慢性阻塞性肺疾病患者肺小血管低氧诱导因子1α与其羟化酶表达

The expression of hypoxia-inducible factor-1α and its hydroxylases in pulmonary arteries of patient with chronic obstructive pulmonary disease

目的:通过观察慢性阻塞性肺疾病(COPD)患者肺小动脉内低氧诱导因子α亚基(HIF-1α)及HIF脯氨酸羟化酶(PHD)、HIF抑制因子的表达,探讨其在肺血管重塑中的可能作用。方法:选因肺肿瘤行肺叶切除者,COPD组(12例),对照组(14例)。取2组患者的肺组织,原位杂交和免疫组化检测HIF-1α、PHD1、PHD2、PHD3、FIH的mRNA及蛋白表达水平。观察并计算肺小动脉管壁厚度(PAMT)及肺小动脉管壁面积与血管总面积的比值(WA%)。结果:①COPD组PAMT(40μm±5μm)、WA%(50%±9%)均较对照组(分别为(31μm±4μm,39%±6%)高(均P<0.01);②COPD组肺小血管HIF-1αmRNA和蛋白表达(吸光度(A)值)(0.230±0.036,0.275±0.039)较对照组(0.174±0.029,0.102±0.015)增强(均P<0.01),蛋白质表达增高更明显。COPD组肺小血管PHD1 mRNA表达(0.180±0.030)与对照组(0.191±0.029)比无明显改变(P>0.05)。COPD组PHD2、PHD3 mRNA表达(0.245±0.044,0.252±0.023)较对照组(0.182±0.028,0.127±0.017)明显增高(均P<0.01)。PHD1蛋白质表达(0.104±0.015)较对照组(0.209±0.023)降低(P<0.01)。PHD2蛋白质表达(0.274±0.044)较对照组(0.219±0.043)增高(P<0.01)。PHD3蛋白质表达(0.161±0.023)较对照组(0.146±0.021)略增高,但差异无统计学意义(P>0.05)。两组间FIHmRNA和蛋白质表达差异均无显著性(P>0.05);③相关分析表明HIF-1α蛋白质水平与WA%,PAMT及PHD2、PHD3 mRNA及PHD2蛋白质呈正相关,与PHD1蛋白质呈负相关。结论:PHDs可能通过调节HIF-1α表达参与COPD患者的肺血管重塑。

Objective： To observe the expression of hypoxia-inducible factor-1α subunit （HIF-1α）, HIF prolyl hydroxylase domain-containing protein（PHDs） and factor inhibiting HIF-1 （FIH） in pulmonary arteries of patient with chronic obstructive pulmonary disease （COPD）. Methods： Pulmonary specimens were obtained from patients undergoing lobectomy for lung cancer, 12 had concurrent COPD （ COPD group） and 14 without COPD （control group）. The ratio of vascular wall area to total vascular area （WA%） and pulmonary artery media thickness （PAMT） was observed, and HIF-1α and its hydroxylases（PHD1, PHD2, PHD3, FIH） mRNA and protein were detected by in situ hybridization and immunohistochemistry respectively. Results： WA% and PAMT of COPD patients（50μm ± 9 μm, 40% ± 5%, were statistically different from those of the control subjects （39μm ± 6μm, 31% ± 4 % P 〈 0.01 ）. Relative quantification of mRNA and protein levels （ absorbance, A ） showed that H1F-la mRNA and protein levels in COPD group （0. 230 ± 0. 036,0. 275 ± 0. 039） were statistically higher than those of the control subjects （0. 174 ± 0.029, 0.102 ± 0.015, P 〈 0.01 ）, and that the protein level increased more markedly. PHD1 mRNA in COPD subjects （0. 180 ± 0.030） was comparable to that in control group（0. 191 ± 0.029, P 〉 0.05）; PHD2 and PHD3 mRNA levels in COPD （0. 245 ± 0. 044, 0. 252 ± 0. 023） were significantly higher than those in control group（0.182 ± 0. 028, 0.127 ± 0. 017, P 〈 0.01 ）. On the other hand, in COPD subjects PHD1 protein （0. 104 ± 0. 015） was significantly lower（ P 〈 0.01 ）, whereas PHD2 protein （0. 274 ± 0. 044） was significantly higher（ P 〈 0.01 ） than those in control group（0. 209 ± 0. 023, 0. 219 ± 0. 043）. As for PHD3 protein, no significant changes were observed between the two groups （0. 161 ± 0.023 in COPD, 0. 146 ± 0.02t in control, P 〉 0.05）. FIH mRNA and protein both showed no differences between the two groups. Linear correlation analysis showed that HIF-1α protein was positively correlated with WA%, PAMT, PHD2 mRNA and protein, PHD3 mRNA, and that HIF-1α protein was negatively correlated with PHD1 protein. Condusion： PHDs may be involved in the process of hypoxic pulmonary vascular remodeling in COPD via regulation of HIF-1α gene expression.