Dataset Information

Identification of endothelin 2 as an inflammatory factor that promotes central nervous system remyelination.

ABSTRACT: The development of new regenerative therapies for multiple sclerosis is hindered by the lack of potential targets for enhancing remyelination. The study of naturally regenerative processes such as the innate immune response represents a powerful approach for target discovery to solve this problem. By 'mining' these processes using transcriptional profiling we can identify candidate factors that can then be tested individually in clinically-relevant models of demyelination and remyelination. Here, therefore, we have examined a previously described in vivo model of the innate immune response in which zymosan-induced macrophage activation in the retina promotes myelin sheath formation by oligodendrocytes generated from transplanted precursor cells. While this model is not itself clinically relevant, it does provide a logical starting point for this study as factors that promote myelination must be present. Microarray analysis of zymosan-treated retinae identified several cytokines (CXCL13, endothelin 2, CCL20 and CXCL2) to be significantly upregulated. When tested in a cerebellar slice culture model, CXCL13 and endothelin 2 promoted myelination and endothelin 2 also promoted remyelination. In studies to identify the receptor responsible for this regenerative effect of endothelin 2, analysis of both remyelination following experimental demyelination and of different stages of multiple sclerosis lesions in human post-mortem tissue revealed high levels of endothelin receptor type B in oligodendrocyte lineage cells. Confirming a role for this receptor in remyelination, small molecule agonists and antagonists of endothelin receptor type B administered in slice cultures promoted and inhibited remyelination, respectively. Antagonists of endothelin receptor type B also inhibited remyelination of experimentally-generated demyelination in vivo. Our work therefore identifies endothelin 2 and the endothelin receptor type B as a regenerative pathway and suggests that endothelin receptor type B agonists represent a promising therapeutic approach to promote myelin regeneration.

SUBMITTER: Yuen TJ

PROVIDER: S-EPMC3613712 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Identification of endothelin 2 as an inflammatory factor that promotes central nervous system remyelination.

Yuen Tracy J TJ Johnson Kory R KR Miron Veronique E VE Zhao Chao C Quandt Jacqueline J Harrisingh Marie C MC Swire Matthew M Williams Anna A McFarland Henry F HF Franklin Robin J M RJ Ffrench-Constant Charles C

Brain : a journal of neurology 20130321 Pt 4

The development of new regenerative therapies for multiple sclerosis is hindered by the lack of potential targets for enhancing remyelination. The study of naturally regenerative processes such as the innate immune response represents a powerful approach for target discovery to solve this problem. By 'mining' these processes using transcriptional profiling we can identify candidate factors that can then be tested individually in clinically-relevant models of demyelination and remyelination. Here ...[more]

PMID: 23518706

Similar Datasets

Project description:BackgroundMultiple sclerosis (MS) is a central nervous system (CNS) autoimmune disease characterized by both inflammatory demyelination and impaired remyelination. Studies indicate that Toll-like receptor 2 (TLR2) signaling contributes to both the inflammatory component and the defective remyelination in MS. While most MS therapeutics target adaptive immunity, we recently reported that reducing TLR2 signaling in innate immune cells by inducing TLR2 tolerance attenuates adoptively transferred experimental autoimmune encephalomyelitis. Given that previous reports suggest TLR2 signaling also inhibits myelin repair, the objective of this study was to assess how reducing TLR2 signaling through TLR2 tolerance induction affects CNS myelin repair.MethodsChow containing 0.2% cuprizone was fed to male and female wild-type (WT) C57BL/6 mice or TLR2-deficient (TLR2-/-) mice for 5?weeks to induce demyelination. During a 2-week remyelination period following discontinuation of cuprizone, WT mice received either low dose TLR2 ligands to induce systemic TLR2 tolerance or vehicle control (VC). Remyelination was evaluated via electron microscopy and immunohistochemical analysis of microglia and oligodendrocytes in the corpus callosum. Statistical tests included 2-way ANOVA and Mann-Whitney U analyses.ResultsInducing TLR2 tolerance in WT mice during remyelination significantly enhanced myelin recovery, restoring unmyelinated axon frequency and myelin thickness to baseline levels compared to VC-treated mice. Mechanistically, enhanced remyelination in TLR2 tolerized mice was associated with a shift in corpus callosum microglia from a pro-inflammatory iNOS+ phenotype to a non-inflammatory/pro-repair Arg1+ phenotype. This result was confirmed in vitro by inducing TLR2 tolerance in WT microglia cultures. TLR2-/- mice, without TLR2 tolerance induction, also significantly enhanced myelin recovery compared to WT mice, adding confirmation that reduced TLR2 signaling is associated with enhanced remyelination.DiscussionOur results suggest that reducing TLR2 signaling in vivo by inducing TLR2 tolerance significantly enhances myelin repair. Furthermore, the enhanced remyelination resulting from TLR2 tolerance induction is associated with a shift in corpus callosum microglia from a pro-inflammatory iNOS+ phenotype to a non-inflammatory/pro-repair Arg1+ phenotype. While deletion of TLR2 would be an impractical approach in vivo, reducing innate immune signaling through TLR2 tolerance induction may represent a novel, two-pronged approach for treating both inflammatory and myelin repair components of MS.

Dataset Information

Identification of endothelin 2 as an inflammatory factor that promotes central nervous system remyelination.

Publications

Identification of endothelin 2 as an inflammatory factor that promotes central nervous system remyelination.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets