Cross-talk among odontoblasts, dental pulp stem cells, and immune cells after exogenous injuries

使用小鼠牙齿再植的体内模型，我们评估了两种类型的合成CpG ODNs溶液：A型（D35，MW：6327.33）和B型（K3，MW：6349.37）对患病牙髓愈合过程的影响。通过在再植后1小时和再植后24小时使用FITC缀合的CpG ODN溶液证实这些溶液在牙髓组织中的渗透，而其强度没有变化。为了评估最合适的条件，我们测试了三种不同浓度：10 mg/ml（1.57 mM）、0.63 mg/ml（0.1 mM）和5 mg / ml（0.8 mM）的每种类型的CpG ODN溶液。Nestin免疫组化定量分析显示，0.1 mM A型和B型CpG ODNs溶液有利于术后2周牙髓组织的愈合，特别是B型。相反，1.25 mM的两种CpG ODN诱导牙髓中巢蛋白阴性硬组织区域的最高比率，表明骨样组织形成的增加。与对照组相比，用低浓度CpG-ODNs溶液处理显著降低了牙髓中增殖细胞的速率，其在第2周恢复。从牙齿再植后的牙髓样品获得的初步体外数据显示，成牙本质细胞分化（巢蛋白mRNA）持续诱导的CpG ODN类型B从第1-5天。骨相关标志物（骨钙素mRNA）在再植后第3天表达也增加。

Using an in vivo model for tooth replantation in mice, we have assessed the effects of two types of synthetic CpG ODNs solutions: Type A (D35, MW:6327.33) and Type B (K3, MW:6349.37) on the healing process of the afflicted dental pulp. The penetration of these solutions in the pulpal tissue was confirmed by using an FITC-conjugated-CpG ODN solution one hour after replantation and 24 hours after replantation without variations on its intensity. For the assessment of the most suitable condition, we tested three different concentrations: 10 mg/ml (1.57 mM), 0.63 mg/ml (0.1 mM) and 5 mg / ml (0.8 mM) for each type of CpG ODN solution. Quantitative analysis of Nestin immunohistochemistry showed that 0.1 mM Type-A and -B CpG ODNs solutions favored the healing of the pulpal tissue two weeks after operation, specially Type B. Conversely, the 1.25 mM of both CpG ODNs induced the highest rate of Nestin-negative hard tissue areas in the dental pulp, suggesting an increase in bone-like tissue formation. The treatment with low-concentration CpG-ODNs solution drastically reduced the rate of proliferative cells in the dental pulp, which is reverted at Week 2, when compared to control groups. Preliminary in vitro data obtained from pulp samples following tooth replantation showed that odontoblast differentiation (Nestin mRNA) is sustainedly induced by CpG ODN type B from days 1-5. Bone-related marker (Osteocalcin mRNA) also increased its expression at day 3 following replantation.