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1.
Immunity ; 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39217987

RESUMEN

The precise neurophysiological changes prompted by meningeal lymphatic dysfunction remain unclear. Here, we showed that inducing meningeal lymphatic vessel ablation in adult mice led to gene expression changes in glial cells, followed by reductions in mature oligodendrocyte numbers and specific lipid species in the brain. These phenomena were accompanied by altered meningeal adaptive immunity and brain myeloid cell activation. During brain remyelination, meningeal lymphatic dysfunction provoked a state of immunosuppression in the brain that contributed to delayed spontaneous oligodendrocyte replenishment and axonal loss. The deficiencies in mature oligodendrocytes and neuroinflammation due to impaired meningeal lymphatic function were solely recapitulated in immunocompetent mice. Patients diagnosed with multiple sclerosis presented reduced vascular endothelial growth factor C in the cerebrospinal fluid, particularly shortly after clinical relapses, possibly indicative of poor meningeal lymphatic function. These data demonstrate that meningeal lymphatics regulate oligodendrocyte function and brain myelination, which might have implications for human demyelinating diseases.

2.
Curr Neurovasc Res ; 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39219420

RESUMEN

Multiple sclerosis [MS] is a progressive autoimmune condition that primarily affects young people and is characterized by demyelination and neurodegeneration of the central nervous system [CNS]. This in-depth review explores the complex involvement of oligodendrocytes, the primary myelin- producing cells in the CNS, in the pathophysiology of MS. It discusses the biochemical processes and signalling pathways required for oligodendrocytes to function and remain alive, as well as how they might fail and cause demyelination to occur. We investigate developing therapeutic options that target remyelination, a fundamental component of MS treatment. Remyelination approaches promote the survival and differentiation of oligodendrocyte precursor cells [OPCs], restoring myelin sheaths. This improves nerve fibre function and may prevent MS from worsening. We examine crucial parameters influencing remyelination success, such as OPC density, ageing, and signalling pathway regulation [e.g., Retinoid X receptor, LINGO-1, Notch]. The review also examines existing neuroprotective and antiinflammatory medications being studied to see if they can assist oligodendrocytes in surviving and reducing the severity of MS symptoms. The review focuses on medicines that target the myelin metabolism in oligodendrocytes. Altering oligodendrocyte metabolism has been linked to reversing demyelination and improving MS patient outcomes through various mechanisms. We also explore potential breakthroughs, including innovative antisense technologies, deep brain stimulation, and the impact of gut health and exercise on MS development. The article discusses the possibility of personalized medicine in MS therapy, emphasizing the importance of specific medicines based on individual molecular profiles. The study emphasizes the need for reliable biomarkers and improved imaging tools for monitoring disease progression and therapy response. Finally, this review focuses on the importance of oligodendrocytes in MS and the potential for remyelination therapy. It also underlines the importance of continued research to develop more effective treatment regimens, taking into account the complexities of MS pathology and the different factors that influence disease progression and treatment.

3.
Tissue Cell ; 91: 102543, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39232355

RESUMEN

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes that affects the angiogenesis and myelination of peripheral nerves. In this study, we investigated the potential of mesenchymal stem cells (MSCs) transplantation to improve DPN by enhancing angiogenesis and remyelination in the sciatic nerve of streptozotocin (STZ)-induced diabetic female rats. The purpose of this study was to evaluate the therapeutic potential of mesenchymal stem cells as a possiblity for clinical intervention to alleviate the symptoms of diabetic peripheral neuropathy. We examined whether transplanted mesenchymal stem cells can produce new and restored angiogenesis, as well as promoting myelination. Overall, our findings suggest that MSCs transplantation has neuroprotective effects. This is particularly the case for Schwann cells. Transplantation may stimulate angiogenesis as well as remyelination of the sciatic nerve in experimentally-induced diabetic peripheral neuropathy. Behavioral assays, histological analysis, and molecular techniques were used to assess the effects of MSCs transplantation. Our results demonstrate that in diabetic rats signs of neuropathy were reversed following a single administration of bone marrow-derived MSCs. Morphological and morphometric analysis of the sciatic nerve revealed that diabetic rats displayed structural alterations that were attenuated with MSCs transplantation.Immunostaining analysis showed increased expression of S100 and VEGF in the sciatic nerve following MSCs transplantation. Western blotting analysis also revealed elevated levels of VEGF and CD31 in rats treated with MSCs compared to diabetic rats.

