Host Genetics and Gut Microbiome: Perspectives for Multiple Sclerosis

Review of evidence linking exposure to environmental stressors and associated alterations in the dynamics of immunosenescence (ISC) with the global increase in multiple sclerosis (MS)

Historical survey confirms that, over the latter part of the 20th century, autoimmune-based diseases, including multiple sclerosis (MS), have shown a worldwide increase in incidence and prevalence. Analytical population studies have established that the exponential rise in MS is not solely due to improvements in diagnosis and healthcare but relates to an increase in autoimmune risk factors. Harmful environmental exposures, including non-communicable social determinants of health, anthropogens and indigenous or transmissible microbes, constitute a group of causal determinants that have been closely linked with the global rise in MS cases. Exposure to environmental stressors has profound effects on the adaptive arm of the immune system and, in particular, the associated intrinsic process of immune ageing or immunosenescence (ISC). Stressor-related disturbances to the dynamics of ISC include immune cell-linked untimely or premature (p) alterations and an accelerated replicative (ar) change. A recognised immune-associated feature of MS is pISC and current evidence supports the presence of an arISC during the disease. Moreover, collated data illustrates the immune-associated alterations that characterise pISC and arISC are inducible by environmental stressors strongly implicated in causing duplicate changes in adaptive immune cells during MS. The close relationship between exposure to environmental risk factors and the induction of pISC and arISC during MS offers a valid mechanism through which pro-immunosenescent stressors may act and contribute to the recorded increase in the global rate and number of new cases of the disease. Confirmation of alterations to the dynamics of ISC during MS provides a rational and valuable therapeutic target for the use of senolytic drugs to either prevent accumulation and enhance ablation of less efficient untimely senescent adaptive immune cells or decelerate the dysregulated process of replicative proliferation. A range of senotherapeutics are available including kinase and transcriptase inhibitors, rapalogs, flavanols and genetically-engineered T cells and the use of selective treatments to control emerging and unspecified aspects of pISC and arISC are discussed.

The role of the "gut microbiota-mitochondria" crosstalk in the pathogenesis of multiple sclerosis

Multiple Sclerosis (MS) is a neurologic autoimmune disease whose exact pathophysiologic mechanisms remain to be elucidated. Recent studies have shown that the onset and progression of MS are associated with dysbiosis of the gut microbiota. Similarly, a large body of evidence suggests that mitochondrial dysfunction may also have a significant impact on the development of MS. Endosymbiotic theory has found that human mitochondria are microbial in origin and share similar biological characteristics with the gut microbiota. Therefore, gut microbiota and mitochondrial function crosstalk are relevant in the development of MS. However, the relationship between gut microbiota and mitochondrial function in the development of MS is not fully understood. Therefore, by synthesizing previous relevant literature, this paper focuses on the changes in gut microbiota and metabolite composition in the development of MS and the possible mechanisms of the crosstalk between gut microbiota and mitochondrial function in the progression of MS, to provide new therapeutic approaches for the prevention or reduction of MS based on this crosstalk.

The effect of multiple sclerosis therapy on gut microbiota dysbiosis: a longitudinal prospective study

Gut microbiota has complex immune functions, related to different pathologies, including multiple sclerosis (MS).This study evaluated the influence of treatments on gut microbiota in people with MS (PwMS). The research comprised 60 participants, including 39 PwMS and 21 healthy controls (HC). Among the PwMS, 20 were prescribed a disease-modifying therapy (DMT), either interferon beta1a or teriflunomide, while 19 received a combination of classical DMT and an immunoglobulin Y (IgY) supplement. For each participant, two sets of gut samples were collected: one at the study's outset and another after two months. Alpha and beta diversity analyses revealed no significant differences between groups. In comparison to the HC, the MS group exhibited an increase in Prevotella stercorea and a decrease in Faecalibacterium prausnitzii. Following treatment, individuals with MS showed enrichment in Lachnospiraceae and Streptococcus. The second sample, compared to the first one, demonstrated an increase in Bifidobacterium angulatum and a decrease in Oscillospira for individuals with MS. Gut microbiota diversity in PwMS is not significantly different to HC.However, specific taxonomic changes indicate the presence of a dysbiosis state. The use of DMTs and immunoglobulin Y supplements may contribute to alterations in microbial composition, potentially leading to the restoration of a healthier microbiome.

