Department of Periodontology, School of Dentistry, University of Athens, 2 Thivon Str., Athens, Greece.
Inflammation. 2010 Jun;33(3):200-6. doi: 10.1007/s10753-009-9174-7.
Recent research evidence shows that the receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) play an important role in osteoclastogenesis and the inflammatory bone loss during periodontitis. Bone remodeling process is dependent on the balance of these two proteins while a high ratio of RANKL/OPG characterizes the increased osteolytic process and it has been reported in inflammatory diseases including the periodontal disease. The purpose of this study was to determine the OPG and RANKL mRNA levels in periodontal tissues derived from patients with advanced chronic periodontitis after non-surgical periodontal therapy (SRP) and to compare the RANKL/OPG ration with that in healthy persons. Gingival biopsies were obtained from subjects with clinically healthy periodontium (H) (N = 11) and patients with advanced chronic periodontitis (CP) (N = 14). Total RNA was isolated from the gingival samples and 1 microg RNA was reverse transcribed to cDNA, followed by polymerase chain reaction (PCR) using specific primers for OPG and RANKL. The efficiency of reverse transcription was verified by the amplification of the GAPDH gene. The intensity of RT-PCR products was analyzed by a densitometer and was normalized to the intensity of the band for the housekeeping gene GAPDH. Immunohistochemical evaluation of the RANKL and OPG expression was also performed. The expression of RANKL as well as of OPG was reduced in CP specimens in comparison to that of healthy persons in a statistical significant way. However, the RANKL/OPG ratio showed to be slightly elevated in CP compared to H specimens but this finding was not of statistical significance. The immunohistochemical analysis revealed a non-uniform expression pattern for both proteins. Although further investigation is needed to identify the specific role of RANKL and OPG protein in periodontitis progression, our data after SRP might indicate the possible involvement of these proteins in the activation of pathways, which regulate the repair of the periodontal tissues.
最近的研究证据表明，核因子-κ B 配体受体激活剂（RANKL）和骨保护素（OPG）在破骨细胞形成和牙周炎中的炎症性骨丢失中发挥重要作用。骨重塑过程依赖于这两种蛋白的平衡，而 RANKL/OPG 的高比值则表明溶骨性过程增加，这已在包括牙周病在内的炎症性疾病中得到报道。本研究旨在测定经非手术牙周治疗（SRP）后来源于慢性牙周炎晚期患者的牙周组织中的 OPG 和 RANKL mRNA 水平，并将 RANKL/OPG 比值与健康人进行比较。从临床健康牙周组织（H）（N = 11）和晚期慢性牙周炎（CP）患者（N = 14）中获取牙龈活检。从牙龈样本中分离总 RNA，并将 1 μg RNA 反转录为 cDNA，然后使用 OPG 和 RANKL 的特异性引物进行聚合酶链反应（PCR）。通过扩增管家基因 GAPDH 基因来验证反转录的效率。通过密度计分析 RT-PCR 产物的强度，并将其标准化为管家基因 GAPDH 的条带强度。还进行了 RANKL 和 OPG 表达的免疫组织化学评估。与健康人相比，CP 标本中的 RANKL 以及 OPG 的表达在统计学上显著降低。然而，与 H 标本相比，CP 标本中的 RANKL/OPG 比值略有升高，但这一发现无统计学意义。免疫组织化学分析显示两种蛋白的表达呈非均匀模式。尽管需要进一步研究以确定 RANKL 和 OPG 蛋白在牙周炎进展中的具体作用，但我们在 SRP 后的数据分析可能表明这些蛋白可能参与了调节牙周组织修复的途径的激活。
