Progressive multiple sclerosis: pathology and pathogenesis

Mesoporous polydopamine nanoparticle-based tolerogenic vaccine induces antigen-specific immune tolerance to prevent and treat autoimmune multiple sclerosis

Multiple sclerosis (MS) is a chronic neurological disorder derived from autoreactive immune system attacking the protective myelin sheath that surrounds nerves in the central nervous system (CNS). Here, a tolerogenic nanovaccine for generating an antigen-specific immune tolerance for treating MS is proposed. It consisted of a mesoporous polydopamine (mPDA) nanoparticle, characterized by high reactive oxygen species (ROS)-scavenging property, loaded with MS-derived autoantigen. Intravenous vaccination of autoantigen-loaded mPDA could induce tolerogenic dendritic cells (DCs) with low expression of co-stimulatory molecules while presenting peptide epitopes. The tolerogenic DCs induced peripheral regulatory T-cells (Tregs), thereby reducing infiltration of autoreactive CD4+ T-cells and inflammatory antigen-presenting cells (APCs) into the CNS. In MS-mimicking mouse model, the tolerogenic nanovaccine prevented MS development in the early therapeutic setup and exhibited an enhanced recovery from complete paralysis in the late therapeutic model. The current platform could be exploited to treat other autoimmune diseases where disease-dependent autoantigen peptides are delivered.

Multiple Sclerosis and Other Acquired Demyelinating Diseases of the Central Nervous System

Acquired demyelinating diseases of the central nervous system (CNS) comprise inflammatory conditions, including multiple sclerosis (MS) and related diseases, as well as noninflammatory conditions caused by toxic, metabolic, infectious, traumatic, and neurodegenerative insults. Here, we review the spectrum of diseases producing acquired CNS demyelination before focusing on the prototypical example of MS, exploring the pathologic mechanisms leading to myelin injury in relapsing and progressive MS and summarizing the mechanisms and modulators of remyelination. We highlight the complex interplay between the immune system, oligodendrocytes and oligodendrocyte progenitor cells (OPCs), and other CNS glia cells such as microglia and astrocytes in the pathogenesis and clinical course of MS. Finally, we review emerging therapeutic strategies that exploit our growing understanding of disease mechanisms to limit progression and promote remyelination.

Neurotropic Murine β-Coronavirus Infection Causes Differential Expression of Connexin 47 in Oligodendrocyte Subpopulations Associated with Demyelination

Gap junctions (GJs) play a crucial role in the survival of oligodendrocytes and myelination of the central nervous system (CNS). In this study, we investigated the spatiotemporal changes in the expression of oligodendroglial GJ protein connexin 47 (Cx47), its primary astroglial coupling partner, Cx43, and their association with demyelination following intracerebral infection with mouse hepatitis virus (MHV). Neurotropic strains of MHV, a β-coronavirus, induce an acute encephalomyelitis followed by a chronic demyelinating disease that shares similarities with the human disease multiple sclerosis (MS). Our results reveal that Cx47 GJs are persistently lost in mature oligodendrocytes, not only in demyelinating lesions but also in surrounding normal appearing white and gray matter areas, following an initial loss of astroglial Cx43 GJs during acute infection. At later stages after viral clearance, astroglial Cx43 GJs re-emerge but mature oligodendrocytes fail to fully re-establish GJs with astrocytes due to lack of Cx47 GJ expression. In contrast, at this later demyelinating stage, the increased oligodendrocyte precursor cells appear to exhibit Cx47 GJs. Our findings further highlight varying degrees of demyelination in distinct spinal cord regions, with the thoracic cord showing the most pronounced demyelination. The regional difference in demyelination correlates well with dynamic changes in the proportion of different oligodendrocyte lineage cells exhibiting differential Cx47 GJ expression, suggesting an important mechanism of progressive demyelination even after viral clearance.

A New Perspective on Mechanisms of Neurodegeneration in Experimental Autoimmune Encephalomyelitis and Multiple Sclerosis: the Early and Critical Role of Platelets in Neuro/Axonal Loss

Multiple sclerosis (MS) is a central nervous system (CNS) autoimmune disorder, with limited treatment options. This disease is characterized by differential pathophysiology between grey matter (GM) and white matter (WM). The predominant WM hallmark is the perivascular plaque, associated with blood brain barrier (BBB) loss of function, lymphocytic infiltration, microglial reactivity, demyelination and axonal injury and is adequately addressed with immunomodulatory drugs. By contrast, mechanisms underlying GM damage remain obscure, with consequences for neuroprotective strategies. Cortical GM pathology is already significant in early MS and characterized by reduced BBB disruption and lymphocytic infiltration relative to WM, but a highly inflammatory environment, microglial reactivity, demyelination and neuro/axonal loss. There is no satisfactory explanation for the occurrence of neurodegeneration without large-scale inflammatory cell influx in cortical GM. A candidate mechanism suggests that it results from soluble factors originating from meningeal inflammatory cell aggregates, which diffuse into the underlying cortical tissue and trigger microglial activation. However, the recent literature highlights the central role of platelets in inflammation, together with the relationship between coagulation factors, particularly fibrinogen, and tissue damage in MS. Using the experimental autoimmune encephalomyelitis (EAE) model, we identified platelets as drivers of neuroinflammation and platelet-neuron associations from the pre-symptomatic stage. We propose that fibrinogen leakage across the BBB is a signal for platelet infiltration and that platelets represent a major and early participant in neurodegeneration. This concept is compatible with the new appreciation of platelets as immune cells and of neuronal damage driven by inflammatory cells sequestered in the meninges.

Sp3 ameliorated experimental autoimmune encephalomyelitis by triggering Socs3 in Th17 cells

INTRODUCTION

Although it is believed that chronic inflammatory and degenerative diseases of the central nervous system are mediated by autoimmune Th17 cells, the underlying mechanisms remain largely unexplored. Recent studies and our research have revealed that Sp3 was blocked in multiple sclerosis (MS) patients and experimental autoimmune encephalomyelitis (EAE). However, it remained unclear why it is silent and how it regulates Th17 cell differentiation in MS.

OBJECTIVES

This study aimed to explore the impact of Sp3 on Th17 cell-mediated EAE and the underlying mechanism.

METHODS

The effect of Sp3 on the clinical symptoms of EAE was evaluated by scoring, histochemistry, and fast blue (FB) techniques, scRNA-seq data analysis, flow cytometry, ELISA, PCR, WB, immunofluorescence and reporter gene techniques were used to explore the molecular mechanism of Sp3 regulating Th17 cell differentiation.

RESULTS

Injection of overexpression Sp3 lentivirus could significantly ameliorate the EAE progress and clinical symptoms and prevent the polarization of Th1 and Th17 cells both in vivo and in vitro. We confirmed the occurrence of EAE in Sp3+/+CD4Cre mice and Sp3+/- knockout mice. Furthermore, we identified Sp3 as a target of miR-223, which is found to be upregulated in the blood of MS patients, as well as in EAE and Th17 cells. Moreover, knockdown of miR-223 led to a marked improvement in EAE symptoms and a suppression of Th1 and Th17 cell polarization in vivo and in vitro. Mechanistically, Sp3 significantly suppressed RORγt expression and the phosphorylation of Stat3 and Smad2/3 by directly upregulating Socs3. Interestingly, Socs3 was found to regulate Sp3 expression in response to TGF-β1 via a feedback loop. Moreover, Socs3 modulated phospho-Smad2/3 by binding to and degrading the transforming growth factor-β receptor II (TβRII).

CONCLUSION

Thus, our study suggests a novel mechanism involving miR-223/Sp3/Socs3/TGF-β signaling as a potential therapeutic strategy for targeting Th17 cells in immunotherapy.

MRI-based morphometric structural changes correlate with histopathology in experimental autoimmune encephalomyelitis

BACKGROUND AND OBJECTIVES

Magnetic resonance imaging (MRI) and neurohistopathology are important correlates for evaluation of disease progression in multiple sclerosis (MS). Here we used experimental autoimmune encephalomyelitis (EAE) as an animal model of MS to determine the correlation between clinical EAE severity, MRI and histopathological parameters.

METHODS

N = 11 female C57BL/6J mice were immunized with human myelin oligodendrocyte glycoprotein 1-125, while N = 9 remained non-immunized. Mice were scanned longitudinally over a period of 13 weeks using a 11.7 Tesla (T) Bruker BioSpec® preclinical MRI instrument, and regional volume changes of the lumbar spinal cord were analyzed using Voxel-Guided Morphometry (VGM). Following the final in vivo T1-weighted MRI scan, the lumbar spinal cord of each mouse was subjected to an ex vivo MRI scan using T1-, T2*- and diffusion tensor imaging (DTI)-weighted sequences. Tissue sections were then stained for immune cell infiltration, demyelination, astrogliosis, and axonal damage using hematoxylin-eosin staining and immunohistochemistry.

RESULTS

While in vivo MRI VGM detected an overall increase in volume over time, no differences were observed between EAE animals and controls. Ex vivo MRI showed a generalized atrophy of the spinal cord, which was pronounced in the anterolateral tract. The most striking correlation was observed between EAE score, white matter atrophy in ex vivo T1-weighted scans and histological parameters.

