摘要
目的探讨转化生长因子-β1(TGF-β1)诱导成肌纤维细胞形成在低氧性肺血管重塑中的作用。方法40只成年雄性Wistar大鼠随机分成:对照组、低氧3、7、14和21 d组,每组8只,测大鼠平均肺动脉压(mPAP)、血管形态学指标、右室肥大指数(RVHI);免疫组化检测α-平滑肌肌动蛋白(α-SMA)的表达,原位杂交和免疫组化检测TGF-β1基因表达,透射电镜观察腺泡内血管壁细胞表型,细胞培养观察低氧和TGF-β1诱导人胚肺成纤维细胞是否发生表型转化。结果(1)低氧7 d后大鼠mPAP升高(P<0.05)。低氧14 d后出现肺血管重塑、右心室肥大。(2)从低氧7 d开始无肌型动脉、部分肌型动脉、肌型动脉的构成比分别是39%、46%和15%,与对照组60%、35%和5%比较差异显著(P<0.005)。(3)腺泡内肺动脉管壁α-SMA的表达随着低氧时间的延长逐渐增多。低氧14 dTGF-β1mRNA表达增高(P<0.01);TGF-β1蛋白在对照组呈弱阳性,低氧3 d表达增强(P<0.01),低氧7 d达高峰(P<0.01)。(4)透射电镜证实成肌纤维细胞含有特异性的微丝和丰富的粗面内质网。(5)细胞培养表明低氧能够刺激成纤维细胞发生表型转化,TGF-β1能够促进成纤维细胞表型转化的发生。结论转化生长因子β1诱导成肌纤维细胞形成是低氧性肺血管重塑的重要原因之一。
Objective To investigate the biological effect of transforming growth factor-β1（TGF-β1） on inducing myofibroblast formation in hypoxic pulmonary vascular remodeling. Methods Forty male Wistar rats were exposed to hypoxia for 0, 3, 7, 14 or 21 days. Mean pulmonary arterial pressure （ mPAP）, vessel morphometry, right ventricle hypertrophy index （RVHI） were measured. Immunocytochemistry was used to measure the expression of α-Smooth-muscle actin（α-SMA） and TGF-β1 in pulmonary artery walls and in situ hybridization was used to measure the expression of TGF-β1 mRNA in pulmonary artery walls. Ultrastructure alveolar wall vessels were observed by electron microscopy. Human embryonic lung fibroblasts（ KMB17 ） phenotype after induction of hypoxia and TGF-β1 were recorded through cell culture. Results （ 1 ） mPAP increased significantly after 7-day of hypoxia （P 〈 0. 05 ）. Pulmonary artery remodeling index and right ventricle hypertrophy became evident after 14-day of hypoxia. （2） The distribution of nonmuscular, partially muscular, and muscular vessels （39% .46%. 15 % ） is significantly different （Px2 〈 0. 005 ） from hypoxia for 7 day than that in the control group （60% .35% .5% ）. （3）The intra-acinar pulmonary arteries with cells expressing α-SMA increased most with hypoxic time by immunocytochemistry. TGF-β1 mRNA expression in pulmonary arterial walls was significantly increased after 14 days of hypoxia （P 〈0. 01 ）. TGF-β1 staining was negative in control rats, but was markedly enhanced after 3 days of hypoxia （P 〈0. 01 ）. （4） The myofibroblast phenotype was confirmed by electron microscopy. （5） Cell culture showed hypoxia induced KMB17 phenotype transforming and TGF-β1 accelerated its transforming. Conclusion Transforming growth factor-β1 （TGF-β1） induces myofibroblast formation is the important causes in hypoxic pulmonary vascular remodeling.
出处
《基础医学与临床》
CSCD
北大核心
2008年第3期232-237,共6页
Basic and Clinical Medicine
基金
湖南省医药卫生科研基金(02-Y081
B2004-137)
湖南省教育厅科研基金(03C397)
