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:We analyzed gene expression of hepatocytic parental progenitor cells in a population of small hepatocytes. The hepatocytic parental progenitor cells possess self-renewal capability. These cells maintain the ability to differentiate into mature hepatocytes.
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:We examined how each chemical contributed to hepatocyte revitalization by removing each component of the 5C induction cocktail individually. We then compared deach chemical contributed to hepatocyte revitalization by removing each component of the 5C induction cocktail individually
Project description:Transplantation of genetically corrected hepatocytes is an attractive alternative to liver transplantation but is hampered by the low amplification potential of these cells in vitro. Here, we describe a method for generating proliferative hepatic progenitor cells (iHPC) from human hepatocytes as an expandable cell source for liver therapy. Dedifferentiation of primary hepatocytes to iHPC was achieved in less than 7 days by culturing the cells in medium with a cocktail of growth factors and small molecules. In culture, iHPC expressed a combination of endoderm hepatic progenitor and mesenchymal stem cell markers and proliferated vigorously, allowing for their expansion by at least 104 times. RNA sequencing of iHPC demonstrated that they displayed far more subtle changes in both transcriptome and transposcriptome, compared to hepatocyte-derived iPSC. Finally, transplantation of iHPC into the liver of immuno-deficient mice showed iHPC differentiation potential in vivo, without triggering detectable tumor development.
Project description:Transplantation of genetically corrected hepatocytes is an attractive alternative to liver transplantation but is hampered by the low amplification potential of these cells in vitro. Here, we describe a method for generating proliferative hepatic progenitor cells (iHPC) from human hepatocytes as an expandable cell source for liver therapy. Dedifferentiation of primary hepatocytes to iHPC was achieved in less than 7 days by culturing the cells in medium with a cocktail of growth factors and small molecules. In culture, iHPC expressed a combination of endoderm hepatic progenitor and mesenchymal stem cell markers and proliferated vigorously, allowing for their expansion by at least 104 times. RNA sequencing of iHPC demonstrated that they displayed far more subtle changes in both transcriptome and transposcriptome, compared to hepatocyte-derived iPSC. Finally, transplantation of iHPC into the liver of immuno-deficient mice showed iHPC differentiation potential in vivo, without triggering detectable tumor development.
Project description:Currently, much effort is directed to the development of new cell sources for clinical therapy using cell fate conversion approaches by small molecules. Direct lineage reprogramming to a progenitor state has been reported in terminally differentiated rodent hepatocytes, yet remains a challenge in human hepatocytes. Human hepatocytes were isolated from healthy and diseased donor livers and reprogrammed into progenitor cells by two small molecules, A83-01 and CHIR99021 (AC), in the presence of EGF and HGF. The stemness properties of human chemically derived hepatic progenitors (hCdHs) were tested by standard in vitro and in vivo assays and transcriptome profiling. We developed a robust culture system for generating hCdHs with therapeutic potential. The use of HGF proved to be an essential determinant of fate conversion process. Based on functional evidence, activation of HGF/MET signal transduction system collaborated with A83-01 and CHIR99021 to allow a rapid expansion of progenitor cells through activation of ERK pathway. hCdHs expressed hepatic progenitor marker genes and proteins, and could self-renew for at least 10 passages while retaining normal karyotype and potential to differentiate into functional hepatocytes and biliary epithelial cells in vitro. RNASeq gene expression profiling confirmed transcriptional reprogramming of hCdHs toward a progenitor state and suppression of mature hepatocyte transcripts. Upon intrasplenic transplantation into immunocompromised mice with acute liver injury, hCdHs effectively repopulated damaged parenchyma. Our study is a first report of successful reprogramming of human hepatocytes to a population of proliferating bipotent cells with regenerative potential. hCdHs may provide a nove tool that permits expansion and genetic manipulation of patient-specific progenitors to study regeneration and repair of diseased liver.
Project description:Neural progenitor cells (NPCs) can be induced from somatic cells by defined factors. Here we report that NPCs can be generated from mouse embryonic fibroblasts by a chemical cocktail, namely VCR (V, VPA, an inhibitor of HDACs; C, CHIR99021, an inhibitor of GSK-3 kinases and R, Repsox, an inhibitor of TGF-β pathways), under a physiological hypoxic condition. These chemical-induced NPCs (ciNPCs) resemble mouse brain-derived NPCs regarding their proliferative and self-renewing abilities, gene expression profiles, and multipotency for different neuroectodermal lineages in vitro and in vivo. Further experiments reveal that alternative cocktails with inhibitors of histone deacetylation, glycogen synthase kinase, and TGF-β pathways show similar efficacies for ciNPC induction. Moreover, ciNPCs can also be induced from mouse tail-tip fibroblasts and human urinary cells with the same chemical cocktail VCR. Thus our study demonstrates that lineage-specific conversion of somatic cells to NPCs could be achieved by chemical cocktails without introducing exogenous factors. To access the exact identity of ciNPCs, we extracted mRNA from mouse brain-derived NPCs (as control NPCs), MEFs, ciNPCs at passage 5 and passage 13 and compared the global gene expression patterns of these cells by microarray analysis.