The setup
Iida, Hayashi, and colleagues at Aichi Gakuin University in Nagoya report in Inflammation and Regeneration (volume 46, article 6, published 2026-01-27, doi:10.1186/s41232-025-00397-y, open access) a time-course study of angiogenesis in regenerated pulp-like tissue. The in vivo model is an ectopic root graft: a human permanent tooth root was cut to a 6 mm cylinder, the canal enlarged to 2 mm and emptied of pulp, then filled with a collagen mixture carrying conditioned medium from stem cells from human exfoliated deciduous teeth (SHED) at a final protein concentration of 10 micrograms per milliliter. The graft went into the abdominal cavity of 5- to 6-week-old male SCID mice and was harvested at days 3, 7, 14, and 21, with four mice per time point. Readouts are histology, immunostaining for Wnt10a, VEGF-A, and Tie-2, and qPCR of the regenerated tissue; there is no functional pulp test.
What the time course showed
Host cells migrated into the canal and built vessel-like structures on schedule. The area covered by lectin-positive vasculature was about 3% of the regenerated tissue on day 3, 12% on day 7, peaked at 14% on day 14, and settled near 10% on day 21. The molecular markers separated into two waves. VEGF-A was high on days 3 and 7, when many small microvessels appeared, and dropped significantly by day 14. Tie-2, a maturation marker, moved later, with its positive-cell rate rising significantly from days 3 and 7 to days 14 and 21, as microvessels consolidated into larger vessels. Wnt10a sat in the early wave: its share of lectin-positive cells peaked on day 7, and in the cell-influx region along the dentin wall the Wnt10a-positive rate rose through day 14 and fell significantly by day 21, back to the day-3 level. At the transcript level in whole graft tissue, Wnt10a was highest on day 14 and significantly below the day-3 baseline by day 21, while beta-catenin and VEGF-A stayed significantly above normal pulp levels at every time point.
What the dish experiments added
To isolate the angiogenesis signal from the mixed tissue in a graft, the group induced vascular differentiation of SHED on Matrigel in VascLife medium. In the early window (0 to 48 hours), Wnt10a transcript rose 4.2-fold by 48 hours, VEGF-A rose 4-fold at 24 hours and 9.4-fold at 48 hours, beta-catenin rose 2.6- and 2.1-fold, and Tie-2 rose 3.7-fold by 48 hours. The Wnt10a protein told a humbler story: it was so low it was essentially flat, detectable only by ELISA, which the authors take as the reason gene expression, not protein level, carries the dynamic signal. Over a 21-day maturation course, Wnt10a transcript peaked around day 7 at roughly 4.7-fold over day 3, dipped at day 14, and returned by day 21, mirroring the rise-then-fall pattern seen in the grafts.
Boundary of the result
Everything in vivo is a human root segment sitting in a mouse abdomen, four animals per time point, with host cells doing the regenerating; nothing is tested in a jaw. The study is descriptive: no Wnt10a blockade or knockdown was done, so the finding that Wnt10a tracks early angiogenesis does not show it drives angiogenesis. The authors themselves note that Wnt10a in this same model system is also tied to odontoblast differentiation, so the day-14 transcript peak in whole graft tissue likely mixes signals from more than one cell population. The biomarker proposal is a hypothesis at this point: a low-abundance, transient signal is the hardest kind to operationalize as a clinical readout.
What it changes for the program
For the pulp-dentin-repair program, the value is a staging map. If pulp regeneration replays development on a schedule, as this group’s earlier work argues, then a cheap temporal marker of where a graft sits between microvessel formation and vessel maturation is genuinely useful for comparing protocols, especially cell-free approaches built on SHED conditioned medium. The same pathway connects to the flagship question from the other direction: in people, loss-of-function mutations in Wnt10a cause congenitally missing teeth, and the anti-USAG-1 program aims at the Wnt/BMP axis to induce a third dentition. This paper adds nothing to that effort directly, but it sharpens the picture of how tightly Wnt signaling is clocked when dental tissue rebuilds itself.
Provenance: grounded in the open-access full text of Iida N, Hayashi Y, Futenma T, Sakatoku S, Sugita Y, Nakamura K, Nawa H. Wnt10a exhibit spatiotemporal singularity in the temporal changes of angiogenesis in regenerated pulp-like tissue. Inflammation and Regeneration. 2026;46:6. doi:10.1186/s41232-025-00397-y, retrieved as PMC12836903 and read in full. Method and sourcing standard at /method/.