‘Bad’ molecules found to be good for wound healing

Molecules long thought to be destructive of tissues and cells actually play a key role in the wound-healing process, according to a recent discovery by researchers in California.

The study, led by Andrew Chisholm, Ph.D., professor of biology at University of California, San Diego, concludes that reactive oxygen species (ROS) - also called free radicals, chemically reactive molecules containing oxygen - are necessary for the proper healing of skin wounds in the laboratory roundworm C. elegans. Indeed, the researchers found that ROS generated in the mitochondria not only are necessary for skin wounds to heal, but that higher levels of it speed up the process.

“There are many ways you can generate ROS in the cell, but no one had looked in the mitochondria in detail,” said Dr. Chisholm, who conducted the study with Suhong Xu, a postdoctoral fellow in his laboratory. “Our discovery was surprising because we didn’t realize that mitochondria were playing these roles in wound healing.”

ROS are known to damage DNA, RNA and proteins, and because such damage is thought to contribute to premature aging and cancer, many people take antioxidants to minimize it. According to the researchers, though, while too much ROS in the cell may be bad, eliminating ROS altogether - in roundworms, anyway - prevents wound healing. The researchers note that while their study focused on roundworms, they are confident the results would apply to higher animals and plan future experiments with rodents.

“Although C. elegans roundworm skin differs in many ways from human skin, ROS-like superoxides have been observed at skin-wound sites,” Dr. Chisholm tells Dermatology Times. “It would be interesting to test whether mild elevation of ROS could have beneficial effects in wound healing. Elevated ROS levels might also be relevant to understanding the efficacy of hyperbaric oxygen therapy.”

The authors say their discovery could help in the development of new pharmaceuticals to treat the elderly and diabetics, who often have ongoing wound-healing issues.

Study results were published in the Oct. 13 issue of the journal Developmental Cell.