Project description:Aims: We investigate sex differences and the role of oestrogen receptor beta (ERbeta) in a mouse model of pressure overload-induced myocardial hypertrophy. Methods and results: We performed transverse aortic constriction (TAC) or sham surgery in male and female wild-type (WT) and ER knockout (ERbeta-/-) C57Bl6 mice. All mice were characterised by echocardiography and haemodynamic measurements and were sacrificed nine weeks after surgery. Left ventricular (LV) samples were analysed by microarray profiling, real-time RT-PCR and histology. After nine weeks, WT males showed more hypertrophy and heart failure signs than WT females. Notably, WT females developed a concentric form of hypertrophy, while males developed eccentric hypertrophy. These sex differences were abolished in ERbeta-/- mice. ERbeta deletion augmented the TAC-induced increase in cardiomyocyte diameter in both sexes. Gene expression profiling revealed that male WT hearts had a stronger induction of matrix-related genes and a stronger repression of mitochondrial genes than female hearts. ERbeta-/- mice exhibited a different transcriptome. Induction of pro-apoptotic genes after TAC occurred in ERbeta-/- mice of both sexes with a stronger expression in ERbeta-/- males. Histological analysis revealed, that cardiac fibrosis was more pronounced in male WT TAC than in female mice. This was abolished in ERbeta-/- mice. Apoptosis was significantly induced in both sexes of ERbeta-/- TAC mice, but it was most prominent in males. Conclusion: Female sex offers protection against ventricular chamber dilation in the TAC model. Both the female sex and ER attenuate the development of fibrosis and apoptosis; thus slowing the progression to heart failure. The influence of sex (male/female) and estrogen receptor beta expression (ERbeta knockout/wildtype) on cardiac hypertrophy (transverse aortic constriction/sham operated) was investigated. The left ventricular transcriptome of four individual mice for each combination of the three factors (sex, genotype, surgery) was detected with Affymetrix RAE 430 2.0 GeneChip arrays.
Project description:Aims: We investigate sex differences and the role of oestrogen receptor beta (ERbeta) in a mouse model of pressure overload-induced myocardial hypertrophy. Methods and results: We performed transverse aortic constriction (TAC) or sham surgery in male and female wild-type (WT) and ERbeta knockout (ERbeta-/-) C57Bl6 mice. All mice were characterised by echocardiography and haemodynamic measurements and were sacrificed nine weeks after surgery. Left ventricular (LV) samples were analysed by microarray profiling, real-time RT-PCR and histology. After nine weeks, WT males showed more hypertrophy and heart failure signs than WT females. Notably, WT females developed a concentric form of hypertrophy, while males developed eccentric hypertrophy. These sex differences were abolished in ERbeta-/- mice. ERbeta deletion augmented the TAC-induced increase in cardiomyocyte diameter in both sexes. Gene expression profiling revealed that male WT hearts had a stronger induction of matrix-related genes and a stronger repression of mitochondrial genes than female hearts. ERbeta-/- mice exhibited a different transcriptome. Induction of pro-apoptotic genes after TAC occurred in ERbeta-/- mice of both sexes with a stronger expression in ERbeta-/- males. Histological analysis revealed, that cardiac fibrosis was more pronounced in male WT TAC than in female mice. This was abolished in ERbeta-/- mice. Apoptosis was significantly induced in both sexes of ERbeta-/- TAC mice, but it was most prominent in males. Conclusion: Female sex offers protection against ventricular chamber dilation in the TAC model. Both the female sex and ERbeta attenuate the development of fibrosis and apoptosis; thus slowing the progression to heart failure.
Project description:Pressure overload (PO) leads first to cardiac hypertrophy and later to heart failure. In mice, PO leads to sex differences in cardiac morphology and function. However, early sex differences in gene regulation that precede sex differences in function have not yet been identified. To identify such changes, we developed a model of PO that is characterized by compensated hypertrophy without sex differences after 2 weeks and by heart failure with sex differences after 9 weeks. We used transverse aortic constriction (TAC) or sham-operation in male and female mice and analyzed gene expression by microarray experiments. Experiment Overall Design: The gene expression induced by pressure overload in female and male mice in comparison to sham operated control mice was investigated. For each of these four conditions four biological replicates were performed and the individual samples were hybridized seperately on Affymetrix RAE 430A GeneChip Arrays.
