Coordination of sonic hedgehog and Wnt signaling determines ventral and dorsal telencephalic neuron types from human embryonic stem cells.
The directed differentiation of forebrain neuronal types from human embryonic stem cells (hESCs) has not been achieved. Here, we show that hESCs differentiate to telencephalic progenitors with a predominantly dorsal identity in a chemically defined medium without known morphogens. This is attributed to endogenous Wnt signaling, which upregulates the truncated form of GLI3, a repressor of sonic hedgehog (SHH). A high concentration of SHH, or the inhibition of Wnt by dickkopf 1 (DKK1) together with a low concentration of SHH, almost completely converts the primitive dorsal precursors to ventral progenitors, which is partially achieved through both downregulation of the truncated GLI3 and upregulation of full-length GLI3 expression. These dorsal and ventral telencephalic progenitors differentiate to functional glutamatergic and GABAergic neurons, respectively. Thus, although hESCs generate dorsal telencephalic cells, as opposed to ventral progenitors in other vertebrates, in the absence of exogenous morphogens, human cells use a similar molecular mechanism to control the dorsal versus ventral fate. The coordination of Wnt and SHH signaling through GLI3 represents a novel mechanism that regulates ventral-dorsal patterning in the development of forebrain neuronal subtypes.
Li
Xue-Jun
XJ
Department of Neuroscience, Stem Cell Institute, University of Connecticut Health Center, Farmington, CT 06030, USA. xjli@uchc.edu
Zhang
Xiaoqing
X
Johnson
M Austin
MA
Wang
Zhi-Bo
ZB
Lavaute
Timothy
T
Zhang
Su-Chun
SC
D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000235:genetics; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000737:chemistry; D053595:Embryonic Stem Cells / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D013687:Telencephalon / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D013997:Time Factors; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism*
D017077:Culture Media, Conditioned; D053823:Hedgehog Proteins; C509239:SHH protein, human; D051153:Wnt Proteins