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Spatiotemporal dynamics of beta-adrenergic cAMP signals and L-type Ca2+ channel regulation in adult rat ventricular myocytes: role of phosphodiesterases.
Circ Res. 2008 May 09; 102(9):1091-100.CircR

Abstract

Steady-state activation of cardiac beta-adrenergic receptors leads to an intracellular compartmentation of cAMP resulting from localized cyclic nucleotide phosphodiesterase (PDE) activity. To evaluate the time course of the cAMP changes in the different compartments, brief (15 seconds) pulses of isoprenaline (100 nmol/L) were applied to adult rat ventricular myocytes (ARVMs) while monitoring cAMP changes beneath the membrane using engineered cyclic nucleotide-gated channels and within the cytosol with the fluorescence resonance energy transfer-based sensor, Epac2-camps. cAMP kinetics in the two compartments were compared to the time course of the L-type Ca(2+) channel current (I(Ca,L)) amplitude. The onset and recovery of cAMP transients were, respectively, 30% and 50% faster at the plasma membrane than in the cytosol, in agreement with a rapid production and degradation of the second messenger at the plasma membrane and a restricted diffusion of cAMP to the cytosol. I(Ca,L) amplitude increased twice slower than cAMP at the membrane, and the current remained elevated for approximately 5 minutes after cAMP had already returned to basal level, indicating that cAMP changes are not rate-limiting in channel phosphorylation/dephosphorylation. Inhibition of PDE4 (with 10 micromol/L Ro 20-1724) increased the amplitude and dramatically slowed down the onset and recovery of cAMP signals, whereas PDE3 blockade (with 1 micromol/L cilostamide) had a minor effect only on subsarcolemmal cAMP. However, when both PDE3 and PDE4 were inhibited, or when all PDEs were blocked using 3-isobutyl-l-methylxanthine (300 micromol/L), cAMP signals and I(Ca,L) declined with a time constant >10 minutes. cAMP-dependent protein kinase inhibition with protein kinase inhibitor produced a similar effect as a partial inhibition of PDE4 on the cytosolic cAMP transient. Consistently, cAMP-PDE assay on ARVMs briefly (15 seconds) exposed to isoprenaline showed a pronounced (up to approximately 50%) dose-dependent increase in total PDE activity, which was mainly attributable to activation of PDE4. These results reveal temporally distinct beta-adrenergic receptor cAMP compartments in ARVMs and shed new light on the intricate roles of PDE3 and PDE4.

Authors+Show Affiliations

INSERM U-769, Université Paris-Sud 11, Faculté de Pharmacie, 5, Rue J.-B. Clément, F-92296 Châtenay-Malabry Cedex, France.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18369156

Citation

Leroy, Jérôme, et al. "Spatiotemporal Dynamics of Beta-adrenergic cAMP Signals and L-type Ca2+ Channel Regulation in Adult Rat Ventricular Myocytes: Role of Phosphodiesterases." Circulation Research, vol. 102, no. 9, 2008, pp. 1091-100.
Leroy J, Abi-Gerges A, Nikolaev VO, et al. Spatiotemporal dynamics of beta-adrenergic cAMP signals and L-type Ca2+ channel regulation in adult rat ventricular myocytes: role of phosphodiesterases. Circ Res. 2008;102(9):1091-100.
Leroy, J., Abi-Gerges, A., Nikolaev, V. O., Richter, W., Lechêne, P., Mazet, J. L., Conti, M., Fischmeister, R., & Vandecasteele, G. (2008). Spatiotemporal dynamics of beta-adrenergic cAMP signals and L-type Ca2+ channel regulation in adult rat ventricular myocytes: role of phosphodiesterases. Circulation Research, 102(9), 1091-100. https://doi.org/10.1161/CIRCRESAHA.107.167817
Leroy J, et al. Spatiotemporal Dynamics of Beta-adrenergic cAMP Signals and L-type Ca2+ Channel Regulation in Adult Rat Ventricular Myocytes: Role of Phosphodiesterases. Circ Res. 2008 May 9;102(9):1091-100. PubMed PMID: 18369156.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Spatiotemporal dynamics of beta-adrenergic cAMP signals and L-type Ca2+ channel regulation in adult rat ventricular myocytes: role of phosphodiesterases. AU - Leroy,Jérôme, AU - Abi-Gerges,Aniella, AU - Nikolaev,Viacheslav O, AU - Richter,Wito, AU - Lechêne,Patrick, AU - Mazet,Jean-Luc, AU - Conti,Marco, AU - Fischmeister,Rodolphe, AU - Vandecasteele,Grégoire, Y1 - 2008/03/27/ PY - 2008/3/29/pubmed PY - 2008/5/23/medline PY - 2008/3/29/entrez SP - 1091 EP - 100 JF - Circulation research JO - Circ Res VL - 102 IS - 9 N2 - Steady-state activation of cardiac beta-adrenergic receptors leads to an intracellular compartmentation of cAMP resulting from localized cyclic nucleotide phosphodiesterase (PDE) activity. To evaluate the time course of the cAMP changes in the different compartments, brief (15 seconds) pulses of isoprenaline (100 nmol/L) were applied to adult rat ventricular myocytes (ARVMs) while monitoring cAMP changes beneath the membrane using engineered cyclic nucleotide-gated channels and within the cytosol with the fluorescence resonance energy transfer-based sensor, Epac2-camps. cAMP kinetics in the two compartments were compared to the time course of the L-type Ca(2+) channel current (I(Ca,L)) amplitude. The onset and recovery of cAMP transients were, respectively, 30% and 50% faster at the plasma membrane than in the cytosol, in agreement with a rapid production and degradation of the second messenger at the plasma membrane and a restricted diffusion of cAMP to the cytosol. I(Ca,L) amplitude increased twice slower than cAMP at the membrane, and the current remained elevated for approximately 5 minutes after cAMP had already returned to basal level, indicating that cAMP changes are not rate-limiting in channel phosphorylation/dephosphorylation. Inhibition of PDE4 (with 10 micromol/L Ro 20-1724) increased the amplitude and dramatically slowed down the onset and recovery of cAMP signals, whereas PDE3 blockade (with 1 micromol/L cilostamide) had a minor effect only on subsarcolemmal cAMP. However, when both PDE3 and PDE4 were inhibited, or when all PDEs were blocked using 3-isobutyl-l-methylxanthine (300 micromol/L), cAMP signals and I(Ca,L) declined with a time constant >10 minutes. cAMP-dependent protein kinase inhibition with protein kinase inhibitor produced a similar effect as a partial inhibition of PDE4 on the cytosolic cAMP transient. Consistently, cAMP-PDE assay on ARVMs briefly (15 seconds) exposed to isoprenaline showed a pronounced (up to approximately 50%) dose-dependent increase in total PDE activity, which was mainly attributable to activation of PDE4. These results reveal temporally distinct beta-adrenergic receptor cAMP compartments in ARVMs and shed new light on the intricate roles of PDE3 and PDE4. SN - 1524-4571 UR - https://www.unboundmedicine.com/medline/citation/18369156/Spatiotemporal_dynamics_of_beta_adrenergic_cAMP_signals_and_L_type_Ca2+_channel_regulation_in_adult_rat_ventricular_myocytes:_role_of_phosphodiesterases_ L2 - https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.107.167817?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -