Department of Operative Dentistry and Endodontics, Guanghua School and Hospital of Stomatology and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China.
J Endod. 2012 Dec;38(12):1592-7. doi: 10.1016/j.joen.2012.09.023. Epub 2012 Oct 18.
One of the best-characterized Nod-like receptor (NLR) family members is pyrin domain containing 3 (NLRP3). Intracellular NLRP3 is the most versatile innate immune receptor. On activation, NLRP3 assembles into a multiprotein complex, termed an inflammasome, which regulates the secretion and bioactivity of interleukin-1 family cytokines. NLRP3 has broad specificity for mediating an immune response to a wide range of microbial stimuli or danger signals. Therefore, we hypothesize that NLRP3 plays an essential role in the detection of bacterial pathogens and the initiation of inflammation within the dental pulp. Thus, the aim of this study was to evaluate the expression of NLRP3 in normal human dental pulp cells (HDPCs) and pulp tissues.
Pulp tissues were collected from freshly extracted human third molars, and HDPCs were prepared from the explants of normal dental pulp tissues. Reverse transcription-polymerase chain reaction and Western blotting were performed to detect the levels of NLRP3 mRNA and protein, respectively. In addition, immunohistochemical staining was used to determine the distribution of NLRP3 in pulp tissues.
Normal human dental pulp tissues displayed high levels of NLRP3 mRNA and protein. NLRP3 proteins were principally expressed in odontoblasts and some pulp vascular endothelial cells. Moreover, HDPCs also expressed NLRP3 but at a relatively low level in comparison with that of dental pulp tissues.
The expression of NLRP3 in HDPCs and pulp tissues suggests that NLRP3-mediated signaling pathways may play an important role in dental immune defense.
Nod 样受体 (NLR) 家族中研究最为透彻的成员之一是富含吡咯烷结构域的蛋白 3（NLRP3）。细胞内的 NLRP3 是最具多功能性的先天免疫受体。在被激活后，NLRP3 会组装成一种多蛋白复合物，称为炎性小体，它调节白细胞介素-1 家族细胞因子的分泌和生物活性。NLRP3 对介导对广泛的微生物刺激物或危险信号的免疫反应具有广泛的特异性。因此，我们假设 NLRP3 在检测细菌病原体和启动牙髓内炎症中发挥重要作用。因此，本研究旨在评估 NLRP3 在正常人类牙髓细胞（HDPCs）和牙髓组织中的表达。
从刚拔出的人类第三磨牙中收集牙髓组织，并从正常牙髓组织的外植体中分离出 HDPCs。采用逆转录-聚合酶链反应和 Western blot 检测 NLRP3 mRNA 和蛋白的水平。此外，还采用免疫组织化学染色法确定 NLRP3 在牙髓组织中的分布。
正常人类牙髓组织显示出 NLRP3 mRNA 和蛋白的高表达水平。NLRP3 蛋白主要在成牙本质细胞和一些牙髓血管内皮细胞中表达。此外，HDPCs 也表达 NLRP3，但表达水平相对牙髓组织较低。
HDPCs 和牙髓组织中 NLRP3 的表达表明 NLRP3 介导的信号通路可能在牙齿免疫防御中发挥重要作用。
