Scientist are aware of some of what occurs in the brain when we age, for example it is known that neurons and other brain cells deteriorate and die and will be replaced by new ones, the process is facilitated by a stem cell called neural stem progenitor cells that with age become less functional causing the brain to produce fewer neurons.What causes neural stem progenitor cells to age and what molecular changes are responsible for impairment in the stem cells is not known. To find the reasons researchers investigated the entire genome of mice.
Genetic changes in neural stem progenitor cells in old mice and young mice were compared, which resulted into identifying upwards of 250 genes that had changed behaviour over time, meaning that these genes may be likely to cause neural stem progenitor cells to malfunction. The search was narrowed to 250 genes which brought to attention increased activity in gene Dbx2 that seemed to change aged neural stem progenitor cells.
Performing in vitro and vivo assays revealed boosting activity in the gene in young neural stem progenitor cells makes them behave more like old stem cells. Increasing activity of Dbx2 stopped neural stem progenitor cells from growing older or proliferating as young cells should. In older neural stem progenitor cells changes in epigenetic marks were identified that may possibly explain why the stem cells deteriorate over time. Scientist were able to find how these marks are placed in the genome telling neural stem progenitor cells to grow more slowly.
Studying Dbx2 genes has shown that the changes may contribute to brain aging. Genes and gene regulator identified are corrupted in neural stem progenitor cells in older mice. Gaining a better understanding of how aging affects the brain will help to identify ways to target neural stem cell decline, finding methods to slow or even reverse brain deterioration, helping to retain mental agility for longer periods into old age.
