Project description:In this work we investigated the molecular mechanisms that sustain the endothelial differentiation of murine embryonic stem cells (ES). When ES cells are co-cultured with the stromal PA6 cells in serum-free medium they differentiate mainly into neurons, thanks to the neural inducing activity exerted by the stroma. The addition of exogenous FGF2 allows also the differentiation of endothelial cells whereas, in presence of exogenous BMP4, ES cells differentiate exclusively into endothelium. The purpose of the gene expression analysis of FGF2 and BMP4 treated co-cultures versus the untreated ones was to profile the transcriptomes of FGF2 and BMP4-driven endothelial differentiation in order to detect molecules and pathways involved upon each of the two exogenous signals. In parallel we also performed transcriptome analysis of single monocultures of stromal PA6 cells to investigate the signals released by the stroma in response to FGF2 and BMP4. We found that TGFb1 is involved in the differentiation of ES cells into endothelium in response to FGF2 while Wnt6 and Wnt pathway sustain the endothelial differentiation of ES cells in response to BMP4. In this work we investigated the molecular mechanisms that sustain the endothelial differentiation of murine embryonic stem cells (ES). When ES cells are co-cultured with the stromal PA6 cells in serum-free medium they differentiate mainly into neurons, thanks to the neural inducing activity exerted by the stroma. The addition of exogenous FGF2 allows also the differentiation of endothelial cells whereas, in presence of exogenous BMP4, ES cells differentiate exclusively into endothelium. The purpose of the gene expression analysis of FGF2 and BMP4 treated co-cultures versus the untreated ones was to profile the transcriptomes of FGF2 and BMP4-driven endothelial differentiation in order to detect molecules and pathways involved upon each of the two exogenous signals. In parallel we also performed transcriptome analysis of single monocultures of stromal PA6 cells to investigate the signals released by the stroma in response to FGF2 and BMP4. We found that TGFb1 is involved in the differentiation of ES cells into endothelium in response to FGF2 while Wnt6 and Wnt pathway sustain the endothelial differentiation of ES cells in response to BMP4.
Project description:In this work we investigated the molecular mechanisms that sustain the endothelial differentiation of murine embryonic stem cells (ES). When ES cells are co-cultured with the stromal PA6 cells in serum-free medium they differentiate mainly into neurons, thanks to the neural inducing activity exerted by the stroma. The addition of exogenous FGF2 allows also the differentiation of endothelial cells whereas, in presence of exogenous BMP4, ES cells differentiate exclusively into endothelium. The purpose of the gene expression analysis of FGF2 and BMP4 treated co-cultures versus the untreated ones was to profile the transcriptomes of FGF2 and BMP4-driven endothelial differentiation in order to detect molecules and pathways involved upon each of the two exogenous signals. In parallel we also performed transcriptome analysis of single monocultures of stromal PA6 cells to investigate the signals released by the stroma in response to FGF2 and BMP4. We found that TGFb1 is involved in the differentiation of ES cells into endothelium in response to FGF2 while Wnt6 and Wnt pathway sustain the endothelial differentiation of ES cells in response to BMP4. In this work we investigated the molecular mechanisms that sustain the endothelial differentiation of murine embryonic stem cells (ES). When ES cells are co-cultured with the stromal PA6 cells in serum-free medium they differentiate mainly into neurons, thanks to the neural inducing activity exerted by the stroma. The addition of exogenous FGF2 allows also the differentiation of endothelial cells whereas, in presence of exogenous BMP4, ES cells differentiate exclusively into endothelium. The purpose of the gene expression analysis of FGF2 and BMP4 treated co-cultures versus the untreated ones was to profile the transcriptomes of FGF2 and BMP4-driven endothelial differentiation in order to detect molecules and pathways involved upon each of the two exogenous signals. In parallel we also performed transcriptome analysis of single monocultures of stromal PA6 cells to investigate the signals released by the stroma in response to FGF2 and BMP4. We found that TGFb1 is involved in the differentiation of ES cells into endothelium in response to FGF2 while Wnt6 and Wnt pathway sustain the endothelial differentiation of ES cells in response to BMP4.
