Expression of leukemia inhibitory factor in Müller glia cells is regulated by a redox-dependent mRNA stability mechanism

BACKGROUND: Photoreceptor degeneration is a main hallmark of many blinding diseases making protection of photoreceptors crucial to prevent vision loss. Thus, regulation of endogenous neuroprotective factors may be key for cell survival and attenuation of disease progression. Important neuroprotective factors in the retina include H(2)O(2) generated by injured photoreceptors, and leukemia inhibitory factor (LIF) expressed in Müller glia cells in response to photoreceptor damage. RESULTS: We present evidence that H(2)O(2) connects to the LIF response by inducing stabilization of Lif transcripts in Müller cells. This process was independent of active gene transcription and p38 MAPK, but relied on AU-rich elements (AREs), which we identified within the highly conserved Lif 3′UTR. Affinity purification combined with quantitative mass spectrometry identified several proteins that bound to these AREs. Among those, interleukin enhancer binding factor 3 (ILF3) was confirmed to participate in the redox-dependent Lif mRNA stabilization. Additionally we show that KH-type splicing regulatory protein (KHSRP) was crucial for maintaining basal Lif expression levels in non-stressed Müller cells. CONCLUSIONS: Our results suggest that H(2)O(2)-induced redox signaling increases Lif transcript levels through ILF3 mediated mRNA stabilization. Generation of H(2)O(2) by injured photoreceptors may thus enhance stability of Lif mRNA and therefore augment neuroprotective LIF signaling during degenerative conditions in vivo. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12915-015-0137-1) contains supplementary material, which is available to authorized users.