To determine the physiological targets of the NELF complex, and provide insight into the mechanism of NELF activity in vivo.
NELF-mediated stalling of Pol II can enhance gene expression by blocking promoter-proximal nucleosome assembly.
No sample metadata fields
View SamplesCAMTA3 is known to be involved in regulation of induction of early cold-responsive genes, CBF1 and CBF2 at cold conditions and of suppression of SA production at warm temperature.
Roles of CAMTA transcription factors and salicylic acid in configuring the low-temperature transcriptome and freezing tolerance of Arabidopsis.
Specimen part
View SamplesSalicylic acid (SA) levels increase in Arabidopsis upon exposure to low temperature for more than a week. This cold-induced SA biosynthesis was found to proceed through the isochorismate synthase (ICS) pathway. The sid2-1 mutant is deficient in ICS1 and does not make SA at low temperature.
Roles of CAMTA transcription factors and salicylic acid in configuring the low-temperature transcriptome and freezing tolerance of Arabidopsis.
Specimen part
View SamplesDevelopment requires the cooperation of tissue-specific and ubiquitously expressed transcription factors, such as Sp-family members. However, the molecular details of how ubiquitous factors participate in developmental processes are still unclear. We previously showed that during the differentiation of embryonic stem cells lacking Sp1 DNA binding activity (Sp1deltaDBD/deltaDBD cells), early blood progenitors are formed. However, gene expression during differentiation becomes progressively deregulated and terminal differentiation is severely compromised. Here we studied the cooperation of Sp1 and its closest paralogue Sp3 in hematopoietic development and demonstrate that Sp1 and Sp3 binding sites largely overlap. Sp3 cooperates with Sp1deltaDBD/deltaDBD but is unable to support hematopoiesis in the complete absence of Sp1. Using single cell gene expression analysis, we show that the lack of Sp1 DNA binding leads to a distortion of cell fate decision timing, indicating that stable chromatin bi nding of Sp1 is required to maintain robust differentiation trajectories. Overall design: RNA-Seq in ESC, Flk, HE1, HE2 and progenitor cells with WT, Sp1deltaDBD or Sp3KO
Robust hematopoietic specification requires the ubiquitous Sp1 and Sp3 transcription factors.
Specimen part, Cell line, Subject
View SamplesDevelopment requires the cooperation of tissue-specifically and ubiquitously expressed transcription factors, such as Sp-family members. However, the molecular details of how ubiquitous factors participate in developmental processes are still unclear. We previously showed that during the differentiation of embryonic stem cells lacking Sp1 DNA binding activity (Sp1DDBD/DDBD cells), early blood progenitors are formed. However, gene expression during differentiation becomes progressively deregulated and terminal differentiation is blocked. Here we studied the cooperation of Sp1 and its homologue Sp3 in hematopoietic development and demonstrate that Sp1 and Sp3 binding sites largely overlap. Sp3 cooperates with Sp1DDBD/DDBD cells but is unable to support hematopoiesis in the complete absence of Sp1. Using single cell gene expression analysis, we show that the lack of Sp1 DNA binding leads to a distortion of cell fate decision timing, indicating that stable chromatin binding of Sp1 is required to maintain robust differentiation trajectories. Overall design: Chromium 10X - Single-cell RNA-seq of Sp1 wild-type and Sp1 DNA binding domain mutant cells
Robust hematopoietic specification requires the ubiquitous Sp1 and Sp3 transcription factors.
Specimen part, Subject
View SamplesDiesel exhaust (DE) has been shown to enhance allergic sensitization in animals following high dose instillation or chronic inhalation exposure scenarios. The purpose of this study was to determine if short term exposures to diluted DE enhance allergic immune responses to antigen, and identify possible mechanisms using microarray technology. BALB/c mice were exposed to filtered air or diluted DE to yield particle concentrations of 500 or 2000 g/m3 4 hr/day on days 0-4. Mice were sensitized intranasally with ovalbumin (OVA) antigen or saline on days 0-2, and 18 and all were challenged with OVA on day 28. Mice were necropsied either 4 hrs after the last DE exposure on day 4, or 18, 48, and 96 hrs after challenge. Immunological endpoints included OVA-specific serum IgE, biochemical and cellular profiles of bronchoalveolar lavage (BAL), and cytokine production in the BAL. OVA-sensitized mice exposed to both concentrations of DE had increased eosinophils, neutrophils, lymphocytes, and IL-6 post-challenge compared to OVA control, while DE/saline exposure yielded increases in neutrophils at the high dose only. Microarray analysis demonstrated distinct gene expression profiles for the high dose DE/OVA and DE/saline groups. DE/OVA induced pathways involved in oxidative stress and metabolism while DE in the absence of allergen sensitization modulated cell cycle control, growth and differentiation, G-proteins, and cell adhesion pathways. This study shows for the first time early changes in gene expression induced by the combination of diesel exhaust inhalation and antigen sensitization, which resulted in stronger development of an allergic asthma phenotype.