4.
Mult Scler Relat Disord ; 91: 105850, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39232395

RESUMEN

BACKGROUND: Assessment of the visual pathway, which is frequently affected by MS, provides the opportunity to measure the remyelination of acute and chronic MS lesions in vivo and non-invasively. VEP can be used in this context. Amplitude is a parameter of axonal loss, whereas latency is an in vivo biomarker of myelin repair. This study aimed to evaluate DMT's neuroprotective and pro-remyelinating potential by evaluating VEP latency and amplitude in MS patients. MATERIALS AND METHODS: A total of 74 patients with relapsing MS who had no evidence of optic neuritis were included in the study. Patient data were retrospectively analyzed and recorded. In the VEP test, latency above 118 ms and amplitude below 5.0 µV were considered abnormal. Classified according to DMTs (injectables, teriflunomide, dimethyl fumarate, fingolimod, cladribine, and alemtuzumab). Visual evoked potential tests, clinical features, and cerebrospinal fluid examinations were evaluated by three independent neurologists and one clinical neurophysiologist. RESULTS: The mean age at diagnosis was 29.2 ± 9.01, and the mean age at first VEP was 34.97 ± 10.64. In women, latency was lower, and amplitude was higher. The mean differences in latency and amplitude were, respectively, latency prolonged by 0.7 ms on the right and 0.5 ms on the left, and amplitude increased by 0.6 µV on the right and 0.37 µV on the left. However, these changes were not statistically significant. Latency worsening was more prominent in those with longer disease duration (p = 0.011). Those with amplitude or latency worsening had higher EDSS (p = 0.016 and 0.013, respectively). DMTs did not affect these changes. CONCLUSION: Prolonged latency is associated with a long disease duration. Deterioration in both amplitude and latency is evident in high EDSS. These results may be an indirect consequence of axonal degeneration dominating remyelination. DMTs do not ameliorate impaired remyelination and neurodegeneration but seem to be sufficient for short-term maintenance of the current state.

5.
Acta Histochem Cytochem ; 57(4): 131-135, 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39228906

RESUMEN

Multiple sclerosis, neuromyelitis optica, Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy are representative demyelinating diseases of the central and peripheral nervous system. Remyelination by myelin forming cells is important for functional recovery from the neurological deficits caused in the demyelinating diseases. Lysophosphatidylcholine-induced demyelination in mice is commonly used to identify and study the molecular pathways of demyelination and remyelination. However, detection of focally demyelinated lesions is difficult and usually requires sectioning of demyelinated lesions in tissues for microscopic analysis. In this review, we describe the development and application of a novel vital staining method for labeling demyelinated lesions using intraperitoneal injection of neutral red (NR) dye. NR labeling reduces the time and effort required to search for demyelinated lesions in tissues, and facilitates electron microscopic analysis of myelin structures. NR labeling also has the potential to contribute to the elucidation of pathologies in the central and peripheral nervous system and assist with identification of drug candidates that promote remyelination.

