Insulin resistance, atherogenicity, and iron metabolism in multiple sclerosis with and without depression: Associations with inflammatory and oxidative stress biomarkers and uric acid

Iron metabolism dysfunction in neuropsychiatric disorders: Implications for therapeutic intervention

Iron is a trace metal that takes part in the maintenance of body homeostasis by, for instance, aiding in energy production and immunity. A body of evidence now demonstrates that dysfunction in iron metabolism can have detrimental effects and is intricately associated with the development of neuropsychiatric disorders, including Major Depressive Disorder (MDD), anxiety, and schizophrenia. For instance, changes in serum and central nervous system (CNS) levels of iron and in proteins mediating iron metabolism have been documented in patients grappling with the aforementioned diseases. By contrast, targeting iron metabolism by using iron chelators, for instance, has proven to be effective in alleviating disease burden. Therefore, here we review the state-of-the-art regarding the role of iron metabolism and its dysfunction in the context of neuropsychiatric disorders. Furthermore, we discuss how targeting iron metabolism can be an effective therapeutic option to tackle this class of diseases. Finally, we discuss the mechanisms linking this dysfunction to behavioral changes in these disorders. Harnessing the knowledge of iron metabolism is not only key to the characterization of novel molecular targets and disease biomarkers but also crucial to drug repurposing and drug design.

Circulatory Indicators of Lipid Peroxidation, the Driver of Ferroptosis, Reflect Differences between Relapsing-Remitting and Progressive Multiple Sclerosis

Ferroptosis, a lipid peroxidation- and iron-mediated type of regulated cell death, relates to both neuroinflammation, which is common in relapsing-remitting multiple sclerosis (RRMS), and neurodegeneration, which is prevalent in progressive (P)MS. Currently, findings related to the molecular markers proposed in this paper in patients are scarce. We analyzed circulatory molecular indicators of the main ferroptosis-related processes, comprising lipid peroxidation (malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), and hexanoyl-lysine adduct (HEL)), glutathione-related antioxidant defense (total glutathione (reduced (GSH) and oxidized (GSSG)) and glutathione peroxidase 4 (GPX4)), and iron metabolism (iron, transferrin and ferritin) to estimate their contributions to the clinical manifestation of MS and differences between RRMS and PMS disease course. In 153 patients with RRMS and 69 with PMS, plasma/serum lipid peroxidation indicators and glutathione were quantified using ELISA and colorimetric reactions, respectively. Iron serum concentrations were determined using spectrophotometry, and transferrin and ferritin were determined using immunoturbidimetry. Compared to those with RRMS, patients with PMS had decreased 4-HNE (median, 1368.42 vs. 1580.17 pg/mL; p = 0.03). Interactive effects of MS course (RRMS/PMS) and disease-modifying therapy status on MDA (p = 0.009) and HEL (p = 0.02) levels were detected. In addition, the interaction of disease course and self-reported fatigue revealed significant impacts on 4-HNE levels (p = 0.01) and the GSH/GSSG ratio (p = 0.04). The results also show an association of MS course (p = 0.03) and EDSS (p = 0.04) with GSH levels. No significant changes were observed in the serum concentrations of iron metabolism indicators between the two patient groups (p > 0.05). We suggest circulatory 4-HNE as an important parameter related to differences between RRMS and PMS. Significant interactions of MS course and other clinically relevant parameters with changes in redox processes associated with ferroptosis support the further investigation of MS with a larger sample while taking into account both circulatory and central nervous system estimation.

Electroacupuncture ameliorates depression-like behaviors in rats with post-stroke depression by inhibiting ferroptosis in the prefrontal cortex

Introduction

Post-stroke depression (PSD) is the most common complication following a stroke, significantly hindering recovery and rehabilitation in affected patients. Despite its prevalence, the pathogenesis of PSD remains poorly understood. Electroacupuncture (EA) has shown antidepressant effects, yet its neuroprotective properties are not well defined. Ferroptosis, a recently identified form of cell death, is implicated in the pathological processes of stroke and is associated with the development of depression-like behaviors. So we aimed to investigate whether PSD induces ferroptosis, identify potential therapeutic targets within these pathways, and elucidate the underlying mechanisms in this study.

Methods

Male Sprague-Dawley rats were subjected to middle carotid artery occlusion and chronic unpredictable mild stress to model PSD. To explore the role of ferroptosis in the effects of EA, the ferroptosis inducer erastin was administered into the rats' lateral ventricles, followed by 14 days of EA treatment, with sessions lasting 30 minutes per day. The Zea-Longa score was used to assess neurological deficits, while the sucrose preference test, elevated plus maze test, and open-field test were employed to evaluate depression-like behaviors in the rats. Hematoxylin-eosin, Nissl, and Perl's staining were used to observe the morphological changes and iron deposition in the prefrontal neurons. Transmission electron microscopy provided detailed observations of mitochondrial morphological changes in neurons. We utilized activity assay kits, enzyme-linked immunosorbent assay (ELISA), and Western blotting to explore potential molecular mechanisms underlying the effects of EA.

