Yuan Zhenglin, Zhu Xiaodan, Li Yuhong, Yan Ping, Jiang Han
The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan, 430079, People's Republic of China.
Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
BMC Oral Health. 2018 Apr 2;18(1):56. doi: 10.1186/s12903-018-0511-9.
Biomaterials could affect the inflammation reaction and wound healing via the activation and polarization of macrophages. However, the influence of iRoot SP and mineral trioxide aggregate (MTA) on macrophage polarization under inflammatory conditions was not reported although these two root filling materials have been applied extensively in patients undergoing endodontic treatment. Therefore, the present study aimed to explore the mechanism how iRoot SP and MTA affect the cell behavior of RAW 264.7 macrophages when stimulated by lipopolysaccharide (LPS) in vitro.
The gene expression of three main related pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) was examined by quantitative real-time polymerase chain reaction (qRT-PCR) in RAW 264.7 macrophages when stimulated by iRoot SP and MTA in the presence of LPS. The protein expression of the M1 and M2 phenotype specific markers, CD11c and CD206, was assessed by immunofluorescence and flow cytometry in RAW 264.7 macrophages.
LPS promoted the expression of IL-1β, TNF-α, and IL-6 in RAW 264.7 macrophages as compared to the control group. Both iRoot SP and MTA were significantly able to enhance the expression of IL-1β, TNF-α, and IL-6 in RAW 264.7 macrophages as compared to LPS group. LPS could increase the expression of CD11c as compared to the control group while iRoot SP and MTA were able to enhance the expression of both CD11c and CD206 as compared to LPS group.
iRoot SP and MTA could potentially promote the release of pro-inflammatory cytokines in RAW 264.7 macrophages and induce into M1/M2 phenotype when cultured with LPS.
生物材料可通过巨噬细胞的激活和极化影响炎症反应和伤口愈合。然而，尽管iRoot SP和三氧化矿物凝聚体（MTA）这两种根管充填材料已广泛应用于接受牙髓治疗的患者，但炎症条件下它们对巨噬细胞极化的影响尚未见报道。因此，本研究旨在探讨体外脂多糖（LPS）刺激时，iRoot SP和MTA影响RAW 264.7巨噬细胞行为的机制。
采用定量实时聚合酶链反应（qRT-PCR）检测RAW 264.7巨噬细胞在LPS存在下受到iRoot SP和MTA刺激时三种主要促炎细胞因子（IL-1β、TNF-α、IL-6）的基因表达。通过免疫荧光和流式细胞术评估RAW 264.7巨噬细胞中M1和M2表型特异性标志物CD11c和CD206的蛋白表达。
与对照组相比，LPS促进RAW 264.7巨噬细胞中IL-1β、TNF-α和IL-6的表达。与LPS组相比，iRoot SP和MTA均能显著增强RAW 264.7巨噬细胞中IL-1β、TNF-α和IL-6的表达。与对照组相比，LPS可增加CD11c的表达，而与LPS组相比，iRoot SP和MTA能增强CD11c和CD206的表达。
iRoot SP和MTA在与LPS共同培养时，可能促进RAW 264.7巨噬细胞中促炎细胞因子的释放并诱导其向M1/M2表型转化。
