A multipurpose protein found in saliva may promote the healing of abnormal skin wounds, say National Institute of Dental and Craniofacial Research scientists.
In the October issue of Nature Medicine, researchers described how they developed a new animal model that mimics the major components of non-healing wounds. Using mice without the gene for the protein secretory leukocyte inhibitor, or SLPI, they found that the protein plays a critical role in wound healing.
The "knockout" mice showed markedly impaired skin wound healing and had increased inflammation and activity of the enzyme elastase, which destroys tissue. When researchers topically applied SLPI to the wounds, they found that it reversed tissue destruction and hastened healing.
SLPI can be found in fluids that bathe the mucosal surfaces such as saliva, bronchial fluids and cervical fluids. It also has anti-inflammatory, antiviral, antifungal and antibacterial properties. In recent years, NIDCR investigators have demonstrated that SLPI found in saliva blocks HIV-1 infection.
Researchers also noted that the fact that animals tend to lick their wounds may be nature’s way of delivering SLPI to the wound site via saliva.
"SLPI appears to be a component of innate or natural host defense that maintains a balance between protective inflammatory responses and overzealous or uncontrolled inflammation that can lead to tissue destruction and failure to heal," explained Sharon Wahl, Ph.D., the study’s principal investigator and chief of NIDCR’s Oral Infection and Immunity Branch.
Researchers say they plan to conduct a clinical trial to test SLPI as a treatment for delayed healing of skin wounds in the elderly. They also suggest that findings from their current study may be extended to other conditions that involve excessive elastase activity, such as gingivitis and bullous pemphigoid.
