TY - JOUR
T1 - Guidance of postural motoneurons requires MAPK/ERK signaling downstream of fibroblast growth factor receptor 1
AU - Soundararajan, Prabakaran
AU - Fawcett, James P.
AU - Rafuse, Victor F.
PY - 2010/5/12
Y1 - 2010/5/12
N2 - Identification of intracellular signaling pathways necessary for appropriate axon guidance is challenging because many CNS populations used to study these events contain multiple cell types. Here, we resolve this issue by using mouse embryonic stem (ES) cells that were directed to differentiate into a population of motoneurons that exclusively innervate epaxial muscles [medial median motor column (MMCm) motoneurons]. These ES cell-derived MMCm motoneurons, like their endogenous counterparts, express fibroblast growth factor receptor 1 (FGFR1) and selectively extend axons toward the epaxial trophin FGF8. Unlike wild-type MMCm motoneurons, FGFR1-/-MMCmmotoneurons show guidance defects when transplanted into the neural tube of chick embryos. Furthermore, activation of FGFR1 selectively signals through mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) for appropriate guidance in vitro, whereas overexpression of constitutively active MAPK/ERK in transplanted, or endogenous chick, MMCm cells causes guidance defects in vivo. These results indicate that MAPK/ERK activation downstream of FGFR1 is necessary for MMCm motor axon guidance and that ES cell-derived neurons provide an important tool for dissecting intracellular pathways required for axon guidance.
AB - Identification of intracellular signaling pathways necessary for appropriate axon guidance is challenging because many CNS populations used to study these events contain multiple cell types. Here, we resolve this issue by using mouse embryonic stem (ES) cells that were directed to differentiate into a population of motoneurons that exclusively innervate epaxial muscles [medial median motor column (MMCm) motoneurons]. These ES cell-derived MMCm motoneurons, like their endogenous counterparts, express fibroblast growth factor receptor 1 (FGFR1) and selectively extend axons toward the epaxial trophin FGF8. Unlike wild-type MMCm motoneurons, FGFR1-/-MMCmmotoneurons show guidance defects when transplanted into the neural tube of chick embryos. Furthermore, activation of FGFR1 selectively signals through mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) for appropriate guidance in vitro, whereas overexpression of constitutively active MAPK/ERK in transplanted, or endogenous chick, MMCm cells causes guidance defects in vivo. These results indicate that MAPK/ERK activation downstream of FGFR1 is necessary for MMCm motor axon guidance and that ES cell-derived neurons provide an important tool for dissecting intracellular pathways required for axon guidance.
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U2 - 10.1523/JNEUROSCI.4932-09.2010
DO - 10.1523/JNEUROSCI.4932-09.2010
M3 - Article
C2 - 20463222
AN - SCOPUS:77952349952
SN - 0270-6474
VL - 30
SP - 6595
EP - 6606
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 19
ER -