6.
Front Neurol ; 15: 1385042, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39148705

RESUMEN

Background: Neuroplasticity as a mechanism to overcome central nervous system injury resulting from different neurological diseases has gained increasing attention in recent years. However, deficiency of these repair mechanisms leads to the accumulation of neuronal damage and therefore long-term disability. To date, the mechanisms by which remyelination occurs and why the extent of remyelination differs interindividually between multiple sclerosis patients regardless of the disease course are unclear. A member of the neurotrophins family, the brain-derived neurotrophic factor (BDNF) has received particular attention in this context as it is thought to play a central role in remyelination and thus neuroplasticity, neuroprotection, and memory. Objective: To analyse the current literature regarding BDNF in different areas of multiple sclerosis and to provide an overview of the current state of knowledge in this field. Conclusion: To date, studies assessing the role of BDNF in patients with multiple sclerosis remain inconclusive. However, there is emerging evidence for a beneficial effect of BDNF in multiple sclerosis, as studies reporting positive effects on clinical as well as MRI characteristics outweighed studies assuming detrimental effects of BDNF. Furthermore, studies regarding the Val66Met polymorphism have not conclusively determined whether this is a protective or harmful factor in multiple sclerosis, but again most studies hypothesized a protective effect through modulation of BDNF secretion and anti-inflammatory effects with different effects in healthy controls and patients with multiple sclerosis, possibly due to the pro-inflammatory milieu in patients with multiple sclerosis. Further studies with larger cohorts and longitudinal follow-ups are needed to improve our understanding of the effects of BDNF in the central nervous system, especially in the context of multiple sclerosis.

7.
CNS Neurosci Ther ; 30(8): e14903, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39139089

RESUMEN

INTRODUCTION: Excessive neuroinflammation, apoptosis, glial scar, and demyelination triggered by spinal cord injury (SCI) are major obstacles to SCI repair. Fucoidan, a natural marine plant extract, possesses broad-spectrum anti-inflammatory and immunomodulatory effects and is regarded as a potential therapeutic for various diseases, including neurological disorders. However, its role in SCI has not been investigated. METHODS: In this study, we established an SCI model in mice and intervened in injury repair by daily intraperitoneal injections of different doses of fucoidan (10 and 20 mg/kg). Concurrently, primary oligodendrocyte precursor cells (OPCs) were treated in vitro to validate the differentiation-promoting effect of fucoidan on OPCs. Basso Mouse Scale (BMS), Louisville Swim Scale (LSS), and Rotarod test were carried out to measure the functional recovery. Immunofluorescence staining, and transmission electron microscopy (TEM) were performed to assess the neuroinflammation, apoptosis, glial scar, and remyelination. Western blot analysis was conducted to clarify the underlying mechanism of remyelination. RESULTS: Our results indicate that in the SCI model, fucoidan exhibits significant anti-inflammatory effects and promotes the transformation of pro-inflammatory M1-type microglia/macrophages into anti-inflammatory M2-type ones. Fucoidan enhances the survival of neurons and axons in the injury area and improves remyelination. Additionally, fucoidan promotes OPCs differentiation into mature oligodendrocytes by activating the PI3K/AKT/mTOR pathway. CONCLUSION: Fucoidan improves SCI repair by modulating the microenvironment and promoting remyelination.


Asunto(s)
Ratones Endogámicos C57BL , Polisacáridos , Recuperación de la Función , Remielinización , Traumatismos de la Médula Espinal , Animales , Polisacáridos/farmacología , Ratones , Traumatismos de la Médula Espinal/tratamiento farmacológico , Traumatismos de la Médula Espinal/patología , Remielinización/efectos de los fármacos , Remielinización/fisiología , Recuperación de la Función/efectos de los fármacos , Células Precursoras de Oligodendrocitos/efectos de los fármacos , Femenino , Microambiente Celular/efectos de los fármacos
8.
Elife ; 122024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39163103

RESUMEN

Revealing unknown cues that regulate oligodendrocyte progenitor cell (OPC) function in remyelination is important to optimise the development of regenerative therapies for multiple sclerosis (MS). Platelets are present in chronic non-remyelinated lesions of MS and an increase in circulating platelets has been described in experimental autoimmune encephalomyelitis (EAE) mice, an animal model for MS. However, the contribution of platelets to remyelination remains unexplored. Here we show platelet aggregation in proximity to OPCs in areas of experimental demyelination. Partial depletion of circulating platelets impaired OPC differentiation and remyelination, without altering blood-brain barrier stability and neuroinflammation. Transient exposure to platelets enhanced OPC differentiation in vitro, whereas sustained exposure suppressed this effect. In a mouse model of thrombocytosis (Calr+/-), there was a sustained increase in platelet aggregation together with a reduction of newly-generated oligodendrocytes following toxin-induced demyelination. These findings reveal a complex bimodal contribution of platelet to remyelination and provide insights into remyelination failure in MS.


