Abstract
Background:
The left ventricular functional recovery by beta-blocker therapy is now attributed to time-dependent biologic effects on cardiomyocytes.
Methods and results:
To elucidate the cellular mechanism of these biologic effects, we treated 9 patients with dilated cardiomyopathy for 4 months with beta-blockers and examined the gene expressions linked to an improvement of left ventricular ejection fraction (EF). Gene expressions of the biopsied right ventricular endomyocardium were assessed by real-time reverse transcription-polymerase chain reaction. A decrease in beta-myosin heavy chain (1.23+/-0.49 versus 0.86+/-0.45, P<.05) was observed 4 months after the administration of beta-blockers. The expression levels of both sarcoplasmic reticulum Ca(2+) ATPase (SERCA) (0.80+/-0.28 versus 1.39+/-0.44, P<.01) and phospholamban (PLB) (0.49+/-0.08 versus 0.88+/-0.34, P<.05) increased, whereas the expression levels of Na(+)-Ca(2+) exchanger (NCX), beta-adrenoreceptor kinase 1, and ryanodine receptor 2 were unchanged. The SERCA/NCX ratio (0.68+/-0.14 versus 0.96+/-0.33, P<.05) also increased. The increase in SERCA mRNA expression correlated with the degree of changes in EF (%deltaEF) (r=0.679, P<.05), and none of changes in these genes expression correlated with changes in the plasma brain natriuretic peptide concentration.
Conclusions:
The functional recovery resulting from beta-blockers may be associated with the restoration of the unfavorable gene expression that controls Ca(2+) handlings in the failing heart.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Adrenergic beta-Antagonists / therapeutic use*
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Adult
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Aged
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Biomarkers / blood
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Calcium-Binding Proteins / biosynthesis
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Calcium-Binding Proteins / drug effects
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Calcium-Transporting ATPases / biosynthesis
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Calcium-Transporting ATPases / drug effects
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Cardiomyopathy, Dilated / complications
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Cardiomyopathy, Dilated / drug therapy
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Cardiomyopathy, Dilated / genetics
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Cyclic AMP-Dependent Protein Kinases / drug effects
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Cyclic AMP-Dependent Protein Kinases / metabolism
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Female
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Gene Expression Regulation / drug effects*
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Heart Failure / drug therapy*
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Heart Failure / etiology
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Heart Failure / physiopathology
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Humans
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Japan
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Male
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Middle Aged
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Myocardial Contraction / drug effects
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Myocardium / chemistry*
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Myocardium / pathology*
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Myosin Heavy Chains / biosynthesis
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Myosin Heavy Chains / drug effects
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Natriuretic Peptide, Brain / blood
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Natriuretic Peptide, Brain / drug effects
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RNA, Messenger / drug effects
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RNA, Messenger / metabolism
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Ryanodine Receptor Calcium Release Channel / drug effects
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Ryanodine Receptor Calcium Release Channel / metabolism
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Sarcoplasmic Reticulum Calcium-Transporting ATPases
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Sodium-Calcium Exchanger / drug effects
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Sodium-Calcium Exchanger / metabolism
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Stroke Volume / drug effects
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Treatment Outcome
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Ventricular Function, Left / drug effects
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beta-Adrenergic Receptor Kinases
Substances
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Adrenergic beta-Antagonists
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Biomarkers
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Calcium-Binding Proteins
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RNA, Messenger
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Ryanodine Receptor Calcium Release Channel
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Sodium-Calcium Exchanger
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phospholamban
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Natriuretic Peptide, Brain
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Cyclic AMP-Dependent Protein Kinases
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beta-Adrenergic Receptor Kinases
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Sarcoplasmic Reticulum Calcium-Transporting ATPases
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Myosin Heavy Chains
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Calcium-Transporting ATPases