Project description:Two natriuretic peptides, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) act through the common receptor, guanylyl cyclase-A (GC-A) to lower blood pressure, induce diuresis/natriuresis and dilate blood vessels. Recently, we discovered that the excessive cardiac hypertrophy accompanied with cardiac dysfunction was induced in the lactating natriuretic peptide receptor 1 (Npr1, which encodes GC-A)-deficient mice. To clarify the cause of lactation-induced cardic hypertrophy in Npr1-/-, we performed the gene expressions analysis using nulliparous (NP) or postpartum lactating wild-type (Npr1+/+) and Npr1-/- mice. Numerous genes were altered in the postpartum lactating period both in Npr1+/+ and Npr1-/-. Additionally, the involvement of inflammatory responce in the cardiac hypertrophy in lactating-Npr1-/- mice was clarified bythe gene ontology analysis.
Project description:Inhibition of fibroblast activation protein promotes cardiac repair by stabilizing brain natriuretic peptide after myocardial infarction
Project description:Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are not only important biological markers, but also regulators of cardiac functions. The natriuretic peptide A receptor (NPRA), also called NPR1 or guanylyl cyclase A (GC-A), binds with ANP or BNP ligand and fulfils transmembrane signalling transduction by elevating the intracellular levels of cGMP. However, the comprehensive effects and mechanisms downstream to NPRA are still largely to be elucidated. Here, the cardiac expressing profiles of mRNA in the mice with myocardium-specific deletion of NPRA were analyzed. It was found that differently expressed mRNAs were detected and proved by Gene Ontology (GO) and pathway analysis to be mainly related to the metabolic process. Moreover, circular RNAs (circRNAs) were scrutinized, and subsequently a possible regulatory network consisting of circRNAs- MicroRNAs (miRNAs) -mRNAs was predicted and constructed by ceRNA (competing endogenous RNA) analysis. In conclusion, NPRA plays possible roles in cardiac metabolism, which might be mediated by circRNAs via endogenous competition mechanisms.
Project description:Cardiac hypertrophy is an important and independent risk factor for the development of cardiac myopathy that may lead to heart failure. Cardiac hypertrophy manifests as an enlargement of the individual cardiomyocytes, which impairs the function of the heart. The only way to cure end-stage cardiac myopathy is by heart transplantation, a possibility limited due to lack of donor hearts. Therefore, early diagnosis of cardiac hypertrophy is needed in order to be able to initiate interventions that may prevent further progression of the disease. The mechanisms underlying the development of cardiac hypertrophy are yet not well understood. To increase the knowledge about mechanisms and regulatory pathways involved in the progression of cardiac hypertrophy, we have developed a human induced pluripotent stem cell (hiPSC)-based in vitro model of cardiac hypertrophy and performed extensive characterization of the model using multi-omics analyses. In a series of experiments, hiPSC-derived cardiomyocytes were stimulated with Endothelin-1 for 8, 24, 48 and 72 hours and their transcriptome and secreted proteome were analyzed thoroughly. The transcriptomic data show many enriched canonical pathways related to cardiac hypertrophy already at the earliest time point, e.g., cardiac hypertrophy signaling, actin cytoskeleton signaling and PI3K/AKT signaling. Cluster analysis of the differentially expressed genes showed that there are numerous clusters of genes that are dysregulated over the time period of 8 to 72h. An integrated transcriptome-secretome analysis enabled the identification of multimodal biomarkers of high relevance for monitoring early cardiac hypertrophy progression. Taken together, the results from this study demonstrate that our in vitro model displays a hypertrophic response on transcriptomic- and secreted proteomic level. The results also provide novel insight into the underlying mechanisms of cardiac hypertrophy and novel putative early cardiac hypertrophy biomarkers have been identified that will be further validated to assess their clinical relevance.
Project description:: The adult heart develops hypertrophy to reduce ventricular wall stress and maintain cardiac function in response to an increased workload. Although pathological hypertrophy generally progresses to heart failure, physiological hypertrophy may be cardioprotective. Cardiac-specific overexpression of the lipid-droplet protein perilipin 5 (Plin5) promotes cardiac hypertrophy, but it is unclear if this response is beneficial. We analyzed human RNA-sequencing data from the left ventricle and showed that cardiac PLIN5 expression correlates with upregulation of cardiac contraction-related processes. To investigate how elevated cardiac Plin5 levels affect cardiac contractility, we generated mice with cardiac-specific overexpression of Plin5 (MHC-Plin5 mice). These mice displayed increased left ventricular mass and cardiomyocyte size but preserved heart function. Quantitative proteomics identified sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2 (SERCA2) as a Plin5-interacting protein. Phosphorylation of phospholamban, the master regulator of SERCA2, was increased in MHC-Plin5 versus wild-type cardiomyocytes. Live imaging showed increases in intracellular Ca2+ release during contraction, Ca2+ removal during relaxation, and SERCA2 function in MHC-Plin5 versus wild-type cardiomyocytes. These results identify a role for Plin5 in improving cardiac contractility through enhanced Ca2+ signaling.
