Peachell P T, Undem B J, Schleimer R P, MacGlashan D W, Lichtenstein L M, Cieslinski L B, Torphy T J
School of Pharmacy, University of London, United Kingdom.
J Immunol. 1992 Apr 15;148(8):2503-10.
We attempted to identify and establish the role of cyclic nucleotide phosphodiesterase (PDE) isozymes in human basophils by using standard biochemical techniques as well as describing the effects of isozyme-selective and nonselective inhibitors of PDE. The nonselective PDE inhibitors, theophylline and 3-isobutyl-1-methylxanthine, inhibited anti-IgE-induced release of histamine and leukotriene C4 (LTC4) from basophils. This inhibition was accompanied by elevations in cAMP levels. Rolipram, an inhibitor of the low Km cAMP-specific PDE (PDE IV), inhibited the release of both histamine and LTC4 from activated basophils and increased cAMP levels in these cells. In contrast, mediator release from basophils was not inhibited by either siguazodan or SK&F 95654, inhibitors of the cGMP-inhibited PDE (PDE III) or zaprinast, an inhibitor of the cGMP-specific PDE (PDE V). SK&F 95654 failed to elevate basophil cAMP in these experiments whereas zaprinast induced significant increases in cAMP content. The inhibitory effect of rolipram on mediator release was potentiated by siguazodan or SK&F 95654, but not by zaprinast. SK&F 95654 also enhanced the ability of rolipram to increase cAMP content. Forskolin, a direct activator of adenylate cyclase, inhibited IgE-dependent release of mediators from basophils and increased cAMP levels in these cells. These effects were enhanced by rolipram, but not by SK&F 95654 or zaprinast. The cell permeant analog of cAMP, dibutyryl cAMP, inhibited mediator release from these cells, a property not shared by either dibutyryl-cGMP or sodium nitroprusside, an activator of soluble guanylate cyclase. The presence of both PDE III and PDE IV was confirmed by partially purifying and characterizing PDE activity in broken cell preparations. Overall, these data lend support to the hypothesis that cAMP inhibits mediator release from basophils and suggest that the major PDE isozyme responsible for regulating cyclic AMP content in these cells is PDE IV, with a minor contribution from PDE III. However, the finding that zaprinast caused increases in cAMP without inhibiting mediator release indicates that cAMP accumulation is not invariably linked to an inhibition of basophil activation.
我们试图通过使用标准生化技术来识别和确立环核苷酸磷酸二酯酶（PDE）同工酶在人嗜碱性粒细胞中的作用，并描述PDE同工酶选择性和非选择性抑制剂的作用效果。非选择性PDE抑制剂茶碱和3-异丁基-1-甲基黄嘌呤抑制了抗IgE诱导的嗜碱性粒细胞组胺和白三烯C4（LTC4）的释放。这种抑制伴随着cAMP水平的升高。咯利普兰，一种低Km cAMP特异性PDE（PDE IV）的抑制剂，抑制了活化嗜碱性粒细胞组胺和LTC4的释放，并提高了这些细胞中的cAMP水平。相比之下，cGMP抑制的PDE（PDE III）的抑制剂西呱旦或SK&F 95654，以及cGMP特异性PDE（PDE V）的抑制剂扎普司特，均未抑制嗜碱性粒细胞的介质释放。在这些实验中，SK&F 95654未能提高嗜碱性粒细胞中的cAMP水平，而扎普司特则显著提高了cAMP含量。咯利普兰对介质释放的抑制作用被西呱旦或SK&F 95654增强，但未被扎普司特增强。SK&F 95654还增强了咯利普兰提高cAMP含量的能力。福斯高林，一种腺苷酸环化酶的直接激活剂，抑制了嗜碱性粒细胞中IgE依赖性介质的释放，并提高了这些细胞中的cAMP水平。这些作用被咯利普兰增强，但未被SK&F 95654或扎普司特增强。cAMP的细胞渗透性类似物二丁酰cAMP抑制了这些细胞的介质释放，这一特性是二丁酰-cGMP或可溶性鸟苷酸环化酶激活剂硝普钠所不具备的。通过对破碎细胞制剂中的PDE活性进行部分纯化和表征，证实了PDE III和PDE IV的存在。总体而言，这些数据支持了cAMP抑制嗜碱性粒细胞介质释放的假说，并表明负责调节这些细胞中环磷酸腺苷含量的主要PDE同工酶是PDE IV，PDE III的贡献较小。然而，扎普司特在不抑制介质释放的情况下导致cAMP增加的发现表明，cAMP的积累并不总是与嗜碱性粒细胞活化的抑制相关联。
