The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
Martina Schmidt - One of the best experts on this subject based on the ideXlab platform.
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monitoring local pulmonary camp levels combining precision cut lung slice pcls and fluorescence resonance energy transfer fret technologies in mice
American Journal of Respiratory and Critical Care Medicine, 2016Co-Authors: Wilfred Jelco Poppinga, Elisabeth Zeisberg, Viacheslav O Nikolaev, Martina SchmidtAbstract:RATIONALE Cyclic AMP (cAMP) is one of the most important second messengers and is involved as a target for the therapy of chronic obstructive pulmonary disease (COPD), an airway disease primarily provoked by cigarette smoke . Cyclic nucleotide hydrolyzing phosphodiesterases (PDEs) are able to degrade cAMP or cGMP within subcellular compartments, thereby potentially altering pulmonary responses including airway contractility and inflammation. In the present study, we combine the precision cut lung slice (PCLS) technique in mice with fluorescence resonance energy transfer (FRET) to monitor cAMP in real time. METHODS To monitor the cAMP levels in lung tissues, transgenic mice (CAG-Epac1-camps) that express the FRET-based cAMP sensor Epac1-camps were used for the preparation of PCLS. The β2-adrenergic receptor agonist fenoterol was applied to elevate intracellular cAMP. To achieve PDE subtype specific inhibition, the PDE4 Inhibitor rolipram, the PDE3 Inhibitor cilostamide and the PDE2 Inhibitor BAY60-7550 were used. The nonselective PDE Inhibitor 3-isobutyl-1-methylxanthine (IBMX) served as a control. Moreover, lung slices were exposed to 2.5 % cigarette smoke extract (CSE) for 24 hours used as a COPD model in vitro. RESULTS and CONCLUSIONS We provide evidence that the FRET and PCLS technologies can be combined in CAG-Epac1-camps mice to measure global cAMP. Moreover, we found in fenoterol-stimulated PCLS that PDE4 accounts for more than 80% of the total cAMP-PDE activity. Besides PDE4, PDE3 known as a cGMP-inhibited PDE also contributes to cAMP hydrolysis, indicating that cGMP may modulate the maintenance of local cAMP in PCLS. In contrast, the cGMP-activated PDE2 plays a limited role in cAMP hydrolysis. Exposure to CSE did not alter the FRET signal in the presence of the PDE4 Inhibitor under fenoterol stimulated conditions. In contrast, we found that a significant increase could be observed in PDE3-dependent FRET responses (p<0.05). Under basal conditions, CSE treatment altered local cAMP levels by significantly increasing both PDE4 and PDE3 Inhibitor effects. Therefore, as the major lung cyclic nucleotide hydrolyzing enzymes PDE3 and PDE4 are both involved in the local regulation of the cAMP levels in the β2-AR microdomain, our findings suggest that exposure to CSE induced alterations in the PDEs activity profile both under basal conditions and in the presence of the β2-agonist fenoterol.
Wilfred Jelco Poppinga - One of the best experts on this subject based on the ideXlab platform.
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monitoring local pulmonary camp levels combining precision cut lung slice pcls and fluorescence resonance energy transfer fret technologies in mice
American Journal of Respiratory and Critical Care Medicine, 2016Co-Authors: Wilfred Jelco Poppinga, Elisabeth Zeisberg, Viacheslav O Nikolaev, Martina SchmidtAbstract:RATIONALE Cyclic AMP (cAMP) is one of the most important second messengers and is involved as a target for the therapy of chronic obstructive pulmonary disease (COPD), an airway disease primarily provoked by cigarette smoke . Cyclic nucleotide hydrolyzing phosphodiesterases (PDEs) are able to degrade cAMP or cGMP within subcellular compartments, thereby potentially altering pulmonary responses including airway contractility and inflammation. In the present study, we combine the precision cut lung slice (PCLS) technique in mice with fluorescence resonance energy transfer (FRET) to monitor cAMP in real time. METHODS To monitor the cAMP levels in lung tissues, transgenic mice (CAG-Epac1-camps) that express the FRET-based cAMP sensor Epac1-camps were used for the preparation of PCLS. The β2-adrenergic receptor agonist fenoterol was applied to elevate intracellular cAMP. To achieve PDE subtype specific inhibition, the PDE4 Inhibitor rolipram, the PDE3 Inhibitor cilostamide and the PDE2 Inhibitor BAY60-7550 were used. The nonselective PDE Inhibitor 3-isobutyl-1-methylxanthine (IBMX) served as a control. Moreover, lung slices were exposed to 2.5 % cigarette smoke extract (CSE) for 24 hours used