Project description:Coronary heart disease is the leading cause of death worldwide. After an acute myocardial infarction, early reperfusion reduces infarct size, which correlates with improved clinical outcomes. Paradoxically, reperfusion although relieving ischemia, accelerates apoptosis in injured cardiomyocytes, which has led to the view that myocardial salvage is futile beyond the first few hours of reperfusion. In murine hearts subjected to 90 min of coronary artery occlusion and then 48 h of reperfusion, we show transient activation of intrinsic prosurvival insulin-like growth factor-1 (IGF-1) signaling. In these hearts, acute IGF-1 receptor inhibition decreases the abundance of prosurvival signaling molecules, and markedly activates caspase-3, a potent effector of apoptosis, in infarct border zone cardiomyocytes. We found that mouse mast cell protease-4 (MMCP-4) degraded IGF-1 in vitro by a novel catalytic activity of chymases. In vivo, this degradation, which is triggered by mast cell infiltration into the peri-infarct region and MMCP-4 extravasation, between 48 and 72 h post-ischemia/reperfusion (I/R), attenuates IGF-1 prosurvival signaling. In MMCP-4-deficient mice, while infarct size is not reduced at 24 h post-I/R, at 72 h post-I/R myocardial IGF-1 levels and signaling are increased, resulting in activation of the survival kinases Akt and ERK, inhibition of caspase-3, and reduced myocardial cell death. As a consequence, I/R-mediated loss of viable myocardium, adverse cardiac remodeling and contractile impairment are markedly reduced. Cardiomyocyte survival with consequent myocardial salvage may thus be possible even days after an ischemic insult, making them a novel therapeutic target for delayed cardioprotective therapy. Group 1 is wild type C57Bl6 uninjured hearts. These mice were not undergone any surgery and used as controls. Group 2 are wild type C57Bl6 72 h post-ischemia reperfusion (IR) injury hearts. These mice for subjected to ischemia reperfusion (IR) involving 90 min of left anterior descending coronary artery occlusion followed by reperfusion for 3 days or 72 h.
Project description:This a model from the article:
Simulation study of cellular electric properties in heart failure
Priebe L, Beuckelmann DJ. Circ Res.
1998; 82(11):1206-23 9633920
Patients with severe heart failure are at high risk of sudden cardiac death. In the majority of these patients, sudden cardiac death is thought to be due to ventricular tachyarrhythmias. Alterations of the electric properties of single myocytes in heart failure may favor the occurrence of ventricular arrhythmias in these patients by inducing early or delayed afterdepolarizations. Mathematical models of the cellular action potential and its underlying ionic currents could help to elucidate possible arrhythmogenic mechanisms on a cellular level. In the present study, selected ionic currents based on human data are incorporated into a model of the ventricular action potential for the purpose of studying the cellular electrophysiological consequences of heart failure. Ionic currents that are not yet sufficiently characterized in human ventricular myocytes are adopted from the action potential model developed by Luo and Rudy (LR model). The main results obtained from this model are as follows: The action potential in ventricular myocytes from failing hearts is longer than in nonfailing control hearts. The major underlying mechanisms for this prolongation are the enhanced activity of the Na+-Ca2+ exchanger, the slowed diastolic decay of the [Ca2+]i transient, and the reduction of the inwardly rectifying K+ current and the Na+-K+ pump current in myocytes of failing hearts. Furthermore, the fast and slow components of the delayed rectifier K+ current (I(Kr) and I(Ks), respectively) are of utmost importance in determining repolarization of the human ventricular action potential. In contrast, the influence of the transient outward K+ current on APD is only small in both cell groups. Inhibition of I(Kr) promotes the development of early afterdepolarizations in failing, but not nonfailing, myocytes. Furthermore, spontaneous Ca2+ release from the sarcoplasmic reticulum triggers a premature action potential only in failing myocytes. This model of the ventricular action potential and its alterations in heart failure is intended to serve as a tool for investigating the effects of therapeutic interventions on the electric excitability of the human ventricular myocardium.
This model was taken from the CellML repository
and automatically converted to SBML.
The original model was:
Priebe, Beuckelmann. (1998) - version02
The original CellML model was created by:
Lloyd, Catherine, May
The University of Auckland
Auckland Bioengineering Institute
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To cite BioModels Database, please use: Li C, Donizelli M, Rodriguez N, Dharuri H, Endler L, Chelliah V, Li L, He E, Henry A, Stefan MI, Snoep JL, Hucka M, Le Novère N, Laibe C (2010) BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models. BMC Syst Biol., 4:92.
