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Updated: Oct 1, 2026
Dissection and Isolation of Murine Glia from Multiple Central Nervous System Regions
Published on: June 4, 2020
Microglia-derived IGF-2 prevents TNFalpha induced death of mature oligodendrocytes in vitro
R S Nicholas1, S Stevens, M G Wing
1Neurology Unit, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK.
Abstract:
Insulin-like growth factor-2 (IGF-2) present in media conditioned by non-activated and interferon gamma (IFN gamma)-treated microglia reduces galactocerebroside(+) (GalC) oligodendrocyte apoptosis in cultures derived both from the CG4 cell line and primary rat cortices. Microglia-derived IGF-2 also acts in each culture system to block GalC(+) oligodendrocyte toxicity resulting from soluble microglial-derived tumour necrosis factor alpha (TNF alpha). IGF-2 inhibits TNF alpha-induced c-Jun kinase (JNK) activation of the CG4 cell line. Microglial activation results in the release of soluble factors that are potentially toxic to oligodendrocytes but this may be offset by the production of soluble factors that protect these vulnerable cells. Allowing for extrapolation of these in vitro findings to intact tissue, our observations suggest one mechanism for limiting bystander damage in the context of inflammatory brain disease.
Insights
Insulin-like growth factor-2 (IGF-2) from microglia protects oligodendrocytes from cell death and toxicity. This finding suggests a mechanism to limit damage in inflammatory brain diseases.
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- Microglia, immune cells in the brain, can release factors that impact neuronal health.
- Oligodendrocytes, crucial for myelin sheath formation, are vulnerable to inflammatory damage.
- Interferon gamma (IFN gamma) activates microglia, potentially altering their secretome.
Purpose of the Study:
- To investigate the role of microglia-derived insulin-like growth factor-2 (IGF-2) in oligodendrocyte survival.
- To determine if IGF-2 can counteract the toxicity of other microglial factors, such as tumor necrosis factor alpha (TNF alpha).
- To explore the signaling pathways involved in IGF-2's protective effects.
Main Methods:
- Utilized cell cultures from the CG4 cell line and primary rat cortices.
- Treated microglia with and without interferon gamma (IFN gamma).
- Assessed oligodendrocyte apoptosis and toxicity using galactocerebroside (GalC) as a marker.
- Measured c-Jun kinase (JNK) activation in response to TNF alpha and IGF-2.
Main Results:
- Microglia-conditioned media, particularly from IFN gamma-treated cells, reduced oligodendrocyte apoptosis.
- IGF-2 was identified as a key protective factor in the conditioned media.
- IGF-2 blocked TNF alpha-induced toxicity to GalC(+) oligodendrocytes.
- IGF-2 inhibited TNF alpha-induced c-Jun kinase (JNK) activation in the CG4 cell line.
Conclusions:
- Microglial activation releases both potentially toxic and protective factors for oligodendrocytes.
- IGF-2 produced by microglia is a significant protective factor, mitigating oligodendrocyte apoptosis and TNF alpha-induced toxicity.
- These findings suggest a neuroprotective mechanism of IGF-2 that could be relevant for limiting bystander damage in inflammatory brain diseases.
