The reduced form of Coenzyme Q10 decreases the expression of LPS-sensitive genes in human THP-1 cells. Homo sapiens

Monocytes are key players in inflammatory processes which are triggered by lipopolysaccharide (LPS), the major outer membrane component of gram-negative bacteria. The present study in human monocytic THP-1 cells was designed in order to identify LPS-inducible genes which are down-regulated by the reduced form of CoQ10 (ubiquinol, Q10H2). For this purpose, THP-1 cells were incubated with 10 µM Q10H2 for 24 h. Subsequently, cells were stimulated for 4 h with 1µg/ml LPS and the resulting gene expression levels were determined using microarrays. 14 LPS-inducible genes were identified to be significantly (p < 0.05) down-regulated by Q10H2 pre-treatment between a factor of 1.32 and 1.65. The strongest effect of Q10H2 incubation was found for the nuclear receptor coactivator 2 gene (NCOA2). Gene Ontology (GO) terms revealed for the Q10H2-sensitive genes an involvement in e.g. signal transduction processes (CENTD1, NCOA2, PSD3, PPP2R5C), transcriptional regulation (NCOA2, POU2F1, ETV3) and cell proliferation pathways (CCDC100, EPS15). In conclusion, we provide evidence in THP-1 cells that the reduced form of CoQ10 (Q10H2) modulates LPS-induced gene expression. Overall design: Whole genome expression profiles were analysed from monocytes pre-incubated with the reduced form of CoQ10 (ubiquinol, Q10H2) before subsequent stimulation with LPS. Stimulated (+LPS) and unstimulated (-LPS) monocytes were used as positive and negative controls, respectively. For every experimental group (3 groups in total), three Affymetrix Human Genome U133 Plus 2.0 arrays were used, thus resulting in the analysis of 9 microarrays.

单核细胞是由革兰氏阴性菌主要外膜成分脂多糖（lipopolysaccharide, LPS）触发的炎症过程中的关键参与者。本研究以人单核细胞THP-1为模型，旨在鉴定可被还原型辅酶Q10（ubiquinol，Q10H2）下调的LPS诱导基因。为此，将THP-1细胞以10μM Q10H2孵育24小时，随后用1μg/ml LPS刺激4小时，通过微阵列技术检测基因表达水平。最终共鉴定出14个经Q10H2预处理后显著（p<0.05）下调的LPS诱导基因，其下调幅度介于1.32至1.65倍之间。Q10H2处理所产生的最强调控效应见于核受体辅激活因子2基因（nuclear receptor coactivator 2, NCOA2）。基因本体（Gene Ontology, GO）注释结果显示，受Q10H2调控的基因参与了多项生物学过程，包括信号转导过程（如CENTD1、NCOA2、PSD3、PPP2R5C）、转录调控（NCOA2、POU2F1、ETV3）以及细胞增殖通路（CCDC100、EPS15）等。综上，本研究在THP-1细胞中证实，还原型辅酶Q10（Q10H2）可调控LPS诱导的基因表达。整体实验设计：本研究对经还原型辅酶Q10（ubiquinol，Q10H2）预处理、后续再经LPS刺激的单核细胞进行全基因组表达谱分析。以LPS刺激组（+LPS）与未刺激组（-LPS）分别作为阳性对照与阴性对照。本研究共设3个实验组，每组均使用3张Affymetrix人类基因组U133 Plus 2.0芯片，最终共完成9张微阵列芯片的数据分析。