Project description:Genome-wide gene expression analysis at different stages of cardiomyocyte differentiation (undifferentiated mouse embryonic stem cells, neonatal mouse cardiomyocytes and adult mouse cardiomyocytes). Results provide important information on the differential expressed genes between undifferentiated mouse embrionic stem cells (mES) and mouse cardiomyocytes (CM) and also between cardiomyocytes from neonatal (CMp) and adult stages (CMa). This dataset allowed us to compare the expression profile of mES, CMp and CMa with the epigenetic profile of histone methylation generated with ChIP-seq experiments. Total RNA was obtained from biological triplicate of undifferentiated mouse embryonic stem cells (mES), neonatal mouse cardiomyocytes (CMp) and adult mouse cardiomyocytes (CMa)
Project description:Expression profiles of microRNAs in neonatal (isolated from day0 newborn rats) and adult rat cardiomyocytes (isolated from 2month old rats) Two condition experiment; Biological replicates: 7 samples of cardiomyocytes from neonatal rats (from independent isolations); 6 samples of cardiomyocytes isolated from adult animals (from independent isolations)
Project description:Cardiomyocytes exhibit differential growth patterns throughout development. In fetal life the increase in cardiac mass is associated with hyperplastic growth and cardiomyocyte proliferation. The majority of fetal cardiomyocytes are also mononucleated. During the early neonatal period in mice there is a switch from hyperplastic to hypertrophic growth of cardiomyocytes. This period is characterized by bi-nucleation and polyploidization of cardiomyocyte nuclei and a decreased capacity for cardiomyocytes to proliferate and complete cytokinesis. Increases in myocardial mass occur predominantly via hypertrophic growth. Adult mammalian cardiomyocytes are generally accepted to have little or no proliferative capacity and to be terminally withdrawn from the cell cycle. The vast majority of adult murine cardiomyocytes are bi-nucleated. The present study sought to accurately establish the growth pattern of cardiomyocytes throughout development in mice and identify genes associated with the switch from hyperplastic to hypertrophic growth. These cell cycle associated genes are crucial to the understanding of the mechanisms of bi-nucleation, polyploidization and hypertrophy in the neonatal period. Cardiomyocytes were FACS sorted from the hearts of ED11-12 embryos, neonatal day 3-4 and adult (10 week) eGFP ?-MHC mice whereby GFP expression is driven constitutively by the ?-MHC promoter. Gene analyses identified genes whose expression was predicted to be particular to day 3 -4 neonatal cardiomyocytes, compared to embryonic or adult cells. Cell cycle associated genes are crucial to the understanding of the mechanisms of bi-nucleation and hypertrophy in the neonatal period, and offer attractive candidates for manipulation. Total RNA obtained from isolated cardiomyocytes from ED11-12; Neonatal day 3-4 and adult timepoints compared with each other. Several hearts per sample, RNA was pooled within samples. FACS samples were prepared in the following manner: embryonic, neonatal and adult hearts were dissected and dissociated to single cell solution with Liberase Blendzyme 3 (0.1 mg/ml) (Roche Diagnostics), washed and spun down and resuspended in cardiomyocyte isolation buffer (130 mM NaCl; 5 mM KCl; 1.2 mM KH2PO4; 6 mM HEPES; 5 mM NaHCO3; 1 mM MgCl2; 5 mM Glucose).
Project description:Epigenetic changes in DNA and chromatin are implicated in organogenesis and cell differentiation. Through a genome-wide chromatin-immunoprecipitation DNA-sequencing approach (ChIP-seq) we analyses the enrichment of H3K79me2 and H3K4me3 (histone methylation marks associated with transcriptional activation) and H3K27me3 and H3K9me3 (histone methylation marks associated with transcriptional repression) in neonatal and adult cardiomyocytes. The histone methylation profile obtained was correlated with an Illumina gene expression profile from the same samples. Our results demonstrate that histone methylation, and in particular the DOT1L-mediated H3K79me2 mark, drives cardiomyogenesis through the definition of a specific transcriptional landscape Profiling of H3K79me2, H3K4me3, H3K27me3 and H3K9me3 in neonatal and adult cardiomyocytes
Project description:We addressed the question of which protein kinases are expressed in cardiomyocytes. We assessed the changes during postnatal development, comparing profiles in rat neonatal ventricular cardiomyocytes (NVMs) with adult ventricular cardiomyocytes (AVMs). Neonatal and adult rat ventricular cardiomyocytes prepared according to established procedures (Marshall et al. PLoS ONE 2010 5(4):e10027; Fuller and Sugden, FEBs Lett. 1989 247:209-12; Rodrigues and Severson In Biochemical Techniques in the Heart (McNeill, J. H., Ed.) pp 101-115, CRC Press, New York.). mRNA expression profiles compared using Affymetrix rat genome 230 2.0 arrays.
