MicroRNAs are endogenously expressed small non-coding RNAs that regulate gene expression on the posttranscriptional level. The miR-17-92 cluster (encoding miR-17, -18a, -19a/b, -20a and miR-92a) is highly expressed in tumor cells and is up-regulated by ischemia. Whereas miR-92a was recently identified as negative regulator of angiogenesis, the specific functions of the other members of the cluster are less clear. Here we demonstrate that overexpression of miR-17, -18a, -19a and -20a significantly inhibited 3D spheroid sprouting in vitro, whereas inhibition of miR-17, -18a and -20a augmented endothelial cell (EC) sprout formation. Inhibition of miR-17 and miR-20a in vivo using antagomirs significantly increased the number of perfused vessels in matrigel plugs, whereas antagomirs, that specifically target miR-18a and miR-19a were less effective. However, systemic inhibition of miR-17/20 did not affect tumor angiogenesis. Further mechanistic studies showed that miR-17/20 targets several pro-angiogenic genes. Specifically, Janus kinase 1 (Jak1) was shown to be a direct target of miR-17. In summary, we show that miR-17/20 exhibit a cell intrinsic anti-angiogenic activity in ECs. Inhibition of miR-17/20 specifically augmented neovascularization of matrigel plugs, but did not affect tumor angiogenesis indicating a context-dependent regulation of angiogenesis by miR-17/20 in vivo.
Members of the microRNA-17-92 cluster exhibit a cell-intrinsic antiangiogenic function in endothelial cells.
Specimen part
View SamplesHuman umbilical vein endothelial cells (HUVECs) were incubated for 48 h after transfection of scrambled siRNA or siRNA targeting Jmjd6 .
Jumonji domain-containing protein 6 (Jmjd6) is required for angiogenic sprouting and regulates splicing of VEGF-receptor 1.
Specimen part, Treatment
View SamplesClass IIa histone deacetylases (HDACs) are signal-responsive regulators of gene expression involved in vascular homeostasis. To investigate the differential role of class IIa HDACs for the regulation of angiogenesis, we used siRNA to specifically suppress the individual HDAC isoenzymes. Among the HDAC isoforms tested, silencing of HDAC5 exhibited a unique pro-angiogenic effect evidenced by increased endothelial cell migration, sprouting and tube formation. Consistently, overexpression of HDAC5 decreased sprout formation, indicating that HDAC5 is a negative regulator of angiogenesis. The anti-angiogenic activity of HDAC5 was independent of MEF2 binding and its deacetylase activity, but required a nuclear localization indicating that HDAC5 might affect the transcriptional regulation of gene expression. To identify putative HDAC5 targets, we performed microarray expression analysis. Silencing of HDAC5 increased the expression of fibroblast growth factor 2 (FGF2) and angiogenic guidance factors including Slit2. Antagonization of FGF2 or Slit2 reduced sprout induction in response to HDAC5 siRNA. ChIP assays demonstrate that HDAC5 binds to the promoter of FGF2 and Slit2. In summary, HDAC5 represses angiogenic genes, like FGF2 and Slit2, which causally contribute to capillary-like sprouting of endothelial cells. The de-repression of angiogenic genes by HDAC5 inactivation may provide a useful therapeutic target for induction of angiogenesis.
HDAC5 is a repressor of angiogenesis and determines the angiogenic gene expression pattern of endothelial cells.
Specimen part
View SamplesWe compared the aorta of 6-weeks-old mice (young) with 18-months-old mice (old). Using the publicly available tools Sylamer and DIANA-mirExTra, we identified an enrichment for miR-29 binding sites in the 3'UTR of genes downregulated in the aged aortas. We subsequently showed that inhibition of miR-29 in aged mice prevented dilation of the aorta.
MicroRNA-29 in aortic dilation: implications for aneurysm formation.
Age, Specimen part
View SamplesThe short-lived turquoise killifish Nothobranchius furzeri (Nfu) is a valid model for aging studies. Here, we investigated its age-associated cardiac function. We observed oxidative stress accumulation and an engagement of microRNAs (miRNAs) in the aging heart. MiRNA-sequencing of 5 week (young), 12-21 week (adult) and 28-40 week (old) Nfu hearts revealed 23 up-regulated and 18 down-regulated miRNAs with age. MiR-29 family turned out as one of the most up-regulated miRNAs during aging. MiR-29 family increase induces a decrease of known targets like collagens and DNA methyl transferases (DNMTs) paralleled by 5´methyl-cytosine (5mC) level decrease. To further investigate miR-29 family role in the fish heart we generated a transgenic zebrafish model where miR-29 was knocked-down. In this model we found significant morphological and functional cardiac alterations and an impairment of oxygen dependent pathways by transcriptome analysis leading to hypoxic marker up-regulation. To get insights the possible hypoxic regulation of miR-29 family, we exposed human cardiac fibroblasts to 1% O2 levels. In hypoxic condition we found miR-29 down-modulation responsible for the accumulation of collagens and 5mC. Overall, our data suggest that miR-29 family up-regulation might represent an endogenous mechanism aimed at ameliorating the age-dependent cardiac damage leading to hypertrophy and fibrosis. Overall design: RNA was isolated from zebrafish heart samples (3 wt and 3 miR-29-sponge) and sequenced.
