Project description:We tested the hypothesis that a set of differentially expressed genes could be used to predict cardiovascular phenotype in mice after prolonged catecholamine stress. Experiment Overall Design: We observed that WT FVB and B2KO mice developed systolic dysfunction in response to continuous catecholamine infusion while WT C57 mice developed diastolic dysfunction. Using these mice as the derivation cohort, we identified a set of 83 genes whose differential expression correlated with left ventricle systolic dysfunction. The gene set was then used to accurately predict development of left ventricle systolic dysfunction in a separate group of mice (WT B6129SF2/J) after catecholamine stress.
Project description:To find which genes were significantly modulated by Valsartan in non-infarcted left ventricle, 4 weeks after coronary artery ligation, and to correlate emerging modulated pathways with histology and cardiac magnetic resonance (CMR) imaging. The goal was to validate the estimation of the systolic dysfunction and of the regions preserved by pharmacological treatment performed with a CMR index. Title of the associated submitted paper: Evaluation of left ventricle function by regional fractional area change (RFAC) in a mouse model of myocardial infarction secondary to Valsartan treatment. Abstract: Purpose: Left ventricle (LV) regional fractional area change (RFAC) measured by cardiac magnetic resonance (CMR) allows the non-invasive localization and quantification of the extent of myocardial infarction (MI), and could be applied to assess the effectiveness of pharmacological or regenerative therapies. Here we investigate the ability of RFAC to identify regional dysfunction and discriminate the effect of pharmacological treatment with valsartan, a selective antagonist of angiotensin II type 1 receptor, in a model of MI. Methods: C57BL/6N mice, undergoing coronary artery ligation, were divided into two groups: untreated (MI) or treated with Valsartan (MI+Val). Sham-operated mice were used as a control. Cardiac dimensions and function were assessed at baseline, 24 hours, 1 and 4 weeks post surgery by CMR and echocardiography. At sacrifice histology and whole-genome gene expression profiling were performed. Results: RFAC was able to detect significant differences between treatment groups whereas the global ejection fraction was not. RFAC showed greater loss of contractility in remote non-infarcted myocardium in MI group than in MI+Val group. Consistently, in the same region MI+Val mice showed reduced myocyte hypertrophy, fibroblast proliferation, and fibrosis and modulation of target genes; in addition, left atrium volumes, appendage length and duct contractility were preserved. Conclusion: In this study, RFAC effectively estimated the degree of systolic dysfunction and discriminated the regions preserved by pharmacological treatment. RFAC index is a promising tool to monitor changes in LV contractility and to assess the effectiveness of therapeutic regimens in clinical settings.
Project description:Cardiomyopathy in type 1 diabetic patients is characterized by early onset diastolic and late onset systolic dysfunction. The mechanism underlying development of diastolic and systolic dysfunction in diabetes remains unknown. We used microarrays to detail the ventricle gene expression changes that underly development of diabetic cardiomyopathy. We identified distinct classes of up-regulated genes during this process. Experiment Overall Design: 150g male Wistar rats (Harlan) we injected with 65 mg/kg streptozotocin to induce Type 1 diabetes. Four replicates of Control and Diabetic rat ventricles were removed and frozen at Three time points for total RNA isolation and hybridization on the Affymetrix RG-U34A microarray. The 3 day samples show a baseline for initial diabetic changes in the ventricle. The 28 day samples show changes associated with diastolic dysfunction in diabetes. The 42 day samples show changes associated with both diastolic and systolic dysfunction in type 1 diabetic rat ventricles.
Project description:Analyses of the age-related changes that occur at a gene expression level and transcriptional profile have not been elucidated in depth. To determine the changes of the vascular transcriptome, we conducted gene expression microarray experiments on aortas of adult and old mice, in which age-related vascular dysfunction was confirmed by increased stiffness and associated systolic hypertension C57BL/6 mice obtained from Janvier (Saint Berthevin, France) were aged 6 months (n=6) and 20 (n=6) months and water and standard rodent chow were fed ad libitum. Briefly, the vessel was flushed thoroughly with ice-cold phosphate-buffered saline (PBS), through the left ventricle of the heart, cleaned of periadventitial fat and connective tissues, and snap-frozen in liquid nitrogen and stored at -80 °C.
Project description:Background: The insulin/IGF/relaxin family represents a group of structurally related but functionally diverse proteins. The family member Relaxin-2 has been evaluated in clinical trials for its efficacy in the treatment of acute heart failure. In this study, we assessed the role of Insulin-like peptide 6 (Insl6), another member of this protein family, in murine heart failure models using genetic loss-of-function and protein delivery methods. Methods and Results: Insl6-deficient (Insl6-KO) and wild-type (C57BL/6N) mice were administered angiotensin II or isoproterenol via continuous infusion with an osmotic pump or via intraperitoneal injection once a day, respectively for 2 weeks. In both models, Insl6-KO mice exhibited greater cardiac systolic dysfunction and left ventricular dilatation hypertrophy. Cardiac dysfunction in the Insl6-KO mice was associated with more extensive cardiac fibrosis and greater expression of fibrosis-associated genes. The continuous infusion of chemically synthesized INSL6 significantly attenuated left ventricular systolic dysfunction and cardiac fibrosis induced by isoproterenol infusion. Gene expression profiling suggests Lxr/ Rxr signaling is activated in the isoproterenol-challenged hearts treated with INSL6 protein. Conclusions: Endogenous Insl6 protein inhibits cardiac systolic dysfunction and cardiac fibrosis in angiotensin II- and isoproterenol-induced cardiac stress models. The administration of recombinant Insl6 protein could have utility for the treatment of heart failure and cardiac fibrosis.
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.