Regulation of gene expression by macrolides in bronchial epithelial cells

弥漫性泛细支气管炎是一种慢性炎症性气道疾病，累及特定的呼吸性细支气管。由于持续的肺炎衣原体感染和呼吸衰竭，该病的预后极差。然而，大环内酯类药物的低剂量和长期给药的引入显着改善了其预后。虽然大环内酯类药物治疗的有效性机制尚未完全了解，但越来越多的证据表明，这可能是由于药物的抗炎和免疫调节特性。为探讨大环内酯类药物作用的分子机制，我们采用差异显示分析（DD）和RT-PCR技术，将HS-24肺鳞癌细胞在红霉素（EM）和/或TNF-α存在或不存在的情况下孵育24小时。提取总RNA后，进行差异显示，并对差异表达的mRNA进行序列分析。人β防御素（hBD-1），表达于支气管上皮细胞， ...更多信息 与生物防御和炎症反应密切相关的Helial细胞，也通过RT-PCR分析了其mRNA的表达。通过DD，在与EM孵育的细胞中检测到几个上调的基因。对不同表达的cDNA进行测序和同源性搜索分析，发现其中一个克隆与人28 S核糖体RNA同源性为98.9%。1基因下调EM有或没有炎症刺激。这些数据表明，包括EM在内的大环内酯类药物通过上调或下调支气管上皮细胞中多个基因的表达以及调节细胞因子如TNF-α对基因表达的影响来赋予其治疗功效。提示大环内酯类药物的调节作用至少部分是通过调节支气管上皮细胞的β-蛋白质合成来实现的，hBD-1可能在支气管上皮细胞的生物防御中发挥一定作用。少

Diffuse panbronchiolitis is a chronic inflammatory airway disease affecting particularyl respiratory bronchioles. The prognosis of the disease used to be extremely poor because of sustained P seudomonas infection and respiratory failure. However, the introduction of low dose and long term administration of macrolides has dramatically improved its prognosis. Although the mechanism of effectiveness of macrolides therapy is not fully understood, a growing body of evidence suggests it is likely due to the anti-inflammatory and immuno-modulating properties of the agents. To investigate the molecular mechanisms of effectiveness of macrolides, we have utilized differential display analysis (DD) and RT-PCR.HS-24 lung squamous carcinoma cells were incubated in the presence or absence of erythromycin (EM) and/or TNF-alpha for 24hr. After total RNA was extracted, DD was performed and sequenses of defferently expressed mRNA was analyzed. The human beta defensin (hBD-1), expressed in bronchial epit … More helial cells and is thought to have close relationship with biological defense and inflammation, was also analyzed by RT-PCR for its mRNA expression. By DD,several up-regulated genes were detected in cells incubated with EM.Further, multiple up-and down-regulated genes were also obseved when exposed to TNF-alpha after pretreatment with or without EM.Sequencing and homology search analysis of the defferentially expressed cDNAs thus far revealed that one of the clones is 98.9% homologous to human 28S ribosomal RNA.Expression of the hBD-1 gene was downregulated by EM with or without inflammatory stimuli. These data suggest macrolides including EM confer their therapeutic efficacy by up-or down-regulating expression of multiple genes in bronchial epithelial cells and modulating effects on gene expression by cytokines such as TNF-alpha. It is also suggested the modulatory effects of macrolides may be, at least in part, throuth pretein synthesis and hBD-1 is likely to have some roles in biological defense of bronchial epitherial cells. Less