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CoCl₂ inhibits neural differentiation of retinoic acid-treated embryoid bodies

Nonaka, Jun-Ichi, Yoshikawa, Masahide, Ouji, Yukiteru, Matsuda, Ryosuke, Nishimura, Fumihiko, Yamada, Shuichi, Nakase, Hiroyuki, Moriya, Kei, Nishiofuku, Mariko, Ishizaka, Shigeaki, Sakaki, Toshisuke
Journal of bioscience and bioengineering 2008 v.106 no.2 pp. 141-147
cultured cells, dose response, retinoic acid, stem cells
The effects of CoCl₂ on retinoic acid (RA)-treated embryoid bodies (EBs) were investigated. Four-day EBs were treated with 5x10⁻⁶ M of RA for 4 d, then subjected to attached culturing for 7 d in the presence of CoCl₂ at 0, 20, and 100 μM. Differentiation into MAP2- and GFAP-immunopositive cells was inhibited by CoCl₂ in a dose-dependent manner. Next, RA-treated EBs were dissociated into single cells and cultured for 7 d at an initial cell density of 1x10³/cm². The number of cells increased in a CoCl₂-dose dependent fashion. In cultures with 100 μM of CoCl₂, more than 90% of the cells were immunopositive for nestin and nestin-immunopositive cells formed clusters, while there were few cells immunopositive for MAP2 or GFAP. These results suggest that CoCl₂ inhibits neural differentiation of RA-treated EB cells and promotes the proliferation of nestin-immunopositive cells, i.e., embryonic stem (ES)-derived neural stem-like cells.