Chronic sleep loss sensitizes Drosophila melanogaster to nitrogen stress

Chronic sleep loss profoundly impacts metabolic health and shortens lifespan, but studies of the mecha-nisms involved have focused largely on acute sleep deprivation.1,2 To identify metabolic consequences of chronically reduced sleep, we conducted unbiased metabolomics on heads of three adult Drosophila short-sleeping mutants with very different mechanisms of sleep loss: fumin (fmn), redeye (rye), and sleepless (sss).3-7 Common features included elevated ornithine and polyamines, with lipid, acyl-carnitine, and TCA cy-cle changes suggesting mitochondrial dysfunction. Studies of excretion demonstrate inefficient nitrogen elimination in adult sleep mutants, likely contributing to their polyamine accumulation. Increasing levels of polyamines, particularly putrescine, promote sleep in control flies but poison sleep mutants. This parallels the broadly enhanced toxicity of high dietary nitrogen load from protein in chronically sleep-restricted Drosophila, including both sleep mutants and flies with hyper-activated wake-promoting neurons. Together, our results implicate nitrogen stress as a novel mechanism linking chronic sleep loss to adverse health out-comes-and perhaps for linking food and sleep homeostasis at the cellular level in healthy organisms.

Automated summary

Chronic sleep loss has significant effects on metabolic health and lifespan. The metabolic consequences of chronically reduced sleep were investigated in three adult Drosophila short-sleeping mutants. The results suggest that nitrogen stress could be a mechanism linking chronic sleep loss to adverse health outcomes and potentially connecting food and sleep homeostasis at the cellular level in healthy organisms.