Asunto(s)
Plaquetas , Diferenciación Celular , Células Precursoras de Oligodendrocitos , Remielinización , Animales , Células Precursoras de Oligodendrocitos/fisiología , Remielinización/fisiología , Ratones , Plaquetas/fisiología , Encefalomielitis Autoinmune Experimental/patología , Ratones Endogámicos C57BL , Esclerosis Múltiple/patología , Modelos Animales de Enfermedad , Oligodendroglía/fisiología , Femenino
9.
Cells ; 13(16)2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39195216

RESUMEN

Axons wrapped around the myelin sheath enable fast transmission of neuronal signals in the Central Nervous System (CNS). Unfortunately, myelin can be damaged by injury, viral infection, and inflammatory and neurodegenerative diseases. Remyelination is a spontaneous process that can restore nerve conductivity and thus movement and cognition after a demyelination event. Cumulative evidence indicates that remyelination can be pharmacologically stimulated, either by targeting natural inhibitors of Oligodendrocyte Precursor Cells (OPCs) differentiation or by reactivating quiescent Neural Stem Cells (qNSCs) proliferation and differentiation in myelinating Oligodendrocytes (OLs). Although promising results were obtained in animal models for demyelination diseases, none of the compounds identified have passed all the clinical stages. The significant number of patients who could benefit from remyelination therapies reinforces the urgent need to reassess drug selection approaches and develop strategies that effectively promote remyelination. Integrating Artificial Intelligence (AI)-driven technologies with patient-derived cell-based assays and organoid models is expected to lead to novel strategies and drug screening pipelines to achieve this goal. In this review, we explore the current literature on these technologies and their potential to enhance the identification of more effective drugs for clinical use in CNS remyelination therapies.


Asunto(s)
Evaluación Preclínica de Medicamentos , Remielinización , Humanos , Remielinización/efectos de los fármacos , Animales , Enfermedades Desmielinizantes/tratamiento farmacológico , Enfermedades Desmielinizantes/patología , Vaina de Mielina/metabolismo , Oligodendroglía/efectos de los fármacos , Oligodendroglía/metabolismo , Oligodendroglía/citología , Células-Madre Neurales/efectos de los fármacos , Células-Madre Neurales/metabolismo , Células-Madre Neurales/citología , Diferenciación Celular/efectos de los fármacos
10.
J Neuroimmunol ; 394: 578421, 2024 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-39088907

RESUMEN

Niacin was found in the lysolecithin model of multiple sclerosis (MS) to promote the phagocytic clearance of debris and enhance remyelination. Lysolecithin lesions have prominent microglia/macrophages but lack lymphocytes that populate plaques of MS or its experimental autoimmune encephalomyelitis (EAE) model. Thus, the current study assessed the efficacy of niacin in EAE. We found that niacin inconsistently affects EAE clinical score, and largely does not ameliorate neuropathology. In culture, niacin enhances phagocytosis by macrophages, but does not reduce T cell proliferation. We suggest that studies of niacin for potential remyelination in MS should include a therapeutic that targets adaptive immunity.


