Stage-specific role for shh in dopaminergic differentiation of human embryonic stem cells induced by stromal cells.
Stromal cells have been used to induce dopaminergic differentiation of mouse, primate, and human embryonic stem cells (hESCs), but the mechanism that governs this induction is unknown. In this manuscript, we show that medium conditioned by the stromal cell line PA6 (PA6-CM) can induce dopaminergic differentiation in neural stem cells (NSCs) derived from hESCs but not directly from hESCs, indicating that soluble factors produced by PA6 cells act at the NSC stage to specify a dopaminergic fate. To identify such soluble factors, we analyzed the transcriptomes of PA6 cells, NSCs, and dopaminergic populations induced by PA6-CM from hESC-derived NSCs. We focused our analysis on growth factors expressed by PA6 and receptors expressed by NSCs, and generated a list of growth factors and receptors that are differentially expressed. Some of the growth factor/receptor pairs are categorized into the Shh, Wnt5A, TGFbeta, and IGF pathways. The expression of genes activated by these pathways in dopaminergic populations was analyzed to confirm that these signals were likely candidates for specifying dopaminergic fate. Results were verified for Shh by using perturbation agents such as cyclopamine to show that Shh is indeed one of the active agents in PA6-CM, and by showing that Shh and FGF8 can substitute for PA6-CM at the NSC induction stage. We conclude that PA6-CM can induce dopaminergic differentiation in hESCs in a stage-specific manner. Shh is likely an important soluble dopaminergic inducing factor secreted by stromal cells and acts after the neural fate determination.
Buck Institute for Aging Research, Novato, CA 94945, USA.
Anna Maria
AM
Swistowska
Alexandre Bettencourt
AB
da Cruz
Yi
Y
Han
Andrzej
A
Swistowski
Ying
Y
Liu
Soojung
S
Shin
Ming
M
Zhan
Mahendra S
MS
Rao
Xianmin
X
Zeng
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D002478:Cells, Cultured; D002970:Cleavage Stage, Ovum / Q000378:metabolism / Q000502:physiology; D018920:Coculture Techniques; D017077:Culture Media, Conditioned / Q000378:metabolism / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D004627:Embryonic Induction / Q000235:genetics / Q000502:physiology; D053595:Embryonic Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D020869:Gene Expression Profiling; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D051379:Mice; D055495:Neurogenesis / Q000235:genetics / Q000502:physiology; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D017154:Stromal Cells / Q000378:metabolism* / Q000502:physiology
D017077:Culture Media, Conditioned; D053823:Hedgehog Proteins; C509239:SHH protein, human; D004298:Dopamine