Optical coherence tomography angiography as a potential tool in differential diagnosis of multiple sclerosis and rheumatic disorders with central nervous system involvement.

PURPOSE: The aim of this study is to analyse whether optical coherence tomography angiography (angio-OCT, OCTA) measurements can be a useful tool to differentiate central nervous system (CNS) involvement in rheumatic disorders (RD) from multiple sclerosis (MS). METHODS: A total of 85 patients- 41 with MS, 21 with RD with CNS involvement and 23 healthy controls were included in the study. All individuals underwent OCTA and the following parameters were measured in each eye separately: average foveal and parafoveal vessel density (VD), average foveal and parafoveal vessel length (VL) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP), as well as area, perimeter, and circularity of the foveal avascular zone. RESULTS: OCTA showed a VD reduction in the foveal region of the SCP in eyes of RD patients when compared to MS patients (21.96 ± 3.39 vs.23.88 ± 3.05 (p = 0.003)). There have been no significant differences in any of the assessed parameters that is average VD and total average VL in the foveal area of the SCP as well as of the DCP in the general population comprising healthy controls, MS and RD groups (p > 0.05 for all). CONCLUSIONS: Our results suggest that an OCTA finding of decreased VD in the foveal region of the SCP may be considered as a potentially useful biomarker of RD in comparison with MS patients.

Histone H3 posttranslational modified enzymes defined neutrophil plasticity and their vulnerability to IL-10 in the course of the inflammation.

BACKGROUND: Neutrophils are a heterogeneous population capable of antimicrobial functions associated with pre-activation/activation and tissue regeneration. The specific polarisation of immune cells is mediated by the modification of 'chromatin landscapes', which enables differentiated access and activity of regulatory elements that guarantee their plasticity during inflammation No specific pattern within histone posttranslational modifications (PTMs) controlling this plasticity has been identified. METHODS: Using the in vitro model of inflammation, reflecting different states of neutrophils from resting, pre-activated cells to activated and reducing tissue regeneration, we have analysed 11 different histone posttranslational modifications (PTMs), PTM enzymes associated with remodelling neutrophil chromatin, and H3K4me3 ChIP-Seq Gene Ontology analysis focusing on the processes related to histone PTMs. These findings were verified by extrapolation to adequate clinical status, using neutrophils derived from the patients with sepsis (systemic septic inflammation with LPS-stimulated neutrophils), neuromyelitis optical spectrum disorders (aseptic inflammation with pre-activated neutrophils) and periodontitis (local self-limiting septic inflammation with IL-10-positive neutrophils). RESULTS: Physiological activation of neutrophils comprises a pre-activation characterised by histone H3K27ac and H3K4me1, which position enhancers; direct LPS exposure is induced explicitly by H3K4me3 which marked Transcription Start Site (TSS) regions and low-level of H3K9me3, H3K79me2 and H3K27me3 which, in turn, marked repressed genes. Contrary to antimicrobial action, IL-10 positively induced levels of H3S10p and negatively H3K9me3, which characterised processes related to the activation of genes within heterochromatin mediated by CHD1 and H3K9me3 specific demethylase JMJD2A. IL-10 protects changes within histone PTMs induced by TNF or LPS that affected H3K4me3-specific methyltransferase SETD1A and MLL1. Neutrophils previously exposed to inflammatory factors become unvulnerable to IL-10 because previous LPS stimulation interrupts TSS regions marked by H3K4me3 of CHD1 and JMJD2A genes. Therefore, LPS-activated neutrophils are disabled to induce CHD1/JMJD2A enzymes by IL-10, making this process irreversible. Because transcription of JMJD2A and CHD1 also depends on TSS positioning by H3K4me3, neutrophils before LPS stimulation become insensitive to IL-10. CONCLUSION: Neutrophils, once pre-activated by TNF or directly stimulated by LPS, become insensitive to the anti-inflammatory effects of IL-10, and vice versa; IL-10 protects neutrophils against these proinflammatory stimuli. This phenomenon is responsible for disturbing the natural process of resolving inflammation and tissue regeneration.

