Tiny RNA, Big Impact: How microRNA-27a Could Boost Tooth and Bone Regeneration
A new study from Japan has uncovered how a small molecule, microRNA-27a, can help dental stem cells repair teeth and bone—paving the way for future regenerative therapies.
Why Teeth Sometimes Need Help to Heal
When tooth decay or injury reaches the pulp—the innermost soft tissue of the tooth—it often triggers painful inflammation. If left untreated, this can spread to the bone surrounding the root, causing further damage. While the body has some natural capacity to heal, large defects in dental or craniofacial bone usually require grafts or implants.
Stem cells from dental pulp (the living tissue inside teeth) have long been recognized as promising “seed cells” for tissue engineering. However, researchers are still looking for ways to guide these cells to reliably form new dentin and bone.
Enter microRNA-27a: A Tiny Molecular Switch
MicroRNAs are short strands of genetic material that help control how cells behave by turning certain genes on or off. In this study, scientists focused on microRNA-27a (miR-27a), which was found to be highly active in dental pulp stem cells under inflammatory conditions.
The team wondered: could boosting miR-27a push dental pulp stem cells to become bone- and dentin-forming cells more efficiently?
What the Researchers Did
Scientists at Tokyo Medical and Dental University cultured human dental pulp stem cells from extracted wisdom teeth. They then artificially increased (or suppressed) miR-27a levels in these cells.
In the lab (in vitro): Cells with extra miR-27a showed stronger signs of turning into dentin- and bone-forming cells. They produced more mineralized nodules and expressed higher levels of key bone markers.
How it works: miR-27a suppresses two genes—DKK3 and SOSTDC1—that normally block the Wnt and BMP signaling pathways. These pathways are essential for bone and tooth development.
In live animals (in vivo): When the modified stem cells were implanted into tiny bone cavities in mice, they formed significantly more bone-like tissue compared to controls.
Why This Matters
The findings suggest that miR-27a acts as a molecular accelerator for dental pulp stem cells, pushing them toward tooth and bone repair. This opens the door to potential miRNA-based regenerative therapies—not only for repairing teeth damaged by decay or trauma, but also for broader craniofacial bone reconstruction.
Such approaches could one day reduce the need for traditional bone grafts, which are often limited by supply and risk of rejection.
Looking Ahead
While the results are promising, researchers caution that more work is needed before miR-27a can be translated into clinical treatments. Future studies must address safety, delivery methods, and how best to combine miRNA therapy with scaffolds and biomaterials.
Still, this study marks an exciting step forward in regenerative dentistry and bone repair—showing how a microscopic RNA molecule could make a macroscopic difference in oral health.
DOI: https://doi.org/10.1186/s12967-025-06208-9
Original Article: Yu, Z., Kawashima, N., Sunada-Nara, K., Wang, S., Han, P., Kieu, T.Q., Ren, C., Noda, S., Tazawa, K., & Okiji, T. (2025). MicroRNA-27a transfected dental pulp stem cells undergo odonto/osteogenic differentiation via targeting DKK3 and SOSTDC1 in Wnt/BMP signaling in vitro and enhance bone formation in vivo. Journal of Translational Medicine, 23:189.