Aging is considered a major risk factor for many diseases, including cancer, cardiovascular disorders, diabetes and neurodegenerative diseases. So anti-aging or healthy aging is a significant scientific question to be solved.

Aging is tightly associated with redox events. Most studies about redox and aging focused on the static status of redox and oxidative stress is regarded as damage effect. There has been little research investigating different dynamic responses to redox challenge between young and old organisms.

A new study conducted by Prof. CHEN Chang at the Institute of Biophysics (IBP) of Chinese Academy of Sciences has proposed a new concept of 'Redox-stress Response Capacity (RRC)', which demonstrated that decay of this dynamic capacity is the substantive characteristic of aging. The study was published online in Redox Biology.

In the study, researchers used C. elegans and human fibroblast senescence cells as models to compare the differential response to oxidative challenge between the young and the old. The results showed that compared with the old worms or senescent cells, the young could generate more reactive oxygen species (ROS) to activate Erk and Akt signal pathways in response to redox stress.

Moreover, the young individuals could induce more antioxidant enzymes through promoting the translocation of NRF2 to maintain the redox homeostasis. The young worms or cells also showed better ability to degrade the oxidative damaged proteins through up-regulating chaperone expression and improving the proteasome activity.

Based on the results, they proposed the new concept RRC, which includes the ability to generate ROS/RNS to activate cellular signaling, the ability to activate the antioxidant system and the ability to degrade the damaged proteins. This is the first comprehensive description of response capacity to redox stress and also the first direct scientific evidence to show the essential difference between young and old.

Different from the traditional redox theory of aging, in which ROS is considered as a marker indicative of the degree of aging, their findings demonstrate the decay of RRC is a substantive characteristic of aging.

This work was supported by the National Natural Science Foundation of China, National Key Research and Development Program, and the "Personalized Medicines——Molecular Signature-based Drug Discovery and Development", Strategic Priority Research Program of the Chinese Academy of Sciences.

Figure: The model of Redox-stress Response Capacity (Image by IBP)