Progressive multiple sclerosis: prospects for disease therapy, repair, and restoration of function

Regulatory Mechanism of lncRNAs in M1/M2 Macrophages Polarization in the Diseases of Different Etiology

Precise expression and regulation of genes in the immune system is important for organisms to produce strong immunity towards pathogens and limit autoimmunity. In recent years, an increasing number of studies has shown that long noncoding RNAs (lncRNAs) are closely related to immune function and can participate in regulating immune responses by regulating immune cell differentiation, development, and function. As immune cells, the polarization response of macrophages (Mφs) plays an important role in immune function and inflammation. LncRNAs can regulate the phenotypic polarization of Mφs to M1 or M2 through various mechanisms; promote pro-inflammatory or anti-inflammatory effects; and participate in the pathogenesis of cancers, inflammatory diseases, infections, metabolic diseases, and autoimmune diseases. In addition, it is important to explore the regulatory mechanisms of lncRNAs on the dynamic transition between different Mφs phenotypes. Thus, the regulatory role of lncRNAs in the polarization of Mφs and their mechanism are discussed in this review.

Cerebrospinal Fluid α-Calcitonin Gene-Related Peptide: A Comparison between Alzheimer's Disease and Multiple Sclerosis

Alzheimer's disease (AD) and Multiple Sclerosis (MS) represent an emerging health problem on a global scale, as they are responsible for a significant contribution to the burden of disability in Western countries. Limited numbers of cerebrospinal fluid (CSF) diagnostic markers are available for each disease (amyloid and tau deposition markers for AD and oligoclonal bands for MS) representing mostly state markers that provide few, if any, clues about the severity of the clinical phenotype. α-CGRP is a neuropeptide implied in nociception, vasodilation, synaptic plasticity and immune functions. This neuropeptide is expressed in encephalic regions connected to memory, attention, autonomic and behavioral functions and is also expressed by spinal motor neurons. The present work confronted α-CGRP levels between 19 AD, 27 MS and 17 control subjects using an ELISA/EIA assay. We measured higher CSF α-CGRP contents in control subjects with respect to AD, as shown in previous studies, as well as in MS patients in comparison to AD. The control subjects and MS patients did not significantly differ between each other. We did not observe a relationship between CSF protein content, albumin quotient and α-CGRP. We also describe, retrospectively, an association between higher CSF CGRP content and higher MRI overall lesion count in MS and between lower α-CGRP and worse attention and visuo-perceptual skills in AD. We speculate that α-CGRP could be differentially involved in both disabling diseases.

Neuroimaging predictors of longitudinal disability and cognition outcomes in multiple sclerosis patients: A systematic review and meta-analysis

BACKGROUND

Cross-sectional magnetic resonance imaging (MRI) studies have generated substantial evidence relating neuroimaging abnormalities to clinical and cognitive decline in multiple sclerosis (MS). Longitudinal neuroimaging studies may have additional value for predicting future cognitive deficits or clinical impairment, potentially leading to earlier interventions and better disease management. We conducted a meta-analysis of longitudinal studies using neuroimaging to predict cognitive decline (i.e. the Symbol Digits Modalities Test, SDMT) and disability outcomes (i.e. the Expanded Disability Status Scale, EDSS) in MS.

METHODS

Our systematic literature search yielded 64 relevant publications encompassing 105 distinct sub-analyses. We performed a multilevel random-effects meta-analysis to estimate overall effect size for neuroimaging's ability to predict longitudinal cognitive and clinical decline, and a meta-regression to investigate the impact of distinct study factors on pooled effect size.

RESULTS

In the EDSS analyses, the meta-analysis yielded a medium overall pooled effect size (Pearson's correlation coefficient r = 0.42, 95% CI [0.37; 0.46]). The meta-regression further indicated that analyses exclusively evaluating gray matter tissue had significantly stronger effect sizes than analyses of white matter tissue or whole brain analyses (p < 0.05). No other study factors significantly influenced the pooled effect size (all p > 0.05). In the SDMT analyses, the meta-analysis yielded a medium overall pooled effect size (r = 0.47, 95% CI [0.32; 0.60]). The meta-regression found no significant study factors influencing the pooled effect size.

CONCLUSION

The present findings indicate that brain imaging is a medium predictor of longitudinal change in both disability progression (EDSS) and cognitive decline (SDMT). These findings reinforce the need for further longitudinal studies standardizing methods, using multimodal approaches, creating data consortiums, and publishing more complete datasets investigating MRI modalities to predict longitudinal disability and cognitive decline.

Exosomes derived from bone marrow mesenchymal stromal cells promote remyelination and reduce neuroinflammation in the demyelinating central nervous system

Injury of oligodendrocytes (OLs) induces demyelination, and patients with neurodegenerative diseases exhibit demyelination concomitantly with neurological deficit and cognitive impairment. Oligodendrocyte progenitor cells (OPCs) are present in the adult central nervous system (CNS), and they can proliferate, differentiate, and remyelinate axons after damage. However, remyelination therapies are not in clinical use. Multiple sclerosis (MS) is a major demyelinating disease in the CNS. Mesenchymal stromal cells (MSCs) have demonstrated therapeutic promise in animal models and in clinical trials of MS. Exosomes are nanoparticles generated by nearly all cells and they mediate cell-cell communication by transferring cargo biomaterials. Here, we hypothesize that exosomes harvested from MSCs have a similar therapeutic effect on enhancement of remyelination as that of MSCs. In the present study we employed exosomes derived from rhesus monkey MSCs (MSC-Exo). Two mouse models of demyelination were employed: 1) experimental autoimmune encephalomyelitis (EAE), an animal model of MS; and 2) cuprizone (CPZ) diet model, a toxic demyelination model. MSC-Exo or PBS were intravenously injected twice a week for 4 weeks, starting on day 10 post immunization in EAE mice, or once a week for 2 weeks starting on the day of CPZ diet withdrawal. Neurological and cognitive function were tested, OPC differentiation and remyelination, neuroinflammation and the potential underlying mechanisms were investigated using immunofluorescent staining, transmission electron microscopy and Western blot. Data generated from the EAE model revealed that MSC-Exo cross the blood brain barrier (BBB) and target neural cells. Compared with the controls (p < 0.05), treatment with MSC-Exo: 1) significantly improved neurological outcome; 2) significantly increased the numbers of newly generated OLs (BrdU+/APC+) and mature OLs (APC+), and the level of myelin basic protein (MBP); 3) decreased amyloid-β precursor protein (APP)+ density; 4) decreased neuroinflammation by increasing the M2 phenotype and decreasing the M1 phenotype of microglia, as well as their related cytokines; 5) inhibited the TLR2/IRAK1/NFκB pathway. Furthermore, we confirmed that the MSC-Exo treatment significantly improved cognitive function, promoted remyelination, increased polarization of M2 phenotype and blocked TLR2 signaling in the CPZ model. Collectively, MSC-Exo treatment promotes remyelination by both directly acting on OPCs and indirectly by acting on microglia in the demyelinating CNS. This study provides the cellular and molecular basis for this cell-free exosome therapy on remyelination and modulation of neuroinflammation in the CNS, with great potential for treatment of demyelinating and neurodegenerative disorders.

Colony-stimulating factor-1 receptor inhibition attenuates microgliosis and myelin loss but exacerbates neurodegeneration in the chronic cuprizone model

Multiple sclerosis (MS), especially in its progressive phase, involves early axonal and neuronal damage resulting from a combination of inflammatory mediators, demyelination, and loss of trophic support. During progressive disease stages, a microenvironment is created within the central nervous system (CNS) favoring the arrival and retention of inflammatory cells. Active demyelination and neurodegeneration have also been linked to microglia (MG) and astrocyte (AST)-activation in early lesions. While reactive MG can damage tissue, exacerbate deleterious effects, and contribute to neurodegeneration, it should be noted that activated MG possess neuroprotective functions as well, including debris phagocytosis and growth factor secretion. The progressive form of MS can be modelled by the prolonged administration to cuprizone (CPZ) in adult mice, as CPZ induces highly reproducible demyelination of different brain regions through oligodendrocyte (OLG) apoptosis, accompanied by MG and AST activation and axonal damage. Therefore, our goal was to evaluate the effects of a reduction in microglial activation through orally administered brain-penetrant colony-stimulating factor-1 receptor (CSF-1R) inhibitor BLZ945 (BLZ) on neurodegeneration and its correlation with demyelination, astroglial activation and behavior in a chronic CPZ-induced demyelination model. Our results show that BLZ treatment successfully reduced the microglial population and myelin loss. However, no correlation was found between myelin preservation and neurodegeneration, as axonal degeneration was more prominent upon BLZ treatment. Concomitantly, BLZ failed to significantly offset CPZ-induced astroglial activation and behavioral alterations. These results should be taken into account when proposing the modulation of microglial activation in the design of therapies relevant for demyelinating diseases.

