Inflammatory biomarkers in multiple sclerosis

Tulehdukselliset biomerkkiaineet multippeliskleroosissa Multippeliskleroosi (MS) on tulehduksellinen keskushermostoa rappeuttava sairaus, jonka esiintyvyys Suomessa on maailman korkeimpia. MS-tauti puhkeaa 20 40 vuoden iässä ja se onkin yleisin nuorten aikuisten vakava neurologinen sairaus, josta aiheutuu merkittäviä kuluja yhteiskunnalle. Suomessa MS-potilaita on noin 7000 ja uusia tapauksia todetaan vuosittain noin 200 250. Useimmiten MS-taudin ensioireet esiintyvät jo nuorella aikuisiällä, mutta niiden tunnistaminen on edelleenkin hankalaa. MS-taudin syytä ei toistaiseksi tunneta, mutta perintö- ja ympäristötekijöiden tiedetään vaikuttavan taudin puhkeamiseen. Nykykäsityksen mukaan CD4+ T-lymfosyyttien ja niiden vapauttamien tulehdusvälittäjäaineiden uskotaan olevan keskeisessä asemassa tulehdusmuutosten synnyssä, mutta myös muut immuunipuolustuksen solut välittävät hermokudosvaurioiden syntyä. Viimeaikaisissa tutkimuksissa on pystytty osoittamaan, että taudin syntymekanismeissa on monimuotoisuutta ja vaihtelua potilaiden välillä. Näiden syntymekanismien selvittäminen parantaisi yksilöllisen hoidon edellytyksiä. Väitöskirjatyön päätavoitteena oli tunnistaa taudin syntymekanismeja kuvaavia veren immunologisia profiileja MS-taudin eri alatyypeissä. Lisäksi tutkimuksen tavoitteena oli tunnistaa biomerkkiaineita, jotka kuvaavat taudin aktiivisuutta ja sen etenemistä ja jotka ennustaisivat MS-taudin kehittymisen riskiä. Tutkimus koostui varhaisen ja myöhäisen vaiheen MS-potilaista ja terveistä kontrolleista, jotka tutkittiin neurologisesti ja aivojen kuvantamisella sekä heidän verinäytteistä tutkittiin ehdokasbiomerkkiaineiden ilmentymisprofiileja. MS-taudissa poikkeavia immunoprofiileja ilmentyi sekä proteiini- että geenitasolla. Primaarisprogressivisessa MS-taudissa havaittiin kohonneita seerumin proteiinipitoisuuksia kolmella tulehduksellisella molekyylillä (TNF-a, Fas ja CCL2), jotka kuvastivat meneillään olevaa tulehduksellista aktiivisuutta tässä tautityypissä. Lisäksi havaitsimme varhaisen vaiheen MS-potilailla poikkeavia ilmentymisprofiileja solukuolemaan liittyvissä geeneissä, jotka viittasivat lisääntyneisiin solukuolemaan liittyviin mekanismeihin taudin aktiivisuuden hillitsemiseksi. Uusia kandidaattimerkkiaineita havaittiin, joista kohonneet TRAIL ja MIF tasot olivat yhteydessä aaltomaisen taudin aktiivisuuteen, kun taas kohonneet Fas ja MIF proteiinien tasot ja TRAIL mRNA:n ilmentyminen invaliditeetin kertymiseen. Lisäksi useita ennustavia kandidaattibiomerkkiaineita löydettiin, joiden yli-ilmentyminen näyttää olevan yhteydessä MS-taudin kehittymisen riskiin. Saatujen tuloksien varmentaminen edellyttää suurempaa potilasaineistoa sekä pidempää seuranta-aikaa.Multiple Sclerosis (MS) is an immune-mediated disease of the central nervous system (CNS) that is characterized by a variable clinical course and heterogeneous and complex pathology. Pathophysiological processes in MS contribute to the disease course and clinical manifestations, and therefore biomarkers that are indicative of these events would provide significant potential for diagnostics, prediction of disease course and optimization of therapeutic responses. The goal of this thesis was to identify biomarkers in the blood that could reflect pathogenetic processes in MS and be used as biomarkers of disease activity and progression. In this regard, the aims were to: 1) define immune profiles in different clinical subtypes of MS and clinically isolated syndrome (CIS); 2) search for biomarkers for disease activity and disability; 3) search for prognostic biomarkers for CIS to MS, and 4) explore whether the postpartum disease activation of MS is related to changes in the apoptotic molecules in the blood. The study included patients with different subtypes of MS, CIS and healthy controls that underwent neurological, magnetic resonance imaging (MRI) and immunological examinations. Altered expression of immune profiles in MS subtypes were found on both the protein and gene levels. Immune profiles in sera of primary progressive MS (PPMS) were characterized by elevated levels of tumor necrosis factor (TNF)-a, soluble Fas (sFas) and C-C chemokine motif ligand 2 (CCL2). Decreased serum levels of macrophage migration inhibitory factor (MIF) were found in relapsing-remitting MS (RRMS). Aberrant expression of six apoptosis-related genes (BAD, BBC3, BCL2L14, TNFRSF25, IKBKE, NFKBID), including B-cell lymphoma 2 (Bcl-2) and nuclear factor kappa B (NF-kB) families and death receptor pathway, were found in RRMS patients. Interestingly, atypical expression profiles of apoptosis-related genes were also seen in CIS (BNIP3, TNFRSF25, IKBKE). Active disease course was associated with upregulation of serum MIF and TNF-related apoptosis inducing ligand (TRAIL), and disease progression was associated with increased TRAIL mRNA, MIF and sTRAIL. In CIS, elevated expression of three apoptosis-related genes (APAF, BIRC6, CFLAR) was found in those patients who fulfilled the diagnostic criteria for MS over the two-year follow up. In the study of the immunomodulatory effect of pregnancy on MS, sTRAIL and sFasL were upregulated in both MS patients and healthy women from late pregnancy to postpartum. The increase in sTRAIL was significantly smaller in the MS patients in comparison with the controls. In summary, this thesis focusing on the identification of biomarkers in MS showed that PPMS was characterized by elevated levels of TNF-a, sFas and CCL2 indicating inflammatory activity in this subtype. Abnormal expression of apoptosis-related genes in RRMS and CIS suggested an enhanced potential for apoptosis in immune cells directed at controlling MS disease activity. Disease activity was associated with increased levels of serum TRAIL and MIF and disease progression was associated with upregulated levels of sFas, MIF and TRAIL mRNA, suggesting these molecules to be candidate biomarkers for disease activity and progression. Interestingly, three new prognostic biomarkers for conversion to MS were found. Increased MS disease activity postpartum may be related to inadequate inhibition of T-cell reactivation after pregnancy. Currently we are validating these findings using larger patient series and longer follow-up periods

