A thorough dynamic interpretation of residual dipolar couplings in ubiquitin.

dipolar couplings (rdcs), ubiquitin The presence of slow motions with large amplitudes, as detected by measurements based on residual dipola

Cluster of differentiation 43 deficiency in leukocytes leads to reduced atherosclerosis - Brief report

© 2014 American Heart Association, Inc.OBJECTIVE - : The aim of this study was to investigate the role of cluster of differentiation 43 (CD43), an integral membrane glycoprotein with both proadhesive and antiadhesive activities, in atherosclerosis. APPROACH AND RESULTS - : Low-density lipoprotein receptor-deficient mice were lethally irradiated and reconstituted with either bone marrow from CD43 mice or from wild-type controls. We found that mice lacking the CD43 on their leukocytes had significantly less severe atherosclerosis and that, contrary to our expectation, macrophage infiltration into the vessel wall was not affected by the lack of CD43 in the leukocytes. However, we found that CD43 mediates cholesterol homeostasis in macrophages by facilitating cholesterol efflux. This resulted in a significant reduction in storage of cholesterol in the aorta of mice lacking CD43 in the leukocytes. CONCLUSIONS - : CD43 may be an important mediator of macrophage lipid homeostasis, thereby affecting macrophage foam cell formation and ultimately atherosclerotic plaque development

Small integral membrane protein 10 like 1 downregulation enhances differentiation of adipose progenitor cells

Small integral membrane protein 10 like 1 (SMIM10L1) was identified by RNA sequencing as the most significantly downregulated gene in Phosphatase and Tensin Homologue (PTEN) knockdown adipose progenitor cells (APCs). PTEN is a tumor suppressor that antagonizes the growth promoting Phosphoinositide 3-kinase (PI3K)/AKT/mechanistic Target of Rapamycin (mTOR) cascade. Diseases caused by germline pathogenic variants in PTEN are summarized as PTEN Hamartoma Tumor Syndrome (PHTS). This overgrowth syndrome is associated with lipoma formation, especially in pediatric patients. The mechanisms underlying this adipose tissue dysfunction remain elusive. We observed that SMIM10L1 downregulation in APCs led to an enhanced adipocyte differentiation in two- and three-dimensional cell culture and increased expression of adipogenesis markers. Furthermore, SMIM10L1 knockdown cells showed a decreased expression of PTEN, pointing to a mutual crosstalk between PTEN and SMIM10L1. In line with these observations, SMIM10L1 knockdown cells showed increased activation of PI3K/AKT/mTOR signaling and concomitantly increased expression of the adipogenic transcription factor SREBP1. We computationally predicted an α-helical structure and membrane association of SMIM10L1. These results support a specific role for SMIM10L1 in regulating adipogenesis, potentially by increasing PI3K/AKT/mTOR signaling, which might be conducive to lipoma formation in pediatric patients with PHTS

Cluster of differentiation 43 deficiency in leukocytes leads to reduced atherosclerosis - Brief report

© 2014 American Heart Association, Inc. OBJECTIVE - : The aim of this study was to investigate the role of cluster of differentiation 43 (CD43), an integral membrane glycoprotein with both proadhesive and antiadhesive activities, in atherosclerosis. APPROACH AND RESULTS - : Low-density lipoprotein receptor-deficient mice were lethally irradiated and reconstituted with either bone marrow from CD43 mice or from wild-type controls. We found that mice lacking the CD43 on their leukocytes had significantly less severe atherosclerosis and that, contrary to our expectation, macrophage infiltration into the vessel wall was not affected by the lack of CD43 in the leukocytes. However, we found that CD43 mediates cholesterol homeostasis in macrophages by facilitating cholesterol efflux. This resulted in a significant reduction in storage of cholesterol in the aorta of mice lacking CD43 in the leukocytes. CONCLUSIONS - : CD43 may be an important mediator of macrophage lipid homeostasis, thereby affecting macrophage foam cell formation and ultimately atherosclerotic plaque development

MicroRNA 302a is a novel modulator of cholesterol homeostasis and atherosclerosis

