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  • A simple strategy to differentiate between H+- and Na+-transporting NADH:quinone oxidoreductases
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-15
    Yulia V. Bertsova; Alexander A. Baykov; Alexander V. Bogachev

    We describe here a simple strategy to characterize transport specificity of NADH:quinone oxidoreductases, using Na+-translocating (NQR) and H+-translocating (NDH-1) enzymes of the soil bacterium Azotobacter vinelandii as the models. Submillimolar concentrations of Na+ and Li+ increased the rate of deaminoNADH oxidation by the inverted membrane vesicles prepared from the NDH-1-deficient strain. The vesicles generated carbonyl cyanide m-chlorophenyl hydrazone (CCCP)-resistant electric potential difference and CCCP-stimulated pH difference (alkalinization inside) in the presence of Na+. These findings testified a primary Na+-pump function of A. vinelandii NQR. Furthermore, ΔpH measurements with fluorescent probes (acridine orange and pyranine) demonstrated that A. vinelandii NQR cannot transport H+ under various conditions. The opposite results obtained in similar measurements with the vesicles prepared from the NQR-deficient strain indicated a primary H+-pump function of NDH-1. Based on our findings, we propose a package of simple experiments that are necessary and sufficient to unequivocally identify the pumping specificity of a bacterial Na+ or H+ transporter. The NQR-deficient strain, but not the NDH-1-deficient one, exhibited impaired growth characteristics under diazotrophic condition, suggesting a role for the Na+ transport in nitrogen fixation by A. vinelandii.

    更新日期:2020-01-15
  • Reaction of human peroxidasin 1 compound I and compound II with one-electron donors
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-15
    Benjamin Sevcnikar; Martina Paumann-Page; Stefan Hofbauer; Vera Pfanzagl; Paul G. Furtmüller; Christian Obinger

    Human peroxidasin 1 (hsPxd01) is a homotrimeric multidomain heme peroxidase embedded in the extracellular matrix. It catalyses the two-electron oxidation of bromide by hydrogen peroxide to hypobromous acid which mediates the formation of essential sulfilimine cross-links between methionine and hydroxylysine residues in collagen IV. This confers critical structural reinforcement to the extracellular matrix. This study presents for the first time transient kinetic measurements of the reactivity of hsPxd01 compound I and compound II with the endogenous one-electron donors nitrite, ascorbate, urate, tyrosine and serotonin using the sequential stopped-flow technique. At pH 7.4 and 25 °C compound I of hsPxd01 is reduced to compound II with apparent second-order rate constants ranging from (1.9 ± 0.1) × 104 M−1 s−1 (urate) to (4.8 ± 0.1) × 105 M−1 s−1 (serotonin). Reduction of compound II to the ferric state occurs with apparent second-order rate constants ranging from (4.3 ± 0.2) × 102 M−1 s−1 (tyrosine) to (7.7 ± 0.1) × 103 M−1 s−1 (serotonin). The relatively fast rates of compound I reduction suggest that these reactions may take place in vivo and modulate bromide oxidation due to formation of compound II. Urate is shown to inhibit the bromination activity of hsPxd01, whereas nitrite stimulates the formation of hypobromous acid. The results are discussed with respect to known kinetic data of homologous mammalian peroxidases and to the physiological role of human peroxidasin 1.

    更新日期:2020-01-15
  • New variants of AADC deficiency expand the knowledge of enzymatic phenotypes
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-15
    Riccardo Montioli; Giovanni Bisello; Mirco Dindo; Giada Rossignoli; Carla Borri Voltattorni; Mariarita Bertoldi

    AADC deficiency is a rare genetic disease caused by mutations in the gene of aromatic amino acid decarboxylase, the pyridoxal 5′-phosphate dependent enzyme responsible for the synthesis of dopamine and serotonin. Here, following a biochemical approach together with an in silico bioinformatic analysis, we present a structural and functional characterization of 13 new variants of AADC. The amino acid substitutions are spread over the entire protein from the N-terminal (V60A), to its loop1 (H70Y and F77L), to the large domain (G96R) and its various motifs, i.e. loop2 (A110E), or a core β-barrel either on the surface (P210L, F251S and E283A) or in a more hydrophobic milieu (L222P, F237S and W267R) or loop3 (L353P), and to the C-terminal domain (R453C). Results show that the β-barrel variants exhibit a low solubility and those belonging to the surface tend to aggregate in their apo form, leading to the identification of a new enzymatic phenotype for AADC deficiency. Moreover, five variants of residues belonging to the large interface of AADC (V60A, G96R, A110E, L353P and R453C) are characterized by a decreased catalytic efficiency. The remaining ones (H70Y and F77L) present features typical of apo-to-holo impaired transition. Thus, defects in catalysis or in the acquirement of the correct holo structure are due not only to specific local domain effects but also to long-range effects at either the protein surface or the subunit interface. Altogether, the new characterized enzymatic phenotypes represent a further step in the elucidation of the molecular basis for the disease.

    更新日期:2020-01-15
  • Interaction of Sp1 and APP promoter elucidates a mechanism for Pb2+ caused neurodegeneration
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-13
    Qi Gao; Ziwen Dai; Shiqing Zhang; Yuqiang Fang; Kin Lam Ken Yung; Pik Kwan Lo; King Wai Chiu Lai

    A ubiquitously expressed transcription factor, specificity protein 1 (Sp1), interacts with the amyloid precursor protein (APP) promoter and likely mediates APP expression. Promoter-interaction strengths variably regulate the level of APP expression. Here, we examined the interactions of finger 3 of Sp1 (Sp1–f3) with a DNA fragment containing the APP promoter in different ionic solutions using atomic force microscope (AFM) spectroscopy. Sp1–f3 molecules immobilized on an Si substrate were bound to the APP promoter, which was linked to the AFM tips via covalent bonds. The interactions were strongly influenced by Pb2+, considering that substituting Zn2+ with Pb2+ increased the binding affinity of Sp1 for the APP promoter. The results revealed that the enhanced interaction force facilitated APP expression and that APP overexpression could confer a high-risk for disease incidence. An increased interaction force between Sp1–f3 and the APP promoter in Pb2+ solutions was consistent with a lower binding free energy, as determined by computer-assisted analysis. The impact of Pb2+ on cell morphology and related mechanical properties were also detected by AFM. The overexpression of APP caused by the enhanced interaction force triggered actin reorganization and further resulted in an increased Young's modulus and viscosity. The correlation with single-force measurements revealed that altered cellular activities could result from alternation of Sp1–APP promoter interaction. Our AFM findings offer a new approach in understanding Pb2+ associated neurodegeneration.

    更新日期:2020-01-14
  • Influence of short peptides with aromatic amino acid residues on aggregation properties of serum amyloid A and its fragments
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-13
    Sandra Skibiszewska; Szymon Żaczek; Agnieszka Dybala-Defratyka; Katarzyna Jędrzejewska; Elżbieta Jankowska
    更新日期:2020-01-13
  • Knockdown of TUG 1 suppresses hypoxia-induced apoptosis of cardiomyocytes by up-regulating miR-133a
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-09
    Han Yang; Xue He; Chao Wang; Lingyan Zhang; Jinsong Yu; Kai Wang

    The roles of lncRNAs in cardiac diseases have received increasing attention. The biological role of taurine up-regulated gene 1 (TUG 1) in hypoxia-induced damage of cardiomyocytes is still poorly defined. Our study aimed to investigate the function of TUG 1 in hypoxia-treated cardiomyocytes and the possible underlying mechanism. TUG 1 and miR-133a expression levels in hypoxia-cultured human AC16 cardiomyocytes were examined by RT-qPCR. The role of TUG 1 and miR-133a in cell proliferation was assayed by CCK-8 assay. AC16 cell apoptosis was assessed by flow cytometry and caspase-3/7 activity assay. The expression levels of cleaved poly ADP ribose polymerase (PARP) and cleaved caspase-3 were evaluated by Western blot analysis. We found that TUG 1 expression was elevated, while miR-133a expression was reduced under hypoxic condition in AC16 cells. TUG 1 silencing and miR-133a restoration relieved hypoxia-induced reduction of proliferation as well as repressed hypoxia-induced AC16 cell apoptosis, while the opposite effects were observed after TUG 1 overexpression and miR-133a inhibition. We identified that TUG 1 acted as a competing endogenous RNA to suppress miR-133a expression. Mechanistically, miR-133a overturned TUG 1 overexpression-mediated inhibition of proliferation and promotion on apoptosis in AC16 cells under hypoxic condition. Conversely, inhibition of miR-133a abolished TUG 1 knockdown-mediated promotion of proliferative ability and repression of apoptosis in hypoxia-cultured AC16 cells. In conclusion, TUG 1 knockdown relieved hypoxia-induced reduction of proliferation and repressed hypoxia-induced AC16 cell apoptosis by up-regulating miR-133a expression.

    更新日期:2020-01-09
  • Highly-expressed micoRNA-21 in adipose derived stem cell exosomes can enhance the migration and proliferation of the HaCaT cells by increasing the MMP-9 expression through the PI3K/AKT pathway
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-09
    Chen Yang; Liang Luo; Xiaozhi Bai; Kuo Shen; Kaituo Liu; Jing Wang; Dahai Hu

    Objective Wound healing remains a challenge in burns and trauma fields. Adipose derived stem cells exosomes (AD-exos) had been confirmed to have a positive effect on the wound healing and the migration and proliferation of keratinocyte. However, the mechanism of the AD-exos is still unclear. The objective of this article is to observe the function of the miR-21 expressed in the adipose AD-exos and the effect on migration and proliferation of the HaCaT cells. Materials and methods The full layer dermal wound of BALb/c mouse was used to observe the vitro effect of the AD-exos and detect the expression of miR-21.The co-culture systems were established by transwell plates for observing the migration, proliferation, apoptosis rate, and detecting the RNA, and protein expression in different treated groups. miR-21 plasmid was used to over-express miR-21 by transfection of HaCaT cells. GW4869 was used to inhibit the secreting of exosomes from ADSCs. Results The results showed that both ADSCs and the AD-exos could improve the wound healing process of BALb/c mouse full layer skin wound at a similar level, especially at 7th day post surgery when compared to the control group (p < 0.01) and the highly expressed miR-21 was detected (p < 0.01 compared with control group and p < 0.001 compared to other microRNAs) in the treated groups at the same time point. AD-exos could obviously enhance the migration and proliferation of the HaCaT cells (p < 0.01), and fall back to the same level when the exosomes inhibitor--GW4869 was added compared with control group (p > 0.05). Over-expressed miR-21 could also significantly improve the migration and proliferation of HaCaT cells. But both AD-exos and miR-21 had no significantly effect on the apoptosis rate of HaCaT cells (p > 0.05 compared with each other). Over-expression of miR-21 plasmid could decrease the TGF-βI protein level (p < 0.001 vs. control group) in HaCaT cells while TGF-βI protein level increased again when antagomiR-21 was added in (p < 0.01 vs. empty plasmid group, p < 0.001 vs. miR-21 plasmid group). MiR-21 expression of HaCaT cells could be increased by the transfect ion of miR-21 plasmid (p < 0.001 vs. empty plasmid group) and be decreased by antagomiR-21 (p < 0.01 vs. empty plasmid group, p < 0.001 vs. miR-21 plasmid group). MiR-21 appeared to have influence on MMP-9 and TIMP-2 (p < 0.001 compared to control group and p < 0.001 compared to TGF-βI group) but not MMP-2 and TIMP-1 (p > 0.05 compared to control group and TGF-βI group). These processes act through PI3K/AKT pathway. Conclusion This research provide the experimental evidence that the miR-21 was highly expressed in AD-exos and can significantly accelerate the wound healing process and enhance the migration and proliferation of the HaCaT cells. Over-expressed miR-21 can inhibit the TGF-βI expression and excess TGF-βI can also have negative feedback influence on miR-21. We have found a reliable evidence that these two factors can act on HaCaT cells by influencing MMP-2 and TIMP-1 protein expression through the PI3K/AKT signal pathway. These results may provide a provide potential perspectives on improving the wound healing.

