Busch Cornelius J, Liu Heling, Graveline Amanda R, Bloch Kenneth D
Department of Anesthesia and Critical Care, Charlestown, MA, USA.
Am J Physiol Lung Cell Mol Physiol. 2006 Apr;290(4):L747-L753. doi: 10.1152/ajplung.00298.2005. Epub 2005 Nov 18.
Phosphodiesterases (PDE) metabolize cyclic nucleotides limiting the effects of vasodilators such as prostacyclin and nitric oxide (NO). In this study, DNA microarray techniques were used to assess the impact of NO on expression of PDE genes in rat pulmonary arterial smooth muscle cells (rPASMC). Incubation of rPASMC with S-nitroso-l-glutathione (GSNO) increased expression of a PDE isoform that specifically metabolizes cAMP (PDE4B) in a dose- and time-dependent manner. GSNO increased PDE4B protein levels, and rolipram-inhibitable PDE activity was 2.3 +/- 1.0-fold greater in GSNO-treated rPASMC than in untreated cells. The soluble guanylate cyclase (sGC) inhibitor, 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one, and the cAMP-dependent protein kinase inhibitor, H89, prevented induction of PDE4B gene expression by GSNO, but the protein kinase G (PKG) inhibitors, Rp-8-pCPT-cGMPs and KT-5823, did not. Incubation of rPASMC with IL-1beta and tumor necrosis factor-alpha induced PDE4B gene expression, an effect that was inhibited by l-N(6)-(1-iminoethyl)lysine, an antagonist of NO synthase 2 (NOS2). The GSNO-induced increase in PDE4B mRNA levels was blocked by actinomycin D but augmented by cycloheximide. Infection of rPASMC with an adenovirus specifying a dominant negative cAMP response element binding protein (CREB) mutant inhibited the GSNO-induced increase of PDE4B gene expression. These results suggest that exposure of rPASMC to NO induces expression of PDE4B via a mechanism that requires cGMP synthesis by sGC but not PKG. The GSNO-induced increase of PDE4B gene expression is CREB dependent. These findings demonstrate that NO increases expression of a cAMP-specific PDE and provide evidence for a novel "cross talk" mechanism between cGMP and cAMP signaling pathways.
磷酸二酯酶（PDE）可代谢环核苷酸，从而限制诸如前列环素和一氧化氮（NO）等血管舒张剂的作用。在本研究中，利用DNA微阵列技术评估NO对大鼠肺动脉平滑肌细胞（rPASMC）中PDE基因表达的影响。用S-亚硝基-L-谷胱甘肽（GSNO）孵育rPASMC，以剂量和时间依赖性方式增加了一种特异性代谢cAMP的PDE同工型（PDE4B）的表达。GSNO增加了PDE4B蛋白水平，且在经GSNO处理的rPASMC中，罗匹尼罗可抑制的PDE活性比未处理细胞高2.3±1.0倍。可溶性鸟苷酸环化酶（sGC）抑制剂1H-[1,2,4]恶二唑并[4,3,-a]喹喔啉-1-酮和cAMP依赖性蛋白激酶抑制剂H89可阻止GSNO诱导的PDE4B基因表达，但蛋白激酶G（PKG）抑制剂Rp-8-pCPT-cGMPs和KT-5823则不能。用白细胞介素-1β和肿瘤坏死因子-α孵育rPASMC可诱导PDE4B基因表达，该效应被一氧化氮合酶2（NOS2）拮抗剂L-N(6)-(亚氨乙基)赖氨酸抑制。GSNO诱导的PDE4B mRNA水平升高被放线菌素D阻断，但被环己酰亚胺增强。用指定显性负性cAMP反应元件结合蛋白（CREB）突变体的腺病毒感染rPASMC可抑制GSNO诱导的PDE4B基因表达增加。这些结果表明，rPASMC暴露于NO通过一种需要sGC合成cGMP而非PKG的机制诱导PDE4B表达。GSNO诱导的PDE4B基因表达增加是CREB依赖性的。这些发现表明NO增加了一种cAMP特异性PDE的表达，并为cGMP和cAMP信号通路之间的新型“串扰”机制提供了证据。
