Project description:The aim of this project was to quantify the effects of different hypertrophic stimuli on synthesis of specific proteins in adult rat ventricular cardiomyocytes
Project description:During the progression of cardiac hypertrophy, cardiomyocytes accelerate RNA biogenesis to meet increasing metabolic demands under exogenous hypertrophic stimuli. We have elucidated the quantitative kinetics of RNA in c-Myc (Myc)-mediated hypermetabolic analytical model using cultured neonatal rat cardiomyocytes. Chromatin immunoprecipitation and high-throughput sequencing demonstrate that overexpressed Myc binds to a specific set of genes directly in cardiomyocytes and recruits RNA polymerase II to these genes.
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Adult mammalian cardiomyocytes are generally accepted to have little or no proliferative capacity and to be terminally withdrawn from the cell cycle.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:RNA-Seq results of adult mouse cardiomyocytes with Jmjd4 knockout and neonatal rat cardiomyocytes with Jmjd4 knockdown. To investigate the role of Jmjd4 in dilated cardiomyopathy, we performed gene expression profiling with RNA-Seq results from heart samples of MCM+ Jmjd4f/f and control Jmjd4f/f mice, as well as neonatal rat ventricuar cardiomyocytes (NRVCs) treated with si-Jmjd4 and si-NC control.
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:We used microarrays to expression profile cardiomyocytes from neonatal Sprague-Dawley rats treated with 50 ug/mL DEHP and control (0.1% DMSO) to identify changes in gene expression related to connexin-43 expression, calcium handling, arrhythmogenesis and mechanical motion. Rat neonatal cardiomyocytes were treated with DEHP (diluted in 0.1% DMSO) for 3 days, control samples were treated with 0.1% DMSO. Cardiomyocytes used in the experiments were from the same litter. Samples within a treatment group (control, DEHP) are biological replicates.
Project description:We used microarrays to expression profile cardiomyocytes from neonatal Sprague-Dawley rats treated with 1 to 50 ug/mL DEHP and control (0.1% DMSO) to identify changes in gene expression related to connexin-43 expression, calcium handling, arrhythmogenesis and mechanical motion. Rat neonatal cardiomyocytes were treated with 1 ug/ml, 10 ug/ml, or 50 ug/ml DEHP (diluted in 0.1% DMSO) for 3 days, control samples were treated with 0.1% DMSO. Cardiomyocytes used in the experiments were from the same litter. Samples within a treatment group (control, DEHP) are biological replicates.