Dickkopf (Dkk) 1 promotes the differentiation of mouse embryonic stem cells toward neuroectoderm

Wnt signaling has been demonstrated to have extensive roles during embryogenesis. The Wnt family is highly conserved. In mice, there are 19 Wnt genes. Dickkopf (Dkk), through its interactions with Wnt co-receptors, low-density lipoprotein receptor-related protein (LRP), Frizzled and Kremen, can act as a negative regulator to block the Wnt-signaling pathway. There are four Dkk genes in the human genome, and three in that of the mouse. Dkk1 is involved in a variety of craniofacial developmental processes and behaves as a strong head inducer and limb regulator. Dkk1 mutant mice are embryonic-lethal. Here, we investigated the effects of Dkk1 on the differentiation of murine ESCs in both the ESC and embryoid body (EB) states. The results demonstrate that Dkk1 overexpression can initiate the differentiation program of ESCs toward neuroectoderm. We believe this finding can augment our understanding of mouse ESC differentiation.