Differences in Brain Atrophy Pattern between People with Multiple Sclerosis and Systemic Diseases with Central Nervous System Involvement Based on Two-Dimensional Linear Measures.

Conventional brain magnetic resonance imaging (MRI) in systemic diseases with central nervous system involvement (SDCNS) may imitate MRI findings of multiple sclerosis (MS). In order to better describe the MRI characteristics of these conditions, in our study we assessed brain volume parameters in MS (n = 58) and SDCNS (n = 41) patients using two-dimensional linear measurements (2DLMs): bicaudate ratio (BCR), corpus callosum index (CCI) and width of third ventricle (W3V). In SDCNS patients, all 2DLMs were affected by age (CCI p = 0.005, BCR p < 0.001, W3V p < 0.001, respectively), whereas in MS patients only BCR and W3V were (p = 0.001 and p = 0.015, respectively). Contrary to SDCNS, in the MS cohort BCR and W3V were associated with T1 lesion volume (T1LV) (p = 0.020, p = 0.009, respectively) and T2 lesion volume (T2LV) (p = 0.015, p = 0.009, respectively). CCI was associated with T1LV in the MS cohort only (p = 0.015). Moreover, BCR was significantly higher in the SDCNS group (p = 0.01) and CCI was significantly lower in MS patients (p = 0.01). The best predictive model to distinguish MS and SDCNS encompassed gender, BCR and T2LV as the explanatory variables (sensitivity 0.91; specificity 0.68; AUC 0.86). Implementation of 2DLMs in the brain MRI analysis of MS and SDCNS patients allowed for the identification of diverse patterns of local brain atrophy in these clinical conditions.

Predictive value of brain atrophy, serum biomarkers and information processing speed for early disease progression in multiple sclerosis.

Introduction: Multiple sclerosis (MS) is a chronic autoimmune-mediated demyelinating disease of the central nervous system (CNS). A clinical presentation of the disease is highly differentiated even from the earliest stages of the disease. The application of stratifying tests in clinical practice would allow for improving clinical decision-making including a proper assessment of treatment benefit/risk balance. Methods: This prospective study included patients with MS diagnosed up to 1 year before recruitment. We analyzed serum biomarkers such as CXCL13, CHI3L1, OPN, IL-6, and GFAP and neurofilament light chains (NfLs); brain MRI parameters of linear atrophy such as bicaudate ratio (BCR), third ventricle width (TVW); and information processing speed were measured using the Symbol Digit Modalities Test (SDMT) during the 2 years follow-up. Results: The study included a total of 50 patients recruited shortly after the diagnosis of MS diagnosis (median 0 months; range 0-11 months), and the mean time of observation was 28 months (SD = 4.75). We observed a statistically significant increase in the EDSS score (Wilcoxon test: Z = 3.06, p = 0.002), BCR (Wilcoxon test: Z = 4.66, p < 0.001), and TVW (Wilcoxon test: Z = 2.84, p = 0.005) after 2 years of disease. Patients who had a significantly higher baseline level of NfL suffered from a more severe disease course as per the EDSS score (Mann-Whitney U-test: U = 107, Z = -2,74, p = 0.006) and presence of relapse (Mann-Whitney U-test: U = 188, Z = -2.01, p = 0.044). In the logistic regression model, none of the parameters was a significant predictor for the achieving of no evidence of disease activity status (NEDA). In the model considering all assessed parameters, only the level of NfL had a significant impact on disease progression, measured as the increase in EDSS (logistic regression: ß = 0.002, p = 0.017). Conclusion: We confirmed that NfL levels in serum are associated with more active disease. Moreover, we found that TVW at the time of diagnosis was associated with an impairment in cognitive function measured by information processing speed at the end of the 2-year observation. The inclusion of serum NfL and TVW assessment early in the disease may be a good predictor of disease progression independent of NEDA.

