基质金属蛋白酶-2和基质金属蛋白酶-9在全氟异丁烯吸入性肺损伤中的作用

Effect of MMP-2 and MMP-9 on acute lung injury induced by perfluoroisobutylene inhalation

目的阐明全氟异丁烯(perfluoroisobutylene,PFIB)吸入暴露致大鼠急性肺损伤形成过程中肺组织内基质金属蛋白酶-2(matrix metalloproteinase 2,MMP-2)和基质金属蛋白酶-9(MMP-9)的变化规律,评价分析盐酸四环素(tetracycline hydrochloride,TET)对大鼠PFIB吸入性急性肺损伤(acute lung injury,ALI)的治疗作用及其作用机制,为临床防治化学源性肺损伤提供参考。方法自制大鼠全身暴露动态吸入染毒系统构建大鼠PFIB吸入性ALI模型。在PFIB暴露前后不同时间采集支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)和组织样品,测定肺系数、BALF中蛋白质和磷脂,并采用酶谱分析检测BALF和肺组织中MMP-2和MMP-9活性。结果亚致死剂量PFIB吸入暴露可诱导形成典型的ALI。在正常大鼠肺组织中MMP-2和MMP-9活性极低,在BALF中几乎检测不到MMP-9。在亚致死剂量PFIB染毒组大鼠肺组织和BALF中,MMP-2活性显著性升高,而且其前体pro-MMP-2活性亦出现显著性升高;MMP-9仅观察到升高的趋势性变化,但差异无统计学意义。TET治疗能够显著改善PFIB吸入性急性肺损伤,而且能剂量依赖性的抑制肺组织和BALF中MMP-2活性,高剂量TET治疗可使肺组织中MMP-2活性降低至正常水平;其对pro-MMP-2的结果也相似。结论 pro-MMP-2与MMP-2在PFIB吸入性急性肺损伤大鼠肺组织和BALF中表达水平显著升高,且与ALI的进程高度一致;TET治疗能够显著下调pro-MMP-2与MMP-2的表达,从而减轻肺组织的损伤。提示这些MMPs在吸入PFIB所致ALI的发生过程中可能起着重要作用。

Objective To study the change rule of MMP-2 and MMP-9 during the process of acute lung injury in rats induced by perfluoroisobutylene（ PFIB） inhalation,evaluate the therapeutic effect of tetracycline hydrochloride（ TET） on acute lung injury（ ALI） induced by PFIB,analyze its mechanism and provide reference for clinical prevention and treatment of chemical lung injury. Methods Wistar rats were exposed to gaseous PFIB in a whole body exposure system,take the samples of bronchoalveolar lavage fluid（ BALF） and lung tissues for the detection of lung coefficient,protein and phosphatide contents in BALF,meanwhile,the activity of MMP-2 and MMP-9 in BALF and lung tissue were also detected by zymography analysis technique. Results The results showed that the sub-lethal dose PFIB-inhalation could induce typical ALI; the activities of MMP-2 and MMP-9 in normal rat lung tissue and BALF were extremely low,but MMP-2 and its precursor pro-MMP-2 were all significantly increased in lung tissue and BALF of PFIB exposed rats,the MMP-9 was only observed some upward trend no statistical significance. TET could significantly alleviate the ALI induced by PFIB and dose-dependently inhibit the activity of MMP-2 in lung tissue and BLAF,high dose of TET could reduce MMP-2 and pro-MMP-2 to normal levels. Conclusion The results showed that the upward expression of pro-MMP-2 and MMP-2 both in lung tissue and BALF of PFIB-inhaled rats was highly consistent with the course of ALI; while TET could reduce the expression of pro-MMP-2 and MMP-2 in lung tissue,alleviate lung injury,which suggested that these two kinds of MMPs may play an important role in ALI induce by PFIB inhalation.