RNA-seq of dissected cardiac septa from a mouse developmental time course
Ontology highlight
ABSTRACT: For this project, we explored the genetic determinants of the heart development condition termed patent foramen ovale (PFO) using quantitative trait loci (QTL) mapping and genomics/transcriptomics analyses. Two mice strains were chosen that exhibit highly divergent phenotypes associated with PFO, 129T2/SvEms and QSi5. In this experiment, we performed bulk RNA sequencing (RNA-seq) on the dissected septa from the hearts of developing 129T2/SvEms or QSi5 mice at three developmental time points: E12.5, E14.5 and E16.5. Each sample contained a pool of RNA from 3 dissected septa.
Project description:Pharmacological and gene ablation studies have demonstrated a crucial role of the cardiac natriuretic peptides (NP) hormones ANF and BNP in the maintenance of cardiovascular homeostasis. In addition, hypertension and chronic congestive heart failure are clinical entities that may be regarded as states of relative NP deficiency. Hence the study of the function of the endocrine heart is highly relevant. To identify genes that are related to the endocrine function of the heart we have conducted differential gene expression studies of the rat atria and ventricles using oligonucleotide arrays. Experiment Overall Design: The atrial appendages and the ventricular free walls were obtained from thirteen normal male Sprague Dawley rats. The total RNA was obtained from four pools of atrial and four pools of ventricular tissues. Four biological replicates for each muscle type were generated, i.e. 4 atrial replicates and 4 ventricular replicates.
Project description:Atrial fibrillation (AF) is often a progressive cardiac arrhythmia that increases the risk of hospitalization and adverse cardiovascular events. There is a clear demand for more inclusive and large-scale approaches to understand the molecular drivers responsible for AF, as well as the fundamental mechanisms governing the transition from paroxysmal to persistent and permanent forms. We aimed to create a molecular map of AF and find the distinct genetic programs underlying cell type-specific atrial remodeling and AF progression. We used a sheep model of long-standing, tachypacing-induced AF, sampled right and left atrial tissue and isolated cardiomyocytes from control, intermediate (transition) and late time points during AF progression, and performed transcriptomic and proteome profiling. We have merged all these layers of information into a meaningful 3-component space in which we explored the genes and proteins detected and their common patterns of expression. Our data-driven analysis points at extracellular matrix remodeling, inflammation, ion channel, myofibril structure, mitochondrial complexes and chromatin remodeling as hallmarks of AF progression. Most important, we prove that these changes occur at early transitional stages of the disease, but not at later stages, and that the left atrium undergoes significantly more profound changes than the right atrium in its expression program. The pattern of dynamic changes in gene and protein expression correspond closely with the electrical and structural remodeling demonstrated previously in the sheep and in humans. The results provide novel insight into the dynamics of gene and protein expression changes that underlie AF-induced atrial remodeling and that make the arrhythmia become more stable and long lasting.
Project description:The developmental origin of the c-kit expressing progenitor cell pool in the adult heart has remained elusive. Recently, it has been discovered that the injured heart is enriched with c-kit+ cells, which also express the hematopoietic marker CD45. In this study, we characterize the phenotype and transcriptome of the c-kit+/CD45+ cell population, originating from the left atrial appendage. These cells are defined as cardiac macrophage progenitors. We also demonstrate that the c-kit+/CD45+ progenitor cell population activates heart development, neural crest and pluripotency associated pathways in vitro, in conjunction with CD45 down-regulation, and acquire a c-kit+/lin- phenotype. This spontaneous reprogramming progresses further to a highly proliferative, partially myogenic phenotype. Our data suggests that c-kit+/lin- cells and cardiac macrophages have a common lineage origin possibly resolving some current conundrums in the field of cardiac regeneration. Two different stem cell types were grown by altering the tissue digestion protocol, from which one type was spontaneously transdifferentiating to other cell types. To investigate their transcriptional profiles we prepared RNA from two cell sorted replicates per cell type (A, B, C1, C2, C3).
Project description:Atrial fibrillation (AF) is the most common sustained arrhythmia characterized by rapid and multiple irregular excitations within the atria. AF is associated with serious morbidity and increased mortality, and its prevalence is prospected to increase as society ages. The limited therapeutic efficacy of AF treatment as well as its high socioeconomic burden makes AF a major clinical challenge. Despite our expanding knowledge of individual proteins and pathways involved in the complex pathophysiology of atrial fibrillation (AF), an unbiased overview of proteins and functionally enriched biological processes as well as their crosstalk is lacking. Here, we performed an explorative proteomics analysis to reveal the global abundance of proteins in cardiac tissue of patients, and deciphered functionally grouped gene ontologies (GO) to uncover a perspective of the disease biology driving or driven by AF. A total of 2703 proteins were identified by liquid chromatography coupled to tandem mass spectrometry. Among them, 150 proteins (accounting for 5.6% of 2703) had a significantly altered abundance (100 proteins increased and 50 decreased) in AF. A significant biological connection was found between those (protein-protein interaction enrichment p-value=1.0e-16). GO enrichment analysis showed that these 150 proteins were mainly located in extracellular/cytoplasmic vesicles, mitochondrion, and cytoskeletal compartments. Correspondingly, the 100 proteins increased in AF were significantly enriched in the GO terms related to immune system, metabolic process, iron process, ECM disassembly, mitochondrial translation and apoptotic signaling. Partially clustered proteins with dense functional link were found in immune system and metabolic process, and were respectively annotated in neutrophil degranulation, and oxoacid metabolic process coupled to the subunits of mitochondrial dehydrogenase NADH. Those processes enriched in AF had crosstalk via the proteins involved in neutrophil degranulation. Selected proteins such as LCN2 (neutrophil degranulation), CA3 (immune system), NDUFS2 (complex I) and MYH10 (actin motor protein) were validated by western blot or qPCR in an independent cohort. The 50 proteins decreased in AF were collectively enriched in vesicle-mediated transport and actin filament-based movement. We demonstrate that important biological processes underlying persistent AF as well as their crosstalk via the components of neutrophil degranulation. Our study provides a novel insight for a more efficient targeting strategy for AF treatment.
