Foxm1 controls a pro-stemness microRNA network in neural stem cells

Area of Science:

• Neuroscience
• Stem Cell Biology
• Molecular Biology

Background:

• Cerebellar neural stem cells (NSCs) rely on Hedgehog-Gli (Hh-Gli) signaling for maintenance.
• Nanog expression is crucial for the self-renewal of these NSCs.

Purpose of the Study:

• To uncover novel molecular regulators of cerebellar NSC self-renewal.
• To elucidate the regulatory network controlling NSC maintenance and self-renewal.

Main Methods:

• Next-generation sequencing was employed to profile mRNA and microRNA expression in NSCs and differentiated NSCs (Diff-NSCs).
• Gene expression analysis identified key regulatory genes and microRNAs.
• Functional assays, including knockdown experiments, assessed the impact on neurosphere formation.

Main Results:

• Foxm1 was identified as a gene upregulated in NSCs, directly regulated by Gli and Nanog.
• Foxm1 was found to regulate specific microRNAs (miR-130b, miR-301a, miR-15~16, miR-17~92 clusters) overexpressed in NSCs.
• Knockdown of these microRNAs significantly impaired neurosphere formation ability.

Conclusions:

• A novel regulatory network, driven by Hh-Gli, Nanog, and Foxm1, controls cerebellar NSC self-renewal.
• This network involves specific microRNAs crucial for maintaining NSC self-renewal capacity.
• The findings provide new insights into the molecular mechanisms governing neural stem cell maintenance.