Increased transcription of immune and metabolic pathways in naive and allergic mice exposed to diesel exhaust.
No sample metadata fields
View SamplesThe specification of hematopoietic cells in the developing embryo occurs in specific stages and is regulated by the successive establishment of specific transcriptional networks. However, the molecular mechanisms of how the different stages switch from one to another are still not well understood. Hematopoietic cells arise from endothelial cells within the dorsal aorta which transit into hematopoietic cells by a process called the endothelial-hematopoietic transition (EHT) which does not involve DNA replication. The transcription factor RUNX1 is essential for this process. Using the differentiation of mouse embryonic stem cells carrying an inducible version of RUNX1, we have previously shown that hematopoietic genes are primed prior to the EHT by the binding of transcription factors required to form both endothelial and hematopoietic cells (FLI-1 and SCL/TAL1). We demonstrated that after induction RUNX1 reshapes the transcription factor binding landscape by causing a relocation of these factors and pulling them towards its binding sites. In the study presented here, we employed the same system to globally dissect the transcriptional processes that underlay the EHT. We demonstrate that the RUNX1-mediated movement of FLI-1 involves the recruitment of the basal transcription components CDK9 and BRD4 to promoters. The looping factor LDB1 to binds to distal elements and after induction relocates towards RUNX1/FLI-1 to form a co-localizing complex in chromatin. This entire process is blocked by treatment with the BRD4 inhibitor JQ1. Our study constitutes a paradigm for transcriptional processes driving transitions in cellular shape and function which are widely observed in development and disease. Overall design: RNA-seq expreiments have been used to study RUNX1 transcription factor during Hematopoietic specification
The Co-operation of RUNX1 with LDB1, CDK9 and BRD4 Drives Transcription Factor Complex Relocation During Haematopoietic Specification.
Specimen part, Subject
View SamplesZinc (Zn) is a major elemental component of respirable ambient particulate matter (PM) detected often at alarming levels in urban air. Exposure to PM has been widely associated with increased cardiovascular morbidity and mortality, however, it is not known what components or sources of PM are causative. We recently demonstrated that long-term episodic inhalation of combustion PM, having similar amount of Zn found in urban PM, caused myocardial lesions in rats. We further demonstrated that a single pulmonary exposure to Zn at high concentration is associated with disturbances in cardiac mitochondrial function, ion channel regulation, calcium homeostasis, and cell signaling. Therefore, in this study we investigated the role of PM-associated Zn in cardiac injury using multiple exposure scenarios. Male Wistar-Kyoto (WKY) rats of 12-14 wks age were intratracheally exposed (once per wk x 8 or16 wks) to either (1) saline (control); (2) PM having no soluble Zn; (3) combustion PM suspension containing 14.5 ug/mg water-soluble Zn at high and (4) low dose levels, (5) the aqueous fraction of this suspension devoid of solid insoluble particulate fraction (14.5 ug/mg soluble Zn), or (6) Zn sulfate. Zn concentrations were identical in groups 3, 5 and 6. Pulmonary toxicity was apparent in all exposure groups when compared to saline as determined by recovery of cells in bronchoalveolar lavage fluid. Long-term exposure to PM with or without soluble Zn, or Zn sulfate caused distinct myocardial lesions characterized by subepicardial and randomly distributed myocardial inflammation, degeneration, and fibrosis. The lesion severity was higher in those groups receiving Zn PM. Because cardiac mitochondria are likely the primary target of inhaled metal or other absorbed PM components, we analyzed mitochondrial DNA damage using QPCR and found that all exposure groups except those exposed to PM without Zn caused variable degree of damage. Aconitase activity, sensitive to inhibition by oxidative stress was inhibited slightly but significantly in rats receiving zinc sulfate. Although modest, microarray (Affymetrix) analysis revealed expression changes in the heart reflective of effects on cell signaling, inflammation/oxidative stress, mitochondrial fatty acid metabolisms and cell cycle regulation in rats exposed to zinc sulfate. However, these changes were minimal following exposure to PM devoid of soluble metals. We demonstrate that episodic subchronic pulmonary exposure to zinc sulfate causes cardiac injury and mitochondrial DNA damage. Thus, water-soluble PM-associated zinc may be one of the PM components responsible for cardiovascular morbidity.
The role of particulate matter-associated zinc in cardiac injury in rats.
No sample metadata fields
View SamplesmicroRNAs are small non-coding RNAs that can affect gene expression. We used microarrays to analyze gene expression in miR-499 transgenic mouse hearts.
Elevated miR-499 levels blunt the cardiac stress response.
Specimen part
View SamplesDose and time course response of lapatinib in breast cancer cell lines.
Delineation of molecular mechanisms of sensitivity to lapatinib in breast cancer cell lines using global gene expression profiles.
Disease, Disease stage, Cell line, Compound, Time
View Samples