23 research outputs found
A Mighty Small Heart: The Cardiac Proteome of Adult Drosophila melanogaster
Drosophila melanogaster is emerging as a powerful model system
for the study of cardiac disease. Establishing peptide and protein maps of the
Drosophila heart is central to implementation of protein
network studies that will allow us to assess the hallmarks of
Drosophila heart pathogenesis and gauge the degree of
conservation with human disease mechanisms on a systems level. Using a
gel-LC-MS/MS approach, we identified 1228 protein clusters from 145 dissected
adult fly hearts. Contractile, cytostructural and mitochondrial proteins were
most abundant consistent with electron micrographs of the
Drosophila cardiac tube. Functional/Ontological enrichment
analysis further showed that proteins involved in glycolysis,
Ca2+-binding, redox, and G-protein signaling, among other
processes, are also over-represented. Comparison with a mouse heart proteome
revealed conservation at the level of molecular function, biological processes
and cellular components. The subsisting peptidome encompassed 5169 distinct
heart-associated peptides, of which 1293 (25%) had not been identified in
a recent Drosophila peptide compendium. PeptideClassifier
analysis was further used to map peptides to specific gene-models. 1872 peptides
provide valuable information about protein isoform groups whereas a further 3112
uniquely identify specific protein isoforms and may be used as a
heart-associated peptide resource for quantitative proteomic approaches based on
multiple-reaction monitoring. In summary, identification of
excitation-contraction protein landmarks, orthologues of proteins associated
with cardiovascular defects, and conservation of protein ontologies, provides
testimony to the heart-like character of the Drosophila cardiac
tube and to the utility of proteomics as a complement to the power of genetics
in this growing model of human heart disease
In utero exposure to butyl benzyl phthalate induces modifications in the morphology and the gene expression profile of the mammary gland: an experimental study in rats
<p>Abstract</p> <p>Background</p> <p>Environmental estrogens are exogenous estrogen-mimicking compounds that can interfere with endogenous endocrine systems. Several of these endocrine disruptors have been shown to alter normal development and influence tumorigenesis in experimental models. N-butyl benzyl phthalate (BBP), a widely used plasticizer, is a well-known endocrine disruptor. The aim of this study was to elucidate the effect of prenatal exposure to BBP on the morphology, proliferative index, and genomic signature of the rat mammary gland at different ages.</p> <p>Methods</p> <p><it>In utero </it>exposure was performed by gavage of pregnant Sprague Dawley CD rats with 120mg or 500mg BBP/kg/day from day 10 post-conception to delivery. Female litters were euthanized at 21, 35, 50 and 100 days. The morphology and proliferative index of the mammary gland were studied from whole mount preparations and BrdU incorporation, respectively. Gene expression profile was assessed by microarrays. Several genes found differentially expressed and related to different functional categories were further validated by real time RT-PCR.</p> <p>Results</p> <p>Prenatal exposure of BBP induced delayed vaginal opening and changes in the post-natal mammary gland long after the end of the treatment, mainly by 35 days of age. Exposure to the high dose resulted in modifications in architecture and proliferative index of the mammary gland, mostly affecting the undifferentiated terminal end buds. Moreover, the expression profiles of this gland in the exposed rats were modified in a dose-dependent fashion. Analysis of functional categories showed that modified genes were related to immune function, cell signaling, proliferation and differentiation, or metabolism.</p> <p>Conclusions</p> <p>Our data suggest that <it>in utero </it>exposure to BBP induced a delayed pubertal onset and modified morphology of the mammary gland. These alterations were accompanied by modifications in gene expression previously associated with an increased susceptibility to carcinogenesis.</p
Constitutively active calcineurin induces cardiac endoplasmic reticulum stress and protects against apoptosis that is mediated by α-crystallin-B
Cardiac-specific overexpression of a constitutively active form of calcineurin A (CNA) leads directly to cardiac hypertrophy in the CNA mouse model. Because cardiac hypertrophy is a prominent characteristic of many cardiomyopathies, we deduced that delineating the proteomic profile of ventricular tissue from this model might identify novel, widely applicable therapeutic targets. Proteomic analysis was carried out by subjecting fractionated cardiac samples from CNA mice and their WT littermates to gel-free liquid chromatography linked to shotgun tandem mass spectrometry. We identified 1,918 proteins with high confidence, of which 290 were differentially expressed. Microarray analysis of the same tissue provided us with alterations in the ventricular transcriptome. Because bioinformatic analyses of both the proteome and transcriptome demonstrated the up-regulation of endoplasmic reticulum stress, we validated its occurrence in adult CNA hearts through a series of immunoblots and RT-PCR analyses. Endoplasmic reticulum stress often leads to increased apoptosis, but apoptosis was minimal in CNA hearts, suggesting that activated calcineurin might protect against apoptosis. Indeed, the viability of cultured neonatal mouse cardiomyocytes (NCMs) from CNA mice was higher than WT after serum starvation, an apoptotic trigger. Proteomic data identified α-crystallin B (Cryab) as a potential mediator of this protective effect and we showed that silencing of Cryab via lentivector-mediated transduction of shRNAs in NCMs led to a significant reduction in NCM viability and loss of protection against apoptosis. The identification of Cryab as a downstream effector of calcineurin-induced protection against apoptosis will permit elucidation of its role in cardiac apoptosis and its potential as a therapeutic target