Results

EA can reduce neurological deficits and enhance the spontaneous activity and exploration behavior of rats. In addition, EA could inhibit prefrontal cortex neuronal ferroptosis by reducing iron deposition, decreasing lipid peroxidation, and enhancing antioxidation.

Discussion

EA improved depression-like behaviors, mitigated mitochondrial damage, and inhibited ferroptosis in prefrontal cortex neurons. Notably, the administration of erastin further enhanced these effects. In conclusion, EA appears to improve PSD by inhibiting ferroptosis in the prefrontal cortex.

Association of atherogenic index of plasma and triglyceride glucose-body mass index and sarcopenia in adults from 20 to 59: a cross-sectional study

Background

The relationship between atherogenic index of plasma (AIP) and triglyceride glucose-body mass index (TyG-BMI) and sarcopenia has not been studied in the United States (US) population.

Methods

This research included 4,835 people from the National Health and Nutrition Examination Survey (NHANES) conducted between 2011 and 2018. The relationship between sarcopenia and TyG-BMI, as well as the AIP index, was examined through the utilization of restricted cubic spline (RCS) analysis, subgroup analysis, and multivariate logistic regression analysis. Diagnostic value of AIP and TyG-BMI for sarcopenia was compared by receiver operating characteristic (ROC) curves.

Results

In this research, 428 people with sarcopenia were identified among the 4,835 subjects that were included in the experiment. AIP and sarcopenia were positively associated with an odds ratio (OR) of 1.58 and a 95% confidence interval (CI) of (1.07, 2.34) on fully adjusted multivariate logistic regression analysis. Similarly, TyG-BMI and sarcopenia were positively associated with an OR of 8.83 and a 95% CI of (5.46, 14.26). AIP and sarcopenia had a non-linear positive connection (P-value<0.001, P-Nonlinear=0.010), while TyG-BMI and sarcopenia had a linear positive correlation (P-value<0.001, P-Nonlinear=0.064), according to RCS analysis. Subgroup analyses showed a significant interaction between TyG-BMI and sarcopenia due to gender (P = 0.023). ROC curves showed that TyG-BMI (AUC:0.738, 95% CI: 0.714 - 0.761) was more useful than AIP (AUC:0.648, 95% CI: 0.622 - 0.673) in diagnosing sarcopenia.

Conclusion

In US adults aged 20-59 years, our study revealed a correlation between elevated AIP and TyG-BMI levels and heightened sarcopenia risk. Moreover, TyG-BMI has better diagnostic validity than AIP.

Exploring the L-shaped relationship between Atherogenic Index of Plasma and depression: Results from NHANES 2005-2018

BACKGROUND

The Atherogenic Index of Plasma (AIP) is a novel metric linked to several diseases. However, there is inadequate evidence to investigate the relationship between AIP and depression. Therefore, we aim to elucidate the non-linear association between AIP and depression.

METHODS

12,453 participants from the National Health and Nutrition Examination Survey (NHANES) 2005-2018 were included. The AIP was calculated as log10 (triglycerides/high-density lipoprotein cholesterol). The Patient Health Questionnaire (PHQ-9) was used to identify depression (PHQ-9 ≥ 10). Weighted multivariate logistic regression, restricted cubic splines (RCS) models, subgroup analysis, and interaction tests were employed to reveal the relationship between AIP and depression.

RESULTS

AIP was found to be significantly correlated with depression. In the fully adjusted model, elevated AIP levels were associated with higher odds of depression (odds ratio [OR] = 1.50; 95 % CI: 1.06-2.12). The RCS analysis indicated an L-shaped pattern in the relationship between depression and AIP, with inflection points at -0.289. Beyond this inflection point, individuals with elevated AIP levels were associated with higher odds of depression (OR = 2.25; 95 % CI: 1.49-3.39). Notably, the association was particularly pronounced among individuals with diabetes.

LIMITATION

This cross-sectional study is unable to establish causal relationships.

CONCLUSION

There was an L-shaped association between AIP and depression among US adults. AIP has the potential value as a biological marker for depression, and maintaining AIP values below a certain threshold may help in managing depression.

Association between insulin resistance and multiple sclerosis: a systematic review and meta-analysis

There is increasing evidence of metabolic perturbations in multiple sclerosis (MS) patients, and insulin is an important parameter that has controversial effects on neurological disease. Therefore, this systematic review and meta-analysis study aimed to explore the association between insulin resistance (IR) and MS as well as insulin levels and MS. Three electronic databases, including Medline, Scopus, and the Web of Science, were examined up to 26 May 2023 for observational studies. Two independent reviewers assessed the studies according to a pre-specified protocol. Random-effects model using a Restricted-maximum Likelihood (REML) estimator was used to meta-analyze the association between IR [assessed by Homeostatic Model Assessment (HOMA-IR)], insulin and MS. Eighteen datasets from 2012 to 2022 were included in this meta-analysis. The standardized mean difference (SMD) for comparison IR and insulin between MS and healthy control group as outcomes 1 and 2 were 0.78 and 0.72 respectively. Furthermore, for outcome 1, we observed a greater effect size in studies that recruited different types of MS (Mix) (SMD: 1.09) than in those that included only relapsing-remitting MS (RRMS) (SMD: 0.59). The meta-analysis revealed a significant association between IR, insulin and MS, with stronger associations in studies that recruited mixed patients. However, high heterogeneity has been observed in the present study. Therefore, more studies are needed to confirm the association between these parameters and MS.

