ERK1/2和P38信号通路在瘦素诱导巨噬细胞TNF-α表达中的作用  

Involvement of ERK1/2 and P38 Signal Pathways in Leptin-Induced TNF-α Expression in Macrophages

作　　者：赵婷[1] 侯孟君[1] 肖勇梅[1] 朱惠莲[1] 唐志红[1] 凌文华[1] 

机构地区：[1]中山大学公共卫生学院

出　　处：《中山大学学报（医学科学版）》2006年第5期500-505,共6页Journal of Sun Yat-Sen University:Medical Sciences

基　　金：广东省自然科学基金资助项目(015042)

摘　　要：【目的】研究瘦素(leptin)诱导小鼠腹腔巨噬细胞(PM)分泌肿瘤坏死因子α(TNF-α)的影响,以及丝裂原活化蛋白激酶(MAPK)信号通路在这一过程中的作用。【方法】体外培养小鼠PMs,按瘦素不同浓度和/或MAPK特异性抑制剂PD98059、U0126、SB203580、SP600125进行分组。分别收集培养细胞和上清液,用酶联免疫吸附试验(ELISA)测定培养上清中TNF-α水平,用蛋白印迹(Westernblot)方法测定细胞内p-ERK1/2、p-p38,以及p-JNK的表达水平,用逆转录-聚合酶链式反应(RT-PCR)测定TNF-αmRNA的表达。【结果】瘦素能够剂量依赖性的诱导小鼠PM产生TNF-α,在瘦素质量浓度为75ng/mL时TNF-α表达至峰值,是对照组的6.6倍。瘦素可以活化ERK1/2和p38MAPK信号转导通路,瘦素处理组的p-ERK1、p-ERK2、p-p38表达水平分别是对照组的2.3、2.4和2.6倍。ERK1/2的特异性抑制剂PD98059、U0126和p38的特异抑制剂SB203580能够分别抑制瘦素引起的ERK1/2、p38蛋白磷酸化以及TNF-αmRNA增加,两者的联合作用可以强烈抑制TNF-αmRNA的表达,而JNK信号转导途径与瘦素诱导PM表达TNF-α无关。【结论】瘦素在小鼠PM中通过同时活化ERK1/2、p38MAPK信号转导通路而诱导细胞产生TNF-α。[Objective] To study the effects of leptin on tumor necrosis factor α （TNF-α） secretion in murine peritoneal macrophages （PM） and the role of mitogen activated protein kinases （MAPK） in this process. [Methods] The murine PMs cultured in vitro were divided into groups according to the concentrations of leptin and/or whether the specific inhibitors of MAPKs, PD98059, U0126, SB203580, and SP600125, were added. Cultured ceils and supernatant were collected. The level of TNF-α in the culture supematant was measured by ELISA and Western blot was used to determine the phosphorylation of ERK1/2, p38 and JNK. Reverse transcription-polymerase chain reaction （RT-PCR） was used to measure the expression of TNF-α mRNA. [Results] Leptin induced TNF-α expression in murine PMs in a dose-dependent manner and the secretion of TNF-α reached the maximum at 75 ng/mL of leptin, which was 6.6-fold of the control group. ERK1/2 and p38 signaling pathways were activated by leptin in murine PM. Expression of p-ERK1, p-ERK2, and p-p38 in leptin-treatod group increased to 2.3, 2.4,and 2.6-fold of the control group, respectively. The specific inhibitors of ERK1/2 and p38 could significantly suppress the activation of ERK1/2 and p38 induced by leptin in murine PM and partly inhibited the TNF-α mRNA expression. Combination of the inhibitors totally abolished the increasing of TNF-α mRNA. Meanwhile, JNK signal pathway was probably not involved in the leptin induced TNF-α production. [Conclusion] Leptin induces TNF-α production by simultaneously activating ERK1/2 and p38 signal pathway in murine PM.

关 键 词：瘦素 巨噬细胞 肿瘤坏死因子α 丝裂原活化蛋白激酶 

分 类 号：R151.1[医药卫生—营养与食品卫生学]