Dentists have long observed that wounds in the mouth heal roughly twice as fast as wounds on the skin and leave fewer scars. Medical researchers have now found the mechanism by which this happens opening avenues to find new clinical ways of treating external injuries.
The research team from the University of Pennsylvania had previously established that the gums, also known as gingiva, are made up of mesenchymal stem cells. Stem cells are undifferentiated cells that can give rise a variety of cell types and have a lot of therapeutic use. In addition, gingival mesemchymal stem cells release a number of proteins. In the new study the team looked into whether these proteins aid accelerated wound healing.
Mesenchymal stem cells perform many of their functions by releasing signaling molecules in small extracellular bodies called vesicles. The study began by comparing extracellular vesicles between gingival cells and skin cells. The researchers found that gingival mesenchymal stem cells contain more proteins, including IL-1RA that helps reduce inflammation by blocking a proinflammatory cytokine. This protein is used already used to treat rheumatoid arthritis.
The team then found that gingival cells had more of a protein called Fas than skin cells. Fas forms a complex with other proteins that triggers the release of extracellular vesicles and so the increase in IL-1RA in gingival cells. They also found that the margins of wounds in the gingival mesenchymal stem cells had higher levels of IL-1RA. In their mouse experiment, the observed that mice lacking IL-1RA or in which the protein was inhibited took longer to heal gingival wounds. In contrast, when the researchers isolated IL-1RA that had been secreted from GMSCs and injected it into wounds, it significantly accelerated wound healing.
The study that has been published in the journal Science Translational Medicine, has may have special significance in treating diabetes in which a major complication is delayed wound healing. The research team also thinks that the finding can be used to treat other inflammatory and autoimmune diseases and be used to reduce scar formation, improve wound healing, and even treat many inflammatory and autoimmune diseases.