Project description:Single cell-based studies have revealed tremendous cellular heterogeneity in stem cell and progenitor compartments, suggesting continuous differentiation trajectories with intermixing of cells at various states of lineage commitment and notable degree of plasticity during organogenesis. The hepato-pancreato-biliary organ system relies on a small endoderm progenitor compartment that gives rise to a variety of different adult tissues, including liver, pancreas, gallbladder, and extra-hepatic bile ducts. Experimental manipulation of various developmental signals in the mouse embryo underscored important cellular plasticity in this embryonic territory. This is also reflected in the existence of human genetic syndromes as well as congenital or environmentally-caused human malformations featuring multiorgan phenotypes in liver, pancreas and gallbladder. Nevertheless, the precise lineage hierarchy and succession of events leading to the segregation of an endoderm progenitor compartment into hepatic, biliary, and pancreatic structures are not yet established. Here, we combine computational modelling approaches with genetic lineage tracing to assess the tissue dynamics accompanying the ontogeny of the hepato-pancreato-biliary organ system. We show that a multipotent progenitor domain persists at the border between liver and pancreas, even after pancreatic fate is specified, contributing to the formation of several organ derivatives, including the liver. Moreover, using single-cell RNA sequencing we define a specialized niche that possibly supports such extended cell fate plasticity.
Project description:Human liver progenitor cells (LPCs) show therapeutic potential, however, their in vitro culture results in inadequate function and phenotypic instability reflecting incomplete understanding of in vivo processes. Foetal LPCs capable of differentiation to a hepatocyte phenotype were isolated and mRNA expression profiling carried out using Exiqon miRCURY microarrays. This was compared to profiles from mature human hepatocytes. Foetal LPCs exhibit a distinct miRNA profile consistent with a stem cell signature, cell division, and some liver-specific functions. 3 independent samples of second trimester liver progenitor cells were prolfiled along with 3 independent mature hepatocyte samples.
Project description:Human liver progenitor cells (LPCs) show therapeutic potential, however, their in vitro culture results in inadequate function and phenotypic instability reflecting incomplete understanding of in vivo processes. Foetal LPCs capable of differentiation to a hepatocyte phenotype were isolated and mRNA expression profiling carried out using Exiqon miRCURY microarrays. This was compared to profiles from mature human hepatocytes. Foetal LPCs exhibit a distinct miRNA profile consistent with a stem cell signature, cell division, and some liver-specific functions.
Project description:Human liver progenitor cells (LPCs) show therapeutic potential, however, their in vitro culture results in inadequate function and phenotypic instability reflecting incomplete understanding of in vivo processes. Foetal LPCs capable of differentiation to a hepatocyte phenotype were isolated and mRNA expression profiling carried out using Affymetrix HGU133plus2 microarrays. This was compared to profiles from mature human hepatocytes and human embryonic stem cells undergoing hepatocytic differentiation. Foetal LPCs exhibit a distinct molecular profile consistent with a stem cell signature, cell division, and some liver-specific functions. 9 independent samples of second trimester liver progenitor cells were profiled along with 3 independent mature hepatocyte samples and 3 each of embryonic stem cells at day 9 and day 17 of differentiation to hepatocyte like cells.
Project description:The liver parenchyma is composed of hepatocytes and bile duct epithelial cells (BECs). Controversy exists regarding the cellular origin of human liver parenchymal tissue generation during embryonic development, homeostasis or repair. Here we report the existence of a hepatobiliary hybrid progenitor (HHyP) population in human fetal liver using single-cell RNA sequencing. HHyPs are anatomically restricted to the ductal plate of fetal liver and maintain a unique transcriptional profile distinct from fetal hepatocytes, mature hepatocytes and mature BECs. In addition, molecular heterogenicity within the EpCAM+ population of freshly isolated fetal and adult human liver reveals diverse gene expression signatures of hepatic and biliary lineage potential. Finally, we FACS isolated fetal HHyPs and confirmed their hybrid progenitor phenotype in vivo. Our study suggests that hepatobiliary progenitor cells previously identified in mice also exist in humans, and can be distinguished from other parenchymal populations, including mature BECs, by distinct gene expression profiles.
Project description:Adult-derived human liver stem/progenitor cells (ADHLSC) are obtained after primary culture of the liver parenchymal fraction. The cells are of fibroblastic morphology and exhibit a hepato-mesenchymal phenotype. Hepatic stellate cells (HSC) derived from the liver non-parenchymal fraction present a comparable morphology as ADHLSC. Because both ADHLSC and HSC are described as liver stem/progenitor cells, we strived to extensively compare both cell populations at different levels and to propose tools demonstrating their singularity. The database include full expression (HGU-219) measurements samples from 7 Adult-Derived Human Liver Stem/progenitor (n=7) and human hepatic stellate samples (n=7)