NAD+ improved experimental autoimmune encephalomyelitis by regulating SIRT1 to inhibit PI3K/Akt/mTOR signaling pathway

OBJECTIVE

To investigate the effect of NAD+ on thymus autophagy in experimental autoimmune encephalomyelitis (EAE) mice through SIRT1.

METHODS

Bioinformatic analysis was used to identify hub genes. Forty female C57BL/6 mice were randomly divided into 4 groups: control, EAE, NAD+, and NAD+ +SIRT1 inhibitor (SIRT-IN-3) groups and SIRT1 group. The NAD+ group and SIRT1 inhibitor group were treated with NAD+ drug and fed for 4 weeks. The neurological function scores were evaluated weekly. The thymus tissues of wild-type mice were removed, ground and filtered into single-cell suspension. MOG 35-55 (1 μg/mL) was given to primary thymic epithelial cells (TECs) to induce EAE model in vitro. The expression of LC-3A/B was observed by immunofluorescence. The expressions or the activation/phosphorylation of associated proteins were detected by Western blot.

RESULTS

Enrichment analysis showed PI3K-Akt-mTOR and autophagy pathway were main terms in EAE diseases, and the relationship between NAD+ and SIRT1. The activation of p-PI3K, p-Akt and p-mTOR were the highest in the EAE group consistent with decreased P62, Beclin1, LC-3A/B and SIRT1, and NAD+ reversed these results, furthermore SIRT1 inhibitor: SIRT-IN3 weakened the NAD+' effects in both in vivo and in vitro experiments. Immunofluorescence study in vivo and in vitro were accord with the results of western blot.

CONCLUSIONS

NAD+ exerted a protective effect on EAE mice by inhibiting PI3K/Akt/mTOR signaling pathway through SIRT1 in TECs, and prevented EAE mice from sustained damage.

Serum and Saliva Myelin Basic Protein as Multiple Sclerosis Biomarker

Introduction:

Multiple Sclerosis (MS) is presented with motor and sensory function loss. It is caused by demyelination and following axonal lesion. As Myelin Basic Protein (MBP) is one of the key elements of the myelin cover, we examined the level of MBP in serum, stimulated, and unstimulated saliva as a suitable biomarker for detecting MS.

Methods:

A case-control study was performed in 29 healthy women and 32 definitive relapsing-remitting MS patients hospitalized in Imam Reza hospital, Tehran, Iran. MBP level was assayed in serum and stimulated and unstimulated whole saliva.

Results:

MBP was expressed at a lower level in serum and stimulated saliva of MS patients compared to the control group. The serum MBP level had a considerable correlation with its stimulated saliva level. The receiver operating characteristic analysis showed significant diagnostic ability for MBP to discriminate MS patients with serum and stimulated saliva from controls.

Conclusion:

Serum and saliva level of MBP is lower in MS, so it may be considered a potential biomarker in MS.

Charting a global research strategy for progressive MS-An international progressive MS Alliance proposal

BACKGROUND

Progressive forms of multiple sclerosis (MS) affect more than 1 million individuals globally. Recent approvals of ocrelizumab for primary progressive MS and siponimod for active secondary progressive MS have opened the therapeutic door, though results from early trials of neuroprotective agents have been mixed. The recent introduction of the term 'active' secondary progressive MS into the therapeutic lexicon has introduced potential confusion to disease description and thereby clinical management.

OBJECTIVE

This paper reviews recent progress, highlights continued knowledge and proposes, on behalf of the International Progressive MS Alliance, a global research strategy for progressive MS.

METHODS

Literature searches of PubMed between 2015 and May, 2021 were conducted using the search terms "progressive multiple sclerosis", "primary progressive multiple sclerosis", "secondary progressive MS". Proposed strategies were developed through a series of in-person and virtual meetings of the International Progressive MS Alliance Scientific Steering Committee.

RESULTS

Sustaining and accelerating progress will require greater understanding of underlying mechanisms, identification of potential therapeutic targets, biomarker discovery and validation, and conduct of clinical trials with improved trial design. Encouraging developments in symptomatic and rehabilitative interventions are starting to address ongoing challenges experienced by people with progressive MS.

CONCLUSION

We need to manage these challenges and realise the opportunities in the context of a global research strategy, which will improve quality of life for people with progressive MS.

Dyschromatopsia in multiple sclerosis reflects diffuse chronic neurodegeneration beyond anatomical landmarks

To formulate and validate a dyschromatopsia linear regression model in patients with multiple sclerosis (MS). 64 MS patients (50 to formulate the model and 14 for its validation) underwent neurological (Expanded Disability Status Scale, EDSS), color vision (Farnsworth D15 test), and peripapillary retinal nerve fiber layer (pRNFL) and retinal evaluation with spectral-domain optical coherence tomography (SD-OCT). Neuroradiological examination permitted to obtain brain parenchymal fraction (BPF) and cervical spinal cord volume (SC). Ophthalmic parameters were calculated as the average of both non-optic neuritis (ON) eyes, and in case the patient had previous ON, the value of the fellow non-ON eye was taken. The influence of sex, age, disease duration, and history of disease-modifying treatment (first- or second-line DMT) was tested as covariables that could influence color perception. Color confusion index (log CCI) correlated with pRNFL (r =  - 0.322, p = 0.009), ganglion cell layer (GCL, r =  - 0.321, p = 0.01), BPF (r =  - 0.287, p = 0.021), SC volume (r =  - 0.33, p = 0.008), patients' age (r = 0.417, p = 0.001), disease duration (r = 0.371, p = 0.003), and EDSS (r = 0.44, p = 0.001). The following CCI equation was obtained: log (CCI) = 0.316-0.224 BPF - 0.187 SC volume (mm3) + 0.226 age (years) + 0.012 disease duration (years) - 0.372 GCL (µm). CCI correlates with MS clinical and paraclinical established biomarkers suggesting chronic diffuse neurodegeneration in MS operates at brain, SC, and retina linking all three compartments. Color vision outcome can be calculated through the aforementioned variables for clinical and research purposes.

Carnosine quenches the reactive carbonyl acrolein in the central nervous system and attenuates autoimmune neuroinflammation

Background

Multiple sclerosis (MS) is a chronic autoimmune disease driven by sustained inflammation in the central nervous system. One of the pathological hallmarks of MS is extensive free radical production. However, the subsequent generation, potential pathological role, and detoxification of different lipid peroxidation-derived reactive carbonyl species during neuroinflammation are unclear, as are the therapeutic benefits of carbonyl quenchers. Here, we investigated the reactive carbonyl acrolein and (the therapeutic effect of) acrolein quenching by carnosine during neuroinflammation.

Methods

The abundance and localization of acrolein was investigated in inflammatory lesions of MS patients and experimental autoimmune encephalomyelitis (EAE) mice. In addition, we analysed carnosine levels and acrolein quenching by endogenous and exogenous carnosine in EAE. Finally, the therapeutic effect of exogenous carnosine was assessed in vivo (EAE) and in vitro (primary mouse microglia, macrophages, astrocytes).

Results

Acrolein was substantially increased in inflammatory lesions of MS patients and EAE mice. Levels of the dipeptide carnosine (β-alanyl-l-histidine), an endogenous carbonyl quencher particularly reactive towards acrolein, and the carnosine-acrolein adduct (carnosine-propanal) were ~ twofold lower within EAE spinal cord tissue. Oral carnosine treatment augmented spinal cord carnosine levels (up to > tenfold), increased carnosine-acrolein quenching, reduced acrolein-protein adduct formation, suppressed inflammatory activity, and alleviated clinical disease severity in EAE. In vivo and in vitro studies indicate that pro-inflammatory microglia/macrophages generate acrolein, which can be efficiently quenched by increasing carnosine availability, resulting in suppressed inflammatory activity. Other properties of carnosine (antioxidant, nitric oxide scavenging) may also contribute to the therapeutic effects.

Conclusions

Our results identify carbonyl (particularly acrolein) quenching by carnosine as a therapeutic strategy to counter inflammation and macromolecular damage in MS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02306-9.