as a COPD model in vitro. RESULTS and CONCLUSIONS We provide evidence that the FRET and PCLS technologies can be combined in CAG-Epac1-camps mice to measure global cAMP. Moreover, we found in fenoterol-stimulated PCLS that PDE4 accounts for more than 80% of the total cAMP-PDE activity. Besides PDE4, PDE3 known as a cGMP-inhibited PDE also contributes to cAMP hydrolysis, indicating that cGMP may modulate the maintenance of local cAMP in PCLS. In contrast, the cGMP-activated PDE2 plays a limited role in cAMP hydrolysis. Exposure to CSE did not alter the FRET signal in the presence of the PDE4 Inhibitor under fenoterol stimulated conditions. In contrast, we found that a significant increase could be observed in PDE3-dependent FRET responses (p<0.05). Under basal conditions, CSE treatment altered local cAMP levels by significantly increasing both PDE4 and PDE3 Inhibitor effects. Therefore, as the major lung cyclic nucleotide hydrolyzing enzymes PDE3 and PDE4 are both involved in the local regulation of the cAMP levels in the β2-AR microdomain, our findings suggest that exposure to CSE induced alterations in the PDEs activity profile both under basal conditions and in the presence of the β2-agonist fenoterol.
Heydar Parsaee - One of the best experts on this subject based on the ideXlab platform.
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design synthesis and pharmacological evaluation of 6 hydroxy 4 methylquinolin 2 1h one derivatives as inotropic agents
Journal of Enzyme Inhibition and Medicinal Chemistry, 2009Co-Authors: Hamid Sadeghian, Seyed Mohammad Seyedi, Mohammad Reza Saberi, Reza Shafiee Nick, Azar Hosseini, Mehdi Bakavoli, Seyed Mohammadtaghi Mansouri, Heydar ParsaeeAbstract:Selective PDE3 Inhibitors improve cardiac contractility and may be used in congestive heart failure. However, their proarrhythmic potential is the most important side effect. In this research we designed, synthesized and evaluated the potential cardiotonic activity of thirteen PDE3 Inhibitors (4-[(4-methyl-2-oxo-1,2-dihydro-6-quinolinyl)oxy]butanamide analogs) using the spontaneously beating atria model. The design strategy was based on the structure of cilostamide, a selective PDE3 Inhibitor. In each experiment, atrium of reserpine-treated rat was isolated and the contractile and chronotropic effects of a synthetic compounds were assessed. All experiments were carried out in comparison with IBMX, amrinone and cilostamide as standard compounds. The results showed that, among the new compounds, the best pharmacological profile was obtained with the compound 6-[4-(4-methylpiperazine-1-yl)-4-oxobutoxy]-4-methylquinolin-2(1H)-one, 4j, which displayed selectivity for increasing the force of contraction (165 ± ...
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Inotropic and Chronotropic Effects of 6-Hydroxy-4- Methylquinolin-2(1H)-One Derivatives in Isolated Rat Atria
2007Co-Authors: Seyed Mohammadtaghi Mansouri, Mohammad Reza Saberi, Heydar Parsaee, Reza Shafiee-nick, Mohammad Seyedi, Hamid SadeghianAbstract:Background: Selective phosphodiesterase (PDE3) Inhibitors improve cardiac contractility and may use in congestive heart failure. However, their proarrhythmic potential is the most important side effect. Methods: In this research, we evaluated the potential cardiotonic activity of six new synthesized selective PDE3 Inhibitors (6-hydroxy-4-methylquinolin-2(1H)-one derivatives) using the spontaneously beating atria model. In each experiment, atrium of reserpine-treated rat was isolated and the contractile and chronotropic effects of a synthesized compound were assessed. The 3-isobutyl-1-methylxanthine, a non-selective PDE Inhibitor, was used for comparison. Results: The results showed that, among new compounds, the best pharmacological profile was obtained with the compound 6-[4-(4-methylpiperazine-1-yl)-4-oxobutoxy]-4-methylquinolin-2(1H)-one, C6, which displayed selectivity for increasing the force of contraction (168 ± 5 % change over the control) rather than the frequency rate (138 ± 5 % change over the control) at 300 µM. However, C6 at concentrations of 10 and 100 µM produced left and upward shift in the positive inotropic concentration-response curve of isoprenaline. The-log EC50 of isoprenaline was 8.843 ± 0.171 in the absence, 9.448 ± 0.138 and 9.456 ± 0.107 in the presence of 10, 100 µM of C6, respectively (P<0.001, n = 6). Also, amrinone, a selective PDE3 Inhibitor, shifted the isoprenaline concentration-response curve to the left and upward. Th
T J Williams - One of the best experts on this subject based on the ideXlab platform.
