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CHCHD10 is mutated in rare cases of FTD and ALS and aggregates in mouse models of disease. Here we show that the disordered N-terminal domain of CHCHD10 forms amyloid fibrils and report their cryoEM structure. Disease-associated mutations cannot be accommodated by the WT fibril structure, while sequence differences between CHCHD10 and CHCHD2 are tolerated, explaining the co-aggregation of the two proteins and linking CHCHD10 and CHCHD2 amyloid fibrils to neurodegeneration.
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G protein-coupled receptors (GPCRs) control intracellular signaling cascades via agonist-dependent coupling to intracellular transducers including heterotrimeric G proteins, GPCR kinases (GRKs), and arrestins. In addition to their critical interactions with the transmembrane core of active GPCRs, all three classes of transducers have also been reported to interact with receptor C-terminal domains (CTDs). An underexplored aspect of GPCR CTDs is their possible role as lipid sensors given their proximity to the membrane. CTD-membrane interactions have the potential to control the accessibility of key regulatory CTD residues to downstream effectors and transducers. Here, we report that the CTDs of two closely related family C GPCRs, metabotropic glutamate receptor 2 (mGluR2) and mGluR3, bind to membranes and that this interaction can regulate receptor function. We first characterize CTD structure with NMR spectroscopy, revealing lipid composition-dependent modes of membrane binding. Using molecular dynamics simulations and structure-guided mutagenesis, we then identify key conserved residues and cancer-associated mutations that modulate CTD-membrane binding. Finally, we provide evidence that mGluR3 transducer coupling is controlled by CTD-membrane interactions in live cells, which may be subject to regulation by CTD phosphorylation and changes in membrane composition. This work reveals an additional mechanism of GPCR modulation, suggesting that CTD-membrane binding may be a general regulatory mode throughout the broad GPCR superfamily.
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Membrana Celular , Simulação de Dinâmica Molecular , Receptores de Glutamato Metabotrópico , Humanos , Receptores de Glutamato Metabotrópico/metabolismo , Receptores de Glutamato Metabotrópico/química , Receptores de Glutamato Metabotrópico/genética , Membrana Celular/metabolismo , Domínios Proteicos , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/química , Ligação Proteica , Células HEK293 , Proteínas Intrinsicamente Desordenadas/metabolismo , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/genética , Transdução de SinaisRESUMO
Thymic and bone marrow outputs were evaluated in 13 sequential samples of 68 multiple sclerosis patients who initiated alemtuzumab and were clinically followed for 48 months. Three months after alemtuzumab infusions, the levels of new T lymphocytes were significantly reduced, but progressively increased reaching the highest values at 36 months, indicating the remarkable capacity of thymic function recovery. Newly produced B cells exceeded baseline levels as early as 3 months after alemtuzumab initiation. Heterogeneous patterns of new T- and B-cell recovery were identified, but without associations with age, sex, previous therapies, development of secondary autoimmunity or infections, and disease re-emergence. Trial registration version 2.0-27/01/2016.
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Esclerose Múltipla , Humanos , Alemtuzumab/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Medula Óssea , Relevância Clínica , Linfócitos TRESUMO
G protein-coupled receptors (GPCRs) control intracellular signaling cascades via agonist-dependent coupling to intracellular transducers including heterotrimeric G proteins, GPCR kinases (GRKs), and arrestins. In addition to their critical interactions with the transmembrane core of active GPCRs, all three classes of transducers have also been reported to interact with receptor C-terminal domains (CTDs). An underexplored aspect of GPCR CTDs is their possible role as lipid sensors given their proximity to the membrane. CTD-membrane interactions have the potential to control the accessibility of key regulatory CTD residues to downstream effectors and transducers. Here we report that the CTDs of two closely related family C GPCRs, metabotropic glutamate receptor 2 (mGluR2) and mGluR3, bind to membranes and that this interaction controls receptor function. We first characterize CTD structure with NMR spectroscopy, revealing lipid composition-dependent modes of membrane binding. Using molecular dynamics simulations and structure-guided mutagenesis, we identify key conserved residues and cancer-associated mutations that control CTD-membrane binding. Finally, we provide evidence that mGluR3 transducer coupling is controlled by CTD-membrane interactions in live cells which can be modulated by disease-associated mutations or CTD phosphorylation. This work reveals a novel mechanism of GPCR modulation, suggesting that CTD-membrane binding may be a general regulatory mode throughout the broad GPCR superfamily.
