California's Stem Cell Agency

Recently, we devised and reported a new regenerative medicine paradigm that entails temporal/transient overexpression of induced pluripotent stem cell based reprogramming factors in skin cells, leading to the rapid generation of “activated” cells, which can then be directed by specific growth factors and small molecules to “relax” back into various defined and homogenous tissue-specific precursor cell types (including nervous cells, heart cells, blood vessel cells, and pancreas and liver progenitor cells), which can be expanded and further differentiated into mature cells entirely distinct from fibroblasts.

In this proposal, combined with small molecules that can functionally replace reprogramming transcription factors as well as substantially improve reprogramming efficiency and kinetics, we aim to further develop and mechanistically characterize chemically defined, non-integrating approaches (e.g., mRNA, miRNA, episomal plasmids and/or small molecule-based) to robustly and efficiently reprogram skin fibroblast cells into expandable heart precursor cells. Specifically, we will: determine if we can use non-integrating methods to destabilize human fibroblasts and facilitate their direct reprogramming into the heart precursor cells; characterize of heart cells generated by the direct programming methods, both in the tissue culture dish and in a mouse model of heart attack; and characterize newly identified reprogramming enhancing small molecules mechanistically.