Project description:Expression profiles of microRNAs in neonatal (isolated from day0 newborn rats) and adult rat cardiomyocytes (isolated from 2month old rats)
Project description:Genome-wide gene expression analysis at different stages of cardiomyocyte differentiation (undifferentiated mouse embryonic stem cells, neonatal mouse cardiomyocytes and adult mouse cardiomyocytes). Results provide important information on the differential expressed genes between undifferentiated mouse embrionic stem cells (mES) and mouse cardiomyocytes (CM) and also between cardiomyocytes from neonatal (CMp) and adult stages (CMa). This dataset allowed us to compare the expression profile of mES, CMp and CMa with the epigenetic profile of histone methylation generated with ChIP-seq experiments.
Project description:Cardiomyocytes exhibit differential growth patterns throughout development. In fetal life the increase in cardiac mass is associated with hyperplastic growth and cardiomyocyte proliferation. The majority of fetal cardiomyocytes are also mononucleated. During the early neonatal period in mice there is a switch from hyperplastic to hypertrophic growth of cardiomyocytes. This period is characterized by bi-nucleation and polyploidization of cardiomyocyte nuclei and a decreased capacity for cardiomyocytes to proliferate and complete cytokinesis. Increases in myocardial mass occur predominantly via hypertrophic growth. Adult mammalian cardiomyocytes are generally accepted to have little or no proliferative capacity and to be terminally withdrawn from the cell cycle. The vast majority of adult murine cardiomyocytes are bi-nucleated. The present study sought to accurately establish the growth pattern of cardiomyocytes throughout development in mice and identify genes associated with the switch from hyperplastic to hypertrophic growth. These cell cycle associated genes are crucial to the understanding of the mechanisms of bi-nucleation, polyploidization and hypertrophy in the neonatal period. Cardiomyocytes were FACS sorted from the hearts of ED11-12 embryos, neonatal day 3-4 and adult (10 week) eGFP ?-MHC mice whereby GFP expression is driven constitutively by the ?-MHC promoter. Gene analyses identified genes whose expression was predicted to be particular to day 3 -4 neonatal cardiomyocytes, compared to embryonic or adult cells. Cell cycle associated genes are crucial to the understanding of the mechanisms of bi-nucleation and hypertrophy in the neonatal period, and offer attractive candidates for manipulation.
Project description:Background - The inability of the adult mammalian heart to regenerate following injury represents a major barrier in cardiovascular medicine. In contrast, the neonatal mammalian heart retains a transient capacity for regeneration, which is lost shortly after birth. Defining the molecular mechanisms that govern regenerative capacity in the neonatal period remains a central goal in cardiac biology. Here, we construct a transcriptional atlas of multiple cardiac cell populations, which enables comparative analyses of the regenerative (neonatal) versus non-regenerative (adult) state for the first time. Methods - Cardiomyocytes, fibroblasts, leukocytes and endothelial cells from infarcted and non-infarcted neonatal (P1) and adult (P56) hearts were isolated by enzymatic dissociation and FACS. RNA sequencing (RNA-seq) was performed on these cell populations to generate a transcriptomic atlas of the major cardiac cell populations during cardiac development, repair and regeneration. In addition, we surveyed the epigenetic landscape of cardiomyocytes during post-natal maturation by performing deep sequencing of accessible chromatin regions using the Assay for Transposase-Accessible Chromatin (ATAC-seq) from purified cardiomyocyte nuclei (P1, P14 and P56). Results - Profiling of cardiomyocyte and non-myocyte transcriptional programs uncovered several injury responsive genes across regenerative and non-regenerative time points. However, the majority of transcriptional changes in all cardiac cell types resulted from developmental maturation from neonatal stages to adulthood rather than activation of a distinct regeneration-specific gene program. Furthermore, adult leukocytes and fibroblasts reverted to a neonatal state and re-activated a neonatal proliferative network following infarction. In contrast, cardiomyocytes failed to re-activate the neonatal proliferative network following infarction, which was associated with loss of chromatin accessibility around cell cycle genes during post-natal maturation. Conclusions – This work provides a comprehensive transcriptional resource of multiple cardiac cell populations during cardiac development, repair and regeneration. Our findings define a transcriptional program underpinning the neonatal regenerative state and identifies an epigenetic barrier to re-induction of the regenerative program in adult cardiomyocytes.