Wnt5a-treated midbrain neural stem cells improve dopamine cell replacement therapy in parkinsonian mice
Clare L. Parish, Gonçalo Castelo-Branco, Nina Rawal, Jan Tonnesen, Andreas Toft Sorensen, Carmen Salto, Merab Kokaia, Olle Lindvall, Ernest Arenas
Clare L. Parish, Gonçalo Castelo-Branco, Nina Rawal, Jan Tonnesen, Andreas Toft Sorensen, Carmen Salto, Merab Kokaia, Olle Lindvall, Ernest Arenas
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Research Article

Wnt5a-treated midbrain neural stem cells improve dopamine cell replacement therapy in parkinsonian mice

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.

Authors

Clare L. Parish, Gonçalo Castelo-Branco, Nina Rawal, Jan Tonnesen, Andreas Toft Sorensen, Carmen Salto, Merab Kokaia, Olle Lindvall, Ernest Arenas

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Figure 4

Transplantation of Wnt5a-overexpressing VMNs induces behavioral and cellular recovery in parkinsonian mice.

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Transplantation of Wnt5a-overexpressing VMNs induces behavioral and cell...
(A) Time course of amphetamine-induced rotational behavior in sham-, VMN-, and VMN-Wnt5a–grafted animals. VMN transplants resulted in significant behavioral improvement at 8 weeks, while VMN-Wnt5a transplants resulted in full restoration of behavior. (B) Confirmation of behavioral improvements following apomorphine-induced rotational testing at 8 weeks. (C) Number of TH+ cells within the striatum of grafted animals. (D–F) Photomicrographs in the striatum of grafts from sham-operated (D), VMN-grafted (E), and VMN-Wnt5a–grafted (F) mice. (G) High-power image of DA neurons residing within a VMN-Wnt5a graft showing classical bipolar morphology (arrow). (H) High-power image of a hypertrophied TH+ fiber located outside the graft site (arrowhead in F). (I) Area of TH-immunoreactive fibers within the striatum following grafting. (J) Area of fibers per TH cell. Note that regardless of the increase in cell numbers, the density of fibers per cell in VMN-Wnt5a grafts was significantly greater, suggesting neuritogenesis and greater integration into the host tissue. Data are mean ± SD (n = 6 per group). *P < 0.05; **P < 0.01; ***P < 0.001, ANOVA with Tukey post-hoc test. Scale bars: 200 μm (D–F); 50 μm (G); 100 μm (H).