Early But Not Delayed Optogenetic RAF Activation Promotes Astrocytogenesis in Mouse Neural Progenitors

https://doi.org/10.1016/j.jmb.2020.06.020Get rights and content
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Highlights

  • Applied optogenetics to study the RAF1 signaling outcome during astrocytogenesis.

  • Early OptoRAF1 activation promotes cell proliferation and astrocytogenesis.

  • Delayed OptoRAF1 activation, however, failed to induce astrocytogenesis.

  • OptoRAF1 did not significantly affect neurogenesis, but promotes neurite growth.

Abstract

The RAS/RAF/MEK/ERK pathway promotes gliogenesis but the kinetic role of RAF1, a key RAF kinase, in the induction of astrocytogenesis remains to be elucidated. To address this challenge, we determine the temporal functional outcome of RAF1 during mouse neural progenitor cell differentiation using an optogenetic RAF1 system (OptoRAF1). OptoRAF1 allows for reversible activation of the RAF/MEK/ERK pathway via plasma membrane recruitment of RAF1 based on blue light-sensitive protein dimerizer CRY2/CIB1. We found that early light-induced OptoRAF1 activation in neural progenitor cells promotes cell proliferation and increased expression of glial markers and glia-enriched genes. However, delayed OptoRAF1 activation in differentiated neural progenitor had little effect on glia marker expression, suggesting that RAF1 is required to promote astrocytogenesis only within a short time window. In addition, activation of OptoRAF1 did not have a significant effect on neurogenesis, but was able to promote neuronal neurite growth.

Keywords

RAF1
Optogenetic
OptoRAF1
neural progenitor
astrocytogenesis

Abbreviations

GLUT1
glucose transporter 1
ALDH1L1
Aldehyde Dehydrogenase 1 Family Member L1
EGF
epidermal growth factor
FGF
fibroblast growth factor

Cited by (0)

Y.S. and X.H. contributed equally to this work.