Preservation of nitric oxide-induced relaxation of porcine coronary artery: roles of the dimers of soluble guanylyl cyclase, phosphodiesterase type 5, and cGMP-dependent protein kinase
Preservation of nitric oxide-induced relaxation of porcine coronary artery: roles of the dimers of soluble guanylyl cyclase, phosphodiesterase type 5, and cGMP-dependent protein kinase
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DOI：
10.1007/s00424-014-1441-2
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发表时间：
2014-01
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影响因子：
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通讯作者：
Juan Liu;Zhengju Chen;L. Ye;Huixia Liu;D. Dou;Limei Liu;Xiaoxing Yu;Yuansheng Gao
中科院分区：
文献类型：
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作者：
Juan Liu;Zhengju Chen;L. Ye;Huixia Liu;D. Dou;Limei Liu;Xiaoxing Yu;Yuansheng Gao
可溶性鸟苷酸环化酶（sGC）、磷酸二酯酶5（PDE 5）和鸟苷3′，5 ′-环磷酸（cGMP）依赖性蛋白激酶（PKG）均为二聚体。本研究旨在确定它们的二聚体状态在一氧化氮诱导的血管舒张中的作用。在离体猪冠状动脉中，与无血清培养基、含血清培养基或磷酸盐缓冲盐水溶液孵育20 h后，sGC、PDE 5和PKG二聚体的蛋白水平降低，而单体水平保持不变，与DETA NONOate引起的cGMP升高降低和PDE 5活性降低相关; PKG活性未发生显著变化。DETA NONOate在孵育20小时与2小时的动脉中引起更大的舒张。1H-[1，2，4]恶二唑并[4，3-a]喹喔啉-1-酮（sGC抑制剂）在很大程度上消除了舒张反应。PDE 5抑制剂Zaprinast对孵育20 h的DETA NONOate引起的动脉舒张无影响，但增强孵育2 h的反应。8-溴-鸟苷3′5′-环一磷酸对孵育20 h的动脉的舒张作用大于孵育2 h的动脉。二硫苏糖醇降低了PDE 5二聚体而非单体的蛋白质水平，且不受过氧化氢的影响，同时伴有PDE 5活性降低和对DETA NONOate的反应降低。这些结果表明，冠状动脉sGC和PDE 5的二聚体而不是单体状态与其活性密切相关。孵育20 h后保留的血管舒张反应可能部分归因于sGC和PDE 5二聚体水平的同步降低以及对cGMP的反应增强。
Soluble guanylyl cyclase (sGC), phosphodiesterase type 5 (PDE5), and guanosine 3′,5′-cyclic monophosphate (cGMP)-dependent protein kinase (PKG) are all dimeric. The present study was to determine the role of their dimeric status in nitric oxide-induced vasodilatation. In isolated porcine coronary arteries, after 20 h incubation with serum-free medium, serum-containing medium, or phosphate-buffered saline solution, the protein levels of the dimers of sGC, PDE5, and PKG were diminished while the monomer levels remained unchanged, associated with reduced cGMP elevation in response to DETA NONOate and decreased PDE5 activity; the activity of PKG was not significantly altered. DETA NONOate caused a greater relaxation in arteries incubated for 20 vs. 2 h. The relaxant response was largely abolished by 1H-[1, 2, 4]oxadiazolo[4,3-a]quinoxalin-1-one, an sGC inhibitor. Zaprinast, a PDE5 inhibitor, had no effect on relaxation caused by DETA NONOate of arteries incubated for 20 h but augmented the response incubated for 2 h. A greater relaxation to 8-bromo-guanosine 3′5′-cyclic monophosphate occurred in arteries incubated for 20 than for 2 h. The protein level of the dimers but not monomers of PDE5 was reduced by dithiothreitol and unaffected by hydrogen peroxide, accompanied with decreased PDE5 activity and reduced response to DETA NONOate. These results demonstrate that the dimeric but not monomeric status of sGC and PDE5 of coronary arteries are closely related to their activities. The preserved vasodilator response after 20 h incubation may result in part from a synchronous reduction of the dimer levels of sGC and PDE5 as well as an augmented response to cGMP.