A study involving laboratory mice has found that a protein previously linked only to cell death plays a key role in wound healing. Humans with eczema have little of the protein caspase 8, while people with diabetes have an excessive amount. The UC San Diego researchers believe that their findings may reveal why diabetics do not have a normal wound response, and as a result, often have severe complications from simple wounds, such as cuts and scraps. They also said that it may explain why people suffering from eczema have chronic inflammation the compromises the skin’s protective ability.
“Not only does the loss of this protein, caspase 8, stimulate inflammation, which brings in a rush of cells designed to stop microbes from infecting the wound,” says Colin Jamora, an assistant professor of biology at UCSD who headed the research team. “But it also stimulates the production of stem cells that provide the materials to help close the wound. That’s important, because in the initial stages of a wound the protective barrier provided by the skin is broken and the internal body is exposed to microbes and environmental toxins.”
Jamora made the discovery by accident. According to reports, a colleague asked Jamora if he wanted to examine a genetically engineered mouse with unusually thick skin. The gene in the mouse epidermis responsible for the production of caspase 8 had been knocked out. “What was happening was not that the skin cells were living longer, but that the lack of caspase 8 was stimulating more skin cells to divide, which was unexpected,” says Jamora. “And when we looked further, we also found that there was inflammation going on in the skin of these mice. Those two things led us to suspect that the loss of caspase 8 can trigger a normal wound-healing response in the absence of any trauma to the skin.”
As a result of the findings, Jamora and his colleagues are now conducting a study on laboratory mouse models of human diabetes that produce excess amounts of caspase 8. Their goal is to find out if artificially reducing the production of the protein would restore a normal healing ability.
News Release: UC San Diego biologists discover a protein link to wound healing www.ucsdnews.ucsd.edu March 24, 2009
