Project description:We systematically identified, annotated and characterised the mouse long non-coding transcriptome during myocardial infarction, revealing hundreds of novel heart specific lncRNAs with unique functional and regulatory characteristics. 2 conditions, 4 biological replicates per condition
Project description:We systematically identified, annotated and characterised the mouse long non-coding transcriptome during myocardial infarction, revealing hundreds of novel heart specific lncRNAs with unique functional and regulatory characteristics.
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:Comparison of both LncRNAs and mRNAs expression in the border zone of the myocardial infarction rats and the sham operation rats Border zone (BZ) of the myocardial infarction is critical to patients. Current treatments of myocardial infarction are primarily aimed to save the dying myocardial cell in the border zone. During myocardial infarction, certain changes in BZ, e.g, apoptosis, fibrosis, inflammation, etc, played an important role in deciding the survival. Impairment and recovery of BZ has been linked to gene expression changes. The aim of our study was to obtain a global expression profile of lncRNAs and mRNAs of the border zone in Wistar rats myocardial infarction, and identify the changes during myocardial infarction.
Project description:In this study, we used a cardiac-specific, inducible expression system to activate YAP in adult mouse heart. Activation of YAP in adult heart promoted cardiomyocyte proliferation and did not deleteriously affect heart function. Furthermore, YAP activation after myocardial infarction (MI) preserved heart function and reduced infarct size. Using adeno-associated virus subtype 9 (AAV9) as a delivery vector, we expressed human YAP in the murine myocardium immediately after MI. We found that AAV9:hYAP significantly improved cardiac function and mouse survival. AAV9:hYAP did not exert its salutary effects by reducing cardiomyocyte apoptosis. Rather, we found that AAV9:hYAP stimulated adult cardiomyocyte proliferation. Gene expression profiling indicated that AAV9:hYAP stimulated cell cycle gene expression, enhanced TGFβ-signaling, and activated of components of the inflammatory response.Cardiac specific YAP activation after MI mitigated myocardial injury after MI, improved cardiac function and mouse survival. These findings suggest that therapeutic activation of hYAP or its downstream targets, potentially through AAV-mediated gene therapy, may be a strategy to improve outcome after MI. Three groups were involved in this study: sham group, AAV9:Luci+MI group and AAV9-YAP+MI group. Each group contained three biological replicates. The sham group had neither myocardial infarction nor AAV injection. The AAV9:Luci +MI(L for brief) group had myocardial infarction and injected with AAV9:Luic. The AAV9:hYAP+MI(YAP for brief) group had myocardial infarction and injected with AAV9:hYAP. 5 days after MI and AAV injection, the heart apexes were collected and the total RNA were isolated for microarray analysis.
Project description:Exogenous glucocorticoids interact with the circadian clock, but little attention is paid to their time of intake. Here we investigated the transcriptional effects of prednisone in heart when pulsed as intermittent once-weekly 1mg/kg i.p. dose in WT mice at ZT0 at 2-weeks after sham or myocardial infarction (MI; permanent ligation) surgeries. Aftter 6 weeks of treatment, we performed RNA-seq analysis in myocardial tissue to quantitate gene expression at isoform level.
Project description:BACKGROUND: Cardiac reprogramming is a technique to directly convert non-myocytes into myocardial cells using genes and/or small molecules. This intervention provides functional benefit to the rodent heart when delivered at the time of myocardial infarction or activated transgenically up to 4 weeks after myocardial infarction. Yet, several hurdles have prevented the advancement of cardiac reprogramming for clinical use. METHODS: Through a combination of screening and rational design, we identified a cardiac reprogramming cocktail that can be encoded in a single AAV. We also created a novel AAV capsid that can transduce cardiac fibroblasts more efficiently than available parental serotypes by mutating post-translationally modified capsid residues. Since a constitutive promoter was needed to drive high expression of these cell-fate altering reprogramming factors, we included binding sites to a cardiomyocyte-restricted microRNA within the 3’ UTR of the expression cassette that limits expression to non-myocytes. After optimizing this expression cassette to reprogram human cardiac fibroblasts into induced cardiomyocyte-like cells in vitro, we also tested the ability of this capsid / cassette combination to confer functional benefit in acute mouse myocardial infarction and chronic rat myocardial infarction models. RESULTS: We demonstrated sustained, dose-dependent improvement in cardiac function when treating a rat model two weeks after MI, showing that cardiac reprogramming, when delivered in a single, clinically relevant AAV vector, can support functional improvement in the post-remodeled heart. This benefit was not observed with GFP or a hepatocyte reprogramming cocktail and was achieved even in the presence of immunosuppression, supporting myocyte formation as the underlying mechanism. CONCLUSION: Collectively, these results advance the application of cardiac reprogramming gene therapy as a viable therapeutic approach to treat chronic heart failure resulting from ischemic injury.