Identification of Small‐Molecule PHD2 Zinc Finger Inhibitors that Activate Hypoxia Inducible Factor

The prolyl hydroxylase domain (PHD) protein:hypoxia inducible factor (HIF) pathway is the main pathway by which changes in oxygen concentration are transduced to changes in gene expression. In mammals, there are three PHD paralogues, and PHD2 has emerged as a particularly critical one for regulating HIF target genes such as erythropoietin (EPO), which controls red cell mass and hematocrit. PHD2 is distinctive among the three PHDs in that it contains an N‐terminal MYND‐type zinc finger. We have proposed that this zinc finger binds a Pro‐Xaa‐Leu‐Glu (PXLE) motif found in proteins of the HSP90 pathway to facilitate HIF‐α hydroxylation. Targeting this motif could provide a means of specifically inhibiting this PHD isoform. Here, we screened a library of chemical compounds for their capacity to inhibit the zinc finger of PHD2. We identified compounds that, in vitro, can inhibit PHD2 binding to a PXLE‐containing peptide and induce activation of HIF. Injection of one of these compounds into mice induces an increase in hematocrit. This study offers proof of principle that inhibition of the zinc finger of PHD2 can provide a means of selectively targeting PHD2 to activate the HIF pathway.     

Effect of pentagon–heptagon defect on thermal transport properties in graphene nanoribbons

The thermal transport properties of graphene nanoribbons (GNRs) with pentagon–heptagon defect (PHD) are studied by using first principles calculations in combination with non-equilibrium Green’s function approach. The results show that the PHD effect on thermal conduction in armchair-oriented GNR is stronger than that in zigzag-oriented GNR. The out-of-plane acoustic mode is almost reflected by the PHD at a particular frequency. When the temperature is larger than 400 K, the thermal conduction ratio is only related to the PHD’s orientation, and insensitive to the width of PHD. These results will be helpful for designing high-performance thermal insulation or thermoelectric device.     

Prolyl Hydroxylase 3 Knockdown Accelerates VHL-Mutant Kidney Cancer Growth In Vivo

Von Hippel Lindau (VHL) inactivation, which is common in clear cell renal cell carcinoma (ccRCC), leads directly to the disruption of oxygen homoeostasis. VHL works through hypoxia-inducible factors (HIFs). Within this VHL-HIF system, prolyl hydroxylases (PHDs) are the intermediary proteins that initiate the degradation of HIFs. PHD isoform 3′s (PHD3) role in ccRCC growth in vivo is poorly understood. Using viral transduction, we knocked down the expression of PHD3 in the human ccRCC cell line UMRC3. Compared with control cells transduced with scrambled vector (UMRC3-SC cells), PHD3-knockdown cells (UMRC3-PHD3KD cells) showed increased cell invasion, tumor growth, and response to sunitinib. PHD3 knockdown reduced HIF2α expression and increased phosphorylated epidermal growth factor (EGFR) expression in untreated tumor models. However, following sunitinib treatment, expression of HIF2α and phosphorylated EGFR were equivalent in both PHD3 knockdown and control tumors. PHD3 knockdown changed the overall redox state of the cell as seen by the increased concentration of glutathione in PHD3 knockdown tumors relative to control tumors. UMRC3-PHD3KD cells had increased proliferation in cell culture when grown in the presence of hydrogen peroxide compared to UMRC3-SC control cells. Our findings illustrate (1) the variable effect of PHD3 on HIF2α expression, (2) an inverse relationship between PHD3 expression and tumor growth in ccRCC animal models, and (3) the role of PHD3 in maintaining the redox state of UMRC3 cells and their proliferative rate under oxidative stress.     

