Fat-soluble vitamins as disease modulators in multiple sclerosis

Exploration of the Role of Vitamins in Preventing Neurodegenerative Diseases: Comprehensive Review on Preclinical and Clinical Findings

Neurodegenerative diseases (NDDs) are a multifaceted and heterogeneous group of complex diseases. Unfortunately, a cure for these conditions has yet to be found, but there are ways to reduce the risk of developing them. Studies have shown that specific vitamins regulate the brain molecules and signaling pathways, which may help prevent degeneration. This review focuses on examining the role of vitamins in preventing five significant types of neurodegenerative diseases, including Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's disease (HD), Multiple Sclerosis (MS), and Amyotrophic Lateral Sclerosis (ALS). This review also highlights promising and controversial findings about the potential impact of vitamins on this group of diseases. Several developed countries standardize daily dietary vitamin intake to meet nutrient requirements, improve health, and prevent chronic diseases like NDDs. However, more research is necessary to gain a more comprehensive understanding of their therapeutic benefits, including studies exploring different drug-dose paradigms, diverse humanized animal models, and clinical trials conducted in various locations.

The role of fat-soluble vitamins in efferocytosis

Cell death and the efficient removal of dead cells are two basic mechanisms that maintain homeostasis in multicellular organisms. efferocytosis, which includes four steps recruitment, recognition, binding and signaling, and engulfment. Effectively and quickly removes apoptotic cells from the body. Any alteration in efferocytosis can lead to several diseases, including autoimmune and inflammatory conditions, atherosclerosis, and cancer. A wide range of dietary components affects apoptosis and, subsequently, efferocytosis. Some vitamins, including fat-soluble vitamins, affect different stages of efferocytosis. Among other things, by affecting macrophages, they are effective in the apoptotic cleansing of cells. Also, polyphenols indirectly intervene in efferocytosis through their effect on apoptosis. Considering that there are limited articles on the effect of nutrition on efferocytosis, in this article we will examine the effect of some dietary components on efferocytosis.

Dietary patterns and risk of multiple sclerosis: Results of a double-center case-control study in Iran

Background: It has been suggested that nutrition might contribute to multiple sclerosis etiology (MS). Aim: This case-control study aimed to determine the role of food habits and dietary patterns in preventing or developing MS in a multicenter study in Iran (Tehran and Shiraz). Methods: In this study, food intake of (106 patients with relapsing/remitting MS (RRMS) and 72 healthy controls in Tehran) and (75 patients with relapsing/remitting MS (RRMS) and 72 healthy controls in Shiraz) were collected using a validated semi-quantitative food frequency questionnaire. Dietary patterns were extracted using factor analysis. The association between dietary patterns and the risk of MS was analyzed by Logistic regression. Results: Two major dietary patterns were extracted: the "healthy" and the "unhealthy" patterns. After adjustment for potential confounders, in Tehran city, subjects in the highest tertile of the unhealthy dietary pattern score had greater odds of having MS, compared with those in the lowest tertile (OR: 2.16; 95% CI: [1.95-2.41]; p for trend  =  0.01). In Shiraz city, subjects in the highest tertile of the unhealthy dietary pattern score had greater odds with MS than those in the lowest tertile (OR: 3.08; 95% CI: [1.27-7.38]; p for trend  =  0.01). However, in both groups, no significant association was found between healthy dietary pattern and MS risk. Conclusions: Adherence to unhealthy dietary pattern may increase the risk of MS in Iran. The results can be used for developing interventions that aim to promote healthy eating for preventing MS.

Diet-related inflammation increases the odds of multiple sclerosis: Results from a large population-based prevalent case-control study in Jordan

BACKGROUND

Multiple sclerosis, a chronic inflammatory disease in young and middle-aged adults, is one of the leading causes of non-traumatic disability in adults. Diet is known to have an important role in the modulating inflammatory processes and influencing molecular pathways.

PURPOSE

This study aims to examine the association of the inflammatory capacity of diet measured by DII with MS in Jordan.