    更新日期:2020-01-09
  • SIRT6 cooperates with SIRT5 to regulate bovine preadipocyte differentiation and lipid metabolism via the AMPKα signaling pathway
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-08
    Jieyun Hong; Chugang Mei; Sayed Haidar Abbas Raza; Rajwali Khan; Gong Cheng; Linsen Zan

    Preadipocyte differentiation and lipid synthesis are critical steps for intramuscular fat (IMF) deposition and lipid metabolism homeostasis. IMF content of beef not only determines the ratio of muscle to adipose, but also determines the beef quality, flavor, and sensory characteristics. Maintaining lipid metabolism homeostasis is the key means of preventing and treating diabetes, obesity, and other metabolic diseases. SIRT6, which is an ADP-ribosyltransferase and NAD+-dependent deacetylase of acetyl and long-chain fatty acyl groups, playing central roles in lipid and glucose metabolism, is closely related to the occurrence of diabetes and obesity caused by overnutrition and aging. This study was based on bovine preadipocyte differentiation and an obese mice model, and comprehensively used transcriptome sequencing (RNA-seq) and morphological identification methods to explore the effects of inhibition of SIRT6 on differentiation and lipid synthesis, and related molecular mechanisms. Additionally, the feedback synergistic regulation of SIRT5 and SIRT6 on differentiation and lipid deposition was analyzed. The results showed that in the differentiation process of bovine preadipocytes, inhibition of SIRT5 significantly promoted SIRT6 expression. In addition, SIRT6 inhibited bovine preadipocyte differentiation and lipid synthesis, cooperating with SIRT5 to decrease lipid deposition, and repressed cell cycle arrest of preadipocytes. Moreover, in vivo verification experiments also obtained consistent results. Furthermore, SIRT6 inhibited preadipocyte differentiation and lipid deposition by activating the adenosine monophosphate activated protein kinase alpha (AMPKα) pathway. The above results provided a novel approach for understanding the functions of SIRT6 in regulating bovine adipocyte differentiation and lipid metabolism, as well as a new target for the treatment of diabetes and obesity in a clinical setting.

    更新日期:2020-01-09
  • Effects of DBD air plasma treatment on the enhancement of black gram (Vigna mungo l.) seed germination and growth
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-07
    M. Billah; S.A. Sajib; N.C. Roy; M.M. Rashid; M.A. Reza; M.M. Hasan; M.R. Talukder

    Effects of black gram (vigna mungo L.cv. Barimash 3) seed treatments with 400 torr dielectric barrier discharge (DBD) air plasma on seed surface morphology, seed germination, seedling growth and antioxidant enzyme activities in the roots, shoots and leaves were investigated. The plasma discharge voltage, frequency, electrode spacing, gas temperature and power were 5kV, 4.5kHz, 60mm, 310K and 45W, respectively. The seeds were treated for the duration ranging from 20 to 180 s. Seed germination rate, seedling growth, total chlorophyll content, total soluble protein and sugar concentrations in the seedlings grown from the treated seeds were found to increase 13.67%, 37.13%, 37.26%,53.60% and 51.71%, respectively, with respect to control. This study reveals that the DBD air plasma was involved in the enhancement of nitrogen complex in the seed coat of black gram which upregulated the protein through nitrogen conversion that was ultimately responsible for the increased seed germination and seedling growth of black gram.

    更新日期:2020-01-07
  • Phenylglyoxal inhibition of the mitochondrial F1FO-ATPase activated by Mg2+ or by Ca2+ provides clues on the mitochondrial permeability transition pore
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-07
    Cristina Algieri; Fabiana Trombetti; Alessandra Pagliarani; Vittoria Ventrella; Salvatore Nesci
    更新日期:2020-01-07
  • Glycolytic oscillations and intracellular K+ concentration are strongly coupled in the yeast Saccharomyces cerevisiae
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-07
    Lars F. Olsen; Roberto P. Stock; L.A. Bagatolli

    We measured temporal oscillations of intracellular K+ concentration in yeast cells exhibiting glycolytic oscillations using fluorescence spectroscopy and microscopy methods. These oscillations showed the same period as those of glycolytic metabolites (NADH, ATP), indicating a strong coupling between them. We experimentally ruled out that oscillations originate in extra- or intracellular K+ fluxes and conclude that these oscillations arise from fluctuations in free and adsorbed states of K+ in the cell interior. Oscillations in K+ showed a strong dependence on ATP and the organization of the cell cytoskeleton. Our results challenge the widely held view that intracellular K+ predominantly exists in a free state. They can, however, be productively understood in terms of Gilbert Ling's Association-Induction hypothesis.

    更新日期:2020-01-07
  • Maintenance of CaV2.2 channel-current by PIP2 unveiled by neomycin in sympathetic neurons of the rat
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-07
    Hector Castro; Karina Bermeo; Isabel Arenas; David E. Garcia

    Membrane lipids are key determinants in the regulation of voltage-gated ion channels. Phosphatidylinositol 4,5-bisphosphate (PIP2), a native membrane phospholipid, has been involved in the maintenance of the current amplitude and in the voltage-independent regulation of voltage-gated calcium channels (VGCC). However, the nature of the PIP2 regulation on VGCC has not been fully elucidated. This work aimed to investigate whether the interacting PIP2 electrostatic charges may account for maintaining the current amplitude of CaV2.2 channels. Furthermore, we tested whether charge shielding of PIP2 mimics the voltage-independent inhibition induced by M1 muscarinic acetylcholine receptor (M1R) activation. Therefore, neomycin, a polycation that has been shown to block electrostatic interactions of PIP2, was intracellularly dialyzed in superior cervical ganglion (SCG) neurons of the rat. Consistently, neomycin time-dependently diminished the calcium current amplitude letting the channel exhibit the hallmarks of the voltage-independent regulation. These results support that interacting PIP2 charges not only underly the maintenance of the channel-current but also that charge screening of PIP2 by itself unveils the voltage-independent features of CaV2.2 channels in SCG neurons.

    更新日期:2020-01-07
  • Structural and kinetic features of aldehyde dehydrogenase 1A (ALDH1A) subfamily members, cancer stem cell markers active in retinoic acid biosynthesis
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-07
    Raquel Pequerul; Javier Vera; Joan Giménez-Dejoz; Isidro Crespo; Joan Coines; Sergio Porté; Carme Rovira; Xavier Parés; Jaume Farrés

    Aldehyde dehydrogenases catalyze the NAD(P)+-dependent oxidation of aldehydes to their corresponding carboxylic acids. The three-dimensional structures of the human ALDH1A enzymes were recently obtained, while a complete kinetic characterization of them, under the same experimental conditions, is lacking. We show that the three enzymes, ALDH1A1, ALDH1A2 and ALDH1A3, have similar topologies, although with decreasing volumes in their substrate-binding pockets. The activity with aliphatic and retinoid aldehydes was characterized side-by-side, using an improved HPLC-based method for retinaldehyde. Hexanal was the most efficient substrate. ALDH1A1 displayed lower Km values with hexanal, trans-2-hexenal and citral, compared to ALDH1A2 and ALDH1A3. ALDH1A2 was the best enzyme for the lipid peroxidation product, 4-hydroxy-2-nonenal, in terms of kcat/Km. The catalytic efficiency towards all-trans and 9-cis-retinaldehyde was in general lower than for alkanals and alkenals. ALDH1A2 and ALDH1A3 showed higher catalytic efficiency for all-trans-retinaldehyde. The lower specificity of ALDH1A3 for 9-cis-retinaldehyde against the all-trans- isomer might be related to the smaller volume of its substrate-binding pocket. Magnesium inhibited ALDH1A1 and ALDH1A2, while it activated ALDH1A3, which is consistent with cofactor dissociation being the rate-limiting step for ALDH1A1 and ALDH1A2, and deacylation for ALDH1A3, with hexanal as a substrate. We mutated both ALDH1A1 (L114P) and ALDH1A2 (N475G, A476V, L477V, N478S) to mimic their counterpart substrate-binding pockets. ALDH1A1 specificity for citral was traced to residue 114 and to residues 458 to 461. Regarding retinaldehyde, the mutants did not show significant differences with their respective wild-type forms, suggesting that the mutated residues are not critical for retinoid specificity.

    更新日期:2020-01-07
  • Oxidative stress in pregnancy complicated by preeclampsia
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-03
    Sindy San Juan-Reyes; Leobardo Manuel Gómez-Oliván; Hariz Islas-Flores; Octavio Dublán-García

    Preeclampsia is a multisystemic disorder of pregnancy that causes perinatal morbidity and mortality. Studies published in the last decade have contributed to a better understanding of physiopathogenesis through key mechanisms involved, such as altered immune response, endothelial dysfunction, oxidative stress and systemic inflammatory response, as well as genetic susceptibility. Oxidative stress (OS) plays an important role in the development of preeclampsia, since it alters placental remodeling and placental vascular endothelial dysfunction, resulting in an ischemia/reperfusion injury with an increase in xanthine oxidase activity that produces high levels of reactive oxygen species (ROS). ROS can be generated through many pathways within cells, mitochondria, endoplasmic reticulum (ER) and enzymes such as NADPH oxidase are the most important sources, causing widespread and indiscriminate damage to cells and tissues, which leads to an intravascular inflammatory response and maternal systemic endothelial dysfunction characteristic of this prenatal syndrome. Therefore, the following review aims to identify the main risk factors and the role of OS as a pathophysiological mechanism in the development of preeclampsia.

