Preferential Inhibition of T Helper 1, but Not T Helper 2, Cytokines in Vitro by L-826,141 [4-{2-(3,4-Bisdifluromethoxyphenyl)-2-{4-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)-phenyl]-ethyl}-3-methylpyridine-1-oxide], a Potent and Selective Phosphodiesterase 4 Inhibitor

Abstract

L-826,141 [4-{2-(3,4-bis-difluromethoxyphenyl)-2-{4-(1,1,1, 3,3,3-hexafluoro-2-hydroxypropan-2-yl)-phenyl]-ethyl}-3-methylpyridine-1-oxide] is a selective and potent inhibitor of phosphodiesterase 4 (PDE4) with an IC 50 value of 0.26 to 2.4 nM for inhibition of the catalytic activity of PDE4A, B, C, and D. The cAMP elevation that can be maintained by PDE4 inhibitors attenuates the signaling cascades that lead to the production of certain cytokines. In cellular-based assays, L-826,141 transcriptionally down-regulates production of tumor necrosis factor (TNF)-␣ in peripheral blood mononuclear cell and whole blood assays with IC 50 values of 31 and 310 nM, respectively. Profiling the effect of this compound on various cytokines in the signaling cascade attenuated by cAMP elevation demonstrates that L-826,141 is also a potent inhibitor of interleukin (IL)-12, granulocyte macrophage-colony stimulating factor, and interferon (IFN)␥ (IC 50 values of 0.3-0.9 M) as well as TNF-␣ formation. We have also shown that the PDE4 inhibitors rolipram and L-826,141 are potent inhibitors of CD3-plus CD28-stimulated IL-2 production in naive human T cells. To address the effect of PDE4 inhibitors on cytokine release from T helper (Th)1 and Th2 effector cells, we used a well characterized model in which T cells are derived from ovalbumin (323-339)-specific T cell receptor transgenic mice. L-826,141 inhibits Th0-mediated IL-2 production with an IC 35 value of 25 nM and Th1-mediated IFN␥ production with an IC 30 value of 46 nM. In contrast, L-826,141 had no significant inhibitory effect (IC 30 value Ͼ 2.5 M) on Th2 cell-mediated IL-4 nor IL-13 production. Together, these data demonstrate that specific inhibition of PDE4 preferentially blocks the production of Th1 versus Th2 effector cytokines in vitro.The second messenger cAMP and the ensuing signaling cascades have been investigated for more than 50 years (Robison et al., 1968). cAMP is generated enzymatically by the action of adenylate cyclase, and this enzyme is activated after the interaction of various ligands with G protein-coupled receptors (Krupinski et al

Dynamic Activation of Cystic Fibrosis Transmembrane Conductance Regulator by Type 3 and Type 4D Phosphodiesterase Inhibitors

“…As summarized by their intrinsic potencies against the multiple recombinant cAMP-PDEs in Table 1, Cpd-A and roflumilast are potent PDE4 inhibitors, with IC 50 values ranging from 0.2 to 2.4 nM and from 0.1 to 0.6 nM for the inhibition of PDE4A, 4B, 4C, and 4D, respectively. Cpd-A and roflumilast are Ͼ400-and 10,000-fold more potent than their weaker PDE3 inhibition, respectively (Claveau et al, 2004). Trequinsin, with IC 50 value of ϳ0.05 nM against PDE3A and 3B, is Ͼ6000-fold more potent compared with its weaker PDE4 inhibition.…”

“…Agents such as PDE4 and PDE4D inhibitors that can reduce the exuberant inflammation response and simultaneously enhance mucociliary clearance through CFTR activation in airway may provide additional benefits over antiinflammatory treatment alone in their management. Cpd-A and roflumilast belong to the second generation nonselective PDE4 inhibitors, effectively suppressing the overproduction of leukotrienes and a variety of proinflammatory cytokines in vitro and in animal models (Hatzelmann and Schudt, 2001;Claveau et al, 2004). Treatment with roflumilast at 0.5 mg once daily has significantly improved airway function in asthmatic and COPD patients, with its plasma concentration reached a C max of 3.8 ng/ml (ϳ9.5 nM) and the active N-oxide metabolite being severalfold higher (Reid, 2002).…”

“…Buffer chemicals were from Sigma-Aldrich (St. Louis, MO). (Marfat and Chambers, 1998;Reid, 2002;Claveau et al, 2004). Forskolin, H89, and trequinsin [9,10-dimethoxy-2-mesitylimino-3-methyl-2,3,6,7-tetrahydro-(6,1-a)-isoquinolin-4-one, HCl] were from Calbiochem (San Diego, CA).…”

“…The lysate cAMP-PDE activity was determined by monitoring the hydrolysis of 0.1 M [ 3 H]cAMP in 10 mM MgCl 2 and 50 mM HEPES, pH 7.2, using the SPA-PDE assay kit from Amersham Biosciences, Inc. (Laliberte et al, 2000). The potencies of inhibitors against multiple PDEs in Table 1 were determined using 0.1 M [ 3 H]cAMP for PDE1, PDE4s, PDE7A, and PDE8B and 0.01 M [ 3 H]cAMP for PDE3A and PDE3B under the same assay conditions as detailed previously (Claveau et al, 2004). Under the conditions, they were close to the apparent K i .…”

Phosphodiesterase Inhibitors for the Treatment of Asthma and Chronic Obstructive Pulmonary Disease

“…Another study demonstrated that specific inhibition of PDE4 had no significant effect on Th2 cell-mediated IL-4 or IL-13 generation, but preferentially inhibited Th1 cell cytokine generation (IFN-γ) [52]. PDE4 inhibitors also partially inhibit phytohemagglutinin and anti-CD3/anti-CD28 stimulates the proliferation of CD4+ and CD8+ T cells [21,53]. A separate study demonstrated that dual PDE4A/B and PDE4D inhibitors inhibited antigen-stimulated human T cell proliferation, with mean IC 50 values significantly correlating with compound potency against the catalytic activity of recombinant PDE4A or PDE4B, but not with the catalytic activity of recombinant PDE4D [43].…”