Chromatin remodelling provides a key mechanism for the regulation of gene expression through dynamic alterations in nucleosome occupancy at promoters and enhancers. Haploinsufficiency for the ATP-dependent chromatin remodeller chromodomain-helicase-DNA-binding protein 7 (CHD7) causes human CHARGE syndrome. CHARGE is characterised by a distinct pattern of congenital anomalies, including cardiovascular malformations, and has traditionally been considered a neurocristopathy. We present a new perspective, by showing severe structural cardiovascular defects following ablation of Chd7 in the anterior mesoderm and other cardiac-related lineages. We identify multiple downstream pathways affected by the loss of Chd7 and disruption of excitation-contraction coupling in cardiomyocytes. Furthermore, we demonstrate CHD7 binding at the Sema3C promoter and alterations to the local chromatin structure in vivo, indicating direct transcriptional regulation. This work therefore provides novel insights into the etiology of heart defects arising in CHARGE syndrome and reveals a requirement for CHD7 activity in mesodermal cardiac progenitors.
A critical role for the chromatin remodeller CHD7 in anterior mesoderm during cardiovascular development.
Specimen part
View SamplesPurpose: The goals of this study are to compare transcriptome profiling (RNA-seq) resulting from the knockout of Hira in undifferentiated mouse embryonic stem cells (mESCs) and in day 15 differentiated cardiomyocytes.Methods: RNA extraction was done in duplicate from WT and Hira-null mESCs at day0 and day15 using TRIzol reagent. RNAseq was done onIllumina Nextseq500 and processed by the ICH genomics facility, reads were aligned and normalised using BOWTIE and DEseq R2 package. Gene lists were filtered using adjusted p-value = 0.05 and absolute fold change = 2. Results:We identified 1680 transcripts changed in the absence of HIRA in day 15 differentiated cardiomyocytes. GO term cardiovascular system development was the most downregulated gene set(p-value = 0.01 and FDR =0.1. Conclusion: this study analysis the role of HIRA in early cardiac mesoderm development usinf an invitro mESCs model. Overall design: mRNA profile of WT(control) and Hira-null (KO) undifferentiated mESCs and mESCs- derived cardiomyocytes at day15 were generated by deep sequencing in duplicates using Illumina Nextseq 500 platform.
HIRA directly targets the enhancers of selected cardiac transcription factors during in vitro differentiation of mouse embryonic stem cells.
Cell line, Subject
View SamplesPurpose: The goals of this study are to compare transcriptome profiling (RNA-seq) resulting from a Mesp1Cre driven ablation of Hira in the heart at E11.5 and E12.5. Methods: RNA extraction was done in triplicate from Mesp1Cre;Hira-/fl and Mesp1Cre;Hira+/fl embryonic hearts at E11.5 and E12.5 using the QIAGEN RNeasy mini kit. RNAseq was processed by the ICH genomics facility, reads were aligned and normalised using BOWTIE and DEseq R package. Strand NGS 2.5 software was used to re-analyse the aligned files (.bam). By applying the Mann Whitney unpaired test, Benjamini Hochberg False discovery rate (FDR) and filtering the genes using adjusted p-value = 0.05 and absolute fold change = 1.5, 95 % of the results were identical to the DEseq package used by the UCL Genomics facility. Results: We identified 360 coding transcripts changed in the mutant hearts (Mann Whitney unpaired test, Benjamini Hochberg FDR, p = 0.05, FC = 1.5) with no trend towards up- or down-regulation of global transcription (48.8% down vs 51.2% up) at E12.5. Conclusions: This work analyses the role of HIRA in mouse cardiac development. It was found that Tnni2 is the most upregulated gene in the absence of Hira. qRT-PCR validation of 25 targets. Little (<5%) or no variation of fold change between RNAseq and qRT-PCR data were observed. Overall design: Cardiac mRNA profiles of 11-day and 12-day embryonic days Mesp1Cre control (Ctrl) and Mesp1Cre;Hira-/fl (mut) were generated by deep sequencing, in triplicate, using Illumina GAIIx.
HIRA Is Required for Heart Development and Directly Regulates Tnni2 and Tnnt3.
Specimen part, Cell line, Subject
View SamplesHira has been implicated in replication-independent chromatin assembly.
Distinct factors control histone variant H3.3 localization at specific genomic regions.
Specimen part
View SamplesThe enumeration of EpCAM-positive circulating tumor cells (CTCs) has allowed clinicians to estimate the overall metastatic burden in breast cancer patients. However, a thorough understanding of CTCs associated with breast cancer brain metastasis (BCBM) is necessary for early identification and evaluation of treatment response to BCBM. In this study, we report that BCBM CTCs are enriched in a distinct sub-population of cells identifiable by their biomarker expression and mutational content.
Molecular characterization of breast cancer CTCs associated with brain metastasis.