METHODS

This prevalent case-control study included participants of both sexes, aged between 20 and 60 years. The cases (n = 541) had a confirmed diagnosis of prevalent Multiple Sclerosis (MS) in the previous 3 years, and controls (n = 607) were apparently healthy individuals matched on sex and age (42 ± 4 years). A validated Arabic food frequency questionnaire (FFQ) was utilized to obtain estimated dietary intake. Dietary data from the FFQ were analyzed using ESHA's Food Processor® nutrition analysis software, and the results were used to calculate the DII scores. Logistic regression analyses, controlling for covariates such as age, sex, body mass index, and smoking status, were used to measure the association between DII score and MS outcomes.

RESULTS

Cases represent a mixed sample of MS phenotypes and controls were comparable on age and sex. However, controls tended to be taller, lighter, had a lower BMI, and had a lower smoking rate. After controlling for age, BMI, sex, and smoking status, there was a consistent increase in MS risk according to DII score, with a 10-fold increase in odds in quartile 4 vs. quartile 1 [ORquartile 4vs1 = 10.17 (95% CI: 6.88; 15.04)]. For each point increase in DII score, there was nearly a doubling of odds [OR1 = 1.75 (95% CI: 1.59; 1.92)]. Individual nutrients and food values aligned according to their contribution to the DII score calculations.

CONCLUSION

The findings of this study, obtained in MS patients with varied illness duration over the previous 3 years, are consistent with an association between the overall inflammatory potential of diet and MS odds. Our findings among MS participants showed a significantly more pro-inflammatory DII scores than age- and sex-matched controls. Our results also suggest that MS group had a diet rich in pro-inflammatory foods and nutrients.

The Role of Vitamins in Neurodegenerative Disease: An Update

Acquiring the recommended daily allowance of vitamins is crucial for maintaining homeostatic balance in humans and other animals. A deficiency in or dysregulation of vitamins adversely affects the neuronal metabolism, which may lead to neurodegenerative diseases. In this article, we discuss how novel vitamin-based approaches aid in attenuating abnormal neuronal functioning in neurodegeneration-based brain diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Amyotrophic lateral sclerosis, and Prion disease. Vitamins show their therapeutic activity in Parkinson's disease by antioxidative and anti-inflammatory activity. In addition, different water- and lipid-soluble vitamins have also prevented amyloid beta and tau pathology. On the other hand, some results also show no correlation between vitamin action and the prevention of neurodegenerative diseases. Some vitamins also exhibit toxic activity too. This review discusses both the beneficial and null effects of vitamin supplementation for neurological disorders. The detailed mechanism of action of both water- and lipid-soluble vitamins is addressed in the manuscript. Hormesis is also an essential factor that is very helpful to determine the effective dose of vitamins. PubMed, Google Scholar, Web of Science, and Scopus were employed to conduct the literature search of original articles, review articles, and meta-analyses.

Macular Xanthophylls and Markers of the Anterior Visual Pathway among Persons with Multiple Sclerosis

BACKGROUND

Multiple sclerosis (MS) can cause retinal thinning among persons with MS with optic neuritis (MS-ON). Macular xanthophylls are carotenoids that comprise the macular pigment, filtering blue light and countering photo-oxidation. However, macular xanthophyll status and its implications for markers of neuroaxonal degeneration have not been examined in MS.

OBJECTIVES

This study characterized differences in macular and serum xanthophylls, and retinal morphometry [retinal nerve fiber layer thickness at the macular (mRNFL) and optic disc (odRNFL) and total macular volume (TMV)] in individuals with MS and healthy controls (HC). Associations between macular pigment optical density (MPOD) and retinal morphometry were also examined.

METHODS

Adults aged 45-64 y (HC, n = 42; MS, n = 40) participated in a cross-sectional study. MPOD was measured via heterochromatic flicker photometry. Retinal morphometry was measured via optical coherence tomography (OCT). Serum carotenoids were quantified using HPLC. Dietary carotenoids were collected using 7-d records. One-factor ANOVA was conducted to determine group effects on macular, serum, and dietary carotenoids. Partial correlations examined the relations between MPOD, retinal morphometry, diet, and serum carotenoids.