Stroke risk in multiple sclerosis: a critical appraisal of the literature

Observational studies suggest that the occurrence of stroke on multiple sclerosis (MS) patients is higher compared to the general population. MS is a heterogeneous disease that involves an interplay of genetic, environmental and immune factors. The occurrence of stroke is subject to a wide range of both modifiable and non-modifiable, short- and long-term risk factors. Both MS and stroke share common risk factors. The immune mechanisms that underlie stroke are similar to neurodegenerative diseases and are attributed to neuroinflammation. The inflammation in autoimmune diseases may, therefore, predispose to an increased risk for stroke or potentiate the effect of conventional stroke risk factors. There are, however, additional determinants that contribute to a higher risk and incidence of stroke in MS. Due to the challenges that are associated with their differential diagnosis, the objective is to present an overview of the factors that may contribute to increased susceptibility or occurrence of stroke in MSpatients by performing a review of the available to date literature. As both MS and stroke can individually detrimentally affect the quality of life of afflicted patients, the identification of factors that contribute to an increased risk for stroke in MS is crucial for the prompt implementation of preventative therapeutic measures to limit the additive burden that stroke imposes.

Iron in multiple sclerosis - Neuropathology, immunology, and real-world considerations

Iron is an essential element involved in a multitude of bodily processes. It is tightly regulated, as elevated deposition in tissues is associated with diseases such as multiple sclerosis (MS). Iron accumulation in the central nervous system (CNS) of MS patients is linked to neurotoxicity through mechanisms including oxidative stress, glutamate excitotoxicity, misfolding of proteins, and ferroptosis. In the past decade, the combination of MRI and histopathology has enhanced our understanding of iron deposition in MS pathophysiology, including in the pro-inflammatory and neurotoxicity of iron-laden rims of chronic active lesions. In this regard, iron accumulation may not only have an impact on different CNS-resident cells but may also promote the innate and adaptive immune dysfunctions in MS. Although there are discordant results, most studies indicate lower levels of iron but higher amounts of the iron storage molecule ferritin in the circulation of people with MS. Considering the importance of iron, there is a need for evidence-guided recommendation for dietary intake in people living with MS. Potential novel therapeutic approaches include the regulation of iron levels using next generation iron chelators, as well as therapies to interfere with toxic consequences of iron overload including antioxidants in MS.

Exploring the impact of ketogenic diet on multiple sclerosis: obesity, anxiety, depression, and the glutamate system

Background

Multiple sclerosis (MS) is a neurodegenerative disorder. Individuals with MS frequently present symptoms such as functional disability, obesity, and anxiety and depression. Axonal demyelination can be observed and implies alterations in mitochondrial activity and increased inflammation associated with disruptions in glutamate neurotransmitter activity. In this context, the ketogenic diet (KD), which promotes the production of ketone bodies in the blood [mainly β-hydroxybutyrate (βHB)], is a non-pharmacological therapeutic alternative that has shown promising results in peripheral obesity reduction and central inflammation reduction. However, the association of this type of diet with emotional symptoms through the modulation of glutamate activity in MS individuals remains unknown.

Aim

To provide an update on the topic and discuss the potential impact of KD on anxiety and depression through the modulation of glutamate activity in subjects with MS.

Discussion

The main findings suggest that the KD, as a source of ketone bodies in the blood, improves glutamate activity by reducing obesity, which is associated with insulin resistance and dyslipidemia, promoting central inflammation (particularly through an increase in interleukins IL-1β, IL-6, and IL-17). This improvement would imply a decrease in extrasynaptic glutamate activity, which has been linked to functional disability and the presence of emotional disorders such as anxiety and depression.

Evaluation of major depressive disorder using 7 Tesla phase sensitive neuroimaging before and after mindfulness-based cognitive therapy

OBJECTIVE

We applied 7 Tesla phase sensitive imaging to evaluate the impact of brain iron levels on depression severity and cognitive function in individuals with major depressive disorder (MDD) treated with mindfulness-based cognitive therapy (MBCT).

METHODS

Seventeen unmedicated MDD participants underwent MRI, evaluation of depression severity, and cognitive testing before and after receiving MBCT, compared to fourteen healthy controls (HC). Local field shift (LFS) values, measures of brain iron levels, were derived from phase images in the putamen, caudate, globus pallidus (GP), anterior cingulate cortex (ACC) and thalamus.

