|M.Sc Thesis||Department of Medicine|
|Supervisor:||Prof. Gepstein Lior|
This study involves generation and characterization of cardiomyocytes derived from human ebryonic stem cells.Human embryonic stem cells are derived from the inner cell mass of blastocysts. These unique cells are characterize by their capacity to proliferate in an undifferentiared state for prolong period in culture, and can differentiate into derivatives of all three germ germ layers. Embryonic stem cells can be induced to differentiate into multicellular aggregates called embryoid bodies (EBs), which contain spontaneous rhythmically contracting areas. Cells from these spontaneously contracting areas derived stained positively with specific cardiac markers (anti cardiac myosin heavy chain, anti-ANP, anti troponin I) and sarcomeric markers ( anti a- actinin, anti desmin). Histomorphometric analysis revealed that throughout the first 20 days in culture ther cells were typically round or oval shaped and then gradually elongate by 20% up to 40-60 days in culture. Transmission electron microscopy showed the progressive development of mature sarcomere, intercalated discs were also found in these cells. Mitotic activity, determine using [3H]thymidine radioautographic labeling, showed that 10 days old beating EBs had the greatest mitotic activity, which was greatly reduced after 30 days in culture. Our study has confirmed that human embryonic stem cells proliferate and can differentiate and develop into cells with structural and immunohistochemical characteristic of cardiomyocytes.
Key words : Human embryonic stem cells, Embryoid bodies, Cardiomyocytes.