丙酮酸乙酯对氧化型低密度脂蛋白刺激巨噬细胞炎性因子IL-1β表达的影响

Effects of ethyl pyruvate on expression of IL-1β in macrophages stimulated by ox-LDL

目的研究丙酮酸乙酯(ethyl pyruvate,EP)对氧化型低密度脂蛋白(oxidized low-density lipoprotein,ox-LDL)作用下巨噬细胞炎性因子白介素1β(interleukin-1β,IL-1β)表达的影响。方法 THP-1细胞经佛波酯(100 ng/ml)诱导分化为巨噬细胞,分别与人ox-LDL(50 mg/L)及ox-LDL(50 mg/L)+EP(5 mmol/L)共培养6 h、12 h、24 h、48 h后提取细胞RNA,实时q PCR检测高迁移率族蛋白1(high mobility group box-1 protein,HMGB1)、Toll样受体4(toll-like receptor 4,TLR4)、IL-1β的表达水平。结果 HMGB1及TLR4在ox-LDL刺激后12 h开始升高,12 h、24 h、48 h刺激组HMGB1表达量分别是对照组的3.23、6.95、8.96倍。12 h、24 h、48 h刺激组TLR4表达量分别是对照组的3.35、5.65、5.98倍。丙酮酸乙酯能显著抑制ox-LDL刺激下巨噬细胞HMGB1、TLR4表达。12 h、24 h、48 h丙酮酸乙酯处理组相比刺激组HMGB1表达抑制率分别为64.4%、83.8%、77.5%。12 h、24 h、48 h丙酮酸乙酯处理组相比刺激组TLR4表达抑制率分别为54.9%、42.6%、65.6%。IL-1β在ox-LDL刺激下6 h开始升高,随着时间增长表达量升高。6 h、12 h、24 h、48 h刺激组IL-1β表达量分别是对照组的2.24、2.88、3.36、3.73倍。6 h、12 h、24 h、48 h丙酮酸乙酯处理组相比刺激组IL-1β表达抑制率分别为31.6%、48.6%、49.3%、51.2%。结论丙酮酸乙酯能够通过抑制ox-LDL刺激下巨噬细胞HMGB1及其受体TLR4的表达而抑制炎性因子IL-1β的表达。

Objective To study the effects of ethyl pyruvate（EP） on expression of inflammatory factor IL-1β in macrophages stimulated by oxidized low-density lipoprotein（ox-LDL）. Methods THP-1 cells were differentiated into macrophages by stimulation of phorbol ester（PMA, 100 ng/ml） and then incubated with ox-LDL（50 mg/L） only or added with EP（5 mmol/L） for 6 h, 12 h, 24 h and 48 h for RNA. The expression level of HMGB1, TLR4 and IL-1β were quantified by real-time PCR. Results The expression of HMGB1 and TLR4 began to increase after stimulated by ox-LDL for 12 h in macrophages. The HMGB1 expression in macrophages stimulated by ox-LDL for 12 h, 24 h and 48 h was 3.23, 6.95, 8.96 times of control group, and the TLR4 expression in macrophages stimulated by ox-LDL for 12 h, 24 h and 48 h was 3.35, 5.65, 5.98 times of control group. Ethyl pyruvate could inhibit the expression of HMGB1 and TLR4 in macrophages. Compared with ox-LDL group, the inhibition rate of HMGB1 in macrophages treated by EP for 12 h, 24 h and 48 h was 64.4%, 83.8%, 77.5%, respectively, and the inhibition rate of TLR4 in macrophages treated by EP for 12 h, 24 h and 48 h was 54.9%, 42.6%, 65.6%, respectively. The expression of IL-1β began to increase after stimulated by ox-LDL for 6 h. The IL-1β expression in macrophages stimulated by ox-LDL for 6 h, 12 h, 24 h and 48 h was 2.24, 2.88, 3.36, 3.73 times of control group. Compared with ox-LDL group, the inhibition rate of IL-1β in macrophages treated by EP for 6 h, 12 h, 24 h and 48 h was 31.6%, 48.6%, 49.3%, 51.2%, respectively. Conclusion EP is an effective agent which reduces the expression of IL-1β by inhibiting the HMGB1 in macrophages stimulated by ox-LDL.