GLIS3 Transcriptionally Activates WNT Genes to Promote Differentiation of Human Embryonic Stem Cells into Posterior Neural Progenitors

Abstract

Anterior–posterior (A–P) specification of the neural tube involves initial acquisition of anterior fate followed by the induction of posterior characteristics in the primitive anterior neuroectoderm. Several morphogens have been implicated in the regulation of A–P neural patterning; however, our understanding of the upstream regulators of these morphogens remains incomplete. Here, we show that the Krüppel‐like zinc finger transcription factor GLI‐Similar 3 (GLIS3) can direct differentiation of human embryonic stem cells (hESCs) into posterior neural progenitor cells in lieu of the default anterior pathway. Transcriptomic analyses reveal that this switch in cell fate is due to rapid activation of Wingless/Integrated (WNT) signaling pathway. Mechanistically, through genome‐wide RNA‐Seq, ChIP‐Seq, and functional analyses, we show that GLIS3 binds to and directly regulates the transcription of several WNT genes, including the strong posteriorizing factor WNT3A, and that inhibition of WNT signaling is sufficient to abrogate GLIS3‐induced posterior specification. Our findings suggest a potential role for GLIS3 in the regulation of A–P specification through direct transcriptional activation of WNT genes. Stem Cells 2018 Stem Cells 2019;37:202–215

GLIS1 regulates trabecular meshwork function and intraocular pressure and is associated with glaucoma in humans

“…Homer de novo and known motif analyses identified a G/C-rich GLISBS-like consensus sequences as the top motifs (Figure 5c). This sequence was very similar to the consensus GLISBS reported previously 32, 46, 47 , indicating that our ChIP-Seq was successful in detecting specific GLIS1 binding sequences. Our GLIS1 ChIP-Seq analysis identified a number of additional motifs, including motifs for bZIP transcription factors (e.g., ATF3, FRA1, BATF, and JUNB, members of the AP-1 complex), forkhead box (FOX) proteins 48 , and TEA domain transcription factors (TEAD) that play a key role in the Hippo pathway 49 .…”

“…About 10% of GLIS1 binding peaks were within proximal promoter regions 1 kb upstream of transcription start sites (TSSs), whereas 16% were further upstream (Figure 5b). GLIS1 binding was most highly enriched at introns within the gene body as we reported for GLIS3 32, 46 . Homer de novo and known motif analyses identified a G/C-rich GLISBS-like consensus sequences as the top motifs (Figure 5c).…”

A GLIS3–CD133–WNT-signaling axis regulates the self-renewal of adult murine pancreatic progenitor-like cells in colonies and organoids

“…This increase was caused by a direct binding of Glis3 to the Wnt3A promoter, demonstrated by ChIP-seq analysis using FLAG-tagged Glis3. In silico analysis utilizing JASPAR motifs and the eukaryotic promoter database demonstrated potential Glis3 consensus-binding sites in promoter regions of CD133, Axin2, Lgr5, and ␤-catenin (data not shown), genes not reported by Jeon et al (62). Again, it is possible that the effects of Glis3 are dependent on cellular context, and further analysis will be necessary to compare how Glis3 may differentially affect Wnt genes in our PCFUs versus hESCs.…”

“…While our manuscript was in revision, Jeon et al (62) showed that overexpression of Glis3 in human embryonic stem cells (hESCs) causes up-regulation of Wnt ligand genes, such as Wnt3A. This increase was caused by a direct binding of Glis3 to the Wnt3A promoter, demonstrated by ChIP-seq analysis using FLAG-tagged Glis3.…”

Updates on Genes and Genetic Mechanisms Implicated in Primary Angle-Closure Glaucoma

“… 65 , 66 Also, GLIS3 has been demonstrated to function as an upstream transcriptional activator of Wnt signaling genes and induce posterior specification of neural progenitor cells. 59 Although the exact molecular mechanism by which a gene involved in a metabolic pathway may contribute to PACG pathogenesis is unknown, the identification of GLIS3 variants associated with diabetes and PACG suggests a high relevance of GLIS3 in cross-phenotype association and overlapping etiology of complex diseases such as PACG. Besides, it is also possible that GLIS expression might affect the development or cell survival of the anterior segment tissue structures and influence PACG risk.…”