Cerebrospinal Fluid Biomarkers in Differential Diagnosis of Multiple Sclerosis and Systemic Inflammatory Diseases with Central Nervous System Involvement.

BACKGROUND: Diagnosis of multiple sclerosis (MS) is established on criteria according to clinical and radiological manifestation. Cerebrospinal fluid (CSF) analysis is an important part of differential diagnosis of MS and other inflammatory processes in the central nervous system (CNS). METHODS: In total, 242 CSF samples were collected from patients undergoing differential MS diagnosis because of the presence of T2-hyperintensive lesions on brain MRI. The non-MS patients were subdivided into systemic inflammatory diseases with CNS involvement (SID) or cerebrovascular diseases (CVD) or other non-inflammatory diseases (NID). All samples were analyzed for the presence of oligoclonal bands and ELISA was performed for detection of: INF gamma, IL-6, neurofilaments light chain (NF-L), GFAP, CHI3L1, CXCL13, and osteopontin. RESULTS: The level of IL-6 (p = 0.024), osteopontin (p = 0.0002), and NF-L (p = 0.002) was significantly different among groups. IL-6 (p = 0.0350) and NF-L (p = 0.0015) level was significantly higher in SID compared to NID patients. A significantly higher level of osteopontin (p = 0.00026) and NF-L (p = 0.002) in MS compared to NID population was noted. ROC analysis found weak diagnostic power for osteopontin and NFL-L. CONCLUSIONS: The classical and non-standard markers of inflammatory process and neurodegeneration do not allow for sufficient differentiation between MS and non-MS inflammatory CNS disorders. Weak diagnostic power observed for the osteopontin and NF-L needs to be further investigated.

Analysis of Side Effects Following Vaccination Against COVID-19 Among Individuals With Multiple Sclerosis Treated With DMTs in Poland.

Background and Objectives: Since vaccination against COVID-19 is available for over a year and the population of immunized individuals with autoimmune disorders is higher than several months before, an evaluation of safety and registered adverse events can be made. We conducted a large study of side effects following the COVID-19 vaccine among patients with multiple (MS) sclerosis treated with disease-modifying therapies (DMTs) and analyzed factors predisposing for particular adverse events. Methods: We gathered data of individuals with MS treated with DMTs from 19 Polish MS Centers, who reported at least one adverse event following COVID-19 vaccination. The information was obtained by neurologists using a questionnaire. The same questionnaire was used at all MS Centers. To assess the relevance of reported adverse events, we used Fisher's exact test, t-test, and U-Menn-Whutney test. Results: A total of 1,668 patients with MS and reports of adverse events after COVID-19 vaccination were finally included in the study. Besides one case marked as "red flag", all adverse events were classified as mild. Pain at the injection site was the most common adverse event, with a greater frequency after the first dose. Pain at the injection site was significantly more frequent after the first dose among individuals with a lower disability (EDSS ≤2). The reported adverse events following immunization did not differ over sex. According to age, pain at the injection site was more common among individuals between 30 and 40 years old, only after the first vaccination dose. None of the DMTs predisposed for particular side effects. Conclusions: According to our findings, vaccination against COVID-19 among patients with MS treated with DMTs is safe. Our study can contribute to reducing hesitancy toward vaccination among patients with MS.

Changes Within H3K4me3-Marked Histone Reveal Molecular Background of Neutrophil Functional Plasticity.

