The gut microbiota has been implicated in obesity and cardiometabolic diseases, although evidence in humans is scarce. We investigated how gut microbiota manipulation by antibiotics (7-day administration of amoxicillin, vancomycin, or placebo) affects host metabolism in 57 obese, prediabetic men. Vancomycin, but not amoxicillin, decreased bacterial diversity and reduced Firmicutes involved in short-chain fatty acid and bile acid metabolism, concomitant with altered plasma and/or fecal metabolite concentrations. Adipose tissue gene expression of oxidative pathways was upregulated by antibiotics, whereas immune-related pathways were downregulated by vancomycin. Antibiotics did not affect tissue-specific insulin sensitivity, energy/substrate metabolism, postprandial hormones and metabolites, systemic inflammation, gut permeability, and adipocyte size. Importantly, energy harvest, adipocyte size, and whole-body insulin sensitivity were not altered at 8-week follow-up, despite a still considerably altered microbial composition, indicating that interference with adult microbiota by 7-day antibiotic treatment has no clinically relevant impact on metabolic health in obese humans.
Effects of Gut Microbiota Manipulation by Antibiotics on Host Metabolism in Obese Humans: A Randomized Double-Blind Placebo-Controlled Trial.
Sex, Specimen part, Disease, Disease stage, Treatment, Subject, Time
View SamplesWe used Illumina-HiSeq4000 to sequence 4sU-labelled RNA samples isolated from unchallenged and DNA damaged HeLa Flp-In cells, which revealed the nature of transcriptional response folowing genotoxic stress and the contribution of P-TEFb kinase in DNA damage-induced gene transcription. Overall design: We mock treated or treated HeLa Flp-In cells for 1 or 2 hr with DMSO, 4-NQO, or 4-NQO + flavopiridol (FP) as indicated below. During the last 30 minutes of the treatments, we labeled the RNA or not with the nucleoside analogue 4-thiouridine (500µM 4sU) for 30 minutes.
P-TEFb Activation by RBM7 Shapes a Pro-survival Transcriptional Response to Genotoxic Stress.
Cell line, Subject
View SamplesThe differential gene expression of human cardiomyocytes induced by kinase inhibitors sorafenib and sunitinib is measured by a high-throughput mRNA-sequencing approach called 3''-DGE, that is based on a 3'' end-focused reference sequence library and a transcript molecule counting method with unique molecular identifiers (UMI) for correcting PCR bias. Overall design: Cells were treated with sunitinib, sorafenib, or vehicle control for 48 hours, and gene expression levels of all samples were measured by 3''-DGE and conventional random-primed mRNA-sequencing methods using paired-end reading to obtain the genome-wide expression profiles for each sample.
A Comparison of mRNA Sequencing with Random Primed and 3'-Directed Libraries.
Specimen part, Subject
View SamplesBackground. Cellular senescence is a mechanism that virtually irreversibly suppresses the proliferative capacity of cells in response to various stress signals. This includes the expression of activated oncogenes, which cause Oncogene-Induced Senescence (OIS). A body of evidence points to the involvement of chromatin reorganization, including the formation of senescence-associated heterochromatic foci (SAHF). The nuclear lamina (NL) is an important contributor to genome organization and has been involved in cellular senescence and organismal aging. It interacts with multiple regions of the genome called lamina-associated domains (LADs). Some LADs are cell type-specific, while others are conserved between cell types and are referred to as constitutive LADs. Here, we used DamID to investigate the changes in genome-NL interactions in a model of OIS triggered by the expression of the BRAFV600E oncogene.Results. We found that OIS cells lose most of their constitutive LADs (cLADS), suggesting the loss of a specific mechanism that targets cLADs to the NL. In addition, multiple genes relocated to the NL. Unexpectedly, they were not repressed, implying the abrogation of the repressive activity of the NL during OIS. Finally, OIS cells displayed an increased association of telomeres with the NL.Conclusions. Our study reveals that senescent cells acquire a new type of LAD organization and suggest the existence of as yet unknown mechanisms that tether cLADs to the NL and repress gene expression at the NL.
Massive reshaping of genome-nuclear lamina interactions during oncogene-induced senescence.
Specimen part, Cell line, Subject, Time
View SamplesWe analyzed the genome-wide expression by RNA-seq of a yeast strain that expresses Cas9d and a guideRNA targeted to the GAL10 locus (called +116), which inhibits GAL10 ncRNA expression from the antisense strand. We compared this strain to a strain expressing a scrambled guideRNA. The goal was to examine the effects of ncRNA inhibition and to examine if CRISPR inhibition of gene expression has off-target effects. We find that CRISPR-mediated inhibtion of GAL10 ncRNA only significantly changes expression of transcripts at the GAL1-10 locus, showing that CRISPR is highly specific, and that GAL10 ncRNA only control genes at the GAL locus. Overall design: RNA-seq of 2 strains with CRISPR scrambled and 2 strains with CRISPR +116, the latter of which inhibits GAL10 ncRNA
Single-Molecule Imaging Reveals a Switch between Spurious and Functional ncRNA Transcription.