Project description:In this work we investigated the molecular mechanisms that sustain the endothelial differentiation of murine embryonic stem cells (ES). When ES cells are co-cultured with the stromal PA6 cells in serum-free medium they differentiate mainly into neurons, thanks to the neural inducing activity exerted by the stroma. The addition of exogenous FGF2 allows also the differentiation of endothelial cells whereas, in presence of exogenous BMP4, ES cells differentiate exclusively into endothelium. A pivotal role in ES cells differentiation is played by the stromal PA6 cells.To analyze the early signals released by PA6 cells in the medium of the co-cultures in response to FGF2 and BMP4, monolayers of PA6 cells were treated with recombinant FGF2 or BMP4 for 3 hours and the gene expression analysis of treated PA6 cultures versus the untreated ones was performed. In this work we investigated the molecular mechanisms that sustain the endothelial differentiation of murine embryonic stem cells (ES). When ES cells are co-cultured with the stromal PA6 cells in serum-free medium they differentiate mainly into neurons, thanks to the neural inducing activity exerted by the stroma. The addition of exogenous FGF2 allows also the differentiation of endothelial cells whereas, in presence of exogenous BMP4, ES cells differentiate exclusively into endothelium. A pivotal role in ES cells differentiation is played by the stromal PA6 cells.To analyze the early signals released by PA6 cells in the medium of the co-cultures in response to FGF2 and BMP4, monolayers of PA6 cells were treated with recombinant FGF2 or BMP4 for 3 hours and the gene expression analysis of treated PA6 cultures versus the untreated ones was performed.
Project description:NANOG has emerged as a central gatekeeper of pluripotency. Here we show that as human embryonic stem (ES) cells exit the pluripotent state, NANOG can play a key role in determining lineage outcome. It has previously been reported that BMPs can induce differentiation of human ES cells into extraembryonic lineages. Here we report that FGF2 switches BMP4 induced differentiation outcome to mesendoderm, characterized by the uniform expression of T (brachyury) and other primitive streak markers. Blocking the MEK-ERK pathway either by chemical inhibitors or by an ERK-specific phosphatase (DUSP6) blocks the FGF2-mediated lineage switch. Active MEK-ERK signaling prolongs NANOG expression during BMP-induced differentiation. Forced NANOG expression results in FGF independent BMP4 induction of mesendoderm, and knockdown of NANOG greatly reduces T induction. Together, our results demonstrate that FGF2 signaling switches the outcome of BMP4 induced differentiation of human ES cells by maintaining NANOG levels through the MEK-ERK pathway. There are three sets of expression data. Set 1 (14 samples) is 5day human ES cells (H1) differentiated with different concentrations of BMP4, in the presence or absence of FGF2. Set 2 (14 samples) is 50ng/mL of BMP4 induced H1 cells differentiation time course, with or without FGF2. Set 3 (22 samples) is 5ng/mL of BMP4 induced H1 cells differentiation time course, with or without FGF2.
Project description:NANOG has emerged as a central gatekeeper of pluripotency. Here we show that as human embryonic stem (ES) cells exit the pluripotent state, NANOG can play a key role in determining lineage outcome. It has previously been reported that BMPs can induce differentiation of human ES cells into extraembryonic lineages. Here we report that FGF2 switches BMP4 induced differentiation outcome to mesendoderm, characterized by the uniform expression of T (brachyury) and other primitive streak markers. Blocking the MEK-ERK pathway either by chemical inhibitors or by an ERK-specific phosphatase (DUSP6) blocks the FGF2-mediated lineage switch. Active MEK-ERK signaling prolongs NANOG expression during BMP-induced differentiation. Forced NANOG expression results in FGF independent BMP4 induction of mesendoderm, and knockdown of NANOG greatly reduces T induction. Together, our results demonstrate that FGF2 signaling switches the outcome of BMP4 induced differentiation of human ES cells by maintaining NANOG levels through the MEK-ERK pathway.
Project description:Embryonic stem cells (ES) are a valuable source of endothelial cells. By co-culturing ES cells with the stromal PA6 cells, the endothelial commitment can be achieved by adding exogenous FGF2 or BMP4. In this work, the molecular pathways that direct the differentiation of ES cells toward endothelium in response to FGF2 are evaluated and compared to those activated by BMP4. To this purpose the genes expression profiles of both ES/PA6 co-cultures and of pure cultures of PA6 cells were obtained by microarray technique at different time points. The bioinformatics processing of the data indicated TGFβ1 as the most represented upstream regulator in FGF2-induced endothelial commitment while WNT pathway as the most represented in BMP4-activated endothelial differentiation. Loss of function experiments were performed to validate the importance of TGFβ1 and WNT6 respectively in FGF2 and BMP4-induced endothelial differentiation. The loss of TGFβ1 expression significantly impaired the accomplishment of the endothelial commitment unless exogenous recombinant TGFβ1 was added to the culture medium. Similarly, silencing WNT6 expression partially affected the endothelial differentiation of the ES cells upon BMP4 stimulation. Such dysfunction was recovered by the addition of recombinant WNT6 to the culture medium. The ES/PA6 co-culture system recreates an in vitro complete microenvironment in which endothelial commitment is accomplished in response to alternative signals through different mechanisms. Given the importance of WNT and TGFβ1 in mediating the crosstalk between tumor and stromal cells this work adds new insights in the mechanism of tumor angiogenesis and of its possible inhibition.