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:Introduction: β-adrenergic stimulation using β-agonists such as isoproterenol has been routinely used to induce cardiac fibrosis in experimental in animal models. While transcriptome changes in surgical models of cardiac fibrosis such as Transverse aortic constriction (TAC), and coronary artery ligation (CAL) are well-studied, transcriptional changes during isoproterenol induced cardiac fibrosis is not well explored. Methods: Cardiac fibrosis was induced in male C57BL6 mice by administration of isoproterenol for 4, 8 or 11 days at 50mg/kg/day dose. Temporal changes in gene expression were studied by RNA sequencing. Results: We observed a significant alteration in the transcriptome profile across the different experimental groups compared to the saline group. Isoproterenol treatment caused upregulation of genes associated with ECM organization, cell-cell contact, three-dimensional structure, and cell growth, while genes associated with fatty acid oxidation, sarcoplasmic reticulum calcium ion transport, and cardiac muscle contraction are downregulated. A number of known long non-coding RNAs (lncRNAs) and putative novel lncRNAs exhibited differential regulation. Conclusion: In conclusion, our study shows that isoproterenol administration leads to the deregulation of genes relevant to ECM deposition and cardiac contraction and serves as an excellent alternate model to the surgical models of heart failure.
Project description:The Set7 methyltransferase regulates the expression of several genes through the methylation of histones and modulates the activity of non-histone proteins. However, the role of Set7 in cardiac remodeling and heart failure remains unknown. To address this question, wild type (WT) and Set7 knockout (KO) male mice were injected with isoproterenol (60 mg/kg) or saline subcutaneously for 14 days. WT mice injected with isoproterenol displayed a decrease in Set7 activity in the heart, although Set7 protein levels were unchanged. WT and Set7 KO mice injected with isoproterenol exhibited an increase in the heart weight and cardiomyocyte area compared to their respective controls. However, Set7 KO mice displayed an exacerbated cardiac hypertrophy in response to isoproterenol compared to WT mice. In addition, Set7 deletion attenuated isoproterenol-induced cardiac fibrosis. Echocardiograms revealed that WT mice injected with isoproterenol had lowered ejection fractions and fractional shortening, and increased E/A ratios compared to their controls. Conversely, Set7 KO mice did not show alteration in these parameters in response to isoproterenol. Both isoproterenol and Set7 deletion changed the transcriptional profile of the heart. Moreover, Set7 deletion increased the expression of mitochondrial biogenesis and antioxidant factors in the heart and reduced the expression of cellular senescence and inflammation markers. Taken together, our data suggest that Set7 deletion reduces isoproterenol-induced myocardial fibrosis and prevents heart failure, suggesting that Set7 plays an important role in cardiac remodeling and function.
Project description:Myoglobin knockout mice (myo-/-) adapt to the loss of myoglobin by the activation of a variety of compensatory mechanisms on the structural and functional level. In order to analyze to what extent myo-/- mice would tolerate cardiac stress we used the model of chronic isoproterenol application to induce cardiac hypertrophy in myo-/- mice and wild type (WT) controls. After 14 d of isoproterenol infusion cardiac hypertrophy in WT and myo-/- mice reached a similar level. WT mice developed lung oedema and left ventricular dilatation indicating the development of heart failure. In contrast, myo-/- mice displayed conserved cardiac function and no signs of heart failure. Analysis of the cardiac gene expression profile using 40 k mouse oligonucleotide arrays showed that isoproterenol affected the expression of 180 genes in WT but only 92 genes of myo-/- hearts. Only 40 of these genes were regulated in WT and myo-/- hearts. Whereas in WT hearts a prononced induction of genes of the extracellular matrix occurred suggesting a higher level of remodelling, in myo-/- hearts genes of carbon metabolism and genes linked to inhibition of apoptosis and muscular repair were altered. Interestingly, a subset of genes which was altered in myo-/- mice already under basal conditions was differentially expressed in WT hearts under isoproterenol treatment. In summary, our data show, that the genetic background (WT, myo-/-) has a major impact on cardiac gene expression even in the context of an aggressive hypertrophy model such as chronic isoproterenol stimulation. Keywords: gene expression profiling of isoproterenol induced heart failure in WT and myo-/- mice We analysed the cardiac gene expression profiles in a total of 32 hearts subdivided into 4 groups (8 WT vehicle, 8 WT ISO, 8 myo-/- vehicle, 8 myo-/- ISO).
Project description:Myoglobin knockout mice (myo-/-) adapt to the loss of myoglobin by the activation of a variety of compensatory mechanisms on the structural and functional level. In order to analyze to what extent myo-/- mice would tolerate cardiac stress we used the model of chronic isoproterenol application to induce cardiac hypertrophy in myo-/- mice and wild type (WT) controls. After 14 d of isoproterenol infusion cardiac hypertrophy in WT and myo-/- mice reached a similar level. WT mice developed lung oedema and left ventricular dilatation indicating the development of heart failure. In contrast, myo-/- mice displayed conserved cardiac function and no signs of heart failure. Analysis of the cardiac gene expression profile using 40 k mouse oligonucleotide arrays showed that isoproterenol affected the expression of 180 genes in WT but only 92 genes of myo-/- hearts. Only 40 of these genes were regulated in WT and myo-/- hearts. Whereas in WT hearts a prononced induction of genes of the extracellular matrix occurred suggesting a higher level of remodelling, in myo-/- hearts genes of carbon metabolism and genes linked to inhibition of apoptosis and muscular repair were altered. Interestingly, a subset of genes which was altered in myo-/- mice already under basal conditions was differentially expressed in WT hearts under isoproterenol treatment. In summary, our data show, that the genetic background (WT, myo-/-) has a major impact on cardiac gene expression even in the context of an aggressive hypertrophy model such as chronic isoproterenol stimulation. Keywords: gene expression profiling of isoproterenol induced heart failure in WT and myo-/- mice We analysed the cardiac gene expression profiles in a total of 32 hearts subdivided into 4 groups (8 WT vehicle, 8 WT ISO, 8 myo-/- vehicle, 8 myo-/- ISO).