Neutrophils are a heterogenous population capable of both antimicrobial functions and suppressor ones, however, no specific pattern of transcription factors controlling this plasticity has been identified. We observed rapid changes in the neutrophil status after stimulation with LPS, pre-activating concentration of TNF-α, or IL-10. Chromatin immunoprecipitation sequencing (ChIP-Seq) analysis of histone H3K4me3 allowed us to identify various transcriptional start sites (TSSs) associated with plasticity and heterogeneity of human neutrophils. Gene Ontology analysis demonstrated great variation within target genes responsible for neutrophil activation, cytokine production, apoptosis, histone remodelling as well as NF-κB transcription factor pathways. These data allowed us to assign specific target genes positioned by H3K4me3-marked histone with a different pattern of gene expression related to NF-κB pathways, apoptosis, and a specific profile of cytokines/chemokines/growth factors realised by neutrophils stimulated by LPS, IL-10, or TNF-α. We discovered IL-10-induced apoptotic neutrophils being transcriptionally active cells capable of switching the profile of cytokines/chemokines/growth factors desired in resolving inflammation via non-canonical NF-κB pathway with simultaneous inhibition of canonical NF-κB pathway. As apoptotic/suppressive neutrophils induced by IL-10 via positioning genes within H3K4me3-marked histone were transcriptionally active, newly described DNA binding sites can be considered as potential targets for immunotherapy.H3K4me3 histone ChIP-Seq analysis reveals molecular drivers critical for switching neutrophils from their pro- to anti-inflammatory properties.

The influence of COVID-19 pandemic lockdown on the physical activity of people with multiple sclerosis. The role of online training.

BACKGROUND: COVID-19 pandemic has affected people with multiple sclerosis (PwMS) on various levels. Pandemic lockdown influenced the access to typical measures of physical activity such as out-door training or gym exercises. METHODS: We performed a survey assessing physical activity during pandemic lockdown among PwMS treated in our MS center. The questionnaire encompassed questions regarding physical activity before and during lockdown, including the employment of online technologies. RESULTS: The survey was completed by 262 PwMS. Physical activity before lockdown was declared by 74.4% of PwMS, regular exercises were declared by 30.9% of participants. Among physically active PwMS 50.5% limited their physical activity during the COVID-19 lockdown. The decrease in physical activity was reported more frequently by PwMS with higher levels of disability, particularly declaring regular exercises before lockdown. In the opinion of 39,7% of PwMS online training could replace standard exercises, however only 19,9% of PwMS were actively looking for online training during the lockdown. The interest in online exercise was greatest in the group ≤30 years of age and EDSS ≤2. Synchronous exercises were the preferred online training, particularly among PwMS with EDSS≥4. CONCLUSION: Our findings indicate a need for systematic educational and organizational measures, promoting physical activity among PwMS and acknowledging pandemic conditions.

Safety of Vaccines against SARS-CoV-2 among Polish Patients with Multiple Sclerosis Treated with Disease-Modifying Therapies.

(1) Background: The present study aims to report the side effects of vaccination against coronavirus disease 2019 (COVID-19) among patients with multiple sclerosis (MS) who were being treated with disease-modifying therapies (DMTs) in Poland. (2) Methods: The study included 2261 patients with MS who were being treated with DMTs, and who were vaccinated against COVID-19 in 16 Polish MS centers. The data collected were demographic information, specific MS characteristics, current DMTs, type of vaccine, side effects after vaccination, time of side-effect symptom onset and resolution, applied treatment, relapse occurrence, and incidence of COVID-19 after vaccination. The results were presented using maximum likelihood estimates of the odds ratio, t-test, Pearson's chi-squared test, Fisher's exact p, and logistic regression. The statistical analyses were performed using STATA 15 software. (3) Of the 2261 sampled patients, 1862 (82.4%) were vaccinated with nucleoside-modified messenger RNA (mRNA) vaccines. Mild symptoms after immunization, often after the first dose, were reported in 70.6% of individuals. Symptoms included arm pain (47.5% after the first dose and 38.7% after the second dose), fever/chills/flu-like symptoms (17.1% after the first dose and 20.5% after the second dose), and fatigue (10.3% after the first dose and 11.3% after the second dose). Only one individual presented with severe side effects (pro-thrombotic complications) after vaccination. None of the DMTs in the presented cohort were predisposed to the development of side effects. Nine patients (0.4%) had a SARS-CoV-2 infection confirmed despite vaccination. (4) Conclusions: Vaccination against SARS-CoV-2 is safe for people with MS who are being treated with DMTs. Most adverse events following vaccination are mild and the acute relapse incidence is low.

