system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, RESULTS. Meshes: Adrenergic beta-Antagonists, Animals, Cells, Cultured, Coronary Vessels, Cyclic AMP Response Element-Binding Protein, Gene Expression, Gene Transfer Techniques, Genetic Vectors, Humans, Isoproterenol, Muromegalovirus, Myocytes, Smooth Muscle, Promoter Regions, Genetic, Swine, Transgenes.
user
Does beta-adrenoceptor blockade markedly attenuate transgene expression from cytomegalovirus promoters within the cardiovascular system? Context: The major immediate-early cytomegalovirus enhancer/promoter (MIECMV), widely used in cardiovascular gene therapy, contains several positively regulatory cAMP response elements (CRE). Catecholamine signaling via beta-adrenoceptors might increase transgene expression from MIECMV, and if so, beta-blockers may have a detrimental effect on the efficacy of clinical cardiovascular gene therapy strategies. Cultured smooth muscle cells were exposed to isoprenaline, atenolol, or propranolol, alone and in combination before infection with adenoviruses expressing beta-galactosidase. beta-galactosidase expression was assayed 72 hours later. Isoprenaline increased transgene expression from MIECMV up to 8-fold (P<0.001), but had no effect on a promoter containing no CRE. The effect of isoprenaline was inhibited by beta-blockade and by specific CRE-decoy oligonucleotides. Beta-blockers did not reduce transgene expression below basal levels. After adenovirus-mediated porcine intracoronary gene transfer, however, beta-blockade reduced beta-galactosidase expression by up to 250-fold compared with non-beta-blocked animals (P<0.01).
assistant
Enhancement of promoter activity by endogenous catecholamines is essential for high-level transgene expression from MIECMV within the vasculature. Beta-blocker-mediated suppression of transgene expression from MIECMV in vascular tissues has a significant bearing on clinical studies of cardiovascular gene transfer. This is the first described interaction to our knowledge between widely prescribed pharmaceuticals and a commonly used promoter of clinical transgene expression. Final Decision: yes