부산대학교 도서관

Recently, human embryonic stem cells(hESCs) have been highlighted to understand early embryogenesis as well as to apply to clinical cell therapy. During human embryogenesis, dynamic processes of early neuronal development are very important to elucidate their developing mechanism. However, the mechanism has not been entirely clear. The formation of embryoid bodies(EBs) derived from hESCs is a tissue-like spheroids in suspension culture and has a potential to differentiate into the three germ layers. Even though many kinds of specific cell makers have been studied, the specific proteins expressed from differentiated cells have been elusive. The objective of this study is to investigate the expression of neuronal protein while EBs is differentiating from hESCs(day 5, 10, 15 and 20). The expressions of neuronal specific makers such as Neurofilament 68kDa(NF 68), tubulin III(TuJ-1) and microtubule-associated protein 2(MAP2) in each EBs stage were analyzed by immunofluorescence(IF). The expressions and localization of neuronal specific markers were shown to be different depending on EBs stages. NF 68 positive cells were expressed on the surface of EBs at day 10 and the expression of NF68 almost disappeared at day 20. MAP2 was not detected in EBs at day 10, whereas it began to be slightly detected on the surface of EBs at day 15. On the other hand, TuJ-1 positive cells were found at all stages and their expression levels were maintained until day 20. These results demonstrate neuronal specific markers can be expressed differently depending on EBs stages, suggesting this allows us to probably understand the early development of neurogenesis in hESCs. Furthermore, this idea expands that we are able to understand the development of all specific cells differentiated from early human embryogenesis.