Project description:The use of anthracycline antibiotics such as doxorubicin (DOX) has greatly improved the mortality and morbidity of cancer patients. However, the associated risk of cardiomyopathy has limited their clinical application. DOX-associated cardiotoxicity is irreversible and progresses to heart failure (HF). For this reason, a better understanding of the molecular mechanisms underlying these adverse cardiac effects is essential to develop improved regimes that include cardioprotective strategies. MicroRNAs (miRNAs) are short non-coding RNAs that are able to post-trascriptionally regulate gene expression. MiRNAs have been demonstrated to be involved in both cancer and cardiovascular disease. Therefore, we were interested in unveiling the potential role of miRNAs in chemotherapy-induced HF. We used a combination of three different models to recreate this cardiac toxicity (acute in vitro DOX treatment, DOX-induced HF in vivo and a myocardial infarction -MI- leading to failure model) to study the pattern of dysregulated miRNAs. Using RNA from all three conditions, miRNA microarray profiling was performed and a common miRNA signature was identified. Interestingly, these dysregulated miRNAs have been previously identified as involved in the failing heart. Our results suggest that DOX is able to alter the expression of miRNAs implicated in HF, in vitro as well as in vivo. The present study is a microRNA profiling of the damaged cardiac muscle (cardiomyocyte cell population), following either myocardial infarction (MI) induction or doxorubicin (DOX) treatment. Two DOX-treated models were included: ARC exposed to DOX in vitro and a validated DOX-induced heart failure model generated by repeated administration of DOX injections.
Project description:Cardiac hypertrophy can lead to heart failure, and is induced either by physiological stimuli eg postnatal development, chronic exrcise training or pathological stimuli eg pressure or volume overload. This data set looks at microRNA profiles in mouse models to examine whether phosphoinositide 3-kinase (p110 alpha isoform) activity is critical for the maintenance of cardiac function and long term survival in a seeting of heart failure (myocardial infarction). The significance and expected outcome are to recognise genes involved in models of heart failure and attempt to examine underlying regulator pathways involved in possible cardica maintenance in the PI3K mouse model. The matching mRNA gene expression profile (GSE7487) is examined to look for mRNA and microRNA interactions. miRNA expression correlates directly with cardiac function. PI3K regulon ameliorates cardiac stress. Keywords: microRNA profiling, regulatory pathway discovery, genotype comparison Ntg (non-transgenics), dnPI3K (cardiac-specific transgenic model with reduced PI3K activity) and caPI3K (transgenic mice with increased PI3K activity) mice at 3-4 months of age were used. Mice were then subjected to myocardial infarction (occlusion of the left anterior descending aorta) and sham (open heart surgery) for 8 weeks. Left ventricles were harvested. The resulting 6 experimental models were profiled accordingly. The assignment of the mouse models is as follows: caPI3K Sham, Ntg Sham, dnPI3K Sham, caPI3K MI (myocardial infarction), Ntg MI and dnPI3K MI with n = 4 in each group.
Project description:Tissue fibrosis and organ dysfunction are hallmarks of age-related diseases including heart failure, but it remains elusive whether there is a common pathway to induce both events. Through single-cell RNA-seq, spatial transcriptomics, and genetic perturbation, we elucidate that high-temperature requirement A serine peptidase 3 (Htra3) is a critical regulator of cardiac fibrosis and heart failure by maintaining the identity of quiescent cardiac fibroblasts through degrading transforming growth factor-β (TGF-β). Pressure overload downregulates expression of Htra3 in cardiac fibroblasts and activated TGF-β signaling, which induces not only cardiac fibrosis but also heart failure through DNA damage accumulation and secretory phenotype induction in failing cardiomyocytes. Overexpression of Htra3 in the heart inhibits TGF-β signaling and ameliorates cardiac dysfunction after pressure overload. Htra3-regulated induction of spatio-temporal cardiac fibrosis and cardiomyocyte secretory phenotype are observed specifically in infarct regions after myocardial infarction. Integrative analyses of single-cardiomyocyte transcriptome and plasma proteome in human reveal that IGFBP7, which is a cytokine downstream of TGF-β and secreted from failing cardiomyocytes, is the most predictable marker of advanced heart failure. These findings highlight the roles of cardiac fibroblasts in regulating cardiomyocyte homeostasis and cardiac fibrosis through the Htra3-TGF-β-IGFBP7 pathway, which would be a therapeutic target for heart failure.
Project description:Affymetrix microarray analysis of molecular changes after myocardial infarction. Samples of heart tissue were analyzed after myocardial infarction from WT and reg3beta knock-out mice. Samples from scar tissue and samples adjacent to the scar were analyzed. In the experiment we primarily compared infarction zone of wild-type to infarction zone of knock-out animals, and remote zone of wild-type to remote zone of knock-outs.