Li Qi-Fang, Dai Ai-Guo
Department of Respiratory Medicine, Geriatric Hospital of Hunan Province, Changsha 410001, China.
Acta Biochim Biophys Sin (Shanghai). 2004 Feb;36(2):133-40. doi: 10.1093/abbs/36.2.133.
To test the hypothesis that hypoxia inducible factor-1 alpha (HIF-1alpha) up-regulated the expression of heme oxygenase-1 (HO-1) gene in pulmonary arteries of rats with hypoxia-induced pulmonary hypertension, 8 male Wistar rats in each of 5 groups were exposed to hypoxia for 0, 3, 7, 14 or 21 d, respectively. Mean pulmonary arterial pressure (mPAP), vessel morphometry and right ventricle hypertrophy index were measured. Lungs were inflation fixed for immunohistochemistry, in situ hybridization; frozen for later measurement of HO-1 enzyme activity. mPAP increased significantly after 7 d of hypoxia [(18.4 +/- 0.4) mmHg, P<0.05], reaching its peak after 14 d of hypoxia, then remained stable. Pulmonary artery remodeling became to develop significantly after 14 d of hypoxia. HIF-1alpha protein in control was poorly positive (0.05 +/- 0.01), but was up-regulated in pulmonary arterial tunica intima of all hypoxic rats. In pulmonary arterial tunica media, the levels of HIF-1alpha protein were markedly up-regulated after 3 d and 7 d of hypoxia (0.20 +/- 0.02; 0.22 +/- 0.02, P<0.05), then declined after 14 d and 21 d of hypoxia. HIF-1alpha mRNA staining was poorly positive in control, hypoxia for 3 and 7 d, but enhanced significantly after 14 d of hypoxia (0.20 +/- 0.02, P<0.05), then remained stable. HO-1 protein increased after 7 d of hypoxia (0.10 +/- 0.01, P<0.05), reaching its peak after 14 d of hypoxia (0.21 +/- 0.02, P<0.05), then remained stable. HO-1 mRNA increased after 3 d of hypoxia, reaching its peak after 7 d of hypoxia (0.17 +/- 0.01, P<0.05), then declined. Linear correlation analysis showed that HIF-1alpha mRNA, HO-1 protein and mPAP were associated with pulmonary remodeling. HIF-1alpha protein (tunica intima) was conversely correlated with HIF-1alpha mRNA (r=0.921,P<0.01), HO-1 protein was conversely correlated with HIF-1alpha protein (tunica intima) (r=0.821, P<0.01). HIF-1alpha and HO-1 were both involved in the pathogenesis of hypoxia-induced pulmonary hypertension in rat. Hypoxia inducible factor-1 alpha correlated the expression of heme oxygenase 1 gene in pulmonary arteries of rat with hypoxia-induced pulmonary hypertension.
为验证缺氧诱导因子-1α（HIF-1α）上调缺氧诱导的肺动脉高压大鼠肺动脉中血红素加氧酶-1（HO-1）基因表达这一假说，将5组每组8只雄性Wistar大鼠分别暴露于缺氧环境0、3、7、14或21天。测量平均肺动脉压（mPAP）、血管形态计量学指标及右心室肥厚指数。取肺进行充气固定用于免疫组织化学、原位杂交；冷冻保存用于后续HO-1酶活性测定。缺氧7天后mPAP显著升高[（18.4±0.4）mmHg，P<0.05]，缺氧14天后达到峰值，随后保持稳定。缺氧14天后肺动脉重塑开始显著发展。对照组HIF-1α蛋白弱阳性（0.05±0.01），但在所有缺氧大鼠的肺动脉内膜中上调。在肺动脉中膜，缺氧3天和7天后HIF-1α蛋白水平显著上调（0.20±0.02；0.22±0.02，P<0.05），缺氧14天和21天后下降。HIF-1α mRNA染色在对照组、缺氧3天和7天时弱阳性，但缺氧14天后显著增强（0.20±0.02，P<0.05），随后保持稳定。缺氧7天后HO-1蛋白增加（0.10±0.01，P<0.05），缺氧14天后达到峰值（0.21±0.02，P<0.05），随后保持稳定。缺氧3天后HO-1 mRNA增加，缺氧7天后达到峰值（0.17±0.01，P<0.05），随后下降。线性相关分析表明，HIF-1α mRNA、HO-1蛋白和mPAP与肺重塑相关。HIF-1α蛋白（内膜）与HIF-1α mRNA呈负相关（r=0.921，P<0.01），HO-1蛋白与HIF-1α蛋白（内膜）呈负相关（r=0.821，P<0.01）。HIF-1α和HO-1均参与大鼠缺氧诱导的肺动脉高压发病机制。缺氧诱导因子-1α与缺氧诱导的肺动脉高压大鼠肺动脉中血红素加氧酶1基因的表达相关。
