早产大鼠宫内感染肺损伤时支气管肺泡灌洗液及肺组织中脂肪型脂肪酸结合蛋白的表达

Effects of intra-amniotic endotoxin exposure on expression of fatty acid binding protein 4 in bronchoalveolar lavage fluid and lung tissue of preterm rats

目的:观察宫内感染肺损伤时脂肪型脂肪酸结合蛋白(FABP4)在早产大鼠支气管肺泡灌洗液(BALF)及肺组织中的表达,探讨其与新型支气管肺发育不良(BPD)发病的关系。方法:定期受孕的SD大鼠分为LPS组和对照组,于孕15 d羊膜腔内注射LPS或生理盐水。2组动物均于出生后第1天(P1)、第4天(P4)和第7天(P7)各取8只,应用ELISA方法检测BALF中FABP4的含量,采用免疫组化法和RT-PCR技术检测肺组织中FABP4蛋白及mRNA的表达水平。结果:FABP4主要在肺泡巨噬细胞、血管内皮细胞及少量支气管上皮细胞表达。LPS组早产大鼠BALF中FABP4含量、肺组织中FABP4蛋白及mRNA的相对表达量较对照组均升高,且与时间存在交互作用(P均<0.05)。结论:宫内感染肺损伤时FABP4表达升高,可能是引起肺微血管病理性重塑及肺泡化进程受阻,进而导致新型BPD发生发展的重要因素。

Aim： To investigate the expression of fatty acid binding protein 4（ FABP4） in bronchoalveolar lavage fluid（ BALF） and lung tissue of preterm rats exposed to intra-amniotic endotoxin and to elucidate the relationship between intrauterine inflammatory exposure and the pathogenesis of bronchopulmonary dysplasia（ BPD）.Methods： Timed pregnant SD rats were randomly divided into two groups： control group and LPS group.LPS or normal saline were injected into the amniotic cavity,respectively.The lungs from eight rats of each group aged postnatal day 1（ P1）,day 4（ P4） and day 7（ P7）were removed and the level of FABP4 in BALF was measured by ELISA.The expressions of FABP4 protein and mRNA in lung tissue were assessed by immunohistochemistry and RT-PCR.Results： FABP4 immunoreactivity was detected in alveolar macrophages,endothelial cells and epithelial cells in both groups.Compared with control group,the FABP4 level in BALF,FABP4 protein and mRNA levels in lung tissue of LPS group increased（ P〈 0.05）.Conclusion： Intra-amniotic endotoxin could change the expression of FABP4,which may contribute to BPD.