医学免费论文:细胞间黏附分子1在红霉素抗炎机制中的作用
【摘要】 目的 从分子水平上探讨红霉素(EM)的抗炎作用机制。方法 体外培养人支气管上皮细胞(16HBE),将细胞随机分为8组,先加入EM干预,后加入肿瘤坏死因子α(TNFα)刺激。分组如下:①空白对照组;②TNFα(20 ng/ml,16 h)组;③EM(0.3 μg/ml,24 h)+TNFα(20 ng/ml,16 h)组;④EM(3 μg/ml,24 h)+TNFα(20 ng/ml,16 h)组;⑤EM(30 μg/ml,24 h)+TNFα(20 ng/ml,16 h)组;⑥EM(0.3 μg/ml,48 h)+TNFα(20 ng/ml,16 h)组;⑦EM(3 μg/ml,48 h)+TNFα(20 ng/ml,16 h)组;⑧EM(30 μg/ml,48 h)+TNFα(20 ng/ml,16 h)。然后收集各组细胞分别提取RNA,应用逆转录聚合酶链反应(RTPCR)方法检测细胞间黏附分子1(ICAM1) mRNA的表达。因ICAM1 RTPCR产物分子大小约为700 bp,与原设计产物分子大小490 bp不相符,进一步作基因克隆测序了解基因之间是否具有同源性。结果 ICAM1的RTPCR产物即为目的基因:ICAM1基因。TNFα刺激人支气管上皮细胞(16HBE)后,细胞ICAM1mRNA表达增高。先加入不同浓度及作用时间的EM,后加入TNFα刺激人支气管上皮细胞(16HBE),各组细胞ICAM1mRNA表达均降低,且提示有浓度与时间依赖性。结论 TNFα能激活人支气管上皮细胞使其ICAM1基因表达增高,促进炎症的发生发展。EM能抑制人支气管上皮细胞ICAM1基因表达,可能是EM的抗炎作用机制之一。
【关键词】 人支气管上皮细胞;细胞间黏附分子1;肿瘤坏死因子α;红霉素
Expression of intercellular adhesion molecule 1 mRNA in the antiinflammatory molecular mechanism of erythromycin医.学.全.在.线www.lindalemus.com
LI MeiHua, ZHONG XiaoNing, LIU GuangNan,et al.
Department of Resperatory, the First Affiliated Hospital of Guangxi Medical University, Nanning 530021, Guangxi, China
【Abstract】 Objective To investigate the antiinflammatory molecular mechanism of erythromycin (EM) in order to find a new way to prevent and treat chronic obstructive pulmonary disease (COPD). Methods Human bronchial epithelial cell line 16HBE was cultured with 10% serum DMEM (high glucose). The cells were randomly divided into eight groups: blank control group, TNFα (20 ng/ml,16 h), EM(0.3 μg/ml,24 h)+TNFα (20 ng/ml,16 h), EM(3 μg/ml,24 h)+TNFα (20 ng/ml,16 h), EM(30 μg/ml,24 h)+TNFα(20 ng/ml,16 h), EM(0.3 μg/ml,48 h)+TNFα (20 ng/ml,16 h), EM(3 μg/ml,48 h)+TNFα(20 ng/ml,16 h), and EM(30 μg/ml,48 h)+TNFα (20 ng/ml,16 h). Then total cellular RNA was extracted to detect the expression of ICAM1 mRNA by RTPCR. The molecular size of ICAM1 RTPCR production was not correspondent for what it was designed,therefore,clone sequencing was applied to confirm it. Results ICAM1 RTPCR production was ICAM1 mRNA. ICAM1mRNA was increased by the addition of TNFα,which was inhibited by the preincubation with EM in dosedependent and timedependent fasion. Conclusions ICAM1mRNA can be increased by the stimulation of TNFα, which indicate that EM modify inflammation presumably by suppressing ICAM1mRNA in human bronchial epithelial cells.
【Key words】 Human bronchial epithelial cells;ICAM1;TNFα;Erythromycin
长期应用小剂量红霉素(EM)治疗慢性气道感染性疾病〔弥漫性泛细支气管炎、支气管哮喘、支气管扩张、慢性阻塞性肺病等(COPD)〕取得良好的效果已经得到临床资料证实〔1~4〕。研究发现,这种疗效与EM抗菌活性无关,而与EM的抗炎活性密切相关〔5,6〕。EM在体内外对许多致炎细胞因子的产生均有调节作用,但是,EM抗炎作用机制仍不清楚。本实验设计研究EM对ICAM1基因表达的影响,从分子水平上探讨EM的抗炎作用机制,为临床防治老年慢性阻塞性肺病提供新的思路。
1 材料与方法
1.1 材料 高糖(DMEM)培养基为Hyclone公司产品,胎牛血清为杭州四季青生物工程材料有限公司产品,肿瘤坏死因子(TNFα)系Sigma公司产品,EM系Amresco公司产品。总RNA提取试剂Trizol购自Invitrogen公司,AMV逆转录酶和dNTPs购自美国Promega公司,TaqDNA聚合酶购自TAKARA公司,DEPC系美国Serva公司产品,琼脂糖购自上海生工生物工程公司。琼脂糖凝胶回收试剂盒及pGEMTeasy试剂盒(含T4 DNA连接酶)系Qbiogene公司产品。常规试剂:异丙醇、乙醇、氯仿、Tris粉、EDTA等系国产分析纯试剂。OligodT15,βactin引物:上游5′TGACGGTCAGGTCATCACTATCGGCAATGA3′,下游5′TTGATCTTCATGGTG(AGC) TAGGAGCGAGGGCA 3′,由上海生工生物工程公司合成。ICAM1引物:上游5′AGGTGGCCGGCCAGCTTATA3′,下游5′CCTGTCCCGGGATAGGTTCA3′,由北京奥科生物技术有限责任公司合成。