Project description:This experiment was carried out to identify the short-term effects of Activin A and BMP4 stimulation on gene expression in human embryonic stem cells grown in a chemically defined medium. Keywords: Growth factor stimulation experiment
Project description:Members of the transforming growth factor (TGF)-β superfamily play essential roles in the pluripotency, self-renewal, and differentiation of embryonic stem cells. While bone morphogenic proteins maintain pluripotency of undifferentiated mouse ES cells, the role of Activin/Nodal signaling is less clear. To determine the target genes of Activin/Nodal-Smad2 signaling in undifferentiated embryonic stem cells, changes in gene expression were examined following stimulation with recombinant Activin (2 hours) or after inhibition of Activin/Nodal with SB431542 (24 hours) using defined media culture conditions with LIF and 20 ng/mL BMP4. SB431542 is a specific inhibitor of ALK4/5/7 receptors and antagonizes both Activin and Nodal signaling. Via western analysis, Activin stimulation increased pSmad2 in ES cells after 2 hours, and treatment with SB431542 for 24 hours virtually eliminated pSmad2. Total Smad2 expression remained unchanged through these manipulations. RNA from cells treated with Activin or SB431542 was extracted by standard methods with Qiagen RNeasy columns. The RNA was analyzed with the Mouse Genome 430A Array from Affymetrix. Samples were performed in duplicate, and RNA from cells treated with Activin or SB431542 was compared to untreated embryonic stem cells.
Project description:Members of the transforming growth factor (TGF)-β superfamily play essential roles in the pluripotency, self-renewal, and differentiation of embryonic stem cells. While bone morphogenic proteins maintain pluripotency of undifferentiated mouse ES cells, the role of Activin/Nodal signaling is less clear. To determine the target genes of Activin/Nodal-Smad2 signaling in undifferentiated embryonic stem cells, changes in gene expression were examined following stimulation with recombinant Activin (2 hours) or after inhibition of Activin/Nodal with SB431542 (24 hours) using defined media culture conditions with LIF and 20 ng/mL BMP4. SB431542 is a specific inhibitor of ALK4/5/7 receptors and antagonizes both Activin and Nodal signaling. Via western analysis, Activin stimulation increased pSmad2 in ES cells after 2 hours, and treatment with SB431542 for 24 hours virtually eliminated pSmad2. Total Smad2 expression remained unchanged through these manipulations. RNA from cells treated with Activin or SB431542 was extracted by standard methods with Qiagen RNeasy columns. The RNA was analyzed with the Mouse Genome 430A Array from Affymetrix. Samples were performed in duplicate, and RNA from cells treated with Activin or SB431542 was compared to untreated embryonic stem cells. Experiment Overall Design: RNA from cells treated with Activin or SB431542 was extracted by standard methods with Qiagen RNeasy columns. The RNA was analyzed with the Mouse Genome 430A Array from Affymetrix. Samples were performed in duplicate, and RNA from cells treated with Activin or SB431542 was compared to untreated embryonic stem cells.
Project description:Human embryonic stem cells can be maintained in a basic Serum Replacement (Invitrogen) based medium that has been conditioned on mouse embryonic fibroblasts (MEFs), yielding MEF-CM. Ligands secreted into the medium by the MEFs include Activin A, TGFß1, and Gremlin. This experiment served the purpose of identifying the short-term effects of MEF-CM and its substitute UM_GTA (unconditioned medium plus Activin A, TGFb1, and Gremlin) on gene expression in human embryonic stem cells. Keywords: Media / growth factor stimulation experiment
Project description:Human embryonic stem cells (HESCs) herald tremendous promise for the production of clinically useful cell types for the treatment of injury and disease. Numerous reports demonstrate their differentiation into definitive endoderm (DE) cells, the germ layer from which pancreatic β cells and hepatocytes arise, solely from exposure to a high dose of recombinant Activin/Nodal. Here, we show that combining a second related ligand, BMP4, in combination with Activin A yields 15 to 20% more DE as compared to Activin A alone. The addition of recombinant BMP4 accelerates the downregulation of pluripotency factors, particularly SOX2, and results in upregulation of endogenous BMP2 and BMP4, which in turn leads to elevated levels of phospho-SMAD1/5/8 over the next three days of differentiation. Combined Activin A and BMP4 treatment also leads to an increase in the expression of DE genes CXCR4, SOX17 and FOXA2 when compared to Activin A addition alone. Comparative microarray studies between DE cells harvested on day 3 of differentiation further reveal a novel set of genes upregulated in response to initial BMP4 exposure. Several of these, including APLNR, LRIG3, MCC and LZTS1, are expressed either in the mouse primitive streak, the site of DE formation, or in nascent DE itself. Thus, this synergism between Activin A and BMP4 during the in vitro differentiation of HESC into DE suggests a complex interplay between BMP and Activin/Nodal signaling during the in vivo allocation and expansion of the endoderm lineage. 