Project description:Pressure overload (PO) leads first to cardiac hypertrophy and later to heart failure. In mice, PO leads to sex differences in cardiac morphology and function. However, early sex differences in gene regulation that precede sex differences in function have not yet been identified. To identify such changes, we developed a model of PO that is characterized by compensated hypertrophy without sex differences after 2 weeks and by heart failure with sex differences after 9 weeks. We used transverse aortic constriction (TAC) or sham-operation in male and female mice and analyzed gene expression by microarray experiments. Keywords: the influence of gender on hypertrophic gene expression
Project description:Trans-aortic constriction (TAC) is a widely used murine model to study pressure overload-induced cardiac hypertrophy and heart failure. Despite its high prevalence during aortic stenosis or chronic arterial hypertension, the global alterations in cardiac proteome and phospho-proteome dynamics following TAC remain incompletely characterised. Here, we present a comprehensive database of detailing the phospho-proteomic signature of the mouse heart one day and seven days after TAC. Utilising proteomic and phosphor-proteomic analyses, we identified and quantified thousands of proteins and phosphorylation sites, revealing hundreds of differential phosphorylation events that are significantly altered in the cardiac response to pressure overload. Our analysis highlights significant changes in pathways related to hypertrophic signalling, metabolic remodelling, contractile function, and the stress response. We also present proteomic data from the main cardiac cell types (endothelial cells, fibroblasts and cardiomyocytes) after TAC to reveal the cellular localization of the detected phosphoproteins. The dataset offers insights into temporal and site-specific phosphorylation events, facilitating the potential discovery of novel therapeutic targets and biomarkers. By making this resource publicly available, we aim to enable further exploration of the molecular basis of cardiac remodelling and advance translational research in heart failure.
Project description:Pressure overload-induced cardiac hypertrophy was examined in IL-18 knockout and littermate control mice. Experiment Overall Design: 4 groups with RNA pooled from 5-6 per group. Role of IL-18 on gene expression in cardiac hypertrophy induced by pressure overload (transaortic constriction)
Project description:Macrophages play a critical role in the pathogenesis and progression of heart failure, wherein sustained cardiomyocyte apoptosis is a key feature. The MER proto-oncogene tyrosine kinase (MERTK) is a critical receptor that mediates the efferocytosis of apoptotic cells by macrophages. However, the role and mechanism of action of MERTK in pressure overload-induced heart failure remains unclear. Here, we demonstrate that MERTK expression was upregulated in cardiac tissue macrophages of mice with pressure overload-induced heart failure. Deletion of MERTK ameliorated transverse aortic constriction (TAC)- and Ang II-induced cardiac hypertrophy and heart failure. This protective effect was associated with reduced type I interferon signaling and was reversed by interferon receptor activation. Efferocytosis assays were performed to demonstrate that mitochondrial double-stranded RNA from apoptotic cardiomyocytes activated Toll-like receptor 3 in macrophages, promoting Interferon beta (IFNb) expression. In vitro experiment identified that IFNb sensitized cardiomyocytes to Ang II stimulation by augmenting the P53 pathway, suppressing Ang II-induced protective mitophagy and promoting cardiomyocyte apoptosis. In conclusion, macrophage MERTK receptor exacerbated post-TAC heart failure and cardiac hypertrophy by mediating the phagocytosis of apoptotic cardiomyocytes and promoting IFNb expression. This study provides novel insights into the role of macrophage MERTK-mediated efferocytosis and type I interferon response in the pathogenesis of heart failure. These findings highlight an unrecognized function of MERTK in pressure overload-induced cardiac remodeling and identify IFNb as a key downstream effector of MERTK in this pathological process