    更新日期:2020-01-04
  • The GPR55 antagonist CID16020046 protects against ox-LDL-induced inflammation in human aortic endothelial cells (HAECs)
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-03
    Yaowen Wang; Wei Pan; Yan Wang; Yuehui Yin

    Atherosclerosis is a commonplace cardiovascular disease which affects most people in old age. While its causes are currently poorly understood, continuous study is being performed in order to elucidate both the pathogenesis and treatment of this insidious disease. Atherosclerosis is presently thought to be linked to several factors such as endothelial dysfunction, monocyte adhesion to the intima of the artery, and increased oxidative stress. Oxidized low-density lipoprotein (ox-LDL), colloquially known as the “bad cholesterol”, is known to play a critical role in the previously mentioned atherosclerotic processes. In this study, our goal was to elucidate the role of the lysophospholipid receptor G protein-coupled receptor 55 (GPR55) and its antagonist, the cannabinoid CID16020046, in endothelial dysfunction. While their existence and especially their role in atherosclerosis has only semi-recently been elucidated, a growing body of research has begun to link their interaction to antiatherosclerosis. In our research, we found CID16020046 to have distinct atheroprotective properties such as anti-inflammation, antioxidant, and inhibition of monocyte attachment to endothelial cells. While there was previously a small body of research regarding the potential of cannabinoids to treat or prevent atherosclerosis, studies on the treatment potential of CID16020046 were even fewer. Thus, this study is one of the first to explore the effects of cannabinoids in atherosclerosis. Our findings in the present study provide a strong argument for the use of CID16020046 in the treatment of atherosclerosis as well as a basis for further experimentation using cannabinoids as therapy against atherosclerosis.

    更新日期:2020-01-04
  • Nanosecond pulsed current under plasma-producing conditions induces morphological alterations and stress fiber formation in human fibrosarcoma HT-1080 cells
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-03
    Chia-Hsing Chang; Ken-ichi Yano; Takehiko Sato

    Cold atmospheric plasma (CAP) is a promising means for various biomedical applications, including cancer therapy. Although the biological action of CAP is considered to be brought about by synergistic effects of reactive species and electrical factors of CAP, limited information is currently available on the contribution of electrical factors to CAP-induced cell responses. We have previously demonstrated that nanosecond pulsed current (nsPC) under CAP-producing conditions significantly promoted the motility of human HT-1080 cells. In this study, we explored the effects of nsPC on cell morphology associated with cell motility. We observed that nsPC stimulation caused extended cell shape, membrane protrusion formation, and increased cell surface area, but not cell death induction. nsPC stimulation also caused elevated intracellular ROS and Ca2+. HT-1080 cells can undergo two modes of cell motility, namely mesenchymal and ameboid motility, and we found that morphological features of mesenchymal motility was partly shared with nsPC-stimulated cells. Furthermore, nsPC-stimulated cells had extended stress fibers composed of filamentous actin. Taken together, this study provides a novel insight into the electrical aspect of CAP action, and we speculate that nsPC activates a certain mechanism involving intracellular signaling for stress fiber formation, leading to altered cell morphology and increased cell motility.

    更新日期:2020-01-04
  • HOTAIRM1 knockdown enhances cytarabine-induced cytotoxicity by suppression of glycolysis through the Wnt/β-catenin/PFKP pathway in acute myeloid leukemia cells
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2020-01-02
    Li Chen; Ning Hu; Chao Wang; Hongmian Zhao

    HOX antisense intergenic RNA myeloid 1 (HOTAIRM1) is a long non-coding RNA (lncRNA) that is highly specific for maturing myeloid cells. Dysregulation of HOTAIRM1 has been found to be implicated in the development of acute myeloid leukemia (AML). However, the role of HOTAIRM1 in the drug resistance in AML remains unknown. The present study aimed to investigate the effect of HOTAIRM1 on the cytarabine (Ara-C) resistance in leukemia cell lines and to explore the underlying mechanism. The leukemia cell lines, HL60 and THP-1, were transfected with HOTAIRM1 specific siRNA (si-HOTAIRM1) or control siRNA (si-ctrl), and then treated with Ara-C for 48 h. The mRNA levels of HOTAIRM1 and platelet-type phosphofructokinase (PFKP) were measured using RT-PCR. Cell viability was evaluated by MTT assay. Apoptosis was determined using flow cytometry and caspase-3/7 activity assay. Glycolysis was evaluated by determining the glucose consumption and lactate production. To activate the Wnt/β-catenin signaling pathway, HL60 and THP-1 cells were transfected with β-catenin overexpressing plasmid (pcDNA-β-catenin). Protein levels of PFKP, β-catenin, and c-Myc were examined using western blot analysis. The results showed that knockdown of HOTAIRM1 enhanced Ara-C-induced reduction of cell viability and increase of cell apoptosis. HOTAIRM1 knockdown suppressed the glucose consumption and lactate production, as well as the expression of PFKP in AML cells. Besides, HOTAIRM1 knockdown resulted in a significant inhibitory effect on the Wnt/β-catenin pathway. Furthermore, activating Wnt/β-catenin pathway mitigated the effects of HOTAIRM1 knockdown on glycolysis and Ara-C cytotoxicity in AML cells. In conclusion, knockdown of HOTAIRM1 enhanced Ara-C cytotoxicity through regulating the Wnt/β-catenin/PFKP signaling pathway. These findings suggested that HOTAIRM1 might be a therapeutic target for overcoming the Ara-C resistance in AML.

    更新日期:2020-01-02
  • Syringin protects against colitis by ameliorating inflammation
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-30
    Haihua Zhang; Haijun Gu; Qinghui Jia; Yanqing Zhao; Hongqiang Li; Shurui Shen; Xin Liu; Guisheng Wang; Qiumei Shi

    Inflammatory bowel disease (IBD) is a chronic inflammatory condition with high incidence. Syringin exhibits multiple pharmacological properties, including anti-inflammatory effects. However, the effect of syringin on inflammation of IBD is still unclear. Here, the dextran sulfate sodium (DSS)-induced colitis model was established in vivo. Rat intestinal epithelium IEC6 cells were treated with lipopolysaccharide (LPS) in vitro. Syringin inhibited DSS or LPS-induced overproduction of proinflammatory cytokines (IL-1β, IL-6, TNF-α) and proinflammatory substances (iNOS, COX-2). Moreover, syringin inactivated the proinflammatory NF-κB p65 pathway by decreasing IκBα phosphorylation at Ser 32. The activation of antioxidant Nrf2 signaling pathway was promoted by syringin. Additionally, LPS-induced inflammation in IEC6 cells was also suppressed by NF-κB inhibitor PDTC and Nrf2 activator RTA408. The anti-inflammatory effects of syringin were comparable to these two reagents. Taken together, our results suggest that syringin shows protective effects on intestinal inflammation through inhibiting NF-κB, while activating Nrf2 signaling pathway in colitis.

    更新日期:2019-12-30
  • Electron transfer and conformational transitions of cytochrome c are modulated by the same dynamical features
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-30
    Santiago Oviedo-Rouco; Juan Manuel Perez-Bertoldi; Celicia Spedalieri; María A. Castro; Florencia Tomasina; Verónica Tortora; Rafael Radi; Daniel H. Murgida
    更新日期:2019-12-30
  • RNA-seq reveal role of bovine TORC2 in the regulation of adipogenesis
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-29
    Rajwali Khan; Sayed Haidar Abbas Raza; Zainaguli Junjvlieke; Hongbao Wang; Gong Cheng; Stephen B. Smith; Jiang Zhongliang; Anning Li; Linsen Zan

    Low intramuscular adipose tissue (marbling) continues to be challenge for improving beef quality in Chinese cattle. Highly marbled meat is very desirable; hence, methods to increase IMF content have become a key aspect of improving meat quality. Therefore, research on the mechanism of adipogenesis provides invaluable information for the improvement of meat quality. This study investigated the effect of TORC2 and its underlying mechanism on lipid metabolism in bovine adipocytes. The TORC2 gene was downregulated in bovine adipocytes by siRNA, and RNA sequencing was performed. Downregulation of TORC2 negatively affected bovine adipocyte differentiation. In addition, a total of 577 DEGs were found, containing 146 up-regulated and 376 down-regulated genes. KEGG pathway analysis revealed that the DEGs were linked with neuroactive ligand-receptor interaction pathway, calcium signaling pathway, cAMP pathway, chemokine signaling pathway and Wnt signaling pathway. Gene Ontology (GO) term analysis of the DEGs showed that down-regulation of TORC2 gene significantly suppressed the genes regulating important GO terms of adipogenesis-related processes in bovine adipocytes, especially regulation of biological activity, regulation of primary metabolic process, regulation of multicellular organismal process, cell adhesion, lipid metabolic process, secretion, chemical homeostasis, regulation of transport, cell-cell signaling, cAMP metabolic process, cellular calcium ion homeostasis, fat cell differentiation, and cell maturation. In conclusion, our results suggest that TORC2 at least in part regulates lipid metabolism in bovine adipocytes. The results of this study provide a basis for studying the function and molecular mechanism of the TORC2 gene in regulating adipogenesis.

    更新日期:2019-12-29
  • The effects of iron overload on mitochondrial function, mitochondrial dynamics, and ferroptosis in cardiomyocytes
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-28
    Natticha Sumneang; Natthaphat Siri-Angkul; Sirinart Kumfu; Siriporn C. Chattipakorn; Nipon Chattipakorn
    更新日期:2019-12-29
  • Characterisation of the non-oxidative degradation pathway of dehydroascorbic acid in slightly acidic aqueous solution
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-26
    Rebecca A. Dewhirst; Lorna Murray; C. Logan Mackay; Ian H. Sadler; Stephen C. Fry
    更新日期:2019-12-27
  • 15-Keto prostaglandin E2 induces heme oxygenase-1 expression through activation of Nrf2 in human colon epithelial CCD 841 CoN cells
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-24
    Jeong-Eun Lee; Xiancai Zhong; Ja-Young Lee; Young-Joon Surh; Hye-Kyung Na

    Prostaglandin E2 (PGE2) plays a key role in inflammation-associated carcinogenesis. NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH) catalyzes the oxidation of the 15(S)-hydroxyl group of PGE2 to generate 15-keto PGE2. 15-PGDH has been known as a tumor suppressor in various malignancies including colon cancer. However, the molecular mechanisms underlying the tumor-suppressive function of 15-PGDH remain largely unresolved. In this study, we found that 15-keto PGE2 upregulated the expression of heme oxygenase-1 (HO-1), a representative antioxidative and anti-inflammatory enzyme, at both transcriptional and translational levels, in human colon epithelial CCD 841 CoN cells. A redox-sensitive transcription factor, NF-E2-related factor (Nrf2) plays a critical role in the regulation of HO-1 and other cytoprotective proteins. 15-Keto PGE2 induced translocation of Nrf2 into the nucleus and antioxidant response element-driven luciferase activity. Furthermore, the silencing of the Nrf2 gene abolished 15-keto PGE2-induced HO-1 expression in CCD 841 CoN cells. 15-Keto PGE2 activated AKT signaling, and the pharmacological AKT inhibitor, LY294002 suppressed the 15-keto PGE2-induced HO-1 expression. 15-Keto PGE2 generates the reactive oxygen species which is suppressed by the general antioxidant N-acetyl-l-cysteine. N-acetyl-l-cysteine treatment attenuated the 15-keto PGE2-induced phosphorylation of GSK3β, transcriptional activity of Nrf2, and subsequently HO-1 expression. However, 13,14-dihydro-15-keto PGE2 lacking the α,β-unsaturated carbonyl moiety failed to induce intracellular production of reactive oxygen species, HO-1 expression and nuclear translocation of Nrf2. In conclusion, 15-keto PGE2 induces HO-1 expression through Nrf2 activation in human colon epithelial cells.