© 2014 American Heart Association, Inc. OBJECTIVE - : Macrophage foam cell formation is a key feature of atherosclerosis. Recent studies have shown that specific microRNAs (miRs) are regulated in modified low-density lipoprotein-treated macrophages, which can affect the cellular cholesterol homeostasis. Undertaking a genome-wide screen of miRs regulated in primary macrophages by modified low-density lipoprotein, miR-302a emerged as a potential candidate that may play a key role in macrophage cholesterol homeostasis. APPROACH AND RESULTS - : The objective of this study was to assess the involvement of miR-302a in macrophage lipid homeostasis and if it can influence circulating lipid levels and atherosclerotic development when it is inhibited in a murine atherosclerosis model. We found that transfection of primary macrophages with either miR-302a or anti-miR-302a regulated the expression of ATP-binding cassette (ABC) transporter ABCA1 mRNA and protein. Luciferase reporter assays showed that miR-302a repressed the 3′ untranslated regions (UTR) activity of mouse Abca1 by 48% and human ABCA1 by 45%. In addition, transfection of murine macrophages with miR-302a attenuated cholesterol efflux to apolipoprotein A-1 (apoA-1) by 38%. Long-term in vivo administration of anti-miR-302a to mice with low-density lipoprotein receptor deficiency (Ldlr) fed an atherogenic diet led to an increase in ABCA1 in the liver and aorta as well as an increase in circulating plasma high-density lipoprotein levels by 35% compared with that of control mice. The anti-miR-302a-treated mice also displayed reduced atherosclerotic plaque size by ≈25% and a more stable plaque morphology with reduced signs of inflammation. CONCLUSIONS - : These studies identify miR-302a as a novel modulator of cholesterol efflux and a potential therapeutic target for suppressing atherosclerosis

Receptor-mediated delivery of engineered nucleases for genome modification

Engineered nucleases, which incise the genome at predetermined sites, have a number of laboratory and clinical applications. There is, however, a need for better methods for controlled intracellular delivery of nucleases. Here, we demonstrate a method for ligand-mediated delivery of zinc finger nucleases (ZFN) proteins using transferrin receptor-mediated endocytosis. Uptake is rapid and efficient in established mammalian cell lines and in primary cells, including mouse and human hematopoietic stem-progenitor cell populations. In contrast to cDNA expression, ZFN protein levels decline rapidly following internalization, affording better temporal control of nuclease activity. We show that transferrin-mediated ZFN uptake leads to site-specific in situ cleavage of the target locus. Additionally, despite the much shorter duration of ZFN activity, the efficiency of gene correction approaches that seen with cDNA-mediated expression. The approach is flexible and general, with the potential for extension to other targeting ligands and nuclease architectures

The Degenerate Parametric Oscillator and Ince's Equation

We construct Green's function for the quantum degenerate parametric oscillator in terms of standard solutions of Ince's equation in a framework of a general approach to harmonic oscillators. Exact time-dependent wave functions and their connections with dynamical invariants and SU(1,1) group are also discussed.Comment: 10 pages, no figure

Regression Analysis of PEM Fuel Cell Transient Response

To develop operating strategies in polymer electrolyte membrane (PEM) fuel cell-powered applications, precise computationally efficient models of the fuel cell stack voltage are required. Models are needed for all operating conditions, including transients. In this work, transient evolutions of voltage, in response to load changes, are modeled with a sum of three exponential decay functions. Amplitude factors are correlated to steady-state operating data (temperature, humidity, average current, resistance, and voltage). The obtained time constants reflect known processes of the membrane heat/water transport. These model parameters can form the basis for the prediction of voltage overshoot/undershoot used in computational-based control systems, used in real-time simulation. Furthermore, the results provide an empirical basis for the estimation of the magnitude of temporary voltage loss to be expected with sudden load changes, as well as a systematic method for the analysis of experimental data. Its applicability is currently limited to thin membranes with low to moderate humidity gases, and with adequately high reactant-gas stoichiometry

Regulation of monocyte/macrophage polarisation by extracellular RNA

© Schattauer 2015. Monocytes/macrophages respond to external stimuli with rapid changes in the expression of numerous inflammation-related genes to undergo polarisation towards the M1 (pro-inflammatory) or M2 (antiinflammatory) phenotype. We have previously shown that, independently of Toll-like receptor activation, extracellular RNA (eRNA) could exert pro-thrombotic and pro-inflammatory properties in the cardiovascular system to provoke cytokine mobilisation. Here, mouse bone marrow-derived-macrophages (BMDM) differentiated with mouse macrophage-colony-stimulating factor (M-CSF) were found to be skewed towards the M1 phenotype when exposed to eRNA. This resulted in up-regulated expression of inflammatory markers such as Tnf-α and Il-6, together with Il-12 and iNOS, whereas anti-inflammatory genes such as chitinase-like proteins (Ym1/2) and macrophage mannose receptor-2 (Cd206) were significantly down-regulated. Human peripheral blood monocytes were treated with eRNA and analysed by micro-array analysis of the whole human genome, revealing an up-regulation of 79 genes by at least four-fold; 27 of which are related to signal transduction and 15 genes associated with inflammatory response. In accordance with the proposed actions of eRNA as a pro-inflammatory “alarm signal”, these data shed light on the role of eRNA in the context of chronic inflammatory diseases such as atherosclerosis