Sarcoplasmic reticulum Ca2+ ATPase gene expression to the rescue of myocardial contractility in hypothyroid associated heart failure (original) (raw)
Related papers
Circulation, 2001
Background-In heart failure, sarcoplasmic reticulum (SR) Ca 2ϩ -ATPase (SERCA2a) activity is decreased, resulting in abnormal calcium handling and contractile dysfunction. We have previously shown that increasing SERCA2a expression by gene transfer improves ventricular function in a rat model of heart failure created by ascending aortic constriction. Methods and Results-In this study, we tested the effects of gene transfer of SERCA2a on survival, left ventricular (LV) volumes, and metabolism. By 26 to 27 weeks after aortic banding, all animals developed heart failure (as documented by Ͼ25% decrease in fractional shortening) and were randomized to receive either an adenovirus carrying the SERCA2a gene (Ad.SERCA2a) or control virus (Ad.gal-GFP) by use of a catheter-based technique. Sham-operated rats, uninfected or infected with either Ad.gal-GFP or Ad.SERCA2a, served as controls. Four weeks after gene transfer, survival in rats with heart failure treated with Ad.gal-GFP was 9%, compared with 63% in rats receiving Ad.SERCA2a. LV volumes were significantly increased in heart failure (0.64Ϯ0.05 versus 0.35Ϯ0.03 mL, PϽ0.02).
Pharmacology & Therapeutics, 2010
Cardiac hypertrophy can be defined as an increase in heart mass. Pathological cardiac hypertrophy (heart growth that occurs in settings of disease, e.g. hypertension) is a key risk factor for heart failure. Pathological hypertrophy is associated with increased interstitial fibrosis, cell death and cardiac dysfunction. In contrast, physiological cardiac hypertrophy (heart growth that occurs in response to chronic exercise training, i.e. the 'athlete's heart') is reversible and is characterized by normal cardiac morphology (i.e. no fibrosis or apoptosis) and normal or enhanced cardiac function. Given that there are clear functional, structural, metabolic and molecular differences between pathological and physiological hypertrophy, a key question in cardiovascular medicine is whether mechanisms responsible for enhancing function of the athlete's heart can be exploited to benefit patients with pathological hypertrophy and heart failure. This review summarizes key experimental findings that have contributed to our understanding of pathological and physiological heart growth. In particular, we focus on signaling pathways that play a causal role in the development of pathological and physiological hypertrophy. We discuss molecular mechanisms associated with features of cardiac hypertrophy, including protein synthesis, sarcomeric organization, fibrosis, cell death and energy metabolism and provide a summary of profiling studies that have examined genes, microRNAs and proteins that are differentially expressed in models of pathological and physiological hypertrophy. How gender and sex hormones affect cardiac hypertrophy is also discussed. Finally, we explore how knowledge of molecular mechanisms underlying pathological and physiological hypertrophy may influence therapeutic strategies for the treatment of cardiovascular disease and heart failure.
Molecular regulation of cardiac hypertrophy
International Journal of Biochemistry & Cell Biology, 2008
Heart failure is one of the leading causes of mortality in the western world and encompasses a wide spectrum of cardiac pathologies. When the heart experiences extended periods of elevated workload, it undergoes hypertrophic enlargement in response to the increased demand. Cardiovascular disease, such as that caused by myocardial infarction, obesity or drug abuse promotes cardiac myocyte hypertrophy and subsequent heart failure. A number of signalling modulators in the vasculature milieu are known to regulate heart mass including those that influence gene expression, apoptosis, cytokine release and growth factor signalling. Recent evidence using genetic and cellular models of cardiac hypertrophy suggests that pathological hypertrophy can be prevented or reversed and has promoted an enormous drive in drug discovery research aiming to identify novel and specific regulators of hypertrophy. In this review we describe the molecular characteristics of cardiac hypertrophy such as the aberrant re-expression of the fetal gene program. We discuss the various molecular pathways responsible for the co-ordinated control of the hypertrophic program including: natriuretic peptides, the adrenergic system, adhesion and cytoskeletal proteins, IL-6 cytokine family, MEK-ERK1/2 signalling, histone acetylation, calcium-mediated modulation and the exciting recent discovery of the role of microRNAs in controlling cardiac hypertrophy. Characterisation of the signalling pathways leading to cardiac hypertrophy has led to a wealth of knowledge about this condition both physiological and pathological. The challenge will be translating this knowledge into potential pharmacological therapies for the treatment of cardiac pathologies.