    更新日期:2019-12-25
  • Dynasore potentiates c-Met inhibitors against hepatocellular carcinoma through destabilizing c-Met
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-24
    Mohamed Y. Zaky; Xiuxiu Liu; Taishu Wang; Shanshan Wang; Fang Liu; Duchuang Wang; Yueguang Wu; Yang Zhang; Dong Guo; Qianhui Sun; Qiong Li; Jinrui Zhang; Yingqiu Zhang; Weijie Dong; Zhenhua Liu; Shuyan Liu; Han Liu

    c-Met receptor is frequently overexpressed in hepatocellular carcinoma and thus considered as an attractive target for pharmacological intervention with small molecule tyrosine kinase inhibitors. Albeit with the development of multiple c-Met inhibitors, none reached clinical application in the treatment of hepatoma so far. To improve the efficacy of c-Met inhibitors towards hepatocellular carcinoma, we investigated the combined effects of the dynamin inhibitor dynasore with several c-Met inhibitors, including tivantinib, PHA-665752, and JNJ-38877605. We provide several lines of evidence that dynasore enhanced the inhibitory effects of these inhibitors on hepatoma cell proliferation and migration, accompanied with increased cell cycle arrest and apoptosis. Mechanically, the combinatorial treatments decreased c-Met levels and hence markedly disrupted downstream signaling, as revealed by the dramatically declined phosphorylation of AKT and MEK. Taken together, our findings demonstrate that the candidate agent dynasore potentiated the inhibitory effects of c-Met inhibitors against hepatoma cells and will shed light on the development of novel therapeutic strategies to target c-Met in the clinical management of hepatocellular carcinoma patients.

    更新日期:2019-12-25
  • Altered dynamics in the circadian oscillation of clock genes in serum-shocked NIH-3T3 cells by the treatment of GYY4137 or AOAA
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-24
    Maria Romerowicz-Misielak; Kozioł Katarzyna; Nowak Sławomir; Lewińska Anna; Koziorowski Marek

    Background and purpose Several members of the core clock mechanism are equipped with a Per-Arnt-Sim (PAS) domain through which they can bind haem [Fe(II)]. Haem is a ligand for the orphan receptors REV-ERBα/β (NR1D1/2), which regulate circadian rhythm and metabolism. The ability to bind haem sensitises these clock components to the action of small molecule gases, including NO, CO and H2S. Studies conducted with European hamsters revealed that during winter sleep, key clock genes stop oscillating. At the same time, H2S, when administered at subtoxic concentrations, can induce a hypometabolic state in the cell. We suppose that core clock components, including the nuclear receptors REV-ERBs, neuronal PAS domain protein 2 (nPAS2) and PER2, can be H2S targets. The general objective of this study was to investigate the effect of the H2S system on the expression profile of the core clock genes in cells in vitro. Experimental approach We analysed the expression of Per1, Per2, Per3, Bmal1, Cry1, Cry2, Nr1d1, Nfil-3 and Dbp messenger RNA (mRNA) in serum-shocked NIH-3T3 cells treated with a slow-releasing H2S donor (GYY4137) or the cystathionine beta-synthase (CBS) inhibitor (AOAA) cultured under constant darkness and collected during 3 days in 3 h interval. Key results and conclusions and implications We found that pharmacological CBS inhibition increased the general expression and dynamics of several clock genes. On the other hand, increased H2S decreased Per2 expression. These data suggest that CBS can affect circadian clock and effect on clock-controlled transcription output.

    更新日期:2019-12-25
  • Teneligliptin prevents doxorubicin-induced inflammation and apoptosis in H9c2 cells
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-24
    Wen Peng; Dan Rao; Meng Zhang; Yuanyuan Shi; Jing Wu; Guqiao Nie; Qinghua Xia

    Doxorubicin is a common chemotherapy treatment with numerous negative ramifications of use such as nephropathy and radiation-induced cardiotoxicity. Doxorubicin has been shown to cause overexpression of proinflammatory cytokines including MCP-1 and IL-1β via activation of the NF-κB pathway. Furthermore, apoptosis marked by dysregulation of the Bax/Bcl-2 ratio and oxidative stress and the production of reactive oxygen species (ROS) are also exacerbated by doxorubicin administration. Teneligliptin is part of the wider dipeptidyl peptidase-4 (DPP-4) inhibitor family which has until recently been almost exclusively used to treat type 2 diabetes mellitus. DPP-4 inhibitors such as teneligliptin control the overexpression of glucagon-like peptidase 1 (GLP-1) which has the downstream effects of general insulin resistance and high blood sugar levels. Our findings indicate a significant protective effect of teneligliptin against the aftereffects of doxorubicin as a chemotherapy treatment. This protective effect includes but is not limited to the reduction of inflammation and the mitigation of dysregulated apoptosis, as evidenced by reduced expression of IL-1β and MCP-1, inhibition of NF-κB activation, and improvement of the Bax/Bcl-2 ratio. The aim of the present study was to establish teneligliptin as a potentially useful agent for the treatment of radiation-induced cardiotoxicity, and our findings support this notion.

    更新日期:2019-12-25
  • Identification and characterization of ChlreSEX4, a novel glucan phosphatase from Chlamydomonas reinhardtii green alga
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-23
    Julieta B. Carrillo; Florencia Torresi; Luisina L. Morales; Micaela Ricordi; Diego F. Gomez-Casati; Maria V. Busi; Mariana Martín
    更新日期:2019-12-23
  • The thioredoxin redox potential and redox charge are surrogate measures for flux in the thioredoxin system
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-23
    Letrisha Padayachee; Johann M. Rohwer; Ché S. Pillay

    The thioredoxin system plays a central role in intracellular redox regulation and its dysregulation is associated with a number of pathologies. However, the connectivity within this system poses a significant challenge for quantification and consequently several disparate measures have been used to characterize the system. For in vitro studies, the thioredoxin system flux has been measured by NADPH oxidation while the thioredoxin redox state has been used to estimate the activity of the system in vivo. The connection between these measures has been obscure although substrate saturation in the thioredoxin system results from the saturation of the thioredoxin redox cycle. We used computational modeling and in vitro kinetic assays to clarify the relationship between flux and the current in vivo measures of the thioredoxin system together with a novel measure, the thioredoxin redox charge (reduced thioredoxin/total thioredoxin). Our results revealed that the thioredoxin redox potential and redox charge closely tracked flux perturbations showing that these indices could be used as surrogate measures of the flux in vivo and, provide a mechanistic explanation for the previously observed correlations between thioredoxin oxidation and certain pathologies. While we found no significant difference in the linear correlations obtained for the thioredoxin redox potential and redox charge with the flux, the redox charge may be preferred because it is bounded between zero and one and can be determined over a wider range of conditions allowing for quantitative flux comparisons between cell types and conditions.

    更新日期:2019-12-23
  • Antioxidant imbalance in the erythrocytes of Myotonic dystrophy Type 1 patients
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-20
    Filiz Koc; Gülüzar Atli; Sule Yildiz Menziletoglu; Sevgul Kose

    The most common form of muscular dystrophy is known as Myotonic dystrophy Type 1 (DM1) in adults. It was aimed to investigate the relationship between antioxidant imbalance and diaphragm thickness with pulmonary function test results in peripheral blood of Myotonic Dystrophy Type 1 patients. In the prospective study, 33 DM1 and 32 healthy control groups were taken after the ethics committee decision (2018–10529). Antioxidant defence system enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S-transferase (GST) and thiobarbituric acid reactive species (TBARS) levels were studied in blood samples. Also, muscular strength (MRC score), creatine kinase (CK) and diaphragm thicknesses were measured, and pulmonary function tests were performed. Among the studied parameters, TBARS levels and GPX, GR and GST activities in erythrocytes of DM1 patients showed a significant decrease in the range of 29–45% compared to the control group. MRC score, diaphragm thickness and inspiratory function test results at the end of inspiration and expiration were found lower though CK levels were higher in DM1 group. In the patient group, a positive correlation was found between antioxidant parameters (TBARS, CAT and GST) with diaphragm thicknesses and pulmonary function test though GPX showed a negative correlation with them. It was emphasized that the data obtained shows the harmful/pathogenic role of oxidative stress caused by free radicals in DM1, and also provide useful data for the treatment and processes of this disease.

    更新日期:2019-12-20
  • The functional diversity of structural disorder in plant proteins
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-20
    Alejandra A. Covarrubias; Paulette S. Romero-Pérez; Cesar L. Cuevas-Velazquez; David F. Rendón-Luna

    Structural disorder in proteins is a widespread feature distributed in all domains of life, particularly abundant in eukaryotes, including plants. In these organisms, intrinsically disordered proteins (IDPs) perform a diversity of functions, participating as integrators of signaling networks, in transcriptional and post-transcriptional regulation, in metabolic control, in stress responses and in the formation of biomolecular condensates by liquid-liquid phase separation. Their roles impact the perception, propagation and control of various developmental and environmental cues, as well as the plant defense against abiotic and biotic adverse conditions. In this review, we focus on primary processes to exhibit a broad perspective of the relevance of IDPs in plant cell functions. The information here might help to incorporate this knowledge into a more dynamic view of plant cells, as well as open more questions and promote new ideas for a better understanding of plant life.