DISCUSSION

The data demonstrate that ex vivo MRI is a valuable tool to assess white matter atrophy in EAE, which was shown to be directly linked to the severity of EAE and spinal cord histopathology.

TIA1-Mediated Stress Granules Promote the Neuroinflammation and Demyelination in Experimental Autoimmune Encephalomyelitis through Upregulating IL-31RA Signaling

The dysfunction of stress granules (SGs) plays a crucial role in the pathogenesis of various neurological disorders, with T cell intracellular antigen 1 (TIA1) being a key component of SGs. However, the role and mechanism of TIA1-mediated SGs in experimental autoimmune encephalomyelitis (EAE) remain unclear. In this study, upregulation of TIA1, its translocation from the nucleus to the cytoplasm, and co-localization with G3BP1 (a marker of SGs) are observed in the spinal cord neurons of EAE mice. Deletion of TIA1 in the CNS alleviates neuroinflammation, suppresses demyelination and axonal damage, and reduces neuronal loss in EAE mice. Furthermore, alleviation of autophagy dysfunction and reduction of chronic persistent SGs are observed in Tia1Nestin-CKO EAE mice. Mechanistically, IL-31RA levels are decreased in Tia1Nestin-CKO EAE mice, which inhibit the downstream PI3K/AKT signaling pathway associated with IL-31RA, thereby enhancing autophagy and suppressing the NF-κB signaling pathway, further alleviating EAE symptoms. Knockdown of TIA1 in primary neurons and N2a cells treated with sodium arsenite also reduces the formation of SGs. These findings reveal an unrecognized role of TIA1-mediated SGs in promoting neuroinflammation and demyelination, offering novel therapeutic targets for MS.

Comparison of practice-related changes in dual task walking performance and neural efficiency between older adults with progressive and relapsing-remitting multiple sclerosis

BACKGROUND

There is limited research comparing both performance and brain control of walking between older adults with progressive and relapsing-remitting MS.

OBJECTIVE

This study compared older adults with progressive and relapsing-remitting MS for differences in prefrontal cortex (PFC) activation in single- and dual-task-walking and practice-related effects on neural efficiency, walking, and cognitive performances.

METHODS

Older adults with progressive (n = 32, age=65±6ys) and relapsing-remitting (n = 63, age=65±4ys) MS completed three conditions (single-task walk, single-task-alpha, i.e., cognitive interference task, and dual-task-walk) with three repeated trials wherein we measured PFC oxygenated hemoglobin (HbO2), stride velocity and letter generation rate. Task, trial, and group effects and interactions were analyzed using linear mixed effects models.

RESULTS

The task-related (i.e. single-to-dual task walking) increase in PFC HbO2 was greater in progressive than in relapsing-remitting MS (p < 0.001), while the practice-related decrease in dual-task PFC HbO2 was smaller in progressive than in relapsing-remitting MS (p < 0.001). Progressive MS was associated with slower stride velocity overall, but repeated trials resulted in faster stride velocity and correct letter generation rate for both groups.

CONCLUSIONS

Practice-related improvements in cognitive and motor performances coupled with reduced PFC HbO2 over dual-task walking trials suggest attenuated improvements of efficiency in brain control of attention-demanding locomotion in progressive MS.

Matrine protects against experimental autoimmune encephalomyelitis through modulating microglial ferroptosis

Multiple sclerosis (MS) is an inflammatory demyelination neurodegenerative disease of the central nervous system (CNS). Ferroptosis has been implicated in a range of brain disorders, and iron-loaded microglia are frequently found in affected brain regions. However, the molecular mechanisms linking ferroptosis with MS have not been well-defined. The present study seeks to bridge this gap and investigate the impact of matrine (MAT), a herbal medicine with immunomodulatory capacities, on the regulation of oxidative stress and ferroptosis in the CNS of mice with experimental autoimmune encephalomyelitis (EAE), an animal model of MS. CNS of EAE mice contained elevated levels of ferroptosis-related molecules, e.g., MDA, LPCAT3 and PTGS2, but decreased expression of antioxidant molecules, including GSH and SOD, GPX4 and SLC7A11. This pathogenic process was reversed by MAT treatment, together with significant reduction of disease severity and CNS inflammatory demyelination. Furthermore, the expression of PTGS2 and LOX was largely increased in microglia of EAE mice, accompanied with increased production of IL-6 and TNF-α, indicating a proinflammatory phenotype of microglia that undergo oxidative stress/ferroptosis, and their expression was significantly reduced after MAT treatment. Together, our results indicate that ferroptosis/inflammation plays an important role in the pathogenesis of CNS autoimmunity, and inhibiting ferroptosis-induced microglial activation/inflammation could be a novel mechanism underlying the therapeutic effects of MAT on CNS inflammatory demyelination in EAE.

Should We Consider Neurodegeneration by Itself or in a Triangulation with Neuroinflammation and Demyelination? The Example of Multiple Sclerosis and Beyond

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.

BCL3, GBP1, IFI16, and CCR1 as potential brain-derived biomarkers for parietal grey matter lesions in multiple sclerosis

Multiple Sclerosis (MS) is a chronic autoimmune disease of the central nervous system, progressing from Relapsing-Remitting MS (RRMS) to Secondary Progressive MS (SPMS) in many cases. The transition involves complex biological changes. Our study aims to identify potential biomarkers for distinguishing SPMS by analyzing gene expression differences between normal-appearing and lesioned parietal grey matter, which may also contribute to understand the pathogenesis of SPMS. We utilized public datasets from the Gene Expression Omnibus (GEO), applying bioinformatics and machine learning techniques including Weighted Gene Co-expression Network Analysis (WGCNA), Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO) enrichment analysis, protein-protein interaction (PPI) networks, the Least Absolute Shrinkage and Selection Operator (LASSO), and Random Forest (RF) for predictive model construction. Our study also included analyses of immune cell infiltration. The study identified 359 DEGs, with 105 up-regulated and 254 down-regulated. WGCNA identified 264 common genes, which were subjected to KEGG and GO enrichment analyses, highlighting their role in immune response and viral infection pathways. Four genes (BCL3, GBP1, IFI16, and CCR1) were identified as key biomarkers for SPMS, supported by LASSO regression and RF analyses. These genes were further validated through receiver operating characteristic (ROC) curves, demonstrating significant predictive potential for SPMS. Our study provides a novel set of biomarkers for SPMS from lesioned grey matter of SPMS cases, offering potential for diagnosis and targeted therapeutic strategies. The identified biomarkers link closely with SPMS pathology, especially regarding immune system modulation.

Validation of a Set of Clinical Criteria for the Diagnosis of Secondary Progressive Multiple Sclerosis

Background/Objectives: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system characterized by progressive impairment of neuronal transmission due to focal demyelination. The most common form is RRMS (relapsing-remitting multiple sclerosis), which, under the influence of certain factors, can progress to SPMS (secondary progressive multiple sclerosis). Our study aimed to validate the criteria proposed by a working group of the Romanian Society of Neurology versus the criteria proposed by a group of experts from Spain, Karolinska, and Croatia concerning the progression from RRMS to SPMS. Methods: This was done by gathering epidemiological data (age, gender) and by applying clinical tests such as the 9HPT (9-hole peg test), 25FWT (25-foot walk test), and EDSS (expanded disability status scale) tests and the SDMT test (symbol digit modalities test). The present research is a cohort study that included a number of 120 patients diagnosed with MS according to the McDonald Diagnostic Criteria 2017. The study was carried out between January 2023 and April 2024, including patients hospitalized in the Neurology Clinic of the Clinical Rehabilitation Hospital from Iasi, Romania. The data were collected at baseline (T0) and at a 12-month interval (T1). Results: The statistical analysis was conducted using Kaiser-Meyer-Olkin analysis, which indicated a value of 0.683, thus validating the clinical tests used. The correlation matrix and the linear regression for all the tests showed highly significant statistical results. Furthermore, the ROC curve analysis of the criteria suggested by the working group of the Romanian Society of Neurology demonstrated that the EDSS, 9HPT, and 25FWT are highly sensitive in diagnosing SPMS, an opinion that is shared with the Spanish experts, but not with the Karolinska expert panel. Using the criteria given by the Croatian expert group in the ROC curve analysis showed that only the EDSS was strongly significant for the progression to the SPMS phase. Conclusions: In conclusion, all clinical methods used demonstrated that they are valid and can contribute to identifying patients with an increased risk of progression. The model proposed by the Romanian Society of Neurology working group is similar to other countries' expert opinions and can be used to detect the risk of disease progression and establish a more tailored therapeutic management of SPMS.

