Cyclopamine treatment of human embryonic stem cells followed by culture in human astrocyte medium promotes differentiation into nestin- and GFAP-expressing astrocytic lineage

Human embryonic stem cells (hESCs) are able to differentiate into various cell types, including neuronal cells and glial cells. However, little information is available regarding astrocyte differentiation. This report describes the differentiation of hESCs into nestin- and GFAP-expressing astrocytes following treatment with cyclopamine, which is an inhibitor of Hedgehog (Hh) signaling, and culturing in human astrocyte medium (HAM). In hESCs, cyclopamine treatment suppressed the expression of Hh signaling molecules, the Hh signaling target gene, and ESC-specific markers. Clyclopamine also induced the differentiation of the cells at the edges of the hESC colonies, and these cells stained positively for the early neural marker nestin. Subsequent culturing in HAM promoted the expression of the astrocyte-specific marker GFAP, and these cells were also nestin-positive. These findings indicate that treatment with cyclopamine followed by culturing in HAM leads to the differentiation of hESCs into nestin- and GFAP-expressing astrocytic lineage.