    更新日期:2019-12-20
  • Biochemical characterization of mono ADP ribosyl transferase activity of human sirtuin SIRT7 and its regulation
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-13
    Nilabhra Mitra; Sanghamitra Dey

    SIRT7, an epigenetic modulator is related to several important cellular processes like aging, genome stability, and metabolism. The mechanistic and regulatory aspect of this enzyme needs to be explored. SIRT7 contains a conserved catalytic core with long flanking N- and C-terminal extensions. We find that the N terminus is involved in substrate binding, thus also in its dual enzyme activity i.e. deacetylation and ADP ribosylation. The C-terminus is not essential for its catalysis. Mutation of certain residues at the active site suggests that mono ADP-ribosylation and deacetylation are two distinct activities of SIRT7. In this study, we also find that the SIRT7 enzyme can specifically transfer a single moiety of ADP ribose on other nuclear proteins, with a preference for NAD+. For this, the ADPr transfer follows the enzymatic reaction mechanism. Nicotinamide and certain metal ions have a significant negative effect on this mono ADP ribosylation process. A comparison of these dual activities suggests SIRT7's preference for the mono ADPr transfer over its deacetylation of H3K18Ac. Mono ADP ribosylation in cells is often linked to different metabolic disease conditions. This kind of modification of transcription factors, p53 and ELK4 by SIRT7 may play a key role in maintaining the tumor phenotype. Thus, SIRT7 becomes an important therapeutic hotspot for drug designing against several diseases. Finally, we can also relate SIRT7 to the DNA repair process through ADP ribosylation of one of its key players, PARP1. Here, SIRT7 positively regulates the PARP1 activity.

    更新日期:2019-12-17
  • The mesa trail and the interacting heads motif of myosin II
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-13
    John L. Woodhead; Roger Craig

    Myosin II molecules in the thick filaments of striated muscle form a structure in which the heads interact with each other and fold back onto the tail. This structure, the “interacting heads motif” (IHM), provides a mechanistic basis for the auto-inhibition of myosin in relaxed thick filaments. Similar IHM interactions occur in single myosin molecules of smooth and nonmuscle cells in the switched-off state. In addition to the interaction between the two heads, which inhibits their activity, the IHM also contains an interaction between the motor domain of one head and the initial part (subfragment 2, S2) of the tail. This is thought to be a crucial anchoring interaction that holds the IHM in place on the thick filament. S2 appears to cross the head at a specific location within a broader region of the motor domain known as the myosin mesa. Here, we show that the positive and negative charge distribution in this part of the mesa is complementary to the charge distribution on S2. We have designated this the “mesa trail” owing to its linear path across the mesa. We studied the structural sequence alignment, the location of charged residues on the surface of myosin head atomic models, and the distribution of surface charge potential along the mesa trail in different types of myosin II and in different species. The charge distribution in both the mesa trail and the adjacent S2 is relatively conserved. This suggests a common basis for IHM formation across different myosin IIs, dependent on attraction between complementary charged patches on S2 and the myosin head. Conservation from mammals to insects suggests that the mesa trail/S2 interaction plays a key role in the inhibitory function of the IHM.

    更新日期:2019-12-17
  • 更新日期:2019-12-13
  • Increased intracellular Cl− concentration by activating FAK promotes airway epithelial BEAS-2B cells proliferation and wound healing
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-12
    Jia Wang; Jinhua Luo; Wenjie Huang; Caixia Liu; Dan Zeng; Huijun Liu; Xiangping Qu; Chi Liu; Yang Xiang; Xiaoqun Qin

    An increase in intracellular Cl− concentration ([Cl−]i) may be a general response of airway epithelial cells to various stimuli and may participate in some basic cellular functions. However, whether the basic functional activities of cells, such as proliferation and wound healing, are related to Cl− activities remains unclear. This study aimed to investigate the effects and potential mechanisms of [Cl−]i on the proliferation and wound healing ability of airway epithelial BEAS-2B cells. BEAS-2B cells were treated with four Cl− channel inhibitors (T16Ainh-A01, CFTRinh-172, CaCCinh-A01, and IAA-94), and the Cl− fluorescence probe N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide was used. Results showed that all Cl− channel inhibitors could increase [Cl−]i in BEAS-2B cells. The increased [Cl−]i induced by Cl− channel inhibitors or clamping [Cl−]i at high levels enhanced the phosphorylation of focal adhesion kinase (FAK) and subsequently promoted the proliferation and wound healing ability of BEAS-2B cells. By contrast, the FAK inhibitor PF573228 abrogated these effects induced by the increased [Cl−]i. FAK also activated the PI3K/AKT signaling pathway. In conclusion, increased [Cl−]i promotes the proliferation and wound healing ability of BEAS-2B cells by activating FAK to activate the PI3K/AKT signaling pathway. Intracellular Cl− may act as a signaling molecule to regulate the proliferation and wound healing ability of airway epithelial cells.

    更新日期:2019-12-13
  • Interaction of diazonamide a with tubulin
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-09
    Ruoli Bai, Zobeida Cruz-Monserrate, William Fenical, George R. Pettit, Ernest Hamel

    [3H]Diazonamide A ([3H]DZA), prepared from the natural product isolated from Diazona angulata, bound to tubulin in larger aberrant assembly products (>500 kDa by sizing HPLC) but not to the α,β-tubulin heterodimer. The binding reaction was rapid, but stoichiometry was low. Stoichiometry was enhanced up to 8-fold by preincubating the tubulin in the reaction mixture prior to adding the [3H]DZA. Although Mg2+ did not affect binding stoichiometry, the cation markedly increased the number of tubulin rings (diameter about 50 nm) observed by negative stain electron microscopy. Bound [3H]DZA did not dissociate from the tubulin oligomers despite extensive column chromatography but did dissociate in the presence of 8 M urea. With preincubated tubulin, a superstoichiometric amount of [3H]DZA appeared to bind to the tubulin oligomeric structures, consistent with observations that neither nonradiolabeled DZA nor DZA analogues inhibited binding of [3H]DZA to the tubulin oligomers. Only weak inhibition of binding was observed with multiple antimitotic compounds. In particular, no inhibition occurred with vinblastine, and the best inhibitors of those examined were dolastatin 10 and cryptophycin 1. We compared the aberrant assembly reaction induced by DZA to those induced by other antimitotic peptides and depsipeptides, in particular dolastatin 10, cryptophycin 1, and hemiasterlin, but the results obtained varied considerably in terms of requirements for maximal reactions, polymer morphology, and inhibitory effects observed with antimitotic compounds.

    更新日期:2019-12-11
  • Pou4f3 gene mutation promotes autophagy and apoptosis of cochlear hair cells in cisplatin-induced deafness mice
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-09
    Feilong Xu, Wenya Yan, Yanjie Cheng

    Pou4f3 plays an important role in the development of hair cells in the inner ear sensory epithelia. Autophagy is related to the auditory damage. However, the role and mechanism of Pou4f3 on drug-induced ototoxicity are incompletely understood. Hence, this study aimed to explore the effects of Pou4f3 on the apoptosis of cochlear hair cells (CHCs) and to explore whether autophagy was involved in this process. The cisplatin was used to produce a loss of CHCs to create mice models of deafness. The AAV vectors were delivered into the scala media through the lateral wall. Compared with the control mice, the cisplatin-treated mice exhibited significantly enhanced apoptosis and autophagy in the cochleae, accompanied by a notably decreased Pou4f3 levels. Both mutation and knockdown of Pou4f3 promoted the apoptosis- and autophagy-related protein levels, and enhanced the cisplatin-induced levels of apoptosis- and autophagy-related proteins. Furthermore, the autophagy activator rapamycin promoted the apoptosis and autophagy in the cochlea. In addition, the autophagy inhibitor 3-MA overturned the promoting effect of Pou4f3 knockdown on the apoptosis and autophagy. Collectively, in cisplatin-induced deafness mice, the Pou4f3 gene mutation facilitated apoptosis of cochlear hair cells, at least partially, through inducing autophagy.

    更新日期:2019-12-11
  • 更新日期:2019-12-07
  • WNK1 phosphorylation sites in TBC1D1 and TBC1D4 modulate cell surface expression of GLUT1
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-06
    Andreia F.A. Henriques, Paulo Matos, Ana Sofia Carvalho, Mikel Azkargorta, Felix Elortza, Rune Matthiesen, Peter Jordan

    Glucose uptake by mammalian cells is a key mechanism to maintain cell and tissue homeostasis and relies mostly on plasma membrane-localized glucose transporter proteins (GLUTs). Two main cellular mechanisms regulate GLUT proteins in the cell: first, expression of GLUT genes is under dynamic transcriptional control and is used by cancer cells to increase glucose availability. Second, GLUT proteins are regulated by membrane traffic from storage vesicles to the plasma membrane (PM). This latter process is triggered by signaling mechanisms and well-studied in the case of insulin-responsive cells, which activate protein kinase AKT to phosphorylate TBC1D4, a RAB-GTPase activating protein involved in membrane traffic regulation. Previously, we identified protein kinase WNK1 as another kinase able to phosphorylate TBC1D4 and regulate the surface expression of the constitutive glucose transporter GLUT1. Here we describe that downregulation of WNK1 through RNA interference in HEK293 cells led to a 2-fold decrease in PM GLUT1 expression, concomitant with a 60% decrease in glucose uptake. By mass spectrometry, we identified serine (S) 704 in TBC1D4 as a WNK1-regulated phosphorylation site, and also S565 in the paralogue TBC1D1. Transfection of the respective phosphomimetic or unphosphorylatable TBC1D mutants into cells revealed that both affected the cell surface abundance of GLUT1. The results reinforce a regulatory role for WNK1 in cell metabolism and have potential impact for the understanding of cancer cell metabolism and therapeutic options in type 2 diabetes.

    更新日期:2019-12-07
  • Aquaporins and male (in)fertility: Expression and role throughout the male reproductive tract
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-06
    David F. Carrageta, Raquel L. Bernardino, Graça Soveral, Giuseppe Calamita, Marco G. Alves, Pedro F. Oliveira

    Aquaporins (AQPs) are a family of transmembrane channel proteins responsible for the transport of water and small uncharged molecules. Thirteen distinct isoforms of AQPs have been identified in mammals (AQP0-12). Throughout the male reproductive tract, AQPs greatly enhance water transport across all biological barriers, providing a constant and expeditious movement of water and playing an active role in the regulation of water and ion homeostasis. This regulation of fluids is particularly important in the male reproductive tract, where proper fluid composition is directly linked with a healthy and competent spermatozoa production. For instance, in the testis, fluid regulation is essential for spermatogenesis and posterior spermatozoa transport into the epididymal ducts, while maintaining proper ionic conditions for their maturation and storage. Alterations in the expression pattern of AQPs or their dysfunction is linked with male subfertility/infertility. Thus, AQPs are important for male reproductive health. In this review, we will discuss the most recent data on the expression and function of the AQPs isoforms in the human, mouse and rat male reproductive tract. In addition, the regulation of AQPs expression and dysfunction linked with male infertility will be discussed.

