Keratins are proteins that are key structural components of hair, nails, and the skin’s outer layer. Now, new research led by Maria Morasso, Ph.D., chief of the Laboratory of Skin Biology at the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), has shown that certain types of hair keratin also help form dental enamel, the tough outer covering of teeth. The study appeared online October 27, 2014, in The Journal of Clinical Investigation.
Following up on an observation in mice suggesting that some types of hair keratin are also produced in developing teeth, Morasso’s team set out to uncover the role these proteins play in tooth structure. The researchers focused on one of these proteins, keratin 75, because mutations in its gene had been linked to certain hair disorders, such as shave bumps, a condition in which shaving causes ingrown hairs and persistent skin irritation.
Curious if these same mutations would also affect the integrity of tooth enamel, Morasso’s team, in collaboration with investigators at the University of Pittsburgh, examined the teeth of 706 adults and 386 children and found that the mutations in keratin 75 correlated with increased numbers of cavities. Further investigation revealed evidence of altered enamel structure and reduced enamel hardness in people with one of these mutations, suggesting that keratin 75 plays an important role in enamel formation.
By uncovering a role for hair keratins in dental enamel structure, this work may lead to new strategies for combating tooth decay, one of the most prevalent health problems worldwide.
This work was supported by the NIAMS intramural program under project number ZIAAR041171-07. Support was also provided by the NIH’s National Institute of Dental and Craniofacial Research (grants R01-DE014899, U01-DE018903 to M. Marazita and R56-DE016703 to E. Beniash).
Duverger O, Ohara T, Shaffer JR, Donahue D, Zerfas P, Dullnig A, Crecelius C, Beniash E, Marazita M, Morasso MI. Hair Keratin Mutations in Teeth Increase Risk for Dental Caries. JCI 2014 Oct 27 Vol (issue): pp-pp
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