Open AccessTransforming Growth Factor β Is Required for Differentiation of Mouse Mesencephalic Progenitors into Dopaminergic Neurons In Vitro and In Vivo: Ectopic Induction in Dorsal Mesencephalon
Author(s) -
Roussa Eleni,
Wiehle Michael,
Dünker Nicole,
BeckerKatins Steffen,
Oehlke Oliver,
Krieglstein Kerstin
Publication year - 2006
Publication title -
stem cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.159
H-Index - 229
eISSN - 1549-4918
pISSN - 1066-5099
DOI - 10.1634/stemcells.2005-0514
Subject(s) - biology , sonic hedgehog , midbrain , fgf8 , tyrosine hydroxylase , progenitor cell , dopaminergic , microbiology and biotechnology , transforming growth factor , smad , cellular differentiation , neuroscience , endocrinology , signal transduction , medicine , fibroblast growth factor , stem cell , central nervous system , receptor , dopamine , genetics , gene
Tissue engineering is a prerequisite for cell replacement as therapeutic strategy for degenerative diseases, such as Parkinson's disease. In the present study, we investigated regional identity of mesencephalic neural progenitors and characterized their development toward ventral mesencephalic dopaminergic neurons. We show that neural progenitors from ventral and dorsal mouse embryonic day 12 mesencephalon exhibit regional identity in vitro. Treatment of ventral midbrain dissociated neurospheres with transforming growth factor β (TGF‐β) increased the number of Nurr1‐ and tyrosine hydroxylase (TH)‐immunoreactive cells, which can be further increased when the spheres are treated with TGF‐β in combination with sonic hedgehog (Shh) and fibroblast growth factor 8 (FGF8). TGF‐β differentiation signaling is TGF‐β receptor‐mediated, involving the Smad pathway, as well as the p38 mitogen‐activated protein kinase pathway. In vivo, TGF‐β2/TGF‐β3 double‐knockout mouse embryos revealed significantly reduced numbers of TH labeled cells in ventral mesencephalon but not in locus coeruleus. TH reduction in Tgfβ2 −/− / Tgfβ3 +/− was higher than in Tgf‐β2 +/− /Tgf‐β3 −/− . Most importantly, TGF‐β may ectopically induce TH‐immunopositive cells in dorsal mesencephalon in vitro, in a Shh‐ and FGF8‐independent manner. Together, the results clearly demonstrate that TGF‐β2 and TGF‐β3 are essential signals for differentiation of midbrain progenitors toward neuronal fate and dopaminergic phenotype.