This study examines the mechanisms underlying fumarate- and glyoxylate-mediated changes in tobraymcyin sensitivity in PAO1 cells
Carbon Sources Tune Antibiotic Susceptibility in Pseudomonas aeruginosa via Tricarboxylic Acid Cycle Control.
No sample metadata fields
View SamplesSenescent cells affect many physiological and pathophysiological processes. While select genetic and epigenetic elements for senescence induction have been identified, the dynamics, epigenetic mechanisms and regulatory networks defining senescence competence, induction and maintenance remain poorly understood, precluding the deliberate therapeutic targeting of senescence for health benefits. Here, we examined the possibility that the epigenetic state of enhancers determines senescent cell fate. We explored this by generating time-resolved transcriptomes and epigenome profiles during oncogenic RAS-induced senescence and validating central findings in different cell biology and disease models of senescence. Through integrative analysis and functional validation, we reveal links between enhancer chromatin, transcription factor recruitment and senescence competence. We demonstrate that activator protein 1 (AP-1) ‘pioneers’ the senescence enhancer landscape and defines the organizational principles of the transcription factor network that drives the transcriptional programme of senescent cells. Together, our findings enabled us to manipulate the senescence phenotype with potential therapeutic implications.
AP-1 imprints a reversible transcriptional programme of senescent cells.
Specimen part, Cell line, Treatment, Time
View SamplesTreatment induced senescence (TIS) is a terminal cell cycle arrest program, increasingly recognized as a tumor suppressor mechanism complementing apoptosis in response to standard chemotherapy regimens. In particular cells with blocked apoptotic pathways rely on senescence as the only remaining failsafe mechanism to keep the neoplastic growth in check. However, little is known about biological properties, long-term fate of senescent tumor cells and their impact on the microenvironment.
AP-1 imprints a reversible transcriptional programme of senescent cells.
Specimen part, Treatment
View SamplesSenescent cells affect many physiological and pathophysiological processes. While select genetic and epigenetic elements for senescence induction have been identified, the dynamics, epigenetic mechanisms and regulatory networks defining senescence competence, induction and maintenance remain poorly understood, precluding the deliberate therapeutic targeting of senescence for health benefits. Here, we examined the possibility that the epigenetic state of enhancers determines senescent cell fate. We explored this by generating time-resolved transcriptomes and epigenome profiles during oncogenic RAS-induced senescence and validating central findings in different cell biology and disease models of senescence. Through integrative analysis and functional validation, we reveal links between enhancer chromatin, transcription factor recruitment and senescence competence. We demonstrate that activator protein 1 (AP-1) 'pioneers' the senescence enhancer landscape and defines the organizational principles of the transcription factor network that drives the transcriptional programme of senescent cells. Together, our findings enabled us to manipulate the senescence phenotype with potential therapeutic implications.
AP-1 imprints a reversible transcriptional programme of senescent cells.
Cell line, Treatment, Time
View SamplesDeeper understanding of antibiotic-induced physiological responses is critical to identifying means for enhancing our current antibiotic arsenal. Bactericidal antibiotics with diverse targets have been hypothesized to kill bacteria, in part, by inducing production of damaging reactive species. This notion has been supported by many groups, but recently challenged. Here we robustly test the hypothesis using biochemical, enzymatic and biophysical assays along with genetic and phenotypic experiments. We first used a novel intracellular hydrogen peroxide (H2O2) sensor, together with a chemically diverse panel of fluorescent dyes sensitive to an array of reactive species, to demonstrate that antibiotics broadly induce redox stress. Subsequent gene expression analyses reveal that complex antibiotic-induced oxidative stress responses are distinct from canonical responses generated by supra-physiological levels of H2O2. We next developed a method to dynamically quantify cellular respiration and found that bactericidal antibiotics elevate oxygen consumption, indicating significant alterations to bacterial redox physiology. We further show that catalase or DNA mismatch repair enzyme overexpression, as well as antioxidant pre-treatment limit antibiotic lethality, indicating that reactive oxygen species causatively contribute to antibiotic killing. Critically, the killing efficacy of antibiotics was diminished under strict anaerobic conditions, but could be enhanced by exposure to molecular oxygen or addition of alternative electron acceptors, suggesting that environmental factors play a role in killing cells physiologically primed for death. This work provides direct evidence that bactericidal antibiotics, downstream of their target-specific interactions, induce complex redox alterations that contribute to cellular damage and death, thus supporting an evolving, expanded model of antibiotic lethality.
