摘要目的 探讨白细胞介素(IL)-1β调节人胶质细胞瘤内环氧合酶(COX)-2系统表达的分子机制.方法 以2.5 μg/L IL-1 β刺激人胶质瘤细胞H4细胞,在刺激培养的12、24、48和72 h收集细胞及上清液.以不同浓度的p38和p42/44 MAPK信号抑制剂SB203580和PD98059分别预处理H4细胞1h后进行IL-1β刺激培养24 h,收集细胞及上清液.Northern印迹杂交法及免疫印迹法检测H4细胞中胞质型磷脂酶A(cPLA)2和COX-2蛋白的表达情况;ELISA法检测细胞培养上清液中前列腺素(PGE)2的含量.结果 2.5 μg/L IL-1β以时间依赖性方式诱导H4细胞中cPLA2和COX-2的表达,在刺激培养24 h时影响最为明显(P＜0.05),之后有下降趋势.同时,IL-1β还能诱导PGE2的产生,刺激培养72 h时PGE2产量增加250倍;p38 MAPK抑制剂SB203580能以剂量依赖性(0.1、1和10 μmol/L)有效抑制IL-1β诱导的cPLA2和COX-2表达(P＜0.05),而p42/44 MAPK抑制剂PD98059则对二者表达影响不明显(P＞0.05).但是,SB203580和PD98059均能显著降低IL-1β诱导PGE2的产生(P＜0.05).结论 IL-1β能明显诱导COX-2和cPLA2的表达,并通过p38和p42/44MAPK信号通路介导PGE2的产生,因此在翻译后水平上影响PGE2的表达.

abstractsObjective To explore the molecular mechanisms by which interleukin-1 β (IL-1β) regulates the expression of cytosolic phospholipase A2 (cPLA2) and cyclooxygenase-2 (COX-2) in human neuroglioma cell.Methods H4 neuroglioma cells were treated with IL-1 β (2.5 μg/L) for different timepoints up to 72 h.For MAPK study,cells were incubated for 1 h with MAPK inhibitors,SB203580 and PD98059 and subsequently stimulated with IL-1β (1 μg/L) for 24 h.Northern and Western blot were used to determine the protein expressions of cPLA2 and COX-2 respectively.And the content of PGE2 in supernatant was determined by enzyme-linked immunosorbent assay (ELISA).Results A dose of 2.5 μg/L IL-1 β induced the protein expressions of cPLA2 and COX-2 and a subsequent release of PGE2 in a time-dependent manner.And the expressions of cPLA2 and COX-2 peaked at 24 h after stimulation (P ＜ 0.05).The expression of PGE2 increased 250 folds after a 72 h culture.Both SB203580 and PD98059 inhibitors reduced IL-1 β-induced PGE2 production while SB203580 alone reduced the expressions of both cPLA2 and COX-2.Conclusion IL-1β induces the expressions of cPLA2 and COX-2 and affects COX-2 at the post-translational level by modulating PGE2 production through the signal transduction pathways of p38 and p42/44 MAPKs.