Asunto(s)
Encefalomielitis Autoinmune Experimental , Ratones Endogámicos C57BL , Esclerosis Múltiple , Niacina , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Encefalomielitis Autoinmune Experimental/inmunología , Animales , Niacina/uso terapéutico , Femenino , Ratones , Esclerosis Múltiple/tratamiento farmacológico , Esclerosis Múltiple/inmunología , Fagocitosis/efectos de los fármacos , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Células Cultivadas , Modelos Animales de Enfermedad , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología
11.
Adv Neurobiol ; 37: 445-456, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39207707

RESUMEN

Multiple sclerosis (MS) is a devastating autoimmune disease that leads to profound disability. This disability arises from the stochastic, regional loss of myelin-the insulating sheath surrounding neurons-in the central nervous system (CNS). The demyelinated regions are dominated by the brain's resident macrophages: microglia. Microglia perform a variety of functions in MS and are thought to initiate and perpetuate demyelination through their interactions with peripheral immune cells that traffic into the brain. However, microglia are also likely essential for recruiting and promoting the differentiation of cells that can restore lost myelin in a process known as remyelination. Given these seemingly opposing functions, an overarching beneficial or detrimental role is yet to be ascribed to these immune cells. In this chapter, we will discuss microglia dynamics throughout the MS disease course and probe the apparent dichotomy of microglia as the drivers of both demyelination and remyelination.


Asunto(s)
Microglía , Esclerosis Múltiple , Vaina de Mielina , Microglía/metabolismo , Microglía/patología , Humanos , Esclerosis Múltiple/patología , Esclerosis Múltiple/inmunología , Vaina de Mielina/patología , Vaina de Mielina/metabolismo , Remielinización/fisiología , Animales , Encéfalo/patología , Encéfalo/inmunología , Enfermedades Desmielinizantes/patología , Enfermedades Desmielinizantes/inmunología , Enfermedades Desmielinizantes/metabolismo
13.
Biochem Biophys Res Commun ; 733: 150592, 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39213705

RESUMEN

Damage to oligodendrocytes (OLs) and myelin sheaths (demyelination) has been shown to be associated with numerous neurological and psychiatric disorders. Remyelination is a rare and reliable regenerative response that occurs in the central nervous system (CNS). It is generally believed that OL progenitor cells (OPCs) are the cell source to generate new OLs to remyelinate the demyelinated axons. However, several recent studies have argued that pre-existing mature OLs that survive within the demyelinated area are responsible for remyelination. Here, by conditional knock-out (KO) of a transcription factor gene that is essential for OPC differentiation, namely myelin regulatory factor (Myrf), to block the production of adult new OLs and examined its effect on remyelination after cuprizone (CPZ)-induced demyelination. We found that OPCs specific Myrf cKO mice show dramatic impairment in remyelination after 4 weeks of recovery from 5 weeks of CPZ diet and they leave over significant behavioral deficits such as anxiety-like behavior, decreased motor skills, and impaired memory compared to control mice that have recovered for the same time. Our data support the idea that OPCs are the major cell sources for myelin regeneration, suggesting that targeting the activation of OPCs and promoting their differentiation to boost new OLs production is critical for therapeutic intervention for demyelinating diseases such as multiple sclerosis (MS).

14.
Int J Mol Sci ; 25(16)2024 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-39201438

RESUMEN

Primary progressive multiple sclerosis (PPMS), the least frequent type of multiple sclerosis (MS), is characterized by a specific course and clinical symptoms, and it is associated with a poor prognosis. It requires extensive differential diagnosis and often a long-term follow-up before its correct recognition. Despite recent progress in research into and treatment for progressive MS, the diagnosis and management of this type of disease still poses a challenge. Considering the modern concept of progression "smoldering" throughout all the stages of disease, a thorough exploration of PPMS may provide a better insight into mechanisms of progression in MS, with potential clinical implications. The goal of this study was to review the current evidence from investigations of PPMS, including its background, clinical characteristics, potential biomarkers and therapeutic opportunities. Processes underlying CNS damage in PPMS are discussed, including chronic immune-mediated inflammation, neurodegeneration, and remyelination failure. A review of potential clinical, biochemical and radiological biomarkers is presented, which is useful in monitoring and predicting the progression of PPMS. Therapeutic options for PPMS are summarized, with approved therapies, ongoing clinical trials and future directions of investigations. The clinical implications of findings from PPMS research would be associated with reliable assessments of disease outcomes, improvements in individualized therapeutic approaches and, hopefully, novel therapeutic targets, relevant for the management of progression.