Cell line, Subject
View SamplesThe p21 RAS subfamily of small GTPases, including KRAS, HRAS, and NRAS, regulates cell proliferation, cytoskeletal organization and other signaling networks, and is the most frequent target of activating mutations in cancer. Activating germline mutations of KRAS and HRAS cause severe developmental abnormalities leading to Noonan, cardio-facial-cutaneous and Costello syndrome, but activating germline mutations of NRAS have not been reported. Autoimmune lymphoproliferative syndrome (ALPS) is the most common genetic disease of lymphocyte apoptosis and causes autoimmunity as well as excessive lymphocyte accumulation, particularly of CD4-, CD8- ab T cells. Mutations in ALPS typically affect CD95 (Fas/APO-1)-mediated apoptosis, one of the extrinsic death pathways involving tumor necrosis factor receptor (TNFR) superfamily proteins, but certain ALPS individuals have no such mutations. We show here that the salient features of ALPS as well as a predisposition to hematological malignancies can be caused by a heterozygous germline Gly13Asp activating mutation of the NRAS oncogene that does not impair CD95-mediated apoptosis. The increase in active, GTP-bound NRAS augments RAF/MEK/ERK signaling which markedly decreases the pro-apoptotic protein BIM and attenuates intrinsic, nonreceptor-mediated mitochondrial apoptosis. Thus, germline activating mutations in NRAS differ from other p21 Ras oncoproteins by causing selective immune abnormalities without general developmental defects. Our observations on the effects of NRAS activation indicate that RAS-inactivating drugs, such as farnesyl-transferase inhibitors (FTIs) should be examined in human autoimmune and lymphocyte homeostasis disorders.
NRAS mutation causes a human autoimmune lymphoproliferative syndrome.
No sample metadata fields
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.
Opposing roles of NF-κB in anti-cancer treatment outcome unveiled by cross-species investigations.
No sample metadata fields
View SamplesDiffuse large B-cell lymphoma (DLBCL) represents a heterogeneous diagnostic category with distinct molecular subtypes that can be defined by gene expression profiling. However, even within these defined subtypes, heterogeneity prevails. To further elucidate the pathogenesis of these entities, we determined the expression of the tumor suppressor phosphatase and tensin homolog (PTEN) in 248 primary DLBCL patient samples. These analyses revealed that loss of PTEN was detectable in 55% of germinal center B-cell-like (GCB) DLBCLs, whereas this abnormality was found in only 14% of non-GCB DLBCL patient samples. In GCB DLBCL, the PTEN status was inversely correlated with activation of the oncogenic PI3K/ protein kinase B (AKT) pathway in both DLBCL cell lines and primary patient samples. Re-expression of PTEN induced cytotoxicity in PTEN-deficient GCB DLBCL cell line models by inhibiting PI3K/AKT signaling, indicating an addiction to this pathway in this subset of GCB DLBCLs. PI3K/AKT inhibition induced down-regulation of the transcription factor MYC. Re-expression of MYC rescued GCB DLBCL cells from PTEN-induced toxicity, identifying a regulatory mechanism of MYC expression in DLBCL. Finally, pharmacologic PI3K inhibition resulted in toxicity selectively in PTEN-deficient GCB DLBCL lines. Collectively, our results indicate that PTEN loss defines a PI3K/ AKT-dependent GCB DLBCL subtype that is addicted to PI3K and MYC signaling and suggest that pharmacologic inhibition of PI3K might represent a promising therapeutic approach in these lymphomas.
PTEN loss defines a PI3K/AKT pathway-dependent germinal center subtype of diffuse large B-cell lymphoma.
Sex, Disease, Cell line, Treatment
View SamplesRORt+ innate lymphoid cells (ILC) are crucial players of innate immune responses and represent a major source of IL-22, which has an important role in mucosal homeostasis. The signals required by RORt+ ILC to express IL-22 and other cytokines, including TNF, have only partially been elucidated. Here we show that RORt+ ILC can directly sense the environment by the engagement of the activating receptor NKp44. NKp44 triggering in RORt+ ILC selectively activates a coordinated pro-inflammatory program, including TNF, while cytokine stimulation induces preferentially IL-22 expression. However, combined engagement of NKp44 and cytokine receptors results in a strong synergistic effect. These data support the concept that NKp44+ RORt+ ILC can be activated without cytokines and are able to switch between IL-22 or TNF production, depending on the triggering stimulus.
RORγt⁺ innate lymphoid cells acquire a proinflammatory program upon engagement of the activating receptor NKp44.
Specimen part, Treatment
View SamplesIn many mammals, halogenated aromatic hydrocarbon (HAH) exposure causes wasting syndrome, defined as lethal weight loss as a result of severe and persistent hypophagia. The most potent HAH in causing wasting is 2,3,7,8-tetrachlorodibenzo--dioxin (TCDD), which exerts its toxic effects through the aryl hydrocarbon receptor (AHR) a transcription factor. Because TCDD toxicity is thought to predominantly arise from dysregulation of AHR-transcribed genes, we hypothesized that wasting syndrome is due to TCDD-induced dysregulation of genes involved in regulation of food-intake. We therefore focused on the hypothalamus, as it is the regulatory center of food-intake and energy balance in the central nervous system. We profiled mRNA abundance in hypothalamic tissue from two rat strains with widely differing sensitivities to wasting syndrome: TCDD-sensitive Long-Evans rats and TCDD-resistant Han/Wistar rats, 23 hours after exposure to TCDD (100 g/kg) or corn oil vehicle. We found that TCDD exposure caused minimal transcriptional dysregulation effects in the hypothalamus, with only 6 genes changed in Long-Evans rats and 15 genes in Han/Wistar rats. Two of the most dysregulated genes were Cyp1a1 and Nqo1, which are induced by TCDD across a wide range of tissues and are considered sensitive markers of TCDD exposure. The minimal response of the hypothalamic transcriptome to a lethal dose of TCDD at an early time-point suggests that the hypothalamus is not the predominant site of initial events leading to hypophagia and associated wasting. TCDD may affect feeding behaviour via events upstream or downstream of the hypothalamus, and further work is required to evaluate this at the level of individual hypothalamic nuclei and subregions.
Transcriptional profiling of rat hypothalamus response to 2,3,7,8-tetrachlorodibenzo-ρ-dioxin.
Sex
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