聚脲多元醇的制备

聚脲多元醇PHD的生产工艺复杂 ,在普通实验室和工厂合成较为困难。为了能够更方便地合成PHD ,华南理工大学材料科学研究所通过大量实验寻找出简易制备PHD的工艺 ,并将制得的PHD用于发泡及对其进行各种性能测试 ,结果令人满意。     

Eutectic‐forming binary system of poly(ethylene oxide) and p‐hydroxybenzaldehyde

The binary system consisting of poly(ethylene oxide) (PEO) and p‐hydroxybenzaldehyde (PHD) was characterized with the aid of differential scanning calorimetry, polarized optical microscopy, scanning electron microscopy and Fourier‐transform infrared spectroscopy. The phase diagram created from thermal analysis data provides clear evidence for the presence of a eutectic at 35.5 °C and PHD weight fraction of 42%. Microscopy studies show that, for the mixtures with a PHD weight fraction below 42%, the resulting morphology of the crystallized sample is coarse spherulitic texture. In the case of eutectic composition, the crystallization of the binary melt produces degenerated homogenous spherulites. For the hypoeutectic PEO–PHD mixtures, the PHD crystals become large and thick with decreasing the PEO fraction. Moreover, the infrared measurements indicate that hydrogen bonding in the PEO–PHD binary system has an important effect on the PEO helical conformation. With increase of the amount of PHD component, the PEO helical conformation in the PEO–PHD mixtures changes from the 7₂ helix to the 10₃ helix. Further increase of the PHD content leads to the destruction of the PEO helical conformation. Copyright © 2003 Society of Chemical Industry     

聚脲多元醇

对聚脲多元醇的合成原理、合成方法、影响其性能的关键因素及研究进展等方面作了综述，展望了其今后的发展方向和应用前景。     

LRP5 Regulates HIF-1α Stability via Interaction with PHD2 in Ischemic Myocardium

Low-density lipoprotein receptor-related protein 5 (LRP5) has been studied as a co-receptor for Wnt/β-catenin signaling. However, its role in the ischemic myocardium is largely unknown. Here, we show that LRP5 may act as a negative regulator of ischemic heart injury via its interaction with prolyl hydroxylase 2 (PHD2), resulting in hypoxia-inducible factor-1α (HIF-1α) degradation. Overexpression of LRP5 in cardiomyocytes promoted hypoxia-induced apoptotic cell death, whereas LRP5-silenced cardiomyocytes were protected from hypoxic insult. Gene expression analysis (mRNA-seq) demonstrated that overexpression of LRP5 limited the expression of HIF-1α target genes. LRP5 promoted HIF-1α degradation, as evidenced by the increased hydroxylation and shorter stability of HIF-1α under hypoxic conditions through the interaction between LRP5 and PHD2. Moreover, the specific phosphorylation of LRP5 at T1492 and S1503 is responsible for enhancing the hydroxylation activity of PHD2, resulting in HIF-1α degradation, which is independent of Wnt/β-catenin signaling. Importantly, direct myocardial delivery of adenoviral constructs, silencing LRP5 in vivo, significantly improved cardiac function in infarcted rat hearts, suggesting the potential value of LRP5 as a new target for ischemic injury treatment.     

Chemo‐enzymatic synthesis of poly(2,2,2‐trichloroethyl 10‐hydroxydecanate)‐block‐polystyrene combining enzymatic self‐condensation polymerization and ATRP

Enzymatic polymerization in a non‐natural environment is of interest as an environmentally friendly methodology as an alternative to the use of conventional chemical organometallic catalysts. Chemo‐enzymatic synthesis of the AB‐type diblock copolymer poly(2,2,2‐trichloroethyl 10‐hydroxydecanate)‐block‐polystyrene (PHD‐b‐PSt) was carried out by combining enzymatic self‐condensation polymerization (eSCP) and atom‐transfer radical polymerization (ATRP). Biocatalyst Novozyme 435 was successful in catalyzing the eSCP of a novel ω‐hydroxyester, i.e. 2,2,2‐trichloroethyl 10‐hydroxydecanate. The resulting ? CCl₃‐terminated PHD initiated the ATRP of styrene, a ‘living’/controlled radical polymerization. The analysis of the hydrolysate from the copolymer proved the presence of a block copolymer structure. In addition, the well‐defined diblock copolymer PHD‐b‐PSt self‐assembled into nanoscale micelles in aqueous solution. The chemo‐enzymatic synthesis of diblock copolymer PHD‐b‐PSt was achieved by the combination of eSCP and ATRP. The structures and composition of the block copolymer were characterized by means of NMR, infrared and gel permeation chromatography measurements. Differential scanning calorimetry analysis showed that a microphase‐separation structure was formed in the copolymer, which was caused by the crystallization of the PHD segments. As investigated with atomic force microscopy and dynamic light scattering, these micelles had a mean diameter and a spherical shape. To our knowledge, this is the first example of a chemo‐enzymatic synthesis based on eSCP and ATRP. Copyright © 2007 Society of Chemical Industry     

