Harris T H, Wallace M R, Huang H, Li H, Shaddox L M
Department of Periodontology, College of Dentistry, University of Florida, Gainesville, FL, USA.
Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA.
JDR Clin Trans Res. 2019 Oct;4(4):342-351. doi: 10.1177/2380084419863789. Epub 2019 Jul 18.
The purpose of this study was to test for the role of the P2X7 receptor in localized aggressive periodontitis (LAP).
Peripheral blood was obtained from 95 subjects with LAP and 76 healthy unrelated controls (HUCs). Three P2RX7 single-nucleotide polymorphisms (rs1718119, rs2230911, and rs3751143) were genotyped from these subjects, and their peripheral blood samples were stimulated with lipopolysaccharide (LPS) from Escherichia coli and tested for inflammatory markers. The 3 P2RX7 single-nucleotide polymorphisms were in found to be in perfect linkage disequilibrium, and a total of 4 haplotypes and 9 diplotypes were identified among all subjects. For both subject populations, the 9 diplotypes were grouped into 4 functional groups and tested for association with subject inflammatory response. To specifically study the effects of extrinsic activation of the P2X7 receptor in LAP, peripheral blood samples from were stimulated under 3 treatments: LPS, LPS + ATP, and LPS +ATP+ P2X7 selective inhibitor. The effects of these treatments on P2X7 receptor activity were measured through Luminex protein assay. Last, to test whether receptor stimulation was related to P2RX7 expression, relative mRNA levels of P2RX7 were quantified with real-time quantitative polymerase chain reaction.
Several associations between the P2RX7 diplotypes and LPS-stimulated blood chemokine/cytokine levels were found between the LAP and HUC populations (P < 0.05). P2X7 activation resulted in statistically significant differences in IL-1β and IL-12p40 concentrations for both subject populations. The relative P2RX7 mRNA levels increased significantly after addition of its inhibitor for both LAP and HUC populations.
This study detected an association between P2RX7 functional diplotypes and in vitro immune response of whole blood from subjects with LAP. In addition, we found that inhibition of the activated P2X7 receptor leads to increased P2RX7 mRNA levels, suggesting a feedback loop ( ClinicalTrials.gov NCT01330719).
The results of this study suggest that P2RX7 functional diplotypes are associated with LAP and their in vitro immune response to bacteria. Ongoing studies to uncover the mechanistic link between P2RX7 and LAP phenotypes could lead to the development of preventive approaches for susceptible subjects.
本研究旨在检测P2X7受体在局限性侵袭性牙周炎（LAP）中的作用。
采集95例LAP患者和76例健康无关对照者（HUCs）的外周血。对这些受试者进行3个P2RX7单核苷酸多态性（rs1718119、rs2230911和rs3751143）的基因分型，并用大肠杆菌脂多糖（LPS）刺激其外周血样本，检测炎症标志物。发现这3个P2RX7单核苷酸多态性处于完全连锁不平衡状态，在所有受试者中总共鉴定出4种单倍型和9种双倍型。对于这两组受试者，将9种双倍型分为4个功能组，并检测其与受试者炎症反应之间的关联。为了具体研究P2X7受体的外源性激活在LAP中的作用，对来自LAP患者的外周血样本进行3种处理：LPS、LPS + ATP和LPS + ATP + P2X7选择性抑制剂。通过Luminex蛋白测定法测量这些处理对P2X7受体活性的影响。最后，为了检测受体刺激是否与P2RX7表达相关，用实时定量聚合酶链反应定量P2RX7的相对mRNA水平。
在LAP组和HUC组之间发现P2RX7双倍型与LPS刺激的血液趋化因子/细胞因子水平之间存在几种关联（P < 0.05）。P2X7激活导致两组受试者的IL-1β和IL-12p40浓度出现统计学显著差异。添加其抑制剂后，LAP组和HUC组的P2RX7相对mRNA水平均显著升高。
本研究检测到P2RX7功能双倍型与LAP患者全血的体外免疫反应之间存在关联。此外，我们发现抑制激活的P2X7受体可导致P2RX7 mRNA水平升高，提示存在反馈回路（ClinicalTrials.gov NCT01330719）。
本研究结果表明，P2RX7功能双倍型与LAP及其对细菌的体外免疫反应相关。正在进行的研究以揭示P2RX7与LAP表型之间的机制联系，可能会为易感受试者开发预防方法。
