A protein that helps build teeth may one day be used to allow damaged teeth to repair themselves.
That possibility is the focus of research led by Anne George , professor in the Department of Oral Biology at the UIC College of Dentistry. George has received a $1.2 million grant from the National Institute of Dental and Craniofacial Research at the National Institutes of Health to advance her studies of dentin phosphophoryn.
Dentin phosphophoryn is mainly found in dentin, which is the mineralized tissue that makes up the bulk of each tooth under its enamel surface. The most acidic protein known in nature, and it helps in the calcification of the protein matrix to form dentin.
"It is amazing how the dentin-forming cells called odontoblasts and the adult dental pulp stem cells survive in the calcium-rich tooth environment," George said. "We think this protein may serve as a protective mechanism for cell survival. We want to understand how it helps protect those cells and preserve their regenerative capacity to allow them to continue forming healthy tooth tissue, during the life of the tooth."
In the newly funded project, George and her team will focus on dentin phosphophoryn's role in autophagy, a cellular process and protective mechanism. "Autophagy is like garbage collection," George said. It removes old or damaged parts of the cell and recycles their components.
In the dental pulp, the soft, living center of the tooth, autophagy could serve an essential protective role during inflammation and injury. Though calcium is essential for building mineralized tissues such as teeth and bone, it can also place cells under significant stress. George and her team believe dental phosphophoryn helps pulp stem cells manage that stress, survive and ultimately develop the cells responsible for producing dentin.
Studying how these cells adapt to stress could open new avenues for regenerative dental treatments.
"We are trying to understand if we can use these proteins to regrow dentin," George said.
Current dental treatments are focused on removing defects, like cavities, and stopping them from spreading, George said.
"But during the process of drilling, you're removing cells in the dental tissue and pulp and putting a synthetic cap on top of that. It is no longer a live tooth," George said. "What we are trying to do is use these proteins in a scaffold in the dental cavity to regrow dentin, have a living matrix that can stop cavity propagation and retain tooth function."
George and her colleagues will combine studies in human dental pulp stem cells with animal models designed to investigate the molecular pathways that control autophagy and tissue regeneration.
The project continues George's studies of biomineralization, the biological process that creates mineralized tissues like teeth and bones. Her work has revealed the key role of several proteins, including dentin matrix protein 1, which helps calcium phosphate crystal formation during mineralization and can stimulate the growth of new blood vessels.
"These proteins are not only structural proteins, but they are signaling molecules, too," George said. "They can communicate with other cells in the vicinity, turn on transcription factors and transfer material."
Sustained support from the National Institutes of Health has enabled George's lab to pursue complex scientific questions over many years while training graduate students, postdoctoral researchers and clinician-scientists, she said. UIC's dental and doctoral dual-degree programs expose future dentists to the scientific foundations of oral health, George added.
The new project also builds on nearly three decades of George's research at the UIC College of Dentistry.
"From the time I joined UIC in 1998, both the department and the college administration supported me to pursue my scientific quest without interruptions or interference," she said.
