Mammalian brain evolved through several transitions between gyrencephaly and lissencephaly. Mechanisms generating gyrified or smooth brain are incompletely understood. Here we demonstrate that a short embryonic pulse of activating mutations in Pik3ca, the catalytic subunit of PI3K enzyme is sufficient to cause mouse cortical gyrification. We demonstrate that this gyrification phenotype is initiated by subtle focal regulation of apical cell adhesion and proliferation via PI3K-dependent localization of Yap protein. Treatment with verteporfin (Drug) a nuclear Yap inhibitor, attenuated over-proliferation and adhesion abnormalities, and subsequently gyrification. The purpose of this study was to compare the control and mutant mouse transcriptome, and their respective effect upon verteprofin treatment. Overall design: Mouse RNA profiles from postnatal day (P)0 hGFAP-cre;Pik3ca H1047R mutant and control hippocampal CA1 region, in presence or absence of a drug Verteporfin
PI3K-Yap activity drives cortical gyrification and hydrocephalus in mice.
No sample metadata fields
View SamplesThe nuclear receptor PPARalpha is recognized as the primary target of the fibrate class of hypolipidemic drugs and mediates lipid lowering in part by activating a transcriptional cascade that induces genes involved in the catabolism of lipids. We report here the characterization of three novel PPARalpha agonists with therapeutic potential for treating dyslipidemia. These structurally related compounds display potent and selective binding to human PPARalpha and support robust recruitment of coactivator peptides in vitro. These compounds markedly potentiate chimeric transcription systems in cell-based assays and strikingly lower serum triglycerides in vivo. The transcription networks induced by these selective PPARalpha agonists were assessed by transcriptional profiling of mouse liver after acute and chronic treatment. The induction of several known PPARalpha target genes involved with fatty acid metabolism were observed, reflecting the expected pharmacology associated with PPARalpha activation. We also noted the downregulation of a number of genes related to immune cell function, the acute phase response, and glucose metabolism; suggesting that these compounds may have anti-inflammatory action in the mammalian liver. Taken together, these studies articulate the therapeutic promise of a selective PPARalpha agonist.
Molecular characterization of novel and selective peroxisome proliferator-activated receptor alpha agonists with robust hypolipidemic activity in vivo.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Preferential epigenetic programming of estrogen response after in utero xenoestrogen (bisphenol-A) exposure.
Age, Specimen part
View SamplesBisphenol-A (BPA) is an environmentally ubiquitous estrogen-like endocrine-disrupting compound. Exposure toBPAin utero hasbeen linked to female reproductive disorders, including endometrial hyperplasia and breast cancer. Estrogens are an etiological factor in many of these conditions. We sought to determine whether in utero exposure to BPA altered the global CpG methylation pattern of the uterine genome, subsequent gene expression, and estrogen response. Pregnant mice were exposed to an environmentally relevant dose of BPA or DMSO control. Uterine DNA and RNA were examined by using methylated DNA immunoprecipitation methylation microarray, expression microarray, and quantitative PCR. In utero BPA exposure altered the global CpG methylation profile of the uterine genome and subsequent gene expression. The effect on gene expression was not apparent until sexual maturation, which suggested that estrogen response was the primary alteration. Indeed, prenatal BPA exposure preferentially altered adult estrogen-responsive gene expression. Changes in estrogen response were accompanied by altered methylation that preferentially affected estrogen receptor-a (ERa)binding genes. The majority of genes that demonstrated both altered expression and ERa binding had decreased methylation. BPA selectively altered the normal developmental programming of estrogen-responsive genes via modification of the genes that bind ERa. Gene environment interactions driven by early life xenoestrogen exposure likely contributes to increased risk of estrogen related disease in adults.Jorgensen, E. M.,Alderman,M.H., III,Taylor, H. S. Preferential epigenetic programmingof estrogen response after in utero xenoestrogen (bisphenol-A) exposure.
Preferential epigenetic programming of estrogen response after in utero xenoestrogen (bisphenol-A) exposure.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MEF2B mutations in non-Hodgkin lymphoma dysregulate cell migration by decreasing MEF2B target gene activation.