Relationship Between Multiple Sclerosis, Gut Dysbiosis, and Inflammation: Considerations for Treatment

Multiple sclerosis is associated with gut dysbiosis, marked by changes in the relative abundances of specific microbes, circulating gut-derived metabolites, and altered gut permeability. This gut dysbiosis promotes disease pathology by increasing circulating proinflammatory bacterial factors, reducing tolerogenic factors, inducing molecular mimicry, and changing microbial nutrient metabolism. Beneficial antiinflammatory effects of the microbiome can be harnessed in therapeutic interventions. In the future, it is essential to assess the efficacy of these therapies in randomized controlled clinical trials to help make dietary and gut dysbiosis management an integral part of multiple sclerosis care.

Targeting gut microbiota: new therapeutic opportunities in multiple sclerosis

Multiple sclerosis (MS) causes long-lasting, multifocal damage to the central nervous system. The complex background of MS is associated with autoimmune inflammation and neurodegeneration processes, and is potentially affected by many contributing factors, including altered composition and function of the gut microbiota. In this review, current experimental and clinical evidence is presented for the characteristics of gut dysbiosis found in MS, as well as for its relevant links with the course of the disease and the dysregulated immune response and metabolic pathways involved in MS pathology. Furthermore, therapeutic implications of these investigations are discussed, with a range of pharmacological, dietary and other interventions targeted at the gut microbiome and thus intended to have beneficial effects on the course of MS.

The β2-adrenergic receptor agonist terbutaline upregulates T helper-17 cells in a protein kinase A-dependent manner

BACKGROUND

T helper 17 (Th17) cells produce IL-17A cytokine and can exacerbate autoimmune diseases and asthma. The β2 adrenergic receptor is a g protein-coupled receptor that induces cAMP second messenger pathways. We tested the hypothesis that terbutaline, a β2-adrenergic receptor-specific agonist, promotes IL-17 secretion by memory Th17 cells in a cAMP and PKA-dependent manner.

METHODS

Venous peripheral blood mononuclear cells (PBMC) from healthy human participants were activated with anti-CD3 and anti-CD28 antibodies. Secreted IL-17A was measured by enzyme linked immunosorbent assay, intracellular IL-17A, and RORγ were measured using flow cytometry, and RORC by qPCR. Memory CD3+CD4+CD45RA-CD45RO+ T cells were obtained by immunomagnetic negative selection and activated with tri-antibody complex CD3/CD28/CD2. Secreted IL-17A, intracellular IL-17A, RORC were measured, and phosphorylated-serine133-CREB was measured by western blotting memory Th cells.

RESULTS

Terbutaline increased IL-17A (p < 0.001), IL-17A+ cells (p < 0.05), and RORC in activated PBMC and memory Th cells. The PKA inhibitors H89 (p < 0.001) and Rp-cAMP (p < 0.01) abrogated the effects of terbutaline on IL-17A secretion in PBMC and memory T cells. Rolipram increased IL-17A (p < 0.01) to a similar extent as terbutaline. P-Ser133-CREB was increased by terbutaline (p < 0.05) in memory T cells.

CONCLUSION

Terbutaline augments memory Th17 cells in lymphocytes from healthy participants. This could exacerbate autoimmune diseases or asthma, in cases where Th17 cells are considered to be pro-inflammatory.

RNA-binding proteins as a common ground for neurodegeneration and inflammation in amyotrophic lateral sclerosis and multiple sclerosis

The neurodegenerative and inflammatory illnesses of amyotrophic lateral sclerosis and multiple sclerosis were once thought to be completely distinct entities that did not share any remarkable features, but new research is beginning to reveal more information about their similarities and differences. Here, we review some of the pathophysiological features of both diseases and their experimental models: RNA-binding proteins, energy balance, protein transportation, and protein degradation at the molecular level. We make a thorough analysis on TDP-43 and hnRNP A1 dysfunction, as a possible common ground in both pathologies, establishing a potential link between neurodegeneration and pathological immunity. Furthermore, we highlight the putative variations that diverge from a common ground in an atemporal course that proposes three phases for all relevant molecular events.

