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Updated: Aug 29, 2026
Experimental Demyelination and Remyelination of Murine Spinal Cord by Focal Injection of Lysolecithin
Published on: March 26, 2015
Remyelination of cytokine- or antibody-demyelinated CNS aggregate cultures is inhibited by macrophage supplementation
Lara T Diemel1, Guus Wolswijk, Samuel J Jackson
1Department of Neuroinflammation, Institute of Neurology, University College London, London, United Kingdom. l.diemel@ion.ucl.ac.uk
Abstract:
Remyelination in CNS aggregate cultures is determined both by macrophage enrichment and the mode of demyelination. Despite the same degree of myelin loss, accumulation of MBP in anti-MOG antibody-demyelinated aggregates overtakes that of controls, while recovery is significantly delayed following IFN-gamma-induced demyelination. In antibody-treated cultures, remyelination was associated with a significant increase in culture supernatant levels of TGF-beta1, FGF-2, and PDGF-AA as well as an induction of TNF-alpha immediately following removal of the demyelinating insult. The impaired recovery in IFN-gamma-treated cultures, denoted by a significant reduction in TGF-beta1, was reversed by treatment with hrTGF-beta1. Macrophage supplementation of the cultures prior to the addition of either demyelinating agent induced a greater degree of myelin loss followed by incomplete remyelination in both cases. This failure to remyelinate was associated in both groups with a several-fold elevation in TNF-alpha and with modest increases in PDGF-AA and FGF-2 in the antibody-treated cultures. In contrast, macrophage supplementation to mature cultures in the absence of any demyelinating treatment resulted in enhanced accumulation of MBP associated with a promyelinative growth factor and TNF-alpha profile similar to that in aggregates enriched with macrophages at the outset of the culture period. Hence, effector elements of the adaptive immune response appear to override promyelinogenic in favor of proinflammatory macrophage factors in mature CNS aggregates, counteracting the potential for myelin repair.
Insights
Macrophage enrichment and demyelination type impact central nervous system (CNS) remyelination. Pro-remyelinative factors are overridden by pro-inflammatory macrophage signals, hindering myelin repair in mature CNS cultures.
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- Remyelination is crucial for CNS repair after demyelination.
- Macrophage activity and demyelination methods influence remyelination success.
- Understanding these factors is key to developing therapies for demyelinating diseases.
Purpose of the Study:
- To investigate the impact of macrophage enrichment and demyelination type on CNS remyelination.
- To identify molecular factors involved in remyelination and its impairment.
- To explore therapeutic potential for enhancing myelin repair.
Main Methods:
- Utilized CNS aggregate cultures with varying demyelination methods (anti-MOG antibody vs. IFN-gamma).
- Assessed myelin basic protein (MBP) accumulation as a marker of remyelination.
- Quantified growth factors (TGF-beta1, FGF-2, PDGF-AA) and TNF-alpha in culture supernatants.
- Investigated the effect of macrophage supplementation and exogenous TGF-beta1.
Main Results:
- Anti-MOG antibody demyelination led to delayed remyelination with increased TGF-beta1, FGF-2, PDGF-AA, and TNF-alpha.
- IFN-gamma-induced demyelination showed impaired recovery, reduced TGF-beta1, which was reversed by TGF-beta1 treatment.
- Macrophage supplementation before demyelination exacerbated myelin loss and inhibited remyelination, associated with elevated TNF-alpha.
- Macrophage addition to mature cultures without demyelination promoted MBP accumulation.
Conclusions:
- The mode of demyelination significantly affects CNS remyelination dynamics.
- Macrophage-driven inflammation, particularly elevated TNF-alpha, can override promyelinative signals, hindering myelin repair in mature CNS aggregates.
- Targeting macrophage-derived inflammatory factors may be a therapeutic strategy for promoting CNS remyelination.