Patient iPSC models reveal glia-intrinsic phenotypes in multiple sclerosis

Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease of the central nervous system (CNS), resulting in neurological disability that worsens over time. While progress has been made in defining the immune system's role in MS pathophysiology, the contribution of intrinsic CNS cell dysfunction remains unclear. Here, we generated a collection of induced pluripotent stem cell (iPSC) lines from people with MS spanning diverse clinical subtypes and differentiated them into glia-enriched cultures. Using single-cell transcriptomic profiling and orthogonal analyses, we observed several distinguishing characteristics of MS cultures pointing to glia-intrinsic disease mechanisms. We found that primary progressive MS-derived cultures contained fewer oligodendrocytes. Moreover, MS-derived oligodendrocyte lineage cells and astrocytes showed increased expression of immune and inflammatory genes, matching those of glia from MS postmortem brains. Thus, iPSC-derived MS models provide a unique platform for dissecting glial contributions to disease phenotypes independent of the peripheral immune system and identify potential glia-specific targets for therapeutic intervention.

Type 2 diabetes mellitus and neurodegenerative disorders: The mitochondrial connection

The incidence of type 2 diabetes mellitus (T2DM) has increased in our society in recent decades as the population ages, and this trend is not expected to revert. This is the same for the incidence of the main neurodegenerative disorders, including the two most common ones, which are, Alzheimer's and Parkinson's disease. Currently, no pharmacological therapies have been developed to revert or cure any of these pathologies. Interestingly, in recent years, an increased number of studies have shown a high co-morbidity between T2DM and neurodegeneration, as well as some common molecular pathways that are affected in both types of diseases. For example, while the etiopathology of T2DM and neurodegenerative disorders is highly complex, mitochondrial dysfunction has been broadly described in the early steps of both diseases; accordingly, this dysfunction has emerged as a plausible molecular link between them. In fact, the prominent role played by mitochondria in the mammalian metabolism of glucose places the physiology of the organelle in a central position to regulate many cellular processes that are affected in both T2DM and neurodegenerative disorders. In this collaborative review, we critically describe the relationship between T2DM and neurodegeneration; making a special emphasis on the mitochondrial mechanisms that could link these diseases. A better understanding of the role of mitochondria on the etiopathology of T2DM and neurodegeneration could pave the way for the development of new pharmacological therapies focused on the regulation of the physiology of the organelle. These therapies could, ultimately, contribute to increase healthspan.

Targeting ferroptosis in autoimmune diseases: Mechanisms and therapeutic prospects

Ferroptosis is a form of regulated cell death that relies on iron and exhibits unique characteristics, including disrupted iron balance, reduced antioxidant defenses, and abnormal lipid peroxidation. Recent research suggests that ferroptosis is associated with the onset and progression of autoimmune disorders such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), inflammatory bowel disease (IBD), and multiple sclerosis (MS). However, the precise effects and molecular mechanisms remain incompletely understood. This article presents an overview of how ferroptosis mechanisms contribute to the development and advancement of autoimmune diseases, as well as the involvement of various immune cells in linking ferroptosis to autoimmune conditions. It also explores potential drug targets within the ferroptosis pathway and recent advancements in therapeutic approaches aimed at preventing and treating autoimmune diseases by targeting ferroptosis. Lastly, the article discusses the challenges and opportunities in utilizing ferroptosis as a potential therapeutic avenue for autoimmune disorders.

Tyzzerella nexilis strains enriched in mobile genetic elements are involved in progressive multiple sclerosis

Multiple sclerosis (MS) is an autoimmune-demyelinating disease with an inflammatory pathology formed by self-reactive lymphocytes with activated glial cells. Progressive MS, characterized by resistance to medications, significantly differs from the non-progressive form in gut microbiome profiles. After confirming an increased abundance of "Tyzzerella nexilis" in various cohorts of progressive MS, we identified a distinct cluster of T. nexilis strains enriched in progressive MS based on long-read metagenomics. The distinct T. nexilis cluster is characterized by a large number of mobile genetic elements (MGEs) and a lack of defense systems against MGEs. Microbial genes for sulfate reduction and flagella formation with pathogenic implications are specific to this cluster. Moreover, these flagellar genes are encoded on MGEs. Mono-colonization with MGE-enriched T. nexilis made germ-free mice more susceptible to experimental autoimmune encephalomyelitis. These results indicate that the progression of MS may be promoted by MGE-enriched T. nexilis with potentially pathogenic properties.

Advanced MRI Measures of Myelin and Axon Volume Identify Repair in Multiple Sclerosis

OBJECTIVE

Pathological studies suggest that multiple sclerosis (MS) lesions endure multiple waves of damage and repair; however, the dynamics and characteristics of these processes are poorly understood in patients living with MS.

METHODS

We studied 128 MS patients (75 relapsing-remitting, 53 progressive) and 72 healthy controls who underwent advanced magnetic resonance imaging and clinical examination at baseline and 2 years later. Magnetization transfer saturation and multi-shell diffusion imaging were used to quantify longitudinal changes in myelin and axon volumes within MS lesions. Lesions were grouped into 4 classes (repair, damage, mixed repair damage, and stable). The frequency of each class was correlated to clinical measures, demographic characteristics, and levels of serum neurofilament light chain (sNfL).

RESULTS

Stable lesions were the most frequent (n = 2,276; 44%), followed by lesions with patterns of "repair" (n = 1,352; 26.2%) and damage (n = 1,214; 23.5%). The frequency of "repair" lesion was negatively associated with disability (β = -0.04; p < 0.001) and sNfL (β = -0.16; p < 0.001) at follow-up. The frequency of the "damage" class was higher in progressive than relapsing-remitting patients (p < 0.05) and was related to disability (baseline: β = -0.078; follow-up: β = -0.076; p < 0.001) and age (baseline: β = -0.078; p < 0.001). Stable lesions were more frequent in relapsing-remitting than in progressive patients (p < 0.05), and in younger patients versus older (β = -0.07; p < 0.001) at baseline. Further, "mixed" lesions were most frequent in older patients (β = 0.004; p < 0.001) at baseline.

INTERPRETATION

These findings show that repair and damage processes within MS lesions occur across the entire disease spectrum and that their frequency correlates with patients disability, age, disease duration, and extent of neuroaxonal damage. ANN NEUROL 2024.

An overview on disease modifying and symptomatic drug treatments for multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is an inflammatory and degenerative autoimmune condition, resulting frequently in a disabling condition. Significant improvements of long-term prognosis have been recently achieved with an early and more aggressive use of disease modifying therapies (DMTs). Addressing the complexity of managing its progressive forms remains a significant challenge.

AREAS COVERED

This review provides an update on DMTs for relapsing-remitting MS (RRMS) and progressive MS and their efficacy, safety, and mechanism of action, emphasizing the critical role of biomarkers in optimizing treatment decisions. Moreover, some key information on drugs used to manage symptoms such as pain, fatigue, spasticity and urinary problems will be provided. The literature search was conducted using PubMed, Embase, and Cochrane Library databases covering the period from January 2000 to January 2024.

EXPERT OPINION

Major advances have been achieved in the treatment of RRMS. Treatment should start immediately as soon as the neurologist is confident with the diagnosis and its choice should be based on the prognostic profile and on the patient's propensity to accept drug-related risks. The therapeutic landscape for progressive MS is quite disappointing and necessitates further innovation. Personalized medicine, leveraging biomarker insights, holds promise for refining treatment efficacy and patient outcomes.

Hospital-Treated Infections and Risk of Disability Worsening in Multiple Sclerosis

OBJECTIVE

To investigate the association between infections and disability worsening in people with multiple sclerosis (MS) treated with either B-cell depleting therapy (rituximab) or interferon-beta/glatiramer acetate (IFN/GA).

METHODS

This cohort study spanned from 2000 to 2021, using data from the Swedish MS Registry linked to national health care registries, comprising 8,759 rituximab and 7,561 IFN/GA treatment episodes. The risk of hospital-treated infection was estimated using multivariable Cox models. The association between infections and increase in Expanded Disability Status Scale (EDSS) scores was assessed using a doubly robust generalized estimating equations model. Additionally, a piece-wise exponential model analyzed events of increased disability beyond defined cut-off values, controlling for relapses, and MRI activity.

RESULTS

Compared with IFN/GA, rituximab displayed increased risk of both inpatient- and outpatient-treated infections (hazard ratio [HR], 2.08; 95% confidence interval [CI], 1.50-2.90 and HR, 1.37; 95% CI, 1.13-1.67, respectively). An inpatient-treated infection was associated with a 0.19-unit increase in EDSS (95% CI, 0.12-0.26). Degree of worsening was greatest for progressive MS, and under IFN/GA treatment, which unlike rituximab, was more commonly associated with MRI activity. After controlling for relapses and MRI activity, inpatient-treated infections were associated with disability worsening in people with relapsing-remitting MS treated with IFN/GA (HR, 2.01; 95% CI, 1.59-2.53), but not in those treated with rituximab.

INTERPRETATION

Compared to IFN/GA, rituximab doubled the infection risk, but reduced the risk of subsequent disability worsening. Further, the risk of worsening after hospital-treated infection was greater with progressive MS than with relapsing-remitting MS. Infection risk should be considered to improve long term outcomes. ANN NEUROL 2024;96:694-703.

Biomarkers of tau phosphorylation state are associated with the clinical course of multiple sclerosis

BACKGROUND

Mechanisms underlying neurodegeneration in multiple sclerosis (MS) remain poorly understood but mostly implicate molecular pathways that are not unique to MS. Recently detected tau seeding activity in MS brain tissues corroborates previous neuropathological reports of hyperphosphorylated tau (p-tau) accumulation in secondary and primary progressive MS (PPMS). We aimed to investigate whether aberrant tau phosphorylation can be detected in the cerebrospinal fluid (CSF) of MS patients by using novel ultrasensitive immunoassays for different p-tau biomarkers.

METHODS

CSF samples of patients with MS (n = 55) and non-inflammatory neurological disorders (NIND, n = 31) were analysed with in-house Single molecule array (Simoa) assays targeting different tau phosphorylation sites (p-tau181, p-tau212, p-tau217 and p-tau231). Additionally, neurofilament light (NFL) and glial fibrillary acidic protein (GFAP) were measured with a multiplexed Simoa assay. Patients were diagnosed with clinically isolated syndrome (CIS, n = 10), relapsing-remitting MS (RRMS, n = 21) and PPMS (n = 24) according to the 2017 McDonald criteria and had MRI, EDSS and basic CSF analysis performed at the time of diagnosis.

RESULTS

Patients with progressive disease course had between 1.4-fold (p-tau217) and 2.2-fold (p-tau212) higher p-tau levels than relapsing MS patients (PPMS compared with CIS + RRMS, p < 0.001 for p-tau181, p-tau212, p-tau231 and p = 0.042 for p-tau217). P-tau biomarkers were associated with disease duration (ρ=0.466-0.622, p < 0.0001), age (ρ=0.318-0.485, p < 0.02, all but p-tau217) and EDSS at diagnosis and follow-up (ρ=0.309-0.440, p < 0.02). In addition, p-tau biomarkers correlated with GFAP (ρ=0.517-0.719, p ≤ 0.0001) but not with the albumin quotient, CSF cell count or NFL. Patients with higher MRI lesion load also had higher p-tau levels p ≤ 0.01 (<10 vs. ≥ 10 lesions, all p ≤ 0.01).

CONCLUSION

CSF concentrations of novel p-tau biomarkers point to a higher degree of tau phosphorylation in PPMS than in RRMS. Associations with age, disease duration and EDSS suggest this process increases with disease severity; however, replication of these results in larger cohorts is needed to further clarify the relevance of altered tau phosphorylation throughout the disease course in MS.

Impact of oral melatonin supplementation on urine and serum melatonin concentrations and quality-of-life measures in persons with relapsing multiple sclerosis

INTRODUCTION

Melatonin is an antioxidant and anti-inflammatory agent that modulates the immune system by scavenging free radicals, reducing the upregulation of pro-inflammatory cytokines, and reducing transendothelial cell migration. Therefore, melatonin may play a role in regulating multiple sclerosis (MS) disease activity. However, little is known about how melatonin supplementation effects individuals with MS.

OBJECTIVE

Determine if there was a dose-dependent elevation in urine and serum melatonin concentrations. Determine if melatonin supplementation had an impact on patient reported outcomes.

METHODS

This was a randomized, dose-blinded exploratory study. Adults (age 18-65) with relapsing forms of multiple sclerosis (RMS) treated with a stable dose of oral disease modifying therapy for at least 6 months were randomized into melatonin 3 mg or 5 mg daily. Urinary and serum melatonin levels and modified fatigue impact scale (MFIS), multiple sclerosis impact scale (MSIS-29), and Pittsburgh sleep quality index (PSQI), patient determined disease steps (PDDS) and performance scales (PS) were measured at baseline, 3, 6, and 12 months. Urinary and serum melatonin analyses was performed to estimate mean concentrations and their differences between treatment arms over time by a repeated measures linear mixed model. The model included treatment, assessment time, and treatment × time interaction.

RESULTS

Thirty patients, randomized 1:1, were analyzed in an intent to treat population. Twenty-three completed the study. The repeated measures linear mixed model analysis of all timepoints revealed higher melatonin concentrations in patients on 5 mg compared to 3 mg melatonin for both urinary 6-SMT (p = 0.03) and serum melatonin (p = 0.04). MFIS, MSIS-29, PSQI, and PDSS-PS scores did not significantly change from baseline to month 12. No significant differences in these measures were seen between the two doses. Five patients stopped melatonin (three on 5 mg and two on 3 mg) due to adverse events, including one patient who developed focal spongiotic dermatitis. One patient experienced three consecutive serious adverse events that were unrelated to melatonin supplementation.

CONCLUSIONS

The 5 mg melatonin supplementation group had higher concentrations of urinary 6-SMT and serum melatonin compared to the 3 mg group over 12 months of treatment. There was a correlation between 6-SMT and serum melatonin concentrations. This suggests that measuring serum melatonin is a reliable alternative to measuring urinary 6-SMT. However, no differences in clinical benefit between the two dosage groups were demonstrated in the patient reported outcomes.

TRIAL REGISTRATION NUMBER

NCT03498131.

Unveiling microglia heterogeneity in intracerebral hemorrhage

Microglia are important innate immune cells in the brain, and a rich diversity of subtypes has recently been discovered that expand beyond the traditional classification of traditional M1 (pro-inflammatory) and M2 (anti-inflammatory) classifications. Intracerebral hemorrhage (ICH) is a devastating form of stroke, and the understanding of its later-stage pathological mechanisms remains incomplete. In this study, through the analysis of single-cell transcripts from mice brains 14 days post-ICH, three disease-associated expression patterns of microglia were identified. These include a lipid metabolism and phagocytosis phenotype reminiscent of Disease-Associated Microglia (DAM) initially discovered in Alzheimer's disease models, a phenotype associated with angiogenesis, and a relatively independent phenotype similar to the pro-inflammatory M1 state. These findings were further validated through immunofluorescence in both mouse and human specimens. In addition, analysis of single-cell transcripts from mice brains 3 days post-ICH suggested that microglia involved in lipid metabolism and phagocytosis likely emerge from early proliferating populations. Given the distinct origins and phenotypic characteristics of pro-inflammatory and reparative microglia, interventions targeting these cells hold the potential to modulate the delicate balance between injury and repair during the pathophysiological process of ICH, highlighting a pivotal direction for future therapeutic strategies.

Immunomodulators and immunosuppressants for progressive multiple sclerosis: a network meta-analysis

BACKGROUND

In recent years a broader range of immunomodulatory and immunosuppressive treatment options have emerged for people with progressive forms of multiple sclerosis (PMS). While consensus supports these options as reducing relapses, their relative benefit and safety profiles remain unclear due to a lack of direct comparison trials.

OBJECTIVES

To compare through network meta-analysis the efficacy and safety of alemtuzumab, azathioprine, cladribine, cyclophosphamide, daclizumab, dimethylfumarate, diroximel fumarate, fingolimod, fludarabine, glatiramer acetate, immunoglobulins, interferon beta 1-a and beta 1-b, interferon beta-1b (Betaferon), interferon beta-1a (Avonex, Rebif), laquinimod, leflunomide, methotrexate, minocycline, mitoxantrone, mycophenolate mofetil, natalizumab, ocrelizumab, ofatumumab, ozanimod, pegylated interferon beta-1a, ponesimod, rituximab, siponimod, corticosteroids, and teriflunomide for PMS.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase up to August 2022, as well as ClinicalTrials.gov and the WHO ICTRP.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that studied one or more treatments as monotherapy, compared to placebo or to another active agent, for use in adults with PMS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. We performed data synthesis by pair-wise and network meta-analysis. We assessed the certainty of the body of evidence according to GRADE.

MAIN RESULTS

We included 23 studies involving a total of 10,167 participants. The most frequent (39% of studies) reason for a rating of high risk of bias was sponsor role in study authorship and data management and analysis. Other concerns were performance, attrition, and selective reporting bias, with 8.7% of studies at high risk of bias for all three of these domains. The common comparator for network analysis was placebo. Relapses over 12 months: assessed in one study (318 participants). None of the treatments assessed showed moderate or high certainty evidence compared to placebo. Relapses over 24 months: assessed in six studies (1622 participants). The number of people with clinical relapses is probably trivially reduced with rituximab (risk ratio (RR) 0.60, 95% confidence interval (CI) 0.19 to 1.95; moderate certainty evidence). None of the remaining treatments assessed showed moderate or high certainty evidence compared to placebo. Relapses over 36 months: assessed in four studies (2095 participants). The number of people with clinical relapses is probably trivially reduced with interferon beta-1b (RR 0.82, 95% CI 0.73 to 0.93; moderate certainty evidence). None of the remaining treatments assessed showed moderate or high certainty evidence compared to placebo. Disability worsening over 24 months: assessed in 11 studies (5284 participants). None of the treatments assessed showed moderate or high certainty evidence compared to placebo. Disability worsening over 36 months: assessed in five studies (2827 participants). None of the treatments assessed showed moderate or high certainty evidence compared to placebo. Serious adverse events: assessed in 15 studies (8019 participants). None of the treatments assessed showed moderate or high certainty evidence compared to placebo. Discontinuation due to adverse events: assessed in 21 studies (9981 participants). The number of people who discontinued treatment due to adverse events is trivially increased with interferon beta-1a (odds ratio (OR) 2.93, 95% CI 1.64 to 5.26; high certainty evidence). The number of people who discontinued treatment due to adverse events is probably trivially increased with rituximab (OR 4.00, 95% CI 0.84 to 19.12; moderate certainty evidence); interferon beta-1b (OR 2.98, 95% CI 1.92 to 4.61; moderate certainty evidence); immunoglobulins (OR 1.95, 95% CI 0.99 to 3.84; moderate certainty evidence); glatiramer acetate (OR 3.98, 95% CI 1.48 to 10.72; moderate certainty evidence); natalizumab (OR 1.02, 95% CI 0.55 to 1.90; moderate certainty evidence); siponimod (OR 1.53, 95% CI 0.98 to 2.38; moderate certainty evidence); fingolimod (OR 2.29, 95% CI 1.46 to 3.60; moderate certainty evidence), and ocrelizumab (OR 1.24, 95% CI 0.54 to 2.86; moderate certainty evidence). None of the remaining treatments assessed showed moderate or high certainty evidence compared to placebo.