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It is well established that neurological and non-neurological autoimmune disorders can be triggered by viral infections. It remains unclear whether SARS-CoV-2 infection induces similar conditions and whether they show a distinctive phenotype. We retrospectively identified patients with acute inflammatory CNS conditions referred to our laboratory for antibody testing during the pandemic (March 1 to August 31, 2020). We screened SARS-COV-2 IgA/IgG in all sera by ELISA and confirmed the positivity with additional assays. Clinical and paraclinical data of SARS-COV-2-IgG seropositive patients were compared to those of seronegative cases matched for clinical phenotype, geographical zone, and timeframe. SARS-CoV-2-IgG positivity was detected in 16/339 (4%) sera, with paired CSF positivity in 3/16. 5 of these patients had atypical demyelinating disorders and 11 autoimmune encephalitis syndromes. 9/16 patients had a previous history of SARS-CoV-2 infection and 6 of them were symptomatic. In comparison with 32 consecutive seronegative controls, SARS-CoV-2-IgG-positive patients were older, frequently presented with encephalopathy, had lower rates of CSF pleocytosis and other neurological autoantibodies, and were less likely to receive immunotherapy. When SARS-CoV-2 seropositive versus seronegative cases with demyelinating disorders were compared no differences were seen. Whereas seropositive encephalitis patients less commonly showed increased CSF cells and protein, our data suggest that an antecedent symptomatic or asymptomatic SARS-CoV-2 infection can be detected in patients with autoimmune neurological conditions. These cases are rare, usually do not have specific neuroglial antibodies.
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Doenças Autoimunes , COVID-19 , Doenças Desmielinizantes , Humanos , Estudos Retrospectivos , SARS-CoV-2 , Anticorpos Antivirais , Imunoglobulina GRESUMO
BACKGROUND: IgG antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) define a subset of associated disorders (myelin oligodendrocyte glycoprotein associated disorders (MOGAD)) that can have a relapsing course. However, information on relapse predictors is scarce. The utility of retesting MOG-IgG over time and measuring their titres is uncertain. We aimed to evaluate the clinical relevance of longitudinal MOG-IgG titre measurement to predict relapses in patients with MOGAD. METHODS: In this retrospective multicentre Italian cohort study, we recruited patients with MOGAD and available longitudinal samples (at least one >3 months after disease onset) and tested them with a live cell-based assay with endpoint titration (1:160 cut-off). Samples were classified as 'attack' (within 30 days since a disease attack (n=59, 17%)) and 'remission' (≥31 days after attack (n=295, 83%)). RESULTS: We included 102 patients with MOGAD (57% adult and 43% paediatric) with a total of 354 samples (83% from remission and 17% from attack). Median titres were higher during attacks (1:1280 vs 1:640, p=0.001). Median onset titres did not correlate with attack-related disability, age or relapses. Remission titres were higher in relapsing patients (p=0.02). When considering the first remission sample available for each patient, titres >1:2560 were predictors of relapsing course in survival (log rank, p<0.001) and multivariate analysis (p<0.001, HR: 10.9, 95% CI 3.4 to 35.2). MOG-IgG seroconversion to negative was associated with a 95% relapse incidence rate reduction (incidence rate ratio: 0.05, p<0.001). CONCLUSIONS: Persistent MOG-IgG positivity and high remission titres are associated with an increased relapse risk. Longitudinal MOG-IgG titres could be useful to stratify patients to be treated with long term immunosuppression.
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Autoanticorpos , Imunoglobulina G , Humanos , Estudos Retrospectivos , Prognóstico , Glicoproteína Mielina-Oligodendrócito , Estudos de Coortes , Doença Crônica , RecidivaRESUMO
Amyloid-beta (Aß) deposition occurs in the early stages of Alzheimer's disease (AD), but the early detection of Aß is a persistent challenge. Herein, we engineered a near-infrared optical nanosensor capable of detecting Aß intracellularly in live cells and intracranially in vivo. The sensor is composed of single-walled carbon nanotubes functionalized with Aß wherein Aß-Aß interactions drive the response. We found that the Aß nanosensors selectively responded to Aß via solvatochromic modulation of the near-infrared emission of the nanotube. The sensor tracked Aß accumulation in live cells and, upon intracranial administration in a genetic model of AD, signaled distinct responses in aged mice. This technology enables the interrogation of molecular mechanisms underlying Aß neurotoxicity in the development of AD in living systems.