Carbon Monoxide is an Inhibitor of HIF Prolyl Hydroxylase Domain 2

Hypoxia-inducible factor prolyl hydroxylase domain 2 (PHD2) is an important oxygen sensor in animals. By using the CO-releasing molecule-2 (CORM-2) as an in situ CO donor, we demonstrate that CO is an inhibitor of PHD2. This report provides further evidence about the emerging role of CO in oxygen sensing and homeostasis.     

Thermal and mechanical properties of the polymers synthesized by the sequential polymerization of propylene and 1‐hexadecene

The block copolymer of poly(1‐hexadecene) (PHD) and polypropylene (PP) was effectively synthesized by the sequential polymerization of propylene and 1‐hexadecene by using highly isospecific TiCl₃/Cp₂Ti(CH₃)₂ (Cp = cyclopentadienyl). The block copolymers had two separate melting temperatures of constituent blocks. The modulus of PHD–PP block copolymer was enhanced as the content of sequentially polymerized PP block was increased. The elongation at break showed positive deviation at the intermediate compositions from the simple additive values of constituent homopolymers. Shape memory effect which utilizes the crystalline PHD block as a reversible phase and the crystalline PP block as a fixed structure was examined. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1709–1715, 2002; DOI 10.1002/app.10551     

Honeywell先进控制在常减压装置上的控制策略

介绍Honeywell先进控制在常减压装置上的控制策略，探讨其先进控制技术应用。     

Down-Regulation of Porcine Heart Diaphorase Reactivity by Trimanganese Hexakis(3,5-Diisopropylsalicylate), Mn(3)(3,5-DIPS)6, and Down-Regulation of Nitric Oxide Synthase Reactivity by Mn(3)(3,5-DIPS)(6) and Cu(II)(2)(3,5-DIPS)(4)

Purposes of this work were to examine the plausible down-regulation of porcine heart diaphorase (PHD) enzyme reactivity and nitric oxide synthase (NOS) enzyme reactivity by trimanganese hexakis(3,5-diisopropylsalicylate), [Mn(3)(3,5-DIPS)(6)] as well as dicopper tetrakis(3,5- diisopropylsalicylate, [Cu(II)(2)(3,5-DIPS)(4)] as a mechanistic accounting for their pharmacological activities.Porcine heart disease was found to oxidize 114 muM reduced nicotinamide-adenine- dinucleotide-'(3)-phosphate (NADPH) with a corresponding reduction of an equivalent concentration of 2,6-dichlorophenolindophenol (DCPIP). As reported for Cu(II)(2) (3,5-DIPS)(4), addition of Mn(3)(3,5-DIPS)(6) to this reaction mixture decreased the reduction of DCPIP without significantly affecting the oxidation of NADPH. The concentration of Mn(3)(3,5-DIPS)(6) that produced a 50% decrease in DCPIP reduction (IC(50)) was found to be 5muM. Mechanistically, this inhibition of DCPIP reduction with ongoing NADPH oxidation by PHD was found to be due to the ability of Mn(3)(3,5-DIPS)(6) to serve as a catalytic electron acceptor for reduced PHD as had been reported for Cu(II)(2)(3,5-DIPS)(4). This catalytic decrease in reduction of DCPIP by Mn(3)(3,5-DIPS)(6) was enhanced by the presence of a large concentration of DCPIP and decreased by the presence of a large concentration of NADPH, consistent with what had been observed for the activity of Cu(II)(2)(3,5-DIPS)(4)Oxidation of NADPH by PHD in the presence of Mn(3)(3,5-DIPS)(6) and the absence of DCPIP was linearly related to the concentration of added Mn(3)(3,5-DIPS)(6) through the concentration range of 2.4 muM to 38muM with a 50% recovery of NADPH oxidation by PHD at a concentration of 6 muM Mn(3)(3,5-DIPS)(6)Conversion of [(3)H] L-Arginine to [(3)H] L-Citrulline by purified rat brain nitric oxide synthase (NOS) was decreased in a concentrated related fashion with the addition of Mn(3)(3,5-DIPS)(6) as well as Cu(II)(2)(3,5-DIPS)(4) which is an extention of results reported earlier for Cu(II)(2)(3,5-DIPS)(4). The concentration of these two compounds required to produce a 50% decrease in L-Citrulline synthesis by NOS, which may be due to down-regulation of NOS, were 0.1 mM and 8muM respectively, consistent with the relative potencies of these two complexes in preventing the reduction of Cytochrome c by NOS.It is concluded that Mn(3)(3,5-DIPS)(6), as has been reported for Cu(II)(2) (3,5-DIPS)(4) , serves as an electron acceptor in down-regulating PHD and both of these complexes down-regulate rat brain NOS reactivity. A decrease in NO synthesis in animal models of seizure and radiation injury may account for the anticonvulsant, radioprotectant, and radiorecovery activities of Mn(3)(3,5-DIPS)(6) and Cu(II)(2)(3,5-DIPS)(4).     

