Dataset Information

Making a predictive heart failure expression profile in Ren2 rat left ventricles

ABSTRACT: The intercalated disc of cardiac myocytes is emerging as a crucial structure in the heart. Loss of intercalated disc proteins like N-cadherin causes lethal cardiac abnormalities, mutations in intercalated disc proteins cause human cardiomyopathy. A comprehensive screen for novel mechanisms in failing hearts demonstrated that expression of the lysosomal integral membrane protein-2 (LIMP-2) is increased in cardiac hypertrophy and heart failure in both rat and human myocardium. Complete loss of LIMP-2 in genetically engineered mice did not affect cardiac development; however these LIMP-2 null mice failed to mount a hypertrophic response to increased blood pressure but developed cardiomyopathy. Disturbed cadherin localization in these hearts suggested that LIMP-2 has important functions outside lysosomes. Indeed, we also find LIMP-2 in the intercalated disc, where it associates with cadherin. RNAi-mediated knockdown of LIMP-2 decreases the binding of phosphorylated b-catenin to cadherin, while overexpression of LIMP-2 has the opposite effect. Taken together, our data show that lysosomal integrated membrane protein-2 is crucial to mount the adaptive hypertrophic response to cardiac loading. We demonstrate a novel role for LIMP-2 as an important mediator of the intercalated disc. Keywords: heart failure, comparison

ORGANISM(S): Rattus norvegicus

PROVIDER: GSE4286 | GEO | 2007/10/05

SECONDARY ACCESSION(S): PRJNA94779

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Rationale: The Id1 and Id3 genes play major roles during cardiac development, despite their expression being confined to non-myocardial layers (endocardium â?? endothelium - epicardium). We previously described that Id1â??/â??Id3â??/â?? double knockout (dKO) mouse embryos die at mid-gestation from multiple cardiac defects, but early demise precluded the studies of the roles of Id in the adult mice. Objective: To elucidate postnatal roles of Id genes in the heart. Methods and Results: We ablated Id1 gene in the vasculature and Id3 gene globally to generate Tie2Cre+Id1F/â??Id3â??/â?? and Tie2Cre+Id1F/FId3â??/â?? conditional KO (Id cKO) embryos. Half of the Id cKO mice die at birth. Postnatal demise was associated with cardiac underdevelopment, enlargement, muscular ventricular septal and endothelial defects. Surviving Id cKO mice exhibited dilated, fibrotic cardiomyopathy associated with defects in the vasculature. The adult cardiac phenotype progressed into heart failure and resembled endomyocardial fibroelastosis. An abnormal vascular response was also observed in the healing process of excisional skin wounds of Id cKO mice. Expression patterns of vascular, fibrotic and hypertrophic markers were altered in the Id cKO hearts, but addition of Insulin-Like Growth Factor binding protein-3 (IGFbp3) reversed gene expression profiles of vascular and fibrotic, but not hypertrophic markers. Conclusions: Conditional ablation of Id genes in the vasculature leads to dilated fibrotic cardiomyopathy. The findings could reveal important insights into the role(s) of the endocardial network of the endothelial lineage to the development of dilated fibrotic cardiomyopathy and identify a potential therapeutic target, IGFbp3, in its treatment. Total RNA from heart tissue was isolated (RNeasy, QIAGEN) from P180 WT, Id control, Id cKO, IGFbp3 incubated Id cKO, and control incubated Id cKO. RNA was converted to cDNA, cRNA, and hybridized to DNA sequences contained in the GeneChip Mouse Gene 1.0 ST Array (Affymetrix). Information from at least duplicate samples was compared and filtered by fold change >2 (Id cKO vs WT, Id control vs WT, IGFbp3 incubated Id cKO vs. control incubated Id cKO) and statistical p-value<0.001.

Dataset Information

Making a predictive heart failure expression profile in Ren2 rat left ventricles

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure