Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Photodiagnosis Photodyn Ther. 2020 Dec;32:102044. doi: 10.1016/j.pdpdt.2020.102044. Epub 2020 Oct 1.
Antimicrobial photodynamic therapy (aPDT) as a complementary step of selective removal of dental caries appears as an ideal choice to help manage caries with minimal interventions. Sub-lethal dose of aPDT (sPDT) impressively effects microbial virulence, although it does not kill microorganisms. Therefore, the present study aimed to investigate the influence of sPDT using diode laser plus chlorophyllin-phycocyanin mixture (PhotoActive) on changes in gtfB gene expression and the subsequent protein expression of GtfB.
sPDT using PhotoActive and 635 ± 10 nm diode laser was used to examine the expression of gtfB mRNA and GtfB protein expression of Streptococcus mutans by quantitative real time PCR (qRT-PCR) method and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), respectively.
In this study, sPDT using 2.4 × 10 mol/L PhotoActive with 3 min irradiation time of diode laser with energy density of 104 J/cm, significantly reduced the gtfB gene expression with rates of 3.5-fold (P < 0.05). Also, PhotoActive mediated sPDT demonstrated a significant reduction in GtfB protein expression of S. mutans up to 54 % (P < 0.05).
This study demonstrated the potential effect of PhotoActive mediated sPDT on one of the most important virulence factors of S. mutans.
作为龋病选择性去除的补充步骤，抗菌光动力疗法（aPDT）作为一种微创治疗方法，似乎是控制龋病的理想选择。亚致死剂量的 aPDT（sPDT）可显著影响微生物的毒力，尽管它不会杀死微生物。因此，本研究旨在探讨使用二极管激光联合叶绿素-藻蓝蛋白混合物（PhotoActive）的 sPDT 对 gtfB 基因表达变化及随后 GtfB 蛋白表达的影响。
采用 635±10nm 二极管激光联合 PhotoActive 进行 sPDT，通过定量实时 PCR（qRT-PCR）方法和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）分别检测变形链球菌 gtfB mRNA 的表达和 GtfB 蛋白的表达。
本研究中，使用 2.4×10-2mol/L 的 PhotoActive 联合二极管激光照射 3 分钟（能量密度为 104J/cm2），可使 gtfB 基因表达降低 3.5 倍（P＜0.05）。此外，PhotoActive 介导的 sPDT 可使 S. mutans 的 GtfB 蛋白表达降低 54%（P＜0.05）。
本研究表明，PhotoActive 介导的 sPDT 可能对 S. mutans 最重要的毒力因子之一产生影响。