Project description:Early reperfusion of ischemic cardiac tissue remains the most effective intervention for improving clinical outcome following myocardial infarction. However, abrupt increases in intracellular Ca2+ during myocardial reperfusion cause cardiomyocyte death and consequent loss of cardiac function, referred to as ischemia/reperfusion (IR) injury. Cardiac IR is accompanied by dynamic changes in expression of microRNAs (miRNAs), which inhibit specific mRNA targets. miR-214 is up-regulated during ischemic injury and heart failure in mice and humans, but its potential role in these processes is unknown. We show that genetic deletion of miR-214 in mice causes loss of cardiac contractility, increased apoptosis, and excessive fibrosis in response to IR injury. The microarray contains 6 samples, each containing cDNA pooled from 3 mice per group. There are no replicates. The array was designed to make 3 different pairwise comparisons between the following: P14 WT and miR-214 KO hearts; adult WT and miR-214 KO skeletal muscle; adult WT and miR-214 KO hearts
Project description:T cells undergo autoimmunization following spinal cord injury (SCI) and play both protective and destructive roles during the recovery process. T-cell deficient athymic nude (AN) rats recover better than immunocompetent Sprague-Dawley (SD) rats following spinal cord transection. In the present study, we evaluated locomotor recovery in SD and AN rats following moderate spinal cord contusion. To explain variable locomotor outcome, we assessed whole-genome expression using RNA sequencing, in the acute (1 week post-injury) and chronic (8 weeks post-injury) phases of recovery. AN rats demonstrated greater locomotor function than SD rats only at 1 week post-injury, coinciding with peak T cell infiltration in immunocompetent rats. Genetic markers for T cells and helper T cells were acutely enriched in SD rats, while AN rats expressed genes for Th2 cells, cytotoxic T cells, NK cells, mast cells, IL-1a, and IL-6 at higher levels. Acute enrichment of cell death-related genes suggested that SD rats undergo secondary tissue damage from T cells. Additionally, SD rats exhibited increased acute expression of voltage-gated potassium (Kv) channel-related genes. However, AN rats demonstrated greater chronic expression of cell death-associated genes and less expression of axon-related genes. We put forth a model in which T cells facilitate early tissue damage, demyelination, and Kv channel dysregulation in SD rats following contusion SCI. However, compensatory features of the immune response in AN rats cause delayed tissue death and limit long-term recovery. T cell inhibition combined with other neuroprotective treatment may thus be a promising therapeutic avenue. 2x2 model with 4 groups and 12 total samples. 2 rat strains (athymic nude [AN] and Sprague-Dawley [SD]) and 2 time points (1 week post-injury [acute] and 8 weeks post-injury [chronic]). 3 samples per group, for a total of 12 samples. No technical replicates were performed. Acute SD group = rats 618, 619, and 620. Chronic SD group = rats 605, 606, and 608. Acute AN group = rats 714, 715, and 717. Chronic AN group = rats 707, 712, and 713.
Project description:In isolated heart preparations, we observed that previous treatment with quinazoline DMA evoked both acute and late phases of cardioprotection. In this study, we adopted whole genome microarrays approach to investigate cardiac transcriptional responses induced in hearts from DMA treated mice in comparison to vehicle-only treatment. Deckmann AC, Rocco SA, Marin RM, Rolim L, Carazzolle MF, Barau JG, Pereira GAG and Franchini KG. DELAYED CARDIOPROTECTION INDUCED BY ADENOSINE KINASE INHIBITION STIMULATES ADIPOCYTOKINES AND ACTIVATORS OF PRO-SURVIVAL KINASES OF RISK PATHWAY. Unpublished yet. Keywords: Mus musculus, ischemic heart diseases, quinazoline compound, late cardioprotection Overall design: Balb/c mice were randomly assigned to two groups, in which they were gavaged with 30 mg DMA/kg body wt (treatment group, T) or DMSO (control group, C). After 24 hours, half of the animals of each group had their hearts excised and the total RNA was isolated as a pool. Same procedures were performed with the remaining animals 48 hours after treatment.
Project description:Stroke is a leading cause of adult disability and death. Inflammation plays an important role in stroke pathology, but the factors which promote brain inflammation in this setting remain to be fully defined. Here we investigate the meninges, the membranes that envelop the brain, for a potential role in modulating immune cell trafficking to the brain. We also investigate the potential of mast cells (MCs) to modulate this response as MCs are often considered as 'first responders' playing a critical role in the initiation and development of inflammation in many disease settings. We find that stroke increases expression of inflammatory and immune response genes in the meninges in mice consistent with a potential role in modulating immune cell trafficking. Moreover, genetic and cell transfer approaches identify MCs as important modulators of this response. Three categories of male mice were used: wild-type (WT) mice, mast cell-deficient (KO) mice, and mast cell-engrafted mice (EN), which are mast cell-deficient mice repaired of their mast cell deficiency by engraftment of mast cells i.v. 8-10 weeks prior to experimentation. The mouse strain was WBB6F1-Kit+/+ (wild-type ) and WBB6F1-KitW/W-v (mast cell-deficient ). Each mouse category was subdivided into two groups, naïve (N) and stroke (S), with n=3 per group. The stroke model was 30 minute filament occlusion of the middle cerebral artery. The dura were removed from the mouse brains at 2d post-stroke and from aged-matched naïve mice for microarray analysis. Dura were not pooled but run on separate arrays.
