Protective associations of HDL with blood-brain barrier injury in multiple sclerosis patients

Apolipoproteins in ischemic stroke progression and recovery: Key molecular mechanisms and therapeutic potential

Ischemic stroke, responsible for 80 % of all strokes, is a leading cause of mortality globally. While altered lipids profiles are recognized as modifiable risk factors, their direct impact on stroke outcomes is less understood due to the brain's distinct lipid metabolism and the selective permeability of the blood-brain barrier for lipoproteins. As key components of lipoproteins, apolipoproteins are essential for lipid transport, redistribution and metabolism in both the central nervous system and peripheral blood circulation. This review provides an updated perspective on the influence of brain-expressed apolipoproteins (such as ApoE, ApoA-I, ApoJ, ApoD, and others) and those that cross the damaged blood-brain barrier following ischemic stroke. We explore hypotheses regarding their involvement in molecular pathways related to lipid metabolism, inflammation, oxidative stress, mitochondrial function and blood-brain barrier integrity. Through this synthesis, we aim to identify potential biomarkers and therapeutic targets, thereby enhancing our understanding of apolipoproteins in ischemic stroke progression and contributing to improved clinical outcomes.

Effects of a Multimodal Lifestyle Intervention on Cardiometabolic Markers in People with Progressive Multiple Sclerosis: A Secondary Analysis of a Pilot Study

Background: Cardiometabolic comorbidities are common in multiple sclerosis (MS), and lifestyle interventions are effective in managing these conditions in the general population, though evidence in the MS patient population is limited. Objective: To evaluate the effect of a multimodal lifestyle intervention on serum apolipoproteins (Apo), creatine kinase (CK), glucose, and insulin in people with progressive MS (PwPMS). Methods: This study included n = 19 PwPMS who participated in a 12-month multimodal lifestyle intervention (including a modified Paleolithic diet, exercise, neuromuscular electrical stimulation, supplements, and stress reduction). Lipid profile (ApoA1, B, and E), CK, glucose, and insulin were obtained at baseline and after 12 months under fasting conditions. Results: At 12 months, there was a marginally significant decrease in ApoB (mean change: -7.17 mg/dL; 95% CI: -14.4, 0.12; p = 0.06), while no significant changes were observed for ApoA1 (mean change: -1.28 mg/dL; 95% CI: 12.33, 9.76; p = 0.80), ApoE (mean change: +0.12 mg/dL; 95% CI: -0.27, 0.52; p = 0.51), CK (mean change: +13.19 U/L; 95% CI: -32.72, 59.11; p = 0.55), Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) (mean change: -0.44; 95% CI: -1.11, 0.22; p = 0.17), and HOMA-β (mean change: +45.62; 95% CI: -95.6, 186.9; p = 0.50). A positive association was observed between changes in HOMA-IR and fatigue changes at 12 months (β = 0.81, p = 0.02), suggesting that an increase in HOMA-IR was linked to increased fatigue, which was no longer significant following the exclusion of outliers (β = 0.71, p = 0.16). Conclusions: A multimodal lifestyle intervention did not negatively impact glycemic and lipid profiles. While improvements were observed in serum biomarkers, these changes were not statistically significant, highlighting the need for stronger evidence from larger, controlled studies to confirm the cardiometabolic health benefits in PwPMS.

Serum Lipid Biomarkers for the Diagnosis and Monitoring of Neuromyelitis Optica Spectrum Disorder: Towards Improved Clinical Management

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a group of immune-mediated disorders that often lead to severe disability. The diagnosis and monitoring of NMOSD can be challenging, particularly in seronegative cases, highlighting the need for reliable biomarkers to enhance clinical management. This study aimed to identify serum lipid biomarkers for the diagnosis and monitoring of NMOSD and to assess their potential to improve clinical decision-making.

Methods

We conducted a comprehensive serum proteomic analysis in a discovery cohort of NMOSD patients and controls to identify lipid-related proteins associated with NMOSD. Subsequently, we validated the candidate biomarkers in the retrospective cohort and developed diagnostic models using a random forest algorithm. The association between these lipid biomarkers and disease activity was further evaluated in longitudinal analysis.

Results

Our analysis identified a panel of serum lipid-related biomarkers that demonstrated significant differences between NMOSD patients and controls. The diagnostic models achieved the impressive accuracy of 72% for the full NMOSD spectrum, 72% for AQP4-IgG+ NMOSD, and 68% for double seronegative NMOSD. Importantly, these biomarkers showed a correlation with disease activity, with levels changing from relapse to remission. Additionally, a combination of these lipid biomarkers was found to predict relapse with the AUC of 0.861. A user-friendly smartphone application was developed to facilitate the straightforward "input-index, output-answer" screening process, enhancing both clinical decision-making and patient care.

Conclusion

The diagnostic model based on the serum lipid-related indexes (TC, TG, LDL, HDL, ApoA1, and ApoB) may be the useful tool for NMOSD in diagnosis and monitoring of disease stage, thereby improving the treatment outcome for patients. Future studies should focus on integrating these biomarkers into routine clinical practice to realize their full potential in enhancing NMOSD management.

The Role of Extracellular Vesicles and Microparticles in Central Nervous System Disorders: Mechanisms, Biomarkers, and Therapeutic Potential

Microscopic, membranous vesicles known as extracellular vesicles (EVs) have been proposed to play a role in the mechanisms underlying central nervous system (CNS) diseases. EVs are secreted by a variety of cells, including myeloid, endothelial, microglial, oligodendroglial, and mesenchymal stem cells (MSCs). Body fluids such as plasma, urine, and cerebrospinal fluid (CSF) contain microparticles (MPs). The detection of MPs in CSF may indicate genetic or environmental susceptibility to conditions such as schizophrenia, schizoaffective disorder, and bipolar disorder. MPs of different origins can exhibit changes in specific biomarkers at various stages of the disease, aiding in the diagnosis and monitoring of neurological conditions. However, understanding the role and clinical applications of MPs is complicated by challenges such as their isolation and dual roles within the CNS. In this review, we discuss the history, characteristics, and roles of MPs in CNS diseases. We also provide practical insights for future research and highlight the challenges that obscure the therapeutic potential of MPs.

Lipid and brain volumetric measures in multiple sclerosis patients: findings from a large observational study

OBJECTIVES

This study aimed to investigate relationships between cholesterol profile, brain volumetric MRI, and clinical measures in a large observational cohort of multiple sclerosis (MS) patients.

MATERIALS AND METHODS

We included 1.505 patients with 4.966 time points including complete lipid, clinical, and imaging data. The time among lipid, brain MRI and clinical measures was under 90 days. Cross-sectional statistical analysis at baseline was performed using an adjusted linear regression and analysis of longitudinal lipid and MRI measures data was performed using adjusted linear mixed models.

RESULTS

We found associations between higher high-density lipoprotein cholesterol (HDL-C) and lower brain parenchymal fraction (BPF) at cross-sectional analysis at baseline (B = -0.43, CI 95%: -0.73, -0.12, p = 0.005), as well as in longitudinal analysis over follow-up (B = -0.32 ± 0.072, χ2 = 36.6; p = < 0.001). Higher HDL-C was also associated with higher T2-lesion volume in longitudinal analysis (B = 0.11 ± 0.023; χ2 = 23.04; p = < 0.001). We observed a weak negative association between low-density lipoprotein cholesterol (LDL-C) levels and BPF at baseline (B = -0.26, CI 95%: -0.4, -0.11, p = < 0.001) as well as in longitudinal analysis (B = -0.06 ± 0.03, χ2 = 4.46; p = 0.03). T2-LV did not show an association with LDL-C. We did not find any association between lipid measures and disability. The effect of lipid levels on MRI measures and disability was minimal (Cohen f2 < 0.02).