Project description:The cardiac natriuretic peptide (NPs) plays an important role in the regulation of cardiovascular and renal function. We examined the miRNAs that could be regulating NPs by subjecting the cardiomyocytes, HCMa cells, to hypoxia.
Project description:Cardiac hypertrophy consists in the enlargement of cardiomyocytes and alteration of the extracellular matrix organization in response to physiological or pathological stress. In pathological hypertrophy ocuurs myocardial damage, loss of cardiomyocytes, fibrosis, inflammation, sarcomere disorganization and metabolic impairment, leading to cardiac dysfunction.The rodent model treated with isoproterenol induces cardiac hypertrophy due the constant activation of β-adrenergic receptors. We conducted a quantitative label-free proteomic analysis of cardiomyocytes isolated from hearts of mice treated or not with isoproterenol to better understand the molecular bases of cellular response due to isoproterenol-induced injury.
Project description:Excessive Ang II signaling through AT1R is shown to cause pathological hypertrophy. Underlying molecular mechanisms are not yet known and expression studies are not available so far. To understand hAT1R signaling, cardiac tissue, from C57BL/6 mouse over expressing hAT1R signaling, is subjected to genomic microarray studies. This data compared with the data from healthy, non transgenic C57BL/6 mouse. Keywords: disease state analysis
Project description:To gain new insights into the complex pathophysiology of dilated cardiomyopathy (DCM) we performed a quantitative approach to identify genes with expression patterns that linearly correlate with parameters of cardiac morphology (left ventricular end-diastolic diameter indexed by body surface are (LVEDDI), systolic function (LV ejection fraction (LVEF)), and serum levels of cardiac peptide hormone N-terminal pro-brain natriuretic peptide (NT-proBNP) in human endomyocardial biopsies of 47 DCM patients and 8 individuals with normal LVEF. A set of genes was identified as common heart failure markers characterized by correlation of their expression with cardiac morphology, systolic function and NT-proBNP. Among them are already known genes encoding e.g. the natriuretic peptide hormones NPPA and NPPB and its converting enzyme corin, but also potential new HF markers like EP300 antisense RNA1 and dimethylarginine dimethylaminohydrolase 1 (DDAH1) along with other genes with so far unknown relation to heart function. In contrast, the expression of other genes including the Ca2+ flux regulating genes phospholamban (PLN), sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA), and extracellular matrix proteins showed significant correlation with LVEF and LVEDDI only. Those genes seem to reflect more specifically pathological alterations of systolic function and morphology in DCM hearts.
Project description:As ambush-hunting predators that consume large prey after long intervals of fasting, Burmese pythons evolved with unique adaptations for regulating organ structure and function. Among these is cardiac hypertrophy that develops within three days following a meal (1, 2), which we previously showed was initiated by circulating growth factors (3). Post-prandial cardiac hypertrophy in pythons also rapidly regresses with subsequent fasting (2); however, the molecular mechanisms that regulate the dynamic cardiac remodeling in pythons during digestion are largely unknown. In this study, we employed a multi-omics approach coupled with targeted molecular analyses to examine remodeling of the python ventricular transcriptome and proteome throughout digestion. We found that forkhead box protein O1 (FoxO1) signaling was suppressed prior to hypertrophy development and then activated with regression, which coincided with decreased and then increased expression, respectively, of FoxO1 transcriptional targets involved in protein degradation. To define the molecular mechanistic role of FoxO1 in hypertrophy regression, we used cultured mammalian cardiomyocytes treated with post-fed python plasma. Hypertrophy regression both in pythons and in vitro coincided with activation of FoxO1-dependent autophagy; however, introduction of a FoxO1-specific inhibitor prevented both regression of cell size and autophagy activation. Finally, to determine if FoxO1 activation could induce regression, we generated an adenovirus expressing a constitutively active FoxO1. FoxO1 activation was sufficient to prevent and reverse post-fed plasma-induced hypertrophy, which was partially prevented by autophagy inhibition. Our results indicate that modulation of FoxO1 activity contributes to the dynamic ventricular remodeling in post-prandial Burmese pythons.