Abstract 18359: Maturation of Reprogrammed Endothelial Cells Using a Single Transcription Factor in a Prolonged Cultivation

Introduction: Endothelial cells (ECs) are an essential component of blood vessels and are crucial for repairing injured and ischemic tissues. Previously, we showed that a single EC transcription factor, ETV2, is able to directly reprogram human postnatal cells into functional ECs. This novel approach can avoid tumorigenic potential of stem cells and enable autologous cell therapy and personalized vascular disease investigation. However, the reprogrammed ECs (rECs) were still in an immature stage. Here, we aimed to investigate whether immature early rECs can be further reprogrammed into a mature EC. Methods and Results: We transduced human dermal fibroblasts (HDFs) with doxycycline (DOX)-inducible lentiviral-ETV2. Then these transduced cells were sorted for KDR at day 7 (D7). The D7-sorted KDR+ cells showed EC characteristics and termed as early rECs. After culturing 20 days, these cells usually lose EC characteristics. We varied coating substrates (i.e. collagen, gelatin, Matrigel, OP9 cells), serum perce...