Have you ever wondered why scars rarely form in the mouth? Researchers at Penn Dental Medicine have pondered this very question, and they are on their way to finding the answer.
“Oral tissues exhibit remarkably regenerative properties, unlike many other organs in the human body,” says Dr. Kang Ko, assistant professor in the department of periodontics. “The goal is to understand the cellular and molecular mechanism by which this occurs in the oral cavity, with the hope of employing therapeutics to enhance oral soft and hard tissue healing, as well as translating these unique healing properties to other body parts to promote regeneration over repair.”
To get a better handle on the exceptionally accelerated wound healing in the oral cavity, Ko’s lab is investigating different populations of oral fibroblasts. These types of cells form connective tissue, and work from Ko’s studies is revealing they may play important roles in the wound healing process.
In a Journal of Experimental Medicine paper, the researchers reported finding a unique subset of oral fibroblasts that is primed to promote rapid wound healing. The team studied what happens to wounds in mice in two different parts of the palate—the front, or anterior, region that heals rapidly and the back, or posterior, palate that heals more slowly. In the study, they identified a distinct population of cells called paired-related homeobox-1+ (Prx1+) fibroblasts in the anterior palate that are missing from the posterior section, and they showed that these cells are responsible for the quick wound healing observed in the mouth. Transplanting these cells to the posterior palate sped up healing, and deleting the cells in the anterior section delayed the process. In human gingival samples, these Prx1+ fibroblasts were in the same locations and expressed the same genes.
The results support an emerging concept that fibroblasts are actively involved in supporting the body’s immune response, contrasting with the traditional view that these cells are featureless building blocks for maintaining structure.
“The potential of this finding is significant not only for periodontal regeneration—for instance, the ability to take grafts from tissues enriched with pro-healing fibroblasts—but also for its implications in other parts of the body that heal sub-optimally,” said Ko. “Regeneration over scar formation in response to injury is a huge topic.”
