The transplantation or loss of healthy hypothalamic stem cells may slow down or accelerate ageing, respectively, suggests a study in mid-aged mice published online in Nature this week. Although it is known that the nervous system has a role in ageing, and recent research has demonstrated that the hypothalamus is particularly important, the exact process, which leads to the physical signs of ageing, is still unknown. Further research is needed to determine whether these effects may also apply to humans.
Adult neural stem cells (NSCs) reside in a few brain regions, notably in the hypothalamus, to mediate neurogenesis - the formation of neurons - and several aspects of brain function. A decrease in neurogenesis is known to correlate with ageing-associated disorders.
Supported by their recent work showing that the hypothalamus has a role in causing systemic ageing, Dongsheng Cai and colleagues studied whether hypothalamic NSCs might be responsible for this process using several mouse models. By inducing the loss of specific stem cells in mice, the authors observed accelerated, ageing-like physiological changes or a shortened lifespan. Conversely, ageing was slowed and longevity was achieved in mid-aged mice implanted with healthy cells. The authors also reveal that the anti-ageing effect of hypothalamic NSCs is partially mediated by exosomal microRNAs, which these cells secrete into the cerebrospinal fluid. The authors conclude that loss of hypothalamic NSCs is an important cause for the whole body’s ageing, an understanding that reinforces their original hypothesis.