Carnosine and skeletal muscle dysfunction in a rodent multiple sclerosis model

Muscle weakness and fatigue are primary manifestations of multiple sclerosis (MS), a chronic disease of the central nervous system. Interventions that enhance muscle function may improve overall physical well-being of MS patients. Recently, we described that levels of carnosine, an endogenous muscle dipeptide involved in contractile function and fatigue-resistance, are reduced in muscle tissue from MS patients and a monophasic rodent MS model (experimental autoimmune encephalomyelitis, EAE). In the present study, we aimed to (1) confirm this finding in a chronic EAE model, along with the characterization of structural and functional muscle alterations, and (2) investigate the effect of carnosine supplementation to increase/restore muscle carnosine levels and improve muscle function in EAE. We performed muscle immunohistochemistry and ex vivo contractility measurements to examine muscle structure and function at different stages of EAE, and following nutritional intervention (oral carnosine: 3, 15 or 30 g/L in drinking water). Immunohistochemistry revealed progressively worsening muscle fiber atrophy and a switch towards a fast-twitch muscle phenotype during EAE. Using ex vivo muscle contractility experiments, we observed reductions in muscle strength and contraction speed, but no changes in muscle fatigability of EAE mice. However, carnosine levels were unaltered during all stages of EAE, and even though oral carnosine supplementation dose-dependently increased muscle carnosine levels up to + 94% after 56 days EAE, this did not improve muscle function of EAE mice. In conclusion, EAE mice display significant, yet time-dependent, muscular alterations, and carnosine intervention does not improve muscle function in EAE.

In vivo evidence of differential frontal cortex metabolic abnormalities in progressive and relapsing-remitting multiple sclerosis

The pathophysiology of progressive multiple sclerosis remains elusive, significantly limiting available disease-modifying therapies. Proton MRS (¹ H-MRS) enables in vivo measurement of small molecules implicated in multiple sclerosis, but its application to key metabolites glutamate, γ-aminobutyric acid (GABA), and glutathione has been sparse. We employed, at 7 T, a previously validated ¹ H-MRS protocol to measure glutamate, GABA, and glutathione, as well as glutamine, N-acetyl aspartate, choline, and myoinositol, in the frontal cortex of individuals with relapsing-remitting (N = 26) or progressive (N = 21) multiple sclerosis or healthy control adults (N = 25) in a cross-sectional analysis. Only individuals with progressive multiple sclerosis demonstrated reduced glutamate (F_2,65  = 3.424, p = 0.04; 12.40 ± 0.62 mM versus control 13.17 ± 0.95 mM, p = 0.03) but not glutamine (F_2,65  = 0.352, p = 0.7; 4.71 ± 0.35 mM versus control 4.84 ± 0.42 mM), reduced GABA (F_2,65  = 3.89, p = 0.03; 1.29 ± 0.23 mM versus control 1.47 ± 0.25 mM, p = 0.05), and possibly reduced glutathione (F_2,65  = 0.352, p = 0.056; 2.23 ± 0.46 mM versus control 2.51 ± 0.48 mM, p < 0.1). As a group, multiple sclerosis patients demonstrated significant negative correlations between disease duration and glutamate or GABA (ρ = -0.4, p = 0.02) but not glutamine or glutathione. Alone, only relapsing-remitting multiple sclerosis patients exhibited a significant negative correlation between disease duration and GABA (ρ = -0.5, p = 0.03). Taken together, these results indicate that frontal cortex metabolism is differentially disturbed in progressive and relapsing-remitting multiple sclerosis.

Alterations in Sensorimotor and Mesiotemporal Cortices and Diffuse White Matter Changes in Primary Progressive Multiple Sclerosis Detected by Adiabatic Relaxometry

Background: The research of primary progressive multiple sclerosis (PPMS) has not been able to capitalize on recent progresses in advanced magnetic resonance imaging (MRI) protocols.

Objective: The presented cross-sectional study evaluated the utility of four different MRI relaxation metrics and diffusion-weighted imaging in PPMS.

Methods: Conventional free precession T1 and T2, and rotating frame adiabatic T1ρ and T2ρ in combination with diffusion-weighted parameters were acquired in 13 PPMS patients and 13 age- and sex-matched controls.

Results: T1ρ, a marker of crucial relevance for PPMS due to its sensitivity to neuronal loss, revealed large-scale changes in mesiotemporal structures, the sensorimotor cortex, and the cingulate, in combination with diffuse alterations in the white matter and cerebellum. T2ρ, particularly sensitive to local tissue background gradients and thus an indicator of iron accumulation, concurred with similar topography of damage, but of lower extent. Moreover, these adiabatic protocols outperformed both conventional T1 and T2 maps and diffusion tensor/kurtosis approaches, methods previously used in the MRI research of PPMS.

Conclusion: This study introduces adiabatic T1ρ and T2ρ as elegant markers confirming large-scale cortical gray matter, cerebellar, and white matter alterations in PPMS invisible to other in vivo biomarkers.

Oxidative Stress and Neurodegeneration: Interconnected Processes in PolyQ Diseases

Neurodegenerative polyglutamine (polyQ) disorders are caused by trinucleotide repeat expansions within the coding region of disease-causing genes. PolyQ-expanded proteins undergo conformational changes leading to the formation of protein inclusions which are associated with selective neuronal degeneration. Several lines of evidence indicate that these mutant proteins are associated with oxidative stress, proteasome impairment and microglia activation. These events may correlate with the induction of inflammation in the nervous system and disease progression. Here, we review the effect of polyQ-induced oxidative stress in cellular and animal models of polyQ diseases. Furthermore, we discuss the interplay between oxidative stress, neurodegeneration and neuroinflammation using as an example the well-known neuroinflammatory disease, Multiple Sclerosis. Finally, we review some of the pharmaceutical interventions which may delay the onset and progression of polyQ disorders by targeting disease-associated mechanisms.

Clinical translation of immunomodulatory therapeutics

Immunomodulatory therapeutics represent a unique class of drug products that have tremendous potential to rebalance malfunctioning immune systems and are quickly becoming one of the fastest-growing areas in the pharmaceutical industry. For these drugs to become mainstream medicines, they must provide greater therapeutic benefit than the currently used treatments without causing severe toxicities. Immunomodulators, cell-based therapies, antibodies, and viral therapies have all achieved varying amounts of success in the treatment of cancers and/or autoimmune diseases. However, many challenges related to precision dosing, off-target effects, and manufacturing hurdles will need to be addressed before we see widespread adoption of these therapies in the clinic. This review provides a perspective on the progress of immunostimulatory and immunosuppressive therapies to date and discusses the opportunities and challenges for clinical translation of the next generation of immunomodulatory therapeutics.

What do we know about the role of lncRNAs in multiple sclerosis?

Multiple sclerosis is a chronic, inflammatory and degenerative disease of the central nervous system of unknown aetiology although well-defined evidence supports an autoimmune pathogenesis. So far, the exact mechanisms leading to autoimmune diseases are still only partially understood. We know that genetic, epigenetic, molecular, and cellular factors resulting in pathogenic inflammatory responses are certainly involved. Long non-coding RNAs (lncRNAs) are non-protein coding transcripts longer than 200 nucleotides that play an important role in both innate and acquired immunity, so there is great interest in lncRNAs involved in autoimmune diseases. The research on multiple sclerosis has been enriched with many studies on the molecular role of lncRNAs in the pathogenesis of the disease and their potential application as diagnostic and prognostic biomarkers. In particular, many multiple sclerosis fields of research are based on the identification of lncRNAs as possible biomarkers able to predict the onset of the disease, its activity degree, its progression phase and the response to disease-modifying drugs. Last but not least, studies on lncRNAs can provide a new molecular target for new therapies, missing, so far, a cure for multiple sclerosis. While our knowledge on the role of lncRNA in multiple sclerosis has recently improved, further studies are required to better understand the specific role of lncRNAs in this neurological disease. In this review, we present the most recent studies on molecular characterization of lncRNAs in multiple sclerosis disorder discussing their clinical relevance as biomarkers for diagnosis and treatments.

[Siponimod: a new view at the therapy of secondary progressive multiple sclerosis]

Siponimod is a selective modulator of sphingosine-1-phosphate (S1P) receptors of types 1 and 5, registered in the Russian Federation for the treatment of patients with secondary progressive multiple sclerosis (SPMS), regardless of the presence or absence of exacerbations. The effectiveness of the drug in comparison with placebo was demonstrated in patients with SPMS in the international clinical trial EXPAND (phase III). This review devotes actual problems in the treatment of patients with SPMS, discusses the pathophysiology of multiple sclerosis progression, describes the peripheral and central mechanisms of siponimod action and its differences from fingolimod. According to analysis of scientific literature experimental, clinical and neuroimaging data are presented, which could explain the reasons for the successful use of siponimod in patients with SPMS, taking into account the pathophysiological mechanisms of the development of progression and the mechanisms of drug action.

Standardizing T1-w/T2-w ratio images in trigeminal neuralgia to estimate the degree of demyelination in vivo

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The T1-w/T2-w ratio image or “myelin-sensitive map (MM)” is a non-invasive tool that can estimate myelin content in different regions of the brain and between different patients in vivo.

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T1-w and T2-w images are standardized post-hoc using histogram matching algorithms to provide tissue-specific intensity information and facilitate MM analysis.