AUTHORS' CONCLUSIONS

The number of people with PMS with relapses is probably slightly reduced with rituximab at two years, and interferon beta-1b at three years, compared to placebo. Both drugs are also probably associated with a slightly higher proportion of withdrawals due to adverse events, as are immunoglobulins, glatiramer acetate, natalizumab, fingolimod, siponimod, and ocrelizumab; we have high confidence that this is the case with interferon beta-1a. We found only low or very low certainty evidence relating to disability progression for the included disease-modifying treatments compared to placebo, largely due to imprecision. We are also uncertain about the effect of interventions on serious adverse events, also because of imprecision. These findings are due in part to the short follow-up of the included RCTs, which lacked detection of less common severe adverse events. Moreover, the funding source of many included studies may have introduced bias into the results. Future research on PMS should include head-to-head rather than placebo-controlled trials, with a longer follow-up of at least three years. Given the relative rarity of PMS, controlled, non-randomised studies on large samples may usefully integrate data from pivotal RCTs. Outcomes valuable and meaningful to people with PMS should be consistently adopted and measured to permit the evaluation of relative effectiveness among treatments.

Can Selected Parameters of Brain Injury Reflect Neuronal Damage in Smoldering Multiple Sclerosis?

BACKGROUND

Inflammatory demyelination and impaired recovery processes result in permanent neurodegeneration and neurological disability in patients with multiple sclerosis (MS). In terms of smoldering MS, chronic neuroinflammation develops in the early period of the disease and leads to confirmed disability accumulation. There is a great need to identify biomarkers of neurodegeneration and disease progression.

METHODS

A single-center prospective observational study was performed. The median age of the patients was 40 (31-52) years. Women comprised 64% of the study population. We evaluated the concentrations of the parameters of brain injury (NF-H, GFAP, S100B and UCHL1) in the cerebrospinal fluid (CSF) and the selected interleukins (ILs) in serum of 123 relapsing-remitting MS (RRMS) and 88 progressive MS (PMS) patients.

RESULTS

The levels of GFAP, S100B and UCHL were higher in the PMS group than the RRMS group, in contrast to the levels of NF-H. We observed a positive correlation between the selected pro-inflammatory cytokines and the parameters of brain injury. The Expanded Disability Status Scale (EDSS) score increased with GFAP and NF-H levels and was correlated with the selected ILs. The concentrations of S100B, UCHL1 and NF-H reflected the duration of MS symptoms.

CONCLUSIONS

The levels of brain injury parameters in the CSF and the selected serum ILs in MS patients seem to be promising biomarkers to determine neurodegeneration and neuroinflammation in smoldering MS. Further studies are warranted in this respect.

De-escalation and Discontinuation of Disease-Modifying Therapies in Multiple Sclerosis

PURPOSE OF REVIEW

Long-term use of multiple sclerosis (MS) disease-modifying therapies (DMTs) is standard practice to prevent accumulation of disability. Immunosenescence and other age-related changes lead to an altered risk-benefit ratio for older patients on DMTs. This article reviews recent research on the topic of de-escalation and discontinuation of MS DMTs.

RECENT FINDINGS

Observational and interventional studies have shed light on what happens to patients who de-escalate or discontinue DMTs and the factors, such as age, treatment type, and presence of recent disease activity, that influence outcomes. Though many questions remain, recent findings have been valuable for the development of an evidence-based approach to making de-escalation and discontinuation decisions in MS.

Senescence- and Immunity-Related Changes in the Central Nervous System: A Comprehensive Review

Senescence is a cellular state characterized by an irreversible halt in the cell cycle, accompanied by alterations in cell morphology, function, and secretion. Senescent cells release a plethora of inflammatory and growth factors, extracellular matrix proteins, and other bioactive substances, collectively known as the senescence-associated secretory phenotype (SASP). These excreted substances serve as crucial mediators of senescent tissues, while the secretion of SASP by senescent neurons and glial cells in the central nervous system modulates the activity of immune cells. Senescent immune cells also influence the physiological activities of various cells in the central nervous system. Further, the interaction between cellular senescence and immune regulation collectively affects the physiological and pathological processes of the central nervous system. Herein, we explore the role of senescence in the physiological and pathological processes underlying embryonic development, aging, degeneration, and injury of the central nervous system, through the immune response. Further, we elucidate the role of senescence in the physiological and pathological processes of the central nervous system, proposing a new theoretical foundation for treating central nervous system diseases.

Myosin superfamily members during myelin formation and regeneration

Myelin is an insulator that forms around axons that enhance the conduction velocity of nerve fibers. Oligodendrocytes dramatically change cell morphology to produce myelin throughout the central nervous system (CNS). Cytoskeletal alterations are critical for the morphogenesis of oligodendrocytes, and actin is involved in cell differentiation and myelin wrapping via polymerization and depolymerization, respectively. Various protein members of the myosin superfamily are known to be major binding partners of actin filaments and have been intensively researched because of their involvement in various cellular functions, including differentiation, cell movement, membrane trafficking, organelle transport, signal transduction, and morphogenesis. Some members of the myosin superfamily have been found to play important roles in the differentiation of oligodendrocytes and in CNS myelination. Interestingly, each member of the myosin superfamily expressed in oligodendrocyte lineage cells also shows specific spatial and temporal expression patterns and different distributions. In this review, we summarize previous findings related to the myosin superfamily and discuss how these molecules contribute to myelin formation and regeneration by oligodendrocytes.

Extracellular vesicle therapy in neurological disorders

Extracellular vesicles (EVs) are vital for cell-to-cell communication, transferring proteins, lipids, and nucleic acids in various physiological and pathological processes. They play crucial roles in immune modulation and tissue regeneration but are also involved in pathogenic conditions like inflammation and degenerative disorders. EVs have heterogeneous populations and cargo, with numerous subpopulations currently under investigations. EV therapy shows promise in stimulating tissue repair and serving as a drug delivery vehicle, offering advantages over cell therapy, such as ease of engineering and minimal risk of tumorigenesis. However, challenges remain, including inconsistent nomenclature, complex characterization, and underdeveloped large-scale production protocols. This review highlights the recent advances and significance of EVs heterogeneity, emphasizing the need for a better understanding of their roles in disease pathologies to develop tailored EV therapies for clinical applications in neurological disorders.

Contrast-Enhancing Lesion Segmentation in Multiple Sclerosis: A Deep Learning Approach Validated in a Multicentric Cohort

The detection of contrast-enhancing lesions (CELs) is fundamental for the diagnosis and monitoring of patients with multiple sclerosis (MS). This task is time-consuming and suffers from high intra- and inter-rater variability in clinical practice. However, only a few studies proposed automatic approaches for CEL detection. This study aimed to develop a deep learning model that automatically detects and segments CELs in clinical Magnetic Resonance Imaging (MRI) scans. A 3D UNet-based network was trained with clinical MRI from the Swiss Multiple Sclerosis Cohort. The dataset comprised 372 scans from 280 MS patients: 162 showed at least one CEL, while 118 showed no CELs. The input dataset consisted of T1-weighted before and after gadolinium injection, and FLuid Attenuated Inversion Recovery images. The sampling strategy was based on a white matter lesion mask to confirm the existence of real contrast-enhancing lesions. To overcome the dataset imbalance, a weighted loss function was implemented. The Dice Score Coefficient and True Positive and False Positive Rates were 0.76, 0.93, and 0.02, respectively. Based on these results, the model developed in this study might well be considered for clinical decision support.

