Project description:Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system with marked heterogeneity in several aspects including pathological processes. Four histopathological patterns of MS have been described. Pattern II is characterized by infiltrating macrophages and T-cells and by antibody and complement deposition. Transcriptome analysis of three patern II demyelinating brain lesions from a multiple sclerosis patient using RNA sequencing demonstrated the presence of mRNA transcripts for genes specific of activated macrophages, T and B cells as well as genes coding for immunoglobulins, complement proteins and some pattern II associated proteins, providing additional evidence supporting pattern II demyelination. Examination of 3 different demyelinating lesions identified by Immunohistopathology.
Project description:Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system with marked heterogeneity in several aspects including pathological processes. Four histopathological patterns of MS have been described. Pattern II is characterized by antibody and complement deposition. MS is considered a prototypic T cell-mediated disease, but until now the study of pathogenic T cells has encountered major challenges, most importantly the limited access of brain-infiltrating T cells. Here, we used next generation sequencing to identify clonally expanded T cells in demyelinating pattern II brain autopsy lesions and subsequently isolated these as T cell clones from autologous cerebrospinal fluid. The functional characterization shows that T cells releasing Th2 cytokines and able to provide B cell help dominate the T cell infiltrate in pattern II brain lesions. Our data provide the first functional evidence for a role of Th2/Tc2 cells in pattern II MS. Two stimulated CD4+ Th2 brain infiltrating T cell clones compared with stimulated circulaiting memory CD4+ T cells and two stimulated CD8+ T cell clones (one Tc1 and one Tc2) compared with each other.
Project description:Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system with marked heterogeneity in several aspects including pathological processes. Four histopathological patterns of MS have been described. Pattern II is characterized by infiltrating macrophages and T-cells and by antibody and complement deposition. Transcriptome analysis of three patern II demyelinating brain lesions from a multiple sclerosis patient using RNA sequencing demonstrated the presence of mRNA transcripts for genes specific of activated macrophages, T and B cells as well as genes coding for immunoglobulins, complement proteins and some pattern II associated proteins, providing additional evidence supporting pattern II demyelination.
Project description:Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system with marked heterogeneity in several aspects including pathological processes. Four histopathological patterns of MS have been described. Pattern II is characterized by antibody and complement deposition. MS is considered a prototypic T cell-mediated disease, but until now the study of pathogenic T cells has encountered major challenges, most importantly the limited access of brain-infiltrating T cells. Here, we used next generation sequencing to identify clonally expanded T cells in demyelinating pattern II brain autopsy lesions and subsequently isolated these as T cell clones from autologous cerebrospinal fluid. The functional characterization shows that T cells releasing Th2 cytokines and able to provide B cell help dominate the T cell infiltrate in pattern II brain lesions. Our data provide the first functional evidence for a role of Th2/Tc2 cells in pattern II MS.
Project description:Canine distemper virus (CDV)-induced demyelinating leukoencephalitis (CDV-DL) in dogs is a translational animal model for human demyelinating diseases such as multiple sclerosis. The aim of this study was to perform an assumption-free microarray analysis of gene expression in different subgroups of CDV-DL as compared to normal controls. Dogs were classified into normal controls (group 1), acute CDV-DL lesions with CDV within the brain but without demyelination and inflammation (group 2), subacute lesions with demyelination but without inflammation (group 3), and subacute to chronic lesions with demyelination and inflammation (group 4).
Project description:Remyelination can occur naturally in demyelinating lesions, but often fails in human demyelinating diseases such as multiple sclerosis (MS). The function of the innate immune system is essential for the regenerative response, but how exactly microglia and macrophages clear myelin debris after injury and tailor a specific regenerative response is unclear. Here, we asked whether pro-inflammatory microglial/macrophage activation is required for this process. We established a novel toxin-based spinal cord model of de- and remyelination in zebrafish and showed that pro-inflammatory nuclear factor κB (NF-κB) dependent activation occurs in phagocytes rapidly after myelin injury. We found that the pro-inflammatory response depends on myeloid differentiation primary response 88 (MyD88), the canonical adaptor for inflammatory signaling pathways downstream of toll-like receptors (TLRs). MyD88-deficient mice and zebrafish were impaired not only in the degradation of myelin debris, but also in initiating the generation of new oligodendrocytes for myelin repair. We identified reduced generation of tumor necrosis factor-α (TNF-α) in lesions of MyD88-deficient animals, a pro-inflammatory molecule that was able to induce the generation of new oligodendrocytes. Our study shows that pro-inflammatory phagocytic signaling is an evolutionary conserved mechanism necessary for degrading myelin debris, essential for inflammation resolution, and for initiating the secretion of pro-inflammatory myelin repair molecules.
Project description:In a previous study performed in our laboratory, the level of FGF1 RNA was found to be increased in remyelinated multiple sclerosis lesions compared to control brain (unpublished observation). Astrocytes play a key role in multiple sclerosis lesion formation. To shed light on potential FGF1-mediated functions in multiple sclerosis, the impact of FGF1 on astrocytes was investigated.
Project description:Multiple Sclerosis (MS) is a chronic inflammatory and demyelinating disease of the central nervous system (CNS), where ongoing demyelination and remyelination failure are the major factors for progressive neurological disability. In this report, we employed a comprehensive proteomic approach and immunohistochemical (IHC) validation to gaininsight into the pathobiological mechanisms that may be associated with the progressive phase of MS disease. Isolated proteins from myelinated regions, demyelinated white matter lesions (WMLs), and grey-matter lesions (GMLs) of well-characterized progressive MS brain tissues were subjected to label-free quantitative mass spectrometry (LFQ-MS). Using a system-biology approach, we detected increased expression of proteins belonging to mitochondrial electron transport complexes and oxidative phosphorylatio pathway in WMLs. Intriguingly, many of these proteins and pathways had opposite expression patterns in GMLs of progressive MS brains. A comparison to the huma MitoCarta database mapped the mitochondrial proteins to mitochondrial subunits in both WMLs and GMLs. Taken together, we provide evidence of opposite expression of mitochondrial proteins in response to demyelination of white- and grey-matter regions in progressive MS brain.
Project description:Neuroprotective, anti-inflammatory and remyelinating properties of androgens are well-characterized in demyelinated male mice and men suffering from multiple sclerosis. However, androgen effects mediated by the androgen receptor AR, have been only poorly studied in females who make low androgen levels. Here, we show a predominant microglial AR expression in demyelinated lesions from female mice and women with multiple sclerosis, but virtually undetectable AR expression in lesions from male animals and men with multiple sclerosis. In female mice, androgens and estrogens act in a synergistic way while androgens drive microglia response towards regeneration. Transcriptomic comparisons of demyelinated mouse spinal cords indicate that, regardless of the sex, androgens up-regulate genes related to neuronal function integrity and myelin production. Depending on the sex, androgens down-regulate genes related to the immune system in females and lipid catabolism in males. Thus, androgens are required for proper myelin regeneration in females and therapeutic approaches of demyelinating diseases need to consider male-female differences.