The objective of this research is to achieve an understanding of the cellular, molecular and functional properties of endothelial cell (EC) cyclic nucleotide phosphodiesterases (CN PDE), the regulatory role(s) of CN PDE in EC cyclic nucleotide metabolism and EC function assessed by relaxing factor (EDRF/NO) production. Our working hypothesis is that a cGMP-activatable CN PDE (PDE II) serves as a novel cellular receptor for cGMP in the EC. CN PDE, cyclic nucleotide accumulation and decay, and the production of EDRF/NO will be studied in cultured bovine coronary EC and isolated primary bovine aortic ECs. Endothelial cells were chosen for study because: 1) coronary artery EC cells have been developed that maintain differentiated functions through many passages in culture, 2) adequate quantities of cultured and primary EC can be obtained for comparative studies, and 3) regulation of EC functions is modified in a variety of vascular pathologies, immune reactions, hypertension, and thrombotic and atherosclerotic diseases. A comprehensive research plan is proposed involving: a) CN PDE isozyme characterization and mRNA analysis, b) examination of the effects of cGMP and PDE II activation on cAMP accumulation and decay in intact EC, c) studies on the possible participation of cyclic nucleotides in the regulation of EDRF/NO production, and d) cloning of PDE II to obtain EC cDNA for future deletion and site-directed mutagenesis to define the structural features of cGMP receptor binding. New isozyme selective inhibitors of CN PDE will be used as probes of cell-free isozyme fractions, intact cell CN PDE isozyme functions and modified EDRF/NO production. Special methods used in these studies include 3-adenine prelabeling to measure cAMP turnover, EC media column transfer bioassays to measure EDRF/NO production, and alanine-scanning mutagenesis. Thorough analysis of endogenous factors (ie. ANF), pharmacological probes and novel transfection experiments using cDNA coding for ANF receptors lacking external membrane domains are planned as methods to modify cGMP and cAMP content and possibly EDRF/NO production EC. We anticipate that an understanding of the fundamental molecular and regulatory mechanisms we propose a study in EC will have broad implications for cardiovascular cellular physiology and pharmacology.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL046494-03
Application #
2222986
Study Section
Pharmacology A Study Section (PHRA)
Project Start
1992-02-01
Project End
1997-01-31
Budget Start
1994-02-01
Budget End
1995-01-31
Support Year
3
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of South Alabama
Department
Pharmacology
Type
Schools of Medicine
DUNS #
City
Mobile
State
AL
Country
United States
Zip Code
36688
Zhu, Bing; Kelly, John; Vemavarapu, Lakshmi et al. (2004) Activation and induction of cyclic AMP phosphodiesterase (PDE4) in rat pulmonary microvascular endothelial cells. Biochem Pharmacol 68:479-91
Tarpey, Siobhan B; Sawmiller, Darrell R; Kelly, Claire et al. (2003) Phosphodiesterase 3 activity is reduced in dog lung following pacing-induced heart failure. Am J Physiol Lung Cell Mol Physiol 284:L766-73
Liu, Li; Underwood, Tashandra; Li, Han et al. (2002) Specific cGMP binding by the cGMP binding domains of cGMP-binding cGMP specific phosphodiesterase. Cell Signal 14:45-51
Thompson, W Joseph; Ashikaga, Takashi; Kelly, John J et al. (2002) Regulation of cyclic AMP in rat pulmonary microvascular endothelial cells by rolipram-sensitive cyclic AMP phosphodiesterase (PDE4). Biochem Pharmacol 63:797-807
Francis, Sharron H; Bessay, Emmanuel P; Kotera, Jun et al. (2002) Phosphorylation of isolated human phosphodiesterase-5 regulatory domain induces an apparent conformational change and increases cGMP binding affinity. J Biol Chem 277:47581-7
Liu, L; Li, H; Underwood, T et al. (2001) Cyclic GMP-dependent protein kinase activation and induction by exisulind and CP461 in colon tumor cells. J Pharmacol Exp Ther 299:583-92
Stevens, T; Creighton, J; Thompson, W J (1999) Control of cAMP in lung endothelial cell phenotypes. Implications for control of barrier function. Am J Physiol 277:L119-26
Zhou, L; Thompson, W J; Potter, D E (1999) Multiple cyclic nucleotide phosphodiesterases in human trabecular meshwork cells. Invest Ophthalmol Vis Sci 40:1745-52
Moore, T M; Chetham, P M; Kelly, J J et al. (1998) Signal transduction and regulation of lung endothelial cell permeability. Interaction between calcium and cAMP. Am J Physiol 275:L203-22
Kelly, J J; Moore, T M; Babal, P et al. (1998) Pulmonary microvascular and macrovascular endothelial cells: differential regulation of Ca2+ and permeability. Am J Physiol 274:L810-9

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