RESULTS

Compared to the HC group, the MDD group had significantly lower baseline LFS (indicative of higher iron) in the left GP and left putamen and had a higher number of subjects with impairment in a test of information processing speed. In the MDD group, lower LFS values in the left and right ACC, right putamen, right GP, and right thalamus were significantly associated with depression severity; and lower LFS in the right GP was correlated with worse performance on measures of attention. All MBCT participants experienced depression relief. MBCT treatment also significantly improved executive function and attention. MBCT participants with lower baseline LFS values in the right caudate experienced significantly greater improvement in depression severity with treatment; and those with lower LFS values in the right ACC, right caudate, and right GB at baseline performed better on measures of verbal learning and memory after MBCT.

CONCLUSIONS

Our study highlights the potential contribution of subtle differences in brain iron to MDD symptoms and their successful treatment.

Dietary protection against the visual and motor deficits induced by experimental autoimmune encephalomyelitis

Introduction

Five to eight percent of the world population currently suffers from at least one autoimmune disorder. Despite multiple immune modulatory therapies for autoimmune demyelinating diseases of the central nervous system, these treatments can be limiting for subsets of patients due to adverse effects and expense. To circumvent these barriers, we investigated a nutritional intervention in mice undergoing experimental autoimmune encephalomyelitis (EAE), a model of autoimmune-mediated demyelination that induces visual and motor pathologies similar to those experienced by people with multiple sclerosis (MS).

Methods

EAE was induced in female and male mice and the impact of limiting dietary carbohydrates by feeding a ketogenic diet (KD) enriched in medium chain triglycerides (MCTs), alpha-linolenic acid (an omega-3 fatty acid), and fiber was evaluated in both a preventive regimen (prior to immunization with MOG antigen) and an interventional regimen (following the onset of symptoms). Motor scores were assigned daily and visual acuity was measured using optokinetic tracking. Immunohistochemical analyses of optic nerves were done to assess inflammatory infiltrates and myelination status. Fatty acid and cytokine profiling from blood were performed to evaluate systemic inflammatory status.

Results

The KD was efficacious when fed as a preventive regimen as well as when initiated as an interventional regimen following symptom onset. The KD minimally impacted body weight during the experimental time course, increased circulating ketones, prevented motor and ocular deficits, preserved myelination of the optic nerve, and reduced infiltration of immune cells to optic nerves. The KD also increased anti-inflammatory-associated omega-3 fatty acids in the plasma and reduced select cytokines in the circulation associated with EAE-mediated pathological inflammation.

Discussion

In light of ongoing clinical trials using dietary strategies to treat people with MS, these findings support that a KD enriched in MCTs, omega-3 fatty acids, and fiber promotes a systemic anti-inflammatory milieu and ameliorates autoimmune-induced demyelinating visual and motor deficits.

Serum uric acid is not associated with major depressive disorder in European and South American populations: a meta-analysis and two-sample bidirectional Mendelian Randomization study

OBJECTIVE

Although previous epidemiological studies have demonstrated that serum uric acid (SUA) is associated with major depressive disorder (MDD), these analyses are prone to biases. Here, we applied the Mendelian Randomization approach to determine whether SUA is causally associated with MDD.

METHODS

We conducted a meta-analysis to evaluate the relationship between SUA and MDD, then applied summary data from the Global Urate Genetics Consortium and the Psychiatric Genomics Consortium to estimate their causal effect using a two-sample bidirectional Mendelian Randomization (MR) analysis. Thereafter, the causal effect was further researched using genetic risk scores (GRS) as instrumental variables (IVs).

RESULTS

Results of a meta-analysis of articles comprising 6975 and 13,589 MDD patients and controls, respectively, revealed that SUA was associated with MDD (SMD = -0.690, 95% CI: -0.930 to -0.440, I2 = 97.4%, P < 0.001). In addition, the five MR methods revealed no causal relationship existed between SUA and MDD, which corroborated the results obtained via the GRS approach.

CONCLUSION

This paper found little evidence that this association between SUA and MDD is casual. Genetically, there was no significant causal association between SUA and MDD.

A pathway phenotype linking metabolic, immune, oxidative, and opioid pathways with comorbid depression, atherosclerosis, and unstable angina

BACKGROUND

There is strong comorbidity between atherosclerosis (ATS) and depression which is attributed to increased atherogenicity, insulin resistance (IR), and immune and oxidative stress.

AIM OF THE STUDY

To examine the role of the above pathways and mu-opioid receptor (MOR), β-endorphin levels, zinc, copper, vitamin D3, calcium, and magnesium in depression due to ATS/unstable angina (UA).

METHODS

Biomarkers were assayed in 58 controls and 120 ATS patients divided into those with moderate and severe depression according to the Beck Depression Inventory-II (BDI-II) scores >19 and >29, respectively.

RESULTS

Neural network and logistic regression models showed that severe depression due to ATS/UA was best predicted by interleukin-6 (IL-6), UA, MOR, zinc, β-endorphin, calcium and magnesium, and that moderate depression was associated with IL-6, zinc, MOR, β-endorphin, UA, atherogenicity, IR, and calcium. Neural networks yielded a significant discrimination of severe and moderate depression with an area under the receiver operating curves of 0.831 and 0.931, respectively. Using Partial Least Squares path analysis, we found that 66.2% of the variance in a latent vector extracted from ATS/UA clinical features, and the BDI-II scores, atherogenicity, and IR could be explained by the regression on IL-6, IL-10, zinc, copper, calcium, MOR, and age. The BDI-II scores increased from controls to ATS to UA class III to UA class IV.