RESULTS

Relative to HC, persons with MS-ON had lower MPOD (Cohen's d = 0.84, P = 0.014), lower odRNFL (Cohen's d = 2.16, P <0.001), lower mRNFL (Cohen's d = 0.57, P = 0.028), and lower TMV (Cohen's d = 0.95, P = 0.011). MS without ON (MS) had lower odRNFL (Cohen's d = 0.93, P = 0.001) than HC and lower serum lutein than MS-ON subjects (Cohen's d = 0.65, P = 0.014). Among MS, MPOD was positively correlated with odRNFL thickness (ρ = 0.43, P = 0.049) and TMV (ρ = 0.45, P = 0.039), whereas odRNFL was negatively correlated with serum lutein (ρ = -0.68, P = 0.016) and zeaxanthin (ρ = -0.62, P = 0.028).

CONCLUSIONS

Persons with MS-ON exhibited poorer xanthophyll status in the macula and serum. MPOD was associated with beneficial anatomical features in the MS group. These findings warrant confirmation with larger cohorts and prospective trials to evaluate xanthophyll effects on the anterior visual pathway in MS.

Paleolithic Diet-Effect on the Health Status and Performance of Athletes?

The aim of this meta-analysis was to review the impact of a Paleolithic diet (PD) on selected health indicators (body composition, lipid profile, blood pressure, and carbohydrate metabolism) in the short and long term of nutrition intervention in healthy and unhealthy adults. A systematic review of randomized controlled trials of 21 full-text original human studies was conducted. Both the PD and a variety of healthy diets (control diets (CDs)) caused reduction in anthropometric parameters, both in the short and long term. For many indicators, such as weight (body mass (BM)), body mass index (BMI), and waist circumference (WC), impact was stronger and especially found in the short term. All diets caused a decrease in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG), albeit the impact of PD was stronger. Among long-term studies, only PD cased a decline in TC and LDL-C. Impact on blood pressure was observed mainly in the short term. PD caused a decrease in fasting plasma (fP) glucose, fP insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) and glycated hemoglobin (HbA1c) in the short run, contrary to CD. In the long term, only PD caused a decrease in fP glucose and fP insulin. Lower positive impact of PD on performance was observed in the group without exercise. Positive effects of the PD on health and the lack of experiments among professional athletes require longer-term interventions to determine the effect of the Paleo diet on athletic performance.

Quantification of fat-soluble vitamins and their metabolites in biological matrices: an updated review

Fat-soluble vitamins (FSVs) are micronutrients essential in maintaining normal physiological function, metabolism and human growth. Ongoing increased awareness regarding FSV concentrations and their impact on human growth along with disease progression warrant the need of developing selective and sensitive analytical methods. LC–MS/MS is currently the method of choice for accurate quantitation of FSVs. However, there are multiple approaches for extraction, separation and calibration of FSVs in biological matrices. This review discusses recent LC–MS/MS methods for the simultaneous quantification of FSVs in biological matrices and summarizes sample pretreatment procedures, chromatographic conditions and calibration approaches. Current challenges and clinical applications in various disease states are also highlighted.

Preclinical Explorative Assessment of Dimethyl Fumarate-Based Biocompatible Nanolipoidal Carriers for the Management of Multiple Sclerosis

Multiple sclerosis (MS) is a neurodegenerative disease in which myelin sheath damage occurs due to internal and external factors. MS especially affects the young population. Dimethyl fumarate (DMF) is a promising agent for MS treatment, although it is associated with concerns such as poor brain permeation, multiple dosing, and gastrointestinal flushing. The present study attempts to evaluate the preclinical performance of specially designed DMF-based lipoidal nanoparticles in a cuprizone-induced demyelination model in rodents. The studies proved the efficacy of lipid-based nanoparticles containing DMF in a once-a-day dosage regimen over that of thrice-a-day plain DMF administration on crucial parameters like motor coordination, grip strength, mortality, body weight, and locomotor activity. However, neither blank lipid nor blank neuroprotective (vitamins A, D, and E) loaded nanoparticles were able to elicit any desirable behavioral response. Histopathological studies showed that the designed once-a-day DMF nanomedicines were well tolerated and rejuvenated the myelin sheath vis-à-vis the plain DMF thrice-a-day regimen. These findings provide proof of concept for a biocompatible nanomedicine for MS with tremendous promise for effective brain delivery and patient compliance on the grounds of a reduction in the dosage frequency.