The Role of Gut Microbiome in the Pathogenesis of Multiple Sclerosis and Related Disorders

Multiple sclerosis (MS) is a chronic, progressive neuroinflammatory disease with a complex pathophysiological background. A variety of diverse factors have been attributed to the propagation of inflammation and neurodegeneration in MS, mainly genetic, immunological, and environmental factors such as vitamin D deficiency, infections, or hormonal disbalance. Recently, the importance of the gut-brain axis for the development of many neurological conditions, including stroke, movement disorders, and neuroinflammatory disorders, has been postulated. The purpose of our paper was to summarize current evidence confirming the role of the gut microbiome in the pathophysiology of MS and related disorders, such as neuromyelitis optica spectrum disorder (NMO-SD). For this aim, we conducted a systematic review of the literature listed in the following databases: Medline, Pubmed, and Scopus, and were able to identify several studies demonstrating the involvement of the gut microbiome in the pathophysiology of MS and NMO-SD. It seems that the most relevant bacteria for the pathophysiology of MS are those belonging to Pseudomonas, Mycoplasma, Haemophilus, Blautia, Dorea, Faecalibacterium, Methanobrevibacter, Akkermansia, and Desulfovibrionaceae genera, while Clostridium perfringens and Streptoccocus have been demonstrated to play a role in the pathophysiology of NMO-SD. Following this line of evidence, there is also some preliminary data supporting the use of probiotics or other agents affecting the microbiome that could potentially have a beneficial effect on MS/NMO-SD symptoms and prognosis. The topic of the gut microbiome in the pathophysiology of MS is therefore relevant since it could be used as a biomarker of disease development and progression as well as a potential disease-modifying therapy.

Feeding the gut microbiome: impact on multiple sclerosis

Multiple sclerosis (MS) is a multifactorial neurological disease characterized by chronic inflammation and immune-driven demyelination of the central nervous system (CNS). The rising number of MS cases in the last decade could be partially attributed to environmental changes, among which the alteration of the gut microbiome driven by novel dietary habits is now of particular interest. The intent of this review is to describe how diet can impact the development and course of MS by feeding the gut microbiome. We discuss the role of nutrition and the gut microbiota in MS disease, describing preclinical studies on experimental autoimmune encephalomyelitis (EAE) and clinical studies on dietary interventions in MS, with particular attention to gut metabolites-immune system interactions. Possible tools that target the gut microbiome in MS, such as the use of probiotics, prebiotics and postbiotics, are analyzed as well. Finally, we discuss the open questions and the prospects of these microbiome-targeted therapies for people with MS and for future research.

The role of multiple sclerosis therapies on the dynamic of human gut microbiota

Gut microbiota, the total microorganisms in our gastrointestinal tract, might have an implication in multiple sclerosis (MS), a demyelinating neurological disease. Our study included 50 MS patients and 21 healthy controls (HC). Twenty patients received a disease modifying therapy (DMT), interferon beta1a or teriflunomide, 19 DMT combined with homeopathy and 11 patients accepted only homeopathy. We collected in total 142 gut samples, two for each individual: at the study enrolment and eight weeks after treatment. We compared MS patients' microbiome with HC, we analysed its evolution in time and the effect of interferon beta1a, teriflunomide and homeopathy. There was no difference in alpha diversity, only two beta diversity results related to homeopathy. Compared to HC, untreated MS patients had a decrease of Actinobacteria, Bifidobacterium, Faecalibacterium prauznitzii and increased Prevotella stercorea, while treated patients presented lowered Ruminococcus and Clostridium. Compared to the initial sample, treated MS patients had a decrease of Lachnospiraceae and Ruminococcus and an increased Enterococcus faecalis. Eubacterium oxidoreducens was reduced after homeopathic treatment. The study revealed that MS patients may present dysbiosis. Treatment with interferon beta1a, teriflunomide or homeopathy implied several taxonomic changes. DMTs and homeopathy might influence the gut microbiota.

Understanding Pathogenesis Intersects With Effective Treatment for Thyroid Eye Disease

CONTEXT

Thyroid eye disease (TED), a vision-threatening and disfiguring autoimmune process, has thwarted our efforts to understand its pathogenesis and develop effective and safe treatments. Recent scientific advances have facilitated improved treatment options.

OBJECTIVE

Review historically remote and recent advances in understanding TED.

DESIGN/SETTING/PARTICIPANTS

PubMed was scanned using search terms including thyroid-associated ophthalmopathy, thyroid eye disease, Graves' orbitopathy, autoimmune thyroid disease, and orbital inflammation.

MAIN OUTCOME MEASURES

Strength of scientific evidence, size, scope, and controls of clinical trials/observations.

RESULTS

Glucocorticoid steroids are widely prescribed systemic medical therapy. They can lessen inflammation-related manifestations of TED but fail to reliably reduce proptosis and diplopia, 2 major causes of morbidity. Other current therapies include mycophenolate, rituximab (anti-CD20 B cell-depleting monoclonal antibody), tocilizumab (interleukin-6 receptor antagonist), and teprotumumab (IGF-I receptor inhibitor). Several new therapeutic approaches have been proposed including targeting prostaglandin receptors, vascular endothelial growth factor, mTOR, and cholesterol pathways. Of potentially greater long-term importance are attempts to restore immune tolerance.