CONCLUSIONS

Immune activation, the endogenous opioid system, antioxidants, trace elements, and macrominerals modulate a common core shared by increased depressive symptoms, ATS, UA, atherogenicity, and IR.

Intestinal flora induces depression by mediating the dysregulation of cerebral cortex gene expression and regulating the metabolism of stroke patients

Post-stroke depression (PSD) is a common cerebrovascular complication characterized by complex pathogenesis and poor treatment effects. Here, we tested the influence of differentially expressed genes (DEGs), non-targeted metabolites, and intestinal microbes on the occurrence and development of PSD. We acquired gene expression profiles for stroke patients, depression patients, and healthy controls from the Gene Expression Omnibus database. After screening for DEGs using differential expression analysis, we identified common DEGs in stroke and depression patients that were considered to form the molecular basis of PSD. Functional enrichment analysis of DEGs also revealed that the majority of biological functions were closely related to metabolism, immunity, the nervous system, and microorganisms, and we also collected blood and stool samples from healthy controls, stroke patients, and PSD patients and performed 16S rDNA sequencing and untargeted metabolomics. After evaluating the quality of the sequencing data, we compared the diversity of the metabolites and intestinal flora within and between groups. Metabolic pathway enrichment analysis was used to identify metabolic pathways that were significantly involved in stroke and PSD, and a global metabolic network was constructed to explore the pathogenesis of PSD. Additionally, we constructed a global regulatory network based on 16S rDNA sequencing, non-targeted metabolomics, and transcriptomics to explore the pathogenesis of PSD through correlation analysis. Our results suggest that intestinal flora associates the dysregulation of cerebral cortex gene expression and could potentially promote the occurrence of depression by affecting the metabolism of stroke patients. Our findings may be helpful in identifying new targets for the prevention and treatment of PSD.

Investigating Associations Between Depressive Symptoms and Anti-/Pro-Inflammatory Nutrients in an Elderly Population in Northern China: A Bayesian Kernel Machine Regression Approach

Backgroud

The potential for dietary inflammation has been shown to be associated with a variety of chronic diseases. The relationship between the potential for dietary inflammation and depression in the elderly is unclear.

Objective

This study aimed to exam the relationship between different nutrients and the risk of depression symptoms in the elderly.

Methods

In total, 1865 elderly in northern China were investigated at baseline from 2018 to 2019 and followed up in 2020. We measured the baseline intake of 22 nutrients and used Least Absolute Shrinkage and Selection Operator(LASSO) regression analysis and Bayesian Kernel Machine Regression (BKMR) to explore the association between exposure to a variety of nutrients with different inflammatory potentials and the risk of depressive symptoms.

Results

A total of 447 individuals (24.0%) were diagnosed with depressive symptoms. Through the lasso regression model, it was found that 11 nutrients are significantly related to the risk of depressive symptoms, of which 6 nutrients are pro-inflammatory nutrients (inflammation effect score>0), and 5 are anti-inflammatory nutrients (inflammation effect score<0). We incorporated the inflammatory effect scores of 11 nutrients into the BKMR model at the same time, and found that the overall inflammatory effect of 11 nutrients increased with the increase of total inflammatory scores, suggesting that the overall effect was pro-inflammatory. BKMR subgroup analysis shows that whether in the pro-inflammatory nutrient group or the anti-inflammatory nutrient group, multiple nutrients have a significant combined effect on depressive symptoms. By comparing the overall and group effects, we found that the inflammatory effects of the pro-inflammatory diet and the anti-inflammatory diet in the study’s diet are offset by each other (P<0.005).

Conclusion

We determined the combined effect of multiple nutrients of different inflammatory potential classifications on depressive symptoms in the elderly.

Cardiovascular risk estimated in individuals with multiple sclerosis: A case-control study

BACKGROUND

Patients with multiple sclerosis (MS) had a 1.5-fold increase in cardiovascular diseases (CVD) mortality, compared with those without MS. Therefore, the aim of this study was to assess the CVD risk in MS patients by multiple cardiometabolic indexes and to investigate associated factors.

METHODS

The MS group included 57 patients matched for age and sex to 57 healthy controls. They were evaluated for physical activity, smoking, anthropometric indices, blood pressure, and plasma biomarkers. Framingham risk score (FRS) and multiple cardiovascular risk indexes were calculated. Clinical course of disease, age at onset, disease duration, disease-modifying therapy, relapse rate, EDSS, physical and functional impairment were investigated.

RESULTS

The mean age was 34.6 years old. The majority (89.5%) in the MS group had a RRMS clinical course and a mild level of disability (EDSS=1.0). WC (p = 0.022) and FM% (p = 0.007) were different between the MS and control groups. The FRS was higher in the MS group (10% versus 0%) and this was related with high prevalence of dyslipidemia (43.8% versus 36.8%). The atherogenic index of plasma (AIP) (0.013) and Castelli risk indexes I (CRI-I) (p = 0.017) and II (CRI-II) (p = 0.008) and non-HDL-C (p = 0.044) were higher in the MS group.

