Department of Endodontics, Stomatological Hospital and Dental School of Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, No.399 Yanchang Middle Road, Jing'an District, Shanghai 200072, China.
Int J Mol Sci. 2024 Jan 17;25(2):1126. doi: 10.3390/ijms25021126.
Homeostatic maintenance is essential for pulp function. Disrupting pulp homeostasis may lead to pulp degeneration, such as fibrosis and calcifications. Sensory nerves constitute a crucial component of the dental pulp. However, the precise involvement of sensory nerves in pulp homeostasis remains uncertain. In this study, we observed the short-term and long-term histological changes in the dental pulp after inferior alveolar nerve transection. Additionally, we cultured primary dental pulp cells (DPCs) from the innervated and denervated groups and compared indicators of cellular senescence and cellular function. The results revealed that pulp fibrosis occurred at 2 w after the operation. Furthermore, the pulp area, as well as the height and width of the pulp cavity, showed accelerated reductions after sensory denervation. Notably, the pulp area at 16 w after the operation was comparable to that of 56 w old rats. Sensory denervation induced excessive extracellular matrix (ECM) deposition and increased predisposition to mineralization. Furthermore, sensory denervation promoted the senescence of DPCs. Denervated DPCs exhibited decelerated cell proliferation, arrest in the G2/M phase of the cell cycle, imbalance in the synthesis and degradation of ECM, and enhanced mineralization. These findings indicate that sensory nerves play an essential role in pulp homeostasis maintenance and dental pulp cell fate decisions, which may provide novel insights into the prevention of pulp degeneration.
牙髓的稳态维持对于其功能至关重要。破坏牙髓稳态可能导致牙髓退变，如纤维化和钙化。感觉神经是牙髓的重要组成部分。然而，感觉神经在牙髓稳态维持中的确切作用尚不清楚。在本研究中，我们观察了下牙槽神经切断后牙髓的短期和长期组织学变化。此外，我们培养了来自有神经支配和去神经支配组的原代牙髓细胞（DPCs），并比较了细胞衰老和细胞功能的指标。结果表明，术后 2w 时发生牙髓纤维化。此外，感觉神经去神经支配后，牙髓面积以及牙髓腔的高度和宽度均加速减小。值得注意的是，术后 16w 的牙髓面积与 56w 大鼠相当。感觉神经去神经支配诱导细胞外基质（ECM）过度沉积并增加矿化倾向。此外，感觉神经去神经支配促进 DPCs 衰老。去神经支配的 DPCs 表现出细胞增殖减慢、细胞周期 G2/M 期阻滞、ECM 合成和降解失衡以及矿化增强。这些发现表明，感觉神经在牙髓稳态维持和牙髓细胞命运决定中发挥重要作用，这可能为预防牙髓退变提供新的思路。
