A Sudden Switch to Declining Proteostasis in Nematodes
These researchers propose that declining proteostasis with aging is something that starts abruptly in nematode worms, which they take as evidence for programmed aging - such as perhaps a coordinated lapse or other unfavorable change in cellular housekeeping and stress response mechanisms has evolved to occur comparatively early in life in this species:
Protein aggregation is associated with many age-related disorders, and increased protein oxidation, mislocalization, and aggregation are observed in aged organisms. Intuitively, these findings can be explained by a gradual decline in protein biosynthetic and quality control pathways and a progressive accumulation of protein damage. However, recent findings in Caenorhabditis elegans challenge this view, suggesting that a decline in proteome integrity may be the result of early programmed events rather than the consequence of a random and gradual accrual of molecular damage.Here, we propose, from studies in Caenorhabditis elegans, that proteostasis collapse is not gradual but rather a sudden and early life event that triggers proteome mismanagement, thereby affecting a multitude of downstream processes. Furthermore, we propose that this phenomenon is not stochastic but is instead a programmed re-modeling of the proteostasis network that may be conserved in other species. As such, we postulate that changes in the proteostasis network may be one of the earliest events dictating healthy aging in metazoans.
One possible interpretation of the results -
Aging stems from the cessation of programmed protein quality control.
Perhaps, the distinction between the "damage accumulation" versus "programmed" theories of aging is only semantic.