Liver stem cells, or oval cells, proliferate in response to chronic liver injury and are believed to differentiate into both hepatocytes and cholangiocytes. We have recently identified a population of CD133+ murine oval cells that demonstrates bi-lineage (i.e. hepatocyte and cholangiocyte) gene expression at the single cell level. In this proposal, we will investigate oval cells phenotypes across multiple murine injury models. Our goal is to identify reliable oval cell immuno-phenotypes, so that we can further dissect the factors that influence proliferation and differentiation. Our hypothesis is that chronic liver injury results in growth factor stimulated proliferation and activates key factors in oval cell differentiation. We will utilize three complementary models of liver injury: 1) chronic oxidative stress (MAT1a KO), 2) environmentally-induced damage (DDC 0.1% diet), and 3) a tissue specific induced regulatory knockout (Pten liver KO). To test our hypothesis, we developed the following specific aims.
Aim 1 : Identify the oval cell phenotype in three models of chronic liver injury. Flow cytometry isolated CD133+ oval cells will be defined by bi-lineage potential and stem cell expression profile (Albumin, aFP, Ck19 and Hnf4a). Single cell in-vitro clonal analysis will document bi-potency. We will perform in-vivo functional analysis using bulk populations.
Aim 2 : Define the oval cell response to growth factors stimulation. Using quantitative PCR, we will demonstrate up-regulation of growth factor receptor expression. Using phospho-protein analysis, we will identify the intra-cellular phosphorylation events in growth factor stimulated oval cells. Lastly, we will define the response to growth factor receptor blockade in-vivo within oval cell population using cell proliferation assays.
Aim 3 : Dissect the role of transcription factor induced differentiation within populations of proliferating oval cells. We will downregulate HNF4a using siRNA to block differentiation in-vitro. We will isolate nuclear proteins from proliferating oval cells and control populations to define transcription factor profile important to oval cell differentiation. In terms of the relevance to public health, this research will provide the cornerstone of future developments to define the potential of adult stem cells in cellular based therapies for human liver disease. This proposal identifies the three key elements to oval cell based therapy: 1) reliable identification, 2) mechanisms of proliferation, and 3) key factors in differentiation.

National Institute of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Clinical Investigator Award (CIA) (K08)
Project #
Application #
Study Section
Diabetes, Endocrinology and Metabolic Diseases B Subcommittee (DDK)
Program Officer
Podskalny, Judith M,
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Pennsylvania State University
Schools of Medicine
United States
Zip Code
Rountree, C Bart; Ding, Wei; Dang, Hein et al. (2011) Isolation of CD133+ liver stem cells for clonal expansion. J Vis Exp :
You, Hanning; Ding, Wei; Dang, Hien et al. (2011) c-Met represents a potential therapeutic target for personalized treatment in hepatocellular carcinoma. Hepatology 54:879-89
Dang, Hien; Ding, Wei; Emerson, Dow et al. (2011) Snail1 induces epithelial-to-mesenchymal transition and tumor initiating stem cell characteristics. BMC Cancer 11:396
Ding, Wei; You, Hanning; Dang, Hien et al. (2010) Epithelial-to-mesenchymal transition of murine liver tumor cells promotes invasion. Hepatology 52:945-53
You, Hanning; Ding, Wei; Rountree, C Bart (2010) Epigenetic regulation of cancer stem cell marker CD133 by transforming growth factor-beta. Hepatology 51:1635-44
Rountree, C Bart; Ding, Wei; He, Lina et al. (2009) Expansion of CD133-expressing liver cancer stem cells in liver-specific phosphatase and tensin homolog deleted on chromosome 10-deleted mice. Stem Cells 27:290-9
Ding, Wei; Mouzaki, Marialena; You, Hanning et al. (2009) CD133+ liver cancer stem cells from methionine adenosyl transferase 1A-deficient mice demonstrate resistance to transforming growth factor (TGF)-beta-induced apoptosis. Hepatology 49:1277-86