Interferon-γ promotes differentiation of neural progenitor cells via the JNK pathway

It has been reported that interferon-γ (IFN-γ) facilitates differentiation of PC-12 cells and murine adult neural stem cells. Here we show that IFN-γ promotes the differentiation of C17.2 neural progenitor cells (NPC) into a neuronal phenotype characterized by neurite outgrowth and the expression of the neuronal marker protein β-III tubulin. IFN-γ induced an increase in the activity c-jun N-terminal kinase (JNK) without affecting activities of extracellular signal-regulated kinases (ERKs 1 and 2). An inhibitor of JNK blocked the ability of IFN-γ to promote differentiation of NPC into neurons, whereas an inhibitor of ERKs 1 and 2 did not. Our findings show that the pro-inflammatory cytokine, IFN-γ has the potential to stimulate neurogenesis, suggesting roles for this cytokine in development and repair of the nervous system.