SARS-CoV-2 Vaccination Responses in Anti-CD20-Treated Progressive Multiple Sclerosis Patients Show Immunosenescence in Antigen-Specific B and T Cells

Clinical, pathological, and imaging evidence in multiple sclerosis (MS) shows that inflammation starts early and progresses with age. B cells play a central role in this process, contributing to cytokine production, defective regulatory functions, and abnormal immunoglobulin production, even in the central nervous system. Anti-CD20 (aCD20) therapies, which deplete CD20+ B cells, are largely used in the treatment of both relapsing remitting (RR) and progressive (PR) forms of MS. Although effective against MS symptoms and lesions detectable by magnetic resonance imaging, aCD20 therapies can reduce the immune response to COVID-19 vaccination. By using high-parameter flow cytometry, we examined the antigen-specific (Ag+) immune response six months post-third COVID-19 mRNA vaccination in MS patients with RR and PR forms on aCD20 therapy. Despite lower Ag+ B cell responses and lower levels of anti-SARS-CoV2, both total and neutralizing antibodies, RR and PR patients developed strong Ag+ T cell responses. We observed similar percentages and numbers of Ag+ CD4+ T cells and a high proportion of Ag+ CD8+ T cells, with slight differences in T cell phenotype and functionality; this, however, suggested the presence of differences in immune responses driven by age and disease severity.

A Comprehensive Examination of the Role of Epigenetic Factors in Multiple Sclerosis

According to various research, the risk of multiple sclerosis (MS) is strongly influenced by genetic variations. Population, familial, and molecular studies provide strong empirical support for a polygenic pattern of inheritance, mainly due to relatively common allelic variants in the general population. The strongest MS susceptibility locus, which was unmistakably identified in tested populations, is the major histocompatibility complex on chromosome 6p21.3. However, the effect of a given predisposing variant remains modest, so there is the possibility that multiple gene-gene and/or gene-environment interactions could significantly increase the contribution of specific variants to the overall genetic risk. Furthermore, as is known, susceptibility genes can be subject to epigenetic modifications, which greatly increase the complexity of MS heritability. Investigating epigenetic and environmental factors can provide new opportunities for the molecular basis of the MS, which shows complicated pathogenesis. Although studies of epigenetic changes in MS only began in the last decade, a growing body of literature suggests that these may be involved in the development of MS. Here, we summarize recent studies regarding epigenetic changes related to MS initiation and progression. Furthermore, we discuss how current studies address important clinical questions and how future studies could be used in clinical practice.

Cortical CD200-CD200R and CD47-SIRPα expression is associated with multiple sclerosis pathology

Control of microglia activity through CD200-CD200R and CD47-SIRPα interactions has been implicated in brain homeostasis. Here, we assessed CD200, CD47, CD200R and SIRPα expression with qPCR and immunohistochemistry in multiple sclerosis (MS) normal-appearing cortical grey matter (NAGM), normal-appearing white matter (NAWM), cortical grey matter (GM) lesions and perilesional GM, and compared this to control GM and white matter (WM), to investigate possible altered control of microglia in MS. In MS NAGM, CD200 expression is lower compared with control GM, specifically in cortical layers 1 and 2, and CD200 expression in NAGM negatively correlates with the cortical lesion rate. Interestingly, NAGM and NAWM CD200 expression is positively correlated, and NAGM CD200 expression negatively correlates with the proportion of active and mixed WM lesions. In GM lesions, CD200 and CD47 expressions are lower compared with NAGM and perilesional GM. CD200R expression is lower in MS NAGM, whereas SIRPα was increased in and around GM lesions. Taken together, our data indicate that CD200 and CD47 play a role in GM MS lesion formation and progression, respectively, and that targeting CD200 pathways may offer therapeutic avenues to mitigate MS pathology in both WM and GM.

A systematic review and meta-analysis of Dietary Inflammatory Index and the likelihood of multiple sclerosis/ demyelinating autoimmune disease

Diet and inflammation may contribute to the development of multiple sclerosis (MS). The aim of this systematic review and meta-analysis was to assess the association between proinflammatory diet, as estimated by the Dietary Inflammatory Index (DII®), and the likelihood of developing MS or other demyelinating autoimmune diseases. A systematic search was performed of search engines and databases (PubMed, ISI Web of Sciences, Scopus, and Embase) to identify relevant studies before 10th June 2023. The search identified 182 potential studies, from which 39 full-text articles were screened for relevance. Five articles with case-control design (n = 4,322, intervention group: 1714; control group: 2608) met the study inclusion criteria. The exposure variable was DII, with studies using two distinct models: quartile-based comparisons of DII and assessment of continuous DII. The meta-analysis of high versus low quartiles of DII with four effect sizes showed a significant association with MS/demyelinating autoimmune disease likelihood, with an odds ratio (OR) of 3.26 (95% confidence interval (CI) 1.16, 9.10). The meta-analysis of four studies with DII fit as a continuous variable showed a 31% increased likelihood of MS per unit increment; which was not statistically significant at the nominal alpha equals 0.05 (OR 1.31; 95% CI 0.95, 1.81). In conclusion, this systematic review and meta-analysis provides evidence of a positive association between higher DII scores with the likelihood of developing MS, highlighting that diet-induced inflammation could play a role in MS or other demyelinating autoimmune diseases risk.

Association of Clinical Relapses With Disease Outcomes in Multiple Sclerosis Patients Older Than 50 Years

BACKGROUND AND OBJECTIVES

Relapse and MRI activity usually decline with aging but are replaced by progression independent of relapse activity (PIRA) in patients with multiple sclerosis (PwMS). However, several older PwMS continue to experience clinical relapses, and the impact on their disease remains undetermined. We aimed to determine the impact of an index relapse on disease outcomes in patients older than 50 years and to identify risk factors of disadvantageous outcomes.

METHODS

We performed a secondary analysis from 3 prospective cohorts in Germany. We evaluated all PwMS 50 years and older with a relapse ≤60 days before a baseline visit and at least 18 months of follow-up compared with a control cohort of PwMS without a relapse. Patients were stratified according to age ("50-54" vs "55-59" vs "60+") or disease outcomes ("stable" vs "active" vs "progressive," according to the Lublin criteria). We analyzed relapses, MRI activity, relapse-associated worsening, and PIRA. Regression analysis was performed to evaluate the association of specific baseline risk factors and treatment regimen changes with disease outcomes at month 18.

RESULTS

A total of 681 patients were included in the "relapse cohort" (50+: 361; 55+: 220; 60+: 100). The "control cohort" comprised 232 patients (50+: 117; 55+: 71; 60+: 44). Baseline epidemiologic parameters were balanced among cohorts and subgroups. We observed increased abundance of inflammatory activity and relapse-independent disability progression in the "relapse" vs "control" cohort. In the "relapse" cohort, we identified 273 patients as "stable" (59.7%), 114 patients as "active" (24.9%), and 70 patients as "progressive" (15.3%) during follow-up. Cardiovascular risk factors (CVRFs) and older age at baseline were identified as risk factors of progressive, whereas disease-modifying treatment (DMT) administration at baseline favored stable disease. DMT during follow-up was associated with stable over active, but not over progressive disease.

DISCUSSION

A relapse-suggesting underlying active disease-in PwMS older than 50 years was associated with continued disease activity and increased risk of PIRA. Presence of CVRF and absence of DMT at baseline appeared as risk factors of disadvantageous disease courses. An escalation of DMT switch was associated with stable over active but not progressive disease.

Coffee and multiple sclerosis (MS)

Multiple Sclerosis (MS) is a long-term autoimmune disorder affecting the central nervous system, marked by inflammation, demyelination, and neurodegeneration. While the exact cause of MS remains unknown, recent research indicates that environmental factors, particularly diet, may influence the disease's risk and progression. As a result, the potential neuroprotective effects of coffee, one of the most popular beverages worldwide, have garnered significant attention due to its rich content of bioactive compounds. This chapter explores the impact of coffee consumption on patients with Multiple Sclerosis, highlighting how coffee compounds like caffeine, polyphenols, and diterpenes can reduce inflammation and oxidative stress while enhancing neural function. It highlights caffeine's effect in regulating adenosine receptors, specifically A1R and A2AR, which play important roles in neuroinflammation and neuroprotection in MS. The dual role of microglial cells, which promote inflammation while also aiding neuroprotection, is also highlighted concerning caffeine's effects. Furthermore, the potential of A2AR as a therapeutic target in MS and the non-A2AR-dependent neuroprotective benefits of coffee. In this chapter we suggest that the consumption of coffee has no harmful effect on an MS patient and to a larger extent on public health, and informs future research directions and clinical practice, ultimately improving outcomes for individuals living with MS.

The interplay of inflammation and remyelination: rethinking MS treatment with a focus on oligodendrocyte progenitor cells

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.