Age-dependent increase of oxidative stress regulates microRNA-29 family preserving cardiac health.
Specimen part, Subject
View SamplesWe compared the heart of 6-weeks-old mice (young) with 18-months-old mice (old)
MicroRNA-34a regulates cardiac ageing and function.
Age, Specimen part
View SamplesAdenosine-to-inosine (A-to-I) RNA editing, which is catalyzed by a family of adenosine deaminase acting on RNA (ADAR) enzymes, is important in the epitranscriptomic regulation of RNA metabolism. However, the role of A-to-I RNA editing in vascular disease is unknown. Here we show that cathepsin S mRNA (CTSS), which encodes a cysteine protease associated with angiogenesis and atherosclerosis, is highly edited in human endothelial cells. The 3' untranslated region (3' UTR) of the CTSS transcript contains two inverted repeats, the AluJo and AluSx+ regions, which form a long stem–loop structure that is recognized by ADAR1 as a substrate for editing. RNA editing enables the recruitment of the stabilizing RNA-binding protein human antigen R (HuR; encoded by ELAVL1) to the 3' UTR of the CTSS transcript, thereby controlling CTSS mRNA stability and expression. In endothelial cells, ADAR1 overexpression or treatment of cells with hypoxia or with the inflammatory cytokines interferon-? and tumor-necrosis-factor-a induces CTSS RNA editing and consequently increases cathepsin S expression. ADAR1 levels and the extent of CTSS RNA editing are associated with changes in cathepsin S levels in patients with atherosclerotic vascular diseases, including subclinical atherosclerosis, coronary artery disease, aortic aneurysms and advanced carotid atherosclerotic disease. These results reveal a previously unrecognized role of RNA editing in gene expression in human atherosclerotic vascular diseases. Overall design: 1) Evaluation of transcriptome expression and RNA editing sites (A-to-G and T-to-C nucleotide mismatches) in poly(A) RNA-seq data derived from endothelial cell transcriptome after ADAR1 or ADAR2 knockdown (n=2 biological replicates per condition, total n=8 biological samples). 2) Evaluation of transcriptome expression and RNA editing sites (A-to-G and T-to-C nucleotide mismatches) in total-RNA-seq data derived from peripheral blood mononuclear cells (n=12 total biological samples; n=4 replicates per condition). 3) Evaluation of transcriptome expression and RNA editing sites (A-to-G and T-to-C nucleotide mismatches) in total-RNA-seq data derived from endothelial cell transcriptome under basal and hypoxic conditions (n=2 biological replicates per condition, total n=4 biological samples). 4) Evaluation of RNA editing sites (A-to-G and T-to-C nucleotide mismatches) in total RNA-seq data derived from endothelial cell transcriptome under basal and hypoxic conditions after ADAR1 knockdown (n=3 replicates per condition, total n=12 biological samples). 5) HuR iCLIP RNA-sequencing data derived from HUVEC HuR iCLIP after ADAR1 knockdown (scrambled control and siADAR1, n=1 per condition, total n=2 biological samples).
Adenosine-to-inosine RNA editing controls cathepsin S expression in atherosclerosis by enabling HuR-mediated post-transcriptional regulation.
No sample metadata fields
View SamplesBackground: 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 SamplesPurpose: We applied cDNA molecule counting using unique molecular identifiers combined with high-throughput sequencing to study the transcriptome of individual mouse embryonic stem cells, with spike-in controls to monitor technical performance. We further examined transcriptional noise in the embryonic stem cells. Overall design: One 96-well plate of single-stranded cDNA libraries generated from 96 single R1 mouse embryonic stem cells sequenced on two lanes, and one 96-well plate of the same libraries further amplified by 9 PCR cycles sequenced on one lane.
Quantitative single-cell RNA-seq with unique molecular identifiers.
No sample metadata fields
View SamplesWe obtained full transcriptome data from single cortical neurons after whole-cell patch-clamp recording (termed “Patch-seq”). By applying “Patch-seq” to cortical neurons, we reveal a close link between biophysical membrane properties and genes coding for neurotransmitter receptors and channels, including well-established and hitherto undescribed subtypes. Overall design: RNA sequencing was performed on a total of 83 individual cells
Integration of electrophysiological recordings with single-cell RNA-seq data identifies neuronal subtypes.
No sample metadata fields
View Samples