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)

It has been suggested that the erythrocytes of myotonic dystrophy (MyD) patients have a decreased calcium-stimulated phosphatidic acid (PA) accumulation. This could be the result of a defect in the calcium-stimulated hydrolysis of the polyphosphoinositides (calcium-dependent phosphodiesterase) or in the subsequent formation of PA from its precursors (diacylglycerol kinase). In vitro assays were established for both enzymes in erythrocyte membranes. Calcium-dependent phosphodiesterase activity was assayed with both endogenous 32P-labeled erythrocyte diphosphoinositide and triphosphoinositide and with the same phospholipids isolated from rat brain. No significant differences in activity were found between MyD patients and normal controls with either method of substrate preparation. No difference in diglyceride kinase activity was found between ghosts prepared from MyD patients and normal controls. Thus, there were no differences in either of the membrane-associated enzymes of phosphatidic acid metabolism.
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PMID:Myotonic muscular dystrophy. Calcium-dependent phosphatidate metabolism in the erythrocyte membrane. 628 81

We have previously reported that concanavalin A (ConA) stimulation of rat thymocytes induces an increase in the cellular phosphatidic acid mass as well as a change in its fatty acid composition. An increase in phosphodiesterase (PDE) activity, mostly due to cAMP-specific (PDE4) isoforms, has also been observed in thymocytes stimulated by ConA. Furthermore, phosphatidic acid was able to stimulate PDE4 activity in vitro. In the present study, cAMP levels have been shown to decrease upon ConA stimulation of thymocytes. Decreasing phosphatidic acid level using diacylglycerol kinase inhibitors induced a parallel decrease of the ConA-stimulated cAMP-specific PDE activity in these cells. Analyses of phosphatidic acid molecular species in cells stimulated for 5 min by ConA revealed a significant increase in 1-stearoyl-2-arachidonoyl-sn-glycerol-3-phosphate and a relative decrease in the other molecular species of phosphatidic acid, mainly species containing palmitate. On the other hand, phosphatidic acid extracted from ConA-stimulated cells activated more efficiently the recombinant PDE4A5 isoform in vitro, as compared to phosphatidic acid extracted from unstimulated cells. In addition, phosphatidic acid species containing unsaturated fatty acids were stimulatory, while those containing two saturated fatty acids had only a marginal effect on the enzyme activity. Taken together, these data suggest that the mitogenic stimulation of thymocytes is accompanied by the synthesis of peculiar phosphatidic acid molecular species able to activate a PDE4 isoform. This activation might be of physiological relevance since cAMP is a major negative effector of the mitogenic response.
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PMID:Selective stimulation of a cAMP-specific phosphodiesterase (PDE4A5) isoform by phosphatidic acid molecular species endogenously formed in rat thymocytes. 928 42

The epidermal growth factor (EGF) receptor plays a pivotal role in growth regulation of epidermal keratinocytes. Its expression and function can be markedly altered during malignant transformation in squamous cell carcinoma. The present study investigated the potential of growth inhibition by signal-transduction inhibitors in EGF-dependent epithelial cell lines in vitro. Benign HaCaT keratinocytes and malignant A431 cells were grown in vitro and exposed to various concentrations of a panel of eleven kinase and phosphodiesterase inhibitors. Cell growth was measured after 24 h and 48 h using fluorescence labeling with Hoechst 33342 and propidium iodide. Significant growth inhibition was achieved with all inhibitors when applied to HaCaT cells. The strongest growth inhibition was achieved with inhibitors H-7, A3 and diacylglycerol kinase inhibitors I and II. A431 cells were inhibited significantly by H-7, A3 and H-9. Selected signal-transduction inhibitors such as A3, H-7 and H-9 acting on intracellular kinases are capable of suppressing growth of EGF-dependent benign and malignant epithelial cell lines in vitro. They might be of future potential in the treatment of epithelial cancer but further studies are necessary.
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PMID:Inhibition of signal transduction in EGF-dependent epithelial cell lines. 1296 53

Leptin is a versatile 16 kDa peptide hormone, with a tertiary structure resembling that of members of the long-chain helical cytokine family. It is mainly produced by adipocytes in proportion to fat size stores, and was originally thought to act only as a satiety factor. However, the ubiquitous distribution of OB-R leptin receptors in almost all tissues underlies the pleiotropism of leptin. OB-Rs belong to the class I cytokine receptor family, which is known to act through JAKs (Janus kinases) and STATs (signal transducers and activators of transcription). The OB-R gene is alternatively spliced to produce at least five isoforms. The full-length isoform, OB-Rb, contains intracellular motifs required for activation of the JAK/STAT signal transduction pathway, and is considered to be the functional receptor. Considerable evidence for systemic effects of leptin on body mass control, reproduction, angiogenesis, immunity, wound healing, bone remodelling and cardiovascular function, as well as on specific metabolic pathways, indicates that leptin operates both directly and indirectly to orchestrate complex pathophysiological processes. Consistent with leptin's pleiotropic role, its participation in and crosstalk with some of the main signalling pathways, including those involving insulin receptor substrates, phosphoinositide 3-kinase, protein kinase B, protein kinase C, extracellular-signal-regulated kinase, mitogen-activated protein kinases, phosphodiesterase, phospholipase C and nitric oxide, has been observed. The impact of leptin on several equally relevant signalling pathways extends also to Rho family GTPases in relation to the actin cytoskeleton, production of reactive oxygen species, stimulation of prostaglandins, binding to diacylglycerol kinase and catecholamine secretion, among others.
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PMID:Intracellular signalling pathways activated by leptin. 1633 96

