One of the hallmarks in hypertension is a pressure-induced change in endothelial cell phenotype. A cytoskeletal protein zyxin, which was seen to translocate from focal adhesion contacts to the nucleus in response to the increased wall tensionis, mediates the tension-induced endothelial signaling.
Zyxin mediation of stretch-induced gene expression in human endothelial cells.
Specimen part
View SamplesType 1 diabetes is characterized by the destruction of pancreatic beta cells, and generating new insulin-producing cells from other cell types is a major aim of regenerative medicine. One promising approach is transdifferentiation of developmentally related pancreatic cell types including glucagon-producing alpha cells. In a genetic model, overexpression of the master regulatory transcription factor Pax4 or loss of its counterplayer Arx are sufficient to induce the conversion of alpha cells to functional beta-like cells. Here we identify artemisinins as small molecules that functionally repress Arx and induce beta-cell characteristics in alpha cells. We show that the protein gephyrin is the mammalian target of these antimalaria drugs. Finally, we demonstrate that gephyrin-mediated enhancement of GABAA receptor signaling is the mechanism of action of these molecules in pancreatic transdifferentiation. Our results indicate that gephyrin is a novel druggable target for the regeneration of pancreatic beta cell mass from alpha cells. Overall design: Transcriptional dissection of Artemether treated, human pancreatic islets of one donor using single-cell RNA-seq
Artemisinins Target GABA<sub>A</sub> Receptor Signaling and Impair α Cell Identity.
Subject
View SamplesType 1 diabetes is characterized by the destruction of pancrea tic beta cells, and generating new insulin-producing cells from other cell types is a major aim of regenerative medicine. One promising approach is transdifferentiation of developmentally related pancreatic cell types including glucagon-producing alpha cells. In a genetic model, loss of the master regulatory transcription factor Arx is sufficient to induce the conversion of alpha cells to functional beta-like cells. Here we identify artemisinins as small molecules that functionally repress Arx by causing its translocation to the cytoplasm. We show that the protein gephyrin is the mammalian target of these antimalaria drugs, and that enhancement of GABAA receptor signaling contributes to the mechanism of action of these molecules in pancreatic transdifferentiation. Our results in zebrafish, rodents and primary human pancreatic islets indicate that gephyrin is a novel druggable target for the regeneration of pancreatic beta cell mass from alpha cells. Overall design: There are two parts in the transcriptional study on mouse cell lines in this project. One part is on Min6-ARX inducible cells with different induction time of Dox. This is done in three different clones. The other part is on alpha-TC1 cells. This is done in one concentration of Artemether, one time point and two biological repeats.
Artemisinins Target GABA<sub>A</sub> Receptor Signaling and Impair α Cell Identity.
Specimen part, Cell line, Subject
View SamplesSmall RNA-seq on MCF10A, HCT116 and HCT116p53-/- cell lines after induction of DNA damage (5 Gy Irradiation). Overall design: Small RNA-seq on MCF10A, HCT116 and HCT116p53-/- at 4 and 24 hours after induction of DNA damage (5 Gy Irradiation), done in duplicate with respective control (0 hour) using illumina Genome Analyzer IIx
p53 shapes genome-wide and cell type-specific changes in microRNA expression during the human DNA damage response.
Cell line, Treatment, Subject, Time
View SamplesTumor cells have an increased need for amino acids. Mammalian cells cannot synthesize essential amino acids; they must obtain these amino acids via specific transporters. Glutamine, though a non-essential amino acid, is critical for tumor cells (glutamine addiction). Entry of amino acids into tumor cells is enhanced by upregulation of specific transporters. If the transporters that are specifically induced in tumor cells are identified, blockade of the induced transporters would constitute a logical strategy for cancer treatment.
Deletion of the amino acid transporter Slc6a14 suppresses tumour growth in spontaneous mouse models of breast cancer.
Age, Specimen part
View SamplesSarcolipin (SLN) is a key regulator of SERCA pump in atria. To determine the role of SLN in atrial Ca2+ homeostasis, we have generated a SLN null (sln-/-) mouse model. Ablation of SLN results in increased SR Ca2+ load and Ca2+ transients in atria. Further, loss of SLN results in electrophysiological and strcutural remodeling of atria.
Ablation of sarcolipin results in atrial remodeling.
Sex, Specimen part
View SamplesMessenger (m)RNA export from the nucleus is essential for eukaryotic gene expression. Here, we identify a transcript-selective nuclear export mechanism affecting certain human transcripts, enriched for functions in genome duplication and repair, controlled by inositol polyphosphate multikinase (IPMK), an enzyme catalyzing inositol polyphosphate and phosphoinositide turnover. We studied transcripts encoding RAD51, a protein essential for DNA repair by homologous recombination (HR), to characterize the mechanism underlying IPMK-regulated mRNA export. IPMK depletion or catalytic inactivation selectively decreases the nuclear export of RAD51 mRNA, and RAD51 protein abundance, thereby impairing HR. Recognition of a sequence motif in the untranslated region of RAD51 transcripts by the mRNA export factor ALY requires IPMK. Phosphatidylinositol (3,4,5)-trisphosphate (PIP3), an IPMK product, restores ALY recognition in IPMK-depleted cell extracts, suggesting a mechanism underlying transcript selection. Our findings implicate IPMK in a transcript-selective mRNA export pathway controlled by phosphoinositide turnover that preserves genome integrity in humans.
Human inositol polyphosphate multikinase regulates transcript-selective nuclear mRNA export to preserve genome integrity.
Cell line
View SamplesVascular smooth muscle cells (VSMCs) respond to biomechanical stretch with specific changes in gene expression which govern the phenotype of these cells. The mechanotransducer zyxin is a
Loss of the mechanotransducer zyxin promotes a synthetic phenotype of vascular smooth muscle cells.
Specimen part, Treatment
View SamplesSynthesis and accumulation of seed storage proteins (SSPs) is an important aspect of the seed maturation program. Genes encoding SSPs are specifically and highly expressed in the seed during maturation. However, the mechanisms that repress the expression of these genes in leaf tissue are not well understood. To gain insight into the repression mechanisms, we have performed a transgenic screening for mutants that express SSPs in leaves. Here we show that mutations of BRAHMA (BRM), a SNF2 chromatin remodelling ATPase, cause the ectopic expression of a subset of SSPs and other embryogenesis related genes in leaf tissue. Consistent with the notion that such SNF2-like ATPases form protein complexes in vivo, we observed similar phenotypes for mutations of AtSWI3C, a BRM interacting partner, and BSH, a SNF5 homolog and essential SWI/SNF subunit. Further, we present chromatin immunoprecipitation evidence that BRM is recruited to the promoters of a number of embryogenesis genes including the 2S genes, which are expressed/elevated in brm leaves. Consistent with its role in nucleosome remodelling, BRM appears to control the chromatin structure of the At2S2 promoter. These results show that a BRM-containing chromatin remodelling ATPase complex is involved in the direct repression of SSPs in leaf tissue.
The Arabidopsis BRAHMA chromatin-remodeling ATPase is involved in repression of seed maturation genes in leaves.
No sample metadata fields
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DAF-16/FOXO and EGL-27/GATA promote developmental growth in response to persistent somatic DNA damage.
Treatment
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