Asunto(s)
Biomarcadores , Progresión de la Enfermedad , Esclerosis Múltiple Crónica Progresiva , Humanos , Esclerosis Múltiple Crónica Progresiva/diagnóstico , Esclerosis Múltiple Crónica Progresiva/patología , Esclerosis Múltiple Crónica Progresiva/terapia , Manejo de la Enfermedad
15.
Brain Pathol ; : e13280, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38946137

RESUMEN

Demyelination of corticospinal tract neurons contributes to long-term disability after cortical stroke. Nonetheless, poststroke myelin loss has not been addressed as a therapeutic target, so far. We hypothesized that an antibody-mediated inhibition of the Nogo receptor-interacting protein (LINGO-1, leucine-rich repeat and immunoglobulin domain-containing Nogo receptor-interacting protein) may counteract myelin loss, enhance remyelination and axonal growth, and thus promote functional recovery following stroke. To verify this hypothesis, mice were subjected to photothrombotic stroke and received either an antibody against LINGO-1 (n = 19) or a control treatment (n = 18). Behavioral tests were performed to assess the effects of anti-LINGO-1 treatment on the functional recovery. Seven weeks after stroke, immunohistochemical analyses were performed to analyze the effect of anti-LINGO-1 treatment on myelination and axonal loss of corticospinal tract neurons, proliferation of oligodendrocytes and neurogenesis. Anti-LINGO-1 treatment resulted in significantly improved functional recovery (p < 0.0001, repeated measures analysis of variance), and increased neurogenesis in the hippocampus and subventricular zone of the ipsilateral hemisphere (p = 0.0094 and p = 0.032, t-test). Notably, we observed a significant increase in myelin (p = 0.0295, t-test), platelet-derived growth factor receptor α-positive oligodendrocyte precursor cells (p = 0.0356, t-test) and myelinating adenomatous polyposis coli-positive cells within the ipsilateral internal capsule of anti-LINGO-1-treated mice (p = 0.0021, t-test). In conclusion, we identified anti-LINGO-1 as the first neuroregenerative treatment that counteracts poststroke demyelination of corticospinal tract neurons, presumably by increased proliferation of myelin precursor cells, and thereby improves functional recovery. Most importantly, our study presents myelin loss as a novel therapeutic target following stroke.

16.
Mol Neurodegener ; 19(1): 53, 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-38997755

RESUMEN

BACKGROUND: Multiple sclerosis (MS) therapeutic goals have traditionally been dichotomized into two distinct avenues: immune-modulatory-centric interventions and pro-regenerative strategies. Oligodendrocyte progenitor cells (OPCs) were regarded for many years solely in concern to their potential to generate oligodendrocytes and myelin in the central nervous system (CNS). However, accumulating data elucidate the multifaceted roles of OPCs, including their immunomodulatory functions, positioning them as cardinal constituents of the CNS's immune landscape. MAIN BODY: In this review, we will discuss how the two therapeutic approaches converge. We present a model by which (1) an inflammation is required for the appropriate pro-myelinating immune function of OPCs in the chronically inflamed CNS, and (2) the immune function of OPCs is crucial for their ability to differentiate and promote remyelination. This model highlights the reciprocal interactions between OPCs' pro-myelinating and immune-modulating functions. Additionally, we review the specific effects of anti- and pro-inflammatory interventions on OPCs, suggesting that immunosuppression adversely affects OPCs' differentiation and immune functions. CONCLUSION: We suggest a multi-systemic therapeutic approach, which necessitates not a unidimensional focus but a harmonious balance between OPCs' pro-myelinating and immune-modulatory functions.


