GATA6 defines endoderm fate by controlling chromatin accessibility during differentiation of human induced pluripotent stem cells [ATAC-seq]
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ABSTRACT: Investigation of the role played by GATA6 in establishing the definitive endoderm chromatin accessbility profile. We used pluripotent stem cells as a model of early development. We derived GATA6-/- pluripotent cells with an inducible GATA6 construct that permits exongenous GATA6 cDNA expression upon supplmentation of doxycycline. We differentiated GATA6 +/+ and GATA6-/- (with and without doxycyline) cells to definitive endoderm and analyzed the chromatin profile using ATAC-seq.
Project description:Investigation of the role played by GATA6 in establishing the definitive endoderm chromatin accessbility profile. We used pluripotent stem cells as a model of early development. We derived GATA6-/- pluripotent cells with an inducible GATA6 construct that permits exongenous GATA6 cDNA expression upon supplmentation of doxycycline. We differentiated GATA6 +/+ and GATA6-/- (with and without doxycyline) cells to definitive endoderm and analyzed the gene expression profile by RNA-seq.
Project description:Investigation of the role played by GATA6 in establishing the definitive endoderm chromatin accessbility profile. We used pluripotent stem cells as a model of early development. We derived GATA6-/- pluripotent cells with an inducible GATA6 construct that permits exongenous GATA6 cDNA expression upon supplmentation of doxycycline. We differentiated GATA6 +/+ and GATA6-/- (with and without doxycyline) cells to definitive endoderm and analyzed histone tail modification profiles using CHIP-seq.
Project description:Investigation of the role played by GATA6 in establishing the definitive endoderm chromatin accessbility profile. We used pluripotent stem cells as a model of early development. We derived GATA6-/- pluripotent cells with an inducible GATA6 or FOXA2 construct that permits exongenous GATA6 or FOXA2 cDNA expression upon supplementation of doxycycline. We differentiated GATA6+/+ and GATA6-/- (with and without doxycyline) cells to definitive endoderm and analyzed transcription factor binding profiles using CHIP-seq.
Project description:Transcriptome analysis has uncovered a series of long noncoding RNAs (lncRNAs) transcribed during cell differentiation. Here, we uncovered lncRNA GATA6-AS1 is a functional lncRNA in definitive endoderm (DE) differentiation. We found GATA6-AS1 positively regulated the expression of endoderm key factor GATA6, which was different from previous reports in other biological contexts. Further investigation showed GATA6-AS1 interacted with SMAD2/3 and recruited SMAD2/3 to the promoter region of the GATA6 gene locus. In addition, overexpression of GATA6 was able to rescue the defect of DE differentiation due to the absence of GATA6-AS1, suggesting GATA6 was the functional target of GATA6-AS1 during endoderm differentiation. Ultimately, our study uncovers GATA6-AS1 is necessary for DE and pancreas differentiation, and reveals the detailed regulation mechanism between GATA6-AS1 and DE differentiation.
Project description:GATA6 is required for proper definitive endoderm formation. The mechanism of this process is poorly understood We used microarrays to identify genes whose expression is altered upon GATA6-depletion
Project description:Transcription factor-mediated reprogramming is a powerful method to study cell fate changes. In this work, we demonstrate that the transcription factor Gata6 can initiate reprograming of multiple cell types to induced extraembryonic endoderm (iXEN) cells. Intriguingly, Gata6 is sufficient to drive iXEN cells from mouse pluripotent cells and differentiated neural cells. Furthermore, GATA6 induction in human ES (hES) cells also downregulates pluripotency gene expression and upregulates extraembryonic endoderm genes, revealing a conserved function in mediating this cell fate switch. Profiling transcriptional changes following Gata6 induction in mES cells reveals step-wise pluripotency factor disengagement, with initial repression of Nanog and Esrrb, then Sox2 and finally Oct4, alongside step-wise activation of extraembryonic endoderm genes. Chromatin immunoprecipitation and subsequent high-throughput sequencing analysis shows Gata6 enrichment near both pluripotency and endoderm genes, suggesting that Gata6 functions as both a direct repressor and activator. Together this demonstrates that Gata6 is a versatile and potent reprogramming factor that can act alone to drive a cell fate switch from diverse cell types. Time-course microarray analysis of Gata6-mediated reprogramming from 12 to 144 hours of doxycycline treatment in mouse embryonic stem (mES) cells compared to uninduced mES cells, embryo-derived extraembryonic endoderm (XEN) cells and Sox7 overexpressing mES cells after 144 hours of doxycycline treatment.
