In:
Stem Cells, Oxford University Press (OUP), Vol. 27, No. 8 ( 2009-08-01), p. 2009-2021
Abstract:
Interleukin-1 (IL-1) plays a pivotal role in terminal dopaminergic differentiation of midbrain-derived neural precursor cells already committed to the mesencephalic dopaminergic phenotype (named mdNPCs for mesencephalic dopaminergic neural precursor cells). Here we characterized the molecular events in long-term expanded rat nuclear receptor related-1− (Nurr1−) mdNPCs in response to IL-1β during their terminal dopaminergic specification. We showed that IL-1β induced a rapid induction of mRNA of dopaminergic key fate-determining transcription factors, such as Nurr1 and Pitx3, and a subsequent increase of tyrosine hydroxylase protein as an early marker for dopaminergic neurons in vitro. These effects of IL-1β were specific for mdNPCs and were not observed in striatal neural precursor cells (NPCs). Surprisingly, IL-1β did not activate the NF-κB pathway or the transcription factor activating protein 1 (AP-1), but inhibition of nuclear translocation of NF-κB by SN50 facilitated IL-1β-induced Nurr1 expression and dopaminergic differentiation of mdNPCs. Incubation of mdNPCs with IL-1β led to a rapid phosphorylation of ERK1/2 and p38 mitogen-activated protein (MAP) kinases within 1 to 3 hours, whereas Jun kinase was not phosphorylated in response to IL-1β. Consistently, inhibition of the ERK1/2 pathway or p38 MAP kinase blocked Nurr1 upregulation and further dopaminergic specification of mdNPCs, but not differentiation into MAP2ab+ neurons. IL-1 receptor antagonist did not block early dopaminergic differentiation events, suggesting that the effects of IL-1β are not mediated through activation of IL-1 receptor type I. Our results indicate that induction of terminal dopaminergic specification of Nurr1− mdNPCs by IL-1β depends on activation of the ERK1/2 and p38 MAP kinase pathway. Disclosure of potential conflicts of interest is found at the end of this article.
Type of Medium:
Online Resource
ISSN:
1066-5099
,
1549-4918
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
2009
detail.hit.zdb_id:
2030643-X
detail.hit.zdb_id:
1143556-2
detail.hit.zdb_id:
605570-9
SSG:
12
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