Wharton John, Strange Julian W, Møller Gigi M O, Growcott Ellena J, Ren Xiaohui, Franklyn Angela P, Phillips Stephen C, Wilkins Martin R
Section on Experimental Medicine and Toxicology, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 ONN, UK.
Am J Respir Crit Care Med. 2005 Jul 1;172(1):105-13. doi: 10.1164/rccm.200411-1587OC. Epub 2005 Apr 7.
Phosphodiesterase Type 5 (PDE5) inhibition represents a novel strategy for the treatment of pulmonary hypertension.
Our aim was to establish the distribution of PDE5 in the pulmonary vasculature and effects of PDE5 inhibition on pulmonary artery smooth muscle cells (PASMCs).
PDE5 expression was examined by immunohistochemistry and Western blotting, in both normal and hypertensive lung tissues. DNA synthesis, proliferation, PDE activity, and apoptosis were measured in distal human PASMCs treated with soluble guanylyl cyclase activators (nitric oxide donors and BAY41-2272) and sildenafil.
Cells containing PDE5 and alpha-smooth muscle actin occurred throughout the pulmonary vasculature, including obstructive intimal lesions. Three molecular forms of PDE5 were identified and protein expression was greater in hypertensive than control lung tissue. Most cyclic guanosine monophosphate hydrolysis (about 80%) in cultured cells was attributed to PDE5. Sildenafil induced a greater elevation of intracellular cyclic guanosine monophosphate levels compared with nitric oxide donors and BAY41-2272 (about 10-fold versus about 2-fold) and cotreatment had a synergistic effect, increasing cyclic nucleotide levels up to 50-fold. Dual stimulation of soluble guanylyl cyclase and inhibition of PDE5 activities also had significant downstream effects, increasing phosphorylation of vasodilator-stimulated phosphoprotein, reducing DNA synthesis and cell proliferation, and stimulating apoptosis, and these effects were mimicked by cyclic guanosine monophosphate analogs.
Phosphodiesterase Type 5 is the main factor regulating cyclic guanosine monophosphate hydrolysis and downstream signaling in human PASMCs. The antiproliferative effects of this signaling pathway may be significant in the chronic treatment of pulmonary hypertension with PDE5 inhibitors such as sildenafil.
5型磷酸二酯酶（PDE5）抑制是一种治疗肺动脉高压的新策略。
我们的目的是确定PDE5在肺血管系统中的分布以及PDE5抑制对肺动脉平滑肌细胞（PASMCs）的影响。
通过免疫组织化学和蛋白质印迹法检测正常和高血压肺组织中PDE5的表达。在用可溶性鸟苷酸环化酶激活剂（一氧化氮供体和BAY41-2272）和西地那非处理的人远端PASMCs中测量DNA合成、增殖、PDE活性和凋亡。
含有PDE5和α-平滑肌肌动蛋白的细胞存在于整个肺血管系统中，包括阻塞性内膜病变。鉴定出PDE5的三种分子形式，高血压肺组织中的蛋白质表达高于对照肺组织。培养细胞中大部分环磷酸鸟苷水解（约80%）归因于PDE5。与一氧化氮供体和BAY41-2272相比，西地那非诱导细胞内环磷酸鸟苷水平升高幅度更大（约10倍对约2倍），联合处理具有协同作用，使环核苷酸水平提高至50倍。可溶性鸟苷酸环化酶的双重刺激和PDE5活性的抑制也有显著的下游效应，增加血管舒张刺激磷蛋白的磷酸化，减少DNA合成和细胞增殖，并刺激凋亡，这些效应被环磷酸鸟苷类似物模拟。
5型磷酸二酯酶是调节人PASMCs中环磷酸鸟苷水解和下游信号传导的主要因素。该信号通路的抗增殖作用在用西地那非等PDE5抑制剂长期治疗肺动脉高压中可能具有重要意义。