CONCLUSIONS

Our results contradict the previously described exclusively positive effect of HDL-C on brain atrophy in patients with MS. Higher LDL-C was weakly associated with higher brain atrophy but not with higher lesion burden.

Protective Role of High-Density Lipoprotein in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic, progressive demyelinating disease with a most likely autoimmune background and a neurodegenerative component. Besides the demyelinating process caused by autoreactive antibodies, an increased permeability in the blood-brain barrier (BBB) also plays a key role. Recently, there has been growing interest in assessing lipid profile alterations in patients with MS. As a result of myelin destruction, there is an increase in the level of cholesterol released from cells, which in turn causes disruptions in lipid metabolism homeostasis both in the central nervous system (CNS) and peripheral tissues. Currently, there is a growing body of evidence suggesting a protective role of HDL in MS through its effect on the BBB by decreasing its permeability. This follows from the impact of HDL on the endothelium and its anti-inflammatory effect, mostly by interacting with adhesion molecules like vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and E-selectin. HDL, through its action via sphingosine-1-phosphate, exerts an inhibitory effect on leukocyte migration, and its antioxidant properties contribute to the improvement of the BBB function. In this review, we want to summarize these studies and focus on HDL as a mediator of the anti-inflammatory response in MS.

The possible connection between neutrophil-to-high-density lipoprotein ratio and cerebral perfusion in clinically established corticobasal syndrome: a pilot study

Introduction

Progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) are tauopathic atypical parkinsonisms. Given their overlap in terms of clinical manifestation, there is growing interest in the mechanisms leading to these entities.

Materials and methods

In total, 71 patients were included in the study, 19 of whom were clinically diagnosed with CBS, 37 with PSP, and 15 with Parkinson's disease (PD). The mean ages of the participants were 72.8, 72.9, and 64.0 years, respectively, and the disease duration varied from 3 to 6 years. Each individual underwent blood collection. Morphological and biochemical evaluation of blood samples was performed to analyze the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and neutrophil-to-high-density lipoprotein ratio (NHR). A single-photon emission computed tomography (SPECT) with technetium-99m hexamethylpropyleneamine oxime (99Tc-HMPAO) tracer was used to assess perfusion in two regions of interest (ROI): the thalamus and insula. Using Pearson correlation to assess the linear relationship between NHR and perfusion in the insula and thalamus for CBS, PSP, and PD patients, the authors intended to verify possible correlations between NLR, PLR, and NHR and perfusion in the indicated ROIs.

Results

The study revealed a negative linear correlation between NHR and perfusion of both the left (Insula L; R = -0.59) and right (Insula R; R = -0.58) insula regions. Similar to the insula, a linear correlation between NHR and activity in both the left (Thalamus L) and right (Thalamus R) thalamus regions in CBS subjects with a relatively stronger correlation in the right thalamus (R = -0.64 vs. R = -0.58) was found. These observations were not confirmed in PSP and PD patients.

Conclusion

Simultaneously using non-specific parameters for peripheral inflammation (NLR, PLR, and NHR) and perfusion, SPECT may be an interesting beginning point for further analysis of inflammatory disease mechanisms. To the best of our knowledge, this is the first study to address the potential correlation between the peripheral neuroinflammatory markers NLR, PLR, and NHR and perfusion disturbances in particular ROIs.

Nuclear-Magnetic-Resonance-Spectroscopy-Derived Serum Biomarkers of Metabolic Vulnerability Are Associated with Disability and Neurodegeneration in Multiple Sclerosis

PURPOSE

Metabolic vulnerabilities can exacerbate inflammatory injury and inhibit repair in multiple sclerosis (MS). The purpose was to evaluate whether blood biomarkers of inflammatory and metabolic vulnerability are associated with MS disability and neurodegeneration.

METHODS

Proton nuclear magnetic resonance spectra were obtained from serum samples from 153 healthy controls, 187 relapsing-remitting, and 91 progressive MS patients. The spectra were analyzed to obtain concentrations of lipoprotein sub-classes, glycated acute-phase proteins, and small-molecule metabolites, including leucine, valine, isoleucine, alanine, and citrate. Composite indices for inflammatory vulnerability, metabolic malnutrition, and metabolic vulnerability were computed. MS disability was measured on the Expanded Disability Status Scale. MRI measures of lesions and whole-brain and tissue-specific volumes were acquired.

RESULTS

Valine, leucine, isoleucine, alanine, the Inflammatory Vulnerability Index, the Metabolic Malnutrition Index, and the Metabolic Vulnerability Index differed between healthy control and MS groups in regression analyses adjusted for age, sex, and body mass index. The Expanded Disability Status Scale was associated with small HDL particle levels, inflammatory vulnerability, and metabolic vulnerability. Timed ambulation was associated with inflammatory vulnerability and metabolic vulnerability. Greater metabolic vulnerability and inflammatory vulnerability were associated with lower gray matter, deep gray matter volumes, and greater lateral ventricle volume.

CONCLUSIONS

Serum-biomarker-derived indices of inflammatory and metabolic vulnerability are associated with disability and neurodegeneration in MS.

Relationship between pattern reversal visual evoked potential P100 wave latency and dysfunctional HDL in patients with multiple sclerosis subjected to an optic neuritis attack: A case-control study

Optic neuritis frequently occurs during the clinical course of multiple sclerosis (MS). In this condition, demyelination of the optic nerve occurs, which electrophysiologically causes a delay in P100 wave latency. Sensitive cholesterol homeostasis is critical for the formation of the myelin sheath and for myelin to become functionally mature. High-density lipoprotein (HDL) becomes dysfunctional under oxidative stress and plays an important role in the pathogenesis of MS. In this study, HDL levels of MS patients suffering from optic neuritis were compared with those of healthy individuals, and the relationship between pattern reversal visual evoked potential (PRVEP) P100 wave latency and HDL levels in patients with optic neuritis attacks was analyzed. PRVEP studies were performed in patients with MS who had an episode of optic neuritis, and P100 wave latencies were measured. Peripheral blood samples were collected from healthy participants and patients. Lipid levels and myeloperoxidase (MPO) and paraoxonase (PON) activities were measured, and the MPO/PON ratio was then calculated. The lipid profiles and dysfunctional HDL levels in the healthy and patient groups were compared. Finally, the relationship between these parameters and the PRVEP-P100 wave latency was examined. Total cholesterol and low-density lipoprotein (LDL) levels were significantly higher in the patient group (P = .044; P = .038, respectively). There was no statistically significant difference in HDL levels between groups (P = .659). The distribution of MPO values was similar between groups (P = .452). PON values were significantly lower, whereas the MPO/PON ratios were significantly higher in the patient group than in the control group (P = .025; P = .028, respectively). A statistically significant positive correlation was found between the elevated MPO/PON ratio, representing dysfunctional HDL, and both the mean and maximum PRVEP-P100 wave latencies (P < .001, R = 0.690; P < .001, R = 0.815, respectively). A dysfunctional form of HDL may lead to poor deactivation of remyelination-limiting factors and may ultimately be associated with poor outcomes in optic neuritis.

Lipid Profile in Multiple Sclerosis: Functional Capacity and Therapeutic Potential of Its Regulation after Intervention with Epigallocatechin Gallate and Coconut Oil

BACKGROUND

Multiple sclerosis (MS) patients present dyslipidemia and functional disability. Epigallocatechin gallate (EGCG) and coconut oil have been shown to be effective against dyslipidemia.

OBJECTIVE

To analyze the relationship between lipid profiles, fat consumption, and functional disability in patients with MS after administering EGCG and coconut oil.