Asunto(s)
Inflamación , Esclerosis Múltiple , Células Precursoras de Oligodendrocitos , Remielinización , Humanos , Remielinización/fisiología , Esclerosis Múltiple/inmunología , Esclerosis Múltiple/terapia , Esclerosis Múltiple/patología , Animales , Inflamación/inmunología , Diferenciación Celular/fisiología , Vaina de Mielina , Oligodendroglía
17.
Immunity ; 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39053462

RESUMEN

The reduced ability of the central nervous system to regenerate with increasing age limits functional recovery following demyelinating injury. Previous work has shown that myelin debris can overwhelm the metabolic capacity of microglia, thereby impeding tissue regeneration in aging, but the underlying mechanisms are unknown. In a model of demyelination, we found that a substantial number of genes that were not effectively activated in aged myeloid cells displayed epigenetic modifications associated with restricted chromatin accessibility. Ablation of two class I histone deacetylases in microglia was sufficient to restore the capacity of aged mice to remyelinate lesioned tissue. We used Bacillus Calmette-Guerin (BCG), a live-attenuated vaccine, to train the innate immune system and detected epigenetic reprogramming of brain-resident myeloid cells and functional restoration of myelin debris clearance and lesion recovery. Our results provide insight into aging-associated decline in myeloid function and how this decay can be prevented by innate immune reprogramming.

18.
J Neuroinflammation ; 21(1): 171, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39010082

RESUMEN

White matter injury (WMI) is thought to be a major contributor to long-term cognitive dysfunctions after traumatic brain injury (TBI). This damage occurs partly due to apoptotic death of oligodendrocyte lineage cells (OLCs) after the injury, triggered directly by the trauma or in response to degenerating axons. Recent research suggests that the gut microbiota modulates the inflammatory response through the regulation of peripheral immune cell infiltration after TBI. Additionally, T-cells directly impact OLCs differentiation and proliferation. Therefore, we hypothesized that the gut microbiota plays a critical role in regulating the OLC response to WMI influencing T-cells differentiation and activation. Gut microbial depletion early after TBI chronically reduced re-myelination, acutely decreased OLCs proliferation, and was associated with increased myelin debris accumulation. Surprisingly, the absence of T-cells in gut microbiota depleted mice restored OLC proliferation and remyelination after TBI. OLCs co-cultured with T-cells derived from gut microbiota depleted mice resulted in impaired proliferation and increased expression of MHC-II compared with T cells from control-injured mice. Furthermore, MHC-II expression in OLCs appears to be linked to impaired proliferation under gut microbiota depletion and TBI conditions. Collectively our data indicates that depletion of the gut microbiota after TBI impaired remyelination, reduced OLCs proliferation with concomitantly increased OLC MHCII expression, and required the presence of T cells. This data suggests that T cells are an important mechanistic link by which the gut microbiota modulate the oligodendrocyte response and white matter recovery after TBI.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Microbioma Gastrointestinal , Ratones Endogámicos C57BL , Oligodendroglía , Animales , Lesiones Traumáticas del Encéfalo/patología , Lesiones Traumáticas del Encéfalo/microbiología , Oligodendroglía/patología , Microbioma Gastrointestinal/fisiología , Ratones , Proliferación Celular/fisiología , Masculino , Linfocitos T/inmunología , Células Cultivadas
19.
Int J Mol Sci ; 25(13)2024 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-39000003

RESUMEN

Peripheral nerve injuries (PNIs) represent a significant clinical challenge, particularly in elderly populations where axonal remyelination and regeneration are impaired. Developing therapies to enhance these processes is crucial for improving PNI repair outcomes. Glutamate carboxypeptidase II (GCPII) is a neuropeptidase that plays a pivotal role in modulating glutamate signaling through its enzymatic cleavage of the abundant neuropeptide N-acetyl aspartyl glutamate (NAAG) to liberate glutamate. Within the PNS, GCPII is expressed in Schwann cells and activated macrophages, and its expression is amplified with aging. In this study, we explored the therapeutic potential of inhibiting GCPII activity following PNI. We report significant GCPII protein and activity upregulation following PNI, which was normalized by the potent and selective GCPII inhibitor 2-(phosphonomethyl)-pentanedioic acid (2-PMPA). In vitro, 2-PMPA robustly enhanced myelination in dorsal root ganglion (DRG) explants. In vivo, using a sciatic nerve crush injury model in aged mice, 2-PMPA accelerated remyelination, as evidenced by increased myelin sheath thickness and higher numbers of remyelinated axons. These findings suggest that GCPII inhibition may be a promising therapeutic strategy to enhance remyelination and potentially improve functional recovery after PNI, which is especially relevant in elderly PNI patients where this process is compromised.


