The GntR-like protein NorG has been shown to affect Staphylococcus aureus genes involved in the resistance to quinolones and beta-lactams such as those encoding the NorB and AbcA transporters. To identify the target genes regulated by NorG, we carried out transcriptional profiling assays using S. aureus RN6390 and its isogenic norG::cat mutant. Our data showed that NorG positively affected the transcription of global regulators mgrA, arlS, and sarZ. The three putative drug efflux pump genes most positively affected by NorG were the NorB efflux pump (5.1-fold), the MmpL-like protein SACOL2566 (5.2-fold), and the BcrA-like drug transporter SACOL2525 (5.7-fold). The S. aureus predicted MmpL protein showed 53% homology with the MmpL lipid transporter of Mycobacterium tuberculosis, and the putative SACOL2525 protein showed 87% homology with the bacitracin drug transporter BcrA of Staphylococcus hominis. Two pump genes most negatively affected by NorG were NorC (4-fold) and AbcA (6-fold). Other categories of genes such as those participating in amino acid, inorganic ion, or nucleotide transporters and metabolism, were also affected by NorG. Real-time RT-PCR assays for mgrA, arlS, sarZ, norB, norC, abcA, mmpL, and bcrA-like were carried out to verify microarray data and showed the same level of up- or down regulation by NorG. The norG mutant showed a twofold increase in the resistance to norfloxacin and rhodamine, both substrates of the NorC transporter, which is consistent with the resistance phenotype conferred by overexpression of norC on a plasmid. These data indicate that NorG has broad regulatory function in S. aureus.
Transcriptional profiling analysis of the global regulator NorG, a GntR-like protein of Staphylococcus aureus.
No sample metadata fields
View SamplesThe bovine chromaffin cell (BCC) is a unique modela highly homogeneous and accessible neuroendocrine cellin which to study gene regulation through first messenger-initiated signaling pathways that are specific to post-mitotic cells. BCCs were treated with tumor necrosis factor (TNF) or pituitary adenylate cyclase activating polypeptide (PACAP), two critical regulators of neural cell transcriptional programming during inflammation that act on TNFR2 and PAC1 receptors, respectively, in post-mitotic neuroendocrine cells. Transcripts which were significantly up regulated by either or both first messenger were identified from microarray analysis using two bovine oligonucleotide arrays (Affymetrix and Agilent) followed by statistical analysis with Partek Genomic suite. Microarray data were combined from the two arrays using qRT-PCR sampling validation, and the first-messenger transcriptome derived from TNF and PACAP signaling were compared. More than 90 percent of the genes up regulated either by TNF or PACAP were specific to a single first messenger. BioBase suite, DIRE and Opossum were used to identify common promoter/enhancer response elements that control the expression of TNF- or PACAP-stimulated genes. Bioinformatic analysis revealed that distinct groups of transcription factors control the expression of genes up regulated by either TNF or PACAP . Most of the genes up regulated by TNF contained response elements for members of the Rel transcription factor family, suggesting TNF-TNFR2 signaling mainly through the NF-kB signaling pathway. On the other hand, the PACAP regulated genes showed no enrichment for any single response element, containing instead response elements for combinations of transcription factors allowing activation through multiple signaling pathways, including cAMP, calcium and ERK, in neuroendocrine cells. Pharmacological strategies for mimicking neuroprotection by either PACAP or TNF in the context of CNS injury or degeneration in disease might focus on individual downstream gene activation pathways to achieve greater specificity in vivo.
Neuropeptides, growth factors, and cytokines: a cohort of informational molecules whose expression is up-regulated by the stress-associated slow transmitter PACAP in chromaffin cells.
