Abstract 18205: Direct Reprogramming of Human Dermal Fibroblasts into Endothelial Cells Using a Single Transcription Factor
Background: Endothelial cells (ECs) are a key element of vasculature and are indispensable for repairing injured or ischemic tissues. Thus, generation of functional ECs has been central to regenerative medicine. Direct conversion or reprogramming of postnatal cells to desired cell types using transcription factors (TFs) has gained attention due to its advantages over stem cells, as it can avoid differentiation processes and tumorigenic potential associated with stem cells. To date, no studies showed direct reprogramming of human postnatal cells into ECs. Here, we sought to investigate whether EC-related TFs can reprogram human dermal fibroblasts (HDFs) into ECs.
Methods and Results: We generated lentiviral vectors for seven EC-related TFs (ETV2, FOXC2, MEF2C, SOX17/SOX18, SMAD1, HEY1/HEY2, and NANOG). We then used various combinations of these seven TFs to transduce HDFs and found that ETV2 alone was best to reprogram fibroblasts into endothelial cells. Accordingly, data is shown for only ETV2 transduced HDFs. Compared to HDFs at D0, ETV2 transduction substantially induced or increased mRNA expression of endothelial genes during the first 7 days: CDH5 (~10,000 fold), KDR (~7,000 fold), TEK (~50 fold), PECAM1 (~50 fold), CD34 (~5 fold), and VWF (~10 fold). ETV2-transduced HDFs displayed a cobble-stone EC morphology, and expressed CDH5 at 50.0 ± 3.3% and KDR at 39.0 ± 4.8% by flow cytometry. Next, we FACS-sorted KDR+ cells at day 7. These KDR+ cells demonstrated significantly higher mRNA expression of endothelial genes compared to the KDR- cells and exhibited endothelial characteristics such as tube formation in Matrigel, lectin binding, and acetylated-LDL uptake. We referred to these cells as reprogrammed ECs (rECs). Injection of rECs into ischemic hindlimbs showed enhanced blood flow recovery from ischemia, better protection from limb loss, and increased capillary density compared to controls. Histologically, the rECs directly contributed to vessel formation through vasculogenesis.
Conclusion: This is the first study showing that a single EC transcription factor, ETV2, is able to directly reprogram human postnatal cells into functional ECs. This novel approach will enable autologous cell therapy and personalized vascular disease investigation.
Author Disclosures: S. Lee: None. C. Park: None. J. Han: None. J. Kim: None. K. Cho: None. E. Kim: None. S. Kim: None. S. Lee: None. H. An: None. M. Sin: None. S. Sharma: None. Y. Yoon: None.
- © 2014 by American Heart Association, Inc.