Reprogramming Fibroblasts into Bipotential Hepatic Stem Cells by Defined Factors

Abstract

Recent studies have demonstrated direct reprogramming of fibroblasts into a range of somatic cell types, but to date stem or 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 bidirectional 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 bipotential expandable iHepSCs provides a strategy to enable efficient derivation of both hepatocytes and cholangiocytes for use in disease modeling and tissue engineering.

Bioinformatic and Genomic Analyses of Cellular Reprogramming and Direct Lineage Conversion

“…The successfully generated iHEP cells from mouse by two separate groups were validated by expressional analysis [37,76]. Induced hepatic stem cells (iHepSCs), which possess the potential to differentiate into both hepatocytic and cholangiocytic cells, were characterized and their potential confirmed by global expression analysis [104]. Again, when a human iHEP reprogramming protocol was published, expressional analysis confirmed hepatocyte gene network activation [24,38].…”

Shortcut Route for Generation of Functional Hepatocyte Cells from Human Skin Allogenically for Autologous Treatment of Chronic Liver Diseases

“…In the same time, Chinese research teams 9 reported in independently that new cocktails of transcription factors of Gata4, HNF1alpha, Foxa3, and RNAi-mediated inactivation of p19Arf for direct induction of functional hepatocyte like from mouse tail-tip fibroblasts. Yu et al, 10 brilliantly decided to explore two liver organogenesis transcription factors Hnf1b and Foxa3, to reprogram mouse embryonic fibroblasts into induced hepatic stem cells and successfully converted to induced hepatic stem cells from mouse embryonic fibroblasts. They proved that these induced Figure 1 (a) Conventional route reprogramming methods for pluripotent state and thereafter hepatic differentiation, (b) Shortcut route reprogramming methods for endodermal state and thereafter hepatic differentiation, (c) Hypothetical future shortest route for liver regeneration of acute and chronic liver by local delivery of hepatic endodermal and liver organogenesis transcription factors.…”

“…Recently, researchers used such liver specific transcription factors for generation of hepatocyte cells from skin fibroblast cells in vitro. [8][9][10][11][12] The ultimate aim of generation of hepatocytes from skin cells to treat liver diseases. If we know the transcription factors and small molecules which have potential to convert hepatocyte from fibroblast, why not to explore transcription factors and small molecules in vivo directly to repair or regenerating the tissue or organs.…”

Direct Conversion of Cord Blood CD34+ Cells Into Neural Stem Cells by OCT4

“…In the past, the use of NSCs for the treatment of neurological disease was hindered by limited fetal and adult NSC sources. Recent advances in cellular reprogramming allowed for the generation of induced pluripotent stem cells (iPS) and somatic stem cells from various somatic tissues [2][3][4][5][6]. To that effect, NSCs can be obtained by differentiation from iPS cells [7,8].…”