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Doença de Alzheimer , Nanotubos de Carbono , Animais , Camundongos , Peptídeos beta-Amiloides , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/genéticaRESUMO
Post-vaccination disease relapses have been reported in patients with MOGAD and AQP4-IgG+NMOSD. In this retrospective multicenter Italian study we assessed the frequency of relapses after SARS-CoV-2 vaccination. We included 56 cases: MOGAD, 30; AQP4-IgG+NMOSD, 26. Vaccines received were BNT162b2-Pfizer-BioNTech in 42 patients and mRNA-1273-Moderna in 14 patients. Six patients had a history of SARS-CoV-2 infection; two of them experienced a post-infection disease relapse (MOGAD). The frequency of relapses within one month of SARS-CoV-2 vaccination was 4% (1/26) in the AQP4-IgG+NMOSD group and 0% in the MOGAD group. In these patients the potential benefits of vaccination overcome the risk of relapses.
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COVID-19 , Neuromielite Óptica , Aquaporina 4 , Autoanticorpos , Vacina BNT162 , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Imunoglobulina G , Glicoproteína Mielina-Oligodendrócito , Recidiva , Estudos Retrospectivos , SARS-CoV-2 , VacinaçãoRESUMO
Antibody-mediated central nervous system (CNS) disorders including those associated with aquaporin-4 or myelin oligodendrocyte glycoprotein IgG and autoimmune encephalitis often affect women of childbearing age. Pathogenic antibodies of these diseases can potentially alter reproductive functions and influence fetal development. Hormonal changes occurring during pregnancy may modify the course of autoimmune diseases by influencing relapse risk, attack severity, and affect the delivery and postpartum period. Moreover, balancing treatment related safety issues with the risk of potentially disabling relapses during pregnancy and breastfeeding are major challenges. Intentional prenatal, gestational, and post-partum counseling is paramount to address these issues and mitigate these risks. Fortunately, new insights on risk factors for adverse pregnancy outcomes and possible preventive strategies are emerging. This review aims to summarize the interplay between antibody-mediated CNS disorders and pregnancy during the prenatal, gestational, and postpartum periods, highlight current treatment recommendations, and discuss future areas of research.
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Post-translationally modified tau is the primary component of tau neurofibrillary tangles, a pathological hallmark of Alzheimer's disease and other tauopathies. Post-translational modifications (PTMs) within the tau microtubule (MT)-binding domain (MBD), which encompasses two hexapeptide motifs that act as critical nucleating regions for tau aggregation, can potentially modulate tau aggregation as well as interactions with MTs and membranes. Here, we characterize the effects of a recently discovered tau PTM, lysine succinylation, on tau-tubulin interactions and compare these to the effects of two previously reported MBD modifications, lysine acetylation and tyrosine phosphorylation. As generation of site-specific PTMs in proteins is challenging, we used short synthetic peptides to quantify the effects on tubulin binding of three site-specific PTMs located within the PHF6∗ (paired helical filament [PHF] residues 275-280) and PHF6 (residues 306-311) hexapeptide motifs: K280 acetylation, Y310 phosphorylation, and K311 succinylation. We compared these effects to those observed for MBD PTM-mimetic point mutations K280Q, Y310E, and K311E. Finally, we evaluated the effects of these PTM-mimetic mutations on MBD membrane binding and membrane-induced fibril and oligomer formation. We found that all three PTMs perturb tau MT binding, with Y310 phosphorylation exerting the strongest effect. PTM-mimetic mutations partially recapitulated the effects of the PTMs on MT binding and also disrupted tau membrane binding and membrane-induced oligomer and fibril formation. These results imply that these PTMs, including the novel and Alzheimer's disease-specific succinylation of tau K311, may influence both the physiological and pathological interactions of tau and thus represent targets for therapeutic intervention.