    更新日期:2019-12-06
  • Quiescin/sulfhydryl oxidase 1b (QSOX1b) induces migration and proliferation of vascular smooth muscle cells by distinct redox pathways
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-05
    Karime C. França, Pierina A. Martinez, Maiara L. Prado, Sze M. Lo, Beatriz E. Borges, Silvio M. Zanata, Alejandra San Martin, Lia S. Nakao

    Quiescent and contractile VSMC can switch to proliferative and migratory phenotype in response to growth factors and cytokines, an effect underscored by Nox family NADPH oxidases, particularly Nox1. We previously showed that quiescin/sulfhydryl oxidase 1 (QSOX1) has a role in neointima formation in balloon-injured rat carotid. Here, we investigated the intracellular redox mechanisms underlying these effects in primary VSMC. Our results show that exogenous incubation with wild type QSOX1b (wt QSOX), or with secreted QSOX1, but not with the inactive C452S QSOX 1b (C452S QSOX) or secreted inactive C455S QSOX1, induces VSMC migration and chemotaxis. PEG-catalase (PEG-CAT) prevented, while PEG-superoxide dismutase (PEG-SOD) increased migration induced by wt QSOX. Moreover, wt QSOX-induced migration was abrogated in NOX1-null VSMC. In contrast, both wt QSOX and C452S QSOX, and both secreted QSOX1 and C455S QSOX1, induce cell proliferation. Such effect was unaltered by PEG-CAT, while being inhibited by PEG-SOD. However, QSOX1-induced proliferation was not significantly affected in NOX1-null VSMC, compared with WT VSMC. These results indicate that hydrogen peroxide and superoxide mediate, respectively, migration and proliferation. However, Nox1 was required only for QSOX1-induced migration. In parallel, QSOX1-induced proliferation was independent of its redox activity, although mediated by intracellular superoxide.

    更新日期:2019-12-05
  • Mutant p53 induces SIRT3/MnSOD axis to moderate ROS production in melanoma cells
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-05
    Margalida Torrens-Mas, Marco Cordani, Nidula Mullappilly, Raffaella Pacchiana, Chiara Riganti, Marta Palmieri, Daniel G. Pons, Pilar Roca, Jordi Oliver, Massimo Donadelli

    The TP53 tumor suppressor gene is the most frequently altered gene in tumors and mutant p53 isoforms can acquire oncogenic properties referred to as gain-of-function (GOF). In this study, we used wild-type (A375) and mutant p53 (MeWo) melanoma cell lines to assess the regulation of the mitochondrial antioxidant manganese superoxide dismutase (MnSOD) by mutant p53. The effects of mutant p53 were evaluated by qPCR, immunoblotting, enzyme activity assay, cell proliferation assay, reactive oxygen species (ROS) assay after cellular transfection. We demonstrate that mutant p53 induces MnSOD expression, which is recovered by the ROS scavenger N-acetyl-l-cysteine. This suggests MnSOD induction as a defense mechanism of melanoma cells to counterbalance the pro-oxidant conditions induced by mutant p53. We also demonstrate that mutant p53 induces the expression of Sirtuin3 (SIRT3), a major mitochondrial NAD+-dependent deacetylase, stimulating MnSOD deacetylation and enzymatic activity. Indeed, the restoration of SIRT3 reverses MnSOD activity decrease by mutant p53 knock-down. Finally, MnSOD knock-down further enhances mutant p53-mediated ROS increase, contracting mutp53-dependent cell hyperproliferation. This indicates that SIRT3 and MnSOD act to maintain ROS levels controlled to promote cell proliferation and survival, providing new therapeutic opportunities to be further considered for clinical studies in cancer patients bearing mutant TP53 gene.

    更新日期:2019-12-05
  • The antidepressant drug; trazodone inhibits Tau amyloidogenesis: Prospects for prophylaxis and treatment of AD
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-02
    Vali Akbari, Sirous Ghobadi, Soheila Mohammadi, Reza Khodarahmi

    Tau protein, characterized as “natively unfolded”, is involved in microtubule assembly/stabilization in physiological conditions. Under pathological conditions, Tau dysfunction leads to its accumulation of insoluble toxic amyloid aggregates and thought to be involved in the degeneration and neuronal death associated with neurodegenerative diseases. Trazodone (TRZ), a triazolopyridine derivative, is a selective serotonin reuptake inhibitor (SSRI) which increases serotonin levels in synaptic cleft and potentiating serotonin activity, with antidepressant and sedative properties. This drug is more effective and tolerable than other therapeutic agents. In this study, the 1N4R isoform of Tau protein was purified and the effect of TRZ on the protein fibrillation was investigated using multi-spectroscopic techniques as well as computational methods. The results showed that TRZ is not only able to affect formation of Tau amyloid fibrils in vitro but also attenuates Tau oligomerization within SH-SY5Y cell line resulting in more cells surviving. Moreover, membrane disrupting activity of Tau aggregates decreased upon TRZ treatment. The binding forces involved in TRZ-Tau interaction were also explored using both experimental as well as theoretical docking/molecular dynamics approaches. The results of the current work may open new insights for applying therapeutic potential of TRZ against Alzheimer's disease.

    更新日期:2019-12-02
  • Novel insights into oxidation of fatty acids and fatty alcohols by cytochrome P450 monooxygenase CYP4B1
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-12-01
    Florian A. Thesseling, Michael C. Hutter, Constanze Wiek, John P. Kowalski, Allan E. Rettie, Marco Girhard

    CYP4B1 is an enigmatic mammalian cytochrome P450 monooxygenase acting at the interface between xenobiotic and endobiotic metabolism. A prominent CYP4B1 substrate is the furan pro-toxin 4-ipomeanol (IPO). Our recent investigation on metabolism of IPO related compounds that maintain the furan functionality of IPO while replacing its alcohol group with alkyl chains of varying structure and length revealed that, in addition to cytotoxic reactive metabolite formation (resulting from furan activation) non-cytotoxic ω-hydroxylation at the alkyl chain can also occur. We hypothesized that substrate reorientations may happen in the active site of CYP4B1. These findings prompted us to re-investigate oxidation of unsaturated fatty acids and fatty alcohols with C9–C16 carbon chain length by CYP4B1. Strikingly, we found that besides the previously reported ω- and ω-1-hydroxylations, CYP4B1 is also capable of α-, β-, γ-, and δ-fatty acid hydroxylation. In contrast, fatty alcohols of the same chain length are exclusively hydroxylated at ω, ω-1, and ω-2 positions. Docking results for the corresponding CYP4B1-substrate complexes revealed that fatty acids can adopt U-shaped bonding conformations, such that carbon atoms in both arms may approach the heme-iron. Quantum chemical estimates of activation energies of the hydrogen radical abstraction by the reactive compound 1 as well as electron densities of the substrate orbitals led to the conclusion that fatty acid and fatty alcohol oxidations by CYP4B1 are kinetically controlled reactions.

    更新日期:2019-12-02
  • Oxidative damage in mitochondrial fatty acids oxidation disorders patients and the in vitro effect of l-carnitine on DNA damage induced by the accumulated metabolites
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-22
    Maira Silmara de Moraes, Gilian Guerreiro, Angela Sitta, Daniella de Moura Coelho, Vanusa Manfredini, Moacir Wajner, Carmen Regla Vargas

    Background The mitochondrial fatty acids oxidation disorders (FAOD) are inherited metabolic disorders (IMD) characterized by the accumulation of fatty acids of different sizes of chain according to the affected enzyme. Methods This study evaluated the lipid peroxidation by the measurement of 8-isoprostanes, nitrosative stress parameters by the measurement of nitrite and nitrate content and DNA and RNA oxidative damage by the measurement of oxidized guanine species in urine samples from long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD), medium-chain acyl-CoA dehydrogenase deficiency (MCADD) and multiple acyl-CoA dehydrogenase deficiency (MADD) patients. Also, we analyzed the in vitro DNA damage by comet assay induced by adipic acid, suberic acid, hexanoylglycine and suberylglycine, separated and in combination, as well as the effect of l-carnitine in human leukocytes. Results An increase on 8-isoprostanes levels in all groups of patients was observed. The nitrite and nitrate levels were increased in LCHADD patients. DNA and RNA damage evaluation revealed increase on oxidized guanine species levels in LCHADD and MADD patients. The in vitro evaluation revealed an increase on the DNA damage induced by all metabolites, besides a potencialyzed effect. l-carnitine decreased the DNA damage induced by the metabolites. Conclusion These results demonstrate that toxic metabolites accumulated could be related to the increased oxidative and nitrosative stress of FAOD patients and that the metabolites, separated and in combination, cause DNA damage, which was reduced by l-carnitine, demonstrating antioxidant protection. General significance This work demonstrated oxidative stress in FAOD patients and the genotoxic potential of MCADD metabolites and the protective effect of l-carnitine.

    更新日期:2019-11-22
  • Fluid flow-induced activation of subcellular AMPK and its interaction with FAK and Src
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-21
    Yunxia Guo, Hannah E. Steele, Bai-Yan Li, Sungsoo Na

    AMP-activated protein kinase (AMPK) is a metabolic energy sensor that plays a critical role in cancer cell survival and growth. While the physical microenvironment is believed to influence tumor growth and progression, its role in AMPK regulation remains largely unknown. In the present study, we evaluated AMPK response to mechanical forces and its interaction with other mechano-responsive signaling proteins, FAK and Src. Using genetically encoded biosensors that can detect AMPK activities at different subcellular locations (cytosol, plasma membrane, nucleus, mitochondria, and Golgi apparatus), we observed that AMPK responds to shear stress in a subcellular location-dependent manner in breast cancer cells (MDA-MB-231). While normal epithelial cells (MCF-10A) also similarly responded to shear stress, they are less sensitive to shear stress compared to MDA-MB-231 cells. Inhibition of FAK and Src significantly decreased the basal activity level of AMPK at all five subcellular locations in MDA-MB-231 cells and selectively blocked shear stress-induced AMPK activation. Moreover, testing with cytoskeletal drugs revealed that myosin II might be the critical mediator of shear stress-induced AMPK activation in MDA-MB-231 cells. These findings suggest that breast cancer cells and normal epithelial cells may have different mechanosensitivity in AMPK signaling and that FAK and Src as well as the myosin II-dependent signaling pathway are involved in subcellular AMPK mechanotransduction in breast cancer cells.