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Analysis of MM intensities demonstrate reduced myelin content in MS plaques compared to its corresponding pontine regions in CTN patients and its surrounding NAWM in MSTN patients.

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MM has the potential to distinguish changes in myelin of NAWM before MS plaques are detectable on conventional MR images.

Background

Novel magnetic resonance (MR) imaging techniques have led to the development of T1-w/T2-w ratio images or “myelin-sensitive maps (MMs)” to estimate and compare myelin content in vivo. Currently, raw image intensities in conventional MR images are unstandardized, preventing meaningful quantitative comparisons. We propose an improved workflow to standardize the MMs, which was applied to patients with classic trigeminal neuralgia (CTN) and trigeminal neuralgia secondary to multiple sclerosis (MSTN), to assess the validity and feasibility of this clinical tool.

Methods

T1-w and T2-w images were obtained for 17 CTN patients and 17 MSTN patients using a 3 T scanner. Template images were obtained from ICBM152. Multiple sclerosis (MS) plaques in the pons were labelled in MSTN patients. For each patient image, a Gaussian curve was fitted to the histogram of its intensity distribution, and transformed to match the Gaussian curve of its template image.

Results

After standardization, the structural contrast of the patient image and its histogram more closely resembled the ICBM152 template. Moreover, there was reduced variability in the histogram peaks of the gray and white matter between patients after standardization (p < 0.001). MM intensities were decreased within MS plaques, compared to normal-appearing white matter (NAWM) in MSTN patients (p < 0.001) and its corresponding regions in CTN patients (p < 0.001).

Conclusions

Images intensities are calibrated according to a mathematic relationship between the intensities of the patient image and its template. Reduced variability among histogram peaks allows for interpretation of tissue-specific intensity and facilitates quantitative analysis. The resultant MMs facilitate comparisons of myelin content between different regions of the brain and between different patients in vivo. MM analysis revealed reduced myelin content in MS plaques compared to its corresponding regions in CTN patients and its surrounding NAWM in MSTN patients. Thus, the standardized MM serves as a non-invasive, easily-automated tool that can be feasibly applied to clinical populations for quantitative analyses of myelin content.

Arctigenin Exerts Neuroprotective Effect by Ameliorating Cortical Activities in Experimental Autoimmune Encephalomyelitis In Vivo

Multiple sclerosis (MS) is a chronic disease in the central nervous system (CNS), characterized by inflammatory cells that invade into the brain and the spinal cord. Among a bulk of different MS models, the most widely used and best understood rodent model is experimental autoimmune encephalomyelitis (EAE). Arctigenin, a botanical extract from Arctium lappa, is reported to exhibit pharmacological properties, including anti-inflammation and neuroprotection. However, the effects of arctigenin on neural activity attacked by inflammation in MS are still unclear. Here, we use two-photon calcium imaging to observe the activity of somatosensory cortex neurons in awake EAE mice in vivo and found added hyperactive cells, calcium influx, network connectivity, and synchronization, mainly at preclinical stage of EAE model. Besides, more silent cells and decreased calcium influx and reduced network synchronization accompanied by a compensatory rise in functional connectivity are found at the remission stage. Arctigenin treatment not only restricts inordinate individually neural spiking, calcium influx, and network activity at preclinical stage but also restores neuronal activity and communication at remission stage. In addition, we confirm that the frequency of AMPA receptor-mediated spontaneous excitatory postsynaptic current (sEPSC) is also increased at preclinical stage and can be blunted by arctigenin. These findings suggest that excitotoxicity characterized by calcium influx is involved in EAE at preclinical stage. What is more, arctigenin exerts neuroprotective effect by limiting hyperactivity at preclinical stage and ameliorates EAE symptoms, indicating that arctigenin could be a potential therapeutic drug for neuroprotection in MS-related neuropsychological disorders.

Ion Channels as New Attractive Targets to Improve Re-Myelination Processes in the Brain

Multiple sclerosis (MS) is the most demyelinating disease of the central nervous system (CNS) characterized by neuroinflammation. Oligodendrocyte progenitor cells (OPCs) are cycling cells in the developing and adult CNS that, under demyelinating conditions, migrate to the site of lesions and differentiate into mature oligodendrocytes to remyelinate damaged axons. However, this process fails during disease chronicization due to impaired OPC differentiation. Moreover, OPCs are crucial players in neuro-glial communication as they receive synaptic inputs from neurons and express ion channels and neurotransmitter/neuromodulator receptors that control their maturation. Ion channels are recognized as attractive therapeutic targets, and indeed ligand-gated and voltage-gated channels can both be found among the top five pharmaceutical target groups of FDA-approved agents. Their modulation ameliorates some of the symptoms of MS and improves the outcome of related animal models. However, the exact mechanism of action of ion-channel targeting compounds is often still unclear due to the wide expression of these channels on neurons, glia, and infiltrating immune cells. The present review summarizes recent findings in the field to get further insights into physio-pathophysiological processes and possible therapeutic mechanisms of drug actions.

Motor Cortical Activation Assessment in Progressive Multiple Sclerosis Patients Enrolled in Gait Rehabilitation: A Secondary Analysis of the RAGTIME Trial Assisted by Functional Near-Infrared Spectroscopy

This study aimed to determine cortical activation responses to two different rehabilitative programs, as measured through functional near-infrared spectroscopy (fNIRS). As a secondary analysis of the RAGTIME trial, we studied 24 patients with progressive multiple sclerosis (MS) and severe disability who were randomized to a regimen of robot-assisted gait training (RAGT) or overground walking (OW). Cortical activation during a treadmill walking task, assessed through fNIRS recordings from the motor and premotor cortexes (M1/PM), was calculated as the area under the curve (AUC) of oxyhemoglobin for each hemisphere and the total area (Tot-Oxy_AUC). Gait speed, endurance, and balance were also measured, along with five healthy control subjects. At baseline, Tot-Oxy_AUC during walking was significantly increased in MS patients compared to healthy people and was significantly higher for those with more severe disabilities; it was also inversely correlated with physical performance. After rehabilitation, significant opposite variations in Tot-Oxy_AUC were observed, with activity levels being increased after OW and decreased after RAGT (+242,080 ± 361,902 and −157,031 ± 172,496 arbitrary units, respectively; p = 0.002), particularly in patients who were trained at a lower speed. Greater reductions in the cortical activation of the more affected hemisphere were significantly related to improvements in gait speed (r = −0.42) and endurance (r = −0.44). Cortical activation, assessed through fNIRS, highlighted the brain activity in response to the type and intensity of rehabilitation.

Determinants of disability development in patients with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is one of the most common chronic neurological diseases affecting the central nervous system in young adults.

OBJECTIVE

To investigate demographic and clinical factors that are effective in the development of irreversible disability from the onset of MS, and to identify factors that affect the transformation from the relapse-remitting MS (RRMS) phase to the progressive MS (PMS) phase.

METHODS

Retrospective study on 741 patients who were diagnosed with RRMS and PMS according to the McDonald criteria, and were enrolled into the Turkish MS database of the Department of Neurology MS Polyclinic, at the Faculty of Medicine, Karadeniz Technical University, in Trabzon, Turkey. Kaplan-Meier analysis was used to evaluate the time taken to reach EDSS 4 and EDSS 6 from the onset of disease, and the time taken between EDSS 4 and EDSS 6.

RESULTS

Age of onset >40 years; having polysymptomatic-type onset, pyramidal or bladder-intestinal system-related first episode; ≥7 episodes in the first 5 years; and <2 years between the first two episodes were found to be effective for MS patients to reach EDSS 4 and EDSS 6. The demographic and clinical parameters that were effective for progression from EDSS 4 to EDSS 6 were: pyramidal or bladder-intestinal system-related first episode; 4‒6 episodes in the first 5 years; >2 years until start of first treatment; and smoking.

CONCLUSIONS

Our findings reveal important characteristics of MS patients in our region. However, the associations between these parameters and MS pathophysiology remain to be elucidated.

Epigenetic Plasticity Enables CNS-Trafficking of EBV-infected B Lymphocytes

Subpopulations of B-lymphocytes traffic to different sites and organs to provide diverse and tissue-specific functions. Here, we provide evidence that epigenetic differences confer a neuroinvasive phenotype. An EBV+ B cell lymphoma cell line (M14) with low frequency trafficking to the CNS was neuroadapted to generate a highly neuroinvasive B-cell population (MUN14). MUN14 B cells efficiently infiltrated the CNS within one week and produced neurological pathologies. We compared the gene expression profiles of viral and cellular genes using RNA-Seq and identified one viral (EBNA1) and several cellular gene candidates, including secreted phosphoprotein 1/osteopontin (SPP1/OPN), neuron navigator 3 (NAV3), CXCR4, and germinal center-associated signaling and motility protein (GCSAM) that were selectively upregulated in MUN14. ATAC-Seq and ChIP-qPCR revealed that these gene expression changes correlated with epigenetic changes at gene regulatory elements. The neuroinvasive phenotype could be attenuated with a neutralizing antibody to OPN, confirming the functional role of this protein in trafficking EBV+ B cells to the CNS. These studies indicate that B-cell trafficking to the CNS can be acquired by epigenetic adaptations and provide a new model to study B-cell neuroinvasion associated CNS lymphoma and autoimmune disease of the CNS, including multiple sclerosis (MS).

