Increased expression of the cGMP-inhibited cAMP-specific (PDE3) and cGMP binding cGMP-specific (PDE5) phosphodiesterases in models of pulmonary hypertension
Increased expression of the cGMP-inhibited cAMP-specific (PDE3) and cGMP binding cGMP-specific (PDE5) phosphodiesterases in models of pulmonary hypertension
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DOI：
10.1038/sj.bjp.0704984
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发表时间：
2002-12-01
影响因子：
7.3
通讯作者：
Pyne, NJ
中科院分区：
文献类型：
--
作者：
Murray, F;MacLean, MR;Pyne, NJ
1慢性低氧14天（诱导肺动脉高压，PHT）可使大鼠肺动脉cAMP特异性磷酸二酯酶（PDE 3）和cGMP结合cGMP特异性磷酸二酯酶（PDE 5）活性升高。本研究的目的是在PHT的动物和细胞模型中建立这些变化的分子基础。在这方面，RT-PCR和定量蛋白质印迹分析应用于大鼠肺动脉匀浆和人肺动脉平滑肌细胞（HPASMC）裂解液。2 PDE 3A/B基因转录水平增加，在主，第一，肺内和阻力肺动脉慢性缺氧。慢性缺氧可增加主肺动脉和第一分支肺动脉中PDE 5A 2的mRNA转录和蛋白水平，但对肺内和阻力血管中PDE 5A 1/A2的表达无影响。这可能是通过蛋白激酶A依赖性机制介导的，因为用Br-cAMP（100 μ M）处理细胞在增加PDE 3A表达方面模拟慢性缺氧，而PKA抑制剂H8肽（50 μ M）消除了PDE 3A转录的缺氧依赖性增加。4我们还发现，用kappaB降解抑制剂甲苯磺酰-亮氨酰-氯酮处理HPASMCs（TLCK，50 μ M）降低了PDE 5的转录水平，表明该转录因子在PDE 5基因表达的调节中发挥作用。5我们的研究结果表明，PDE 3和PDE 5的表达增加可能解释了PHT大鼠肺血管反应性的一些变化。我们还报道了NF-κ B可能调节基础PDE 5表达。
1 Chronic hypoxic treatment of rats (to induce pulmonary hypertension, PHT) for 14 days increased cGMP-inhibited cAMP specific phosphodiesterase (PDE3) and cGMP binding cGMP specific phosphodiesterase (PDE5) activities in pulmonary arteries. The objective of this study was to establish the molecular basis for these changes in both animal and cell models of PHT. In this regard, RT-PCR and quantitative Western blotting analysis was applied to rat pulmonary artery homogenates and human pulmonary 'artery' smooth muscle cell (HPASMC) lysates.2 PDE3A/B gene transcript levels were increased in the main, first, intrapulmonary and resistance pulmonary arteries by chronic hypoxia. mRNA transcript and protein levels of PDE5A2 in the main and first branch pulmonary arteries were also increased by chronic hypoxia, with no effect on PDE5A1/A2 in the intra-pulmonary and resistance vessels.3 The expression of PDE3A was increased in HPASMCs maintained under chronic hypoxic conditions for 14 days. This may be mediated via a protein kinase A-dependent mechanism, as treatment of cells with Br-cAMP (100 mum) mimicked chronic hypoxia in increasing PDE3A expression, while the PKA inhibitor, H8 peptide (50 muM) abolished the hypoxic-dependent increase in PDE3A transcript.4 We also found that the treatment of HPASMCs with the inhibitor Of kappaB degradation Tosyl-Leucyl-Chloro-Ketone (TLCK, 50 muM) reduced PDE5 transcript levels, suggesting a role for this transcription factor in the regulation of PDE5 gene expression.5 Our results show that increased expression of PDE3 and PDE5 might explain some changes in vascular reactivity of pulmonary vessels from rats with PHT. We also report that NF-kappaB might regulate basal PDE5 expression.