Project description:Muscle atrophy F-box (MAFbx) is an E3 ubiquitin ligase which plays a critical role in mediating skeletal muscle atrophy. We investigated the effect of MAFbx KO in cardiac hypertrophy in response to pressure overload. A DNA microarray analysis was conducted using total RNA prepared from wild type and MAFbx KO mouse hearts subject to transverse aortic constriction (TAC). Results provide insight into the molecular mechanism to mediate the effect of MAFbx upon pathological hypertrophy.
Project description:Muscle atrophy F-box (MAFbx) is an E3 ubiquitin ligase which plays a critical role in mediating skeletal muscle atrophy. We investigated the effect of MAFbx KO in cardiac hypertrophy in response to pressure overload. A DNA microarray analysis was conducted using total RNA prepared from wild type and MAFbx KO mouse hearts subject to transverse aortic constriction (TAC). Results provide insight into the molecular mechanism to mediate the effect of MAFbx upon pathological hypertrophy. We applied TAC to wild type and MAFbx KO mice, and extracted total RNA one week after the surgery. The gene expression profiles were examined by Affymetrix Mouse Gene ST Array.
Project description:Muscle atrophy F-box (MAFbx/atrogin-1), an E3 ubiquitin ligase, is a crucial mediator of skeletal muscle atrophy and cardiac hypertrophy in response to pressure overload and exercise. We investigated the role of MAFbx in the regulation of cardiac remodeling following MI. A DNA microarray analysis was conducted using total RNA from wild type and MAFbx KO mouse hearts subject to permanet coronary ligation. Results provide insight into the molecular mechanism to mediate the role of MAFbx upon cardiac remodeling after myocardial infarction
Project description:Pressure overload-induced cardiac hypertrophy was examined in IL-18 knockout and littermate control mice. Experiment Overall Design: 4 groups with RNA pooled from 5-6 per group. Role of IL-18 on gene expression in cardiac hypertrophy induced by pressure overload (transaortic constriction)
Project description:Background: BMPER, an orthologue of Drosophila melanogaster crossveinless-2, is a secreted factor that regulates BMP activity in endothelial cell precursors and during early cardiomyocyte differentiation. Although previously described in the heart, the role of Bmper in cardiac development and function remained unknown. Methods: BMPER deficient hearts were phenotyped histologically and functionally using echocardiography and Doppler analysis. Since BMPER -/- mice die perinatally, BMPER +/- mice were then challenged to pressure overload induced cardiac hypertrophy and hind limb ischemia to determine changes in angiogensis and regulation of cardiomyocyte size. Results: We identified for the first time the cardiac phenotype associated with BMPER haploinsufficiency. BMPER mRNA and protein are present in the heart during cardiac development through at least E14.5 but is lost by E18.5. BMPER +/- ventricles are thinner and less compact than sibling wild-type hearts. In the adult, BMPER +/- hearts present with decreased anterior and posterior wall thickness, decreased cardiomyocyte size, and an increase in cardiac vessel density. Despite these changes, BMPER +/- mice respond to pressure overload-induced cardiac hypertrophy challenge largely to the same extent as wild-type mice. Conclusion: BMPER appears to play a role in regulating both vessel density and cardiac development in vivo; however, BMPER haploinsufficiency does not result in marked effects on cardiac function or adaptation to pressure overload hypertrophy. Unpaired, two-condition experiment, wild-type vs BMPER+/- adult hearts. Biological replicates: 4 per condition.
Project description:Expression profiles at various time points after surgical intervention for pressure-overload induced cardiac hypertrophy and failure.
Project description:The heart responds to pathological overload through myocyte hypertrophy. In our study, we found that this response is regulated by cardiac fibroblasts via a novel paracrine mechanism involving plasma membrane calcium ATPase 4 (PMCA4). PMCA4 deletion in mice, both systemically and specifically in fibroblasts, reduces the hypertrophic response to pressure overload; however, knocking out PMCA4 specifically in cardiomyocytes does not produce this effect. Mechanistically, our microarray data on fibroblasts isolated from PMCA4 WT and PMCA4 knockout animals showed that cardiac fibroblasts lacking PMCA4 produce higher levels of secreted frizzled related protein 2 (sFRP2), which inhibits the hypertrophic response in neighbouring cardiomyocytes. Furthermore, we show that treatment with the PMCA4 inhibitor aurintricarboxylic acid (ATA) inhibits and reverses cardiac hypertrophy induced by pressure overload in mice. Our results reveal that PMCA4 regulates the development of cardiac hypertrophy and provide proof of principle for a novel approach to treat this condition.