Aging nasal cells show early signs of impaired protein upkeep
In 213 healthy volunteers aged 2–97, nasal-cell signs of impaired protein upkeep appeared from 40, while damage at protective chromosome tips appeared almost exclusively after 80.
Cohort study
Limit: No single marker definitively identifies senescent cells
Stake: Cancer Research UK funded the study.
Edited by Boris Djordjevic · AgingResearch.News
Researchers conducted an observational study of nasal lining cells brushed from 213 healthy volunteers aged 2–97, including 117 females and 96 males. They also examined lung tissue from 20 organ donors.
Telomeres, protective chromosome tips, shortened with age in both systems. Signs of damage at these tips increased in the lung airway lining only after age 75. In nasal cells, such damage was rare and appeared almost exclusively after 80. By contrast, signs of impaired protein upkeep were apparent from age 40 in nasal cells and were linked to a poorer sense of smell. These signs included greater activity of an enzyme associated with senescence, a state in which cells stop dividing, and increased amounts of lysosomes, the cells’ waste-processing compartments.
Why it matters
Cell senescence contributes to age-related diseases. The authors suggested that protein stress may play a more prominent role than telomere dysfunction in this process in the respiratory tract.
Caveats
The cross-sectional comparisons cannot establish cause and effect, and no single marker definitively identifies senescent cells. The nasal findings do not establish the same patterns in people with recent upper respiratory infections or a history of chemotherapy or radiotherapy, whom the study excluded.
