Abstract 16082: HDAC1 Plays an Essential Role in the Differentiation of Embryonic and Induced Pluripotent Stem Cells into Cardiovascular Lineages.
Despite advancements in the treatment of myocardial infarction (MI), the majority of patients are at increased risk for developing heart failure due to the loss of cardiomyocytes and microvasculature. Therefore regenerative medicine is considered one of the most promising therapies in this field. However, reasons that continue to hinder in the realization of the full potential of iPS/ES cells include incomplete understanding of the molecular mechanisms and epigenetic modifications that result in the reprogramming of somatic cells and directed cardiovascular differentiation. Real-Time array experiments revealed that HDAC1 is highly expressed in pluripotent cells. Additionally the lack of this molecule is embryonically lethal, suggesting it plays a key role in development. Thus, we hypothesized that HDAC1 plays a critical role in maintaining pluripotency and directing cardiovascular differentiation of mES and iPS cells in vitro. HDAC1 was stably knocked down in mES cells (C57BL/6) and iPS cells using a shRNA vector. Differentiation was induced in wild type mES and iPS cell as well as in their clones in which HDAC1 was selectively knocked down. We monitored the ability of these cells to differentiate into any of the three early embryonic lineages and more specifically cardiovascular lineage. RNA was isolated from embryoid bodies on day 4, 6, 8 and 10. Embryoid bodies lacking HDAC1 differentiated slower and showed delayed suppression of pluripotent genes such as Oct4 and Nanog. In addition cells lacking HDAC1 showed differential expression of early endodermal, mesodermal and ectodermal markers. Beating of the embryoid bodies in HDAC1 knocked down cells was also delayed and fewer embryoid bodies showed spontaneous beating. Expression of cardiomyocyte markers as well as markers of other cardiovascular lineage cells was significantly repressed in HDAC1 knocked down cells. Taken together our data suggests that HDAC1 plays a critical role in directing cardiovascular differentiation of mES and iPS cells. Further research in the molecular mechanisms involved in this process will greatly aid our understanding of the epigenetic circuity of pluripotency and cardiovascular differentiation in ES and iPS cells.
- Stem/progenitor cells
- Cardiovascular development
- Molecular biology
- Regenerative medicine stem cells
- © 2010 by American Heart Association, Inc.