We describe a new mutant allele of the ACTIN2 gene with enhanced actin dynamics, displaying a broad array of twisting and bending phenotypes that resemble BR-treated plants. Moreover, auxin transcriptional regulation is enhanced on the mutant background, supporting the idea that shaping actin filaments is sufficient to modulate BR-mediated auxin responsiveness. The actin cytoskeleton thus functions as a scaffold for integration of auxin and BR signaling pathways.
Role of actin cytoskeleton in brassinosteroid signaling and in its integration with the auxin response in plants.
No sample metadata fields
View SamplesStress constantly challenges plant adaptation to the environment. Of all stress types, arsenic was a major threat during the early evolution of plants. The most prevalent chemical form of arsenic is arsenate, whose similarity to phosphate renders it easily incorporated into cells via the phosphate transporters. Here we found that arsenate stress provokes a notable transposon burst in plants, in coordination with arsenate/phosphate transporter repression, which immediately restricts arsenate uptake. This repression was accompanied by delocalization of the phosphate transporter from the plasma membrane. When arsenate was removed, the system rapidly restored transcriptional expression and membrane localization of the transporter. We identify WRKY6 as an arsenate-responsive transcription factor that mediates arsenate/phosphate transporter gene expression and restricts arsenate-induced transposon activation. Plants therefore have a dual WRKY-dependent signaling mechanism that modulates arsenate uptake and transposon expression, providing a coordinated strategy for arsenate tolerance and transposon gene silencing.
WRKY6 transcription factor restricts arsenate uptake and transposon activation in Arabidopsis.
Time
View SamplesThis is a transcriptomics analysis contributing to a bigger project that tries to shed light on the role of type 2 diabetes mellitus (T2DM) as a risk factor for colon cancer (CC). Here we present a gene expression screening of paired tumor and normal colon mucosa samples in a cohort of 42 CC patients, 23 of them with T2DM. Using gene set enrichment, we identified an unexpected overlap of pathways over-represented in diabetics compared to non-diabetics, both in tumor and normal mucosa, including diabetes-related metabolic and signaling processes. An integration with other -omic studies suggests that in diabetics, the local micro-environment in normal colon mucosa may be a factor driving field cancerization which may promote carcinogenesis. Several of these pathways converged on the tumor initiation axis TEAD/YAP-TAZ. Cell culture studies confirmed that high glucose concentrations upregulate this pathway in non-tumor colon cells. In conclusion, diabetes is associated to deregulation of cancer-related processes in normal colon mucosa adjacent to tissue which has undergone a malignant transformation. These data support the existence of the field of cancerization paradigm in diabetes and set a new framework to study link between diabetes and cancer.
Molecular evidence of field cancerization initiated by diabetes in colon cancer patients.
Specimen part
View SamplesThis is a transcriptomics analysis contributing to a bigger project that tries to shed light on the role of type 2 diabetes mellitus (T2DM) as a risk factor for colon cancer (CC). Here we present a gene expression screening of 7 colon tumor xenograft samples, 2 with diabetic mice and 5 with normal blood glucose levels. For xenograft model details see: Prieto I, et al. (2017) Colon cancer modulation by a diabetic environment: A single institutional experience. PLoS One 12(3):e0172300
Molecular evidence of field cancerization initiated by diabetes in colon cancer patients.
Specimen part
View SamplesCells adapt to environmental changes, including fluctuations in oxygen levels, through the induction of specific gene expression programs. To identify genes regulated by hypoxia at the transcriptional level, we pulse-labeled HUVEC cells with 4-thiouridine and sequenced nascent transcripts. Then, we searched genome-wide binding profiles from the ENCODE project for factors that correlated with changes in transcription and identified binding of several components of the Sin3A co-repressor complex, including SIN3A, SAP30 and HDAC1/2, proximal to genes repressed by hypoxia. SIN3A interference revealed that it participates in the downregulation of 75% of the hypoxia-repressed genes in endothelial cells. Unexpectedly, it also blunted the induction of 47% of the upregulated genes, suggesting a role for this corepressor in gene induction. In agreement, ChIP-seq experiments showed that SIN3A preferentially localizes to the promoter region of actively transcribed genes and that SIN3A signal was enriched in hypoxia-repressed genes, prior exposure to the stimulus. Importantly, SINA3 occupancy was not altered by hypoxia in spite of changes in H3K27ac signal. In summary, our results reveal a prominent role for SIN3A in the transcriptional response to hypoxia and suggest a model where modulation of the associated histone deacetylase activity, rather than its recruitment, determines the transcriptional output. Overall design: Exponentially growing non-synchronized HUVEC were exposed to normoxia or hypoxia (21% or 1% oxygen respectively) for 8 hours and pulse-labelled with 4-thiouridine during the last two hours of treatment. RNA was extracted from samples in each condition (total RNA) and an aliquot was subjected to affinity chromatography to purify the 4-thiouridine-labelled (newly transcribed RNA, Newly Tr) and non-labelled (Pre-existent) RNA fractions. All three RNA fractions (total, newly transcribed and pre-existent) from each sample were analyzed by high-throughput sequencing. Submission includes 12 samples corresponding to 3 independent biological replicates.
The SIN3A histone deacetylase complex is required for a complete transcriptional response to hypoxia.
