The influence and impact of ageing and immunosenescence (ISC) on adaptive immunity during multiple sclerosis (MS) and the animal counterpart experimental autoimmune encephalomyelitis (EAE).
Bolton Christopher,Smith Paul A
Ageing research reviews
The human ageing process encompasses mechanisms that effect a decline in homeostasis with increased susceptibility to disease and the development of chronic life-threatening illness. Increasing age affects the immune system which undergoes a progressive loss of efficiency, termed immunosenescence (ISC), to impact on quantitative and functional aspects of innate and adaptive immunity. The human demyelinating disease multiple sclerosis (MS) and the corresponding animal model experimental autoimmune encephalomyelitis (EAE) are strongly governed by immunological events that primarily involve the adaptive arm of the immune response. MS and EAE are frequently characterised by a chronic pathology and a protracted disease course which thereby creates the potential for exposure to the inherent, on-going effects and consequences of ISC. Collective evidence is presented to confirm the occurrence of established and unendorsed biological markers of ISC during the development of both diseases. Moreover, results are discussed from studies during the course of MS and EAE that reveal a premature upregulation of ISC-related biomarkers which indicates untimely alterations to the adaptive immune system. The effects of ISC and a prematurely aged immune system on autoimmune-associated neurodegenerative conditions such as MS and EAE are largely unknown but current evaluation of data justifies and encourages further investigation.
The endocannabinoid system and its therapeutic exploitation in multiple sclerosis: Clues for other neuroinflammatory diseases.
Chiurchiù Valerio,van der Stelt Mario,Centonze Diego,Maccarrone Mauro
Progress in neurobiology
Multiple sclerosis is the most common inflammatory demyelinating disease of the central nervous system, caused by an autoimmune response against myelin that eventually leads to progressive neurodegeneration and disability. Although the knowledge on its underlying neurobiological mechanisms has considerably improved, there is a still unmet need for new treatment options, especially for the progressive forms of the disease. Both preclinical and clinical data suggest that cannabinoids, derived from the Cannabis sativa plant, may be used to control symptoms such as spasticity and chronic pain, whereas only preclinical data indicate that these compounds and their endogenous counterparts, i.e. the endocannabinoids, may also exert neuroprotective effects and slow down disease progression. Here, we review the preclinical and clinical studies that could explain the therapeutic action of cannabinoid-based medicines, as well as the medical potential of modulating endocannabinoid signaling in multiple sclerosis, with a link to other neuroinflammatory disorders that share common hallmarks and pathogenetic features.
Vascular pathology in multiple sclerosis: reframing pathogenesis around the blood-brain barrier.
Spencer Jonathan I,Bell Jack S,DeLuca Gabriele C
Journal of neurology, neurosurgery, and psychiatry
Blood-brain barrier (BBB) disruption has long been recognised as an important early feature of multiple sclerosis (MS) pathology. Traditionally, this has been seen as a by-product of the myelin-specific immune response. Here, we consider whether vascular changes instead play a central role in disease pathogenesis, rather than representing a secondary effect of neuroinflammation or neurodegeneration. Importantly, this is not necessarily mutually exclusive from current hypotheses. Vascular pathology in a genetically predisposed individual, influenced by environmental factors such as pathogens, hypovitaminosis D and smoking, may be a critical initiator of a series of events including hypoxia, protein deposition and immune cell egress that allows the development of a CNS-specific immune response and the classical pathological and clinical hallmarks of disease. We review the changes that occur in BBB function and cerebral perfusion in patients with MS and highlight genetic and environmental risk factors that, in addition to modulating immune function, may also converge to act on the vasculature. Further context is provided by contrasting these changes with other neurological diseases in which there is also BBB malfunction, and highlighting current disease-modifying therapies that may also have an effect on the BBB. Indeed, in reframing current evidence in this model, the vasculature could become an important therapeutic target in MS.
Complementary and alternative treatments of multiple sclerosis: a review of the evidence from 2001 to 2016.
Claflin Suzi B,van der Mei Ingrid A F,Taylor Bruce V
Journal of neurology, neurosurgery, and psychiatry
People with multiple sclerosis (PwMS) commonly use complementary and alternative medicines (CAM), but an understanding of their efficacy is lacking. Here, we quantitatively review the class I and class II studies of treatment efficacy for multiple sclerosis from January 2001 to January 2017, in order to assess the modern evidence for CAM use. The 38 studies included in this review are divided across five CAM types (cannabis, diet, exercise, psychological approaches and other). We found little evidence to support CAM efficacy. The studies contained little replication in intervention, primary outcomes or study design. Six of 16 CAMs included in this review were only researched in a single study. Future work in this area should build consensus around study methodologies and primary outcomes.
The role of diet in multiple sclerosis: A review.
Esposito Sabrina,Bonavita Simona,Sparaco Maddalena,Gallo Antonio,Tedeschi Gioacchino
Multiple sclerosis (MS) is a multifactorial, inflammatory, and neurodegenerative disease of the central nervous system, where environmental factors interact with genetic susceptibility. The role of diet on MS has not been comprehensively elucidated; therefore, through an extensive search of relevant literature, this review reports the most significant evidence regarding nutrition as a possible co-factor influencing the inflammatory cascade by acting on both its molecular pathways and gut microbiota. Since nutritional status and dietary habits in MS patients have not been extensively reported, the lack of a scientific-based consensus on dietary recommendation in MS could encourage many patients to experiment alternative dietetic regimens, increasing the risk of malnutrition. This work investigates the health implications of an unbalanced diet in MS, and collects recent findings on nutrients of great interest among MS patients and physicians. The aim of this review is to elucidate the role of an accurate nutritional counseling in MS to move toward a multidisciplinary management of the disease and to encourage future studies demonstrating the role of a healthy diet on the onset and course of MS.
Serotonin: A mediator of the gut-brain axis in multiple sclerosis.
Malinova Tsveta S,Dijkstra Christine D,de Vries Helga E
Multiple sclerosis (Houndmills, Basingstoke, England)
BACKGROUND:The significance of the gut microbiome for the pathogenesis of multiple sclerosis (MS) has been established, although the underlying signaling mechanisms of this interaction have not been sufficiently explored. OBJECTIVES:We address this point and use serotonin (5-hydroxytryptamine (5-HT))-a microbial-modulated neurotransmitter (NT) as a showcase to demonstrate that NTs regulated by the gut microbiome are potent candidates for mediators of the gut-brain axis in demyelinating disorders. Methods, Results, and Conclusion: Our comprehensive overview of literature provides evidence that 5-HT levels in the gut are controlled by the microbiome, both via secretion and through regulation of metabolites. In addition, we demonstrate that the gut microbiome can influence the formation of the serotonergic system (SS) in the brain. We also show that SS alterations have been related to MS directly-altered expression of 5-HT transporters in central nervous system (CNS) and indirectly-beneficial effects of 5-HT modulating drugs on the course of the disease and higher prevalence of depression in patients with MS. Finally, we discuss briefly the role of other microbiome-modulated NTs such as γ-aminobutyric acid and dopamine in MS to highlight a new direction for future research aiming to relate microbiome-regulated NTs to demyelinating disorders.