Aggressive multiple sclerosis in Argentina: Data from the nationwide registry RelevarEM

The objectives of the present study were to describe the frequency of aggressive multiple sclerosis (aMS) as well as to compare clinical and radiological characteristics in aMS and non-aMS patients included in RelevarEM (NCT03375177).

METHODS

The eligible study population and cohort selection included adult-onset patients (≥18 years) with definite MS. AMS were defined as those reaching confirmed EDSS ≥ 6 within 5 years from symptom onset. Confirmation was achieved when a subsequent EDSS ≥ 6 was recorded at least six months later but within 5 years of the first clinical presentation. AMS and non-aMS were compared using the χ2 test for categorical and the Mann-Whitney for continuous variables at MS onset and multivariable analysis was performed using forward stepwise logistic regression with baseline characteristics at disease onset.

RESULTS

A total of 2158 patients with MS were included: 74 aMS and 2084 non-aMS. The prevalence of aMS in our cohort was 3.4% (95%CI 2.7-4.2). AMS were more likely to be male (p = 0.003), older at MS onset (p < 0.001), have primary progressive MS (PPMS) phenotype (p = 0.03), multifocal presentation (p < 0.001), and spinal cord as well as infratentorial lesions at MRI during disease onset (p = 0.004 and p = 0.002, respectively).

CONCLUSION

3.4% of our patient population could be considered aMS. Men, patients older at symptom onset, multifocal presentation, PPMS phenotype, and spinal cord as well as brainstem lesions on MRI at clinical presentation all had higher odds of having aMS.

Epigallocatechin Gallate in Progressive MS: A Randomized, Placebo-Controlled Trial

OBJECTIVE

To examine whether treatment with epigallocatechin gallate (EGCG) influences progression of brain atrophy, reduces clinical and further radiologic disease activity markers, and is safe in patients with progressive multiple sclerosis (PMS).

METHODS

We enrolled 61 patients with primary or secondary PMS in a randomized double-blind, parallel-group, phase II trial on oral EGCG (up to 1,200 mg daily) or placebo for 36 months with an optional open-label EGCG treatment extension (OE) of 12-month duration. The primary end point was the rate of brain atrophy, quantified as brain parenchymal fraction (BPF). The secondary end points were radiologic and clinical disease parameters and safety assessments.

RESULTS

In our cohort, 30 patients were randomized to EGCG treatment and 31 to placebo. Thirty-eight patients (19 from each group) completed the study. The primary endpoint was not met, as in 36 months the rate of decrease in BPF was 0.0092 ± 0.0152 in the treatment group and -0.0078 ± 0.0159 in placebo-treated patients. None of the secondary MRI and clinical end points revealed group differences. Adverse events of EGCG were mostly mild and occurred with a similar incidence in the placebo group. One patient in the EGCG group had to stop treatment due to elevated aminotransferases (>3.5 times above normal limit).

CONCLUSIONS

In a phase II trial including patients with multiple sclerosis (MS) with progressive disease course, we were unable to demonstrate a treatment effect of EGCG on the primary and secondary radiologic and clinical disease parameters while confirming on overall beneficial safety profile.

CLINICALTRIALGOV IDENTIFIER

NCT00799890.

CLASSIFICATION OF EVIDENCE

This phase II trial provides Class II evidence that for patients with PMS, EGCG was safe, well tolerated, and did not significantly reduce the rate of brain atrophy.

Therapeutic potential of the target on NLRP3 inflammasome in multiple sclerosis

Inflammasomes are multi-protein macromolecular complexes that typically comprise of three units, a sensor, an adaptor and procaspase-1. The assembly of each inflammasome is dictated by a unique pattern recognition receptors (PRRs) in response to pathogen-associated molecular patterns (PAMPs) or other endogenous danger-associated molecular patterns (DAMPs) in the cytosol of the host cells, and promote the maturation and secretion of IL-1β and IL-18 during the inflammatory process. Specific inflammasomes are involved in the host defense response against different pathogens, and the latter have evolved multiple corresponding mechanisms to inhibit inflammasome activation. The nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome is the best understood in terms of molecular mechanisms, and is a promising therapeutic target in immune-related disorders. Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory demyelination of white matter in the central nervous system, increased levels of IL-1β in the cerebrospinal fluid (CSF) of relapsed patients, and deposition of caspase-1 in the spinal cord. The direct involvement of the NLRP3 inflammasome in the occurrence and development of MS was ascertained in the experimental autoimmune encephalomyelitis (EAE) animal model. In this review, we have focused on the mechanisms underlying activation of the NLRP3 inflammasome in MS or EAE, as well as inhibitors that specifically target the complex and alleviate disease progression, in order to unearth new therapeutic strategies against MS.

Modeling compartmentalized chronic immune-mediated demyelinating CNS disease in the Biozzi ABH mouse

We explored whether experimental autoimmune encephalomyelitis (EAE) in Biozzi mice recapitulates temporal dynamics of tissue injury, immune-pathogenesis and CNS compartmentalization occurring in progressive multiple sclerosis (MS). Chronic EAE exhibited relapsing and progressing disease, partial closure of BBB, reduced tissue inflammatory activity, and development of meningeal ectopic lymphoid tissue, directly opposing (potentially driving) spinal subpial demyelinated plaques. A T cell predominant disease during relapses transformed into a B cell predominant disease in late chronic EAE, with high serum anti-MOG reactivity. Thus, late chronic Biozzi EAE recapitulates essential features of progressive MS, and is suitable for developing disease modifying and regenerative therapies.

Visual evoked potential latency predicts cognitive function in people with multiple sclerosis

Prior studies have reported an association between visual evoked potentials (VEPs) and cognitive performance in people with multiple sclerosis (PwMS), but the specific mechanisms that account for this relationship remain unclear. We examined the relationship between VEP latency and cognitive performance in a large sample of PwMS, hypothesizing that VEP latency indexes not only visual system functioning but also general neural efficiency. Standardized performance index scores were obtained for the domains of memory, executive function, visual-spatial processing, verbal function, attention, information processing speed, and motor skills, as well as global cognitive performance (NeuroTrax battery). VEP P100 component latency was obtained using a standard checkerboard pattern-reversal paradigm. Prolonged VEP latency was significantly associated with poorer performance in multiple cognitive domains, and with the number of cognitive domains in which performance was ≥ 1 SD below the normative mean. Relationships between VEP latency and cognitive performance were significant for information processing speed, executive function, attention, motor skills, and global cognitive performance after controlling for disease duration, visual acuity, and inter-ocular latency differences. This study provides evidence that VEP latency delays index general neural inefficiency that is associated with cognitive disturbances in PwMS.

Illumination of Molecular Pathways in Multiple Sclerosis Lesions and the Immune Mechanism of Matrine Treatment in EAE, a Mouse Model of MS

The etiology of multiple sclerosis (MS) is not clear, and the treatment of MS presents a great challenge. This study aimed to investigate the pathogenesis and potential therapeutic targets of MS and to define target genes of matrine, a quinolizidine alkaloid component derived from the root of Sophorae flavescens that effectively suppressed experimental autoimmune encephalomyelitis (EAE), an animal model of MS. To this end, the GSE108000 gene data set in the Gene Expression Omnibus Database, which included 7 chronic active MS lesions and 10 control samples of white matter, was analyzed for differentially expressed genes (DEGs). X cell was used to analyze the microenvironmental differences in brain tissue samples of MS patients, including 64 types of immune cells and stromal cells. The biological functions and enriched signaling pathways of DEGs were analyzed by multiple approaches, including GO, KEGG, GSEA, and GSVA. The results by X cell showed significantly increased numbers of immune cell populations in the MS lesions, with decreased erythrocytes, megakaryocytes, adipocytes, keratinocytes, endothelial cells, Th1 cells and Tregs. In GSE108000, there were 637 DEGs, including 428 up-regulated and 209 down-regulated genes. Potential target genes of matrine were then predicted by the network pharmacology method of Traditional Chinese medicine, and 12 key genes were obtained by cross analysis of the target genes of matrine and DEGs in MS lesions. Finally, we confirmed by RT-PCR the predicted expression of these genes in brain tissues of matrine-treated EAE mice. Among these genes, 2 were significantly downregulated and 6 upregulated by matrine treatment, and the significance of this gene regulation was further investigated. In conclusion, our study defined several possible matrine target genes, which can be further elucidated as mechanism(s) of matrine action, and novel targets in the treatment of MS.

