Set7 deletion attenuates isoproterenol-induced cardiac fibrosis and prevents heart failure
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ABSTRACT: 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: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
Project description:Background: The insulin/IGF/relaxin family represents a group of structurally related but functionally diverse proteins. The family member Relaxin-2 has been evaluated in clinical trials for its efficacy in the treatment of acute heart failure. In this study, we assessed the role of Insulin-like peptide 6 (Insl6), another member of this protein family, in murine heart failure models using genetic loss-of-function and protein delivery methods. Methods and Results: Insl6-deficient (Insl6-KO) and wild-type (C57BL/6N) mice were administered angiotensin II or isoproterenol via continuous infusion with an osmotic pump or via intraperitoneal injection once a day, respectively for 2 weeks. In both models, Insl6-KO mice exhibited greater cardiac systolic dysfunction and left ventricular dilatation hypertrophy. Cardiac dysfunction in the Insl6-KO mice was associated with more extensive cardiac fibrosis and greater expression of fibrosis-associated genes. The continuous infusion of chemically synthesized INSL6 significantly attenuated left ventricular systolic dysfunction and cardiac fibrosis induced by isoproterenol infusion. Gene expression profiling suggests Lxr/ Rxr signaling is activated in the isoproterenol-challenged hearts treated with INSL6 protein. Conclusions: Endogenous Insl6 protein inhibits cardiac systolic dysfunction and cardiac fibrosis in angiotensin II- and isoproterenol-induced cardiac stress models. The administration of recombinant Insl6 protein could have utility for the treatment of heart failure and cardiac fibrosis.
Project description:To investigate the physiological role of BH4 in cardiac function, we developed mice with cardiomyocyte-specific deletion of (cm)Gch1, the gene that encodes for GTPCH, which responsible for de novo synthesis of BH4. We performed RNA sequencing in heart tissues from cmGch1 KO and WT mice.
Project description:Early reperfusion of ischemic cardiac tissue remains the most effective intervention for improving clinical outcome following myocardial infarction. However, abrupt increases in intracellular Ca2+ during myocardial reperfusion cause cardiomyocyte death and consequent loss of cardiac function, referred to as ischemia/reperfusion (IR) injury. Cardiac IR is accompanied by dynamic changes in expression of microRNAs (miRNAs), which inhibit specific mRNA targets. miR-214 is up-regulated during ischemic injury and heart failure in mice and humans, but its potential role in these processes is unknown. We show that genetic deletion of miR-214 in mice causes loss of cardiac contractility, increased apoptosis, and excessive fibrosis in response to IR injury. The microarray contains 6 samples, each containing cDNA pooled from 3 mice per group. There are no replicates. The array was designed to make 3 different pairwise comparisons between the following: P14 WT and miR-214 KO hearts; adult WT and miR-214 KO skeletal muscle; adult WT and miR-214 KO hearts
Project description:Rationale: Chagasic disease is associated with high morbidity in Latin America. Acute Chagasic myocarditis is consistently found in acute infections but little is known about its contribution to chronic cardiomyopathy. The aim of the study was to phenotypically characterize two strains of mice with differential Chagas infection susceptibility and correlate strain myocarditis phenotypes with heart tissue gene expression. Methods: C57BL/6J and Balb/c mice were injected intraperitoneally with 0 or 150-200 tissue-derived trypomastigotes (Tulahuen strain). Echocardiograms, brain natriuretic peptide and troponin were measured. Heart tissue was harvested for histopathological analysis and gene expression profiling on microarrays. Genes differently expressed between infected Balb/c and C57BL/6J were identified Results: Echocardiograms demonstrated differences in heart rate in Balb/c vs. C57BL/6J infected mice: 413 vs. 476 bpm, (p=0.0001), stroke volume: 31.9 ± 9.3 vs. 39.2 ± 5.5 µl (p=0.03); and cardiac output: 13.1 ± 3.5 vs. 18.7 ± 3.2 µl/min (p=0.002). Gene expression at 4 weeks analysis demonstrated 32 statistically significant (q-value < 0.05) differentially expressed genes between infected Balb/c and C57BL/6J which were enriched for genes related to protein kinase B (AKT) pathway 8 Balb/c mice and 8 C57BL/6J mice were infected and 8 Balb/c and 8 C57BL/6J were used as controls. 6 mice per group were used for gene expression analysis.
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.