阳离子型高分子分散剂的制备及应用研究

通过自由基引发溶液聚合,以二甲基二烯丙基氯化铵（DMDAAC）为阳离子共聚单体,过硫酸钾（KPS）为引发剂,与羟乙基纤维素（HEC）共聚制得阳离子型高分子分散剂PHD,通过正交实验得到最优反应条件为：m（HEC）∶m（DMDAAC）=0.6∶10,引发剂w（KPS）=1%（以DMDAAC的质量计,以下同）,反应温度75℃,反应时间2h。用IR对产物进行了表征,将产品（PHD）应用到高岭土泥浆中,对其流动性能进行测试,并通过SEM对分散体系的微观形貌进行分析,结果表明,PHD对陶瓷用高岭土具有良好的分散效果。     

Nutritional anemia in nursing women in Costa Rica

It is reported the prevalence, magnitude and determinant factors of nutritional anaemia in a sample of nursing women (NW), collected during the National Nutrition Survey, of Costa Rica done in 1996. Nutritional anaemia was determinate through measurements of haemoglobin, and plasma ferritin, folates, cianocobalamin and retinol. Methodologies used were cianometahaemoglobin, solid phase immunoradiometric assay, solid phase radioimmunoassay and high-pressure liquid chromatography. WHO cut-off points were used. Anaemia was present in 22.1% of the women. Iron and folate deficiency were found in 48.7 and 84.2% NW, respectively. The magnitude of anaemia was mild and iron and folate deficiencies were severe. Vitamin B12 and A deficiencies were 5.3 and 4.9%, respectively and did not represent a public health problem in this group. Prevalent deficiency was mixed (iron and folates, 46.6%) followed by exclusive folates deficiency (32%). Anaemia was caused by a combined deficiency of iron and folates (61.1%) and most iron deficiencies were accompanied by folates (92%). The logistic regression analysis demonstrated that low socio-economic level of NW and their families was the principal factor determining the appearance of nutritional anaemia, and educative interventions to the mother are possibly recommended. In conclusion anaemia in NW is a moderate health problem of nutritional type, that is more important when severe folates and iron deficiencies are present in Costa Rica. These problems have remained constant throughout the last three decades; although recently, possibly an improvement has occurred because the prevalence of neural tube defects in the infant population has reduced, maybe due to food iron and folates fortification public health policies implementation.     

氨基树脂制备聚脲多元醇

将三聚氰胺进行改性制备氨基树脂即多元胺溶液,再将氨基树脂用于制备聚脲多元醇(PHD),并对其合成原理、合成工艺及其关键影响因素等进行了研究。用红外光谱、NDJ-1型旋转式黏度计、LG10-24型离心机、透射电镜(TEM)、热重分析(TG)等对聚脲分散体进行测试与表征。     

A critical assessment of the secondary structure {alpha}-helices and their termini in proteins

Secondary structure prediction from amino acid sequence is akey component of protein structure prediction, with currentaccuracy at ~75%. We analysed two state-of-the-art secondarystructure prediction methods, PHD and JPRED, comparing predictionswith secondary structure assigned by the algorithms DSSP andSTRIDE. The specific focus of our study was