Conversion of mouse fibroblast to hepatocyte-like cells by defined factors
ABSTRACT: Plasticity of differentiated cells has been proved by nuclear transfer, induced pluripotent cells and transdifferentiation. Here we show that by transduction of 3 factors (Hnf1alpha, Gata4, and Foxa3) and p19Arf inactivation, tail-tip fibroblasts can be converted to hepatocyte-like (iHep) cells, expressing hepatocyte marker genes, and acquiring many mature hepatocyte functions in vitro and in vivo. p19Arf-null TTFs were tranfected with 3 liver enriched transcription factors, then changed to modified Block's medium. To enrich iHep cells, epithelial cells were enriched by partial trypsin digestion.
Project description:Plasticity of differentiated cells has been proved by nuclear transfer, induced pluripotent cells and transdifferentiation. Here we show that by transduction of 3 factors (Hnf1alpha, Gata4, and Foxa3) and p19Arf inactivation, tail-tip fibroblasts can be converted to hepatocyte-like (iHep) cells, expressing hepatocyte marker genes, and acquiring many mature hepatocyte functions in vitro and in vivo. Overall design: p19Arf-null TTFs were tranfected with 3 liver enriched transcription factors, then changed to modified Block's medium. To enrich iHep cells, epithelial cells were enriched by partial trypsin digestion.
Project description:To compare the transcriptional profile of endogenous Sertoli cells from different Stage of Sertoli cell development (embryonic, immature, mature) to the transcriptionla profile of induced embryonic Sertoli cells derived from MEFs or TTFs we employed the agilent whole genome microarray Keywords: Expression profiling by array The following samples were analyzed in duplicates (MEFs, TTFs, ieSCs (derived from MEFs), ieSCs (derived from TTFs), 14.5 dpc male gonad, immature Sertoli (19 dpc embryo testis) and mature (8 week-old mouse testis))
Project description:Plasticity of differentiated cells has been proved by nuclear transfer, induced pluripotent cells and transdifferentiation. Here we show that by transduction of 3 factors (FOXA3, HNF1A and HNF4A), human fetal fibroblasts can be converted to hepatocyte-like cells (hiHep cells), expressing hepatic marker genes, and acquiring many mature hepatocyte functions in vitro and in vivo. Human fetal fibroblasts (HFF) were tranfected with 3 liver enriched transcription factors (FOXA3, HNF1A, HNF4A), and converted to hepatocyte-like cells (hiHep cells). HFF and primary human hepatocytes (PHH) serve as control.
Project description:To investigate the molecular features underlying senescence and rejuvenation during aged cell reprogramming and identify novel factors that can overcome age-associated barriers, we compared gene expression for reprogramming intermediates on D8 of tail-tip fibroblasts (TTFs) from young Wild Type (WT), old WT, and old p16 knockout (KO) mice. We collected TTFs from young WT, old WT, and old p16 KO mice and reprogrammed the cells by introducing four reprogramming factors, including Oct4, Sox2, Klf4, and c-Myc. Gene expression of reprogramming intermediates on D8 were compared. Two independent experiments were performed using different mice donors for each experiment.
Project description:In order to characterize iHep cells more precisely, we conducted global gene expression analyses using microarrays to compare among the gene expression profiles of MEFs, iHep cells and adult mouse hepatocytes. Three MEF samples that were individually prepared from 13.5 days post coitum (dpc) embryos, three types of iHep cells and hepatocytes obtained from the adult mouse liver were used.