Project description:The cellular and molecular aspects of post-infarct left-ventricle remodeling in presence of type-2 diabetes is poorly understood. In this study we have addressed the cellular and molecular aspects underlying post-infarct left-ventricle remodeling in type 2 diabetic (T2DM) mice using genome-wide mRNA-sequencing. Myocardial infarction was induced by ligating left-anterior descending artery (LAD) in 12-14 month old T2DM and control mice. Cardiac MRI was performed at baseline, day 7 and 14 post-LAD ligation. Blood and tissue samples were collected for biochemical and immunohistochemical, molecular biology analysis after sacrification at day 7 and 14. Genome-wide mRNA sequencing analysis was performed from left-ventricular tissues collected at day 7 post-LAD ligation. Mitochondrial dynamics, Leukocyte recruitment and Collagen I deposition were analyzed using electron microscopy, fluorescent assisted cell sorting (FACS) and fourier-transform infra-red (FTIR) spectroscopy from left ventricular tissues collected at day 7 and 14 post-LAD ligation. Cardiac ejection fraction (EF) and stroke volume (SV) were significantly reduced along with increased mortality in T2DM compared to controls. Ingenuity pathway analyses of differentially expressed genes were enriched for mitochondrial dysfunction, TCA cycle and fatty acid oxidation. Additionally, upstream transcription factor analysis showed inhibition of PGC1a, PGC1b, ESRRA, ESRRB and TFAM in infarcted myocardium of T2DM mice. Electron microscopy analysis showed an altered mitochondrial dynamics and cardiomyocyte death in ischemic myocardium of T2DM mice. Leukocytes exhibited an altered phenotype in ischemic myocardium of T2DM mice. Neovascularization was impaired and collagen deposition was increased in ischemic myocardium of T2DM mice. We conclude that an altered mitochondrial dynamics, cell death modalities, leukocyte phenotype, neovascularization responses and fibrosis may contribute to an increased mortality after myocardial infarction in T2DM. Modulation of mitochondrial dynamics and cardiomyocyte cell death modalities may offer a novel therapeutic target. Overall design: Myocardial infarction was induced by ligating left anterior descending artery (LAD). Total RNA was isolated from remote, Infarct and border zones at day 7 after myocardial infarction. Poly (A)+RNA fraction was subjected to RNA sequencing using Illumina HiSeq.
Project description:A goal of this study was to identify and investigate previously unrecognized components of the remodeling process in the progression to heart failure by comparing gene expression in ischemic, failing (F) to non-failing (NF) hearts. These results also were compared to the changes observed in a proteomic analysis of F and NF hearts. RNA extracted from the left ventricle was hybridized to Affymetrix arrays to identify gene expression differences in ischemic, end-stage failing versus non-failing hearts. biological replicate: LV_NF_001, LV_NF002, LV_NF004, LV_NF005 biological replicate: LV_F_003, LV_F005, LV_F009, LV_F006
Project description:Global gene expression is altered in heart failure. This syndrome can be caused by cardiovascular diseases, including dilated cardiomyopathy (DCM), ischemic cardiomyopathy (ICM), hypertrophic cardiomyopathy, viral or toxic myocarditis, hypertension, and valvular diseases. We used microarrays to evaluate the impact of heart failure on human nucleocytoplasmic transport-related genes examining simultaneoulsly both dilated and ischemic human cardiomyopathies compared to normal hearts. Overall design: Transmural samples were taken from near the apex of the left ventricle. 29 heart samples were used in the microarray assay (dilated cardiomypathy, n = 12; ischemic cardiomyopathy, n = 12, and control hearts n = 5).
Project description:'This study investigates the effects produced by IGF-1 partial deficiency and if those effects were restored with the hormone''s substitutive therapy. Partial IGF-1 deficiency is achieved by heterozygous animals for a truncated gene of IGF-1 (Hz Igf1+/-), supplied by The Jackson Laboratories, which show a 60-75% reduction in circulating IGF-1 levels. The mice were a cross of 129SV Igf1+/- mice with non-consanguineous MF-1 mice to avoid consanguinity. Animals are treated for 10 days 2ug/100g bw/day with rhIGF-1 in succinate vehicle. After the 10 days of treatment, the animals were sacrificed, hearts were extracted, stored in RNAlater and frozen. On the day of the experiment, hearts were thawed, homogenised and subsequently processed as the RNA extraction kit instructions indicate (RNAqueousH-Micro Kit, Ambion, USA).'