粒细胞-巨噬细胞集落刺激因子对人气道平滑肌细胞内皮素-1及内皮素转换酶基因表达的影响及茶碱对其的作用

The effect of GM CSF on endothelin 1 and endothelin converting enzyme gene expression in human airway smooth muscle cells with or without theophylline incubation

目的观察炎前细胞因子粒细胞－巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）对培养的人气道平滑肌细胞内皮素－１（ＥＴ－１）基因及内皮素转换酶（ＥＣＥ）基因表达的影响及茶碱对此种表达的作用，探讨在炎症环境下气道平滑肌细胞在气道高反应性发生、发展中的作用及低剂量茶碱在遏制气道高反应性的可能机制。方法分别以ＧＭ－ＣＳＦ（１０００μｇ／ｍｌ）或与茶碱（１２５ｎｇ／ｍｌ）联合刺激离体培养人气道平滑肌细胞８小时，运用ＲＴ－ＰＣＲ方法检测平滑肌细胞ＥＴ－１及ＥＣＥ基因的表达。结果对照组基本不表达ＥＴ－１基因；ＧＭ－ＣＳＦ刺激组ＥＴ－１基因显著扩增；同时加入氨茶碱组则ＥＴ－１基因表达完全受抑制；而ＥＣＥ基因表达在上述三组无差别。结论ＧＭ－ＣＳＦ可刺激人气道平滑肌ＥＴ－１基因使其表达增强，而对ＥＣＥ基因无此作用；茶碱可抑制此ＥＴ－１基因的异常表达，这可能是小剂量茶碱在控制气道炎症及气道高反应性方面的一个新机制。

Objective To explore the role of airway smooth muscle cells (ASMC) stimulated by inflammatory factors in the development of asthma and bronchial hyperresponsiveness (BHR) and the possible mechanism of low dose theophylline in the treatment of airway inflammation, the effects of GM CSF on endothelin 1 and endothelin converting enzyme (ECE) gene expression in human ASMC and theophylline on their expressions were investigated. Method The cultured human ASMCs were treated with GM CSF (1 000 μg/ml), GM CSF plus theophylline (125 ng/ml) respectively for 8 hours. Endothelin 1 and ECE gene expresion were measured by RT PCR. Result There was no ET 1 gene expression in control group, but strong expression in GM CSF treated group; theophylline entirely inhibited GM CSF induced ET 1 gene expression in the ASMC; no significant difference of ECE gene expression was found in three groups. Conclusion GM CSF causes a strong ET 1 gene expression but not ECE gene expression in cultured human airway smooth muscle cells; theophyllin inhibites this abnormal expression which may be one of the anti inflammatory mechanisms of low dose theophylline in the management of chronic airway inflammation.