Project description:Drug resistance, caused by complex and redundant mechanisms, is a major obstacle in cancer treatment, especially in liver and kidney cancers. Combinational therapy of miRNAs, which concurrently target multiple pathways, with anticancer drugs represent a new strategy to improve the drug response. By a systems approach, we identified that miR-27b, a miRNA deleted in liver and kidney cancers, sensitizes cancer cells to a broad spectrum of anticancer drugs in vitro and in vivo. Two samples transfected with nontarget miRNA control or miR-27b mimics followed by 48 hours doxorubicin treatment
Project description:X chromosome inactivation (XCI) compensates for differences in X-chromosome number between male and female mammals. XCI is orchestrated by Xist RNA, whose expression in early development leads to transcriptional silencing of one X-chromosome in the female. Knockout studies have established a requirement for Xist, with inviability of female embryos that inherit an Xist deletion from the father. Here, we report that female mice lacking Xist RNA can, surprisingly, develop and survive to term. Xist-null females are born at lower frequency and are smaller at birth, but organogenesis is mostly normal. Transcriptomic analysis indicates significant overexpression of hundreds of X-linked genes across multiple tissues. Therefore, Xist-null mice can develop to term in spite of a deficiency of dosage compensation. However, the degree of X-autosomal dosage imbalance was less than anticipated (1.14- to 1.36-fold). Thus, partial dosage compensation can be achieved without Xist, supporting the idea of inherent genome balance. Nevertheless, to date, none of the mutant mice has survived beyond weaning stage. Sudden death is associated with failure of postnatal organ maturation. Our data suggest Xist-independent mechanisms of dosage compensation and demonstrate that small deviations from X-autosomal balance can have profound effects on overall fitness. RNA-sequencing of tail-tip fibroblasts (TTFs), spleen, liver and heart tissue from Xist-null and control female mice. Sequencing performed with 50nt read length on Illumina HiSeq2000 or 2500. Data consists of 3 biological replicates for TTFs (6 datasets) and 2 biological replicates for tissues (12 datasets).
Project description:Direct induction of induced hepatocytes (iHeps) from fibroblasts holds potential as a strategy for regenerative medicine, but until now has only been shown in culture settings. Here, we describe in vivo iHep formation using transcription factor induction and genetic fate tracing in mouse models of chronic liver disease. We show that ectopic expression of the transcription factors FOXA3, GATA4, HNF1A and HNF4A from a polycistronic lentiviral vector converts mouse myofibroblasts into cells with a hepatocyte phenotype. In vivo expression of the same set of transcription factors from a p75 neurotrophin receptor peptide (p75NTRp)-tagged adenovirus enabled the generation of hepatocyte-like cells from myofibroblasts in fibrotic mouse livers and reduced liver fibrosis. We have therefore been able to convert profibrogenic myofibroblasts in the liver into hepatocyte-like cells with positive functional benefits. This direct in vivo reprogramming approach may open new avenues for the treatment of chronic liver disease. Whole Mouse Genome Oligo Microarray v2 (4x44K) (Agilent Technologies) was used to characterize global gene expression profiles of iHeps compared to myofibroblasts and primary mouse hepatocytes. All microarrays were performed at the Research Core Unit Transcriptomics of the Hanover Medical School. Briefly, total RNA was used to prepare the aminoallyl-UTPmodified (aaUTP) cRNAs (Amino Allyl MessageAmp™ II Kit; #AM1753; Life Technologies) as directed by the company. The aaUTP-cRNAs were labelled with Alexa Fluor 555 Reactive Dye (#A32756; LifeTechnologies). Prior to the reverse transcription reaction, 1μl of a 1:5000 dilution of Agilent’s One-Color spike-in Kit stock solution (#5188-5282, Agilent Technologies) was added to 100ng of total RNA of each analyzed sample. The cRNA fragmentation, hybridization, and washing steps were carried out according to Agilent’s One-Color Microarray-Based Gene Expression Analysis Protocol V5.7 except that 500ng of each labelled cRNA sample were used for hybridization. Slides were scanned on the Agilent Micro Array Scanner G2565 CA (pixel resolution 5 μm, bit depth 20). Data extraction was performed with the Feature Extraction Software V10.7.3.1. 12 samples were analyzed: Pr-mHSC: Primary myofibroblasts derived from hepatic stellate cells (HSCs), 2 replicates; In-vivo iHep: In-vivo myofibroblasts-derived from induced hepatocytes (iHep), 3 replicates; In-vivo eHep: In-vivo endogenous hepatocytes (eHep), 3 replicates; In-vitro iHep: In-vitro myofibroblasts-derived from induced hepatocytes (iHep), 3 replicates; PH24h: Primary hepatocytes (PH) cultured for 24 hours, 1 replicate.
