Congenital heart defects (CHDs) occur in 0.51% of live births, yet the underlying genetic etiology remains mostly unknown. Recently, a new source of myocardial cells, namely the second heart field (SHF), was discovered in the splanchnic mesoderm. Abnormal development of the SHF leads to a spectrum of outflow tract defects, such as persistent truncus arteriosus and tetralogy of Fallot. Intracellular Ca2+ signaling is known to be essential formany aspects of heart biology including heart development, but its role in the SHF is uncertain. Here, we analyzed mice deficient for genes encoding inositol 1,4,5-trisphosphate receptors (IP3Rs), which are intracellular Ca2+ release channels on the endo/sarcoplasmic reticulum that mediate Ca2+ mobilization. Mouse embryos that are double mutant for IP3R type 1 and type 3 (IP3R1/IP3R3/) show hypoplasia of the outflow tract and the right ventricle, reduced expression of specific molecular markers and enhanced apoptosis ofmesodermal cells in the SHF. Gene expression analyses suggest that IP3R-mediated Ca2+ signalingmay involve, at least in part, theMef2CSmyd1 pathway, a transcriptional cascade essential for the SHF. These data reveal that IP3R type 1 and type 3 may play a redundant role in the development of the SHF.
Inositol 1,4,5-trisphosphate receptors are essential for the development of the second heart field.
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Ewing Sarcoma is caused by a pathognomonic genomic translocation that places an N-terminal EWSR1 gene in approximation with one of several ETS genes (typically FLI1). This aberration, in turn, alters the transcriptional regulation of more than five hundred genes and perturbs a number of critical pathways that promote oncogenesis, cell growth, invasion, and metastasis. Among them, translocation-mediated up-regulation of the insulin-like growth factor receptor 1 (IGF-1R) and mammalian target of rapamycin (mTOR) are of particular importance since they work in concert to facilitate IGF-1R expression and ligand-induced activation, respectively, of proven importance in ES transformation. When used as a single agent in Ewing sarcoma therapy, IGF-1R or mTOR inhibition leads to rapid counter-regulatory effects that blunt the intended therapeutic purpose. Therefore, identify new mechanisms of resistance that are used by Ewing sarcoma to evade cell death to single-agent IGF-1R or mTOR inhibition might suggest a number of therapeutic combinations that could improve their clinical activity.
IGF-1R and mTOR Blockade: Novel Resistance Mechanisms and Synergistic Drug Combinations for Ewing Sarcoma.
Specimen partView Samples
It is becoming increasingly apparent that Staphylococcus aureus are able to survive engulfment by macrophages, and that the intracellular environment of these cells, which is essential to innate host defenses against invading microorganisms, may in fact provide a refuge for staphylococcal survival and dissemination. Based on this, we postulated that S. aureus might induce cytoprotective mechanisms by changing gene expression profiles inside macrophages similar to obligate intracellular pathogens, such as Mycobacterium tuberculosis.
Phagocytosis of Staphylococcus aureus by macrophages exerts cytoprotective effects manifested by the upregulation of antiapoptotic factors.
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NCoR and SMRT are two paralogous vertebrate proteins that function as corepressors with unliganded nuclear receptors. Although C. elegans has a large number of nuclear receptors, orthologues of the corepressors NCoR and SMRT have not unambiguously been identified in Drosophila or C. elegans. Here, we identify GEI-8 as the closest homologue of NCoR and SMRT in C. elegans and demonstrate that GEI-8 is expressed as at least two isoforms throughout development in multiple tissues, including neurons, muscle and intestinal cells. We demonstrate that a homozygous deletion within the gei-8 coding region, which is predicted to encode a truncated protein lacking the predicted NR domain, results in severe mutant phenotypes with developmental defects, slow movement and growth, arrested gonadogenesis and defects in cholinergic neurotransmission. Whole genome expression analysis by microarrays identified sets of de-regulated genes consistent with both the observed mutant phenotypes and a role of GEI-8 in regulating transcription. Interestingly, the upregulated transcripts included a predicted mitochondrial sulfide:quinine reductase encoded by Y9C9A.16. This locus also contains non-coding, 21-U RNAs of the piRNA. Inhibition of the expression of the region coding for 21-U RNAs leads to irregular gonadogenesis in the homozygous gei-8 mutants, but not in an otherwise wild-type background, suggesting that GEI-8 may function in concert with the 21-U RNAs to regulate gonadogenesis. Our results confirm that GEI-8 is the orthologue of the vertebrate NCoR/SMRT corepressors and demonstrate important roles for this putative transcriptional corepressor in development and neuronal function.
GEI-8, a homologue of vertebrate nuclear receptor corepressor NCoR/SMRT, regulates gonad development and neuronal functions in Caenorhabditis elegans.