The 2009 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension (PH) have been adopted for Germany. While the guidelines contain detailed recommendations regarding pulmonary arterial hypertension (PAH), they contain only a relatively short paragraph on other, much more frequent forms of PH including PH owing to left heart disease. The guidelines point out that the drugs currently used to treat patients with PAH (prostanoids, endothelin receptor antagonists and phosphodiesterase type 5 inhibitors) have not been sufficiently investigated in other forms of PH. However, despite the lack of respective efficacy data an uncritical use of targeted PAH drugs in patients with PH associated with left heart disease is currently observed at an increasing rate. This development is a matter of concern. On the other hand, PH is a frequent problem that is highly relevant for morbidity and mortality in patients with left heart disease. It that sense, the practical implementation of the European Guidelines in Germany requires the consideration of several specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2010, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups was initiated, one of which was specifically dedicated to PH due to left heart disease. This commentary describes in detail the results and recommendations of the working group which were last updated in October 2011.
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PMID:Pulmonary hypertension due to left heart disease: updated Recommendations of the Cologne Consensus Conference 2011. 2222 72

The 2009 European Guidelines on Pulmonary Hypertension did not cover only pulmonary arterial hypertension (PAH) but also some aspects of pulmonary hypertension (PH) in chronic lung disease. These guidelines point out that the drugs currently used to treat patients with PAH (prostanoids, endothelin receptor antagonists and phosphodiesterase type-5 inhibitors) have not been sufficiently investigated in other forms of PH. Therefore, the use of these drugs in patients with chronic lung disease and PH is not recommended. This recommendation, however, is not always in agreement with medical needs as physicians feel sometimes inclined to also treat other forms of pulmonary hypertension which may affect the quality of life and survival of these patients in a similar manner as in PAH. In June 2010, a consensus conference was held in Cologne, Germany, to discuss open and controversial issues surrounding the practical implementation of the European Guidelines. The conference was sponsored by the German Society of Cardiology, the German Society of Respiratory Medicine and the German Society of Pediatric Cardiology (DGK, DGP and DGPK). To this end, a number of working groups were initiated, one of which was specifically dedicated to the diagnosis and treatment of PH due to chronic lung disease. This manuscript describes in detail the results and recommendations of this working group which were last updated in October 2011.
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PMID:Pulmonary hypertension due to chronic lung disease: updated Recommendations of the Cologne Consensus Conference 2011. 2222 73

The 2015 European Guidelines on Pulmonary Hypertension did not cover only pulmonary arterial hypertension (PAH) but also some aspects of pulmonary hypertension (PH) associated with chronic lung disease. The European Guidelines point out that the drugs currently used to treat patients with PAH (prostanoids, endothelin receptor antagonists, phosphodiesterase-5 inhibitors, sGC stimulators) have not been sufficiently investigated in other forms of PH. Therefore, the European Guidelines do not recommend the use of these drugs in patients with chronic lung disease and PH. This recommendation, however, is not always in agreement with medical ethics as physicians feel sometimes inclined to treat other form of PH which may affect quality of life and survival of these patients in a similar manner. To this end, it is crucial to consider the severity of both PH and the underlying lung disease. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany, to discuss open and controversial issues surrounding the practical implementation of the European Guidelines. Several working groups were initiated, one of which was dedicated to the diagnosis and treatment of PH in patients with chronic lung disease. The recommendations of this working group are summarized in the present paper.
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PMID:[Pulmonary hypertension due to chronic lung disease: Recommendations of the Cologne Consensus Conference 2016]. 2776 Apr 51

In the summer of 2016, delegates from the German Society of Cardiology (DGK), the German Respiratory Society (DGP), and the German Society of Pediatric Cardiology (DGPK) met in Cologne, Germany, to define consensus-based practice recommendations for the management of patients with pulmonary hypertension (PH). These recommendations were built on the 2015 European Pulmonary Hypertension guidelines, aiming at their practical implementation, considering country-specific issues, and including new evidence, where available. To this end, a number of working groups was initiated, one of which was specifically dedicated to PH associated with left heart disease. In this context, the European Guidelines point out that the drugs currently approved to treat patients with PAH (prostanoids, endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, sGC stimulators) have not sufficiently been investigated in other forms of PH. However, despite the lack of respective efficacy data, an uncritical use of targeted PAH drugs in patients with PH associated with left heart disease is currently observed at an increasing rate. This development is a matter of concern. On the other hand, PH is a frequent problem that is highly relevant for morbidity and mortality in patients with left heart disease. In that sense, the distinction between isolated post-capillary pulmonary hypertension (IpcPH) and combined post- and pre-capillary pulmonary hypertension (CpcPH) and their proper definition may be of particular relevance. The detailed results and recommendations of the working group on PH associated with left heart disease, which were last updated in the spring of 2018, are summarized in this article.
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PMID:Pulmonary hypertension associated with left heart disease: Updated Recommendations of the Cologne Consensus Conference 2018. 3052 96


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