Confirmed disability progression provides limited predictive information regarding future disease progression in multiple sclerosis

Background

Although confirmed disability progression (CDP) is a common outcome in multiple sclerosis (MS) clinical trials, its predictive value for long-term outcomes is uncertain.

Objective

To investigate whether CDP at month 24 predicts subsequent disability accumulation in MS.

Methods

The Comprehensive Longitudinal Investigation of Multiple Sclerosis at Brigham and Women's Hospital includes participants with relapsing-remitting MS or clinically isolated syndrome with Expanded Disability Status Scale (EDSS) scores ≤5 (N = 1214). CDP was assessed as a predictor of time to EDSS score 6 (EDSS 6) and to secondary progressive MS (SPMS) using a Cox proportional hazards model; adjusted models included additional clinical/participant characteristics. Models were compared using Akaike's An Information Criterion.

Results

CDP was directionally associated with faster time to EDSS 6 in univariate analysis (HR = 1.61 [95% CI: 0.83, 3.13]). After adjusting for month 24 EDSS, CDP was directionally associated with slower time to EDSS 6 (adjusted HR = 0.65 [0.32, 1.28]). Models including CDP had worse fit statistics than those using EDSS scores without CDP. When models included clinical and magnetic resonance imaging measures, T2 lesion volume improved fit statistics. Results were similar for time to SPMS.

Conclusions

CDP was less predictive of time to subsequent events than other MS clinical features.

NAD+ attenuates experimental autoimmune encephalomyelitis through induction of CD11b+ gr-1+ myeloid-derived suppressor cells

Objective: To investigate the effects of nicotinamide adenine dinucleotide (NAD⁺) on the pathogenesis of the animal model for multiple sclerosis (MS)-experimental autoimmune encephalomyelitis (EAE).

Methods: EAE model was induced by myelin oligodendrocyte protein (MOG 35-55). Clinical scores of EAE were measured in mice with or without NAD⁺ treatment. Hematoxylin and Eosin (HE) and Luxol Fast Blue (LFB) staining were performed to assess inflammation and demyelination, respectively. Expressions of target proteins were measured by Western blot. The numbers of myeloid-derived suppressor cells (MDSCs) were measured by immunofluorescent staining and flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was used to measure the expressions of inflammatory cytokine in serum.

Results: NAD⁺ treatment could decrease inflammatory cells and demyelination foci, attenuate the clinical scores of EAE and slightly delay disease onset. Western blot showed that NAD⁺ treatment up-regulated the expression of phosphorylated-STAT6 (p-STAT6) and SIRT1. Besides, NAD⁺ treatment up-regulated the expression of p-IκB and down-regulated the expression of p-NF-κB. In addition, NAD⁺ treatment could increase the numbers of CD11b⁺ gr-1⁺ MDSCs and the expression of Arginase-1. Moreover, NAD⁺ treatment up-regulated the expressions of IL-13 and down-regulated the expression of IFN-γ and IL-17.

Conclusions: The present study demonstrated that NAD⁺ treatment may induce the CD11b⁺ gr-1⁺ MDSCs to attenuate EAE via activating the phosphorylation of STAT6 expression. Therefore, NAD⁺ should be considered as a potential novel therapeutic strategy for MS.

Montelukast alleviates inflammation in experimental autoimmune encephalomyelitis by altering Th17 differentiation in a mouse model

Montelukast is a leukotriene receptor antagonist that is known to prevent allergic rhinitis and asthma. Blocking the Cysteinyl leukotriene receptor (CysLTR1), one of the primary receptors of leukotrienes, has been demonstrated to be efficacious in ameliorating experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), through disrupting chemotaxis of infiltrating T cells. However, the role of CysLTR1 in the pathogenesis of MS is not well understood. Here, we show that MS patients had higher expression of CysLTR1 in the circulation and central nervous system (CNS). The majority of CD4⁺ T cells expressed CysLTR1 in MS lesions. Among T-cell subsets, Th17 cells had the highest expression of CysLTR1, and blocking CysLTR1 signalling abrogated their development in vitro. Inhibition of CysLTR1 by montelukast suppressed EAE development in both a prophylactic and therapeutic manner and inhibited myelin loss in EAE mice. Similarly, the in vivo results showed that montelukast inhibited Th17 response in EAE mice and that Th17 cells treated with montelukast had reduced encephalitogenic in adoptive EAE. Our findings strongly suggest that targeting Th17 response by inhibiting CysLTR1 signalling could be a promising therapeutic strategy for the treatment of MS and CNS inflammatory diseases.

Platelets in Multiple Sclerosis: Early and Central Mediators of Inflammation and Neurodegeneration and Attractive Targets for Molecular Imaging and Site-Directed Therapy

Platelets are clearly central to thrombosis and hemostasis. In addition, more recently, evidence has emerged for non-hemostatic roles of platelets including inflammatory and immune reactions/responses. Platelets express immunologically relevant ligands and receptors, demonstrate adhesive interactions with endothelial cells, monocytes and neutrophils, and toll-like receptor (TLR) mediated responses. These properties make platelets central to innate and adaptive immunity and potential candidate key mediators of autoimmune disorders. Multiple sclerosis (MS) is the most common chronic autoimmune central nervous system (CNS) disease. An association between platelets and MS was first indicated by the increased adhesion of platelets to endothelial cells. This was followed by reports identifying structural and functional changes of platelets, their chronic activation in the peripheral blood of MS patients, platelet presence in MS lesions and the more recent revelation that these structural and functional abnormalities are associated with all MS forms and stages. Investigations based on the murine experimental autoimmune encephalomyelitis (EAE) MS model first revealed a contribution to EAE pathogenesis by exacerbation of CNS inflammation and an early role for platelets in EAE development via platelet-neuron and platelet-astrocyte associations, through sialated gangliosides in lipid rafts. Our own studies refined and extended these findings by identifying the critical timing of platelet accumulation in pre-clinical EAE and establishing an initiating and central rather than merely exacerbating role for platelets in disease development. Furthermore, we demonstrated platelet-neuron associations in EAE, coincident with behavioral changes, but preceding the earliest detectable autoreactive T cell accumulation. In combination, these findings establish a new paradigm by asserting that platelets play a neurodegenerative as well as a neuroinflammatory role in MS and therefore, that these two pathological processes are causally linked. This review will discuss the implications of these findings for our understanding of MS, for future applications for imaging toward early detection of MS, and for novel strategies for platelet-targeted treatment of MS.

Gray Matter Atrophy in the Cortico-Striatal-Thalamic Network and Sensorimotor Network in Relapsing-Remitting and Primary Progressive Multiple Sclerosis

Gray matter atrophy in multiple sclerosis (MS) is thought to be associated with disability and cognitive impairment, but previous studies have sometimes had discordant results, and the atrophy patterns of relapsing-remitting multiple sclerosis (RRMS) and primary progressive multiple sclerosis (PPMS) remain to be clarified. We conducted a meta-analysis using anisotropic effect-size-based algorithms (AES-SDM) to identify consistent findings from whole-brain voxel-based morphometry (VBM) studies of gray matter volume (GMV) in 924 RRMS patients and 204 PPMS patients. This study is registered with PROSPERO (number CRD42019121319). Compared with healthy controls, RRMS and PPMS patients showed gray matter atrophy in the cortico-striatal-thalamic network, sensorimotor network, and bilateral insula. RRMS patients had a larger GMV in the left insula, cerebellum, right precentral gyrus, and bilateral putamen as well as a smaller GMV in the bilateral cingulate, caudate nucleus, right thalamus, superior temporal gyrus and left postcentral gyrus than PPMS patients. The disease duration, Expanded Disability Status Scale score, Paced Auditory Serial Addition Test z-score, and T2-weighted lesion load were associated with specific gray matter regions in RRMS or PPMS. Alterations in the cortico-striatal-thalamic networks, sensorimotor network, and insula may be involved in the common pathogenesis of RRMS and PPMS. The deficits in the cingulate gyrus and caudate nucleus are more apparent in RRMS than in PPMS. The more severe cerebellum atrophy in PPMS may be a brain feature associated with its neurological manifestations. These imaging biomarkers provide morphological evidence for the pathophysiology of MS and should be verified in future research.