METHODS

A four-month pilot study was conducted on 45 MS patients, divided into an intervention group (IG) and a control group (CG). The IG received 800 mg of EGCG and 60 mL of coconut oil. Lipid profiles were measured before and after the intervention, along with other data such as dietary habits, inflammatory markers, and functional capacity.

RESULTS

Dyslipidemia did not correlate with the patients' fat consumption. After the intervention, triglycerides (TG) levels were lower in IG compared to CG. This decrease was positively correlated with an improvement in functional disability (determined by the Expanded Disability Status Scale (EDSS)) and negatively with high-density cholesterol (HDL) and apolipoprotein A1. Significant and positive correlations were observed between EDSS and C-reactive protein (CRP) in the IG. These changes in the IG could be related to body fat decrease, whose percentage shows a positive correlation with CRP and TG levels, and a negative correlation with HDL levels.

CONCLUSIONS

Patients with MS present a certain type of dyslipemia not associated with their nutritional habits. The administration of EGCG and coconut oil seems to decrease blood TG levels, which could explain the functional improvements.

Metabolic syndrome parameters and multiple sclerosis disease outcomes: A Portuguese cross-sectional study

BACKGROUND

Metabolic syndrome and multiple sclerosis [MS] share the presence of chronic inflammation in their pathogenic mechanisms. This study aimed to estimate the prevalence of metabolic syndrome parameters in MS and their association with disease disability, cognitive function, and Neurofilament Light chain [NfL] levels.

METHODS

Clinical, analytical, and magnetic resonance imaging data were obtained through medical records. Disease disability was measured by the Expanded Disability Status Scale [EDSS], the MS Severity Scale [MSSS] along with cognitive impairment by the Brief International Cognitive Assessment for MS [BICAMS] and Word List Generation test [WLG]. Metabolic syndrome parameters were evaluated by fasting blood glucose, triglycerides, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol, total cholesterol, blood pressure, and waist circumference [WC]. We also analysed serum leptin and ghrelin and cerebrospinal fluid NfL.

RESULTS

Our sample included 51 people with MS, 34 (66.7%) females, mean age of 38.20±12.12 years and median disease duration of 3 years (P25=2.0, P75=5.0). Multivariate linear regression analysis confirmed that WC correlates with EDSS (β=0.04, p=.001) and MSSS (β=0.07, p=.002) as well as Brief Visuospatial Memory Test-Revised (β=-0.29, p=.008), WLG (β=-0.20, p=.039). NfL is also negatively associated with HDL-C (β=-4.51, p=.038).

CONCLUSIONS

Waist circumference is associated with disability and deficits in cognitive tests. A decrease in HDL-C is associated with an increase in NfL. This suggests metabolic syndrome might be an important factor in MS disease course.

Cholesterol pathway biomarkers are associated with neuropsychological measures in multiple sclerosis

BACKGROUND

Cognitive impairment (CI) is frequent in persons with multiple sclerosis (PwMS) and is linked to neurodegeneration. Cholesterol pathway biomarkers (CPB) are associated with blood-brain barrier breakdown, lesions, and neurodegeneration in multiple sclerosis (MS). CPB could influence CI.

METHODS

This cross-sectional study (n = 163) included 74 relapsing-remitting MS (RR-MS), 48 progressive MS (P-MS) and 41 healthy control (HC) subjects. The assessed physical disability and cognitive measures were: Nine-hole Peg Test (NHPT), Timed 25-Foot Walk, Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test-3, and Beck Depression Inventory-Fast Screen. CPB panel included plasma total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and the apolipoproteins (Apo), ApoA-I, ApoA-II, ApoB, ApoC-II and ApoE. Disability and cognitive measures were assessed as dependent variables in regression analyzes with age, sex, body mass index, years of education, HC vs. RR-MS vs. P-MS status, CPB, and a HC vs. RR-MS vs. P-MS status × CPB interaction term as predictors.

RESULTS

SDMT was associated with the interaction terms for HDL-C (p = 0.045), ApoA-I (p = 0.032), ApoB (p = 0.032), TC/HDL-C (p = 0.013), and ApoB/ApoA-I (p = 0.008) ratios. CPB associations of SDMT were not abrogated upon adjusting for brain parenchymal volume. NHPT performance was associated with the interaction terms for TC (p = 0.047), LDL-C (p = 0.017), ApoB (p = 0.001), HDL-C (p = 0.035), ApoA-I (p = 0.032), ApoC-II (p = 0.049) and ApoE (p = 0.037), TC/HDL-C (p < 0.001), and ApoB/ApoA-I ratios (p < 0.001).

CONCLUSIONS

The LDL to HDL proportion is associated with SDMT and NHPT in MS. The findings are consistent with a potential role for CPB in CI.

Plasma lipid profiles and homocysteine levels in anti-N-methyl-D-aspartate receptor encephalitis

Introduction

We aimed to investigate whether lipid profiles and homocysteine levels in patients with anti-N-methyl-D-aspartate receptor encephalitis are related to clinical presentation and prognosis, which may contribute to further research on the pathogenesis and treatment of this disease.

Methods

This study included a total of 43 patients with anti-N-methyl-D-aspartate receptor encephalitis and 43 sex-age-matched healthy controls. Baseline demography, clinical data, patient outcomes, and ancillary examination results were recorded. Patients were followed up every 2-3 months during the first year. The modified Rankin Scale score was used to evaluate the therapeutic effect and clinical outcome.

Results

Among the 43 patients included in this study, 55.81% were male, the mean age of onset was 27 years old, and the median modified Rankin Scale score on admission was 3.0. Apolipoprotein A-1 was significantly lower in patients with anti-N-methyl-D-aspartate receptor encephalitis compared with healthy controls (p = 0.004). Compared with healthy controls, homocysteine (p = 0.002), apolipoprotein B (p = 0.004), Lpa (p = 0.045), and apolipoprotein B/apolipoprotein A-1 (p = 0.001) were significantly increased in patients with anti-N-methyl-D-aspartate receptor encephalitis. According to the modified Rankin Scale scores, 6 months after discharge, 72.09% of patients had a good prognosis and 27.91% had a poor prognosis. In the good prognosis group, age (p = 0.031), lipoprotein a (p = 0.023), apolipoprotein A-1 (p = 0.027) at baseline, and the modified Rankin Scale score on admission (p = 0.019) were significantly higher than those in the poor prognosis group.

Conclusion

This study suggests the possibility that serum lipid profile and homocysteine play an important role in the pathogenesis of anti-N-methyl-D-aspartate receptor encephalitis, providing support for lipid-lowering treatment of anti-N-methyl-D-aspartate receptor encephalitis patients.

Fingolimod treatment modulates PPARγ and CD36 gene expression in women with multiple sclerosis

Fingolimod is an oral immunomodulatory drug used in the treatment of multiple sclerosis (MS) that may change lipid metabolism. Peroxisome proliferator-activated receptors (PPAR) are transcription factors that regulate lipoprotein metabolism and immune functions and have been implicated in the pathophysiology of MS. CD36 is a scavenger receptor whose transcription is PPAR regulated. The objective of this study was to evaluate whether fingolimod treatment modifies PPAR and CD36 gene expression as part of its action mechanisms. Serum lipoprotein profiles and PPAR and CD36 gene expression levels in peripheral leukocytes were analysed in 17 female MS patients before and at 6 and 12 months after fingolimod treatment initiation. Clinical data during the follow-up period of treatment were obtained. We found that fingolimod treatment increased HDL-Cholesterol and Apolipoprotein E levels and leukocyte PPARγ and CD36 gene expression. No correlations were found between lipid levels and variations in PPARγ and CD36 gene expression. PPARγ and CD36 variations were significantly correlated during therapy and in patients free of relapse and stable disease. Our results suggest that PPARγ and CD36-mediated processes may contribute to the mechanisms of action of fingolimod in MS. Further studies are required to explore the relation of the PPARγ/CD36 pathway to the clinical efficacy of the drug and its involvement in the pathogenesis of the disease.

