Cholesterol and markers of cholesterol turnover in multiple sclerosis: relationship with disease outcomes

Relapsing-Remitting Multiple Sclerosis diagnosis from cerebrospinal fluids via Fourier transform infrared spectroscopy coupled with multivariate analysis

Multiple sclerosis (MS) is a chronic, progressive, inflammatory and degenerative disease of central nervous system. Here, we aimed to develop a method for differential diagnosis of Relapsing-Remitting MS (RRMS) and clinically isolated syndrome (CIS) patients, as well as to identify CIS patients who will progress to RRMS, from cerebrospinal fluid (CSF) by infrared (IR) spectroscopy and multivariate analysis. Spectral analyses demonstrated significant differences in the molecular contents, especially in the lipids and Z conformation of DNA of CSF from CIS, CIS to RRMS transformed (TCIS) and RRMS groups. These changes enables the discrimination of diseased groups and controls (individuals with no neurological disease) from each other using hierarchical cluster and principal component analysis. Some CIS samples were consistently clustered in RRMS class, which may indicate that these CIS patients potentially will transform to RRMS over time. Z-DNA band at 795 cm⁻¹ that is existent only in diseased groups and significant increase in carbonyl amount, decrease in amideI/amide II and lipid/protein ratios observed only for RRMS groups can be used as diagnostic biomarkers. The results of the present study shed light on the early diagnosis of RRMS by IR spectroscopy complemented with multivariate analysis tools.

Twelve Weeks of Medium-Intensity Exercise Therapy Affects the Lipoprotein Profile of Multiple Sclerosis Patients

Multiple sclerosis (MS) is an inflammatory auto-immune disease of the central nervous system (CNS). Serum glucose alterations and impaired glucose tolerance (IGT) are reported in MS patients, and are commonly associated with the development of cardio-metabolic co-morbidities. We previously found that a subgroup of MS patients shows alterations in their lipoprotein profile that are similar to a pre-cardiovascular risk profile. In addition, we showed that a high-intensity exercise training has a positive effect on IGT in MS patients. In this study, we hypothesize that exercise training positively influences the lipoprotein profile of MS patients. To this end, we performed a pilot study and determined the lipoprotein profile before (controls, n = 40; MS patients, n = 41) and after (n = 41 MS only) 12 weeks of medium-intensity continuous training (MIT, n = 21, ~60% of VO_2max) or high-intensity interval training (HIT, n = 20, ~100-200% of VO_2max) using nuclear magnetic resonance spectroscopy (NMR). Twelve weeks of MIT reduced intermediate-density lipoprotein particle count ((nmol/L); -43.4%; p < 0.01), low-density lipoprotein cholesterol (LDL-c (mg/dL); -7.6%; p < 0.05) and VLDL size ((nm); -6.6%; p < 0.05), whereas HIT did not influence the lipoprotein profile. These results show that MIT partially normalizes lipoprotein alterations in MS patients. Future studies including larger patient and control groups should determine whether MIT can reverse other lipoprotein levels and function and if these alterations are related to MS disease progression and the development of co-morbidities.

Contribution of dietary intake to relapse rate in early paediatric multiple sclerosis

OBJECTIVE

The role of diet in multiple sclerosis (MS) course remains largely unknown. Children with MS have a higher relapse rate compared with MS in adults. Thus, studying the effect of diet on relapse rate in this age group is likely to provide more robust answers.

METHODS

This is a multicentre study done at 11 paediatric MS centres in the USA. Patients with relapsing-remitting MS (RRMS) or clinically isolated syndrome (CIS) with disease onset before 18 years of age and duration of less than 4 years were included in this study. Dietary intake during the week before enrolment was assessed with the validated Block Kids Food Screener. The outcome of the study was time from enrolment to the next relapse. 219 patients with paediatric RRMS or CIS were enrolled. Each 10% increase in energy intake from fat increased the hazard of relapse by 56% (adjusted HR 1.56, 95% CI 1.05 to 2.31, p=0.027), and in particular each 10% increase in saturated fat tripled this hazard (adjusted HR: 3.37, 95% CI 1.34 to 8.43, p=0.009). In contrast, each additional one cup equivalent of vegetable decreased the hazard of relapse by 50% (adjusted HR: 0.50, 95% CI 0.27 to 0.91, p=0.024). These associations remained with mutual adjustment and persisted when adjusting for baseline 25(OH) vitamin D serum level. Other studied nutrients were not associated with relapse.

CONCLUSIONS

This study suggests that in children with MS, high energy intake from fat, especially saturated fat, may increase the hazard to relapse, while vegetable intake may be independently protective.