Chemokine CX3CL1 (Fractalkine) Signaling and Diabetic Encephalopathy

Diabetes mellitus (DM) is the most common metabolic disease in humans, and its prevalence is increasing worldwide in parallel with the obesity pandemic. A lack of insulin or insulin resistance, and consequently hyperglycemia, leads to many systemic disorders, among which diabetic encephalopathy (DE) is a long-term complication of the central nervous system (CNS), characterized by cognitive impairment and motor dysfunctions. The role of oxidative stress and neuroinflammation in the pathomechanism of DE has been proven. Fractalkine (CX3CL1) has unique properties as an adhesion molecule and chemoattractant, and by acting on its only receptor, CX3CR1, it regulates the activity of microglia in physiological states and neuroinflammation. Depending on the clinical context, CX3CL1-CX3CR1 signaling may have neuroprotective effects by inhibiting the inflammatory process in microglia or, conversely, maintaining/intensifying inflammation and neurotoxicity. This review discusses the evidence supporting that the CX3CL1-CX3CR1 pair is neuroprotective and other evidence that it is neurotoxic. Therefore, interrupting the vicious cycle within neuron-microglia interactions by promoting neuroprotective effects or inhibiting the neurotoxic effects of the CX3CL1-CX3CR1 signaling axis may be a therapeutic goal in DE by limiting the inflammatory response. However, the optimal approach to prevent DE is simply tight glycemic control, because the elimination of dysglycemic states in the CNS abolishes the fundamental mechanisms that induce this vicious cycle.

Characterization of cortico-meningeal translocator protein expression in multiple sclerosis

Compartmentalized meningeal inflammation is thought to represent one of the key players in the pathogenesis of cortical demyelination in multiple sclerosis. PET targeting the 18 kDa mitochondrial translocator protein (TSPO) is a molecular-specific approach to quantifying immune cell-mediated density in the cortico-meningeal tissue compartment in vivo. This study aimed to characterize cortical and meningeal TSPO expression in a heterogeneous cohort of multiple sclerosis cases using in vivo simultaneous MR-PET with 11C-PBR28, a second-generation TSPO radioligand, and ex vivo immunohistochemistry. Forty-nine multiple sclerosis patients (21 with secondary progressive and 28 with relapsing-remitting multiple sclerosis) with mixed or high affinity binding for 11C-PBR28 underwent 90-min 11C-PBR28 simultaneous MR-PET. Tracer binding was measured using 60-90 min normalized standardized uptake value ratios sampled at mid-cortical depth and ∼3 mm above the pial surface. Data in multiple sclerosis patients were compared to 21 age-matched healthy controls. To characterize the nature of 11C-PBR28 PET uptake, the meningeal and cortical lesion cellular expression of TSPO was further described in post-mortem brain tissue from 20 cases with secondary progressive multiple sclerosis and five age-matched healthy donors. Relative to healthy controls, patients with multiple sclerosis exhibited abnormally increased TSPO signal in the cortex and meningeal tissue, diffusively in progressive disease and more localized in relapsing-remitting multiple sclerosis. In multiple sclerosis, increased meningeal TSPO levels were associated with increased Expanded Disability Status Scale scores (P = 0.007, by linear regression). Immunohistochemistry, validated using in situ sequencing analysis, revealed increased TSPO expression in the meninges and adjacent subpial cortical lesions of post-mortem secondary progressive multiple sclerosis cases relative to control tissue. In these cases, increased TSPO expression was related to meningeal inflammation. Translocator protein immunostaining was detected on meningeal MHC-class II+ macrophages and cortical-activated MHC-class II+ TMEM119+ microglia. In vivo arterial blood data and neuropathology showed that endothelial binding did not significantly account for increased TSPO cortico-meningeal expression in multiple sclerosis. Our findings support the use of TSPO-PET in multiple sclerosis for imaging in vivo inflammation in the cortico-meningeal brain tissue compartment and provide in vivo evidence implicating meningeal inflammation in the pathogenesis of the disease.

MiR-223 enhances lipophagy by suppressing CTSB in microglia following lysolecithin-induced demyelination in mice

BACKGROUND

Lipid droplet (LD)-laden microglia is a key pathological hallmark of multiple sclerosis. The recent discovery of this novel microglial subtype, lipid-droplet-accumulating microglia (LDAM), is notable for increased inflammatory factor secretion and diminished phagocytic capability. Lipophagy, the autophagy-mediated selective degradation of LDs, plays a critical role in this context. This study investigated the involvement of microRNAs (miRNAs) in lipophagy during demyelinating diseases, assessed their capacity to modulate LDAM subtypes, and elucidated the potential underlying mechanisms involved.

METHODS

C57BL/6 mice were used for in vivo experiments. Two weeks post demyelination induction at cervical level 4 (C4), histological assessments and confocal imaging were performed to examine LD accumulation in microglia within the lesion site. Autophagic changes were observed using transmission electron microscopy. miRNA and mRNA multi-omics analyses identified differentially expressed miRNAs and mRNAs under demyelinating conditions and the related autophagy target genes. The role of miR-223 in lipophagy under these conditions was specifically explored. In vitro studies, including miR-223 upregulation in BV2 cells via lentiviral infection, validated the bioinformatics findings. Immunofluorescence staining was used to measure LD accumulation, autophagy levels, target gene expression, and inflammatory mediator levels to elucidate the mechanisms of action of miR-223 in LDAM.

RESULTS

Oil Red O staining and confocal imaging revealed substantial LD accumulation in the demyelinated spinal cord. Transmission electron microscopy revealed increased numbers of autophagic vacuoles at the injury site. Multi-omics analysis revealed miR-223 as a crucial regulatory gene in lipophagy during demyelination. It was identified that cathepsin B (CTSB) targets miR-223 in autophagy to integrate miRNA, mRNA, and autophagy gene databases. In vitro, miR-223 upregulation suppressed CTSB expression in BV2 cells, augmented autophagy, alleviated LD accumulation, and decreased the expression of the inflammatory mediator IL-1β.

CONCLUSION

These findings indicate that miR-223 plays a pivotal role in lipophagy under demyelinating conditions. By inhibiting CTSB, miR-223 promotes selective LD degradation, thereby reducing the lipid burden and inflammatory phenotype in LDAM. This study broadens the understanding of the molecular mechanisms of lipophagy and proposes lipophagy induction as a potential therapeutic approach to mitigate inflammatory responses in demyelinating diseases.

Extracellular Vesicles in Multiple Sclerosis: Their Significance in the Development and Possible Applications as Therapeutic Agents and Biomarkers

Extracellular vesicles (EVs) are "micro-shuttles" that play a role as mediators of intercellular communication. Cells release EVs into the extracellular environment in both physiological and pathological conditions and are involved in intercellular communication, due to their ability to transfer proteins, lipids, and nucleic acids, and in the modulation of the immune system and neuroinflammation. Because EVs can penetrate the blood-brain barrier and move from the central nervous system to the peripheral circulation, and vice versa, recent studies have shown a substantial role for EVs in several neurological diseases, including multiple sclerosis (MS). MS is a demyelinating disease where the main event is caused by T and B cells triggering an autoimmune reaction against myelin constituents. Recent research has elucidate the potential involvement of extracellular vesicles (EVs) in the pathophysiology of MS, although, to date, their potential role both as agents and therapeutic targets in MS is not fully defined. We present in this review a summary and comprehensive examination of EVs' involvement in the pathophysiology of multiple sclerosis, exploring their potential applications as biomarkers and indicators of therapy response.

CHIT1 at diagnosis predicts faster disability progression and reflects early microglial activation in multiple sclerosis

Multiple sclerosis (MS) is characterized by heterogeneity in disease course and prediction of long-term outcome remains a major challenge. Here, we investigate five myeloid markers - CHIT1, CHI3L1, sTREM2, GPNMB and CCL18 - in the cerebrospinal fluid (CSF) at diagnostic lumbar puncture in a longitudinal cohort of 192 MS patients. Through mixed-effects and machine learning models, we show that CHIT1 is a robust predictor for faster disability progression. Integrative analysis of 11 CSF and 26 central nervous system (CNS) parenchyma single-cell/nucleus RNA sequencing samples reveals CHIT1 to be predominantly expressed by microglia located in active MS lesions and enriched for lipid metabolism pathways. Furthermore, we find CHIT1 expression to accompany the transition from a homeostatic towards a more activated, MS-associated cell state in microglia. Neuropathological evaluation in post-mortem tissue from 12 MS patients confirms CHIT1 production by lipid-laden phagocytes in actively demyelinating lesions, already in early disease stages. Altogether, we provide a rationale for CHIT1 as an early biomarker for faster disability progression in MS.

The Study of Remyelinating Therapies in Multiple Sclerosis: Visual Outcomes as a Window Into Repair

INTRODUCTION

Amelioration of disability in multiple sclerosis requires the development of complementary therapies that target neurodegeneration and promote repair. Remyelination is a promising neuroprotective strategy that may protect axons from damage and subsequent neurodegeneration.

METHODS

A review of key literature plus additional targeted search of PubMed and Google Scholar was conducted.

RESULTS

There has been a rapid expansion of clinical trials studying putative remyelinating candidates, but further growth of the field is limited by the lack of consensus on key aspects of trial design. We have not yet defined the ideal study population, duration of therapy, or the appropriate outcome measures to detect remyelination in humans. The varied natural history of multiple sclerosis, coupled with the short time frame of phase II clinical trials, requires that we develop and validate biomarkers of remyelination that can serve as surrogate endpoints in clinical trials.

CONCLUSIONS

We propose that the visual system may be the most well-suited and validated model for the study potential remyelinating agents. In this review, we discuss the pathophysiology of demyelination and summarize the current clinical trial landscape of remyelinating agents. We present some of the challenges in the study of remyelinating agents and discuss current potential biomarkers of remyelination and repair, emphasizing both established and emerging visual outcome measures.

