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SIRT1 is increasingly recognized as a critical regulator of stress responses, replicative senescence, inflammation, metabolism, and aging. SIRT1 expression is regulated transcriptionally and post-transcriptionally, and its enzymatic activity is controlled by NAD+ levels and interacting proteins. We found that SIRT1 protein levels were much higher in mouse(More)
We have investigated the contribution of intrasplenic bone marrow transplants or in vivo mobilized hematopoietic stem cells to the formation of hepatocytes in normal and injured liver. Direct intrasplenic injections of bone marrow mononuclear cells (5 x 10(5) cells), Scal+/lin- hematopoietic stem cells (5 x 10(3)) cells, and highly purified "side(More)
UNLABELLED MicroRNAs (miRNAs) constitute a new class of regulators of gene expression. Among other actions, miRNAs have been shown to control cell proliferation in development and cancer. However, whether miRNAs regulate hepatocyte proliferation during liver regeneration is unknown. We addressed this question by performing 2/3 partial hepatectomy (2/3 PH)(More)
Differentiation of adult bone marrow (BM) cells into nonhematopoietic cells is a rare phenomenon. Several reports, however, suggest that human umbilical cord blood (hUCB)-derived cells give rise to hepatocytes after transplantation into nonobese diabetic-severe combined immunodeficient (NOD-SCID) mice. Therefore, we analyzed the hepatic differentiation(More)
BACKGROUND & AIMS Current hepatic differentiation protocols for human embryonic stem cells (ESCs) require substantial improvements. MicroRNAs (miRNAs) have been reported to regulate hepatocyte cell fate during liver development, but their utility to improve hepatocyte differentiation from ESCs remains to be investigated. Therefore, our aim was to identify(More)
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(More)
Using the murine model of tyrosinemia type 1 (fumarylacetoacetate hydrolase [FAH] deficiency; FAH⁻/⁻ mice) as a paradigm for orphan disorders, such as hereditary metabolic liver diseases, we evaluated fibroblast-derived FAH⁻/⁻-induced pluripotent stem cells (iPS cells) as targets for gene correction in combination with the tetraploid embryo complementation(More)
UNLABELLED The tightly controlled replication of hepatocytes in liver regeneration and uncontrolled proliferation of tumor cells in hepatocellular carcinoma (HCC) are often modulated by common regulatory pathways. Several microRNAs (miRNAs) are involved in HCC progression by modulating posttranscriptional expression of multiple target genes. miR-221, which(More)
Accumulation of toxic metabolites in hereditary tyrosinemia type I (HT1) patients leads to chronic DNA damage and the highest risk for hepatocellular carcinomas (HCCs) of any human disease. Here we show that hepatocytes of HT1 mice exhibit a profound cell-cycle arrest that, despite concomitant apoptosis resistance, causes mortality from impaired liver(More)
UNLABELLED Hepatocellular carcinoma (HCC) frequently arises in the context of chronic injury that promotes DNA damage and chromosomal aberrations. The cyclin-dependent kinase inhibitor p21 is an important transcriptional target of several tumor suppressors, which promotes cell cycle arrest in response to many stimuli. The aim of this study was to further(More)