Effect of Multiple Sclerosis Cerebrospinal Fluid and Oligodendroglia Cell Line Environment on Human Wharton's Jelly Mesenchymal Stem Cells Secretome.

Multiple sclerosis (MS) is a neurological disorder of autoimmune aetiology. Experimental therapies with the use of mesenchymal stem cells (MSCs) have emerged as a response to the unmet need for new treatment options. The unique immunomodulatory features of stem cells obtained from Wharton's jelly (WJ-MSCs) make them an interesting research and therapeutic model. Most WJ-MSCs transplants for multiple sclerosis use intrathecal administration. We studied the effect of cerebrospinal fluid (CSF) obtained from MS patients on the secretory activity of WJ-MSCs and broaden this observation with WJ-MSCs interactions with human oligodendroglia cell line (OLs). Analysis of the WJ-MSCs secretory activity with use of Bio-Plex Pro™ Human Cytokine confirmed significant and diverse immunomodulatory potential. Our data reveal rich WJ-MSCs secretome with markedly increased levels of IL-6, IL-8, IP-10 and MCP-1 synthesis and a favourable profile of growth factors. The addition of MS CSF to the WJ-MSCs culture caused depletion of most proteins measured, only IL-12, RANTES and GM-CSF levels were increased. Most cytokines and chemokines decreased their concentrations in WJ-MSCs co-cultured with OLs, only eotaxin and RANTES levels were slightly increased. These results emphasize the spectrum of the immunomodulatory properties of WJ-MSCs and show how those effects can be modulated depending on the transplantation milieu.

Optical Coherence Tomography in the Differential Diagnosis of Patients with Multiple Sclerosis and Patients with MRI Nonspecific White Matter Lesions.

In the differential diagnosis of nonspecific white matter lesions (NSWMLs) detected on magnetic resonance imaging (MRI), multiple sclerosis (MS) should be taken into consideration. Optical coherence tomography (OCT) is a promising tool applied in the differential diagnostic process of MS. We tested whether OCT may be useful in distinguishing between MS and NSWMLs patients. In patients with MS (n = 41) and NSWMLs (n = 19), the following OCT parameters were measured: thickness of the peripapillary Retinal Nerve Fibre Layer (pRNFL) in superior, inferior, nasal, and temporal segments; thickness of the ganglion cell-inner plexiform layer (GCIPL); thickness of macular RNFL (mRNFL); and macular volume (MV). In MS patients, GCIPL was significantly lower than in NSWMLs patients (p = 0.024). Additionally, in MS patients, mRNFL was significantly lower than in NSWMLs patients (p = 0.030). The average segmental pRNFL and MV did not differ between MS and NSWMLs patients (p > 0.05). GCIPL and macular RNFL thinning significantly influenced the risk of MS (18.6% [95% CI 2.7%, 25.3%]; 27.4% [95% CI 4.5%, 62.3%]), and reduced GCIPL thickness appeared to be the best predictor of MS. We conclude that OCT may be helpful in the differential diagnosis of MS and NSWMLs patients in real-world settings.

Speech Pathology-Specific Questionnaire for Persons with Multiple Sclerosis (SMS): adaptation, validation and preliminary assessment of the diagnostic potential.