Brain-specific loss of Abcg1 disturbs cholesterol metabolism and aggravates pyroptosis and neurological deficits after traumatic brain injury

Based on accumulating evidence, cholesterol metabolism dysfunction has been suggested to contribute to the pathophysiological process of traumatic brain injury (TBI) and lead to neurological deficits. As a key transporter of cholesterol that efflux from cells, the ATP-binding cassette (ABC) transporter family exerts many beneficial effects on central nervous system (CNS) diseases. However, there is no study regarding the effects and mechanisms of ABCG1 on TBI. As expected, TBI resulted in the different time-course changes of cholesterol metabolism-related molecules in the injured cortex. Considering ABCG1 is expressed in neuron and glia post-TBI, we generated nestin-specific Abcg1 knockout (Abcg1-KO) mice using the Cre/loxP recombination system. These Abcg1-KO mice showed reduced plasma high-density lipoprotein cholesterol levels and increased plasma lower-density lipoprotein cholesterol levels under the base condition. After TBI, these Abcg1-KO mice were susceptible to cholesterol metabolism turbulence. Moreover, Abcg1-KO exacerbated TBI-induced pyroptosis, apoptosis, neuronal cell insult, brain edema, neurological deficits, and brain lesion volume. Importantly, we found that treating with retinoid X receptor (RXR, the upstream molecule of ABCG1) agonist, bexarotene, in Abcg1-KO mice partly rescued TBI-induced neuronal damages mentioned above and improved functional deficits versus vehicle-treated group. These data show that, in addition to regulating brain cholesterol metabolism, Abcg1 improves neurological deficits through inhibiting pyroptosis, apoptosis, neuronal cell insult, and brain edema. Moreover, our findings demonstrate that the cerebroprotection of Abcg1 on TBI partly relies on the activation of the RXRalpha/PPARgamma pathway, which provides a potential therapeutic target for treating TBI.

Influential Factors, Treatment and Prognosis of Autoimmune Encephalitis Patients With Poor Response to Short-Term First-Line Treatment

Objective

This study was performed to assess the potential factors for poor short-term first-line treatment response, the appropriate further treatment options, and the prognosis in patients with autoimmune encephalitis (AE).

Methods

This retrospective study consisted of 135 patients with AE. According to their short-term first-line treatment response, patients were divided into the response group and the non-response group. The demographics, clinical characteristics, main accessory examinations, immunotherapy, and outcomes of patients were compared between the two groups. Univariate and multivariate logistic regression models were used to analyze whether non-responders have poor long-term outcomes. Further treatment and prognosis of non-responders were also analyzed.

Results

Of the 128 patients who were treated with first-line immunotherapy, 59 (46.1%) were non-responders. Patients in the non-response group had more symptoms and exhibited a higher proportion of mental behavior disorder, central hypoventilation, and autonomic nervous dysfunction. The modified Rankin scale (mRS) scores and neutrophil-to-lymphocyte ratio (NLR) levels were significantly higher and albumin, high-density lipoprotein cholesterol (HDL-C), apolipoprotein A (apoA) levels were significantly lower in the non-response group (p < 0.05, all). Multivariate logistic regression analysis showed that the number of clinical symptoms, mental behavior disorder, central hypoventilation, maximum mRS score, and albumin level was independently associated with non-response to short-term first-line treatment. Non-responders had poor long-term outcomes compared with the responders at all times of followed-up (p < 0.05, all). In multivariable analysis, initial first-line treatment response was independently associated with the long-term prognosis, both at 12-month [odds ratio (OR), 4.74, 95% CI, 1.44–15.59, and p=0.010] and 24-month follow-ups (OR, 8.81, 95% CI, 1.65–47.16; and p = 0.011). Among the non-responders, a higher improvement of mRS scores was observed in those who received second-line treatment than those who had no further treatment or repetition of first-line immunotherapy in the follow-up. However, the rate of a good outcome and median mRS scores were not significantly different among the three groups.

Conclusion

Disease severity, clinical features, anti-N-methyl-D-aspartate receptor subtypes, antibody titers, NLR, albumin, HDL-C, and apoA levels were all associated with non-response to short-term first-line treatment. The short-term first-line treatment response is a valuable predictor of long-term outcomes in patients with AE. Second-line immunotherapy may be a more aggressive treatment option for patients who failed short-term first-line immunotherapy.

Low high-density lipoprotein cholesterol and apolipoprotein A-I levels are associated with poor outcome and relapse in autoimmune encephalitis

BACKGROUND

Growing evidence suggests an association between dyslipidemia and autoimmune diseases. This study aimed to investigate the relationship between lipid profiles and prognosis of autoimmune encephalitis (AE) patients.

METHODS

This retrospective study consisted of 114 AE patients from September 2014 to September 2020. Data of clinical parameters, including age, sex, body mass index (BMI), clinical features, comorbidities, therapeutic management, lipid profiles, modified Rankin scale (mRS) scores, outcomes, and relapses were collected. Logistic regression models were used to examine the associations between lipid profiles and outcomes of AE. Correlations between lipid profiles and C-reactive protein (CRP), which is an inflammatory marker, were assessed.

RESULTS

In the univariate logistic analysis, sex (P = 0.030), mental behavior disorder (P = 0.004), disturbance of consciousness (P = 0.002), mRS at study entry (P = 0.020), tumor comorbidity (P = 0.028), high-density lipoprotein cholesterol (HDL-C) (P = 0.029), apolipoprotein A-I (apoA-I) (P = 0.012), apolipoprotein B (apoB) (P = 0.036) and apoA-I/apoB (P = 0.001) levels were all associated with the unfavorable outcomes of patients. After adjustment for age, sex and mRS at study entry, lower apoA-I and apoA-I /apoB levels were still significantly associated with the unfavorable outcomes of patients. Low HDL-C (P = 0.048) and apoA-I levels (P = 0.026) were also significantly associated with the relapse of AE patients. HDL-C and apoA-I levels were negatively correlated with CRP levels in correlation analysis.

CONCLUSIONS

Lipid profiles, especially low HDL-C and apoA-I levels, are significantly associated with the poor outcomes and relapse of AE patients, and seem associated with inflammatory responses. HDL-C and apoA-I levels may be good candidates for predicting prognosis of AE patients.

Interactions of Lipids, Lipoproteins, and Apolipoproteins with the Blood-Brain Barrier

Lipids and lipoproteins are a diverse group of substances and their interactions with the blood-brain barrier (BBB) is similarly diverse. Some lipoproteins such as high density lipoprotein (HDL), apolipoprotein (apo) A-I, apoJ, some free fatty acids, and triglycerides cross the BBB whereas others such as apoE do not. Some forms of cholesterol can cross the BBB and others do not. Lipids can have effects on BBB preservation and function: HDL may protect the BBB during multiple sclerosis, cholesterol can disrupt the BBB, and triglycerides inhibit the transport of leptin across the BBB and the activation of the hypothalamic leptin receptor. ApoE is associated with many effects on the BBB, with the specific isoform apoE4 having detrimental effects. In summary, the diverse ways in which lipids, lipoproteins, and apolipoproteins interact with the BBB is important in both health and disease.

The cholesterol autoxidation products, 7-ketocholesterol and 7β-hydroxycholesterol are associated with serum neurofilaments in multiple sclerosis

BACKGROUND

Serum neurofilament light chain (sNfL) is an established marker of neuroaxonal injury in multiple sclerosis (MS).