CONCLUSION

MS patients, with controlled disease course, have a higher cardiovascular risk than comparable healthy individuals. We emphasize that the use of FRS, and the monitoring of CRI-I and II, as well as AIP, are important lipid markers to manage CVD risk in individuals with MS.

Neutrophil-to-lymphocyte ratio and CRP as biomarkers in multiple sclerosis: A systematic review

Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system, which causes demyelination and neuroaxonal damage. Low-grade systemic inflammation has been suggested to contribute to the pathogenesis due to amplification of pathogenic immune activation. However, there is a lack of reliable biomarkers of systemic inflammation predicting disease activity and progression in MS. The neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein (CRP) have been identified as biomarkers of severity and disease activity in various disorders. In September 2020, we conducted a systematic literature search on multiple databases on studies reporting NLR values or CRP levels in MS. The aim of this systematic review was to highlight the current knowledge about the potential of NLR and CRP as biomarkers in MS. A total of nineteen articles qualified for inclusion. Data on CRP were included in fourteen studies and NLR in nine studies. The results regarding CRP were inconsistent, and present literature does not support the use of CRP as a diagnostic or prognostic biomarker in MS. In contrast, NLR values were increased in MS patients compared with healthy controls in all case-control studies. Furthermore, NLR was associated with disease activity in untreated patients. Our systematic review therefore indicates that NLR might serve as a potential biomarker of disease activity. Given that the results of NLR are mainly drawn from retrospective case-control or cross-sectional studies, future prospective studies with long-term follow-up are required to accurately determine optimal timing and cutoff values that may be used in the clinical setting.

Oxidative stress and neuroinflammation should be both considered in the occurrence of fatigue and depression in multiple sclerosis

Oxidative stress and neuroinflammation have a role in the pathogenesis of multiple sclerosis (MS) and in depression. Fatigue is the most disabling symptom in patients with MS and could also be a part of depressive symptomatology. In this study, we measured the serum levels of uric acid (UA) as a marker of oxidative stress and C-reactive protein (CRP) as an inflammatory marker, in 98 patients with MS in relapse and remitting phase of illness and 35 healthy subjects. Degree of depressive symptomatology and fatigue were assessed with Beck's Depression Inventory (BDI) and Fatigue Severity Scale (FSS). Further, we examined the possible correlation of these biomarkers with symptoms of depression and fatigue. Relapse and remitting MS had a lower serum UA levels than controls (236.97 ± 9.25 µmol/L vs. 268.27 ± 0.09 µmol/L vs. 314.82 ± 11.02 µmol/L; p = 0.000), while sera levels of CRP were higher in relapse than remitting patients (4.46 ± 0.40 mg/L vs. 1.01 ± 0.38 mg/L; p = 0.000). Patients in relapse had higher BDI scores (15.68 ± 16.62 vs. 8.36 ± 7.10; p = 0.045). Decreased UA levels showed weak negative correlation with the presence of sadness and disturbed daily activities, higher CRP levels positively correlated with severe depression and the correlation between depression and fatigue was also observed (p < 0.05). It is possible that decreased UA levels lead to sadness, disturbed daily activities and severe disability. Every attack of CRP elevation in relapse could additionally precipitate the depression onset. The clinicians must pay special attention to early detection of fatigue because it could precede depression and improve further treatment.

Ketogenic diet and fasting diet as Nutritional Approaches in Multiple Sclerosis (NAMS): protocol of a randomized controlled study

BACKGROUND

Multiple sclerosis (MS) is the most common inflammatory disease of the central nervous system in young adults that may lead to progressive disability. Since pharmacological treatments may have substantial side effects, there is a need for complementary treatment options such as specific dietary approaches. Ketone bodies that are produced during fasting diets (FDs) and ketogenic diets (KDs) are an alternative and presumably more efficient energy source for the brain. Studies on mice with experimental autoimmune encephalomyelitis showed beneficial effects of KDs and FDs on disease progression, disability, cognition and inflammatory markers. However, clinical evidence on these diets is scarce. In the clinical study protocol presented here, we investigate whether a KD and a FD are superior to a standard diet (SD) in terms of therapeutic effects and disease progression.

METHODS

This study is a single-center, randomized, controlled, parallel-group study. One hundred and eleven patients with relapsing-remitting MS with current disease activity and stable immunomodulatory therapy or no disease-modifying therapy will be randomized to one of three 18-month dietary interventions: a KD with a restricted carbohydrate intake of 20-40 g/day; a FD with a 7-day fast every 6 months and 14-h daily intermittent fasting in between; and a fat-modified SD as recommended by the German Nutrition Society. The primary outcome measure is the number of new T2-weighted MRI lesions after 18 months. Secondary endpoints are safety, changes in relapse rate, disability progression, fatigue, depression, cognition, quality of life, changes of gut microbiome as well as markers of inflammation, oxidative stress and autophagy. Safety and feasibility will also be assessed.