Targeting the brain lesions using peptides: A review focused on the possibility of targeted drug delivery to multiple sclerosis lesions

As described by Jean Martin Charcot in 1868, multiple sclerosis (MS) is an inflammatory, demyelinating and neurodegenerative disease of the central nervous system (CNS) which leads to permanent disability in patients. Following CNS insults, astrocytes and microglial cells undergo changes, which lead to scar formation in the site of injury. Owning to the pathophysiology of MS lesions, changes in both cellular and extracellular matrix (ECM) components occur over the progression of disease. In spite of advances in therapeutic approaches, drug delivery to MS lesions appears of great interest with big challenges and limitations. Targeting with peptides is a novel promising approach in the field of drug delivery. Recently peptides have been used for active targeting of different pathological disorders in which specific peptides make targeted accumulation of cargos to enhance local drug concentration at the pathological area, lead to increased therapeutic efficacy and decreased side effects. However, specific approaches for targeting the lesion in MS are still lacking. In this review, we discuss the changes of the ECM components as well as the cellular characteristics of demyelinated lesions and emphasis on opportunities for peptide based targeted drug delivery to highlight the possibility of such approaches for neurodegenerative disease with specific focus on MS.

Brain-derived neurotrophic factor precursor in the immune system is a novel target for treating multiple sclerosis

Rationale: Brain-derived neurotrophic factor precursor (proBDNF) is expressed in the central nervous system (CNS) and the immune system. However, the role of proBDNF in the pathogenesis of multiple sclerosis (MS) is unknown.

Methods: Peripheral blood and post-mortem brain and spinal cord specimens were obtained from multiple sclerosis patients to analyze proBDNF expression in peripheral lymphocytes and infiltrating immune cells in the lesion site. The proBDNF expression profile was also examined in the experimental autoimmune encephalomyelitis (EAE) mouse model, and polyclonal and monoclonal anti-proBDNF antibodies were used to explore their therapeutic effect in EAE. Finally, the role of proBDNF in the inflammatory immune activity of peripheral blood mononuclear cells (PBMCs) was verified in vitro experiments.

Results: High proBDNF expression was detected in the circulating lymphocytes and infiltrated inflammatory cells at the lesion sites of the brain and spinal cord in MS patients. In the EAE mouse model, proBDNF was upregulated in CNS and in circulating and splenic lymphocytes. Systemic but not intracranial administration of anti-proBDNF blocking antibodies attenuated clinical scores, limited demyelination, and inhibited proinflammatory cytokines in EAE mice. Immuno-stimulants treatment increased the proBDNF release and upregulated the expression of p75 neurotrophic receptors (p75^NTR) in lymphocytes. The monoclonal antibody against proBDNF inhibited the inflammatory response of PBMCs upon stimulations.

Conclusion: The findings suggest that proBDNF from immune cells promotes the immunopathogenesis of MS. Monoclonal Ab-proB may be a promising therapeutic agent for treating MS.

Relapses in Patients Treated with High-Dose Biotin for Progressive Multiple Sclerosis

High-dose biotin (HDB) is a therapy used in non-active progressive multiple sclerosis (PMS). Several reports have suggested that HDB treatment may be associated with an increased risk of relapse. We aimed to determine whether HDB increases the risk of clinical relapse in PMS and describe the characteristics of the patients who experience it. We conducted a French, multicenter, retrospective study, comparing a group of PMS patients treated with HDB to a matched control group. Poisson regression was applied to model the specific statistical distribution of the annualized relapse rate (ARR). A propensity score (PS), based on the inverse probability of treatment weighting (IPTW), was used to adjust for indication bias and included the following variables: gender, primary PMS or not, age, EDSS, time since the last relapse, and co-prescription of a DMT. Two thousand six hundred twenty-eight patients treated with HDB and 654 controls were analyzed with a follow-up of 17 ± 8 months. Among them, 148 validated relapses were observed in the group treated with biotin and 38 in the control group (p = 0.62). After adjustment based on the PS, the ARR was 0.044 ± 0.23 for the biotin-treated group and 0.028 ± 0.16 for the control group (p = 0.18). The more relapses there were before biotin, the higher the risk of relapse during treatment, independently from the use of HDB. While the number of relapses reported for patients with no previous inflammatory activity receiving biotin has gradually increased, the present retrospective study is adequately powered to exclude an elevated risk of relapse for patients with PMS treated with HDB.

Safinamide in neurological disorders and beyond: Evidence from preclinical and clinical studies

The discovery and development of safinamide, an alpha-aminoamide, has been a valuable addition to the existing clinical management of Parkinson's disease (PD). The journey of safinamide dates back to the year 1983, when an alpha-aminoamide called milacemide showed a weak anticonvulsant activity. Milacemide was then structurally modified to give rise to safinamide, which in turn produced robust anticonvulsant activity. The underlying mechanism behind this action of safinamide is attributed to the inhibition of voltage gated calcium and sodium channels. Moreover, owing to the importance of ion channels in maintaining neuronal circuitry and neurotransmitter release, numerous studies explored the potential of safinamide in neurological diseases including PD, stroke, multiple sclerosis and neuromuscular disorders such as Duchenne muscular dystrophy and non-dystrophic myotonias. Nevertheless, evidence from multiple preclinical studies suggested a potent, selective and reversible inhibitory activity of safinamide against monoamine oxidase (MAO)-B enzyme which is responsible for degrading dopamine, a neurotransmitter primarily implicated in the pathophysiology of PD. Therefore, clinical studies were conducted to assess safety and efficacy of safinamide in PD. Indeed, results from various Phase 3 clinical trials suggested strong evidence of safinamide as an add-on therapy in controlling the exacerbation of PD. This review presents a thorough developmental history of safinamide in PD and provides comprehensive insight into plausible mechanisms via which safinamide can be explored in other neurological and muscular diseases.

Serum amyloid A level correlates with T2 lesion volume and cortical volume in patients with multiple sclerosis

It is unclear whether brain atrophy in multiple sclerosis (MS) is associated with not only neuroinflammation but also systemic inflammation. Here we found that systemic inflammatory marker serum amyloid A (SAA) was moderately correlated with cortical volume in the patients with clinically isolated syndrome (CIS) and MS (r = -0.41, p = 0.019). SAA was also significantly correlated with T2 lesion volume (T2LV) even after adjusting for age, disease duration, and disease modifying therapy (p = 0.0050). Thus, systemic inflammation may be associated with cortical atrophy, possibly via an increase in the T2LV in patients with CIS/MS.

Aryl Hydrocarbon Receptor Plasma Agonist Activity Correlates With Disease Activity in Progressive MS

OBJECTIVE

The relationship between serum aryl hydrocarbon receptor (AHR) agonistic activity levels with disease severity, its modulation over the course of relapsing-remitting MS (RRMS), and its regulation in progressive MS (PMS) are unknown. Here, we report the analysis of AHR agonistic activity levels in cross-sectional and longitudinal serum samples of patients with RRMS and PMS.

METHODS

In a cross-sectional investigation, a total of 36 control patients diagnosed with noninflammatory diseases, 84 patients with RRMS, 35 patients with secondary progressive MS (SPMS), and 41 patients with primary progressive MS (PPMS) were included in this study. AHR activity was measured in a cell-based luciferase assay and correlated with age, sex, the presence of disease-modifying therapies, Expanded Disability Status Scale scores, and disease duration. In a second longitudinal investigation, we analyzed AHR activity in 13 patients diagnosed with RRMS over a period from 4 to 10 years and correlated AHR agonistic activity with white matter atrophy and lesion load volume changes.

RESULTS

In RRMS, AHR ligand levels were globally decreased and associated with disease duration and neurologic disability. In SPMS and PPMS, serum AHR agonistic activity was decreased and correlated with disease severity. Finally, in longitudinal serum samples of patients with RRMS, decreased AHR agonistic activity was linked to progressive CNS atrophy and increased lesion load.

CONCLUSIONS

These findings suggest that serum AHR agonist levels negatively correlate with disability in RRMS and PMS and decrease longitudinally in correlation with MRI markers of disease progression. Thus, serum AHR agonistic activity may serve as novel biomarker for disability progression in MS.

A literature review of biosensors for multiple sclerosis: Towards personalized medicine and point-of-care testing

Multiple sclerosis (MS) is a chronic neuroinflammatory disease of the central nervous system that leads to severe motor and sensory deficits in patients. Although some biomolecules in serum or cerebrospinal fluid have been suggested as biomarkers for MS diagnosis, following disease activity and monitoring treatment response, most of these potential biomarkers are not currently in clinical use and available for all patients. The reasons behind this are generally related to insufficient robustness of biomarker or technical difficulties, high prices, and requirements for technical personnel for their detection. Point-of-care testing (POCT) is an emerging field of healthcare that can be applied at the hospital as well as at home without the need for a centralized laboratory. Biosensor devices offer a convenient means for POCT. A biosensor is a compact analytical device that uses a bioreceptor, such as an antibody, enzyme, or oligonucleotide, to capture the analyte of interest. The interaction between the analyte and the bioreceptor is sensed and transduced into a suitable signal by the signal transducer. The advantages of using a biosensor for detecting the biomolecule of interest include speed, simplicity, accuracy, relatively lower cost, and lack of requirements for highly qualified personnel to perform the testing. Owing to these advantages and with the help of innovations in biosensor development technologies, there has been a great interest in developing biosensor devices for MS in recent years. Hence, the purpose of this review was to provide researchers with an up-to-date summary of the literature as well as to highlight the challenges and opportunities in this translational research field. In addition, because this is a highly interdisciplinary field of study, potentially concerning MS specialists, neurologists, biomedical researchers, and engineers, another aim of this review was to bridge the gap between these disciplines.