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Doença de Alzheimer , Microtúbulos , Emaranhados Neurofibrilares , Processamento de Proteína Pós-Traducional , Proteínas tau , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Humanos , Lisina/metabolismo , Microtúbulos/metabolismo , Emaranhados Neurofibrilares/metabolismo , Fosforilação , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo , Proteínas tau/metabolismoRESUMO
The success of selective B-cells depleting therapies, as the anti-CD20 antibodies, in patients with multiple sclerosis (MS) has confirmed that B-cells are critical in the immune pathogenesis of the disease. Ocrelizumab, a humanized monoclonal antibody that selectively targets CD20+ B-cells, profoundly suppresses acute inflammatory disease activity, representing a highly effective therapy for relapsing-remitting multiple sclerosis (RRMS). It is also the first proven therapy able to slow disability progression in primary progressive multiple sclerosis (PPMS), particularly in patients with signs of acute radiological activity before being enrolled. Effectiveness has widely been demonstrated in randomized clinical trials (RCTs), and recently confirmed in open-label extension trials. Here, we review the role of B-cells in MS, the mechanism of action of ocrelizumab, its pharmacokinetics and pharmacodynamics, and the clinical data supporting its use, as well as safety data. We focus on issues related to the maintenance of immunocompetence, essential to ensure an immune response to either a primary infection or a vaccination. Lastly, we discuss about the possible role of ocrelizumab as an exit strategy from natalizumab-treated patients at risk of developing multifocal progressive leukoencephalopathy. In view of using ocrelizumab chronically, collecting long-term safety data and finding strategies to minimize adverse events will be extremely relevant.
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The unpredictable course and uncertain impact of relapses make treatment strategies of anti-myelin oligodendrocyte glycoprotein antibodies associated disorders (MOGAD) challenging. We analysed neurofilament light chain levels (NfL) in onset and follow-up sera of 18 patients with MOGAD to clarify the timing of axonal damage. In comparison with disease onset values (median 8.9 pg/mL, range 1.8-97), NfL levels remained stable or decreased in most follow-up measurements (n=52, median 6.7 pg/mL, range 0.2-207), including those measured on relapses. The predominant axonal damage occurs during onset, which could be the main driving factor of final disability, with subsequent relevant clinical and therapeutic implications.
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Autoanticorpos , Humanos , Glicoproteína Mielina-OligodendrócitoRESUMO
Discontinuation of natalizumab in patients with relapsing-remitting multiple sclerosis (RRMS) at risk of progressive multifocal leukoencephalopathy (PML) is associated with disease reactivation. Forty-two RRMS patients, who switched from an extended interval dose (EID) of natalizumab to ocrelizumab, underwent magnetic resonance imaging (MRI) and clinical monitoring during washout and after ocrelizumab starting. During the first 3 months, disease reactivation was observed in five (12%) patients; 6 months after ocrelizumab starting, no further relapses were recorded, and Expanded Disability Status Scale (EDSS) remained stable in 38 (90%) patients. In conclusion, ocrelizumab could be considered a choice to mitigate the risk of disease reactivation in patients previously treated with natalizumab-EID.
