脂多糖刺激肺血管内巨噬细胞环氧合酶-2表达的意义

Changes of cyclooxygenase-2 in pulmonary intravascular macrophages stimulated by lipopolysaccharides

目的 探讨脂多糖 (LPS)对肺血管内巨噬细胞 (PIM)环氧合酶 - 2 (COX - 2 )的作用及意义。 方法 改良法分离、培养猪PIM ,以LPS(10 μg/ml)刺激 ,反转录聚合酶链反应 (RT -PCR)检测COX - 2mRNA的变化 ;免疫组化染色法观察COX - 2酶蛋白的改变 ;放射免疫分析法 (RIA)测定前列腺素E2 (PGE2 )变化 ,以间接显示COX活性的改变。 结果 LPS刺激后 ,PIMCOX - 2mRNA和酶蛋白表达及PGE2 浓度急剧增加 ,显著高于对照组 (P <0 .0 1) ;COX - 2酶蛋白表达与细胞上清PGE2 含量呈正相关 (r =0 .94,P <0 .0 1)。 结论 LPS刺激后 ,PIMCOX - 2诱导性表达 ,导致前列腺素 (PGs)大量合成和释放 ,可能在急性肺损伤 (ALI)的发病中起重要作用。

Objective To study the changes of cyclooxygenase 2 (COX-2) in pulmonary intravascular macrophages (PIMs) stimulated by lipopolysaccharides (LPS). Methods With modification, porcine PIMs were isolated, cultured and stimulated by LPS (10 μg/ml). The changes of COX-2 mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). The changes of enzyme protein of COX-2 were observed with a method of immunohistochemistry stain. The content of prostaglandin E 2 (PGE 2) in the supernatant of PIMs was measured by radio-immunoassay (RIA) so as to indirectly show activity change of COX.Results With LPS stimulation, the expression of PIMs, COX-2 mRNA, enzyme protein and the levels of PGE 2 were increased more rapidly than those in the control group ( P <0.01). Positive correlation was found between the expression of COX-2 enzyme protein and the content of PGE2 ( r =0.94, P <0.01). Conclusions After stimulation of LPS, the synthesis and release of PGs caused by inducible expression of COX-2 in PIMs might play an important role in development of acute lung injury (ALI).