JCPyV microRNA in plasma inversely correlates with JCPyV seropositivity among long-term natalizumab-treated relapsing-remitting multiple sclerosis patients

Sensitive biomarkers are needed to better manage multiple sclerosis (MS) patients for natalizumab (NTZ)-associated risk of progressive multifocal leukoencephalopathy (PML). A currently used risk stratification algorithm, mainly based on JC polyomavirus (JCPyV) serology, has not led to a reduction of PML incidence. Therefore, this study was designed to evaluate the presence and prevalence of JCPyV miRNAs in plasma of NTZ-treated MS patients, and to explore their biomarker potential for NTZ-associated PML risk assessment. Altogether, 102 plasma samples from 49 NTZ-treated and 28 interferon-beta (IFN-beta)-treated relapsing-remitting MS patients, and 25 healthy controls (HCs) were analyzed for jcv-miR-J1-5p (5p miRNA) and jcv-miR-J1-3p (3p miRNA) expression. The overall detection rate of 5p miRNA was 84% (41/49) among NTZ-treated patients, 75% (21/28) among IFN-beta-treated patients, and 92% (23/25) in HCs. Relative 5p miRNA expression levels were lower in NTZ-treated patients as compared to patients treated with IFN-beta (p = 0.027) but not to HCs. Moreover, 5p miRNA expression inversely correlated with anti-JCPyV antibody index among JCPyV seropositive long-term NTZ-treated patients (r = -0.756; p = 0.002). The overall detection rate of 3p miRNA was low. Our results suggest that JCPyV miRNA in plasma may be linked to the reactivation of persistent JCPyV, to enhanced virus replication, and eventually to the risk of developing PML among NTZ-treated MS patients. However, further study is warranted in a larger data set including samples from PML patients to confirm the clinical relevance of JCPyV miRNA as a sign of/in viral reactivation, and to identify its potential to predict developing PML risk.Peer reviewe

Composition and short-term stability of gut microbiota in lean and spontaneously overweight healthy Labrador retriever dogs

Background The gut microbiota and its metabolic end-products act in close collaboration with the nutrient metabolism of the animal. A relationship between excess adiposity and alterations in gut microbiota composition has been identified in humans and rodents, but data are scarce for overweight dogs. This study compared composition and temporal variations of gut microbiota in healthy lean and spontaneously overweight dogs. The analysis was based on three individual fresh faeces samples from each dog during a 10-day period. Twenty-seven healthy and intact male Labrador retriever dogs were included, 12 of which were classified as lean (body condition score (BCS) 4-5 on a 9-point scale) and 15 as overweight (BCS 6-8). Gut microbiota was analysed by Illumina sequencing of the V3-V4 region of the 16S rRNA gene. Results Lean and overweight groups of dogs were not separated by principal coordinate analysis (PCoA), analysis of similarity (one-way ANOSIM, P = 0.99) or species indicator analysis (IndVal) using operational taxonomic units (OTU) data. Gut microbial taxa at phylum, family or genus level did not differ between lean and overweight dogs in mixed-model repeated measures analyses. Short-term stability, evaluated by similarity index, did not differ between lean and overweight dogs over the 10-day period. Pooled Firmicutes/Bacteroidetes (F/B) ratio was 3.1 +/- 3.7 in overweight dogs and 2.1 +/- 1.2 in lean dogs (P = 0.83). Individual dogs, irrespective of body condition (lean or overweight), displayed variation in mean alpha diversity (Chao-1 index range 122-245, Shannon index range 2.6-3.6) and mean similarity index (range 44-85%). Conclusions Healthy lean and spontaneously overweight Labrador retriever dogs had comparable gut microbiota composition and short-term stability over a 10-day sampling period. There were no alterations in microbial diversity or in relative abundance of specific taxa at phylum, family or genus level in overweight compared to lean dogs. Our findings suggest that there are few detectable differences in gut microbiota composition between healthy spontaneously overweight and lean dogs by the current method. Future application of metagenomic or metabolomic techniques could be used to investigate microbial genes or microbial end-products that may differ even when microbiota compositional analyses fail to detect a significant difference between lean and overweight dogs

