Cell type-dependent Erk-Akt pathway crosstalk regulates the proliferation of fetal neural progenitor cells

Area of Science:

• Neuroscience
• Developmental Biology
• Cell Biology

Background:

• Neural progenitor (NP) cells are crucial for generating neurons and glia in the central nervous system.
• Understanding NP cell proliferation is vital for brain development and regenerative medicine strategies.
• Existing regulators of NP cell homeostasis, like GSK-3 signaling, are known but novel pathways are sought.

Purpose of the Study:

• To identify compounds that regulate neural progenitor cell proliferation.
• To elucidate the signaling pathways involved in NP cell self-renewal and differentiation.
• To explore the potential of identified pathways for therapeutic applications in regenerative repair.

Main Methods:

• Conducted a chemical screen to identify modulators of fetal NP cell proliferation.
• Investigated signaling crosstalk, specifically between Erk and Akt pathways, using in vitro and in vivo models.
• Assessed the impact of Erk inhibition on NP cell expansion, multipotency, differentiation, and in vivo progenitor cell populations.

Main Results:

• Erk signaling inhibitors were found to potently promote self-renewing divisions of fetal NP cells through Erk/Akt crosstalk.
• This crosstalk mechanism is specific to fetal NP cells and not observed in adult NP cells or brain tumor cells.
• In vitro Erk inhibition led to sustained NP cell expansion while maintaining multipotency; in vivo administration reduced neuronal differentiation and increased progenitor cells in the embryonic cortex.

Conclusions:

• A novel pathway regulating NP cell proliferation in the developing brain, involving Erk/Akt signaling crosstalk, has been uncovered.
• Erk inhibition provides a pharmacological means for the in vitro expansion of fetal NP cells, preserving their multipotency.
• The findings offer a basis for manipulating NP cells in vivo, potentially advancing regenerative strategies for neurological disorders.