Transcription profiling of rat right heart pulmonary embolism vs control
ABSTRACT: 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: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. Overall design: Pulmonary thromoembolism was simulated by injecting rats with 25-micron polystyrene microspheres into the right jugular vein. A dose of 2 million microspheres per 100 grams rat weight was used to generate chronic pulmonary embolism (~350 gram rats; injections ware 0.15 ml/100 gram of a 13 million microsphere per ml suspension in sterile 0.01% Tween-20). Control rats were injected with 0.01 ml/100 grams of Tween-20 "vehicle". After 6 weeks of PE or control, rats were euthanized and hearts surgically excised. Hearts were briefly perfused with buffer to remove blood. Right venticles were removed from whole hearts and separated into "apex" and "outflow-tract" (base) sections. Tisssues were then processed for RNA. More complete descriptions of these methods are available in PMID: 18430806, PMID: 18025228 and PMID: 16814320.
Project description:Rats were given pulmonary embolism by i.v. injection of 25 micron polystyrene microspheres or 0.01% Tween20 solution as vehicle control Embolism of microspheres is irreversible and causes dose dependent pulmonary hypertension Keywords: time course and dose response Overall design: Rats received one of three treatments: 0.15 ml/100 grams weight of 0.01% Tween20 as "vehicle" control; 0.10 ml/100 grams of 10% microsphere suspension in 0.01% Tween20 = 1.3 million/100 grams = "PE1.3" dose; 0.15 ml/100 grams of 10% microspheres = 2.0 million/100 grams = "PE2.0" dose; rats were euthanized at either 2 hours or 18 hours after treatment
Project description:Right ventricular failure was induced thourgh pulmonary banding in 11 pigs. Right ventricular failure was defined as a SRVP >50 mmHg during two hours. After right ventricular failure was induced, half the pigs were treatmed with a Glenn-shunt combined with pulmonary banding for one hour, and the other half served as control group with pulmonary banding only. The aim was to study the change in global gene expression during right ventricular failure due to pulmonary banding, and the effect of volume unloading during pulmonary banding. 11 pigs. Samples at the following time periods: 1) Baseline 2) Right ventricular failure 3) Treatment with modified Glenn-shunt/Control. After Right ventricular failure, pigs were divided into two groups a) Treatment with modified Glenn-shunt or b) Control group
Project description:Gene expression in the right ventricle is different in control patients as compared to either idiopathic dilated cardiomyopathy or pulmonary arterial hypertension Two human hearts obtained at autopsy from each of control, pulmonary hypertension, and dilated cardiomyopathy
Project description:The right ventricle (RV) differs in several aspects from the left ventricle (LV) including its embryonic origin, physiological role and anatomical design. In contrast to LV hypertrophy, little is known about the molecular circuits, which are activated upon RV hypertrophy (RVH). We established a highly reproducible model of RVH in mice using pulmonary artery clipping (PAC), which avoids detrimental RV pressure overload and thus allows long-term survival of operated mice. Magnetic resonance imaging revealed pathognomonic changes with striking similarities to human congenital heart disease- or pulmonary arterial hypertension- patients. Comparative, microarray based transcriptome analysis of right- and left-ventricular remodeling identified distinct transcriptional responses to pressure-induced hypertrophy of either ventricle, which were mainly characterized by stronger transcriptional responses of the RV compared to the LV myocardium. Hierarchic cluster analysis revealed a RV- and LV-specific pattern of gene activity after induction of hypertrophy, however, we did not find evidence for qualitatively distinct regulatory pathways in RV compared to LV. Data mining of nearly three thousand RV-enriched genes under PAC disclosed novel potential (co)-regulators of long-term RV remodeling and hypertrophy. We reason that specific inhibitory mechanisms in RV restrict excessive myocardial hypertrophy and thereby contribute to its vulnerability to pressure overload. Alternative splicing and gene expression analysis during development of the heart and cardiomyoyte differentiation.
Project description:A porcine microarray study of right ventricular failure due to coronary artery ligation of the right ventricular free wall and subsequent treatment of right ventricular failure by volume unloading using a shunt between superior vena cava and the pulmonary artery (Glenn-shunt) 1. Surgical preparation with a 12 mm graft between superior vena cava and pulmonary artery, the graft is then clamped - Baseline sample using a biopsy needle. 2. After surgical preparation the coronary arteries of the right ventricular free wall are ligated, then heart failure develops over 120 minutes - Failure sample using a biopsy needle. 3. The shunt is then opened and the superior vena cava closed between the shunt and right atrium, diverting the blood from superior vena cava through the shunt for a period of 15 minutes partially unloading the right ventricle - Shunt sample using a biopsy needle. A series of six pigs, three samples from each animal: baseline, failure and shunt/treatment.
Project description:Right ventricular dysfunction (RVD) independently predicts worse outcomes in both heart failure (HF) and pulmonary hypertension (PH), irrespective of their etiologies. Yet no evidence-based therapies exist for RVD and progression towards RV failure (RVF) can occur in spite of optimal medical treatment of HF or PH. This disparity reflects our insufficient understanding of the molecular pathophysiology of RVF. To identify molecular mechanisms that may uniquely underlie RVF, we investigated the cardiac ventricular transcriptome of advanced HF patients, with and without RVF. Using weighted gene co-expression network and module-phenotype analyses, we identified a 279-member gene module that correlated significantly and specifically with RVF. Within this module, WIPI1 served as a genetic hub, HSPB6, SNAP47, and MAP4 as drivers, and PRDX5 as a repressor of RVF. We subsequently confirmed the ventricular specificity and temporal relationship of Wipi1, Hspb6, and Map4 transcript expression changes in murine models of pressure overload induced RV failure versus LV failure and subsequently uncovered differential dysregulation of autophagy in the failing RV versus the failing LV, namely a shift towards excessive non-canonical, Beclin1-independent, Wipi1/LC3II-mediated autophagy in RVF. In vitro siRNA silencing of Wipi1 partially protected isolated neonatal rat ventricular cardiac myocytes against aldosterone-induced failing phenotype. Moreover, silencing Wipi1 blunted mitochondrial superoxide production and limited non-canonical autophagy in this in vitro RVF model. Our findings suggest that Wipi1 regulates mitochondrial oxidative signaling and autophagy in cardiac myocytes. Inhibition of Wipi1 may hold promise as a therapeutic target for RVF. Overall design: Examination of RNAseq results from Left and Right Ventricles of 15 individuals, 5 control, 5 left-sided Heart Failure, 5 bi-ventricular Heart Failure