N-乙酰半胱氨酸对被动吸烟大鼠巨噬细胞弹性蛋白酶表达的影响

Effects of N-acetyl-cysteine on macrophage metalloelastase mRNA expression in rats passively inhaled cigarette smoke

目的:探讨香烟烟雾对被动吸烟大鼠巨噬细胞弹性蛋白酶(MMP-12)表达的影响及N-乙酰半胱氨酸(NAC)在慢性阻塞性肺疾病中的治疗作用。方法:复制被动吸烟大鼠模型,分离与培养大鼠肺泡巨噬细胞(AM);制备香烟烟雾提出物(CSM)。以半定量RT-PCR法检测MMP-12 mRNA表达水平。结果:以0%、1%、3%、5%、10%、15%CSM刺激AM,当CSM浓度小于5%时,MMP-12 mRNA的表达随CSM浓度的增加而增加;当CSM浓度超过5%时,MMP-12mRNA的表达则随CSM浓度的增加而降低。以5%CSM刺激AM时,在24h内,MMP-12 mRNA的表达水平随CSM刺激时间的延长而增加。若先分别以5、10、25、50mmol/L的NAC和AM孵育1.5h,再以5%CSM刺激24h,CSM诱导的MMP-12 mRNA的表达水平则随NAC剂量增加而降低。结论:香烟烟雾可诱导AM表达MMP-12,NAC在一定程度上可以抑制香烟烟雾诱导的AM源性MMP-12的表达。

Objective To study the effects of cigarette smoke on macrophage metalloelastase （MMP-12） mRNA expression in the rats passively inhaled the smoke and the role of N-aeetyl-eysteine （NAC） in the management of COPD. Methods A rat model of passive inhalation of eigarette smoke was eonstrueted. The rat alveolar maerophage （AM） was then isolated and eultured. Cigarette smoke medium （CSM） was generated. Semi-quantitative reverse transeriptionpolymerase ehain reaetion （RT-PCR） was used to deteet the level of MMP-12 mRNA expression. Results AMs were stimulated with CSM of 0%, 1%, 3%, 5%, 10%, and 15%, respeetively. When the eoneentration of CSM was below 5%, the level of MMP-12 mRNA expression was signitieantly inereased in a dose-dependent manner （P 〈 0.05）. While the eoneentration of CSM exeeeded 5%, the level of MMP-12 mRNA expression was eorrespondingly deereased （P 〈 0.05）. If AMs were stimulated with 5% CSM, the level of MMP-12 mRNA expression was eorrespondingly inereased within 24 hours in a time-dependent manner （P 〈 0.05）. When AMs were ineubated for 1.5 hours with NAC in eoneentrations of 5, 10, 25, and 50 mmol/L, the level of MMP-12 expression indueed by CSM was eorrespondingly deereased with the inereasing of NAC （P 〈 0.05）. Conclusion NAC ean inhibit MMP-12 expression indueed by CSM.