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CC-671 has been identified as an inhibitor of Cdc2-like kinase 2 (CLK2) and TTK in direct enzyme assays. CLK2 is a member of the CLK family that phosphorylates serine- and arginine-rich (SR) proteins of the spliceosomal complex as part of a regulatory mechanism for control of pre-mRNA splicing. SR proteins are a family of small nuclear ribonucleoprotein particle (snRNP) splicing factors involved in constitutive and alternative splicing. Monitoring specific phospho-biomarkers of CLK2 demonstrated that CC-671 inhibited phosphorylation of CLK2 substrates in cancer cells with mean IC50 of 549 nM in the triple negative breast cancer (TNBC) line CAL51. In this study, RNA sequencing approach was used to quantify the impact of CC-671 treatment on gene transcription and global alternative splicing in CAL51 cells. Differential exon usage analysis demonstrated that CC-671 changed alternative splicing of many genes. In addition, different sets of genes are impacted by CC-671 at both the alternative splicing and mRNA expression. Genes impacted by alternative splicing shared a set of common pathways with genes altered by mRNA expression. This result indicates that CC-671 regulates transcription via both gene expression and alternative splicing mechanisms. Overall design: Triple negative breast cancer (TNBC) line CAL51 was grown in DMEM medium containing 10% fetal bovine serum, as recommended by vendor. The growing cells were treated by CC-671 in three biological replicates at the following concentrations and time intervals. The treatment time points were 6 hour and 24 hour. Concentration of compounds used was 3 and 10 uM. Six million cells from each treatment were harvested and RNA was isolated by RNeasy kit. Poly-A selection and strand-specific RNA library construction were performed, followed by multiplexing indexed libraries and sequencing on the HiSeq 2500 with 2x100 bp read lengths. A total of 16 samples were included in this experiment, including 4 treatment groups with three biological replicates and 2 vehicle control groups with two biological replicates
Synthetic Lethal Strategy Identifies a Potent and Selective TTK and CLK1/2 Inhibitor for Treatment of Triple-Negative Breast Cancer with a Compromised G<sub>1</sub>-S Checkpoint.
Specimen part, Cell line, Treatment, SubjectView Samples
To examine whether energy starvation caused by the increase in rRNA transcription affects liver metabolism, we compared the gene expression profiles of WT and NML-KO livers using Affymetrix microarray technology.
Hepatic rRNA transcription regulates high-fat-diet-induced obesity.
Age, Specimen partView Samples
Purpose:Next-generation sequencing has revolutionized sytems-level celluar pathway analysis. The goals of this study are to compare the U87 cell xenograft GBM mice (U87 cell line) to TWIST1 knock out U87 cell xenograft GBM mice (TWIST1 knock out U87 cell line) using their transcriptomes Overall design: Methods: Investigation of TWIST1 expression on glioblastoma malignancy in vitro and in vivo.
Targeting TWIST1 through loss of function inhibits tumorigenicity of human glioblastoma.
Specimen part, SubjectView Samples
This study aims to demonstrate the link between epigenome-wide methylation aberrations at birth and genomic transcriptional changes upon allergen sensitization that occur in the neonatal dendritic cells (DC) due to maternal asthma. In an in vivo model reproducing human epidemiology findings, maternal but not paternal asthma predisposes the neonate to increased asthma risk, the effect is allergen-independent and is not genetic or environmental. Earlier we demonstrated that neonates of asthmatic mothers are born with a functional skew in splenic DCs that mediates the early-life asthma origin. These allergen-naive cells convey allergy responses to normal recipients, however minimal to no transcriptional or phenotypic changes were found to explain the functional pro-allergic alterations. In this study we profiled both allergen-nave dendritic cells, and cells after allergen sensitization in vivo. We found that while allergen-naive DCs from asthma-at-risk neonates have minimal transcriptional change compared to controls, upon allergen sensitization, multiple genes with pre-existing epigenetic alterations show significant transcriptional change. .
Link between epigenomic alterations and genome-wide aberrant transcriptional response to allergen in dendritic cells conveying maternal asthma risk.
Specimen part, TreatmentView Samples
XRN2 is a conserved 5’-->3’ exoribonuclease that complexes with XTB-domain containing proteins. Thus, in Caenorhabditis elegans (C. elegans), the XTBD-protein PAXT-1 stabilizes XRN2 to retain its activity. XRN2 activity is also promoted by 3''(2''),5''-bisphosphate nucleotidase 1 (BPNT1) through its hydrolysis of 3’-phosphoadenosine-5''-bisphosphate (PAP), an endogenous XRN inhibitor. Here, we find through unbiased screening that loss of bpnt-1 function suppresses lethality caused by paxt-1 deletion. This unexpected finding is explained by XRN2 autoregulation, which occurs through repression of a cryptic promoter activity and destabilization of the xrn-2 transcript. Autoregulation appears to be triggered at different thresholds of XRN2 inactivation, such that more robust XRN2 perturbation, by elimination of both PAXT-1 and BPNT1, is less detrimental to worm viability than absence of PAXT-1 alone. Like more than 15% of C. elegans genes, xrn-2 occurs in an operon, and we identify additional operons under its control, consistent with a broader function of XRN2 in polycistronic gene regulation. Regulation occurs through intercistronic regions that link genes in an operon, but similar mechanisms may allow XRN2 to operate on monocistronic genes in organisms lacking operons. Overall design: Wild-type C. elegans worms were subjected to mock or xrn-2 RNAi from L1 to L4 stage at 20°C. Total RNA was extracted from the worms, and polyadenylated RNA was analyzed.
XRN2 Autoregulation and Control of Polycistronic Gene Expresssion in Caenorhabditis elegans.
Cell line, SubjectView Samples