Vitamin-Derived Nanolipoidal Carriers for Brain Delivery of Dimethyl Fumarate: A Novel Approach with Preclinical Evidence

Various oral treatment options have been reported for relapsing multiple sclerosis. Recently, dimethyl fumarate (DMF) has been approved for the management of the same. Though effective, DMF is associated with concerns like multiple dosing, patient incompliance, gastrointestinal flushing, lower brain permeation, and economic hurdles. Henceforth, the objective of the present study was to develop vitamin-based solid lipid nanoparticles (SLNs) for effective brain delivery of DMF with a promise of once-a-day dosing. The developed SLNs were characterized for micromeritics, morphology, entrapment efficiency, drug loading and in vitro drug release. Caco-2 and SH-SY5Y cell lines were used to assess the intestinal permeability and neuronal uptake. Pharmacokinetic and biodistribution studies were performed on rats. The developed nanometeric lipidparticles were able to control the drug release and substantially enhance the Caco-2 as well as SH-5YSY cell permeability. The developed systems not only enhanced the oral bioavailability of the drug, but also offered substantially elevated brain drug levels to that of plain drug. The drug was protected from liver and biological residence was increased, indicating promising potential of the carriers in effective brain delivery of DMF. Enhanced bioavailability and elevated bioresidence of DMF by vitamin-based SLNs provided the evidence for once-a-day delivery potential for DMF in the management of neurological disorders.

Effect of vitamin E on 24(S)-hydroxycholesterol-induced necroptosis-like cell death and apoptosis

24(S)-Hydroxycholesterol (24S-OHC) has diverse physiological and pathological functions. In particular, cytotoxic effects of 24S-OHC in neuronal cells are important in development of neurodegenerative diseases. 24S-OHC induces necroptosis-like cell death in SH-SY5Y cells expressing little caspase-8. In the present study, 24S-OHC was found to induce apoptosis as determined by caspase-3 activation in all-trans-retinoic acid (atRA)-treated SH-SY5Y cells in which expression of caspase-8 was induced. 24S-OHC-induced cell death was inhibited by α-tocopherol (α-Toc) but not by α-tocotrienol (α-Toc3) in SH-SY5Y cells regardless of whether cells were treated with atRA. In contrast, cumene hydroperoxide (CumOOH)-induced cell death was significantly inhibited by α-Toc and α-Toc3. In atRA-treated SH-SY5Y cells, generation of reactive oxygen species (ROS) was induced by stimulation with CumOOH but was not induced by stimulation with 24S-OHC. These results suggest that inhibition of 24S-OHC-induced cell death by α-Toc cannot be explained by its radical scavenging antioxidant activity. Esterification of 24S-OHC followed by lipid droplet (LD) formation due to acyl-CoA:cholesterol acyltransferase 1 (ACAT1) are key events in 24S-OHC-induced cell death in atRA-treated SH-SY5Y cells as demonstrated by inhibition of cell death by ACAT1 inhibitor. LD number was not changed by treatment with either α-Toc or α-Toc3. The different physical properties of α-Toc and α-Toc3 may account for their different inhibitory effects on 24S-OHC-induced cell death.

Excitotoxins, Mitochondrial and Redox Disturbances in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). There is increasing evidence that MS is not only characterized by immune mediated inflammatory reactions, but also by neurodegenerative processes. There is cumulating evidence that neurodegenerative processes, for example mitochondrial dysfunction, oxidative stress, and glutamate (Glu) excitotoxicity, seem to play an important role in the pathogenesis of MS. The alteration of mitochondrial homeostasis leads to the formation of excitotoxins and redox disturbances. Mitochondrial dysfunction (energy disposal failure, apoptosis, etc.), redox disturbances (oxidative stress and enhanced reactive oxygen and nitrogen species production), and excitotoxicity (Glu mediated toxicity) may play an important role in the progression of the disease, causing axonal and neuronal damage. This review focuses on the mechanisms of mitochondrial dysfunction (including mitochondrial DNA (mtDNA) defects and mitochondrial structural/functional changes), oxidative stress (including reactive oxygen and nitric species), and excitotoxicity that are involved in MS and also discusses the potential targets and tools for therapeutic approaches in the future.

