Yiling Hong, PhD
Associate Professor, Stem Cell Biology and Nanotoxicity
College of Allied Health Professions
Phone: 8685 | Fax: 5635
Project 1: Stem Cell Reprogramming and Transdifferentation
It is well known that cells have a significant degree of plasticity. This plasticity indicates that somatic cell scan be reprogrammed into another cell lineage or to stem cells. Recent reports showed that the reprogramming of mouse and human fibroblasts to a pluripotent state can be achieved by ectopic expression of defined factors, such as Oct4, Sox2, Nanog, c-Myc, and Klf4 (or Lin28). The induced pluripotent stem (iPS) cells are very similar to embryonic stem (ES) cells. But the major problem in using these iPS cells is that they are genetically modified. These iPS cells have the potential to activate oncogenes and lead to cancer formation. Reprogramming stem cells without genetic modification and leaving the iPS cells in a genetically pristine state becomes the next big milestone for stem cell reprogramming research.
Unlike most stem cell reprogramming systems, our research is to develop a novel approach to derive stem cells through the manipulation of cell culture conditions using albumin-associated lipids and small molecules. The reprogramming medium will be chemically-defined, safe, and animal component free, and thus suitable for future cell therapy. Furthermore, we are also interested in chemical-based cell lineage reprogramming, which is a process where mature somatic cells transforms into other mature somatic cells without undergoing an intermediate state or progenitor cell type. Stem cell reprogramming and transdifferentiation could provide a virtually unlimited supply of known genetic background, patient-specific cells for disease modeling, drug discovery and regenerative medicines.
Project 2: Stem Cells in Nanotoxicity Testing.
Engineered nanoparticles (NPs) have enormous potential to revolutionize many fields and are currently being developed for diverse applications. As the commercial use of NPs becomes more widespread, human exposure will consequently increase. Due to NPs unique properties, some NPs have toxic characteristics that are different from the bulk forms of the same materials. There is a growing need for systematic toxicity tests for these new materials. Stem cells are a unique cell population with the ability to undergo both self-renewal and differentiation, and have the potential to be a sensitive cellular model for this toxicity study. Understanding of the effects of NPs on stem cell fates, factor expressions, and epigenetic modifications will help us better understand stem cell stress responses and greatly enhance consumer confidence in using nanoparticles.
Principal Investigator: Grant title “Cytotoxic and genotoxic effects of manufactured nanoparticles on stem cells” National Institutes of Health. 2011-2014.