Project description:This SuperSeries is composed of the following subset Series: GSE34457: Molecular Signatures of cardiac defects in Down syndrome lymphoblastoid cell lines (congenital heart disease) GSE34458: Molecular Signatures of cardiac defects in Down syndrome lymphoblastoid cell lines (trisomy 21) Refer to individual Series
Project description:Molecular Signatures of cardiac defects in Down syndrome lymphoblastoid cell lines. In this study, we want to identify genes and pathways specifically dysregulated in atrioventricular septal defect and /or atrial septal defect + ventricular septal defect in case of trisomy 21. Total RNA obtained from DS lymphoblastoid cell lines without congenital heart disease compared to cell lines from DS with congenital heart disease.
Project description:Molecular Signatures of cardiac defects in Down syndrome lymphoblastoid cell lines. In this study, we want to identify genes and pathways specifically dysregulated in atrioventricular septal defect and /or atrial septal defect + ventricular septal defect in case of trisomy 21.
Project description:The Dp1Tyb mouse model for Down syndrome contains a duplication of 23Mb of mouse chromosome 16 (Mmu16) that is orthologous to human chromosome 21 (Hsa21). This region contains 145 coding genes, and thus these genes are present in 3 copies. Dp1Tyb mice display congenital heart defects, similar to the ones seen in people with Down syndrome. These defects include ventricular and atrio-ventricular septal defects and are seen at embryonic day 14.5 (E14.5) of gestation. One of the 145 genes present in 3 copies in Dp1Tyb mice codes for a kinase called DYRK1A. We found that by crossing Dp1Tyb mice with mice carrying a heterozygous Dyrk1a loss of function allele, thereby reducing the dosage of the Dyrk1a gene from 3 to 2 copies, we rescue the congenital heart defects. Thus 3 copies of Dyrk1a are required to cause heart defects, and, presumably, increased DYRK1A protein is required for the heart defects. We compared the phosphoproteome in Dp1Tyb versus Dp1TybDyrk1a+/+/- embryonic hearts in order to discover alterations in phosphoproteins that could pinpoint molecular mechanisms that give rise to the congenital heart defects. The two strains (Dp1Tyb and Dp1TybDyrk1a+/+/-) differ only in the copy number of Dyrk1a (3 v 2) and thus differences in phosphoproteins would include both direct and indirect targets of DYRK1A activity.
Project description:The Pitx2 gene encodes a homeobox transcription factor that is required for mammalian development. Disruption of PITX2 expression in humans causes congenital heart diseases and is associated with atrial fibrillation (AF), however, the cellular and molecular processes dictated by Pitx2 during cardiac ontogeny remain unclear. To characterize the role of Pitx2 during murine heart development we sequenced over 75,000 single cardiac cell transcriptomes between two key developmental timepoints in control and Pitx2-null embryos. We uncovered that cardiac cell composition was dramatically altered in mutants at both E10.5 and E13.5. Interestingly, the differentiation dynamics of both anterior and posterior second heart field derived progenitor cells were disrupted in Pitx2 mutants. We also uncovered evidence for defects in left-right asymmetry within atrial cardiomyocyte populations. Furthermore, we were able to detail defects in cardiac outflow tract and valve development associated with Pitx2. Our findings offer insight into Pitx2 biology and provide a compilation of gene expression signatures for further detailing the complexities of heart development that will serve as the foundation for future studies of cardiac morphogenesis, congenital heart disease, and arrhythmogenesis.
Project description:To identify the molecular causes of heterotaxy syndrome patients with congenital heart defects, an Affymetrix CytoScan HD array was used to identify possible pathogenic CNVs in 63 patients. A total of 59 samples passed initial quality control.
Project description:Rationale: 22q11 deletion syndrome arises from recombination between low copy repeats on chromosome 22. Typical deletions result in hemizygosity for TBX1 associated with congenital cardiovascular disease. Deletions distal to the typically deleted region result in a similar cardiac phenotype but lack extra-cardiac features of the syndrome suggesting that a second haploinsufficient gene maps to this interval. Objective: The transcription factor HIC2 is lost in most distal deletions as well as a minority of typical deletions. We used mouse models to test the hypothesis that HIC2 hemizygosity causes congenital heart disease. Methods and Results: We created a genetrap mouse allele of Hic2. The genetrap reporter was expressed in the heart throughout the key stages of cardiac morphogenesis. Homozygosity for the genetrap allele was embryonic lethal before embryonic day E10.5 while the heterozygous condition exhibited a partially penetrant late lethality. One third of heterozygous embryos had a cardiac phenotype. Magnetic resonance imaging demonstrated a ventricular septal defect with overriding aorta. Conditional targeting indicated a requirement for Hic2 within the Nkx2.5+ and Mesp1+ cardiovascular progenitor lineages but not in the Wnt1+ neural crest or Mef2c+ second heart field lineages. Microarray analysis revealed increased expression of BMP10. Conclusions: Our results demonstrate a novel role for Hic2 in cardiac development. Hic2 is the first gene within the distal 22q11 interval to have a demonstrated haploinsufficient cardiac phenotype in mice. Together our data suggests HIC2 haploinsufficiency likely contributes to the cardiac defects seen in distal 22q11 deletion syndrome. The aim of this microarray experiment was to compare gene expression changes in the E13.5 mouse heart in a conditional knockout of Hic2 (Mesp1Cre/+; Hic2FL/FL) against control. All samples represent pools of isolated hearts from E13.5 mouse embryos. 3 replicates of each genotype were assayed. The genotypes are: 'WT' (Hic2FL/FL) 'KO' (Mesp1Cre/+; Hic2 FL/FL)
Project description:Embryos from the Dp1Tyb mouse model for Down syndrome (DS) present with congenital heart defects similar to the heart defects seen in humans with DS. We found that genetically reducing the copy number of the Dyrk1a gene (one of the genes in 3 copies in DS) from 3 to 2, normalised some of the transcriptomic changes in Dp1Tyb embryonic hearts and rescued congenital heart defects. Here we treated pregnant mice carrying Dp1Tyb and wild-type (WT) embryos with a Dyrk1a pharmacological inhibitor (Leucettinib-21 or L21) or an inactive isomer (Iso-L21) to study the effect of L21 on the transcriptome of Dp1Tyb and WT embryonic hearts.