Sex
View SamplesImbalances in endoplasmic reticulum (ER) proteostasis are associated with etiologically-diverse degenerative diseases linked to excessive extracellular protein misfolding and aggregation. Reprogramming of the ER proteostasis environment through genetic activation of the Unfolded Protein Response (UPR)-associated transcription factor ATF6 attenuates secretion and extracellular aggregation of amyloidogenic proteins. Here, we employed a screening approach that included complementary arm-specific UPR reporters and medium-throughput transcriptional profiling to identify non-toxic small molecules that phenocopy the ATF6-mediated reprogramming of the ER proteostasis environment. Comprehensive transcriptome analysis was employed to validate the capacity of three prioritized compounds to remodel the ER proteostasis environment, and to assess the prefential activation of ATF6 transcriptional targets relative to targets of the IRE1/XBP1s and PERK arms of the UPR. Overall design: HEK293T-Rex and HEK293-DAX cells were treated for 6 hr with vehicle (DMSO), 1 µM Tg, 10 mM TMP (in HEK293DAX), or 10 µM 132, 147 or 263 in biological triplicate at 37 °C
Small molecule proteostasis regulators that reprogram the ER to reduce extracellular protein aggregation.
Specimen part, Cell line, Treatment, Subject
View SamplesPRC, a member of the PGC-1 coactivator family, is responsive to serum growth factors and up regulated in proliferating cells. Here, we investigated its in vivo role by stably silencing PRC expression with two different short hairpin RNAs (shRNA#1 and shRNA#4) that were lentivirally introduced into U2OS cells. ShRNA#1 transductants exhibited nearly complete knockdown of PRC protein whereas shRNA#4 transductants expressed PRC protein at approximately 15 percent of the control level. Complete PRC silencing by shRNA#1 resulted in a severe inhibition of respiratory growth, reduced expression of respiratory protein subunits from complexes I, II, III and IV, markedly lower complex I and IV respiratory enzyme levels and diminished mitochondrial ATP production. Surprisingly, shRNA#1 transductants exhibited a striking proliferation of abnormal mitochondria that were devoid of organized cristae and displayed severe membrane abnormalities. Although shRNA#4 transductants had normal respiratory subunit expression and a moderately diminished respiratory growth rate, both transductants showed markedly reduced growth on glucose accompanied by inhibition of G1/S cell cycle progression. Microarray analysis revealed striking overlaps in the genes affected by PRC silencing in the two transductants and the functional identities of these overlapping genes were consistent with the observed mitochondrial and cell growth phenotypes. The consistency between phenotype and PRC expression levels in the two independent transductant lines argues that the defects result from PRC silencing and not from off target effects. These results support a role for PRC in the integration of pathways directing mitochondrial respiratory function and cell growth.
Short hairpin RNA-mediated silencing of PRC (PGC-1-related coactivator) results in a severe respiratory chain deficiency associated with the proliferation of aberrant mitochondria.
No sample metadata fields
View SamplesWe report that TAF3, a TBP-associated core promoter factor, is highly enriched in ES cells. In addition to its role in the core promoter recognition complex TFIID, genome-wide binding studies reveal that TAF3 localizes to chromosomal regions bound by CTCF and cohesin. Enrichment for TAF3/CTCF/cohesin bound regions distinguishes TAF3-activated from TAF3-repressed genes. Our findings support a new role of TAF3 in mediating long-range chromatin regulatory interactions to safeguard the finely-balanced transcriptional programs that give rise to pluripotency. Overall design: Comparison of genome-wide expression patterns between TAF3-knockdown and WT embryonic stem cells using mRNA-Seq. Significantly differentially expressed protein-coding genes were identified by comparing control and knock-down samples at each timepoint (ES, embryoid body day 3 (EB3), EB6). Single and paired-end samples were combined at each timepoint, resulting in 3 tests for each gene (based on 8, 4, 4 independent measurements at ES ,EB3, EB6, respectively).
Control of embryonic stem cell lineage commitment by core promoter factor, TAF3.
Specimen part, Cell line, Subject, Time
View SamplesPhosphatidylcholine transfer protein (PC-TP, a.k.a StarD2) is abundantly expressed in liver and is regulated by PPAR. When fed the synthetic PPAR ligand fenofibrate, Pctp-/- mice exhibited altered lipid and glucose homeostasis. Microarray profiling of liver from fenofibrate fed wild type and Pctp-/- mice revealed differential expression of a broad array of metabolic genes, as well as their regulatory transcription factors. Because its expression controlled the transcriptional activities of both PPAR and HNF4 in cell culture, the broader impact of PC-TP on nutrient metabolism is most likely secondary to its role in fatty acid metabolism.
Regulatory role for phosphatidylcholine transfer protein/StarD2 in the metabolic response to peroxisome proliferator activated receptor alpha (PPARalpha).
Sex, Age, Specimen part
View SamplesCharacterize the gpm1 mutant growth on dual substrate of ethanol and glycerol
Phosphoglycerate mutase knock-out mutant Saccharomyces cerevisiae: physiological investigation and transcriptome analysis.
No sample metadata fields
View Samples