Cell line-dependent differentiation of mouse induced-pluripotent stem cells into cardiomyocytes

Cell line-dependent differentiation of mouse induced-pluripotent stem cells into cardiomyocytes

Shinji Kaichi1, Koji Hasegawa2, Tomohide Takaya2, Noritaka Yokoo1, Teruhisa Kawamura2, Tatsuya Morimoto2, Koh Ono3, Shiro Baba1, Shinya Yamanaka4, Tatsutoshi Nakahata1, Toshio Heike1.

  1. Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
  2. Division of Translational Research, Kyoto Medical Center, National Hospital Organization, Kyoto, Japan.
  3. Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
  4. Department of Stem Cell Biology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan.

第73回日本循環器学会学術集会 (大阪), 2009/03/22 (ポスター).

Abstract

Mouse and human fibroblasts can be reprogrammed to pluripotency by ectopic expression of transcription factors (Oct3/4, Sox2, Klf4, and c-Myc) to yield induced pluripotent stem (iPS) cells. Recently iPS cells can be generated without c-Myc. However, detailed characteristics regarding abilities of iPS cells to differentiate into cardiomyocytes has yet to be determined. The present study examined patterns on myocardial differentiation of four cell lines of mouse iPS cells reprogrammed by 3 or 4 factors. The level of SSEA-1, a stem cell marker, was almost similar among four cell lines in undifferentiated iPS cells. During induction of differentiation, expression of genes involved in cardiogenesis and heart beats occurred similarly as in ES cells. However, in one iPS cell line (20D17) generated by 4 factors, expression of cardiac-specific genes was extremely low, and no heart beating occurred. In contrast, patterns of VEGF and Flk-1 expressions were similar among four cell lines. Treatment of iPS cells with trichostatin A (TSA), and HDAC inhibitor, increased Nkx2.5 expression in all cell lines. While the basal Nkx2.5 expression was very low in 20D17, TSA-induced increase was greatest. After all, Nkx2.5 mRNA levels in TSA-stimulated cells were similar among four lines. These findings demonstrate that mouse iPS cells can differentiate into cardiomyocytes while cell line-dependent variation exists. The results also suggest that TSA can overcome such variation.