Abstract 11147: NF-κB P50 and Oct 3/4 Determine the Facilitation of C-Kit+ Cardiac Stem Cells Into Cardiac Commitments by Hdac Inhibition
Background: We have demonstrated that inhibition of histone deacetylates promotes self-renewal and cardiogenesis in mouse embryonic stem cells. However, the molecular mechanism by which HDAC inhibition modulates the fate of cardiac stem cells (CSCs) and facilitates their adaptation into cardiac phenotypes remains unknown.
Objective: We tested whether NF-κB p50 and Oct3/4 are involved in directing cardiac stem cells into cardiac lineage commitments elicited by HDAC inhibition.
Methods: c-kit+ CSCs were isolated from the adult mouse heart and by magnetic cell sorting using a MACS separator. The cultured c-kit+ CSCs were treated with trichostatin A (TSA), a selective HDAC inhibitor at the concentration of 50nmol/L, for one week. Specific Oct3/4 and NF-κB p50 siRNA (500 nmol/L) were transfected to genetically knockdown of Oct3/4, and NF-κB p50, respectively, in c-kit+CSCs treated with TSA. Cardiogenesis and angiogenesis were analyzed and quantified using immunostaining and were analyzed with real time polymerase chain reaction (PCR).
Results: HDAC inhibition increased Oct 3/4 and NF-κB p50 in cultured c-kit+CSCs, which is associated with an increase in transcription activity of Oct 3/4. Ki67 and phosphorylated-histone 3 positive c-kit+ CSCs were observed to a greater extent in CSCs treated with TSA. C-kit+CSCs-derived Nkx2.5, MEF2C, and GATA4 myocytes were markedly increased by HDAC inhibition. The expressions of these cardiac specific genes were strongly elevated after HDAC inhibition. In contrast, the increases in magnitude were fully disrupted by knockdown of Oct 3/4 and NF-κB p50.
Conclusion: HDAC inhibition selectively activates NF-κB p50 and Oct-3/4 to achieve cardiac commitments. Disruption of NF-κB p50 and Oct3/4 eliminated the capacity of HDAC inhibition to induce cardiogenesis and angiogensis.
- © 2011 by American Heart Association, Inc.