Randomized control trial evaluation of a modified Paleolithic dietary intervention in the treatment of relapsing-remitting multiple sclerosis: a pilot study

BACKGROUND/OBJECTIVE

A Paleolithic diet may improve fatigue and quality of life in progressive multiple sclerosis (MS) patients, but past research has evaluated the effects of this dietary intervention in combination with other treatments such as exercise. Thus, the purpose of this pilot study was to evaluate a modified Paleolithic dietary intervention (MPDI) in the treatment of fatigue and other symptoms in relapsing-remitting MS (RRMS).

METHODS

We measured the effects of a MPDI in 17 individuals with RRMS. Of 34 subjects randomly assigned to control (maintain usual diet) and intervention (MPDI) groups, nine subjects (one man) completed the control group and eight subjects (one man) completed the MPDI.

RESULTS

Significant improvements were seen in Fatigue Severity Scale score and also in Multiple Sclerosis Quality of Life-54 and time to complete (dominant hand) 9-Hole Peg Test from baseline in MPDI subjects compared to controls. Increased vitamin K serum levels were also observed in MPDI subjects postprotocol compared to controls.

CONCLUSION

A Paleolithic diet may be useful in the treatment and management of MS, by reducing perceived fatigue, increasing mental and physical quality of life, increasing exercise capacity, and improving hand and leg function. By increasing vitamin K serum levels, the MPDI may also reduce inflammation.

The influence of retinoic acid on the human oligodendrocyte precursor cells by RNA-sequencing

Retinoic acid (RA), a metabolite of vitamin A, has been found to influence regeneration in the adult central nervous system (CNS). There may be an effect of RA in the recovery/repair in multiple sclerosis (MS), an autoimmune and neurodegenerative disease of the CNS. We hypothesized that RA is a regulator of the further differentiation of oligodendrocyte precursor cells (OPCs) – cells key to the remyelination process in MS. We conducted studies utilizing RNA-sequencing in human embryonic stem cell (hESC)-derived neural stem cells (NSCs) and OPCs so as to understand the role of transcriptional regulators during transition from both ESCs to NSCs and NSCs to OPCs. We identified that expression of retinoic acid receptors β and γ (RARβ and RARγ ) was significantly increased following the transition from NSCs to OPCs. We also demonstrated that long term in vitro culture of hESC-derived OPC with different isoforms of RA led to the significant up-regulation of two known transcriptional inhibitors of oligodendrocyte differentiation: Hes5 following prolonged treatment with all-trans-RA, 9-cis RA and 13-cis RA; and Id4 following treatment with 13cisRA. These results suggest that long term exposure to certain RA isoforms may impact the continued differentiation of this population.

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Retinoic acid (ATRA) might have an effect on generation of oligodendrocyte precursor cells (OPC) in the CNS.

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RNA-sequencing used for identification of up-regulation of RARβ and RARɣ expression during OPC differentiation.

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Activation of RARβ and RARɣ by using three different agonists led increase expression of Hes5 and Id4.

Anti-adipogenic effect of Artemisia annua in diet-induced-obesity mice model

Obesity has increased continuously in western countries during the last several decades and recently become a problem in developing countries. Currently, anti-obesity drugs originating from natural products are being investigated for their potential to overcome adverse effects associated with chemical drugs. Artemisinic acid, which was isolated from the well-known anti-malaria herb Artemisia annua (AA) L., was recently shown to possess anti-adipogenic effects in vitro. However, the anti-adipogenic effects of AA in animal models have not yet been investigated. Therefore, we conducted daily oral administration with AA water extract in a diet-induced obesity animal model and treated 3T3-L1 cells with AA to confirm the anti-adipogenic effects in the related protein expressions. We then evaluated the physiology, adipose tissue histology and mRNA expressions of many related genes. Inhibition of adipogenesis by the AA water extract was observed in vitro. In the animal model, weight gain was significantly lower in the AA treated group, but there were no changes in food intake volume or calories. Reductions in lipid droplet size and mRNA expression associated with adipogenesis were also observed in animal epididymal fat. This study is the first to report that AA has an anti-obese effects in vivo.

