Chun Yuan, PhD
Dr. Yuan is the Director of the Bio-Molecular Imaging Center (BMIC) that develops novel imaging techniques for anatomic, functional, tissue and molecular applications, provides a full range of imaging services, and facilitates research for scientific and biomedical institutions throughout the Pacific Northwest. BMIC aims to be a place where new collaborative research opportunities are established, as well as a primary resource for the international scientific community. In collaboration with Philips Medical Systems, BMIC is equipped with a state-of-the-art Philips Achieva 3T Whole Body Scanner geared primarily towards human and translational research.
Heart failure due to myocardial infarction is a major cause of death worldwide. Stem cell transplantation is a promising therapeutic approach for heart failure. New imaging technologies are essential to enable longitudinal non-invasive studies of grafted cells viability and growth. The long term goal of this study is to develop a molecular imaging system, using magnetic resonance imaging (MRI) technique, to track stem cell dynamics after transplantation in the heart. Cell transplantation using derivatives of adult or embryonic stem cells (ESC) is a promising therapeutic approach for heart failure. Stem cell imaging is essential to understanding of biological mechanisms of cell replacement therapy in vivo, and its key challenges are to accurately estimate cell numbers and to track their distribution over time. While MRI is well suited for serial in vivo studies of cardiac structure and function, stem cell labeling with MRI-visible nanoparticles does not provide long term information about survival and expansion. Molecular tagging of graft cells using overexpression of ferritin, a non-toxic iron-binding protein, may solve this problem and enable longitudinal tracking of stem cell distribution and growth after engraftment. The potential of using ferritin overexpression for cardiac stem cell imaging has not yet been explored. Our pilot studies have shown the feasibility of ferritin over expression in a model stem cell system and the successful detection of transduced cells by MRI after transplantation into the infarcted mouse heart. Ferritin overexpression did not affect cell viability, proliferation and differentiation. In this proposal, we will test the hypothesis that ferritin overexpression can be used to non-invasively track therapeutic human ESC derived cardiomyocytes engrafted into the infarcted heart. If successful, ferritin tagging could provide a generally useful approach for high resolution tracking of stem cell dynamics and biodistribution in multiple systems.