OBJECTIVES

To investigate if oxysterols produced from non-enzymatic and enzymatic cholesterol oxidation are differentially associated with sNfL measurements in MS.

METHODS

This longitudinal study included 62 relapsing-remitting (RR-MS) and 36 progressive MS (PMS) patients with baseline and 5-year follow-up measures of serum levels of 6 oxysterols, sNfL and lipids. The oxysterols, 24-hydroxycholesterol (24HC), 25HC, 27HC, 7αHC, 7βHC and 7-ketocholesterol (7KC), were measured using liquid chromatography-mass spectrometry. sNfL was measured using single molecular array assay. Serum high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels were obtained from a lipid profile.

RESULTS

The enzymatically produced oxysterols 24HC, 25HC, 27HC and 7αHC were not associated with sNfL. However, baseline levels of reactive oxygen species (ROS) produced oxysterols, 7KC (p = 0.032) and 7βHC (p = 0.0025), were positively associated with sNfL levels at follow-up. Follow-up 7KC (p = 0.038) levels were also associated with follow-up sNfL levels. The associations of 7KC or 7βHC with sNfL remained significant after adjusting for LDL-C or HDL-C.

CONCLUSIONS

7KC and 7βHC, produced by ROS-mediated cholesterol oxidation are associated with neuroaxonal injury as assessed by sNfL in MS.

Disrupted Lipid Metabolism in Multiple Sclerosis: A Role for Liver X Receptors?

Multiple sclerosis (MS) is a chronic neurological disease driven by autoimmune, inflammatory and neurodegenerative processes leading to neuronal demyelination and subsequent degeneration. Systemic lipid metabolism is disturbed in people with MS, and lipid metabolic pathways are crucial to the protective process of remyelination. The lipid-activated transcription factors liver X receptors (LXRs) are important integrators of lipid metabolism and immunity. Consequently, there is a strong interest in targeting these receptors in a number of metabolic and inflammatory diseases, including MS. We have reviewed the evidence for involvement of LXR-driven lipid metabolism in the dysfunction of peripheral and brain-resident immune cells in MS, focusing on human studies, both the relapsing remitting and progressive phases of the disease are discussed. Finally, we discuss the therapeutic potential of modulating the activity of these receptors with existing pharmacological agents and highlight important areas of future research.

Lipid profiles and their potential inflammatory effects in anti-N-methyl-D-aspartate receptor encephalitis

BACKGROUND

Growing evidence suggests an association between dyslipidemia and autoimmune diseases. This study aimed to perform a preliminary analysis to investigate the role of lipid profiles in anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis and to preliminarily explore the potential inflammatory effects of lipids on this disease by analyzing the association of lipid profiles with different inflammatory markers.

METHODS

This retrospective study consisted of 40 anti-NMDAR encephalitis patients and 74 healthy controls. Serum lipid profiles and different inflammatory markers were analyzed upon admission and at each follow-up. Lipid profiles were compared among subgroups of patients, which were divided according to clinical characteristics. Correlations between lipid profiles and different inflammatory markers were assessed.

RESULTS

The results showed that lipid profiles were abnormal and were correlated with both disease severity and prognosis in patients with anti-NMDAR encephalitis. Correlations between lipid profiles and different inflammatory markers were observed. After 12 months of treatment, inflammatory markers changed with lipid profiles, and these changes were significantly correlated.

CONCLUSIONS

Lipid profiles are associated with pathogenesis and progression of anti-NMDAR encephalitis, and they are significantly correlated with different inflammatory markers, suggesting that the association of lipids with the disease might be influenced by the inflammatory response.

Apolipoproteins AI and E are associated with neuroaxonal injury to gray matter in multiple sclerosis

Purpose To investigate the associations between longitudinal changes in lipid biomarkers and serum neurofilament (sNfL) levels in multiple sclerosis (MS) neurodegeneration and disease progression. Methods 5-year prospective, longitudinal study included 75 relapsing-remitting MS (RR-MS) and 37 progressive-MS (P-MS) patients. sNfL, plasma total cholesterol (TC), high-density (HDL-C) and low-density (LDL-C) lipoprotein cholesterol, apolipoproteins (Apo), ApoA-I, Apo-II, ApoB, ApoC-II and ApoE were measured at baseline and 5-years. Annual percent changes in whole brain volume (PBVC), gray matter volume (PGMVC) and cortical volume (PCVC) were obtained from MRI at baseline and 5-years. Results sNfL levels at 5-year follow-up were associated with ApoE at follow-up (p = 0.014), age at follow-up, body mass index (p < 0.001) and RR vs. P-MS status at follow-up. APOE4 allele was associated with greater sNfL levels at 5-years (p = 0.022) and pronounced in the P-MS group. PGMVC and PCVC were associated with percent changes in HDL-C (p = 0018 and p < 0.001, respectively) and ApoA-I (p = 0.0073 and p = 0.006). PGMVC and PCVC remained associated with percent change in HDL-C (p = 0.0024 and p < 0.001, respectively) after sNfL was included as a predictor. Conclusions HDL-C percent change is associated with decreased gray matter atrophy after adjusting for baseline sNfL.

Serum Levels of HDL Cholesterol are Associated with Diffuse Axonal Injury in Patients with Traumatic Brain Injury

BACKGROUND

It is well known that lipids are vital for axonal myelin repair. Diffuse axonal injury (DAI) is characterized by widespread axonal injury. The association between serum lipids and DAI is not well known. The purpose of this study was to investigate the associations of serum lipid profile variables (triglycerides, high- and low-density lipoproteins, and total cholesterol) with DAI detected by magnetic resonance imaging (MRI) and with clinical outcome for patients suffering from traumatic brain injury (TBI).

METHODS

This study included 176 patients with a history of TBI who had undergone initial serum lipid measurements within 1 week and brain MRIs within 30 days. Based on MRI findings, patients were divided into negative and positive DAI groups.

RESULTS

Of the 176 patients, 70 (39.8%) were assigned to DAI group and 106 (60.2%) patients to non-DAI group. Compared with the non-DAI group, patients with DAI had significantly lower levels of high-density lipoprotein cholesterol (HDL-C) in serum during the first week following TBI. Multivariate analysis identified HDL-C as an independent predictor of DAI. Patients with lower serum HDL-C levels were less likely to regain consciousness within 6 months in TBI patients with DAI lesions identified by MRI.

CONCLUSIONS

Plasma levels of HDL-C may be a viable addition to biomarker panels for predicting the presence and prognosis of DAI on subsequent MRI following TBI.

Neurofilament levels are associated with blood–brain barrier integrity, lymphocyte extravasation, and risk factors following the first demyelinating event in multiple sclerosis

Background:

Increased blood brain barrier (BBB) permeability, CNS inflammation and neuroaxonal damage are pathological hallmarks in early multiple sclerosis (MS).

Objective:

To investigate the associations of neurofilament light chain (NfL) levels with measures of BBB integrity and central nervous system (CNS) inflammation in MS during the first demyelinating event.

Methods:

Blood and cerebrospinal fluid (CSF) were obtained from 142 MS (McDonald 2017) treatment-naive patients from the SET study (63% female; age: 29.7 ± 7.9 years) following the disease onset. NfL, albumin, immunoglobulin G (IgG), and immunoglobulin M (IgM) levels were measured in CSF and blood samples. Albumin quotient was computed as a marker of BBB integrity. Immune cell subset counts in CSF were measured using flow cytometry. MS risk factors, such as Human leukocyte antigen DRB1 locus gene ( HLA DRB1)*1501, anti-Epstein–Barr virus (EBV) antibodies, and 25-hydroxy vitamin D3, were also measured.

