Year 2

Aging is accompanied by a decline in the number and the function of adult stem cells in several tissues. In the brain, the depletion of adult neural stem cells (NSC) may underlie impaired cognitive performance associated with aging. Discovering the factors that govern the maintenance of adult NSC during aging should allow us to harness their regenerative potential for therapeutic purposes during normal aging and age-related neurodegenerative disorders. We have recently found that two ‘longevity genes’, Foxo3 and Sirt1, are critical for adult NSC function. In the past year, we have published a manuscript showing that Foxo3 is necessary for the maintenance of NSC in the adult brain. We have also started to explore the critical mechanisms by which Foxo3 maintains adult neural stem cells in the brain. We have used ultra-high throughput sequencing approach to reveal that Foxo3 is recruited to the regulatory regions of 3,000 genes in the adult neural stem cells, thereby triggering a gene expression network that regulates both the ability of neural stem cells to divide and their ability to give rise to progeny. Finally, we have obtained new results in the past year, showing that Sirt1, another ‘longevity gene’ is critical for the proper function of neural stem cells in the adult brain, and their ability to give rise to differentiated cells. Together, our results will help understand the regulation of neural stem cell maintenance in aging individuals and will provide new avenues to preserve the pool of these cells in the brain. Modulating longevity genes to harness the regenerative power of stem cells will provide new avenues for stem cell therapeutics for neurological and neurodegenerative diseases, most of which are age-dependent.