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effect of pde4 Inhibitors on zymosan induced il 8 release from human neutrophils synergism with prostanoids and salbutamol
British Journal of Pharmacology, 1998Co-Authors: M M Teixeira, P D Collins, T J WilliamsAbstract:1 The activation of neutrophils with particulate stimuli such as zymosan induces the generation of the C-X-C chemokine interleukin (IL)-8. There is evidence that neutrophil derived IL-8 plays an important role in human diseases such as the adult respiratory distress syndrome. In the present study, we examined the effects of cyclic AMP elevating agents on the ability of human neutrophils to generate IL-8 in response to zymosan particles. 2 The PDE4 Inhibitor rolipram had limited effect on zymosan-induced IL-8 generation. In contrast, the PDE4 Inhibitors RP 73401 and SB 207499 concentration-dependently suppressed IL-8 generation. The potency of these Inhibitors was RP 73401 > SB 207499 > rolipram which is correlated with their rank order of potency at inhibiting the catalytic site of purified neutrophil PDE4. Pretreatment of neutrophils with the PDE3 Inhibitor ORG 9935 or the PDE5 Inhibitor zaprinast had no effect on IL-8 generation. 3 The prostanoids prostaglandin E1 (PGE1) and PGE2 inhibited zymosan-induced IL-8 release from neutrophils in a dose-dependent manner, in response to 10−5M PGE1 and PGE2 inhibiting IL-8 generation by 89% and 75%, respectively. Similarly, the β2-adrenoceptor agonist salbutamol also inhibited IL-8 generation, but it was less effective than the prostanoids. 4 Significant synergism between prostanoids or salbutamol and the PDE4 Inhibitors to inhibit IL-8 generation was observed. In contrast, there was no significant synergism between PGE2 and the PDE3 Inhibitor ORG 9935 or the PDE5 Inhibitor zaprinast. 5 In order to evaluate the potential role of protein kinase A in mediating the Inhibitory effects of cyclic AMP-elevating agents, we used the protein kinase A Inhibitors, H 89 and KT 5720. Pretreatment of neutrophils with these drugs completely reversed the Inhibitory effects of a combination treatment with rolipram and PGE2 on zymosan-induced IL-8 release. 6 Microscopic examination revealed that most neutrophils contained one or more zymosan particles and that combination treatment with rolipram and PGE2 noticeably reduced the number of ingested particles. Moreover, there was a significant reduction in the percentage of neutrophils which ingested three or more zymosan particles. 7 Thus, our results demonstrate that cyclic AMP-elevating agents modulate the ability of neutrophils to generate IL-8 in response to a particulate stimulus. However, these agents also modulate the ability of neutrophils to phagocytose zymosan particles. Whether this effect will translate into inhibition of the ability of neutrophils to deal with infectious agents needs to be investigated further. British Journal of Pharmacology (1998) 123, 1260–1266; doi:10.1038/sj.bjp.0701723
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effect of pde4 Inhibitors on zymosan induced il 8 release from human neutrophils synergism with prostanoids and salbutamol
British Journal of Pharmacology, 1998Co-Authors: M M Teixeira, P D Collins, T J WilliamsAbstract:1. The activation of neutrophils with particulate stimuli such as zymosan induces the generation of the C-X-C chemokine interleukin (IL)-8. There is evidence that neutrophil derived IL-8 plays an important role in human diseases such as the adult respiratory distress syndrome. In the present study, we examined the effects of cyclic AMP elevating agents on the ability of human neutrophils to generate IL-8 in response to zymosan particles. 2. The PDE4 Inhibitor rolipram had limited effect on zymosan-induced IL-8 generation. In contrast, the PDE4 Inhibitors RP 73401 and SB 207499 concentration-dependently suppressed IL-8 generation. The potency of these Inhibitors was RP 73401 > SB 207499 > rolipram which is correlated with their rank order of potency at inhibiting the catalytic site of purified neutrophil PDE4. Pretreatment of neutrophils with the PDE3 Inhibitor ORG 9935 or the PDE5 Inhibitor zaprinast had no effect on IL-8 generation. 3. The prostanoids prostaglandin E1 (PGE1) and PGE2 inhibited zymosan-induced IL-8 release from neutrophils in a dose-dependent manner, in response to 10(-5) M PGE1 and PGE2 inhibiting IL-8 generation by 89% and 75%, respectively. Similarly, the beta2-adrenoceptor agonist salbutamol also inhibited IL-8 generation, but it was less effective than the prostanoids. 