基于HIF-1信号通路基因变化探讨COPD肺血管病变的发生机制

Exploring the pathogenesis of pulmonary vascular disease in COPD based on gene changes in the HIF-1 signaling pathway

目的以慢性阻塞性肺疾病(COPD)动物模型为基础,探索COPD肺血管病变发生发展与低氧诱导因子(HIF)-1复合信号通路的关系。方法将30只SD雄性大鼠随机分为正常组10只,模型组20只,模型组后续分为造模6 w组与造模12 w组。以香烟烟雾暴露结合鼻腔滴入内毒素法建立COPD模型,收集正常组、造模6、12 w组肺组织,q-聚合酶链反应(PCR)法检测COPD模型造模后不同时间点HIF-1复合通路关键基因HIF-1α、热休克蛋白(HSP)90、血管内皮生长因子(VEGF)、诱导型一氧化氮合酶(iNOS)及内皮素(ET)-1 mRNA表达。结果与正常组相比,COPD模型组黏膜下存在明显的炎细胞浸润,肺泡壁变薄或断裂引起部分肺泡扩大融合形成肺大泡,肺血管也显示出不同程度增生,管壁增厚或管腔变形,微血管数量明显增多。与正常组相比,造模6、12 w后肺组织中HIF-1α、HSP90、VEGF、ET-1 mRNA表达显著上调(P<0.05,P<0.01),且造模12 w后肺组织中HIF-1α、VEGF、iNOS mRNA表达与造模6 w时相比显著上调(P<0.05)。与造模6 w时相比,造模12 w后肺组织中HSP90、ET-1 mRNA表达无显著差异(P>0.05)。与正常组相比,肺组织中iNOS mRNA表达在造模6 w时无显著差异(P>0.05),造模12 w后肺组织中iNOS mRNA表达显著上调(P>0.05)。结论COPD肺血管病变的发生发展与HIF-1复合信号通路的表达相关,且严重程度与造模时长呈正相关。

Objective Based on an animal model of chronic obstructive pulmonary disease(COPD),to explore the relationship between the occurrence and development of pulmonary vascular disease in COPD and the complex signaling pathway of hypoxia inducible factor(HIF)-1.Methods 30 male SD rats were randomly divided into normal group with 10 rats and model group with 20 rats.The model group was further divided into modeling 6 w group and modeling 12 w group.A COPD model was established using cigarette smoke exposure combined with nasal instillation of human endotoxins.The lung tissues of normal group,modeling 6 w and 12 w groups were collected.The expressions of key genes in the HIF-1 complex pathway including HIF-1α,heat shock protein(HSP)90,vascular endothelial growth factor(VEGF),inducible nitric oxide synthase(iNOS),and endothelin(ET)-1 mRNA were detected by q-polymerase chain reaction(PCR)method at different time points after the COPD model was established.Results Compared with the normal group,the COPD model group showed significant infiltration of inflammatory cells under the mucosa.The thinning or rupture of alveolar walls caused partial alveolar expansion and fusion to form large alveoli.Pulmonary blood vessels also showed varying degrees of proliferation,wall thickening or lumen deformation,and a significant increase in the number of microvessels.Compared with the normal group,the expressions of HIF-1α,HSP90,VEGF,and ET-1 mRNA in lung tissue were significantly up-regulated after 6 and 12 w of modeling(P<0.05,P<0.01),the expressions of HIF-1α,VEGF and iNOS mRNA in lung tissues after 12 w of modeling were significantly up-regulated compared with those at 6 w of modeling(P<0.05).Compared with 6 w of modeling,there was no significant difference in HSP90,ET-1 mRNA expressions in lung tissues after 12 w of modeling(P>0.05).Compared with the normal group,there was no significant difference in iNOS mRNA expression in lung tissue at 6 w of modeling(P>0.05),while iNOS mRNA expression was significantly up-regulated in lung tissue after 12 w of modeling(P<0.05).Conclusions The occurrence and development of pulmonary vascular disease in COPD are related to the expression of HIF-1 complex signaling pathway,and the severity is positively correlated with the duration of modeling.