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Leucoencefalopatia Multifocal Progressiva , Esclerose Múltipla Recidivante-Remitente , Anticorpos Monoclonais Humanizados , Humanos , Fatores Imunológicos/efeitos adversos , Leucoencefalopatia Multifocal Progressiva/induzido quimicamente , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Natalizumab/efeitos adversos , Estudos RetrospectivosRESUMO
BACKGROUND: Pneumonia with severe respiratory failure represents the principal cause of death in COVID-19, where hyper-inflammation plays an important role in lung damage. An effective treatment aiming at reducing the inflammation without preventing virus clearance is thus urgently needed. Tocilizumab, an anti-soluble IL-6 receptor monoclonal antibody, has been proposed for treatment of patients with COVID-19. METHODS: A retrospective cohort study at the Montichiari Hospital, Brescia, Italy, was conducted. We included consecutive patients with COVID-19 related pneumonia at the early stage of respiratory failure, all treated with a standard protocol (hydroxychloroquine 400 mg daily, lopinavir 800 mg plus ritonavir 200 mg per day). We compared survival rate and clinical status in a cohort of patients who received additional treatment with tocilizumab once (either 400 mg intravenous or 324 mg subcutaneous) with a retrospective cohort of patients who did not receive tocilizumab (referred to as the standard treatment group). All outcomes were assessed at the end of the follow-up, that correspond to death or complete recovery and discharge from the hospital. FINDINGS: 158 patients were included, 90 of which received tocilizumab. 34 out of 68 (50%) patients in the standard treatment group and 7 out of 90 (7.7%) in the tocilizumab group died. Tocilizumab significantly improved survival compared to standard care (multivariate HR: 0.057; 95% C.I = 0.017- 0.187, p < 0.001). No differences between the two administration routes of tocilizumab were observed. No tocilizumab-related infections and/or side effects were observed. INTERPRETATION: Early treatment with tocilizumab could be helpful to prevent excessive hyper-inflammation and death in COVID-19 related pneumonia. Low dose administration of tocilizumab is not associated with adverse events. FUNDING: none.
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BACKGROUND: Myelin oligodendrocyte glycoprotein (MOG)-IgG associated disorders are increasingly recognized as a distinct disease entity. However, diagnostic sensitivity and specificity of serum MOG-IgG as well as recommendations for testing are still debated. MATERIALS AND METHODS: Between October 2015 and July 2017 we tested serum MOG-IgG in 91 adult patients (49 females) with a demyelinating event (DE) not fulfilling 2010 McDonald criteria for MS at sampling, negative for neuromyelitis optica (NMO)-IgG and followed-up for at least 12 months. We assessed the sensitivity and specificity of a live-cell MOG-IgG assay for each final diagnosis at last follow-up, for the 2018 international recommendations for MOG-IgG testing, and for other combinations of clinical and laboratory characteristics. RESULTS: Clinical presentations included acute myelitis (n = 48), optic neuritis (n = 36), multifocal encephalomyelitis (n = 4), and brainstem syndrome (n = 3). Twenty-four patients were MOG-IgG positive. Sensitivity and specificity of MOG-IgG test applied to the 2018 international recommendations were 28.4% and 86.7%, while they were 42.1% and 88.6% when applied to DE of unclear aetiology as defined above with two or more among: 1_no periventricular and juxtacortical MS-like lesions on brain MRI; 2_longitudinally extensive MRI optic nerve lesion; 3_no CSF-restricted oligoclonal bands; 4_CSF protein > 50 mg/dl. CONCLUSIONS: Simplified requirements compared to those currently proposed for MOG-IgG testing could facilitate the applicability of the assay in the diagnosis of adults with DEs of unclear aetiology.
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Autoanticorpos/sangue , Doenças Desmielinizantes/sangue , Doenças Desmielinizantes/diagnóstico por imagem , Imunoglobulina G/sangue , Glicoproteína Mielina-Oligodendrócito/sangue , Adulto , Idoso , Autoanticorpos/líquido cefalorraquidiano , Estudos de Coortes , Doenças Desmielinizantes/líquido cefalorraquidiano , Feminino , Seguimentos , Células HEK293 , Humanos , Imunoglobulina G/líquido cefalorraquidiano , Masculino , Pessoa de Meia-Idade , Glicoproteína Mielina-Oligodendrócito/líquido cefalorraquidiano , Adulto JovemRESUMO
In this independent, multicenter, post-marketing study, we directly compare induction immunosuppression versus escalation strategies on the risk of reaching the disability milestone of Expanded Disability Status Scale (EDSS) ≥ 6.0 over 10 years in previously untreated patients with relapsing-remitting multiple sclerosis. We collected data of patients who started interferon beta (escalation) versus mitoxantrone or cyclophosphamide (induction) as initial treatment. Main eligibility criteria included an EDSS score ≤ 4.0 at treatment start and either ≥ 2 relapses or 1 disabling relapse with evidence of ≥ 1 gadolinium-enhancing lesion at magnetic resonance imaging scan in the pre-treatment year. Since patients were not randomized to treatment group, we performed a propensity score (PS)-based matching procedure to select individuals with homogeneous baseline characteristics. Comparisons were then conducted using Cox models stratified by matched pairs. Overall, 75 and 738 patients started with induction and escalation, respectively. Patients in the induction group were older and more disabled than those in the escalation group (p < 0.05). The PS-matching procedure retained 75 patients per group. In the re-sampled population, a lower proportion of patients reached the outcome after induction (21/75, 28.0%) than escalation (29/75, 38.7%) (hazard ratio = 0.48; p = 0.024). Considering the whole sample, serious adverse events occurred more frequently after induction (8/75, 10.7%) than escalation (18/738, 2.4%) (odds ratio = 3.36, p = 0.015). These findings suggest that, in patients with poor prognostic factors, induction was more effective than escalation in reducing the risk of reaching the disability milestone, albeit with a worse safety profile. Future studies are warranted to explore if newer induction agents may provide a more advantageous long-lasting risk:benefit profile.