Results:

Higher serum NfL (sNfL) levels were associated with higher albumin quotient ( p < 0.001), CSF CD80+ ( p = 0.012), and CD80+ CD19+ ( p = 0.015) cell frequency. sNfL levels were also associated with contrast-enhancing and T2 lesions on brain magnetic resonance imaging (MRI; all p ⩽ 0.001). Albumin quotient was not associated with any of the MS risk factors assessed. sNfL levels were associated with anti-EBV viral capsid antigen (VCA) IgG levels ( p = 0.0026).

Conclusion:

sNfL levels during the first demyelinating event of MS are associated with greater impairment of BBB integrity, immune cell extravasation, and brain lesion activity on MRI.

Apolipoprotein M-bound sphingosine-1-phosphate regulates blood-brain barrier paracellular permeability and transcytosis

The blood-brain barrier (BBB) is formed by the endothelial cells lining cerebral microvessels, but how blood-borne signaling molecules influence permeability is incompletely understood. We here examined how the apolipoprotein M (apoM)-bound sphingosine 1-phosphate (S1P) signaling pathway affects the BBB in different categories of cerebral microvessels using ApoM deficient mice (Apom-/-). We used two-photon microscopy to monitor BBB permeability of sodium fluorescein (376 Da), Alexa Fluor (643 Da), and fluorescent albumin (45 kDA). We show that BBB permeability to small molecules increases in Apom-/- mice. Vesicle-mediated transfer of albumin in arterioles increased 3 to 10-fold in Apom-/- mice, whereas transcytosis in capillaries and venules remained unchanged. The S1P receptor 1 agonist SEW2871 rapidly normalized paracellular BBB permeability in Apom-/- mice, and inhibited transcytosis in penetrating arterioles, but not in pial arterioles. Thus, apoM-bound S1P maintains low paracellular BBB permeability in all cerebral microvessels and low levels of vesicle-mediated transport in penetrating arterioles.

HDL-cholesterol elevation associated with fingolimod and dimethyl fumarate therapies in multiple sclerosis

BACKGROUND

Patients with Multiple Sclerosis (PwMS) display altered lipoproteins levels and function, which seem to affect disease risk and progress. Whether disease-modifying therapies affect the lipoprotein profile in PwMS has scarcely been studied.

OBJECTIVE

The study aims to assess whether fingolimod and dimethyl fumarate (DMF) affect lipoproteins in PwMS.

METHODS

We compared retrospectively the blood lipoprotein levels of 29 fingolimod-treated and 41 DMF-treated patients before and after 3 and 12 months of therapy. Patients treated with cholesterol-reducing medications were not included. Data on weight change and disease activity during 1-year follow-up were obtained.

RESULTS

HDL level, HDL/LDL ratio and HDL/total cholesterol ratio were increased in both treatment groups after 3 months' therapy and sustained, with no change in LDL or triglycerides. While at baseline only 26% of patients met the recommended minimum of HDL 60 mg/dl, after 3 months' therapy, 43% of fingolimod-treated and 47% of DMF-treated patients reached the recommended level. The majority of patients had no weight reduction.

CONCLUSIONS

Fingolimod and DMF therapies are associated with a specific increase in HDL in PwMS. Further studies are required to validate these findings and their potential implication as biomarker of reduced inflammatory state and/or reduced risk of neurodegeneration or cardiovascular comorbidity.

Emerging roles for high-density lipoproteins in neurodegenerative disorders

Lipoproteins are the complexes of different lipids and proteins, which are devoted to the transport and clearance of lipids or lipid-related molecules in the circulation. Lipoproteins have been found to play a crucial role in brain function and may influence myelination process. Among lipoproteins, high-density lipoproteins (HDLs) and their major protein component, apoA-I, are directly involved in cholesterol efflux in the brain. It has been suggested that inadequate or dysfunctional brain HDLs may contribute to cerebrovascular dysfunctions, neurodegeneration, or neurovascular instability. HDL deficiency could also promote cognitive decline through impacting on atherosclerotic risk. The focus of this review is to discuss knowledge on HDL dysregulation in neurological disorders. A better understanding on how changes in cellular HDL and apolipoprotein homeostasis affect central nervous system function may provide promising novel avenues for the treatment of specific HDL-related neurological disorders.

Cholesterol and neurodegeneration: longitudinal changes in serum cholesterol biomarkers are associated with new lesions and gray matter atrophy in multiple sclerosis over 5 years of follow-up

BACKGROUND AND PURPOSE

Cholesterol is an important structural component of myelin and essential for brain homeostasis. Our objective was to investigate whether longitudinal changes in cholesterol biomarkers are associated with neurodegeneration in multiple sclerosis (MS).

METHODS

This prospective, longitudinal study (n = 154) included 41 healthy controls, 76 relapsing-remitting MS subjects and 37 progressive MS subjects. Neurological examination, brain magnetic resonance imaging and blood samples were obtained at baseline and at 5-year follow-up visits. Cholesterol biomarkers measured included plasma total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol and the apolipoproteins ApoA-I, Apo-II, ApoB, ApoC-II and ApoE. Key cholesterol pathway single nucleotide polymorphisms were genotyped.

RESULTS

Greater percentage increases in HDL-C and ApoA-I levels were associated with a lower rate of gray matter and cortical volume loss. Greater percentage increases in low-density lipoprotein cholesterol were associated with increases in new T2 lesions. The percentage increases in HDL-C (P = 0.032) and ApoA-I (P = 0.007) were smaller in patients with relapsing-remitting MS at baseline who converted to secondary progressive MS during the 5-year follow-up period. Changes in HDL-C and ApoA-I were associated with lipoprotein lipase rs328 genotype status.

CONCLUSIONS

Increases in HDL-C and ApoA-I have protective associations with magnetic resonance imaging measures of neurodegeneration in MS.

High-density lipoprotein cholesterol is associated with multiple sclerosis fatigue: A fatigue-metabolism nexus?

BACKGROUND

Fatigue is a frequent symptom in multiple sclerosis (MS). The role of cholesterol and lipids in MS fatigue has not been investigated.

OBJECTIVE

To investigate the associations of cholesterol biomarkers and serum neurofilament light chain (sNfL) with fatigue in relapsing-remitting MS.

METHODS

This cross-sectional study included 75 relapsing-remitting MS patients (69% female, mean age ± SD: 49.6 ± 11 years and median Expanded Disability Status Scale score: 2.0). Fatigue, disability, and depression were assessed with Fatigue Severity Scale (FSS), Expanded Disability Status Scale, and the Beck Depression Index-Fast Screen, respectively. sNfL was measured using single-molecule array technology. Plasma total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and an apolipoprotein panel data were obtained. Soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular adhesion molecule-1 (sVCAM-1), chemokine (C-C motif) ligand 5 (CCL5 or RANTES), and CCL18 levels were measured to assess inflammation.

RESULTS

The mean FSS was 4.27 ± 1.73, and 57% had severe fatigue status (SFS, FSS ≥ 4.0). In regression analyses adjusted for age, sex, disability, and depression, lower FSS and SFS were associated with greater HDL-C (P = .006 for FSS, and P = .016 for SFS) and lower TC to HDL-C ratio (P = .011 for FSS, and P = .009 for SFS). Apolipoprotein A-II was also associated with FSS (P = .022). sNfL, CCL5, CCL18, sICAM-1, and sVCAM-1 levels were not associated with fatigue after adjusting for disability and depression.

CONCLUSIONS

TC to HDL-C ratio is associated with MS fatigue. Our results implicate a potential role for the HDL-C pathway in MS fatigue and could provide possible targets for the treatment of MS fatigue.

