Project description:The goal of this study was to document the gene expression profile of FOXN1+ thymic endoderm cells derived from the in vitro differentiation of human pluripotent stem cells. Thymic epithelial cells (TECs) play a critical role in T-cell maturation and tolerance induction. The generation of TECs from in vitro differentiation of human pluripotent stem cells (PSCs) would provide a platform for studying the mechanisms of this interaction and have implications for immune reconstitution. To facilitate analysis of PSC-derived TECs, we generated human embryonic stem cell (hESC) reporter lines in which sequences encoding GFP were targeted to FOXN1, a gene required for TEC development. Using this FOXN1GFP/w line as a read out, we developed a reproducible protocol for generating FOXN1-GFP+ thymic endoderm cells. Transcriptional profiling and flow cytometry identified Integrin-β4 (ITGB4, CD104) and HLA-DR as markers that could be used in combination with EpCAM to selectively purify FOXN1+ TEC progenitors from differentiating cultures of unmanipulated PSCs. Human FOXN1+ TEC progenitors generated from PSCs will facilitate the study of thymus biology and are a valuable resource for future applications in regenerative medicine Human embryonic stem cells were differentiated for 30 days using the protocol described by Soh et al, 2014. The hESCs used in this protocol had been genetically modified by targeting sequences encoding GFP to the FOXN1 locus, thus enabling FOXN1 expressing cells to be identified on the basis of GFP expression. At differentiation day 30, differentiating cells were separated into three fractions using FACS. These fractions were the FOXN1+(GFP+)EpCAM+, FOXN1-(GFP-)EpCAM+, FOXN1-(GFP-)EpCAM-.
Project description:The goal of this study was to document the gene expression profile of FOXN1+ thymic endoderm cells derived from the in vitro differentiation of human pluripotent stem cells. Thymic epithelial cells (TECs) play a critical role in T-cell maturation and tolerance induction. The generation of TECs from in vitro differentiation of human pluripotent stem cells (PSCs) would provide a platform for studying the mechanisms of this interaction and have implications for immune reconstitution. To facilitate analysis of PSC-derived TECs, we generated human embryonic stem cell (hESC) reporter lines in which sequences encoding GFP were targeted to FOXN1, a gene required for TEC development. Using this FOXN1GFP/w line as a read out, we developed a reproducible protocol for generating FOXN1-GFP+ thymic endoderm cells. Transcriptional profiling and flow cytometry identified Integrin-β4 (ITGB4, CD104) and HLA-DR as markers that could be used in combination with EpCAM to selectively purify FOXN1+ TEC progenitors from differentiating cultures of unmanipulated PSCs. Human FOXN1+ TEC progenitors generated from PSCs will facilitate the study of thymus biology and are a valuable resource for future applications in regenerative medicine
Project description:Metabolism is vital to cellular function and tissue homeostasis during human lung development. In utero, embryonic pluripotent stem cells undergo endodermal differentiation towards a lung progenitor cell fate that can be mimicked in vitro using induced human pluripotent stem cells (hiPSCs) to study genetic mutations. To identify differences between wild type and surfactant protein B (SFTPB)-deficient cell lines during endoderm specification towards lung, we used an untargeted metabolomics approach to evaluate the developmental changes in metabolites. We found that the metabolites most enriched during the differentiation from pluripotent stem cell to lung progenitor cell, regardless of cell line, were sphingomyelins and phosphatidylcholines, two important lipid classes in fetal lung development. The SFTPB mutation had no metabolic impact on early endodermal lung development. The identified metabolite signatures during lung progenitor cell differentiation may be utilized as biomarkers for normal embryonic lung development.
Project description:During mammalian pre-implantation development, the cells of the blastocyst’s inner cell mass differentiate into the epiblast and primitive endoderm lineages, which give rise to the fetus and extra-embryonic tissues, respectively. Extra-embryonic endoderm differentiation can be modeled in vitro by induced expression of GATA transcription factors in mouse embryonic stem cells. Here we use this GATA-inducible system to quantitatively monitor the dynamics of global proteomic changes during the early stages of this differentiation event and also investigate the fully differentiated phenotype, as represented by embryo-derived extra-embryonic endoderm (XEN) cells. Using mass spectrometry-based quantitative proteomic profiling with multivariate data analysis tools, we reproducibly quantified 2,336 proteins across three biological replicates and have identified clusters of proteins characterized by distinct, dynamic temporal abundance profiles. We first used this approach to highlight novel marker candidates of the pluripotent state and extra-embryonic endoderm differentiation. Through functional annotation enrichment analysis, we have shown that the downregulation of chromatin-modifying enzymes, the re-organization of membrane trafficking machinery and the breakdown of cell-cell adhesion are successive steps of the extra-embryonic differentiation process. Thus, applying a range of sophisticated clustering approaches to a time-resolved proteomic dataset has allowed the elucidation of complex biological processes which characterize stem cell differentiation and could establish a general paradigm for the investigation of these processes.
