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- Bryja, V, et al.
(författare)
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Wnt-5a induces Dishevelled phosphorylation and dopaminergic differentiation via a CK1-dependent mechanism
- 2007
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Ingår i: Journal of cell science. - : The Company of Biologists. - 0021-9533 .- 1477-9137. ; 120:4Pt 4, s. 586-595
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Tidskriftsartikel (refereegranskat)abstract
- Previously, we have shown that Wnt-5a strongly regulates dopaminergic neuron differentiation by inducing phosphorylation of Dishevelled (Dvl). Here, we identify additional components of the Wnt-5a-Dvl pathway in dopaminergic cells. Using in vitro gain-of-function and loss-of-function approaches, we reveal that casein kinase 1 (CK1) δ and CK1ϵ are crucial for Dvl phosphorylation by non-canonical Wnts. We show that in response to Wnt-5a, CK1ϵ binds Dvl and is subsequently phosphorylated. Moreover, in response to Wnt-5a or CK1ϵ, the distribution of Dvl changed from punctate to an even appearance within the cytoplasm. The opposite effect was induced by a CK1ϵ kinase-dead mutant or by CK1 inhibitors. As expected, Wnt-5a blocked the Wnt-3a-induced activation of β-catenin. However, both Wnt-3a and Wnt-5a activated Dvl2 by a CK1-dependent mechanism in a cooperative manner. Finally, we show that CK1 kinase activity is necessary for Wnt-5a-induced differentiation of primary dopaminergic precursors. Thus, our data identify CK1 as a component of Wnt-5a-induced signalling machinery that regulates dopaminergic differentiation, and suggest that CK1δ/ϵ-mediated phosphorylation of Dvl is a common step in both canonical and non-canonical Wnt signalling.
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- Parish, CL, et al.
(författare)
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Wnt5a-treated midbrain neural stem cells improve dopamine cell replacement therapy in parkinsonian mice
- 2008
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Ingår i: Journal of Clinical Investigation. - 0021-9738. ; 118:1, s. 149-160
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Tidskriftsartikel (refereegranskat)abstract
- Dopamine (DA) cell replacement therapy in Parkinson disease (PD) can be achieved using human fetal mesencephalic tissue; however, limited tissue availability has hindered further developments. Embryonic stem cells provide a promising alternative, but poor survival and risk of teratoma formation have prevented their clinical application. We present here a method for generating large numbers of DA neurons based on expanding and differentiating ventral midbrain (VM) neural stem cells/progenitors in the presence of key signals necessary for VM DA neuron development. Mouse VM neurospheres (VMNs) expanded with FGF2, differentiated with sonic hedgehog and FGF8, and transfected with Wnt5a (VMN-Wnt5a) generated 10-fold more DA neurons than did conventional FGF2-treated VMNs. VMN-Wnt5a cells exhibited the transcriptional and biochemical profiles and intrinsic electrophysiological properties of midbrain DA cells. Transplantation of these cells into parkinsonian mice resulted in significant cellular and functional recovery. Importantly, no tumors were detected and only a few transplanted grafts contained sporadic nestin-expressing progenitors. Our findings show that Wnt5a improves the differentiation and functional integration of stem cell-derived DA neurons in vivo and define Wnt5a-treated neural stem cells as an efficient and safe source of DA neurons for cell replacement therapy in PD.
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