Candidate: This career development proposal is designed to complete formal preparation for my academic career as a transplant surgeon and independent investigator in immuno- and cellular biology. The training program has three components: formal coursework, other didactics, and an intensive mentorship to complete the proposed research plan's aims. During years 1-2: two advanced courses in immunology and two in cellular biology will be taken. These will be complemented by an intensive workshop during year 1 that will expand my basic science techniques in molecular biology. Weekly laboratory meetings and journal club activities will be ongoing. During the past two years I have focused on learning the principles of isolating stem cells and this preliminary work is part of the research plan. I will be working closely with both mentors to develop a broader understanding of the critical experiments required to isolate hepatic stem cells. This structured program will prepare me to think critically, ask questions, form hypotheses and subsequently perform innovative experiments in the transplant and cell biology field. Lastly, my clinical training as a transplant surgeon is an ideal complement to my scientific pursuits, as I have insight into developing translational projects that address pertinent clinical questions. Environment: The University of North Carolina has multiple core laboratory facilities on campus that will allow the completion of these and future experiments. They include the Fluorescence Activated Cell Sorting facility, the Center for Gastrointestinal and Biliary Disease Biology that includes the Advanced Cell Technologies and Tissue Engineering Core, the Immunoassay Core, and the Confocal Facility. This proposal is supported by the Department of Surgery and allows the PI to dedicate 75% of his time on this project. The majority of the work will be carried out in the PI's lab. Research: With the ongoing shortage of organs that challenges organ transplantation and the lack of success with freshly isolated mature hepatocytes in liver cell therapy I have proposed a series of experiments based on hepatic progenitors (with their ability to proliferate), as a promising alternative. To test this hypothesis I will determine the hepatic progenitor's ability to expand and function after transplantation. Research will focus on their immunogenicity and will provide a foundation for future experiments.
The specific aims are to 1) To identify the sequence of expression of liver-enriched transcription factors and hepatocyte lineage genes in hepatic progenitors during cellular expansion; 2) To determine the engraftment and migration pattern of hepatic progenitors and subsequent cellular differentiation using a green fluorescent protein (transgenic) """"""""green"""""""" mouse; 3) Using selected transgenic mouse models (i.e. sphingomyelinase deficient, hypercholesterolemia) I will analyze the function of hepatic progenitor cells along with their ability to reconstitute a liver after injury; 4) Analyze the capacity of CD4+, CD8+ and non-T cells to initiate acute rejection of allogeneic hepatic progenitor cells.

National Institute of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Clinical Investigator Award (CIA) (K08)
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Diabetes, Endocrinology and Metabolic Diseases B Subcommittee (DDK)
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Podskalny, Judith M,
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University of North Carolina Chapel Hill
Schools of Medicine
Chapel Hill
United States
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Wright, Natasha; Samuelson, Lisa; Walkup, Maggie H et al. (2008) Enrichment of a bipotent hepatic progenitor cell from naive adult liver tissue. Biochem Biophys Res Commun 366:367-72
Walkup, Maggie H; Gerber, David A (2006) Hepatic stem cells: in search of. Stem Cells 24:1833-40