Multiple sclerosis and vitamin D during pregnancy and lactation

BACKGROUND

Both pregnancy and high vitamin D concentration seem to generate a protective environment against multiple sclerosis (MS) relapses. Longitudinal case-control analysis of vitamin D concentrations during pregnancy and lactation of MS mothers is lacking.

AIMS OF THE STUDY

To examine serum 25-hydroxyvitamin-D3 levels of MS patients during and after pregnancy and compare these to the levels measured in healthy controls.

METHODS

Fifteen relapsing-remitting MS mothers underwent repeated testing for 25-hydroxyvitamin-D3 at 10-12, 26-28 and 35-37 gestational weeks and 1, 3 and 6 months post-partum. An identical series of samples was collected from six control mothers.

RESULTS

The prevalence of vitamin D deficiency (<50 nmol/l) during pregnancy was high (73%) among MS patients. Vitamin D levels were significantly higher during pregnancy when compared to early post-partum values among MS patients. At the end of the follow-up period, the vitamin D levels returned to levels observed in early pregnancy. In healthy controls, the alterations during and after pregnancy were similar in nature, but the vitamin D concentrations were higher at all time points when compared to MS patients (P = 0.037).

CONCLUSIONS

Vitamin D deficiency during the pregnancy and lactation seems to be common in mothers with MS and needs to be treated adequately.

"Disease modifying nutricals" for multiple sclerosis

The association between vitamin D and multiple sclerosis has (re)-opened new interest in nutrition and natural compounds in the prevention and treatment of this neuroinflammatory disease. The dietary amount and type of fat, probiotics and biologicals, salmon proteoglycans, phytoestrogens and protease inhibitor of soy, sodium chloride and trace elements, and fat soluble vitamins including D, A and E were all considered as disease-modifying nutraceuticals. Studies in experimental autoimmune encephalomyelitis mice suggest that poly-unsaturated fatty acids and their 'inflammation-resolving' metabolites and the gut microflora may reduce auto-aggressive immune cells and reduce progression or risk of relapse, and infection with whipworm eggs may positively change the gut-brain communication. Encouraged by the recent interest in multiple sclerosis-nutrition nature's pharmacy has been searched for novel compounds with anti-inflammatory, immune-modifying and antioxidative properties, the most interesting being the scorpion toxins that inhibit specific potassium channels of T cells and antioxidative compounds including the green tea flavonoid epigallocatechin-3-gallate, curcumin and the mustard oil glycoside from e.g. broccoli and sulforaphane. They mostly also inhibit pro-inflammatory signaling through NF-κB or toll-like receptors and stabilize the blood brain barrier. Disease modifying functions may also complement analgesic and anti-spastic effects of cannabis, its constituents, and of 'endocannabinoid enhancing' drugs or nutricals like inhibitors of fatty acid amide hydrolase. Nutricals will not solve multiple sclerosis therapeutic challenges but possibly support pharmacological interventions or unearth novel structures.

Multiple sclerosis: evaluation of purine nucleotide metabolism in central nervous system in association with serum levels of selected fat-soluble antioxidants

In the pathogenesis of demyelinating diseases including multiple sclerosis (MS) an important role is played by oxidative stress. Increased energy requirements during remyelination of axons and mitochondria failure is one of the causes of axonal degeneration and disability in MS. In this context, we analyzed to what extent the increase in purine catabolism is associated with selected blood lipophilic antioxidants and if there is any association with alterations in serum levels of coenzyme Q10. Blood serum and cerebrospinal fluid (CSF) samples from 42 patients with diagnosed MS and 34 noninflammatory neurologic patients (control group) were analyzed. Compared to control group, MS patients had significantly elevated values of all purine nucleotide metabolites, except adenosine. Serum lipophilic antioxidants γ -tocopherol, β -carotene, and coenzyme Q10 for the vast majority of MS patients were deficient or moved within the border of lower physiological values. Serum levels of TBARS, marker of lipid peroxidation, were increased by 81% in the MS patients. The results indicate that the deficit of lipophilic antioxidants in blood of MS patients may have a negative impact on bioenergetics of reparative remyelinating processes and promote neurodegeneration.