DISCUSSION

Preclinical data suggest that a KD and a FD may modulate immunity, reduce disease severity and promote remyelination in the mouse model of MS. However, clinical evidence is lacking. This study is the first clinical study investigating the effects of a KD and a FD on disease progression of MS.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03508414. Retrospectively registered on 25 April 2018.

Multiple Sclerosis: Melatonin, Orexin, and Ceramide Interact with Platelet Activation Coagulation Factors and Gut-Microbiome-Derived Butyrate in the Circadian Dysregulation of Mitochondria in Glia and Immune Cells

Recent data highlight the important roles of the gut microbiome, gut permeability, and alterations in mitochondria functioning in the pathophysiology of multiple sclerosis (MS). This article reviews such data, indicating two important aspects of alterations in the gut in the modulation of mitochondria: (1) Gut permeability increases toll-like receptor (TLR) activators, viz circulating lipopolysaccharide (LPS), and exosomal high-mobility group box (HMGB)1. LPS and HMGB1 increase inducible nitric oxide synthase and superoxide, leading to peroxynitrite-driven acidic sphingomyelinase and ceramide. Ceramide is a major driver of MS pathophysiology via its impacts on glia mitochondria functioning; (2) Gut dysbiosis lowers production of the short-chain fatty acid, butyrate. Butyrate is a significant positive regulator of mitochondrial function, as well as suppressing the levels and effects of ceramide. Ceramide acts to suppress the circadian optimizers of mitochondria functioning, viz daytime orexin and night-time melatonin. Orexin, melatonin, and butyrate increase mitochondria oxidative phosphorylation partly via the disinhibition of the pyruvate dehydrogenase complex, leading to an increase in acetyl-coenzyme A (CoA). Acetyl-CoA is a necessary co-substrate for activation of the mitochondria melatonergic pathway, allowing melatonin to optimize mitochondrial function. Data would indicate that gut-driven alterations in ceramide and mitochondrial function, particularly in glia and immune cells, underpin MS pathophysiology. Aryl hydrocarbon receptor (AhR) activators, such as stress-induced kynurenine and air pollutants, may interact with the mitochondrial melatonergic pathway via AhR-induced cytochrome P450 (CYP)1b1, which backward converts melatonin to N-acetylserotonin (NAS). The loss of mitochnodria melatonin coupled with increased NAS has implications for altered mitochondrial function in many cell types that are relevant to MS pathophysiology. NAS is increased in secondary progressive MS, indicating a role for changes in the mitochondria melatonergic pathway in the progression of MS symptomatology. This provides a framework for the integration of diverse bodies of data on MS pathophysiology, with a number of readily applicable treatment interventions, including the utilization of sodium butyrate.

Disability in multiple sclerosis is associated with age and inflammatory, metabolic and oxidative/nitrosative stress biomarkers: results of multivariate and machine learning procedures

The aim of this study was to evaluate the immune-inflammatory, metabolic, and nitro-oxidative stress (IM&NO) biomarkers as predictors of disability in multiple sclerosis (MS) patients. A total of 122 patients with MS were included; their disability was evaluated using the Expanded Disability Status Scale (EDSS) and IM&NO biomarkers were evaluated in peripheral blood samples. Patients with EDSS ≥3 were older and showed higher homocysteine, uric acid, advanced oxidized protein products (AOPP) and low-density lipoprotein (LDL)-cholesterol and higher rate of metabolic syndrome (MetS), while high-density lipoprotein (HDL)-cholesterol was lower than in patients with EDSS <3; 84.6% of all patients were correctly classified in these EDSS subgroups. We found that 36.3% of the variance in EDSS score was explained by age, Th17/T regulatory (Treg) and LDL/HDL ratios and homocysteine (all positively related) and body mass index (BMI) (inversely related). After adjusting for MS treatment modalities, the effects of the LDL/HDL and zTh17/Treg ratios, homocysteine and age on disability remained, whilst BMI was no longer significant. Moreover, carbonyl proteins were associated with increased disability. In conclusion, the results showed that an inflammatory Th17 profile coupled with age and increased carbonyl proteins were the most important variables associated with high disability followed at a distance by homocysteine, MetS and LDL/HDL ratio. These data underscore that IM&NO pathways play a key role in increased disability in MS patient and may be possible new targets for the treatment of these patients. Moreover, a panel of these laboratory biomarkers may be used to predict the disability in MS.

Serum NADPH oxidase concentrations and the associations with iron metabolism in relapsing remitting multiple sclerosis

BACKGROUND

Overproduction of reactive oxygen species (ROS) and impaired iron metabolism are considered to be possible factors in the pathogenesis of Multiple sclerosis (MS). Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases are the primary sources of regulated ROS production. The NADPH oxidase (NOX) family consists of seven catalytic homologues, NOX1-5 and two dual oxidases. NOX1 and NOX5 are associated with endothelial dysfunction and inflammation but NOX4 has a protective effect on vascular function. The aims of this study were to investigate the status of NOX1, NOX4 and NOX5 and its relationship with serum iron metabolism biomarkers in relapsing-remitting MS patients.