Lipid profile is associated with decreased fatigue in individuals with progressive multiple sclerosis following a diet-based intervention: Results from a pilot study

Purpose

To investigate associations between lipid profiles and fatigue in a cohort of progressive multiple sclerosis (MS) patients on a diet-based multimodal intervention.

Methods

This pilot study included 18 progressive MS patients who participated in a prospective longitudinal study of fatigue following a diet-based multimodal intervention that included exercise, neuromuscular electrical stimulation and stress reduction. The diet recommended high intake of vegetables and fruits, encouraged consumption of animal and plant protein and excluded foods with gluten-containing grains, dairy and eggs. Fatigue was measured on the Fatigue Severity Scale (FSS) at baseline and every 3 months for 12 months. A lipid profile consisting of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) and triglycerides (TG) was obtained on fasting blood samples at baseline and 12 months.

Results

FSS scores decreased from a baseline of 5.51 (95% CI: 4.86, 6.16) to a mean of 3.03 (95% CI: 2.23, 3.82) at 12 months (p < 0.001). At 12 months, increases in HDL-C (mean change: +6.0 mg/dl; 95% CI: 0.3, 12.0; p = 0.049) and decreases in BMI (mean change: -2.6 kg/m²; 95% CI: -3.6, -2.5; p < 0.001), LDL-C (mean change: -10.4 mg/dl; 95% CI:-19.7, -1.2; p = 0.029), TG (mean change: -29.2 mg/dl; 95% CI: -44.3, -14.2; p = 0.001), TG to HDL-C ratio (mean change: -0.6; 95% CI: -1.0, -0.3; p = 0.002) and TC to HDL-C ratio (mean change:-0.6; 95% CI: -1.0, -0.3; p = 0.003) were observed compared to baseline. Improvements in FSS were associated with increases in HDL-C (β = -0.05; 95% CI: -0.1, -0.0004; p = 0.048) and changes in TC (p = 0.005) from baseline to 12 months.

Conclusions

Lipid profile variables are associated with improvements in fatigue in progressive MS patients on a diet-based multimodal intervention.

Lifestyle-based modifiable risk factors in multiple sclerosis: review of experimental and clinical findings

Multiple sclerosis (MS) is a lifelong inflammatory and neurodegenerative disease influenced by multiple lifestyle-based factors. We provide a narrative review of the effects of modifiable risk factors that are identified as being associated with risk to develop MS and/or influencing the future clinical disease outcomes. The emerging data regarding the beneficial effects of diet modifications and exercise are further reviewed. In contrast, obesity and comorbid cardiovascular diseases are associated with increased MS susceptibility and worse disease progression. In addition, the potential influence of smoking, coffee and alcohol consumption on MS onset and disability development are discussed. Successful management of the modifiable risk factors may lead to better long-term outcomes and improve patients' quality of life. MS specialists should participate in educating and facilitating lifestyle-based modifications as part of their neurological consults.

Serum Lipoprotein Profile Is Associated With Protective Effects of Oral Contraceptive Use on Multiple Sclerosis Severity: A Cross-Sectional Study

Background: The mechanisms underlying the influence of sex hormones in multiple sclerosis (MS) are uncertain. Sex steroids interact with cholesterol metabolism and the serum lipid profile has been associated with the severity of the disease. We hypothesized that the putative associations between lipoprotein metabolism and MS could be modulated by sex steroids exposure. The aim of this study was to investigate whether oral contraceptives (OC) use changes the lipoprotein profile associated with disability in patients with multiple sclerosis. Methods: Clinical data was collected from 133 relapsing-remitting multiple sclerosis (RRMS) women with a mean of 6.5 years of disease duration and prior to the start of disease-modifying therapies. Patients who were using OC after disease onset (DO) (OC+, n = 57) were compared to those who never used OC or discontinued its intake before DO (OC-, n = 76). In both cohorts of subjects, the associations between the apolipoprotein E (ApoE) polymorphism, and plasma lipid levels, and the annualized relapse rate (RR), the Expanded Disability Status Score (EDSS), and the Multiple Sclerosis Severity Score (MSSS) were evaluated using a hierarchic multiple regression analysis after adjustment for confounders. Results: Low density lipoprotein (LDL) levels were associated with higher EDSS (p = 0.010) and MSSS (p = 0.024) in the whole studied cohort. In E3/E3 phenotype carriers (73.7%), EDSS and MSSS were lower in OC+ in comparison with OC- subgroup of patients (p < 0.01). LDL and total cholesterol were associated with EDSS (p = 0.005 and p = 0.043, respectively), and LDL and the triglyceride/high density lipoprotein ratio with MSSS (p = 0.011 and p = 0.048, respectively) in OC+ patients. In OC- subgroup of patients, ApoE levels were associated with EDSS (p = 0.012) and MSSS (p = 0.031). No significant interactions between the lipid variables or OC use and RR were observed. Conclusions: Serum lipid profile is associated with protective effects of OC use on disability of RRMS patients. Lipoprotein metabolism may be involved in the modulatory effects of sex steroids on the severity of the disease.

The physiology of foamy phagocytes in multiple sclerosis

Multiple sclerosis (MS) is a chronic disease of the central nervous system characterized by massive infiltration of immune cells, demyelination, and axonal loss. Active MS lesions mainly consist of macrophages and microglia containing abundant intracellular myelin remnants. Initial studies showed that these foamy phagocytes primarily promote MS disease progression by internalizing myelin debris, presenting brain-derived autoantigens, and adopting an inflammatory phenotype. However, more recent studies indicate that phagocytes can also adopt a beneficial phenotype upon myelin internalization. In this review, we summarize and discuss the current knowledge on the spatiotemporal physiology of foamy phagocytes in MS lesions, and elaborate on extrinsic and intrinsic factors regulating their behavior. In addition, we discuss and link the physiology of myelin-containing phagocytes to that of foamy macrophages in other disorders such atherosclerosis.

High-fat diet protects the blood-brain barrier in an Alzheimer's disease mouse model

Type 2 diabetes (T2D) is associated with increased risk of Alzheimer's disease (AD). There is evidence for impaired blood-brain barrier (BBB) in both diseases, but its role in the interplay between them is not clear. Here, we investigated the effects of high-fat diet (HFD), a model for T2D, on the Tg2576 mouse model of AD, in regard to BBB function. We showed that HFD mice had higher weight, more insulin resistance, and higher serum HDL cholesterol levels, primarily in Tg2576 mice, which also had higher brain lipids content. In terms of behavior, Tg2576 HFD mice were less active and more anxious, but had better learning in the Morris Water Maze compared to Tg2576 on regular diet. HFD had no effect on the level of amyloid beta 1-42 in the cortex of Tg2576 mice, but increased the transcription level of insulin receptor in the hippocampus. Tg2576 mice on regular diet demonstrated more BBB disruption at 8 and 12 months accompanied by larger lateral ventricles volume in contrast to Tg2576 HFD mice, whose BBB leakage and ventricular volume were similar to wild-type (WT) mice. Our results suggest that in AD, HFD may promote better cognitive function through improvements of BBB function and of brain atrophy but not of amyloid beta levels. Lipid metabolism in the CNS and peripheral tissues and brain insulin signaling may underlie this protection.

LDL and HDL lipoprotein subfractions in multiple sclerosis patients with decreased insulin sensitivity

Objectives. Increased metabolic and cardiovascular morbidity has been reported in multiple sclerosis (MS) patients. Previously, we have found decreased insulin sensitivity and hyperinsulinemia in a group of newly diagnosed MS patients. We hypothesize that these features may be associated with an altered lipid profile and low, intermediate, or high density lipoprotein (LDL, IDL, HDL) subclasses accelerating atherosclerosis and thus contributing to the cardiovascular risk increase in these patients.