The evidence for a beneficial role of vitamin A in multiple sclerosis

Vitamin A is an essential nutrient with important roles in immunological responses and in brain development. Its main metabolite is retinoic acid (RA), which is responsible for the neuroimmunological functions related to vitamin A. In the brain, RA is known to have interactions with other nuclear receptor-mediated signalling pathways. RA is involved in plasticity, regeneration, cognition and behaviour. In the peripheral blood, RA plays a major role both in increasing tolerance and in decreasing inflammation, through balancing T-lymphocyte populations. It is likely that RA synthesis may be manipulated by complex cross-talk among cells during infection and inflammation. The role of vitamin A in multiple sclerosis (MS) could be dual: at the same time as it decreases inflammation and increases tolerance of autoimmunity, it may also help in brain protection. The present review discusses the beneficial effects that vitamin A might have for controlling MS, although it must be clearly stated that, at the present time, there is no clear indication for using vitamin A as a treatment for MS. However, the results from the present review should encourage clinical trials with vitamin supplementation as a potential treatment or as an add-on option. Vitamin A acts in synergy with vitamin D, and the immunological homeostasis ensured by these vitamins should not be unbalanced in favour of only one of them.

Tocopherol derivative TFA-12 promotes myelin repair in experimental models of multiple sclerosis

Multiple sclerosis (MS) is an inflammatory disease of the CNS that is associated with demyelination and axonal loss, resulting in severe neurological handicap. Current MS therapies mostly target neuroinflammation but have only a little impact on CNS myelin repair. Progress toward treatments that enhance remyelination would therefore represent major advances in MS treatment. Here, we examined the ability of TFA-12, a new synthetic compound belonging to tocopherol long-chain fatty alcohols, to promote oligodendrocyte regeneration and remyelination in experimental models of MS. We showed that TFA-12 significantly ameliorates neurological deficit and severity of myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis (EAE) in mice. Histological evaluation of mouse EAE spinal cords showed that TFA-12 treatment reduces inflammation, astrogliosis, and myelin loss. Additionally, we demonstrated that TFA-12 accelerates remyelination of focal demyelinated lesions induced by lysolecithin injections. We also found that this compound induces the differentiation of oligodendrocyte precursor cells into mature oligodendrocytes through the inhibition of the Notch/Jagged1 signaling pathway. Altogether, our data provide important proof of principle indicating that TFA-12 could be a potential therapeutic compound for myelin repair in MS.

Biomarkers in Multiple Sclerosis: An Up-to-Date Overview

During the last decades, the effort of establishing satisfactory biomarkers for multiple sclerosis has been proven to be very difficult, due to the clinical and pathophysiological complexities of the disease. Recent knowledge acquired in the domains of genomics-immunogenetics and neuroimmunology, as well as the evolution in neuroimaging, has provided a whole new list of biomarkers. This variety, though, leads inevitably to confusion in the effort of decision making concerning strategic and individualized therapeutics. In this paper, our primary goal is to provide the reader with a list of the most important characteristics that a biomarker must possess in order to be considered as reliable. Additionally, up-to-date biomarkers are further divided into three subgroups, genetic-immunogenetic, laboratorial, and imaging. The most important representatives of each category are presented in the text and for the first time in a summarizing workable table, in a critical way, estimating their diagnostic potential and their efficacy to correlate with phenotypical expression, neuroinflammation, neurodegeneration, disability, and therapeutical response. Special attention is given to the "gold standards" of each category, like HLA-DRB1∗ polymorphisms, oligoclonal bands, vitamin D, and conventional and nonconventional imaging techniques. Moreover, not adequately established but quite promising, recently characterized biomarkers, like TOB-1 polymorphisms, are further discussed.