    更新日期:2019-11-22
  • Role of sorbitol-mediated cellular stress response in obesity-associated retinal degeneration
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-21
    Kishore K. Godisela, Singareddy Sreenivasa Reddy, P. Yadagiri Reddy, Ch Uday Kumar, V. Sudhakar Reddy, Radha Ayyagari, G. Bhanuprakash Reddy

    Purpose Obesity is a global health problem associated with several diseases including ocular complications. Earlier we reported progressive retinal degeneration because of obesity in a spontaneous obese rat (WNIN/Ob) model. In the current study, we examined the molecular mechanisms leading to retinal degeneration in WNIN/Ob rat. Methods Sorbitol was estimated by the fluorometric method in the retina of WNIN/Ob rats at different age (3-, 6- and 12- months), along with their respective lean rats. Immunoblotting was performed in the retina to assess the status of the insulin signaling pathway, ER stress and cellular stress (p38MAPK and ERK1/2). Human SK-N-SH neuronal cells were treated with 0.5 and 1.0 M sorbitol for 30 min to study insulin signaling, ER stress, and cellular stress. TUNEL assay was done to measure apoptosis. The retinal function in the rats was determined by electroretinogram. Results A gradual but significantly higher intracellular sorbitol accumulation was observed in the retina of obese rats from 3- to 12-months. The cellular osmotic stress has activated the insulin signaling mechanism without activating AKT and also triggered ER stress. Both the stresses activated the ERK and p38MAPK signaling causing apoptosis in the retina leading to retinal degeneration. Retinal dysfunction was confirmed by altered scotopic and photopic electroretinogram responses. These in vivo results were mimicked in SK-N-SH cells when exposed to sorbitol in vitro. Conclusions These results suggest cellular stress due to sorbitol accumulation impairing the ER function leading to progressive retinal degeneration under obese conditions.

    更新日期:2019-11-21
  • The potential effect of methylseleninic acid (MSA) against γ-irradiation induced testicular damage in rats: Impact on JAK/STAT pathway
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-20
    Rania A. Gawish, Hanan A. Fahmy, Abeer I. Abd El Fattah, Ahmed S. Nada

    This study theorized that methylseleninic acid (MSA) could respond the inflammatory signaling associated with ionizing radiation (IR)-induced testicular damage. Mature male rats were divided into four groups: negative control group, whole body γ-irradiated (IRR) group (5 Gy), MSA group (0.5 mg/kg, daily for 9 consecutive days) and group subjected to combination of MSA+IRR. MSA preserve male fertility manifested by increasing serum testosterone level and testicular glutathione peroxidase (GPx) as well as decreasing percentage of sperm abnormalities. Radiation prompted inflammmatory signaling in the testis through upstream of phospho-Janus kinase1 (p-JAK1), phospho-signal transducers and activators of transcription 3 (p-STAT3) protein expressions which convinced the inflammatory markers including nuclear factor- kappa B (NF-κB) and interleukin-1beta (IL-1β) levels as well as nitric oxide (NO) and malondialdhyde (MDA) contents with consequent reduction in testicular reduced glutathione content (GSH) and superoxide dismutase (SOD) activity. MSA significantly counteract the radiation effect and upstream of testicular nuclear factor erythroid-2-related factor-2 (Nrf2) and suppressor of cytokine signaling (SOCS3) protein expressions. MSA- activated Nrf2 protein expression was associated with reduction of p-JAK1, p-STAT3 and NF-κB levels- mediated inflammatory response. This study suggest that MSA restored spermatogenesis via increasing testosterone levels and GPx activity, diminishing testicular inflammation via upstream of Nrf2 and SOCS3 leading to downstream of p-JAK1, p-STAT3 and NF-κB provoked inflammatory response. Histopathological examination results of testicular tissues showed coincidence with biochemical inspection.

    更新日期:2019-11-20
  • Protective role of hesperetin against posttranslational oxidation of tryptophan residue of human γD-crystallin: A molecular level study
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-20
    Shiwani Rana, Kalyan Sundar Ghosh

    Crystallin proteins undergo various posttranslational modifications with aging of eye lens. Oxidation of tryptophan (Trp) residues of a major γ-crystallin namely human γD-crystallin (HGD) was found to be inhibited by a naturally occurring flavonoid hesperetin at relatively low concentration mostly due to its antioxidant activity. Further the molecular interactions between HGD and hesperetin were elucidated on the basis of the quenching of Trp fluorescence of the protein by the flavonoid. Ground state complexation between HGD and hesperetin caused static quenching of the Trp fluorescence of HGD. Binding and quenching constants were in the order of (103- 104 M−1). Energy transfer from protein to hesperetin was suggested by FRET calculations. Thermodynamic parameters reveal significant hydrophobic association between the protein and hesperetin. Synchronous fluorescence and CD spectroscopic results had ruled out conformational changes in the protein due to binding of hesperetin. Docking studies suggested the proximity of hesperetin with Trp 42, which largely corroborates our experimental findings.

    更新日期:2019-11-20
  • 更新日期:2019-11-18
  • 3,3′-Diindolylmethane suppresses ovarian cancer cell viability and metastasis and enhances chemotherapy sensitivity via STAT3 and Akt signaling in vitro and in vivo
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2018-07-21
    Minghua Zou, Changhua Xu, Hua Li, Xianquan Zhang, Weidong Fan

    Signal transducer and activator of transcription-3 (STAT3) protein is constitutively activated in ovarian cancer. The purpose of this study was to investigate the effects of 3,3′-diindolylmethane (DIM) on the regulation of STAT3 signaling and ovarian cancer cell viability, invasion, and sensitivity to chemotherapy. Ovarian cancer SKOV3 and A2780 cell lines were treated with various concentrations of DIM for different periods of time for assessment of cell viability as well as gene expression before and after knockdown of STAT3 expression using STAT3 shRNA. DIM treatment potently suppressed the viabilities of ovarian cancer cells. Consequently, DIM inhibited xenograft growth in nude mice. In addition, at the gene level, DIM inhibited phosphorylation of STAT3 and AKT proteins and expression of their downstream proteins. Moreover, knockdown of STAT3 expression significantly enhanced DIM antitumor activity and cisplatin sensitivity. Their combination suppressed the protein expression of survivin, Bcl-2, Mcl-1, HIF-1α, VEGF, and MMPs, but activated caspase-3. Taken together, the antitumor activity of DIM is via inhibition of the STAT3 and Akt signaling pathways. The combination of STAT3 knockdown with DIM treatment could be further evaluated as a therapeutic strategy for the treatment of advanced ovarian cancer.

    更新日期:2019-11-18
  • Fatty acid nitration in human low-density lipoprotein
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-15
    Mauricio Mastrogiovanni, Andrés Trostchansky, Homero Rubbo

    Lipid nitration occurs during physiological and pathophysiological conditions, generating a variety of biomolecules capable to modulate inflammatory cell responses. Low-density lipoprotein (LDL) oxidation has been extensively related to atherosclerotic lesion development while oxidative modifications confer the particle pro-atherogenic features. Herein, we reviewed the oxidation versus nitration of human LDL protein and lipid fractions. We propose that unsaturated fatty acids present in LDL can be nitrated under mild nitration conditions, suggesting an anti-atherogenic role for LDL carrying nitro-fatty acids (NFA).

    更新日期:2019-11-15
  • Aerobic exercise-induced inhibition of PKCα/CaV1.2 pathway enhances the vasodilation of mesenteric arteries in hypertension
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-13
    Yu Chen, Yanyan Zhang, Meiling Shan, Yang Zhou, Yanjun Huang, Lijun Shi

    Regular exercise is regarded as a nonpharmacological therapy for controlling hypertension by improving the function of vascular smooth muscle cells (VSMCs). The underlying mechanism is unclear. L-type-voltage-dependent Ca2+ channel (CaV1.2) on the plasma membrane and PKCα of VSMCs are pivotal modulators of vascular tone. PKCα is hyperactivated and concentrated at the surface membrane during hypertension. This study investigated the effects of aerobic exercise on the PKCα and CaV1.2 in mesenteric arterial smooth muscle cells from spontaneously hypertensive rats (SHRs). SHRs and Wistar-Kyoto (WKY) rats were randomly assigned into sedentary groups (SHR-SED and WKY-SED) and exercise training groups (SHR-EX and WKY-EX). Exercise groups were performed a 12-week moderate-intensity (18–20 m/min) treadmill training. Mesenteric arterial mechanical and functional properties were evaluated. Exercise reduced body weight and systolic blood pressure in both SHR-EX and WKY-EX. PDBu (PKC activator) and BayK 8644 (CaV1.2 agonist) elicited vasoconstriction, while Gö6976 (PKCα inhibitor) and nifedipine (CaV1.2 blocker) induced vasodilation of the vessel rings. In SHRs, exercise normalized the increased vascular sensitivity to these activators and inhibitors. Nifedipine greatly suppressed PDBu-induced vasoconstriction. Upon incubation with Gö6976, the effects of both PDBu and nifedipine were markedly suppressed. In patch-clamp studies, PDBu increased and Gö6976 decreased the CaV1.2 current density. Exercise ameliorated the responses of both PDBu and Gö6976 in SHRs. Immunofluorescence staining suggested that exercise training alleviated the hypertension-induced increase of colocalization rate of PKCα and CaV1.2 α1C subunit in VSMCs. These data indicate that hypertension enhanced PKCα/CaV1.2 pathway-induced constriction of mesenteric arteries, and this pathological enhancement is inhibited by aerobic exercise training.

    更新日期:2019-11-13
  • Modification by transferrin increases the efficiency of delivery and the photodynamic effect of the quantum dot–phthalocyanine complex on A431 cells
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-13
    D.A. Gvozdev, А.А. Ramonova, Y.B. Slonimskiy, Е.G. Maksimov, М.М. Moisenovich, V.Z. Paschenko

    Hybrid complexes of fluorescent nanoparticles and tetrapyrrole dyes are currently considered as promising third-generation photosensitizers for photodynamic therapy, including cancer treatment. Using nanoparticles as a platform for delivery of photosensitizers to target cells can increase the efficiency of photodynamic action. In this work, we synthesized a complex of polymer-coated CdSe/ZnS quantum dots, substituted phthalocyanines and human transferrin. Such complexes effectively enter human epidermoid carcinoma cells (A431) due to transferrin-mediated endocytosis and are localized in the perinuclear compartment. We observed an efficient excitation energy transfer from the quantum dot to phthalocyanine in the cells, which indicates stability of the complex upon its internalization. It was shown that the photodynamic activity of hybrid complexes covalently bonded to transferrin is 15% higher than the activity of unmodified hybrid complexes. Our results confirm the feasibility of using fluorescent nanoparticles to enhance the photodynamic properties of photosensitizers based on tetrapyrrole dyes.

    更新日期:2019-11-13
  • Binding partners of NRF2: Functions and regulatory mechanisms
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-13
    Le Ba Nam, Young-Sam Keum

    NRF2 is a redox-sensitive transcription factor that plays an important role in protecting organisms against diverse types of electrophiles or oxidants. The level of NRF2 is maintained low in normal cells, but highly elevated in cancer provoking chemoresistance or radioresistance. It is now recognized that NRF2 does not merely maintain the redox balance, but also plays significant roles in autophagy, apoptosis, cell cycle progression, and stem cell differentiation, all of which could be possibly attributable to the existence of multiple binding proteins. In the present manuscript, we summarize direct binding partners of NRF2 and illustrate how they bind to NRF2 and regulate its stability or activity.