Effect of physical exercise on brain and lipid metabolism in mouse models of multiple sclerosis

Multiple sclerosis (MS) is a central nervous demyelinating disease characterized by cyclic loss and repair of myelin sheaths associated with chronic inflammation and neuronal loss. This degenerative pathology is accompanied by modified levels of oxysterols (oxidative derivatives of cholesterol, implicated in cholesterol metabolism), highlighted in the brain, blood and cerebrospinal fluid of MS patients. The pathological accumulation of such derivatives is thought to participate in the onset and progression of the disease through their implication in inflammation, oxidative stress, demyelination and neurodegeneration. In this context, physical exercise is envisaged as a complementary resource to ameliorate therapeutic strategies. Indeed, physical activity exerts beneficial effects on neuronal plasticity, decreases inflammation and oxidative stress and improves blood-brain integrity in extents that could be beneficial for brain health. The present review attempts to summarize the available data on the positive effect of physical exercise to highlight possible links between physical activity and modulation of cholesterol/oxysterol homeostasis in MS.

Machine-Learned Data Structures of Lipid Marker Serum Concentrations in Multiple Sclerosis Patients Differ from Those in Healthy Subjects

Lipid signaling has been suggested to be a major pathophysiological mechanism of multiple sclerosis (MS). With the increasing knowledge about lipid signaling, acquired data become increasingly complex making bioinformatics necessary in lipid research. We used unsupervised machine-learning to analyze lipid marker serum concentrations, pursuing the hypothesis that for the most relevant markers the emerging data structures will coincide with the diagnosis of MS. Machine learning was implemented as emergent self-organizing feature maps (ESOM) combined with the U*-matrix visualization technique. The data space consisted of serum concentrations of three main classes of lipid markers comprising eicosanoids (d = 11 markers), ceramides (d = 10), and lyosophosphatidic acids (d = 6). They were analyzed in cohorts of MS patients (n = 102) and healthy subjects (n = 301). Clear data structures in the high-dimensional data space were observed in eicosanoid and ceramides serum concentrations whereas no clear structure could be found in lysophosphatidic acid concentrations. With ceramide concentrations, the structures that had emerged from unsupervised machine-learning almost completely overlapped with the known grouping of MS patients versus healthy subjects. This was only partly provided by eicosanoid serum concentrations. Thus, unsupervised machine-learning identified distinct data structures of bioactive lipid serum concentrations. These structures could be superimposed with the known grouping of MS patients versus healthy subjects, which was almost completely possible with ceramides. Therefore, based on the present analysis, ceramides are first-line candidates for further exploration as drug-gable targets or biomarkers in MS.

Expression profiles of cholesterol metabolism-related genes are altered during development of experimental autoimmune encephalomyelitis in the rat spinal cord

Increased evidence suggests that dysregulation of cholesterol metabolism may be a key event contributing to progression of multiple sclerosis (MS). Using an experimental autoimmune encephalomyelitis (EAE) model of MS we revealed specific changes in the mRNA and protein expression of key molecules involved in the maintaining of cholesterol homeostasis in the rat spinal cord: 3-hydroxy-3-methylglutaryl-coenzyme-A reductase (HMGCR), apolipoprotein E (ApoE) and cholesterol 24-hydroxylase (CYP46A1) during the course of disease. The presence of myelin lipid debris was seen only at the peak of EAE in demyelination loci being efficiently removed during the recovery period. Since CYP46A1 is responsible for removal of cholesterol excess, we performed a detailed profiling of CYP46A1 expression and revealed regional and temporal specificities in its distribution. Double immunofluorescence staining demonstrated CYP46A1 localization with neurons, infiltrated macrophages, microglia and astrocytes in the areas of demyelination, suggesting that these cells play a role in cholesterol turnover in EAE. We propose that alterations in the regulation of cholesterol metabolism at the onset and peak of EAE may add to the progression of disease, while during the recovery period may have beneficial effects contributing to the regeneration of myelin sheath and restoration of neuronal function.

Interdependence of oxysterols with cholesterol profiles in multiple sclerosis

PURPOSE

To investigate levels of oxysterols in healthy control (HC) and multiple sclerosis (MS) patients and their interdependence with demographic, clinical characteristics, and cholesterol biomarkers.

METHODS

This study included 550 subjects (203 HC, 221 relapsing-remitting MS (RR-MS), 126 progressive MS (P-MS)). A complete lipid profile including total cholesterol (TC); high-density lipoprotein-cholesterol (HDL-C); low-density lipoprotein-cholesterol (LDL-C); apolipoproteins (Apo) A1, A2, B, and E; C-reactive protein (CRP); 24-hydroxycholesterol (HC); 25-HC; 27-HC; 7α-HC; and 7-ketocholesterol (KC) was obtained. Lipoprotein particle sizing by proton nuclear magnetic resonance (H¹ NMR) was available for 432 subjects.

RESULTS

The levels of 24-HC, 27-HC, and 7α-HC (all p < 0.015) were lower in MS compared to HC, and 7-KC was higher in P-MS compared to RR-MS ( p < 0.001). TC, LDL-C, and ApoB were associated with higher levels of all oxysterols (all p < 0.05) in HC. In MS, LDL-C was associated with higher levels of 24-HC, 25-HC, 7-KC, and 7α-HC (all p < 0.05), while TC and ApoB were associated with increased levels of all oxysterols (all p < 0.005).

CONCLUSION

The findings of lower 24-HC, 27-HC, and 7α-HC in MS compared to HC and higher 7-KC in P-MS compared to RR-MS indicate that the oxysterol network is disrupted in MS.