Promyelocytic Leukemia Zinc Finger Protein Activates GATA4 Transcription and Mediates Cardiac Hypertrophic Signaling from Angiotensin II Receptor 2

Background: Pressure overload and prolonged angiotensin II (Ang II) infusion elicit cardiac hypertrophy in Ang II receptor 1 (AT1) null mouse, whereas Ang II receptor 2 (AT2) gene deletion abolishes the hypertrophic response. The roles and signals of the cardiac AT2 receptor still remain unsettled. Promyelocytic leukemia zinc finger protein (PLZF) was shown to bind to the AT2 receptor and transmit the hypertrophic signal. Using PLZF knockout mice we directed our studies on the function of PLZF concerning the cardiac specific transcription factor GATA4, and GATA4 targets. Methodology and Principal Findings: PLZF knockout and age-matched wild-type (WT) mice were treated with Ang II, infused at a rate of 4.2 ng?kg 21?min 21 for 3 weeks. Ang II elevated systolic blood pressure to comparable levels in PLZF knockout and WT mice (140 mmHg). WT mice developed prominent cardiac hypertrophy and fibrosis after Ang II infusion. In contrast, there was no obvious cardiac hypertrophy or fibrosis in PLZF knockout mice. An AT 2 receptor blocker given to Ang II-infused wild type mice prevented hypertrophy, verifying the role of AT2 receptor for cardiac hypertrophy. Chromatin immunoprecipitation and electrophoretic mobility shift assay showed that PLZF bound to the GATA4 gene regulatory region. A Luciferase assay verified that PLZF up-regulated GATA4 gene expression and the absence of PLZF expression in vivo produced a corresponding repression of GATA4 protein. Conclusions: PLZF is an important AT2 receptor binding protein in mediating Ang II induced cardiac hypertrophy throug

Electrochemical and Corrosion Stability of Nanostructured Silicon by Graphene Coatings: Toward High Power Porous Silicon Supercapacitors

We demonstrate the electrochemical stability of nanostructured silicon in corrosive aqueous, organic, and ionic liquid media enabled by conformal few-layered graphene heterogeneous interfaces. We demonstrate direct gas-phase few-layered graphene passivation (<i>d</i> = 0.35 nm) at temperatures that preserve the structural integrity of the nanostructured silicon. This passivation technique is transferrable both to silicon nanoparticles (Si-NPs) as well as to electrochemically etched porous silicon (P-Si) materials. For Si-NPs, we find the graphene-passivated silicon to withstand physical corrosion in NaOH aqueous conditions where unpassivated Si-NPs spontaneously dissolve. For P-Si, we demonstrate electrochemical stability with widely different electrolytes, including NaOH, enabling these materials for electrochemical supercapacitors. This leads us to develop high-power on-chip porous silicon supercapacitors capable of up to 10 Wh/kg and 65 kW/kg energy and power densities, respectively, and 5 Wh/kg energy density at 35 kW/kgcomparable to many of the best high-power carbon-based supercapacitors. As surface reactivity wholly dictates the utilization of nanoscale silicon in diverse applications across electronics, energy storage, biological systems, energy conversion, and sensing, we emphasize direct formation of few-layered graphene on nanostructured silicon as a means to form heterogeneous on-chip interfaces that can maintain stability in even the most reactive of environments

Engineered Porous Silicon Counter Electrodes for High Efficiency Dye-Sensitized Solar Cells

In this work, we demonstrate for the first time, the use of porous silicon (P-Si) as counter electrodes in dye-sensitized solar cells (DSSCs) with efficiencies (5.38%) comparable to that achieved with platinum counter electrodes (5.80%). To activate the P-Si for triiodide reduction, few layer carbon passivation is utilized to enable electrochemical stability of the silicon surface. Our results suggest porous silicon as a promising sustainable and manufacturable alternative to rare metals for electrochemical solar cells, following appropriate surface modification

Late Permian continental sediments in the SE Iberian Ranges, eastern Spain: Petrological and mineralogical characteristics and palaeoenvironmental significance

A detailed mineralogical and petrological study and the analysis of paleosol profiles in continental alluvial sediments of the Late Permian in the SE Iberian Ranges (Spain) allow us to infer the significant environmental changes that occurred during this time period. Three parts have been distinguished in the Late Permian sediments (Alcotas Formation). The lower part includes abundant and well-preserved carbonate paleosol profiles and fine-grained sediments made up by quartz, feldspar, hematite and illite, with scarce kaolinite. The preservation of dolomicrite in some paleosols suggests that they originally developed as dolocretes in an arid to semi-arid climate with marked seasonality. A change towards more humid and acid conditions can be deduced from the presence of siderite and goethite in paleosols in the middle part of the Alcotas Formation. Moreover, the presence of plant remains, coal beds and/or carbonaceous shales at the top of the middle part, and the lack of carbonate paleosols in the upper part of the formation would indicate a further step towards acid conditions. These conditions would increase until the Early Triassic, as indicated by the lack of carbonates and the presence of Sr-rich aluminium phosphate sulphates (APS minerals) at the base of the Triassic (Can˜ izar Formation), which clearly indicates extreme acid conditions during the Permian–Triassic transition of the study area

All Silicon Electrode Photocapacitor for Integrated Energy Storage and Conversion

We demonstrate a simple wafer-scale process by which an individual silicon wafer can be processed into a multifunctional platform where one side is adapted to replace platinum and enable triiodide reduction in a dye-sensitized solar cell and the other side provides on-board charge storage as an electrochemical supercapacitor. This builds upon electrochemical fabrication of dual-sided porous silicon and subsequent carbon surface passivation for silicon electrochemical stability. The utilization of this silicon multifunctional platform as a combined energy storage and conversion system yields a total device efficiency of 2.1%, where the high frequency discharge capability of the integrated supercapacitor gives promise for dynamic load-leveling operations to overcome current and voltage fluctuations during solar energy harvesting

PLZF-/- mice weigh less than their wild type and heterozygote siblings.

<p>Mice were weighed for comparison. (* indicates p<0.05 vs all other groups; n = 12; data are mean±S.E.M).</p

PLZF binds to the regulatory region of <i>GATA4</i> gene.

<p>(A) Elctrophoretic mobility shift assay (EMSA) verified the PLZF binding activity at <i>GATA4</i> gene. Lane 1: negative control with nuclear extract of COS7 cells not expressing PLZF. Lane 2: positive control with PLZF expressing cell nuclear extract. (B)Chromatin immunoprecipitation assay (ChIPs) analysis determined the PLZF occupancy in GATA4 gene at the chromatin level.</p

GATA4 protein expression is significantly elevated in the Ang II treated wild type mouse heart.

<p>Protein extracts from mice left ventricles were measured by Western blot (* indicates p<0.05 vs all other groups; n = 5; data are mean±S.E.M.). Ordinate axis indicates protein amount normalized by GAPDH, control is set to 1.0.</p