Explore the vast range of titles available.

Despite the large number of immunomodulatory or immunosuppressive treatments available to treat relapsing–remitting multiple sclerosis (MS), treatment of the progressive phase of the disease has not yet been achieved. This lack of successful treatment approaches is caused by our poor understanding of the mechanisms driving disease progression. Emerging concepts suggest that a combination of persisting focal and diffuse inflammation within the CNS and a gradual failure of compensatory mechanisms, including remyelination, result in disease progression. Therefore, promotion of remyelination presents a promising intervention approach. However, despite our increasing knowledge regarding the cellular and molecular mechanisms regulating remyelination in animal models, therapeutic increases in remyelination remain an unmet need in MS, which suggests that mechanisms of remyelination and remyelination failure differ fundamentally between humans and demyelinating animal models. New and emerging technologies now allow us to investigate the cellular and molecular mechanisms underlying remyelination failure in human tissue samples in an unprecedented way. The aim of this Review is to summarize our current knowledge regarding mechanisms of remyelination and remyelination failure in MS and in animal models of the disease, identify open questions, challenge existing concepts, and discuss strategies to overcome the translational roadblock in the field of remyelination-promoting therapies.Here, the authors summarize current knowledge regarding mechanisms of remyelination and remyelination failure in multiple sclerosis and animal models of the disease and discuss strategies to overcome the translational roadblock in the field of remyelination-promoting therapies.

There is emerging evidence that the commensal microbiota has a role in the pathogenesis of multiple sclerosis (MS), a putative autoimmune disease of the CNS. Here, we compared the gut microbial composition of 34 monozygotic twin pairs discordant for MS. While there were no major differences in the overall microbial profiles, we found a significant increase in some taxa such as Akkermansia in untreated MS twins. Furthermore, most notably, when transplanted to a transgenic mouse model of spontaneous brain autoimmunity, MS twin-derived microbiota induced a significantly higher incidence of autoimmunity than the healthy twinderived microbiota. The microbial profiles of the colonized mice showed a high intraindividual and remarkable temporal stability with several differences, including Sutterella, an organism shown to induce a protective immunoregulatory profile in vitro. Immune cells from mouse recipients of MS-twin samples produced less IL-10 than immune cells from mice colonized with healthy-twin samples. IL-10 may have a regulatory role in spontaneous CNS autoimmunity, as neutralization of the cytokine in mice colonized with healthy-twin fecal samples increased disease incidence. These findings provide evidence that MS-derived microbiota contain factors that precipitate an MS-like autoimmune disease in a transgenic mouse model. They hence encourage the detailed search for protective and pathogenic microbial components in human MS.

The nuclear receptor Liver X Receptor (LXR) is a ligand-activated transcription factor that has been implicated in control of chronic inflammation by downregulating pro-inflammatory T cell responses. An impaired function of regulatory T cells, a subset of CD4+ T cells with a crucial role in maintaining lymphocytes homeostasis and immune regulation, is frequently observed in chronic inflammatory diseases. We observed that pharmacological activation of LXR in T cells not only resulted in a thorough suppression of Th1 and Th17 polarization in vitro, but also significantly induced regulatory T cells (Treg) cell differentiation in a receptor-specific fashion. In line with this, systemic LXR activation by oral treatment of mice with the LXR agonist GW3965 induced gut-associated regulatory T cells in vivo. Importantly, such LXR-activated Tregs had a higher suppressive capacity in functional in vitro coculture assays with effector T cells. Our data thus point towards a dual role of LXR-mediated control of inflammation by suppression of pro-inflammatory T cells and reciprocal induction of regulatory T cells.