Cell line, Treatment
View SamplesMyocyte enhancer factor 2B (MEF2B) is a transcription factor with somatic mutation hotspots at K4, Y69 and D83 in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). The recurrence of these mutations indicates that they may drive lymphoma development. However, inferring the mechanisms by which they may drive lymphoma development was complicated by our limited understanding of MEF2Bs normal functions. To expand our understanding of the cellular activities of wildtype (WT) and mutant MEF2B, I developed and addressed two hypotheses: (1) identifying genes regulated by WT MEF2B will allow identification of cellular phenotypes affected by MEF2B activity and (2) contrasting the DNA binding sites, effects on gene expression and effects on cellular phenotypes of mutant and WT MEF2B will help refine hypotheses about how MEF2B mutations may contribute to lymphoma development. To address these hypotheses, I first identified genome-wide WT MEF2B binding sites and transcriptome-wide gene expression changes mediated by WT MEF2B. Using these data I identified and validated novel MEF2B target genes. I found that target genes of MEF2B included the cancer genes MYC, TGFB1, CARD11, NDRG1, RHOB, BCL2 and JUN. Identification of target genes led to findings that WT MEF2B promotes expression of mesenchymal markers, promotes HEK293A cell migration, and inhibits DLBCL cell chemotaxis. I then investigated how K4E, Y69H and D83V mutations change MEF2Bs activity. I found that K4E, Y69H and D83V mutations decreased MEF2B DNA binding and decreased MEF2Bs capacity to promote gene expression in both HEK293A and DLBCL cells. These mutations also reduced MEF2Bs capacity to alter HEK293A and DLBCL cell movement. From these data, I hypothesize that MEF2B mutations may promote DLBCL and FL development by reducing expression of MEF2B target genes that would otherwise function to help confine germinal centre B-cells to germinal centres. Overall, my research demonstrates how observations from genome-scale data can be used to identify cellular effects of candidate driver mutations. Moreover, my work provides a unique resource for exploring the role of MEF2B in cell biology: I map for the first time the MEF2B regulome, demonstrating connections between a relatively understudied transcription factor and genes significant to oncogenesis.
MEF2B mutations in non-Hodgkin lymphoma dysregulate cell migration by decreasing MEF2B target gene activation.
Cell line, Treatment
View SamplesMyocyte enhancer factor 2B (MEF2B) is a transcription factor with somatic mutation hotspots at K4, Y69 and D83 in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). The recurrence of these mutations indicates that they may drive lymphoma development. However, inferring the mechanisms by which they may drive lymphoma development was complicated by our limited understanding of MEF2B’s normal functions. To expand our understanding of the cellular activities of wildtype (WT) and mutant MEF2B, I developed and addressed two hypotheses: (1) identifying genes regulated by WT MEF2B will allow identification of cellular phenotypes affected by MEF2B activity and (2) contrasting the DNA binding sites, effects on gene expression and effects on cellular phenotypes of mutant and WT MEF2B will help refine hypotheses about how MEF2B mutations may contribute to lymphoma development. To address these hypotheses, I first identified genome-wide WT MEF2B binding sites and transcriptome-wide gene expression changes mediated by WT MEF2B. Using these data I identified and validated novel MEF2B target genes. I found that target genes of MEF2B included the cancer genes MYC, TGFB1, CARD11, NDRG1, RHOB, BCL2 and JUN. Identification of target genes led to findings that WT MEF2B promotes expression of mesenchymal markers, promotes HEK293A cell migration, and inhibits DLBCL cell chemotaxis. I then investigated how K4E, Y69H and D83V mutations change MEF2B’s activity. I found that K4E, Y69H and D83V mutations decreased MEF2B DNA binding and decreased MEF2B’s capacity to promote gene expression in both HEK293A and DLBCL cells. These mutations also reduced MEF2B’s capacity to alter HEK293A and DLBCL cell movement. From these data, I hypothesize that MEF2B mutations may promote DLBCL and FL development by reducing expression of MEF2B target genes that would otherwise function to help confine germinal centre B-cells to germinal centres. Overall, my research demonstrates how observations from genome-scale data can be used to identify cellular effects of candidate driver mutations. Moreover, my work provides a unique resource for exploring the role of MEF2B in cell biology: I map for the first time the MEF2B ‘regulome’, demonstrating connections between a relatively understudied transcription factor and genes significant to oncogenesis. Overall design: RNA-seq was performed on cells expressing V5 tagged WT or mutant MEF2B and on empty vector control cells. One biological replicates was performed on cell treated with either ionomycin or a solvent-only control.