Project description:Adverse cardiac remodeling contributes to the development and progression of heart failure (HF) driven, in part, by inappropriate sympathetic nervous system activation. While blockade of β-adrenergic receptors (β-AR) is a common therapeutic strategy in HF, not all patients respond necessitating elucidation of additional therapeutic approaches. Minocycline is an FDA-approved antibiotic with pleiotropic properties, independent of its antimicrobial action, and recent evidence suggests it may act by altering gene expression via changes in miRNA expression. Therefore, we hypothesized that minocycline would prevent adverse cardiac remodeling induced by the β-AR agonist isoproterenol involving relevant alterations in the miRNA-mRNA transcriptome. Male C57BL/6J mice received Iso (30 mg/kg/d, sc) or vehicle for 21 days via osmotic minipump and daily treatment with either minocycline (50 mg/kg, ip) or sterile saline. Isoproterenol infusion induced cardiac hypertrophy, with no change in cardiac function, that was prevented by minocycline. Total mRNA sequencing revealed that isoproterenol altered gene networks associated with inflammation and metabolism while activation of fibrosis was predicted by integrated miRNA-mRNA sequencing, involving miR-21, -30a, -34a, -92a, and -150, among others. Conversely, the cardiac miRNA-mRNA transcriptome predicted inhibition of fibrosis in hearts from mice treated with minocycline plus isoproterenol involving anti-fibrotic shifts in Atf3 and Itgb6 gene expression associated with upregulation of miR-194. Consistent with these gene signatures, picrosirius red staining confirmed isoproterenol-induced cardiac fibrosis and that this was prevented by minocycline. These results demonstrate the therapeutic potential of minocycline to attenuate adverse cardiac remodeling via miRNA-mRNA-dependent mechanisms, especially related to reduced cardiac fibrosis.
Project description:Mice were infusion with either vehicle or isoproterenol for 21 days. Another group of mice received both isoproterenol infusion and daily minocycline administration for the duration of the experiment. After 21 days mice were assessed for cardiac function and hearts collected to isolate miRNA.
Project description:Myoglobin knockout mice (myo-/-) adapt to the loss of myoglobin by the activation of a variety of compensatory mechanisms on the structural and functional level. In order to analyze to what extent myo-/- mice would tolerate cardiac stress we used the model of chronic isoproterenol application to induce cardiac hypertrophy in myo-/- mice and wild type (WT) controls. After 14 d of isoproterenol infusion cardiac hypertrophy in WT and myo-/- mice reached a similar level. WT mice developed lung oedema and left ventricular dilatation indicating the development of heart failure. In contrast, myo-/- mice displayed conserved cardiac function and no signs of heart failure. Analysis of the cardiac gene expression profile using 40 k mouse oligonucleotide arrays showed that isoproterenol affected the expression of 180 genes in WT but only 92 genes of myo-/- hearts. Only 40 of these genes were regulated in WT and myo-/- hearts. Whereas in WT hearts a prononced induction of genes of the extracellular matrix occurred suggesting a higher level of remodelling, in myo-/- hearts genes of carbon metabolism and genes linked to inhibition of apoptosis and muscular repair were altered. Interestingly, a subset of genes which was altered in myo-/- mice already under basal conditions was differentially expressed in WT hearts under isoproterenol treatment. In summary, our data show, that the genetic background (WT, myo-/-) has a major impact on cardiac gene expression even in the context of an aggressive hypertrophy model such as chronic isoproterenol stimulation. Keywords: gene expression profiling of isoproterenol induced heart failure in WT and myo-/- mice
Project description:Myoglobin knockout mice (myo-/-) adapt to the loss of myoglobin by the activation of a variety of compensatory mechanisms on the structural and functional level. In order to analyze to what extent myo-/- mice would tolerate cardiac stress we used the model of chronic isoproterenol application to induce cardiac hypertrophy in myo-/- mice and wild type (WT) controls. After 14 d of isoproterenol infusion cardiac hypertrophy in WT and myo-/- mice reached a similar level. WT mice developed lung oedema and left ventricular dilatation indicating the development of heart failure. In contrast, myo-/- mice displayed conserved cardiac function and no signs of heart failure. Analysis of the cardiac gene expression profile using 40 k mouse oligonucleotide arrays showed that isoproterenol affected the expression of 180 genes in WT but only 92 genes of myo-/- hearts. Only 40 of these genes were regulated in WT and myo-/- hearts. Whereas in WT hearts a prononced induction of genes of the extracellular matrix occurred suggesting a higher level of remodelling, in myo-/- hearts genes of carbon metabolism and genes linked to inhibition of apoptosis and muscular repair were altered. Interestingly, a subset of genes which was altered in myo-/- mice already under basal conditions was differentially expressed in WT hearts under isoproterenol treatment. In summary, our data show, that the genetic background (WT, myo-/-) has a major impact on cardiac gene expression even in the context of an aggressive hypertrophy model such as chronic isoproterenol stimulation. Keywords: gene expression profiling of isoproterenol induced heart failure in WT and myo-/- mice