Potentiation of beta-adrenergic signaling by adenoviral-mediated gene transfer in adult rabbit ventricular myocytes.

Abstract

Our laboratory has been testing the hypothesis that genetic modulation of the beta-adrenergic signaling cascade can enhance cardiac function. We have previously shown that transgenic mice with cardiac overexpression of either the human beta2-adrenergic receptor (beta2AR) or an inhibitor of the beta-adrenergic receptor kinase (betaARK), an enzyme that phosphorylates and uncouples agonist-bound receptors, have increased myocardial inotropy. We now have created recombinant adenoviruses encoding either the beta2AR (Adeno-beta2AR) or a peptide betaARK inhibitor (consisting of the carboxyl terminus of betaARK1, Adeno-betaARKct) and tested their ability to potentiate beta-adrenergic signaling in cultured adult rabbit ventricular myocytes. As assessed by radioligand binding, Adeno-beta2AR infection led to approximately 20-fold overexpression of beta-adrenergic receptors. Protein immunoblots demonstrated the presence of the Adeno-betaARKct transgene. Both transgenes significantly increased isoproterenol-stimulated cAMP as compared to myocytes infected with an adenovirus encoding beta-galactosidase (Adeno-betaGal) but did not affect the sarcolemmal adenylyl cyclase response to Forskolin or NaF. beta-Adrenergic agonist-induced desensitization was significantly inhibited in Adeno-betaARKct-infected myocytes (16+/-2%) as compared to Adeno-betaGal-infected myocytes (37+/-1%, P < 0.001). We conclude that recombinant adenoviral gene transfer of the beta2AR or an inhibitor of betaARK-mediated desensitization can potentiate beta-adrenergic signaling.

• Authors: M H Drazner, K C Peppel, S Dyer, A O Grant, W J Koch, R J Lefkowitz
• Journal: The Journal of clinical investigation (J Clin Invest) Vol. 99 Issue 2 Pg. 288-96 (Jan 15 1997) ISSN: 0021-9738 [Print] United States
• PMID: 9005997 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Adrenergic beta-Agonists
• Receptors, Adrenergic, beta-2
• Cyclic AMP
• Adenylyl Cyclases
• Isoproterenol

Topics

• Adenoviridae (genetics)
• Adenylyl Cyclases (analysis)
• Adrenergic beta-Agonists (pharmacology)
• Animals
• Cell Survival
• Cells, Cultured
• Cyclic AMP (metabolism)
• Gene Transfer Techniques
• Genetic Vectors
• Heart Ventricles (cytology, metabolism)
• Humans
• Isoproterenol (pharmacology)
• Male
• Rabbits
• Receptors, Adrenergic, beta-2 (genetics, metabolism)
• Sarcolemma (enzymology)
• Signal Transduction
• Transgenes