Project description:Transcription factor-mediated reprogramming is a powerful method to study cell fate changes. In this work, we demonstrate that the transcription factor Gata6 can initiate reprograming of multiple cell types to induced extraembryonic endoderm (iXEN) cells. Intriguingly, Gata6 is sufficient to drive iXEN cells from mouse pluripotent cells and differentiated neural cells. Furthermore, GATA6 induction in human ES (hES) cells also downregulates pluripotency gene expression and upregulates extraembryonic endoderm genes, revealing a conserved function in mediating this cell fate switch. Profiling transcriptional changes following Gata6 induction in mES cells reveals step-wise pluripotency factor disengagement, with initial repression of Nanog and Esrrb, then Sox2 and finally Oct4, alongside step-wise activation of extraembryonic endoderm genes. Chromatin immunoprecipitation and subsequent high-throughput sequencing analysis shows Gata6 enrichment near both pluripotency and endoderm genes, suggesting that Gata6 functions as both a direct repressor and activator. Together this demonstrates that Gata6 is a versatile and potent reprogramming factor that can act alone to drive a cell fate switch from diverse cell types.
Project description:N6-methyladenonsine (m6A) modification locates ubiquitously in mammalian mRNA, and profoundly impacts various physiological processes and pathogenesis. However, the precise involvement of m6A in early endoderm development has yet to be fully elucidated. Here, we reported that depletion of the m6A demethylase ALKBH5 in human embryonic stem cells (hESCs) severely impaired definitive endoderm (DE) differentiation. Within this process, ALKBH5-/- hESCs failed to undergo the primitive streak (PS) intermediate transition, which is considered as a prelude to endoderm specification. Mechanistically, we demonstrated that ALKBH5 deficiency induced m6A hypermethylation around the 3’ untranslated region (3’UTR) of GATA6 transcripts and destabilized GATA6 mRNA in a YTHDF2-dependent manner. Moreover, dysregulation of GATA6 expression ablated its occupancy with critical regulators of Wnt/β-catenin signaling pathway, thereby disrupting the signaling logic underlying DE formation. Overall, our findings unveil a mechanism whereby the ALKBH5-GATA6-WNT/β-catenin axis modulates human in vitro DE induction, and present novel insights on m6A modification in early embryonic development.
Project description:N6-methyladenonsine (m6A) modification locates ubiquitously in mammalian mRNA, and profoundly impacts various physiological processes and pathogenesis. However, the precise involvement of m6A in early endoderm development has yet to be fully elucidated. Here, we reported that depletion of the m6A demethylase ALKBH5 in human embryonic stem cells (hESCs) severely impaired definitive endoderm (DE) differentiation. Within this process, ALKBH5-/- hESCs failed to undergo the primitive streak (PS) intermediate transition, which is considered as a prelude to endoderm specification. Mechanistically, we demonstrated that ALKBH5 deficiency induced m6A hypermethylation around the 3’ untranslated region (3’UTR) of GATA6 transcripts and destabilized GATA6 mRNA in a YTHDF2-dependent manner. Moreover, dysregulation of GATA6 expression ablated its occupancy with critical regulators of Wnt/β-catenin signaling pathway, thereby disrupting the signaling logic underlying DE formation. Overall, our findings unveil a mechanism whereby the ALKBH5-GATA6-WNT/β-catenin axis modulates human in vitro DE induction, and present novel insights on m6A modification in early embryonic development.