Specimen part
View SamplesPro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta/alpha (IL1beta/alpha) modulate catecholamine secretion, and long-term gene regulation, in chromaffin cells of the adrenal medulla. Interleukin-6 (IL6), also released during inflammation, affects transcriptional responses in primary chromaffin cells, and may coordinate immune and autonomic adrenomedullary responses via an autocrine mechanism, as TNFalpha itself strongly induces IL6 expression in chromaffin cells, which in turn express receptors responsive to IL6. We have examined the signaling mechanisms employed by IL6 to affect tyrosine hydroxylase (TH) enzymatic activation, and adrenomedullary gene transcription, in cultured bovine chromaffin cells. IL6 caused acute tyrosine/threonine phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), and serine phosphorylation of signal transducer and activator of transcription 3 (STAT3), as do several other first messengers acting on the chromaffin cell, including histamine, nicotine and angiotensin II. IL6 uniquely activated tyrosine phosphorylation of STAT3. Consistent with a short-term ERK1/2 activation, IL6 treatment caused prompt regulation of TH phosphorylation, and up-regulation of genes encoding secreted proteins of the adrenal medulla including galanin, vasoactive intestinal peptide (VIP), gastrin releasing peptide (GRP) and parathyroid hormone-like hormone (PTHLH). We further examined the effects of IL6 treatment on the entire bovine chromaffin cell transcriptome. Of 90 genes up-regulated by IL6, only 16 of which are known targets of IL6 in the immune system. The remaining genes likely represent a combination of novel IL6/STAT3 targets, targets of ERK1/2 shared by other first messengers, and, potentially, IL6-dependent genes activated in a secondary cascade via transcription mediated by IL6-induced transcription factors, such as HIF-1alpha. Notably, genes induced by IL6 represent a cohort with a profile that includes both neuroendocrine-specific genes, including several that are activated by G-protein couple receptor (GPCR) signaling pathways initiated by histamine and pituitary adenylate cyclase-activating polypeptide (PACAP), and some transcripts also activated by cytokines including interferon-alpha (INFalpha and TNFalpha. These results suggest an integrative role for IL6 in overall fine-tuning of the chromaffin cell response to a wide range of physiological and paraphysiological stressors, particularly when immune and endocrine stimuli converge in the adrenal medulla.
Interleukin-6-mediated signaling in adrenal medullary chromaffin cells.
Specimen part
View SamplesPurpose: The oxidation resistance gene 1 (OXR1) is crucial for protecting against oxidative stress, limiting neurodegeneration and maintaining normal lifespan in eukaryotes. However, the molecular function of OXR1 is still unknown. Previously we showed that human OXR1 regulates expression of antioxidant genes GPX2 and HO-1 via the p21 signaling pathway. To examine the role of hOXR1 in global transcription regulation during cellular stress, we employed RNA sequencing to investigate the transcription profile in hOXR1 depleted HeLa cells. Methods: Control siRNA (siCon) and human OXR1 siRNA (siOXR1) transfected HeLa cells were either harvested directly (siCon_NT, siOXR1_NT) or exposed to 0.5 mM H2O2 for 1 h and then harvested immediately without recovery (siCon_R0h, siOXR1_R0h). Total RNA pooled from duplicate samples was used for RNA sequencing on an Illumina HiSeq2000 platform. The sequence reads that passed quality filters were analyzed at gene level. The Blast2GO program was used to generate gene ontology (GO) annotation of differentially expressed genes (DEGs).The WEGO software was used to further perform GO functional classification and to predict pathways affected. qRT–PCR validation was performed using SYBR Green assays. Results: In total, in non-treated and hydrogen peroxide exposed cells, hOXR1 depletion results in the down-regulation of 554 genes and the up-regulation of 253 genes. These differentially expressed genes include transcription factors (i.e. HIF1A, SP6, E2F8 and TCF3) and numerous genes of the p53 signaling pathway involved in cell-cycle arrest (i.e. cyclin D, CDK6 and p21) and apoptosis (i.e. CytC and CASP9). Western blot analysis reveals that hOXR1 suppresses CASP9 protein expression and reduces post-translational cleavage into its active form. After exposure to hydrogen peroxide (1 h), 56 early response genes were up-regulated in hOXR1 depleted cells, in which 38 of these genes were not induced in control cells. In addition, a subset of the commonly up-regulated early response genes showed a stronger induction in hOXR1 depleted cells (i.e. FOS, JUN and DUSP1). Out of a total of 52 differentially expressed transcription factors in hOXR1 depleted cells under normal physiology and oxidative stress condition, 14 genes (including HIF1A, STAT5A, E2F8 and TCF3) are differentially regulated under H2O2 treatment in hOXR1 silenced cells as compared to control cells. Finally, we demonstrate that hOXR1 depleted cells undergo cell cycle arrest in G2/M phase during oxidative stress. Conclusions: Human OXR1 is important for regulation of the early stress response to oxidative stress in HeLa cells. HOXR1 modulates the p53 signaling pathway via regulation of genes involved in cell cycle arrest, apoptosis and anti-oxidation. Further, hOXR1 regulates numerous transcription factors of importance for cellular stress responses. In summary, hOXR1 may act as a sensor of cellular oxidative stress to regulate the transcriptional networks required to detoxify reactive oxygen species (ROS) and modulate cell cycle arrest and cell death (apoptosis). Overall design: The mRNA profiles of hOXR1 depleted and control Hela cells with or without H2O2 treatment 1 h were generated by RNA sequencing using Illumina Hiseq 2000.
