A Spanish research team, led by a Brock University researcher, has uncovered a key link between oxidative stress, aging and chronic diseases.

Professor of Health Sciences Newman Sze and his team found that oxidative stress plays a critical role in altering an amino acid in proteins called cysteine.

The change creates a harmful trioxidized cysteine product, which contributes to tissue degeneration by interfering with a crucial process called protein phosphorylation. This process regulates essential cell functions and normal bodily activities, says Sze.

“This discovery opens doors to new research areas, deepening our understanding of how and why oxidative stress causes damage to vital proteins, ultimately leading to chronic, age-related diseases,” says Sze, Canada Research Chair in Mechanisms of Health and Disease. “This breakthrough could pave the way for innovative treatment to extend the human healthy lifespan.”

Oxidative stress occurs as a result of the body using oxygen to burn molecules from food for energy, leading to the production of reactive oxygen species (ROS).

The body is able to counteract the toxic effects of ROS up to a point, says Sze, but unhealthy environments and poor lifestyle choices can exacerbate oxidative stress.

Cysteine, an essential amino acid in proteins, plays a critical role in sensing oxidative stress and signalling cells to detoxify ROS in the body. However, when cysteine undergoes trioxidation, it not only loses its detoxification function but also acquires new harmful functions.

Sze’s research revealed that the chemical structure of trioxidized cysteine closely resembles the phosphate group involved in protein phosphorylation.

The similar chemical structure between trioxidized cysteine and the phosphate group connects oxidative stress to age-related diseases such as diabetes, heart disease and dementia.

“When trioxidized cysteine hijacks phosphorylation, it alters the normal physiology of our bodies, harming our health and causing diseases,” he says.

Sze says this is the first time a connection has been made between oxidative stress and abnormal signalling in protein phosphorylation.

“This knowledge can be harnessed to detect and measure oxidation levels in the body, offering a potential clinical marker for assessing the risk of developing certain diseases associated with aging,” he says. “It also holds promise for the exploration of new anti-aging treatment methods.”

Sze says the research also shows the need for people to maintain a healthy lifestyle of eating nutritious and unprocessed foods, exercising, not smoking, protecting against radiation from the sun and taking other steps to reduce oxidative stress levels in their bodies.

The study, “Trioxidized cysteine in the aging proteome mimics the structural dynamics and interactome of phosphorylated serine,” was published last month in the key aging research journal Aging Cell.