肺炎链球菌诱导SPLUNC1表达及白藜芦醇对SPLUNC1表达的影响

Streptococcus pneumoniae induces SPLUNC1 and the regulatory effects of resveratrol

摘要:

目的 探讨肺炎链球菌（SP）感染时短腭、肺及鼻咽上皮克隆1（SPLUNC1）的宿主防御作用，及白藜芦醇（Res）对SPLUNC1表达的影响，为SP感染性疾病的治疗提供新的思路。方法 根据感染复数（MOI）不同将SP感染BEAS-2B细胞分为对照组、MOI20 SP组和MOI50 SP组；根据Res药物浓度不同将Res预处理MOI20 SP感染BEAS-2B细胞分为12.5Res+SP组、25Res+SP组、50Res+SP组（Res终浓度分别为12.5 μmol/L、25 μmol/L、50 μmol/L）。通过CCK-8法检测细胞活性，并选出SP、Res最佳作用浓度及时间。正式实验分为对照组、Res组、SP组和Res+SP组，采用实时定量PCR法和ELISA法检测各组SPLUNC1 mRNA及蛋白表达。结果 随SP感染时间延长，细胞活性呈降低趋势；与对照组和MOI20 SP组相比，MOI50 SP组细胞活性有下降趋势；与MOI20 SP组相比，25Res+SP组细胞活性增强（P < 0.05），50Res+SP组细胞活性降低（P < 0.05）。以MOI20 SP菌悬液和25 μmol/L Res进行正式实验。SP组和Res+SP组随感染时间延长，BEAS-2B细胞SPLUNC1 mRNA水平表达先增高，后降低（P < 0.05）；与SP组相比，各时间点Res+SP组SPLUNC1 mRNA及蛋白表达水平均增高（P < 0.05）；与对照组相比，仅Res组SPLUNC1 mRNA及蛋白表达水平随时间延长未见明显改变（P > 0.05）。结论 SP感染可以诱导SPLUNC1表达，发挥宿主防御作用，Res可以在感染发生时上调SPLUNC1的表达，以浓度及时间依赖的方式加强细胞保护。

Abstract:

Objective To investigate the host-defense role of short palate, lung, and nasal epithelium clone 1 (SPLUNC1) in Streptococcus pneumoniae (SP) infection and the effect of resveratrol (Res) on SPLUNC1 expression, and to provide new thoughts for the treatment of diseases caused by SP infection. Methods According to the multiplicity of infection (MOI), BEAS-2B cells with SP infection were divided into control group, MOI20 SP group, and MOI50 SP group. According to the different concentrations of Res, the BEAS-2B cells with MOI20 SP infection pretreated by Res were divided into 12.5Res+SP group, 25Res+SP group, and 50Res+SP group (the final concentrations of Res were 12.5, 25, and 50 μmol/L, respectively). Cell Counting Kit-8 was used to measure cell activity and determine the optimal concentration and action time of SP and Res. In the formal experiment, the cells were divided into control group, Res group, SP group, and Res+SP group. Real-time PCR and ELISA were used to measure the mRNA and protein expression of SPLUNC1. Results Over the time of SP infection, cell activity tended to decrease. Compared with the control group and the MOI20 SP group, the MOI50 SP group had a reduction in cell activity. Compared with the MOI20 SP group, the 25Res+SP group had increased cell activity and the 50Res+SP group had reduced cell activity (P < 0.05). MOI20 SP bacterial suspension and 25 μmol/L Res were used for the formal experiment. Over the time of SP infection, the mRNA expression of SPLUNC1 in BEAS-2B cells firstly increased and then decreased in the SP group and the Res+SP group (P < 0.05). Compared with the SP group, the Res+SP group had significant increases in the mRNA and protein expression of SPLUNC1 at all time points (P < 0.05). Compared with the control group, the Res group had no significant changes in the mRNA and protein expression of SPLUNC1 (P > 0.05). Conclusions SP infection can induce SPLUNC1 expression and the host-defense role of SPLUNC1. Res can upregulate SPLUNC1 expression during the development of infection and enhance cell protection in a concentration- and time-dependent manner.