INTRODUCTION: Speech and voice disorders are among the least well-described clinical manifestations of Multiple Sclerosis (MS) although their estimated prevalence reaches 40-50%. The aim of the present study was adaptation and validation of the Speech Pathology-Specific Questionnaire for Persons with Multiple Sclerosis (SMS) into the Polish language to be used as part of the diagnostic procedure to quantify important speech-related changes and to improve individual tailoring of therapeutic activities. MATERIAL AND METHODS: The study included a total number of 178 participants. The study group consisted of 107 patients diagnosed with Multiple Sclerosis, mean age 42.8±11.6 years and the Control Group were 71 healthy sex and age matched normophonic subjects, mean age 44.2±12.5 years with no neurological symptoms. Translated version of SMS was administered to all participants of the study. Voice Handicap Index (VHI) questionnaire was used for comparison purposes. Test-retest reproducibility, internal consistency, floor and ceiling effects, discriminant validity and construct validity of the Polish SMS were investigated. Preliminary assessment of diagnostic value of SMS was conducted on the basis of the results recorded in duration-related quartiles of the Study Group. RESULTS: High value of Intraclass Correlation Coefficient (ICC= 0 .930) obtained for the test-retest indicates a good level of reproducibility of the Polish SMS. High Cronbach's alpha (α=0.94) proves the test's good internal consistency. There were no floor and ceiling effects for the SMS test score in the Study Group and they were negligible in the Control Group. A significant difference in mean SMS total scores between patients and controls (14.22 points vs. 6.06 points) shows discriminant validity of SMS. Similar differences were observed for all the subscales of the test (in t test: p<0.001). A statistically significant correlation was found for the SMS score and its all subscales, as well as between all the subscales of the test proving good construct validity of the test. Similarly, statistically significant correlations were observed for the total score of SMS and VHI (r=.817, p <0.001) as well as between the particular subscales of SMS test and the subscales of VHI. There was a statistically significant difference in the mean total score of SMS in the distinguished quartiles of the Study Group with the highest values (20 points) recorded in the group of patients suffering from MS for over 15 years. CONCLUSION: The psychometric properties of the Polish version of Speech Pathology-Specific Questionnaire indicate that it is a valid patient-reported outcome measure suitable for the assessment of speech-language pathology aspects on the population of Multiple Sclerosis patients and can be used as an complementary diagnostic tool in clinical practice.

The Role of Optical Coherence Tomography in Differential Diagnosis of Multiple Sclerosis and Autoimmune Connective Tissue Diseases with CNS Involvement.

The purpose of this study was to examine whether application of optical coherence tomography (OCT) measurements can provide a useful biomarker for distinguishing central nervous system (CNS) involvement in autoimmune connective tissue diseases (CTD) from multiple sclerosis (MS). An observational study included non-optic neuritis eyes of 121 individuals: 59 patients with MS, 30 patients with CNS involvement in CTD, and 32 healthy controls. OCT examination was performed in all subjects to measure retinal nerve fiber layer (RNFL) thickness, ganglion cell complex (GCC) thickness, ganglion cell layer-inner plexiform layer (GCIPL) thickness, and volume of the macula. There was a significant group effect with regard to superior optic disc RNFL, macular RNFL, GCC, and GCIPL thickness, and macular volume. Post-hoc analysis revealed that MS patients have significantly smaller macular volume and thinner superior optic disc RNFL, macular RNFL, GCC, and GCIPL compared to healthy controls. CTD patients have significantly smaller superior optic disc RNFL, GCIPL, and GCC thickness compared to healthy controls. However, no significant group differences were observed between the patient groups (MS vs. CTD) on any outcome. Although a prominent retinal thinning may be a useful biomarker in MS patients, in a general population of individuals with a confirmed CNS involvement the use of OCT is not specific enough to discriminate between MS and autoimmune CTD.

Cognitive Dysfunction in the Early Stages of Multiple Sclerosis-How Much and How Important?

PURPOSE OF REVIEW: Multiple sclerosis (MS) is a demyelinating disease of the central nervous system that mainly affects young adults and that is one of the leading causes of disability in this age group, with cognitive impairment occurring early in the course of the disease. This article summarizes the current knowledge about cognitive dysfunction in the early phase of MS, including biomarkers, MRI correlates, and its value as a prognostic marker. RECENT FINDINGS: New sets of neuropsychological tests have been established to screen for cognitive dysfunction more easily and accurately. Moreover, structural changes detected by brain MRI and several biomarkers found in cerebrospinal fluid and blood serum have been recently correlated with decreased cognitive performance. Additionally, factors influencing cognition in MS, such as disease-modifying therapy, mood disorders, and lifestyle, are better described. Cognitive impairment early in the course of MS is suggested as a prognostic factor for disease progression. However, clear-cut definitions of the early stage of MS as well as unified criteria for the diagnosis of cognitive impairment are still lacking. New and more reliable tools for evaluating cognition in MS patients should be developed and introduced into everyday practice to facilitate the implementation of effective disease-modifying therapy, cognitive rehabilitation, and lifestyle management.

