巢蛋白在低氧大鼠肺组织及肺动脉平滑肌细胞的表达及意义

目的研究不同间期低氧大鼠肺组织及低氧培养的肺动脉平滑肌细胞（PASMC）中巢蛋白的表达变化。方法24只雄性sD大鼠随机分为正常对照组（N组），低氧2周组（H2W组），低氧4周组（H4w组）。测定大鼠肺动脉平均压（mPAP）、颈动脉平均压（mCAP）、右心室／（左心室＋室间隔）质量比RV/（LV＋S）]、肺动脉相对中膜厚度（PAMT）；免疫组织化学染色测定肺动脉巢蛋白含量。分别采用逆转录PCR和蛋白印迹法检测各组大鼠肺组织巢蛋白的mRNA及蛋白含量。蛋白印迹法检测常氧和缺氧培养的PASMC中巢蛋白的蛋白含量。结果H2W组、H4w组mPAP、RV／（LV＋S）、PAMT、肺动脉巢蛋白的蛋白含量、肺组织匀浆巢蛋白mRNA及蛋白含量均显著高于N组（P〈0．01），且随着低氧时间的延长，逐渐增加；肺动脉平滑肌细胞中的巢蛋白的蛋白含量，随着低氧培养的时间的增加而逐渐增高（P均〈0．05）。结论低氧时巢蛋白在大鼠肺组织及肺动脉平滑肌细胞中的表达增加，后者可能在肺血管重构中起着重要作用。

Significance of nestin expression in lung tissues and pulmonary artery smooth muscle cells of rats underhypoxic condition

Objective To study the expression of nestin in lung tissues and pulmonary artery smooth muscle cells of rats treated by different periods of hypoxia. Methods Twenty-four male Sprague-Dawley rats were randomly divided into three groups： normal-group （N） , hypoxic 2-week group （H2w） , hypoxie 4-week group （H4w）. The mean pulmonary arterial pressure （mPAP）, mean carotid arterial pressure （mCAP）, weight ratio of right ventricle （RV） to left ventricle plus septum（ LV ＋ S） RV/（ LV ＋ S） ] and the medium thickness of pulmonary artery （PAMT） were detected. Nestin protein expression in lung artery was detected by immunohistochemistry. RT-PCR and Western blotting were used to examine the mRNA level and protein level of nestin in pulmonary tissues. Western blotting was also used to detect the nestin protein in PASMCs, which were cultured under normoxia or hypoxia. Results Compared with N group, the mPAP, RV/（ LV ＋ S） PAMT, nestin protein expression in lung artery, mRNA and protein of nestin in pulmonary tissues were all significantly higher in both H2W group and H4W group（ P 〈 0.01 ）, and they were gradually increased with the extension of hypoxia time. Nestin protein expression in PASMCs, with the increased time of hypoxia, was gradually up-regulated（all P 〈 0. 05 ）. Conclusion Lung tissues and pulmonary ratery smooth muscle cells expressed more nestin in hypoxic environment, which may play an important role in pulmonary vascular remodeling.