Tcl1 tg mice develop a chronic lymphocytic leukemia (CLL) -like disease. To investigate the contribution of the adhesion molecule CD44 to CLL pathophysiology, we developed a CD19Cre CD44flox/flox Tcl1 tg mouse with a B cell specific CD44 deficiency (CD44B Tcl1 tg).
Microenvironment-induced CD44v6 promotes early disease progression in chronic lymphocytic leukemia.
Specimen part
View SamplesBackground The RNA steady-state levels in the cell are a balance between synthesis and degradation rates. Although transcription is important, RNA processing and turnover are also key factors in the regulation of gene expression. In Escherichia coli there are three main exoribonucleases (RNase II, RNase R and PNPase) involved in RNA degradation. Although there are many studies about these exoribonucleases not much is known about their global effect in the transcriptome. Results In order to study the effects of the exoribonucleases on the transcriptome, we sequenced the total RNA (RNA-Seq) from wild-type cells and from mutants for each of the exoribonucleases (?rnb, ?rnr and ?pnp). We compared each of the mutant transcriptome with the wild-type to determine the global effects of the deletion of each exoribonucleases in exponential phase. We determined that the deletion of RNase II significantly affected 187 transcripts, while deletion of RNase R affects 202 transcripts and deletion of PNPase affected 226 transcripts. Surprisingly, many of the transcripts are actually down-regulated in the exoribonuclease mutants when compared to the wild-type control. The results obtained from the transcriptomic analysis pointed to the fact that these enzymes were changing the expression of genes related with flagellum assembly, motility and biofilm formation. The three exoribonucleases affected some stable RNAs, but PNPase was the main exoribonuclease affecting this class of RNAs. We confirmed by qPCR some fold-change values obtained from the RNA-Seq data, we also observed that all the exoribonuclease mutants were significantly less motile than the wild-type cells. Additionally, RNase II and RNase R mutants were shown to produce more biofilm than the wild-type control while the PNPase mutant did not form biofilms. Conclusions In this work we demonstrate how deep sequencing can be used to discover new and relevant functions of the exoribonucleases. We were able to obtain valuable information about the transcripts affected by each of the exoribonucleases and compare the roles of the three enzymes. Our results show that the three exoribonucleases affect cell motility and biofilm formation that are two very important factors for cell survival, especially for pathogenic cells. Overall design: RNA-Seq of E. coli K-12 MG1693 wild-type(wt) and three exoribonucleases mutants was done with Illumina Hi-Seq platform.
PNPase is involved in the coordination of mRNA degradation and expression in stationary phase cells of Escherichia coli.
Cell line, Subject
View SamplesDevelopmental morphogenesis, tissue injury, and oncogenic transformation can cause the detachment of epithelial cells. These cells are eliminated by a specialized form of apoptosis (anoikis). While the processes that contribute to this form of cell death have been studied, the underlying mechanisms remain unclear. Here we tested the role of the cJUN NH2-terminal kinase (JNK) signaling pathway using murine models with compound JNK-deficiency in mammary and kidney epithelial cells. These studies demonstrated that JNK is required for efficient anoikis in vitro and in vivo. Moreover, JNK-promoted anoikis required pro-apoptotic members of the BCL2 family of proteins. We show that JNK acts through a BAK/BAX-dependent apoptotic pathway by increasing BIM expression and phosphorylating BMF leading to death of detached epithelial cells. Overall design: In order to understand the role of the JNK pathway in anoikis, Rosa-CreER (Control) and Jnk1flox/flox Jnk2-/- Rosa-CreER (Jnk1-/-Jnk2-/-) cells were grown as attached monoloayers or suspended for 4 hours. RNA was isolated from these cells and subjected to RNASeq to measure differential gene expression. Three separate samples from each condition were analyzed.
JNK Promotes Epithelial Cell Anoikis by Transcriptional and Post-translational Regulation of BH3-Only Proteins.
Cell line, Subject
View SamplesIdentification of the coding elements in the genome is a fundamental step to understanding the building blocks of living systems. Short peptides (< 100 aa) have emerged as important regulators of development and physiology, but their identification has been limited by their size. We have leveraged the periodicity of ribosome movement on the mRNA to define actively translated ORFs by ribosome footprinting. This approach identifies several hundred translated small ORFs in zebrafish and human. Computational prediction of small ORFs from codon conservation patterns corroborates and extends these findings and identifies conserved sequences in zebrafish and human, suggesting functional peptide products (micropeptides). These results identify micropeptide-encoding genes in vertebrates, providing an entry point to define their function in vivo. Overall design: Ribosome profiling experiments at five timepoints across zebrafish development in WT embryos
Upstream ORFs are prevalent translational repressors in vertebrates.