3 biological replicates of 3-day ActivinA treated HES3 human stem cell culture were compared to 3-day ActivinA+Bmp4 treated HES3 human stem cell culture and observed for differential genes expression
Project description:Human embryonic stem cells (HESCs) herald tremendous promise for the production of clinically useful cell types for the treatment of injury and disease. Numerous reports demonstrate their differentiation into definitive endoderm (DE) cells, the germ layer from which pancreatic β cells and hepatocytes arise, solely from exposure to a high dose of recombinant Activin/Nodal. Here, we show that combining a second related ligand, BMP4, in combination with Activin A yields 15 to 20% more DE as compared to Activin A alone. The addition of recombinant BMP4 accelerates the downregulation of pluripotency factors, particularly SOX2, and results in upregulation of endogenous BMP2 and BMP4, which in turn leads to elevated levels of phospho-SMAD1/5/8 over the next three days of differentiation. Combined Activin A and BMP4 treatment also leads to an increase in the expression of DE genes CXCR4, SOX17 and FOXA2 when compared to Activin A addition alone. Comparative microarray studies between DE cells harvested on day 3 of differentiation further reveal a novel set of genes upregulated in response to initial BMP4 exposure. Several of these, including APLNR, LRIG3, MCC and LZTS1, are expressed either in the mouse primitive streak, the site of DE formation, or in nascent DE itself. Thus, this synergism between Activin A and BMP4 during the in vitro differentiation of HESC into DE suggests a complex interplay between BMP and Activin/Nodal signaling during the in vivo allocation and expansion of the endoderm lineage.
Project description:Bone morphogenetic protein (BMP) signaling is known to support differentiation of human embryonic stem cells (hESCs) into mesoderm and extraembryonic lineages, whereas other signaling pathways can largely influence this lineage specification. Here, we set out to reinvestigate the influence of ACTIVIN/NODAL and fibroblast growth factor (FGF) pathways on the lineage choices made by hESCs during BMP4-driven differentiation. We show that BMP activation, coupled with inhibition of both ACTIVIN/NODAL and FGF signaling, induces differentiation of hESCs, specifically to M-NM-2hCG hormone-secreting multinucleated syncytiotrophoblast and does not support induction of embryonic and extraembryonic lineages, extravillous trophoblast, and primitive endoderm. It has been previously reported that FGF2 can switch BMP4-induced hESC differentiation outcome to mesendoderm. Here, we show that FGF inhibition alone, or in combination with either ACTIVIN/NODAL inhibition or BMP activation, supports hESC differentiation to hCG-secreting syncytiotrophoblast. We show that the inhibition of the FGF pathway acts as a key in directing BMP4-mediated hESC differentiation to syncytiotrophoblast. Human embryonic Stem Cells (hESCs) were treated under defined conditions (N2B27) with BMP4 (B), SB431542 (SB) (ACTIVIN/NODAL inhibitor), SU5402 (SU) (FGFR1 inhibitor), FGF2 (F) either alone or in various combinations as mentioned, followed by isolation of total RNA.
Project description:We cultured hESC and hiPSC lines and compared the transcriptome of untreated cells with cells treated with Activin or BMP4 during 5 days Pluripotent cell lines cultured in feeder-free conditions were treated with 100 ng/ml of activin or 50 ng/ml BMP4 daily during 5 days and collected for analysis
Project description:This experiment was designed to probe the function of Activin/Nodal signalling in the deposition of m6A in human pluripotent stem cells (hPSCs). hPSCs were cultured in presence of Activin or subjected to short-term inhibition of Activin/Nodal signalling for 2h using the receptor antagonist SB-431542 (IP). The global abundance of m6A was then measured by nuclear-enriched methylated RNA immunoprecipitation followed by deep sequencing (NeMeRIP-seq). Pre-NeMeRIP input RNA was used as control to normalise for the changes in gene expression in the two conditions.