Canakçi Cenk Fatih, Canakçi Varol, Tatar Abdulgani, Eltas Abubekir, Sezer Ufuk, Ciçek Yasin, Oztas Sitki
Department of Periodontology, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
Arch Immunol Ther Exp (Warsz). 2009 May-Jun;57(3):205-11. doi: 10.1007/s00005-009-0026-9. Epub 2009 May 29.
Oxidative stress may contribute to the pathogenesis of periodontitis. However, the detailed molecular mechanism remains unclear. Both 8-hydroxydeoxyguanosine (8-OHdG) and mitochondrial DNA (mtDNA) deletion have been reported as early oxidative DNA damage markers. In this study, 8-OHdG levels in saliva and mtDNA deletions in gingival tissue of patients with chronic periodontitis (CP) were evaluated.
Gingival tissue and whole saliva samples were collected from 32 patients with CP and 32 healthy control subjects. To determine the clinical condition of each subject, the plaque index, gingival index, clinical attachment level (CAL), and probing depth (PD) were measured. Using the ELISA and polymerase chain reaction methods, the salivary 8-OHdG levels and the 7.4-kbp and 5-kbp mtDNA deletions were examined.
The 5-kbp mtDNA deletion was detected in 20 of the 32 periodontitis patients (62.5%), but was not detected in the healthy controls. The mean value of 8-OHdG in the saliva of the periodontitis patients with deleted mtDNA was significantly higher than in the patients with non-deleted mtDNA (p<0.01). Also, significant correlation was found between the occurrence of the 5-kbp mtDNA deletion and salivary 8-OHdG levels (p<0.01). Similar correlations were detected between salivary 8-OHdG levels and age, PD, and CAL (p<0.01, p<0.05).
Increased oxidative stress may lead to premature oxidative DNA damage in the gingival tissue of periodontitis patients and the salivary 8-OHdG level may signify premature oxidative mtDNA damage in diseased gingival tissue.
氧化应激可能在牙周炎的发病机制中起作用。然而，具体的分子机制仍不清楚。8-羟基脱氧鸟苷（8-OHdG）和线粒体DNA（mtDNA）缺失均已被报道为早期氧化DNA损伤标志物。在本研究中，对慢性牙周炎（CP）患者唾液中的8-OHdG水平和牙龈组织中的mtDNA缺失情况进行了评估。
收集了32例CP患者和32例健康对照者的牙龈组织及全唾液样本。为确定每个受试者的临床状况，测量了菌斑指数、牙龈指数、临床附着水平（CAL）和探诊深度（PD）。采用酶联免疫吸附测定（ELISA）和聚合酶链反应方法，检测唾液中8-OHdG水平以及7.4-kbp和5-kbp的mtDNA缺失情况。
32例牙周炎患者中有20例（62.5%）检测到5-kbp的mtDNA缺失，而健康对照者中未检测到。mtDNA缺失的牙周炎患者唾液中8-OHdG的平均值显著高于mtDNA未缺失的患者（p<0.01）。此外，发现5-kbp的mtDNA缺失的发生与唾液中8-OHdG水平之间存在显著相关性（p<0.01）。在唾液中8-OHdG水平与年龄、PD和CAL之间也检测到类似的相关性（p<0.01，p<0.05）。
氧化应激增加可能导致牙周炎患者牙龈组织中过早出现氧化DNA损伤，唾液中8-OHdG水平可能表明患病牙龈组织中过早出现氧化mtDNA损伤。