Project description:Human cardiomyocytes can be generated from human embryonic stem cells (hESCs) in vitro by a variety of methods, including co-culture with visceral endoderm-like cell lines and growth factor directed differentiation as monolayers or three-dimensional embryonic bodies. To enable the identification, purification and characterisation of human embryonic stem cell derived cardiomyocytes (CMs) and cardiac progenitor cells (CPCs), we introduced sequences encoding GFP into the NKX2-5 locus by homologous recombination. We found that NKX2-5GFP hESCs facilitate quantification of cardiac differentiation, purification of hESC-derived committed cardiac progenitor cells and cardiomyocytes and the standardization of differentiation protocols.
Project description:Normal commitment of the endoderm of the third pharyngeal pouch (3PP) is essential for the development and differentiation of the thymus. The aim of this study was to investigate the role of transcription factor HOXA3 in the development and differentiation of the third pharyngeal pouch endoderm from human embryonic stem cells (hESCs). 3PP endoderm (3PPE) was differentiated from hESC-derived definitive endoderm (DE) by mimicking developmental queues with Activin A, WNT3A, retinoic acid and BMP4. The function of 3PPE was assessed by further differentiating into functional thymic epithelial cells. The effect of HOXA3 inhibition on cells of 3PPE was subsequently investigated. A highly efficient approach for differentiating 3PPE cells has been developed and these cells expressed 3PPE related genes HOXA3, SIX1, PAX9 as well as EpCAM. 3PPE cells had a strong potential to develop into thymic epithelia which expressed both the cortical epithelial cell markers K8 and CD205, and the medullary epithelial cell markers K5 and AIRE, and also promoted T cell maturation. More importantly, transcription factor HOXA3 not only regulated the differentiation of 3PPE, but also had a crucial role for the proliferation and migration 3PPE cells. Our further investigation revealed that HOXA3 controlled the commitment and function of 3PPE through the regulation of the Wnt signaling pathway by EPHB2. Our results demonstrated that HOXA3 functioned as the on-off switch to regulate the development of hESC-derived 3PPE through EPHB2-mediated Wnt pathway, and our findings will provide new insights into studying the development of the third pharyngeal pouch and thymic organ in vitro and in vivo.
Project description:The transcription factor FOXN1 is a master regulator of thymic epithelial cell development and function. Here we demonstrate that FOXN1 expression is differentially regulated during organogenesis and participates in multi-molecular nuclear condensates essential for the factor's transcriptional activity. FOXN1's C-terminal sequence regulates the diffusion velocity within these aggregates and modulates the binding to proximal gene regulatory regions. These dynamics are significantly altered in a patient's FOXN1 mutant modified in its C-terminal sequence. This mutant is transcriptionally inactive and acts as a dominant negative factor displacing wild-type FOXN1 from condensates and causing athymia and severe lymphopenia in heterozygotes. Expression of the mutated mouse ortholog, Foxn1, selectively impairs mouse thymic epithelial cell (TEC) differentiation, revealing a gene dose dependency for individual TEC subtypes. We have therefore identified the cause for a primary immunodeficiency disease and determined the mechanism by which this FOXN1 gain-of-function mutant mediates its dominant negative effect.
Project description:The future clinical use of embryonic stem cell (ESC)-based hepatocyte replacement therapy depends on the development of an efficient procedure for differentiation of hepatocyes from ESCs. Here we report that a high density of human embryonic stem cell (ESC)-derived fibroblast-like cells (hESdFs) supported the efficient generation of hepatocyte-like cells (HLCs) with functional and mature hepatic phenotypes from primate ESCs and human induced pluripotent stem cells (iPSCs). Molecular and immunocytochemistry analyses revealed that hESdFs caused a rapid loss of pluripotency and induced a sequential endoderm-to-hepatocyte differentiation in the central area of ESC colonies. Knockdown experiments demonstrated that pluripotent stem cells were directed toward endodermal and hepatic lineages by FGF2 and Activin A secreted from hESdFs. Furthermore, we found that the central region of ESC colonies was essential for the hepatic endoderm-specific differentiation, as its removal caused a complete disruption of endodermal differentiation. In conclusion, we describe a novel in vitro differentiation model, and show that hESdF-secreted factors act in concert with regional features of ESC colonies to induce robust hepatic endoderm differentiation in primate pluripotent stem cells. Total RNA were isolated from ORMES6 ESC, differentiated cells at IVDS2 and 3, and cells in the central foci (IVDS2-C) and peripheral (IVDS2-P) area of ESC colonies at IVDS2. Each condition was repeated twice and used ORMES6 ESC as control.