Temporal variability of serum miR-191, miR-223, miR-128, and miR-24 in multiple sclerosis : A 4-year follow-up study

Background: Circulating microRNAs (miRNA) are suggested to be a promising biomarker for multiple sclerosis (MS). Previously, miR-128-3p, miR-24-3p, miR-191-5p and miR-223-3p have been reported to associate with MS pathology. However, their longitudinal changes and association with the disease activity have not been studied. Objectives: To evaluate the serum temporal variability of miR-128-3p, miR-191-5p, miR-24-3p, and miR-223-3p and their association with disability and disease activity in MS. Methods: The expression of four miRNAs in serum was studied in 57 MS patients, 18 clinically isolated syndrome patients, and 32 healthy controls over the four-year follow-up. Results: At the baseline, miR-191-5p was overexpressed in RRMS in comparison to controls, and its levels correlated positively with EDSS and progression index (PI) in RRMS. Increased levels of miR-128-3p were detected in PPMS in comparison to controls, and increased levels correlated with EDSS and PI in RRMS. The expression of miR-24-3p and miR-223-3p did not differ between the subtypes, but miR-223-3p correlated negatively with T1 lesions volumes in SPMS and PPMS. Over the four-years follow-up period, the expression of miR-128-3p and miR-24-3p was stable longitudinally, while temporal changes of miR-191-5p and miR-223-3p were observed in MS. Temporal changes in miR-191-5p were observed to be associated with an increase of EDSS or MRI activity, while the variability of miR-223-3p was associated with relapses. Conclusion: Temporal variability of miR-191-5p and miR-223-3p are associated with changes in disability accumulation and disease activity. While, miR-128-3p was stably expressed and associated with the PPMS subtype and correlated with disability accumulation.publishedVersionPeer reviewe

Establishment of a human induced pluripotent stem cell line (TAUi008-A) derived from a multiple sclerosis patient

Multiple sclerosis (MS) is a complex autoimmune disease of the central nervous system where the main pathogenetic events include demyelination and axonal degeneration. Here, we generated a human induced pluripotent stem cell (hiPSC) line from peripheral blood mononuclear cells of an MS patient utilizing Sendai virus reprogramming. The produced hiPSC line expressed pluripotency markers, differentiated into three germ layers, showed a normal karyotype and was free of virus vectors, transgenes and mycoplasma. Established hiPSCs are a valuable source for studies of MS disease modeling and drug discovery.</p

Adipsin Is Associated with Multiple Sclerosis: A Follow-Up Study of Adipokines

Background and Objective. The role of adipokines in regulation of immune responses has been recognized, but very little is known about their impact on multiple sclerosis (MS). In this study, we analysed whether the major adipokines are differentially expressed in plasma of patients with different MS subtypes and clinically isolated syndrome (CIS) and explored their association with major disease characteristics. Methods. The levels of adiponectin, adipsin, leptin, and resistin in the plasma of 80 patients with different subtypes of MS and CIS were followed up annually over the two years. The data obtained were correlated with disease activity, EDSS and volumes of T1-weighted lesions (T1-LV), and fluid attenuation inversion recovery lesions (FLAIR-LV) on MRI. Results. In MS group, a correlation was found between the level of adipsin and EDSS score at baseline (r=0.506, p<0.001). In RRMS, the levels of adipsin correlated with EDSS scores (r=0.542, p=0.002), T1-LV (r=0.410, p=0.034), and FLAIR-LV (r=0.601, p=0.0001) at baseline and an increase in the T1-LV over the follow-up (r=0.582, p=0.003). Associations with other adipokines were not detected. Conclusion. Our exploratory study provides novel insights on the impact of adipokines in MS and suggests that adipsin exerts predictive potential as a biomarker of neurodegeneration

Co-stimulation with IL-1β and TNF-α induces an inflammatory reactive astrocyte phenotype with neurosupportive characteristics in a human pluripotent stem cell model system

Without abstract.Absztrakt nélkül