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Imunossupressores/administração & dosagem , Esclerose Múltipla Recidivante-Remitente/diagnóstico , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Adulto , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Humanos , Masculino , Esclerose Múltipla Recidivante-Remitente/imunologia , Vigilância de Produtos Comercializados/métodos , Indução de Remissão/métodos , Estudos Retrospectivos , Fatores de Tempo , Adulto JovemRESUMO
OBJECTIVE: This study aimed to define the minimal evidence of disease activity (MEDA) during treatment that can be tolerated without exposing patients with relapsing-remitting multiple sclerosis at risk of long-term disability. METHODS: We retrospectively collected data of patients followed up to 10 years after starting interferon beta or glatiramer acetate. Survival analyses explored the association between the long-term risk of reaching an Expanded Disability Status Scale≥6.0 and early clinical and MRI activity assessed after the first and second year of treatment. Early disease activity was classified by the so-called 'MAGNIMS score' (low: no relapses and <3 new T2 lesions; medium: no relapses and ≥3 new T2 lesions or 1 relapse and 0-2 new T2 lesions; high: 1 relapse and ≥3 new T2 lesions or ≥2 relapses) and the absence or presence of contrast-enhancing lesions (CELs). RESULTS: At follow-up, 148/1036 (14.3%) patients reached the outcome: 61/685 (8.9%) with low score (reference category), 57/241 (23.7%) with medium score (HR=1.94, p=0.002) and 30/110 (27.3%) with high score (HR=2.47, p<0.001) after the first year of treatment. In the low score subgroup, the risk was further reduced in the absence (49/607, 8.1%) than in the presence of CELs (12/78, 15.4%; HR=2.11, p=0.01). No evident disease activity and low score in the absence of CELs shared the same risk (p=0.54). Similar findings were obtained even after the second year of treatment. CONCLUSIONS: Early marginal MRI activity of one to two new T2 lesions, in the absence of both relapses and CELs, is associated with a minor risk of future disability, thus representing a simple and valuable definition for MEDA.
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Esclerose Múltipla Recidivante-Remitente/diagnóstico , Adulto , Progressão da Doença , Feminino , Acetato de Glatiramer/uso terapêutico , Humanos , Fatores Imunológicos/uso terapêutico , Interferon beta/uso terapêutico , Imageamento por Ressonância Magnética , Masculino , Esclerose Múltipla Recidivante-Remitente/complicações , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de DoençaRESUMO
Electrospinning is a valuable technology for cartilage tissue engineering (CTE) due to its ability to produce fibrous scaffolds mimicking the nanoscale and alignment of collagen fibers present within the superficial zone of articular cartilage. Coaxial electrospinning allows the fabrication of core-shell fibers able to incorporate and release bioactive molecules (e.g., drugs or growth factors) in a controlled manner. Herein, we used coaxial electrospinning to produce coaxial poly(glycerol sebacate) (PGS)/poly(caprolactone) (PCL) aligned nanofibers (core:PGS/shell:PCL). The obtained scaffolds were characterized in terms of their structure, chemical composition, thermal properties, mechanical performance and in vitro degradation kinetics, in comparison to monoaxial PCL aligned fibers and respective non-aligned controls. All the electrospun scaffolds produced presented average fiber diameters within the nanometer-scale and the core-shell structure of the composite fibers was clearly confirmed by TEM. Additionally, fiber alignment significantly increased (>2-fold) the elastic modulus of both coaxial and monoxial scaffolds. Kartogenin (KGN), a small molecule known to promote mesenchymal stem/stromal cells (MSC) chondrogenesis, was loaded into the core PGS solution to generate coaxial PGS-KGN/PCL nanofibers. The KGN release kinetics and scaffold biological performance were evaluated in comparison to KGN-loaded monoaxial fibers and respective non-loaded controls. Coaxial PGS-KGN/PCL nanofibers showed a more controlled and sustained KGN release over 21 days than monoaxial PCL-KGN nanofibers. When cultured with human bone marrow MSC in incomplete chondrogenic medium (without TGF-ß3), KGN-loaded scaffolds enhanced significantly cell proliferation and chondrogenic differentiation, as suggested by the increased sGAG amounts and chondrogenic markers gene expression levels. Overall, these findings highlight the potential of using coaxial PGS-KGN/PCL aligned nanofibers as a bioactive scaffold for CTE applications.