CONCLUSION

Despite their current wide use, steroids may no longer enjoy first-tier status for TED as more effective and better tolerated medical options become available. Multiple current and emerging therapies, the rationales for which are rooted in theoretical and experimental science, promise better options. These include teprotumumab, rituximab, and tocilizumab. Restoration of immune tolerance could ultimately become the most effective and safe medical management for TED.

Molecular Biomarkers and Their Implications for the Early Diagnosis of Selected Neurodegenerative Diseases

The degeneration and dysfunction of neurons are key features of neurodegenerative diseases (NDs). Currently, one of the main challenges facing researchers and clinicians is the ability to obtain reliable diagnostic tools that will allow for the diagnosis of NDs as early as possible and the detection of neuronal dysfunction, preferably in the presymptomatic stage. Additionally, better tools for assessing disease progression in this group of disorders are also being sought. The ideal biomarker must have high sensitivity and specificity, be easy to measure, give reproducible results, and reflect the disease progression. Molecular biomarkers include miRNAs and extracellular microvesicles known as exosomes. They may be measured in two extracellular fluids of the highest importance in NDs, i.e., cerebrospinal fluid (CSF) and blood. The aim of the current review is to summarize the pathophysiology of the four most frequent NDs—i.e., Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS)—as well as current progress in the research into miRNAs as biomarkers in these major neurodegenerative diseases. In addition, we discuss the possibility of using miRNA-based therapies in the treatment of neurodegenerative diseases, and present the limitations of this type of therapy.

Emerging Biomarkers of Multiple Sclerosis in the Blood and the CSF: A Focus on Neurofilaments and Therapeutic Considerations

INTRODUCTION

Multiple Sclerosis (MS) is the most common immune-mediated chronic neurodegenerative disease of the central nervous system (CNS) affecting young people. This is due to the permanent disability, cognitive impairment, and the enormous detrimental impact MS can exert on a patient's health-related quality of life. It is of great importance to recognise it in time and commence adequate treatment at an early stage. The currently used disease-modifying therapies (DMT) aim to reduce disease activity and thus halt disability development, which in current clinical practice are monitored by clinical and imaging parameters but not by biomarkers found in blood and/or the cerebrospinal fluid (CSF). Both clinical and radiological measures routinely used to monitor disease activity lack information on the fundamental pathophysiological features and mechanisms of MS. Furthermore, they lag behind the disease process itself. By the time a clinical relapse becomes evident or a new lesion appears on the MRI scan, potentially irreversible damage has already occurred in the CNS. In recent years, several biomarkers that previously have been linked to other neurological and immunological diseases have received increased attention in MS. Additionally, other novel, potential biomarkers with prognostic and diagnostic properties have been detected in the CSF and blood of MS patients.

AREAS COVERED

In this review, we summarise the most up-to-date knowledge and research conducted on the already known and most promising new biomarker candidates found in the CSF and blood of MS patients.

DISCUSSION

the current diagnostic criteria of MS relies on three pillars: MRI imaging, clinical events, and the presence of oligoclonal bands in the CSF (which was reinstated into the diagnostic criteria by the most recent revision). Even though the most recent McDonald criteria made the diagnosis of MS faster than the prior iteration, it is still not an infallible diagnostic toolset, especially at the very early stage of the clinically isolated syndrome. Together with the gold standard MRI and clinical measures, ancillary blood and CSF biomarkers may not just improve diagnostic accuracy and speed but very well may become agents to monitor therapeutic efficacy and make even more personalised treatment in MS a reality in the near future. The major disadvantage of these biomarkers in the past has been the need to obtain CSF to measure them. However, the recent advances in extremely sensitive immunoassays made their measurement possible from peripheral blood even when present only in minuscule concentrations. This should mark the beginning of a new biomarker research and utilisation era in MS.

Viral Proteins with PxxP and PY Motifs May Play a Role in Multiple Sclerosis

Multiple sclerosis (MS) is a debilitating disease that arises from immune system attacks to the protective myelin sheath that covers nerve fibers and ensures optimal communication between brain and body. Although the cause of MS is unknown, a number of factors, which include viruses, have been identified as increasing the risk of displaying MS symptoms. Specifically, the ubiquitous and highly prevalent Epstein–Barr virus, human herpesvirus 6, cytomegalovirus, varicella–zoster virus, and other viruses have been identified as potential triggering agents. In this review, we examine the specific role of proline-rich proteins encoded by these viruses and their potential role in MS at a molecular level.