Although glucocorticoids (GC) represent the most frequently used immunosuppressive drugs, their effects are still not well understood. In our previous studies, we have shown that treatment of monocytes with GC does not cause a global suppression of monocytic effector functions, but rather induces differentiation of a specific anti-inflammatory phenotype. The anti-inflammatory role of peroxisome proliferator-activated receptor (PPAR)-γ has been extensively studied during recent years. However, a relationship between GC treatment and PPAR-γ expression in macrophages has not been investigated so far. Studies using PPAR-γ-deficient mice have frequently provided controversial results. A potential reason is the use of primary cells, which commonly represent inhomogeneous populations burdened with side effects and influenced by bystander cells. To overcome this constraint, we established ER-Hoxb8-immortalized bone marrow-derived macrophages from and mice in this study. In contrast to primary macrophages, the ER-Hoxb8 system allows the generation of a homogeneous and well-defined population of resting macrophages. We could show that the loss of PPAR-γ resulted in delayed kinetic of differentiation of monocytes into macrophages as assessed by reduced F4/80, but increased Ly6C expression in early phases of differentiation. As expected, PPAR-γ-deficient macrophages displayed an increased pro-inflammatory phenotype upon long-term LPS stimulation characterized by an elevated production of pro-inflammatory cytokines TNF-α, IL1-β, IL-6, IL-12 and a reduced production of anti-inflammatory cytokine IL-10 compared to PPAR-γ WT cells. Moreover, PPAR-γ-deficient macrophages showed impaired phagocytosis. GC treatment of macrophages led to the upregulation of PPAR-γ expression. However, there were no differences in GC-induced suppression of cytokines between both cell types, implicating a PPAR-γ-independent mechanism. Intriguingly, GC treatment resulted in an increased migration only in PPAR-γ-deficient macrophages. Performing a newly developed cell-tracking experiment, we could confirm that GC induces an increased recruitment of PPAR-γ KO, but not PPAR-γ WT macrophages to the site of inflammation. Our findings suggest a specific effect of PPAR-γ on GC-induced migration in macrophages. In conclusion, we could demonstrate that PPAR-γ exerts anti-inflammatory activities and shapes macrophage functions. Moreover, we identified a molecular link between GC and PPAR-γ and could show for the first time that PPAR-γ modulates GC-induced migration in macrophages.

BackgroundLimited assessment tools for estimating the oral health of nursing home residents are available in the German language.AimsTo develop a German version of the Oral Health Assessment Tool (OHAT) and to evaluate test–retest and inter-examiner reliability in use for the assessment of nursing home residents’ oral health by caregivers before and after dental training.MethodsThe original English version of the OHAT was translated into German by a forward–backward translation process. Reliability assessments were conducted in a nursing home (n = 18) by independent application of the OHAT by two trained dentists and four professional caregivers. After receiving dental training, the caregivers repeated the OHAT with the same participants. Reliability analyses of single items were performed using Cohen’s kappa statistics. Intra-class correlations were compiled to assess reliability of the total scores. T tests were used to compare percentage agreement, and under- and overestimation of findings between a reference dentist and the caregivers before and after the training unit.ResultsSpecificity and sensitivity of the German OHAT were 87% and 86%. Test–retest reliability of the total OHAT score as estimated by the dentists was excellent (ICC 0.910; 95% CI 0.776–0.965). Before training, mean κ values between the reference dentist and caregivers ranged between 0.155 and 0.912, whereas the inter-examiner reliability of most items was only fair. After training, overall agreement between the dentist and the caregivers improved significantly from 62.1 to 83.1% (p < 0.001), as well as satisfying inter-examiner agreement for the single items.ConclusionsThe German version of the OHAT is a reliable and valid tool for the assessment of oral health conditions of nursing home residents. When used by caregivers, instruction on the tool and practical training are mandatory to ensure reliable estimations. However, further studies with a larger sample size are encouraged to verify the outcomes of this study.

In recent years, there has been a paradigm shift in the treatment of multiple sclerosis (MS) owing to the approval of a number of new drugs with very distinct mechanisms of action. All approved disease-modifying drugs primarily work directly on the immune system. However, the identification of an ‘optimal choice’ for individual patients with regard to treatment efficacy, treatment adherence and side-effect profile has become increasingly complex including conceptual as well as practical considerations. Similarly, there are peculiarities and specific requirements with regard to treatment monitoring, especially in relation to immunosuppression, the development of secondary immune-related complications, as well as the existence of drug-specific on- and off-target effects. Both classical immunosuppression and selective immune interventions generate a spectrum of potential therapy-related complications. This article provides a comprehensive overview of available immunotherapeutics for MS and their risks, detailing individual mechanisms of action and side-effect profiles. Furthermore, practical recommendations for patients treated with modern MS immunotherapeutics are provided.

The Association of British Neurologists (ABN) 2015 guidelines suggested classifying multiple sclerosis therapies according to their average relapse reduction. We sought to classify newer therapies (cladribine, ocrelizumab, ofatumumab, ozanimod) based on these guidelines. Therapies were classified by using direct comparative trial results as per ABN guidelines and generating classification probabilities for each therapy based on comparisons versus placebo in a network meta-analysis for annualized relapse rate. For both approaches, cladribine and ofatumumab were classified as high efficacy. Ocrelizumab and ozanimod (1.0 mg) were classified as moderate or high efficacy depending on the approach used. Cladribine and ofatumumab have an efficacy comparable with therapies classified in the ABN guidelines as high efficacy.