Subjects and methods. In a group of 19 newly diagnosed untreated MS patients with previously found hyperinsulinemia and insulin resistance and a matched group of 19 healthy controls, the lipoprotein subclasses profile was determined. Polyacrylamide gel electrophoresis was used to separate and measure the LDL (large LDL and small dense LDL), HDL (large, intermediate and small), and IDL (A, B and C) subclasses with the Lipoprint© System (Quantimetrix Corporation, Redondo Beach, CA, USA).

Results. No difference was found either in the conventional lipid or lipoprotein subclasses profile between the MS patients and healthy controls. We found an inverse association between the level of IDL-B with fasting insulin (r=–0.504, p=0.032), the insulin resistance estimated by homeo-static model assessment – insulin resistance (HOMA-IR) (r=–0.498, p=0.035), insulin response expressed as area under the curve (AUC; r=–0.519, p=0.027), and area above the baseline (AAB; r=–0.476, p=0.045) and positive association with insulin sensitivity estimated by insulin sensitivity index (ISI) Matsuda (r=0.470, 0.048) in MS patients, but not in healthy controls suggesting the first signs in lipoprotein subclasses profile change.

Conclusions. Our data indicate that changes in lipoprotein profile and subclasses are preceded by insulin resistance and hyperinsulinemia in patients with newly diagnosed MS.

Steroid Transport, Local Synthesis, and Signaling within the Brain: Roles in Neurogenesis, Neuroprotection, and Sexual Behaviors

Sex steroid hormones are synthesized from cholesterol and exert pleiotropic effects notably in the central nervous system. Pioneering studies from Baulieu and colleagues have suggested that steroids are also locally-synthesized in the brain. Such steroids, called neurosteroids, can rapidly modulate neuronal excitability and functions, brain plasticity, and behavior. Accumulating data obtained on a wide variety of species demonstrate that neurosteroidogenesis is an evolutionary conserved feature across fish, birds, and mammals. In this review, we will first document neurosteroidogenesis and steroid signaling for estrogens, progestagens, and androgens in the brain of teleost fish, birds, and mammals. We will next consider the effects of sex steroids in homeostatic and regenerative neurogenesis, in neuroprotection, and in sexual behaviors. In a last part, we will discuss the transport of steroids and lipoproteins from the periphery within the brain (and vice-versa) and document their effects on the blood-brain barrier (BBB) permeability and on neuroprotection. We will emphasize the potential interaction between lipoproteins and sex steroids, addressing the beneficial effects of steroids and lipoproteins, particularly HDL-cholesterol, against the breakdown of the BBB reported to occur during brain ischemic stroke. We will consequently highlight the potential anti-inflammatory, anti-oxidant, and neuroprotective properties of sex steroid and lipoproteins, these latest improving cholesterol and steroid ester transport within the brain after insults.

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.

Circulating metabolites and general cognitive ability and dementia: Evidence from 11 cohort studies

INTRODUCTION

Identifying circulating metabolites that are associated with cognition and dementia may improve our understanding of the pathogenesis of dementia and provide crucial readouts for preventive and therapeutic interventions.

METHODS

We studied 299 metabolites in relation to cognition (general cognitive ability) in two discovery cohorts (N total = 5658). Metabolites significantly associated with cognition after adjusting for multiple testing were replicated in four independent cohorts (N total = 6652), and the associations with dementia and Alzheimer's disease (N = 25,872) and lifestyle factors (N = 5168) were examined.

RESULTS

We discovered and replicated 15 metabolites associated with cognition including subfractions of high-density lipoprotein, docosahexaenoic acid, ornithine, glutamine, and glycoprotein acetyls. These associations were independent of classical risk factors including high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, glucose, and apolipoprotein E (APOE) genotypes. Six of the cognition-associated metabolites were related to the risk of dementia and lifestyle factors.

DISCUSSION

Circulating metabolites were consistently associated with cognition, dementia, and lifestyle factors, opening new avenues for prevention of cognitive decline and dementia.

The pleiotropic vasoprotective functions of high density lipoproteins (HDL)

The pleiotropic functions of circulating high density lipoprotein (HDL) on peripheral vascular health are well established. HDL plays a pivotal role in reverse cholesterol transport and is also known to suppress inflammation, endothelial activation and apoptosis in peripheral vessels. Although not expressed in the central nervous system, HDL has nevertheless emerged as a potential resilience factor for dementia in multiple epidemiological studies. Animal model data specifically support a role for HDL in attenuating the accumulation of β-amyloid within cerebral vessels concomitant with reduced neuroinflammation and improved cognitive performance. As the vascular contributions to dementia are increasingly appreciated, this review seeks to summarize recent literature focused on the vasoprotective properties of HDL that may extend to cerebral vessels, discuss potential roles of HDL in dementia relative to brain-derived lipoproteins, identify gaps in current knowledge, and highlight new opportunities for research and discovery.

Relapsing-remitting multiple sclerosis patients display an altered lipoprotein profile with dysfunctional HDL

Lipoproteins modulate innate and adaptive immune responses. In the chronic inflammatory disease multiple sclerosis (MS), reports on lipoprotein level alterations are inconsistent and it is unclear whether lipoprotein function is affected. Using nuclear magnetic resonance (NMR) spectroscopy, we analysed the lipoprotein profile of relapsing-remitting (RR) MS patients, progressive MS patients and healthy controls (HC). We observed smaller LDL in RRMS patients compared to healthy controls and to progressive MS patients. Furthermore, low-BMI (BMI ≤ 23 kg/m²) RRMS patients show increased levels of small HDL (sHDL), accompanied by larger, triglyceride (TG)-rich VLDL, and a higher lipoprotein insulin resistance (LP-IR) index. These alterations coincide with a reduced serum capacity to accept cholesterol via ATP-binding cassette (ABC) transporter G1, an impaired ability of HDL₃ to suppress inflammatory activity of human monocytes, and modifications of HDL₃’s main protein component ApoA-I. In summary, lipoprotein levels and function are altered in RRMS patients, especially in low-BMI patients, which may contribute to disease progression in these patients.

Lipid Metabolism in Patients with Anti-N-Methyl-D-Aspartate Receptor Encephalitis

OBJECTIVE

Lipid metabolism has been implicated in autoimmune disorders, but its relationship with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is unclear. This study examined the association of serum lipids with anti-NMDAR encephalitis.

METHODS

Serum lipid profiles and C-reactive protein (CRP) were evaluated in 68 patients with anti-NMDAR encephalitis, and 68 age- and sex-matched healthy controls (CTLs). Follow-up evaluations were conducted 3 months after admission in 32 of the 68 patients. Modified Rankin scale (mRS) scores and clinical and cerebrospinal fluid parameters were evaluated in all patients.

RESULTS

Compared with CTLs, patients with anti-NMDAR encephalitis had significantly lower serum high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (apoA-I) levels but significantly higher serum apoB levels and apoB/apoA-I ratios. Serum HDL and apoA-I were significantly and negatively associated with serum CRP levels, whereas serum aopB levels and apoB/apoA-I ratios were positively associated with age, CRP levels, and mRS scores. Follow-up evaluations revealed that serum total cholesterol, apoA-I, and HDL-C levels were significantly higher but mRS scores were significantly lower than those before treatment, and that the increased HDL-C levels were significantly and negatively correlated with decreased mRS scores.

CONCLUSION

Serum HDL-C and apoA-I levels are reduced in the initial phase of anti-NMDAR encephalitis and recover after treatment. Further studies about the role of serum lipid in anti-NMDAR encephalitis are needed.

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.