Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eotaxin is a potent eosinophil chemoattractant that contributes to the eosinophilia seen in asthma and other allergic disorders. Recent studies have identified human airway smooth muscle (HASM) as a rich source of eotaxin, but the factors regulating its production are poorly understood. Here we describe for the first time that beta2-agonists can inhibit cytokine-induced eotaxin release. We found that TNF-alpha stimulated eotaxin release (assayed by ELISA) from HASM cells and that the release was partially inhibited by salbutamol and salmeterol. The effect of beta2-agonists was mimicked by forskolin and 8-bromo-cAMP and potentiated by the cAMP-dependent phosphodiesterase inhibitor rolipram, suggesting that it is cAMP dependent. We also found that the cAMP inhibition was likely at the transcription stage, although experiments with the PKA inhibitors H-89 and Rp-cAMP or the PKG inhibitor KT5823 suggested that none of these kinases was involved. Partial inhibition of eotaxin release was also seen with the corticosteroids dexamethasone and fluticasone. The combined use of beta2-agonists, rolipram, and steroids abolished TNF-alpha-induced eotaxin release. These results suggest that the combination of a beta2-agonist, PDE inhibitor, and a corticosteroid may have additive beneficial effects in the treatment of the eosinophilia associated with asthma and other allergic diseases.
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PMID:Regulation of TNF-alpha-induced eotaxin release from cultured human airway smooth muscle cells by beta2-agonists and corticosteroids. 1114 14

Diabetic nephropathy is a major complication of diabetes leading to end-stage renal disease, which requires hemodialysis. Although the mechanism by which it progresses is largely unknown, the role of hyperglycemia-derived oxidative stress has recently been the focus of attention as the cause of diabetic complications. Constituent cells of the renal glomeruli have the capacity to release reactive oxygen species (ROS) upon stimulation of NADPH oxidase activated by protein kinase C (PKC). Hyperglycemia and insulin resistance in the diabetic state are often associated with activation of PKC and tumor necrosis factor (TNF)-alpha, respectively. The aim of this study is to clarify the signaling pathway leading to ROS production by PKC and TNF-alpha in rat glomeruli. Isolated rat glomeruli were stimulated with phorbol 12-myristate 13-acetate (PMA) and TNF-alpha, and the amount of ROS was measured using a chemiluminescence method. Stimulation with PMA (10 ng/ml) generated ROS with a peak value of 136+/-1.2 cpm/mg protein (mean+/-SEM). The PKC inhibitor H-7, the NADPH oxidase inhibitor diphenylene iodonium and the phosphatidylinositol-3 (PI-3) kinase inhibitor wortmannin inhibited PMA-induced ROS production by 100%, 100% and 80%, respectively. In addition, TNF-alpha stimulated ROS production (283+/-5.8/mg protein/20 min). The phosphodiesterase inhibitor cilostazol activates protein kinase A and is reported to improve albuminuria in diabetic rats. Cilostazol (100 microg/ml) inhibited PMA, and TNF-alpha-induced ROS production by 78+/-1.8, and 19+/-2.7%, respectively. The effects of cilostazol were not additive with wortmannin. Cilostazol arrests oxidative stress induced by PKC activation by inhibiting the PI-3 kinase-dependent pathway, and may thus prevent the development of diabetic nephropathy.
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PMID:Induction of reactive oxygen species from isolated rat glomeruli by protein kinase C activation and TNF-alpha stimulation, and effects of a phosphodiesterase inhibitor. 1734 51