Background: Here, the role of a-ketoglutarate (aKG) in the epi-metabolic control of DNA demethylation has been investigated in therapeutically relevant cardiac mesenchymal cells (CMSCs) isolated from controls and type 2 diabetes donors. Methods & results: Quantitative global analysis, methylated and hydroxymethylated DNA sequencing and gene specific GC methylation detection revealed an accumulation of 5mC, 5hmC and 5fC in the genomic DNA of human CMSCs isolated from diabetic (D) donors (D-CMSCs). Whole heart genomic DNA analysis revealed iterative oxidative cytosine modification accumulation in mice exposed to high fat diet (HFD), injected with streptozotocin (STZ) or both in combination (STZ-HFD). In this context, untargeted and targeted metabolomics indicated an intracellular reduction of aKG synthesis in D-CMSCs and in the whole heart of HFD mice. This observation was paralleled by a compromised thymine DNA glycosylase (TDG) and ten eleven translocation protein 1 (TET1) association and function with TET1 relocating out of the nucleus. Molecular dynamics and mutational analyses showed that aKG binds TDG on Arg275 providing an enzymatic allosteric activation. As a consequence, the enzyme significantly increased its capacity to remove G/T nucleotide mismatched or 5fC. Accordingly, an exogenous source of aKG restored the DNA demethylation cycle by promoting TDG function, TET1 nuclear localization and TET/TDG association. TDG inactivation by CRISPR/Cas9 knockout or TET/TDG siRNA knockdown induced 5fC accumulation thus partially mimicking the diabetic epigenetic landscape in cells of non- diabetic origin. The novel compound (S)-2-[(2,6-dichlorobenzoyl)amino]succinic acid (AA6), identified as an inhibitor of aKG-dehydrogenase, increased the aKG level in D- CMSCs and in the heart of HFD mice eliciting DNA demethylation, glucose uptake and insulin response. Conclusions: In this report we established that diabetes may epigenetically modify and compromise function of therapeutically relevant cardiac mesenchymal cells. Restoring the epi-metabolic control of DNA demethylation cycle promises beneficial effects on cells compromised by environmental metabolic changes. Overall design: Human primary cardiac mesenchymal cells (CMSC) from 7 diabetic (D) and 7 non-diabetic (ND) donors were analyzed after few rounds of ex vivo expansion. RNA was isolated and sequenced.
Stable Oxidative Cytosine Modifications Accumulate in Cardiac Mesenchymal Cells From Type2 Diabetes Patients: Rescue by α-Ketoglutarate and TET-TDG Functional Reactivation.
Specimen part, Subject
View SamplesBacteria selectively consume some carbon sources over others through a regulatory mechanism termed catabolite repression. Here, we show that the base pairing RNA Spot 42 plays a broad role in catabolite repression in Escherichia coli by directly repressing genes involved in central and secondary metabolism, redox balancing, and the consumption of diverse non-preferred carbon sources. Many of the genes repressed by Spot 42 are transcriptionally activated by the global regulator CRP. Since CRP represses Spot 42, these regulators participate in a specific regulatory circuit called a multi-output feedforward loop. We found that this loop can reduce leaky expression of target genes in the presence of glucose and can maintain repression of target genes under changing nutrient conditions. Our results suggest that base pairing RNAs in feedforward loops can help shape the steady-state levels and dynamics of gene expression.
The base-pairing RNA spot 42 participates in a multioutput feedforward loop to help enact catabolite repression in Escherichia coli.
Specimen part
View SamplesThe transcriptome is the complete set of all RNA transcripts produced by the genome in a cell and reflects the genes that are being actively expressed. Transcriptome analysis is essential for understanding the genetic mechanism controlling the phenotype of a cell.
Characterization of transcriptomes of cochlear inner and outer hair cells.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A chromatin-modifying function of JNK during stem cell differentiation.
Specimen part, Treatment
View SamplesExpression profiling of from DMSO and SP600125 treated glutamatergic neurons reveals JNK target genes that are transcriptionally regulated by JNK signaling.