Differential diagnosis of multiple sclerosis and other inflammatory CNS diseases.

Multiple sclerosis (MS) is the most common acquired demyelinating disorder of the central nervous system (CNS). Diagnosing MS can be very challenging owing to its variable clinical features and lack of specific tests. Magnetic resonance imaging (MRI) is a key measure in this process. Although white matter lesions on brain MRI are regarded as a hallmark of MS, they are a common radiological finding and their pattern may overlap in particular CNS inflammatory diseases. The increasing availability of therapies for MS and the knowledge of benefits associated with an early treatment underscore the importance of precise and quick diagnosis. Despite an extensive research, currently no fully specific diagnostic test is available to distinguish between CNS inflammatory disorders. In this review, we discuss characteristic findings and distinctive features of CNS inflammatory disorders, with particular focus on rheumatic diseases.

Multiple Sclerosis CD49d+CD154+ As Myelin-Specific Lymphocytes Induced During Remyelination.

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system (CNS) mediated by autoreactive lymphocytes. The role of autoreactive lymphocytes in the CNS demyelination is well described, whereas very little is known about their role in remyelination during MS remission. In this study, we identified a new subpopulation of myelin-specific CD49d+CD154+ lymphocytes presented in the peripheral blood of MS patients during remission, that proliferated in vitro in response to myelin peptides. These lymphocytes possessed the unique ability to migrate towards maturing oligodendrocyte precursor cells (OPCs) and synthetize proinflammatory chemokines/cytokines. The co-culture of maturing OPCs with myelin-specific CD49d+CD154+ lymphocytes was characterized by the increase in proinflammatory chemokine/cytokine secretion that was not only a result of their cumulative effect of what OPCs and CD49d+CD154+ lymphocytes produced alone. Moreover, maturing OPCs exposed to exogenous myelin peptides managed to induce CD40-CD154-dependent CD49d+CD154+ lymphocyte proliferation. We confirmed, in vivo, the presence of CD49d+CD154+ cells close to maturating OPCs and remyelinating plaque during disease remission in the MS mouse model (C57Bl/6 mice immunized with MOG35-55) by immunohistochemistry. Three weeks after an acute phase of experimental autoimmune encephalomyelitis, CD49d+/CD154+ cells were found to be co-localized with O4+ cells (oligodendrocyte progenitors) in the areas of remyelination identified by myelin basic protein (MBP) labelling. These data suggested that myelin-specific CD49d+CD154+ lymphocytes present in the brain can interfere with remyelination mediated by oligodendrocytes probably as a result of establishing proinflammatory environment.

C5a-Preactivated Neutrophils Are Critical for Autoimmune-Induced Astrocyte Dysregulation in Neuromyelitis Optica Spectrum Disorder.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune neuroinflammatory disease. In contrast to multiple sclerosis, autoantibodies against aquaporin-4 (AQP4) expressed on astrocytic end-feet have been exclusively detected in sera of NMOSD patients. Several lines of evidence suggested that anti-AQP4 autoantibodies are pathogenic, but the mechanism triggering inflammation, impairment of astrocyte function, and the role of neutrophils presented in NMOSD cerebrospinal fluid remains unknown. In this study, we tested how human neutrophils affect astrocytes in the presence of anti-AQP4 Ab-positive serum derived from NMOSD patients. An in vitro model of inflammation consisted of human astrocyte line, NMOSD serum, and allogenic peripheral blood neutrophils from healthy individuals. We showed evidence of pathogenicity of NMOSD serum, which by consecutive action of anti-AQP4 Abs, complement system, and neutrophils affected astrocyte function. Anti-AQP4 Ab binding astrocytes initiated two parallel complementary reactions. The first one was dependent on the complement cytotoxicity via C5b-9 complex formation, and the second one on the reverse of astrocyte glutamate pump into extracellular space by C5a-preactivated neutrophils. As a consequence, astrocytes were partially destroyed; however, a major population of astrocytes polarized into proinflammatory cells which were characterized by pathological glutamate removal from extracellular space.