Sirtuins and Metabolism Biomarkers in Relapsing-Remitting and Secondary Progressive Multiple Sclerosis: a Correlation Study with Clinical Outcomes and Cognitive Impairments

Multiple sclerosis (MS) is a primary inflammatory demyelinating disease with different clinical courses and subtypes. The present study aimed to determine whether mitochondrial dysfunction and sirtuins 1 and 3, as metabolism and epigenetic modifying factors, might contribute to MS disease progression measured by physical disability and cognitive impairment.The volunteers (n = 20 controls, n = 59 MS) were recruited and assessed for cognitive function and disability scores; then, patients were clinically classified as relapsing-remitting (RR) in remission phase, RR in relapse phase, and secondary progressive MS. We measured sirtuin (SIRT) 1 and 3 levels, mitochondrial complex I, IV, aconitase, and α-ketoglutarate dehydrogenase (α-KGD) activity in the peripheral blood mononuclear cells (PBMCs). Furthermore, SIRT1, pyruvate, lactate, and cytochrome c (Cyt c) were determined in plasma. Finally, we performed postmortem tissue immunohistochemistry to assess the level of SIRT1 and SIRT3 in the brain lesions of patients with MS.Increased disability and cognitive impairment in patients were correlated. Plasma level of lactate showed a correlation with the disability in MS patients; moreover, a trend toward increased Cyt c plasma level was observed. Investigation of PBMCs exhibited decreased SIRT1 during the relapse phase along with a reduced complex IV activity in all MS subgroups. α-KGD activity was significantly increased in the RR-remission, and SIRT3 was elevated in RR-relapse group. This elevation correlated with disability and cognitive impairment. Finally, immunohistochemistry demonstrated increased levels of SIRT1 and 3 in the brain active lesion of patients with MS.Our data suggest that mitochondrial dysfunction and alteration in some epigenetics and metabolism modifying factors in the CNS and peripheral blood cells may contribute or correlate with MS progression.

Therapeutic potential of thymoquinone and its nanoformulations in neuropsychological disorders: a comprehensive review on molecular mechanisms in preclinical studies

Thymoquinone (THQ) and its nanoformulation (NFs) have emerged as promising candidates for the treatment of neurological diseases due to their diverse pharmacological properties, which include anti-inflammatory, antioxidant, and neuroprotective effects. In this study, we conducted an extensive search across reputable scientific websites such as PubMed, ScienceDirect, Scopus, and Google Scholar to gather relevant information. The antioxidant and anti-inflammatory properties of THQ have been observed to enhance the survival of neurons in affected areas of the brain, leading to significant improvements in behavioral and motor dysfunctions. Moreover, THQ and its NFs have demonstrated the capacity to restore antioxidant enzymes and mitigate oxidative stress. The primary mechanism underlying THQ's antioxidant effects involves the regulation of the Nrf2/HO-1 signaling pathway. Furthermore, THQ has been found to modulate key components of inflammatory signaling pathways, including toll-like receptors (TLRs), nuclear factor-κB (NF-κB), interleukin 6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNFα), thereby exerting anti-inflammatory effects. This comprehensive review explores the various beneficial effects of THQ and its NFs on neurological disorders and provides insights into the underlying mechanisms involved.

Neuroprotective effects of dantrolene in neurodegenerative disease: Role of inhibition of pathological inflammation

Neurodegenerative diseases (NDs) refer to a group of diseases in which slow, continuous cell death is the main pathogenic event in the nervous system. Most NDs are characterized by cognitive dysfunction or progressive motor dysfunction. Treatments of NDs mainly target alleviating symptoms, and most NDs do not have disease-modifying drugs. The pathogenesis of NDs involves inflammation and apoptosis mediated by mitochondrial dysfunction. Dantrolene, approved by the US Food and Drug Administration, acts as a RyRs antagonist for the treatment of malignant hyperthermia, spasticity, neuroleptic syndrome, ecstasy intoxication and exertional heat stroke with tolerable side effects. Recently, dantrolene has also shown therapeutic effects in some NDs. Its neuroprotective mechanisms include the reduction of excitotoxicity, apoptosis and neuroinflammation. In summary, dantrolene can be considered as a potential therapeutic candidate for NDs.

Recommendations for nutritional supplements for dry eye disease: current advances

Dry eye disease (DED) represents a prevalent ocular surface disease. The development of effective nutritional management strategies for DED is crucial due to its association with various factors such as inflammation, oxidative stress, deficiencies in polyunsaturated fatty acids (PUFAs), imbalanced PUFA ratios, and vitamin insufficiencies. Extensive research has explored the impact of oral nutritional supplements, varying in composition and dosage, on the symptoms of DED. The main components of these supplements include fish oils (Omega-3 fatty acids), vitamins, trace elements, and phytochemical extracts. Beyond these well-known nutrients, it is necessary to explore whether novel nutrients might contribute to more effective DED management. This review provides a comprehensive update on the therapeutic potential of nutrients and presents new perspectives for combination supplements in DED treatment.

Renal disease associated with multiple sclerosis: A narrative review

Multiple sclerosis (MS) is a chronic autoimmune neurological disorder characterized by central nervous system demyelination, leading to various neurological impairments. While the primary focus of research and clinical management has centered on the neurological aspects of MS, emerging evidence suggests a complex interplay between MS and renal disease. This narrative review endeavors to elucidate the intriguing association between MS and renal disease, providing a comprehensive overview of the current knowledge on this topic. Our review begins by outlining the pathophysiology of MS and the diverse mechanisms contributing to its progression. We then delve into renal disease, categorizing the various types and their clinical presentations. This review focuses on exploring the intricate relationship between these seemingly distinct conditions. We analyze existing literature to uncover shared risk factors, potential pathophysiological links, and the impact of MS on renal function. Furthermore, we discuss the clinical presentation and diagnostic challenges in identifying renal disease in MS patients. Importantly, we examine available treatment options and their efficacy in managing renal complications in this unique patient population. The consequences of renal disease on the overall quality of life (QOL) for individuals living with MS are also examined, shedding light on the multifaceted burden of these coexisting conditions.

Gut Bacteria Provide Genetic and Molecular Reporter Systems to Identify Specific Diseases

With genetic information gained from next-generation sequencing (NGS) and genome-wide association studies (GWAS), it is now possible to select for genes that encode reporter molecules that may be used to detect abnormalities such as alcohol-related liver disease (ARLD), cancer, cognitive impairment, multiple sclerosis (MS), diabesity, and ischemic stroke (IS). This, however, requires a thorough understanding of the gut-brain axis (GBA), the effect diets have on the selection of gut microbiota, conditions that influence the expression of microbial genes, and human physiology. Bacterial metabolites such as short-chain fatty acids (SCFAs) play a major role in gut homeostasis, maintain intestinal epithelial cells (IECs), and regulate the immune system, neurological, and endocrine functions. Changes in butyrate levels may serve as an early warning of colon cancer. Other cancer-reporting molecules are colibactin, a genotoxin produced by polyketide synthetase-positive Escherichia coli strains, and spermine oxidase (SMO). Increased butyrate levels are also associated with inflammation and impaired cognition. Dysbiosis may lead to increased production of oxidized low-density lipoproteins (OX-LDLs), known to restrict blood vessels and cause hypertension. Sudden changes in SCFA levels may also serve as a warning of IS. Early signs of ARLD may be detected by an increase in regenerating islet-derived 3 gamma (REG3G), which is associated with changes in the secretion of mucin-2 (Muc2). Pro-inflammatory molecules such as cytokines, interferons, and TNF may serve as early reporters of MS. Other examples of microbial enzymes and metabolites that may be used as reporters in the early detection of life-threatening diseases are reviewed.

The possible role of oxidative stress marker glutathione in the assessment of cognitive impairment in multiple sclerosis

Oxidative stress markers have a distinct role in the process of demyelination in multiple sclerosis. This study investigated the potential correlation of markers of oxidative stress (glutathione [GSH], catalase) with the number of demyelinating lesions and the degree of disability, cognitive deficit, and depression in patients with relapsing-remitting multiple sclerosis (RRMS). Sixty subjects meeting the criteria for RRMS (19 men and 41 women), and 66 healthy controls (24 men, 42 women) were included. In this study, GSH significantly negatively correlated with the degree of cognitive impairment. This is the first study of subjects with RRMS that performed the mentioned research of serum GSH levels on the degree of cognitive damage examined by the Montreal Scale of Cognitive Assessment (MoCA) test. The development of cognitive changes, verified by the MoCA test, was statistically significantly influenced by the positive number of magnetic resonance lesions, degree of depression, expanded disability status scale (EDSS), age, and GSH values. Based on these results, it can be concluded that it is necessary to monitor cognitive status early in RRMS patients, especially in those with a larger number of demyelinating lesions and a higher EDSS level and in older subjects. Also, the serum level of GSH is a potential biomarker of disease progression, which could be used more widely in RRMS.