METHODS

The study included 53 RRMS patients and 45 control subjects. Serum NOX1,4,5, ferritin, iron, unbound-iron binding capacity, C-reactive protein (CRP), white blood count (WBC) and erythrocyte sedimentation rate (ESR) levels were measured in all the study subjects.

RESULTS

Higher serum NOX5 (p < 0.0001), CRP (p = 0.014), ferritin (p = 0.040) and lower serum NOX4 (p < 0.0001) and iron (p = 0.013) concentrations were found in the patients than in controls. No correlation was found between NOXs, CRP, WBC, ESR and iron metabolism biomarkers in patients.

CONCLUSION

Our data suggest that increased NOX5 expression and decreased levels of NOX4 might be related with oxidative stress related vascular changes in MS patients. These findings provide future opportunities to combat MS with separately target individual NOX isoforms.

High-dose ω-3 Fatty Acid Plus Vitamin D3 Supplementation Affects Clinical Symptoms and Metabolic Status of Patients with Multiple Sclerosis: A Randomized Controlled Clinical Trial

Background

Combined omega-3 fatty acid and vitamin D supplementation may improve multiple sclerosis (MS) by correcting metabolic abnormalities and attenuating oxidative stress and inflammation.

Objective

This study aimed to determine the effects of ω-3 fatty acid and vitamin D cosupplementation on the disability score and metabolic status of patients with MS.

Methods

This was a randomized, placebo-controlled clinical trial with Expanded Disability Status Scale (EDSS) score and inflammation as primary outcomes and oxidative stress biomarkers and metabolic profile as secondary outcomes. Patients, aged 18-55 y, were matched for disease EDSS scores, gender, medications, BMI, and age (n = 53) and randomly received a combined 2 × 1000 mg/d ω-3 fatty acid and 50,000 IU/biweekly cholecalciferol supplement or placebo for 12 wk. The placebos were matched in colour, shape, size, packaging, smell, and taste with supplements. Fasting blood samples were collected at baseline and end of intervention to measure different outcomes. Multiple linear regression models were used to assess treatment effects on outcomes adjusting for confounding variables.

Results

Patients taking ω-3 fatty acid plus vitamin D supplements showed a significant improvement in EDSS (β -0.18; 95% CI: -0.33, -0.04; P = 0.01), compared with placebo. Serum high-sensitivity C-reactive protein (β -1.70 mg/L; 95% CI: -2.49, -0.90 mg/L; P < 0.001), plasma total antioxidant capacity (β +55.4 mmol/L; 95% CI: 9.2, 101.6 mmol/L; P = 0.02), total glutathione (β +51.14 µmol/L; 95% CI: 14.42, 87.87 µmol/L; P = 0.007), and malondialdehyde concentrations (β -0.86 µmol/L; 95% CI: -1.10, -0.63 µmol/L; P < 0.001) were significantly improved in the supplemented group compared with the placebo group. In addition, ω-3 fatty acid and vitamin D cosupplementation resulted in a significant reduction in serum insulin, insulin resistance, and total/HDL-cholesterol, and a significant increase in insulin sensitivity and serum HDL-cholesterol concentrations.

Conclusion

Overall, taking ω-3 fatty acid and vitamin D supplements for 12 wk by patients with MS had beneficial effects on EDSS and metabolic status. This trial was registered at the Iranian website (www.irct.ir) for registration of clinical trials as IRCT2017090133941N20.

Ceramide and Its Related Neurochemical Networks as Targets for Some Brain Disorder Therapies

Correlational and causal comparative research link ceramide (Cer), the precursor of complex sphingolipids, to some psychiatric (e.g., depression, schizophrenia (SZ), alcohol use disorder, and morphine antinociceptive tolerance) and neurological (e.g., Alzheimer's disease (AD), Parkinson disease (PD)) disorders. Cer generation can occur through the de novo synthesis pathway, the sphingomyelinase pathways, and the salvage pathway. The discoveries that plasma Cer concentration increase during depressive episodes in patients and that tricyclic and tetracyclic antidepressants functionally inhibit acid sphingomyelinase (ASM), the enzyme that catalyzes the degradation of sphingomyelin to Cer, have initiated a series of studies on the role of the ASM-Cer system in depressive disorder. Disturbances in the metabolism of Cer or SM are associated with the occurrence of SZ and PD. In both PD and SZ patients, the elevated levels of Cer or SM in the brain regions were associated with the disease. AD patients showed also an abnormal metabolism of brain Cer at early stages of the disease which may suggest Cer as an AD biomarker. In plasma of AD patients and in AD transgenic mice, ASM activity was increased. In contrast, partial ASM inhibition of Aβ deposition improved memory deficits. Furthermore, in clinical and preclinical research, ethanol enhanced activation of ASM followed by Cer production. Limited data have shown that Cer plays an important role in the development of morphine antinociceptive tolerance. In summary, clinical and preclinical findings provide evidence that targeting the Cer system should be considered as an innovative translational strategy for some brain disorders.