4. Significant synergism between prostanoids or salbutamol and the PDE4 Inhibitors to inhibit IL-8 generation was observed. In contrast, there was no significant synergism between PGE2 and the PDE3 Inhibitor ORG 9935 or the PDE5 Inhibitor zaprinast. 5. In order to evaluate the potential role of protein kinase A in mediating the Inhibitory effects of cyclic AMP-elevating agents, we used the protein kinase A Inhibitors, H 89 and KT 5720. Pretreatment of neutrophils with these drugs completely reversed the Inhibitory effects of a combination treatment with rolipram and PGE2 on zymosan-induced IL-8 release. 6. Microscopic examination revealed that most neutrophils contained one or more zymosan particles and that combination treatment with rolipram and PGE2 noticeably reduced the number of ingested particles. Moreover, there was a significant reduction in the percentage of neutrophils which ingested three or more zymosan particles. 7. Thus, our results demonstrate that cyclic AMP-elevating agents modulate the ability of neutrophils to generate IL-8 in response to a particulate stimulus. However, these agents also modulate the ability of neutrophils to phagocytose zymosan particles. Whether this effect will translate into inhibition of the ability of neutrophils to deal with infectious agents needs to be investigated further.
Elisabeth Zeisberg - One of the best experts on this subject based on the ideXlab platform.
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monitoring local pulmonary camp levels combining precision cut lung slice pcls and fluorescence resonance energy transfer fret technologies in mice
American Journal of Respiratory and Critical Care Medicine, 2016Co-Authors: Wilfred Jelco Poppinga, Elisabeth Zeisberg, Viacheslav O Nikolaev, Martina SchmidtAbstract:RATIONALE Cyclic AMP (cAMP) is one of the most important second messengers and is involved as a target for the therapy of chronic obstructive pulmonary disease (COPD), an airway disease primarily provoked by cigarette smoke . Cyclic nucleotide hydrolyzing phosphodiesterases (PDEs) are able to degrade cAMP or cGMP within subcellular compartments, thereby potentially altering pulmonary responses including airway contractility and inflammation. In the present study, we combine the precision cut lung slice (PCLS) technique in mice with fluorescence resonance energy transfer (FRET) to monitor cAMP in real time. METHODS To monitor the cAMP levels in lung tissues, transgenic mice (CAG-Epac1-camps) that express the FRET-based cAMP sensor Epac1-camps were used for the preparation of PCLS. The β2-adrenergic receptor agonist fenoterol was applied to elevate intracellular cAMP. To achieve PDE subtype specific inhibition, the PDE4 Inhibitor rolipram, the PDE3 Inhibitor cilostamide and the PDE2 Inhibitor BAY60-7550 were used. The nonselective PDE Inhibitor 3-isobutyl-1-methylxanthine (IBMX) served as a control. Moreover, lung slices were exposed to 2.5 % cigarette smoke extract (CSE) for 24 hours used as a COPD model in vitro. RESULTS and CONCLUSIONS We provide evidence that the FRET and PCLS technologies can be combined in CAG-Epac1-camps mice to measure global cAMP. Moreover, we found in fenoterol-stimulated PCLS that PDE4 accounts for more than 80% of the total cAMP-PDE activity. Besides PDE4, PDE3 known as a cGMP-inhibited PDE also contributes to cAMP hydrolysis, indicating that cGMP may modulate the maintenance of local cAMP in PCLS. In contrast, the cGMP-activated PDE2 plays a limited role in cAMP hydrolysis. Exposure to CSE did not alter the FRET signal in the presence of the PDE4 Inhibitor under fenoterol stimulated conditions. In contrast, we found that a significant increase could be observed in PDE3-dependent FRET responses (p<0.05). Under basal conditions, CSE treatment altered local cAMP levels by significantly increasing both PDE4 and PDE3 Inhibitor effects. Therefore, as the major lung cyclic nucleotide hydrolyzing enzymes PDE3 and PDE4 are both involved in the local regulation of the cAMP levels in the β2-AR microdomain, our findings suggest that exposure to CSE induced alterations in the PDEs activity profile both under basal conditions and in the presence of the β2-agonist fenoterol.