上海交通大学学报(医学版)

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LPS诱导大鼠急性肺损伤后早期肺纤维化进展过程中肺组织AT1R/Mas受体表达的动态变化

刘玉静,曹永梅,平凤,李颖川   

  1. 上海交通大学 附属第六人民医院麻醉科, 上海 200233
  • 出版日期:2016-05-28 发布日期:2016-05-26
  • 通讯作者: 李颖川, 电子信箱: dr.yingchuan.li@gmail.com。
  • 作者简介:刘玉静(1991—), 女, 硕士生; 电子信箱: liuyujing0823@126.com。
  • 基金资助:

    国家自然科学基金(81272145)

Dynamic changes in expressions of AT1R and Mas receptors in lung tissues during the development of early pulmonary fibrosis following LPS-induced acute lung injury in rats

LIU Yu-jing, CAO Yong-mei, PING Feng, LI Ying-chuan   

  1. Department of Anesthesiology, Shanghai Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
  • Online:2016-05-28 Published:2016-05-26
  • Supported by:

    National Natural Science Foundation of China,81272145

摘要:

目的 建立脂多糖(LPS)介导的大鼠急性肺损伤后早期肺纤维化模型并观察其过程中血管紧张素系统主要组分血管紧张素Ⅱ1型受体(AT1R)和Mas受体的变化趋势。方法 分别由腹腔和气道内间断3次注射LPS建立大鼠急性肺损伤后早期肺纤维化模型,并于末次注射后第3、7、14和21日处死大鼠,取肺组织及血浆。H-E染色和Masson染色观察肺组织形态结构改变;ELISA试剂盒检测血浆中TGF-β的水平;RT-qPCR及Western blotting检测肺组织中AT1R和Mas mRNA和蛋白表达变化。结果 经LPS复合打击后,大鼠肺组织病理改变在第3日以肺部炎症反应为主要表现,而第7日后炎症减弱,肺组织正常形态结构遭到破坏,Masson染色提示胶原纤维沉积逐渐增加,血浆中TGF-β的含量逐渐升高(P<0.01),从而形成早期肺纤维化。另外,随着LPS诱导肺纤维化的发展,AT1R mRNA表达无显著变化,但其蛋白表达在第14日及21日明显增加;肺组织内Mas mRNA表达逐渐增加,至第21日明显升高至对照组的15倍,而Mas受体蛋白的表达在第14日及21日明显下调至对照组的30%(P<0.01)。结论 LPS复合多次打击能有效建立大鼠急性肺损伤后早期肺纤维化模型,且随着肺纤维化发展,AT1R/Mas受体呈上升/下降相反的表达变化。

关键词: 脂多糖, 急性肺损伤, 早期肺纤维化, AT1R, Mas

Abstract:

Objective To construct a rat model of early pulmonary fibrosis following lipopolysaccharide (LPS)-induced acute lung injury and observe the change trend in major members of renin-angiotensin-system angiotensin Ⅱ type 1 receptor (AT1R) and Mas receptor during lung injury process. Methods A rat model of early pulmonary fibrosis following acute lung injury was built by three intermittent injections of LPS into the abdomen and airway. Rats were sacrificed 3, 7, 14, and 21 d after last injection. Lung tissues and blood samples were harvested. The histomorphological changes in lung tissues were observed with H-E and Masson staining. The plasma TGF-β level was measured with ELISA kits. The mRNA and protein expressions of AT1R and Mas receptors in lung tissues were detected with RT-qPCR and Western blotting, respectively. Results The main presentation of histomorphological changes in lung tissues was inflammatory response at day 3 after LPS injections. The inflammation was reduced 7 d after LPS injections and the normal morphology of lung tissues was damaged. Masson staining revealed increased collagen protein deposition and plasma TGF-β level (P<0.01), which resulted in early pulmonary fibrosis. In addition, with the development of LPS-induced pulmonary fibrosis, the mRNA expression of AT1R did not change significantly, but the protein expression of AT1R markedly increased on day 14 and 21. The mRNA expression of Mas in lung tissues increased gradually and was 15 folds higher than that in the control group on day 21, while the protein expression of Mas significantly decreased to 30% of that in the control group on day 14 and 21 (P<0.01). Conclusion Repeated LPS injections can effectively construct the rat model of early pulmonary fibrosis following acute lung injury. The expressions of AT1R and Mas receptors show opposite changes with the development of pulmonary fibrosis.

Key words: LPS, acute lung injury, early pulmonary fibrosis, AT1R, Mas