重症急性胰腺炎大鼠脾脏巨噬细胞Toll样受体4的表达及分泌细胞因子水平的变化

The change of Toll-like receptor 4 expression and cytokines secretion of spleen macrophages in se- vere acute pancreatitis

目的观察重症急性胰腺炎(SAP)大鼠脾脏巨噬细胞(sMΦ)Toll样受体4(TLR4)基因表达及分泌细胞因子水平的变化。方法建立大鼠SAP模型,分别于6、12、24、72 h分离sMΦ),观察sMΦ静息状态下和经1 mg/L脂多糖(LPS)刺激后分泌肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6、白细胞介素(IL)-10水平的变化,逆转录-聚合酶链反应(RT-PCR)法检测sMΦTLR4 mRNA表达。结果予LPS刺激后,对照组sMΦ分泌TNF-α、IL-6和IL-10水平显著升高,分别由(1.1844±0.3490)μg/L、(214.14±33.41)ng/L、(20.26±3.71)ng/L升至(9.3110±1.9962)μg/ L、(519.01±52.64)ng/L和(55.43±6.28)ng/L,TLR4 mRNA表达亦由0.9091±0.2763明显升高至2.1944±0.6098;而模型各亚组分泌TNF-α和IL-6水平较刺激前无明显变化,同时TLR4 mRNA表达出现不同程度下调,且各指标均明显低于对照组。结论SAP大鼠sMΦ对内毒素耐受的发生与TLR4 mRNA表达下调有关。

Objective To observe Toll-like receptor 4 （TLR4） expression and cytokines secretion of the spleen macrophages （sMΦ） in severe acute pancreatitis （SAP）. Methods SAP was induced on healthy rats. sMΦ were isolated from model rats at 6,12,24 and 72 after the operation, and incubated with or without LPS （ 1 mg/L） respectively for 24 h. TNF-α, IL-6 and IL-10 levels of the culture fluid were measured. By using RT-PCR,TLR4 mRNA expression changes of sMΦ were also detected. Results After stimulation with LPS, TLR4 mRNA expression of sMΦ in control group was increased obviously （0.9091 ±0.2763 vs 2. 1944 ± 0.6098）, and the cytokines secretion levels increased also （TNF-α 1. 1844±0.3490μg/L vs 9.311± 1.9962μg/L, IL-6 214.14 ±33.41 ng/L vs 519.01 ±52.64 ng/L, IL-10 20.26 ±3.71 ng/L vs 55.43 ±6.28 ng/L）. The TLR4 mRNA expression of sMΦ in SAP group was decreased markedly, and the secretion levels of TNF-α and IL-6 were significantly less than in control group. Condusion The occurrence of endotoxin tolerance of sMΦ in SAP model rats is related to the down-regulation of the TLR4 mRNA expression.