Skin aging begins with a damaged antioxidant protein
Skin does not age solely because of the sun or smoking. Deep inside skin cells, a protein that normally prevents damage becomes damaged itself. That sets off a chain of events that is difficult to stop.
Cells constantly produce reactive oxygen species (ROS) as a byproduct of their metabolism. Normally, an enzyme called SOD1 keeps these in check. But with aging, SOD1 can itself be damaged through oxidation. It then becomes not only inactive, but may also form toxic protein species. The researchers describe how this initiates a chain reaction in skin cells: more oxidative damage, more disrupted proteins, and less capacity for self-repair.
A vicious cycle in skin cells
The core of the finding is a two-way relationship between protein quality control (proteostasis) and mitochondrial function. When SOD1 fails, damaged proteins accumulate. That accumulation disrupts the mitochondria (the cell’s energy-generating structures). Disrupted mitochondria in turn produce more ROS. And more ROS damages more SOD1. The problem thus reinforces itself.
In skin cells, this process is especially relevant because the skin is continuously exposed to external oxidative stress, such as UV light and air pollution. The review study, published in the journal Ageing Research Reviews, carefully distinguishes between what has been directly demonstrated in skin cells and what has been extrapolated from research in other tissues. That is an important caveat: not all findings apply equally to every skin cell type.
Wrinkles as the outcome of cellular chain reactions
The visible signs of skin aging (wrinkles, reduced elasticity, impaired barrier function) result from changes in the extracellular matrix, the network of proteins between cells. Those changes are driven by the chain reactions occurring inside the cell. This suggests that skin aging is more deeply rooted than surface wear, and that antioxidant strategies may be more effective when targeted at specific enzymes like SOD1 rather than general antioxidants alone.
Clinical studies demonstrating whether protecting or restoring SOD1 activity actually slows visible skin aging are still lacking.
Search terms for further research: SOD1 oxidative modification skin cells, proteostasis mitochondrial dysfunction aging, reactive oxygen species skin aging