Project description:Human induced pluripotent stem cells (hiPSCs) have potential for personalized and regenerative medicine. While most methods of utilizing these cells have focused on deriving homogenous populations of specialized cells, there has been modest success in producing hiPSC-derived organotypic tissues or organoids. Here we present a novel approach for generating and then co-differentiating hiPSC-derived progenitors. With a genetically engineered pulse of GATA6 expression, we initiate rapid emergence of all three germ layers as a complex function of GATA6 expression levels and tissue context. Within two weeks we obtain a complex tissue that recapitulates early developmental processes and exhibits a liver bud-like phenotype, including haematopoietic and stromal cells, as well as a neuronal niche. Our approach addresses two major issues in derivation of tissues from hiPSCs: using a single autologous hiPSCs as source and generating a range of stromal cells that co-develop with parenchymal cells to form complex tissues. Gene expression profiling (microarray) of iPS cells (PGP1) at X days post- doxycycline induction of mouse Gata6. Either total cells or immunomagnetic isolation of cells with specific surface markers. Three samples per group.
Project description:Human induced pluripotent stem cells (hiPSCs) have potential for personalized and regenerative medicine. While most methods of utilizing these cells have focused on deriving homogenous populations of specialized cells, there has been modest success in producing hiPSC-derived organotypic tissues or organoids. Here we present a novel approach for generating and then co-differentiating hiPSC-derived progenitors. With a genetically engineered pulse of GATA6 expression, we initiate rapid emergence of all three germ layers as a complex function of GATA6 expression levels and tissue context. Within two weeks we obtain a complex tissue that recapitulates early developmental processes and exhibits a liver bud-like phenotype, including haematopoietic and stromal cells, as well as a neuronal niche. Our approach addresses two major issues in derivation of tissues from hiPSCs: using a single autologous hiPSCs as source and generating a range of stromal cells that co-develop with parenchymal cells to form complex tissues.
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 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 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:Here, we demonstrate a generalized method for organ bud formation from diverse tissues by combining pluripotent stem cell-derived tissue-specific progenitors or relevant tissue samples with endothelial cells and mesenchymal stem cells (MSCs). The MSCs initiated condensation within these heterotypic cell mixtures, which was dependent upon substrate matrix stiffness. Defining optimal mechanical properties promoted formation of 3D, transplantable organ buds from tissues including kidney, pancreas, intestine, heart, lung, and brain. Transplanted pancreatic and renal buds were rapidly vascularized and self-organized into functional, tissue-specific structures. These findings provide a general platform for harnessing mechanical properties to generate vascularized, complex organ buds with broad applications for regenerative medicine. Gene expression profiles of development-related gene expression in kidney bud transplants and murine kidneys.
Project description:We sequenced mRNA from zebrafish wild-type embryos, gata5 morphants, gata6 morphants, and gata5/6 morphants at bud and 6-somite developmental stages to identify genes co-operatively regulated by gata5 and gata6 during cardiomyocyte progenitor specification.
Project description:Human embryonic stem cells (hESC) display substantial heterogeneity in gene expression, implying the existence of discrete substates within the stem cell compartment. To determine whether these substates impact fate decisions of hESC we used a GFP reporter line to investigate the properties of fractions of putative undifferentiated cells defined by their differential expression of the endoderm transcription factor, GATA6, together with the hESC surface marker, SSEA3. By single cell cloning, we confirmed that substates characterized by expression of GATA6 and SSEA3 include pluripotent stem cells capable of long term self-renewal. When clonal stem cell colonies were formed from GATA6-positive and GATA6-negative cells, more of those derived from GATA6-positive cells contained spontaneously differentiated endoderm cells than similar colonies derived from the GATA6-negative cells. We characterized these discrete cellular states using single cell transcriptomic analysis, identifying a potential role for SOX17 in the establishment of the endoderm biased stem cell state.
