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:Transcription profiling by array of cardic ventricle tissues from mice with cardiac-specific constitutive expression of an activated Akt (caAkt) and wild-type controls to test whether Akt activation contributes to mitochondrial dysfunction in pathological cardiac hypertrophy
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.