中文摘要：

目的通过观察肝X受体α（LXRα）激动剂对脂多糖（LPS）刺激后Kupffer细胞干扰素调节因子3（IRF3）、糖皮质激素受体反应蛋白1（GRIP1）、LXRα表达的影响,探讨LXRα负性调控炎症反应的相关机制。方法采用胶原酶原位灌注法分离和培养雄性KM小鼠肝脏中的Kupffer细胞,所得细胞在含20%小牛血清和1%青霉素/链霉素的1640培养基中培养。将分离的Kupffer细胞随机分为4组：空白对照组、TLR4配体激活剂LPS（1μg/ml）组、LXRα配体激活剂T0901317（5μg/ml）组、LPS和T0901317共同处理组。收集培养细胞,采用Western boltting法检测Kupffer细胞的LXRα、GRIP1及IRF3蛋白表达水平。ELISA检测Kupffer细胞培养上清液中干扰素（IFN）β、肿瘤坏死因子（TNF）-α和白细胞介素（IL）-1β含量。结果LXRα蛋白质表达水平在T0901317处理组最高,LPS处理组最低。联合处理组中,LXRα表达明显低于T0901317处理组（P〈0.05）,但又显著高于其他两组（P〈0.05）。IRF3及GRIP1蛋白表达量在LPS组最高,联合处理组表达明显降低,两组间均有显著差异（P〈0.05）;在LPS组及联合处理组中,IRF3及GRIP1蛋白表达量均高于对照组及T0901317处理组（P〈0.05）。IFNβ在LPS处理组的含量较对照组和T0901317处理组明显增高（P〈0.05）;联合处理组IFNβ含量比LPS处理组明显降低（P〈0.05）;IFNβ表达T0901317处理组表达最低。TNF-α在LPS处理组的含量较其他3组明显增高（P〈0.05）;对照组、T0901317处理组和联合处理组水平较低,且他们3组之间无明显差别（P〉0.05）。IL-1β的表达趋势与TNF-α相同。结论在应用LPS处理之前预防性应用LXRα激动剂,能明显抑制Kupffer细胞的IRF3及GRIP1表达,通过抑制IRF3、GRIP1的表达而发挥抗炎效应,从而抑制LPS所诱导的Kupffer细胞活化。

英文摘要：

Objective To explore the possible mechanism of the inhibitory effect of liver X receptor α （LXRα） on lipopolysaccharide （LPS）-induced inflammation in mouse Kupffer cells （KCs）. Methods The KCs isolated from the liver of male KM mice and cultured in RPMI 1640 containing 20% FBS for 24 h were divided into control, LPS, T0901317, and LPS＋T0901317 groups with corresponding treatments. The expressions of LXRα, interferon regulatory factor 3 （IRF3） and glucocorticoid receptor interacting protein 1 （GRIP1） in the KCs were detected by Westem blotting. The levels of interferon β （IFNβ）, tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β） in the supernatant were detected by enzymelinked immunosorbent assay （ELISA）. Results The level of LXRα protein was highest in T0901317 group and lowest in LPS group, and was significantly higher in LPS＋T0901317 group than in LPS group but lower than in T0901317 group （P〈0.05）. The levels of IRF3 and GRIP1 protein were the highest in LPS group, and significantly lowered by T0901317 treatment （P〈0.05）. The expression of IRF3 and GRIP1 proteins in LPS group and LPS＋ T0901317 group were significantly higher than those in the control and T0901317 groups （P〈0.05）. The concentration of IFN-β was significantly higher in LPS group thah in the control and T0901317 group （P〈0.05）, and decreased in LPS＋T0901317 group in comparison with that in LPS group （P〈0.05）. IFN-β was the lowest in T0901317 group. The levels of TNF-α and IL-1β were the highest in LPS group （P〈0.05）, and comparable between the other 3 groups （P〉0.05）. Conclusion Pre-treatment with T0901317 before LPS stimulation can suppress the expressions of IRF3 and GRIP1 to inhibit the inflammation and hence Kupffer cell actovation.