Fusion of metabolomics and proteomics data for biomarkers discovery: case study on the experimental autoimmune encephalomyelitis

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Macrophages in inflammatory multiple sclerosis lesions have an intermediate activation status

BACKGROUND: Macrophages play a dual role in multiple sclerosis (MS) pathology. They can exert neuroprotective and growth promoting effects but also contribute to tissue damage by production of inflammatory mediators. The effector function of macrophages is determined by the way they are activated. Stimulation of monocyte-derived macrophages in vitro with interferon-γ and lipopolysaccharide results in classically activated (CA/M1) macrophages, and activation with interleukin 4 induces alternatively activated (AA/M2) macrophages. METHODS: For this study, the expression of a panel of typical M1 and M2 markers on human monocyte derived M1 and M2 macrophages was analyzed using flow cytometry. This revealed that CD40 and mannose receptor (MR) were the most distinctive markers for human M1 and M2 macrophages, respectively. Using a panel of M1 and M2 markers we next examined the activation status of macrophages/microglia in MS lesions, normal appearing white matter and healthy control samples. RESULTS: Our data show that M1 markers, including CD40, CD86, CD64 and CD32 were abundantly expressed by microglia in normal appearing white matter and by activated microglia and macrophages throughout active demyelinating MS lesions. M2 markers, such as MR and CD163 were expressed by myelin-laden macrophages in active lesions and perivascular macrophages. Double staining with anti-CD40 and anti-MR revealed that approximately 70% of the CD40-positive macrophages in MS lesions also expressed MR, indicating that the majority of infiltrating macrophages and activated microglial cells display an intermediate activation status. CONCLUSIONS: Our findings show that, although macrophages in active MS lesions predominantly display M1 characteristics, a major subset of macrophages have an intermediate activation status

Selection of reference genes for gene expression studies in rat oligodendrocytes using quantitative real time PCR

Quantitative real time polymerase chain reaction (qPCR) has become a widely used tool to examine gene expression levels. Reliable quantification, however, depends on a proper normalization strategy. Normalization with multiple reference genes is becoming the standard, although the most suitable reference genes depend on the applied treatment as well as the tissue or cell type studied. In this study the stability of various reference genes was investigated in cultures of oligodendrocytes derived from either mature or neonatal rats, the latter also in the presence of the liver X receptor (LXR) agonist. The expression stability of ten commonly used reference genes (HPRT, GAPDH, 18S, ActB, CycA, Tbp, Rpl13A, YWHAZ, HMBS, Pgk1) was analyzed using geNorm and NormFinder. When comparing the different types of cell cultures, Rpl13A, CycA, Pgk1 and YWHAZ were identified as most stable genes. After LXR agonist treatment, CycA, Pgk1 and Rpl13A were found to be the most stable by both geNorm and NormFinder. HMBS and the commonly used housekeeping genes GAPDH and 18S turned out to be the most variable according to geNorm and NormFinder. In conclusion, the use of multiple reference genes, instead of only one, in qPCR experiments with rat oligodendrocytes is strongly advised and standard housekeeping genes such as GAPDH and 18S are not recommended as they appear to be relatively unstable under the experimental conditions used. Reference gene selection should always be performed for each individual experiment, since useful reference genes are very specific for every situation. (C) 2010 Elsevier B.V. All rights reserved

Plant sterols: Friend or foe in CNS disorders?

In mammals, the central nervous system (CNS) is the most cholesterol rich organ by weight. Cholesterol metabolism is tightly regulated in the CNS and all cholesterol available is synthesized in situ. Deficits in cholesterol homeostasis at the level of synthesis, transport, or catabolism result in severe disorders featured by neurological disability. Recent studies indicate that a disturbed cholesterol metabolism is involved in CNS disorders, such as Alzheimer's disease (AD), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS). In contrast to circulating cholesterol, dietary plant sterols, can cross the blood brain barrier and accumulate in the membranes of CNS cells. Plant sterols are well-known for their ability to lower circulating cholesterol levels. The finding that they gain access to the CNS has fueled research focusing on the physiological roles of plant sterols in the healthy and diseased CNS. To date, both beneficial and detrimental effects of plant sterols on CNS disorders are defined. In this review, we discuss recent findings regarding the impact of plant sterols on homeostatic and pathogenic processes in the CNS, and elaborate on the therapeutic potential of plant sterols in CNS disorders. (C) 2015 Elsevier Ltd. All rights reserved

Leukemia inhibitory factor is produced by myelin-reactive T cells from multiple sclerosis patients and protects against tumor necrosis factor-alpha-induced oligodendrocyte apoptosis

In multiple sclerosis (MS), damage to oligodendrocytes is believed to be caused by an aberrant immune response initiated by autoreactive T cells. Increasing evidence indicates that these T cells are not exclusively detrimental but might also exert protective effects. We report for the first time that myelin-reactive T-cell clones from eight MS patients (6/19) and five healthy controls (4/11) produce leukemia inhibitory factor (LIF), a member of the neuropoietic family of neurotrophins. In addition, T-cell clones specific for tetanus toxoid, CD4(+) and CD8(+) T cells, and monocytes, but not B cells, secreted LIF LIF-producing T lymphocytes and macrophages were also identified immunohistochemically in both active and chronic-active MS lesions. We further demonstrated dose-dependent protective effects of LIF on tumor necrosis factor-alpha-induced apoptosis of oligodendrocytes. In conclusion, our data demonstrate that peripheral and CNS-infiltrating T cells from MS patients produce LIF, a protective factor for oligodendrocytes. This study emphasizes that secretion of LIF may contribute to the neuroprotective effects of auto reactive T cells. (C) 2006 Wiley- Liss, Inc

Myelin-Derived Lipids Modulate Macrophage Activity by Liver X Receptor Activation

Multiple sclerosis is a chronic, inflammatory, demyelinating disease of the central nervous system in which macrophages and microglia play a central role. Foamy macrophages and microglia, containing degenerated myelin, are abundantly found in active multiple sclerosis lesions. Recent studies have described an altered macrophage phenotype after myelin internalization. However, it is unclear by which mechanisms myelin affects the phenotype of macrophages and how this phenotype can influence lesion progression. Here we demonstrate, by using genome wide gene expression analysis, that myelin-phagocytosing macrophages have an enhanced expression of genes involved in migration, phagocytosis and inflammation. Interestingly, myelin internalization also induced the expression of genes involved in liver-X-receptor signaling and cholesterol efflux. In vitro validation shows that myelin-phagocytosing macrophages indeed have an increased capacity to dispose intracellular cholesterol. In addition, myelin suppresses the secretion of the pro-inflammatory mediator IL-6 by macrophages, which was mediated by activation of liver-X-receptor beta. Our data show that myelin modulates the phenotype of macrophages by nuclear receptor activation, which may subsequently affect lesion progression in demyelinating diseases such as multiple sclerosis

Urodynamic changes in mice with experimental autoimmune encephalomyelitis correlate with neurological impairment

Neurogenic bladder dysfunction is a major issue in Multiple Sclerosis (MS). High intravesical pressure should be treated early. Available therapies are insufficient and there is need for drug development and investigation of pathogenesis. Experimental Autoimmune Encephalomyelitis (EAE) in rodents is a well validated model to study MS. Previous research has shown that these animals develop urinary symptoms. However, from clinical studies, we know that symptoms do not necessarily reflect changes in bladder pressure. This paper aims to provide a complete overview of urodynamic changes in a model for detrusor overactivity in MS.status: publishe