A chromatin-modifying function of JNK during stem cell differentiation.
Specimen part
View SamplesTo understand the basic biological property of hair cells (HCs) from lower vertebrates, we examined transcriptomes of adult zebrafish HCs. GFP-labeled HCs were isolated from the utricle, saccule, and lagena, the three inner-ear sensory epithelia of a pou4f3 promoter-driven GAP-GFP line of transgenic zebrafish. 2,000 HCs and 2,000 non-sensory cells from the inner ear were individually collected by suction pipet technique. RNA sequencing was performed and the resulting sequences were mapped, analyzed, and compared. Comparisons allow us to identify enriched genes in HCs, which may underlie HC specialization. Overall design: Examination of transcriptomes of adult zebrafish inner ear hair cells and surrounding cells individually collected and sorted using pou4f3 promoter-driven GFP marking hair cells.
RNA-seq transcriptomic analysis of adult zebrafish inner ear hair cells.
No sample metadata fields
View SamplesWe have characterised the zebrafish ortholog, setb, and investigated its role in embryogenesis. Phylogenetic analysis showed that zebrafish Setb has an amino acid sequence identity of approximately 96% with the mammalian orthologs. Whole mount immunofluorescence analysis revealed that Setb is expressed mainly in the eye, the lateral line neuromasts and the olfactory pit. Knockdown of setb using antisense morpholino oligonucleotides resulted in increased apoptosis, reduced cell proliferation and severe morphological defects. The morphant phenotypes were partially rescued when setb MO1 was co-injected with human set mRNA. In vivo labelling of hair cells in the lateral line of setb morphants with the vital fluorescent dye FM1-43 showed a significant decreased number of functional neuromasts. Gene expression analysis of setb morphants, employing DNA microarrays revealed a role of Setb in neurogenesis and the mechanosensory lateral line system.
The zebrafish homologs of SET/I2PP2A oncoprotein: expression patterns and insights into their physiological roles during development.
Treatment
View SamplesCre recombinase-mediated conditional knockout of floxed Dicer1 alleles causes depletion of small RNAs including microRNAs, which function to repress target mRNA expression by inhibiting translation and/or stimulating mRNA degradation.
MicroRNA-183 family expression in hair cell development and requirement of microRNAs for hair cell maintenance and survival.
Specimen part
View SamplesThe p53 family is known as a family of transcription factors with functions in tumor suppression and development. Whereas the central DNA binding domain is highly conserved among the three family members p53, p63 and p73, the C-terminal domains (CTDs) are diverse and subject to alternative splicing and post-translational modification. Here we demonstrate that the CTDs strongly influence DNA binding and transcriptional activity. While p53 and the p73 isoform p73gamma have basic CTDs and form weak sequence-specific protein-DNA complexes, the major p73 isoforms alpha, beta and delta have neutral CTDs and bind DNA strongly. A basic CTD has been previously shown to enable sliding along the DNA backbone and to facilitate the search for binding sites in the complex genome. Our experiments, however, reveal that a basic CTD also reduces protein-DNA complex stability, intranuclear mobility, promoter occupancy in vivo, transgene activation and induction of cell cycle arrest or apoptosis. A basic CTD in p53 and p73gamma therefore provides both positive and negative regulatory functions presumably to enable rapid switching of protein activity in response to stress. In contrast, most p73 isoforms exhibit constitutive DNA binding activity consistent with a predominant role in developmental control.
C-terminal diversity within the p53 family accounts for differences in DNA binding and transcriptional activity.
No sample metadata fields
View Samplessee Super Series Summary Overall design: We treated Drosophila S2-DRSC cells for 1, 2, 4 and 20 h with 10 µM JQ1 and compared their gene expression to DMSO-treated control cells (1 and 20 h).
The BET protein FSH functionally interacts with ASH1 to orchestrate global gene activity in Drosophila.
Cell line, Treatment, Subject
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