Korean J Fertil Steril.  2002 Jun;29(2):139-147.

Functional Cardiomyocytes Formation Derived from Parthenogenetic Mouse Embryonic Stem Cells

• Shin HA
• Kim EY
• Lee YJ
• Lee KS
• Park EM
• Lee HT
• Chung KS
• Park S
• Lim JH

Abstract

OBJECTIVE
This study was to establish a reproducible differentiation system from the parthenogenetic mouse embryonic stem (P-mES02) cells into functional cardiomyocytes like as in vitro fertilization mouse embryonic stem (mES01) cells.
MATERIALS AND METHODS
To induce differentiation, P-mES02 cells were dissociated and aggregated in suspension culture environment for embryoid (EB) formation. For differentiation into cardiomyocytes, day 4 EBs were treated with 0.75% dimethyl sulfoxide (DMSO) for another 4 days (4-/4+) and then were plated onto gelatin-coated dish. Cultured cells were observed daily using an inverted light microscope to determine the day of contraction onset and total duration of continuous contractile activity for each contracting focus. This frequency was compared with the results of DMSO not treated P-mES02 group (4-/4-) and mES01 groups (4-/4+ or 4-/4-). For confirm the generation of cardiomyocytes, beating cell masses were treated with trypsin-EDTA, dispersed cells were plated onto glass coverslips and incubated for 48 h. Attached cells were fixed using 4% paraformaldehyde and incubated with specific antibodies (Abs) to defect cardiomyocytes (anti-sarcomeric alpha-actinin Ab, 1: 100; anti-cardiac troponin I Ab, 1: 2000) for 1 h. And the cells were finally treated with FITC or TRITC labelled 2nd Abs, respectively, then they were examined under fluorescence microscopy.
RESULTS
Rhythmically contracting areas in mES01 or P-mES02 cells were firstly appeared at 9 or 10 days after EBs plating, respectively. The highest cumulative frequency of beating EBs was not different in both treatment groups (mES01 and P-mES02, 4-/4+) with the results of 61.3% at 13 days and 69.8% at 15 days, respectively. Also the contracting duration of individual beating EBs was different from minimal 7 days to maximal 53 days. However, DMSO not treated groups (mES01 and mES02,4-/4-) also had contracting characteristics although their frequency was a few compared to those of DMSO treated groups (6.0% and 4.0%). Cells recovered from the spontaneously contracting areas within EBs in both treated groups were stained positively with muscle specific anti-sarcomeric alpha-actinin Ab and cardiac specific anti-cardiac troponin I Ab.
CONCLUSION
This study demonstrated that the P-mES02 cell-derived cardiomyocytes displayed similarly structural properties to mES01 cell-derived cardiomyocytes and that the DMSO treatment enhanced the cardiomyocytes differentiation in vitro.

MeSH Terms

Actinin
Animals
Antibodies
Cells, Cultured
Dimethyl Sulfoxide
Embryonic Stem Cells*
Fertilization in Vitro
Fluorescein-5-isothiocyanate
Glass
Mice*
Microscopy, Fluorescence
Myocytes, Cardiac*
Troponin I
Actinin
Antibodies
Dimethyl Sulfoxide
Fluorescein-5-isothiocyanate
Troponin I