MEF2B mutations in non-Hodgkin lymphoma dysregulate cell migration by decreasing MEF2B target gene activation.
No sample metadata fields
View SamplesThe endoplasmic reticulum (ER) is the site of secretory lipoprotein production and de novo cholesterol synthesis, yet little is known about how these activities are coordinated with each other, or with the activity of the COPII machinery, which transports ER cargo to the Golgi. The Sar1B component of this machinery is mutated in Chylomicron Retention Disorder, establishing that this Sar1 isoform secures delivery of dietary lipids into the circulation.
The endoplasmic reticulum coat protein II transport machinery coordinates cellular lipid secretion and cholesterol biosynthesis.
No sample metadata fields
View SamplesPrions consist of aggregates of abnormal conformers of cellular prion protein (PrPC). They propagate by recruiting host-encoded PrPC although the critical interacting proteins and the reasons for the differences in susceptibility of distinct cell lines and populations are unknown. We derived a lineage of cell lines with markedly differing susceptibilities, unexplained by PrPC expression differences, to identify such factors. We examined the transcriptomes of prion-resistant revertants, isolated from highly susceptible cells, and identified a gene expression signature associated with susceptibility. Several of these genes encode proteins with a role in extracellular matrix (ECM) remodelling, a compartment in which disease-related PrP deposits. Loss-of-function of nine of these genes significantly increased susceptibility. Remarkably, inhibition of fibronectin 1 binding to integrin 8 by RGD peptide inhibited metalloproteinases (MMP)-2/9 whilst increasing prion propagation rates. This indicates that prion replication may be controlled by MMPs at the ECM in an integrin-dependent manner.
Identification of a gene regulatory network associated with prion replication.
Treatment
View SamplesThe adoptive transfer of chimeric antigen receptor- (CAR) modified T cells is revolutionizing the treatment of B cell malignancies and has the potential to be applied to other diseases. CARs redirect T cell specificity by linking an antigen recognition domain to T cell signaling modules comprised of CD3z to provide signal 1, and CD28 or 4-1BB to provide costimulation. CD28/CD3z and 4-1BB/CD3z CARs confer differences in effector function and cell fate that affect clinical efficacy and toxicity. These differences may result from activation of divergent transcriptional programs. To gain this insight, we analyzed changes in gene expression in stimulated and resting CD28/CD3z or 4-1BB/CD3z CAR T cells. CD28/CD3z CAR stimulation initiated more marked early transcriptional changes with greater fold increases in the expression of effector molecules including GZMB, IFNG, IL2, TNF, and IL6. Direct comparison of CD28/CD3z and 4-1BB/CD3z samples stimulated for 6 hours identified 1,673 differentially expressed genes. Of these, the memory T cell-associated genes KLF2, IL7R, and FAM65B were expressed at lower levels in CD28/CD3z CAR T cells. KLF2 and IL7R are FOXO transcription factor family targets and we found that FOXO4 expression was similarly reduced in CD28/CD3z CAR T cells. CD28/CD3z CAR stimulation induces an effector T cell-like transcriptional profile that may underlie the decreased persistence and increased risks of toxicities observed with CD28/CD3z CAR T cells in early clinical trials. Overall design: Purified CD28/CD3z and 4-1BB/CD3z CAR T cells were prepared from healthy donors and stimulated by incubation with anti-CAR beads, or left unstimulated by incubation with control beads. Total RNA was harvested 6 or 24 hours after treatment. Three biological replicates for each treatment condition were prepared, yielding 24 total samples for analysis. A42 and A44 denote 4-1BB/CD3z CARs, A43 and A45 denote CD28/CD3z CARs.
Phosphoproteomic analysis of chimeric antigen receptor signaling reveals kinetic and quantitative differences that affect cell function.
Subject, Time
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