Project description:We performed microarray analyses on RNA from mice with isoproterenol-induced cardiac hypertrophy and mice with exercise-induced physiological hypertrophy and identified 865 and 2,534 genes that were significantly altered in pathological and physiological cardiac hypertrophy models, respectively. Experiment Overall Design: Three different sets of mouse hearts were compared: Sedentary mice, mice that were exercised (swimming) for 3 months, and mice that were given isoproterenol via a surgically implanted pump. Each experiment was performed in triplicate - one heart per array. This resulted in a total of 9 arrays.
Project description:Cardiac hypertrophy consists in the enlargement of cardiomyocytes and alteration of the extracellular matrix organization in response to physiological or pathological stress. In pathological hypertrophy ocuurs myocardial damage, loss of cardiomyocytes, fibrosis, inflammation, sarcomere disorganization and metabolic impairment, leading to cardiac dysfunction.The rodent model treated with isoproterenol induces cardiac hypertrophy due the constant activation of β-adrenergic receptors. We conducted a quantitative label-free proteomic analysis of cardiomyocytes isolated from hearts of mice treated or not with isoproterenol to better understand the molecular bases of cellular response due to isoproterenol-induced injury.
Project description:We performed microarray analyses on RNA from mice with isoproterenol-induced cardiac hypertrophy and mice with exercise-induced physiological hypertrophy and identified 865 and 2,534 genes that were significantly altered in pathological and physiological cardiac hypertrophy models, respectively.
Project description:The heart undergoes physiological hypertrophy during pregnancy in healthy individuals. Metabolic syndrome (MetS) is now prevalent in women of child-bearing age and might add risks of adverse cardiovascular events during pregnancy. The present study asks if cardiac remodeling during pregnancy in obese individuals with MetS is abnormal and whether this predisposes them to a higher risk for cardiovascular disorders. The idea that MetS induces pathological cardiac remodeling during pregnancy was studied in a long-term (15 weeks) Western diet–feeding animal model that recapitulated features of human MetS. Pregnant female mice with Western diet (45% kcal fat)–induced MetS were compared with pregnant and nonpregnant females fed a control diet (10% kcal fat). Pregnant mice fed a Western diet had increased heart mass and exhibited key features of pathological hypertrophy, including fibrosis and upregulation of fetal genes associated with pathological hypertrophy. Hearts from pregnant animals with WD-induced MetS had a distinct gene expression profile that could underlie their pathological remodeling. Concurrently, pregnant female mice with MetS showed more severe cardiac hypertrophy and exacerbated cardiac dysfunction when challenged with angiotensin II/phenylephrine infusion after delivery. These results suggest that preexisting MetS could disrupt physiological hypertrophy during pregnancy to produce pathological cardiac remodeling that could predispose the heart to chronic disorders.
Project description:Familial hypertrophic cardiomyopathy (FHC) is a disease characterized by ventricular hypertrophy, fibrosis, and aberrant systolic and/or diastolic function. Our laboratories have previously developed 2 mouse models that affect cardiac performance. One transgenic mouse model encodes an FHC-associated mutation in α-tropomyosin (Tm180) that displays severe cardiac hypertrophy with fibrosis and impaired physiological performance. The other model was a gene knockout of phospholamban (PLB), a regulator of calcium uptake in the sarcoplasmic reticulum of cardiomyocytes; the hearts of these mice exhibit hypercontractility with no pathological abnormalities. Previous work in our laboratories show that the hearts of mice that were genetically crossed between the Tm180 and PLB KO mice rescues the hypertrophic phenotype and improves their cardiac morphology and function. We used microarrays to detail the global program of gene expression underlying cardiac remodeling and rescue of the hypertrophic cardiomyopathic phenotype and identified distinct classes of regulated genes during this process. To understand the changes in gene expression that occur over time in these animal models (Tm180, PLB KO, Tm180/PLB KO and nontransgenic control mice), we conducted microarray analyses of left ventricular tissue at 4 and 12 months of age.
Project description:Treatment of pathological cardiac remodeling and subsequent heart failure represents an unmet clinical need. The well conserved lncRNA H19 shows as powerful therapeutic potential in the treatment of pathological cardiac hypertrophy. H19 is strongly repressed in failing hearts from mice, pigs and humans. Gene therapy using murine but also human H19 strongly attenuated heart failure even when cardiac hypertrophy was already established. Using microarray , GSEA and ChIP-Seq we identified a link between H19 and NFAT signalling. H19 physically interacts with PRC2 to epigenetically induced Tescalcin repression which in turn leads to reduced NFAT expression and activity.
Project description:Treatment of pathological cardiac remodeling and subsequent heart failure represents an unmet clinical need. The well conserved lncRNA H19 shows as powerful therapeutic potential in the treatment of pathological cardiac hypertrophy. H19 is strongly repressed in failing hearts from mice, pigs and humans. Gene therapy using murine but also human H19 strongly attenuated heart failure even when cardiac hypertrophy was already established. Using microarray , GSEA and ChIP-Seq we identified a link between H19 and NFAT signalling. H19 physically interacts with PRC2 to epigenetically induced Tescalcin repression which in turn leads to reduced NFAT expression and activity.
Project description:Muscle ring finger-1 (MuRF1) is a muscle-specific protein implicated in the regulation of cardiac myocyte size and contractility. MuRF2, a closely related family member, redundantly interacts with protein substrates, and hetero-dimerizes with MuRF1. Mice lacking either MuRF1 or MuRF2 are phenotypically normal whereas mice lacking both proteins develop a spontaneous cardiac and skeletal muscle hypertrophy indicating cooperative control of muscle mass by MuRF1 and MuRF2. In order to identify the role that MuRF1 plays in regulating cardiac hypertrophy in vivo, we created transgenic mice expressing increased amounts of cardiac MuRF1. Adult MuRF1 transgenic (Tg+) hearts exhibited a non-progressive thinning of the left ventricular wall and a concomitant decrease in cardiac function. Experimental induction of cardiac hypertrophy by trans-aortic constriction (TAC) induced rapid failure of MuRF1 Tg+ hearts. Microarray analysis identified that the levels of genes associated with metabolism (and in particular mitochondrial processes) were significantly altered in MuRF1 Tg+ hearts, both at baseline and during the development of cardiac hypertrophy. Surprisingly, ATP levels in MuRF1 Tg+ mice did not differ from wild type mice despite the depressed contractility following TAC. To explain this discrepancy between the ongoing heart failure and maintained ATP levels in MuRF1 Tg+ hearts, we compared the level and activity of creatine kinase (CK) between wild type and MuRF1 Tg+ hearts. Although mCK and CK-M/B protein levels were unaffected in MuRF1 Tg+ hearts, total CK activity was significantly inhibited. We conclude that MuRF1’s inhibition of CK activity leads to increased susceptibility to heart failure following TAC, demonstrating for the first time that MuRF1 regulates cardiac energetics in vivo. Keywords: Genetic modification, physiological manipulation. Three-condition experiment, MuRF1 Tg+ vs. WT mice. Biological replicates: 4 WT baseline, 3 MuRF1 Tg+ baseline, cardiac overpressure hypertrophy induced by trans-aortic banding at 1 week (3 WT, 3 MurF Tg) and 4 weeks (3 WT, 3 MurF Tg), hearts harvested. One replicate per array.