Unlocking Tooth Repair: How Stem Cells Build New Teeth

Jenn Hoskins
27th June, 2025

Unlocking Tooth Repair: How Stem Cells Build New Teeth

Highlighting the spatiotemporal activation of the Hippo-YAP/β-catenin axis, the data demonstrates a progressive upregulation and co-expression of YAP and β-catenin proteins during the odontogenic differentiation of human dental pulp stem cells (a) and within the odontoblast layer of murine incisors (b), accompanied by the transcriptional elevation of these factors and downstream Wnt pathway targets (c).

Image adapted from: Chen et al. / CC BY (Source)

Key Findings

  • Researchers at The Second Xiangya Hospital, Central South University, found that two key cell signals, YAP and β-catenin, work together to guide dental stem cells to form new tooth dentin
  • Activating YAP boosts the growth of these stem cells and their ability to make dentin, while also increasing β-catenin, showing a crucial two-way communication between these signals for tooth repair
Damage to teeth, whether from cavities or trauma, often leads to significant pain and can result in tooth loss. While current dental treatments can repair damaged teeth, they typically involve artificial materials. A more ideal solution would be to regenerate the tooth's natural tissues, particularly the dentin and pulp, which are vital for tooth health and sensation. This is where dental pulp stem cells (DPSCs) come into play. These remarkable cells, found within the soft pulp of a tooth, possess the ability to develop into various cell types, including odontoblasts, which are responsible for forming dentin, the hard tissue beneath the enamel. Understanding how these stem cells are instructed to differentiate into dentin-forming cells is a critical step towards developing new regenerative dental therapies. Recent research conducted by The Second Xiangya Hospital, Central South University, has shed light on the intricate cellular mechanisms that govern the differentiation of human dental pulp stem cells (DPSCs) into dentin-producing cells[1]. This study focused on the interplay between two crucial cellular communication networks, known as signaling pathways: the Hippo-YAP pathway and the Wnt/β-catenin pathway. These pathways act like internal control panels, dictating cell growth, movement, and specialization. The Yes-associated protein (YAP) is a key component of the Hippo pathway, acting as a "transcriptional co-activator" – essentially, a helper molecule that turns on specific genes. It is known to interact with the Wnt signaling pathway, particularly with β-catenin, another important transcriptional co-activator[2]. The Wnt/β-catenin pathway itself is well-established for its role in guiding the differentiation of various mesenchymal stem cells (MSCs) – a broad category of cells that includes DPSCs – into bone-forming cells, similar to how DPSCs form dentin[3]. The current study aimed to understand how YAP and β-catenin coordinate their actions specifically within DPSCs to promote dentin formation. To investigate this, the researchers manipulated the activity of YAP and β-catenin in DPSCs in laboratory settings. They used methods to either boost or suppress YAP activity, and similarly, to reduce β-catenin levels or block the Wnt pathway. They then observed how these changes affected the DPSCs' ability to multiply, move, and undergo mineralization – the process of forming hard, dentin-like tissue. The findings were significant. Activating YAP in DPSCs not only enhanced their proliferation (growth) and migration but also significantly boosted their ability to differentiate into odontoblast-like cells, leading to increased mineralization. This was confirmed by observing higher levels of specific molecular markers associated with dentin formation, such as RUNX2, DSPP, DMP1, OCN, and ALP. Importantly, the study revealed a coordinated expression pattern between YAP and β-catenin during this differentiation process. When YAP was activated, the researchers also saw an increase in β-catenin and other components of the Wnt pathway. Conversely, when β-catenin was silenced or the Wnt pathway was inhibited, the positive effects of YAP on DPSC function were diminished, and YAP expression itself was suppressed. This suggests a reciprocal, two-way regulation between these two signaling pathways. To validate these laboratory findings, the researchers transplanted DPSC-seeded scaffolds into mouse models. They found that DPSCs with activated YAP successfully promoted the formation of dentin-specific markers and β-catenin in these living systems, whereas suppressing YAP hindered this process. These results highlight that the coordinated action of YAP and β-catenin signaling is crucial for driving the differentiation of DPSCs into dentin-forming cells. This understanding is a vital step towards "development-inspired regeneration"[4], an approach that seeks to mimic natural developmental processes to regenerate tissues. Just as mesenchymal stem cells naturally aggregate and differentiate during embryonic development to form organs like teeth, understanding these intrinsic cellular abilities can inform strategies for regenerative medicine. This research provides a deeper insight into the fundamental biology of stem cells and offers a potential target for future regenerative strategies aimed at reconstructing dentin and pulp tissues. Other ongoing research also contributes to this broader goal of optimizing the regenerative microenvironment for pulp-dentin complex engineering. For instance, studies have explored the use of exosomes – tiny vesicles released by cells – from DPSCs to facilitate regeneration, demonstrating their promising potential in reconstructing dentin-like tissue, vascular networks, and nerve structures[5]. By unraveling the complex interplay of internal cellular pathways, as demonstrated by the current study, and combining it with external biomimetic tools, scientists are steadily advancing towards effective natural tooth regeneration. While the precise molecular interactions between YAP and β-catenin still require further investigation, this study provides strong evidence for their collaborative role in guiding DPSC behavior for dentin regeneration.

MedicineBiotechBiochem

References

Main Study

1) The Hippo-YAP/β-catenin signaling axis coordinates odontogenic differentiation in dental pulp stem cells: Implications for dentin-pulp regeneration

Published 26th June, 2025

https://doi.org/10.1371/journal.pone.0326978

Related Studies

2) YAP‑mediated crosstalk between the Wnt and Hippo signaling pathways (Review).

https://doi.org/10.3892/mmr.2020.11529

3) miR-214 promotes periodontal ligament stem cell osteoblastic differentiation by modulating Wnt/β‑catenin signaling.

https://doi.org/10.3892/mmr.2017.7821

4) [Theory and practice of mesenchymal condensation directing tooth development and regeneration].

Journal: Zhonghua kou qiang yi xue za zhi = Zhonghua kouqiang yixue zazhi = Chinese journal of stomatology, Issue: Vol 59, Issue 5, May 2024

5) Odontogenic exosomes simulating the developmental microenvironment promote complete regeneration of pulp-dentin complex in vivo.

https://doi.org/10.1016/j.jare.2024.12.048


Related Articles

An unhandled error has occurred. Reload 🗙