Project description:Recent studies have demonstrated direct reprogramming of fibroblasts into a range of somatic cell types, but to date stem/progenitor cells have only been reprogrammed for the blood and neuronal lineages. We previously reported generation of induced hepatocyte-like (iHep) cells by transduction of Gata4, Hnf1α, and Foxa3 in p19 Arf null mouse embryonic fibroblasts (MEFs). Here, we show that Hnf1β and Foxa3, liver organogenesis transcription factors, are sufficient to reprogram MEFs into induced hepatic stem cells (iHepSCs). iHepSCs can be stably expanded in vitro and possess the potential of bi-directional differentiation into both hepatocytic and cholangiocytic lineages. In the injured liver of fumarylacetoacetate hydrolase (Fah)-deficient mice, repopulating iHepSCs become hepatocyte-like cells. They also engraft as cholangiocytes into bile ducts of mice with DDC-induced bile ductular injury. Lineage-conversion into bi-potential expandable iHepSCs provides a strategy to enable efficient derivation of both hepatocytes and cholangiocytes for use in disease modeling and tissue engineering. iHepSCs were converted form fibroblasts by transduction of Hnf1β and Foxa3. iHepSCs were induced to differentiate into hepatocyte-like cells and cholangiocytes in vitro. Totally, 9 samples including four clones of iHepSCS, one clone of LEPCs, two samples of MEFs and two samples of iHepSCs-derived cholangocytes were analyzed.
Project description:Induced pluripotent stem cell-derived human hepatocyte-like cells (iHeps) could provide a powerful tool for studying the mechanisms underlying human liver development and disease, testing the efficacy and safety of pharmaceuticals across different patients (i.e. personalized medicine), and enabling cell-based therapies in the clinic. However, current in vitro protocols that rely upon growth factors and extracellular matrices (ECM) alone yield iHeps with low levels of liver functions relative to adult primary human hepatocytes (PHHs). Moreover, these low hepatic functions in iHeps are difficult to maintain for prolonged times (weeks to months) in culture. Here, we engineered a micropatterned co-culture (iMPCC) platform in a multi-well format that, in contrast to conventional confluent cultures, significantly enhanced the functional maturation and longevity of iHeps in culture for 4 weeks in vitro when benchmarked against multiple donors of PHHs. In particular, iHeps were micropatterned onto collagen-coated domains of empirically optimized dimensions, surrounded by 3T3-J2 murine embryonic fibroblasts, and then sandwiched with a thin layer of ECM gel (Matrigel™). We assessed iHep maturity via global gene expression profiles, hepatic polarity, secretion of albumin and urea, basal CYP450 activities, phase-II conjugation, drug-mediated CYP450 induction, and drug-induced hepatotoxicity. Conclusion: Controlling both homotypic interactions between iHeps and heterotypic interactions with stromal fibroblasts significantly matures iHep functions and maintains them for several weeks in culture. In the future, iMPCCs could prove useful for drug screening, studying molecular mechanisms underlying iHep differentiation, modeling liver diseases, and integration into human-on-a-chip systems being designed to assess multi-organ responses to compounds. We used Affymetrix microarrays to profile the global gene expression of co-culture stabilized iHeps (iMPCCs) relative to freshly isolated and co-culture stabilized primary human hepatocytes (2 donors). To assess the transcriptomic stability of iHeps in iMPCCs, RNA was extracted following 9 and 21 days of culture for hybridization to Affymetrix microarrays. The hepatic maturation state of iHeps was assessed by comparing gene expression against microarrays containing data from two primary human hepatocyte donors, both following hepatocyte isolation (day 0) and after stabilization in the micropatterened co-culture platform (day 6 and day 42 MPCCs), as previously described.