Project description:Ischemic cardiomyopathy (ICM) leads to congestive heart failure and can cause sudden cardiac death due to arrhythmia. Existing molecular knowledge base of ICM is rudimentary because of lack of specific attribution to cell type and function. This study was designed to investigate cell-specific molecular remodeling of ion channels, exchangers and pumps, which are signaling molecules (SM) involved in electrical, signaling and mechanical functions of the heart. Atrial and ventricular myocytes were isolated by laser-capture microdissection from left atrium and ventricle of healthy and ICM human hearts. SM and their splice variants altered by ICM in cardiomyocytes were identified by splice microarray and validated by RT-PCR. Molecular profiling of ICM-related changes showed that SM in atrial and ventricular myocytes remodel following their unique programs. ICM affected 63 genes in ventricular myocytes and 12 genes in atrial myocytes. Only few of the identified genes were previously linked to human cardiac disfunctions. In our experiments we used 3 healthy hearts rejected from transplantation procedure and explanted ICM hearts from three male patients. Tissue samples were dissected from left ventricle and left atrial appendages. Atrial and ventricular myocytes were laser-capture microdissected from serial 7-8-µm thick cryostat sections. Individual cellular total RNA samples were analyzed on custom-built Human Ion Channel Splice Arrays slides (ExonHit) manufactured on the Ion Channel Splice Array sv1.1 platform representing 287 human SM, including 248 alternatively spliced ones in total 1655 splicing events and supplemented with capabilities to recognize connexins and ryanodine receptors.
Project description:We have found that the expression pattern of Atf5 is highly restricted to the olfactory system, strongly suggesting that Atf5 is an olfactory sensory neuron-specific transcription factor. To test this possiblity, we compared gene expression profiles in olfactory epithelium (septa and turbinates) from Atf5+/+ and Atf5-/- mice. Olfactory septa and turbinates were dissected from Atf5+/+ and Atf5-/- P0 pups from different litters (n=3 for each genotype) and pooled into a single sample. Three independent samples were prepared for each genotype.
Project description:The developmental origin of the c-kit expressing progenitor cell pool in the adult heart has remained elusive. Recently, it has been discovered that the injured heart is enriched with c-kit+ cells, which also express the hematopoietic marker CD45. In this study, we characterize the phenotype and transcriptome of the c-kit+/CD45+ cell population, originating from the left atrial appendage. These cells are defined as cardiac macrophage progenitors. We also demonstrate that the c-kit+/CD45+ progenitor cell population activates heart development, neural crest and pluripotency associated pathways in vitro, in conjunction with CD45 down-regulation, and acquire a c-kit+/lin- phenotype. This spontaneous reprogramming progresses further to a highly proliferative, partially myogenic phenotype. Our data suggests that c-kit+/lin- cells and cardiac macrophages have a common lineage origin possibly resolving some current conundrums in the field of cardiac regeneration. Two different stem cell types were grown by altering the tissue digestion protocol. To investigate their transcriptional profiles we prepared RNA from two cell sorted replicates per cell type and from two left ventricular biopsy samples as controls.
Project description:Forelimbs were manually dissected from three individual Bcl9/9l-deltaHD1/deltaHD2 mutants and three control littermates, at 10.5 days post coitum. BCL9 and BCL9L are paralogous beta-catenin cofactors involved in the transcriptional machinery of Wnt target genes.
Project description:Heart performance declines with age. Reduced protein quality control (PQC) due to decreased function of the ubiquitin/proteasome system (UPS), autophagy, and/or chaperone-mediated protein refolding is a likely contributor to age-associated cardiac performance decline. The transcription factor FOXO participates in the regulation of genes involved PQC and a host of other processes. Here, the effect of cardiac-restricted dFOXO overexpression was investigated in Drosophila, a genetically pliable and rapidly aging model. Modest dFOXO overexpression in the heart was protective, ameliorating functional decline with age. Increased expression of genes associated predominantly with UPS relative to other PQC components accompanied dFOXO-mediated cardioprotection, which was corroborated by a significant decrease in ubiquitinated myocardial proteins. In agreement, knockdown of upregulated UPS components seemingly induced premature aging. Despite these findings, excessive dFOXO overexpression or knockdown proved detrimental to heart function and overall organismal development. This study highlights Drosophila as a model of cardiac aging and FOXO as a tightly-regulated mediator of proteostasis and heart performance over time. Two replicates of 4 different samples were analyzed. Two of these samples were controls (GMH5 x yw 1 week and GMH5 x yw 5 week).