Proteins are the compounds that are responsible for balancing and regulating all of the intricate chemical reactions that coordinate the biochemistry that goes on non-stop in each cell of the body. They are long strings, like links in a chain, of building blocks called amino acids hooked end to end. To become activated they must first be wrapped into a precise three dimensional structure. This brings together the functional components of the long protein molecule that bind specific compounds, place them together in an appropriate configuration, and manipulate chemical reactions. As cells age, these proteins lose their distinctive configurations. When this happens, other proteins unwind and then rewind around, or recycle, each of the functional proteins.

As part of the cellular repair and maintenance process, these repair proteins work like the recycling arm of the waste management company. They wrap around the misfolded proteins and enable them to be reconfigured in a functional fashion. The effective action of this system keeps cells young. When it goes awry, parameters of aging are accelerated.

Researchers at the University of Pennsylvania School of Medicine investigated this unfolding protein response (UPR) in sleep-deprived young and old mice. When nerve cells in the cerebral cortex were evaluated after a period of sleep deprivation, the UPR was appropriately active in the younger group but it failed to do its job in the older group. As a result, misfolded proteins built up within the cells. In addition, protein synthesis, rather than being down regulated, continued unabated thus complicating the situation. In addition, old sleep-deprived mice had more "cell death" proteins accumulate as well.

Thus, several protective neuronal mechanisms were found to be upset by sleep deprivation in the old mice. The first author of the paper that appeared in the June, 2008 issue of the Journal of Neuroscience, Nirinjini Naidoo, speculated that sleep disturbances in older humans might place an additional burden on an already stressed protein folding and degradation system. He suggested that future studies should examine whether interventions that augment key protective proteins will delay the effects of aging and reduce sleep disturbances.