Project description:Here we show through genome-wide binding studies that transcription factor 7-like 1 (TCF7L1) represses structure-related genes during adipogenesis. Intriguingly, TCF7L1 is induced in a cell contact-dependent manner by confluency in preadipocytes and is required for adipocyte differentiation by repressing transcription of cell structure genes. TCF7L1 is also sufficient to bestow adipogenic potential upon non-adipogenic cells. These results implicate TCF7L1 as a novel adipogenic competency factor that uniquely determines adipogenic fate through cell structure organization required for adipocyte gene activation. Examination of TCF7L1 binding in preadipocytes treated for 24 hours with adipogenic stimuli.
Project description:Here we show through genome-wide binding studies that transcription factor 7-like 1 (TCF7L1) represses structure-related genes during adipogenesis. Intriguingly, TCF7L1 is induced in a cell contact-dependent manner by confluency in preadipocytes and is required for adipocyte differentiation by repressing transcription of cell structure genes. TCF7L1 is also sufficient to bestow adipogenic potential upon non-adipogenic cells. These results implicate TCF7L1 as a novel adipogenic competency factor that uniquely determines adipogenic fate through cell structure organization required for adipocyte gene activation.
Project description:RNAi mediated depletion of TCF7L1 increases activity of a Wnt-based reporter and imparts more aggressive tumor phenotypes in vitro in pancreatic cancer cell lines that express TCF7L1. We sought to determine what changes in transcription ocurred after RNAi mediated knockdown of TCF7L1 in these cells by RNA-sequencing
Project description:To study the functions of Tcf7l1 during gut development, we have ablated Tcf7l1 specifically in the intestinal epithelium using Shh-Cre. To determine transcriptional changes upon loss of Tcf7l1, we have isolated EpCAM-positive epithelial cells from mouse embryos using fluorescence activated cell sorting (FACS) and performed RNA-sequencing analysis.
Project description:Early during preimplantation development and in heterogeneous mouse embryonic stem cells (mESC) culture, pluripotent cells are specified towards either the primed epiblast or the primitive endoderm (PE) lineage. Canonical Wnt signaling is crucial for safeguarding naive pluripotency and embryo implantation, yet the role and relevance of canonical Wnt inhibition during early mammalian development remains unknown. Here, we demonstrate that transcriptional repression exerted by Wnt/TCF7L1 promotes PE differentiation of mESCs and in preimplantation inner cell mass. Time-series RNA sequencing and promoter occupancy data reveal that TCF7L1 binds and represses genes encoding essential naive pluripotency factors and indispensable regulators of the formative pluripotency program, including Otx2 and Lef1. Consequently, TCF7L1 promotes pluripotency exit and suppresses epiblast lineage formation, thereby driving cells into PE specification. Conversely, TCF7L1 is required for PE specification as deletion of Tcf7l1 abrogates PE differentiation without restraining epiblast priming. Taken together, our study underscores the importance of transcriptional Wnt inhibition in regulating lineage specification in ESCs and preimplantation embryo development as well as identifies TCF7L1 as key regulator of this process.
Project description:Cell density affects numerous biological processes, including gene expression and cell fate specification. However, mechanistic understanding of how changes in cell density alter the transcriptome is lacking. Here, we reveal that the expression of thousands of genes in mouse embryonic stem cells is affected by cell density. Furthermore, we find that low cell density enhances the efficiency of differentiation. Mechanistically, β-catenin is localized primarily to adherens junctions during conditions of high cell-cell contact. At low seeding density during differentiation, we observe that β-catenin translocates to the nucleus and co-activates target genes in concert with Tcf7l1, leading to the induction of lineage markers. Meanwhile, Esrrb sustains the expression of high density-specific, pluripotency-associated genes, but low seeding density differentiation reduces its occupancy on its target loci. Our demonstration of factors that transcriptionally regulate genes responsive to cell density contributes to our understanding of gene regulation in stem cells and has implications for reproducibility, as density can vary between substantially labs and experimental protocols.