Impairments of white matter tracts and connectivity alterations in five cognitive networks of patients with multiple sclerosis

INTRODUCTION

MS is associated with structural and functional brain alterations leading to cognitive impairments across multiple domains including attention, memory, and speed of information processing. Here, we analyzed the white matter damage and topological organization of white matter tracts in specific brain regions responsible for cognition in MS.

METHODS

Brain DTI, rs-fMRI, T1, T2, and T2-FLAIR were acquired for 22 MS subjects and 22 healthy controls. Automatic brain parcellation was performed on T1-weighted images. Skull-stripped T1-weighted intensity inverted images were co-registered to the b0 image. Diffusion-weighted images were processed to perform whole brain tractography. The rs-fMRI data were processed, and the connectivity matrixes were analyzed to identify significant differences in the network of nodes between the two groups using NBS analysis. In addition, diffusion entropy maps were produced from DTI data sets using in-house software.

RESULTS

MS subjects exhibited significantly reduced mean FA and entropy in 38 and 34 regions, respectively, out of a total of 54 regions. The connectivity values in both structural and functional analyses were decreased in most regions of the default mode network and in four other cognitive networks in MS subjects compared to healthy controls. MS also induced significant reduction in the normalized hippocampus and corpus callosum volumes; the normalized hippocampus volume was significantly correlated with EDSS scores.

CONCLUSION

MS subjects have significant white matter damage and reduction of FA and entropy in various brain regions involved in cognitive networks. Structural and functional connectivity within the default mode network and an additional four cognitive networks exhibited significant changes compared with healthy controls.

NAA is a Marker of Disability in Secondary-Progressive MS: A Proton MR Spectroscopic Imaging Study

BACKGROUND AND PURPOSE

The secondary progressive phase of multiple sclerosis is characterised by disability progression due to processes that lead to neurodegeneration. Surrogate markers such as those derived from MRI are beneficial in understanding the pathophysiology that drives disease progression and its relationship to clinical disability. We undertook a 1H-MRS imaging study in a large secondary progressive MS (SPMS) cohort, to examine whether metabolic markers of brain injury are associated with measures of disability, both physical and cognitive.

MATERIALS AND METHODS

A cross-sectional analysis of individuals with secondary-progressive MS was performed in 119 participants. They underwent ¹H-MR spectroscopy to obtain estimated concentrations and ratios to total Cr for total NAA, mIns, Glx, and total Cho in normal-appearing WM and GM. Clinical outcome measures chosen were the following: Paced Auditory Serial Addition Test, Symbol Digit Modalities Test, Nine-Hole Peg Test, Timed 25-foot Walk Test, and the Expanded Disability Status Scale. The relationship between these neurometabolites and clinical disability measures was initially examined using Spearman rank correlations. Significant associations were then further analyzed in multiple regression models adjusting for age, sex, disease duration, T2 lesion load, normalized brain volume, and occurrence of relapses in 2 years preceding study entry.

RESULTS

Significant associations, which were then confirmed by multiple linear regression, were found in normal-appearing WM for total NAA (tNAA)/total Cr (tCr) and the Nine-Hole Peg Test (ρ = 0.23; 95% CI, 0.06-0.40); tNAA and tNAA/tCr and the Paced Auditory Serial Addition Test (ρ = 0.21; 95% CI, 0.03-0.38) (ρ = 0.19; 95% CI, 0.01-0.36); mIns/tCr and the Paced Auditory Serial Addition Test, (ρ = -0.23; 95% CI, -0.39 to -0.05); and in GM for tCho and the Paced Auditory Serial Addition Test (ρ = -0.24; 95% CI, -0.40 to -0.06). No other GM or normal-appearing WM relationships were found with any metabolite, with associations found during initial correlation testing losing significance after multiple linear regression analysis.

CONCLUSIONS

This study suggests that metabolic markers of neuroaxonal integrity and astrogliosis in normal-appearing WM and membrane turnover in GM may act as markers of disability in secondary-progressive MS.

Siponimod: Disentangling disability and relapses in secondary progressive multiple sclerosis

Background:

In multiple sclerosis, impact of treatment on disability progression can be confounded if treatment also reduces relapses.

Objective:

To distinguish siponimod’s direct effects on disability progression from those on relapses in the EXPAND phase 3 trial.

Methods:

Three estimands, one based on principal stratum and two on hypothetical scenarios (no relapses, or equal relapses in both treatment arms), were defined to determine the extent to which siponimod’s effects on 3- and 6-month confirmed disability progression were independent of on-study relapses.

Results:

Principal stratum analysis estimated that siponimod reduced the risk of 3- and 6-month confirmed disability progression by 14%–20% and 29%–33%, respectively, compared with placebo in non-relapsing patients. In the hypothetical scenarios, risk reductions independent of relapses were 14%–18% and 23% for 3- and 6-month confirmed disability progression, respectively.

Conclusion:

By controlling the confounding impact of on-study relapses on confirmed disability progression, these statistical approaches provide a methodological framework to assess treatment effects on disability progression in relapsing and non-relapsing patients. The analyses support that siponimod may be useful for treating secondary progressive multiple sclerosis in patients with or without relapses.

Evaluation of the rate of COVID-19 infection, hospitalization and death among Iranian patients with multiple sclerosis

BACKGROUND

COVID-19 is increasingly expanding all over the world. People who have an underlying disease or taking immunosuppressive drugs are generally more likely to be infected than the others. Multiple sclerosis (MS) patients may also be at risk of the disease and its complications depending on the medication they are taking. In this study, we evaluated a large population of patients with MS with different disease modifying drugs to show if any of them increases the risk. In addition, this study evaluates the incidence of COVID-19 in patients with MS, the rate of hospitalization or death in these patients.

METHOD

This study was performed at the MS Clinic of Sina Hospital. All patients were contacted and their demographic characteristics were recorded. They were then asked about their COVID-19 symptoms. Patients with these symptoms were further evaluated. The documents were reviewed by treating neurologist and MS nurses to be sure about diagnosis of COVID19. The positive polymerase chain reaction (PCR) result or compatible lung computed tomography (CT) scan was acceptable for COVID-19 diagnosis.

RESULTS

4647 patients answered the phone contact. Of these, 68 were infected with the COVID-19. The rate of hospitalization was 25% which is far more than general population. Two patients died from COVID-19. Rituximab was associated with increase rate of COVID-19 infection but not with hospitalization rate. There was no significant correlation between use of other drugs and rate of infection.

CONCLUSION

This study revealed that the incidence of COVID-19 in MS patients is not more than general population, but the risk of hospitalization in these patients is higher than estimated for the disease. This highlights the importance of communicating to patients the severity of COVID-19 and the importance of risk reduction behaviors like social distancing and mask use.

Anti-CD20 Agents for Multiple Sclerosis: Spotlight on Ocrelizumab and Ofatumumab

Until recently, in the pathogenesis of Multiple Sclerosis (MS), the contribution of B cells has been largely underestimated, and the disease was considered a T-cell-mediated disorder. However, newer evidence shows that B cells play a crucial role in the pathogenesis of MS via antigen-driven autoantibody responses and through the cross regulation of T-helper cells. As B cells express the surface molecule CD20 at all points of differentiation, it provides a specific target for monoclonal antibodies, and the development and clinical testing of anti-CD20 antibody treatments for MS have been successful. After some observations, some small clinical trials found positive effects for the first anti-CD20 therapeutic rituximab in MS; newer agents have been specifically evaluated, resulting in the development of ocrelizumab and ofatumumab. Ocrelizumab, a humanized anti-CD20 monoclonal antibody, was approved in March 2017 by the Food and Drug Administration (FDA) and is also the first proven therapy to reduce disability progression in primary progressive MS. This is particularly significant considering that disease-modifying treatment options are few for both primary and secondary progressive MS. Ofatumumab, a fully human anti-CD20 monoclonal antibody, that binds a distinct epitope, has been further investigated in phase 3 trials for relapsing forms of MS. In this review, we discuss in detail these two anti-CD20 agents and their advent for treatment of MS.