본 연구는 단위발생유래 생쥐 배아줄기세포(P-mES)지가 체외수정유래 생쥐 배아줄기세포 (mES)와 마찬가지로 기능성 심근세포로 체외 분화되는지를 조사하였다. 각 세포주 P-mES04와 MES03를 4일간 부유 배양하여 배아체 (EB)를 형성한 다음 4일간 DMSO를 추가적으로 처리한 뒤 젤라틴이 코팅된 배양접시에 부착시켰다(4-/4+). P-mES04와 mES03으로부터 수축성 심근세포 생성 여부를 30일간 관찰한 결과, 각각 13일(69.83%)과 22일 (61.3%)에 누적 형성율이 가장 높았다. 면역 세포화학염색 결과, 수축성을 나타내는 P-mES04 세포는 수축성 mES03 세포에서와 같이 근육 특이적인 anti-sarcomeric a-actinin 항체와 심근 특이적인 anti-cardiac troponin I 항체에 염색되는 것을 확인하였다. 또한 RT-PCR 결과, 수축성을 나타내는 P-mES04 세포는 심근특이적인 L-type calcium channel, a1C, cardiac myosin heavy chain a, cardiac muscle heavy polypeptide $7{eta}$, GATA binding protein 4와 atrial natriuretic factor는 발현하나, 골격근 특이적인 L-type calcium channel, a1S는 발현하지 않아 웅성 성체의 심장세포와 유사한 양상을 보였다. 본 연구의 결과는 단위발생 유래 생쥐 배아 줄기세포를 배아줄기세포의 연구의 대체제로 이용할 수 있음을 보여준다.
This study was conducted to examine whether the parthenogenetic mouse embryonic stem (P-mES) cells can differentiate into functional cardiomyocytes in vitro similar to (mES) cells. p-mES04 and IVF-derived mES03 cells were cultured by suspension culture for 4 days. The formed embryoid bodies (EBs) were treated with 0.75% dimethyl-sulfoxide (DMSO) for further 4 days (4-/4+), and then plated onto gelatin coated culture dish. The appearance of contracting cardiomyocytes from the P-mES04 and mES03 cells was examined for 30 days. The highest cumulative frequency was detected at days 13 (69.83%) and 22 (61.3%), respectively. By immunocytochemistry, beating P-mES04 cells were positively stained with muscle specific anti-sarcomeric a-actinin Ab and cardiac specific anti-cardiac troponin I Ab similar to contracted mES03 cells. When the expression of cardiac muscle-specific genes was analyzed by RT-PCR, beating P-mES04 cells were expressed cardiac specific L-type calcium channel, a1C, cardiac myosin heavy chain a, cardiac muscle heavy polypeptide $7{eta}$, GATA binding protein 4 and atrial natriuretic factor, but not expressed skeletal muscle specific L-type calcium channel, a1S, which was similar to male adult heart cells and mES03-derived beating cardiomyocytes. The result demonstrates that the P-mES cells can be used as an alternative for the study on the characteristic analysis of in vitro cardiomyocyte differentiation from the ES cells.