Rescue of familial cardiomyopathies by modifications at the level of sarcomere and Ca 2+ fluxes
Journal of Molecular and Cellular Cardiology, 2010
Cardiomypathies are a heterogeneous group of diseases of the myocardium associated with mechanical and/or electrical dysfunction that frequently show inappropriate ventricular hypertrophy or dilation. Current data suggest that numerous mutations in several genes can cause cardiomyopathies, and the severity of their phenotypes is also influenced by modifier genes. Two major types of inherited cardiomyopathies include familial hypertrophic cardiomyopathy (FHC) and dilated cardiomyopathy (DCM). FHC typically involves increased myofilament Ca 2+ sensitivity associated with diastolic dysfunction, whereas DCM often results in decreased myofilament Ca 2+ sensitivity and systolic dysfunction. Besides alterations in myofilament Ca 2+ sensitivity, alterations in the levels of Ca 2+ -handling proteins have also been described in both diseases. Recent work in animal models has attempted to rescue FHC and DCM via modifications at the myofilament level, altering Ca 2+ homeostasis by targeting Ca 2+ -handling proteins, such as the sarcoplasmic reticulum ATPase and phospholamban, or by interfering with the products of different modifiers genes. Although attempts to rescue cardiomyopathies in animal models have shown great promise, further studies are needed to validate these strategies in order to provide more effective and specific treatments.
2014
Cardiovascular disease is one of the most devastating illness across the world causing more number of casualties and deaths every day. Of the multitude of ways through which the normal physiology of conduction system is affected, increase if heart size, also called as Cardiac Hypertrophy (CH), causes a significant number of deaths in affected patients. Cardiac Hypertrophy is classified into Physiological and Pathological variants based on the stimulus that leads to the increase of the size of heart. Also, the effects following the stimulus are different in each variant in regard to signaling events, signaling molecules affected, changes in the anatomy of the heart, etc. There exists clear structural, functional, molecular and metabolic, differences in progression of each variant of CH.
Molecular targets and regulators of cardiac hypertrophy
Pharmacological Research, 2010
Cardiac hypertrophy is one of the main ways in which cardiomyocytes respond to mechanical and neurohormonal stimuli. It enables myocytes to increase their work output, which improves cardiac pump function. Although cardiac hypertrophy may initially represent an adaptive response of the myocardium, ultimately, it often progresses to ventricular dilatation and heart failure which is one of the leading causes of mortality in the western world. A number of signaling modulators that influence gene expression, apoptosis, cytokine release and growth factor signaling, etc. are known to regulate heart. By using genetic and cellular models of cardiac hypertrophy it has been proved that pathological hypertrophy can be prevented or reversed. This finding has promoted an enormous drive to identify novel and specific regulators of hypertrophy. In this review, we have discussed the various molecular signal transduction pathways and the regulators of hypertrophic response which includes calcineurin, cGMP, NFAT, natriuretic peptides, histone deacetylase, IL-6 cytokine family, Gq/G11 signaling, PI3K, MAPK pathways, Na/H exchanger, RAS, polypeptide growth factors, ANP, NO, TNF-␣, PPAR and JAK/STAT pathway, microRNA, Cardiac angiogenesis and gene mutations in adult heart. Augmented knowledge of these signaling pathways and their interactions may potentially be translated into pharmacological therapies for the treatment of various cardiac diseases that are adversely affected by hypertrophy. The purpose of this review is to provide the current knowledge about the molecular pathogenesis of cardiac hypertrophy, with special emphasis on novel researches and investigations.
Changes in gene expression during the transition from compensated hypertrophy to heart failure
Heart failure reviews, 1999
With the advancement in molecular techniques for characterizing genes and the use of animal models as tools to study heart failure, considerable progress has been made in improving our understanding of the regulation and function of genes associated with heart failure. Studies now indicate that autocrine/paracrine factors including neurohormones such as norepinephrine, angiotensin II, proin_ammatory cytokines and peptide growth factors produced locally in the heart may affect myocyte growth and function through intricate signaling mechanisms. While changes in gene expression for the proteins involved in cell signaling may lead to myocyte hypertrophy and/or apoptosis, alteration in calcium homeostasis, excitation-contraction coupling and the extracellular matrix also contribute to systolic and diastolic dysfunction leading to heart failure. Thus, heart failure is a complex process, which involves changes in expression of multiple genes. With the advent of new techniques involving microarray and gene chip technology, it is now possible to de~ne and/or identify sets of genes involved in heart failure. The purpose of this review is to provide an overview of molecular signals, intracellular signaling mechanisms and the changes in gene expression associated with the transition from compensated hypertrophy to failure.