Project description:Time and dose related expression profiles of rat right heart tissue in microsphere bead model for Pulmonary embolism Experiment Overall Design: Rat right tissues of the Vehicle(no beads- control), low dose and high dose from rat bead model for Pulmonary Embolism were collected after 2, 6 and 18 hour time points. The extracted RNA was hybridized to Affymetrix Rat 230-2.0 microarrays to look for the dose and/or time related transcriptional changes associated with experimental Pulmonary Embolism.
Project description:The molecular mechanisms of progressive right heart failure are incompletely understood. We systematically examined transcriptomic changes occurring over months in isolated cardiomyocytes or whole heart tissues from failing right and left ventricles in rat models of pulmonary artery (PAB) or aortic banding (AOB). Detailed bioinformatics analyses resulted in the identification of gene signatures, protein, and transcription factor networks specific to ventricles and compensated or decompensated disease states. Proteomic and RNA-FISH analyses confirmed PAB-mediated regulation of key genes (including proenkephalin) and revealed spatially heterogeneous mRNA expression in the heart. Intersection of rat PAB-specific gene sets with transcriptome data sets from human patients with chronic thromboembolic pulmonary hypertension led to the identification of more than 50 genes whose expression levels correlated with the severity of right heart disease, including multiple matrix-regulating and secreted factors. These data define a conserved, differentially regulated genetic network associated with right heart failure in rats and humans
Project description:Pulmonary vascular occlusions due to thromboemboli can result in pulmonary hypertension and right heart damage. Treatments to clear the vascular obstructions such as i.v. heparain or thrombolytics can resolve the hypertension but right ventricular damage often occurs first. Methods of protecting the right ventricle from hypertensive damage during the course of acute treatment to clear the thromboemboli are needed. Monocyte- and neutrophil-mediated inflammation and fibrosis are associated with chronic right ventricular damage but the pathways involved are not understood. A comprehesive survey of gene expression during chronic pulmonary embolism verses control rats has been conducted in this study.
Project description:Time and dose related expression profiles of rat right heart tissue in microsphere bead model for Pulmonary embolism Keywords: Time course and dose response in experimental PE
Project description:Right ventricular heart failure (RVF) associated with pulmonary hypertension (PH) is characterized by a distinct gene expression pattern when compared with functional compensatory hypertrophy. Carvedilol treatment after RVF has been established reduces right ventricle (RV) hypertrophy and improves the RV function. In addition, carvedilol treatment has been shown to alter the gene expression of select genes. We sought to identify, on a genome-wide basis, the effect of carvedilol on gene expression. RVF was induced in male Sprague-Dawley rats by the combination of VEGF-receptor blockade and chronic hypoxia; thereafter, one group was treated with carvedilol. RNA was isolated from the RV and subjected to microarray analysis. A prediction analysis of the carvedilol-treated RVs showed that carvedilol treated RVs most resembled in their expression pattern the RVF pattern. However, an analysis beyond the boundaries of the prediction set revealed a small set of genes associated with carvedilol reversal of RVF. Pathway analysis of this set of genes revealed expression changes of genes involved in cardiac hypertrophy, mitochondrial dysfunction, protein ubiquitination, and sphingolipid metabolism. Genes encoding proteins in the cardiac hypertrophy and protein ubiquitination pathways were downregulated in the RV by carvedilol, while genes encoding proteins in the mitochondrial dysfunction and sphingolipid metabolism pathways were upregulated by carvedilol.