Bimodal effect of interferon-β on astrocyte proliferation and survival: Importance of nuclear factor-κB.

Accumulating evidence indicates that interferon-β (IFN-β) can modify the complex immunopathogenic scenario causing clinical relapse activity and disease progression in MS. However, the beneficial effects of IFN-β in MS patients may also depend on non-immune mechanisms, including the modulation of astrocyte function. In the present report, we have shown that, depending on the dose, IFN-β treatment can either promote astrocyte proliferation and survival, or result astrocyte death. These actions depend, at least in part, on the regulation of nuclear factor-kappa B (NF-κB), an inducible transcription factor present in neurons and glia. This bimodal effect of IFN-β adds a new layer of complexity in the actions of IFN-β within the CNS.