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Anilidas , Cartilagem , Nanofibras/química , Ácidos Ftálicos , Engenharia Tecidual , Alicerces Teciduais , Anilidas/química , Anilidas/metabolismo , Anilidas/farmacocinética , Anilidas/farmacologia , Cartilagem/citologia , Cartilagem/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Decanoatos/química , Técnicas Eletroquímicas , Desenho de Equipamento , Glicerol/análogos & derivados , Glicerol/química , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Ácidos Ftálicos/química , Ácidos Ftálicos/metabolismo , Ácidos Ftálicos/farmacocinética , Ácidos Ftálicos/farmacologia , Poliésteres/química , Polímeros/química , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodosRESUMO
BACKGROUND: Demyelinating diseases of the central nervous system associated with autoantibodies against aquaporin-4 and myelin-oligodendrocyte-glycoprotein are mediated by different immunopathological mechanisms compared to multiple sclerosis. OBJECTIVE: The purpose of this study was to evaluate serum and cerebrospinal fluid cytokine/chemokine profiles in patients with autoantibodies against aquaporin-4 or autoantibodies against myelin-oligodendrocyte-glycoprotein-associated demyelination compared to multiple sclerosis and autoimmune encephalitis. METHODS: Serum and cerebrospinal fluid cytokine/chemokine levels were analysed using Procartaplex Multiplex Immunoassays. First, we analysed a panel of 32 cytokines/chemokines in a discovery group (nine aquaporin-4-antibody seropositive, nine myelin oligodendrocyte glycoprotein-antibody seropositive, eight encephalitis, 10 multiple sclerosis). Significantly dysregulated cytokines/chemokines were validated in a second cohort (11 aquaporin-4-antibody seropositive, 18 myelin oligodendrocyte glycoprotein-antibody seropositive, 18 encephalitis, 33 multiple sclerosis). RESULTS: We found 11 significantly altered cytokines/chemokines in cerebrospinal fluid and serum samples in the discovery group (a proliferation-inducing ligand, fractalkine=CX3CL1, growth-regulated oncogene-α, interleukin-1 receptor antagonist, interleukin-6, interleukin-8=CXCL8, interleukin-10, interleukin-21, interferon-É£-induced protein-10=CXCL10, monokine induced by interferon-É£=CXCL9, macrophage inflammatory protein-1ß=CCL4). Most of these cytokines/chemokines were up-regulated in autoantibodies against aquaporin-4 or autoantibodies against myelin-oligodendrocyte-glycoprotein positive patients compared to multiple sclerosis. We confirmed these results for cerebrospinal fluid interleukin-6 and serum interleukin-8, growth-regulated oncogene-α, a proliferation-inducing ligand and macrophage inflammatory protein-1ß in the validation set. Receiver-operating characteristic analysis revealed increased levels of cerebrospinal fluid interleukin-6, serum interleukin-8 and growth-regulated oncogene-α in most patients with autoantibody-associated neurological diseases. CONCLUSION: This study suggests that distinctive cerebrospinal fluid and serum cytokine/chemokine profiles are associated with autoantibody-mediated demyelination, but not with multiple sclerosis.