FoxOs cooperatively regulate diverse pathways governing neural stem cell homeostasis.

Area of Science:

• Neuroscience
• Cell Biology
• Genetics

Background:

• The PI3K-AKT-FoxO pathway regulates lifespan in simpler organisms.
• This pathway is vital for long-lived cell stability in mammals.
• The role of FoxO transcription factors in mammalian brain development is not fully understood.

Purpose of the Study:

• To investigate the impact of combined FoxO1, 3, and 4 deficiencies on mammalian brain physiology.
• To specifically examine the role of FoxO factors in the neural stem/progenitor cell (NSC) pool.

Main Methods:

• Analysis of FoxO1, 3, and 4 deficient mice.
• Study of neural stem/progenitor cell proliferation and renewal.
• Integrated transcriptomic, promoter, and functional analyses of FoxO-deficient NSC cultures.

Main Results:

• FoxO-deficient mice exhibit increased brain size and neural progenitor cell proliferation in early life.
• A precocious and significant decline in the NSC pool and neurogenesis is observed in adult FoxO-deficient brains.
• Identified direct gene targets of FoxO factors linked to human brain size, cell proliferation, differentiation, and oxidative defense.

Conclusions:

• The FoxO family plays a critical role in regulating NSC homeostasis in the mammalian brain.
• FoxO factors coordinate diverse genes and pathways essential for NSC proliferation, renewal, and function.
• Understanding FoxO regulation is key to comprehending mammalian brain development and aging.