Transcriptome analysis of human OXR1 depleted cells reveals its role in regulating the p53 signaling pathway.
No sample metadata fields
View SamplesPurpose: ATG41 is involved both in autophagy and zinc-deficient growth. The goal of this study is to compare transcriptomic profiles of wild-type and atg41? strains to discover autophagy-independent molecular phenotypes for the mutant. The atg1? mutant is a control for autophagy activity. Methods: Wild-type and mutant yeast were grown to mid-log phase in replete medium and shifted to zinc-deficient medium for 8 hours, after which, cells were harvested for RNA sequencing to detect differential gene expression. Results: Gene expression data for virtually every gene (~6,000) was obtained with ~12,000,000 reads per sample. Differential gene expression analysis showed that several hundred genes were differentially experessed in the atg41? mutant (greater than 2-fold) at an FDR of 0.5. Conclusions: Most strikingly, we found that the atg41? mutant transcriptome shows signs that sulfur metabolism is distrupted during zinc-deficinet growth. Expression of Met4 gene targets is increased. Overall design: mRNA from wild-type, atg1?, and atg41? yeast strains was prepared from zinc-deficient cultures in quadruplicate and sequenced. Single-end, 100bp sequencing was performed, using v4 SBS chemistry on an Illumina HiSeq2500 sequencer.
An Autophagy-Independent Role for <i>ATG41</i> in Sulfur Metabolism During Zinc Deficiency.
Cell line, Subject
View SamplesWe have performed post-treatment gene expression profiling of cell lines to analyze response mechanisms to PARP inhibition.
Molecular correlates of sensitivity to PARP inhibition beyond homologous recombination deficiency in pre-clinical models of colorectal cancer point to wild-type TP53 activity.
Specimen part, Cell line, Treatment
View SamplesPeripheral circadian clocks regulate many aspects of physiology. In this study we deleted the core circadian clock component Bmal1 specifically in mouse adipocytes in order to study the role of the adipocyte clock in energy homeostasis and body weight. We used microarrays to indentify changes in gene expression in the adipose tissue of mice lacking a functional adipocyte circadian clock and identified a small number of up- and down- regulated genes.
Obesity in mice with adipocyte-specific deletion of clock component Arntl.
Specimen part
View SamplesOxidative DNA damage has been associated with cognitive decline. The Ogg1 and Mutyh DNA glycosylases cooperate to prevent mutations caused by 8-oxoG, a major premutagenic oxidative DNA base lesion. Here, we have examined behavior and cognitive function in mice deficient of these glycosylases. We found that Ogg1-/-Mutyh-/- mice were more active and less anxious and that their learning ability was impaired. In contrast, Mutyh-/- mice showed moderately improved memory compared to WT. There was no change in genomic 8-oxoG levels, suggesting that Ogg1 and Mutyh play minor roles in global repair in adult brain. Notably, transcriptome analysis of hippocampus revealed that differentially expressed genes in the mutant mice belong to pathways known to be involved in anxiety and cognitive function. Thus, beyond their involvement in DNA repair, Ogg1 and Mutyh modulate cognitive function and behavior, and related hippocampal gene expression, suggesting a novel role for 8-oxoG in regulating adaptive behavior. Overall design: The mRNA profiles from hippocampus of WT, Ogg1-/-, Mutyh-/- and Ogg1-/- Mutyh-/- C57BL/6 mice at 6month of age were generated by RNA sequencing using Illumina Hiseq 2000
Synergistic Actions of Ogg1 and Mutyh DNA Glycosylases Modulate Anxiety-like Behavior in Mice.
Age, Specimen part, Cell line, Subject
View SamplesProduction of reactive oxygen species (ROS) is one of the important antimicrobial mechanisms of phagocytic cells. Enhanced oxidative burst requires these cells to be primed with agents such as IFNg and LPS with a synergistic effect of these agents on the level of the burst. However, excessive ROS generation will lead to tissue damage and has been implicated in a variety of inflammatory and autoimmune disease. Therefore, this process needs to be tightly regulated. In order to understand the genes regulating this process, we will treat bone marrow derived macrophages with above mentioned priming agents and study the gene expression.
NRROS negatively regulates reactive oxygen species during host defence and autoimmunity.
Specimen part, Treatment
View SamplesWe have analyzed the gene expression-based consensus molecular subtypes of colorectal cancer. These samples represent a subset of the total series analyzed.
Colorectal Cancer Consensus Molecular Subtypes Translated to Preclinical Models Uncover Potentially Targetable Cancer Cell Dependencies.
Specimen part
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