategy to modulate the function of microglia and counteract neurodegenerative changes associated with various disease states. If successful, these and other immuno-neurology drugs have the potential to revolutionize the treatment of neurodegenerative disorders by harnessing the brain’s immune system and shifting it from an inflammatory/pathological state to an enhanced physiological/homeostatic state. Full article

Modeling chronic cortical demyelination allows the study of long-lasting pathological changes observed in multiple sclerosis such as failure of remyelination, chronically disturbed functions of oligodendrocytes, neurons and astrocytes, brain atrophy and cognitive impairments. We aimed at generating an animal model for studying the consequences of chronic cortical demyelination and meningeal inflammation. To induce long-lasting cortical demyelination and chronic meningeal inflammation, we immunized female Lewis rats against myelin oligodendrocyte glycoprotein (MOG) and injected lentiviruses for continuing overexpression of the cytokines TNFα and IFNγ in the cortical brain parenchyma. Immunization with MOG and overexpression of TNFα and IFNγ led to widespread subpial demyelination and meningeal inflammation that were stable for at least 10 weeks. We demonstrate here that immunization with MOG is necessary for acute as well as chronic cortical demyelination. In addition, long-lasting overexpression of TNFα and IFNγ in the brain parenchyma is sufficient to induce chronic meningeal inflammation. Our model simulates key features of chronic cortical demyelination and inflammation, reminiscent of human multiple sclerosis pathology. This will allow molecular, cellular and functional investigations for a better understanding of the adaptation mechanisms of the cerebral cortex in multiple sclerosis. Full article

During inflammatory, demyelinating diseases such as multiple sclerosis (MS), inflammation and axonal damage are prevalent early in the course. Axonal damage includes swelling, defects in transport, and failure to clear damaged intracellular proteins, all of which affect recovery and compromise neuronal integrity. The clearance of damaged cell components is important to maintain normal turnover and restore homeostasis. In this study, we used mass spectrometry to identify insoluble proteins within high-speed/mercaptoethanol/sarcosyl-insoluble pellets from purified white matter plaques isolated from the brains of individuals with relapsing–remitting MS (RRMS). We determined that the transmembrane protein 106B (TMEM106B), normally lysosome-associated, is insoluble in RRMS plaques relative to normal-appearing white matter from individuals with Alzheimer’s disease and non-neurologic controls. Relative to wild-type mice, hypomorphic mice with a reduction in TMEM106B have increased axonal damage and lipid droplet accumulation in the spinal cord following myelin-oligodendrocyte-glycoprotein-induced experimental autoimmune encephalomyelitis. Additionally, the corpora callosa from cuprizone-challenged hypomorphic mice fail to clear lipid droplets efficiently during remyelination, suggesting that when TMEM106B is compromised, protein and lipid clearance by the lysosome is delayed. As TMEM106B contains putative lipid- and LC3-binding sites, further exploration of these sites is warranted. Full article

The aim of this study was to investigate the involvement of the mesencephalic superior colliculus (SC) in the pathogenetic mechanism of SIDS, a syndrome frequently ascribed to arousal failure from sleep. We analyzed the brains of 44 infants who died suddenly within the first 7 months of life, among which were 26 infants with SIDS and 18 controls. In-depth neuropathological investigations of serial sections of the midbrain showed the SC layered cytoarchitectural organization already well known in animals, as made up of seven distinct layers, but so far never highlighted in humans, albeit with some differences. In 69% of SIDS cases but never in the controls, we observed alterations of the laminar arrangement of the SC deep layers (precisely, an increased number of polygonal cells invading the superficial layers and an increased presence of intensely stained myelinated fibers). Since it has been demonstrated in experimental studies that the deep layers of the SC exert motor control including that of the head, their developmental disorder could lead to the failure of newborns who are in a prone position to resume regular breathing by moving their heads in the sleep-arousal phase. The SC anomalies highlighted here represent a new step in understanding the pathogenetic process that leads to SIDS. Full article

Endometrial receptivity is one of the main factors underlying a successful pregnancy, with reports substantiating the fact that suboptimal endometrial receptivity accounts for two-thirds of early implantation event failures. The association between circRNAs and endometrial receptivity in the goat remains unclear. This study aims to identify potential circRNAs and regulatory mechanisms related to goat endometrial receptivity. Therefore, the endometrial samples on day 16 of pregnancy and day 16 of the estrous cycle were analyzed using high-throughput RNA-seq and bioinformatics. The results show that 4666 circRNAs were identified, including 7 downregulated and 11 upregulated differentially expressed circRNAs (DE-circRNAs). Back-splicing and RNase R resistance verified the identified circRNAs. We predicted the competing endogenous RNA (ceRNA) regulatory mechanism and potential target genes of DE-circRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of these predicted target genes suggest that DE-circRNAs were significantly involved in establishing endometrial receptivity. Furthermore, Sanger sequencing, qPCR, correlation analysis and Fluorescence in Situ Hybridization (FISH) show that circ_MYRF derived from the host gene myelin regulatory factor (MYRF) might regulate the expression of interferon stimulating gene 15 (ISG15), thereby promoting the formation of endometrial receptivity. These novel findings may contribute to a better understanding of the molecular mechanisms regulating endometrial receptivity and promoting the maternal recognition of pregnancy (MRP). Full article