Cell line, Treatment, Subject
View SamplesCells adapt to environmental changes, including fluctuations in oxygen levels, through the induction of specific gene expression programs. To identify genes regulated by hypoxia at the transcriptional level, we pulse-labeled HUVEC cells with 4-thiouridine and sequenced nascent transcripts. Then, we searched genome-wide binding profiles from the ENCODE project for factors that correlated with changes in transcription and identified binding of several components of the Sin3A co-repressor complex, including SIN3A, SAP30 and HDAC1/2, proximal to genes repressed by hypoxia. SIN3A interference revealed that it participates in the downregulation of 75% of the hypoxia-repressed genes in endothelial cells. Unexpectedly, it also blunted the induction of 47% of the upregulated genes, suggesting a role for this corepressor in gene induction. In agreement, ChIP-seq experiments showed that SIN3A preferentially localizes to the promoter region of actively transcribed genes and that SIN3A signal was enriched in hypoxia-repressed genes, prior exposure to the stimulus. Importantly, SINA3 occupancy was not altered by hypoxia in spite of changes in H3K27ac signal. In summary, our results reveal a prominent role for SIN3A in the transcriptional response to hypoxia and suggest a model where modulation of the associated histone deacetylase activity, rather than its recruitment, determines the transcriptional output. Overall design: Exponentially growing non-synchronized HUVEC were transduced with lentiviral particles encoding for shRNA targeting EPAS1 or control shRNA. 72h after infection, cells were exposed to normoxia or hypoxia (21% or 1% oxygen respectively) for 8 hours and pulse-labelled with 4-thiouridine during the last two hours of treatment. RNA was extracted from samples in each condition (total RNA) and an aliquot subjected to affinity chromatography to purify the 4-thiouridine-labelled RNA fraction (newly transcribed RNA, Newly Tr). Both RNA fractions from each condition were analyzed by high-throughput sequencing. Data includes 8 samples from a single biological replicate.
The SIN3A histone deacetylase complex is required for a complete transcriptional response to hypoxia.
Cell line, Subject
View SamplesWe describe here a male infant with a 100 kb de novo Xq28 deletion encompassing parts of the TMEM187 and MECP2 protein-coding genes and the IRAK1 protein-coding gene, as well as the MIR3202-1, MIR3202-2, and MIR718 RNA-coding genes. We analyzed the impact of human IRAK-1 deficiency on a genome-wide gene expression in human fibroblasts in response to TLR2/6, TLR4 agonists as well as to IL-1 and TNF-, using primary fibroblasts from healthy controls and IRAK-4-, MyD88- and MECP2-deficient patients for comparison.
Inherited human IRAK-1 deficiency selectively impairs TLR signaling in fibroblasts.
No sample metadata fields
View Samplesdifferential display between WT and FLCN KO Overall design: Global gene expression pattern of ingWAT from wildtype and FLCN adipKO animals
The tumor suppressor FLCN mediates an alternate mTOR pathway to regulate browning of adipose tissue.
Specimen part, Subject
View SamplesDioxygenases of the TET family impact genome functions by converting 5-methylcytosine in DNA to 5-hydroxymethylcytosine, but the individual contribution of the three family members to differentiation and function of myeloid cells is still incompletely understood. Using cells with a deletion in the Tet2 gene, we show that TET2 contributes to the regulation of mast cell differentiation, proliferation and effector functions. The differentiation defect observed in absence of TET2 could be however completely rescued or further exacerbated by modulating TET3 activity, and it was primarily linked to dysregulated expression of the C/EBP family of transcription factors. In contrast, hyper-proliferation induced by the lack of TET2 could not be modified by TET3. Together, our data indicate the existence of both overlapping and unique roles of individual TET proteins in regulating myeloid cell gene expression, proliferation and function. Overall design: Total mRNA of FACS-sorted Kit+ FceRIa+ populations of primary bone marrow-derived mast cells (BMMCs) from Tet2-/- and Tet2+/+ animals was extracted and subjected to multiparallel sequencing.
TET2 Regulates Mast Cell Differentiation and Proliferation through Catalytic and Non-catalytic Activities.
No sample metadata fields
View SamplesLineage-specific transcription factors, which drive cellular identity during embryogenesis, have been shown to convert cell fate when express ectopically in heterologous cells. Herein, we screened the key molecular factors governing the dopaminergic neuronal specification during brain development for their ability to generate similar neurons directly from mouse and human fibroblasts. Remarkably, we found a minimal set of three factors Mash1, Nurr1 and Lmx1a/b able to elicit such cellular reprogramming. Molecular and transcriptome studies showed reprogrammed DA neurons to faithfully recapitulate gene expression of their brain homolog cells while lacking expression of other catecholaminergic neuronal types. Induced neurons showed spontaneous electrical activity organized in regular spikes consistent with the pacemaker activity featured by brain DA neurons. The three factors were able to elicit DA neuronal conversion in human fibroblasts from prenatal or adult fibroblasts of healthy donors and a Parkinsons disease patient. Generation of DA induced neurons from somatic cells might have significant implications in studies of neural development, disease in vitro modeling and cell replacement therapies.
Direct generation of functional dopaminergic neurons from mouse and human fibroblasts.
Specimen part
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