Asunto(s)
Glutamato Carboxipeptidasa II , Traumatismos de los Nervios Periféricos , Remielinización , Animales , Ratones , Traumatismos de los Nervios Periféricos/tratamiento farmacológico , Traumatismos de los Nervios Periféricos/metabolismo , Remielinización/efectos de los fármacos , Glutamato Carboxipeptidasa II/antagonistas & inhibidores , Glutamato Carboxipeptidasa II/metabolismo , Vaina de Mielina/metabolismo , Vaina de Mielina/efectos de los fármacos , Envejecimiento/efectos de los fármacos , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/metabolismo , Ratones Endogámicos C57BL , Regeneración Nerviosa/efectos de los fármacos , Nervio Ciático/lesiones , Nervio Ciático/efectos de los fármacos , Masculino , Axones/efectos de los fármacos , Axones/metabolismo
20.
Int J Biol Macromol ; 277(Pt 1): 134144, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39053824

RESUMEN

Multiple sclerosis is a chronic inflammatory demyelinating disorder of the CNS characterized by continuous myelin damage accompanied by deterioration in functions. Clobetasol propionate (CP) is the most potent topical corticosteroid with serious side effects related to systemic absorption. Previous studies introduced CP for remyelination without considering systemic toxicity. This work aimed at fabrication and optimization of double coated nano-oleosomes loaded with CP to achieve brain targeting through intranasal administration. The optimized formulation was coated with lactoferrin and chitosan for the first time. The obtained double-coated oleosomes had particle size (220.07 ± 0.77 nm), zeta potential (+30.23 ± 0.41 mV) along with antioxidant capacity 9.8 µM ascorbic acid equivalents. Double coating was well visualized by TEM and significantly decreased drug release. Three different doses of CP were assessed in-vivo using cuprizone-induced demyelination in C57Bl/6 mice. Neurobehavioral tests revealed improvement in motor and cognitive functions of mice in a dose-dependent manner. Histopathological examination of the brain showed about 2.3 folds increase in corpus callosum thickness in 0.3 mg/kg CP dose. Moreover, the measured biomarkers highlighted the significant antioxidant and anti-inflammatory capacity of the formulation. In conclusion, the elaborated biopolymer-integrating nanocarrier succeeded in remyelination with 6.6 folds reduction in CP dose compared to previous studies.


Asunto(s)
Quitosano , Clobetasol , Cuprizona , Enfermedades Desmielinizantes , Modelos Animales de Enfermedad , Lactoferrina , Esclerosis Múltiple , Remielinización , Animales , Lactoferrina/química , Lactoferrina/farmacología , Quitosano/química , Ratones , Clobetasol/farmacología , Clobetasol/química , Remielinización/efectos de los fármacos , Enfermedades Desmielinizantes/inducido químicamente , Enfermedades Desmielinizantes/tratamiento farmacológico , Enfermedades Desmielinizantes/patología , Esclerosis Múltiple/tratamiento farmacológico , Esclerosis Múltiple/inducido químicamente , Liposomas/química , Ratones Endogámicos C57BL , Masculino , Tamaño de la Partícula , Encéfalo/efectos de los fármacos , Encéfalo/patología , Encéfalo/metabolismo , Antioxidantes/farmacología , Antioxidantes/química , Liberación de Fármacos
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