Abstract 3823: Imprinting Gene-Modified Parthenogenic ES Cells Can be a Novel Autologous Cell Source for Generating Regenerative Cardiomyocytes
[Background] Parthenogenesis is a production manner of a new progeny from a female without sexual involvement of a male that is found in lower animals in nature, and it is considered applicable to the production of immuno-compatible ES cells. However, in mammals, inappropriate genomic imprinting prevents normal embryonic development and the use of parthenogenic cells for regenerative medicine. To address this problem, we tried to overcome this issue by modifying Igf2 and Dlk1 genes that are critically involved in genomic imprinting and investigated the potential use of parthenogenic ES cells as a source of regenerated cardiomyocytes.
[Methods and Results]
We produced bi-maternal murine embryos using nuclear transfer that consisted of two maternal alleles using fully grown oocytes (fg: maternal imprinting), non-growing oocytes (ng: free from imprinting), and modified ng, in which H19 and Gtl2 genes were deleted, resulting in normal expression of Igf2 and Dlk1-Dio3 (paternal imprinting). We obtained parthenogenic ES cells from these oocytes. We also generated wild type (WT) ES cells for the control.
Progenies were obtained from WT and modified ng/fg oocytes, but fg/fg and ng/fg embryos died at E10.5 and E14.5, respectively.
ES cells were obtained from WT, fg/fg, ng/fg and modified ng/fg by 51%, 31%, 38%, respectively.
Growth speeds of fg/fg and ng/fg were lower than that of WT ES cells, but that of modified ng/fg-derived ES cells was almost similar to WT.
All bi-maternal ES cells could differentiate into cardiomyocytes, but the efficiency of cardiomyocyte differentiation was quite different among cell types.
All of them expressed Nkx2.5, GATA4, MEF2C, αMHC, MLC-2a, and MLC-2v.
[Conclusions] Parthenogenic ES cells can differentiate into cardiomyocytes, but the growth speed and differentiation efficiency were distinct by imprinting pattern. Gene-modified ng/fg ES cells could be a novel autologous cell source for the generation of cardiomyocytes.