Sox2 Controls Neural Stem Cell Self-Renewal Through a Fos-Centered Gene Regulatory Network. (29th March 2021)

• Record Type: Journal Article
• Authors: Pagin, Miriam; Pernebrink, Mattias; Giubbolini, Simone; Barone, Cristiana; Sambruni, Gaia; Zhu, Yanfen; Chiara, Matteo; Ottolenghi, Sergio; Pavesi, Giulio; Wei, Chia-Lin; Cantù, Claudio; Nicolis, Silvia K.
• Is Part Of: Stem cells. Volume 39:Number 8(2021)
• Page Start: 1107
• Page End: 1119
• Publication Date: 2021-03-29
• Subjects: AP1 inhibitor T-5224 -- CRISPR -- CUT&RUN -- Fos -- lentiviral vector -- neural stem cells (NSCs) -- self-renewal -- Socs3 -- Sox2 -- transcription factors; Cloning -- Periodicals; Clone cells -- Periodicals; Stem cells -- Periodicals; Cell Differentiation -- Periodicals; Cell Division -- Periodicals; Clone Cells -- Periodicals; Hematopoietic Stem Cells -- Periodicals; Stem Cells -- Periodicals; 571.84
• DOI: 10.1002/stem.3373
• Languages: English
• ISSNs: 1066-5099

Abstract

Abstract: The Sox2 transcription factor is necessary for the long-term self-renewal of neural stem cells (NSCs). Its mechanism of action is still poorly defined. To identify molecules regulated by Sox2, and acting in mouse NSC maintenance, we transduced, into Sox2-deleted NSC, genes whose expression is strongly downregulated following Sox2 loss (Fos, Jun, Egr2), individually or in combination. Fos alone rescued long-term proliferation, as shown by in vitro cell growth and clonal analysis. Furthermore, pharmacological inhibition by T-5224 of FOS/JUN AP1 complex binding to its targets decreased cell proliferation and expression of the putative target Suppressor of cytokine signaling 3 (Socs3). Additionally, Fos requirement for efficient long-term proliferation was demonstrated by the reduction of NSC clones capable of long-term expansion following CRISPR/Cas9-mediated Fos inactivation. Previous work showed that the Socs3 gene is strongly downregulated following Sox2 deletion, and its re-expression by lentiviral transduction rescues long-term NSC proliferation. Fos appears to be an upstream regulator of Socs3, possibly together with Jun and Egr2; indeed, Sox2 re-expression in Sox2-deleted NSC progressively activates both Fos and Socs3 expression; in turn, Fos transduction activates Socs3 expression. Based on available SOX2 ChIPseq and ChIA-PET data, we propose a model whereby Sox2 is a direct activator of both Socs3 and Fos, as well as possibly Jun and Egr2; furthermore, we provide direct evidence for FOS and JUN binding on Socs3 promoter, suggesting direct transcriptional regulation. These results provide the basis for developing a model of a network of interactions, regulating critical effectors of NSC proliferation and long-term maintenance. Abstract : Sox2 is necessary for long-term neural stem cell (NSC) self-renewal and for Socs3, Fos, Jun, and Egr2 gene expression. We previously showed that Socs3 overexpression rescues Sox2-deleted NSC self-renewal. Fos, Jun, and Egr2 transduction into Sox2-deleted NSC rescues self-renewal, Fos alone being both sufficient and necessary. Sox2 transduction upregulates Fos and Socs3 in Sox2-deleted cells, and Fos upregulates Socs3, defining a Sox2-dependent regulatory network.