No sample metadata fields
View SamplesMicroRNAs regulate gene expression through deadenylation, repression and mRNA decay. However, the contribution of each mechanism in non-steady-state situations remains unclear. We monitored the impact of miR-430 on ribosome occupancy of endogenous mRNAs in wild type and dicer mutants lacking mature miR-430. Our results indicate that miR-430 reduces the number of ribosomes on target mRNAs before causing mRNA decay. Translational repression occurs before complete deadenylation, and disrupting deadenylation using an internal poly(A) tail did not block target repression. Finally, we observe that ribosome density along the length of the target mRNA remains constant, suggesting that translational repression occurs by reducing the initiation rate rather than reducing elongation or causing ribosomal drop-off. In summary, our results show that miR-430 regulates translation initiation before inducing mRNA decay. Overall design: Time course parallel ribosome profiling and input mRNA quantification in wildtype and MZdicer mutant embryos
Ribosome profiling shows that miR-430 reduces translation before causing mRNA decay in zebrafish.
No sample metadata fields
View SamplesResults of knocking-down AREG expression in SUM-149 cells by lenitviral infection of shRNA vectors and measuring gene expression provides information as to what genes are regulated by AERG in inflammatory breast cancer cells.
Knock-down of amphiregulin inhibits cellular invasion in inflammatory breast cancer.
Disease, Disease stage, Cell line
View SamplesWe used oligonucleotide microarrays to address the specificities of transcriptional responses of adult Drosophila to different stresses induced by paraquat and H2O2, two oxidative stressors, and by tunicamycin which induces an endoplasmic reticulum (ER) stress. Flies were tested 24 hours after exposure to continuous stresses induced by ingestion of paraquat, H2O2 or tunicamycin at concentrations leading to similar effects on viability. We used concentrations of 1% H2O2, 5mM paraquat and 12uM of tunicamycin which lead to negligeable mortality at 24 hours. A paraquat concentration of 15mM was also used for comparison with previous studies Both specific and common responses to the three stressors were observed and whole genome functional analysis identified several important classes of stress responsive genes. Within some functional classes, we observed large variabilities of transcriptional changes between isozymes, which may reflect unsuspected functional specificities.
Genome wide analysis of common and specific stress responses in adult drosophila melanogaster.
Sex, Age, Compound, Time
View SamplesDCA (3,5-Dichloroanthranilic acid) is a newly identified synthetic defense elicitor. To perform a comparative analysis of defense responses triggered by DCA and the structurally related defense inducer INA (2,6-Dichloroisonicotinic acid) Affymetrix chip experiments were performed with Arabidopsis thaliana seedlings treated with one of these two compounds.
The synthetic elicitor 3,5-dichloroanthranilic acid induces NPR1-dependent and NPR1-independent mechanisms of disease resistance in Arabidopsis.
No sample metadata fields
View SamplesWe have derived hESC from biopsied blastomeres of cleavage stage embryos under virtually the same conditions we used for the derivation of hESC lines from inner cell mass of blastocyst stage embryos. Blastomere-derived hESC lines exhibited all the standard characteristics of hESC including undifferentiated proliferation, genomic stability, expression of pluripotency markers and the ability to differentiate into the cells of all three germ layers both in vitro and in vivo. To examine whether hESC lines derived from two developmental stages of the embryo differ in gene expression, we have subjected three blastomere-derived hESC lines and two ICM-derived hESC lines grown under identical culture conditions to transcriptome analysis using gene expression arrays. Unlike previously reported comparisons of hESC lines which demonstrated, apart from core hESC-associated pluripotency signature, significant variations in gene expression profiles of different lines, our data show that hESC lines derived and grown under well-controlled defined culture conditions adopt nearly identical gene expression profiles. Moreover, blastomere-derived and ICM-derived hESC exhibited very similar transcriptional profiles independent of the developmental stage of the embryo from which they originated. Furthermore, this profile was evident in very early passages of the cells and did not appear to be affected by extensive passaging. These results suggest that during derivation process cells which give rise to hESC acquire virtually identical stable phenotype and are not affected by the developmental stage of the starting cell population.
Human embryonic stem cells derived from embryos at different stages of development share similar transcription profiles.
Specimen part, Disease, Cell line
View SamplesInvolution returns the lactating mammary gland to a quiescent state after weaning. The mechanism of involution involves collapse of the mammary epithelial cell compartment. To test whether the cJUN NH2-terminal kinase (JNK) signal transduction pathway contributes to involution, we established mice with JNK deficiency in the mammary epithelium. We found that JNK is required for efficient involution. JNK deficiency did not alter the STAT3/5 or SMAD2/3 signaling pathways that have been previously implicated in this process. Nevertheless, JNK promotes the expression of genes that drive involution, including matrix metalloproteases, cathepsins, and BH3-only proteins. These data demonstrate that JNK has a key role in mammary gland involution post lactation. Overall design: WAP-Cre and Jnk1f/f Jnk2f/f WAP-Cre mice were bred for a single pregnancy and litters were normalized to 6-8 pups. The pups were allowed to nurse for 9 days before forced weaning. At that point, some mice were euthanized and their mammary glands were harvested to isolate RNA (0 days). Other mice were kept for 3 days before euthanasia and mammary gland harvest (3d). In this way, gene expression differences could be determined between JNK-null and JNK-wildtype mammary glands before and during involution.
The cJUN NH<sub>2</sub>-terminal kinase (JNK) pathway contributes to mouse mammary gland remodeling during involution.
Specimen part, Cell line, Subject
View Samples