Plasmocytoid dendritic cell deficit of early response to toll-like receptor 7 agonist stimulation in multiple sclerosis patients.

Plasmacytoid dendritic cells (pDCs), an important immunoregulatory population, are characterized by vigorous secretion of type I interferons (IFNs) in response to toll-like receptor (TLR) 7 and 9 stimulation. We studied the function of pDCs in multiple sclerosis (MS) patients by analysis of TLR7 responses. We assessed a pDC secretion pattern of cytokines in the short term PBMC cultures stimulated with TLR7 agonist. pDCs sorted from PBMCs of both MS patients and controls were used to assess TLR7 expression profile. TLR7 induced signaling in pDCs has been analyzed with intracellular flow cytometry. We have identified a clinically correlated significant decrease of the TLR7-induced IFN-alfa (IFNa) secretion by pDCs from MS patients. This deficit has been accompanied by insufficient intracellular phosphorylation of protein kinase Akt and a decrease of the TLR7 gene expression in MS pDCs. Our results demonstrated a selective pDC deficit in MS supporting a relationship between pDCs and mechanisms of MS.

MicroRNA-146a negatively regulates the immunoregulatory activity of bone marrow stem cells by targeting prostaglandin E2 synthase-2.

The molecular mechanisms that regulate the immune function of bone marrow-derived mesenchymal stem cells (BMSCs) are not known. We have shown previously that freshly isolated BMSCs when induced to express neuronal stem cell markers lose immunoregulatory function when transferred into mice sensitized to develop experimental autoimmune encephalomyelitis. Recently, microRNAs (miRs) have been shown to be involved in the regulation of several immune responses in both innate and acquired immunity. We now show that among several differentially expressed miRs, miR-146a was strongly upregulated in neuronally differentiated when compared with miR-146a expression in freshly isolated BMSCs or control BMSCs cultured in parallel but in nondifferentiating medium. Inhibition of miR-146a with a selective antagomir restored the immunoregulatory activity of nBMSCs. We mapped miR-146a to its multiple predicted target mRNA transcripts and found that miR-146a was predicted to block PGE2 synthase (ptges-2). We then showed that Ptges-2 was directly targeted by miR-146a using a luciferase reporter assay. Furthermore, increased expression of miR-146a in BMSCs correlated with inhibition of PGE synthase-2 and inhibition of PGE2 release. Accordingly, inhibition of miR-146a restored synthesis of PGE2. These data support the conclusion that miR-146a plays a critical role in the control of the immunoregulatory potential of BMSCs.

Immunoregulatory function of bone marrow mesenchymal stem cells in EAE depends on their differentiation state and secretion of PGE2.

Bone marrow mesenchymal stem cells (BMSC)-induced amelioration of experimental autoimmune encephalomyelitis (EAE) was diminished with neuronal differentiantion of BMSC (nBMSC). BMSC secreted large amounts of PGE2, compared to nBMSC, which correlated with higher efficacy to EAE inhibition. EAE mice treated with PGE2 inhibitor, meloxicam showed decreased serum levels of PGE2 and in parallel decreased inhibitory effect on EAE course. In addition, high levels of PGE2 secretion correlated with high expression of indoleamine-2,3-dioxygenase (IDO). Meloxicam blocked IDO expression in BMSC transferred mice indicating functional relation between PGE2 and IDO induction. The current findings demonstrates PGE2 involvement in BMSC-induced inhibition of EAE and provides a mechanistic link between BMSC-derived PGE2 and IDO-dependent immunoregulation of this autoimmune condition.