    更新日期:2019-11-13
  • The crystal structure and insight into the substrate specificity of the α-L rhamnosidase RHA-P from Novosphingobium sp. PP1Y
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-11
    Brendan Terry, Joseph Ha, Federica De Lise, Francesca Mensitieri, Viviana Izzo, Matthew H. Sazinsky

    Flavonoid natural products are well known for their beneficial antimicrobial, antitumor, and anti-inflammatory properties, however, some of these natural products often are rhamnosylated, which severely limits their bioavailability. The lack of endogenous rhamnosidases in the human GI tract not only prevents many of these glycosylated compounds from being of value in functional foods but also limits the modification of natural product libraries being tested for drug discovery. RHA-P is a catalytically efficient, thermostable α-l-rhamnosidase from the marine bacterium Novosphingobium sp. PP1Y that selectively hydrolyzes α-1,6 and α-1,2 glycosidic linkages between a terminal rhamnose and a flavonoid moiety. This work reports the 2.2 Å resolution crystal structure of RHA-P, which is an essential step forward in the characterization of RHA-P as a potential catalyst to increase the bioavailability of rhamnosylated natural compounds. The structure shows highly conserved rhamnose- and calcium-binding residues in a shallow active site that is housed in the (α/β)8 barrel domain. In comparison to BT0986 (pdbID: 5MQN), the only known structure of an RHA-P homolog, the morphology, electrostatic potentials and amino acid composition of the substrate binding pocket are significantly different, offering insight into the substrate preference of RHA-P for glycosylated aryl compounds such as hesperidin, naringin, rutin, and quercitrin, over polysaccharides, which are preferred by BT0986. These preferences were further explored by using in silico docking, the results of which are consistent with the known kinetic data for RHA-P acting on different rhamnosylated flavonoids. Due to its promiscuity, relative thermostability compared to other known rhamnosidases, and catalytic efficiency even in significant concentrations of organic solvents, RHA-P continues to show potential for biocatalytic applications.

    更新日期:2019-11-13
  • Omentin-1 attenuates lipopolysaccharide (LPS)-induced U937 macrophages activation by inhibiting the TLR4/MyD88/NF-κB signaling
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-09
    Jinzhong Wang, Yi Gao, Feng Lin, Kui Han, Xiaozhi Wang

    Macrophages play a pivotal role in the defense response against harmful pathogens and stimuli by releasing various pro-inflammatory mediators. However, overproduction of pro-inflammatory mediators will do harm to the organism and cause inflammation-associated diseases. Omentin-1, which is a newly discovered adipokine, is specifically expressed in omental adipose tissue. Recent studies have found correlations between omentin-1 and insulin resistance, diabetes, obesity, inflammation, atherosclerosis, bone metabolism, and tumor cell proliferation. Some studies have shown that the association between omentin-1, insulin resistance, and inflammation might suggest that omentin-1 plays an important role in chronic inflammatory diseases. In this study, we found that omentin-1 inhibited LPS-induced expression of inflammatory mediators and pro-inflammatory cytokines in macrophages. Furthermore, omentin-1 inhibited activation of the NF-κB pathway by suppressing both nuclear p65 accumulation and transfected NFκB promoter activity. Importantly, omentin-1 increased nuclear translocation of Nrf2. Our findings demonstrate that omentin-1 exerts anti-inflammatory effects on LPS-induced macrophages and has potential implication in the treatment of inflammation-associated diseases.

    更新日期:2019-11-11
  • Hydrophobicity and oligomerization are essential parameters for membrane penetration activity of the VP4 peptide from Hepatitis A Virus (HAV)
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-08
    Priyanka Nair, Debajit Dey, Subhomoi Borkotoky, Ashutosh Shukla, Manidipa Banerjee
    更新日期:2019-11-08
  • Neuroprotection of miR-214 against isoflurane-induced neurotoxicity involves the PTEN/PI3K/Akt pathway in human neuroblastoma cell line SH-SY5Y
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-05
    Qiaoling Wu, You Shang, Tu Shen, Feifei Liu, Yong Xu, Hao Wang

    Isoflurane, one of the commonly used inhalation anesthetics worldwide in clinical practice, may generate substantial risks of neurotoxicity in the developing brains. The present study aimed to illustrate the effects and underlying mechanisms of miR-214 on isoflurane-induced neurotoxicity in human neuroblastoma cell line SH-SY5Y. SH-SY5Y cells were transfected with miR-214 or miR-con alone or in combination with pcDNA empty vector or pcDNA-PTEN in the presence of 3% isoflurane and incubated for 48 h. Cell viability, lactate dehydrogenase (LDH) release, apoptosis, and caspase-3/7 activity were evaluated using CCK-8, LDH release assay, flow cytometry analysis, and caspase-3/7 activity assay, respectively. The superoxide dismutase (SOD), glutathione (GSH), and malondialdehyde (MDA) activities were measured using commercial kits. miR-214 expression and alterations of the phosphatase and tensin homolog (PTEN)/phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway were detected by qRT-PCR and Western blot, respectively. The interaction between miR-214 and PTEN was explored by luciferase reporter assay. We found that isoflurane exposure induced neurotoxicity in SH-SY5Y cells, as evidenced by the reduced cell viability, increased LDH release, apoptotic rate, caspase-3/7 activity, and oxidative stress levels. Moreover, isoflurane exposure decreased the expression of miR-214 and affected the PTEN/PI3K/Akt pathway in SH-SY5Y cells. miR-214 overexpression significantly suppressed isoflurane-induced viability reduction, LDH release, apoptosis and oxidative stress, as well as inactivation of the PI3K/Akt pathway in SH-SY5Y cells. Interestingly, PTEN was identified as a target of miR-214. Moreover, PTEN upregulation blocked the effects of miR-214 on isoflurane-induced neurotoxicity in SH-SY5Y cells. In conclusion, miR-214 protected against isoflurane-induced neurotoxicity in SH-SY5Y cells via regulation of PI3K/Akt pathway by targeting PTEN, contributing to better understanding the underlying mechanisms of anesthetics-induce neurotoxicity.

    更新日期:2019-11-06
  • 15-Deoxy-Δ12,14-prostaglandin J2 ameliorates dextran sulfate sodium-induced colitis in mice through heme oxygenase-1 induction
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-05
    Tomohisa Takagi, Yuji Naito, Katsura Mizuhima, Yasuko Hirai, Kazuhiro Kamada, Kazuhiko Uchiyama, Osamu Handa, Takeshi Ishikawa, Yoshito Itoh

    The prostaglandin D2 metabolite, 15-deoxy-Δ12,14-Prostaglandin J2 (15d-PGJ2), exerts an anti-inflammatory effect through peroxisome proliferator-activated receptor γ (PPARγ)-dependent and -independent anti-inflammatory actions. In the present study, we focused on heme oxygenase-1 (HO-1) induced by 15d-PGJ2, and evaluated the effects of enema treatment with 15d-PGJ2 in the development of intestinal inflammation using a murine colitis model. Acute colitis was induced with dextran sulfate sodium (DSS) in male C57BL/6 mice (8 weeks old) and NF-E2-related factor-2 (Nrf2) deficient mice. Mice were rectally administered 15d-PGJ2 (1 μM, 0.2 mL: 66.9 ng) daily during DSS administration. Intestinal expression of HO-1 mRNA and protein after rectal administration of 15d-PGJ2 was evaluated by real-time PCR and western blotting, respectively. A disease activity index (DAI) was determined on a daily basis for each animal, and consisted of a calculated score based on changes in body weight, stool consistency, and intestinal bleeding. Tissue-associated myeloperoxidase (MPO) activity as an index of neutrophil infiltration and mRNA expression levels of TNF-α, IFN-γ, and IL-17A were measured in the colonic mucosa. In addition, we evaluated the effects of co-treatment with a HO-1 inhibitor, zinc protoporphyrin IX (ZnPP), or a specific PPARγ antagonist, GW9662. As a result, rectal administration of 15d-PGJ2 markedly induced HO-1 protein and mRNA expression in the colonic mucosa. Treatment with 15d-PGJ2 ameliorated the increase in DAI score and MPO activity and the mRNA expression levels of TNF-α, IFN-γ, and IL-17A after DSS administration. These effects of 15d-PGJ2 against intestinal inflammation were negated by co-treatment with ZnPP, but not with GW9662. In Nrf2 deficient mice, the rectal administration of 15d-PGJ2 did not affect colonic HO-1 expression and activity of DSS-induced colitis. These results demonstrate that 15d-PGJ2 inhibits development of intestinal inflammation in mice via PPAR-independent and Nrf2-HO-1-dependent mechanisms.

    更新日期:2019-11-06
  • CO ameliorates endothelial senescence induced by 5-fluorouracil through SIRT1 activation
    Arch. Biochem. Biophys. (IF 3.559) Pub Date : 2019-11-05
    Min Zheng, Yubing Chen, Jeongmin Park, Hyun-Chul Song, Yingqing Chen, Jeong Woo Park, Yeonsoo Joe, Hun Taeg Chung

    Endothelial senescence is the main risk factor that contributes to vascular dysfunction and the progression of vascular disease. Carbon monoxide (CO) plays an important role in preventing vascular dysfunction and in maintaining vascular physiology or homeostasis. The application of exogenous CO has been shown to confer protection in several models of cardiovascular injury or disease, including hypertension, atherosclerosis, balloon-catheter injury, and graft rejection. However, the mechanism by which CO prevents endothelial senescence has been largely unexplored. The aim of this study was to evaluate the effects of CO on endothelial senescence and to investigate the possible mechanisms underlying this process. We measured the levels of senescence-associated-β-galactosidase activity, senescence-associated secretory phenotype, reactive oxygen species (ROS) production, and stress granule in human umbilical vein endothelial cells and the WI-38 human diploid fibroblast cell line. We found that 5-fluorouracil (5FU)-induced ROS generation was inhibited by CO-releasing molecules (CORM)-A1 treatment, and endothelial senescence induced by 5FU was attenuated by CORM-A1 treatment. The SIRT1 inhibitor EX527 reversed the inhibitory effect of CO on the 5FU-induced endothelial senescence. Furthermore, SIRT1 deficiency abolished the stress granule formation by CO. Our results suggest that CO alleviates the endothelial senescence induced by 5FU through SIRT1 activation and may hence have therapeutic potential for the treatment of vascular diseases.

    更新日期:2019-11-06
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