Sodium chloride promotes vascular fibrosis, arterial hypertension, pro-inflammatory immune cell polarization and endothelial dysfunction, all of which might influence outcomes following stroke. But despite enormous translational relevance, the functional importance of sodium chloride in the pathophysiology of acute ischemic stroke is still unclear. In the current study, we show that high-salt diet leads to significantly worse functional outcomes, increased infarct volumes, and a loss of astrocytes and cortical neurons in acute ischemic stroke. While analyzing the underlying pathologic processes, we identified the migrasome as a novel, sodium chloride-driven pathomechanism in acute ischemic stroke. The migrasome was previously described in vitro as a migrating organelle, which incorporates and dispatches cytosol of surrounding cells and plays a role in intercellular signaling, whereas a pathophysiological meaning has not been elaborated. We here confirm previously reported characteristics of the migrasome in vivo. Immunohistochemistry, electron microscopy and proteomic analyses further demonstrate that the migrasome incorporates and dispatches cytosol of surrounding neurons following stroke. The clinical relevance of these findings is emphasized by neuropathological examinations, which detected migrasome formation in infarcted brain parenchyma of human stroke patients. In summary, we demonstrate that high-salt diet aggravates stroke outcomes, and we characterize the migrasome as a novel mechanism in acute stroke pathophysiology.

Despite being a major cause of ischemic stroke in young adults, the biological underpinnings of cervical artery dissection (CeAD) remain poorly defined. Recent data implicate immune activation as a potential contributor. We aimed to determine whether patients with CeAD display a distinct peripheral immune signature, which may provide insights into pathogenic inflammatory processes. Peripheral blood mononuclear cells (PBMCs) from patients with spontaneous CeAD (n = 7 without and n = 11 with ischemic stroke) and ten age-matched healthy controls were analyzed via multi-color flow cytometry. Immune cell composition and activation markers were assessed, and sparse partial least squares discriminant analysis (sPLS-DA) was employed to identify CeAD-associated immune features. A secondary comparison with ischemic stroke controls was included to assess the specificity of identified immune alterations. Compared to healthy controls, CeAD patients displayed increased frequencies of CD4 ⁺ T cells and decreased natural killer T (NKT) cells. sPLS-DA demonstrated clear separation of CeAD and control immune profiles, driven by increased CD28 expression on naïve CD8 ⁺ T cells, NKp46 on NK cells, and IL-2Rα (CD25) on myeloid dendritic cells (mDC2). Elevated granzyme K in naïve CD8 ⁺ T cells indicated enhanced cytotoxic potential, while regulatory T cells were diminished. These alterations were largely preserved when compared to ischemic stroke controls, suggesting CeAD-specific immune activation. No microbial pathogens were detected by untargeted metagenomic sequencing. CeAD is associated with a distinct peripheral immune signature characterized by enhanced cytotoxic activity and reduced regulatory features. These alterations may reflect a post-infectious autoimmune mechanism triggering CeAD or a secondary immune-inflammatory response to vascular injury. Larger, longitudinal studies are needed to clarify causality and assess whether immune modulation could serve as a therapeutic target in CeAD.

Demyelination due to autoreactive T cells and inflammation in the central nervous system are principal features of multiple sclerosis (MS), a chronic and highly disabling human disease affecting brain and spinal cord. Here, we show that treatment with apelin, a secreted peptide ligand for the G protein-coupled receptor APJ/Aplnr, is protective in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Apelin reduces immune cell entry into the brain, delays the onset and reduces the severity of EAE. Apelin affects the trafficking of leukocytes through the lung by modulating the expression of cell adhesion molecules that mediate leukocyte recruitment. In addition, apelin induces the internalization and desensitization of its receptor in endothelial cells (ECs). Accordingly, protection against EAE major outcomes of apelin treatment are phenocopied by loss of APJ/Aplnr function, achieved by EC-specific gene inactivation in mice or knockdown experiments in cultured primary endothelial cells. Our findings highlight the importance of the lung-brain axis in neuroinflammation and indicate that apelin targets the transendothelial migration of immune cells into the lung during acute inflammation. Apelin is a G protein-coupled receptor ligand that is proteolytically converted into a 13-aa active peptide (A13) involved in a number of physiological processes, including inflammation. Here, the authors demonstrate that A13 reduces the severity of experimental autoimmune encephalitis by modulating leukocyte trafficking and inflammation.