Human von Willebrand factor (VWF) gene sequences؉155 to ؉247 contain cis-acting elements that contribute toward endothelial specific activation of the VWF promoter. Analyses of this region demonstrated the presence of a GATA-binding site that is necessary for the promoter activation in endothelial cells. We have reported recently the presence of a novel NFY-binding sequence in this region that does not conform to the consensus NFY-binding sequence CCAAT. NFY was shown to function as a repressor of the VWF promoter through interaction with this novel binding site. Here we report that the NFY interacts with histone deacetylases (HDACs) in a cell type-specific manner and recruits them to the VWF promoter to inhibit the promoter activity in non-endothelial cells. Analyses of the acetylation status of histones in the chromatin region containing the VWF promoter sequences demonstrated that these sequences are associated with acetylated histone H4 specifically in endothelial cells. It was also demonstrated that HDACs are specifically recruited to the same chromatin region in non-endothelial cells. We also demonstrated that GATA6 is the GATA family member that interacts with the VWF promoter and that GATA6 is associated with NFY specifically in non-endothelial cells. We propose that NFY recruits HDACs to the VWF promoter, which may result in deacetylation of GATA6 as well as of histones in non-endothelial cells, thus leading to promoter inactivation. In endothelial cells, however, association of HDACs, NFY, and GATA6 is interrupted potentially through endothelial cell-specific signaling/mechanism, thus favoring the balance toward acetylation and activation of the VWF promoter.
Human von Willebrand factor (VWF) gene sequences ؊487 to ؉247 function as an endothelial-specific promoter in vitro. Analysis of the activation mechanism of the VWF promoter has resulted in the identification of a number of cis-acting elements and trans-acting factors that regulate its activity. The GATA and Ets transcription factors were shown to function as activators of transcription, whereas NF1 and Oct1 were shown to repress transcription. We have reported the presence of another repressor element in exon 1 that interacted with a protein complex designated "R." In the absence of NF1 binding, inhibition of this interaction resulted in promoter activation in nonendothelial cells. We have now identified the "R" protein complex as the NFY transcription factor. Using DNA methylation interference assay and base substitution mutation analysis, we show that NFY interacts with a novel DNA sequence corresponding to nucleotides ؉226 to ؉234 in the VWF promoter that does not conform to the consensus NFY binding sequence CCAAT. The VWF gene does contain a CCAAT element that is located downstream of the TATA box and we show that the NFY factor also interacts with this CCAAT element. Using antibodies specific against the A, B, and C subunits of NFY, we demonstrate that the NFY complexes interacting with the CCAAT sequence have a composition similar to that of the repressor binding to the first exon sequences. The results of mutation analysis and transfection studies demonstrated that the interaction of NFY with the upstream CCAAT element is required for VWF promoter activation. Based on these results, we hypothesize that NFY can function both as a repressor and activator of transcription and its function may be modulated through its DNA binding sequences. IntroductionEndothelial cells form a monolayer that covers the surface of all blood vessels. These cells participate in many physiologic and pathophysiologic processes, and their accessible locations make them an attractive target for development of gene therapy approaches for the treatment of many diseases. [1][2][3][4][5][6] Interest in endothelial cells has resulted in an expanding body of research on the mechanism of endothelial-specific gene regulation. The goals of many of these studies are to first identify the regulatory regions of the endothelial-specific genes and then determine the molecular mechanism that governs the endothelial-specific activation of gene expression. Target genes for these studies include tie-1, 7 tie-2, 8 VEGF receptors 1 and 2, 9-11 endothelin, 12 PECAM-1, 13 and VWF. [14][15][16] The activation patterns of these promoters have been studied in cell culture, and for some promoters also in transgenic mice. 8,14,15,17,18 Despite its limitations, in vitro analysis in cell culture provides a feasible approach toward determining the role of the multiple potential cis-acting elements involved in regulating promoter activation.We have previously demonstrated that a 734-bp region of the VWF gene spanning sequences Ϫ487 to ϩ247 activated gene expre...
Hospital buildings usually contain sophisticated facility systems and special medical equipment, strict security requirements, and business systems. Traditional methods such as BIM are becoming less capable of real-time updates of building status and big data volume. By proposing innovations both in technique and management—a “continuous lifecycle integration” method based on the concept of Digital Twin (DT) and “early movement” of the general contractor, this paper reported a successful project case in a large hospital in China. The case realized continuous, scheduled integration of static data and dynamic data of more than 20 management systems from the design, construction, pre-O&M phase up to the O&M phase. Then, a DT software system with real-time visual management and artificial intelligent diagnosis modules was developed and deployed in a newly built DT control center. Managers have the ability to grasp the detailed status of the whole hospital by visual management and receive timely facility diagnosis and operation suggestions that are automatically sent back from the digital building to reality. The case has been steadily running for more than a year in the hospital and achieved desired performance by reducing energy consumption, avoiding facility faults, reducing the number of requested repairs, and enhancing the quality of daily maintenance work.
Oxidative transformation of organic contaminants by manganese oxides was commonly investigated with pure MnO(2) suspension, which deviates from the fact that natural manganese oxides are seldom present as a pure form in the natural environment. In this study, we prepared manganese oxide-coated sand (MOCS) and evaluated its oxidative capacity using bisphenol A (BPA) as the model compound. BPA was transformed by MOCS and the reaction followed an exponential decay model. The reaction was pH dependent and followed the order of pH 4.5>pH 5.5>pH 6.5>pH 7.5>pH 8.6>pH 9.6, indicating that acidic conditions facilitated BPA transformation while basic conditions disfavored the reaction. Coexisting metal ions exhibited inhibitory effects and followed the order of Fe(3+) > Zn(2+) > Cu(2+) > Ca(2+) > Mg(2+) > Na(+). Transformation of BPA by MOCS was much slower than that by pure MnO(2) suspension. However, similar transformation products were identified in both studies, suggesting the same reaction pathways. This work suggests that the reactivity of MnO(2) in the environment might be overestimated if extrapolating the result from the pure MnO(2) suspension because natural MnO(2) is mainly present as coating on the surface of soils and sediments.
Post-irradiation complications including thrombus formation result from increased procoagulant activity of vascular endothelial cells and elevated levels of von Willebrand factor (VWF) contribute to this process. We have previously demonstrated that irradiation induction of the VWF is mediated through interaction of NF-Y transcription factor with its cognate binding site in the VWF promoter. We have also demonstrated that irradiation increases the association of NF-Y with histone acetyltransferase p300/CBP-associated factor (PCAF). We now report that irradiation decreases the association of NF-Y with histone deacetylase 1 (HDAC1). We demonstrate that irradiation-induced changes in association of NF-Y with HDAC1 and PCAF lead to increased PCAF recruitment to the VWF promoter, increased association of acetylated histone H4 with the VWF promoter and subsequently increased transcription. We also demonstrate that this process is correlated to dephosphorylation of HDAC1 and is inhibited by calyculin A, an inhibitor of protein phosphatase1.
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