Stem cells on a stress-busting diet

Knowing how an organism's tissues handle stress throughout life is key to understanding ageing and disease. Stems cells of the blood system seem to tackle metabolic stress by means of a process called autophagy. See Article p.323 Autophagy a double-edged sword This study in mice shows that the self-renewing haematopoietic stem cells (HSCs) that give rise to mature blood cells throughout life are protected from metabolic stress by an autophagy-mediated survival response triggered by the expression of the transcription factor FOXO3A. Thus at the same time as helping to maintain blood homeostasis by protecting adult HSCs, autophagy may indirectly contribute to the ageing of the blood system by allowing the survival of damaged, dysfunctional or transformed old HSCs, which are key actors in the development of age-related blood disorders.