DNMT3A-coordinated splicing governs the stem state switch towards differentiation in embryonic and haematopoietic stem cells.

Upon stimulation by extrinsic stimuli, stem cells initiate a programme that enables differentiation or self-renewal. Disruption of the stem state exit has catastrophic consequences for embryogenesis and can lead to cancer. While some elements of this stem state switch are known, major regulatory mechanisms remain unclear.

First-in-Class Allosteric Inhibitors of DNMT3A Disrupt Protein-Protein Interactions and Induce Acute Myeloid Leukemia Cell Differentiation.

We previously identified two structurally related pyrazolone (compound 1) and pyridazine (compound 2) allosteric inhibitors of DNMT3A through screening of a small chemical library. Here, we show that these compounds bind and disrupt protein-protein interactions (PPIs) at the DNMT3A tetramer interface. This disruption is observed with distinct partner proteins and occurs even when the complexes are acting on DNA, which better reflects the cellular context.

Constitutive loss of DNMT3A causes morbid obesity through misregulation of adipogenesis.

DNA Methyltransferase 3 A (DNMT3A) is an important facilitator of differentiation of both embryonic and hematopoietic stem cells. Heterozygous germline mutations in lead to Tatton-Brown-Rahman Syndrome (TBRS), characterized by obesity and excessive height. While DNMT3A is known to impact feeding behavior via the hypothalamus, here we investigated a role in adipocyte progenitors utilizing heterozygous knockout mice that recapitulate cardinal TBRS phenotypes.

Mutant NPM1 Maintains the Leukemic State through HOX Expression.

NPM1 is the most frequently mutated gene in cytogenetically normal acute myeloid leukemia (AML). In AML cells, NPM1 mutations result in abnormal cytoplasmic localization of the mutant protein (NPM1c); however, it is unknown whether NPM1c is required to maintain the leukemic state. Here, we show that loss of NPM1c from the cytoplasm, either through nuclear relocalization or targeted degradation, results in immediate downregulation of homeobox (HOX) genes followed by differentiation.

Targeted gene silencing of tumor necrosis factor attenuates the negative inotropic effects of lipopolysaccharide in isolated contracting cardiac myocytes.

Bacterial endotoxin (lipopolysaccharide) depresses cardiovascular function; however, the mediators and signaling pathways that are responsible for the negative inotropic effects of lipopolysaccharide are not fully known. We used RNA interference to determine the relative role of tumor necrosis factor with respect to mediating the negative inotropic effects of lipopolysaccharide in isolated cardiac myocytes. Cardiac myocyte cultures were treated with lipopolysaccharide in the presence or absence of small interfering RNAs (siRNA) for tumor necrosis factor.

Effect of ranitidine on the antiplatelet effects of aspirin in healthy human subjects.

Aspirin is often taken with H2-receptor antagonists. In vitro data suggest that certain antagonists, such as ranitidine, have inhibitory effects on platelet function. There are no reports on the combined effect of aspirin and H2-receptor antagonists on platelet function in humans.

Triphasic waveforms are superior to biphasic waveforms for transthoracic defibrillation: experimental studies.

Objectives: Our objective was to evaluate the efficacy of triphasic waveforms for transthoracic defibrillation in a swine model.

Background: Triphasic shocks have been found to cause less post-shock dysfunction than biphasic shocks in chick embryo studies.

Methods: After 30 s of electrically induced ventricular fibrillation (VF), each pig in part I (n = 32) received truncated exponential biphasic (7.

Assembly of deletion mutants of the Rieske iron-sulfur protein into the cytochrome bc1 complex of yeast mitochondria.

The assembly of two deletion mutants of the Rieske iron-sulfur protein into the cytochrome bc1 complex was investigated after import in vitro into mitochondria isolated from a strain of yeast, JPJ1, from which the iron-sulfur protein gene (RIP) had been deleted. The assembly process was investigated by immunoprecipitation of the labeled iron-sulfur protein or the two deletion mutants from detergent-solubilized mitochondria with specific antisera against either the iron-sulfur protein or the bc1 complex (complex III) [Fu and Beattie (1991). J.

Processing of the intermediate form of the iron-sulfur protein of the BC1 complex to the mature form after import into yeast mitochondria.

The Rieske iron-sulfur protein of the cytochrome bc1 complex is synthesized in the cytosol as a precursor with an additional 30 amino acids at the amino terminus. After import into the mitochondrial matrix, the precursor is processed to the mature form by two distinct proteolytic cleavages. Addition of 2.