Antibiotics induce redox-related physiological alterations as part of their lethality.
Treatment
View SamplesThe goal of this study is to simultaneously interrogate host and parasite gene expression programs in human macrophages infected with the intracellular parasites from the genus Leishmania. We conducted high-resolution sequencing of the transcriptomes of human macrophages infected with Leishmania spp. using an RNA-seq approach. An array of computational tools was applied to map reads to the Leishmania and human genomes and reconstruct full-length transcripts. mRNA abundance was determined for Leishmania and human genes at various time points post-infection, enabling us to identify co-expression patterns that correlate with the biology of the parasite and to obtain a preliminary analysis of the dynamic nature of parasite and host cell gene expression programs in the context of infection. This study provides a solid framework for future functional and genomic studies of leishmaniasis as well as intracellular pathogenesis in general.
Dual Transcriptome Profiling of Leishmania-Infected Human Macrophages Reveals Distinct Reprogramming Signatures.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of post-transcriptional regulatory networks during myeloblast-to-monocyte differentiation transition.
Specimen part, Treatment
View SamplesTreatment of leukemia cells with 1,25-dihydroxyvitamin D3 may overcome their differentiation block and lead to the transition from myeloblasts to monocytes. To identify microRNA-mRNA networks relevant for myeloid differentiation, we profiled the expression of mRNAs and microRNAs associated to the low- and high-density ribosomal fractions in leukemic cells and in their differentiated monocytic counterpart. Intersection between mRNAs shifted across the fractions after treatment with putative target genes of modulated microRNAs showed a series of molecular networks relevant for the monocyte cell fate determination
Identification of post-transcriptional regulatory networks during myeloblast-to-monocyte differentiation transition.
Specimen part, Treatment
View SamplesA greater understanding of the molecular pathways that underpin the unique human hematopoietic stem and progenitor cell (HSPC) self-renewal program will improve strategies to expand these critical cell types for regenerative therapies. The post-transcriptional mechanisms guiding HSPC fate during ex vivo expansion have not been closely investigated. Using shRNA-mediated knockdown, we show that the RNA-binding protein (RBP) Musashi-2 (MSI2) is required for human HSPC self-renewal. Conversely, when overexpressed, MSI2 induces multiple pro-self-renewal phenotypes, including significant ex vivo expansion of short- and long-term repopulating cells through direct attenuation of aryl hydrocarbon receptor (AHR) signaling. Using a global analysis of MSI2-RNA interactions, we determined that MSI2 post-transcriptionally downregulates canonical AHR pathway components in cord blood HSPCs. Our study provides new mechanistic insight into RBP-controlled RNA networks that underlie the self-renewal process and provides evidence that manipulating such networks can provide a novel means to enhance the regenerative potential of human HSPCs expanded ex vivo. Overall design: 4 samples were used for RNA-seq (4 biological duplicate) including 2 sets of control samples (irrelvant shRNA kncok-downs)
Musashi-2 attenuates AHR signalling to expand human haematopoietic stem cells.
No sample metadata fields
View SamplesBackground: Renal cell carcinoma (RCC) is characterized by a number of diverse molecular aberrations that differ among individuals. Recent approaches to molecularly classify RCC were based on clinical, pathological as well as on single molecular parameters. As a consequence, gene expression patterns reflecting the sum of genetic aberrations in individual tumors may not have been recognized. In an attempt to uncover such molecular features in RCC, we used a novel, unbiased and integrative approach.
Integrative genome-wide expression profiling identifies three distinct molecular subgroups of renal cell carcinoma with different patient outcome.
Sex, Specimen part, Disease, Disease stage, Cell line
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