The McGowan Institute for Regenerative Medicine congratulates Rohan Manohar for having been selected as the 2011 Stephen L. Phillips Scientific Achievement Award recipient for the upcoming Biomedical Graduate Student Association (BGSA) retreat. The BGSA is a University of Pittsburgh-affiliated group composed of the School of Medicine biomedical graduate students. This is the second year in a row that a Cellular and Molecular Pathology (CMP) student has won this award for outstanding research by a graduate student.
It is Rohan Manohar's research that led to him receiving this prestigious award. His publication, "Identification and expansion of a unique stem cell population from adult mouse gallbladder," is now in press in the journal Hepatology. Co-authors on this study include McGowan Institute for Regenerative Medicine faculty members Donna Stolz, PhD, associate director of the Center for Biologic Imaging and associate professor in the Department of Cell Biology and Physiology at the University of Pittsburgh, and Eric Lagasse, PharmD, PhD, associate professor in the Department of Pathology and the director of the Cancer Stem Cell Center at the McGowan Institute.
The abstract from Mr. Manohar's paper reads:
The identification of resident stem cells in the mouse gallbladder is to date, unexplored. In addition, the relationship between adult gallbladder stem cells and intrahepatic bile duct (IHBD) cells is not well understood. The goal of this study was to isolate stem cells from an adult mouse gallbladder and determine if they were unique compared to IHBD cells. By limiting dilution analyses and index sorts, we found that an EpCAM+CD49f(hi) sub-population from primary gallbladder is enriched in colony forming cells compared to EpCAM+CD49f(lo) cells. EpCAM+CD49f(hi) cells expressed CD29, CD133 and Sca1 but were negative for lineage markers CD31, CD45 and F4/80. Using a novel feeder cell culture system, we observed long-term (>passage 20) and clonal expansion of the EpCAM+CD49f(hi) cells in vitro. In a matrigel differentiation assay, EpCAM+CD49f+ cells expanding in vitro underwent organotypic morphogenesis forming ductular structures and cysts. These structures are similar to, and recapitulate a transport function of primary gallbladder. EpCAM+CD49f+ cells also engraft into the subcutaneous space of recipient mice. We compared primary gallbladder and IHBD cells by flow cytometry and found phenotypic differences in expression of CD49f, CD49e, CD81, CD26, CD54 and CD166. In addition, oligonucleotide microarrays showed that the expanded EpCAM+CD49f+ gallbladder cells and IHBD cells exhibit differences related to lipid and drug metabolism. Notable genes that were different are cytochrome P450, glutathione-S-transferase, Indian hedgehog and solute carrier family genes. Conclusion: we have isolated an epithelial cell population from primary mouse gallbladder with stem cell characteristics and found it to be unique compared to IHBD cells.
Illustration: University of Pittsburgh.
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Abstract (Identification and expansion of a unique stem cell population from adult mouse gallbladder. Manohar R, Komori J, Guzik L, Stolz DB, Chandran UR, Laframboise WA, Lagasse E. Hepatology. 2011 Jul 25.)